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1

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

E-print Network

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...

Qi, Ruifeng

2012-10-19

2

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

E-print Network

STUDY OF THE EFFECTS OF OBSTACLES IN LIQUEFIED NATURAL GAS (LNG) VAPOR DISPERSION USING CFD MODELING A Thesis by ROBERTO EDUARDO RUIZ VASQUEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2012 Major Subject: Safety Engineering 2 Study of the Effects of Obstacles in Liquefied Natural Gas (LNG) Vapor Dispersion using...

Ruiz Vasquez, Roberto

2012-10-19

3

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

E-print Network

with valuable guidance as team leader. Special thanks to the previous LNG team members, Dr. Geunwoong Yun, Dr. Morshed Rana, Dr. Ruifeng Qi, and Ms. Carolina Herrera, for providing me with great support during the initial stage of my research. I want to thank... dispersion was investigated for different commercial spray nozzles. It was found that the conical spray 15 installed in upward direction was most effective in diluting LNG vapors at all elevations (Rana, Guo & Mannan, 2010). Fig. 8. LNG...

Kim, Byung-Kyu

2013-05-31

4

LNG vapor dispersion prediction with the DEGADIS dense-gas dispersion model. Topical report, April 1988-July 1990. Documentation  

SciTech Connect

The topical report is one of a series on the development of methods for LNG vapor dispersion prediction for regulatory application. The results indicate that the DEGADIS model is superior both phenomenologically and in performance to the Gaussian line source model promulgated in 49 CFR 193 for LNG vapor dispersion simulation. Availability of the DEGADIS model for VAX and IBM-PC formats provides for wider use of the model and greater potential for industry and regulatory acceptance. The acceptance is seen as an important interim objective while research continues on vapor dispersion estimation methods which provide for effects of vapor detention systems, turbulence induced by plant structure, and plant/area topographical features.

Havens, J.; Spicer, T.

1990-09-01

5

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

E-print Network

Liquefied Natural Gas (LNG) hazards include LNG flammable vapor dispersion and LNG pool fire thermal radiation. A large LNG pool fire emits high thermal radiation thus preventing fire fighters from approaching and extinguishing the fire. One...

Suardin, Jaffee Arizon

2009-05-15

6

LNG vapor dispersion prediction with the DEGADIS dense-gas dispersion model (for microcomputers). Model-Simulation  

SciTech Connect

The DEGADIS model is consistent with a wide range of laboratory and field test data for dense gas releases on a flat surface with dispersion over unobstructed flat terrain. Comparisons indicate that the DEGADIS model is superior in performance to the Gaussian line source (GLS) model prescribed in liquefied natural gas (LNG) storage facility standards (49 CFR 193). DEGADIS was modified to operate on either an IBM-PC or VAX computer. DEGADIS source and executable code is provided, along with a user manual which includes example problems for flammable gas dispersion with emphasis on LNG vapor.

Not Available

1991-01-01

7

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

E-print Network

Liquefied Natural Gas (LNG) is flammable when it forms a 5 – 15 percent volumetric concentration mixture with air at atmospheric conditions. When the LNG vapor comes in contact with an ignition source, it may result in fire and/or explosion. Because...

Yun, Geun Woong

2011-10-21

8

FDAS hardware and firmware description, Liquefied Gaseous Fuels (LGF) Data-Acquisition System. [LNG dispersion, vapor burn experiments  

SciTech Connect

The FDAS are the front-end data acquisition units of the Liquefied Gaseous Fuels Data Acquisition System (LGFDAS). They acquired data from numerous sensors during liquefied natural gas (LNG) dispersion and vapor burn experiments conducted at the Naval Weapons Center, China Lake, California, in 1980 and 1981. This is a description of the hardware, functions, commands, messages, and firmware of the FDAS units.

Baker, J.

1982-03-01

9

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

E-print Network

?of?spreading?...............................................................?20? 2.1.6? Heat?transfer?and?turbulence?effect?on?evaporation?rate?.?23? 2.1.7? Estimation?of?the?mass?evaporated?at?any?given?time?......?25? 2.1.8? Other?parameter?considerations?.......................................?26? 2.1.9? Incorporation...?LNG?deliverability?growth?...........................................................................................?3? Figure?3.?Exclusion?zone?description?..............................................................................................?7? Figure?4.?Typical?representation?of?LNG?base?load...

Cormier, Benjamin Rodolphe

2009-05-15

10

LNG fire and vapor control system technologies  

SciTech Connect

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.

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

1982-06-01

11

FEM3A simulations of selected LNG vapor barrier verification field tests  

Microsoft Academic Search

In order to evaluate and eventually predict the possible mitigating effects of vapor fences on the dispersion of the vapor cloud resulting from an accidental liquefied natural gas (LNG) spill in storage areas, a research program was initiated to evaluate methods for predicting LNG dispersion distances for realistic facility configurations. As part of the program, Lawrence Livermore National Laboratory (LLNL)

Chan

1990-01-01

12

Power generation from LNG vaporization. Technical memo  

Microsoft Academic Search

A method of generating electrical power to take full advantage of the energy released in the vaporization of LNG is described. The process is one of many which might be used to recover energy from the cryogenic LNG-oil slurry pipeline. The process of cooling and liquefying natural gas consumes large amounts of energy which is, in a sense, stored in

Rennert

1975-01-01

13

FEM3A simulations of selected LNG vapor barrier verification field tests  

SciTech Connect

In order to evaluate and eventually predict the possible mitigating effects of vapor fences on the dispersion of the vapor cloud resulting from an accidental liquefied natural gas (LNG) spill in storage areas, a research program was initiated to evaluate methods for predicting LNG dispersion distances for realistic facility configurations. As part of the program, Lawrence Livermore National Laboratory (LLNL) conducted a series of large-scale field experiments called the LNG Vapor Barrier Verification Field Trials (also referred to as the Falcon Series) at the Liquefied Gaseous Fuels Spill Test Facility (LGFSTF), Nevada. Objectives were (1) to provide a data base on LNG vapor dispersion from spill involving complex field obstacles to assist in validation of wind tunnel and mathematical models, and (2) to assess the effectiveness of vapor fences for mitigating LNG vapor dispersion hazards in the events of an accidental spill. Five spill experiments were conducted on water in order to generate vapor at rates equivalent to the liquid spill rates. In this study, the FEM3A model was applied to simulate four of the Falcon experiments. The objectives of this study were, through numerical modeling and a detailed model-data comparison: (1) to improve our understanding of LNG vapor dispersion involving vapor barriers, (2) to assess FEM3A in modeling such complex vapor dispersion scenarios, and (3) to complement the results of field and wind tunnel tests, such as providing plausible explanations for unexpected results and filling in data gaps due to instrument failure or limited array size. Toward these goals, the relevant field measurements were analyzed and several series of 2-D and 3-D simulations were carried out. 11 refs., 93 figs., 11 tabs.

Chan, S.T.

1990-10-01

14

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

SciTech Connect

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.

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

1995-12-31

15

Numerical simulation of the mitigating effects of an LNG vapor fence  

Microsoft Academic Search

FEM3A, a fully three-dimensional numerical model for simulating the atmospheric dispersion of heavy gases involving complex geometry, has been used to investigate the mitigating effects of a vapor fence for LNG storage areas. In this paper, a brief description of the numerical model used to perform such calculations is given, the problem being simulated is described, and an intercomparison among

Chan

1990-01-01

16

Four band differential radiometer for monitoring LNG vapors  

NASA Technical Reports Server (NTRS)

The development by JPL of a four band differential radiometer (FBDR) which is capable of providing a fast rate of response, accurate measurements of methane, ethane, and propane concentrations on the periphery of a dispersing LNG cloud. The FBDR is a small, low power, lightweight, portable instrument system that uses differential absorption of near infrared radiation by the LNG cloud as a technique for the determination of concentration of the three gases as the LNG cloud passes the instrument position. Instrument design and data analysis approaches are described. The data obtained from the FBDR prototype instrument system deployed in an instrument array during two 40 cubic meter spill tests are discussed.

Simmonds, J. J.

1981-01-01

17

Dispersion of vapor from LNG spills: simulation in a meteorological wind tunnel of spills at China Lake Naval Weapons Center, California. Final report  

Microsoft Academic Search

Physical simulation of a series of four, six cubic meter Liquefied Natural Gas (LNG) spills on water was provided by the Meteorological Wind Tunnel facilities at Colorado State University. Field data were collected from spills performed at Naval Weapons Center, China Lake, California, in Fall 1978. The simulation test series was to provide field test planning information, extend the value

D. E. Neff; R. N. Meroney

1979-01-01

18

Vapor burn analysis for the Coyote series LNG spill experiments  

SciTech Connect

A major purpose of the Coyote series of field experiments at China Lake, California, in 1981 was to study the burning of vapor clouds from spills of liquefied natural gas (LNG) on water. Extensive arrays of instrumentation were deployed to obtain micrometeorological, gas concentration, and fire-related data. The instrumentation included in situ sensors of various types, high-speed motion picture cameras, and infrared (IR) imagers. Five of the total of ten Coyote spill experiments investigated vapor burns. The first vapor-burn experiment, Coyote 2, was done with a small spill of LNG to assess instrument capability and survivability in vapor cloud fires. The emphasis in this report is on the other four vapor-burn experiments: Coyotes 3, 5, 6, and 7. The data are analyzed to determine fire spread, flame propagation, and heat flux - quantities that are related to the determination of the damage zone for vapor burns. The results of the analyses are given here. 20 references, 57 figures, 7 tables.

Rodean, H.C.; Hogan, W.J.; Urtiew, P.A.; Goldwire, H.C. Jr.; McRae, T.G.; Morgan, D.L. Jr.

1984-04-01

19

LNG vapor barrier and obstacle evaluation: Wind-tunnel simulation of 1987 Falcon Spill Series. Final report, July 1987-February 1991  

SciTech Connect

Measurements of the behavior of simulated liquefied natural gas clouds dispersing over small-scale model placed in environmental wind tunnels permits evaluations of the fluid physics of dense cloud movement and dispersion in a controlled environment. A large data base on the interaction of simulated LNG plumes with the Falcon test configuration of vapor barrier fences and vortex generators was obtained. The purpose of the reported test program is to provide post-field-spill wind tunnel experiments to augment the LNG Vapor Fence Field Program data obtained during the Falcon Test Series in 1987. The goal of the program is to determine the probable response of a dense LNG Vapor cloud to vortex inducer obstacles and fences, examine the sensitivity of results to various scaling arguments which might augment limit, or extend the value of the field and wind-tunnel tests, and identify important details of the spill behavior which were not predicted during the pretest planning phase.

Shin, S.H.; Meroney, R.N.; Neff, D.E.

1991-03-01

20

Numerical simulation of the mitigating effects of an LNG vapor fence  

SciTech Connect

FEM3A, a fully three-dimensional numerical model for simulating the atmospheric dispersion of heavy gases involving complex geometry, has been used to investigate the mitigating effects of a vapor fence for LNG storage areas. In this paper, a brief description of the numerical model used to perform such calculations is given, the problem being simulated is described, and an intercomparison among the results from numerical simulations (with and without the vapor fence) and field data (with vapor fence) is made. The numerical results indicate that, with the present fence configuration, the maximum concentration on the cloud centerline was reduced by a factor of two or more within 250 m behind the fence, and the downwind distance to the 2.5% concentration was reduced from 365 m to 230 m. However, a vapor fence could also cause the vapor cloud to linger considerably longer in the source area, thus increasing the potential for ignition and combustion within the vapor fence and the area nearby over time. 8 refs., 10 figs.

Chan, S.T.

1990-05-01

21

The influence of ice formation on vaporization of LNG on water surfaces.  

PubMed

The spillage of LNG on water surfaces can lead, under certain circumstances, to a decrease in the surface temperature of water and subsequent freezing. A model for heat transfer from water to LNG is proposed and used to calculate the surface temperature of water and examine its influence on the vaporization rate of LNG. For this purpose LNG was modeled based on the properties of pure methane. It was concluded that when LNG spills on a confined, shallow-water surface the surface temperature of water will decrease rapidly leading to ice formation. The formation of an ice layer, that will continue to grow for the duration of the spill, will have a profound effect upon the vaporization rate. The decreasing surface temperature of ice will decrease the temperature differential between LNG and ice that drives the heat transfer and will lead to a change of the boiling regime. The overall effect would be that the vaporization flux would first decrease during the film boiling; followed by an increase during the transition boiling and a steady decrease during the nucleate boiling. PMID:17112657

Vesovic, V

2007-02-20

22

Cost-benefit analysis of alternative LNG vapor-mitigation measures. Topical report, September 14, 1987-January 15, 1991  

SciTech Connect

A generalized methodology is presented for comparing the costs and safety benefits of alternative hazard mitigation measures for a large LNG vapor release. The procedure involves the quantification of the risk to the public before and after the application of LNG vapor mitigation measures. In the study, risk was defined as the product of the annual accident frequency, estimated from a fault tree analysis, and the severity of the accident. Severity was measured in terms of the number of people who may be exposed to 2.5% or higher concentration. The ratios of the annual costs of the various mitigation measures to their safety benefits (as determined by the differences between the risk before and after mitigation measure implementation), were then used to identify the most cost-effective approaches to vapor cloud mitigation.

Atallah, S.

1992-06-25

23

Experimental plan for 40-m/sup 3/ liquefied natural gas (LNG) dispersion tests. 1981 tests  

SciTech Connect

Details on instruments and types of tests to be performed in the study of liquefied natural gas dispersion at the China Lake Naval Weapons Center are presented. Possible scheduling of the tests to coincide with the closing of the spill facility is discussed. The experiments will be a continuation of those conducted earlier on gas dispersion. The investigation will be expanded into studies on rapid phase transformation explosions. Combustion and dispersion measurements will be made during vapor cloud fires. (DMC)

Koopman, R.P.; Lind, C.D.

1981-04-01

24

LNG SAFETY RESEARCH: FEM3A MODEL DEVELOPMENT  

Microsoft Academic Search

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

Jerry Havens; Iraj A. Salehi

2005-01-01

25

Behavior of LNG vapor clouds: wind-tunnel simulation of 40 m³ LNG spill tests at China Lake Naval Weapons Center, California. Final report Jul 79Jul 81  

Microsoft Academic Search

Wind-tunnel transient concentration data were obtained from modeling tests which reproduced gaseous dispersion from five different forty cubic meter or less liquefied natural gas (LNG) spills performed at China Lake Naval Weapons Center during the spring and summer of 1980. Comparisons in the transient concentration data between these modeled tests and the field tests indicated which parameters are dominant in

D. E. Neff; R. N. Meroney

1981-01-01

26

Behavior of LNG vapor clouds: wind-tunnel simulation of 40 m/sup 3/ LNG spill tests at China Lake Naval Weapons Center, California. Final report Jul 79-Jul 81  

SciTech Connect

Wind-tunnel transient concentration data were obtained from modeling tests which reproduced gaseous dispersion from five different forty cubic meter or less liquefied natural gas (LNG) spills performed at China Lake Naval Weapons Center during the spring and summer of 1980. Comparisons in the transient concentration data between these modeled tests and the field tests indicated which parameters are dominant in the modeling process. Model tests which reproduced the wind shear and turbulence structure of the approach wind reproduced the concentration patterns measured at the field site. This result reinforced the predictive reliability of wind tunnel modeling of larger volume spills.

Neff, D.E.; Meroney, R.N.

1981-07-01

27

Falcon series data report: 1987 LNG vapor barrier verification field trials  

SciTech Connect

A series of five Liquefied Natural Gas Spills up to 66 m{sup 3} in volume were performed on water within a vapor barrier structure at Frenchman Flat on the Nevada Test Site as a part of a joint government/industry study. This data report presents a description of the tests, the test apparatus, the instrumentation, the meteorological conditions, and the data from the tests. 16 refs., 27 figs., 8 tabs.

Brown, T.C.; Cederwall, R.T.; Chan, S.T.; Ermak, D.L.; Koopman, R.P.; Lamson, K.C.; McClure, J.W.; Morris, L.K.

1990-06-01

28

Lessons learned from LNG safety research.  

PubMed

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

Koopman, Ronald P; Ermak, Donald L

2007-02-20

29

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

E-print Network

FORCED DISPERSION OF LIQUEFIED NATURAL GAS VAPOR CLOUDS WITH WATER SPRAY CURTAIN APPLICATION A Dissertation by MORSHED ALI RANA 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 December 2009 Major Subject: Chemical Engineering FORCED DISPERSION OF LIQUEFIED NATURAL GAS VAPOR CLOUDS WITH WATER SPRAY CURTAIN APPLICATION A Dissertation by MORSHED ALI RANA...

Rana, Morshed A.

2011-02-22

30

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

PubMed

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

Gavelli, Filippo; Bullister, Edward; Kytomaa, Harri

2008-11-15

31

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

SciTech Connect

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 and 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. 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.

Not Available

1982-05-01

32

Pressurized release of liquefied fuel gases (LNG and LPG). Topical report, May 1993-February 1996  

SciTech Connect

This report is an important contribution to the behavior of pressurized liquefied gases when accidentally released into the atmosphere. LNG vehicle fueling stations and LPG storage facilities operate at elevated pressures. Accidental releases could result in rainout and the formation of an aerosol in the vapor cloud. These factors must be considered when estimating the extent of the hazard zone of the vapor cloud using a heavier-than-air gas dispersion model such as DEGADIS (or its Windows equivalent DEGATEC). The DOS program PREL has been incorporated in the Windows program LFGRISK.

Atallah, S.; Janardhan, A.

1996-02-01

33

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

NASA Technical Reports Server (NTRS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young Laplace Equation. These isothermal results characterized the interfacial force field in-siru at the start of the heat transfer experiments by quantifying the dispersion constant, which is a function of the liquid-solid system and cleaning procedures. The experimentally obtained values of the disjoining pressure and the dispersion constants were compared to that predicted from the DLP theory and good agreements were obtained. The measurements are critical to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the Constrained Vapor Bubble Thermosyphon, CVBT, is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'estimated'. One of the major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally, we find that the extended Young-Laplace Equation is an excellent model for the force field at the solid-liquid-vapor interfaces.

Dasgupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

1995-01-01

34

Efficient vapor sensors using foils of dispersed nitrogen-doped and pure carbon multiwalled nanotubes.  

PubMed

We fabricated vapor sensors using nitrogen-doped (CNx) and pure multi-walled carbon nanotubes (MWNTs), and compared their performance. The sensors were constructed by dispersing the nanotube materials in methanol so as to form millimeter-long foils (nanotube paper), consisting of compact arrays of crisscrossing nanotubes. The devices were characterized by electrical resistance measurements and SEM studies. For CNx-based sensors, we observed that low concentrations of vapors such an acetone, ethanol, and chloroform were efficiently detected within 0.1-0.3 seconds via a physisorption mechanism. This physisorption is explained in terms of a weak interaction of the vapor molecules with the pyridinic sites (N bonded to two carbon atoms) present in the doped tubes. We believe that the methanol used for preparing the foils has a strong effect in saturating substitutional N atoms (N atoms bonded to three carbon atoms) that are also located in the CNx tubes. However, when pure carbon MWNTs were tested as sensors, we witnessed chemisorption of these vapors. First-principles density functional calculations confirmed that the gaseous molecules are able to interact with N-doped carbon nanotubes, via a physisorption mechanism, in which pyridine sites play a crucial role. PMID:20355399

Rebollo-Plata, Bernabe; Muñoz-Sandoval, Emilio; López-Urías, Florentino; Hernández-Cortina, Edson L; Terrones, Humberto; Terrones, Mauricio

2010-06-01

35

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

Federal Register 2010, 2011, 2012, 2013

...Facilities: Guide to the LNG Model Validation Database, Version 11.0...assessment, model verification and model validation. The scientific assessment...model. For Computational Fluid Dynamics (CFD) models, a grid sensitivity...

2010-08-31

36

Demonstration of a Tunable-Bandwidth White Light Interferometer using Anomalous Dispersion in Atomic Vapor  

E-print Network

Recently, the design of a white-light-cavity has been proposed using negative dispersion in an intra-cavity medium to make the cavity resonate over a large range of frequencies and still maintain a high cavity build-up. This paper presents the demonstration of this effect in a free-space cavity. The negative dispersion of the intra-cavity medium is caused by bi-frequency Raman gain in an atomic vapor cell. A significantly broad cavity response over a bandwidth greater than 20 MHz has been observed. The experimental results agree well with the theoretical model, taking into account effects of residual absorption. A key application of this device would be in enhancing the sensitivity-bandwidth product of the next generation gravitational wave detectors that make use of the so-called signal-recycling mirror.

G. S. Pati; M. Salit; K. Salit; M. S. Shahriar

2006-10-04

37

Determination of the dispersion constant in a constrained vapor bubble thermosyphon  

NASA Technical Reports Server (NTRS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using an image analyzing interferometer which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace equation. These isothermal results characterized the interfacial force field in-situ at the start of the heat transfer experiments by quantifying the dispersion constant, which is a function of the liquid-solid system and cleaning procedures. The experimentally obtained values of the disjoining pressure and the dispersion constants were compared to that predicted from the DLP theory and good agreements were obtained. The measurements are critical to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the CVBT is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'guesstimated'. One of the major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally. we find that the extended Young-Laplace equation is an excellent model for the force field at the solid-liquid-vapor interfaces.

Dasgupta, SUNANDO.; Plawsky, Joel L.; Wayner, Peter C., Jr.

1993-01-01

38

New LNG process scheme  

SciTech Connect

A new LNG cycle has been developed for base load liquefaction facilities. This new design offers a different technical and economical solution comparing in efficiency with the classical technologies. The new LNG scheme could offer attractive business opportunities to oil and gas companies that are trying to find paths to monetize gas sources more effectively; particularly for remote or offshore locations where smaller scale LNG facilities might be applicable. This design offers also an alternative route to classic LNG projects, as well as alternative fuel sources. Conceived to offer simplicity and access to industry standard equipment, This design is a hybrid result of combining a standard refrigeration system and turboexpander technology.

Foglietta, J.H.

1999-07-01

39

Comparative safety analysis of LNG storage tanks  

SciTech Connect

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)

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

1982-07-01

40

Risk assessment of membrane type LNG storage tanks in Korea-based on fault tree analysis  

Microsoft Academic Search

For a liquefied natural gas (LNG) storage tank, the greatest concern is for the release of a large amount of LNG or its vapor\\u000a due to the mechanical failures of main tank and its ancillary equipments or the malfunctions of various hardware components.\\u000a Nowadays two types of LNG storage tank design, that is, 9%-Ni full containment and membrane concepts, are

Hyo Kim; Jae-Sun Koh; Youngsoo Kim; Theofanius G. Theofanous

2005-01-01

41

High efficiency Brayton cycles using LNG  

DOEpatents

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.

Morrow, Charles W. (Albuquerque, NM)

2006-04-18

42

Safety guided design of LNG terminal  

Microsoft Academic Search

The safety philosophy used by Southern Energy Co., at its Elba Island, Ga., LNG terminal was developed by Energy Analysis Inc., The terminal is surrounded by marshland, with no houses closer than two miles. Safety-related equipment at the terminal includes ultraviolet sensors to detect fires; cold sensors, set to alarm at -100°F, installed along pipeways and pump and vaporizer areas

J. Anderson; M. Smith

1979-01-01

43

Insulating LNG (liquified natural gas) storage tank containment dikes with a lightweight polymer concrete  

SciTech Connect

The natural gas industry has always been concerned ith accidental spills of liquified natural gas (LNG) from storage tanks into surrounding containment dikes. The LNG that is leaked to the dike area boils off and the vapors mix with the atmosphere forming a hazardous explsoive mixture within the dike walls. These hazardous mixtures can travel long distances into industrial or residential areas surroungind LNG storage facilities. Studies by the natural gas industry indicate that the hazards associated with accidental spills of LNG from storage tanks can be makedly reduced by insulating the diked areas surrounding these tanks. In this manner, the heat transfer from the dike surface to the LNG is reduced. The insulating composite is used to construct a thermal barrier between the walls and floor of the dike an the spilled LNG. The thermal conductivity, porosity, and compression strength of a concrete, polymer composite insulating material is discussed. 6 refs., 8 figs., 5 tbs.

Fontana, J.J.

1987-08-01

44

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

Federal Register 2010, 2011, 2012, 2013

...requesting: (1) Authorization to site, construct and operate a new liquefied natural gas (LNG) import, storage, and vaporization terminal and associated facilities on the St. Croix River in Calais, Maine and authority to utilize the terminal as...

2010-01-14

45

Vapor spill pipe monitor  

DOEpatents

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.

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

1983-06-23

46

LNG infrastructure and equipment  

SciTech Connect

Sound engineering principals have been used by every company involved in the development of the LNG infrastructure, but there is very little that is new. The same cryogenic technology that is used in the manufacture and sale of nitrogen, argon, and oxygen infrastructure is used in LNG infrastructure. The key component of the refueling infrastructure is the LNG tank which should have a capacity of at least 15,000 gallons. These stainless steel tanks are actually a tank within a tank separated by an annular space that is void of air creating a vacuum between the inner and outer tank where superinsulation is applied. Dispensing can be accomplished by pressure or pump. Either works well and has been demonstrated in the field. Until work is complete on NFPA 57 or The Texas Railroad Commission Rules for LNG are complete, the industry is setting the standards for the safe installation of refueling infrastructure. As a new industry, the safety record to date has been outstanding.

Forgash, D.J.

1995-12-31

47

46 CFR 154.703 - Methane (LNG).  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Methane (LNG). 154.703 Section 154.703...Pressure and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG) can withstand the pressure...

2010-10-01

48

46 CFR 154.703 - Methane (LNG).  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Methane (LNG). 154.703 Section 154.703...Pressure and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG) can withstand the pressure...

2013-10-01

49

46 CFR 154.703 - Methane (LNG).  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Methane (LNG). 154.703 Section 154.703...Pressure and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG) can withstand the pressure...

2012-10-01

50

46 CFR 154.703 - Methane (LNG).  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Methane (LNG). 154.703 Section 154.703...Pressure and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG) can withstand the pressure...

2011-10-01

51

Modeling of LNG Pool Spreading and Vaporization  

E-print Network

to preferential boiling within the mixture and the effect of boiling on conductive heat transfer. The heat, mass and momentum balance equations are derived for continuous and instantaneous spills and mixture thermodynamic effects are incorporated. A parameter...

Basha, Omar 1988-

2012-11-20

52

LNG pool fire spectral data and calculation of emissive power.  

PubMed

Spectral description of thermal emission from fires provides a fundamental basis on which the fire thermal radiation hazard assessment models can be developed. Several field experiments were conducted during the 1970s and 1980s to measure the thermal radiation field surrounding LNG fires. Most of these tests involved the measurement of fire thermal radiation to objects outside the fire envelope using either narrow-angle or wide-angle radiometers. Extrapolating the wide-angle radiometer data without understanding the nature of fire emission is prone to errors. Spectral emissions from LNG fires have been recorded in four test series conducted with LNG fires on different substrates and of different diameters. These include the AGA test series of LNG fires on land of diameters 1.8 and 6m, 35 m diameter fire on an insulated concrete dike in the Montoir tests conducted by Gaz de France, a 1976 test with 13 m diameter and the 1980 tests with 10 m diameter LNG fire on water carried out at China Lake, CA. The spectral data from the Montoir test series have not been published in technical journals; only recently has some data from this series have become available. This paper presents the details of the LNG fire spectral data from, primarily, the China Lake test series, their analysis and results. Available data from other test series are also discussed. China Lake data indicate that the thermal radiation emission from 13 m diameter LNG fire is made up of band emissions of about 50% of energy by water vapor (band emission), about 25% by carbon dioxide and the remainder constituting the continuum emission by luminous soot. The emissions from the H2O and CO2 bands are completely absorbed by the intervening atmosphere in less than about 200 m from the fire, even in the relatively dry desert air. The effective soot radiation constitutes only about 23% during the burning period of methane and increases slightly when other higher hydrocarbon species (ethane, propane, etc.) are burning in the LNG fire. The paper discusses the procedure by which the fire spectral data are used to predict the thermal emission from large LNG fires. Unfortunately, no direct measurements of the soot density or smoke characteristics were made in the tests. These parameters have significant effect on the thermal emission from large LNG fires. PMID:16920262

Raj, Phani K

2007-04-11

53

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

Federal Register 2010, 2011, 2012, 2013

...160,000 m\\3\\ (net capacity) full-containment LNG storage tanks; A closed-loop shell and tube heat exchanger vaporization system; Various ancillary facilities including administrative offices, warehouse, main control room, security...

2010-04-20

54

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

Federal Register 2010, 2011, 2012, 2013

...160,000 m\\3\\ (net capacity) full-containment LNG storage tanks; A closed-loop shell and tube heat exchanger vaporization system; Various ancillary facilities including administrative offices, warehouse, main control room, security...

2010-03-10

55

Remote sensing for diagnosing vapor dispersion in spills of liquid energy fuels. [LIDAR  

Microsoft Academic Search

The measurement of gas concentrations in Liquid Energy Fuel (LEF) dispersion clouds by remote LIDAR sensing is an attractive alternative to the use of in situ instruments in regions where the gas concentration level is low. A comparison of Raman and DIAL LIDAR has shown that Raman LIDAR is best suited to measure the concentration levels of interest in the

L. G. Multhauf; A. M. Frank; R. O. Koopman

1979-01-01

56

Demonstration of a Tunable-Bandwidth White-Light Interferometer Using Anomalous Dispersion in Atomic Vapor  

E-print Network

. This Letter presents the first demonstration of this effect in a free-space cavity. The negative dispersion but without the inverse loss of bandwidth by tailoring the path length of the cavity as a function resonator [12]. However, such a resonator is incompatible with free-space gravitational wave laser

Shahriar, Selim

57

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

PubMed

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

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

2014-09-15

58

LNG Observer: Second Qatargas train goes onstream  

SciTech Connect

The January-February, 1997 issue of the LNG Observer is presented. The following topics are discussed: second Qatargas train goes onstream; financing for the eighth Indonesian liquefaction train; Koreans take stakes in Oman LNG; US imports and exports of LNG in 1996; A 60% increase in proved reserves on the North West Shelf; proposals for Indian LNG terminal CEDIGAZ forecasts world LNG trade by 2010; growth for North African gas production and exports; and new forecast sees strong growth for Asian gas.

NONE

1997-01-01

59

Polymer-dispersed liquid crystal doped with carbon nanotubes for dimethyl methylphosphonate vapor-sensing application  

NASA Astrophysics Data System (ADS)

This paper proposes a sensitive gas sensor composed of polymer-dispersed liquid crystal (PDLC) for dimethyl methylphosphonate (DMMP) detection. The sensing element comprises a PDLC sensing film doped with carbon nanotubes (CNT-PDLC) and a planar interdigital electrode pair. The concentration of DMMP exposed to the CNT-PDLC material is detectable by measuring the change in conductivity of the material. Compared to conventional LC-based sensors, the proposed PDLC device is robust against mechanical shocks, and can fully operate with a simple read-out circuit. The sensor response is linear for gas concentrations from 5 to 250 ppm, and the response time is approximately 125 s.

Lai, Yu-Tse; Kuo, Jui-Chang; Yang, Yao-Joe

2013-05-01

60

Large Neighborhood Search for LNG Inventory Routing  

E-print Network

perspective. From an operations perspective, managing an LNG project involves negotiating ... This Annual Delivery Program. (ADP) is ... operational LNG inventory routing and test these models on a number of operational plan- ning cases ...

2011-12-15

61

Montoir terminal has latest LNG technology  

Microsoft Academic Search

Equipment is being added to increase capacity of France's Montoir-de-Bretagne LNG terminal to about 10 billion cubic meters. The author gives a technical description of one of the world's most modern LNG facilities.

Goy

1983-01-01

62

Effect of Mo Dispersion Size and Water Vapor on Oxidation of Two-Phase Directionally Solidified NiAl-9Mo In-Situ Composites  

SciTech Connect

Oxidation of two-phase NiAl-9Mo eutectics with 3 different growth rates/2nd phase Mo dispersion sizes were investigated at 900 C in air and air with 10% water vapor. Good oxidation resistance via alumina formation was observed in dry air, with Mo volatilization loss minimized by fine submicron Mo dispersions. However, extensive Mo volatilization and in-place internal oxidation of prior Mo phase regions was observed in wet air oxidation. Ramifications of this phenomenon for the development of multi-phase high-temperature alloys are discussed

Brady, Michael P [ORNL] [ORNL; Bei, Hongbin [ORNL] [ORNL; Meisner, Roberta Ann [ORNL] [ORNL; Lance, Michael J [ORNL] [ORNL; Tortorelli, Peter F [ORNL] [ORNL

2014-01-01

63

Recommended research on LNG safety  

SciTech Connect

The US Department of Energy (DOE) is conducting research on the safety and other environmental aspects of liquefied energy gases including liquefied natural gas (LNG). The effort reported here was conducted as part of the planning for further research into the safety aspects of transporting and storing LNG, with primary emphasis on public safety. Although the modern LNG industry has enjoyed excellent success in providing for safe operations, significant questions remain on the part of many, the expressions of which were intensified with the addition of marine-based LNG import terminals. Public safety with regard to large-scale importation of this fuel has received widespread attention in the US Congress, state legislatures, county and city governments, and from various individuals and public groups, with coverage in all the news media, including books published on the subject. The safety concerns have centered around the consequences to the public of a large spill of the cryogenic liquid from an ocean tanker or a larger storage tank, either of which might hold as much as 125,000 m/sup 3/ of LNG.

Carpenter, H.J.; Gilmore, F.R.

1981-03-01

64

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

SciTech Connect

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.

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

65

LNG vehicle technology, economics, and safety assessment  

NASA Astrophysics Data System (ADS)

Liquid natural gas (LNG) is an attractive transportation fuel because of its high heating value and energy density (i.e., Btu/lb. and Btu/gal.), clean burning characteristics, relatively low cost ($/Btu), and domestic availability. This research evaluated LNG vehicle and refueling system technology, economics, and safety. Prior and current LNG vehicle projects were studied to identify needed technology improvements. Life-cycle cost analyses considered various LNG vehicle and fuel supply options. Safety records, standards, and analysis methods were reviewed. The LNG market niche is centrally fueled heavy-duty fleet vehicles with high fuel consumption. For these applications, fuel cost savings can amortize equipment capital costs.

Powars, Charles A.; Moyer, Carl B.; Lowell, Douglas D.

1994-02-01

66

Potential Application of Floating LNG  

Microsoft Academic Search

The paper describes the efficiency of LNG and its contribution to world energy resources. It also examines the political, economical and technical drivers for successful realization of offshore liquefaction vessel development, main challenges and risks associated with it; it also reviews the current status of technology development and projects which are under development today. Objective: This paper seeks to identify

Elena Voskresenskaya

67

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

E-print Network

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...

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

68

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

E-print Network

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 arrangement is investigated...

Kuriakose, Vinu P.

2005-11-01

69

LNG vehicle technology, economics, and safety assessment  

Microsoft Academic Search

Liquid natural gas (LNG) is an attractive transportation fuel because of its high heating value and energy density (i.e., Btu\\/lb. and Btu\\/gal.), clean burning characteristics, relatively low cost ($\\/Btu), and domestic availability. This research evaluated LNG vehicle and refueling system technology, economics, and safety. Prior and current LNG vehicle projects were studied to identify needed technology improvements. Life-cycle cost analyses

Charles A. Powars; Carl B. Moyer; Douglas D. Lowell

1994-01-01

70

Optimizing PT Arun LNG main heat exchanger  

SciTech Connect

The capacity of a LNG liquefaction unit has been increased by upgrading the refrigeration system, without making changes to the main heat exchanger (MHE). It is interesting, that after all modifications were completed, a higher refrigerant circulation alone could not increase LNG production. However, by optimizing the refrigerant component ratio, the UA of the MHE increased and LNG production improved. This technical evaluation will provide recommendations and show how the evaluation of the internal temperature profile helped optimize the MHE operating conditions.

Irawan, B. [PT Arun NGL Co., Sumatra (Indonesia)

1995-12-01

71

COGAS propulsion for LNG ships  

Microsoft Academic Search

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.

Edwin G. Wiggins

2011-01-01

72

COGAS propulsion for LNG ships  

NASA Astrophysics Data System (ADS)

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.

Wiggins, Edwin G.

2011-06-01

73

COGAS propulsion for LNG ships  

Microsoft Academic Search

Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor\\u000a because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service,\\u000a and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers\\u000a significant advantages over steam and diesel propulsion.

Edwin G. Wiggins

2011-01-01

74

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

SciTech Connect

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-{var_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.

Luketa-Hanlin, Anay Josephine; Koopman, Ronald P. (Lawrence Livermore National Laboratory, Livermore, CA); Ermak, Donald (Lawrence Livermore National Laboratory, Livermore, CA)

2006-02-01

75

Prospects good for LNG cold recovery  

Microsoft Academic Search

Increasing emphasis is expected on more efficient use of increasing emphasis is expected on more efficient use of LNG's refrigeration potential. The continuing escalation in the cost of energy, together with a clearer understanding of the potential uses, should facilitate acceptance of LNG cold-recovery projects. A balance must be established between the quantity and level of potential refrigeration recovered and

DiNapoli

1975-01-01

76

Feasibility of methods and systems for reducng LNG tanker fire hazards  

SciTech Connect

In this program concepts for reducing fire hazards that may result from LNG tanker collisions are identified and their technical feasibility evaluated. Concepts considered include modifications to the shipborne LNG containers so that in the event of a container rupture less of the contents would spill and/or the contents would spill at a reduced rate. Changes in the cargo itself, including making the LNG into a gel, solidifying it, converting it to methanol, and adding flame suppressants are also evaluated. The relative effectiveness and the costs of implementing these methods in terms of increased cost of gas at the receiving terminal, are explained. The vulnerability of an LNG tanker and its crew to the thermal effects of a large pool fire caused by a collision spill is estimated and methods of protecting the crew are considered. It is shown that the protection of ship and crew so that further deterioration of a damaged ship might be ameliorated, would require the design and installation of extraordinary insulation systems and life support assistance for the crew. Methods of salvaging or disposing of cargo from a damaged and disabled ship are evaluated, and it is concluded that if the cargo cannot be transferred to another (empty) LNG tanker because of lack of availability, then the burning of the cargo at a location somewhat distant from the disabled tanker appears to be a promising approach. Finally, the likelihood of the vapors from a spill being ignited due to the frictional impact of the colliding ships was examined. It is found that the heating of metal sufficient to ignite flammable vapors would occur during a collision, but it is questionable whether flammable vapor and air will, in fact, come in contact with the hot metal surfaces.

Not Available

1980-08-01

77

Potential for BLEVE associated with marine LNG vessel fires  

Microsoft Academic Search

Recent LNG marine shipping hazard studies have discounted BLEVE hazards associated with LNG vessels. This exclusion of a potential major hazard event has been queried, particularly since a recent LNG truck BLEVE-like event in Spain. This paper reviews the physical factors associated with the Spanish LNG truck event and accepts that this had features of a classical BLEVE event and

Robin Pitblado

2007-01-01

78

FLOATING LNG PLANTS - SCALE-UP OF FAMILIAR TECHNOLOGY  

Microsoft Academic Search

Increasing costs of onshore base load LNG plants and technology developments in offshore LNG storage and transfer have resulted in offshore LNG production now being commercially viable, even at plant capacities of 1 to 2 million tonnes per annum. At these LNG production rates, floating plants will use liquefaction processes based on turbo-expanders to generate the refrigeration for liquefaction. This

Adrian J. Finn

79

LNG Safety Research: FEM3A Model Development  

SciTech Connect

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.

Liese Dallbauman

2004-06-30

80

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

SciTech Connect

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.

Droppo, James G.

2004-07-30

81

Raley's LNG Truck Site Final Data Report  

SciTech Connect

Raley's is a 120-store grocery chain with headquarters in Sacramento, California, that has been operating eight heavy-duty LNG trucks (Kenworth T800 trucks with Cummins L10-300G engines) and two LNG yard tractors (Ottawa trucks with Cummins B5.9G engines) since April 1997. This report describes the results of data collection and evaluation of the eight heavy-duty LNG trucks compared to similar heavy-duty diesel trucks operating at Raley's. The data collection and evaluation are a part of the U.S. Department of Energy (DOE)/National Renewable Energy Laboratory (NREL) Alternative Fuel Truck Evaluation Project.

Battelle

1999-07-01

82

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

PubMed

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

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

2014-09-01

83

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

E-print Network

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...

Yun, Geun-Woong

2009-05-15

84

Operating history of Arun LNG Plant  

SciTech Connect

The Arun LNG plant is owned by PERTAMINA (The Oil And Gas State Enterprise Of The Republic Of Indonesia) and is located at Blang Lancang, North Aceh, Sumatra, Indonesia. It is about 15 km west of the port of Lhokseumawe, or about 300 km north-west of the city of Medan. The plant is operated by PT Arun NGL Co. The Arun LNG plant receives gas and unstabilized hydrocarbon condensate from the Arun Field gas reservoir which is developed and operated by MOBIL OIL INDONESIA under Production Sharing Contract with PERTAMINA and is located about 30 km south-east of the plant. The gas and condensate are transported by pipeline to the plant. Operation of the condensate recovery unit began in April 1977 and the three LNG trains began producing LNG in August 1978, September 1978 and February 1979 respectively. The original three-train plant now produces 34000 m/sup 3//day of LNG and 85000 bbl/day of condensate. An additional two LNG trains have been constructed and recently began production.

Suyanto, J.R.O.

1984-02-01

85

Grain structure and growth of dispersed phase BN-AlN coatings grown via chemical vapor deposition  

SciTech Connect

This paper discusses the variation in microstructures encountered during the separate depositions of boron nitride (BN) and aluminium nitride (AlN) as well as during the codeposition of BN-AlN dispersed phase ceramic coatings. This combination was chosen in order to take advantage of the self lubricating properties of hexagonal BN along with the hard, erosion resistance of AlN. Films were characterized using scanning and transmission electron microscopy (SEM and TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD). A range of coating microstructures are possible depending on the conditions of deposition. The best films produced, in terms of hardness, density, and tenacity, were a fine mixture of turbostratic BN and preferentially oriented A1N whiskers aligned with the whisker axis perpendicular to the substrate surface as seen by both electron microscopy and x-ray diffraction. 4 refs., 9 figs., 1 tab.

Freeman, G.B.; Lackey, W.J.; Hanigofsky, J.A. (Georgia Inst. of Tech., Atlanta, GA (USA). Georgia Technology Research Inst.); Lee, Woo Y. (United Technologies Research Center, East Hartford, CT (USA)); More, K.L. (Oak Ridge National Lab., TN (USA))

1990-01-01

86

GRI workshop on LNG vehicle technology, economics, and safety issues: Focus-group recommendations summary. Topical report, April 29 and 30, 1992  

SciTech Connect

GRI organized and conducted the Workshop on LNG Vehicle Technology, Economics, and Safety Issues on April 29 and 30, 1992, in Houston, Texas. The workshop included various presentations, a tour of Houston Metro (LNG bus project) facilities, and focus group discussions. The report documents the recommendations generated by the focus group. There were five separate focus groups with an average of ten members each. They met for 2-1/2 hours to discuss LNG vehicle issues and evolve recommendations for GRI R and D. Fifty-three recommendations were generated and prioritized (through voting) by the focus groups. The report consolidates these recommendations. Recommendations relative to the LNG fuel composition issue received the most votes, followed by consolidated recommendations pertaining to gas venting elimination, safety codes, and odorants or leak detectors. Component development recommendations (in order of votes) included the refueling nozzle, fuel level gage, refueling pump and meter, vehicle pump/regulator/vaporizer, and vehicle tank.

Not Available

1992-07-07

87

49 CFR 193.2623 - Inspecting LNG storage tanks.  

Code of Federal Regulations, 2010 CFR

...STANDARDS Maintenance § 193.2623 Inspecting LNG storage tanks. Each LNG storage tank must be inspected or tested to verify that...structural integrity or safety of the tank: (a) Foundation and tank movement during normal operation...

2010-10-01

88

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

E-print Network

standards, NFPA 59A Standard for the Production, Storage, and Handling of LNG. 1969 United States exports, incorporating NFPA 59A standards. 1977 California enacts LNG Terminal Siting Act, allowing the California Public

89

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

Federal Register 2010, 2011, 2012, 2013

...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 protect...entitled Security Zone; Freeport LNG Basin, Freeport, TX in the Federal...

2010-03-10

90

Safety implications of a large LNG tanker spill over water.  

SciTech Connect

The increasing demand for natural gas in the United States could significantly increase the number and frequency of marine LNG (liquefied natural gas) imports. Although many studies have been conducted to assess the consequences and risks of potential LNG spills, the increasing importance of LNG imports suggests that consistent methods and approaches be identified and implemented to help ensure protection of public safety and property from a potential LNG spill. For that reason the U.S. Department of Energy (DOE), Office of Fossil Energy, requested that Sandia National Laboratories (Sandia) develop guidance on a risk-based analysis approach to assess and quantify potential threats to an LNG ship, the potential hazards and consequences of a large spill from an LNG ship, and review prevention and mitigation strategies that could be implemented to reduce both the potential and the risks of an LNG spill over water. Specifically, DOE requested: (1) An in-depth literature search of the experimental and technical studies associated with evaluating the safety and hazards of an LNG spill from an LNG ship; (2) A detailed review of four recent spill modeling studies related to the safety implications of a large-scale LNG spill over water; (3) Evaluation of the potential for breaching an LNG ship cargo tank, both accidentally and intentionally, identification of the potential for such breaches and the potential size of an LNG spill for each breach scenario, and an assessment of the potential range of hazards involved in an LNG spill; (4) Development of guidance on the use of modern, performance-based, risk management approaches to analyze and manage the threats, hazards, and consequences of an LNG spill over water to reduce the overall risks of an LNG spill to levels that are protective of public safety and property.

Hightower, Marion Michael; Gritzo, Louis Alan; Luketa-Hanlin, Anay Josephine

2005-04-01

91

ERC policy statement on LNG imports. [Energy Resources Council LNG policy study  

Microsoft Academic Search

USA energy policy considerations by the Energy Resources Council (ERC) are reviewed. The risks of dependence, supply disruption, and arbitrary price hikes should be minimized by the recommendation that LNG imports from a single country be limited to 0.8 to 1.0 Tcf\\/yr for national security reasons and total LNG imports to about 2 Tcf\\/yr. These recommendations are based on diversification

Zarb

1976-01-01

92

77 FR 73627 - 2012 LNG Export Study  

Federal Register 2010, 2011, 2012, 2013

...non-free trade agreement (FTA) countries.\\1\\ The LNG Export Study...authority to export natural gas to countries with which the United States...of 5.6 billion cubic feet per day (Bcf/ day) of natural...opportunity to intervene in or protest those pending matters by...

2012-12-11

93

LNG slurry formation. Preliminary technical memo  

Microsoft Academic Search

The process of forming particles of frozen crude oil by spraying oil into LNG was originally conceived by LeFever. Analyses by Coulter have shown that the particles formed for slurry transportation must be as small as possible, on the order of 30 micrometers (.001 inch). Such small pellets can be achieved by freezing oil spray, but direct spraying of crude

Coulter

1975-01-01

94

Beauty of Simplicity: Phillips Optimized Cascade LNG Liquefaction Process  

NASA Astrophysics Data System (ADS)

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.

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

2004-06-01

95

LNG pump anti-slam device  

SciTech Connect

In pumping LNG (liquefied natural gas) from one receiver to another, eg., from a vessel's tank to a shore installation, it is conventional to use a submerged pump, a riser pipe connecting the pump to a stop valve and flexible joint connecting the stop valve to a header. If a pocket of gaseous lng is present in the riser pipe, when the pump commences its operation, the advancing column of liquid in the riser pipe slams against the stop valve and may damage it. The invention provides the improvement of a removable or bypassable flow restrictor incorporated between the pump and the riser pipe, permitting to ensure that the riser pipe is completely liquid-filled, before the pump commences to operate.

Tornay, E.G.

1980-05-27

96

Monitor terminal has latest LNG technology  

Microsoft Academic Search

The Montoir de Bretagne (France) methane terminal is the third one constructed by Gaz de France to receive Algerian LNG. Initially designed to handle 192 billion CF (5.15 billion m³)\\/yr of natural gas, the plant is now being enlarged to increase its regasification capacity to about 370 billion CF (10 billion m³). Descriptions of the unloading facilities, storage tanks, high-pressure

Goy

1983-01-01

97

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

Federal Register 2010, 2011, 2012, 2013

...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...

2011-11-29

98

Project financing knits parts of costly LNG supply chain  

Microsoft Academic Search

The supply and distribution infrastructure of an LNG project requires project sponsors and LNG buyers to make large, interdependent capital investments. For a grassroots project, substantial investments may be necessary for each link in the supply chain: field development; liquefaction plant and storage; ports and utilities; ships; receiving terminal and related facilities; and end-user facilities such as power stations or

R. J. Minyard; M. O. Strode

1997-01-01

99

Liquefaction through expander for base load LNG  

SciTech Connect

New natural gas liquefaction process using turbo expander has been developed to improve process thermal efficiency. The new process consists of precooling section which uses refrigerant with shell and tube heat exchangers or brazed aluminum plate-fin exchangers or spool wound heat exchanger and liquefaction section by iso-entropic expander. As a result of design study, thermal efficiency of the new liquefaction process has been confirmed to be in the highest level compared with other liquefaction processes. Also, since the new liquefaction process is constructed with commonly available equipment in industry, it can be readily adapted to base load LNG plants of any capacity without requiring expensive and specially designed equipment.

Nakamura, Moritaka; Kikkawa, Yoshitsugi [Chiyoda Corp., Yokohama (Japan)

1998-12-31

100

Electric propulsion for LNG Carriers Full-size LNG carriers with dual fuel diesel engines and electric propulsion are now under construction in France. The authors present the benefits and design features of electric propulsion systems in LNG shipping applications  

Microsoft Academic Search

he current world usage of LNG is about 110 million tons per year and current analysis indicates this grow- ing in the next 10 years by 70 to 100 million tons. This may lead to demand for more than 80 new LNG carriers by 2010, in addi- tion to those already under construction. Traditionally LNG carriers have been pro- pelled

Jan Fredrik; Rune Lysebo

101

New energy saving system for future LNG carriers  

SciTech Connect

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.

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

1994-12-31

102

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

SciTech Connect

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.

None

1980-10-01

103

Conceptual Liquefied Natural Gas (LNG) terminal design for Kuwait  

E-print Network

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...

Aljeeran, Fares

2006-08-16

104

49 CFR 193.2019 - Mobile and temporary LNG facilities.  

Code of Federal Regulations, 2010 CFR

...facilities. (a) Mobile and temporary LNG facilities for peakshaving application, for service maintenance during gas pipeline systems repair/alteration, or for other short term applications need not meet the requirements of this part...

2010-10-01

105

Parallel Large-Neighborhood Search Techniques for LNG Inventory ...  

E-print Network

For profitable operation of a capital intensive LNG project, it is necessary to optimally design ..... Parallel efficiency is a metric quantifying overall fraction ... Choice of static vs. dynamic resource allocation could have significant impact on the.

2014-04-17

106

LNG SAFETY RESEARCH: FEM3A MODEL DEVELOPMENT  

Microsoft Academic Search

This quarterly report for DE-FG26-04NT42030 covers a period from October 1, 2004 to December 31, 2004. On December 9, 2004 a meeting was held in Morgantown to rescope the LNG safety modeling project such that the work would complement the DOE's efforts relative to the development of the intended LNG-Fluent model. It was noted and discussed at the December 9th

Jerry Havens; Iraj A. Salehi

2005-01-01

107

The Phoenix series large scale LNG pool fire experiments.  

SciTech Connect

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.

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

108

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

...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...

2010-01-05

109

Development of vapor-dispersion models for nonneutrally buoyant gas mixtures - analysis of TFI/NH/sub 3/ test data. Final report, March 1986-March 1987  

SciTech Connect

Field-scale releases of pressurized anhydrous ammonia were performed by the Lawrence Livermore National Laboratories in 1983 for the U.S. Coast Guard, the Fertilizer Institute, and Environment Canada. Release rates for the four experiments ranged between 80 and 130 kilograms per second. The pressurized liquid-ammonia jet formed a denser-than-air aerosol cloud. A method of determining the relative importance of jet and nonjet dispersion processes is discussed. The data from these experiments were analyzed to determine the mass flux of ammonia and the lateral and vertical concentration profile parameters for the cloud (sigma y and sigma z for the Gaussian plume model and SY and SZ for DEGADIS) at 800 meters downwind. These observed values of maximum concentration and concentration profile parameters were compared with DEGADIS and Gaussian plume model predictions. (DEGADIS is an atmospheric dispersion model designed to account for the influences of denser-than-air gases.) In addition, analysis of the experimental data indicated heat transfer to the aerosol cloud was insignificant although the cloud temperature was as low as -60/sup 0/.

Spicer, T.O.; Havens, J.

1988-10-01

110

LNG Safety Research: FEM3A Model Development  

SciTech Connect

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.

Iraj A. Salehi; Jerry Havens; Tom Spicer

2006-09-30

111

LNG Safety Research: FEM3A Model Development  

SciTech Connect

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.

None

2006-09-30

112

The diseconomics of long-haul LNG trading  

SciTech Connect

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.

Stauffer, T.R.

1995-12-31

113

Insulating polymer concrete for LNG impounding dikes. [Polymer concretes  

SciTech Connect

An insulating polymer concrete (IPC) composite has been developed under contract to the Gas Research Institute for possible use as a dike insulation material at Liquid Natural Gas (LNG) storage facilities. In the advent of an LNG spill into the impounding dike area, the boiloff rate of the LNG can be substantially reduced if the surfaces of the dike are insulated. This increased safety at the LNG facility will tend to reduce the hazardous explosive mixture with atmospheric air in the surrounding region. The dike insulation material must have a low thermal conductivity and be unaffected by environmental conditions. The IPC composites developed consist of perlite or glass nodule aggregates bound together as a closed cell structure with a polyester resin. In addition to low thermal conductivity and porosity, these composites have correspondingly high strengths and, therefore, can carry transient loads of workmen and maintenance equipment. Prefabricated IPC panels have been installed experimentally and at least one utility is currently considering a complete installation at its LNG facility. 5 refs., 5 tabs.

Fontana, J.J.; Steinberg, M.

1986-03-01

114

Floating LNG plant will stress reliability and safety  

SciTech Connect

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.

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

1997-07-01

115

Performance enhancement of propane pre-cooled mixed refrigerant LNG plant  

Microsoft Academic Search

Liquefied Natural Gas (LNG) and chemical processing are energy-intensive facilities, such that any enhancement of their efficiency will result in abundant reduction of energy consumption and green house gas emissions. To enhance LNG plant energy efficiency, the potential of various options for improving liquefaction cycle efficiency is investigated in this study. After developing models for the LNG process using ASPEN

A. Mortazavi; C. Somers; Y. Hwang; R. Radermacher; P. Rodgers; S. Al-Hashimi

2012-01-01

116

Hazards to nuclear power plants from large liquefied natural gas (LNG) spills on water  

Microsoft Academic Search

The hazards to nuclear power plants arising from large spills of liquefied natural gas (LNG) on water transportation routes are treated by deterministic analytical procedures. Global models, which address the salient features of the LNG spill phenomena are used in the analysis. A coupled computational model for the combined LNG spill, spreading, and fire scenario is developed. To predict the

C. A. Kot; T. V. Eichler; A. H. Wiedermann; R. Pape; M. G. Srinivasan

1981-01-01

117

Analysis of LNG peakshaving-facility release-prevention systems  

SciTech Connect

The purpose of this study is to provide an analysis of release prevention systems for a reference LNG peakshaving facility. An overview assessment of the reference peakshaving facility, which preceeded this effort, identified 14 release scenarios which are typical of the potential hazards involved in the operation of LNG peakshaving facilities. These scenarios formed the basis for this more detailed study. Failure modes and effects analysis and fault tree analysis were used to estimate the expected frequency of each release scenario for the reference peakshaving facility. In addition, the effectiveness of release prevention, release detection, and release control systems were evaluated.

Pelto, P.J.; Baker, E.G.; Powers, T.B.; Schreiber, A.M.; Hobbs, J.M.; Daling, P.M.

1982-05-01

118

Monitoring, safety systems for LNG and LPG operators  

SciTech Connect

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.

True, W.R.

1998-11-16

119

Comparison of CNG and LNG technologies for transportation applications  

SciTech Connect

This report provides a head-to-head comparison of compressed natural gas (CNG) and liquefied natural gas (LNG) supplied to heavy-duty vehicles. The comparison includes an assessment of the overall efficiency of the fuel delivery system, the cost of the fuel supply system, the efficiency of use in heavy-duty vehicles, and the environmental impact of each technology. The report concludes that there are applications in which CNG will have the advantage, and applications in which LNG will be preferred.

Sinor, J.E. (Sinor (J.E.) Consultants, Inc., Niwot, CO (United States))

1992-01-01

120

Hawaii energy strategy project 2: Fossil energy review. Task 3 -- Greenfield options: Prospects for LNG use  

SciTech Connect

This paper begins with an overview of the Asia-Pacific LNG market, its major players, and the likely availability of LNG supplies in the region. The discussion then examines the possibilities for the economic supply of LNG to Hawaii, the potential Hawaiian market, and the viability of an LNG project on Oahu. This survey is far from a complete technical assessment or an actual engineering/feasibility study. The economics alone cannot justify LNG`s introduction. The debate may continue as to whether fuel diversification and environmental reasons can outweigh the higher costs. Several points are made. LNG is not a spot commodity. Switching to LNG in Hawaii would require a massive, long-term commitment and substantial investments. LNG supplies are growing very tight in the Asia-Pacific region. Some of the environmental benefits of LNG are not entirely relevant in Hawaii because Hawaii`s air quality is generally excellent. Any air quality benefits may be more than counterbalanced by the environmental hazards connected with large-scale coastal zone construction, and by the safety hazards of LNG carriers, pipelines, etc. Lastly, LNG is not suitable for all energy uses, and is likely to be entirely unsuitable for neighbor island energy needs.

Breazeale, K. [ed.; Fesharaki, F.; Fridley, D.; Pezeshki, S.; Wu, K.

1993-12-01

121

Supplying LNG markets using nitrogen rejection units at Exxon Shute Creek Facility  

SciTech Connect

Interest is growing in the United States for using Liquid Natural Gas (LNG) as an alternative transportation fuel for diesel and as a source of heating fuel. For gas producers, LNG offers a premium price opportunity versus conventional natural gas sales. To supply this developing market, two existing Nitrogen Rejection Units (NRU) at the Exxon Shute Creek Facility in Wyoming were modified allowing LNG extraction and truck loading for transport to customers. The modifications involved adding heat exchanger capacity to the NRUs to compensate for the refrigeration loss when LNG is removed. Besides allowing for LNG extraction, the modifications also debottlenecked the NRUs resulting in higher methane recovery and lower compression costs. With the modifications, the NRUs are capable of producing for sale 60,000 gpd (5 MMscfd gas equivalent) of high purity LNG. Total investment has been $5 million with initial sales of LNG occurring in September 1994.

Hanus, P.M.; Kimble, E.L. [Exxon Co. USA, Midland, TX (United States)

1995-11-01

122

Cours Titre Professeur Horaire Local examen LNG 1010 Langage et cognition Daniel Valois Jeudi 16 h 19 h  

E-print Network

16 h à 19 h LNG 1080 Lexicologie, sémantique et morphologie Mireille Tremblay Vendredi 8 h 30 à 11 h 30 LNG 1120 Histoire de la langue française Lundi 8 h 30 à 11 h 30 LNG 1125 Temps et espaces francophones Lundi 13 h à 16 h LNG 1400A Notions de phonétique et de phonologie Mercredi 13 h à 16 h LNG 1400B

Parrott, Lael

123

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

Microsoft Academic Search

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

Rajesh Varma; Deepali Sinha; Janesh K. Gupta

2006-01-01

124

LNG pool fire spectral data and calculation of emissive power  

Microsoft Academic Search

Spectral description of thermal emission from fires provides a fundamental basis on which the fire thermal radiation hazard assessment models can be developed. Several field experiments were conducted during the 1970s and 1980s to measure the thermal radiation field surrounding LNG fires. Most of these tests involved the measurement of fire thermal radiation to objects outside the fire envelope using

Phani K. Raj

2007-01-01

125

Gas turbines prove effective as drivers for LNG plants  

Microsoft Academic Search

For baseload LNG applications, gas turbines - particularly the modular, lightweight machines - are proven, efficient drivers for the large refrigeration compressors. The proper choice of a turbine and the careful integration of waste-heat recovery into the total plant energy balance can maximize the individual train throughputs while maintaining high overall thermal efficiencies. Because the capital investment associated with the

DiNapoli

1980-01-01

126

LSG 500/LNG 300 (607) 777-2400  

E-print Network

LSG 500/LNG 300 (607) 777-2400 http://cdc.binghamton.edu facebook.com/BinghamtonCDC Twitter in a team structure 2. ability to make decisions and solve problems 3. ability to plan, organize it anticipating problems creating images designing programs displaying creating images brainstorming new ideas

Suzuki, Masatsugu

127

LSG 500/LNG 300 (607) 777-2400  

E-print Network

LSG 500/LNG 300 (607) 777-2400 http://cdc.binghamton.edu facebook.com/BinghamtonCDC Twitter. Ability to make decisions and solve problems 4. Ability to obtain and process information 5. Ability it anticipating problems creating images designing programs displaying creating images brainstorming new ideas

Suzuki, Masatsugu

128

LNG Safety Research: FEM3A Model Development  

Microsoft Academic Search

This quarterly report for DE-FG26-04NT42030 covers a period from July 1, 2004 to September 30, 2004. Activity during this period included preparation of a CD containing the FEM3a FORTRAN code for distribution and organization of an LNG safety workshop. Contract negotiation between GTI and University of Arkansas continued.

Iraj A. Salehi

2004-01-01

129

LNG Safety Research: FEM3A Model Development  

SciTech Connect

This quarterly report for DE-FG26-04NT42030 covers a period from July 1, 2004 to September 30, 2004. Activity during this period included preparation of a CD containing the FEM3a FORTRAN code for distribution and organization of an LNG safety workshop. Contract negotiation between GTI and University of Arkansas continued.

Iraj A. Salehi

2004-09-30

130

Analysis of LNG import terminal release prevention systems  

SciTech Connect

The release prevention systems of liquefied natural gas (LNG) import terminal were analyzed. A series of potential release scenarios were analyzed to determine the frequency of the release events, the probability these releases are not stopped or isolated by emergency shutdown systems, the estimated release quantities, and the critical components of the system. The two plant areas identified as being most significant with respect to safety are the unloading system and the storage system. Rupture of the main transfer line and gross failure of the storage tanks are the two release scenarios of primary safety interest. Reducing the rate of failure by improved design, better maintenance and testing, or adding redundancy of the critical system components for these plant areas and release scenarios will result in improved safety. Several design alternatives which have the potential to significantly reduce the probability of a large release of LNG occurring at an import terminal are identified. These design alternatives would reduce the probability of a large release of LNG by reducing the expected number of failures which could cause a release or by reducing the magnitude of releases that do occur. All of these alternatives are technically feasible and have been used or considered for use in at least one LNG facility. A more rigorous analysis of the absolute risk of LNG import terminal operation is necessary before the benefits of these design alternatives can be determined. In addition, an economic evaluation of these alternatives must be made so the costs and benefits can be compared. It is concludd that for remotely located facilities many of these alternatives are probably not justified; however, for facilities located in highly populated areas, these alternatives deserve serious consideration.

Baker, E G

1982-04-01

131

Development of a simple 5-15 litre per hour LNG refueling system  

SciTech Connect

A variable capacity, small-scale liquefied natural gas (LNG) refueling system has been designed, built, and tested at the Cryofuel Systems` Laboratory, University of Victoria, Canada. The system, designed to continuously liquefy between 5 and 15 litres of NG, utilizes liquid nitrogen (LN{sub 2}) as its cold source and contains most of the components found in a typical commercial refueling system; i.e. purification system, liquefier, LNG storage, automatic control and monitoring system. This paper describes the design of the system as well as the results of a set of LNG production trials. The performance of the system exceeded expected LNG production rates, but at levels of efficiency somewhat less than predicted. Cryofuel Systems expects to use this system to implement an LNG vehicle demonstration program and to gain experience in the integration of LNG refueling systems which exploit advanced liquefaction technology such as magnetic refrigeration.

Corless, A.J.; Sarangi, S.; Hall, J.L.; Barclay, J.A. [Univ. of Victoria, British Columbia (Canada)

1994-12-31

132

Vaporizer performance  

NASA Astrophysics Data System (ADS)

This paper examines the nature of the flow leaving a vaporizer, its dependence on the flowrates of air and kerosene fuel, the inlet air temperature, and the possible consequences for the performance of a combustor fueled by the vaporizer. A phase Doppler velocimeter was used to examine the distribution of droplet diameters, velocities of the droplets, and the liquid-fuel flux at the exit. Measurements are also reported which show the nature of the two-phase flow away from the vaporizer exits and in important regions within a combustor corresponding to a one-sixth annular sector of a reverse-flow arrangement. The distribution of droplets within the combustor was observed and photographs of the combusting flow are presented.

Liu, C. H.; Perez-Ortiz, B. M.; Whitelaw, J. H.

133

Thermal boundary layer development in dispersed flow film boiling  

E-print Network

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 ...

Hull, Lawrence M.

1982-01-01

134

Dryout droplet distribution and dispersed flow film boiling  

E-print Network

Dispersed flow film boiling is characterized by liquid-phase droplets entrained in a continuous vapor-phase flow. In a previous work at MIT, a model of dispersed flow heat transfer was developed, called the Local Conditions ...

Hill, Wayne S.

1982-01-01

135

Lng vehicle technology, economics, and safety assessment. Final report, April 1991June 1993  

Microsoft Academic Search

Liquid natural gas (LNG) is an attractive transportation fuel because of its high heating value and energy density (i.e. Btu\\/lb and Btu\\/gal), clean burning characteristics, relatively low cost ($\\/Btu), and domestic availability. This research evaluated LNG vehicle and refueling system technology, economics, and safety. Prior and current LNG vehicle projects were studied to identify needed technology improvements. Life-cycle cost analyses

C. A. Powars; C. B. Moyer; D. D. Lowell

1994-01-01

136

Natural Gas Liquefaction Process for Small-scale LNG Project  

Microsoft Academic Search

In the field of natural gas liquefaction, the small-scale natural gas liquefier has been attracting more and more attentions home and abroad, thanks to its small volume, mobile transportation, easy start-up and shut-down, as well as skid-mounted package. A study was made to choose the optimum liquefaction process to improve the economy of small-scale liquefied natural gas (LNG) plant. The

Cao Wensheng

2012-01-01

137

Radiation scanning aids tower diagnosis at Arun LNG plant  

SciTech Connect

Radiation scanning has been used effectively to troubleshoot the treating towers of the Arun LNG plant in Sumatra, Indonesia. The plant is one of the world's largest such facilities. The analysis was part of an investigation aimed at increasing the capacity of the treater section of the plant. Radiation scanning is a tool which, in addition to tower differential pressure and product purity, can aid in diagnosing tower performance.

Naklie, M.M. (Mobil Exploration and Producing Services Inc., Dallas, TX (US)); Pless, L. (Tru-Tec Inc., Houston, TX (US)); Gurning, T.P.; Hyasak, M. (P.T. Arun Natural Gas Liquefaction Co., Sumatera (USA))

1990-03-26

138

Users, utilities ask rejection of high-cost Algerian LNG  

SciTech Connect

Recent purchases of expensive Algerian liquefied natural gas (LNG) by the Panhandle Eastern Pipeline Co. will increase rates for industrial customers 8 to 25%. Four midwest utilities protested to federal regulatory agencies and expressed their concerns that the new rate increases will lead to additional fuel switching, and argued that the Algerian gas is not needed. While originally supportive of the Algerian purchase, the utilities argue that the timing is wrong now because of adequate supplies. (DCK)

Galvin, C.

1982-09-13

139

LNG (liquefied natural gas) in the Asia-Pacific region: Twenty years of trade and outlook for the future  

SciTech Connect

This report discusses the following topics: the current status of LNG trade in the Asia-Pacific region; present structure and projected demand in the Asia-Pacific region; prospective and tentative projects; and LNG contracts: stability versus flexibility.

Kiani, B.

1990-01-01

140

Impact Vaporization of Planetesimal Cores  

NASA Astrophysics Data System (ADS)

The degree of mixing and chemical equilibration between the iron cores of planetesimals and the mantle of the growing Earth has important consequences for understanding the end stages of Earth's formation and planet formation in general. At the Sandia Z machine, we developed a new shock-and-release technique to determine the density on the liquid-vapor dome of iron, the entropy on the iron shock Hugoniot, and the criteria for shock-induced vaporization of iron. We find that the critical shock pressure to vaporize iron is 507(+65,-85) GPa and show that decompression from a 15 km/s impact will initiate vaporization of iron cores, which is a velocity that is readily achieved at the end stages of planet formation. Vaporization of the iron cores increases dispersal of planetesimal cores, enables more complete chemical equilibration of the planetesimal cores with Earth's mantle, and reduces the highly siderophile element abundance on the Moon relative to Earth due to the expanding iron vapor exceeding the Moon's escape velocity. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Securities Administration under Contract No. DE-AC04-94AL85000.

Kraus, R. G.; Root, S.; Lemke, R. W.; Stewart, S. T.; Jacobsen, S. B.; Mattsson, T. R.

2013-12-01

141

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

Code of Federal Regulations, 2011 CFR

...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. 165...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. (a...Cook Inlet, Alaska between the Phillips Petroleum LNG Pier, 60°40?43? N and...

2011-07-01

142

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

Code of Federal Regulations, 2013 CFR

...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. 165...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. (a...Cook Inlet, Alaska between the Phillips Petroleum LNG Pier, 60°40?43? N and...

2013-07-01

143

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

...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. 165...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. (a...Cook Inlet, Alaska between the Phillips Petroleum LNG Pier, 60°40?43? N and...

2014-07-01

144

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

Code of Federal Regulations, 2012 CFR

...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. 165...Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. (a...Cook Inlet, Alaska between the Phillips Petroleum LNG Pier, 60°40?43? N and...

2012-07-01

145

LNG as a fuel for railroads: Assessment of technology status and economics. Topical report, June-September 1992  

Microsoft Academic Search

The objective of the research was to investigate the feasibility of liquefied natural gas (LNG) as a fuel for railroads. The investigation included assessment of the status of relevant technologies (i.e., LNG-fueled locomotive engines, tender cars, refueling equipment), a review of current demonstration projects, and an analytical evaluation of LNG railroad economics.

C. J. Pera; C. B. Moyer

1993-01-01

146

Long-term outlook for LNG trade and regulation in the Unites States  

Microsoft Academic Search

Most of the world's natural gas resources can be made available to major markets only by the transportation of liquefied natural gas (LNG). Passage of the Natural Gas Policy Act of 1978 (NGPA), which improved the domestic gas supply outlook, will not favor LNG imports in the short term, but the prospects for future increases are enhanced by the three

G. H. Lawrence; D. J. Muchow; N. E. Hay

1983-01-01

147

Baseload LNG plants with spherical storage tanks, all built as very large modules  

Microsoft Academic Search

Moss Rosenberg's experience in building LNG tanker ships led the company to investigate barge-mounted LNG plants as well. A floating plant could represent an attractive option in situations where the gas fields to be exploited lie far offshore or where harbor conditions are extremely inhospitable. Probably the best way to construct the plant would be to complete the process section

J. Bakke; P. G. Andersen

1981-01-01

148

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

149

LNG projects make progress in Oman and Yemen  

SciTech Connect

Two LNG projects in the Middle East, one in Oman and the other in Yemen, are due on stream at the turn of the century--each the largest single project ever put together in its country. Officials described their projects at a yearend 1996 conference in Paris by Institut Francais du Petrole and Petrostrategies. The Oman project develops gas reserves, does gas processing, and transports the gas 360 km to a liquefaction plant to be built on the coast. The Yemen project involves a liquefaction plant and an export terminal.

NONE

1997-02-24

150

Dispersion Basics  

NSDL National Science Digital Library

A webcast presentation by Dr. Timothy Spangler (Director of the COMET Program and a former air quality consultant). This 25-minute lecture provides an overview of the basics of dispersion, the effects of different atmospheric conditions on dispersion, and how dispersion is commonly modeled after an accidental release of a hazardous material.

Comet

2002-11-12

151

A NOVEL PROCESS TO USE SALT CAVERNS TO RECEIVE SHIP BORNE LNG  

SciTech Connect

This cooperative research project validates use of man made salt caverns to receive and store the cargoes of LNG ships in lieu of large liquid LNG tanks. Salt caverns will not tolerate direct injection of LNG because it is a cryogenic liquid, too cold for contact with salt. This research confirmed the technical processes and the economic benefits of pressuring the LNG up to dense phase, warming it to salt compatible temperatures and then directly injecting the dense phase gas into salt caverns for storage. The use of salt caverns to store natural gas sourced from LNG imports, particularly when located offshore, provides a highly secure, large scale and lower cost import facility as an alternative to tank based LNG import terminals. This design can unload a ship in the same time as unloading at a tank based terminal. The Strategic Petroleum Reserve uses man made salt caverns to securely store large quantities of crude oil. Similarly, this project describes a novel application of salt cavern gas storage technologies used for the first time in conjunction with LNG receiving. The energy industry uses man made salt caverns to store an array of gases and liquids but has never used man made salt caverns directly in the importation of LNG. This project has adapted and expanded the field of salt cavern storage technology and combined it with novel equipment and processes to accommodate LNG importation. The salt cavern based LNG receiving terminal described in the project can be located onshore or offshore, but the focus of the design and cost estimates has been on an offshore location, away from congested channels and ports. The salt cavern based terminal can provide large volumes of gas storage, high deliverability from storage, and is simplified in operation compared to tank based LNG terminals. Phase I of this project included mathematical modeling that proved a salt cavern based receiving terminal could be built at lower capital cost, and would have significantly higher delivery capacity, shorter construction time, and be much more secure than a conventional liquid tank based terminal. Operating costs of a salt cavern terminal are lower than tank based terminals because ''boil off'' is eliminated and maintenance costs of caverns are lower than LNG tanks. Phase II included the development of offshore mooring designs, wave tank tests, high pressure LNG pump field tests, heat exchanger field tests, and development of a model offshore LNG facility and cavern design. Engineers designed a model facility, prepared equipment lists, and confirmed capital and operating costs. In addition, vendors quoted fabrication and installation costs, confirming that an offshore salt cavern based LNG terminal would have lower capital and operating costs than a similarly sized offshore tank based terminal. Salt cavern storage is infinitely more secure than surface storage tanks, far less susceptible to accidents or purposeful damage, and much more acceptable to the community. More than thirty industry participants provided cost sharing, technical expertise, and guidance in the conduct and evaluation of the field tests, facility design and operating and cost estimates. Their close participation has accelerated the industry's acceptance of the conclusions of this research. The industry participants also developed and submitted several alternative designs for offshore mooring and for high pressure LNG heat exchangers in addition to those that were field tested in this project. HNG Storage, a developer, owner, and operator of natural gas storage facilities, and a participant in the DOE research has announced they will lead the development of the first offshore salt cavern based LNG import facility. Which will be called the Freedom LNG Terminal. It will be located offshore Louisiana, and is expected to be jointly developed with other members of the research group yet to be named. An offshore port license application is scheduled to be filed by fourth quarter 2005 and the terminal could be operational by 2009. This terminal allows the large volume importa

Michael M. McCall; William M. Bishop; Marcus Krekel; James F. Davis; D. Braxton Scherz

2005-05-31

152

The effects of refueling system operating pressure on LNG and CNG economics  

SciTech Connect

Natural gas (NG) liquefaction and compression are energy intensive processes which make up a significant portion of the overall delivered price of liquefied NG (LNG) and compressed NG (CNG). Increases in system efficiency and/or process changes which reduce the required amount of work will improve the overall economics of NG as a vehicle fuel. This paper describes a method of reducing the delivered cost of LNG by liquefying the gas above ambient pressures. Higher pressure LNG is desirable because OEM NG engine manufacturers would like NG delivered to the engine intake manifold at elevated pressures to avoid compromising engine performance. Producing LNG at higher pressures reduces the amount of work required for liquefaction but it is only practical when the LNG is liquefied on-site. Using a thermo-economic approach, it is shown that NG fuel costs can be reduced by as much as 10% when producing LNG at higher pressures. A reduction in the delivered cost is also demonstrated for CNG produced on-site from high pressure LNG.

Corless, A.J.; Barclay, J.A. [Univ. of Victoria (Canada)

1996-12-31

153

Specific heat and dispersion curve for helium II  

Microsoft Academic Search

The dispersion curve for elementary excitations in He II at low temperatures and at the vapor pressure is evaluated using inelastic neutron scattering data. It is found that this dispersion curve is consistent with recent specific heat measurements of high resolution. We represent the dispersion curve by means of cubic splines, and emphasize the need for further neutron scattering studies

R. J. Donnelly; J. A. Donnelly; R. N. Hills

1981-01-01

154

International LNG trade : the emergence of a short-term market  

E-print Network

Natural gas is estimated to be the fastest growing component of world primary energy consumption. Liquefied natural gas (LNG) supply chain is a way of transporting natural gas over seas, by following a procedure of gas ...

Athanasopoulos, Panagiotis G

2006-01-01

155

Opportunities for LNG supply infrastructure and demand growth in US and International markets  

E-print Network

Countries are looking beyond their borders for options to satiate a forecasted increase in natural gas consumption. A strong option for importing natural gas is by way of a liquefied natural gas (LNG) supply chain where ...

Connell, Richard Perry

2004-01-01

156

Columbia-Iran LNG project will have first commercial barge-mounted plant  

Microsoft Academic Search

An agreement of understanding signed by Columbia LNG Corp. and the National Iranian Gas Co. (NIGC) in Apr. 1978 provides for delivery of 300 million cu ft\\/day of gas as LNG to the Cove Point, Md., terminal for 20 yr beginning in 1982. A barge-mounted liquefaction plant is to be designed and built and 90% financed by Norway's Moss-Rosenberg Verft

1978-01-01

157

Results of the evaluation and preliminary validation of a primary LNG mass flow standard  

NASA Astrophysics Data System (ADS)

LNG custody transfer measurements at large terminals have been based on ship tank level gauging for more than 50 years. Flow meter application has mainly been limited to process control in spite of the promise of simplified operations, potentially smaller uncertainties and better control over the measurements for buyers. The reason for this has been the lack of LNG flow calibration standards as well as written standards. In the framework of the EMRP1 ‘Metrology for LNG’ project, Van Swinden Laboratory (VSL) has developed a primary LNG mass flow standard. This standard is so far the only one in the world except for a liquid nitrogen flow standard at the National Institute of Standards and Technology (NIST). The VSL standard is based on weighing and holds a Calibration and Measurement Capability (CMC) of 0.12% to 0.15%. This paper discusses the measurement principle, results of the uncertainty validation with LNG and the differences between water and LNG calibration results of four Coriolis mass flow meters. Most of the calibrated meters do not comply with their respective accuracy claims. Recommendations for further improvement of the measurement uncertainty will also be discussed.

van der Beek, Mijndert; Lucas, Peter; Kerkhof, Oswin; Mirzaei, Maria; Blom, Gerard

2014-10-01

158

Calibrated vapor generator source  

DOEpatents

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.

Davies, John P. (Idaho Falls, ID); Larson, Ronald A. (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Hall, Harold J. (Idaho Falls, ID); Stoddard, Billy D. (Idaho Falls, ID); Davis, Sean G. (Idaho Falls, ID); Kaser, Timothy G. (Idaho Falls, ID); Conrad, Frank J. (Albuquerque, NM)

1995-01-01

159

Calibrated vapor generator source  

DOEpatents

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.

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

160

Water Vapor Imagery: Water Vapor Imagery Basics  

NSDL National Science Digital Library

This self-paced, interactive tutorial enables learners to discover practical uses for water vapor imagery from weather satellites. The module introduces the concept and function of the water vapor channel of satellite imagery, and teaches how to interpret and apply data obtained from the water vapor channel. At the end of the tutorial, links are provided to real world data collected by NASA satellites where learners can apply the skills they have acquired. This resource is part of the tutorial series, Satellite Observations in Science Education, and is the first of three modules in the tutorial, Water Vapor Imagery. (Note: requires Java plug-in)

161

Vaporizing liquid microthruster  

Microsoft Academic Search

MEMS technology is expanding into increasingly diverse applications. As part of a micropropulsion system, microthruster attitude controls have been micromachined in silicon. This paper presents the microthruster design, fabrication, and test results. Fluid injected into a microchamber is vaporized by resistive silicon heaters. The exiting vapor generates the thruster force as it exits a silicon micro-nozzle. The vaporization chamber, inlet

E. V Mukerjee; A. P Wallace; K. Y Yan; D. W Howard; R. L Smith; S. D Collins

2000-01-01

162

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

PubMed Central

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

Ulvestad, Marte; Overland, Indra

2012-01-01

163

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

Microsoft Academic Search

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

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

1977-01-01

164

The utilization of LH2 and LNG cold for generation of electric power by a cryogenic-type Stirling engine  

Microsoft Academic Search

In a regasification process for LNG and LH2, a cryogenic-type Stirling engine combined with an electric generator is used as the main component. This engine is cooled by LNG or LH2 and is heated by hot water rejected from the power station, so that the engine runs and supplies additional electric power together with fuel gas supplied at room temperature.

K. Oshima; Y. Ishizaki; S. Kamiyama; M. Akiyama; M. Okuda

1978-01-01

165

Applications of human factors engineering to LNG release prevention and control  

SciTech Connect

The results of an investigation of human factors engineering and human reliability applications to LNG release prevention and control are reported. The report includes a discussion of possible human error contributions to previous LNG accidents and incidents, and a discussion of generic HF considerations for peakshaving plants. More specific recommendations for improving HF practices at peakshaving plants are offered based on visits to six facilities. The HF aspects of the recently promulgated DOT regulations are reviewed, and recommendations are made concerning how these regulations can be implemented utilizing standard HF practices. Finally, the integration of HF considerations into overall system safety is illustrated by a presentation of human error probabilities applicable to LNG operations and by an expanded fault tree analysis which explicitly recognizes man-machine interfaces.

Shikiar, R.; Rankin, W.L.; Rideout, T.B.

1982-06-01

166

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

SciTech Connect

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.

Chan, S.T.

1997-09-01

167

Comparison of CNG and LNG technologies for transportation applications. Final subcontract report, June 1991--December 1991  

SciTech Connect

This report provides a head-to-head comparison of compressed natural gas (CNG) and liquefied natural gas (LNG) supplied to heavy-duty vehicles. The comparison includes an assessment of the overall efficiency of the fuel delivery system, the cost of the fuel supply system, the efficiency of use in heavy-duty vehicles, and the environmental impact of each technology. The report concludes that there are applications in which CNG will have the advantage, and applications in which LNG will be preferred.

Sinor, J.E. [Sinor (J.E.) Consultants, Inc., Niwot, CO (United States)

1992-01-01

168

Vaporization of droplets in premixing chambers  

NASA Technical Reports Server (NTRS)

Detailed measurements were made of the structures of turbulent fuel sprays vaporizing in heated airstreams. The measurements show the size dependent vaporization and dispersion of the droplets and the important influence of the large eddies in the turbulence. The measurements form a data base for the development of models of fuel spray vaporization. Two laser techniques were specially developed for the investigation. A laser tomography technique converts line-of-sight light scattering measurements into time averaged 'point' measurements of droplet size distribution and volume concentration. A laser anemometer particle sizing technique was further developed to permit accurate measurements of individual particle sizes and velocities, with backscatter collection of light. The experiments are combined with heat transfer models to analyze the performance of miniature thermocouples in liquid sprays.

Yule, A. J.; Chigier, N. A.

1980-01-01

169

Vapor spill monitoring method  

DOEpatents

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.

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

1985-01-01

170

Directed vapor deposition  

Microsoft Academic Search

This dissertation describes the invention, design, construction, experimental evaluation and modeling of a new physical vapor deposition technique (U.S. Patent #5,534,314) for high rate, efficient deposition of refractory elements, alloys, and compounds onto flat or curved surfaces. The new Directed Vapor Deposition (DVD) technique examined in this dissertation was distinct from previous physical vapor deposition techniques because it used low

James Frederick Groves

1998-01-01

171

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

SciTech Connect

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).

VANDOR,D.

1999-03-01

172

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

E-print Network

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

Demirel, Melik C.

173

Fundamental Study on Sulfur Attack and Coking of LNG Rocket Engines  

NASA Astrophysics Data System (ADS)

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.

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

174

A review of the Arun field gas production/cycling and LNG export project. [Sumatra, Indonesia  

SciTech Connect

The Arun field was discovered by Mobil Oil Indonesia Inc. in late 1971 in its Bee block in the Aceh province on the north coast of Sumatra, Indonesia. Mobil's operations in this area are conducted under the terms of a production sharing agreement with Pertamina, the Indonesian state-owned oil and gas enterprise. The scope of operations covered by this paper is from production of gas and raw condensate in the field through stabilization and export of condensate and purification, liquefaction, and export of gas at the LNG plant at Blang Lancang, near Lho Seumawe (Sumatra) Indonesia. Mobil Oil Indonesia, Inc. is the field operator and P.T. Arun NGL Company operates the pipelines and LNG plant facilities. All the facilities which will be described are owned by Pertamina; P.T. Arun is owned by Pertamina, Mobil Oil Indonesia, and Japan Indonesia LNG company (JILCO). JILCO represents the five (5) original Japanese LNG purchasers. Brief descriptions are included of the geology, reservoir geometry, well producing characteristics, field producing and cycling facilities, and the treating, liquefaction and export facilities.

Alford, M.E.

1983-03-01

175

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

E-print Network

PENNSTATE Department of Mechanical Engineering Spring 2012 LNG Test Rig Movable LSD Vanes Overview test rigs to find the optimized angle and use it in the centrifugal compressors they produce, removing the need to take the test rig apart. Objectives The objective of the project is to design

Demirel, Melik C.

176

75 FR 54025 - Revision of LNG and LHG Waterfront Facility General Requirements  

Federal Register 2010, 2011, 2012, 2013

In a final rule published May 26, 2010, the Coast Guard amended Letter of Intent (LOI) and Waterway Suitability Assessment (WSA) requirements for liquefied natural gas (LNG) and liquefied hazardous gas (LHG) facilities. The amendment triggered information collection requirements affecting these facilities. The Coast Guard now announces that the collection of information has been approved by the......

2010-09-03

177

A floating LNG plant reduces construction costs and aids in difficult recoveries  

Microsoft Academic Search

A floating LNG plant reduces construction costs and aids in difficult recoveries, i.e., from natural gas reserves once considered noncommercial due to their small size and remote location. The barges, much cheaper to build and operate than conventional land units, could halve the cost of an onshore facility. In addition to the economics of construction time and operation, the benefits

Cozens

1976-01-01

178

Operational study of LNG-crude oil slurry pipeline design requirements. Technical memo  

Microsoft Academic Search

The report details a procedure for establishing the operational design requirements for an LNG-crude oil slurry pipeline, once certain design parameters have been decided upon. The procedure establishes maximum cooling and pumping station power requirements, minimum station spacings, and maximum operating temperatures and pressures for a given flow range, particle diameter, and weight concentration. The results of this procedure are

Coulter

1975-01-01

179

Theoretical model for a slurry pipeline. Technical memo. [Frozen crude oil slurry in LNG  

Microsoft Academic Search

A mathematical model for describing the theoretical behavior of frozen crude oil slurry in liquid natural gas (LNG) is presented in two modules in the following. The 'Pressure Module' is derived from the Newitt equations and the 'Temperature Module' is derived from the 'Design Considerations and Optimization of a Liquified Natural Gas Pipeline' by Coulter. A final section describes the

Rennert

1975-01-01

180

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

Federal Register 2010, 2011, 2012, 2013

...alternative to higher CO 2- emitting fossil fuels such as coal and fuel oil. LNG exports...States would serve as an interim fuel for countries that are in the process...Global Security and Supply, Office of Fossil Energy. [FR Doc. 2012-4205...

2012-02-23

181

Vapor core turbulence in annular two-phase flow  

SciTech Connect

This paper reports a new technique to measure vapor turbulence in two-phase flows using hot-film anemometry. Continuous vapor turbulence measurements along with local void fraction, droplet frequency, droplet velocity and droplet diameter were measured in a thin, vertical duct. By first eliminating the portion of the output voltage signal resulting from the interaction of dispersed liquid droplets with the HFA sensor, the discrete voltage samples associated with the vapor phase were separately analyzed. The data revealed that, over the range of liquid droplet sizes and concentrations encountered, the presence of the droplet field acts to enhance vapor turbulence. In addition, there is evidence that vapor turbulence is significantly influenced by the wall-bounded liquid film. The present results are qualitatively consistent with the limited data available in the open literature.

Trabold, T.A.; Kumar, R. [Lockheed Martin Corp., Schenectady, NY (United States)

1998-06-01

182

Vapor Pressure Data  

NSDL National Science Digital Library

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.

Ohe, Shuzo.

183

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 ...

184

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

SciTech Connect

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.

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

185

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

...which Commission staff may make a selection to assist in the preparation of the requisite NEPA document. (9) For natural gas facilities other than LNG terminal...which Commission staff may make a selection to assist in the preparation...

2014-04-01

186

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

Code of Federal Regulations, 2012 CFR

...which Commission staff may make a selection to assist in the preparation of the requisite NEPA document. (9) For natural gas facilities other than LNG terminal...which Commission staff may make a selection to assist in the preparation...

2012-04-01

187

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

Code of Federal Regulations, 2013 CFR

...which Commission staff may make a selection to assist in the preparation of the requisite NEPA document. (9) For natural gas facilities other than LNG terminal...which Commission staff may make a selection to assist in the preparation...

2013-04-01

188

Vacuum vapor deposition  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

189

Comparison between the levonorgestrel intrauterine system (LNG-IUS) and thermal balloon ablation in the treatment of menorrhagia  

Microsoft Academic Search

Objectives: To compare the effectiveness of endometrial thermal ablation and the levonorgestrel intrauterine system (LNG-IUS) in the management of menorrhagia. Study design: Fifty women attending a gynaecology clinic at a District General Hospital in south-west England were randomised to either surgical treatment using thermal ablation (Thermochoice, Gynecare) or medical treatment using a LNG-IUS (Mirena, Schering Healthcare). A pictorial menstrual chart

Julian W. Barrington; Angamuthu S. Arunkalaivanan; Mohammed Abdel-Fattah

2003-01-01

190

Vaporizers for medical marijuana.  

PubMed

A major concern about the medical use of marijuana is the harmful effects that come from smoking it. Vaporizers are designed to release the active ingredients in marijuana without burning it, and therefore do not release the harmful substances found in the marijuana smoke. The Institute of Medicine recommends against the long-term medical use of smoked marijuana because of carcinogens and other chemicals in the smoke. Several vaporizers are on the market, but they have not been tested in the laboratory yet. A review of two vaporizers is given. Contact information is provided. PMID:11366582

Mirken, B

1999-09-17

191

Light guiding light: Nonlinear refraction in rubidium vapor  

Microsoft Academic Search

Recently there has been experimental and theoretical interest in cross-dispersion effects in rubidium vapor, which allows one beam of light to be guided by another. We present theoretical results which account for the complications created by the D line hyperfine structure of rubidium as well as the presence of the two major isotopes of rubidium. This allows the complex frequency

J. A. Andersen; M. E. Friese; A. G. Truscott; Z. Ficek; P. D. Drummond; N. R. Heckenberg; H. Rubinsztein-Dunlop

2001-01-01

192

Light guiding light:?Nonlinear refraction in rubidium vapor  

Microsoft Academic Search

Recently there has been experimental and theoretical interest in cross-dispersion effects in rubidium vapor, which allows one beam of light to be guided by another. We present theoretical results which account for the complications created by the D line hyperfine structure of rubidium as well as the presence of the two major isotopes of rubidium. This allows the complex frequency

J. A. Andersen; M. E. J. Friese; A. G. Truscott; Z. Ficek; P. D. Drummond; N. R. Heckenberg; H. Rubinsztein-Dunlop

2001-01-01

193

LNGFIRE: A thermal radiation model for LNG fires. Topical report, June 29, 1990. Documentation  

SciTech Connect

The Federal Code Model for predicting exclusion distances from LNG fires (49 CFR 193.2057) was critically evaluated. The results of LNG fire tests carried out to date were reviewed and an improved model for predicting exclusion distances was developed and verified. This model assumes that the flame takes the shape of a cylinder or a parallellepiped, depending on whether the fuel impoundment area is circular or rectangular in shape. It allows for flame drag and tilt in the presence of wind. Based on experimental data, the maximum surface emissive power and the flame attenuation coefficient were estimated at 190 kw/sq m (60,267 Btu/hr sq ft) and 0.3/m (0.09/ft), respectively.

Atallah, S.; Shah, J.N.

1990-06-29

194

Survey of fire-protection systems at LNG facilities. Topical report, July-November 1990  

SciTech Connect

The objectives of the study were to collect and analyze data relating to the types, costs, and operational problems of gas leak and fire detection devices and of fire prevention and suppression systems used at LNG facilities operating in the United States. Data from 39 LNG facilities, which accounted for 45% of the total U.S. storage capacity, were collected. The report provides information relating to equipment manufacturers, site applications, operational problems, initial installation costs, annual operational costs, and equipment lifetime. Equipment of interest included fixed gas leak, fire and cryogenic detection systems, water deluge and barrier systems, thermal radiation walls and protective coatings, and fixed high expansion foam, dry chemical, carbon dioxide and halon fire suppression systems. In addition, internal fire fighting capabilities were reviewed.

Atallah, S.; Borows, K.A.

1991-04-05

195

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

196

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

NASA Astrophysics Data System (ADS)

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).

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

197

Who knew? looks like we're in for an LNG glut  

SciTech Connect

U.S. domestic production of natural gas has grown considerably in the recent past, especially from unconventional domestic resources. Recession has reduced demand. Further, the U.S. may end up on the receiving end of much of the excess global production and transportation capacity because of its massive storage capacity. Charts of U.S. natural gas production and LNG imports are given.

NONE

2009-04-15

198

Extreme sloshing and whipping-induced pressures and structural response in membrane LNG tanks  

Microsoft Academic Search

The long-term extreme pressure in the membrane LNG tank and structural response of the Mark III containment system are addressed. The effect of hull slamming-induced vibrations on the vertical acceleration is investigated and found to be important in certain situations. Determining structural response due to sloshing requires a stepwise approach considering long-term variation of the sea state, ship motion in

Mateusz Graczyk; Torgeir Moan; MingKang Wu

2007-01-01

199

A study on availability and safety of new propulsion systems for LNG carriers  

Microsoft Academic Search

This study investigated the availability and safety concerns of the conventional and prospective propulsion systems for LNG carriers:•dual-fuel steam turbine mechanical (DFSM) propulsion,•dual-fuel diesel electric (DFDE) propulsion,•dual-fuel gas turbine electric (DFGE) propulsion,•dual-fuel diesel mechanical (DFDM) propulsion, and•diesel mechanical propulsion with reliquefaction (SFDM+R).The two prospective candidates, the DFDM and DFGE, exhibited the availabilities of design and emergency propulsion loads as high

Daejun Chang; Taejin Rhee; Kiil Nam; Kwangpil Chang; Donghun Lee; Samheon Jeong

2008-01-01

200

Australian LNG plant debottlenecked to 7.5 million tons/year  

SciTech Connect

The North West Shelf gas project, Karratha, Western Australia, has successfully carried out a three-train LNG plant debottlenecking to increase capacity from 6.9 million metric tons/year (mty) to more than 7.5 mty. The two major constraints targeted by the project were the CO{sub 2}-removal column and the main refrigerant compressor drivers. Replacement of the original trays by structured packing in the Sulfinol absorber columns and a change of solvent composition has cured foaming problems and increased gas-treating capacity. Installation of a performance-improvement package known as Advanced Technology Parts (ATP) has effectively uprated the gas-turbine drivers of the refrigerant compressors from GE Frame 5B to 5C. An increase in turbine power of 9% has been achieved. Together with modifications to the precooling propane compressors and other plant equipment, the LNG capacity of the plant has increased to 118% of design, an increase of 10 LNG cargoes/year, while retaining the same operating flexibility for different ambient temperatures. This paper reviews these procedures.

Brehaut, W.J.; Concannon, M.J. [Woodside Offshore Petroleum Pty., Karratha, Western Australia (Australia)

1996-01-08

201

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

NASA Astrophysics Data System (ADS)

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%.

Xu, Wendong; Duan, Jiao; Mao, Wenjun

2014-02-01

202

Vapor core propulsion reactors  

NASA Technical Reports Server (NTRS)

Many research issues were addressed. For example, it became obvious that uranium tetrafluoride (UF4) is a most preferred fuel over uranium hexafluoride (UF6). UF4 has a very attractive vaporization point (1 atm at 1800 K). Materials compatible with UF4 were looked at, like tungsten, molybdenum, rhenium, carbon. It was found that in the molten state, UF4 and uranium attacked most everything, but in the vapor state they are not that bad. Compatible materials were identified for both the liquid and vapor states. A series of analyses were established to determine how the cavity should be designed. A series of experiments were performed to determine the properties of the fluid, including enhancement of the electrical conductivity of the system. CFD's and experimental programs are available that deal with most of the major issues.

Diaz, Nils J.

1991-01-01

203

Fuel Vaporization Effects  

NASA Technical Reports Server (NTRS)

A study of the effects of fuel-air preparation characteristics on combustor performance and emissions at temperature and pressure ranges representative of actual gas turbine combustors is discussed. The effect of flameholding devices on the vaporization process and NOx formation is discussed. Flameholder blockage and geometry are some of the elements that affect the recirculation zone characteristics and subsequently alter combustion stability, emissions and performance. A water cooled combustor is used as the test rig. Preheated air and Jet A fuel are mixed at the entrance of the apparatus. A vaporization probe is used to determine percentage of vaporization and a gas sample probe to determine concentration of emissions in the exhaust gases. The experimental design is presented and experimental expected results are discussed.

Bosque, M. A.

1983-01-01

204

Large effective area all-solid dispersion compensating fiber  

NASA Astrophysics Data System (ADS)

We present a large-mode-area (LMA) dispersion compensating fiber (DCF) design amenable to fabrication by the modified chemical vapor deposition (MCVD) technique. The design utilizes resonance between two concentric cores, one of which is highly asymmetric to achieve high negative dispersion. The magnitude and wavelength bandwidth of negative dispersion can be controlled by various design parameters. Here we demonstrate numerically simulated designs for (i) narrowband dispersion compensation and (ii) broadband dispersion compensation. In narrowband DCF designs we show negative dispersion as large as - 14 500 ps nm - 1 km - 1 with corresponding mode effective area 86 µm2. In the broadband designs, we show dispersion ranging between - 80 and - 280 ps nm - 1 km - 1 over a 40 nm wavelength range, the kappa value (ratio of dispersion and dispersion slope) near 30 nm, the figure of merit (ratio of magnitude of dispersion and fiber loss coefficient) 1030 ps (dB km) - 1, and the mode effective area 63 µm2. A fiber with such a high negative dispersion and large effective area would be useful for efficient dispersion compensation in single-wavelength as well as wavelength division multiplexing (WDM) optical communication systems.

Rastogi, Vipul; Kumar, Rajiv; Kumar, Ajeet

2011-12-01

205

Chapter 6--Dispersal Introduction  

E-print Network

. Helens was that plant dispersal abilities have been substantially overrated. I have described species, can disperse only a few meters, not kilometers as people might think (Clark et al. 2001). Plant. Helens was impeded. Dispersal mechanisms Plants disperse by methods both simple and obscure. We have all

del Moral, Roger

206

Electrolyte vapor condenser  

DOEpatents

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.

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

1983-02-08

207

Electrolyte vapor condenser  

DOEpatents

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.

Sederquist, Richard A. (Newington, CT); Szydlowski, Donald F. (East Hartford, CT); Sawyer, Richard D. (Canton, CT)

1983-01-01

208

Vaporizing particle velocimeter  

NASA Technical Reports Server (NTRS)

A velocimeter measures flow characteristics of a flow traveling through a chamber in a given direction. Tracer particles are entrained in the flow and a source of radiant energy produces an output stream directed transversely to the chamber, having a sufficient intensity to vaporize the particles as they pass through the output stream. Each of the vaporized particles explodes to produce a shock wave and a hot core, and a flow visualization system tracks the motion of the hot cores and shock waves to measure the velocity of each tracer particle and the temperature of the flow around the tracer.

Weinstein, Leonard M. (inventor)

1992-01-01

209

LNG Safety Research: FEM3A Model Development  

SciTech Connect

This quarterly report for DE-FG26-04NT42030 covers a period from July 1, 2006 to October 31, 2006. GTI's activities during the report quarter were limited to administrative work. The work at the University of Arkansas continued in line with the initial scope of work and the identified questions regarding surface to cloud heat transfer as being largely responsible for the instability problems previously encountered. A brief summary of results is discussed in this section and the complete report from University of Arkansas is provided. All work planned for this project has been completed. Specifically: Task A--Simulation of Low-Wind-Speed Stable Atmospheric Conditions: This task has been completed, and a new version of FEM3A will be received by GTI. Task B--Verification for Dispersion over Rough Surfaces With and Without Obstacles: This task has been completed, and a new version of FEM3A will be received by GTI. Task C--Adapting the FEM3A Model for More General Application This task was obviated when DOE redirected the contract near the project midpoint. Task D--Provide assistance and wind tunnel data to DOE for FLUENT development This task has been completed and data requested by DOE-NETL has been delivered. Researchers at the University of Arkansas are preparing the final report that will be received by GTI by November 30, 2006.

Iraj A. Salehi; Jerry Havens; Tom Spicer

2006-09-30

210

LNG Safety Research: FEM3A Model Development  

SciTech Connect

Work continued to address numerical problems experienced with simulation of low-wind-speed, stable, atmospheric conditions with FEM3A. Steps 1 through 8 in the plan outlined in the first Quarterly report have been completed successfully for the FEM3A model utilizing the Planetary Boundary Layer (PBL) turbulence closure model. Researchers at the University of Arkansas have solved the problems related to stability of the simulations at regulatory conditions of low wind speed and stable atmospheric conditions with FEM3A using the PBL model, and are continuing our program to verify the operation of the model using an updated, verified, version of the k-epsilon turbulence closure model which has been modified to handle dense gas dispersion effects. This quarterly report for DE-FG26-04NT42030 covers a period from January 1, 2006 to March 31, 2006. GTI's activities during the report quarter were limited to administrative work. The work at the University of Arkansas continued in line with the initial scope of work and the identified questions regarding surface to cloud heat transfer as being largely responsible for the instability problems previously encountered. A brief summary of results is discussed in this section and the complete report from University of Arkansas is attached.

Iraj A Salehi; Jerry Havens; Tom Spicer

2006-05-01

211

Overfill testing of anaesthetic vaporizers.  

PubMed

We tested six anaesthetic vaporizers with keyed filler adaptors to see if it was possible to overfill them. For those vaporizers which could be overfilled, the maximum level of overfill was determined and the effect of overfilling on the vaporizer output concentration was measured. Three of the vaporizers, the TEC 4, PPV Mk 1 and MIE Vapamasta 5, could be overfilled. In the case of the TEC 4 and PPV vaporizers, overfilling by more than 100 ml caused a large increase in the vaporizer output concentration. Overfilling the Vapamasta 5 by this amount caused the output concentration to decrease. PMID:7880686

Palayiwa, E; Hahn, C E

1995-01-01

212

Occupational Exposure Evaluation of Complex Vapor Mixtures at the Hanford Nuclear Waste Site, Washington Work-site Vapor Characterization  

SciTech Connect

Extensive sampling and analysis has been done over the years to characterize the radioactive and chemical properties of hazardous waste stored in 177 underground tanks at the Hanford site in eastern Washington State. The purpose of these analyses was to evaluate safety and environmental concerns related to tank stability. More recently, characterization studies have broadened to evaluate potential health hazards of chemical vapors at the ground surface, where workers perform maintenance and waste transfer activities. Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. The extensive sampling done during this campaign evaluated vapor concentrations of more than 100 different chemical at 70 sites in and around one section of the tank farms. Sampling identified only four vapors (ammonia, nitrous oxide, nitrosodimethylamine, and nitrosomethylethylamine) that were present above occupational exposure limits. These elevated concentrations were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors were measured above 10% of their OELs more than five feet from the source. This suggests that vapor controls can be focused on limited hazard zones around sources. (authors)

Anderson, T. J. [CH2M HILL Hanford Group, Inc. / Environmental Health, P.O. Box 1000, S7-70, Richland, WA 99352 (United States)

2006-07-01

213

40 CFR Table W - 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment  

...2013-07-01 true 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment W ...Table W-6 Table W-6 of Subpart W of Part 98—Default Methane Emission Factors for LNG Import and Export Equipment...

2014-07-01

214

40 CFR Table W - 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment W ...Table W-6 Table W-6 of Subpart W of Part 98—Default Methane Emission Factors for LNG Import and Export Equipment...

2013-07-01

215

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

...2013-07-01 true 5 of Subpart W of Part 98-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage...Table W-5 Table W-5 of Subpart W of Part 98—Default Methane Emission Factors for Liquefied Natural Gas (LNG)...

2014-07-01

216

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

2013-07-01

217

Soil vapor well construction  

Microsoft Academic Search

This patent describes a soil vapor well for removing volatile hydrocarbons from the vadose zone in the earth. It comprises a larger diameter first bore hole and having side edges extending from the surface of the earth to a first depth; an impervious casing; concrete filling the space in the first bore hole between the casing and the side edges

L. J. Corte; A. Brown

1992-01-01

218

Water vapor lidar  

NASA Technical Reports Server (NTRS)

The feasibility was studied of measuring atmospheric water vapor by means of a tunable lidar operated from the space shuttle. The specific method evaluated was differential absorption, a two-color method in which the atmospheric path of interest is traversed by two laser pulses. Results are reported.

Ellingson, R.; Mcilrath, T.; Schwemmer, G.; Wilkerson, T. D.

1976-01-01

219

Passive Vaporizing Heat Sink  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

220

Enthalpy of Vaporization and Vapor Pressures: An Inexpensive Apparatus  

ERIC Educational Resources Information Center

A simple and inexpensive method to determine the enthalpy of vaporization of liquids by measuring vapor pressure as a function of temperature is described. The vapor pressures measured with the stopcock cell were higher than the literature values and those measured with the sidearm rubber septum cell were both higher and lower than literature…

Battino, Rubin; Dolson, David A.; Hall, Michael A.; Letcher, Trevor M.

2007-01-01

221

Vapor Pressures and Vaporization Enthalpies of a Series of Dialkyl Phthalates by Correlation Gas Chromatography  

E-print Network

: Experimental vapor pressures, vaporization, fusion and sublimation enthalpies of a number of dialkyl. The compounds, the vaporization, fusion, and sublimation enthalpies and liquid and solid vapor pressures enthalpies of several liquid dialkyl benzenedicarboxylates and the fusion, sublimation, and vaporization

Chickos, James S.

222

Water Vapor: Distribution and Trends  

Microsoft Academic Search

Water in the gaseous phase, water vapor, is the most significant atmospheric trace constituent vis-` a-vis climate, weather, hydro- logy, and atmospheric chemistry. Water vapor is the most abundant atmospheric greenhouse gas, and without it the planet's sur- face temperature would be well below freezing. Phase changes involving water vapor - the condensation and evaporation pro- cesses - involve exchanges

Dian J Seidel

2002-01-01

223

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

E-print Network

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...

Ritz, Robert A.

2014-07-31

224

LNGFIRE: A thermal-radiation model for LNG fires. Topical report, October 25, 1988-June 29, 1990. documentation  

SciTech Connect

The Federal Code Model for predicting exclusion distances from Liquified Natural Gas (LNG) fires (49 CFR 193.2057) was critically evaluated. The results of LNG fire tests carried out to date were reviewed, and an improved model for predicting exclusion distances was developed and verified. The model assumes that the flame takes the shape of a cylinder or a parallellepiped, depending on whether the fuel impoundment area is circular or rectangular in shape. It allows for flame drag and tilt in the presence of wind.

Atallah, S.; Shah, J.N.

1990-06-29

225

Vapor explosion phenomena: Scaling considerations  

SciTech Connect

Past safety analyses considered the hazard from vapor explosions in a conservative manner where engineering judgment and conservative analyses were used to estimate the likelihood of nuclear reactor containment failure from explosion-induced missile generation [alpha-mode failure]. However, recent safety analyses may require less conservative methods to determine the hazard from vapor explosions; thus one may need to consider more detailed scaling of vapor explosion phenomena. This paper proposes particular scaling considerations for vapor explosions based on recent experimental results and that vapor explosions with prototypic reactor fuel material may be less of a hazard.

Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

1996-08-01

226

Stratified vapor generator  

DOEpatents

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).

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

2008-05-20

227

Water vaporization on Ceres  

NASA Technical Reports Server (NTRS)

A search is presently conducted for OH generated by the photodissociation of atmospheric water vapor in long-exposure IUE spectra of the region around Ceres. A statistically significant detection of OH is noted in an exposure off the northern limb of Ceres after perihelion. The amount of OH is consistent with a polar cap that might be replenished during winter by subsurface percolation, but which dissipates in summer.

A'Hearn, Michael F.; Feldman, Paul D.

1992-01-01

228

Seed Dispersal 101  

NSDL National Science Digital Library

This two-minute radio program introduces listeners to the variety of agents that disperse seeds. The program's guest, a plant biologist, cites examples of nonliving and living dispersal agents that include the wind, water, and such animals as birds and bats. He also explains that a plant's fruits or seeds often offer clues about how they are dispersed. The program, which is available here in audio and text, is the first in a series about seed dispersal. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2007-07-26

229

The vapor pressures of explosives  

SciTech Connect

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.

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

2013-01-05

230

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...

231

Theory of dispersive microlenses  

NASA Technical Reports Server (NTRS)

A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

Herman, B.; Gal, George

1993-01-01

232

75 FR 13755 - Freeport LNG Development, L.P.; Application To Amend Blanket Authorization To Export Liquefied...  

Federal Register 2010, 2011, 2012, 2013

...to any other country (in addition...6, 2007). Protests, motions to...invited. DATES: Protests, motions to...feet (Bcf) per day of LNG...to any other country (in addition...to a foreign country must be authorized...person may file a protest, motion to...

2010-03-23

233

78 FR 75337 - Eos LNG LLC; Application for Long-Term Authorization To Export Liquefied Natural Gas Produced...  

Federal Register 2010, 2011, 2012, 2013

...Non-Free Trade Agreement Countries for a 25-Year Period...584 billion cubic feet per year (Bcf/yr) of natural gas, or 1.6 Bcf per day (Bcf/d). Eos...to export LNG to any country with which the United...C. 717b. DATES: Protests, motions to...

2013-12-11

234

78 FR 75339 - Barca LNG LLC; Application for Long-Term Authorization To Export Liquefied Natural Gas Produced...  

Federal Register 2010, 2011, 2012, 2013

...Non-Free Trade Agreement Countries for a 25-Year Period...584 billion cubic feet per year (Bcf/yr) of natural gas, or 1.6 Bcf per day (Bcf/d). Barca...to export LNG to any country with which the United...C. 717b. DATES: Protests, motions to...

2013-12-11

235

Effects of a spill of LNG on mean flow and turbulence under low wind speed, slightly stable atmospheric conditions  

Microsoft Academic Search

Of the many liquefied natural gas (LNG) spill experiments in the 1980 Burro and 1981 Coyote series at the Naval Weapons Center (NWC), China Lake, California, only one was observed to affect the mean flow and turbulence in the near-surface atmospheric boundary layer. This experiment, Burro 8, was conducted under atmospheric conditions that permitted the gravity flow of the cold,

Rodean

1983-01-01

236

Effects of a spill of LNG on mean flow and turbulence under low wind speed, slightly stable atmospheric conditions  

Microsoft Academic Search

Of the many liquefied natural gas (LNG) spill experiments in the 1980 Burro and 1981 Coyote series at the Naval Weapons Center (NWC), China Lake, California, only one was observed to affect the mean flow and turbulence in the near-surface atmospheric boundary layer. This experiment, Burro 8, was conducted under very low wind speed, slightly stable atmospheric conditions that permitted

Rodean

1983-01-01

237

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.

238

Biofiltration of methanol vapor  

SciTech Connect

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. The bacteria were immobilized on solid support and packed into a 5-cm diameter, 60-cm-high column provided with appropriate flowmeters and sampling ports. The solid support was prepared by mixing two volumes of peat with three volumes of perlite particles. Two series of experiments were performed. In the first, the inlet methanol concentration was kept constant while the superficial air velocity was varied from run to run. In the second series, the air flow rate (velocity) was kept constant while the inlet methanol concentration was varied. The unit proved effective in removing methanol at rates up to 112.8 g h[sup [minus]1] m[sup [minus]3] packing. A mathematical model has been derived and validated. The model described and predicted experimental results closely. Both experimental data and model predictions suggest that the methanol biofiltration process was limited by oxygen diffusion and methanol degradation kinetics.

Shareefdeen, Z.; Baltzis, B.C. (New Jersey Inst. of Tech., Newark, (United States)); Oh, Youngsook; Bartha, R. (Rutgers, The State Univ. of New Jersey, New Brunswick (United States))

1993-03-05

239

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

240

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

SciTech Connect

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.

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

241

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

SciTech Connect

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.

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

2000-10-20

242

A Planar-Fluorescence Imaging Technique for Studying Droplet-Turbulence Interactions in Vaporizing Sprays  

NASA Technical Reports Server (NTRS)

Droplet turbulence interactions directly affect the vaporization and dispersion of droplets in liquid sprays and therefore play a major role in fuel oxidizer mixing in liquid fueled combustion systems. Proper characterization of droplet turbulence interactions in vaporizing sprays require measurement of droplet size velocity and size temperature correlations. A planar, fluorescence imaging technique is described which is being developed for simultaneously measuring the size, velocity, and temperature of individual droplets in vaporizing sprays. Preliminary droplet size velocity correlation measurements made with this technique are presented. These measurements are also compared to and show very good agreement with measurements made in the same spray using a phase Doppler particle analyzer.

Santavicca, Dom A.; Coy, E.

1990-01-01

243

Soil vapor well construction  

SciTech Connect

This patent describes a soil vapor well for removing volatile hydrocarbons from the vadose zone in the earth. It comprises a larger diameter first bore hole and having side edges extending from the surface of the earth to a first depth; an impervious casing; concrete filling the space in the first bore hole between the casing and the side edges of the first bore hole; a second bore hole, having a smaller diameter than the diameter of the casing; aggregate filling the second hole and the casing; and means connected to the upper end of the casing from drawing a vacuum in the second bore to extract the volatile hydrocarbons from the surrounding portion of the vadose zone through the aggregate and the casing.

Corte, L.J.; Brown, A.

1992-05-26

244

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

SciTech Connect

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.

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

1995-12-31

245

Analytical and experimental investigation of the dispersion process during rapid transients for the aluminum-based nuclear fuel plates  

SciTech Connect

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

Georgevich, V.; Taleyarkhan, R.P.; Kim, S.H. [Oak Ridge National Lab., TN (United States); Fuketa, T.; Soyama, K.; Ishijima, K. [Japan Atomic Energy Research Inst., Takai, Ibaraki (Japan)

1995-06-01

246

Constrained Vapor Bubble  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

247

Vapor phase heat transport systems  

NASA Astrophysics Data System (ADS)

Progress in theoretical and experimental investigations of various forms of a vapor transport system for solar space heating is described, which could also be applied to service water heating. The refrigerant is evaporated in a solar collector, which may be located on the external wall or roof of a building. The vapor is condensed in a passively discharged thermal storage unit located within the building. The condensed liquid can be returned to the collector either by a motor-driven pump or by a completely passive self-pumping mechanism in which the vapor pressure lifts the liquid from the condenser to the collector. The theoretical investigation analyzes this self-pumping scheme. Experiments in solar test cells compared the operation of both passive and active forms of the vapor system with the operation of a passive water wall. The vapor system operates as expected, with potential advantages over other passive systems in design flexibility and energy yield.

Hedstrom, J. C.; Neeper, D. A.

1985-09-01

248

Spores Disperse, Too!  

ERIC Educational Resources Information Center

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)

Schumann, Donna N.

1981-01-01

249

Visualizing Dispersion Interactions  

ERIC Educational Resources Information Center

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…

Gottschalk, Elinor; Venkataraman, Bhawani

2014-01-01

250

Dispersive Body Waves  

Microsoft Academic Search

Although the attenuation of body waves in an infinite medium has often been considered, little emphasis is usually given to the attendant dispersion, which is a necessary consequence of the medium absorption and is determined unambiguously by it. Dispersion equations are obtained from the application of an integral transform in the frequency domain. Such relations are of the Kramers-KrSnig type,

Walter I. Futterman

1962-01-01

251

Tested Demonstrations. Gasoline Vapor: An Invisible Pollutant  

ERIC Educational Resources Information Center

Describes a demonstration concerning the air pollution aspects of gasoline vapor which provides an estimation of the vapor pressure of test fuel, the molecular weight of the vapor, and illustrates a method of controlling the pollution. (SL)

Stephens, Edgar R.

1977-01-01

252

Evolution of dispersal distance.  

PubMed

The problem of how often to disperse in a randomly fluctuating environment has long been investigated, primarily using patch models with uniform dispersal. Here, we consider the problem of choice of seed size for plants in a stable environment when there is a trade off between survivability and dispersal range. Ezoe (J Theor Biol 190:287-293, 1998) and Levin and Muller-Landau (Evol Ecol Res 2:409-435, 2000) approached this problem using models that were essentially deterministic, and used calculus to find optimal dispersal parameters. Here we follow Hiebeler (Theor Pop Biol 66:205-218, 2004) and use a stochastic spatial model to study the competition of different dispersal strategies. Most work on such systems is done by simulation or nonrigorous methods such as pair approximation. Here, we use machinery developed by Cox et al. (Voter model perturbations and reaction diffusion equations 2011) to rigorously and explicitly compute evolutionarily stable strategies. PMID:21681566

Durrett, Rick; Remenik, Daniel

2012-03-01

253

Vapor Pressure, Vapor Composition and Fractional Vaporization of High Temperature Lavas on Io  

NASA Technical Reports Server (NTRS)

Observations show that Io's atmosphere is dominated by SO2 and other sulfur and sulfur oxide species, with minor amounts of Na, K, and Cl gases. Theoretical modeling and recent observations show that NaCl, which is produced volcanically, is a constituent of the atmosphere. Recent Galileo, HST and ground-based observations show that some volcanic hot spots on Io have extremely high temperatures, in the range 1400-1900 K. At similar temperatures in laboratory experiments, molten silicates and oxides have significant vapor pressures of Na, K, SiO, Fe, Mg, and other gases. Thus vaporization of these species from high temperature lavas on Io seems likely. We therefore modeled the vaporization of silicate and oxide lavas suggested for Io. Our results for vapor chemistry are reported here. The effects of fractional vaporization on lava chemistry are given in a companion abstract by Kargel et al.

Fegley, B., Jr.; Schaefer, L.; Kargel, J. S.

2003-01-01

254

Passive vapor extraction feasibility study  

SciTech Connect

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.

Rohay, V.J.

1994-06-30

255

Bias-corrected estimators for dispersion models with dispersion covariates  

Microsoft Academic Search

In this paper we discuss bias-corrected estimators for the regression and the dispersion parameters in an extended class of dispersion models (Jørgensen, 1997b). This class extends the regular dispersion models by letting the dispersion parameter vary throughout the observations, and contains the dispersion models as particular case. General formulae for the O(n?1) bias are obtained explicitly in dispersion models with

Alexandre B. Simas; Andréa V. Rocha; Wagner Barreto-Souza

2011-01-01

256

Vapor-liquid contacting system  

SciTech Connect

A vapor-liquid contacting tray is described wherein a perforated portion of the tray member forms an active surface area for vapor-liquid contact in the interior of the tray member. The active surface area portion of the tray member is circumscribed by an imperforate peripheral portion of the tray member with a width of from 0.05 to 0.35 times the radius of the tray. The disclosed tray provides upwardly directed laminar jetting of liquid over the tray perforation openings for high selectivity vapor-liquid contacting and has particular utility in the absorption of hydrogen sulfide from a gas mixture containing hydrogen sulfide and carbon dioxide.

Butwell, K.F.; Sigmund, P.W.

1981-10-27

257

Suggested method for evaluating the safety and durability of vehicle LNG containment systems. Final report, December 1992-December 1993  

SciTech Connect

The report describes a series of tests that could be conducted which will indicate an ability of an LNG vehicle tank to withstand forces encountered in (1) over-the-road operations, (2) truck coupling, (3) denting, and (4) 30 mph impact. These operating conditions are the ones thought by the NFPA 57 committee to be the ones of greatest concern, from a safety viewpoint.

Ripling, E.J.; Crosley, P.B.; Geiger, R.J.

1994-05-01

258

Stochastic and Risk Management Models and Solution Algorithm for Natural Gas Transmission Network Expansion and LNG Terminal Location Planning  

Microsoft Academic Search

Due to the increasing demands for natural gas, it is playing a more important role in the energy system, and its system expansion\\u000a planning is drawing more attentions. In this paper, we propose expansion planning models which include both natural gas transmission\\u000a network expansion and LNG (Liquified Natural Gas) terminals location planning. These models take into account the uncertainties\\u000a of

Qipeng P. Zheng; Panos M. Pardalos

2010-01-01

259

Supercritical microgravity droplet vaporization  

NASA Technical Reports Server (NTRS)

Supercritical droplet vaporization is an important issue in many combustion systems, such as liquid fueled rockets and compression-ignition (diesel) engines. In order to study the details of droplet behavior at these conditions, an experiment was designed to provide a gas phase environment which is above the critical pressure and critical temperature of a single liquid droplet. In general, the droplet begins as a cold droplet in the hot, high pressure environment. In order to eliminate disruptions to the droplet by convective motion in the gas, forced and natural convection gas motion are required to be small. Implementation of this requirement for forced convection is straightforward, while reduction of natural convection is achieved by reduction in the g-level for the experiment. The resulting experiment consists of a rig which can stably position a droplet without restraint in a high-pressure, high temperature gas field in microgravity. The microgravity field is currently achieved by dropping the device in the NASA Lewis 2.2 second drop tower. The performance of the experimental device and results to date are presented.

Hartfield, J.; Curtis, E.; Farrell, P.

1990-01-01

260

Dimers in nucleating vapors  

NASA Astrophysics Data System (ADS)

The dimer stage of nucleation may affect considerably the rate of the nucleation process at high supersaturation of the nucleating vapor. Assuming that the dimer formation limits the nucleation rate, the kinetics of the particle formation-growth process is studied starting with the definition of dimers as bound states of two associating molecules. The partition function of dimer states is calculated by summing the Boltzmann factor over all classical bound states, and the equilibrium population of dimers is found for two types of intermolecular forces: the Lennard-Jones (LJ) and rectangular well+hard core (RW) potentials. The principle of detailed balance is used for calculating the evaporation rate of dimers. The kinetics of the particle formation-growth process is then investigated under the assumption that the trimers are stable with respect to evaporation and that the condensation rate is a power function of the particle mass. If the power exponent ?=n/(n+1) (n is a non-negative integer), the kinetics of the process is described by a finite set of moments of particle mass distribution. When the characteristic time of the particle formation by nucleation is much shorter than that of the condensational growth, n+2 universal functions of a nondimensional time define the kinetic process. These functions are calculated for ?=2/3 (gas-to-particle conversion in the free molecular regime) and ?=1/2 (formation of islands on surfaces).

Lushnikov, A. A.; Kulmala, M.

1998-09-01

261

Chemical vapor deposition growth  

NASA Technical Reports Server (NTRS)

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 an existing vertical-chamber 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 impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.

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

1978-01-01

262

Thermogravity system designed for use in dispersion strengthening studies  

NASA Technical Reports Server (NTRS)

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.

Herbell, T. P.

1972-01-01

263

Thermogravimetry system designed for use in dispersion strengthening studies.  

NASA Technical Reports Server (NTRS)

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.

Herbell, T. P.

1972-01-01

264

Anomalous dispersion in atomic line filters applied for spatial frequency detection  

SciTech Connect

The anomalous dispersion of an atomic line filter near a resonant transition is exploited for full-field frequency measurements. The influence of the line shape function on the dispersion in atomic vapors near resonance and the possibilities to increase sensitivity are discussed. From the model-calculated absorption of iodine vapor at frequency-doubled Nd:YAG laser wavelengths, the corresponding refractive index is obtained through the Kramers-Kronig relations. Both variables are used to assess the performance of a iodine vapor cell as a dispersive element in an interferometric setup for Doppler frequency shift detection. With good agreement, the predicted sensitivity of the setup is compared to an experimental calibration. Observed discrepancies are attributed to the assumption of a Gaussian line shape in the absorption model. The full-field Doppler frequency measurement capacity of the technique is demonstrated in a rotating disk experiment, and the measurement performance is assessed.

Landolt, Andrin; Roesgen, Thomas

2009-11-01

265

Dispersion strengthened copper  

DOEpatents

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.

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

1990-01-01

266

Dispersion strengthened copper  

DOEpatents

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.

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

1989-01-01

267

Tubing For Sampling Hydrazine Vapor  

NASA Technical Reports Server (NTRS)

Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

1993-01-01

268

Portable vapor diffusion coefficient meter  

DOEpatents

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.

Ho, Clifford K. (Albuquerque, NM)

2007-06-12

269

Nanocrystal dispersed amorphous alloys  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

270

Calculated refractivity of water vapor and moist air in the atmospheric window at 10 mum  

Microsoft Academic Search

The HITRAN 2000 database of infrared line transitions has been used to calculate the dispersion coefficient of water vapor at room temperature in the atmospheric window up to 25 mum, confirming an equivalent earlier compilation [Infrared Phys. 26, 371 (1986)]. I complement this line set by using an previously published ultraviolet pseudospectrum [J. Chem. Phys. 68, 1426 (1978)] to improve

Richard J. Mathar

2004-01-01

271

Collapse of large vapor bubbles  

NASA Technical Reports Server (NTRS)

The refilling of propellant tanks while in a low-gravity environment requires that entrapped vapor bubbles be collapsed by increasing the system pressure. Tests were performed to verify the mechanism of collapse for these large vapor bubbles with the thermodynamic conditions, geometry, and boundary conditions being those applicable to propellant storage systems. For these conditions it was found that conduction heat transfer determined the collapse rate, with the specific bubble geometry having a significant influence.

Tegart, J.; Dominick, S.

1982-01-01

272

Packed Alumina Absorbs Hypergolic Vapors  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

273

AIAA 2000-0645 PARTICLE VAPORIZATION VELOCIMETRY  

E-print Network

AIAA 2000-0645 PARTICLE VAPORIZATION VELOCIMETRY FOR SOOT-CONTAINING FLOWS P. Yang and J. M-0645 PARTICLE VAPORIZATION VELOCIMETRY FOR SOOT-CONTAINING FLOWS P. Yang* and J. M. Seitzman Georgia Institute, Particle Vaporization Velocimetry (PVV), is a form of flow tagging based on laser vaporization of absorbing

Seitzman, Jerry M.

274

Vapor deposition of tantalum and tantalum compounds  

Microsoft Academic Search

Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the

Trkula

1996-01-01

275

Breakup and vaporization of droplets under locally supersonic conditions  

NASA Astrophysics Data System (ADS)

The disruption and vaporization of simulated fuel droplets in an accelerating supersonic flow was examined experimentally in a draw-down supersonic wind tunnel. The droplets achieved supersonic velocities relative to the surrounding air to give relative Mach numbers of up to 1.8 and Weber numbers of up to 300. Mono-disperse, 100 ?m-diameter fluid droplets were generated using a droplet-on-demand generator upstream of the tunnel entrance. Direct close-up single- and multiple-exposure imaging was used to examine the features of droplet breakup and to determine the droplet velocities. Laser-induced fluorescence (LIF) imaging of the disrupting droplets was performed using acetone fluorescence to determine the dispersion of the expelled vapor. Three test liquids were employed: 2-propanol and tetraethylene glycol dimethyl ether as non-volatile fluids and a 50/50 hexanol-pentane mixture (Hex-Pen 50/50). The vapor pressure of the Hex-Pen 50/50 was sufficiently high to cause the droplet fluid to potentially become superheated in the decreased static pressure of the supersonic stream. The dynamics for 2-propanol and Hex-Pen 50/50 droplets were similar up to the point of disruption, which occurred more rapidly for the more volatile Hex-Pen 50/50. A 1D dynamic droplet model was developed to provide a first estimate of the expected droplet acceleration and velocity. The actual droplet velocities were in reasonable agreement with the model up to the point at which significant droplet disruption and mass loss commenced. The droplet deformation and breakup patterns for these supersonic flow conditions can be classified into four different flow regions characterized by changes in the Weber number with downstream distance as the droplets accelerate, however, those flow regimes and Weber number ranges were different than those seen for droplets disrupting in shock tubes. The disruption patterns were seen to be generally similar for the different fluids, though droplet disruption occurred more rapidly for the more volatile fluid. LIF imaging established the extent of the dispersion of the expelled vapor. Examination of the vapor clouds surrounding the droplets suggests that Hex-Pen 50/50 droplets had a greater rate of vaporization than 2-propanol droplets starting at approximately 2 mm downstream of the nozzle throat, where the air static pressure became lower than the liquid vapor pressure. This suggests that droplet superheating can have an effect on the extent and rate of droplet vaporization under locally supersonic conditions. The degree of vaporization for Hex-Pen 50/50 was approximately 1.3 times greater than that of the non-volatile fluids over all downstream distances in the supersonic flow.

Kim, YoungJun; Hermanson, James C.

2012-07-01

276

Simulations and parameter variation studies of heavy gas dispersion using the SLAB model - condensed  

SciTech Connect

We are employing the SLAB model in ongoing studies of the atmospheric dispersion of heavy gases. SLAB computer simulations of four of the Burro series large-scale 40-m/sup 3/ liquefied natural gas (LNG) spill experiments at China Lake, California have been successful in predicting distances to the lower flammability limit (LFL). WE have used this model in simulations of three of the Coyote series of experiments as well as in parameter variation and sensitivity studies and improved simulations of some of the Burro tests. The parameters studied include source rate, wind speed, atmospheric stability, type of source gas, and source duration, as well as the parameters important to certain physics submodels. 8 references, 5 figures.

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

1983-12-01

277

When Seed Dispersal Matters  

NSDL National Science Digital Library

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.

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

2004-07-01

278

Atomization and vaporization characteristics of airblast fuel injection inside a venturi tube  

NASA Technical Reports Server (NTRS)

This paper describes the experimental and numerical characterization of the capillary fuel injection, atomization, dispersion, and vaporization of liquid fuel in a coflowing air stream inside a single venturi tube. The experimental techniques used are all laser-based. Phase Doppler analyzer was used to characterize the atomization and vaporization process. Planar laser-induced fluorescence visualizations give good qualitative picture of the fuel droplet and vapor distribution. Limited quantitative capabilities of the technique are also demonstrated. A modified version of the KIVA-II was used to simulate the entire spray process, including breakup and vaporization. The advantage of venturi nozzle is demonstrated in terms of better atomization, more uniform F/A distribution, and less pressure drop. Multidimensional spray calculations can be used as a design tool only if care is taken for the proper breakup model, and wall impingement process.

Sun, H.; Chue, T.-H.; Lai, M.-C.; Tacina, R. R.

1993-01-01

279

Dispersal characteristics of swift foxes  

Microsoft Academic Search

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

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

2004-01-01

280

Image Storage in Hot Vapors  

E-print Network

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.

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

2007-10-22

281

Silicon Detectors For Helium Liquid And Vapor  

NASA Technical Reports Server (NTRS)

Simple electrical-resistance devices made of silicon indicate whether helium liquid or helium vapor present. Devices designed primarily for use in outer space, were tested and found to operate in normal Earth gravity. Silicon cubes supported by stainless-steel wires and strips. Voltage across each cube at fixed current indicates whether immersed in helium liquid or vapor. Liquid cools more than vapor does, resulting in greater electrical resistance. Such helium-liquid/vapor detectors incorporated into ducts or containers of laboratory equipment, and used to infer locations of liquid/vapor interfaces in order to measure quantities of liquid and vapor or to control refill operations.

Di Pirro, M. J.; Serlemitsos, A. T.

1990-01-01

282

Application of waste heat powered absorption refrigeration system to the LNG recovery process  

Microsoft Academic Search

The recovery process of the liquefied natural gas requires low temperature cooling, which is typically provided by the vapor compression refrigeration systems. The usage of an absorption refrigeration system powered by waste heat from the electric power generating gas turbine could provide the necessary cooling at reduced overall energy consumption. In this study, a potential replacement of propane chillers with

Paul Kalinowski; Yunho Hwang; Reinhard Radermacher; Saleh Al Hashimi; Peter Rodgers

2009-01-01

283

Waste Tank Vapor Project: Tank vapor database development  

SciTech Connect

The objective of the Tank Vapor Database (TVD) Development task in FY 1994 was to create a database to store, retrieve, and analyze data collected from the vapor phase of Hanford waste tanks. The data needed to be accessible over the Hanford Local Area Network to users at both Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL). The data were restricted to results published in cleared reports from the laboratories analyzing vapor samples. Emphasis was placed on ease of access and flexibility of data formatting and reporting mechanisms. Because of time and budget constraints, a Rapid Application Development strategy was adopted by the database development team. An extensive data modeling exercise was conducted to determine the scope of information contained in the database. a A SUN Sparcstation 1000 was procured as the database file server. A multi-user relational database management system, Sybase{reg_sign}, was chosen to provide the basic data storage and retrieval capabilities. Two packages were chosen for the user interface to the database: DataPrism{reg_sign} and Business Objects{trademark}. A prototype database was constructed to provide the Waste Tank Vapor Project`s Toxicology task with summarized and detailed information presented at Vapor Conference 4 by WHC, PNL, Oak Ridge National Laboratory, and Oregon Graduate Institute. The prototype was used to develop a list of reported compounds, and the range of values for compounds reported by the analytical laboratories using different sample containers and analysis methodologies. The prototype allowed a panel of toxicology experts to identify carcinogens and compounds whose concentrations were within the reach of regulatory limits. The database and user documentation was made available for general access in September 1994.

Seesing, P.R.; Birn, M.B.; Manke, K.L.

1994-09-01

284

46 CFR 182.480 - Flammable vapor detection systems.  

Code of Federal Regulations, 2013 CFR

... false Flammable vapor detection systems. 182.480 ...CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS...480 Flammable vapor detection systems. (a) A flammable vapor detection system required...

2013-10-01

285

46 CFR 182.480 - Flammable vapor detection systems.  

Code of Federal Regulations, 2010 CFR

... false Flammable vapor detection systems. 182.480 ...CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS...480 Flammable vapor detection systems. (a) A flammable vapor detection system required...

2010-10-01

286

46 CFR 182.480 - Flammable vapor detection systems.  

Code of Federal Regulations, 2011 CFR

... false Flammable vapor detection systems. 182.480 ...CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS...480 Flammable vapor detection systems. (a) A flammable vapor detection system required...

2011-10-01

287

46 CFR 182.480 - Flammable vapor detection systems.  

Code of Federal Regulations, 2012 CFR

... false Flammable vapor detection systems. 182.480 ...CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS...480 Flammable vapor detection systems. (a) A flammable vapor detection system required...

2012-10-01

288

Vapor generation methods for explosives detection research  

SciTech Connect

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.

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

2012-12-01

289

Evaporation by mechanical vapor recompression  

Microsoft Academic Search

Progress in the development of a study of the application of the technologies of mechanical vapor recompression and falling film evaporation as applied to the beet sugar industry is reported. Progress is reported in the following areas: technical literature search; report on visit to European factories using these technologies; energy balance studies of factories offered by the industry as candidates

C. H. Iverson; G. E. Coury

1980-01-01

290

Evaporation by mechanical vapor compression  

Microsoft Academic Search

A review of existing technology and application of the mechanical vapor recompression and falling film evaporation in both the sugar and nonsugar industries, and the potential of application to the domestic beet sugar industry is made. Upon assimilating the information gathered, certain design guidelines were established, possible candidate factories for a demonstration project were identified, and a preliminary technical and

C. H. Iverson; G. E. Coury; J. H. Fischer

1980-01-01

291

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...

292

Simple Chemical Vapor Deposition Experiment  

ERIC Educational Resources Information Center

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…

Pedersen, Henrik

2014-01-01

293

Motor vehicle fuel vapor emission control assembly  

SciTech Connect

This patent describes a motor vehicle fuel vapor emission control assembly. It comprises fuel vapor emission control means and structural vehicle support means integral with the motor vehicle for providing structural support for the motor vehicle, the fuel vapor emission control means being for controlling emissions of fuel vapor from the motor vehicle. It comprises adsorption means for releasably adsorbing fuel vapors from a fuel reservoir of the vehicle; housing means for containing such adsorption means, the housing means being positioned within a hollow in a structural member of the structural vehicle support means; and vapor communication means for communicating fuel vapor from the reservoir to the adsorption means within the housing means and for communicating fuel vapor from within the housing means to a fuel burning engine of the vehicle.

Oslapas, A.G.

1991-10-29

294

Boiler for generating high quality vapor  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

295

Dispersal range analysis: quantifying individual variation in dispersal behaviour  

Microsoft Academic Search

A complete understanding of animal dispersal requires knowledge not only of its consequences at population and community levels, but also of the behavioural decisions made by dispersing individuals. Recent theoretical work has emphasised the importance of this dispersal process, particularly the phase in which individuals search the landscape for breeding opportunities. However, empirical advances are currently hampered by a lack

Erik D. Doerr; Veronica A. J. Doerr

2005-01-01

296

Experimental investigation of the thermal transport properties of a carbon nanohybrid dispersed nanofluid  

Microsoft Academic Search

A hybrid nanostructure consisting of 1D carbon nanotubes and 2D graphene was successfully synthesized. Nanofluids were made by dispersing the hybrid nanostructure in deionized (DI) water and ethylene glycol (EG) separately, without any surfactant. Later the thermal conductivity and heat transfer coefficient of the nanofluids were experimentally measured. Meanwhile, multiwalled carbon nanotubes (MWNT) were prepared by catalytic chemical vapor deposition

Tessy Theres Baby; Sundara Ramaprabhu

2011-01-01

297

Modeling vapor transients in heat pipes  

NASA Astrophysics Data System (ADS)

In this paper an implicit solution method for modeling transient vapor flow in a heat pipe is compared to an earlier explicit model. For both models the vapor is assumed to be spatially incompressible, compressible in time, and one dimensional. The vapor is also treated like a saturated vapor, not an ideal gas. It is shown that the implicit solution method is a factor of 102 faster than the explicit method.

Bowman, W. Jerry; Beran, Philip S.

1993-01-01

298

Remote sensing of water vapor features  

NASA Technical Reports Server (NTRS)

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.

Fuelberg, Henry E.

1991-01-01

299

Nikolaevskiy equation with dispersion.  

PubMed

The Nikolaevskiy equation was originally proposed as a model for seismic waves and is also a model for a wide variety of systems incorporating a neutral "Goldstone" mode, including electroconvection and reaction-diffusion systems. It is known to exhibit chaotic dynamics at the onset of pattern formation, at least when the dispersive terms in the equation are suppressed, as is commonly the practice in previous analyses. In this paper, the effects of reinstating the dispersive terms are examined. It is shown that such terms can stabilize some of the spatially periodic traveling waves; this allows us to study the loss of stability and transition to chaos of the waves. The secondary stability diagram ("Busse balloon") for the traveling waves can be remarkably complicated. PMID:20365845

Simbawa, Eman; Matthews, Paul C; Cox, Stephen M

2010-03-01

300

CPMG relaxation dispersion.  

PubMed

NMR relaxation is sensitive to molecular and internal motion of proteins. (15)N longitudinal relaxation rate (R 1), transverse relaxation rate (R 2), and {(1)H}-(15)N Nuclear Overhauser Effect (NOE) experiments are often performed to globally elucidate protein dynamics, primarily on the sub-nanosecond timescale. In contrast, constant relaxation time R 2 dispersion experiments are applied to characterize protein equilibrium conformations that interconvert on the millisecond timescale. Information on local conformational equilibria of proteins provides important insights about protein energy landscapes and is useful to interpret molecular recognition mechanisms as well. Here, we describe a protocol for performing (15)N Carr-Purcell-Meiboom-Gill (CPMG) R 2 dispersion measurements in solution, including protein preparation, step-by-step experimental parameter settings, and the first step of data analysis. PMID:24061914

Ishima, Rieko

2014-01-01

301

Derivative Dispersion Relations  

E-print Network

We discuss some analytical and numerical aspects related to the replacement of integral dispersion relations by derivative relations and also the practical applicability of the derivative approach in the investigation of high-energy elastic hadron-hadron scattering. Making use of a Monopole Pomeron model and singly subtracted integral and derivative dispersion relations, we present the results of fits to the experimental data on the total cross sections and the ratio of the real to the imaginary part of the forward elastic scattering amplitude (proton-proton and antiproton-proton interactions). The emphasis is on the region of low energies and, in particular, we show that once the subtraction constant is used as a free fit parameter the derivative approach is equivalent to the integral approach even below the energy cutoff of the fitted data.

R. F. Avila; M. J. Menon

2004-11-30

302

Extended Derivative Dispersion Relations  

E-print Network

It is shown that, for a wide class of functions with physical interest as forward scattering amplitudes, integral dispersion relations can be replaced by derivative forms without any high-energy approximation. The applicability of these extended derivative relations, in the investigation of forward proton-proton and antiproton-proton elastic scattering, is exemplified by means of a Pomeron-Reggeon model with totally nondegenerate trajectories.

R. F. Avila; M. J. Menon

2006-01-24

303

Disabling Radiological Dispersal Terror  

SciTech Connect

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.

Hart, M

2002-11-08

304

Thermorheological properties of nanostructured dispersions  

E-print Network

Nanostructured dispersions, which consist of nanometer-sized particles, tubes, sheets, or droplets that are dispersed in liquids, have exhibited substantially higher thermal conductivities over those of the liquids alone. ...

Gordon, Jeremy B

2007-01-01

305

Oil well fluids and dispersants  

SciTech Connect

The invention of this application is a dispersant system with various embodiments and subcombinations with exceptional dispersions including colloidal suspensions, aqueous hydrocarbon emulsions and emulsions with solid particulate additives dispersed therein. The basic dispersant system which makes the high stability, high weight dispersions or emulsions possible comprises an emulsifier composition containing a fatty acid amide , oleic acid, dimerized oleic acid and a particular type of surfactant dispersant. For certain applications the following optional components can be used: particulate filler or carrier; a hydrocarbon phase which can be either liquid or a colloidal solid; water soluble salts weighting agents; insoluble salts and conventional additives. This dispersant system can be used for aqueous hydrocarbon well fluids such as spacer and packer fluid, for aqueous hydrocarbon dispersions such as asphaltic colloids in an oil free fluid for sealing and lubricating a well bore, or for other aqueous hydrocarbon emulsions which can be used with salts, weighting agents, etc. For a drilling fluid.

Carney, L.L.

1980-11-11

306

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...

307

Succinimide lubricating oil dispersant  

SciTech Connect

A lubricating oil composition is described exhibiting improved dispersancy in both gasoline and diesel engines comprising a major amount of lubricating oil and 0.5 to 10 weight percent of a dispersant, the dispersant being prepared in a sequential process comprising the steps of: (a) in a first step reacting an oil-soluble polyolefin succinic anhydride, the olefin being a C/sub 3/ or C/sub 4/ olefin and an alkylene polyamine of the formula H/sub 2/N(CH/sub 2/)/sub n/(NH(CH/sub 2/)/sub n/)/sub m/sup -// NH/sub 2/ wherein n is 2 or 3 and m is 0 to 10, in a molar ratio of about 1.0 to 2.2 moles of polyolefin succinic anhydride per mole of polyamine, and (b) reacting the product of step (a) with dicarboxylic acid anhydride selected from the group consisting of maleic anhydride and succinic anhydride in sufficient molar proportions to provide a total mole ratio of about 2,3 to 3.0 moles of anhydride compounds per mole of polyamine.

Wisotsky, M.J.; Bloch, R.; Brownwell, D.W.; Chen, F.J.; Gutierrez, A.

1987-08-11

308

Dispersibility of Amphibious Montmorillonite  

NASA Astrophysics Data System (ADS)

The objective of this study is to develop a suitable method to convert hydrophilic montmorillonite into amphibious montmorillonite by replacing the sodium ions normally found in clay with poly(oxyethylene) (POE)-amide chlorite cations. Amphibious montmorillonite has a high d-spacing and good dispersion characteristics in many different types of solutions, including those having an intermediate hydrophilic lipophilic balance (HLB) value. Four different modifying cations are tested and X-ray diffraction analysis is performed to measure the resulting changes in the d-spacing of the MMT. Scanning electron microscopy is employed to investigate the morphology of the modified clays. A laser-doppler particle analyzer is used to measure the particle size of the clays in various solutions. Dobrat’s method is applied to calculate the dispersibility of each clay and Stoke’s law is used to evaluate the settling rate. The results indicate that the d-spacing of the POE-amide chlorite cation modified montmorillonite increases from 1.28 to 3.51 nm. The amphibious montmorillonite demonstrates good dispersion characteristics in eight commonly employed coating solutions with intermediate HLB values.

Yeh, Meng-Heng; Hwang, Weng-Sing; Kuo, Wuei-Jueng

2005-09-01

309

TROPOSPHERIC WATER VAPOR, CONVECTION, AND CLIMATE  

E-print Network

with water vapor and changes associated with water vapor in warmer climates. Progress includes new observing consequences of increased specific humidity in a warmer climate. A theory appears to be in place to predict on climate changes driven by other influences. The latent heat of water vapor also accounts for roughly half

Sherwood, Steven

310

Preparation Of Sources For Plasma Vapor Deposition  

NASA Technical Reports Server (NTRS)

Multicomponent metal targets serving as sources of vapor for plasma vapor deposition made in modified pressureless-sintering process. By use of targets made in modified process, one coats components with materials previously plasma-sprayed or sintered but not plasma-vapor-deposited.

Waters, William J.; Sliney, Hal; Kowalski, D.

1993-01-01

311

Mechanical vapor recompression for waste energy recovery  

Microsoft Academic Search

This paper is concerned with energy recovery in petroleum distillation processes utilizing mechanical vapor recompression. Several examples illustrating recompression of head vapors for heating the reboiler of a distillation tower are presented. The advantages of the mechanical vapor recompression system using a screw compressor are discussed in detail. The system is economically attractive with simple payback periods often less than

F. E. Becker; A. I. Zakak

1985-01-01

312

Mechanical Vapor Recompression for waste energy recovery  

Microsoft Academic Search

This paper describes energy recovery in petroleum refineries utilizing mechanical vapor recompression. Several examples illustrating recompression of waste steam or vapors from turbine exhausts, vents and distillation towers are presented. The advantages of the Mechanical Vapor Recompression System (MVRS) using a screw compressor are discussed in detail. Significant energy savings can be achieved by integration of the MVRS into the

F. E. Becker; A. I. Zakak

1985-01-01

313

WATER VAPOR FEEDBACK AND GLOBAL WARMING1  

Microsoft Academic Search

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,

Isaac M. Held; Brian J. Soden

2000-01-01

314

Vapor Pressure Measurements in a Closed System  

ERIC Educational Resources Information Center

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…

Iannone, Mark

2006-01-01

315

Vaporization Enthalpy and Vapor Pressure of Valproic Acid by Correlation Gas Chromatography  

E-print Network

Vaporization Enthalpy and Vapor Pressure of Valproic Acid by Correlation Gas Chromatography Joe A by correlation-gas chromatography. This resulted in a vaporization enthalpy, Hvap(298.15 K) of (74.8 ± 2.4) k at T/K = 298.15, both derived by correlation-gas chromatography. The measurement of vaporization

Chickos, James S.

316

Seed Dispersal by Japanese Macaques  

Microsoft Academic Search

\\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

Tatsuya Otani

317

Characteristics of dispersal in wolverines  

Microsoft Academic Search

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

Knut Morten Vangen; Jens Persson; Arild Landa; Roy Andersen; Peter Segerström

2001-01-01

318

Nozzle for electric dispersion reactor  

DOEpatents

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.

Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

1998-06-02

319

Nozzle for electric dispersion reactor  

DOEpatents

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.

Sisson, W.G.; Basaran, O.A.; Harris, M.T.

1998-04-14

320

Nozzle for electric dispersion reactor  

DOEpatents

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.

Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

1996-04-02

321

Nozzle for electric dispersion reactor  

DOEpatents

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.

Sisson, W.G.; Basaran, O.A.; Harris, M.T.

1995-11-07

322

Mechanical vapor recompression for waste energy recovery  

SciTech Connect

This paper is concerned with energy recovery in petroleum distillation processes utilizing mechanical vapor recompression. Several examples illustrating recompression of head vapors for heating the reboiler of a distillation tower are presented. The advantages of the mechanical vapor recompression system using a screw compressor are discussed in detail. The system is economically attractive with simple payback periods often less than two years. The paper describes the merits of mechanical vapor recompression, using a screw-type compressor for recovering energy at the distillation tower, and how it can be accomplished by using an intermediary fluid such as steam or by recompressing the distillation column vapors directly.

Becker, F.E.; Zakak, A.I.

1985-03-01

323

What Good is Raman Water Vapor Lidar?  

NASA Technical Reports Server (NTRS)

Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

Whitman, David

2011-01-01

324

Active Hydrazine Vapor Sampler (AHVS)  

NASA Technical Reports Server (NTRS)

The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

Young, Rebecca C.; Mcbrearty, Charles F.; Curran, Daniel J.

1993-01-01

325

Size-dependent phase transition temperatures of dispersed systems  

NASA Astrophysics Data System (ADS)

A phase transition equation on the basis of the additional pressure on the curved surfaces of dispersed systems has been proposed, and the specific differential equations for various kinds of phase transitions of dispersed systems have been derived by the phase transition equation. Applying the fusion transition equations, the melting temperatures of Au and Sn nanoparticles have been calculated, and the predicted melting temperatures are in good agreement with the available experimental data. The results show that the phase transition equations can be used to predict the temperatures of phase transitions of dispersed systems and to explain the phenomenon of metastable states; the size of the dispersed phase has noticeable effect on the phase transition temperature; all temperatures of fusion, solidification, condensation, vaporization, sublimation and desublimation decrease with decreasing radius of the dispersed phase, but the bubble point temperature of a planar liquid increases with decreasing absolute value of radius of the bubbles; the depression of melting temperature for a nanowire is approximately half of that for a spherical nanoparticle with identical radius.

Xue, Yong-Qiang; Zhao, Miao-Zhi; Lai, Wei-Peng

2013-01-01

326

Evaporation by mechanical vapor recompression  

NASA Astrophysics Data System (ADS)

Progress in the development of a study of the application of the technologies of mechanical vapor recompression and falling film evaporation as applied to the beet sugar industry is reported. Progress is reported in the following areas: technical literature search; report on visit to European factories using these technologies; energy balance studies of factories offered by the industry as candidates for the demonstration plants; and report on energy balance studies and the recommendations as to the site for the demonstration plant.

Iverson, C. H.; Coury, G. E.

1980-04-01

327

Vaporization Would Cool Primary Battery  

NASA Technical Reports Server (NTRS)

Temperature of discharging high-power-density primary battery maintained below specified level by evaporation of suitable liquid from jacket surrounding battery, according to proposal. Pressure-relief valve regulates pressure and boiling temperature of liquid. Less material needed in cooling by vaporization than in cooling by melting. Technique used to cool batteries in situations in which engineering constraints on volume, mass, and location prevent attachment of cooling fins, heat pipes, or like.

Bhandari, Pradeep; Miyake, Robert N.

1991-01-01

328

Internal Water Vapor Photoacoustic Calibration  

NASA Technical Reports Server (NTRS)

Water vapor absorption is ubiquitous in the infrared wavelength range where photoacoustic trace gas detectors operate. This technique allows for discontinuous wavelength tuning by temperature-jumping a laser diode from one range to another within a time span suitable for photoacoustic calibration. The use of an internal calibration eliminates the need for external calibrated reference gases. Commercial applications include an improvement of photoacoustic spectrometers in all fields of use.

Pilgrim, Jeffrey S.

2009-01-01

329

CC Cryostat Vapor Pressure Thermometers  

SciTech Connect

Vapor pressure thermometers will be used to measure the temperature or the liquid argon in the cryostat at two different levels. One bulb will be positioned near the top of the vessel, and a second bulb will be located near the bottom of the vessel. The volume of the bulbs is dependent upon the charge temperature and pressure chosen, the temperature range of the thermometer desired, the size and length of tubing used, and the warm volume involved.

Kurita, C.H.; /Fermilab

1987-10-01

330

Studies on Vapor Adsorption Systems  

NASA Technical Reports Server (NTRS)

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.

Shamsundar, N.; Ramotowski, M.

1998-01-01

331

Far-field dispersal modeling for fuel-air-explosive devices  

SciTech Connect

A computer model for simulating the explosive dispersal of a fuel agent in the far-field regime is described and is applied to a wide variety of initial conditions to judge their effect upon the resulting fuel/air cloud. This work was directed toward modeling the dispersal process associated with Fuel-Air-Explosives devices. The far-field dispersal regime is taken to be that time after the initial burster charge detonation in which the shock forces no longer dominate the flow field and initial canister and fuel mass breakup has occurred. The model was applied to a low vapor pressure fuel, a high vapor pressure fuel and a solid fuel. A strong dependence of the final cloud characteristics upon the initial droplet size distribution was demonstrated. The predicted fuel-air clouds were highly non-uniform in concentration. 18 refs., 86 figs., 4 tabs.

Glass, M.W.

1990-05-01

332

Means and method for vapor generation  

DOEpatents

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.

Carlson, Larry W. (Oswego, IL)

1984-01-01

333

Vapor phase lubrication of ceramics  

SciTech Connect

Vapor phase lubrication of ceramics under sliding wear has been extended up to 500{degrees}C, using tricresyl phosphate as the vaporized lubricant. In order to successfully lubricate ceramics, it was necessary to first activate the surface with a metal. Different methods of activating the surface have been investigated, including in-situ reaction with metal components. Continuous vapor phase lubrication of the activated ceramic reduced the coefficient of friction from 0.7 to less than 0.1, resulting in essentially no wear. The reduction in the wear rate and friction coefficient was due to a polymeric derivative of the original TCP which was formed on the high temperature surfaces. The deposit formed on the surface was analyzed using high performance liquid chromotography (HPLC). Results have suggested that it ins an organic polymer with a molecular range of 6000 to 60000 gmole/mole and an average molecular weight of approximately 30000 gmole/mole. This method of lubrication has direct application for the continuous lubrication of ceramic engines. 9 refs., 12 figs., 1 tab.

Hanyaloglu, B.; Graham, E.E. [Cleveland State Univ., OH (United States)

1994-10-01

334

Phonon dispersion in graphene  

E-print Network

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.

L. A. Falkovsky

2007-02-17

335

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

PubMed

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

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

2014-11-11

336

LANDFILL GAS CONVERSION TO LNG AND LCO{sub 2}. PHASE 1, FINAL REPORT FOR THE PERIOD MARCH 1998-FEBRUARY 1999  

SciTech Connect

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.

COOK,W.J.; NEYMAN,M.; SIWAJEK,L.A.; BROWN,W.R.; VAN HAUWAERT,P.M.; CURREN,E.D.

1998-02-25

337

Process for recovering organic vapors from air  

DOEpatents

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.

Baker, Richard W. (Mountain View, CA)

1985-01-01

338

Chiroptical Spectroscopy in the Vapor Phase  

NASA Astrophysics Data System (ADS)

Electromagnetic radiation propagating through an isotropic chiral medium experiences a complex index of refraction that differs in both real (in-phase) and imaginary (in-quadrature) parts for the right-circular and left-circular polarization states that define the helicity basis. The resulting phenomena of circular birefringence (CB) and circular dichroism (CD) lead to observable effects in the form of dispersive rotation and absorptive elliptization for an impinging beam of plane-polarized light, which commonly are measured under conditions of nonresonant and resonant excitation, respectively. This talk will discuss ongoing efforts designed to elucidate the provenance of electronic optical activity under complementary solvated and isolated conditions, with the latter vapor-phase work made possible by our continuing development of Cavity Ring-Down Polarimetry (CRDP). Molecules of interest include the rigid bicyclic ketone (1R,4R)-norbornenone, where the spatial arrangement of distal alkene and carbonyl moeities gives rise to extraordinarily large specific rotation (CB) parameters that are predicted incongruously by different quantum-chemical methods; the monoterpene constitutional isomers (S)-2-carene and (S)-3-carene, which display surprisingly distinct chiroptical properties; and conjugated ketones such as (S)-verbenone, where CD probes of weak ?*?n absorption bands have been performed at vibronic resolution. The disparate nature of gas-phase and condensed-phase optical activity will be highlighted, with complementary ab initio calculations serving to elucidate the structural, chemical, and electronic origins of observed behavior. T. Müller, K. B. Wiberg, P. H. Vaccaro, J. R. Cheeseman, and M. J. Frisch, J. Opt. Soc. Am. B 19, 125 (2002) P. H. Vaccaro, ``Chapter 1.II.10: Optical Rotation and Intrinsic Optical Activity'' in Comprehensive Chiroptical Spectroscopy, N. Berova, P. L. Polavarapu, K. Nakanishi, and R. W. Woody, eds. (John Wiley and Sons, Inc., Hoboken, NJ, 2011).

Lahiri, Priyanka; Long, Benjamin D.; Wiberg, Kenneth B.; Vaccaro, Patrick H.

2011-06-01

339

Gas phase dispersion in compost as a function of different water contents and air flow rates  

NASA Astrophysics Data System (ADS)

Gas phase dispersion in a natural porous medium (yard waste compost) was investigated as a function of gas flow velocity and compost volumetric water content using oxygen and nitrogen as tracer gases. The compost was chosen because it has a very wide water content range and because it represents a wide range of porous media, including soils and biofilter media. Column breakthrough curves for oxygen and nitrogen were measured at relatively low pore gas velocities, corresponding to those observed in for instance soil vapor extraction systems or biofilters for air cleaning at biogas plants or composting facilities. Total gas mechanical dispersion-molecular diffusion coefficients were fitted from the breakthrough curves using a one-dimensional numerical solution to the advection-dispersion equation and used to determine gas dispersivities at different volumetric gas contents. The results showed that gas mechanical dispersion dominated over molecular diffusion with mechanical dispersion for all water contents and pore gas velocities investigated. Importance of mechanical dispersion increased with increasing pore gas velocity and compost water content. The results further showed that gas dispersivity was relatively constant at high values of compost gas-filled porosity but increased with decreasing gas-filled porosity at lower values of gas-filled porosity. Results finally showed that measurement uncertainty in gas dispersivity is generally highest at low values of pore gas velocity.

Sharma, Prabhakar; Poulsen, Tjalfe G.

2009-07-01

340

Polymer Solutions and Dispersions  

NSDL National Science Digital Library

So far, we have spent a considerable amount of time discussing the strength of polymers and their unique physical and mechanical properties. However, some applications take excellent advantage of the interesting properties polymers bring to solutions. Examples include paints, motor oils, and some of the products we put on our hair. In addition, as we saw in the last chapter, some polymers are synthesized in solution. In this chapter, we will present some of the important properties of polymer solutions and develop a basic understanding of their origin. Some polymers would "like" to dissolve but can't. We'll try to understand why, and see how to take advantage of this. And, finally, we'll investigate some uses for polymers that are not actually dissolved in a solvent but rather are dispersed in a liquid.

Teegarden, David

2004-01-01

341

Advanced Raman water vapor lidar  

NASA Technical Reports Server (NTRS)

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.

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

342

Water vapor in protoplanetary disks  

NASA Astrophysics Data System (ADS)

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.

Banzatti, Andrea

2013-03-01

343

Chemical vapor deposition of sialon  

SciTech Connect

A laminated composite and a method for forming the composite by chemical vapor deposition. The composite includes a layer of sialon and a material to which the layer is bonded. The method includes the steps of exposing a surface of the material to an ammonia containing atmosphere; heating the surface to at least about 1200/sup 0/ C; and impinging a gas containing in a flowing atmosphere of air N/sup 2/, SiCl/sub 4/, and AlCl/sub 3/ on the surface.

Casey, A.W.; Landingham, R.L.

1982-06-22

344

Wick for metal vapor laser  

DOEpatents

An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

Duncan, David B. (Livermore, CA)

1992-01-01

345

Vapor Compression Distillation Flight Experiment  

NASA Technical Reports Server (NTRS)

One of the major requirements associated with operating the International Space Station is the transportation -- space shuttle and Russian Progress spacecraft launches - necessary to re-supply station crews with food and water. The Vapor Compression Distillation (VCD) Flight Experiment, managed by NASA's Marshall Space Flight Center in Huntsville, Ala., is a full-scale demonstration of technology being developed to recycle crewmember urine and wastewater aboard the International Space Station and thereby reduce the amount of water that must be re-supplied. Based on results of the VCD Flight Experiment, an operational urine processor will be installed in Node 3 of the space station in 2005.

Hutchens, Cindy F.

2002-01-01

346

Microwave assisted chemical vapor infiltration  

SciTech Connect

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.

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

1991-01-01

347

Microwave assisted chemical vapor infiltration  

SciTech Connect

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.

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

1991-12-31

348

Dispersion Relation for MHD Waves  

NASA Astrophysics Data System (ADS)

We have derived a seventh degree polynomial for the dispersion relation, using the same set of basic equations which is used in Dwivedi & Pandey and Kumar et al.. Further, we have shown that the results for the fast and slow modes of magneto hydrostatic waves are independent of the degree of polynomial for the dispersion relation and the fifth degree polynomial is sufficient. For application of magneto hydrodynamics (MHD) in solar physics as well as in plasma physics, dispersion relation plays key role.

Dak, Ganpat

349

Acoustic Rectification in Dispersive Media  

NASA Technical Reports Server (NTRS)

It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

Cantrell, John H.

2008-01-01

350

Development of polymer concrete for dike insulation at LNG (Liquid Natural Gas) facilities. Final report, August 1983-July 1984  

SciTech Connect

An insulating polymer concrete (IPC) composite has been developed for possible use as a dike insulation material at Liquid Natural Gas (LNG) storage facilities. Using hermetically sealed glass nodules or expanded perlite aggregates and unsaturated polyester resins, a new class of lightweight polymer concretes can be manufactured. Two application procedures have been identified and shown to be feasible in laboratory studies. Precast IPC composite panels 1-in thick can be bonded to concrete substrates using epoxy gel type adhesives or mortars. Cast-in-place IPC to concrete substrates have been shown to have good bonding and insulating characteristics. Modifications of the mix design to improve the workability and sagging of the IPC for installation on vertical or sloped surfaces is necessary.

Fontana, J.J.; Steinberg, M.

1984-11-01

351

Geometry of physical dispersion relations  

SciTech Connect

To serve as a dispersion relation, a cotangent bundle function must satisfy three simple algebraic properties. These conditions are derived from the inescapable physical requirements that local matter field dynamics must be predictive and allow for an observer-independent notion of positive energy. Possible modifications of the standard relativistic dispersion relation are thereby severely restricted. For instance, the dispersion relations associated with popular deformations of Maxwell theory by Gambini-Pullin or Myers-Pospelov are not admissible. Dispersion relations passing the simple algebraic checks derived here correspond to physically admissible Finslerian refinements of Lorentzian geometry.

Raetzel, Dennis; Rivera, Sergio; Schuller, Frederic P. [Albert Einstein Institute, Max Planck Institute for Gravitational Physics, Am Muehlenberg 1, 14476 Golm (Germany)

2011-02-15

352

Mechanical Vapor Recompression for waste energy recovery  

SciTech Connect

This paper describes energy recovery in petroleum refineries utilizing mechanical vapor recompression. Several examples illustrating recompression of waste steam or vapors from turbine exhausts, vents and distillation towers are presented. The advantages of the Mechanical Vapor Recompression System (MVRS) using a screw compressor are discussed in detail. Significant energy savings can be achieved by integration of the MVRS into the steam flow loop. Attractive simple payback periods, often less than two years, can be achieved.

Becker, F.E.; Zakak, A.I.

1985-01-01

353

Droplet Vaporization in a Supercritical Microgravity Environment  

NASA Technical Reports Server (NTRS)

A model is presented which describes single liquid droplet vaporization at nearly critical liquid pressures and temperatures. A modified Redlich-Kwong equation of state is used to evaluate the fugacities and liquid and vapor mole fractions at the interface under the assumption of interface equilibrium. Results obtained for different droplet sizes and conditions indicate significant differences in behavior in comparison with low-pressure quasi-steady droplet vaporization.

Curtis, E. W.; Farrell, P. V.

1987-01-01

354

Vapor deposited release layers for nanoimprint lithography  

Microsoft Academic Search

This paper presents the advantages of using a vapor deposited self-assembled monolayer (SAM) as a mold release layer for nano-imprint lithography. The release SAM was formed from a perfluorinated organo-silane precursor at room temperature in the gaseous state by a technique called Molecular Vapor Deposition (MVDTM). In contrast to a conventional coating from a liquid immersion sequence, the vapor deposition

Tong Zhang; Boris Kobrin; Mike Wanebo; Romek Nowak; Richard Yi; Jeff Chinn; Markus Bender; Andreas Fuchs; Martin Otto

2006-01-01

355

Environmental Pollution Air Pollution Dispersion Practical Air Pollution Dispersion  

E-print Network

Environmental Pollution Air Pollution Dispersion 1 of 5 Practical ­ Air Pollution Dispersion in the lectures how such models can be used to explain observed concentrations of air pollutants in an area to a large extent, downwind air pollution levels on a local or regional scale. The Gaussian Plume Model

Moncrieff, John B.

356

Ambient air heated electrically assisted cryogen vaporizer  

SciTech Connect

A high volume cryogen vaporizer includes a radiator where a working fluid draws heat from ambient air for vaporizing a cryogen in a heat exchanger. An electrical heater is provided for periodically heating the working fluid to defrost the radiator, thereby allowing sustained operation of the vaporizer. When not required for defrosting the radiator, the heater may be operated to heat a working fluid in a circuit separate from that of the radiator, and in which the heated working fluid is used for further elevating the temperature of the vaporized cryogen in a second heat exchanger, thereby making possible a gas output temperature higher than ambient air temperature.

Brigham, W. D.; Dung, N. D.

1985-05-28

357

Recover heat by mechanical vapor recompression  

SciTech Connect

Several examples illustrating recompression of head vapors for heating the reboiler of a distillation tower are presented. The advantages of the mechanical vapor recompression system using a screw compressor are discussed in detail. The system is economically attractive with simple payback periods often less than two years. Numerous studies have identified a number of alternatives for lowering energy consumption in the distillation process through various heat recovery techniques. One such technique utilizes mechanical vapor recompression. By mechanically recompressing low-pressure vapors, a better match can be made between low-grade waste energy sources and process uses, thereby improving plant energy efficiency.

Becker, F.E.; Zakak, A.I.

1985-05-01

358

Venus Balloons using Water Vapor  

NASA Astrophysics Data System (ADS)

We propose an inflatable balloon using water vapor for the lifting gas, which is liquid in the transportation stage before entry into the high temperature atmosphere. The envelope of the balloon has an outer layer for gas barrier (a high-temperature resistant film) and an inner layer for liquid water keeping. In the descent stage using a parachute, water widely held just inside the balloon envelope can be quickly vaporized by a lot of heat flux from the surrounding high-temperature atmosphere owing to the large surface area of the balloon. As neither gas containers nor heat exchangers are necessary, we can construct a simple, lightweight and small size Venus balloon probe system. Tentative floating altitude is 35 km below the thick clouds in the Venusian atmosphere. Selection of balloon shape and material for balloon envelope are discussed in consideration of the Venusian environment such as high-temperature, high-pressure, and sulfuric acid. Balloon deployment and inflation sequence is numerically simulated. In case of the total floating mass of 10 kg at the altitude of 35 km, the volume and mass of the balloon is 1.5 cubic meters, and 3.5 kg, respectively. The shape of the balloon is chosen to be cylindrical with a small diameter. The mass of li fting gas can be determined as 4.3 kg and the remaining 2.2 kg becomes the payload mass. The mass of the total balloon system is also just 10 kg excluding the entry capsule.

Izutsu, N.; Yajima, N.; Honda, H.; Imamura, T.

359

Saturation vapor pressures and vaporization enthalpies of esters of ethylene glycol and lower carboxylic acids  

NASA Astrophysics Data System (ADS)

Saturation vapor pressures and vaporization enthalpies of ethylene glycol and C1-C5 carboxylic acid disubstituted esters of normal and branched structures are determined by the transfer method in the temperature range of 295 to 327 K. Dependences of vaporization enthalpies versus the number of carbon atoms in a molecule and the retention indices are determined. An analysis of existing calculation schemes is given to help predict the vaporization enthalpy of the compounds under study.

Maslakova, A. S.; Krasnykh, E. L.; Levanova, S. V.

2011-10-01

360

Interfacial Force Field Characterization in a Constrained Vapor Bubble Thermosyphon  

NASA Technical Reports Server (NTRS)

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

DasGupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

1995-01-01

361

A Simple Liquid Helium Vapor Cooled Field Ion Microscope for the Study of Vapor Deposition  

NASA Astrophysics Data System (ADS)

A bakable liquid helium vapor cooled field ion microscope suitable for ultrahigh vacuum studies of vapor deposition and thin film growth is described. The features include simplicity of design and economy of operation over the full temperature range down to liquid helium temperature. Movable evaporators allow in situ studies of thin metal films formed by vapor deposition.

Reed, D. A.; Graham, W. R.

1972-09-01

362

Molecular Vapor Deposition - An Improved Vapor-Phase Deposition Technique of Molecular Coatings for MEMS Devices  

Microsoft Academic Search

This paper reports the results of a new surface modification technique called Molecular Vapor Deposition (MVD). The MVD technique is an enhancement of a conventional vapor deposition of ultra-thin organic molecules by incorporating an in-situ surface plasma treatment and the precise delivery of precursor vapors. Properties of the MVD coatings can be tailored and were found to exhibit superior performance

Boris Kobrin; Victor Fuentes; Srikanth Dasaradhi; Richard Yi; Romuald Nowak; Jeff Chinn; Robert Ashurst; Carlo Carraro; Roya Maboudian

2004-01-01

363

Near real time vapor detection and enhancement using aerosol adsorption  

DOEpatents

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.

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

1999-01-01

364

Near real time vapor detection and enhancement using aerosol adsorption  

DOEpatents

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.

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

1999-08-03

365

Multiple overseas dispersal in amphibians  

Microsoft Academic Search

Amphibians are thought to be unable to disperse over ocean barriers because they do not tolerate the osmotic stress of salt water. Their distribution patterns have therefore generally been explained by vicari- ance biogeography. Here, we present compelling evidence for overseas dispersal of frogs in the Indian Ocean region based on the discovery of two endemic species on Mayotte. This

Miguel Vences; D. Rodriguez Vieites; Frank Glaw; Henner Brinkmann; Joachim Kosuch; Michael Veith; Axel Meyer

2003-01-01

366

Preparation of alkali metal dispersions  

NASA Technical Reports Server (NTRS)

A method is described for producing alkali metal dispersions of high purity. The dispersions are prepared by varying the equilibrium solubility of the alkali metal in a suitable organic solvent in the presence of aromatic hydrocarbons. The equilibrium variation is produced by temperature change. The size of the particles is controlled by controlling the rate of temperature change.

Rembaum, A.; Landel, R. F. (inventors)

1968-01-01

367

Dispersal of Anoplophora glabripennis (Cerambycidae)  

Microsoft Academic Search

Asa bas isfor the development of both eradication and management s trategiesfor control of Anoplophora glabripennis Motschulsky (Asian longhorned beetle) investigations of A. glabripennis dispersal were undertaken in Gansu Province, China, in 1999. Data analysis of the Þrst year study of population dispersal, in which 16,000 adult A. glabripennis were marked and released (mass-mark recapture method), has shown that the

Michael T. Smith; Jay Bancroft; Guohong Li; Ruitong Gao; Stephen Teale

2001-01-01

368

Carbon nanotube suspensions, dispersions, & composites  

NASA Astrophysics Data System (ADS)

Carbon Nanotubes (CNTs) are amazing structures that hold the potential to revolutionize many areas of scientific research. CNTs can be behave both as semiconductors and metals, can be grown in highly ordered arrays and patterns or in random orientation, and can be comprised of one graphene cylinder (single wall nanotube, SWNT) or several concentric graphene cylinders (multi-wall nanotube, MWNT). Although these structures are usually only a few nanometers wide, they can be grown up to centimeter lengths, and in massive quantities. CNTs can be produced in a variety of processes ranging from repeated combustion of organic material such as dried grass, arc-discharge with graphite electrodes, laser ablation of a graphitic target, to sophisticated chemical vapor deposition (CVD) techniques. CNTs are stronger than steel but lighter than aluminum, and can be more conductive than copper or semiconducting like silicon. This variety of properties has been matched by the wide variety of applications that have been developed for CNTs. Many of these applications have been limited by the inability of researchers to tame these structures, and incorporating CNTs into existing technologies can be exceedingly difficult and prohibitively expensive. It is therefore the aim of the current study to develop strategies for the solution processing and deposition of CNTs and CNT-composites, which will enable the use of CNTs in existing and emerging technologies. CNTs are not easily suspended in polar solvents and are extremely hydrophobic materials, which has limited much of the solution processing to organic solvents, which also cannot afford high quality dispersions of CNTs. The current study has developed a variety of aqueous CNT solutions that employ surfactants, water-soluble polymers, or both to create suspensions of CNTs. These CNT 'ink' solutions were deposited with a variety of techniques that have afforded many interesting structures, both randomly oriented as well as highly ordered CNT architectures, and electroactive devices such as sensors were subsequently produced from these materials. The aqueous solutions developed contain some of the longest CNTs to be suspended in water, which have many benefits for electronic and mechanical properties of the resultant composite materials. A non-covalent alternative to standard oxidative acid treatment was developed that has an equal ability to suspend CNTs in various solvents, but does not damage the CNT structure like the covalent functionalization with acids. This strategy has the potential to supplant a widely used method with improved CNT properties, faster and safer processing, and reduced environmental impact of waste materials. The results of this work also suggest that the conductivity of the CNTs may actually be improved by the processing, maximizing the utility if these materials. Electroactive devices have been successfully developed that exploit the unique electrical and physical properties of CNTs. Sensitive moisture sensors, which can possibly out-perform existing part per million sensors, have been developed with CNT inks and alumina nanoparticles. These sensor materials can be easily deposited on a wide variety of substrate materials and have an increased resistance to fouling compared to mesoporous sensors currently available. Electric double-layer supercapacitors based on novel cellulose-CNT composites have also been developed, and have commercially viable capacitance values, which make them a competitive technology with applications such as cell phones, computers, hand-held electronics, and possibly even electric automobiles. These supercapacitors employ less hazardous materials than competing technologies, and the ease of production of these devices could enable large-scale production of these materials.

Simmons, Trevor John

369

Hybrid Dispersion Laser Scanner  

PubMed Central

Laser scanning technology is one of the most integral parts of today's scientific research, manufacturing, defense, and biomedicine. In many applications, high-speed scanning capability is essential for scanning a large area in a short time and multi-dimensional sensing of moving objects and dynamical processes with fine temporal resolution. Unfortunately, conventional laser scanners are often too slow, resulting in limited precision and utility. Here we present a new type of laser scanner that offers ?1,000 times higher scan rates than conventional state-of-the-art scanners. This method employs spatial dispersion of temporally stretched broadband optical pulses onto the target, enabling inertia-free laser scans at unprecedented scan rates of nearly 100?MHz at 800?nm. To show our scanner's broad utility, we use it to demonstrate unique and previously difficult-to-achieve capabilities in imaging, surface vibrometry, and flow cytometry at a record 2D raster scan rate of more than 100?kHz with 27,000 resolvable points. PMID:22685627

Goda, K.; Mahjoubfar, A.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.

2012-01-01

370

Modeling volcanic ash dispersal  

ScienceCinema

Explosive volcanic eruptions inject into the atmosphere large amounts of volcanic material (ash, blocks and lapilli). Blocks and larger lapilli follow ballistic and non-ballistic trajectories and fall rapidly close to the volcano. In contrast, very fine ashes can remain entrapped in the atmosphere for months to years, and may affect the global climate in the case of large eruptions. Particles having sizes between these two end-members remain airborne from hours to days and can cover wide areas downwind. Such volcanic fallout entails a serious threat to aircraft safety and can create many undesirable effects to the communities located around the volcano. The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard scenarios and/or to give short-term forecasts during emergency situations. This talk will be focused on the main aspects related to modeling volcanic ash dispersal and fallout with application to the well known problem created by the Eyjafjöll volcano in Iceland. Moreover, a short description of the main volcanic monitoring techniques is presented.

None

2011-10-06

371

Experimental study of flash boiling spray vaporization through quantitative vapor concentration and liquid temperature measurements  

NASA Astrophysics Data System (ADS)

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.

Zhang, Gaoming; Hung, David L. S.; Xu, Min

2014-08-01

372

Eyeing the Sky's Water Vapor  

NASA Technical Reports Server (NTRS)

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

2008-01-01

373

Does Air Contain Water Vapor?  

NSDL National Science Digital Library

In this activity, students monitor the change that takes place when water vapor condenses from a gas to a liquid and see how a change in temperature affects this transformation. Materials needed to conduct the investigation include two thermometers, a clear glass container, ice cubes and tap water. The resource includes background information, teaching tips and questions to guide student discussion. This is chapter 10 of Meteorology: An Educator's Resource for Inquiry-Based Learning for Grades 5-9. The guide includes a discussion of learning science, the use of inquiry in the classroom, instructions for making simple weather instruments, and more than 20 weather investigations ranging from teacher-centered to guided and open inquiry investigations.

374

Quantitative organic vapor-particle sampler  

DOEpatents

A quantitative organic vapor-particle sampler for sampling semi-volatile organic gases and particulate components. A semi-volatile organic reversible gas sorbent macroreticular resin agglomerates of randomly packed microspheres with the continuous porous structure of particles ranging in size between 0.05-10 .mu.m for use in an integrated diffusion vapor-particle sampler.

Gundel, Lara (Berkeley, CA); Daisey, Joan M. (Walnut Creek, CA); Stevens, Robert K. (Cary, NC)

1998-01-01

375

8, 44834498, 2008 Water vapor release  

E-print Network

monoxide and carbon dioxide are used to scale the concentra- tions of water vapor found, and are compared We report on the emission of water vapor from biofuel combustion. Concurrent mea- surements of carbon to carbon in the biofuel. Fuel types included hardwood (oak and African musasa), softwood (pine and spruce

Paris-Sud XI, Université de

376

Recover heat by mechanical vapor recompression  

Microsoft Academic Search

Several examples illustrating recompression of head vapors for heating the reboiler of a distillation tower are presented. The advantages of the mechanical vapor recompression system using a screw compressor are discussed in detail. The system is economically attractive with simple payback periods often less than two years. Numerous studies have identified a number of alternatives for lowering energy consumption in

F. E. Becker; A. I. Zakak

1985-01-01

377

IN SITU SOIL VAPOR EXTRACTION TREATMENT  

EPA Science Inventory

Soil vapor extraction (SVE) is designed to physically remove volatile compounds, generally from the vadose or unsaturated zone. t is an in situ process employing vapor extraction wells alone or in combination with air injection wells. acuum blowers supply the motive force, induci...

378

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...

379

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...

380

Environmental Chemistry at Vapor/Water Interfaces  

E-print Network

Environmental Chemistry at Vapor/Water Interfaces: Insights from Vibrational Sum Frequency for manyyearsowingtoitscomplexityandimportanceindescribingawiderange of physical phenomena. The vapor/water interface is particularly interesting from an environmental chemistry perspective as this surface plays host to a wide range of chemistries that influence atmospheric

381

Effect of impact angle on vaporization  

Microsoft Academic Search

Impacts into easily vaporized targets such as dry ice and carbonates generate a rapidly expanding vapor cloud. Laboratory experiments performed ,n a tenuous atmosphere allow deriving the internal energy of this cloud through well-established and tested theoretical descriptions. A second set of experiments under near-vacuum conditions provides a second measure of energy as the internal energy converts to kinetic energy

Peter H. Schultz

1996-01-01

382

Applied Magnetic Field Enhances Arc Vapor Deposition  

NASA Technical Reports Server (NTRS)

Applied magnetic field enhances performance of vaporization part of arc vapor deposition apparatus. When no magnetic field applied by external means, arc wonders semirandomly over cathode, with net motion toward electrical feedthrough. When magnetic field applied arc moves circumferentially around cathode, and downward motion suppressed.

Miller, T. A.; Loutfy, R. O.; Withers, J. C.

1993-01-01

383

High bandwidth vapor density diagnostic system  

DOEpatents

A high bandwidth vapor density diagnostic system for measuring the density of an atomic vapor during one or more photoionization events. The system translates the measurements from a low frequency region to a high frequency, relatively noise-free region in the spectrum to provide improved signal to noise ratio.

Globig, Michael A. (Antioch, CA); Story, Thomas W. (Oakley, CA)

1992-01-01

384

Challenges for ionized physical vapor deposition  

Microsoft Academic Search

Summary form only given. Vapor deposition using ionic species has several advantages over neutral vapor deposition methods. These include the ability to use the electric field within the plasma sheath to modify the energy and direction of the depositing particle. Energetic deposition allows one to produce thin film materials with tailored properties. The control of particle direction, on the other

J. A. Hopwood; D. Mao

2004-01-01

385

Parabolic pulse generation in a dispersion-decreasing solid-core photonic bandgap Bragg fiber  

NASA Astrophysics Data System (ADS)

We analyze the interplay of nonlinearity and dispersion in a dispersion-decreasing photonic bandgap Bragg fiber as a new platform for generating parabolic pulses. A suitably designed linearly tapered, low-index-contrast, solid-core Bragg fiber - amenable to fabrication by conventional modified chemical vapor deposition technology - is shown to yield stable parabolic pulses. The fiber design was optimized through a simple and accurate transfer-matrix formalism and pulse evolution was studied by the well-known split-step Fourier method. Our study revealed feasibility of generating parabolic pulses in such a dispersion-decreasing Bragg fiber of length as short as 1 m. We have also studied the effect of third order dispersion on generated parabolic pulse, which is an important deteriorating factor in such applications. The effective single-mode operation of the proposed device is achieved through appropriate tailoring of the outer cladding layers.

Nagaraju, B.; Varshney, R. K.; Agrawal, Govind P.; Pal, Bishnu P.

2010-06-01

386

Stacked vapor fed amtec modules  

DOEpatents

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.

Sievers, Robert K. (North Huntingdon, PA)

1989-01-01

387

Condensation coefficient of methanol vapor near vapor-liquid equilibrium states  

NASA Astrophysics Data System (ADS)

This paper is concerned with the nonequilibrium condensation from a vapor to a liquid phase on the plate endwall of a shock tube behind a reflected shock wave. The growth of a liquid film on the endwall is measured by an optical interferometer using a laser beam. The experiment is carefully conducted on the precisely designed apparatus, and thereby the condensation coefficient of methanol vapor is determined in a wide range of vapor-liquid conditions from near to far from equilibrium states. The result shows that the condensation coefficient increases with the increase of the ratio of number densities of vapor and saturated vapor at the interface.

Fujikawa, S.; Yano, T.; Ichijo, M.; Iwanami, K.

388

Natal Dispersal by Pygmy Rabbits (Brachylagus idahoensis)  

Microsoft Academic Search

Multiple factors likely influence natal dispersal behavior of juvenile mammals, which is typically male-biased. Because of their small body size and specific habitat requirements, pygmy rabbits (Brachylagus idahoensis) are expected to exhibit limited dispersal. We predicted that dispersal would be male-biased, that juveniles born later in the year would disperse farther, and that juveniles would be more likely to disperse

Wendy A. Estes-Zumpf; Janet L. Rachlow

2009-01-01

389

Acne Resolution Rates: Results of a Single-Blind, Randomized, Controlled, Parallel Phase III Trial with EE\\/CMA (Belara®) and EE\\/LNG (Microgynon®)  

Microsoft Academic Search

Background and Objective: Acne in women can often be successfully treated by the intake of oral contraceptives containing gestagens with anti-androgenic properties. This study aimed to evaluate the efficacy of the monophasic oral contraceptive ethinylestradiol\\/chlormadinone acetate (EE\\/CMA; Belara®) for the treatment of mild to moderate papulopustular acne of the face and acne-related disorders in comparison to EE\\/levonorgestrel (LNG; Microgynon®). Methods:

I. Worret; W. Arp; H.-P. Zahradnik; J.-O. Andreas; N. Binder

2001-01-01

390

Migration of dispersive GPR data  

USGS Publications Warehouse

Electrical conductivity and dielectric and magnetic relaxation phenomena cause electromagnetic propagation to be dispersive in earth materials. Both velocity and attenuation may vary with frequency, depending on the frequency content of the propagating energy and the nature of the relaxation phenomena. A minor amount of velocity dispersion is associated with high attenuation. For this reason, measuring effects of velocity dispersion in ground penetrating radar (GPR) data is difficult. With a dispersive forward model, GPR responses to propagation through materials with known frequency-dependent properties have been created. These responses are used as test data for migration algorithms that have been modified to handle specific aspects of dispersive media. When either Stolt or Gazdag migration methods are modified to correct for just velocity dispersion, the results are little changed from standard migration. For nondispersive propagating wavefield data, like deep seismic, ensuring correct phase summation in a migration algorithm is more important than correctly handling amplitude. However, the results of migrating model responses to dispersive media with modified algorithms indicate that, in this case, correcting for frequency-dependent amplitude loss has a much greater effect on the result than correcting for proper phase summation. A modified migration is only effective when it includes attenuation recovery, performing deconvolution and migration simultaneously.

Powers, M. H.; Oden, C. P.

2004-01-01

391

Vaporization and Autoignition Characteristics of Ethanol and 1-  

E-print Network

Vaporization and Autoignition Characteristics of Ethanol and 1- propanol Droplets: Influence vaporization, which involves heat, mass and momentum transfer processes in gas and liquid phases to improve efficiency of internal combustion engines generally. Both vaporization and autoigni- tion

Paris-Sud XI, Université de

392

The impact of vaporized nanoemulsions on ultrasound-mediated ablation  

PubMed Central

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

2013-01-01

393

Velocity Dispersions Across Bulge Types  

SciTech Connect

We present first results from a long-slit spectroscopic survey of bulge kinematics in local spiral galaxies. Our optical spectra were obtained at the Hobby-Eberly Telescope with the LRS spectrograph and have a velocity resolution of 45 km/s (sigma*), which allows us to resolve the velocity dispersions in the bulge regions of most objects in our sample. We find that the velocity dispersion profiles in morphological classical bulge galaxies are always centrally peaked while the velocity dispersion of morphologically disk-like bulges stays relatively flat towards the center--once strongly barred galaxies are discarded.

Fabricius, Maximilian; Bender, Ralf; Hopp, Ulrich [University Observatory of the Ludwig-Maximilians University (LMU) (Germany); Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Saglia, Roberto; Drory, Niv [Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Fisher, David [Department of Astronomy, University of Texas at Austin (United States)

2010-06-08

394

The effect of the London-van der Waals dispersion force on interline heat transfer  

NASA Technical Reports Server (NTRS)

A theoretical procedure to determine the heat transfer characteristics of the interline region (junction of liquid-solid-vapor) from the macroscopic optical and thermophysical properties of the system is outlined. The analysis is based on the premise that the interline transport processes are controlled by the London-van der Waals dispersion force between condensed phases (solid and liquid). Numerical values of the dispersion constant are presented. The procedure is used to compare the relative size of the interline heat sink of various systems using a constant heat flux mode. This solution demonstrates the importance of the interline heat flow number, which is evaluated for various systems.

Wayner, P. C., Jr.

1978-01-01

395

Fractional reproduction-dispersal equations and heavy tail dispersal kernels.  

PubMed

Reproduction-Dispersal equations, called reaction-diffusion equations in the physics literature, model the growth and spreading of biological species. Integro-Difference equations were introduced to address the shortcomings of this model, since the dispersal of invasive species is often more widespread than what the classical RD model predicts. In this paper, we extend the RD model, replacing the classical second derivative dispersal term by a fractional derivative of order 1dispersal kernel. The general theory developed here accommodates a wide variety of infinitely divisible dispersal kernels that adapt to any scale. Each one corresponds to a generalised RD model with a different dispersal operator. The connection established here between RD and ID equations can also be exploited to generate convergent numerical solutions of RD equations along with explicit error bounds. PMID:17546475

Baeumer, Boris; Kovács, Mihály; Meerschaert, Mark M

2007-10-01

396

Water vapor retrieval from OMI visible spectra  

NASA Astrophysics Data System (ADS)

There are distinct spectral features of water vapor in the wavelength range covered by the Ozone Monitoring Instrument (OMI) visible channel. Although these features are much weaker than those at longer wavelengths, they can be exploited to retrieve useful information about water vapor. They have an advantage in that their small optical depth leads to fairly simple interpretation as measurements of the total water vapor column density. We have used the Smithsonian Astrophysical Observatory (SAO) OMI operational retrieval algorithm to derive the slant column density (SCD) of water vapor using the 430-480 nm spectral region after extensive optimization. We convert from SCD to vertical column density (VCD) using the air mass factor (AMF), which is calculated using look-up tables of scattering weights and assimilated water vapor profiles. Our Level 2 product includes not only water vapor VCD but also the associated scattering weights and AMF. In the tropics, our standard water vapor product has a median SCD of 1.3 × 1023 molecules cm-2 and a median relative uncertainty of about 11%, about a factor of 2 better than that from a similar OMI algorithm that uses a narrower retrieval window. The corresponding median VCD is about 1.2 × 1023 molecules cm-2. We have examined the sensitivities of SCD and AMF to various parameters and compared our results with those from the GlobVapour product, the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic NETwork (AERONET).

Wang, H.; Liu, X.; Chance, K.; González Abad, G.; Miller, C. Chan

2014-06-01

397

Vaporization of perfluorocarbon droplets using optical irradiation  

PubMed Central

Micron-sized liquid perfluorocarbon (PFC) droplets are currently being investigated as activatable agents for medical imaging and cancer therapy. After injection into the bloodstream, superheated PFC droplets can be vaporized to a gas phase for ultrasound imaging, or for cancer therapy via targeted drug delivery and vessel occlusion. Droplet vaporization has been previously demonstrated using acoustic methods. We propose using laser irradiation as a means to induce PFC droplet vaporization using a method we term optical droplet vaporization (ODV). In order to facilitate ODV of PFC droplets which have negligible absorption in the infrared spectrum, optical absorbing nanoparticles were incorporated into the droplet. In this study, micron-sized PFC droplets loaded with silica-coated lead sulfide (PbS) nanoparticles were evaluated using a 1064 nm laser and ultra-high frequency photoacoustic ultrasound (at 200 and 375 MHz). The photoacoustic response was proportional to nanoparticle loading and successful optical droplet vaporization of individual PFC droplets was confirmed using photoacoustic, acoustic, and optical measurements. A minimum laser fluence of 1.4 J/cm2 was required to vaporize the droplets. The vaporization of PFC droplets via laser irradiation can lead to the activation of PFC agents in tissues previously not accessible using standard ultrasound-based techniques. PMID:21698007

Strohm, Eric; Rui, Min; Gorelikov, Ivan; Matsuura, Naomi; Kolios, Michael

2011-01-01

398

The Dispersal of Protoplanetary Disks  

E-print Network

Protoplanetary disks are the sites of planet formation, and the evolution and eventual dispersal of these disks strongly influences the formation of planetary systems. Disk evolution during the planet-forming epoch is driven by accretion and mass-loss due to winds, and in typical environments photoevaporation by high-energy radiation from the central star is likely to dominate final gas disk dispersal. We present a critical review of current theoretical models, and discuss the observations that are used to test these models and inform our understanding of the underlying physics. We also discuss the role disk dispersal plays in shaping planetary systems, considering its influence on both the process(es) of planet formation and the architectures of planetary systems. We conclude by presenting a schematic picture of protoplanetary disk evolution and dispersal, and discussing prospects for future work.

Alexander, Richard; Andrews, Sean; Armitage, Philip; Cieza, Lucas

2013-01-01

399

MOVEMENT, FIDELITY AND DISPERSAL OF  

E-print Network

Department, 4200 Smith School Road, Austin, TX 78744, USA Abstract: Wild turkey (Meleagris gallopavo) studies of the National Wild Turkey Symposium 9:149­157 Key words: dispersal, emigration, Meleagris gallopavo intermedia

400

Dispersion-strengthened chromium alloy  

NASA Technical Reports Server (NTRS)

Finely divided powder mixture produced by vapor deposition of CR on small ThO2 particles was hot pressed or pressure bonded. Resulting alloy has lower ductile-to-brittle transition temperature than pure chromium, and high strength and oxidation resistance at elevated temperatures, both in as-rolled condition and after annealing.

Blocker, J. M., Jr.; Veigel, N. D.

1972-01-01

401

Automated Test Systems for Toxic Vapor Detectors  

NASA Technical Reports Server (NTRS)

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.

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

402

Automated Test Systems for Toxic Vapor Detectors  

NASA Technical Reports Server (NTRS)

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.

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

403

Pigment Dispersion Syndrome - Update 2003  

Microsoft Academic Search

\\u000a Pigment dispersion syndrome (PDS) is a unique and fascinating entity. It is far more prevalent, actually by an order of magnitude,\\u000a than previously suspected, comprising 2.45% of the screened Caucasian population in one study [76]. PDS and pigmentary glaucoma (PG) are characterized by disruption of the iris pigment epithelium (IPE) and deposition of\\u000a the dispersed pigment granules throughout the anterior

Robert Ritch

404

Florida panther dispersal and conservation  

Microsoft Academic Search

We studied dispersal in 27 radio-collared Florida panthers Puma concolor coryi in southern Florida from 1986 to 2000. Male dispersal was longer (mean=68.4 km) than that of females (mean=20.3 km), tended to be circular, frustrated, and of insufficient length to ameliorate inbreeding. Females were philopatric and established home ranges that were less than one home range width away from their

David S. Maehr; E. Darrell Land; David B. Shindle; Oron L. Bass; Thomas S. Hoctor

2002-01-01

405

Neutrino dispersion in magnetized plasma  

E-print Network

The neutrino dispersion in the charge symmetric magnetized plasma is investigated. We have studied the plasma contribution into the additional energy of neutrino and obtained the simple expression for it. We consider in detail the neutrino self-energy under physical conditions of weak field, moderate field and strong field limits. It is shown that our result for neutrino dispersion in moderate magnetic field differ substantially from the previous one in the literature.

N. V. Mikheev; E. N. Narynskaya

2008-12-02

406

Mathematical Modeling and Experimental Investigation of Heavier-Than Gas Dispersion in the Atmosphere  

NASA Astrophysics Data System (ADS)

The mathematical modeling methods which have been proposed for prediction of dispersion of heavier-than-air gases (HTAG) are reviewed. The phenomenology of atmospheric dispersion of HTAG is described, and the general HTAG dispersion scenario is considered to involve three phases: (1) Negative buoyancy-dominated flow; (2) Stably stratified shear flow; (3) Passive diffusion due to atmospheric turbulence. Modeling concepts based on investigations of laboratory experiments are used to describe the flow and dilution processes that characterize the negative buoyancy regime. Laboratory measurements of the spreading and dilution of HTAG volumes released suddenly in calm air have demonstrated scaling methods for small releases from 35 to 530 liters, and the scaled laboratory releases are in good agreement with the experimental data from the Thorney Island 2000 m('3) releases. The laboratory releases are modeled using a radial momentum balance and a box model approach with dilution during the gravity spreading phase represented by a frontal entrainment velocity. Experimental laboratory data on stratified shear flow mixing from McQuaid (1976), Kantha et al. (1977), and Lofquist (1960) are used to model the vertical diffusion of HTAG in the atmospheric constant stress layer. The approach is consistent with the limiting passive dispersion behavior of demonstrated air pollution models. An interactive computer model (DEGADIS) is developed which can be used to simulate a wide variety of HTAG release scenarios including instantaneous releases, time-varying releases, and continuous releases on a flat, obstacle-free surface. The model accounts for the three regimes of dispersion stated above and provides for effects due to energy exchange between the dispersing cloud and the underlying surface. DEGADIS -predicted maximum concentration as a function of distance is compared to the maximum reported concentration for field scale releases of liquefied natural gas (LNG), liquefied petroleum gas (LPG), and Freon-12/air mixtures from the Burro/Coyote, Maplin Sands, and Thorney Island trials, representing the range of currently available field scale data. Based upon this comparison, the variability of the distance realized to a concentration level of 5, 2-1/2, or 1% for a given release is quantified based on the predicted distance.

Spicer, Thomas O.

407

Measuring Water Vapor with Differential Absorption Lidar  

NASA Astrophysics Data System (ADS)

Despite the need for global measurements of water vapor profiles with low bias and high vertical resolution there is currently no operational remote sensing system that would deliver such data. A possible solution to this problem is offered by the differential absorption lidar (DIAL) approach. The basic principle of operation will be described and some background on atmospheric light absorption by water vapor will be given. DLR's airborne water vapor DIAL system WALES represents the currently most advanced system worldwide using a multiwavelength technique to cover the troposphere and lower stratosphere simultaneously. A few examples of measurements made with this system will illustrate the power of this active remote sensing method.

Wirth, Martin

408

The vapor pressure of iron pentacarbonyl  

NASA Technical Reports Server (NTRS)

Vapor pressure measurements have been made on pure iron pentacarbonyl between +31 and -19 C. The experimental results may be expressed by the logarithm of pressure (mm Hg) to the base 10 equals -(2096.7 K/T) + 8.4959, which corresponds to a heat of vaporization for the liquid carbonyl of delta H ? (9.588 plus or minus 0.12) kcal/mole. This result confirms and extends the earlier measurements made by Trautz and Badstuebner between 0 and 140 C. The need for careful purification of commercially available iron pentacarbonyl is emphasized, particularly for establishing the correct vapor pressure below 45 C.

Gilbert, A. G.; Sulzmann, K. G. P.

1974-01-01

409

Biological vapor-phase treatment  

SciTech Connect

The biological treatment of VOCs and air toxics has received increased attention in recent years. Biotreatment of air-borne contaminants offers an inexpensive alternative to conventional air treatment technologies such as carbon adsorption and incineration. Most biological air treatment technologies commercially available are fixed-film systems that rely on growth of a liquid biofilm layer on an inert organic support such as compost or peat (biofilters), or an inorganic support such as ceramic or plastic (biotrickling filters). If designed properly, these systems combine the advantages of high biomass concentration with high specific surface area for mass transfer. Alternatively, suspended culture biotreatment systems analogues to wet scrubbers, bubble columns, and spray chambers can also be applied to vapor-phase problems. In this study, the biological treatment of a variety of VOCs and VOC mixture using biofilters and biotrickling filters is investigated, with emphasis on the practical operating regimes of these two systems. In addition, the operating regimes and limitations of suspended culture biotreatment systems are also addressed.

Togna, A.P.; Singh, M. [ENVIROGEN, Inc., Lawrenceville, NJ (United States)

1993-12-31

410

Discharge excitation of dye vapors  

NASA Astrophysics Data System (ADS)

Experiments have been conducted to assess the feasibility of obtaining a discharge-pumped dye vapor laser. A 15 (or 50) cm active length, UV-preionized device has been developed which exhibits a specific power loading of the medium of approx. 5 MW/cu cm and will operate continuously at temperatures exceeding 400 C. Recently, hydrogen thyratron switching of the device and corona preionization have been installed to minimize jitter and dye fragmentation. Optimization of the rare gas/N2 diluent mixture has been completed and fragmentation studies for several dye molecules have been conducted. POPOP and alpha-NPO are excellent in the latter regard but Coumarin 6 rapidly decomposes in the discharge environment. The fluorescence efficiency of alpha-NPO is only 40 percent of that for POPOP under comparable conditions. BBO and PBBO are similar in structure and molecular weight to POPOP and appear to be excellent candidates for discharge excitation. Fluorescence and small signal gain measurements are in progress.

Eden, J. G.

1987-09-01

411

Fundamentals of Chemical Vapor Deposition  

NSDL National Science Digital Library

This web page offers a tutorial by Daniel M. Dobkin, Ph.D, proprietor of Enigmatics Consulting of Sunnyvale, California that introduces fundamental principles of chemical vapor deposition of films. Topics covered include CVD Basics, Review of Ideal Gases, Review of Kinetic Theory, Zero-Dimensional Transport: Stirred Reactor, Transport in Gaseous Media, Chemistry for CVD, Plasmas for CVD, CVD Films, and CVD Reactor Designs. According to the author, "The tutorial assumes a general background roughly equivalent to a BS degree in the physical sciences. The aspects of thermodynamics, statistical mechanics, chemistry, and electromagnetism needed for understanding CVD processes are reviewed here, but only in sufficient depth to remind the reader of a past acquaintance with the topicsÃÂ. Some knowledge of the basics of semiconductor manufacturing is also helpful in following the discussion of films and applications." Visitors are free to copy and use any materials in the site, so long as licensing conditions stipulated by Creative Commons are met. (Details of the license can be found by clicking on a hyperlink to Creative Commons.)

Dobkin, Daniel M.

2012-12-11

412

Microwave assisted chemical vapor infiltration  

SciTech Connect

The purpose of this program is to develop a new process for the fabrication of ceramic matrix composites by chemical vapor infiltration. This period has been devoted in part to the exploration of material systems suitable for MACVI processing. A number of potential processing schemes are possible using combinations of absorbing and transparent material as composite components. This includes the use of an absorbing preform (nicalon fiber) combined with a transparent matrix (silicon nitride). Composites 5 cm in diameter by 1 cm. thick have been fabricated to densities of 65% theoretical. Processing times for these materials are under 20 hours. Higher densities will require additional microwave power now possible with the new reactor. The most effective MACVI scheme will involve the use of a transparent fiber with an absorbing matrix. The hot spot will be initiated by appropriate treatment of the central region of the preform. To this end alumna fibers with pretreatments to control thermal gradients has been explored. Nextel 610 fibers have been effectively pretreated carbon coating resulting in preferential heating in the interior of the preform. Possible matrix materials include siliconized silicon carbide, doped silicon carbide, alumna and zirconia. A patent for MACVI has been issued 10/19/93.

Devlin, D.J.

1993-12-31

413

Modeling of chemical vapor infiltration  

SciTech Connect

Ceramic matrix composites can be fabricated by chemical vapor infiltration (CVI) of a fibrous preform. In conventional processing, the reactant gases diffuse into the preform under isothermal conditions, depositing material onto the fibers and forming a continuous matrix as coating thickness increases. This technique usually requires several weeks to achieve high density. Recent development of a forced flow, thermal gradient technique can reduce infiltration time to several hours. While successful composites have been produced, understanding of the process and its critical parameters is incomplete. In order to gain this insight an analytical model of this process is being developed. The developed CVI model will simulate the infiltration process based on input of the controlling process parameters and preform properties. Providing detailed information on the composition of the partially dense composite throughout the process period, the model will allow rapid selection of optimum processing conditions for a particular preform. Beyond this, the model also can be used to design the preform (geometry and fiber architecture) and the infiltration reactor. The CVI model is developed based on fundamentals of mass and heat transport and on the microstructure and physical properties of the preform and matrix materials. 36 refs., 28 figs., 2 tabs.

Starr, T.L.

1989-02-01

414

Particle/vapor concentrations and distributions of PAHs in the atmosphere of southern Chesapeake Bay  

SciTech Connect

Atmospheric PAH concentrations were measured at four sites characterized as rural (Haven Beach), semiurban (York River), urban (Hampton), and industrialized (Elizabeth River) areas as part of a study to quantify gaseous exchange fluxes across the air-water interface of southern Chesapeake Bay. Aerosol particle-associated PAH concentrations were similar at all sites; however, PAH vapor concentrations in the urban areas were as much as a factor of 50 greater than those at the rural site. Mean total PAH concentrations ranged from 7.87 ng/m{sup 3} at the rural site to 92.8 ng/m{sup 3} at the urban site. Daily total PAH concentrations ranged from 1.60 to 198 ng/m{sup 3}. Exponential increases in PAH vapor concentrations with temperature were observed at the non-rural sites, suggesting volatilization from contaminated surfaces during warmer weather; whereas PAH vapor concentrations at the rural Haven Beach site exhibited little seasonal variability. Aerosol particle-associated PAH levels were similar at all sites and increased in winter due to the temperature dependence of vapor-particle partitioning, increased sources from combustion of fossil fuel and wood for home heating, and cold condensation of source vapors to background aerosols as air masses are dispersed to remote regions. Plots of log K{sub d} vs. log P{sub sat,SC1} indicate PAH partitioning is not at equilibrium in rural areas of Southern Chesapeake Bay. In addition, plots of log K{sub d} vs. 1/T for individual PAHs indicate difference particle characteristics or partitioning processes influence particle/vapor distributions at the urban and rural sites.

Gustafson, K.E. [Univ. of West Florida, Pensacola, FL (United States). Inst. for Coastal and Estuarine Research; Dickhut, R.M. [Coll. of William and Mary, Gloucester Point, VA (United States)

1995-12-31

415

Excitation spectrum of the vapor-liquid sup 4 He interface  

SciTech Connect

We analyze the elementary excitations in a vapor-liquid {sup 4}He interface with planar symmetry under saturation conditions. They are characterized by a momentum {h bar}{bold q} parallel to the interface plane and may be described by bound or continuum states. The wave functions of bound states are confined to the interface region. The continuum states may be described by their properties in the asymptotic region far apart from the interface layer. There, they are representing plane waves with momentum {h bar}{bold q}{sub {ital L}} and/or {h bar}{bold q}{sub {ital V}} vertical to the interface plane. The dispersion of these waves is determined by the energy-momentum relation in bulk liquid or vapor {sup 4}He. We may distinguish liquid, vapor, or vapor-liquid continuum states. The wave functions and energies are numerically evaluated in a generalized Feynman approximation, at various temperatures, 0{le}{ital T}{le}2 K. At nonvanishing temperatures, the wave functions of bound states represent rotons with wave number {ital q}{congruent}{ital q}{sub {ital R}}=1.8 A {sup {minus}1} trapped in the interface layer. At zero temperature, bound states appear at any wave number 0.2 A {sup {minus}1}{le}{ital q}{le}{ital q}{sub {ital R}} describing excitations of the free {sup 4}He surface. At temperatures 0{lt}{ital T}{le}1.5 K, the numerical results show that there are resonant vapor continuum states that have a very small amplitude in the asymptotic vapor region but develop an anomalously large amplitude in the interface layer. Our results on the excitation energies and on the corresponding wave functions in the interface region are displayed in a series of figures and are discussed in detail.

Gernoth, K.A.; Ristig, M.L. (Institut fuer Theoretische Physik, Universitaet zu Koeln, D-5000 Koeln 41 (Germany))

1992-02-01

416

Foreword for Non-Dispersive Infrared (NDIR) Gas Measurement Today  

SciTech Connect

Infrared spectroscopy provides the analytical laboratory with essential capabilities to identify and to quantify components of gas mixtures in a relatively straightforward manner. Except for symmetric diatomic species, most molecules are 'IR active' that is, they absorb IR light at specific energies associated with that molecule's vibrational and rotation modes. Simple molecules have a few predominant absorption energies and are easy to identify, while more complicated molecules with many bonds have many absorption peaks. To cover the full range of possible absorption energies, laboratory instruments initially employed dispersive elements, typically gratings, to scan over the wavelengths of interest. Today, Fourier-transform infrared (FTIR) spectroscopy has replaced most dispersive IR spectrometry due to improvements in speed and the signal-to-noise ratio but at the expense of instrumental complexity. The impressive analytical power of IR spectroscopy can be distilled into a tiny sensor for a restricted, but nevertheless very useful, set of chemical vapors. Non-dispersive infrared (NDIR) sensors use bandpass filters to select one, or at most a few, energy bands corresponding absorption by carbon dioxide, water, hydrocarbons, etc. Although the concept is simple, the task has proved to be elusive for constructing an NDIR sensor that maintains its calibration in spite of aging and environmental factors. Over the past four decades, Dr. Wong has been on the quest to perfect NDIR sensing, yet in very practical designs. This book reflects his journey, and more recently that of his coauthor, to do just that.

Warmack, Robert J Bruce [ORNL

2012-01-01

417

Safety, efficacy and patient acceptability of the contraceptive and non-contraceptive uses of the LNG-IUS  

PubMed Central

Intrauterine devices (IUDs) provide highly effective, long-term, safe, reversible contraception, and are the most widely used reversible contraceptive method worldwide. The levonorgestrel-releasing intrauterine system (LNG-IUS) is a T-shaped IUD with a steroid reservoir containing 52 mg of levonorgestrel that is released at an initial rate of 20 ?g daily. It is highly effective, with a typical-use first year pregnancy rate of 0.1% – similar to surgical tubal occlusion. It is approved for 5 years of contraceptive use, and there is evidence that it can be effective for up to 7 years of continuous use. After removal, there is rapid return to fertility, with 1-year life-table pregnancy rates of 89 per 100 for women less than 30 years of age. Most users experience a dramatic reduction in menstrual bleeding, and about 15% to 20% of women become amenorrheic 1 year after insertion. The device’s strong local effects on the endometrium benefit women with various benign gynecological conditions such as menorrhagia, dysmenorrhea, leiomyomata, adenomyosis, and endometriosis. There is also evidence to support its role in endometrial protection during postmenopausal estrogen replacement therapy, and in the treatment of endometrial hyperplasia. PMID:21072274

Bednarek, Paula H; Jensen, Jeffrey T

2010-01-01

418

Chemical vapor infiltration using microwave energy  

DOEpatents

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.

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

419

Chemical vapor deposition of functionalized isobenzofuran polymers  

E-print Network

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 ...

Olsson, Ylva Kristina

2007-01-01

420

Colorometric detection of ethylene glycol vapor  

NASA Technical Reports Server (NTRS)

Very low concentrations of ethylene glycol in air or other gases are detected by passing a sample through a glass tube with three partitioned compartments containing reagents which successively convert the ethylene glycol vapor into a colored compound.

Helm, C.; Mosier, B.; Verostko, C. E.

1970-01-01

421

AVIRIS Spectrometer Maps Total Water Vapor Column  

NASA Technical Reports Server (NTRS)

Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) processes maps of vertical-column abundances of water vapor in atmosphere with good precision and spatial resolution. Maps provide information for meteorology, climatology, and agriculture.

Conel, James E.; Green, Robert O.; Carrere, Veronique; Margolis, Jack S.; Alley, Ronald E.; Vane, Gregg A.; Bruegge, Carol J.; Gary, Bruce L.

1992-01-01

422

Designing polymer surfaces via vapor deposition  

E-print Network

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 ...

Asatekin, Ayse

423

Impact vaporization: Late time phenomena from experiments  

NASA Technical Reports Server (NTRS)

While simple airflow produced by the outward movement of the ejecta curtain can be scaled to large dimensions, the interaction between an impact-vaporized component and the ejecta curtain is more complicated. The goal of these experiments was to examine such interaction in a real system involving crater growth, ejection of material, two phased mixtures of gas and dust, and strong pressure gradients. The results will be complemented by theoretical studies at laboratory scales in order to separate the various parameters for planetary scale processes. These experiments prompt, however, the following conclusions that may have relevance at broader scales. First, under near vacuum or low atmospheric pressures, an expanding vapor cloud scours the surrounding surface in advance of arriving ejecta. Second, the effect of early-time vaporization is relatively unimportant at late-times. Third, the overpressure created within the crater cavity by significant vaporization results in increased cratering efficiency and larger aspect ratios.

Schultz, P. H.; Gault, D. E.

1987-01-01

424

Rubidium "whiskers" in a vapor cell  

E-print Network

Crystals of metallic rubidium are observed ``growing'' from paraffin coating of buffer-gas-free glass vapor cells. The crystals have uniform square cross-section, $\\approx 30 \\mu$m on the side, and reach several mm in length.

M. V. Balabas; A. O. Sushkov; D. Budker

2006-11-26

425

Chemical vapor deposition of antimicrobial polymer coatings  

E-print Network

There is large and growing interest in making a wide variety of materials and surfaces antimicrobial. Initiated chemical vapor deposition (iCVD), a solventless low-temperature process, is used to form thin films of polymers ...

Martin, Tyler Philip, 1977-

2007-01-01

426

Perfluorocarbon vapor tagging of blasting cap detonators  

DOEpatents

A plug for a blasting cap is made of an elastomer in which is dissolved a perfluorocarbon. The perfluorocarbon is released as a vapor into the ambient over a long period of time to serve as a detectable taggant.

Dietz, Russell N. (Shoreham, NY); Senum, Gunnar I. (Patchogue, NY)

1981-01-01

427

Refractory Metal Coatings by Chemical Vapor Deposition.  

National Technical Information Service (NTIS)

The basic processes necessary to manufacture refractory metal coatings using chemical vapor deposition technology were investigated. The processes developed were demonstrated on a typical oxidation resistant coating of titanium-chromium-silicon but would ...

G. F. Wakefield

1966-01-01

428

Vapor-liquid turbine expansion engines  

Microsoft Academic Search

In the last years vapor-liquid turbine expansion engines have been developed and manufactured at the Geliimash Joint Stock Company, which work on the boiling up of a stream of a cryogenic fluid in the flow-through section of the turbine expansion engine. It is characteristic for a vapor-liquid turbine expansion engine (VLT) that the line of the expansion process intersects the

I. A. Davydenkov; A. B. Davydov; G. A. Perestoronin

1995-01-01

429

Metal Vapor Arcing Risk Assessment Tool  

NASA Technical Reports Server (NTRS)

The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

Hill, Monika C.; Leidecker, Henning W.

2010-01-01

430

Solar-powered alkali metal vapor lasers  

NASA Technical Reports Server (NTRS)

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.

Blount, Charles E.

1989-01-01

431

Studies of oscillatory combustion and fuel vaporization  

NASA Technical Reports Server (NTRS)

Research projects involving oscillatory combustion and fuel vaporization are reported. Comparisons of experimental and theoretical droplet vaporization histories under ambient conditions such that the droplet may approach its thermodynamic critical point are presented. Experimental data on instantaneous heat transfer from a gas to a solid surface under conditions of oscillatory pressure with comparisons to an unsteady one-dimensional model are analyzed. Droplet size and velocity distribution in a spray as obtained by use of a double flash fluorescent method were investigated.

Borman, G. L.; Myers, P. S.; Uyehara, O. A.

1972-01-01

432

Anthropogenic water vapor emissions in Tokyo  

NASA Astrophysics Data System (ADS)

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.

Moriwaki, Ryo; Kanda, Manabu; Senoo, Hiroshi; Hagishima, Aya; Kinouchi, Tsuyoshi

2008-11-01

433

Water vapor - Stratospheric injection by thunderstorms.  

NASA Technical Reports Server (NTRS)

Infrared radiometric inference measurements of the mass of water vapor injected into the lower stratosphere and upper troposphere by a number of plains thunderstorms show an average threefold increase over the fair weather background mass of water vapor. These airborne measurements, made from the National Aeronautics and Space Administration Convair 990 jet laboratory, extended over a sample size much larger than that possible by balloon and other techniques.

Kuhn, P. M.; Lojko, M. S.; Petersen, E. V.

1971-01-01

434

Multicomponent fuel vaporization at high pressures.  

SciTech Connect

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.

Torres, D. J. (David J.); O'Rourke, P. J. (Peter J.)

2002-01-01

435

Vapor Deposits in the Lunar Regolith  

NASA Technical Reports Server (NTRS)

Since the Apollo missions, we have emphasized the following points, which are based on theoretical calculations and on laboratory studies of the properties of evaporated silicate deposits and of lunar samples. The mass of vapor generated by impacts on the lunar surface is comparable in magnitude to the mass of impact melt glasses; the physics of impact into a porous regolith requires that much of this vapor be retained in the soil rather than lost to space (as is widely believed); experimental coatings made from vaporized or sputtered lunar basalt contain abundant inclusions of submicroscopic, super paramagnetic metallic Fe; and this Fe may explain the magnetic signature, low albedo, reddened spectrum, and subdued absorption bands of lunar regolith. Our conclusions have been generally rejected by the lunar geochemical community for two reasons: there seemed to be no direct evidence for vapor deposits in Apollo samples, and it seemed that the lunar optical properties could be explained by the presence of impact melt glasses alone. However, advances in our understanding of the optical properties of glasses and of light scattering by planetary regoliths, and now the direct detection of vapor deposits, show that these objections are not valid. Vapor phase transport is a major process on the lunar surface, and unless its effects are taken into account, the chemical, magnetic, and optical properties of the regolith cannot be understood.

Hapke, Bruce; Cassidy, William; Wells, Eddie

1994-01-01

436

Optical monitor for water vapor concentration  

SciTech Connect

A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma.

Kebabian, Paul (Acton, MA)

1998-01-01

437

Water vapor retrieval from OMI visible spectra  

NASA Astrophysics Data System (ADS)

There are distinct spectral features of water vapor in the wavelength range covered by the Ozone Monitoring Instrument (OMI) visible channel. Although these features are much weaker than those at longer wavelengths, they can be exploited to retrieve useful information about water vapor. They have an advantage in that their small optical depth leads to fairly simple interpretation as measurements of the total water vapor column density. We have used the Smithsonian Astrophysical Observatory (SAO)'s OMI operational retrieval algorithm to derive the Slant Column Density (SCD) of water vapor from OMI measurements using the 430-480 nm spectral region after extensive optimization of retrieval windows and parameters. The Air Mass Factor (AMF) is calculated using look-up tables of scattering weights and monthly mean water vapor profiles from the GEOS-5 assimilation products. We convert from SCD to Vertical Column Density (VCD) using the AMF and generate associated retrieval averaging kernels and shape factors. Our standard water vapor product has a median SCD of ~ 1.3 × 1023 molecule cm-2 and a median relative uncertainty of ~ 11% in the tropics, about a factor of 2 better than that from a similar OMI algorithm but using narrower retrieval window. The corresponding median VCD is ~ 1.2 × 1023 molecule cm-2. We have also explored the sensitivities to various parameters and compared our results with those from the Moderate-resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic NETwork (AERONET).

Wang, H.; Liu, X.; Chance, K.; Gonzalez Abad, G.; Miller, C. Chan

2014-01-01

438

Families of discrete kernels for modeling dispersal  

Microsoft Academic Search

Integer lattices are important theoretical landscapes for studying the consequences of dispersal and spatial population structure, but convenient dispersal kernels able to represent important features of dispersal in nature have been lacking for lattices. Because leptokurtic (centrally peakedandlong-tailed ) kernels are common in nature andhave important effects in mod els, of particular interest are families of dispersal kernels in which

Peter Chesson; Charlotte T. Lee

439

Dispersal of deer mice, Peromyscus maniculatus  

Microsoft Academic Search

Dispersal of deer mice, Peromyscus maniculatus, was measured as immigration to and emigration from two control areas, and as immigration to a removal area. The number of mice dispersing was linearly related to the densities on the control areas, while the proportion of the population dispersing (rate of dispersal) was correlated primarily with the rate of increase of control populations.

Daphne J. Fairbairn

1978-01-01

440

Ballistic dispersion in temperature gradient focusing  

E-print Network

Ballistic dispersion in temperature gradient focusing BY DAVID E. HUBER* AND JUAN G. SANTIAGO kinematic (or ballistic) dispersion. In most microfluidic systems, this dispersion regime is transient­Aris; ballistic; electroosmotic flow 1. Introduction Dispersion, the natural tendency for ordered molecules

Santiago, Juan G.

441

Inter- and intramolecular dispersion interactions.  

PubMed

We have investigated the performance of a variety of density functional methods for weak intra- and intermolecular dispersion interactions. Grimme's empirical dispersion correction method is shown to give a good description for these interactions and helps to improve the description of water-hexamer isomers, noble-gas dimers, hydrocarbon C(12)H(12) isomers, branching energy of linear versus branched octane, dissociation of the covalently bound anthracene dimer, and stacking within the adenine dimer. However, the dispersion correction does not correct all shortcomings of the different density functionals, which leads to sizeable differences compared to ab initio CCSD(T) and experimental reference data. The only exception is shown to be our recently presented SSB-D functional that works well for all systems studied here. PMID:21387338

Swart, Marcel; Solà, Miquel; Bickelhaupt, F Matthias

2011-04-30

442

Visualization and numerical simulation of fine particle transport in a low-pressure parallel plate chemical vapor deposition reactor  

Microsoft Academic Search

The behavior of fine particles in a low-pressure parallel plate chemical vapor deposition reactor was investigated by constructing a system that permits particle motion in the reactor to be visualized. The test spherical silica aerosol particles, which were 1.0?m in diameter and dispersed in argon gas, were fed into the reactor from the outside and particle motion was detected by

Heru Setyawan; Manabu Shimada; Kenji Ohtsuka; Kikuo Okuyama

2002-01-01

443

Synthesis of tungsten oxide (WO 3) nanorods using carbon nanotubes as templates by hot filament chemical vapor deposition  

Microsoft Academic Search

Synthesis of tungsten oxide (WO3) nanorods using CNTs as templates under typical diamond growing conditions in a hot-filament chemical vapor deposition system is described. Tungsten oxide nanorods were grown on two types of CNT substrates, a Si [100] wafer with dispersed multiwalled CNT and a fresh-grown multiwalled CNT film. The templated growth resulted in an order of magnitude increase in

Nagraj Shankar; Min-Feng Yu; S. P. Vanka; Nick G. Glumac

2006-01-01

444

Running head: Stochastic dispersal models Stochastic Dispersal Processes in Plant  

E-print Network

assessing the risk of spread of genetically modified organisms. Knowing the dispersal variance as well for local differentiation due to either genetic drift or local selection pressures. Of particular interest­ proximation determines the amount of genetic differentiation due to selection (e.g. Slatkin, 1973) and genetic

Tufto, Jarle

445

Printed circuit dispersive transmission line  

DOEpatents

A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

Ikezi, Hiroyuki (Rancho Santa Fe, CA); Lin-Liu, Yuh-Ren (San Diego, CA); DeGrassie, John S. (Encinitas, CA)

1991-01-01

446

Dispersion-compensated fresnel lens  

DOEpatents

A transmission grating is used to reduce chromatic aberration in a Fresnel lens, wherein the lens chromatic dispersion is offset and substantially canceled by the grating's diffraction-induced dispersion. The grating comprises a Fresnel-type pattern of microscopic facets molded directly into the lens surface. The facets would typically have a profile height of around 4.multidot.10.sup.-5 inch and a profile width of at least 10.sup.-3 inch. In its primary intended application, the invention would function to improve the optical performance of a Fresnel lens used to concentrate direct sunlight.

Johnson, Kenneth C. (1215 Brewster Dr., El Cerrito, CA 94530)

1992-01-01

447

Fog dispersion. [charged particle technique  

NASA Technical Reports Server (NTRS)

The concept of using the charged particle technique to disperse warm fog at airports is investigated and compared with other techniques. The charged particle technique shows potential for warm fog dispersal, but experimental verification of several significant parameters, such as particle mobility and charge density, is needed. Seeding and helicopter downwash techniques are also effective for warm fog disperals, but presently are not believed to be viable techniques for routine airport operations. Thermal systems are currently used at a few overseas airports; however, they are expensive and pose potential environmental problems.

Christensen, L. S.; Frost, W.

1980-01-01

448

Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions  

E-print Network

-vapor chemical reactions. . ~ Heat pumps using liquid-vapor reactions f (items 1 and 5, above) are the subjects of this paper. Configurations discussed are: r , ! 1. Electric drive 2. Temperature amplifier (TA) using Rankine heat engine and liquid...-vapor reaction heat pump 3. Heat amplifier (HA) using liquid-vapor ' " reaction heat engine and reverse Rankine heat pump 4. HA and TA in which both heat engine and heat pump use liquid-vapor reactions. Thermodynamic requirements for working fluids...

Kirol, L.

449

A Simple Experiment for Determining Vapor Pressure and Enthalpy of Vaporization of Water.  

ERIC Educational Resources Information Center

Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

Levinson, Gerald S.

1982-01-01

450

Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids  

E-print Network

Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids Joe A. Wilson and James S. Chickos* Department of Chemistry and Biochemistry, University of MissouriSt. Louis, St. Louis, Missouri 63121, United States *S Supporting Information ABSTRACT: Sublimation enthalpies

Chickos, James S.

451

Properties of Coatings: Comparisons of Electroplated, Physical Vapor Deposited, Chemical Vapor Deposited, and Plasma Sprayed Coatings  

Microsoft Academic Search

Properties of coatings (structure, porosity, density, stress, corrosion, hydrogen permeation, adhesion, tribology, fatigue and thermal contact conductance) produced by a number of deposition methods including electrodeposition, physical vapor deposition, chemical vapor deposition, and flame spraying art; compared. In most cases, the films did not exhibit similar properties. In addition, process conditions often could be varied for any given coating process

J. W. Dini

1997-01-01

452

Dimension-sensitive optical responses of electromagnetically induced transparency vapor in a waveguide  

SciTech Connect

A three-level EIT (electromagnetically induced transparency) vapor is used to manipulate the transparency and absorption properties of the probe light in a waveguide. The most remarkable feature of the present scheme is such that the optical responses resulting from both electromagnetically induced transparency and large spontaneous emission enhancement are very sensitive to the frequency detunings of the probe light as well as to the small changes of the waveguide dimension. The potential applications of the dimension- and dispersion-sensitive EIT responses are discussed, and the sensitivity limits of some waveguide-based sensors, including electric absorption modulator, optical switch, wavelength sensor, and sensitive magnetometer, are analyzed.

Jian Qishen [Centre for Optical and Electromagnetic Research, Joint Research Centre of Photonics of the Royal Institute of Technology, Stockholm, Sweden and Zhejiang University, East Building No. 5, Zijingang Campus, Hangzhou 310058 (China); He Sailing [Division of Electromagnetic Theory, Alfven Laboratory, Royal Institute of Technology, S-100 44 Stockholm (Sweden)

2006-12-15

453

Influence of Soil Moisture on Soil Gas Vapor Concentration for Vapor Intrusion  

PubMed Central

Abstract Mathematical models have been widely used in analyzing the effects of various environmental factors in the vapor intrusion process. Soil moisture content is one of the key factors determining the subsurface vapor concentration profile. This manuscript considers the effects of soil moisture profiles on the soil gas vapor concentration away from any surface capping by buildings or pavement. The “open field” soil gas vapor concentration profile is observed to be sensitive to the soil moisture distribution. The van Genuchten relations can be used for describing the soil moisture retention curve, and give results consistent with the results from a previous experimental study. Other modeling methods that account for soil moisture are evaluated. These modeling results are also compared with the measured subsurface concentration profiles in the U.S. EPA vapor intrusion database. PMID:24170970

Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

2013-01-01

454

Multiple overseas dispersal in amphibians.  

PubMed Central

Amphibians are thought to be unable to disperse over ocean barriers because they do not tolerate the osmotic stress of salt water. Their distribution patterns have therefore generally been explained by vicariance biogeography. Here, we present compelling evidence for overseas dispersal of frogs in the Indian Ocean region based on the discovery of two endemic species on Mayotte. This island belongs to the Comoro archipelago, which is entirely volcanic and surrounded by sea depths of more than 3500 m. This constitutes the first observation of endemic amphibians on oceanic islands that did not have any past physical contact to other land masses. The two species of frogs had previously been thought to be nonendemic and introduced from Madagascar, but clearly represent new species based on their morphological and genetic differentiation. They belong to the genera Mantidactylus and Boophis in the family Mantellidae that is otherwise restricted to Madagascar, and are distinguished by morphology and mitochondrial and nuclear DNA sequences from mantellid species occurring in Madagascar. This discovery permits us to update and test molecular clocks for frogs distributed in this region. The new calibrations are in agreement with previous rate estimates and indicate two further Cenozoic transmarine dispersal events that had previously been interpreted as vicariance: hyperoliid frogs from Africa to Madagascar (Heterixalus) and from Madagascar to the Seychelles islands (Tachycnemis). Our results provide the strongest evidence so far that overseas dispersal of amphibians exists and is no rare exception, although vicariance certainly retains much of its importance in explaining amphibian biogeography. PMID:14667332

Vences, Miguel; Vieites, David R; Glaw, Frank; Brinkmann, Henner; Kosuch, Joachim; Veith, Michael; Meyer, Axel

2003-01-01

455

An Introduction to Dispersive Interactions  

ERIC Educational Resources Information Center

Dispersive forces are a kind of van der Waals intermolecular force which could only be fully understood with the establishment of quantum mechanics and, in particular, of quantum electrodynamics. In this pedagogical paper, we introduce the subject in a more elementary approach, aiming at students with basic knowledge of quantum mechanics. We…

Taddei, M. M.; Mendes, T. N. C.; Farina, C.

2010-01-01

456

Dispersion-Enhanced Laser Gyroscope  

NASA Technical Reports Server (NTRS)

We analyze the effect of a highly dispersive element placed inside a modulated optical cavity on the frequency and amplitude of the output modulation to determine the conditions for enhanced gyroscopic sensitivities. The element is treated as both a phase and amplitude filter, and the time-dependence of the cavity field is considered. Both atomic gases (two-level and multi-level) and optical resonators (single and coupled) are considered and compared as dispersive elements. We find that it is possible to simultaneously enhance the gyro scale factor sensitivity and suppress the dead band by using an element with anomalous dispersion that has greater loss at the carrier frequency than at the side-band frequencies, i.e., an element that simultaneously pushes and intensifies the perturbed cavity modes, e.g. a two-level absorber or an under-coupled optical resonator. The sensitivity enhancement is inversely proportional to the effective group index, becoming infinite at a group index of zero. However, the number of round trips required to reach a steady-state also becomes infinite when the group index is zero (or two). For even larger dispersions a steady-state cannot be achieved, and nonlinear dynamic effects such as bistability and periodic oscillations are predicted in the gyro response.

Smith, David D.; Chang, Hongrok; Arissian, L.; Diels, J. C.

2008-01-01

457

CVA Fog-Dispersal Experiment.  

National Technical Information Service (NTIS)

Experiments using jet engines for the dispersal of airfield fogs have been conducted since 1951 with varying degrees of success. In this report, the concept of thermal fog-clearing techniques is discussed with respect to aircraft carrier operations, and s...

C. J. Todd, J. W. Nickerson

1968-01-01

458

Organic vapor fluxes through the vadose zone  

SciTech Connect

Volatilization from shallow ground water followed by air-phase transport through the unsaturated zone is a poorly understood process that may be a significant natural remediation mechanism for volatile organic pollutants including chlorinated solvents and gasoline constituents (e.g., benzene, toluene, etc.). To improve understanding of this process, the upward flux of trichloroethene (TCE) vapor through the unsaturated zone above a contaminated, water-table aquifer at Picatinny Arsenal, New Jersey, has been studied under natural conditions over a 12-mo period. Vertical gas-phase diffusion fluxes were determined indirectly by measuring the TCE vapor concentration gradient in the unsaturated zone and using Fick`s Law to calculate the flux. The total gas-phase flux (e.g., the sum of diffusion and advection fluxes) was measured directly with a vertical flux chamber (VFC). In many cases, the upward TCE vapor flux was several orders of magnitude greater than the upward TCE diffusion flux, suggesting that the vertical transport of TCE vapors by gas advection is significant relative to vertical transport by diffusion. The measured total flux of TCE vapor from the subsurface to the atmosphere is approximately 50 kg/yr and is comparable in magnitude to the removal rate of TCE from the aquifer by an existing pump-and-treat system and by discharge into a nearby stream.

Smith, J.A. [Univ. of Virginia, Charlottesville, VA (United States); Tisdale, A.K. [IT Corp., Austin, TX (United States); Cho, H.J. [Vanderbilt Univ., Nashville, TN (United States)

1996-10-01

459

Distribution of tropical tropospheric water vapor  

NASA Technical Reports Server (NTRS)

Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

Sun, De-Zheng; Lindzen, Richard S.

1993-01-01

460

A review of vapor intrusion models.  

PubMed

A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts: one part describing vapor transport in the soil and the other describing its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulation, and can increase the difficulty of obtaining a solution, especially when explicitly considering coupled oxygen transport and consumption. The models of contaminant building entry pathway are often coupled to calculations of indoor air contaminant concentration, and both are influenced by building construction and operational features. The description of entry pathway involves consideration of building foundation characteristics, while calculation of indoor air contaminant levels requires characterization of building enclosed space and air exchange within this. This review summarizes existing VI models, and discusses the limits of current screening tools commonly used in this field. PMID:23360069

Yao, Yijun; Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

2013-03-19

461

Vapor scavenging by atmospheric aerosol particles  

SciTech Connect

Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

Andrews, E.

1996-05-01

462

Global Dispersal of Dust Following Impact Cratering Events on Mars  

NASA Astrophysics Data System (ADS)

Hypervelocity impacts on Mars inject dust and vapors into the upper atmosphere. If the particles derived from the projectile or surface are widely distributed, impact events could drive intense weather patterns and perhaps transient climate change on Mars [Segura et al., Science (2002)]. Recent work on small impact events (100 m-sized projectiles) find that the mass of dust stirred into the troposphere may be equivalent to global dust storms [Nemtchinov et al., JGR (2002)]. For ˜10 to ˜100 km-sized impactors, dust and greenhouse vapors may be delivered to the upper troposphere and lower stratosphere, where the long residence time has the potential for regional or perhaps even global effects on the weather. In this work, we investigate the transport mechanisms that control the dispersion of dust injected into the upper troposphere from large impact events using a high-resolution global atmospheric dynamics model [Cho & Polvani, Science (1996)]. The spreading rates, dispersal extent, and the potential for weather and climatological perturbations from both large ( ˜10 km) and giant ( ˜100 km) impactors are studied. The overarching goals in this study are to identify locations of persistent concentrations of aerosols and to estimate the smallest impact which may generate transient rainfall on Mars. From our simulations we find that modeling of the climatological response from giant, basin-forming events may assume nearly homogeneous aerosol distribution. However, understanding the atmospheric response to the more frequent, smaller cratering events requires explicit treatment of the spatial inhomogeneities caused by the atmospheric motion. Hence, 2-D or 3-D atmospheric models are needed. Intriguing flow concentrations in the southern hemisphere, which could serve as locations for storm fronts, are observed following large impacts over a wide range of conditions.

Cho, J. Y.; Stewart, S. T.

2003-12-01

463

Furnace chemical vapor deposition (FCVD) method for special optical fibers fabrication  

NASA Astrophysics Data System (ADS)

The features of the Furnace Chemical Vapor Deposition (FCVD) method of manufacturing preforms for special optical fibers are considered. It is shown that misalignment of substrate silica tube and furnace hole axes has a negative effect on the quality of fabricated preforms, leading to angular and radial asymmetry of the refractive index profile. Ways of getting rid of this and other disadvantages of the FCVD method are described. Some advantages of the FCVD method over the MCVD method are shown. It was demonstrated that the FCVD method, despite some drawbacks, allows to manufacture high-quality fiber preforms with good symmetry of the refractive index profile, and thus it is promising for fabrication of dispersion, dispersion varying and active fibers.

Malinin, A. A.; Zlenko, A. S.; Akhmetshin, U. G.; Semjonov, S. L.

2011-03-01

464

Propellent and chemical spill and dispersion model  

SciTech Connect

The defense services transport, store, and use many kinds of chemicals including fuels, oxidizers, propellants, and weapons-related chemicals. Many of these chemicals are volatile and may form dense vapor clouds if they are released into the atmosphere. Depending on the physical properties of the chemical, storage conditions, release conditions and weather conditions different types of vapor clouds may be formed (heavy clouds, aerosol-bearing clouds, instantaneous puffs, continuous plumes, etc.). In addition, some of the chemicals may react with ambient moisture. It has been shown in the literature that the behavior of heavy vapor clouds is considerably different from that of neutral density vapor clouds.

Raj, P.K.; Morris, J.A.; Kunkel, B.A.

1988-09-22

465

Recovering energy by mechanical vapor recompression  

SciTech Connect

It is estimated that 25 to 40% of the total energy consumed by the chemical and petrochemical industries is used in separation processes. Because of increasing energy costs, a great number of plants are being reexamined to make their processes more energy-efficient. Distillation is one such process, in which large energy reductions can often be achieved. Studies have identified a number of alternatives for lowering energy consumption in the distillation process through various heat recovery techniques. One such technique utilizes mechanical vapor recompression. In this approach, a compressor is used to recycle the latent heat from overhead or flashed vapors and then recompress the vapors to conditions suitable for driving the reboiler at the bottom of the tower. This reduces the energy input to the tower to 10-15% of the energy normally consumed in the reboiler.

Becker, F.E.; Zakak, A.I.

1985-07-01

466

Vapor flow to trench in leaky aquifer  

SciTech Connect

Soil-vapor extraction has become the most common innovative technology for treating subsurface soils contaminated with volatile and semivolatile organic compounds. This popularity is due partly to the low cost of vapor extraction and partly to the fact that migration is completed in situ. Previous applications of this technology have generally considered flow to either vertical or horizontal wells. However, vapor flow to a trench offers the advantages of a more uniform velocity field and lower construction costs at sites with shallow water tables. Therefore, an analytical solution is obtained for steady flow to a trench. The trench is assumed to partially penetrate an anisotropic aquifer and to have a finite horizontal length. The bottom aquifer boundary is assumed to be an impermeable water table, and the top boundary is a semipermeable aquitard. A comparison is made with field measurements to illustrate the application of the solution and to give confidence in its use.

Hunt, B.; Massmann, J.

2000-04-01

467

Propagation of detonations in hydrazine vapor  

NASA Technical Reports Server (NTRS)

In the range of greater hydrazine vapor pressure, detonation speed depends exclusively on the extent of the ammonia decomposition in the second reaction stage. As vapor pressure decreases, the ammonia disintegration speed becomes increasingly slower and the reaction reached in the reaction zone increasingly decreases until finally, in the vapor pressure range between 53 and 16 Torr, the contribution of the second stage to detonation propagation disappears, and only the first stage remains active. Since the disintegration speed of the hydrazine in this pressure range has decreased markedly as well, no level, but rather only spinning, detonations occur. Temporary separations of the impact front and the reaction zone in the process lead to fluctuations of the detonation speed.

Heinrich, H. J.

1985-01-01

468

ISOL TARGET-VAPOR TRANSPORT SYSTEM SIMULATIONS  

SciTech Connect

Computational simulation studies with state-of-the-art codes offer cost effective means for designing ISOL targets with optimized diffusion release properties and vapor transport systems with short effusion path lengths. To demonstrate the power of the technique for designing optimum thickness targets, analytic solutions to the diffusion equation are compared with those obtained from a finite-difference code for radioactive isotope diffusion release from simple geometry targets. The viability of the Monte Carlo technique as a practical means for optimally designing target-vapor transport systems is demonstrated by simulating the effusive-flow of neutral particles through several complex target-vapor transport systems. Important issues which affect the yield rates of short-lived species generated in high power ISOL targets are also discussed

Zhang, Yan [ORNL; Remec, Igor [ORNL; Liu, Zhengzheng [ORNL

2010-01-01

469

Vapor wall deposition in Teflon chambers  

NASA Astrophysics Data System (ADS)

Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors 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. The dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (?w,i), which can be correlated through its volatility (Ci*) with the number of carbons (nC) and oxygens (nO) in the molecule. Among the 25 compounds studied, the maximum wall deposition rate is approached by the most highly oxygenated and least volatile compounds. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and chamber walls. Gas-particle equilibrium partitioning is established relatively rapidly in the presence of perfect accommodation of organic vapors onto particles or when a sufficiently large concentration of suspended particles is present. 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 be dominant for typical particle number concentrations in chamber experiments. For large ?w,i, vapor transport to particles is suppressed by competition with the chamber walls even with perfect particle accommodation.

Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

2014-10-01

470

Vapor characterization of Tank 241-C-103  

SciTech Connect

The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program.

Huckaby, J.L. [Westinghouse Hanford Co., Richland, WA (United States); Story, M.S. [Northwest Instrument Systems, Inc. Richland, WA (United States)

1994-06-01

471

Realistic dispersion kernels applied to cohabitation reaction dispersion equations  

NASA Astrophysics Data System (ADS)

We develop front spreading models for several jump distance probability distributions (dispersion kernels). We derive expressions for a cohabitation model (cohabitation of parents and children) and a non-cohabitation model, and apply them to the Neolithic using data from real human populations. The speeds that we obtain are consistent with observations of the Neolithic transition. The correction due to the cohabitation effect is up to 38%.

Isern, Neus; Fort, Joaquim; Pérez-Losada, Joaquim

2008-10-01

472

Vacuum distillation/vapor filtration water recovery  

NASA Technical Reports Server (NTRS)

The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

Honegger, R. J.; Neveril, R. B.; Remus, G. A.

1974-01-01

473

Shock melting and vaporization of metals.  

NASA Technical Reports Server (NTRS)

The effect of initial porosity on shock induction of melting and vaporization is investigated for Ba, Sr, Li, Fe, Al, U, and Th. For the less compressible of these metals, it is found that for a given strong shock-generation system (explosive in contact, or flyer-plate impact) an optimum initial specific volume exists such that the total entropy production, and hence the amount of metal liquid or vapor, is a maximum. Initial volumes from 1.4 to 2.0 times crystal volumes, depending on the metal sample and shock-inducing system, will result in optimum post-shock entropies.

Ahrens, T. J.

1972-01-01

474

Vapor deposition in basaltic stalactites, Kilauea, Hawaii  

NASA Astrophysics Data System (ADS)

Basaltic stalacties suspended from the ceiling of a large lava tube at Kilauea, Hawaii, have totally enclosed vesicles whose walls are covered with euhedral Fe?Ti oxide and silicate crystals. The walls of the vesicles and the exterior surfaces of stalactites are Fe and Ti enriched and Si depleted compared to common basalt. Minerals in vesicles have surface ornamentations on crystal faces which include alkali-enriched, aluminosilicate glass(?) hemispheres. No sulfide-, chloride-, fluoride-, phosphate- or carbonate-bearing minerals are present. Minerals in the stalactites must have formed by deposition from an iron oxide-rich vapor phase produced by the partial melting and vaporization of wall rocks in the tube.

Baird, A. K.; Mohrig, D. C.; Welday, E. E.

475

Catalytic combustion with incompletely vaporized residual fuel  

NASA Technical Reports Server (NTRS)

Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.

Rosfjord, T. J.

1981-01-01

476

Metal vapor arc switch electromagnetic accelerator technology  

NASA Technical Reports Server (NTRS)

A multielectrode device housed in an insulator vacuum vessel, the metal vapor vacuum switch has high power capability and can hold off voltages up to the 100 kilovolt level. Such switches can be electronically triggered and can interrupt or commutate at a zero current crossing. The physics of arc initiation, arc conduction, and interruption are examined, including material considerations; inefficiencies; arc modes; magnetic field effects; passive and forced extinction; and voltage recovery. Heating, electrode lifetime, device configuration, and external circuit configuration are discussed. The metal vapor vacuum switch is compared with SCRs, GTOs, spark gaps, ignitrons, and mechanical breakers.

Mongeau, P. P.

1984-01-01

477

Method and Apparatus for Concentrating Vapors for Analysis  

DOEpatents

An apparatus and method are disclosed for pre-concentrating gaseous vapors for analysis. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable. Vapors sorbed and concentrated within the bed of the apparatus can be thermally desorbed achieving at least partial separation of vapor mixtures. The apparatus is suitable, e.g., for preconcentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than for direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications.

Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

2008-10-07

478

Interfacial force field characterization of a constrained vapor bubble thermosyphon using IAI  

NASA Technical Reports Server (NTRS)

The isothermal profiles of the extended meniscus in a quartz cuvette were measured in a gravitational field using IAI (image analyzing interferometer) which is based on computer enhanced video microscopy of the naturally occurring interference fringes. The experimental results for heptane and pentane menisci were analyzed using the extended Young-Laplace Equation. These isothermal results characterized the interfacial force field in-situ at the start of the heat transfer experiments by quantifying the dispersion constant for the specific liquid-solid system. The experimentally obtained values of the disjoining pressures and the dispersion constants are compared to the subsequent non-isothermal experiments because one of the major variables in the heat sink capability of the CVBT is the dispersion constant. In all previous studies of micro heat pipes the value of the dispersion constant has been 'guesstimated'. The major advantages of the current glass cell is the ability to view the extended meniscus at all times. Experimentally, we find that the extended Young-Laplace Equation is an excellent model for for the force field at the solid-liquid vapor interfaces.

Dasgupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

1994-01-01

479

Temporal dispersion of a spectrometer.  

PubMed

The temporal dispersion of an optical spectrometer has been characterized for a variety of conditions related to optical diagnostics to be fielded at the National Ignition Facility (e.g., full-aperture backscatter station, Thomson scattering). Significant time smear is introduced into these systems by the path length difference through the spectrometer. The temporal resolution is shown to depend only on the order of the grating, wavelength, and the number of grooves illuminated. To enhance the temporal resolution, the spectral gratings can be masked limiting the number of grooves illuminated. Experiments have been conducted to verify these calculations. The size and shape of masks are investigated and correlated with the exact shape of the temporal instrument function, which is required when interpreting temporally resolved data. The experiments used a 300 fs laser pulse and a picosecond optical streak camera to determine the temporal dispersion. This was done for multiple spectral orders, gratings, and optical masks. PMID:19044687

Visco, A; Drake, R P; Froula, D H; Glenzer, S H; Pollock, B B

2008-10-01

480

Dispersal Patterns in Tarsius spectrum  

Microsoft Academic Search

One of the most widely accepted explanations for the difference in the sex bias between mammals and birds is that male-biased\\u000a dispersal in mammals is due to the preponderance of polygynous mating systems exhibited by this class, whereas birds are predominantly\\u000a monogamous. Spectral tarsiers (Tarsius spectrum) are unusual in that they exhibit variation in its mating system. Although the majority

Sharon Gursky

2010-01-01

481

Acoustic nonlinearity in dispersive solids  

NASA Technical Reports Server (NTRS)

An investigation to consider the effects of dispersion on the generation of the static acoustic wave component is presented. It is considered that an acoustic toneburst may be modeled as a modulated continuous waveform and that the generated initial static displacement pulse may be viewed as a modulation-confined disturbance. A theoretical model for the generation of the acoustic modulation solitons evolved is developed and experimental evidence in samples of vitreous silica demonstrating the essential validity of the model is provided.

Cantrell, John H.; Yost, William T.

1991-01-01

482

Dispersant application by fire monitor  

SciTech Connect

Several years ago, Exxon Company, International, found itself with a need for a rugged system for open ocean use in applying dispersant which could be quickly installed on supply boats and would use readily available parts at remote offshore drilling sites. Fire monitors appeared promising, since they had been used effectively to disperse some minor spills in the past, and visually they appeared to produce a relatively-uniform spray pattern. Calculations also showed that fire monitors could potentially cover three to four times the area covered by a conventional boom because of a wide swatch and the potential for greater boat speed due to a lesser effect of pitching and rolling on monitors than on booms. There were questions, however, about the uniformity of the dosage, the difference in the droplet size produced, and their effect on dispersant performance. Exxon conducted several test programs to more thoroughly evaluate fire monitors for dispersant application, and these programs are the subject of this paper. The first test program involved the testing of numerous nozzles with modifications and monitor elevation angles to determine what combination would give the most uniform dosage in the likely offshore wind conditions. Once a nozzle was selected, the droplet pattern from the monitoring nozzle and from a conventional dilute spray boom were analyzed using high speed video. These tests were followed by application tests of COREXIT 9527 by fire monitor, dilute boom, and neat boom to spilled oil at the Imperial Oil Limited Wave Basin in Calgary. The major content of this paper deals with the results of those tests. Finally, at-sea tests were successfully conducted in the North Sea.

Major, R.A.; Chen, A.C.T. [Exxon Production Research Co., Houston, TX (United States). Production Operations Div.

1995-06-01

483

Dispersal dynamics of groundwater bacteria  

Microsoft Academic Search

Dispersal of bacteria in saturated, porous soils can be characterized by the partitioning of cells between the aqueous and\\u000a solid phases, as a result of the physical and chemical nature of the soil and water and cell surface modifications. The purpose\\u000a of this work is to understand variations in partitioning as a consequence of the nutrient conditions and to use

Roland Lindqvist; Göran Bengtsson

1991-01-01

484

Turbulent Dispersion of Traffic Emissions  

NASA Astrophysics Data System (ADS)

Emissions from the transportation sector are a significant source of air pollution. Ongoing efforts to reduce the impacts require tools to provide guidance on policies regarding fuels, vehicle types and traffic control. The air quality models currently used to predict the effectiveness of policies typically treat traffic emissions as a source uniformly distributed across the surface of a model grid. In reality, emissions occur along lines above the surface, in an initially highly concentrated form, and are immediately mixed by traffic-enhanced turbulence. Differences between model and reality in terms of both chemistry and dispersion are to be expected. The ALMITEE (Advancing Local-scale Modeling through Inclusion of Transportation Emission Experiments) subproject FEVER (Fast Evolution of Vehicle Emissions from Roadways), conducted on multi-lane highways in the Toronto area in the summer of 2010, included measurements to quantify the evolution and dispersion of traffic emissions. Continuous micro-meteorological data (heat and momentum fluxes, temperature, humidity and incoming solar radiation) were collected 10m from the road, next to a traffic camera used to determine traffic density, composition and speed. Sonic anemometers and an aircraft turbulence probe mounted on a mobile lab provided measurements of turbulent dispersion both directly in traffic on the highway as well as on perpendicular side roads, as a function of distance from the highway. The mobile lab was equipped with instruments to characterize the aerosol size and mass distributions, aerosol composition including black carbon content, NO, NO2, CO2, CO, SO2 and VOCs at high time resolution. Preliminary results on the consequences of turbulent dispersion of traffic emissions levels under a variety of conditions will be disseminated.

Staebler, R. M.; Gordon, M.; Liggio, J.; Makar, P.; Mihele, C.; Brook, J.; Wentzell, J. J.; Gong, S.; Lu, G.; Lee, P.

2010-12-01

485

40 CFR 63.463 - Batch vapor and in-line cleaning machine standards.  

Code of Federal Regulations, 2010 CFR

...superheated vapor. 2 Freeboard refrigeration device, superheated vapor...Working-mode cover, freeboard refrigeration device. 4 Reduced room draft...superheated vapor. 5 Freeboard refrigeration device, reduced room...

2010-07-01

486

40 CFR 110.4 - Dispersants.  

Code of Federal Regulations, 2010 CFR

...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the provisions of this part is...

2010-07-01