These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

PubMed

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

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

2010-11-15

2

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

3

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

E-print Network

?site?description....................................................................................................?62? Figure?17.?LNG?delivery?system?at?the?BFTF?at?Texas?A&M?University?........................................?63? Figure?18.?Side?view?of?hydrocarbon?point?gas?sensor?position?for?test?one?...............................?67? Figure?19.?Top...?view?of?gas?sensors?location?for?each?test?............................................................?69? Figure?20.?Comparison?between?condensate?and?hydrocarbon?vapor?cloud?..............................?71? Figure?21.?Concentration?profile?at?fixed?point?along?the?centerline?...........................................?72? Figure?22.?Top...

Cormier, Benjamin Rodolphe

2009-05-15

4

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

E-print Network

, this study aimed to obtain key parameters, such as the temperature changes of methane and foam and the extent reduction of vapor concentration. This study also focused on identifying the effectiveness of foam and thermal exclusion zone by investigating...

Yun, Geun Woong

2011-10-21

5

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

6

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

E-print Network

of the strategies used in the LNG industry and recommended by federal regulation National Fire Protection Association (NFPA) 59A is to use expansion foam to suppress LNG vapors and to control LNG fire by reducing the fire size. In its application, expansion foam...

Suardin, Jaffee Arizon

2009-05-15

7

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

8

Atmospheric Dispersion about a Heavy Gas Vapor Detention System.  

NASA Astrophysics Data System (ADS)

Dispersion of liquefied natural gas (LNG) in the event of an accidental spill is a major concern in LNG storage and transport safety planning, hazard response, and facility siting. Falcon Series large scale LNG spill experiments were planned by Lawrence Livermore National Laboratory (LLNL) for the Department of Transportation (DOT) and the Gas Research Institute (GRI) as part of a joint government/industry study in 1987 to evaluate the effectiveness of vapor fences as a mitigating technique for accidental release of LNG and to assist in validating wind tunnel and numerical methods for vapor dispersion simulation. Post-field-spill wind-tunnel experiments were performed in Environmental Wind Tunnel (EWT) (1988, 1989) to augment the LNG Vapor Fence Program data obtained during the Falcon Test Series. The program included four different model length scales and two different simulant gases. The purpose of this program is to provide a basis for the analysis of the simulation of physical modeling tests using proper physical modeling techniques and to assist in the development and verification of analytical models. Field data and model data were compared and analyzed by surface pattern comparisons and statistical methods. A layer-averaged slab model developed by Meroney et al. (1988) (FENC23) was expanded to evaluate an enhanced entrainment model proposed for dense gas dispersion including the effect of vapor barriers, and the numerical model was simulated for Falcon tests without the fence and with the vapor fence to examine the effectiveness of vapor detention system on heavy gas dispersion. Model data and the field data were compared with the numerical model data, and degree of similarity between data were assessed.

Shin, Seong-Hee

9

Closed-cycle gas turbines for power generation and LNG vaporization  

NASA Astrophysics Data System (ADS)

Cooling by LNG (liquefied nitrogen gas) in closed-cycle gas turbines results in double the electrical output of water cooled turbines. A circuit scheme of the LNG turbine is presented with the temperatures and pressures of the cycle. The turbine inlet temperature is limited to 720 C. Pressure level control and bypass control are the two basic types of control applied. The power station has an output of 4 x 100 MW, with four heaters arranged in series. The basic design of the heater, turbine, compressor, recuperator, and vaporizer is given. A cost comparison is made between the closed cycle gas turbine and steam turbine power stations with open rack vaporizer, submerged combustion vaporizer, or both. Using an LNG terminal with a closed-cycle gas turbine for the generation of electric power and LNG vaporization would mean a potential world-wide saving of 2,350 MW thermal power or 4.2 x 10(6) kg of LNG/day by 1985.

Weber, D.

1980-09-01

10

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

E-print Network

There has been, and will continue to be, tremendous growth in the use and distribution of liquefied natural gas (LNG). As LNG poses the hazard of flammable vapor cloud formation from a release, which may result in a massive fire, increased public...

Rana, Morshed A.

2011-02-22

11

49 CFR 193.2059 - Flammable vapor-gas dispersion protection.  

Code of Federal Regulations, 2014 CFR

...order to account for additional cloud dilution which may be caused...parameters must be used in computing dispersion distances: ...upwind and downwind of the vapor cloud has dense vegetation and that the vapor cloud height is more than ten...

2014-10-01

12

49 CFR 193.2059 - Flammable vapor-gas dispersion protection.  

Code of Federal Regulations, 2012 CFR

...order to account for additional cloud dilution which may be caused...parameters must be used in computing dispersion distances: ...upwind and downwind of the vapor cloud has dense vegetation and that the vapor cloud height is more than ten...

2012-10-01

13

49 CFR 193.2059 - Flammable vapor-gas dispersion protection.  

Code of Federal Regulations, 2013 CFR

...order to account for additional cloud dilution which may be caused...parameters must be used in computing dispersion distances: ...upwind and downwind of the vapor cloud has dense vegetation and that the vapor cloud height is more than ten...

2013-10-01

14

77 FR 43589 - Freeport LNG Development, L.P., Freeport LNG Expansion, L.P., FLNG Liquefaction LLC; Supplemental...  

Federal Register 2010, 2011, 2012, 2013, 2014

...pipelines (boil-off gas, natural gas, natural gas liquids, nitrogen) and utility...Freeport LNG's Stratton Ridge underground gas storage facility, and interconnects...additional LNG vaporization and natural gas send-out facilities...

2012-07-25

15

Study of gelled LNG  

SciTech Connect

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

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

1981-05-01

16

Research on energy efficiency design index for sea-going LNG carriers  

NASA Astrophysics Data System (ADS)

This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters—fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.

Lin, Yan; Yu, Yanyun; Guan, Guan

2014-12-01

17

LNG tanker  

Microsoft Academic Search

Compared with LNG tankers installed with bottle-type tanks having diameter\\/height ratios of 1:15, the tanker design proposed by Naval Project Development Sarl, Luxembourg, uses a unique arrangement of cylindrical vessels with diameter\\/height ratios of 1:2 to 1:5. This configuration reduces the number of tanks required to more completely fill the hold, provides greater stability to the tank-support structure, and allows

Verolme

1978-01-01

18

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

PubMed

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

Havens, Jerry; Spicer, Tom

2007-02-20

19

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

20

Analysis and optimization of a cascading power cycle with liquefied natural gas (LNG) cold energy recovery  

Microsoft Academic Search

The effective utilization of the cryogenic energy associated with LNG vaporization is quite important. In this paper a cascading power cycle with LNG directly expanding consisting of a Rankine cycle with ammonia–water as working fluid and a power cycle of combustion gas is proposed to recover cryogenic energy of LNG. Energy equilibrium equations and exergy equilibrium equations of each equipment

T. Lu

2009-01-01

21

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

NASA Astrophysics Data System (ADS)

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

Roszak, E. A.; Chorowski, M.

2014-01-01

22

A novel cryogenic power cycle for LNG cold energy recovery  

Microsoft Academic Search

A novel cryogenic cycle by using a binary mixture as working fluids and combined with a vapor absorption process was proposed to improve the energy recovery efficiency of an LNG (liquefied natural gas) cold power generation. The cycle was simulated with seawater as the heat source and LNG as the heat sink, and the optimization of the power generated per

Yanni Liu; Kaihua Guo

2011-01-01

23

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

24

Caribbean LNG project marks progress; LNG tanker launched  

SciTech Connect

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

NONE

1997-10-20

25

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

26

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

27

Chemical vapor deposited tungsten with dispersed carbides for Space Shuttle check valves  

NASA Technical Reports Server (NTRS)

A chemical vapor deposited tungsten with dispersed carbides was selected as the material for Space Shuttle Orbital Maneuvering and Reaction Control Systems check valve poppets and seats. The selection followed a NASA-sponsored prototype check valve development program utilizing the cutter-seal shell poppet concept. The poppet material is deposited as a coating approximately 0.9 mm thick and fabricated into a shell as a free standing body. The seat material is deposited as a coating 1.1 mm thick on a seat blank, and the cutter seal is machined in the coating. Module tests demonstrated that the material could be ground and lapped to very sharp edges and could cut through typical system contaminants without excessive damage to the sealing surfaces. The material was also determined to be unaffected by exposure to a strongly oxidizing storable propellant.

Williams, G. E.

1980-01-01

28

Thermal and chemical vapor deposition of Si nanowires: Shape control, dispersion, and electrical properties  

SciTech Connect

We investigate and compare complementary approaches to SiNW production in terms of yield, morphology control, and electrical properties. Vapor-phase techniques are considered, including chemical vapor deposition (with or without the assistance of a plasma) and thermal evaporation. We report Au-catalyzed nucleation of SiNWs at temperatures as low as 300 deg. C using SiH{sub 4} as precursor. We get yields up to several milligrams by metal-free condensation of SiO powders. For all processes, we control the final nanostructure morphology. We then report concentrated and stable dispersions of SiNWs in solvents compatible with semiconducting organic polymers. Finally, we investigate the electrical response of intrinsic SiNWs grown by different methods. All our SiNWs exhibit p-type behavior and comparable performance, though in some cases ambipolar devices are observed. Thus, processing and morphology, rather than the growth technique, are key to achieve optimal samples for applications.

Colli, A.; Fasoli, A.; Beecher, P.; Servati, P.; Pisana, S.; Fu, Y.; Flewitt, A. J.; Milne, W. I.; Robertson, J.; Ducati, C.; De Franceschi, S.; Hofmann, S.; Ferrari, A. C. [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 6GF (United Kingdom); Laboratoire de Transport Electronique Quantique et Supraconductivite, CEA-Grenoble, 38054 Grenoble cedex 9 (France); Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2007-08-01

29

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

SciTech Connect

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

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

2011-10-13

30

Safety features on LNG ships  

NASA Astrophysics Data System (ADS)

The technology to transport liquefied natural gas (LNG) safely by sea is well established and many variations of cargo containment systems have been tested and developed since the early 1950s. Examples of four current LNG ships incorporating different containment systems are briefly described. Safety features are examined, now considered standard practice on a modern LNG carrier, which have made a major contribution to the outstandingly good record of LNG ship operations. Examples are given of some LNG ship casualty incidents.

Harris, F. S.

31

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

32

Preliminary investigation of uncombusted auto fuel vapor dispersion within a residential garage microenvironment  

SciTech Connect

Evaporative emissions from vehicles in an attached garage may represent a significant source of indoor pollution and human exposure. A pilot field study was undertaken to investigate potential in-house dispersion of evaporative emissions of uncombusted fuels from a vehicle parked inside an attached garage. In a set of experiments using sulfur hexafluoride tracer gas, the multizonal mass balance model, CONTAM88, was used to predict interzonal air flow rates and SF6 concentration distributions within the garage and house. Several experiments were included to evaluate the effect of meteorology and mechanical mixing mechanisms on the dispersion of automobile fuel vapor. Measurements indicated that approximately three percent of the garage maximum concentration was measured in a room adjacent to the garage. The model successfully predicted garage concentrations under well mixed conditions, but underpredicted the measured concentrations within various rooms of the house, in which mixing was incomplete. Multizonal mass balance models such as CONTAM88 may be useful in approximating contaminant concentrations at various locations within the house.

Lansari, A.; Streicher, J.J.; Huber, A.H.; Crescenti, G.H.; Zweidinger, R.B.

1993-01-01

33

Determination of octane numbers and Reid vapor pressure in commercial gasoline using dispersive fiber-optic Raman spectroscopy  

Microsoft Academic Search

Dispersive fiber-optic Raman spectroscopy utilizing CCD detection and near-IR DBR diode laser excitation is used to remotely analyze 205 petroleum fuels of varying composition for pump octane number, motor octane number (MON), research octane number (RON), and Reid vapor pressure (RVP). Partial least squares regression analysis in tandem with several preprocessing techniques was used to model pump octane, MON, RON,

Philip E. Flecher; William T. Welch; Sacharia Albin; John B. Cooper

1997-01-01

34

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

PubMed

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

Luketa-Hanlin, Anay

2006-05-20

35

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

SciTech Connect

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

Luketa-Hanlin, Anay Josephine

2005-04-01

36

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

37

Introduction to LNG vehicle safety  

NASA Astrophysics Data System (ADS)

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

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

1994-03-01

38

LNG risk management  

NASA Astrophysics Data System (ADS)

A general methodology is presented for conducting an analysis of the various aspects of the hazards associated with the storage and transportation of liquefied natural gas (LNG) which should be considered during the planning stages of a typical LNG ship terminal. The procedure includes the performance of a hazards and system analysis of the proposed site, a probability analysis of accident scenarios and safety impacts, an analysis of the consequences of credible accidents such as tanker accidents, spills and fires, the assessment of risks and the design and evaluation of risk mitigation measures.

Martino, P.

1980-12-01

39

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

Federal Register 2010, 2011, 2012, 2013, 2014

...two liquefaction trains of 4.5 million metric tons per annum each, for an overall nominal liquefaction rate of up to 9.0 MTPA; (iii) vaporization facilities with a base load natural gas send out capacity of 0.5 Bscf/d; (iv) LNG storage...

2013-06-27

40

LNG annotated bibliography  

SciTech Connect

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

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

1982-09-01

41

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

42

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

43

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

44

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

45

Modeling of LNG Pool Spreading and Vaporization  

E-print Network

I am deeply grateful to my advisor, Dr. Luc N. V?chot, for all his feedback and his guidance throughout this process. I would like to acknowledge my committee members: Dr. Sam M. Mannan and Dr. Eyad Masad. Thanks to all the members and staff... of the Process Safety Group at Texas A&M University at Qatar. I would like to acknowledge Dr. Simon Waldram for introducing me to the field of process safety and his guidance and help. I want to acknowledge the long term, not only financial, support provided...

Basha, Omar 1988-

2012-11-20

46

PRELIMINARY INVESTIGATION OF UNCOMBUSTED AUTO FUEL VAPOR DISPERSION WITHIN A RESIDENTIAL GARAGE MICROENVIRONMENT  

EPA Science Inventory

Evaporative emissions from vehicles in an attached garage may represent a significant source of indoor pollution and human exposure. ilot field study was undertaken to investigate potential in-house dispersion of evaporative emissions of uncombusted fuels from a vehicle parked in...

47

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

48

Enhanced reflection via phase compensation from anomalous dispersion in atomic vapor  

SciTech Connect

The phase compensation mechanism induced by anomalous dispersion in the reflection process of four-wave mixing (or reflection from a grating) in a three-level system is investigated, where the four wave vectors do not match in vacuum. An efficiency of the reflected signal of as high as 43% from a hot atomic cell of Cs is observed. The maximum reflection occurs when the frequency of the probe beam (and consequently the frequency of the reflected signal) is slightly red detuned from the transition frequency, which is attributed to the phase compensation from the steep anomalous dispersion accompanied with a strong probe absorption. The dependences of the efficiency on the angle between the coupling and probe lights, on the intensity of the coupling, field and on atomic density are studied. A theoretical model is presented and it is in good agreement with the experimental results.

Zhang Junxiang; Zhou Haitao [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China); Wang Dawei [Beijing Computational Science Research Center, Beijing 100084 (China); Zhu Shiyao [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China); Beijing Computational Science Research Center, Beijing 100084 (China); Department of Physics, Hong Kong Baptist University (Hong Kong)

2011-05-15

49

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

PubMed

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

Johnson, David W; Cornwell, John B

2007-02-20

50

LNG plants in the US and abroad  

SciTech Connect

The Institute of Gas Technology recently conducted a comprehensive survey of LNG production and storage facilities in North America. This survey was performed as part of IGT`s LNG Observer newsletter which covers both domestic and international LNG news, reports on LNG related economics and statistics, and routinely conducts interviews with key industry leaders. In addition to providing consulting services to the LNG industry, IGT has cosponsored the International Conference on Liquefied Natural Gas for the part 20 years. The objective of this paper is to present a summary of our recent survey results as well as provide an overview of world LNG trade. This information is important in assessing the potential near term availability of LNG for transportation applications. The IGT LNG Survey appraised the capacity and current market activity of LNG peak shaving, satellite storage, and import receiving facilities in the United States and Canada. Information was requested from facilities on three main topics: liquefaction, storage, and regasification. Additional questions were posed regarding the year of operation, designer/contractor for liquefaction cycle and storage, source of LNG (for storage-only facilities), plans for expansion, and level of interest in providing LNG as a vehicle fuel. The IGT LNG Survey has to date received information on 56 LNG peak shaving facilities, 28 satellite storage facilities, and 4 LNG import receiving terminals.

Blazek, C.F.; Biederman, R.T.

1992-12-31

51

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

E-print Network

SIGNIFICANT EVENTS IN THE HISTORY OF LNG 1914 First (U.S.) patent awarded for LNG handling-shaving plant in Cleveland, an LNG storage tank with a low nickel- steel content (only 3.5%) fails. LNG spills

52

North American LNG Project Sourcebook  

SciTech Connect

The report provides a status of the development of LNG Import Terminal projects in North America, and includes 1-2 page profiles of 63 LNG projects in North America which are either in operation, under construction, or under development. For each project, the sourcebook provides information on the following elements: project description, project ownership, project status, projected operation date, storage capacity, sendout capacity, and pipeline interconnection.

NONE

2007-06-15

53

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

54

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

55

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

56

LNG plants in the US and abroad. [Liquefied Natural Gas (LNG)  

SciTech Connect

The Institute of Gas Technology recently conducted a comprehensive survey of LNG production and storage facilities in North America. This survey was performed as part of IGT's LNG Observer newsletter which covers both domestic and international LNG news, reports on LNG related economics and statistics, and routinely conducts interviews with key industry leaders. In addition to providing consulting services to the LNG industry, IGT has cosponsored the International Conference on Liquefied Natural Gas for the part 20 years. The objective of this paper is to present a summary of our recent survey results as well as provide an overview of world LNG trade. This information is important in assessing the potential near term availability of LNG for transportation applications. The IGT LNG Survey appraised the capacity and current market activity of LNG peak shaving, satellite storage, and import receiving facilities in the United States and Canada. Information was requested from facilities on three main topics: liquefaction, storage, and regasification. Additional questions were posed regarding the year of operation, designer/contractor for liquefaction cycle and storage, source of LNG (for storage-only facilities), plans for expansion, and level of interest in providing LNG as a vehicle fuel. The IGT LNG Survey has to date received information on 56 LNG peak shaving facilities, 28 satellite storage facilities, and 4 LNG import receiving terminals.

Blazek, C.F.; Biederman, R.T.

1992-01-01

57

Thermal Hazard from LNG Fireballs  

Microsoft Academic Search

Accidents with many hydrocarbon materials such as propane, butane and gasoline frequently result in the formation of fireballs. The shipment of liquified natural gas (LNG) involves large quantities of fuel which, in the event of an accident, could ignite to form a fireball. Depending on atmospheric conditions, the thermal effects from such a fireball could produce third degree skin burns

H. C. HARDEE; D. O. LEE; W. B. BENEDICK

1978-01-01

58

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

SciTech Connect

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

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

1981-12-01

59

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

PubMed

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

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

2007-02-20

60

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

61

77 FR 73627 - 2012 LNG Export Study  

Federal Register 2010, 2011, 2012, 2013, 2014

...impact of LNG exports on the U.S. economy using a general equilibrium macroeconomic model of the U.S. economy with an emphasis on the energy sector...impact of LNG exports on the U.S. economy using a general equilibrium...

2012-12-11

62

LNG links remote supplies and markets  

SciTech Connect

Liquefied natural gas (LNG) has established a niche for itself by matching remote gas supplies to markets that both lacked indigenous gas reserves and felt threatened in the aftermath of the energy crises of the 1970s and 1980s. It has provided a cost-effective energy source for these markets, while also offering an environmentally friendly fuel long before that was fashionable. The introduction of natural-gas use via LNG in the early years (mostly into France and Japan) has also allowed LNG to play a major role in developing gas infrastructure. Today, natural gas, often supplied as LNG, is particularly well-suited for use in the combined cycle technology used in independent power generation projects (IPPs). Today, LNG players cannot simply focus on monetizing gas resources. Instead, they must adapt their projects to meet the needs of changing markets. The impact of these changes on the LNG industry has been felt throughout the value chain from finding and producing gas, gas treatment, liquefaction, transport as a liquid, receiving terminals and regasification, and finally, to consumption by power producers, industrial users, and households. These factors have influenced the evolution of the LNG industry and have implications for the future of LNG, particularly in the context of worldwide natural gas.

Avidan, A.A.; Gardner, R.E.; Nelson, D.; Borrelli, E.N. [Mobil LNG Inc., Houston, TX (United States); Rethore, T.J. [Arthur D. Little Inc., Houston, TX (United States)

1997-06-02

63

Comparative safety analysis of LNG storage tanks  

Microsoft Academic Search

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

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

1982-01-01

64

Study of gelled LNG. Final technical report  

SciTech Connect

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

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

1980-01-01

65

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

66

Dispersion of UO{sub 2}F{sub 2} aerosol and HF vapor in the operating floor during winter ventilation at the Paducah Gaseous Diffusion Plant  

SciTech Connect

The gaseous diffusion process is currently employed at two plants in the US: the Paducah Gaseous Diffusion Plant and the Portsmouth Gaseous Diffusion Plant. As part of a facility-wide safety evaluation, a postulated design basis accident involving large line-rupture induced releases of uranium hexafluoride (UF{sub 6}) into the process building of a gaseous diffusion plant (GDP) is evaluated. When UF{sub 6} is released into the atmosphere, it undergoes an exothermic chemical reaction with moisture (H{sub 2}O) in the air to form vaporized hydrogen fluoride (HF) and aerosolized uranyl fluoride (UO{sub 2}F{sub 2}). These reactants disperse in the process building and transport through the building ventilation system. The ventilation system draws outside air into the process building, distributes it evenly throughout the building, and discharges it to the atmosphere at an elevated temperature. Since air is recirculated from the cell floor area to the operating floor, issues concerning in-building worker safety and evacuation need to be addressed. Therefore, the objective of this study is to evaluate the transport of HF vapor and UO{sub 2}F{sub 2} aerosols throughout the operating floor area following B-line break accident in the cell floor area.

Kim, S.H.; Chen, N.C.J.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W. [Oak Ridge National Lab., TN (United States); Carter, J.C. [J.C. Carter Associates, Inc., Knoxville, TN (United States)

1996-12-30

67

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

SciTech Connect

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

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

2011-09-28

68

46 CFR 154.703 - Methane (LNG).  

Code of Federal Regulations, 2014 CFR

... Design, Construction and Equipment Cargo Pressure and Temperature Control § 154.703 Methane (LNG). Unless...boil-off gas, and: (1) Maintains the stack exhaust temperature below 535 °C (995 °F); (2) Exhibits no visible...

2014-10-01

69

Damage-detection system for LNG carriers  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

70

Norcal Prototype LNG Truck Fleet: Final Results  

SciTech Connect

U.S. DOE and National Renewable Energy Laboratory evaluated Norcal Waste Systems liquefied natural gas (LNG) waste transfer trucks. Trucks had prototype Cummins Westport ISXG engines. Report gives final evaluation results.

Not Available

2004-07-01

71

LNG production for peak shaving operations  

SciTech Connect

LNG production facilities are being developed as an alternative or in addition to underground storage throughout the US to provide gas supply during peak gas demand periods. These facilities typically involved a small liquefaction unit with a large LNG storage tank and gas sendout facilities capable of responding to peak loads during the winter. Black and Veatch is active in the development of LNG peak shaving projects for clients using a patented mixed refrigerant technology for efficient production of LNG at a low installed cost. The mixed refrigerant technology has been applied in a range of project sizes both with gas turbine and electric motor driven compression systems. This paper will cover peak shaving concepts as well as specific designs and projects which have been completed to meet this market need.

Price, B.C.

1999-07-01

72

Potential seen for doubling U. S. LNG imports  

SciTech Connect

According to a U.S. Office of Technology Assessment report, Nigeria, Indonesia, Australia, Malaysia, Trinidad, Colombia, and Chile are the most likely sources of U.S. imports of LNG, although the areas with the greatest amounts of exportable surplus LNG are the Persian Gulf, with > 231 trillion cu ft/yr, and the U.S.S.R., with 439 trillion cu ft/yr. The import of LNG would increase the U.S. balance of payments deficit, but LNG imports seem preferable to oil imports. LNG producers have a tendency to sell to Europe or Japan, since these areas are closer to the LNG sources. Maritime Administration and Export-Import Bank programs favor the use of domestic rather than foreign LNG tankers, which tends to reduce the financial stake of foreign suppliers in uninterrupted deliveries. Exportable LNG surpluses (in trillions of cu ft/yr) include: Algeria, 8; Nigeria, 33; Southeast Asia, 41; and Western Hemisphere, 19.

Not Available

1980-04-21

73

Potential for BLEVE associated with marine LNG vessel fires.  

PubMed

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 that there is no inherent property of LNG excluding BLEVE-like events, although US LNG trucks would be safer due to design features. Marine LNG vessels have differently designed tanks and it is demonstrated that the combination of physical barriers makes direct thermal input to the LNG inner tank more limited than hypothesized by some, but if it occurs these tanks cannot rise to a pressure sufficient to cause a large flash of liquid and consequent BLEVE event of a scale hypothesized in the literature. PMID:17137713

Pitblado, Robin

2007-02-20

74

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

PubMed

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

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

2006-03-17

75

Analysis of liquefied natural gas (LNG) release prevention systems  

Microsoft Academic Search

Liquefied Natural Gas (LNG) is playing an important role in meeting the energy needs of the U.S. and other countries. Since one unit volume of LNG is equivalent to 600 unit volumes of natural gas, liquefaction permits large volumes of gas to be economically stored and transported. In the United States, LNG has a twenty-year record of safe handling and

P. J. Pelto; E. G. Baker

1984-01-01

76

International Trade in Natural Gas: Golden Age of LNG?  

E-print Network

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

Gabrieli, John

77

The diseconomics of long-haul LNG trading  

Microsoft Academic Search

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),

Stauffer

1995-01-01

78

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

79

Status report on GELNG (gelled LNG)  

SciTech Connect

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

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

1980-01-01

80

3 , LNG (Liquefied Natural Gas) -165oC  

E-print Network

Temperature to be maintained Gravity Contents in 1 m3 solid liquid -20oC -162oC 0.85 ~ 0.95 0.42 ~ 0.47 Natural Gas : 170 Nm3 Water : 0.8 m3 Natural Gas : 600 Nm3 #12; . PNG LNG . . , . 170cc 1cc -20oC -162oC LNG , . #12; LNG Boil-Off Gas (BOG

Hong, Deog Ki

81

Holographic investigation of thermal nonequilibrium vapor generation  

NASA Astrophysics Data System (ADS)

The vapor generation rate and associated thermal hydraulic parameters in a rapidly depressurizing, steady water flow was measured for understanding of the thermal nonequilibrium vapor generation process. This phenomenon is important for prediction and analysis of blowdown and flashing processes which may occur in nuclear reactor safety analysis (Loss of Coolant Accidents), in characterizing the expansion and flow of Liquified Gas (LNG) and develops alternative energy sources such as solar and geothermal. The development of advanced predictive capabilities for design and analysis of these and other similar systems is considered. The holographic recording and image analysis methods may evolve into a reliable and useful tool for two phase flow investigations.

Bates, J. M.

1984-04-01

82

Constraint Programming for LNG Ship Scheduling and Inventory ...  

E-print Network

also constructing the ships and the production-side terminals, berths and storage tanks. Operationally, a delivery .... In other words, LNG ships are always filled to their maximum capacity prior to departing an LNG ... ship requires one day of operation during which a berth has to be occupied. Ships are allowed to wait outside ...

2013-10-29

83

Optimal operation of a mixed fluid cascade LNG process  

E-print Network

Deparment of Chemical Engineering, NTNU Trondheim Norway Introduction Large amounts of natural gas (NG distances is to first produce liquefied natural gas (LNG) and then transport the LNG by ships pipelines or as compressed NG) to the customers. The most economic way of transport- ing NG over long

Skogestad, Sigurd

84

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

Code of Federal Regulations, 2011 CFR

(a) LNG impounding spaces must be located so that the heat flux from a fire over the impounding spaces does not cause structural damage to an LNG vessel moored or berthed at the waterfront facility handling LNG. (b) Each LNG loading flange must be located at least 300 meters...

2011-07-01

85

Union Pacific Railroad`s LNG locomotive test program  

SciTech Connect

Union Pacific Railroad is testing LNG in six locomotives through 1997 to determine if the liquefied natural gas technology is right for them. Two of the six LNG test locomotives are switch, or yard, locomotives. These 1,350 horsepower locomotives are the industry`s first locomotives totally fueled by natural gas. They`re being tested in the yard in the Los Angeles area. The other four locomotives are long-haul locomotives fueled by two tenders. These units are duel-fueled, operating on a mixture of LNG and diesel and are being tested primarily on the Los Angeles to North Platte, Nebraska corridor. All the information concerning locomotive emissions, locomotive performance, maintenance requirements, the overall LNG system design and the economic feasibility of the project will be analyzed to determine if UPR should expand, or abandon, the LNG technology.

Grimaila, B.

1995-12-31

86

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

87

Studies of capillary condensation of vapors in highly disperse systems Part 1. Calculation of capillary condensation in the vicinity of points of contact of spherical particles  

Microsoft Academic Search

Summary 1.A theoretical analysis of the process of capillary condensation in a system consisting of two contiguous spherical particles of the same radius has been conducted.2.An expression has been found for the meniscus of the liquid in a sorption cell, on the assumption of full wetting, and the volume of sorbed vapor has been calculated as a function of the

L. V. Radusbkerich

1952-01-01

88

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

89

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

E-print Network

. KURIAKOSE 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 Approved by: Chair of Committee, M. H. Kim Committee Members, Robert Randall...) Vinu P. Kuriakose, B.Tech., Cochin University of Science and Technology Chair of Advisory Committee: Dr. M. H. Kim Floating LNG terminals are a relatively new concept with the first such terminal in the world installed this year...

Kuriakose, Vinu P.

2005-11-01

90

Ultra-dispersive adaptive prism  

E-print Network

We have experimentally demonstrated an ultra-dispersive optical prism made from coherently driven Rb atomic vapor. The prism possesses spectral angular dispersion that is six orders of magnitude higher than that of a prism made of optical glass; it is the highest spectral angular dispersion that has ever been shown (such angular dispersion allows one to spatially resolve light beams with different frequencies separated by a few kHz). The prism operates near the resonant frequency of atomic vapor and its dispersion is optically controlled by a coherent driving field.

Vladimir A. Sautenkov; Hebin Li; Yuri V. Rostovtsev; Marlan O. Scully

2007-01-30

91

Norcal Prototype LNG Truck Fleet: Final Data Report  

SciTech Connect

U.S. DOE and National Renewable Energy Laboratory evaluated Norcal Waste Systems liquefied natural gas (LNG) waste transfer trucks. Trucks had prototype Cummins Westport ISXG engines. Report gives final data.

Chandler, K.; Proc, K.

2005-02-01

92

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

E-print Network

Liquefied natural gas (LNG) is estimated to account for a growing portion of the ..... Eqs. (2)-(4) are network-flow conservation constraints for each ship. ... since it achieves better utilization of the computational resources which directly impacts.

2014-04-17

93

International Trade in Natural Gas: Golden Age of LNG?  

E-print Network

The introduction of liquefied natural gas (LNG) as an option for international trade has created a market for natural gas where global prices may eventually be differentiated by the transportation costs between world ...

Du, Y.

94

Simulation and integration of liquefied natural gas (lng) processes  

E-print Network

Figure 1.2 World energy consumption by fuel.................................................. 3 Figure 1.3 Worldwide LNG exports in 2005..................................................... 8 Figure 1.4 Worldwide LNG imports in 2005... for exchanger E1_2_1 ..................... 84 Table 6.7 ICARUS fixed cost estimation for exchanger E1_3_1 ..................... 85 Table 6.8 ICARUS fixed cost estimation for exchanger E7_13_2 ................... 86 Table 6.9 ICARUS fixed cost...

Al-Sobhi, Saad Ali

2009-05-15

95

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

96

Offshore LNG (liquefied natural gas) production and storage systems  

Microsoft Academic Search

A barge, outfitted with gas liquefaction processing equipment and liquefied natural gas (LNG) storage tanks, is suggested as a possible way to exploit remote offshore gas production. A similar study with a barge-mounted methanol plant was conducted several years ago, also using remote offshore feed gas. This barge-mounted, LNG system is bow-moored to a single point mooring through which feed

Barden

1982-01-01

97

Rollover and Interfacial Studies in Lng Mixtures  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Requires signed TDF. An experimental investigation into LNG rollover has been performed, using cryogenic liquids to simulate a two-layered LNG system. A vacuum insulated glass vessel was designed and constructed for rollover simulation experiments. Thin metal oxide coatings on the inner jacket of the vessel enabled the simultaneous heating and visualisation of the liquid in the vessel. Mixtures of liquid nitrogen and liquid oxygen were successfully used to form two differing density layers. An oxygen analysing system with an accuracy of 0.01% by volume oxygen, and a fifteen junction copper -constantan thermocouple array were used for primary measurements of mass concentration and temperature. For a number of initial density differences between layers, various liquid layer heating configurations were used to obtain the variations in evaporation flowrate, and detailed temperature and concentration profiles during experiments. Convective flow patterns, in single and two -component liquid mixtures were obtained, using the Schlieren method. Results show that the mixing of layers is primarily due to entrainment of fluid from the intermediate layer separating the two convective layers. The intermediate layer can be described by Double-Diffusive convection theory, and controls the transport of heat and mass between layers. The measured peak flowrate is a function of the initial density difference between layers. The peak to equilibrium flowrate values are much lower than those reported in rollover incidents, due to the enhanced mixing processes occurring in the simulation mixture. A correlation between the evaporative mass flux and bulk fluid superheat fails during transient heating conditions, and cannot predict very high flowrates. Schlieren flow - visualisation studies clearly show various surface patterns for increasing surface evaporation mass fluxes.

Agbabi, Tom

1987-09-01

98

76 FR 53440 - Freeport LNG Development, LP; Freeport LNG Expansion, LP; FLNG Liquefaction LLC; Notice of Intent...  

Federal Register 2010, 2011, 2012, 2013, 2014

...existing liquefied natural gas (LNG) import terminal...and export of domestic natural gas. In addition, A nonjurisdictional...near the Stratton Ridge underground storage and meter station sites...components: Three natural gas liquefaction...

2011-08-26

99

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

100

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

101

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

Federal Register 2010, 2011, 2012, 2013, 2014

...released the report ``Liquefied Natural Gas Safety Research Report to Congress'' detailing the results of research conducted by Sandia National Laboratories on intentional breaches of LNG carrier cargo tanks and the resulting LNG spills on water. Based on...

2013-04-04

102

75 FR 29420 - Revision of LNG and LHG Waterfront Facility General Requirements  

Federal Register 2010, 2011, 2012, 2013, 2014

...handling liquefied natural gas (LNG) and...Waterway Safety, and the...hazardous gas LNG Liquefied natural gas LOI Letter...transportation of liquefied natural gas (LNG) has...pose similar risks to the waterway...applicant-prepared risk-based...

2010-05-26

103

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

104

75 FR 68347 - Sabine Pass Liquefaction LLC, and Sabine Pass LNG, L.P.; Notice of Intent To Prepare an...  

Federal Register 2010, 2011, 2012, 2013, 2014

...authorization to export up to 16 million metric tons per annum (mtpa) of domestic natural gas as LNG for a 20-year period, commencing...the natural gas, store the LNG, and export approximately 16 mtpa of LNG via LNG carriers. According to Sabine Pass, its...

2010-11-05

105

Developments in the safe design of LNG tanks  

NASA Astrophysics Data System (ADS)

The objective of this paper is to discuss how the gradual development of design concepts for liquefied natural gas (LNG) storage systems has helped to enhance storage safety and economy. The experience in the UK is compared with practice in other countries with similar LNG storage requirements. Emphasis is placed on the excellent record of safety and reliability exhibited by tanks with a primary metal container designed and constructed to approved standards. The work carried out to promote the development of new materials, fire protection, and monitoring systems for use in LNG storage is also summarized, and specific examples described from British Gas experience. Finally, the trends in storage tank design world-wide and options for future design concepts are discussed, bearing in mind planned legislation and design codes governing hazardous installations.

Fulford, N. J.; Slatter, M. D.

106

Landfill Gas Conversion to LNG and LCO{sub 2}. Final Report  

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. Work was done in the following areas: (1) production of natural gas pipeline methane for liquefaction at an existing LNG facility, (2) production of LNG from sewage digester gas, (3) the use of mixed refrigerants for process cooling in the production of LNG, liquid CO{sub 2} and pipeline methane, (4) cost estimates for an LNG production facility at the Arden Landfill in Washington PA.

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

2000-10-20

107

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

108

Soot-Free Combustion Of Methane And LNG  

NASA Technical Reports Server (NTRS)

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

Bossard, John

1992-01-01

109

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

110

Development of mid-scale and floating LNG facilities  

SciTech Connect

The development of large-scale base load LNG facilities has dominated the process industry for decades. However, in many areas of the world, base load facilities are not feasible due to inadequate reserves. Mid-scale facilities can be economically attractive in certain locations and, in fact, have several advantages which aid in their development. The PRICO II LNG liquefaction process offers a process configuration which fits well with these developments. The process has been used in a range of facility sizes from base load to peak shaving applications. In addition to onshore facilities, floating liquefaction facilities can be developed on barges or tankers to handle mid-scale to large scale LNG production. Concepts for several sizes and configurations of floating facilities have been developed using the PRICO II process integrated into a total production, liquefaction, and load-out system. This paper covers the PRICO process concept, application areas and facility configurations which are currently being developed for mid-scale and floating LNG facilities.

Price, B.C.; Mortko, R.A. [Black and Veatch Pritchard, Inc., Overland Park, KS (United States)

1998-12-31

111

A predictive model for rollover in stratified LNG tanks  

SciTech Connect

The incubation period preceding ''rollover'' within a stratified LNG tank involves intensive heat and mass transfers between layers. Numerical integration of equations describing these processes leads to predicted time-history and boil-off characteristics which are in excellent agreement with Sarsten's (1972) documentation of the LaSpezia rollover incident.

Heestand, J.; Meader, J.W.; Shipman, C.W.

1983-03-01

112

Field experiments on high expansion (HEX) foam application for controlling LNG pool fire.  

PubMed

Previous research suggests that high expansion foam with an expansion ratio of 500 to 1 is one of the best options for controlling liquefied natural gas (LNG) pool fire on land. However, its effectiveness heavily depends on the foam application rate, foam generator location, and the design of LNG spill containment dike. Examination of these factors is necessary to achieve the maximum benefit for applying HEX on LNG pool fires. While theoretical study of the effects of foam on LNG fires is important, the complicated phenomena involved in LNG pool fire and foam application increase the need for LNG field experimentation. Therefore, five LNG experiments were conducted at Texas A&M University's Brayton Fire Training Field. ANGUS FIRE provided Expandol solution to form 500 to 1 high expansion foam (HEX) and its latest LNG Turbex Fixed High Expansion Foam Generators. In this paper, data collected during five experiments are presented and analyzed. The effectiveness of high expansion foam for controlling LNG pool fires with various application rates at two different types of containment pits is discussed. LNG fire behaviors and the effects of dike wall height are also presented and discussed. PMID:19056175

Suardin, Jaffee A; Wang, Yanjun; Willson, Mike; Mannan, M Sam

2009-06-15

113

Investigation of propulsion system for large LNG ships  

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

114

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

115

Vapor-phase photo-oxidation of methanol over nano-size titanium dioxide clusters dispersed in MCM-41 host material part 2: catalytic properties and surface transient species.  

PubMed

We report in this paper on the ultraviolet-assisted vapor-phase oxidation of methanol at room temperature, with the help of nano-size clusters of titanium dioxide dispersed in an MCM-41 silicate matrix. The surface species formed during the adsorption/oxidation of methanol and the transformation that they undergo as a result of ultraviolet irradiation were monitored using in-situ Fourier transform infrared and thermal desorption spectroscopy techniques. Parallel experiments conducted on TiO2/MCM, bulk titania, and pristine MCM-41 samples helped in identifying the individual role of titanium dioxide and host matrix in these processes. The photo-catalytic oxidation of methanol, at concentrations of 0.1 to 1.1 mol% in air, gave rise to formation of CO2 and H2O as products, for both the TiO2/MCM and bulk TiO2 samples. No such reaction occurred on titania-free MCM. Furthermore, the rate of reaction depended upon the TiO2 content of a sample and also on the concentration of methanol in reaction mixture. Thus, the rate of conversion increased progressively with the increase in TiO2 loading from 5 to 21 wt% in TiO2/MCM samples, particularly for the experiments with high concentration of methanol. For low methanol concentration (0.1 mol%) in air, the effect of titania content in MCM was very small. The specific activity (per g of titania) of a sample, on the other hand, showed an inverse relationship with the loading of titanium dioxide in a sample. Infrared and temperature-programmed desorption results revealed that the mode of CH3OH adsorption and the reactivity of the transient species formed during the oxidation process were independent of the size of dispersed titania particles. Thus, the particles of approximately 2-6 nm size, present in TiO2/MCM, exhibited a chemisorption behavior similar to that of the bulk titania. The results of the present study provide strong evidence that the hydroxyl groups, both on the host matrix and at the titania sites, participate independently in the formation of methoxyl groups and at the same time promote the heterogeneous photo-catalytic oxidation of methanol molecules via formation of transient formate groups. Our results also show that the effect of titania crystallite size in the photo-catalytic properties relate mainly to the larger surface area and hence to the enhanced number of chemisorption sites, rather than to the changes in electronic properties. PMID:16010942

Bhattacharyya, K; Varma, S; Kumar, D; Tripathi, A K; Gupta, N M

2005-05-01

116

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

SciTech Connect

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

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

1998-02-01

117

Interim qualitative risk assessment for an LNG refueling station and review of relevant safety issues  

SciTech Connect

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

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

1997-07-01

118

Vapor fragrancer  

NASA Astrophysics Data System (ADS)

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

Sang, Q. Tran; Bryant, Timothy D.

1987-05-01

119

The role of consequence modeling in LNG facility siting.  

PubMed

Liquefied natural gas (LNG) project modeling focuses on two primary issues, facility siting and the physical layout of element spacing. Modeling often begins with an analysis of these issues, while ensuring code compliance and sound engineering practice. The most commonly performed analysis involves verifying compliance with the siting provisions of NFPA 59A, which primarily concern property-line spacing (offsite hazard impacts). If the facility is located in the US, compliance with 49 CFR 193 is also required. Other consequence modeling is often performed to determine the spacing of elements within the facility (onsite hazard impacts). Often, many issues concerning in-plant spacing are addressed with the guidance provided in Europe's LNG standard, EN-1473. Spacing of plant buildings in relation to process areas is also a concern as analyzed using the approach given in API RP 752. Studies may also include probabilistic analysis, depending on the perceived risk and cost of mitigation. PMID:16934395

Taylor, Dennis W

2007-04-11

120

US North Slope gas and Asian LNG markets  

USGS Publications Warehouse

Prospects for export of liquified natural gas (LNG) from Alaska's North Slope are assessed. Projected market conditions to 2010 show that new LNG capacity beyond announced expansions will be needed to meet regional demand and that supplies will probably come from outside the region. The estimated delivered costs of likely suppliers show that Alaska North Slope gas will not be competitive. The alternative North Slope gas development strategies of transport and sale to the lower 48 states and use on the North Slope for either enhanced oil recovery or conversion to liquids are examined. The alternative options require delaying development until US gas prices increase, exhaustion of certain North Slope oil fields, or advances occur in gas to liquid fuels conversion technology. ?? 1995.

Attanasi, E.D.

1994-01-01

121

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

122

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

123

77 FR 59603 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Oregon LNG Export...  

Federal Register 2010, 2011, 2012, 2013, 2014

...the export of approximately 9 million metric tons per annum (MTPA) of LNG via LNG carriers. Specifically, the Export Project...each capable of a liquefaction capacity of approximately 4.5 MTPA; Refrigerant storage; New flare system; and New...

2012-09-28

124

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

Federal Register 2010, 2011, 2012, 2013, 2014

...within the LNG Terminal site; Dredging an approximate 118 acre area in the Patapsco River to 45 feet below mean lower low water to accommodate the LNG vessels and transport of the processed dredge material to its disposal location; and...

2010-03-10

125

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Docket No. CP11-72-000] Sabine Pass Liquefaction, LLC and Sabine Pass LNG, L.P.; Notice of Application Take notice that on January 31, 2011, Sabine Pass Liquefaction, LLC and Sabine Pass LNG,...

2011-02-18

126

Coupling dynamic blow down and pool evaporation model for LNG.  

PubMed

Treating the dynamic effects of accidental discharges of liquefied natural gas (LNG) is important for realistic predictions of pool radius. Two phenomena have important influence on pool spread dynamics, time-varying discharge (blow down) and pool ignition. Time-varying discharge occurs because a punctured LNG tanker or storage tank drains with a decreasing liquid head and decreasing head-space pressure. Pool ignition increases the evaporation rate of a pool and consequently decreases the ultimate pool area. This paper describes an approach to treat these phenomena in a dynamic pool evaporation model. The pool evaporation model developed here has two separate regimes. Early in the spill, momentum forces dominate and the pool spreads independently of pool evaporation rate and the corresponding heat transfer rate. After the average pool depth drops below a minimum value, momentum forces are largely dissipated and the thin edges of the pool completely evaporate, so pool area is established by the heat transfer rate. The maximum extent of a burning pool is predicted to be significantly less than that of an unignited pool because the duration of the first regime is reduced by higher heat transfer rates. The maximum extent of an LNG pool is predicted to be larger upon accounting for blow down compared with using a constant average discharge rate. However, the maximum pool extent occurs only momentarily before retreating. PMID:17184912

Woodward, John L

2007-02-20

127

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

128

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

129

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

Code of Federal Regulations, 2010 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...

2010-07-01

130

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

131

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

Code of Federal Regulations, 2014 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...

2014-07-01

132

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

133

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

SciTech Connect

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.

Pera, C.J.; Moyer, C.B.

1993-01-06

134

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

E-print Network

In the liquefied natural gas (LNG) shipping industry, the phenomenon of slosh- ing can lead to the occurrence In the liquefied natural gas (LNG) shipping industry, sloshing refers to an hydraulic phenomenon which arises when are effectively part of the ship. The gas in the cargo is liquefied and kept at a very low temperature (-163C

135

A combined power cycle utilizing low-temperature waste heat and LNG cold energy  

Microsoft Academic Search

This paper has proposed a combined power system, in which low-temperature waste heat can be efficiently recovered and cold energy of liquefied natural gas (LNG) can be fully utilized as well. This system consists of an ammonia–water mixture Rankine cycle and an LNG power generation cycle, and it is modelled by considering mass, energy and species balances for every component

Xiaojun Shi; Defu Che

2009-01-01

136

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Docket No. CP11-32-000] Sabine Pass LNG, L.P.; Notice of Application November 22, 2010. Take notice that on November 12, 2010, Sabine Pass LNG, L.P. (Sabine Pass), 700 Milam Street, Suite 800, Houston,...

2010-11-30

137

The potential for LNG as a railroad fuel in the U.S.  

SciTech Connect

Freight railroad operations in the US represent a substantial opportunity for liquefied natural gas (LNG) to displace diesel fuel. With the promise of achieving an overwhelming economic advantage over diesel fuel, this paper presents some discussion to the question, ``Why is the application of LNG for railroad use in the US moving so slowly?'' A brief overview of the freight railroad operations in the US is given, along with a summary of several railroad LNG demonstration projects. US Environmental Protection Agency and California Air Resources Board exhaust emission regulations may cause the railroad industry to move from small-scale LNG demonstration projects to using LNG as a primary freight railroad transportation fuel in selected regions or route-specific applications.

Fritz, S.G.

2000-01-01

138

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

NASA Astrophysics Data System (ADS)

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

?aciak, Mariusz

2013-06-01

139

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

140

Chrysler to race hybrid electric-LNG car  

SciTech Connect

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

NONE

1994-03-07

141

Comparison of hypothetical LNG and fuel oil fires on water.  

PubMed

Large spills of refined petroleum products have been an occasional occurrence over the past few decades. This has not been true for large spills of liquefied natural gas (LNG). This paper compares the likely similarities and differences between accidental releases from a ship of sizable quantities of these different hydrocarbon fuels, their subsequent spreading, and possible pool-fire behavior. Quantitative estimates are made of the spread rate and maximum slick size, burn rate, and duration; effective thermal radiation; and subsequent soot generation. PMID:15036638

Lehr, William; Simecek-Beatty, Debra

2004-02-27

142

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

143

White paper: Preliminary assessment of LNG vehicle technology, economics, and safety issues, revision 1  

NASA Astrophysics Data System (ADS)

The objective of the study is to evaluate the potential of liquified natural gas (LNG) as a vehicle fuel, to determine market inches, and to identify needed technology improvements. The white paper is being issued when the work is approximately 30 percent complete to preview the study direction, draw preliminary conclusions, and make initial recommendations. Interim findings relative to LNG vehicle technology, economics, and safety are presented. It is important to decide if heavier hydrocarbons should be allowed in LNG vehicle fuel. Development of suitable refueling couplings and vehicle fuel supply pressure systems are recommended. Initial economics analyses considered transit buses and pickup and delivery trucks fueled via onsite liquefiers and imported LNG. Net user costs were more than (but in some cases close to) those for diesel fuel and gasoline. Lowering the cost of small-scale liquefiers would significantly improve the economics of LNG vehicles. New emissions regulations may introduce considerations beyond simple cost comparisons. LNG vehicle safety and available accident data are reviewed. Consistent codes for LNG vehicles and refueling facilities are needed.

Powars, Charles; Lucher, Dan; Moyer, Carl; Browning, Lou

1992-01-01

144

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

E-print Network

than other methods. For LOPA application, failure data are essential to compute risk frequencies. However, the failure data from the LNG industry are very sparse. Bayesian estimation is identified as one method to compensate for its weaknesses. It can...

Yun, Geun-Woong

2009-05-15

145

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

146

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Terminal LP, Bienville Offshore Energy Terminal Liquefied Natural Gas (LNG) Deepwater Port Application AGENCY: Maritime...construct, and operate a deepwater port for a liquefied natural gas deepwater port facility, located...

2012-06-26

147

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

148

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

149

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

150

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

151

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

152

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

153

Developments in non-utility uses of liquefied natural gas (LNG)  

SciTech Connect

The development uses, and market for liquefied natural gas (LNG) is addressed. Applications discussed include aircraft fuel, rocket fuel, diesel locomotive fuel, and as a refrigeration source for a shrimp boat in a demonstration program. 3 figs. (CBS)

Anderson, P.J.

1988-01-01

154

Calibrated vapor generator source  

SciTech Connect

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

155

Video-based training program for LNG plant personnel  

SciTech Connect

The Industrial Education Group at the Institute of Gas Technology (IGT) has developed video-based training programs for LNG plant personnel under the guidance of an industry advisory panel. The programs consist of 39 video taped lessons with accompanying text for peakshaving plant personnel and 24 video taped lessons with accompanying text for satellite plant personnel. A computer-based testing/grading/record-keeping service is also provided as an option with either program. The training programs were developed in response to requirements of the ''Liquefied Natural Gas Facilities: Federal Safety Standards'' issued by the Department of Transportation, Material Transportation Bureau's Research and Special Programs. That standard, promulgated under the Natural Gas Pipeline Safety Act of 1968, as amended, was issued in 1980 as a new Part 193 contained under Title 49 of the Code of Federal Regulations. Subpart H, ''Qualifications and Training,'' specifies the training requirements for operating and maintenance personnel. 5 tabs.

Bukacek, R.F.; Anderson, P.J.; Raines, J.T.

1986-04-01

156

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

157

HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION  

SciTech Connect

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

ANDERSON, T.J.

2006-12-20

158

Ocular dispersion  

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

159

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

SciTech Connect

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

Beck, Douglas S.

2003-01-10

160

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

161

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

PubMed Central

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

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

1996-01-01

162

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

Federal Register 2010, 2011, 2012, 2013, 2014

...natural gas), the equivalent of 8 million metric tons per annum (mtpa), from its proposed South Texas LNG Export Project (ST LNG...natural gas), the equivalent of 8 million metric tons per annum (mtpa), for a period of 25 years beginning on the earlier of...

2013-02-27

163

78 FR 35625 - Sabine Pass Liquefaction Expansion, LLC; Sabine Pass Liquefaction, LLC; Sabine Pass LNG, L.P...  

Federal Register 2010, 2011, 2012, 2013, 2014

...million metric tonnes of liquefied natural gas (LNG) per annum (mtpa) via LNG carriers. Trains 5 and 6 would comprise Stage 3 of...of 4.0 Bcf/d of natural gas and to export about 27 million mtpa. The SPLE Project would be located within areas that have...

2013-06-13

164

77 FR 66454 - Gulf LNG Liquefaction Company, LLC; Application for Long-Term Authorization To Export Liquefied...  

Federal Register 2010, 2011, 2012, 2013, 2014

...export up to 11.5 million tons per annum (mtpa) of domestically produced liquefied natural...contract authorization to export up to 11.5 mtpa of domestically produced LNG for 25 years...facilities with a capacity of up to 11.5 mtpa of LNG, plus enhancements to the...

2012-11-05

165

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

Microsoft Academic Search

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

Sophia Ruester; Anne Neumann

166

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

Microsoft Academic Search

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

Sophia Ruester; Anne Neumann

167

An Analysis of the Risks of a Terrorist Attack on LNG Receiving Facilities in the United States  

E-print Network

miles long.] Graphic produced by Google Earth. Abstract: The placement of liquefied natural gas (LNG;2DRAFT #12;Introduction The renewed interest in establishing liquefied natural gas (LNG) receiving, the continuing increase in demand for natural gas in the U.S., and the resurgence of U.S. natural gas prices

Wang, Hai

168

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

PubMed

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

2012-06-01

169

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

170

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

171

Water Vapor Protocol  

NSDL National Science Digital Library

The purpose of this activity is to measure the total precipitable water vapor (column water vapor) in the atmosphere above an observer's site. Students point a GLOBE/GIFTS water vapor instrument at the sun and record the voltage readings from a digital voltmeter. They observe sky conditions near the Sun and perform the Cloud Protocols. Intended outcomes are that students understand the concept that the atmosphere prevents some of the sun's light from reaching Earth's surface, how water vapor measurements relate to the hydrologic cycle, and how greenhouse gases, such as water vapor, play an important role in weather and climate. Supporting background materials for both student and teacher are included.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

172

Stratospheric water vapor feedback.  

PubMed

We show here that stratospheric water vapor variations play an important role in the evolution of our climate. This comes from analysis of observations showing that stratospheric water vapor increases with tropospheric temperature, implying the existence of a stratospheric water vapor feedback. We estimate the strength of this feedback in a chemistry-climate model to be +0.3 W/(m(2)?K), which would be a significant contributor to the overall climate sensitivity. One-third of this feedback comes from increases in water vapor entering the stratosphere through the tropical tropopause layer, with the rest coming from increases in water vapor entering through the extratropical tropopause. PMID:24082126

Dessler, A E; Schoeberl, M R; Wang, T; Davis, S M; Rosenlof, K H

2013-11-01

173

Stratospheric water vapor feedback  

PubMed Central

We show here that stratospheric water vapor variations play an important role in the evolution of our climate. This comes from analysis of observations showing that stratospheric water vapor increases with tropospheric temperature, implying the existence of a stratospheric water vapor feedback. We estimate the strength of this feedback in a chemistry–climate model to be +0.3 W/(m2?K), which would be a significant contributor to the overall climate sensitivity. One-third of this feedback comes from increases in water vapor entering the stratosphere through the tropical tropopause layer, with the rest coming from increases in water vapor entering through the extratropical tropopause. PMID:24082126

Dessler, A. E.; Schoeberl, M. R.; Wang, T.; Davis, S. M.; Rosenlof, K. H.

2013-01-01

174

Puerto Rico`s EcoElectrica LNG/power project marks a project financing first  

SciTech Connect

On Dec. 15, 1997, Enron International and Kenetech Energy Services achieved financial close on the $670 million EcoElectrica liquefied natural gas terminal and cogeneration project proposed for Puerto Rico. The project involves construction of a liquefied natural gas terminal, cogeneration plant, and desalination unit on the southern coast of Puerto Rico, in the Penuelas/Guayanilla area. EcoElectrica will include a 500-mw, combined-cycle cogeneration power plant fueled mainly by LNG imported from the 400 MMcfd Atlantic LNG project on the island of Trinidad. Achieving financial close on a project of this size is always a time-consuming matter and one with a number of challenges. These challenges were increased by the unique nature of both the project and its financing--no project financing had ever before been completed that combined an LNG terminal and power plant. The paper discusses the project, financing details and challenges, key investment considerations, and integrated project prospects.

Lammers, R. [Enron International, Houston, TX (United States); Taylor, S. [Kenetech Energy Systems Inc., Houston, TX (United States)

1998-02-23

175

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

176

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

177

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

178

Shock temperature as a criterion for the detonability of LNG/LPG constituents  

SciTech Connect

Detonation limit data obtained at ambient conditions for some aliphatic LNG/LNG constituents with oxygen and nitrogen (air) have been analyzed in search of a single critical parameter for detonation propagation. It was established the shock, rather than C-J reaction temperatures, provides a firm basis for marginal detonability prediction and that, furthermore, classical reaction mechanisms and relatively simple calculation methods can be used for their reliable evaluation. In this paper the result is used to formulate a criterion, for predicting composition limits to detonation. For the systems investigated, this criterion is accurate to within approximately 0.2% for fuel-lean and around 1% for fuel-rich mixtures.

Michels, H.J. (Imperial Coll. of Science and Technology, London (United Kingdom). Dept. of Chemical Engineering and Chemical Technology); Rashidi, F. (Middle East Technical Univ., Petroleum Engineering Dept. Ankara (Turkey))

1992-12-01

179

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

180

VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA  

E-print Network

1 VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA Rudnyi E of thermodynamic properties of the vapor and the vaporization process, coupling pressure measurements the various studies ina general way. New values for thermodynamic properties of the monomer and dimer vapor

Rudnyi, Evgenii B.

181

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

SciTech Connect

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

Staats, E.B.

1980-12-16

182

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

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

183

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

184

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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

185

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

186

Liquified Natural Gas (LNG) for Hawaii: Policy, Economic, and Technical Questions  

E-print Network

Liquified Natural Gas (LNG) for Hawaii: Policy, Economic, and Technical Questions This report Natural Gas for Hawai`i: Policy Economic and Technical Questions Prepared for the U.S. Department Hawai`i Energy Sustainability Program Task 4: Deliverable on Liquefied Natural Gas Prepared by FACTS

187

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

Code of Federal Regulations, 2014 CFR

(1) Personnel who work at the waterfront facility handling LNG including persons assigned for transfer operations, vessel personnel, and delivery and service personnel in the course of their business; (2) Coast Guard personnel; and (3) Other persons authorized by the operator;...

2014-07-01

188

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 (LSD) vanes are used to smoothly align the flow and minimize the losses. These vanes are fixed a diffuser with movable LSD vanes that can be incorporated into test rigs for centrifugal gas compressors

Demirel, Melik C.

189

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.

190

Vapor pressure of explosives  

Microsoft Academic Search

New vapor pressure data is presented for RDX, PETN, TNT, nitroglycerin, and ammonium nitrate. By comparison with the data of previous workers, it has been possible to calculate global vapor pressure expressions which are valid over a wide range of temperatures.

B. C. Dionne; D. P. Rounbehler; E. K. Achter; J. R. Hobbs; D. H. Fine

1986-01-01

191

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 ...

192

Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor Pressure Isotope Effects  

E-print Network

Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor pressures as a function of temperature and enthalpies of vaporization of a series of both liquid and solid. The applicability of this technique is first demonstrated by reproducing the vapor pressure isotope effect

Chickos, James S.

193

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

NASA Astrophysics Data System (ADS)

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

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

2007-09-01

194

A survey of vapor cloud explosions: Second update  

SciTech Connect

Since publishing a listing of vapor cloud explosion incidents in 1977 and 1983, Industrial Risk Insurers has maintained an active database on these incidents. This second update gives the available data and reference sources on all known incidents. Modeling of blast effects of vapor cloud explosions has evolved in recent years. The multi-energy method is very promising by presently only models quiescent clouds. Losses show that quiescent dispersion of clouds is not always realistic. Explosively dispersed clouds or violent dispersion of clouds have occurred recently. Very powerful explosions have resulted. As an insurance company trying to evaluate worse case scenarios, it is essential that research focuses on the modeling of explosively dispersed clouds or very turbulent clouds. The applicability of the multi-energy method or the development of new methods for turbulent clouds should be investigated. 8 refs., 1 tab.

Lenoir, E.M.; Davenport, J.A. (Industrial Risk Insurers, Hartford, CT (United States))

1993-01-01

195

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

196

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

Federal Register 2010, 2011, 2012, 2013, 2014

...liquefaction trains, each capable of producing a nominal 4.4 million metric tons of LNG per annum (mtpa), for a total capacity of 13.2 mtpa. In addition, Freeport also proposes to construct natural gas pretreatment facilities, located...

2012-09-19

197

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

Federal Register 2010, 2011, 2012, 2013, 2014

...there presently is no domestic reliance on the volumes...shows there is sufficient supply of natural gas to satisfy domestic demand from multiple other sources...United States not support domestic sale of those supplies. Freeport LNG...

2010-03-23

198

77 FR 277 - Sabine Pass Liquefaction, LLC and Sabine Pass LNG, L.P; Notice of Availability of the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Docket No. CP11-72-00] Sabine Pass Liquefaction, LLC and Sabine Pass LNG, L.P; Notice of Availability of the Environmental Assessment for the Proposed Sabine Pass Liquefaction Project The staff of the Federal...

2012-01-04

199

78 FR 25432 - Sabine Pass LNG, L.P., Sabine Pass Liquefaction, LLC; Notice of Availability of the Environmental...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [ Docket No. CP13-2-000] Sabine Pass LNG, L.P., Sabine Pass Liquefaction, LLC; Notice of Availability of the Environmental Assessment for the Proposed Sabine Pass Liquefaction Project Modification The staff of...

2013-05-01

200

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Commission [Docket No. CP13-552-000; Docket No. CP13-553-000] Sabine Pass Liquefaction Expansion, LLC, Sabine Pass Liquefaction, LLC, and Sabine Pass LNG, L.P., Cheniere Creole Trail Pipeline, L.P.; Notice of...

2013-10-18

201

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

202

Vapor resistant arteries  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

203

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

SciTech Connect

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

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

2007-09-15

204

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

PubMed

The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/ LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG. PMID:17937317

Jaramillo, Paulina; Griffin, W Michael; Matthews, H Scott

2007-09-01

205

AMTEC vapor-vapor series connected cells  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

206

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

207

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

208

Biofiltration of methanol vapor  

Microsoft Academic Search

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.

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

1993-01-01

209

Cost-effectiveness analysis of levonorgestrel-releasing intrauterine system (LNG-IUS) 13.5mg in contraception  

PubMed Central

Background LNG-IUS 13.5mg (total content) is a low-dose levonorgestrel intrauterine system for up to three years of use. This analysis evaluated the cost-effectiveness of LNG-IUS 13.5mg in comparison with short-acting reversible contraceptive (SARC) methods in a cohort of young women in the US from a third-party payer’s perspective. Study Design A state-transition model consisting of three mutually exclusive health states – initial method, unintended pregnancy (UP) and subsequent method – was developed. Cost-effectiveness of LNG-IUS 13.5mg was assessed versus SARC methods in a cohort of 1,000 women aged 20–29 years. SARC methods comprise oral contraceptives (OC), ring, patch and injections which are the methods commonly used by this cohort. Failure and discontinuation probabilities were based on published literature, contraceptive uptake was determined by the most recent data from the National Survey of Family Growth and costs were taken from standard US databases. One-way sensitivity analysis was conducted around key inputs while scenario analysis assessed a comparison between LNG-IUS 13.5mg and the existing IUS, LNG-IUS 20mcg/24 hours. The key model output was cost per UP avoided. Results Compared to SARC methods, initiating contraception with LNG-IUS 13.5mg resulted in fewer UP (64 UP vs. 276 UP) and lower total costs ($1,283,479 USD vs. $1,862,633 USD, a 31% saving) over the three-year time horizon. Results were most sensitive to the probability of failure on OC, the probability of LNG-IUS 13.5mg discontinuation and the cost of live births. Scenario analysis suggests that further cost savings may be generated with the initiation of LNG-IUS 20mcg/24 hours in place of SARC methods. Conclusions From a third-party payer perspective, LNG-IUS 13.5mg is a more cost-effective contraceptive option than SARC. Therefore, women switching from current SARC use to LNG-IUS 13.5mg are likely to generate cost savings to third-party healthcare payers, driven principally by decreased UP-related expenditures and long-term savings in contraceptive costs. PMID:24576791

Trussell, James; Hassan, Fareen; Henry, Nathaniel; Pocoski, Jennifer; Law, Amy; Filonenko, Anna

2014-01-01

210

Second Stage Intercooling Using LNG for Turbocharged Heavy Duty Road Vehicles Phase I Final Report  

SciTech Connect

It is well documented in engine performance literature that reduced engine inlet air temperature increases power output and reduces NO, emissions for both diesel and spark ignited (SI) engines. In addition, reduced inlet temperature increases the knock resistance of SI engines. In that most HD natural gas engines are SI derivatives of diesel engines it is appropriate to evaluate the benefits of reduced engine air temperature through LNG fuel. This project investigated the ''real world'' possibilities of a patented process for utilizing the ''cold'' in LNG to chill engine inlet air. The results support the conclusion that doing so is a practical means to increase engine power and reduce engine-out NO{sub x}.

None

1999-09-21

211

Integrated Cryogenic System for CO2 Separation and Lng Production from Landfill Gas  

NASA Astrophysics Data System (ADS)

An integrated cryogenic system to separate carbon dioxide (CO2) and produce LNG from landfill gas is investigated and designed. The main objective of this design is to eliminate the requirement of a standard CO2 removal process in the liquefaction system such distillation or (temperature or pressure) swing adsorption, and to directly separate carbon dioxide as frost at the liquefying channel of methane. Two identical sets of heat exchangers are installed in parallel and switched alternatively with a time period so that one is in separation-liquefaction mode while the other is in CO2 clean-up mode. A thermal regeneration scheme is presented for the purpose of saving energy and avoiding the stoppage of LNG production followed by the flow switching. The switching period is determined from results of a combined heat and mass transfer analysis on the CO2 freeze-out process.

Chang, H. M.; Chung, M. J.; Park, S. B.

2010-04-01

212

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

213

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

214

An exergy analysis of small-scale liquefied natural gas (LNG) liquefaction processes  

Microsoft Academic Search

Four processes for small-scale liquefied natural gas (LNG) production are evaluated. These include a single-stage mixed refrigerant (SMR), a two-stage expander nitrogen refrigerant and two open-loop expander processes. Steady-state simulations were undertaken to ensure that each process was compared on an identical basis, was fully optimised and was in agreement with published results. Composite curves for the feed and recycle

C. W. Remeljej; A. F. A. Hoadley

2006-01-01

215

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

216

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

217

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

218

Vapor transport mechanisms  

NASA Technical Reports Server (NTRS)

The Raman scattering furnace for investigating vapor transport mechanisms was completed and checked out. Preliminary experiments demonstate that a temperature resolution of plus and minus 5 C is possible with this system operating in a backscatter mode. In the experiments presented with the GeI 4 plus excess Ge system at temperatures up to 600 C, only the GeI4 band at 150 cm superscript minus 1 was observed. Further experiments are in progress to determine if GeI2 does become the major vapor species above 440 C.

Workman, G. L.

1978-01-01

219

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

220

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

221

BTSC VAPOR INSTRUSION PRIMER "VAPOR INTRUSION CONSIDERATION FOR REDEVELOPMENT"  

EPA Science Inventory

This primer is designed for brownfields stakeholders concerned about vapor intrusion, including property owners, real estate developers, and contractors performing environmental site investigations. It provides an overview of the vapor intrusion issue and how it can impact the ap...

222

Cesar water vapor, aerosol  

E-print Network

Fig ure A: Cesar water vapor, aerosol and Clo ud lidar (Cae li) Fig ure B: IIR 3-channe l composite) Fig ure C: Lidar returns on 13 Sept. 2006 from Caeli (To p) and CALIPSO (bottom) 1) KNMI Royal aerosol property profiles measured with lidar M. de Graaf 1,2 , D.P. Donovan 1 , A. Apituley 2 , K

Graaf, Martin de

223

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

224

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

225

Propandiol vapor nucleation rates  

NASA Astrophysics Data System (ADS)

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

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

2000-08-01

226

BioVapor Model Evaluation  

EPA Science Inventory

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

227

Vapor Pressure measurements for dichlorosilane  

E-print Network

trichlorosilane and silicon tetrachloride, or other chemicals which are not in the silane family. Accurate information about the vapor pressure is necessary in the production of these mixtures. Measurements reported previously for the vapor pressure of pure...

Morris, Tony Knimbula

2012-06-07

228

Chemical vapor deposition reactor. [providing uniform film thickness  

NASA Technical Reports Server (NTRS)

An improved chemical vapor deposition reactor is characterized by a vapor deposition chamber configured to substantially eliminate non-uniformities in films deposited on substrates by control of gas flow and removing gas phase reaction materials from the chamber. Uniformity in the thickness of films is produced by having reactive gases injected through multiple jets which are placed at uniformally distributed locations. Gas phase reaction materials are removed through an exhaust chimney which is positioned above the centrally located, heated pad or platform on which substrates are placed. A baffle is situated above the heated platform below the mouth of the chimney to prevent downdraft dispersion and scattering of gas phase reactant materials.

Chern, S. S.; Maserjian, J. (inventors)

1977-01-01

229

7, 1183911894, 2007 Vapor pressure  

E-print Network

ACPD 7, 11839­11894, 2007 Vapor pressure prediction J. F. Pankow and W. E. Asher Title Page pressures and enthalpies of vaporization of multifunctional organic compounds J. F. Pankow 1 and W. E. Asher (pankow@ebs.ogi.edu) 11839 #12;ACPD 7, 11839­11894, 2007 Vapor pressure prediction J. F. Pankow and W. E

Paris-Sud XI, Université de

230

Vapor Pressure Formulation for Ice  

Microsoft Academic Search

A new formulation is presented for the vapor pressure of ice from the triple point to —100 °C based on thermodynamic calculations. Use is made of the definitive experimental value of the vapor pressure of water at its triple point recently obtained by Guildner, Johnson, and Jones. A table is given of the vapor pressure as a function of temperature

Arnold Wexler

1977-01-01

231

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

232

Deposition of Highly Dispersed Gold on Alumina Support  

Microsoft Academic Search

Gold catalysts of Au\\/Al2O3, prepared by the methods of deposition precipitation (DP, AuCl3 was the precursor of gold) and chemical vapor deposition (CVD, an organic gold complex was the precursor), were tested in the reaction of CO oxidation at subambient temperatures. The activity observed for prepared catalysts generally increased with their gold dispersion characterized by transmission electron microscopy. Finely dispersed

Yeong-Jey Chen; Chuin-tih Yeh

2001-01-01

233

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

234

Public summaries of feasibility studies conducted for the trinidad LNG project. Export trade information  

SciTech Connect

The study, conducted by The M. W. Kellog Company, was funded by the U.S. Trade and Development Agency on behalf of the National Gas Company of Trinidad and Tobago. It shows the results of Project Definition Phase which was implemented as a follow-up to two previous feasibility studies which were conducted for a LNG plant in Trinidad. The objective of this report is to develop a project design basis and implementation plan plus a cost estimate. The study is divided into the following sections: (1) Introduction; (2) Project Design Basis; (3) Seismic Hazard Assessment; (4) Geotechnical; and (5) Environmental Assessment.

NONE

1995-04-01

235

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

236

Chemical vapor deposition growth  

NASA Technical Reports Server (NTRS)

A chemical vapor deposition (CVD) reactor system with a vertical deposition chamber was used for the growth of Si films on glass, glass-ceramic, and polycrystalline ceramic substrates. Silicon vapor was produced by pyrolysis of SiH4 in a H2 or He carrier gas. Preliminary deposition experiments with two of the available glasses were not encouraging. Moderately encouraging results, however, were obtained with fired polycrystalline alumina substrates, which were used for Si deposition at temperatures above 1,000 C. The surfaces of both the substrates and the films were characterized by X-ray diffraction, reflection electron diffraction, scanning electron microscopy optical microscopy, and surface profilometric techniques. Several experiments were conducted to establish baseline performance data for the reactor system, including temperature distributions on the sample pedestal, effects of carrier gas flow rate on temperature and film thickness, and Si film growth rate as a function of temperature.

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

1976-01-01

237

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

238

Biofiltration of gasoline vapors from a soil vapor extraction system  

SciTech Connect

Biofiltration was used to treat gasoline vapors produced by soil vapor extraction (SVE) from an area contaminated by a leaking underground gasoline tank. The biofilter was installed upstream of an activated carbon unit. The biofilter removed 25--50% of the vapors in the early months of the project, when more volatile components dominated. Later, the vapors were mostly less volatile materials, and the biofilter removed 40--75%. This behavior was predicted by bench scale experiments. The biofilter was economically successful, and the project provided data for projecting the economic viability of biofilters in similar applications.

Devinny, J.S.; Chang, A.N. [Univ. of Southern California, Los Angeles, CA (United States). Civil and Environmental Engineering; Hodge, D.S.; Reynolds, F.E. Jr. [Reynolds Group, Tustin, CA (United States)

1995-11-01

239

Analysis of heat transfer to axial dispersed flow between rod bundles under reactor emergency cooling conditions  

Microsoft Academic Search

Analysis is carried out for dispersed flow heat transfer under reactor emergency cooling conditions. The present formulation explicitly reveals an extra dependence of the heat transfer coefficient and Nusselt number on the mean vapor temperature for droplet dispersed flow which is not found in single phase flow heat transfer. The heat transfer results obtained from three different geometries: an infinite

S. Wong; L. E. Hochreiter

1980-01-01

240

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

Federal Register 2010, 2011, 2012, 2013, 2014

...to of 15 million metric tons per annum (mtpa), the equivalent of 730 billion cubic...of 1.8 Bcf/d of natural gas (13.7 mtpa of LNG); a peak send-out capacity of...LCE and TLNG Export will not exceed 15 mtpa (approximately 730 Bcf/y)....

2013-03-20

241

Comparative analysis of liquefied natural gas (LNG) and compressed natural gas (CNG) used by transit agencies in Texas. Research report  

Microsoft Academic Search

This study is a detailed comparative analysis of liquefied natural gas (LNG) and compressed natural gas (CNG). The study provides data on two alternative fuels used by transit agencies in Texas. First, we examine the `state-of-the- art` in alternative fuels to established a framework for the study. Efforts were made to examine selected characteristics of two types of natural gas

Lede

1997-01-01

242

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

Microsoft Academic Search

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

Marte Ulvestad; Indra Overland

2012-01-01

243

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

Microsoft Academic Search

The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of

Paulina Jaramillo; W. Michael Griffin; H. Scott Matthews

2007-01-01

244

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Notice of Petition To Amend Authorizations Under Section 3 of the Natural Gas Act; Cameron LNG, LLC September 15, 2010...2003, in Docket No. CP02-378- 000 under section 3 of the Natural Gas Act operate its existing liquefied...

2010-09-22

245

Studies on formation of unconfined detonable vapor cloud using explosive means.  

PubMed

Certain organic liquid fuels like hydrocarbons, hydrocarbon oxides, when dispersed in air in the form of small droplets, mix with surrounding atmosphere forming vapor cloud (aerosol) and acquire explosive properties. This paper describes the studies on establishment of conditions for dispersion of fuels in air using explosive means resulting in formation of detonable aerosols of propylene oxide and ethylene oxide. Burster charges based on different explosives were evaluated for the capability to disperse the fuels without causing ignition. Parameters like design of canister, burster tube, burster charge type, etc. have been studied based on dispersion experiments. The detonability of the aerosol formed by the optimized burster charge system was also tested. PMID:23618658

Apparao, A; Rao, C R; Tewari, S P

2013-06-15

246

Vapor Diffusion Apparatus  

NASA Technical Reports Server (NTRS)

Vapor Diffusion Apparatus (VDA and VDA-2) was developed by the University of Alabama in Birmingham for NASA's Marshall Space Flight Center. In the original VDA, a protein solution and a precipitant are extruded by two plungers onto the tip of a small syringe and allowed to evaporate, raising the concentration and prompting protein molecules to crystallize. In the VDA-2 version, a third plunger was added to mix the two solutions before returning the mix to the syringe tip. The principal investigator is Dr. Larry Delucas of the University of Alabama in Birmingham

2001-01-01

247

Vapor Diffusion Apparatus  

NASA Technical Reports Server (NTRS)

Vapor Diffusion Apparatus (VDA-2) was developed by the University of Alabama in Birmingham for NASA's Marshall Space Flight Center. In the original VDA, a protein solution and a precipitant are extruded by two plungers onto the tip of a small syringe and allowed to evaporate, raising the concentration and prompting protein molecules to crystallize. In the VDA-2 version, a third plunger was added to mix the two solutions before returning the mix to the syringe tip. The principal investigator is Dr. Larry Delucas of the University of Alabama in Birmingham.

2001-01-01

248

Hydrazine-Vapor Samplers  

NASA Technical Reports Server (NTRS)

Active sampling unit capable of detecting hydrazine and monomethyl hydrazine vapors at levels as low as 10 ppb in air developed. Includes detachable badge holder and pump which draws air through badge holder at selectable rate of 1 or 2 L/min. Coated strip in each badge designed to align with air passage in badge holder. Two types of badge holders constructed: one has open-face design for general monitoring of air in open spaces, while other has closed-face design with viewing window and intended for sampling through small openings to detect leaks.

Young, Rebecca; Mcbrearty, Charles; Curran, Dan; Leavitt, Nilgun

1994-01-01

249

Vapor-Liquid Equilibria for Some Concentrated Aqueous PolymerSolutions  

SciTech Connect

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

Striolo, Alberto; Prausnitz, John M.

1999-07-01

250

Water Vapor Circulation on Earth  

NSDL National Science Digital Library

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

2010-08-27

251

Vapor pressure of perfluoroalkylalkanes: the role of the dipole.  

PubMed

The vapor pressure of four liquid perfluoroalkylalkanes (CF3(CF2)n(CH2)mCH3; n = 3, m = 4,5,7; n = 5, m = 5) was measured as a function of temperature between 278 and 328 K. Molar enthalpies of vaporization were calculated from the experimental data, and the results were compared with data from the literature for the corresponding alkanes and perfluoroalkanes. The heterosegmented statistical associating fluid theory was used to interpret the results at the molecular level both with and without the explicit inclusion of the dipolar nature of the molecules. Additionally, ab initio calculations were performed for all perfluoroalkylalkanes studied to determine the dipole moment to be used in the theoretical calculations. We demonstrate that the inclusion of a dipolar term is essential for describing the vapor-liquid equilibria of perfluoroalkylalkanes. It is also shown that vapor-liquid equilibria in these compounds result from a subtle balance between dipolar interactions, which decrease the vapor pressure, and the relatively weak dispersive interactions between the hydrogenated and fluorinated segments. PMID:25526174

Morgado, Pedro; Das, Gaurav; McCabe, Clare; Filipe, Eduardo J M

2015-01-29

252

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

253

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

E-print Network

Vapor Pressures and Vaporization Enthalpies of a Series of Dialkyl Phthalates by Correlation Gas in this regard include dimethyl phthalate dimethyl terephthalate, dimethyl isophthalate, diethyl phthalate, dibutyl phthalate, and bis(2-ethylhexyl) phthalate. New vaporization enthalpies and liquid vapor pressure

Chickos, James S.

254

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...

255

DISPERSAL IN FRESHWATER INVERTEBRATES  

Microsoft Academic Search

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

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

2001-01-01

256

Analysis of Class 8 Hybrid-Electric Truck Technologies Using Diesel, LNG, Electricity, and Hydrogen, as the Fuel for Various Applications  

E-print Network

Lower Heating Value Liquefied Natural Gas Powertrain Systemsoptions included liquefied natural gas (LNG) used in SI andliquefied from pressure drop between CNG transmission lines and distribution lines ‡ Natural gas

Zhao, Hengbing

2013-01-01

257

Advanced Raman water vapor lidar  

Microsoft Academic Search

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

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

1992-01-01

258

Student Exposure to Mercury Vapors.  

ERIC Educational Resources Information Center

Discusses the problem of mercury vapors caused by spills in high school and college laboratories. Describes a study which compared the mercury vapor levels of laboratories in both an older and a newer building. Concludes that the mercurial contamination of chemistry laboratories presents minimal risks to the students. (TW)

Weber, Joyce

1986-01-01

259

Chemical vapor deposition growth  

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

260

Vapor compression distillation module  

NASA Technical Reports Server (NTRS)

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

Nuccio, P. P.

1975-01-01

261

SOFIA Water Vapor Monitor Design  

NASA Technical Reports Server (NTRS)

The SOFIA Water Vapor Monitor (WVM) is a heterodyne radiometer designed to determine the integrated amount of water vapor along the telescope line of sight and directly to the zenith. The basic technique that was chosen for the WVM uses radiometric measurements of the center and wings of the 183.3 GHz rotational line of water to measure the water vapor. The WVM reports its measured water vapor levels to the aircraft Mission Controls and Communication System (MCCS) while the SOFIA observatory is in normal operation at flight altitude. The water vapor measurements are also available to other scientific instruments aboard the observatory. The electrical, mechanical and software design of the WVM are discussed.

Cooper, R.; Roellig, T. L.; Yuen, L.; Shiroyama, B.; Meyer, A.; Devincenzi, D. (Technical Monitor)

2002-01-01

262

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

263

Vapor pressure measured with inflatable plastic bag  

NASA Technical Reports Server (NTRS)

Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

1965-01-01

264

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

265

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

266

Precision ozone vapor pressure measurements  

NASA Technical Reports Server (NTRS)

The vapor pressure above liquid ozone has been measured with a high accuracy over a temperature range of 85 to 95 K. At the boiling point of liquid argon (87.3 K) an ozone vapor pressure of 0.0403 Torr was obtained with an accuracy of + or - 0.7 percent. A least square fit of the data provided the Clausius-Clapeyron equation for liquid ozone; a latent heat of 82.7 cal/g was calculated. High-precision vapor pressure data are expected to aid research in atmospheric ozone measurements and in many laboratory ozone studies such as measurements of cross sections and reaction rates.

Hanson, D.; Mauersberger, K.

1985-01-01

267

Is dispersal neutral?  

PubMed

Dispersal is difficult to quantify and often treated as purely stochastic and extrinsically controlled. Consequently, there remains uncertainty about how individual traits mediate dispersal and its ecological effects. Addressing this uncertainty is crucial for distinguishing neutral versus non-neutral drivers of community assembly. Neutral theory assumes that dispersal is stochastic and equivalent among species. This assumption can be rejected on principle, but common research approaches tacitly support the 'neutral dispersal' assumption. Theory and empirical evidence that dispersal traits are under selection should be broadly integrated in community-level research, stimulating greater scrutiny of this assumption. A tighter empirical connection between the ecological and evolutionary forces that shape dispersal will enable richer understanding of this fundamental process and its role in community assembly. PMID:24962790

Lowe, Winsor H; McPeek, Mark A

2014-08-01

268

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

269

Vapor detection using resonating microcantilevers  

SciTech Connect

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

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

1995-02-01

270

Vapor phase SAW immunoassay sensors  

Microsoft Academic Search

In this paper, we present the results of a series of experiments demonstrating real-time vapor phase detection of cocaine molecules using immunosensors based on surface acoustic wave (SAW) resonators.

D. D. Stubbs; Sang-Hun Lee; W. D. Hunt

2002-01-01

271

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

272

Formation of thermal decomposition cavities in physical vapor transport of silicon carbide  

Microsoft Academic Search

The relationship between seed mounting and the formation of thermal decomposition cavities in physical vapor transport grown silicon carbide was investigated. Scanning electron microscopy, energy dispersive x-ray spectroscopy, Auger electron spectroscopy, and optical microscopy were used to characterize thermal decomposition cavities at various stages of their development. The observations indicate that the attachment layer that holds the seed to the

Edward K. Sanchez; Thomas Kuhr; Volker D. Heydemann; David W. Snyder; Gregory S. Rohrer; Marek Skowronski

2000-01-01

273

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

274

Vapor deposition of hardened niobium  

DOEpatents

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

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

1983-04-19

275

A micromachined vapor jet pump  

Microsoft Academic Search

Initial results from a micro-pump based on the principle of macroscopic vapor-jet- and diffusion-pumps are presented. A mathematical description of the underlying gas dynamics is given and equations for the calculation of pump geometry are derived. Several planar micro-vapor jet pumps with different geometries were designed and fabricated by means of silicon micromachining (STS Advanced Silicon Etch™). The pumps consist

M. Doms; J. Mueller

2005-01-01

276

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

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

277

Vapor passage fuel blockage removal  

SciTech Connect

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

Faeth, W.P.

1993-08-31

278

Dispersal of forest insects  

NASA Technical Reports Server (NTRS)

Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

Mcmanus, M. L.

1979-01-01

279

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

280

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

281

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

282

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

E-print Network

Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures The vaporization enthalpies and vapor pressures of the liqiud phase from T ) 298.15 K to T ) 500 K of a series in the literature was measured on a hydrated form. Vapor pressures and normal boiling temperatures for the liquid

Chickos, James S.

283

Quantitative dispersion microscopy  

PubMed Central

Refractive index dispersion is an intrinsic optical property and a useful source of contrast in biological imaging studies. In this report, we present the first dispersion phase imaging of living eukaryotic cells. We have developed quantitative dispersion microscopy based on the principle of quantitative phase microscopy. The dual-wavelength quantitative phase microscope makes phase measurements at 310 nm and 400 nm wavelengths to quantify dispersion (refractive index increment ratio) of live cells. The measured dispersion of living HeLa cells is found to be around 1.088, which agrees well with that measured directly for protein solutions using total internal reflection. This technique, together with the dry mass and morphology measurements provided by quantitative phase microscopy, could prove to be a useful tool for distinguishing different types of biomaterials and studying spatial inhomogeneities of biological samples. PMID:21113234

Fu, Dan; Choi, Wonshik; Sung, Yongjin; Yaqoob, Zahid; Dasari, Ramachandra R.; Feld, Michael

2010-01-01

284

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

285

A model for dispersed flow heat transfer in rod bundles during reflood  

Microsoft Academic Search

The present model calculates the heat transfer characteristics of the non-equilibrium dispersed droplet flow regime above the quench front during reflood by solving simultaneously the wall-to-vapor interactions, wall-to-droplet interactions and vapor-to-droplet interactions by an iterative numerical method. The unique feature in the present study is various heat transfer mechanisms are combined in an overall energy balance equation, and the convective

1980-01-01

286

A model for the differentiation of components in a gas cloud dispersion in a gravity field  

NASA Astrophysics Data System (ADS)

The gas dynamics of a disintegrating multicomponent vapor cloud in vacuum in the presence of gravity field is investigated in connection with the development of a shock vaporization model for the accretion stage of planet formation. It is shown that the vaporization of matter as a result of a high-velocity impact and the subsequent dispersion will result in a partial escape of vapor outside the growing planet if the combined gas-dynamical and thermal velocity of the atomic-molecular particles is higher than the escape velocity. The selective dissipation of the impact-generated cloud is one of the mechanisms of planetary matter differentiation at the accretion stage. The differentiation is brought about by the difference of the thermal velocities of vapor-cloud components of different masses during the transition from the expansion phase of the cloud to nonimpact regime.

Manzon, B. M.; Khrilev, I. L.; Iakovlev, O. I.

1990-02-01

287

Series-Connected Vapor/Vapor AMTEC Cells  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

288

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

E-print Network

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

Chickos, James S.

289

Electrical Breakdown in Water Vapor  

SciTech Connect

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

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

2011-11-15

290

Pallid Sturgeon Egg Dispersal  

USGS Multimedia Gallery

Fertilized pallid sturgeon eggs are gently dispersed over the gravel substrate.  The PVC pipes are used to support a canopy of shade cloth to more closely mimic the muddy depths of the Missouri River. ...

291

Chapter 6--Dispersal Introduction  

E-print Network

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

del Moral, Roger

292

Dispersion management with filtering.  

PubMed

We present analytical and numerical results for dispersion-managed solitons in a fiber link including guiding filters and compensating gain, both taken in the distributed approximation. Stationary propagation regimes with anomalous, zero, and normal path-average dispersion (PAD) are identified. New features, compared with those of the case without filters, are the absence of a critical strength for propagation at zero and normal PAD and, instead, the existence of a critical power for stationary propagation at any PAD. PMID:18071554

Berntson, A; Malomed, B A

1999-04-15

293

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

294

Low level vapor verification of monomethyl hydrazine  

NASA Technical Reports Server (NTRS)

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

Mehta, Narinder

1990-01-01

295

Quantification of vapor screen analysis  

NASA Astrophysics Data System (ADS)

The traditionally qualitative method of vapor screening is applied to the task of gathering quantitative density measurements in supersonic flows. Quantitative density information for flow around a two-dimensional biconvex airfoil at Mach 2.8 is extracted from digitized images of vapor screens by assuming a linear relation between particle density and scattering intensity. Intensity readings are calibrated through known conditions in the free stream and at the airfoil bow shock. The experimental results are compared to densities generated by a Euler code and determined to have errors of less than ten percent.

Benedict, Lance H.; Griffith, Wayland C.; Yanta, William J.; Spring, W. C., III; Boyd, Christopher F.

1991-06-01

296

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

297

Method and apparatus for vapor detection  

NASA Technical Reports Server (NTRS)

The method disclosed herein may be practiced by passing the vapors to be sampled along a path with halogen vapor, preferably chlorine vapor, heating the mixed vapors to halogenate those of the sampled vapors subject to halogenation, removing unreacted halogen vapor, and then sensing the vapors for organic halogenated compounds. The apparatus disclosed herein comprises means for flowing the vapors, both sample and halogen vapors, into a common path, means for heating the mixed vapors to effect the halogenation reaction, means for removing unreacted halogen vapor, and a sensing device for sensing halogenated compounds. By such a method and means, the vapors of low molecular weight hydrocarbons, ketones and alcohols, when present, such as methane, ethane, acetone, ethanol, and the like are converted, at least in part, to halogenated compounds, then the excess halogen removed or trapped, and the resultant vapors of the halogenated compounds sensed or detected. The system is highly sensitive. For example, acetone in a concentration of 30 parts per billion (volume) is readily detected.

Lerner, Melvin (Inventor); Hood, Lyal V. (Inventor); Rommel, Marjorie A. (Inventor); Pettitt, Bruce C. (Inventor); Erikson, Charles M. (Inventor)

1980-01-01

298

Dispersion and edge absorption of Y2O3 thin films obtained by different methods  

NASA Astrophysics Data System (ADS)

In the visible and near UV regions of the spectrum, we have measured optical dispersion in Y2O3 thin films obtained by stepwise vaporization and high-frequency RF ion plasma sputtering. We studied the edge absorption spectrum. We have determined the parameters of the single-oscillator approximation and determined the dispersion energy, the bond ionicity, and the coordination number. We compare the results obtained with the structural perfection of the Y2O3 films.

Bordun, O. M.; Bordun, I. O.; Kukharskyy, I. Yo.

2013-01-01

299

FEM3 modeling of ammonia and hydrofluoric acid dispersion. [A phase-change submodel  

Microsoft Academic Search

FEM3 is a three-dimensional computer model that was designed to simulate the atmospheric dispersion of heavier-than-air gas releases. Recently a phase-change submodel based on local thermodynamic equilibrium has been implemented to treat vapor-liquid transition of the dispersed material. A preliminary evaluation of the phase-change submodel was performed by using data obtained from two recently conducted series of field experiments, namely,

S. T. Chan; H. C. Rodean; D. N. Blewitt

1987-01-01

300

Raman water vapor lidar calibration  

Microsoft Academic Search

We show here new results of a Raman LIDAR calibration methodology effort putting emphasis in the assessment of the cross-section ratio between water vapor and nitrogen by the use of a calibrated NIST traceable tungsten lamp. Therein we give a step by step procedure of how to employ such equipment by means of a mapping\\/scanning procedure over the receiving optics

E. Landulfo; R. F. da Costa; A. S. Torres; F. J. S. Lopes; D. N. Whiteman; D. D. Venable

2009-01-01

301

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

302

INDOOR AIR VAPOR INTRUSION SEMINAR  

EPA Science Inventory

This seminar is sponsored by the ORD in collaboration with the Office of Solid Waste and Emergency Response. The goal of this seminar is to present information and guidance to evaluate, assess and characterize chemical vapor pathways migrating into structures resulting from conta...

303

Vacuum vapor deposition gun assembly  

DOEpatents

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

Zeren, Joseph D. (Boulder, CO)

1985-01-01

304

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...

305

Hot window, metal vapor tube  

Microsoft Academic Search

A new quartz laser tube, which can operate at 1000°C for metal vapors, has been built. The tube was operated in a three-zone oven, with the Brewster windows at a slightly higher temperature than the main laser body. Thus, a buffer gas was not necessary to prevent condensation of the metal on the windows. A technique for fusing the quartz

D. E. Altman; G. J. Barstow; M. Geller; G. Mooradian; C. Ingram; G. T. Andry

1975-01-01

306

Biofilter treatment of ethanol vapors  

Microsoft Academic Search

Bench scale experiments and a numerical model were used to test the effectiveness of biofiltration in treating air contaminated with ethanol vapors. Three packing materials, granular activated carbon, compost, and a mixture of compost and diatomaceous earth were tested. The GAC material supported the highest elimination rates, ranging from 53 to 219 grams\\/m[sup 3]-hr for a range of loading rates.

Douglas S. Hodge; Joseph S. Devinny

1994-01-01

307

Photovoltaic driven vapor compression cycles  

Microsoft Academic Search

Since the vast majority of heat pumps, air conditioning and refrigeration equipment employs the vapor compression cycle (VCC), the use of renewable energy represents a significant opportunity. As discussed in this report, it is clear that the use of photovoltaics (PV) to drive the VCC has more potential than any other active solar cooling approach. This potential exists due to

D. K. Anand

1985-01-01

308

Acoustic Behavior of Vapor Bubbles  

NASA Technical Reports Server (NTRS)

In a microgravity environment vapor bubbles generated at a boiling surface tend to remain near it for a long time. This affects the boiling heat transfer and in particular promotes an early transition to the highly inefficient film boiling regime. This paper describes the physical basis underlying attempts to remove the bubbles by means of pressure radiation forces.

Prosperetti, Andrea; Oguz, Hasan N.

1996-01-01

309

RTE with Li vapor target  

Microsoft Academic Search

High resolution projectile Auger electron spectroscopy is being used to measure cross sections for resonant transfer and excitation (RTE) as a function of projectile energy, in collisions of highly charged ions with a lithium vapor target. Previously H2 and He have been used [4] as targets for RTE studies via high resolution projectile Auger electron spectroscopy. With Li as a

R. Parameswaran; W. J. Axmann; T. J. M. Zouros; B. D. Depaola

1989-01-01

310

Atomic vapor laser isotope separation process  

DOEpatents

A laser spectroscopy system is utilized in an atomic vapor laser isotope separation process. The system determines spectral components of an atomic vapor utilizing a laser heterodyne technique. 23 figs.

Wyeth, R.W.; Paisner, J.A.; Story, T.

1990-08-21

311

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

312

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

313

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

314

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

315

Acoustic droplet vaporization is initiated by superharmonic focusing  

PubMed Central

Acoustically sensitive emulsion droplets composed of a liquid perfluorocarbon have the potential to be a highly efficient system for local drug delivery, embolotherapy, or for tumor imaging. The physical mechanisms underlying the acoustic activation of these phase-change emulsions into a bubbly dispersion, termed acoustic droplet vaporization, have not been well understood. The droplets have a very high activation threshold; its frequency dependence does not comply with homogeneous nucleation theory and localized nucleation spots have been observed. Here we show that acoustic droplet vaporization is initiated by a combination of two phenomena: highly nonlinear distortion of the acoustic wave before it hits the droplet and focusing of the distorted wave by the droplet itself. At high excitation pressures, nonlinear distortion causes significant superharmonics with wavelengths of the order of the droplet size. These superharmonics strongly contribute to the focusing effect; therefore, the proposed mechanism also explains the observed pressure thresholding effect. Our interpretation is validated with experimental data captured with an ultrahigh-speed camera on the positions of the nucleation spots, where we find excellent agreement with the theoretical prediction. Moreover, the presented mechanism explains the hitherto counterintuitive dependence of the nucleation threshold on the ultrasound frequency. The physical insight allows for the optimization of acoustic droplet vaporization for therapeutic applications, in particular with respect to the acoustic pressures required for activation, thereby minimizing the negative bioeffects associated with the use of high-intensity ultrasound. PMID:24449879

Shpak, Oleksandr; Verweij, Martin; Vos, Hendrik J.; de Jong, Nico; Lohse, Detlef; Versluis, Michel

2014-01-01

316

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

E-print Network

Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures and liquid vapor pressures from T ) 298.15 K to T ) 510 K of a series of polyaromatic hydrocarbons have been of a thermochemical cycle, and agreement is within the combined experimental uncertainties. Vapor pressures

Chickos, James S.

317

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.

318

4, 83278355, 2004 Water vapor LIDAR  

E-print Network

ACPD 4, 8327­8355, 2004 Water vapor LIDAR measurements during stratospheric intrusions P. D and Physics Discussions Analysis of water vapor LIDAR measurements during the MAP campaign: evidence of sub Commons License. 8327 #12;ACPD 4, 8327­8355, 2004 Water vapor LIDAR measurements during stratospheric

Paris-Sud XI, Université de

319

Meteorological water vapor Raman lidar: advances  

Microsoft Academic Search

We present the design and preliminary results of a water vapor Raman lidar, developed explicitly for meteorological applications. The lidar was designed for Meteoswiss as a fully automated, eye-safe instrument for routine water vapor measurements in the troposphere. The lidar is capable of day and nighttime vertical profiling of the tropospheric water vapor with 15 to 30 min temporal resolution.

T. Dinoev; P. Ristori; Y. Arshinov; S. Bobrovnikov; I. Serikov; B. Calpini; H. van den Bergh; V. Simeonov

2006-01-01

320

Vapor pressures of the polychlorinated naphthalenes  

Microsoft Academic Search

The vapor pressures of the supercooled liquid P{sub L} for 17 polychlorinated naphthalene congeners were determined as a function of temperature with a gas chromatographic retention time technique. The method was calibrated with vapor pressure data for polychlorinated biphenyls (PCBs) which had been measured by other techniques. These data were employed to predict temperature-dependent vapor pressures for all polychlorinated naphthalenes

Ying Duan Lei; W. Y. Shiu; F. Wania

1999-01-01

321

MESOSCOPIC SCALE MODELING FOR CHEMICAL VAPOR DEPOSITION  

E-print Network

. GOBBERT \\Lambda AND CHRISTIAN RINGHOFER y Abstract. Low pressure chemical vapor deposition is a process is typically run at very low pressure. A typical value for the total pressure in low pressure chemical vaporMESOSCOPIC SCALE MODELING FOR CHEMICAL VAPOR DEPOSITION IN SEMICONDUCTOR MANUFACTURING MATTHIAS K

Ringhofer, Christian

322

Vapor-Resistant Heat-Pipe Artery  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

323

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

324

Seed Dispersal: Lemurs  

NSDL National Science Digital Library

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

Pulse of the Planet

2007-09-20

325

Terahertz Spectroscopy of Water Vapors, Chemical Vapors and Ionized Air  

NASA Astrophysics Data System (ADS)

In the past, a few research groups have demonstrated that terahertz spectroscopy could be a useful tool for the identification of chemicals. However most of those demonstrations have been done with solid-phase or liquid-phase chemicals. There are little demonstrations for the detection and identification of chemicals in the gas-phase, as it is very difficult in part due to the presence of water-absorption lines in the terahertz frequency range. As the water absorption lines predominate in the 0.1 - 2THz spectral range, and can interfere with already weak terahertz signatures generated by chemical vapors, it is often very hard to obtain meaningful terahertz spectrum of chemical vapor. Regardless we recently have been able to obtain some terahertz spectra of chemical vapors and ionized air produced by several different ionization sources, including corona discharge and nuclear isotopes. Throughout data analysis we learned that water molecules, nitrogen and oxygen molecules play very important roles in these terahertz spectra. In this presentation we will discuss our experiments and the roles of these molecules.

Graber, Benjamin; Tao, Rongjia; Wu, Dong Ho

2013-03-01

326

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

327

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

328

Vapor deposition of tantalum and tantalum compounds  

SciTech Connect

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 techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition.

Trkula, M. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1996-04-01

329

Comparative analysis of liquefied natural gas (LNG) and compressed natural gas (CNG) used by transit agencies in Texas. Research report  

SciTech Connect

This study is a detailed comparative analysis of liquefied natural gas (LNG) and compressed natural gas (CNG). The study provides data on two alternative fuels used by transit agencies in Texas. First, we examine the `state-of-the- art` in alternative fuels to established a framework for the study. Efforts were made to examine selected characteristics of two types of natural gas demonstrations in terms of the following properties: energy source characteristics, vehicle performance and emissions, operations, maintenance, reliability, safety costs, and fuel availability. Where feasible, two alternative fuels were compared with conventional gasoline and diesel fuel. Environmental considerations relative to fuel distribution and use are analyzed, with a focus on examining flammability an other safety-related issues. The objectives of the study included: (1) assess the state-of-the-art and document relevant findings pertaining to alternative fuels; (2) analyze and synthesize existing databases on two natural gas alternatives: liquefied natural gas (LNG) and compressed natural gas (CNG): and (3) compare two alterative fuels used by transit properties in Texas, and address selected aspects of alternative fuels such as energy source characteristics, vehicle performance and emissions, safety, costs, maintenance and operations, environmental and related issues.

Lede, N.W.

1997-09-01

330

Fatigue crack growth properties of the base metal and weld metal of a 9% Ni steel for LNG storage tank  

NASA Astrophysics Data System (ADS)

Newly developed heavy thick plates of 9% Ni steel for large capacity of LNG tank were fabricated to conduct a fatigue crack growth test. The weld metal specimens were also fabricated by taking the same weld procedures which are applied to actual LNG storage tank inner shell. The effect of changes in load ratio, R, and test temperature on the fatigue crack growth rate has been investigated. Separate fatigue crack growth experiments were performed at load ratio of 0.1 and 0.5 at -162°C and compared to the behavior at room temperature. The fatigue crack growth rates of weld metal were nearly the same as those of the base metal irrespective of load ratio change at room temperature. A decrease in temperature decreased the fatigue crack growth rates of base metal but in the case of weld metal only small scatters appeared in the fatigue crack growth rate compared with those of base metals. The fatigue crack growth rates were dominated by residual stress due to welding processes rather than temperature effects.

Kim, Young-Kyun; Shim, Kyu-Taek; Kim, Jae-Hoon

2009-07-01

331

Vapor stabilizing surfaces for superhydrophobicity  

NASA Astrophysics Data System (ADS)

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

Patankar, Neelesh

2010-11-01

332

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

333

Oxide dispersion strengthened superalloy  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

334

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

335

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

336

Water vapor diffusion membrane development  

NASA Technical Reports Server (NTRS)

An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.

Tan, M. K.

1977-01-01

337

Acoustic Droplet Vaporization through PDMS  

NASA Astrophysics Data System (ADS)

Acoustic droplet vaporization (ADV) involves the generation of bubbles from albumin-encapsulated perfluorocarbon (PFC) droplets that have been insonated with high intensity ultrasound (US). Gas embolotherapy, utilizing ADV, may facilitate occlusion of blood flow in the vasculature as bubbles undergo volume expansion of up to 125 times. Cancer therapy could benefit from such occlusions through starvation of the tumor. In order to visualize the detailed mechanics of vaporization and expansion process of the PFC droplets, idealized microvessels were constructed using polydimethylsiloxane (PDMS) channels. Microchannels (20 micron diameter) were fabricated using PDMS with polymer-crosslinker mixing ratios ranging from 5:1 to 20:1. Droplets were introduced into the channels and exposed to US for vaporization. Mixing ratios were observed to impact the impedance matching at the water-PDMS interface, which affected the threshold for ADV. The threshold was lowest for mixing ratios of 5:1 and 20:1, and greatest for 9:1. Final bubble volumes were compared with a computational model by Ye & Bull and were found to be consistent. This work is supported by NIH grant R01EB006476.

Li, David; Samuel, Stanley; Fowlkes, J. Brian; Bull, Joseph

2009-11-01

338

Triply-resonant optical parametric oscillator by four-wave mixing with rubidium vapor inside an optical cavity  

E-print Network

is detuned from the atomic resonances 1 0 and 2 0 by the amount of b= p- 01 and a= p - 02 thus a- b= 12Triply-resonant optical parametric oscillator by four-wave mixing with rubidium vapor inside. The triple resonant conditions can be achieved easily by making use of the large dispersions due to two

Zhang, Jing

339

Numerical Analysis of coupled liquid water, water vapor and heat transport in a sandy loam soil  

NASA Astrophysics Data System (ADS)

Water vapor transport could be significant in arid areas such as southern New Mexico. Temporal soil moisture variations in unsaturated soils due to temperature gradients are characterized by the water vapor transport in the surface soil layer as liquid water movement could be very small especially when surface soil moisture is low. Numerical model Hydrus-1D was applied to investigate non-isothermal liquid and vapor flow closely coupled with the heat transport in a furrow-irrigated onion field located at Leyendecker Plant Science Research Center, Las Cruces. TDR and temperature sensors were installed to continuously monitor diurnal soil moisture and temperature variations in sandy loam onion beds at 5, 10, 20, and 50 cm depths during the entire growing season. Meteorological data were obtained from PSRC weather station. Hydrus-1D simulated soil moisture and temperature favorably contrasted against measured data at different depths. Simulations indicated that both liquid and vapor fluxes contributed to the water transport near surface. Liquid flux dominated the water movement during an irrigation event, while contribution of vapor flux increased with increasing soil drying. Vapor flux decreased from 5 cm to 25 cm depth, indicating that water vapor flux is much higher in the layer near soil surface. Both diffusive and dispersive transports are responsible for the vapor flux in the near-surface dry zone, while convective liquid flux was the main transport mechanism in the near-surface wet lower zone. In near-surface wet zone, diffusive flux decreased and changed from upward to downward flux.

Shukla, M. K.; Deb, S.; Sharma, P.

2009-12-01

340

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

NASA Technical Reports Server (NTRS)

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

Kandula, Max

2012-01-01

341

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

342

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

343

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

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

344

Formation of thermal decomposition cavities in physical vapor transport of silicon carbide  

Microsoft Academic Search

The relationship between seed mounting and the formation of thermal decomposition cavities in physical vapor transport grown\\u000a silicon carbide was investigated. Scanning electron microscopy, energy dispersive x-ray spectroscopy, Auger electron spectroscopy,\\u000a and optical microscopy were used to characterize thermal decomposition cavities at various stages of their development. The\\u000a observations indicate that the attachment layer that holds the seed to the

Edward K. Sanchez; Thomas Kuhr; Volker D. Heydemann; David W. Snyder; Gregory S. Rohrer; Marek Skowronski

2000-01-01

345

Gas monitoring with a Fabry–Perot based bolometer: Cross-sensitivity to water vapor  

Microsoft Academic Search

Recently, Fabry–Perot IR-absorbing structures have been proven suitable as low cost detectors in non-dispersive infrared (NDIR) gas-sensors for measuring diluted gases (e.g., CO2) in a pure nitrogen (N2) atmosphere. To identify the monitoring capability of the devised prototype system in ambient air, the cross-sensitivity to other gases, mainly water vapor, has to be explored. The absorption coefficient associated with the

J. Mayrwöger; W. Reichl; C. Krutzer; B. Jakoby

2010-01-01

346

IMPROVED LABORATORY DISPERSANT EFFECTIVENESS TEST  

EPA Science Inventory

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

347

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

348

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

349

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

350

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

351

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

352

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

353

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.

Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)

1996-01-01

354

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.

Sisson, Warren G. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN)

1998-01-01

355

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

356

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

357

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.

Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)

1995-01-01

358

How accurate are dispersion predictions  

Microsoft Academic Search

Past widespread use of Gaussian dispersion models to predict stack gas plume dispersions has led to the misconception that dispersion models predict plume concentrations within a factor of two or three of real world concentrations. The consistent prediction of actual plume concentrations within a factor of 10 is a more realistic assessment for the short time models. Constraints and assumptions

Beychok

1979-01-01

359

Nozzle for electric dispersion reactor  

SciTech Connect

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.

Sisson, Warren G. (Oak Ridge, TN); Basaran, Osman A. (Oak Ridge, TN); Harris, Michael T. (Knoxville, TN)

1998-01-01

360

A Vaporizer for Decaborane and Octadecaborane  

NASA Astrophysics Data System (ADS)

Decaborane (B10H14) and Octadecaborane (B18H22) are two promising new doping materials for performing very shallow boron implants at high implanter throughput. However, because these new materials are low-vapor pressure solids at room temperature, their delivery to the implanter's ion source requires specialized techniques to deliver the desired mass flow without condensation. Data are presented which describe several features of a vaporizer for producing Decaborane and Octadecaborane flows in a production environment. This paper will also focus on the critical design aspects of the vapor delivery system, including the effects of vaporizer geometry on vapor flow rate, the performance of various flow control systems, and the overall thermal design. In addition, data on physical and environmental, safety, and health properties of these materials are presented. The effectiveness of this system as a stable vapor source for an ion implanter will be described.

Adams, Doug; Horsky, Tom; Gilchrist, Glen; Milgate, Robert; Sweeney, Joe; Marganski, Paul

2006-11-01

361

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

362

Biofilter treatment of ethanol vapors  

SciTech Connect

Bench scale experiments and a numerical model were used to test the effectiveness of biofiltration in treating air contaminated with ethanol vapors. Three packing materials, granular activated carbon, compost, and a mixture of compost and diatomaceous earth were tested. The GAC material supported the highest elimination rates, ranging from 53 to 219 grams/m[sup 3]-hr for a range of loading rates. Partitioning coefficients for the contaminant on the biofilter packing material had a strong effect on the efficiency of the biofilters. 10 refs., 12 figs.

Hodge, D.S. (Reynolds Group, Tustin, CA (United States)); Devinny, J.S. (Univ. of Southern California, Los Angeles, CA (United States))

1994-08-01

363

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

364

Coupling apparatus for a metal vapor laser  

DOEpatents

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

Ball, Don G. (Livermore, CA); Miller, John L. (Dublin, CA)

1993-01-01

365

X-ray-induced water vaporization  

SciTech Connect

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

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

2011-09-15

366

Dispersal dynamics in food webs.  

PubMed

Abstract Studies of food webs suggest that limited nonrandom dispersal can play an important role in structuring food webs. It is not clear, however, whether density-dependent dispersal fits empirical patterns of food webs better than density-independent dispersal. Here, we study a spatially distributed food web, using a series of population-dispersal models that contrast density-independent and density-dependent dispersal in landscapes where sampled sites are either homogeneously or heterogeneously distributed. These models are fitted to empirical data, allowing us to infer mechanisms that are consistent with the data. Our results show that models with density-dependent dispersal fit the ?, ?, and ? tritrophic richness observed in empirical data best. Our results also show that density-dependent dispersal leads to a critical distance threshold beyond which site similarity (i.e., ? tritrophic richness) starts to decrease much faster. Such a threshold can also be detected in the empirical data. In contrast, models with density-independent dispersal do not predict such a threshold. Moreover, preferential dispersal from more centrally located sites to peripheral sites does not provide a better fit to empirical data when compared with symmetric dispersal between sites. Our results suggest that nonrandom dispersal in heterogeneous landscapes is an important driver that shapes local and regional richness (i.e., ? and ? tritrophic richness, respectively) as well as the distance-decay relationship (i.e., ? tritrophic richness) in food webs. PMID:25616136

Melián, Carlos J; K?ivan, Vlastimil; Altermatt, Florian; Starý, Petr; Pellissier, Loïc; De Laender, Frederik

2015-02-01

367

Dispersion toughened ceramic composites and method for making same  

DOEpatents

Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa..sqrt..m which represents a significant increase over that of silicon carbide.

Stinton, D.P.; Lackey, W.J.; Lauf, R.J.

1984-09-28

368

Dispersion toughened ceramic composites and method for making same  

DOEpatents

Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa.sqroot.m which represents a significant increase over that of silicon carbide.

Stinton, David P. (Knoxville, TN); Lackey, Walter J. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

1986-01-01

369

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

370

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

371

Waves on the surface of a vapor film under conditions of intensive heat fluxes.  

PubMed

We investigate surface waves on the interface between a thin vapor film and a layer of liquid in the presence of a high steady heat flux. This problem arises when a metal surface heated to a high temperature is immersed into a cold liquid. The general boundary conditions, which take into account the temperature dependence of saturation pressure on the vapor-liquid interface, are derived. These boundary conditions generalize the traditional conditions on the free surface of liquid in the gravity field. The stability of the planar vapor-liquid interface is investigated analytically with linear approximations. The dispersion equation for surface waves on the vapor-liquid interface in the presence of strong heat flux is derived. A number of different, distinct from the classical surface wave problem, effects arise in the problem under consideration. The thermal processes, which occur on the phase boundary and are possible in the absence of gravity force, lead to the generation of weakly decaying periodic waves of low amplitude, whose velocities may exceed significantly those of gravity waves. The heat flux through the interface may cause periodic surface waves of small length (ripple), which are not capillary. The processes of phase transition on the interface are capable of providing the stability of vapor film under a layer of liquid in the gravity field. PMID:18851154

Sinkevich, Oleg A

2008-09-01

372

Effects of vertical distribution of water vapor and temperature on total column water vapor retrieval error  

Microsoft Academic Search

The physically based total column water vapor retrieval algorithm of Wentz (1992) is tested for sensitivity to realistic vertical distributions of temperature and water vapor. The spatial pattern of systematic retrieval error of total column water vapor due to this sensitivity is simulated using the European Center for Medium Range Weather Forecasts (ECMWF) monthly averaged temperature and humidity fields. Effects

Jielun Sun

1993-01-01

373

Optical sensor for diverse organic vapors at ppm concentration ranges.  

PubMed

A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index) and sensor response are discussed. PMID:22163798

Thomas, J Christopher; Trend, John E; Rakow, Neal A; Wendland, Michael S; Poirier, Richard J; Paolucci, Dora M

2011-01-01

374

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

375

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

376

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

377

Characterization of Carbon Nanotubes Grown by Chemical Vapor Deposition  

NASA Technical Reports Server (NTRS)

Since the superior properties of multi-wall carbon nanotubes (MWCNT) could improve numerous devices such as electronics and sensors, many efforts have been made in investigating the growth mechanism of MWCNT to synthesize high quality MWCNT. Chemical vapor deposition (CVD) is widely used for MWCNT synthesis, and scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) are useful methods for analyzing the structure, morphology and composition of MWCNT. Temperature and pressure are two important growth parameters for fabricating carbon nanotubes. In MWCNT growth by CVD, the plasma assisted method is normally used for low temperature growth. However a high temperature environment is required for thermal CVD. A systematic study of temperature and pressure-dependence is very helpful to understanding MWCNT growth. Transition metal particles are commonly used as catalysis in carbon nanotube growth. It is also interesting to know how temperature and pressure affect the interface of carbon species and catalyst particles

Cochrane, J. C.; Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

2001-01-01

378

Vapor-phase molar Kerr constant values from solution measurements  

NASA Astrophysics Data System (ADS)

A method is proposed for determination of molar Kerr constants (mK) by extrapolation of the values measured in a series of selected solvents. The mK values of 19 organic compounds were calculated. Most of the compounds cannot be studied in the vapor phase. The discrete-continuum solvation model was applied to investigate the influence of solvent nature on solubility of the compounds under investigation. It is shown that universal interactions between the solvent and solute molecules, including the dispersive, inductive, and dipole-dipole interactions, dominate the solvation process. The optimum model of internal field was chosen to determine the Kerr constant. The values of mKgas measured experimentally coincide with the values of mK??=0? that were obtained by extrapolation of mK?. Hence, this method can be applied to calculate the values of molar Kerr constants on the basis of measurements in solutions.

Prezhdo, Victor; Olan, Karol; Prezhdo, Oleg; Zubkova, Valentina

2015-01-01

379

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

380

Dispersion in Solids  

NASA Astrophysics Data System (ADS)

To make good use of the physical properties of nanoparticles (see Part II of this book), most applications require them to be incorporated within solid materials, such as glasses, ceramics, oxides, etc. The inclusions obtained in this way are thereby protected from chemical (e.g., oxidation) or mechanical (e.g., friction or wear) alteration due to the environment. They are also separated from one another from an electrical or magnetic point of view, which limits this kind of interaction between the particles. The dispersion of particles within solid materials can be achieved in the ordinary way by exploiting precipitation effects in the solid state (e.g., alloys hardened by dispersions of nanometric precipitates, Guinier-Preston zones), but also by a great many less direct methods. Which method is finally chosen depends on several factors such as the kind of matrix and size, shape and spatial organisation of the particles, but also on the volume of material to be produced, the cost, and the difficulty involved in the process.

Babonneau, D.

381

Vapor phase lubrication of a Ni-based superalloy  

SciTech Connect

In addition to ceramics, alloys such as tool steel and nickel- and iron-based superalloys are being considered for high temperature applications such as missile bearings and low heat rejection engines. Studies were made to lubricate a nickel-based superalloy at 500{degrees}C, by using a vaporized aryl phosphate ester, at a concentration of 0.1% in air. From deposition and wear studies it was found that it was impossible to form a good polymeric coating on the superalloy surface. Energy dispersive X-ray analyzer (EDXA) analysis showed that this was due to minute quantities of aluminum in the alloy segregating to the surface, upon being heated to 500{degrees}C, forming a passive oxide coating. It was necessary to activate the surface, in order to lubricate the material successfully. A method of activation by electrodepositing the surface with a layer of iron oxide was developed. Once activated, a good lubricous polymer was formed on the superalloy surface. Tests performed under dynamic conditions and 1 MPa pressure, using an activated specimen surface showed no wear and a coefficient of friction ({mu}) of 0.05. These results stress the importance of material selection for high temperature vapor phase lubrication. 15 refs., 13 figs., 2 tabs.

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

1995-03-01

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

Water Vapor Raman LIDAR Within the Ndsc  

Microsoft Academic Search

This work is a joint effort to provide best water vapor measurements in the upper troposphere lower stratosphere within the NDSC. It is only recently that NDSC decided to include water vapor lidar measurements as a standard tool. While the NDSC project is centered on the stratosphere, detection of the Raman measurements is improved to reach the highest altitude. Here

Philippe Keckhut; Gelsomina Pappalardo; Arnoud Apituley; Fernando Congeduti; Thierry Leblanc; Franz Immler; Marion Muller; Choo Hie Lee; Laurent Robert; Valentin Simeonov; Geraint Vaughan; Dave Whiteman

2004-01-01

384

Comparison Of Measurments Of Atmospheric Water Vapor  

NASA Technical Reports Server (NTRS)

Report presents experimental intercomparison among measurements by four spectrometric instruments for determining concentration of atmospheric water vapor. Three instruments ground-based and needed to provide independent data to calibrate and validate measurements taken by fourth instrument, which is airborne visible/infrared imaging spectrometer (AVIRIS). Remote down-looking instruments like AVIRIS increases accuracy and coverage of water-vapor measurements.

Bruegge, Carol J.; Conel, James E.; Margolis, Jack S.; Green, Robert O.; Toon, Geoffrey C.; Carrere, Veronique; Holm, Ronald G.; Hoover, Gordon L.

1994-01-01

385

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

386

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...

387

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...

388

Cell for electrolysis of water vapor  

NASA Technical Reports Server (NTRS)

Electrolytic cells regenerate oxygen from the water vapor in the air of closed-loop life-support system and remove water vapor from air circulated through them. Water is converted into oxygen and hydrogen; the oxygen is returned to the air, the hydrogen is vented or used elsewhere.

Celino, V. A.; Roebelen, G.

1972-01-01

389

ON-LINE CALCULATOR: VAPOR INTRUSION MODELING  

EPA Science Inventory

Migration of volatile chemicals from the subsurface into overlying buildings is called vapor intrusion (VI). Volatile organic chemicals in contaminated soils or groundwater can emit vapors, which may migrate through subsurface soils and may enter the indoor air of overlying build...

390

On the mechanism of acoustic droplet vaporization  

Microsoft Academic Search

It has been observed in the past that micrometer sized droplets can be vaporized into gas bubbles by the application of diagnostic ultrasound. This paper will discuss the possible underlying mechanism of acoustic droplet vaporization (ADV) including acoustic cavitation, acoustic heating, shape oscillations during acoustic irradiation, and hydrodynamic cavitation. Experiments were performed on droplet emulsions as well as on single

Oliver D. Kripfgans; Paul L. Carson; J. Brian Fowlkes

2002-01-01

391

Risk assessment of metal vapor arcing  

NASA Technical Reports Server (NTRS)

A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

2009-01-01

392

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.

393

Vapor Phase Catalytic Ammonia Reduction  

NASA Technical Reports Server (NTRS)

This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

1994-01-01

394

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

395

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.

2012-08-03

396

21 CFR 888.4220 - Cement monomer vapor evacuator.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Cement monomer vapor evacuator. 888.4220...DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a...

2011-04-01

397

21 CFR 888.4220 - Cement monomer vapor evacuator.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Cement monomer vapor evacuator. 888.4220...DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a...

2012-04-01

398

21 CFR 888.4220 - Cement monomer vapor evacuator.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Cement monomer vapor evacuator. 888.4220...DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a...

2014-04-01

399

21 CFR 888.4220 - Cement monomer vapor evacuator.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220...DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a...

2010-04-01

400

21 CFR 888.4220 - Cement monomer vapor evacuator.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Cement monomer vapor evacuator. 888.4220...DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a...

2013-04-01

401

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

402

Intermediate Vapor Expansion Distillation and Nested Enrichment Cascade Distillation  

E-print Network

is described in three configurations overhead vapor compresed, bottoms vapor compressed, or completely closed cycle. As with conventional cascades, conventional heat pumping does to increase the distillation efficiency. Heat pumping merely substitutes...) from overhead to interreboiler; 2) from intercondenser to bottoms reboilerj or 3) from intercondenser to interreboiler. Also, the vapor being compressed can be overhead vapor, bottoms vapor, or a separate closed cycle vapor. Thus there are nine...

Erickson, D. C.

403

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

404

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

405

Human factors applications to computer-aided system design in LNG (liquefied natural gas) facilities. Volume 1. Design principles. Final report, August 1983October 1985  

Microsoft Academic Search

The principal objectives of this project were to: (1) develop HF design guidelines for computer-aided control and display systems in LNG facilities, and (2) assist the GRI in disseminating project results and developing industry-standard guidelines. A comprehensive collection of state-of-the-art HF guidelines were developed for the workspace, data display, operator-computer dialogue, data entry, annunciator systems and support systems. Examples illustrate

B. A. Fecht; T. B. Rideout; W. L. Rankin; V. E. Barnes; L. M. Saari

1985-01-01

406

Properties of water along the liquid-vapor coexistence curve via molecular dynamics simulations using the polarizable TIP4P-QDP-LJ water model  

Microsoft Academic Search

We present an extension of the TIP4P-QDP model, TIP4P-QDP-LJ, that is designed to couple changes in repulsive and dispersive nonbond interactions to changes in polarizability. Polarizability is intimately related to the dispersion component of classical force field models of interactions, and we explore the effect of incorporating this connection explicitly on properties along the liquid-vapor coexistence curve of pure water.

Brad A. Bauer; Sandeep Patel

2009-01-01

407

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

408

Tropical upper tropospheric water vapor distribution  

NASA Astrophysics Data System (ADS)

Water vapor is a powerful greenhouse gas and its fast response to temperature makes it a good candidates for creating feedback mechanisms that could modify global climate substantially. For one of the most important climate system on the Earth, the tropical climate system, it is particularly relevant because one of the major determinants has been identified as clear sky OLR averaged over the entire Tropics. Due to the radiative importance of water vapor in higher altitudes and drier regions, the major (but not exclusive) focus of our attention is the tropical upper tropospheric water vapor in the subsiding regions. Furthermore, the nonlinearity of Outgoing Longwave Radiation (OLR) responses to humidity entails a more detailed statistical analysis than zonally averaged humidity. The main vehicle to conduct this statistical analysis is Probability Distribution Function (PDF) of water vapor mixing ratio. The general task of this study is to investigate water vapor distribution, maintenance and radiative impacts, as well evaluation of General Circulation Model (GCM) water vapor performances. Previous research on water vapor maintenance had lead to Large Scale Advection hypothesis, which serves as the basis for our study. Traditional observation has been lacking in both coverage and accuracy, Tiros Observational Vertical Sounder (TOVS) water vapor data, assisted by more recent CEPEX tropical sounding, are employed in the data analysis. The observational chapter is devoted to the examination of the morphology, regional, seasonal variation and vertical variation of PDF, possible climate impact as well as the effects of resolution are also examined. Our data analysis shows that TOVS water vapor PDF has a skewed appearance. A linear transform procedure is shown to be able to bring PDF from different layer to a close fit. The mean and deviation of water vapor mixing ratio display a positive correlation. These information are further used to evaluate GCM water vapor performance. Similar data analysis procedures are performed on GCM water vapor PDF's and results are compared with TOVS counterparts. GCM PDF shows similar morphological features, but its capability in capturing the seasonality needs improvement. Our theoretical effort concentrates on two aspects. The initial PDF problem and the geometry of humidity distribution field The moist tail of humidity PDF is found to be influenced by the mixing ratio inside convective region and the mass flux into the subsiding region. It is also demonstrated that the combination of subsidence drying and stretching could result in a power law of water vapor concentration field.

Zhang, Hui

2002-09-01

409

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.

410

CO(2) DIAL measurements of water vapor.  

PubMed

CO(2) lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microm, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO(2) laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO(2) lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficient for the 1P(14) CO(2) laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO(2) lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures. PMID:20490006

Grant, W B; Margolis, J S; Brothers, A M; Tratt, D M

1987-08-01

411

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

412

Process for vaporizing a liquid hydrocarbon fuel  

DOEpatents

The object of the invention is to provide a process for vaporizing liquid hydrocarbon fuels efficiently and without the formation of carbon residue on the apparatus used. The process includes simultaneously passing the liquid fuel and an inert hot gas downwardly through a plurality of vertically spaed apart regions of high surface area packing material. The liquid thinly coats the packing surface, and the sensible heat of the hot gas vaporizes this coating of liquid. Unvaporized liquid passing through one region of packing is uniformly redistributed over the top surface of the next region until all fuel has been vaporized using only the sensible heat of the hot gas stream.

Szydlowski, Donald F. (East Hartford, CT); Kuzminskas, Vaidotas (Glastonbury, CT); Bittner, Joseph E. (East Hartford, CT)

1981-01-01

413

Growth of single crystals by vapor transport  

NASA Technical Reports Server (NTRS)

The primary objectives of the program were to establish basic vapor transport and crystal growth properties and to determine thermodynamic, kinetic and structural parameters relevant to chemical vapor transport systems for different classes of materials. An important aspect of these studies was the observation of the effects of gravity-caused convection on the mass transport rate and crystal morphology. These objectives were accomplished through extensive vapor transport, thermochemical and structural studies on selected Mn-chalcogenides, II-VI and IV-VI compounds.

Wiedemeier, H.

1978-01-01

414

Recovering hydrocarbons from hydrocarbon-containing vapors  

DOEpatents

Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

1980-09-30

415

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

416

Phase transition in colloidal dispersions  

NASA Astrophysics Data System (ADS)

Dynamic light scattering (DLS) is applied to the glass transition of concentrated N-isopropylacrylamde (NIPA) gel nanoparticle dispersions. These dispersions are treated as simple superatomic systems. Intermediate scattering functions are obtained as the function of temperature and scattering angle. The observed phase behavior is consistent with an essentially hard-sphere interaction between the particles.

Li, Jianyou; Gao, Jun; Hu, Zhibing

2000-10-01

417

Stimulation of vapor nucleation on perfect and imperfect hexagonal lattice surfaces  

SciTech Connect

Monte Carlo simulations of water vapor nucleation on a perfect crystal surface and on a surface with defects are performed. Mass exchange with the vapor phase is modeled by using an open ensemble. Cluster-substrate interaction is described in terms of conventional atom-atom potentials. The Hamiltonian of the system includes expressions for electrostatic, polarization, exchange, and dispersion interactions. The Gibbs free energy and work of adsorption are calculated by Monte Carlo simulation in the bicanoinical ensemble. The microscopic structure of nuclei is analyzed in terms of pair correlation functions. Periodic boundary conditions are used to simulate an infinite substrate surface. Molecule-substrate and molecule-molecule long-range electrostatic interactions are calculated by summing the Fourier harmonics of the electrostatic potential. Dispersion interactions are calculated by direct summation over layers of unit cells. Nucleation on a surface with matching structure follows a layer-by-layer mechanism. The work of adsorption per molecule of a monolayer on the substrate surface has a maximum as a function of nucleus size. The steady rate of nucleation of islands of supercritical size is evaluated. The work of adsorption per molecule for layer-by-layer film growth is an oscillating function of cluster size. As a function of layer number, it has a minimum depending on the vapor pressure. The electric field generated by a microscopic surface protrusion destroys the layered structure of the condensate and eliminates free-energy nucleation barriers. However, point lattice defects do not stimulate explosive nucleation.

Shevkunov, S. V. [St. Petersburg State Polytechnic University (Russian Federation)], E-mail: root@svsh.tu.neva.ru

2008-12-15

418

NASA Experiment on Tropospheric-Stratospheric Water Vapor Transport in the Intertropical Convergence Zone  

NASA Technical Reports Server (NTRS)

The following six papers report preliminary results obtained from a field experiment designed to study the role of tropical cumulo-nimbus clouds in the transfer of water vapor from the troposphere to the stratosphere over the region of Panama. The measurements were made utilizing special NOAA enhanced IR satellite images, radiosonde-ozonesondes and a NASA U-2 aircraft carrying. nine experiments. The experiments were provided by a group of NASA, NOAA, industry, and university scientists. Measurements included atmospheric humidity, air and cloud top temperatures, atmospheric tracer constituents, cloud particle characteristics and cloud morphology. The aircraft made a total of eleven flights from August 30 through September 18, 1980, from Howard Air Force Base, Panama; the pilots obtained horizontal and vertical profiles in and near convectively active regions and flew around and over cumulo-nimbus towers and through the extended anvils in the stratosphere. Cumulo-nimbus clouds in the tropics appear to play an important role in upward water vapor transport and may represent the principal source influencing the stratospheric water vapor budget. The clouds provide strong vertical circulation in the troposphere, mixing surface air and its trace materials (water vapor, CFM's sulfur compounds, etc.) quickly up to the tropopause. It is usually assumed that large scale mean motions or eddy scale motions transport the trace materials through the tropopause and into the stratosphere where they are further dispersed and react with other stratospheric constituents. The important step between the troposphere and stratosphere for water vapor appears to depend upon the processes occurring at or near the tropopause at the tops of the cumulo-nimbus towers. Several processes have been sugested: (1) The highest towers penetrate the tropopause and carry water in the form of small ice particles directly into the stratosphere. (2) Water vapor from the tops of the cumulonimbus clouds is transported somehow through the tropopause, the vapor pressure being controlled by the temperature at the tops of the clouds; the dryness of the stratosphere could be explained if most of the transport occurs in connection with very high clouds in regions with very high and cold tropopause. (3) Cumulo-nimbus anvils act as terrestrial-radiation shields allowing the ice particle temperatures near cloud tops to cool radiatively below the supersaturation point; this cooling would cause a vapor deposition on the ice particles which will settle out and thus act as water scavengers. The experiment was designed to collect information on these detailed physical processes near and above the tropopause in order to assess their importance and the role they play in controlling stratospheric water vapor humidity.

Page, William A.

1982-01-01

419

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

420

Field tests on human tolerance to (LNG) fire radiant heat exposure, and attenuation effects of clothing and other objects.  

PubMed

A series of field tests exposing mannequins clothed with civilian clothing to a 3m x 3m square liquefied natural gas (LNG) pool fire was conducted. Both single layer clothing and double layer clothing were used. The radiant heat flux incident outside the clothing and incident on the skin covered by clothing were measured using wide-angle radiometers, for durations of 100-200 s (per test). The levels of heat flux incident on the clothing were close to 5 kW/m(2). The magnitude of the radiant heat attenuation factor (AF) across the thickness was determined. AF varies between 2 and higher for cotton and polyester clothing (thickness 0.286-1.347 mm); AF value of 6 was measured for 1.347 mm thickness. Single sheet newspaper held about 5 cm in front of mannequins and exposed to incident flux of 5 kW/m(2) resulted in AF of 5, and AF of 8 with double sheets. AF decreases linearly with increasing heat flux values and linearly increases with thickness. The author exposed himself, in normal civilian clothing (of full sleeve cotton/polyester shirt and jean pants), to radiant heat from a LNG fire. The exposure was for several tens of seconds to heat flux levels ranging from 3.5 kW/m(2) to 5(+) kW/m(2) (exposure times from 25s to 97 s at average heat flux values in the 4 kW/m(2) and 5 kW/m(2)range). Occasionally, he was exposed to (as high as) 7 kW/m(2) for durations of several seconds. He did not suffer any unbearable or even severe pain nor did he experience blisters or burns or any other injury on the unprotected skin of his body. The incident heat fluxes on the author were measured by a hand-held radiometer (with digital display) as well as by strapped on wide-angle radiometers connected to a computer. He could withstand the US regulatory criterion of 5 kW/m(2) (for 30 s) without suffering any damage or burns. Temperature measured on author's skin covered by clothing did not rise above the normal body temperature even after 200 s of exposure to 4 kW/m(2) average heat flux. PMID:18291577

Raj, Phani K

2008-09-15

421

Hybrid dispersion laser scanner.  

PubMed

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

422

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

423

Hybrid Dispersion Laser Scanner  

NASA Astrophysics Data System (ADS)

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.

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.

2012-06-01

424

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

425

Probe for measurement of velocity and density of vapor in vapor plume  

DOEpatents

A probe is disclosed which directs a light beam through a vapor plume in a first direction at a first angle ranging from greater than 0{degree} to less than 90{degree}, reflecting the light beam back through the vapor plume at a 90{degree} angle, and then reflecting the light beam through the vapor plume a third time at a second angle equal to the first angle, using a series of mirrors to deflect the light beam while protecting the mirrors from the vapor plume with shields. The velocity, density, temperature and flow direction of the vapor plume may be determined by a comparison of the energy from a reference portion of the beam with the energy of the beam after it has passed through the vapor plume. 10 figs.

Berzins, L.V.; Bratton, B.A.; Fuhrman, P.W.

1997-03-11

426

Analytical modeling of the subsurface volatile organic vapor concentration in vapor intrusion  

PubMed Central

The inhalation of volatile and semi-volatile organic compounds that intrude from a subsurface contaminant source into indoor air has become the subject of health and safety concerns over the last twenty years. Building subslab and soil gas contaminant vapor concentration sampling have become integral parts of vapor intrusion field investigations. While numerical models can be of use in analyzing field data and in helping understand the subslab and soil gas vapor concentrations, they are not widely used due to the perceived effort in setting them up. In this manuscript, we present a new closed-form analytical expression describing subsurface contaminant vapor concentrations, including subslab vapor concentrations. The expression was derived using Schwarz-Christoffel mapping. Results from this analytical model match well the numerical modeling results. This manuscript also explores the relationship between subslab and exterior soil gas vapor concentrations, and offers insights on what parameters need to receive greater focus in field studies. PMID:24034829

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

2014-01-01

427

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

428

Chemical vapor infiltration using microwave energy  

SciTech Connect

This invention is comprised of a method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

Devlin, D.J.; Currier, R.P.; Laia, J.R.; Barbero, R.S.

1992-12-31

429

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

430

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

431

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

2006-11-28

432

External fuel vaporization study, phase 1  

NASA Technical Reports Server (NTRS)

A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

Szetela, E. J.; Chiappetta, L.

1980-01-01

433

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

434

Atmospheric dispersion of ammonia: an ammonia fog model  

SciTech Connect

A simplification to the two-phase ammonia vapor-droplet fog problem has been implemented to study the dispersion of a spill of 40 tons of ammonia. We have circumvented the necessity of adding the partial differential equations for mass, momentum, and energy for the ammonia in the liquid phase by certain assumptions. It is assumed that the ammonia fog behaves as an ideal gas including the droplets. A temperature-dependent molecular weight was introduced to simulate the transition from a vapor-droplet cloud to a pure vapor cloud of ammonia. Likewise, the vaporization of ammonia was spread out over a temperature range. Mass, momentum, energy, and total ammonia is conserved rigorously. The observed features of the ammonia spill simulation have pointed out phenomena that could not be predicted in simpler calculations. Perhaps the most obvious feature is the cloud bifurcation due to the strength of the gravity current relative to the ambient wind. The gravity spreading of the denser ammonia fog significantly perturbs the unidirectional windfield in the vicinity of the spill, setting up complex eddy patterns in the cloud which are enhanced by ground heating and warm dry air entrainment. The lower concentrations appear to lift off by a buoyancy-induced flow. The ammonia cloud, rather than being cigar shaped as assumed in simpler models, ranges from pancake shaped to pear shaped, depending upon the ambient windfield. The fact that the ammonia cloud remains cold, very low, and wide is in qualitative agreement with some of the large-scale ammonia spill accidents. 14 figures.

Kansa, E.J.; Rodean, H.C.; Chan, S.T.; Ermak, D.L.

1983-01-01

435

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

436

Water Vapor Distribution in Protoplanetary Disks  

NASA Astrophysics Data System (ADS)

Water vapor has been detected in protoplanetary disks. In this work, we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorption by water of Ly? photons, since the Ly? line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapor with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more extended distribution of warm water vapor, while dust growth and settling tends to reduce the amount of warm water vapor. Based on typical assumptions regarding the elemental oxygen abundance and the water chemistry, the column density of warm water vapor can be as high as 1022 cm-2. A small amount of hot water vapor with temperature higher than ~300 K exists in a more extended region in the upper atmosphere of the disk. Cold water vapor with temperature lower than 100 K is distributed over the entire disk, produced by photodesorption of the water ice.

Du, Fujun; Bergin, Edwin A.

2014-09-01

437

Desalination Using Vapor-Compression Distillation  

E-print Network

to thank my committee members, Dr. Barrufet and Dr. El- Halwagi, for their guidance throughout the completion of this research. I am truly grateful to Dr. Jorge Lara, the faculty, and the staff of the Chemical Engineering Department of Texas A... is commonly used for small- and medium-scale desalination units. There are two methods to compress the vapor: mechanical compressors and steam jets. Lara [6] states that mechanical vapor compression is very efficient. Unlike other distillation systems...

Lubis, Mirna R.

2010-07-14

438

Gradient Solvent Vapor Annealing of Thin Films  

Microsoft Academic Search

The development of block copolymer materials for emerging nanotechnologies requires an understanding of how surface energy\\/chemistry and annealing conditions affect thin film self-assembly. Specifically, in solvent vapor annealing (SVA), the use of solvent mixtures and the manipulation of solvent vapor concentration are promising approaches for obtaining a desired morphology or nanostructure orientation. We designed and fabricated solvent-resistant devices to produce

Julie Albert; Timothy Bogart; Ronald Lewis; Thomas Epps

2011-01-01

439

Multivariable Control of Vapor Compression Systems  

Microsoft Academic Search

This paper presents the results of a study of multi-input multi-output (MIMO) control of vapor compression cycles that have multiple actuators and sensors for regulating multiple outputs, e.g. superheat and evaporating temperature. The conventional single-input single-output (SISO) control was shown to have very limited performance. A low order lumped-parameter model was developed to describe the significant dynamics of vapor compression

Xiang-Dong He; Sheng Liu; Harry H. Asada; Hiroyuki Itoh

1998-01-01

440

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

441

Contaminant Dispersion from a Line Source in a Turbulent Boundary Layer  

Microsoft Academic Search

Experiments of smoke dispersion from a line source in a turbulent boundary layer have been performed in a low-speed wind tunnel. To illuminate the smoke a laser light sheet, oriented in the x-y plane, was created by a copper-vapor plused laser with a variety of optics. The evolving smoke plume was photographed, synchronously with 4-sensor hot-wire probe data, on 16

K.-F. Chiang; L. Ong; J. Wallace; P. Bernard

1996-01-01

442

Holographic studies of the vapor explosion of vaporizing water-in-fuel emulsion droplets  

NASA Technical Reports Server (NTRS)

Holographic studies were performed which examined the fragmentation process during vapor explosion of a water-in-fuel (hexadecane/water) emulsion droplet. Holograms were taken at 700 to 1000 microseconds after the vapor explosion. Photographs of the reconstructed holograms reveal a wide range of fragment droplet sizes created during the explosion process. Fragment droplet diameters range from below 10 microns to over 100 microns. It is estimated that between ten thousand and a million fragment droplets can result from this extremely violent vapor explosion process. This enhanced atomization is thus expected to have a pronounced effect on vaporization processes which are present during combustion of emulsified fuels.

Sheffield, S. A.; Hess, C. F.; Trolinger, J. D.

1982-01-01

443

The Enceladus Torus: Saturn's Vaporous Ring T. A. Cassidy  

E-print Network

The Enceladus Torus: Saturn's Vaporous Ring T. A. Cassidy Top-down view of water vapor ejected from) eject water vapor with escape speed, into Saturn orbit. (similar to how E-ring is formed) Most of this talk will be about what happens to the vapor as it orbits Saturn. 2 #12;3 Enceladus' torus is one

444

Vapor phase lubrication of high temperature alloys  

SciTech Connect

In a previous study, it was found that when a nickel-based superalloy IN750 was heated to high temperatures, a passive layer of aluminum oxide formed on the surface, preventing vapor phase lubrication. In this study, two nickel-chrome-iron alloys and a nickel-copper alloy were studied for high temperature lubrication to see if these alloys, which contained small amounts of aluminum, would exhibit similar behavior. It was found that under static conditions, all three alloys formed a lubricious nodular coating when exposed to a vapor of aryl phosphate. Under dynamic sliding conditions at 500{degrees}C, these alloys were successfully lubricated with a coefficient of friction of 0.1 and no detectable wear. In order to explain these results, a direct correlation between successful vapor phase lubrication and the composition of the alloys containing aluminum has been proposed. If the ratio of copper/aluminum or iron/aluminum is greater that 100 vapor phase, lubrication will be successful. If the ratio is less than 10, a passive aluminum oxide layer will prevent vapor phase lubrication. By selecting alloys with a high iron or copper content, vapor phase lubrication can provide excellent lubrication at high temperatures. 14 refs., 11 figs., 1 tab.

Hanyaloglu, B.F.; Graham, E.E.; Oreskovic, T.; Hajj, C.G. [Cleveland State Univ., OH (United States)

1995-06-01

445

Optical monitor for water vapor concentration  

DOEpatents

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

446

Bhopal atmospheric dispersion revisited.  

PubMed

There is a vital need to understand details of the methylisocyanate (MIC) release that occurred at the 1984 Union Carbide Ltd. pesticide plant in Bhopal, India in order to avoid or respond to such releases in the future. However, we believe there are serious deficiencies in currently available dispersion predictions of the impact of toxic materials on humans and animals downwind of the plant. Specifically, cloud densities have been underestimated due to failure to account for the presence of a liquid/solid aerosol that would have been produced by the chemical reactions that caused the problem. Using data reported in Union Carbide's own investigation of the accident, which included chemical reaction data, we estimated aerosol compositions and cloud densities, then modeled the Bhopal release, simulating potential exposure levels at various locations under a number of wind-condition scenarios. For the worst-case (low wind speed and high aerosol densities), our predicted MIC concentrations at ground level are at least one order of magnitude greater than any previously published estimates. The centerline elevation of the jetting plume released at 33 m elevation is predicted to rise to about 41 m before falling, resulting in a 40 ppm (Immediately Dangerous to Life or Health, IDLH) concentration contour that reaches the ground at about 410 m downwind of the release location. This is consistent with observations that the plant environs were not hard-hit while the public immediately downwind of the plant perimeter was severely exposed. Concentrations on the order of 1000 ppm are predicted at some ground-level locations, which are more consistent than previous estimates with the reported large numbers of deaths and injuries of humans and animals. PMID:22819479

Havens, Jerry; Walker, Heather; Spicer, Tom

2012-09-30

447

Hydrodynamics of CNT dispersion in high shear dispersion mixers  

NASA Astrophysics Data System (ADS)

In this work, we investigate the carbon nanotube (CNT) fragmentation mechanism and dispersion in high shear homogenizers as a plausible dispersion technique, correlating with device geometries and processing conditions, for mass production of CNT-aluminum composites for automobile industries. A CNT dispersion model has been established in a turbulent flow regime and an experimental method in characterizing the critical yield stress of CNT flocs are presented. Considering CNT dispersion in ethanol as a model system, we tested two different geometries of high shear mixers — blade-stirrer type and rotor-stator type homogenizers — and reported the particle size distributions in time and the comparison has been made with the modeling approach and partly with the computational results.

Park, Young Min; Lee, Dong Hyun; Hwang, Wook Ryol; Lee, Sang Bok; Jung, Seung-Il

2014-11-01

448

49 CFR 193.2059 - Flammable vapor-gas dispersion protection.  

Code of Federal Regulations, 2010 CFR

...sections 2.2.3.3 and 2.2.3.4 of NFPA 59A (incorporated by reference, see ...the Gas Research Institute report GRI-96/0396.5 (incorporated by reference...accordance with section 2.2.3.5 of NFPA 59A (incorporated by reference, see...

2010-10-01

449

49 CFR 193.2059 - Flammable vapor-gas dispersion protection.  

Code of Federal Regulations, 2011 CFR

...sections 2.2.3.3 and 2.2.3.4 of NFPA 59A (incorporated by reference, see ...the Gas Research Institute report GRI-96/0396.5 (incorporated by reference...accordance with section 2.2.3.5 of NFPA 59A (incorporated by reference, see...

2011-10-01

450

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

Federal Register 2010, 2011, 2012, 2013, 2014

...clearly state the limitations of the model related to its ability to model sloping terrain, including any special methods to model (e.g., gravity vector adjustment, sub-model for adjusting Cartesian grids, etc). Unique modeling...

2010-08-31

451

Vapor Hydrogen Peroxide Sterilization Certification  

NASA Astrophysics Data System (ADS)

For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be presented.

Chen, Fei; Chung, Shirley; Barengoltz, Jack

452

FEM3 modeling of ammonia and hydrofluoric acid dispersion. [A phase-change submodel  

SciTech Connect

FEM3 is a three-dimensional computer model that was designed to simulate the atmospheric dispersion of heavier-than-air gas releases. Recently a phase-change submodel based on local thermodynamic equilibrium has been implemented to treat vapor-liquid transition of the dispersed material. A preliminary evaluation of the phase-change submodel was performed by using data obtained from two recently conducted series of field experiments, namely, the pressurized ammonia spills conducted by LLNL and the anhydrous hydrofluoric acid dispersion experiments conducted by Amoco Oil Company and LLNL. FEM3 results compare reasonably well with the good data available from one ammonia spill and two hydrofluoric acid spills and, in particular, the results obtained by using the phase-change submodel represent considerable improvements over those from all-vapor simulations. While the present phase-change submodel qualitatively handles the aerosol effects, including gravity flow and heat transfer between the vapor and droplets, it tends to over-estimate the rate of droplet evaporation. 16 refs., 12 figs., 7 tabs.

Chan, S.T.; Rodean, H.C.; Blewitt, D.N.

1987-07-01

453

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

454

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

455

Cross-correlation video recording of gas-vapor-droplet two-phase flows  

NASA Astrophysics Data System (ADS)

The experimental investigations of gas-vapor-droplet two-phase flow formation during single water droplets and their aggregate motion through high-temperature (more than 1000 K) combustion products have been conducted with usage of cross-correlation measuring facility and optical methods of "tracer" visualization ("Particle Image Velocimetry" and "Interferometric Particle Imaging"). Modes of droplet motion in high-temperature gases area have been established. It has been determined the influence of the main droplet (sizes, composition, temperature, dispersability, form, velocity) and gas (temperature and velocity) characteristics on parameters of forming gas-vapor-droplet mixtures. The main elements of advanced firefighting technologies with the usage of time and space apportioned polydisperse composition water droplet flows have been formulated. Physical and predictive mathematical models have been developed to determine the basic parameters of equipment which is necessary for operation with these technology usage.

Volkov, Roman S.; Vysokomornaya, Olga V.; Zhdanova, Alyona O.; Strizhak, Pavel A.

2015-01-01

456

Condensation/evaporation of insoluble organic vapor as functions of source rate and saturation vapor pressure  

NASA Astrophysics Data System (ADS)

Condensation growth of atmospheric particles by insoluble organic vapors was studied by a monodisperse aerosol dynamics model MONO32 including atmospheric chemistry mechanism. The source rate of the vapor and its saturation vapor density at a particle surface were varied. The initial particle number size distribution was assumed to be bimodal, and aerosol was initially an internal mixture of particles consisting of soluble sulphuric acid and insoluble organic material in a ratio of 1:1. Model simulations predicted that if the ratio of the vapor source rate and the condensation sink of particles, Q/CS, exceeded 108 cm-3 and the vapor was nonvolatile or low volatile, the 10 nm nuclei grew with the growth rates of 2.5-3 nm h-1 and could act as cloud condensation nuclei in supersaturations of 1.6% or lower after 24 h simulation. Then the vapors must have saturation vapor pressures less than 7 × 106 cm-3. However, the higher the ratio of Q/CS, the higher the saturation vapor pressure could be. When the vapor was highly volatile, i.e., the saturation vapor density was high enough, in our simulations greater than 6 × 107 cm-3 the Ostwald ripening was observed. Then the nucleation mode particles were not able to grow but coagulated with larger particles without causing any significant impact on climate. An analytical expression for the saturation vapor density for the Ostwald ripening (cOst) was derived as a function of the ratio of Q/CS. Sensitivity tests for the accommodation coefficient and thermodynamic parameters as well as their effects on cOst were investigated.

Pirjola, Liisa; Korhonen, Hannele; Kulmala, Markku

2002-06-01

457

Water Vapor Measurement and Compensation in the Near and Mid-infrared with the Keck Interferometer Nuller  

NASA Technical Reports Server (NTRS)

A viewgraph presentation describing the methods, motivation and methods for water vapor measurement with the Keck interferometer near and mid infrared radiation band is shown. The topics include: 1) Motivation: Why measure H2O?; 2) Method: How do we measure H2O?; 3) Data: Phase and Group Delays for the K and N Bands; 4) Predicted and Actual Nband Phase and Dispersion; and 5) Validation of Atmospheric Turbulence Models with KI Data.

Koresko, Chris D.; Colavita, Mark M.; Serabyn, Eugene; Booth, Andrew; Garcia, Jean I.

2006-01-01

458

CO oxidation activity of Cu–CeO 2 nano-composite catalysts prepared by laser vaporization and controlled condensation  

Microsoft Academic Search

Ceria supported copper catalysts were synthesized by laser vaporization and controlled condensation method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX) and temperature programmed reduction (TPR). The catalytic activity of the nanopowders for CO oxidation reaction was tested in a fixed bed flow tube reactor in Ar–20%O2–4%CO mixture. Irrespective of the copper content,

Rangaraj S. Sundar; Sarojini Deevi

2006-01-01

459

Modeling and Simulation of Effects of Turbulence on Vaporization, Mixing and Combustion of Liquid-Fuel Sprays  

Microsoft Academic Search

The objective of this work is twofold. Firstly, the effects of turbulence intensity variations on the turbulent droplet dispersion,\\u000a vaporization and mixing for non-reacting sprays (with and without swirl) are pointed out. Secondly, the effects of the coupling\\u000a of the turbulence modulation with external parameters, such as swirl intensity, on turbulent spray combustion are analyzed\\u000a in configurations of engineering importance.

A. Sadiki; M. Chrigui; J. Janicka; M. R. Maneshkarimi

2005-01-01

460

Vapor phase diamond growth technology  

NASA Technical Reports Server (NTRS)

Ion beam deposition chambers used for carbon film generation were designed and constructed. Features of the developed equipment include: (1) carbon ion energies down to approx. 50 eV; (2) in suit surface monitoring with HEED; (3) provision for flooding the surface with ultraviolet radiation; (4) infrared laser heating of substrate; (5) residual gas monitoring; (6) provision for several source gases, including diborane for doping studies; and (7) growth from either hydrocarbon source gases or from carbon/argon arc sources. Various analytical techniques for characterization of from carbon/argon arc sources. Various analytical techniques for characterization of the ion deposited carbon films used to establish the nature of the chemical bonding and crystallographic structure of the films are discussed. These include: H2204/HN03 etch; resistance measurements; hardness tests; Fourier transform infrared spectroscopy; scanning auger microscopy; electron spectroscopy for chemical analysis; electron diffraction and energy dispersive X-ray analysis; electron energy loss spectroscopy; density measurements; secondary ion mass spectroscopy; high energy electron diffraction; and electron spin resonance. Results of the tests are summarized.

Angus, J. C.

1981-01-01

461

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

462

Interferometric phase-dispersion microscopy  

Microsoft Academic Search

We describe a new scanning microscopy technique, phase-dispersion microscopy (PDM). The technique is based on measuring the phase difference between the fundamental and the second-harmonic light in a novel interferometer. PDM is highly sensitive to subtle refractive-index differences that are due to dispersion (differential optical path sensitivity, 5 nm). We apply PDM to measure minute amounts of DNA in solution

Changhuei Yang; Adam Wax; Irene Georgakoudi; Eugene B. Hanlon; Kamran Badizadegan; Ramachandra R. Dasari; Michael S. Feld

2000-01-01

463

Daytime Raman lidar measurements of water vapor during the ARM 1997 water vapor intensive observation period  

Microsoft Academic Search

Because of the importance of water vapor, the ARM program initiated a series of three intensive operating periods (IOPs) at its CART (Cloud And Radiation Testbed) site. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of

D. D. Turner; J. E. M. Goldsmith

1998-01-01

464

Interphase phenomena and the condensation of liquid metal vapors. The condensation mechanism of nitrogen tetroxide vapor  

SciTech Connect

Thesis. Submitted by J. Lorrain. Theoretical analyses of interphase processes involving vapors and liquids are presented. Monoatomic and reacting vapors were considered in situations such as condensation, evaporation and heat transfer between the vapor and its liquid. These developments are believed to be the most accurate to date in describing such processes. The implications of the presence of diatomic and heavier naolecules in liquid metal vapors in their condensation heat transfer are discussed. It is shown that some assumed detailed mechanisms of condensation of these species can explain the low experimental condensation heat transfer coefficients of liquid metals. Results of an experimental investigation of the condensation mechanism and condensation heat transfer of nitrogen tetroxide vapor are presented. From measurements of temperature profiles in the vapor near the vapor-llquid interface during condensation it was concluded that both major components of the vapor (nitrogen dioxide and nitrogen tetroxide) condense at comparable rates. This mechanism is in qualitative agreement with the experimental condensation heat transfer coefficients, which were found to be 10 to 20% higher than predicted by Nusselt's theory. This is apparentiy the first determination of a detailed condensation mechanism at moderate pressures where traditional methods (e.g., vacuum evaporation techniques) can not be used. (auth)

Larrain, J.; Bonilla, C.F.

1974-04-30

465

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

E-print Network

similar to amphetamine, is used medicinally as an appetite suppressant for patients who suffer from obesity.7 Tranylcypromine or trans-1-phenylcyclopropylamine, developed as an analogue of amphetamine the vaporization enthalpies and vapor pressures of a series of primary n-alkylamines including those of amphetamine

Chickos, James S.

466

33 CFR 154.2111 - Vapor control system connected to a facility's main vapor control system.  

Code of Federal Regulations, 2014 CFR

...33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01...system connected to a facility's main vapor control system. 154...2111 Navigation and Navigable Waters COAST GUARD, DEPARTMENT...connected to a facility's main vapor control system....

2014-07-01

467

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

468

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

PubMed

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

2013-10-01

469

Growth of carbon nanotubes by Fe-catalyzed chemical vapor processes on silicon-based substrates  

NASA Astrophysics Data System (ADS)

In this paper, a site-selective catalytic chemical vapor deposition synthesis of carbon nanotubes on silicon-based substrates has been developed in order to get horizontally oriented nanotubes for field effect transistors and other electronic devices. Properly micro-fabricated silicon oxide and polysilicon structures have been used as substrates. Iron nanoparticles have been obtained both from a thin Fe film evaporated by e-gun and from iron nitrate solutions accurately dispersed on the substrates. Single-walled nanotubes with diameters as small as 1 nm, bridging polysilicon and silicon dioxide “pillars”, have been grown. The morphology and structure of CNTs have been characterized by SEM, AFM and Raman spectroscopy.

Angelucci, Renato; Rizzoli, Rita; Vinciguerra, Vincenzo; Fortuna Bevilacqua, Maria; Guerri, Sergio; Corticelli, Franco; Passini, Mara

2007-03-01

470

A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events  

PubMed Central

The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining the vapor intrusion risk. In addition, soil organic carbon retarded the transport process, and damped the contaminant concentration fluctuations. PMID:22922135

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

2013-01-01

471

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

472

Explosive vapor detection payload for small robots  

NASA Astrophysics Data System (ADS)

Detection of explosive hazards is a critical component of enabling and improving operational mobility and protection of US Forces. The Autonomous Mine Detection System (AMDS) developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) is addressing this challenge for dismounted soldiers. Under the AMDS program, ARA has developed a vapor sampling system that enhances the detection of explosive residues using commercial-off-the-shelf (COTS) sensors. The Explosives Hazard Trace Detection (EHTD) payload is designed for plug-and-play installation and operation on small robotic platforms, addressing critical Army needs for more safely detecting concealed or exposed explosives in areas such as culverts, walls and vehicles. In this paper, we describe the development, robotic integration and performance of the explosive vapor sampling system, which consists of a sampling "head," a vapor transport tube and an extendable "boom." The sampling head and transport tube are integrated with the boom, allowing samples to be collected from targeted surfaces up to 7-ft away from the robotic platform. During sample collection, an IR lamp in the sampling head is used to heat a suspected object/surface and the vapors are drawn through the heated vapor transport tube to an ion mobility spectrometer (IMS) for detection. The EHTD payload is capable of quickly (less than 30 seconds) detecting explosives such as TNT, PETN, and RDX at nanogram levels on common surfaces (brick, concrete, wood, glass, etc.).

Stimac, Phil J.; Pettit, Michael; Wetzel, John P.; Haas, John W.

2013-05-01

473

DISTRIBUTION OF WATER VAPOR IN MOLECULAR CLOUDS  

SciTech Connect

We report the results of a large-area study of water vapor along the Orion Molecular Cloud ridge, the purpose of which was to determine the depth-dependent distribution of gas-phase water in dense molecular clouds. We find that the water vapor measured toward 77 spatial positions along the face-on Orion ridge, excluding positions surrounding the outflow associated with BN/KL and IRc2, display integrated intensities that correlate strongly with known cloud surface tracers such as CN, C{sub 2}H, {sup 13}CO J = 5-4, and HCN, and less well with the volume tracer N{sub 2}H{sup +}. Moreover, at total column densities corresponding to A{sub V}< 15 mag, the ratio of H{sub 2}O to C{sup 18}O integrated intensities shows a clear rise approaching the cloud surface. We show that this behavior cannot be accounted for by either optical depth or excitation effects, but suggests that gas-phase water abundances fall at large A{sub V}. These results are important as they affect measures of the true water-vapor abundance in molecular clouds by highlighting the limitations of comparing measured water-vapor column densities with such traditional cloud tracers as {sup 13}CO or C{sup 18}O. These results also support cloud models that incorporate freeze out of molecules as a critical component in determining the depth-dependent abundance of water vapor.

Melnick, Gary J.; Tolls, Volker [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Snell, Ronald L. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Bergin, Edwin A. [Department of Astronomy, University of Michigan, 825 Dennison Building, Ann Arbor, MI 48109 (United States); Hollenbach, David J. [SETI Institute, 515 North Whisman Road, Mountain View, CA 94043 (United States); Kaufman, Michael J. [Department of Physics and Astronomy, San Jose State University, One Washington Square, San Jose, CA 95192-0106 (United States); Li Di [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Neufeld, David A., E-mail: gmelnick@cfa.harvard.edu, E-mail: vtolls@cfa.harvard.edu, E-mail: snell@astro.umass.edu, E-mail: ebergin@umich.edu, E-mail: dhollenbach@seti.org, E-mail: mkaufman@email.sjsu.edu, E-mail: dili@jpl.nasa.gov, E-mail: neufeld@pha.jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

2011-01-20

474

Multivariable control of vapor compression systems  

SciTech Connect

This paper presents the results of a study of multi-input multi-output (MIMO) control of vapor compression cycles that have multiple actuators and sensors for regulating multiple outputs, e.g., superheat and evaporating temperature. The conventional single-input single-output (SISO) control was shown to have very limited performance. A low order lumped-parameter model was developed to describe the significant dynamics of vapor compression cycles. Dynamic modes were analyzed based on the low order model to provide physical insight of system dynamic behavior. To synthesize a MIMO control system, the Linear-Quadratic Gaussian (LQG) technique was applied to coordinate compressor speed and expansion valve opening with guaranteed stability robustness in the design. Furthermore, to control a vapor compression cycle over a wide range of operating conditions where system nonlinearities become evident, a gain scheduling scheme was used so that the MIMO controller could adapt to changing operating conditions. Both analytical studies and experimental tests showed that the MIMO control could significantly improve the transient behavior of vapor compression cycles compared to the conventional SISO control scheme. The MIMO control proposed in this paper could be extended to the control of vapor compression cycles in a variety of HVAC and refrigeration applications to improve system performance and energy efficiency.

He, X.D.; Liu, S.; Asada, H.H.; Itoh, Hiroyuki

1999-07-01

475

Short circuit of water vapor and polluted air to the global stratosphere by convective transport over the Tibetan Plateau  

PubMed Central

During boreal summer, much of the water vapor and CO entering the global tropical stratosphere is transported over the Asian monsoon/Tibetan Plateau (TP) region. Studies have suggested that most of this transport is carried out either by tropical convection over the South Asian monsoon region or by extratropical convection over southern China. By using measurements from the newly available National Aeronautics and Space Administration Aura Microwave Limb Sounder, along with observations from the Aqua and Tropical Rainfall-Measuring Mission satellites, we establish that the TP provides the main pathway for cross-tropopause transport in this region. Tropospheric moist convection driven by elevated surface heating over the TP is deeper and detrains more water vapor, CO, and ice at the tropopause than over the monsoon area. Warmer tropopause temperatures and slower-falling, smaller cirrus cloud particles in less saturated ambient air at the tropopause also allow more water vapor to travel into the lower stratosphere over the TP, effectively short-circuiting the slower ascent of water vapor across the cold tropical tropopause over the monsoon area. Air that is high in water vapor and CO over the Asian monsoon/TP region enters the lower stratosphere primarily over the TP, and it is then transported toward the Asian monsoon area and disperses into the large-scale upward motion of the global stratospheric circulation. Thus, hydration of the global stratosphere could be especially sensitive to changes of convection over the TP. PMID:16585523

Fu, Rong; Hu, Yuanlong; Wright, Jonathon S.; Jiang, Jonathan H.; Dickinson, Robert E.; Chen, Mingxuan; Filipiak, Mark; Read, William G.; Waters, Joe W.; Wu, Dong L.

2006-01-01

476

Pressure drop in fully developed, turbulent, liquid-vapor annular flows in zero gravity  

NASA Technical Reports Server (NTRS)

The prediction of frictional pressure drop in fully developed, turbulent, annular liquid-vapor flows in zero gravity using simulation experiments conducted on earth is described. The scheme extends the authors' earlier work on dispersed flows. The simulation experiments used two immiscible liquids of identical density, namely, water and n-butyl benzoate. Because of the lack of rigorous analytical models for turbulent, annular flows, the proposed scheme resorts to existing semiempirical correlations. Results based on two different correlations are presented and compared. Others may be used. It was shown that, for both dispersed and annular flow regimes, the predicted frictional pressure gradients in 0-g are lower than those in 1-g under otherwise identical conditions. The physical basis for this finding is given.

Sridhar, K. R.; Chao, B. T.; Soo, S. L.

1992-01-01

477

Weak-value amplification of the fast-light effect in rubidium vapor  

E-print Network

We use weak-value amplification to enhance the polarization-sensitive fast-light effect from induced Raman absorption in hot rubidium vapor. We experimentally demonstrate that projecting the output signal into an appropriate polarization state enables a pulse advancement of 4.2 {\\mu}s, which is 15 times larger than that naturally caused by dispersion. More significantly, we show that combining weak-value amplification with the dispersive response of an atomic system provides a clear advantage in terms of the maximum pulse advancement achievable for a given value of loss. This technique has potential applications for designing novel quantum-information-processing gates and optical buffers for telecommunication systems.

Mohammad Mirhosseini; Gerardo Viza; Omar S. Magaña-Loaiza; Mehul Malik; John C. Howell; Robert W. Boyd

2014-12-09

478

Vapor concentration measurement with photothermal deflectometry  

NASA Technical Reports Server (NTRS)

Theoretical and experimental results for using the photothermal deflection technique to measure vapor species concentration, while minimizing the disturbance of the transport (material) parameters due to vapor heating, are developed and described. In contrast to common practice, the above constraints require using a pump-beam duty cycle of less than 50 percent. The theoretical description of the shortened heating time is based on a step-function formulation of the pumping cycle. The results are obtained as closed-form solutions of the energy equation for many chopping cycles until steady state is reached, by use of a Green's-function method. The Euler formulation of the Fermat principle is used to calculate the deflection angle. The equations are expanded to include the effects of vapor velocity on both the temperature and temperature gradient profiles. The effects of finite (unfocused) pump and probe beams and thermal (Soret) diffusion are also accounted for. Excellent agreement between theory and experiment is obtained.

Banish, R. Michael; Xiao, Rong-Fu; Rosenberger, Franz

1988-01-01

479

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

480

Advanced Atmospheric Water Vapor DIAL Detection System  

NASA Technical Reports Server (NTRS)

Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

2000-01-01

481

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

482

Refraction of microwave signals by water vapor  

NASA Technical Reports Server (NTRS)

Tropospheric water vapor causes a refractive path length effect which is typically 5-10% of the 'dry' tropospheric effect and as large as several meters at elevation angles below 5 deg. The vertical water vapor profile is quite variable, and measurements of intensive atmospheric parameters such as temperature and humidity limited to the surface do not adequately predict the refractive effect. It is suggested that a water vapor refraction model that is a function of the amount of precipitable water alone can be successful at low elevation angles. From an extensive study of numerical ray tracings through radiosonde balloon data, such a model has been constructed. The model predicts the effect at all latitudes and elevation angles between 2 and 10 deg to an accuracy of better than 4% (11 cm at 3 deg elevation angle).

Goldfinger, A. D.

1980-01-01

483

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

484

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

485

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

486

Filter control polarization mode dispersion in dispersion managed soliton systems  

NASA Astrophysics Data System (ADS)

In this paper, the dispersion managed soliton (DMS) transmission equation is built on considering the effects of polarization mode dispersion (PMD) and filter control. The DMS transmission of filtering control in constant birefringence fibers is firstly analyzed by varitional method, from which the evolving rules of characteristical DMS parameters are obtained. Secondly, the stability of DMS transmission and its timing jitter are investigated in the random varying birefringence fibers with the conventional model of PMD. The results reveal that filter control DMS system has powerful robustness to PMD effects and DMS's timing jitter can be decreased considerably with the help of filters.

Xu, Ming; Pu, Tao; Yang, Shuwen; Yang, Xianglin

2003-10-01

487

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

488

Diamond film deposition by chemical vapor transport  

NASA Astrophysics Data System (ADS)

Chemical vapor deposition techniques for depositing diamond films at low pressure are reviewed, along with current and potential applications for these films. A new chemical vapor transport technique is described that is simpler and suitable for microgravity and centrifuge experiments. It was used to deposit diamond on silicon, molybdenum, graphite, glass, and carbon felt. Selective patterned deposition was achieved on a copper pattern on oxidized silicon. Centrifugation at only ˜2 g greatly increased the nucleation density, area of deposition, and growth rate. The self-regulating behavior of this new technique is explained in terms of chemical and transport mechanisms.

L. Regel, Liya; R. Wilcox, William

489

Diode pumped alkali vapor fiber laser  

DOEpatents

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2007-10-23

490

Diode pumped alkali vapor fiber laser  

DOEpatents

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2006-07-26

491

Preprototype Vapor Compression Distillation Subsystem development  

NASA Technical Reports Server (NTRS)

Vapor Compression Distillation (VCD) has evolved as the most promising approach to reclaim potable water from wastewater for future long-term manned space missions. Life Systems, Inc. (LSI), working with NASA, has developed a preprototype Vapor Compression Distillation Subsystem (VCDS) which processes wastewater at 1.4 kg/h. The preprototype unit weighs 143 kg, occupies a volume of 0.47 cu m, and will reclaim 96 percent of the available wastewater. This unit has been tested by LSI and is scheduled for further testing at NASA-JSC. This paper presents the preprototype VCDS design, configuration, performance data, test results and flight system projections.

Thompson, C. D.; Ellis, G. S.; Schubert, F. H.

1981-01-01

492

Observe animated satellite images of water vapor  

NSDL National Science Digital Library

This animation shows Earth science students how jet streams drive the movement of water vapor in the atmosphere. The introduction explains how the infrared images were taken from a satellite positioned about 8 kilometers above the Earth's surface. Students are instructed to observe how the jet streams (indicated by dark areas) are juxtaposed against areas of dense water vapor (indicated by light areas). Movie controls allow students to repeat, pause, or step through the animation, which can give students more time to analyze the images. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

493

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

494

Dispersion interactions between semiconducting wires  

NASA Astrophysics Data System (ADS)

The dispersion energy between extended molecular chains (or equivalently infinite wires) with nonzero band gaps is generally assumed to be expressible as a pair-wise sum of atom-atom terms which decay as R-6 . Using a model system of two parallel wires with a variable band gap, we show that this is not the case. The dispersion interaction scales as z-5 for large interwire separations z , as expected for an insulator, but as the band gap decreases the interaction is greatly enhanced; while at shorter (but nonoverlapping) separations it approaches a power-law scaling given by z-2 , i.e., the dispersion interaction expected between metallic wires. We demonstrate that these effects can be understood from the increasing length scale of the plasmon modes (charge fluctuations), and their increasing contribution to the molecular dipole polarizability and the dispersion interaction, as the band gaps are reduced. This result calls into question methods which invoke locality assumptions in deriving dispersion interactions between extended small-gap systems.

Misquitta, Alston J.; Spencer, James; Stone, Anthony J.; Alavi, Ali

2010-08-01

495

FTIR-luminescence mapping of dispersed single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

We have applied the FTIR-luminescence/FT-Raman technique to map the near-infrared photoluminescence (PL) of water surfactant dispersions of single-walled carbon nanotubes (SWNTs) in broad excitation (250 1500 nm) and emission (800 1700 nm) ranges. The excitation wavelength was scanned by using the monochromatized light of standard xenon and tungsten halogen lamps. The PL maps are presented for SWNTs with a mean diameter of ~1.3 nm prepared by the pulsed laser vaporization method. When dispersed by powerful ultrasonic agitation and separated by ultracentrifugation, these nanotubes show structured absorption bands and a PL quantum yield as high as ~10-3. This indicates a large fraction of individual nanotubes in the dispersion. Electronic interband transition energies of nanotubes derived from the PL data correspond reasonably to the energies calculated in the modified tight-binding model of Ding et al.

Lebedkin, Sergei; Arnold, Katharina; Hennrich, Frank; Krupke, Ralph; Renker, Burkhard; Kappes, Manfred M.

2003-10-01

496

Broadband dispersion-compensating fiber for high-bit-rate transmission network use.  

PubMed

The optimum refractive-index profile and drawing temperature were investigated so as to maximize the figure of merit for multicladding broadband dispersion-compensating fibers. Based on the results of the investigation, the authors have fabricated a highly bend-resistant fiber with a 92.6-ps/(nm dB) figure of merit using the modified chemical-vapor deposition method for dispersion compensation in the 1.5-1.6-µm wavelength region. The manufactured dispersion compensator does not suffer bend loss at 1.55 µm for curvatures of radia of 6.3 and 3.3 cm, and it has a 1.1-dB/km bend loss at a curvature of radius of 1.6 cm. Codoping the germanium silicate core with fluorine diminishes the optical loss down to 0.70 dB/km at a 1.55-µm wavelength. PMID:21060352

Semenov, V A; Belov, A V; Dianov, E M; Abramov, A A; Bubnov, M M; Semjonov, S L; Shchebunjaev, A G; Khopin, V F; Guryanov, A N; Vechkanov, N N

1995-08-20

497

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

498

DISPERSANT EFFECTIVENESS AT VARIOUS SEA STATES  

EPA Science Inventory

In 2002, a dispersant effectiveness protocol, which tested the effectiveness of dispersants to disperse crude oil into the water column, was developed. A new and highly reproducible protocol that uses a baffled flask as the primary vehicle for getting the oil dispersed has emerge...

499

Temporal Dispersion of a Spectrometer  

SciTech Connect

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 can be calculated to depend only on the order of the grating, wavelength, and the number of grooves illuminated. To enhance the temporal dispersion, 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 to the exact shape of the temporal instrument function, which is required when interpreting temporally resolved data. The experiments used a 300fs laser pulse and a picosecond optical streak camera to determine the temporal dispersion. This was done for multiple spectral orders, gratings, and optical masks.

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

2008-05-08

500

Evaluation of dispersants for gelcasting  

SciTech Connect

Dispersants were evaluated for producing fluid and pourable 50 vol % alumina slurries for use in aqueous gelcasting. The best dispersants are anionic polyelectrolytes with carboxylic acid sites. The major mechanism by which the anionic polyelectrolytes stabilize aqueous alumina suspensions is electrostatic. However, the presence of Mg(NO{sub 3}){sub 2}, a precursor for MgO used as sintering aid for the alumina, and acrylamide monomer, used to form the gel, enhances the steric contribution of the adsorbed polymer to the interaction between alumina particles.

Omatete, O.O.; Bleier, A.

1992-05-01