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Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Suppressant:Perfluorocarbons (PFCs)  

Science Conference Proceedings (OSTI)

... Acid Gas Production in Inhibited Diffusion Flames.. ... Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) for ... to an External Energy Source.. ...

2012-03-20T23:59:59.000Z

2

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents (OSTI)

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases. 3 figs.

Turick, C.E.

1997-06-10T23:59:59.000Z

3

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents (OSTI)

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases.

Turick, Charles E. (Idaho Falls, ID)

1997-01-01T23:59:59.000Z

4

Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane  

E-Print Network (OSTI)

We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane ...

Muhle, J.

5

Perfluorocarbon vapor tagging of blasting cap detonators  

DOE Patents (OSTI)

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)

1981-01-01T23:59:59.000Z

6

Perfluorocarbon vapor tagging of blasting cap detonators  

SciTech Connect

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, R.N.; Senum, G.I.

1981-03-17T23:59:59.000Z

7

Petroleum characterization by perfluorocarbon tracers  

SciTech Connect

Perfluorocarbon tracers (PFTs), a class of six compounds, were used to help characterize the Shallow Oil Zone (SOZ) reservoir at the Naval Petroleum Reserve in California (NPRC) at Elk Hills. The SOZ reservoir is undergoing a pilot gas injection program to assess the technical feasibility and economic viability of injecting gas into the SOZ for improved oil recovery. PFTs were utilized in the pilot gas injection to qualitatively assess the extent of the pilot gas injection so as to determine the degree of gas containment within the SOZ reservoir.

Senum, G.I.; Fajer, R.W. (Brookhaven National Lab., Upton, NY (United States)); Harris, B.R. Jr. (USDOE Naval Petroleum Reserves in California, Tupman, CA (United States)); DeRose, W.E. (Bechtel Petroleum Operations, Inc., Tupman, CA (United States)); Ottaviani, W.L. (Chevron U.S.A., Inc., Bakersfield, CA (United States))

1992-02-01T23:59:59.000Z

8

SUBMISSION BY FINLAND ON BEHALF OF THE EUROPEAN COMMUNITY AND ITS MEMBER STATES OF INFORMATION ON AVAILABLE AND POTENTIAL WAYS AND MEANS OF LIMITING HFC, PFC AND SF 6 EMISSIONS  

E-Print Network (OSTI)

Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF 6) are used in a wide variety of applications ranging from aerosol cans to industrial refrigeration and electrical systems which may contain thousands of kilograms of these substances. The paper at hand describes the uses and emission sources of these gases

unknown authors

1999-01-01T23:59:59.000Z

9

Perfluorocarbon tracer method for air-infiltration measurements  

DOE Patents (OSTI)

A method of measuring air infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, sampling the air containing the emitted perfluorocarbons over a period of time, and analyzing the samples at a laboratory or other facility.

Dietz, R.N.

1982-09-23T23:59:59.000Z

10

Dispersion of Perfluorocarbon Tracers within the Salt Lake Valley during VTMX 2000  

Science Conference Proceedings (OSTI)

Six perfluorocarbon tracer experiments were conducted in Salt Lake City, Utah, during October 2000 as part of the Vertical Transport and Mixing (VTMX) field campaign. Four tracers were released at different sites to obtain information on ...

Jerome D. Fast; K. Jerry Allwine; Russell N. Dietz; Kirk L. Clawson; Joel C. Torcolini

2006-06-01T23:59:59.000Z

11

EIA - Greenhouse Gas Emissions - High-GWP gases  

Gasoline and Diesel Fuel Update (EIA)

5. High-GWP gases 5. High-GWP gases 5.1. Total emissions Greenhouse gases with high global warming potential (high-GWP gases) are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which together represented 3 percent of U.S. greenhouse gas emissions in 2009. Emissions estimates for the high-GWP gases are provided to EIA by the EPA's Office of Air and Radiation. The estimates for emissions of HFCs not related to industrial processes or electric transmission are derived from the EPA Vintaging Model. Emissions from manufacturing and utilities are derived by the EPA from a mix of public and proprietary data, including from the EPA's voluntary emission reduction partnership programs. For this year's EIA inventory, 2008 values for HFC-23 from HCFC-22

12

Environment II: PFCs  

Science Conference Proceedings (OSTI)

Mar 6, 2013 ... Anode effects have been characterized in the industry by measuring their frequency and duration when the cell voltage is above 8 volts. Efforts ...

13

QUANTIFICATION OF FUGITIVE REACTIVE ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS.  

SciTech Connect

Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissions are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.

SENUM,G.I.; DIETZ,R.N.

2004-06-30T23:59:59.000Z

14

Feasibility of perfluorocarbon tracers (PFTs) in atmospheric source-receptor experiments  

SciTech Connect

A brief description of the perfluorocarbon tracer (PFT) system, which includes the tracers and the release equipment, the air samplers and the analyzers, is presented along with details on the research needs to provide a viable system for MATEX-scenario experiments. The present family of 2 viable PFTs needs to be increased to 5 to 6. Given the present precision of the analysis system, a one year long tracer experiment consisting of 4 hour releases every 60 hours from 5 different sites would require nearly 150 metric tons of PFTs at a cost of $15,000,000. Shortcomings in the programmable sampler include the pump, the sampling sequence control flexibility, data storage and retrieval, and the lack of remote communication capability; sampler adsorbent studies are also needed. The analytical system, including the catalyst processing bed, the chromatography column resolution, and the linearity of the detector, is in need of significant improvement. A higher resolution analysis system could significantly reduce analysis time but, more importantly, reduce tracer requirements more than 10-fold, for a cost savings potential of more than $13,000,000. A model is presented to demonstrate the feasibility of tracer material balances. Assessment of earlier long-range tracer experiments indicates the need for possibly 400 ground sampling sites requiring $8 to $14 million worth of samplers for a one-year tracer experiment. As many as six aircraft would be needed to conduct airborne model validation and material balance studies for each tracer plume.

Dietz, R.N.; Senum, G.I.

1984-03-01T23:59:59.000Z

15

USE OF PERFLUOROCARBON TRACER (PFT) TECHNOLOGY FOR SUBSURFACE BARRIER INTEGRITY VERIFICATION AT THE WALDO TEST SITE.  

SciTech Connect

Testing of perfluorocarbon gas tracers (PFT) on a subsurface barrier with known flaws was conducted at the Waldo Test Site operated by Science and Engineering Associates, Inc (SEA). The tests involved the use of five unique PFTs with a different tracer injected along the interior of each wall of the barrier. A fifth tracer was injected exterior to the barrier to examine the validity of diffusion controlled transport of the PFTs. The PFTs were injected for three days at a nominal flow rate of 15 cm{sup 3}/min and concentrations in the range of a few hundred ppm. Approximately 65 liters of air laced with tracer was injected for each tracer. The tracers were able to accurately detect the presence of the engineered flaws. Two flaws were detected on the north and east walls, and one flaw was detected on the south and west walls. In addition, one non-engineered flaw at the seam between the north and east walls was also detected. The use of multiple tracers provided independent confirmation of the flaws and permitted a distinction between tracers arriving at a monitoring port after being released from a nearby flaw and non-engineered flaws. The PFTs detected the smallest flaw, 0.5 inches in diameter. Visual inspection of the data showed excellent agreement with the known flaw locations and the relative size of the flaws was accurately estimated. Simultaneous with the PFT tests, SEA conducted tests with another gas tracer sulfur hexafluoride (SF{sub 6}).

SULLIVAN,T.

1999-06-01T23:59:59.000Z

16

Word Pro - S12  

U.S. Energy Information Administration (EIA) Indexed Site

Note 1. Emissions of Carbon Dioxide and Other Green- Note 1. Emissions of Carbon Dioxide and Other Green- house Gases. Greenhouse gases are those gases-such as water vapor, carbon dioxide (CO 2 ), methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride-that are transparent to solar (short- wave) radiation but opaque to long-wave (infrared) radiation, thus preventing long-wave radiant energy from leaving Earth's atmosphere. The net effect is a trapping of absorbed radiation and a tendency to warm the planet's surface. Energy-related carbon dioxide emissions account for about 98 percent of U.S. CO 2 emissions. The vast majority of CO 2 emissions come from fossil fuel combustion, with smaller amounts from the nonfuel use of fossil fuels, as well as from electricity generation using geothermal energy and non-

17

Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers  

SciTech Connect

Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called ``hi-pot`` (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven`s Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the ``double source`` method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

Loss, W.M.; Dietz, R.N.

1991-09-01T23:59:59.000Z

18

Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers  

SciTech Connect

Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called hi-pot'' (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven's Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the double source'' method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

Loss, W.M.; Dietz, R.N.

1991-09-01T23:59:59.000Z

19

CHARACTERIZATION OF LEAK PATHWAYS IN THE BELOW GRADE DUCTS OF THE BROOKHAVEN GRAPHITE RESEARCH REACTOR USING PERFLUOROCARBON TRACERS.  

SciTech Connect

The focus of this program was the characterization of the soils beneath the main air ducts connecting the exhaust plenums with the Fan House. The air plenums experienced water intrusion during BGRR operations and after shutdown. The water intrusions were attributed to rainwater leaks into degraded parts of the system and to internal cooling water system leaks. As part of the overall characterization efforts, a state-of-the-art gaseous perfluorocarbon tracer technology was utilized to characterize leak pathways from the ducts. This in turn suggests what soil regions under or adjacent to the ductwork should be emphasized in the characterization process. Knowledge of where gaseous tracers leak from the ducts yields a conservative picture of where water transport, out of or into, the ducts might have occurred.

HEISER,J.; SULLIVAN,T.; KALB,P.; MILIAN,L.; WILKE,R.; NEWSON,C.; LILIMPAKIS,M.

2001-04-01T23:59:59.000Z

20

Using CO2 Lidar for Standoff Detection of a Perfluorocarbon Tracer in Air  

SciTech Connect

The Tag, Track and Location System Program (TTL) is investigating the use of PFTs as tracers for tagging and tracking items of interest or fallen soldiers. In order for the tagging and tracking to be valuable there must be a location system that can detect the PFTs. This report details the development of an infrared lidar platform for standoff detection of PFTs released into the air from a tagged object or person. Furthering work performed using a table top lidar system in an indoor environment; a mobile mini lidar platform was assembled using an existing Raman lidar platform, a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was then successfully demonstrated at an outdoor test. The lidar system was able to detect PFTs released into a vehicle from a distance of 100 meters. In its final, fully optimized configuration the lidar was capable of repeatedly detecting PFTs in the air released from tagged vehicles. Responses were immediate and clear. This report details the results of a proof-of-concept demonstration for standoff detection of a perfluorocarbon tracer (PFT) using infrared lidar. The project is part of the Tag, Track and Location System Program and was performed under a contract with Tracer Detection Technology Corp. with funding from the Office of Naval Research. A lidar capable of detecting PFT releases at distance was assembled by modifying an existing Raman lidar platform by incorporating a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was successfully demonstrated at an outdoor test. The demonstration test (scripted by the sponsor) consisted of three parked cars, two of which were tagged with the PFT. The cars were located 70 (closest) to 100 meters (farthest) from the lidar (the lidar beam path was limited by site constraints and was {approx}100 meters). When one door of each of the cars was opened (sequentially), the lidar was clearly able to determine which vehicles had been tagged and which one was not. The lidar is probably capable of greater than 0.5 kilometer standoff distances based on the extreme amount of signal return achieved (so much that the system had to be de-tuned). The BNL lidar system, while optimized to the extent possible with available parts and budget, was not as sensitive as it could be. Steps to improve the lidar are detailed in this report and include using a better laser system (for more stable power output), dual wavelengths (to improve the sensitivity and allow common mode noise reduction and to allow the use of the lidar in a scanning configuration), heterodyning (for range resolved PFT detection) and an off-axis optical configuration (for improved near field sensitivity).

Heiser,J.H.; Smith, S.; Sedlacek, A.

2008-02-06T23:59:59.000Z

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


21

Primary aluminum production : climate policy, emissions and costs  

E-Print Network (OSTI)

Climate policy regarding perfluorocarbons (PFCs) may have a significant influence on investment decisions in the production of primary aluminum. This work demonstrates an integrated analysis of the effectiveness and likely ...

Harnisch, Jochen.; Sue Wing, Ian.; Jacoby, Henry D.; Prinn, Ronald G.

22

Demonstration of the BNL Continuous Dual Trap Analyzer to Detect Perfluorocarbon Tracers for the Tag, Track and Location Program  

SciTech Connect

The Tag, Track and Location System (TTL) Program is investigating methods of tracking an asset using perfluorocarbon tracers (PFT). The success of any TTL method requires sound detection/location instrumentation. Tracer Detection Technologies Corp (TDT), through a contract with the Office of Naval Research (ONR), is investigating different detection systems. The detections systems generally fall into two categories; proximity detectors and standoff detectors. Proximity detectors, as the name implies, need to be in close proximity (e.g., meter to 10's of meters) to the PFT source. Standoff detection searches for the PFT from a greater distance away from the source (e.g., 100's of meters to kilometers). Gas Chromatographs (GC) are generally considered a proximity detection systems, but in the case of PFTs should be considered for both proximity and standoff detection with the caveat that in standoff use the GC needs to be somewhere in the PFT plume, i.e., generally downwind of the source. With a properly sized PFT source, the right GC can afford fairly large standoff (distance from the source) distances; 100's of meters to kilometers downwind. Brookhaven National Laboratory (BNL) has such a GC system and offered to demonstrate the CDTA for TTL as a no cost addition to the TDTTTL project, of which BNL was a participant. BNL is a leading authority on the sampling, collection, release and detection of PFTs. In addition, the BNL team has extensive background in atmospheric dispersion, the application of PFTs to such studies and the development of applications utilizing PFTs such as building infiltration measurements, control room integrity determination, leak location and environmental investigations. This experience and expertise is essential in developing any PFT application were dispersion, dilution and overcoming environmental conditions and interferences are integral to success. BNL has developed sophisticated gas chromatography methods and instruments that allow detection of up to seven PFTs at part per quadrillion levels (1015) with sample times as short as 60 seconds. The Continuous Dual-Trap Analyzer (CDTA) was developed for leak hunting applications and can continuously sample the air for PFTs without interruption. Sample time can be as short as 60 seconds. The CDTA has been extensively used in the commercial sector to detect PFTs that have been introduced to leaking buried dielectric fluid-filled cables or leaking subsurface gas lines. The PFTs travel through the cable or pipe until they reach the leak site. PFTs then escape into the surrounding soil and permeate/diffuse to the surface where they can be detected with the CDTA. Typically a cable is tagged with ppm levels of PFTs resulting in ppt to ppq concentrations in the air at the leak site. The CDTA is proven to be rugged, reliable and has a proven track record of successful leak location. The application of the CDTA to PFT detection for TTL is identical to application for leak detection. The CDTA operator has a general idea, with a few miles of roadway, where the leak is located, but no specific knowledge of the location (it can be any where along the road). The CDTA is mounted in a Chevy Astro Van and is dispatched to the field. In the field the van is driven at nominally 15 mph along the road. The CDTA continuously samples the air outside the van (via a 1/4-inch plastic sample tube stuck out a side window) until a positive detection occurs. The van then covers the road section where the detection occurred at a slightly slower pace to pin-point the area where the leak is and to direct soil probe samples. The soil probe samples take soil gas samples every 10 yards or so and the samples are analyzed on the CDTA. The leak can be located to within a few feet in 95% of the cases. To date the CDTA has been successful in every leak hunt performed by BNL. One interesting case was a leak hunt that resulted in repeated negative detections. The confidence in the CDTA forced the utility to recheck its 'plumbing' which lead to the discovery that a valve was turned that sho

Heiser,J.H.; Adams, J.; Dietz, R..; Milian, L.; Watson, T.

2008-10-07T23:59:59.000Z

23

Climate Change 2001: The Scientific Basis  

Office of Scientific and Technical Information (OSTI)

Climate Change 2001: Climate Change 2001: Working Group I: The Scientific Basis Get Javascript Other reports in this collection 4. Atmospheric Chemistry and Greenhouse Gases Contents Executive Summary 4.1 Introduction 4.1.1 Sources of Greenhouse Gases 4.1.2 Atmospheric Chemistry and Feedbacks 4.1.3 Trace Gas Budgets and Trends 4.1.4 Atmospheric Lifetimes and Time-Scales 4.2 Trace Gases: Current Observations, Trends and Budgets 4.2.1 Non-CO2 Kyoto Gases 4.2.1.1 Methane (CH4) 4.2.1.2 Nitrous oxide (N2O) 4.2.1.3 Hydrofluorocarbons (HFCs) 4.2.1.4 Perfluorocarbons (PFCs) and sulphur hexafluoride (SF6) 4.2.2 Montreal Protocol Gases and Stratospheric Ozone (O3) 4.2.3 Reactive Gases 4.2.3.1 Carbon monoxide (CO) and hydrogen (H2) 4.2.3.2 Volatile organic compounds (VOC) 4.2.3.3 Nitrogen oxides (NOx)

24

Emissions of greenhouse gases in the United States 1995  

Science Conference Proceedings (OSTI)

This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.

NONE

1996-10-01T23:59:59.000Z

25

PROCESS FOR PURIFYING CRUDE PERFLUOROCARBONS  

DOE Patents (OSTI)

A method is described for refining organic perfluoro compounds. In the manufacture of perfluorinated compounds by the fluorination of hydrocarbons, the product frequently is contaminated ny incompletely fluorimated hydrogen containing impurities. These impurities can be removed by contacting the products in a fluid conditions with an active adsorbents such as silica gel or alumina gel. The patent claims are restricted to this refining of crude perfluorinated lubricating oil.

Holeton, R.E.

1959-03-24T23:59:59.000Z

26

MIT Joint Program on the Science and Policy of Global Change  

E-Print Network (OSTI)

, the greenhouse gas and atmospheric aerosol assumptions underlying climate analysis need to be related for the greenhouse gas and urban gas emissions. The GTAP5 dataset aggregates all the different types of petroleum for greenhouse gas (CO2, CH4, N2O, HFCs, PFCs, and SF6) and urban gas emissions (SO2, NOx, CO, black carbon

27

Multi-gas assessment of the Kyoto protocol  

E-Print Network (OSTI)

The Kyoto Protocol is an international agreement aimed at limiting emissions of several greenhouse gases (GHGs; specifically: CO2, CH4, N2O, PFCs, HFCs, and SF6), and allows credit for approved sinks for CO2. It does not ...

Reilly, John M.; Prinn, Ronald G.; Harnisch, Jochen.; Fitzmaurice, Jean.; Jacoby, Henry D.; Kicklighter, David W.; Stone, Peter H.; Sokolov, Andrei P.; Wang, Chien.

28

EIA - Voluntary Reporting of the Greenhouse Gases 2004 - 6. HFCs ...  

U.S. Energy Information Administration (EIA)

The reductions were accomplished, respectively, by replacing SF 6 with helium in test procedures ...

29

Greenhouse Gas Management Program Overview (Fact Sheet)  

Science Conference Proceedings (OSTI)

Program fact sheet highlighting federal requirements for GHG emissions management, FEMP services to help agencies reduce emissions, and additional resources. The U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) assists Federal agencies with managing their greenhouse gas (GHG) emissions. GHG management entails measuring emissions and understanding their sources, setting a goal for reducing emissions, developing a plan to meet this goal, and implementing the plan to achieve reductions in emissions. FEMP provides the following services to help Federal agencies meet the requirements of inventorying and reducing their GHG emissions: (1) FEMP offers one-on-one technical assistance to help agencies understand and implement the Federal Greenhouse Gas Accounting and Reporting Guidance and fulfill their inventory reporting requirements. (2) FEMP provides training, tools, and resources on FedCenter to help agencies complete their annual inventories. (3) FEMP serves a leadership role in the interagency Federal Working Group on Greenhouse Gas Accounting and Reporting that develops recommendations to the Council on Environmental Quality (CEQ) for the Federal Greenhouse Gas Accounting and Reporting Guidance. (4) As the focus continues to shift from measuring emissions (completing inventories) to mitigating emissions (achieving reductions), FEMP is developing a strategic planning framework and resources for agencies to prioritize among a variety of options for mitigating their GHG emissions, so that they achieve their reduction goals in the most cost-effective manner. These resources will help agencies analyze their high-quality inventories to make strategic decisions about where to use limited resources to have the greatest impact on reducing emissions. Greenhouse gases trap heat in the lower atmosphere, warming the earth's surface temperature in a natural process known as the 'greenhouse effect.' GHGs include carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF{sub 6}). Human activities have caused a rapid increase in GHG concentrations. This rising level contributes to global climate change, which contributes to environmental and public health problems.

Not Available

2011-11-01T23:59:59.000Z

30

Name that compound: The numbers game for CFCs, HFCs, HCFCs, and...  

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

chemical formula, given the number: first add 90 to the abc number, to obtain a 3-digit def number, where: d is the number of carbon atoms; e is the number of hydrogen atoms; f...

31

Studies of Perfluorocarbon Formation on Anodes in Cryolite Melts  

Science Conference Proceedings (OSTI)

Cryoscopic Data for Hall-Héroult Bath Containing Magnesium Fluoride, Calcium Fluoride, Potassium Cryolite, and Sodium Chloride · Current Distribution and ...

32

Controlling the hydrogenic fuel inventory in plasma facing components (PFCs) will be necessary for the successful operation of  

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

defect defect existing defect Surface before ion implantation T collecting and distorting lattice incident ion W atom T in lattice T 2 T 2 + nm + + + + T ions are implanted into the tungsten (W) lattice and diffuse through it until they are trapped at a defect (typically a missing or diplaced W atom). The pressure of T atoms in the lattice can also be so high that they displace W atoms creating more traps. Such high pressures are enhanced by the slow recombination and release of T 2 . Contact: Bruce Lipschultz blip@psfc.mit.edu 617-253-8636 Fusion 'fuel economy' studied under reactor-like conditions New results from the Alcator C-Mod tokamak raise concerns about retention of tritium fuel in the metal walls of fusion reactors like ITER. Recent experiments on Alcator C-Mod, the first diverted tokamak with all metal walls, showed

33

Controlling the hydrogenic fuel inventory in plasma facing components (PFCs) will be necessary for the successful operation of  

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

Dennis Whyte Dennis Whyte whyte@psfc.mit.edu 617-253-1748 Mixing-up magnetic fields may solve a runaway problem for fusion walls New results from the Alcator C-Mod tokamak suggests that a major concern for ITER, the generation of high energy electrons during plasma disruptions, may be mitigated by stochastic magnetic fields generated during the disruption process. The goal of magnetic fusion is to confine very hot plasma with magnetic fields that circulate around a central axis forming a toroidally (donut) shaped geometry. However there is a case where good confinement is bad for the fusion device: runaway electrons. If the electric field around the torus is large enough so that electrons gain energy faster from the field than they lose it to collisions, they can be accelerated up to near the speed of light. This "runaway" condition is

34

Kyoto Protocol | Open Energy Information  

Open Energy Info (EERE)

Kyoto Protocol Kyoto Protocol Jump to: navigation, search http://www.wired.com/thisdayintech/tag/climate-change/ Kyoto protocol negotiation The Kyoto Protocol, negotiated in 1997 and into force in 2005, is a binding agreement in which industrialized nations will seek emission-reducing strategies for the future years to come. "The Kyoto Protocol is a legally binding agreement under which industrialized countries will reduce their collective emissions of greenhouse gases by 5.2% compared to the year 1990 (but note that, compared to the emissions levels that would be expected by 2010 without the Protocol, this target represents a 29% cut). The goal is to lower overall emissions from six greenhouse gases - carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, HFCs, and PFCs - calculated as an average over

35

Carbon Sequestration 101  

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

Field Efforts Field Efforts Sequestering CO 2 in Geologic Formations SPE 2003 Eastern Section Meeting of AAPG September 6 - 10, 2003 Pittsburgh, Pennsylvania Scott M. Klara - National Energy Technology Laboratory What's All The Fuss About? CO 2 Concentrations On The Rise (~280 ppm to 370 ppm over last 100 years) Temperature Change from Present ( o C) CO 2 Concentration (ppmv) 200 150 50 350 300 250 200 100 0 ∆T atm (Vostok) CO 2 (Vostok) 2 0 -2 -4 Time Before Present (kyr) CO 2 & CH 4 - The Primary GHG Contributors Methane 9% Nitrous Oxide 5% HFCs, PFCs, SF 6 2% CO 2 from Energy 81% Other CO 2 3% "EIA Emissions of Greenhouse Gases in the U.S.: 2000" United States Greenhouse Gas Emissions (Equivalent Global Warming Basis) All Fossil Fuels & Energy Sectors Contribute CO 2 Emissions Industry 32% Industry 32% Commercial

36

Microsoft PowerPoint - Sequestration Briefing - October-07.ppt  

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

Carbon Sequestration R&D Overview Carbon Sequestration R&D Overview Office of Fossil Energy Carbon Sequestration Briefing October 2007 Sean Plasynski, PhD Sequestration Technology Manager Office of Fossil Energy R&D Focus is on Coal & Electricity Oil 43% Oil 43% Coal 36% Coal 36% Natural Gas 21% Electricity 39% Electricity 39% Other 30% Other 30% Transportation 32% Transportation 32% United States CO2 Emissions 36% Emissions From Coal 39% Emissions From Electricity Office of Fossil Energy R&D Focus is on CO 2 Methane 9% Nitrous Oxide 5% HFCs, PFCs, SF 6 2% CO 2 from Energy 81% Other CO 2 3% "EIA Emissions of Greenhouse Gases in the U.S.: 2000" United States Greenhouse Gas Emissions (Equivalent Global Warming Basis) Office of Fossil Energy Annual CO 2 Emissions Extremely Large 6,300,000,000 Carbon Dioxide (CO

37

Climate VISION: Private Sector Initiatives: Aluminum  

Office of Scientific and Technical Information (OSTI)

Letters of Intent/Agreements Letters of Intent/Agreements Aluminum Association Logo The Aluminum Association and its members participating in the Voluntary Aluminum Industry Partnership (VAIP), representing 98% of primary aluminum production in the United States, have committed under the Climate VISION program to a direct carbon intensity reduction of emissions of perfluorocarbons (PFCs) and of emissions of CO2 from the consumption of the carbon anode from the primary aluminum reduction process. The Climate VISION target is a 53% total carbon equivalent reduction from these sources by 2010 from 1990 levels. The industry has been working to reduce greenhouse gas emissions for over a decade and this new commitment equates to an additional direct carbon-intensity reduction of 65% since 2000. As a

38

Material and Power-Handling Properties of Tungsten PFCs After Steady-State Melting and Additional Transient High-Heat-Flux Exposure  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

J. W. Coenen; B. Bazylev; S. Brezinsek; V. Philipps; T. Hirai; A. Kreter; J. Linke; G. Pintsuk; G. Sergienko; A. Pospieszczyk; T. Tanabe; Y. Ueda; U. Samm; The TEXTOR Team

39

Laboratory testing and modeling to evaluate perfluorocarbon compounds as tracers in geothermal systems  

Science Conference Proceedings (OSTI)

The thermal stability and adsorption characteristics of three perfluorinated hydrocarbon compounds were evaluated under geothermal conditions to determine the potential to use these compounds as conservative or thermally-degrading tracers in Engineered (or Enhanced) Geothermal Systems (EGS). The three compounds tested were perfluorodimethyl-cyclobutane (PDCB), perfluoromethylcyclohexane (PMCH), and perfluorotrimethylcyclohexane (PTCH), which are collectively referred to as perfluorinated tracers, or PFTs. Two sets of duplicate tests were conducted in batch mode in gold-bag reactors, with one pair of reactors charged with a synthetic geothermal brine containing the PFTs and a second pair was charged with the brine-PFT mixture plus a mineral assemblage chosen to be representative of activated fractures in an EGS reservoir. A fifth reactor was charged with deionized water containing the three PFTs. The experiments were conducted at {approx}100 bar, with temperatures ranging from 230 C to 300 C. Semi-analytical and numerical modeling was also conducted to show how the PFTs could be used in conjunction with other tracers to interrogate surface area to volume ratios and temperature profiles in EGS reservoirs. Both single-well and cross-hole tracer tests are simulated to illustrate how different suites of tracers could be used to accomplish these objectives. The single-well tests are especially attractive for EGS applications because they allow the effectiveness of a stimulation to be evaluated without drilling a second well.

Reimus, Paul W [Los Alamos National Laboratory

2011-01-21T23:59:59.000Z

40

NETL: LabNotes - November 2010  

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

Accounting (MVA) Research Underway to Assure that CO2 Injected Underground Stays There NETL Researcher adding Perfluorocarbon tracers to the carbon dioxide Perfluorocarbon tracers...

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


41

Carbon Capital: The Political Ecology of Carbon Forestry and Development in Chiapas, Mexico  

E-Print Network (OSTI)

fuel switching; LFG = landfill gas; CMM = coal mine methane;HFCs) and landfill methane gas (LFG) (which do not transform

Osborne, Tracey Muttoo

2010-01-01T23:59:59.000Z

42

Effect of temperature and iron-oxide nano-particle inclusions on the ultrasound vaporization pressure of perfluorocarbon droplets for disease detection and therapy  

E-Print Network (OSTI)

Temperature and Iron-Oxide Nano-particle inclusions on the22 1.9.1 Why Iron-Oxide NanoTemperature and Iron-Oxide Nano-particle inclusions on the

Amirriazi, Seyed Saleh

2009-01-01T23:59:59.000Z

43

PFC and CO2 Emissions from an Australian Aluminium Smelter ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The accurate measurement of perfluorocarbon and CO2 emissions from aluminium smelters is becoming increasingly important. CSIRO has ...

44

For Refrigeration Problems, a Magnetically Attractive Solution  

Science Conference Proceedings (OSTI)

... cycles use different physical effects to cool ... The effect can be used in a classic ... commonly use hydrofluorocarbons (HFCs), greenhouse gases that ...

2011-04-12T23:59:59.000Z

45

Reference Tools  

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

Reference Tools Current Greenhouse Gas Concentrations Name that compound: The numbers game for CFCs, HFCs, HCFCs, and Halons Conversion Tables and More Glossary Acronyms CDIAC's...

46

Laminar burning speed and flame structure of 1,1-difluoroethane (HFC-152a)/air and difluoromethane (HFC-32)/air mixtures.  

E-Print Network (OSTI)

??Of recent importance is the laminar burning speed of hydrofluorocarbons (HFCs) used in the refrigerant industry. Since the adoption of the Montreal Protocol in 1989… (more)

Bennett, Casey Paul

2011-01-01T23:59:59.000Z

47

Ventilation Control of Volatile Organic Compounds in New U  

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

methods were used for VOC concentration measurements, and passive perfluorocarbon tracer gas emitters with active sampling were used to determine the overall air exchange rate...

48

Low Cost Video Emissions Monitoring Technique for Aluminum ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Aluminum smelting plants emit gaseous and particulate fluoride, sulfur dioxide (SO2), carbon oxides (CO and CO2), perfluorocarbons CF4 and ...

49

A Study of Low Voltage PFC Emissions at Dubal  

Science Conference Proceedings (OSTI)

Abstract Scope, Perfluorocarbon (PFC) emissions are the result of a phenomenon ... PFC and CO2 Emissions from an Australian Aluminium Smelter Using ...

50

Award-Winning DOE Technology Scores Success in Carbon Storage...  

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

uses perfluorocarbon tracers (PFTs) - non-toxic, chemically inert clear colorless liquids - to provide a verifiable way to measure CO2 movement as well as provide leak...

51

Review of air flow measurement techniques  

E-Print Network (OSTI)

chamber, passive sampling, passive solar house, measurementhouse, we planed the distribution of fresh air, passivepassive perfluorocarbon tracer technique for determining air infiltration rates into houses

McWilliams, Jennifer

2002-01-01T23:59:59.000Z

52

Application of a Method for the Determination of Pfc Emissions ...  

Science Conference Proceedings (OSTI)

The significant reductions achieved in the main source of PFCs, anode effects, had led to questions about the quantification of PFC emissions beyond anode ...

53

Study on the Interaction Coefficients in PR Equation with VdW ...  

Science Conference Proceedings (OSTI)

... The values of ki for HFCs and HCs, including Propane, Isobutane, n-butane, HFC32, HFC125, HFC134a, HFC143a, HFC152a and HFC227ea ...

2006-07-20T23:59:59.000Z

54

An Analysis of Government Policy Impacts in the Ethanol and Sugar Markets.  

E-Print Network (OSTI)

??ABSTRACT This study determines the impact of U.S. government policies on U.S. ethanol market and its consequences for the U.S. corn, sugar, and HFCS markets.… (more)

Marzoughi_Ardakani, Hassan

2009-01-01T23:59:59.000Z

55

Evaluation of metrics and baselines for tracking greenhouse gas emissions trends: Recommendations for the California climate action registry  

Science Conference Proceedings (OSTI)

Executive Summary: The California Climate Action Registry, which was initially established in 2000 and began operation in Fall 2002, is a voluntary registry for recording annual greenhouse gas (GHG) emissions. The purpose of the Registry is to assist California businesses and organizations in their efforts to inventory and document emissions in order to establish a baseline and to document early actions to increase energy efficiency and decrease GHG emissions. The State of California has committed to use its ''best efforts'' to ensure that entities that establish GHG emissions baselines and register their emissions will receive ''appropriate consideration under any future international, federal, or state regulatory scheme relating to greenhouse gas emissions.'' Reporting of GHG emissions involves documentation of both ''direct'' emissions from sources that are under the entity's control and indirect emissions controlled by others. Electricity generated by an off-site power source is consider ed to be an indirect GHG emission and is required to be included in the entity's report. Registry participants include businesses, non-profit organizations, municipalities, state agencies, and other entities. Participants are required to register the GHG emissions of all operations in California, and are encouraged to report nationwide. For the first three years of participation, the Registry only requires the reporting of carbon dioxide (CO2) emissions, although participants are encouraged to report the remaining five Kyoto Protocol GHGs (CH4, N2O, HFCs, PFCs, and SF6). After three years, reporting of all six Kyoto GHG emissions is required. The enabling legislation for the Registry (SB 527) requires total GHG emissions to be registered and requires reporting of ''industry-specific metrics'' once such metrics have been adopted by the Registry. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) was asked to provide technical assistance to the California Energy Commission (Energy Commission) related to the Registry in three areas: (1) assessing the availability and usefulness of industry-specific metrics, (2) evaluating various methods for establishing baselines for calculating GHG emissions reductions related to specific actions taken by Registry participants, and (3) establishing methods for calculating electricity CO2 emission factors. The third area of research was completed in 2002 and is documented in Estimating Carbon Dioxide Emissions Factors for the California Electric Power Sector (Marnay et al., 2002). This report documents our findings related to the first areas of research. For the first area of research, the overall objective was to evaluate the metrics, such as emissions per economic unit or emissions per unit of production that can be used to report GHG emissions trends for potential Registry participants. This research began with an effort to identify methodologies, benchmarking programs, inventories, protocols, and registries that u se industry-specific metrics to track trends in energy use or GHG emissions in order to determine what types of metrics have already been developed. The next step in developing industry-specific metrics was to assess the availability of data needed to determine metric development priorities. Berkeley Lab also determined the relative importance of different potential Registry participant categories in order to asses s the availability of sectoral or industry-specific metrics and then identified industry-specific metrics in use around the world. While a plethora of metrics was identified, no one metric that adequately tracks trends in GHG emissions while maintaining confidentiality of data was identified. As a result of this review, Berkeley Lab recommends the development of a GHG intensity index as a new metric for reporting and tracking GHG emissions trends.Such an index could provide an industry-specific metric for reporting and tracking GHG emissions trends to accurately reflect year to year changes while protecting proprietary data. This GHG intensity index changes

Price, Lynn; Murtishaw, Scott; Worrell, Ernst

2003-06-01T23:59:59.000Z

56

Tracer Verification of Trajectory Models  

Science Conference Proceedings (OSTI)

Perfluorocarbon tracer data collected during the Cross Appalachian Tracer Experiment (CAPTEX '83) are used to determine the accuracy of three trajectory models: an isentropic, an isobaric, and a dimensional sigma model. The root-mean-square ...

Philip L. Haagenson; Ying-Hwa Kuo; Marina Syumanich; Nelson L. Seaman

1987-03-01T23:59:59.000Z

57

Numerical Simulations of Airflows and Tracer Transport in the Southwestern United States  

Science Conference Proceedings (OSTI)

Project MOHAVE (Measurement of Haze and Visual Effects) produced a unique set of tracer data over the southwestern United States. During the summer of 1992, a perfluorocarbon tracer gas was released from the Mohave Power Project (MPP), a large ...

Tetsuji Yamada

2000-03-01T23:59:59.000Z

58

The Dispersion of Atmospheric Tracers in Nocturnal Drainage Flows  

Science Conference Proceedings (OSTI)

This paper summarizes the results of a series of perfluorocarbon tracer experiments that were carried out in the Brush Creek Valley in western Colorado under the auspices of the Atmospheric Studies in Complex Terrain (ASCOT) program. The results ...

Paul H. Gudiksen; Donald L. Shearer

1989-07-01T23:59:59.000Z

59

Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model  

Science Conference Proceedings (OSTI)

During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical ...

K. Shankar Rao; Richard M. Eckman; Rayford P. Hosker Jr.

1989-07-01T23:59:59.000Z

60

A Continuous Fast-Response Dual-Tracer Analyzer for Halogenated Atmospheric Tracer Studies  

Science Conference Proceedings (OSTI)

An apparatus for the simultaneous measurement of two tracers, sulfur hexafluoride (SF6) and a perfluorocarbon compound, is introduced. The new instrument is a modification of a commercially available fast-response, continuous analyzer for single ...

James P. Rydock; Brian K. Lamb

1994-10-01T23:59:59.000Z

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


61

Industry  

Science Conference Proceedings (OSTI)

This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of industrial mitigation for sustainable development is discussed in Section 7.7. Section 7.8 discusses the sector's vulnerability to climate change and options for adaptation. A number of policies have been designed either to encourage voluntary GHG emission reductions from the industrial sector or to mandate such reductions. Section 7.9 describes these policies and the experience gained to date. Co-benefits of reducing GHG emissions from the industrial sector are discussed in Section 7.10. Development of new technology is key to the cost-effective control of industrial GHG emissions. Section 7.11 discusses research, development, deployment and diffusion in the industrial sector and Section 7.12, the long-term (post-2030) technologies for GHG emissions reduction from the industrial sector. Section 7.13 summarizes gaps in knowledge.

Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

2007-12-01T23:59:59.000Z

62

Comparison of H-Mode Plasmas Diverted to Solid and Liquid Lithium Surfaces  

SciTech Connect

Experiments were conducted with a Liquid Lithium Divertor (LLD) in NSTX. Among the goals was to use lithium recoating to sustain deuterium (D) retention by a static liquid lithium surface, approximating the ability of flowing liquid lithium to maintain chemical reactivity. Lithium evaporators were used to deposit lithium on the LLD surface. Improvements in plasma edge conditions were similar to those with lithiated graphite plasma-facing components (PFCs), including an increase in confinement over discharges without lithiumcoated PFCs and ELM reduction during H-modes. With the outer strike point on the LLD, the D retention in the LLD was about the same as that for solid lithium coatings on graphite, or about two times that achieved without lithium PFC coatings. There were also indications of contamination of the LLD surface, possibly due erosion and redeposition of carbon from PFCs. Flowing lithium may thus be needed for chemically active PFCs during long-pulse operation.

R. Kaita, et. al.

2012-07-20T23:59:59.000Z

63

Climate VISION: Private Sector Initiatives: Aluminum: GHG Information  

Office of Scientific and Technical Information (OSTI)

GHG Information The primary aluminum industry emits PFCs and CO2 directly from the production process and indirectly emits CO2 from its energy consumption. In 2001, the U.S....

64

Modeling Time-dependent Responses of Piezoelectric Fiber Composite  

E-Print Network (OSTI)

The existence of polymer constituent in piezoelectric fiber composites (PFCs) could lead to significant viscoelastic behaviors, affecting overall performance of PFCs. High mechanical and electrical stimuli often generate significant amount of heat, increasing temperatures of the PFCs. At elevated temperatures, most materials, especially polymers show pronounced time-dependent behaviors. Predicting time-dependent responses of the PFCs becomes important to improve reliability in using PFCs. We study overall performance of PFCs having unidirectional piezoceramic fibers, such as PZT fibers, dispersed in viscoelastic polymer matrix. Two types of PFCs are studied, which are active fiber composites (AFCs) and macro fiber composites (MFCs). AFCs and MFCs consist of unidirectional PZT fibers dispersed in epoxy placed between two interdigitated electrode and kapton layers. The AFCs have a circular fiber cross-section while the MFCs have a square fiber cross-section. Finite element (FE) models of representative volume elements (RVEs) of active PFCs, having square and circular fiber cross-sections, are generated for composites with 20, 40, and 60 percent fiber contents. Two FE micromechanical models having one fiber embedded in epoxy matrix and five fibers placed in epoxy matrix are considered. A continuum 3D piezoelectric element in ABAQUS FE is used. A general time-integral function is applied for the mechanical, electrical, and piezoelectric properties in order to incorporate the time-dependent effect and histories of loadings. The effective properties of PZT-5A/epoxy and PZT-7A/LaRC-SI piezocomposites determined from the FE micromechanical models are compared to available experimental data and analytical solutions in the literature. Furthermore, the effect of viscoelastic behaviors of the LaRC-SI matrix at an elevated temperature on the overall electro-mechanical and piezoelectric constants are examined.

Li, Kuo-An

2009-12-01T23:59:59.000Z

65

Transportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation  

E-Print Network (OSTI)

Transportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation Oak Ridge sector is believed to be responsible for 28.4% of our greenhouse gas emissions (see figure), including 33% of the carbon dioxide we produce. As such it is a leading candidate for greenhouse gas ((GHG) (CO2, NH4, HFCs

66

Effect of Lithium PFC Coatings on NSTX Density Control  

Science Conference Proceedings (OSTI)

Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.

Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L

2006-08-21T23:59:59.000Z

67

Discussion Paper Industrial Organization of  

E-Print Network (OSTI)

. Fassett (2010) noted that production from coal bed methane reservoirs in the San Juan Basin reached about the site consist of two coal beds, each separated by a shale parting. This observation indicates that the coal reservoirs consist of six separate coal beds rather than three. Perfluorocarbon tracer monitoring

68

www.defra.gov.uk SMALL BUSINESS USER GUIDE  

E-Print Network (OSTI)

is caused by the release of greenhouse gases into the atmosphere. What are greenhouse gas emissions? The key greenhouse gas emissions are carbon dioxide, methane and nitrous oxide hydrofluorocarbons, perfluorocarbons gas emissions? Human activities release greenhouse gas emissions into the atmosphere ­ using

69

IIII1'op 1.32 IIIIINIllllgIllllg  

E-Print Network (OSTI)

to protect the structure better than condensed phase properties. The minimum coating thickness required The performance of plasma facing components (PFCs) in magnetic fusion devices will be dictated to a large degree commercially. The end-of-life analysis assumes the thickness of the CFC to be eroded down to 3 mm

Harilal, S. S.

70

Fusion Engineering and Design 46 (1999) 207220 ITER divertor, design issues and research and development  

E-Print Network (OSTI)

of the PFCs is performed ex-vessel in a hot cell, where it is anticipated the refurbishment of 60 cassettes, November 1997. [19] E. Martin, et al., Design of the ITER Divertor Remote Handling System; 19th SOFT, tritium inventory, impurity control, armour lifetime, electromagnetic loads, diagnostics, and remote

Raffray, A. René

71

New concepts for refrigerant leak detection and mixture measurement  

Science Conference Proceedings (OSTI)

Since the discovery that chlorofluorocarbons (CFCs) destroy the ozone layer, the need to reduce the release of these refrigerants into the environment has become critical. A total ban of ozone-depleting CFCs is expected within a few years, and hydrofluorocarbons (HFCs) and fluorocarbons (FCs) and their mixtures are expected to be used during a transition period. Several HFC and FC refrigerants are currently being considered as CFC substitutes. The electronic refrigerant leak detectors currently being considered as CFC substitutes. The electronic refrigerant leak detectors currently on the market were developed to detect CFCs and are not as sensitive to HFCs. Although incremental improvement can be made to these devices to detect HFCs, they often lead to increased false signals. Also, there is no simple device available to measure the composition of a refrigerant mixture. The authors present two new concepts to aid in the development of two portable instruments that can be used for HFC leak detection and for quantitative measurement of refrigerant mixture compositions. The development of simple, easy-to-use portable leak detectors and refrigerant mixture meters is essential to the wide use of alternative refrigerants in industry.

Chen, F.C.; Allman, S.L.; Chen, C.H.

1993-12-31T23:59:59.000Z

72

Final_Tech_Session_Schedule_and_Location.xls  

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

Monitoring Geologically Sequestered Monitoring Geologically Sequestered CO 2 during the Frio Brine Pilot Test using Perfluorocarbon Tracers 1 McCallum, S.D., 1 Riestenberg, D.E., 1 Cole, D.R., 2 Freifeld, B.M., 2 Trautz, R.C., 3 Hovorka, S.D., and 1 Phelps*, T.J. 1 Oak Ridge National Laboratory, 1505 Bethel Valley Road, Oak Ridge, TN, 37831- 6036 USA 2 Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720- 90R1116, USA 3 Texas Bureau of Economic Geology, The University of Texas at Austin, University Station, Box X, Austin, Texas 78713-8924, USA *Corresponding author and presenter (phelpstj@ornl.gov) Abstract A suite of gaseous perfluorocarbon (PFT) conservative tracers were successfully employed to monitor migration of the CO 2 plume during the Frio Brine Pilot Test. The conservative tracers enabled

73

Microsoft PowerPoint - Proceedings Cover Sheets  

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

Geological CO Geological CO 2 Sequestration using Perfluorocarbon Gas Tracers and Isotopes Phelps, T.J., McCallum, S.D., Cole, D.R., Kharaka, Y.K., and Hovorka, S.D. ABSTRACT The Frio Brine Field Test, Phase I, demonstrated the relatively straight forward method of CO 2 injection and its rapid transport to the monitoring well. Our field monitoring methodologies, especially measurements of conservative perfluorocarbon gas tracers (PFTs), pH, alkalinity, gas compositions and stable isotopes proved to be sensitive for tracking the injected CO 2 . Multiple PFT tracer suites were introduced via an injection well at three separate times during the Frio Test. The use of PFT suites provided data for identification of multiple breakthroughs at a monitoring well 30 meters up-dip. Travel times for each

74

PFT Air Infiltration Measurement Technique | Department of Energy  

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

PFT Air Infiltration Measurement Technique PFT Air Infiltration Measurement Technique PFT Air Infiltration Measurement Technique April 2, 2012 - 3:11pm Addthis The Brookhaven National Laboratory developed the PFT (PerFluorocarbon tracer gas) technique to measure changes over time when determining a building's air-infiltration rate. The Brookhaven National Laboratory developed the PFT (PerFluorocarbon tracer gas) technique to measure changes over time when determining a building's air-infiltration rate. What does this mean for me? You can save 5%-30% on your energy bill by making upgrades following a home energy assessment. A professional energy auditor may use the PFT air infiltration measurement technique to find out where your home has air leaks, though a blower door test is more commonly used.

75

Modeling of the ITER-like wide-angle infrared thermography view of JET  

SciTech Connect

Infrared (IR) thermography systems are mandatory to ensure safe plasma operation in fusion devices. However, IR measurements are made much more complicated in metallic environment because of the spurious contributions of the reflected fluxes. This paper presents a full predictive photonic simulation able to assess accurately the surface temperature measurement with classical IR thermography from a given plasma scenario and by taking into account the optical properties of PFCs materials. This simulation has been carried out the ITER-like wide angle infrared camera view of JET in comparing with experimental data. The consequences and the effects of the low emissivity and the bidirectional reflectivity distribution function used in the model for the metallic PFCs on the contribution of the reflected flux in the analysis are discussed.

Aumeunier, M.-H. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); OPTIS, ZE de La Farlede, F-83078 Toulon Cedex 9 (France); Firdaouss, M.; Travere, J.-M.; Loarer, T.; Gauthier, E.; Martin, V. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Chabaud, D.; Humbert, E. [OPTIS, ZE de La Farlede, F-83078 Toulon Cedex 9 (France); Collaboration: JET-EFDA Contributors

2012-10-15T23:59:59.000Z

76

Plasma-materials interaction results at Sandia National Laboratories.  

DOE Green Energy (OSTI)

Overview of Plasma Materials Interaction (PMI) activities are: (1) Hydrogen diffusion and trapping in metals - (a) Growth of hydrogen precipitates in tungsten PFCs, (b) Temperature dependence of deuterium retention at displacement damage, (c) D retention in W at elevated temperatures; (2) Permeation - (a) Gas driven permeation results for W/Mo/SiC, (b) Plasma-driven permeation test stand for TPE; and (3) Surface studies - (a) H-sensor development, (b) Adsorption of oxygen and hydrogen on beryllium surfaces.

Causey, Rion A.; Wampler, William R. (Sandia National Laboratories, Albuquerque, NM); Buchenauer, Dean A.; Karnesky, Richard A.; Whaley, Josh A.; Cowgill, Donald F.; Kolasinski, Robert D.

2010-08-01T23:59:59.000Z

77

Liquid Metal Walls, Lithium, And Low Recycling Boundary Conditions In Tokamaks  

DOE Green Energy (OSTI)

At present, the only solid material believed to be a viable option for plasma-facing components (PFCs) in a fusion reactor is tungsten. Operated at the lower temperatures typical of present-day fusion experiments, tungsten is known to suffer from surface degradation during long-term exposure to helium-containing plasmas, leading to reduced thermal conduction to the bulk, and enhanced erosion. Existing alloys are also quite brittle at temperatures under 700oC. However, at a sufficiently high operating temperature (700 - 1000 oC), tungsten is selfannealing and it is expected that surface damage will be reduced to the point where tungsten PFCs will have an acceptable lifetime in a reactor environment. The existence of only one potentially viable option for solid PFCs, though, constitutes one of the most significant restrictions on design space for DEMO and follow-on fusion reactors. In contrast, there are several candidates for liquid metal-based PFCs, including gallium, tin, lithium, and tin-lithium eutectics. We will discuss options for liquid metal walls in tokamaks, looking at both high and low recycling materials. We will then focus in particular on one of the candidate liquids, lithium. Lithium is known to have a high chemical affinity for hydrogen, and has been shown in test stands1 and fusion experiments2,3 to produce a low recycling surface, especially when liquid. Because it is also low-Z and is usable in a tokamak over a reasonable temperature range (200 - 400 oC), it has been now been used as a PFC in several confinement experiments (TFTR, T11- M, CDX-U, NSTX, FTU, and TJ-II), with favorable results. The consequences of substituting low recycling walls for the traditional high recycling variety on tokamak equilibria are very extensive. We will discuss some of the expected modifications, briefly reviewing experimental results, and comparing the results to expectations.

R. Majeski

2010-01-15T23:59:59.000Z

78

Overview of the US-Japan collaborative investigation on hydrogen isotope retention in neutron-irradiated and ion-damaged tungsten  

Science Conference Proceedings (OSTI)

Plasma-facing components (PFCs) will be exposed to 14 MeV neutrons from deuterium-tritium (D-T) fusion reactions, and tungsten, a candidate PFC for the divertor in ITER, is expected to receive a neutron dose of 0.7 displacement per atom (dpa) by the end of operation in ITER. The effect of neutron-irradiation damage has been mainly simulated using high-energy ion bombardment. While this prior database of results is quite valuable for understanding the behavior of hydrogen isotopes in PFCs, it does not encompass the full range of effects that must be considered in a practical fusion environment due to short penetration depth, damage gradient, high damage rate, and high PKA energy spectrum of the ion bombardment. In addition, neutrons change the elemental composition via transmutations, and create a high radiation environment inside PFCs, which influence the behavior of hydrogen isotope in PFCs, suggesting the utilization of fission reactors is necessary for neutron irradiation. Therefore, the effort to correlate among high-energy ions, fission neutrons, and fusion neutrons is crucial for accurately estimating tritium retention under a neutron-irradiation environment. Under the framework of the US-Japan TITAN program, tungsten samples (99.99 at. % purity from A.L.M.T. Co.) were irradiated by neutron in the High Flux Isotope Reactor (HFIR), ORNL, at 50 and 300C to 0.025, 0.3, and 1.2 dpa, and the investigation of deuterium retention in neutron-irradiation was performed in the INL Tritium Plasma Experiment (TPE), the unique high-flux linear plasma facility that can handle tritium, beryllium and activated materials. This paper reports the recent results from the comparison of ion-damaged tungsten via various ion species (2.8 MeV Fe2+, 20 MeV W2+, and 700 keV H-) with that from neutron-irradiated tungsten to identify the similarities and differences among them.

Masashi Shimada; Y. Hatano; Y. Oya; T. Oda; M. Hara; G. Cao; M. Kobayashi; M. Sokolov; H. Watanabe; B. Tyburska; Y. Ueda; P. Calderoni

2011-09-01T23:59:59.000Z

79

Gunnar I. Senum | BNL  

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

Gunnar I. Senum Gunnar I. Senum Chemist Education State University of New York at Stony Brook, Ph.D., Chemistry Brooklyn College of the City University of New York, B.S., Chemistry Professional Affiliations American Chemical Society American Physical Society American Association for the Advancement of Science Areas of Interest Application and modeling of chromatographic systems for the development of techniques for the detection and quantification of trace components with the consequent application to geophysical trace gases, indoor pollution and various industrial applications Development of chemicalcompounds as atmospheric, hydrological or aerosol tracers Experience Presently responsible for the development and applications of new techniques using perfluorocarbon tracers in the Tracer Technology Center,

80

Climate VISION: Private Sector Initiatives: Aluminum: Resources and Links -  

Office of Scientific and Technical Information (OSTI)

Federal/State Programs Federal/State Programs DOE Aluminum Industry of the Future Collaborative R&D partnerships between DOE Industrial Technologies Program and industry to maximize technology investments. EPA Voluntary Aluminum Industrial Partnership The Voluntary Aluminum Industrial Partnership (VAIP) is an innovative pollution prevention program developed jointly by the U.S. Environmental Protection Agency (EPA) and the primary aluminum industry. Participating companies (Partners) work with EPA to improve aluminum production efficiency while reducing perfluorocarbon (PFC) emissions, potent greenhouse gases that may remain in the atmosphere for thousands of years. See all Federal/State Programs DOE State Activities For information on activities, financial assistance, and solicitations

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


81

FINAL REPORT: EDDY-COVARIANCE FLUX TOWER AND TRACER TECHNOLOGY SUPPORT FOR THE UNIVERSITY OF GEORGIA PROPOSAL: FROM TOWER TO PIXEL: INTEGRATION OF PATCH-SIZE NEE USING EXPERIMENTAL MODELING FOOTPRINT ANALYSIS.  

SciTech Connect

Brookhaven National Laboratory has been funded since October of 2000 to provide assistance to the University of Georgia in conducting footprint analyses of individual towers based on meteorology and trace gas measurements. Brookhaven researchers conducted air flow measurements using perfluorocarbon tracers and meteorological instrumentation for three experimental campaigns at an AmeriFlux research site maintained by Dr. Monique Leclerc near Gainesville, FL. In addition, BNL provided assistance with remote data collection and distribution from remote field sites operated by Dr. John Hom of the US Forest Service in the Pine Barrens of New Jersey and at FACE research sites in North Carolina and Wisconsin.

LEWIN,K.F.; NAGY, J.; WATSON, T.B.

2007-09-01T23:59:59.000Z

82

New fluorocarbon elastomers for seals for geothermal and other aggressive environments  

DOE Green Energy (OSTI)

Geothermal brines at 600 F which contain metallic salts, H{sub 2}S, and hydrocarbons quickly degrade conventional hydrocarbon elastomers, and hydrolyse crosslinks. Carbon-carbon and carbon-fluorine bonds are expected to be superior, but no such elastomer is now commercially available. We have prepared crosslinked, perfluorocarbon elastomers by radiation crosslinking VDFHFP and TFEP (alternating) copolymers in film and sheet form, and then converting C-H bonds to C-F bonds with elemental Fluorine gas. EPLM elastomers became brittle on fluorination. The best products exceeded 100 days survival at 300 C in simulated geothermal brine. Tensile, elongation, solvent swelling, and TCA methods were used to study the products.

Dumitru, Earl T.; Lagow, R.J.; Kukacka L.E.

1982-10-08T23:59:59.000Z

83

Method for inducing hypothermia  

DOE Patents (OSTI)

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2003-04-15T23:59:59.000Z

84

Method for inducing hypothermia  

DOE Patents (OSTI)

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2008-09-09T23:59:59.000Z

85

PaperOV/3-2 Work supported by US DoE Office of Fusion Energy Sciences S. Scott for the C-Mod team  

E-Print Network (OSTI)

-Z PFCs - Power density in SOL - Divertor opacity to neutrals and radiation - Momentum input and fueling tokamak ápñ = 1.8 atm at bn = 1.74. Marmar, EX/3-4 #12;P (1023 eV/m3) 0 0.5 1.0 1.5 2.0 Pedestal neTe (1023 eV/m3) 0.0 0.5 1.0 1.5 2.0 H89 Pre-boronization Post-boronization H-mode · H-modes readily

86

The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants  

Science Conference Proceedings (OSTI)

The heat loading on plasma facing components (PFCs) provides a critical limitation for design and operation of the first wall, divertor, and other special components. Power plants will have high power entering the scrape-off layer and transporting to the first wall and divertor. Although the design for steady heat loads is understood, the approach for transient and offnormal loading is not. The characterization of heat loads developed for ITER1 can be applied to power plants to better develop the operating space of viable solutions and point to research focus areas.

C.E. Kessel, M.S. Tillack and J. Blanchard

2012-09-07T23:59:59.000Z

87

A protection system for the JET ITER-like wall based on imaging diagnostics  

SciTech Connect

The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite wall and requires active protection to prevent excessive heat loads on the plasma facing components (PFC). Analog CCD cameras operating in the near infrared wavelength are used to measure surface temperature of the PFCs. Region of interest (ROI) analysis is performed in real time and the maximum temperature measured in each ROI is sent to the vessel thermal map. The protection of the ITER-like wall system started in October 2011 and has already successfully led to a safe landing of the plasma when hot spots were observed on the Be main chamber PFCs. Divertor protection is more of a challenge due to dust deposits that often generate false hot spots. In this contribution we describe the camera, data capture and real time processing systems. We discuss the calibration strategy for the temperature measurements with cross validation with thermal IR cameras and bi-color pyrometers. Most importantly, we demonstrate that a protection system based on CCD cameras can work and show examples of hot spot detections that stop the plasma pulse. The limits of such a design and the associated constraints on the operations are also presented.

Arnoux, G.; Balboa, I.; Balshaw, N.; Beldishevski, M.; Cramp, S.; Felton, R.; Goodyear, A.; Horton, A.; Kinna, D.; McCullen, P.; Obrejan, K.; Patel, K.; Lomas, P. J.; Rimini, F.; Stamp, M.; Stephen, A.; Thomas, P. D.; Williams, J.; Wilson, J.; Zastrow, K.-D. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); and others

2012-10-15T23:59:59.000Z

88

Liquid Metal Plasma Facing Component Research for the ITER Era and Beyond A White Paper to the FESAC Subcommittee on MFE Priorities  

E-Print Network (OSTI)

In this white paper, we argue that the suitability of solid Plasma Facing Components (PFCs) (e.g. tungsten) for a reactor is far from certain. The only potential alternative is a liquid metal PFC. Furthermore, liquid metals have the potential to out-perform any solid-PFC approach in areas such as erosion lifetime and heat-flux handling. A US research program on liquid-metal PFCs could uniquely position the US to capture ITER burning-plasma physics while leading the world in a PFC technology that scales to a reactor. The Plasma-facing Component Problem The ITER project is already advancing fusion science and technology to a reactor-scale device. Several areas of research, however, are not the main focus of the project and are not likely to be resolved by ITER such as net erosion and redeposition of wall and divertor materials. Most design studies rely on the use of solid components, mainly tungsten, as the only plasma-facing material (PFM) likely to be available for a reactor. The issue here is that however one designs and shapes such a component, continued exposure to the plasma inside a fusion device will continually redistribute and reform those components due to sputter erosion and plasma transport effects. In addition, plasma transients may result in melting and permanent damage to solid, metal components. The strategy adopted for these

Ma Jaworski; R Goldston; R Majeski; Ch Skinner (pppl; Nb Morley (ucla

2012-01-01T23:59:59.000Z

89

The ALE/GAGE/AGAGE Network (DB1001)  

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

Atmospheric Trace Gases » ALE/GAGE/AGAGE Network Atmospheric Trace Gases » ALE/GAGE/AGAGE Network The ALE / GAGE / AGAGE Network (DB1001) DOI: 10.3334/CDIAC/atg.db1001 Links to Additional Sources Advanced Global Atmospheric Gases Experiment (AGAGE) home page How halocarbons (CFCs, HFCs, HCFCs, and halons) are named CDIAC data base including some of the same compounds, and a tabulation of their uses and atmospheric lifetimes Investigators R.G. Prinn, R.F. Weiss, P.J. Fraser, P.G. Simmonds, S. O'Doherty, P. Salameh, L. Porter, P. Krummel, R.H.J. Wang, B. Miller, C. Harth, B. Greally, F.A. Van Woy, L.P. Steele, J. Müehle, G. Sturrock, F.N. Alyea, J. Huang, and D.E. Hartley Description In the ALE/GAGE/AGAGE global network program, continuous high frequency gas chromatographic measurements of four biogenic/anthropogenic gases (methane,

90

Sandeman-012113 - Argonne National Laboratories, Materials Sicence Division  

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

Sandeman-012113 Sandeman-012113 JOINT PSE/MSD SEMINAR SPEAKER: Karl G. Sandeman Department of Physics TITLE: "(Tri)critical Phase Transitions in Magnetocaloric Materials " DATE: Monday, January 21, 2013 TIME: 3:00 p.m. PLACE: Building 223 / S-105 HOST: Seungbum Hong ABSTRACT: Much of today's research in so-called functional materials is driven by the quest for technologies that use energy more efficiently and reduce our impact on the environment. Such pressures drive a renewed investigation of some of the most fundamental properties of condensed matter. Solid-state phase transitions are one good example. In order to find an energy efficient solution to the problem of reducing our use of HFCs in a variety of cooling applications, a new field has been defined.

91

Super Building Insulation by CO2 Foaming Process Research Project |  

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

Emerging Technologies » Super Building Insulation by CO2 Foaming Emerging Technologies » Super Building Insulation by CO2 Foaming Process Research Project Super Building Insulation by CO2 Foaming Process Research Project The Department of Energy is currently researching the development of building superinsulation through a carbon dioxide (CO2) foaming process. Project Description This project seeks to develop building super insulation through a carbon dioxide foaming process that does not use hydrofluorocarbons (HFCs), and which produces insulation with a high R-value. Project Partners Research is being undertaken between the Department of Energy and The Industrial Science & Technology Network. Project Goals The goal of this project is to develop advanced insulation without HFC, and to achieve a competitive processing cost for CO2 foaming technology.

92

Atmospheric Measurements of Climate-Relevant Species  

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

Atmospheric Measurements of Climate-Relevant Species Atmospheric Measurements of Climate-Relevant Species CDIAC's data collection includes measurements of the following climate-relevant chemical species. A summary of recent greenhouse gas concentrations is also available. To determine how compounds are named, see the CDIAC "Name that compound" page. Butane (C4H10) Carbon Dioxide (CO2) Carbon Isotopes Carbon Monoxide (CO) Carbon Tetrachloride (CCl4) Chlorofluorocarbons Chloroform (CHCl3) Deuterium (2H) Ethane (C2H6) Ethyl Nitrate (C2H5ONO2) Ethyne (C2H2) Fluoroform (CHF3) Halogenated Compounds (modern records) Halons (fluorocarbons) Hydrogen (H2) Hydrochlorofluorocarbons (HCFCs) Hydrofluorocarbons (HFCs) i-Propyl Nitrate (C3H7ONO2) Methane (CH4) Methyl Bromide (CH3Br) Methyl Chloride (CH3Cl) Methyl Chloroform (CH3CCl3)

93

From fire to ice  

Science Conference Proceedings (OSTI)

Absorption chillers are heat-operate refrigeration without harmful environmental emissions (CFCs, HCFCS, and HFCS). The machine uses either steam or a gas-fired burner as the energy source and utilizes endothermic evaporation to provide refrigeration to an external process fluid, usually chilled water. In the United States, absorption chillers are used in regions where the cost of electricity is high relative to natural gas. Absorption chillers are also used in applications where steam is readily available or in areas where seasonal load peaks cause utilities to subsidize gas cooling. This paper will describe the history of absorption, the basic absorption refrigeration cycle and some advanced high efficiency cycles. Practical applications of absorption refrigeration to commercial end uses will also be discussed.

Adcock, P.W.

1995-06-01T23:59:59.000Z

94

Demonstration of High Efficiency Elastocaloric Cooling with Large Delta- T Using NiTi Wires  

Science Conference Proceedings (OSTI)

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit, but its envi-ronmental footprint remains a global problem. VC refrigerants such as hydrochlo-roflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas (GHG) emissions, and their global warming potential (GWP) is as high as 1000 times that of CO2. It is expected that building space cooling and re-frigeration alone will amount to {approx} 5% of primary energy consumption and {approx}5% of all CO2 emission in U.S. in 2030 . As such, there is an urgent need to develop an al-ternative high-efficiency cooling technology that is affordable and environmentally friendly. Among the proposed candidates, magnetocaloric cooling (MC) is currently received a lot of attention because of its high efficiency. However, MC is inherently expensive because of the requirement of large magnetic field and rare earth materi-als. Here, we demonstrate an entirely new type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation. We call it elasto-caloric cooling (EC) after the superelastic transformation of austenite it utilizes. The solid-state refrigerant of EC is cost-effective, and it completely eliminates the use of any refrigerants including HCFCs/HFCs. We show that the COP (coefficient of per-formance) of a jugular EC with optimized materials can be as high as > 10 with measured {Delta}T of 17 C.

Cui, Jun; Wu, Yiming; Muehlbauer, Jan; Hwang, Yunho; Radermacher, Reinhard; Fackler, Sean; Wuttig, Manfred; Takeuchi, Ichiro

2012-08-01T23:59:59.000Z

95

Energy and global warming impacts of HFC refrigerants and emerging technologies: TEWI-III  

Science Conference Proceedings (OSTI)

The use of hydrofluorocarbons (BFCs) which were developed as alternative refrigerants and insulating foam blowing agents to replace chlorofluorocarbons (CFCs) is now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants and blowing agents on global warming. A Total Equivalent Warming Impact (TEWI) assessment analyzes the environmental affects of these halogenated working fluids in energy consuming applications by combining a direct effect resulting from the inadvertent release of HFCs to the atmosphere with an indirect effect resulting from the combustion of fossil fuels needed to provide the energy to operate equipment using these compounds as working fluids. TEWI is a more balanced measure of environmental impact because it is not based solely on the global warming potential (GWP) of the working fluid. It also shows the environmental benefit of efficient technologies that result in less CO{sub 2} generation and eventual emission to the earth`s atmosphere. The goal of TEWI is to assess total global warming impact of all the gases released to the atmosphere, including CO{sub 2} emissions from energy conversion. Alternative chemicals and technologies have been proposed as substitutes for HFCs in the vapor-compression cycle for refrigeration and air conditioning and for polymer foams in appliance and building insulations which claim substantial environmental benefits. Among these alternatives are: (1) Hydrocarbon (HC) refrigerants and blowing agents which have zero ozone depleting potential and a negligible global warming potential, (2) CO{sub 2} as a refrigerant and blowing agent, (3) Ammonia (NH{sub 3}) vapor compression systems, (4) Absorption chiller and heat pumping cycles using ammonia/water or lithium bromide/water, and (5) Evacuated panel insulations. This paper summarizes major results and conclusions of the detailed final report on the TEWI-111 study.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1997-06-01T23:59:59.000Z

96

Home Energy Audits | Department of Energy  

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

April 4, 2012 April 4, 2012 This Month on Energy Savers: March 2012 We also covered some driving tips to help save money at the pump, ideas for new parents, and unveiled how you can connect with energy savings tips on the go. April 2, 2012 Energy 101: Home Energy Checkup (Text Version) The text version for the Home Energy Checkup 101 video. April 2, 2012 Blower door test during a home energy audit. Credit: Holtkamp Heating & A/C, Inc. Blower Door Tests Professional energy auditors use blower door tests to help determine a home's airtightness. April 2, 2012 The Brookhaven National Laboratory developed the PFT (PerFluorocarbon tracer gas) technique to measure changes over time when determining a building's air-infiltration rate. PFT Air Infiltration Measurement Technique

97

Climate VISION: Private Sector Initiatives: Aluminum: Resources and Links -  

Office of Scientific and Technical Information (OSTI)

Resources & Links Resources & Links Technical Information Publications Case Studies Publications Some of the following publications are available for download as Adobe PDF documents. Download Acrobat Reader Factors Affecting Emissions from Commercial Aluminum Reduction Cells (PDF 316 KB) The U.S. EPA and the Aluminum Association sponsored measurements of two perfluorocarbon (PFC) gases: tetrafluoromethane and hexafluoroethane. The measurements at six primary aluminum production facilities provided data on emissions of these compounds during normal aluminum smelting operations. Technology and Economics of Reducing PFC Emissions from Aluminium Production (PDF 139 KB) The paper, presented in 2002 at the Third International Symposium on Non-CO2 Greenhouse Gases (NCGG-3), provides an overview of global efforts

98

BNL | Tracer Technology Group | BNL  

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

Tracer Technology Group Tracer Technology Group Tracer Technology Image The Tracer Technology Group (TTG) developed the use of perfluorocarbon tracers (PFTs) as tools for studying long range atmospheric transport and dispersion in the early 1980s.We are world leaders in the use of PFTs for solving diverse research and engineering problems in the atmospheric sciences, the energy production and utility industries, and building characterization. The unique capabilities of the TTG are derived from our analytical expertise, infrastructure, and experience. We have developed PFT analytical methods that have detection limits at the femtogram level. We can measure global background levels of PFTS at the parts per quadrillion levels. Our scientists and technical staff have extensive experience in

99

Project Title  

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

Monitoring Geological CO Monitoring Geological CO 2 Sequestration using Perfluorocarbon and Stable Isotope Tracers Project Number FEAA-045 Tommy J. Phelps and David R. Cole* Oak Ridge National Laboratory Phone: 865-574-7290 email: phelpstj@ornl.gov (*The Ohio State University) U.S. Department of Energy National Energy Technology Laboratory Carbon Storage R&D Project Review Developing the Technologies and Building the Infrastructure for CO 2 Storage August 22, 2013 2 Project Overview: Goals and Objectives Goal: Develop methods to interrogate subsurface for improved CO 2 sequestration, field test characterization and MVA, demonstrate CO 2 remains in zone, and tech transfer. Objectives: 1. Assessment of injections in field. PFT gas tracers are analyzed by GC-ECD to

100

NATIONAL ENERGY TECHNOLOGY LABORATORY  

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

0 0 NETL Accomplishments 2 Advancing energy options to fuel our economy, strengthen our security, and improve our environment. Our Mission 3 2010 NETL Accomplishments 86 66 54 52 28 8 6 4 CONTENTS NETL Mission Message from the Director NETL Powers the Future of Energy Advanced Power Systems 10 Gasification 14 Fuel Cells 16 SECA Reaches 2010 Program Goal 18 Turbines 22 Turbine Program Develops Prototypes for Reducing Emissions 24 Materials Clean Energy 30 Carbon Capture 34 Carbon Storage 36 Perfluorocarbon Tracers Go with the Flow 38 Carbon Sequestration Partnerships 44 Demand-Side Efficiency 48 Air, Water, Land A Century of Science Reliable Supply 56 Energy Infrastructure 60 Methane Hydrates 62 Natural Gas and Oil Production

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


101

Climate VISION: Private Sector Initiatives: Semiconductors  

Office of Scientific and Technical Information (OSTI)

Letters of Intent/Agreements Letters of Intent/Agreements The U.S. semiconductor industry, represented by the members of the Environmental Protection Agency's PFC Reduction/Climate Partnership for the Semiconductor Industry, has committed to reduce absolute perfluorocompound (PFC) emissions by 10% below the 1995 baseline level by the year 2010. Perfluorocompounds include the most potent and long-lived greenhouse gases such as perfluorocarbons (e.g., CF4, C2F6, C3F8), trifluoromethane (CHF3), nitrogen trifluoride (NF3), and sulfur hexafluoride (SF6). The Environmental Protection Agency's (EPA) voluntary semiconductor industry partnership was developed collaboratively with the Semiconductor Industry Association (SIA). EPA, SIA, and the Partner companies (listed below) are working to reduce industry greenhouse gas (GHG) emissions. EPA's

102

Thermal modeling of W rod armor.  

Science Conference Proceedings (OSTI)

Sandia has developed and tested mockups armored with W rods over the last decade and pioneered the initial development of W rod armor for International Thermonuclear Experimental Reactor (ITER) in the 1990's. We have also developed 2D and 3D thermal and stress models of W rod-armored plasma facing components (PFCs) and test mockups and are applying the models to both short pulses, i.e. edge localized modes (ELMs), and thermal performance in steady state for applications in C-MOD, DiMES testing and ITER. This paper briefly describes the 2D and 3D models and their applications with emphasis on modeling for an ongoing test program that simulates repeated heat loads from ITER ELMs.

Nygren, Richard Einar

2004-09-01T23:59:59.000Z

103

Theory and models of material erosion and lifetime during plasma instabilities in a tokamak environment.  

SciTech Connect

Surface and structural damage to plasma-facing components (PFCs) due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the HEIGHTS computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials are being examined. The design requirements and implications of plasma-facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components.

Hassanein, A.; Konkashbaev, I.

1999-11-08T23:59:59.000Z

104

Lithium Wall Conditioning And Surface Dust Detection On NSTX  

Science Conference Proceedings (OSTI)

Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors

Skinner, C H; Bell, M G; Friesen, F.Q.L.; Heim, B; Jaworski, M A; Kugel, H; Maingi, R; Rais, B

2011-05-23T23:59:59.000Z

105

up_to_air_060606.xls  

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

Task Task Responsible People Major Projects: Cryopump installation Vieira, Pierson, LaBombard Tungsten Tile installation Vieira, Blip New lower hybrid couplers Vieira, Parker Rotate DNB Scott, Vieira Repair ICRF antennas/feeds as required Wuktich, Vieira Complete installation of FFT on E-Port Wukitch, Binus Continue Upgrades to LH fault protection Terry Finalize design of new 4-Strap Antenna Vieira, Wukitch Continue design of 2nd launcher Vieira, Parker General Ops: Alternator High-Pot and minor inspection Rowell Service Liquid Nitrogen System Dekow Service LN2 vent duct Dekow, Pfeiffer Service Power System Cochran Sparker Development Irby Service/Repair PFCs Vieira, Blip, LaBombard Replace HEAT TC Scanner Burke Replace HV reed relays in TF Scanner Burke Real-Time TF Voltage Tap Monitors?

106

Buildings Energy Data Book: 7.1 National Legislation  

Buildings Energy Data Book (EERE)

5 5 Phase Out Schedule of Halocarbons in the U.S. (1) Gas % By % By Chlorofluorocarbons 75% 1994 75% 1994 (CFCs) 100% 1996 (4) 100% 1996 Bromofluorocarbons 100% 1994 (4) 100% 1994 (Halons) Hydrochlorofluorocarbons 35.0% 2004 35% 2003 (HCFCs) 75.0% 2010 75% 2010 90.0% 2015 90% 2015 99.5% 2020 99.5% 2020 100% 2030 (4) 100% 2030 Hydrofluorocarbons N.A. N.A. N.A. N.A. (HFCs) Note(s): Source(s): 1989 HCFC consumption + 2.8 % of 1989 CFC consumption 1996 N.A. N.A. 1) The phase out of halocarbons is consistent with Title VI of the Clean Air Act and is in accordance with the Montreal Protocol and Amendments. 2) The amount of gas produced and consumed in this year is established and defined as the base level. To meet basic domestic needs, levels of production are allowed to exceed the base level by up to 10%. 3) After this year, levels of production are no longer

107

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01T23:59:59.000Z

108

Global warming and end-use efficiency implications of replacing CFCs  

SciTech Connect

The direct contribution of CFCs to calculated global warming has been recognized for some time. As a result of the international agreement to phase out CFCs due to stratospheric ozone and the ensuing search for suitable alternatives, there has recently been increased attention on the DIRECT global warming potential (GWP) of the fluorocarbon alternatives as greenhouse gases. However, to date there has been little focus on the INDIRECT global warming effect arising from end-use efficiency changes and associated CO{sub 2} emissions. A study being conducted at Oak Ridge National Laboratory (ORNL) addresses this combined or total global warming impact of viable options to replace CFCs in their major energy-related applications. This paper reviews selected results for air-conditioning, refrigeration, and heat pump applications. The analysis indicates that the CFC user industries have made substantial progress in approaching near-equal energy efficiency with the HCFC/HFC alternative refrigerants. The findings also bring into question the relative importance of the DIRECT (chemical-related) effect in many applications. Replacing CFCs is an important step in reducing the total global warming impact, and at present the HCFC and HFCS appear to offer the best efficiency and lowest total impact of options available in the relatively short time period required for the transition away from CFCs.

Fairchild, P.D.; Fischer, S.K.

1991-12-31T23:59:59.000Z

109

Global warming implications of non-fluorocarbon technologies as CFC replacements  

SciTech Connect

Many technologies could be developed for use in place of conventional compression systems for refrigeration and air conditioning. Comparisons of the global warming impacts using TEWI (Total Equivalent Warming Impact) can be used to identify alternatives that have the potential for lower environmental impacts than electric-driven vapor compression systems using HCFCs and HFCs. Some options, such as secondary heat transfer loops in commercial refrigeration systems to reduce refrigerant charge and emission rates, could be useful in reducing the losses of refrigerants to the atmosphere. Use of ammonia instead of a fluorocarbon in a system with a secondary loop offers only a small potential for decreasing TEWI, and this may not warrant the increased complexity and risks of using ammonia in a retail sales environment. A few technologies, such as adsorption heat pumps, have efficiency levels that show reduced TEWI levels compared to conventional and state of the art compression systems, and further development could lead to an even more favorable comparison. Health and safety risks of the alternative technologies and the materials they employ must also be considered.

Fischer, S.K.; Tomlinson, J.J.

1993-12-31T23:59:59.000Z

110

DOE/ORNL heat pump design model, overview and application to R-22 alternatives  

SciTech Connect

This computer program is a public-domain system design tool for application to air-to-air heat pumps. The main aspects of the program are reviewed with emphasis on the newest features of the current fifth-generation version (Mark V) and an upcoming more fully HFC-capable release (Mark VI). Current model predictions are compared to test data for a leading HFC alternative to HCFC-22 in heat pumps. Examples are shown of some user interfaces that have been recently developed for the program. To demonstrate the design capabilities of the model for R-22 alternatives, a refrigerant-side optimization was conducted to find the best balance of heat transfer versus pressure drop for HCFC R-22, HFCs R-134a and R-410A, and the natural refrigerant propane. COP was maximized while refrigerant charge and tube size were minimized. Independent design parameters were fraction of total area in the outdoor coil, tube diameter and number of circuits for each heat exchanger, and condenser subcooling. Heat exchanger design tradeoffs are discussed for a heat pump relative to air conditioners and heating-only units. A design optimized for heating-only operation is presented.

Rice, C.K.

1997-12-01T23:59:59.000Z

111

Lithium As Plasma Facing Component for Magnetic Fusion Research  

SciTech Connect

The use of lithium in magnetic fusion confinement experiments started in the 1990's in order to improve tokamak plasma performance as a low-recycling plasma-facing component (PFC). Lithium is the lightest alkali metal and it is highly chemically reactive with relevant ion species in fusion plasmas including hydrogen, deuterium, tritium, carbon, and oxygen. Because of the reactive properties, lithium can provide strong pumping for those ions. It was indeed a spectacular success in TFTR where a very small amount (~ 0.02 gram) of lithium coating of the PFCs resulted in the fusion power output to improve by nearly a factor of two. The plasma confinement also improved by a factor of two. This success was attributed to the reduced recycling of cold gas surrounding the fusion plasma due to highly reactive lithium on the wall. The plasma confinement and performance improvements have since been confirmed in a large number of fusion devices with various magnetic configurations including CDX-U/LTX (US), CPD (Japan), HT-7 (China), EAST (China), FTU (Italy), NSTX (US), T-10, T-11M (Russia), TJ-II (Spain), and RFX (Italy). Additionally, lithium was shown to broaden the plasma pressure profile in NSTX, which is advantageous in achieving high performance H-mode operation for tokamak reactors. It is also noted that even with significant applications (up to 1,000 grams in NSTX) of lithium on PFCs, very little contamination (< 0.1%) of lithium fraction in main fusion plasma core was observed even during high confinement modes. The lithium therefore appears to be a highly desirable material to be used as a plasma PFC material from the magnetic fusion plasma performance and operational point of view. An exciting development in recent years is the growing realization of lithium as a potential solution to solve the exceptionally challenging need to handle the fusion reactor divertor heat flux, which could reach 60 MW/m2 . By placing the liquid lithium (LL) surface in the path of the main divertor heat flux (divertor strike point), the lithium is evaporated from the surface. The evaporated lithium is quickly ionized by the plasma and the ionized lithium ions can provide a strongly radiative layer of plasma ("radiative mantle"), thus could significantly reduce the heat flux to the divertor strike point surfaces, thus protecting the divertor surface. The protective effects of LL have been observed in many experiments and test stands. As a possible reactor divertor candidate, a closed LL divertor system is described. Finally, it is noted that the lithium applications as a PFC can be quite flexible and broad. The lithium application should be quite compatible with various divertor configurations, and it can be also applied to protecting the presently envisioned tungsten based solid PFC surfaces such as the ones for ITER. Lithium based PFCs therefore have the exciting prospect of providing a cost effective flexible means to improve the fusion reactor performance, while providing a practical solution to the highly challenging divertor heat handling issue confronting the steadystate magnetic fusion reactors.

Masayuki Ono

2012-09-10T23:59:59.000Z

112

Lithium As Plasma Facing Component for Magnetic Fusion Research  

Science Conference Proceedings (OSTI)

The use of lithium in magnetic fusion confinement experiments started in the 1990's in order to improve tokamak plasma performance as a low-recycling plasma-facing component (PFC). Lithium is the lightest alkali metal and it is highly chemically reactive with relevant ion species in fusion plasmas including hydrogen, deuterium, tritium, carbon, and oxygen. Because of the reactive properties, lithium can provide strong pumping for those ions. It was indeed a spectacular success in TFTR where a very small amount (~ 0.02 gram) of lithium coating of the PFCs resulted in the fusion power output to improve by nearly a factor of two. The plasma confinement also improved by a factor of two. This success was attributed to the reduced recycling of cold gas surrounding the fusion plasma due to highly reactive lithium on the wall. The plasma confinement and performance improvements have since been confirmed in a large number of fusion devices with various magnetic configurations including CDX-U/LTX (US), CPD (Japan), HT-7 (China), EAST (China), FTU (Italy), NSTX (US), T-10, T-11M (Russia), TJ-II (Spain), and RFX (Italy). Additionally, lithium was shown to broaden the plasma pressure profile in NSTX, which is advantageous in achieving high performance H-mode operation for tokamak reactors. It is also noted that even with significant applications (up to 1,000 grams in NSTX) of lithium on PFCs, very little contamination (fusion plasma core was observed even during high confinement modes. The lithium therefore appears to be a highly desirable material to be used as a plasma PFC material from the magnetic fusion plasma performance and operational point of view. An exciting development in recent years is the growing realization of lithium as a potential solution to solve the exceptionally challenging need to handle the fusion reactor divertor heat flux, which could reach 60 MW/m2 . By placing the liquid lithium (LL) surface in the path of the main divertor heat flux (divertor strike point), the lithium is evaporated from the surface. The evaporated lithium is quickly ionized by the plasma and the ionized lithium ions can provide a strongly radiative layer of plasma ("radiative mantle"), thus could significantly reduce the heat flux to the divertor strike point surfaces, thus protecting the divertor surface. The protective effects of LL have been observed in many experiments and test stands. As a possible reactor divertor candidate, a closed LL divertor system is described. Finally, it is noted that the lithium applications as a PFC can be quite flexible and broad. The lithium application should be quite compatible with various divertor configurations, and it can be also applied to protecting the presently envisioned tungsten based solid PFC surfaces such as the ones for ITER. Lithium based PFCs therefore have the exciting prospect of providing a cost effective flexible means to improve the fusion reactor performance, while providing a practical solution to the highly challenging divertor heat handling issue confronting the steadystate magnetic fusion reactors.

Masayuki Ono

2012-09-10T23:59:59.000Z

113

Greenhouse warming potential of candidate gaseous diffusion plant coolants  

SciTech Connect

A preliminary estimate has been made of the greenhouse warming potential (GWP) of coolants under consideration as substitutes for CFC-114 in the gaseous diffusion plants. Coolants are not at present regulated on the basis of GWP, but may well be in the future. Use of c-C{sub 4}F{sub 8} or n-C{sub 4}F{sub 10} is estimated to have three to four times the greenhouse impact of an equivalent use of CFC-114. Neither of the substitutes, of course, would cause any ozone depletion. HCFC-124 (a probable commercial substitute for CFC-114, but not presently under serious consideration due to its relatively high UF{sub 6} reactivity) would have much less greenhouse and ozone depletion impact than CFC-114. The GWP estimates derive from a simple model that approximately reproduces literature values for similar compounds. The major uncertainty in these estimates lies in the atmospheric lifetime, especially of the perfluorocarbon compounds, for which little reliable information exists. In addition to GWP estimates for coolants, the overall greenhouse impact of the gaseous diffusion plants is calculated, including indirect power-related CO{sub 2} emissions. This result is used to compare greenhouse impacts of nuclear- and coal-produced electricity. 11 refs., 2 figs., 5 tabs.

Trowbridge, L.D.

1991-03-01T23:59:59.000Z

114

Brookhaven air infiltration measurement system (BNL/AIMS) description and application  

SciTech Connect

A unique capability to measure part-per-quadrillion concentrations of a family of perfluorocarbon tracers (PFTs) is presented. Together with our unique PFT source and passive sampler, measurement of average air exchange and infiltration rate can be determined for periods as short as 12 hours. A more expensive programmable sampler can provide information on a frequency of as little as once per minute for each of its 23 sampling tubes. The principal of AIMS is based on the applicable steady-state assumption that the average concentration (e.g., in pL/L) of a tracer vapor in a chamber (i.e., a building or room) is equal to the emission rate of the tracer source (e.g., in pL/min) divided by the air leakage or infiltration rate (e.g., in L/min). Knowing the source rate and measuring the average concentration then provides a means to calculate the air leakage rate. Extending this technique to a multichamber concept, in which a different type of PFT source is deployed in each chamber of a building, allows the calculation of not only the infiltration rates in each chamber but also the air exchange rates between chambers as well. Since both the PFT source and the passive sampler, a miniature Capillary Adsorption Tube Sampler (CATS), are about the size of a cigarette, inexpensive, and reusable, the BNL/AIMS is a very cost-effective means (if not the only means) for determining these air exchange rates.

Dietz, R.N.; Goodrich, R.W.; Cote, E.A.; Wieser, R.F.

1983-08-01T23:59:59.000Z

115

FLORIDA TOWER FOOTPRINT EXPERIMENTS  

SciTech Connect

The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

2007-01-01T23:59:59.000Z

116

THE MADISON SQUARE GARDEN DISPERSION STUDY (MSG05) METEOROLOGICAL DATA DESCRIPTION.  

SciTech Connect

MSG05 was a study of atmospheric transport and dispersion in the deep urban canyons of Midtown New York City, in the area of Madison Square Garden. This downtown area is considered to be a prime target for terrorist activities, and has one of the largest commuter populations in the world. Little is known about air flow and hazardous gas dispersion in such scenarios, since previous urban field experiments have focused on small to medium sized cities with much smaller street canyons. On March 10 and 14, 2005, a series of Perfluorocarbon Tracer (PFT) tracers were released and tracked with about 30 sampling stations at radial distances of about 0.2 and 0.4 km, with vertical profiles near a 250 m tall building (One Penn Plaza). Meteorological stations collected wind data in the MSG vicinity, at street level and rooftop level. MSG05 is expected to provide useful information on rapid vertical dispersion will assist in planning for more extensive studies. This data release is being made available to a restricted group of key scientists who have worked on the project. Part of the QA program involves feedback from scientists and modelers who are working on this study. This document describes the meteorological component of the project. The file organization and metadata are detailed so that a researcher can work with the data sets.

REYNOLDS, R.M.

2006-10-01T23:59:59.000Z

117

Midwestern efforts to address climate change  

Science Conference Proceedings (OSTI)

Six Midwestern governors and a Canadian premier signed the Midwestern Greenhouse Gas Reduction Accord in November 2007. The governors agreed to begin the process of developing a market-based cap-and-trade program that would reduce GHG emissions (e.g., carbon dioxide, methane, nitrous oxide, hydro-fluorocarbons, perfluorocarbons, and sulfur hexafluoride) to meet reduction targets. Member jurisdictions include Illinois, Iowa, Kansas, Manitoba, Michigan, Minnesota, and Wisconsin. Observer jurisdictions - those who are participating in the program design, but will decide later whether to be full members-include Indiana, Ohio, Ontario, and South Dakota. To date, the advisory group has proposed target ranges for GHG emissions reductions of 15-25% below 2005 levels by 2020 and 60-80% by 2050. The following sectors are currently being considered for the cap-and-trade program: electricity generation and imports (power plants); industrial combustion sources (factories and other industrial facilities); and industrial process sources (to the extent credible measurement and monitoring protocols exist or can be developed prior to inclusion).

Daniel Stenberg [Midwestern Governors Association (United States)

2008-12-15T23:59:59.000Z

118

A database of PFT ventilation measurements  

SciTech Connect

About five years ago, a method for measuring the ventilation flows of a building was developed at Brookhaven National Laboratory (BNL). This method is based on the use of a family of compounds known as perfluorocarbon tracers or PFTs. Since 1982, BNL has measured ventilation in more than 4000 homes, comprising about 100 separate research projects throughout the world. This measurement set is unique in that it is the only set of ventilation measurements that acknowledge and measure the multizone characteristics of residences. Other large measurement sets assume that a home can be treated as a single well-mixed zone. This report describes the creation of a database of approximately half of the PFT ventilation measurements made by BNL over the last five years. The PFT database is currently available for use on any IBM PC or Apple Macintosh based personal computer system. In addition to its utility in modeling indoor pollutant dispersion, this database may also be useful to those people studying energy conservation, thermal comfort and heating system design in residential buildings. 2 refs.

D' Ottavio, T.W.; Goodrich, R.W.; Spandau, D.J.; Dietz, R.N.

1988-08-01T23:59:59.000Z

119

Taggants, method for forming a taggant, and a method for detecting an object  

DOE Patents (OSTI)

A taggant comprising at least one perfluorocarbon compound surrounded by a polyphosphazene compound. The polyphosphazene compound has the chemical structure: ##STR00001## wherein G.sub.1 and G.sub.2 are pendant groups having different polarities, m is an integer greater than or equal to 100, and each of A and B is independently selected from hydrogen, an alkyl, an alkene, an alkoxide, a polyether, a polythioether, a siloxane, and --X(CH.sub.2).sub.nY.sup.1(CH.sub.2)p.sub.1Y.sup.2(CH.sub.2)p.sub.2 . . . Y.sup.i(CH.sub.2)p.sub.iCH.sub.3, where n ranges from 1 to 6, X and Y are independently selected from oxygen, sulfur, selenium, tellurium, and polonium, and p.sub.1 through p.sub.i range from 1 to 6. Cyclic polyphosphazene compounds lacking the A and B groups are also disclosed, as are methods of forming the taggant and of detecting an object.

Harrup, Mason K. (Idaho Falls, ID); Stewart, Frederick F. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID)

2012-02-28T23:59:59.000Z

120

Urban Dispersion Program MSG05 Field Study: Summary of Tracer and Meteorological Measurements  

SciTech Connect

The Urban Dispersion Program is a multi-year project, funded by the U.S. Department of Homeland Security, to better understand the flow and dispersion of airborne contaminants through and around the deep street canyons of New York City. The first tracer and meteorological field study was a limited study conducted during March 2005 near the Madison Square Garden in midtown Manhattan. Six safe, inert, gaseous perfluorocarbon tracers were released simultaneously at five street-level locations during two experimental days. In addition to collecting tracer data, meteorological data were also collected. Brookhaven National Laboratory conducted the bulk of the tracer and meteorological field efforts with Pacific Northwest National Laboratory and Stevens Institute of Technology assisting by measuring the vertical profile of winds. The Environmental Protection Agency worked with Brookhaven National Laboratory in accomplishing the personal exposure component of the study. This report presents some results from this analysis. In general, different release locations showed vastly different plume footprints for tracer materials, and the situation was made very complex with upwind and/or crosswind transport of tracer near street-level for the different release locations. Overall wind speeds and directions upwind and over the city were generally constant throughout each of the two experimental periods.

Allwine, K Jerry; Flaherty, Julia E.

2006-08-09T23:59:59.000Z

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


121

Air Exchange Rates in New Energy-Efficient Manufactured Housing  

E-Print Network (OSTI)

During the 1989-1990 heating season, Pacific Northwest Laboratory, for the Bonneville Power Administration, measured the ventilation characteristics of 139 newly constructed energy-efficient manufactured homes and a control sample of 35 newer manufactured homes. A standard door fan pressurization technique was used to estimate shell leakiness, and a passive perfluorocarbon tracer technique was used to estimate overall air exchange rates. A measurement of the designated whole-house exhaust system flow rate was taken as well as an occupant and structure survey. The energy-efficient manufactured homes have very low air exchange rates, significantly lower than either existing manufactured homes or site-built homes. The standard deviation of the effective leakage area for this sample of homes is small (25% to 30% of the mean), indicating that the leakiness of manufactured housing stock can be confidently characterized by the mean value. There is some indication of increased ventilation due to the energy-efficient whole-house ventilation specification, but not directly related to the operation of the wholehouse system. The mechanical systems as installed and operated do not provide the intended ventilation; consequently indoor air quality could possibly be adversely impacted and moisture/condensation in the living space is a potential problem.

Hadley, D. L.; Bailey, S. A.

1990-01-01T23:59:59.000Z

122

Alcator C-Mod Program C Mod Alcator  

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

Program Program C Mod Alcator - Program Science Objectives Hutchinson 15m Budget, Schedules, and Manpower Marmar 20 MIT Institutional Issues Porkolab 10 OFES Budget Planning Meeting, Gaithersburg, Mar 2003 C Mod Alcator - Program Exploits Unique Features of the C-Mod Tokamak Major thrusts: Quasi-steady Advanced Tokamak: utilizing long pulse length cf L/R, new LH facility. Burning Plasma Support: High B; reactor pressure, q ; i-e coupled; Mo PFCs. Unique dimensional parameters give special relevance to topical science research: Transport: Marginal stability, pedestal, electron transp. Edge/Divertor: SOL transport, Neutrals, Power handling. Wave/Particle: Purely RF driven. ICRF, LH physics. MHD: Active MHD spectroscopy. ICRF/LH stabilization. C Mod Alcator - Momentum Transport Without Sources 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 -1 0 1 2 3 4 V Tor (10 4 m/s) 0.6 0.3 0.0 0.50

123

Comprehensive physical models and simulation package for plasma/material interactions during plasma instabilities.  

SciTech Connect

Damage to plasma-facing components (PFCS) from plasma instabilities remains a major obstacle to a successful tokamak concept. The extent of the damage depends on the detailed physics of the disrupting plasma, as well as on the physics of plasma-material interactions. A comprehensive computer package called High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS) has been developed and consists of several integrated computer models that follow the beginning of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the deposited energy. The package can study, for the first time, plasma-turbulent behavior in the SOL and predict the plasma parameters and conditions at the divertor plate. Full two-dimensional (2-D) comprehensive radiation magnetohydrodynamic (MHD) models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. Factors that influence the lifetime of plasma-facing and nearby components, such as loss of vapor-cloud confinement and vapor removal due to MHD effects, damage to nearby components due to intense vapor radiation, melt splashing, and brittle destruction of target materials, are also modeled and discussed.

Hassanein, A.

1998-08-26T23:59:59.000Z

124

J. Plasma Fusion Res. SERIES, Vol. 10 (2013) Simulating Tritium Retention in Tungsten with a Multiple Trap Model in the TMAP Code a  

E-Print Network (OSTI)

Accurately predicting the quantity of tritium retained in plasma facing components is a key safety issue for licensing future fusion power reactors. Retention of tritium in the lattice damage caused when high energy neutrons collide with atoms in the structural material of the reactor’s plasma facing components (PFCs) is an area of ongoing experimental research at the Idaho National Laboratory (INL) under the US/Japan TITAN collaboration. Recent experiments with the Tritium Plasma Experiment (TPE), located in the INL’s Safety and Tritium Applied Research (STAR) facility, demonstrate that this damage can only be simulated by computer codes like the Tritium Migration Analysis Program (TMAP) if one assumes that the lattice damage produced by these neutrons results in multiple types of hydrogen traps (energy wells) within the material, each possessing a different trap energy and density. Previous attempts to simulate the quantity of deuterium released from neutron irradiated TPE tungsten targets indicated that at least six different traps are required by TMAP to model this release. In this paper we describe a recent extension of the TMAP trap site model to include as many traps as required by the user to simulate retention of tritium in neutron damaged tungsten. This model has been applied to data obtained for tungsten irradiated to a damage level of 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) after exposure to a plasma in TPE.

Brad J. Merrill; Masashi Shimada; Paul W. Humrickhouse

2012-01-01T23:59:59.000Z

125

Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium  

DOE Green Energy (OSTI)

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

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

2004-12-14T23:59:59.000Z

126

TEWI Analysis: Its Utility, Its Shortcomings, and Its Results  

Science Conference Proceedings (OSTI)

The past decade has been a challenging time for the refrigeration and air conditioning industry worldwide. Provisions of the Montreal Protocol and its amendments require the phaseout of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds that have been used extensively as insulating foam blowing agents and refrigerants in refrigeration systems, heat pumps, and air conditioners. In response, hydrofluorocarbon (HFC) compounds were proposed, developed, and are starting to be used as the primary alternatives to CFCs and HCFCs. However, in 1997 under the Kyoto Protocol, industrialized nations have agreed to roll back emissions of HCFCs, carbon dioxide (CO*), and four other greenhouse gases which threaten to cause excessive global warming. The US. Department of Energy and the Alternative Fluorocarbon Environmental Acceptability Study (AFEAS) jointly sponsored research projects to identify the major applications of CFCs, HCFCs, and HFCs and to examine the impacts of these compounds and the energy use of applications employing these compounds on global warming. The five major uses of fluorocarbons based on sales were automobile air conditioning, supermarket refrigeration, unitary heat pumps and air conditioning, chillers for cooling large office buildings, and household refrigeration. Almost all of the refrigerants used in these applications are global warming gases, and if the refrigerant leaks out of the system during operation, is lost during maintenance or is not recovered when the system is scraped, it contributes to global warming. But, it is also true that the energy consumed by refrigeration and air conditioning systems, in the form of electricity or the direct combustion of fossil fuel, results in the release of CO*, the primary cause of atmospheric global warming.

Baxter, V.D.; Fischer, S.K.; Sand, J.R.

1999-09-13T23:59:59.000Z

127

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01T23:59:59.000Z

128

Atmospheric Radiation Measurement Program facilities newsletter, July 2001.  

Science Conference Proceedings (OSTI)

Global Warming and Methane--Global warming, an increase in Earth's near-surface temperature, is believed to result from the buildup of what scientists refer to as ''greenhouse gases.'' These gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, perfluorocarbons, hydrofluoro-carbons, and sulfur hexafluoride. Greenhouse gases can absorb outgoing infrared (heat) radiation and re-emit it back to Earth, warming the surface. Thus, these gases act like the glass of a greenhouse enclosure, trapping infrared radiation inside and warming the space. One of the more important greenhouse gases is the naturally occurring hydrocarbon methane. Methane, a primary component of natural gas, is the second most important contributor to the greenhouse effect (after carbon dioxide). Natural sources of methane include wetlands, fossil sources, termites, oceans, fresh-waters, and non-wetland soils. Methane is also produced by human-related (or anthropogenic) activities such as fossil fuel production, coal mining, rice cultivation, biomass burning, water treatment facilities, waste management operations and landfills, and domesticated livestock operations (Figure 1). These anthropogenic activities account for approximately 70% of the methane emissions to the atmosphere. Methane is removed naturally from the atmosphere in three ways. These methods, commonly referred to as sinks, are oxidation by chemical reaction with tropospheric hydroxyl ion, oxidation within the stratosphere, and microbial uptake by soils. In spite of their important role in removing excess methane from the atmosphere, the sinks cannot keep up with global methane production. Methane concentrations in the atmosphere have increased by 145% since 1800. Increases in atmospheric methane roughly parallel world population growth, pointing to anthropogenic sources as the cause (Figure 2). Increases in the methane concentration reduce Earth's natural cooling efficiency by trapping more of the outgoing terrestrial infrared radiation, increasing the near-surface temperature.

Holdridge, D. J.

2001-07-23T23:59:59.000Z

129

The Climate Change Action Plan: Technical supplement  

SciTech Connect

This Technical Annex documents the assumptions and parameters used in developing the supporting analysis for the Climate Change Action Plan (the Plan) issued by President Clinton on October 19, 1993. The Annex is intended to meet the needs of independent energy and environmental analysts who wish to better understand the Plan, its analytical underpinnings, and the events that need to transpire for the emissions reductions called for in the Plan to be realized. The Plan documented in this Annex reflects the outcome of a wide-ranging effort by Government agencies and interested members of the public to develop and implement actions that can reduce net greenhouse gas emissions in the year 2000 to their aggregate 1990 level. Based on agency and public input, the Climate Change Mitigation Group, chaired by the White House Office on Environmental Policy, developed the Plan`s content. Many of the actions called for in the Plan are now underway, while others are in advanced planning pending congressional action on the fiscal year 1995 budget. The analysis supporting the Plan represents the results of an interagency effort. The US Department of Energy (DOE) was responsible for the integrated analysis of energy-related options, based on the analysis of individual energy-related options by DOE, the US Environmental Protection Agency (EPA), and the US Department of Transportation (DOT). EPA led in providing analysis for actions related to methane, hydrofluorocarbons, and perfluorocarbons. The US Department of Agriculture (USDA) led the analysis of carbon sequestration actions and cooperated with EPA in the analysis of actions to reduce nitrous oxide emissions.

Not Available

1994-03-01T23:59:59.000Z

130

Innovative techniques for the description of reservoir heterogeneity using tracers. Final report, October 1992--December 1993  

SciTech Connect

This is the final report of a three year research project on the use of tracers for reservoir characterization. The objective of this research was to develop advanced, innovative techniques for the description of reservoir characteristics using both single-well backflow and interwell tracer tests. (1) The authors implemented and validated tracer modeling features in a compositional simulator (UTCOMP). (2) They developed and applied a new single well tracer test for estimating reservoir heterogeneity. (3) They developed and applied a new single well tracer test for estimating reservoir wettability in-situ. (4) They developed a new, simple and efficient method to analyze two well tracer tests based upon type curve matching and illustrated its use with actual field tracer data. (5) They developed a new method for deriving an integrated reservoir description based upon combinatorial optimization schemes. (6) They developed a new, interwell tracer test for reservoir heterogeneity called vertical tracer profiling (VTP) and demonstrated its advantages over conventional interwell tracer testing. (7) They developed a simple and easy analytical method to estimate swept pore volume from interwell tracer data and showed both the theoretical basis for this method and its practical utility. (8) They made numerous enhancements to our compositional reservoir simulator such as including the full permeability tensor, adding faster solvers, improving its speed and robustness and making it easier to use (better I/0) for tracer simulation problems. (9) They applied the enhanced version of UTCOMP to the analysis of interwell tracer data using perfluorocarbons at Elks Hill Naval Petroleum Reserve. All of these accomplishments taken together have significantly improved the state of reservoir tracer technology and have demonstrated that it is a far more powerful and useful tool for quantitative reservoir characterization than previously realized or practiced by the industry.

Pope, G.A.; Sepehrnoori, K.; Delshad, M.; Ferreira, L.; Gupta, A.; Maroongroge, V.

1994-11-01T23:59:59.000Z

131

MHD equilibrium and stability considerations for high-aspect-ratio ARIES-I tokamak reactors  

SciTech Connect

The requirements of an external poloidal field coil (PFC) system with minimum stored energy, double-null divertor plasmas with elongated D shape, adequate passive stabilization of plasma vertical displacement by a vacuum vessel located behind the blanket zone, and an enhanced plasma beta limit in the first stability regime are incorporated in the ARIES-I concept for a high-field tokamak reactor with high aspect ratio (A = 4.5). The plasma current and pressure profiles are also made consistent with enhanced bootstrap current I{sub bs} and reduced current drive power by means of ion cyclotron wave (ICW) or neutral beam (NB) injection. These lead to plasmas characterized by an elongation k{sub x} of 1.8 to the divertor X-point, a triangularity {delta}{sub x} of 0.7, a safety factor q on axis of q{sub 0} {approx} 1.5, a safety factor at the edge q{sub 95} > 4, a plasma beta {beta} {approx} 2%, and a poloidal beta given by {epsilon}{beta}{sub p} {approx} 0.5 ({epsilon} = 1/A). With a plasma current I{sub p} of 11 MA, a toroidal field B{sub t} of 13 T at the major radius R{sub 0} of 6.5 m, and over 3.5 m of clearance between the PFCs and the plasma edge, the stored energy in the PFC system ranges from 20 GJ during plasma operation at low beta to 12 GJ during plasma operation at high beta. 16 refs., 6 figs., 2 tabs.

Peng, Y.K.M.; Strickler, D.J.; Hogan, J.T.; Whitson, J.C.; Bathke, C.G.; Evans, K. Jr.; Jardin, S.C.; Klasky, M.; Leuer, J.A. (Oak Ridge National Lab., TN (USA); Los Alamos National Lab., NM (USA); Argonne National Lab., IL (USA); Princeton Univ., NJ (USA). Plasma Physics Lab.; Rensselaer Polytechnic Inst., Troy, NY (USA); General Atomics, San Diego, CA (USA))

1989-01-01T23:59:59.000Z

132

Modeling of CBM production, CO{sub 2} injection, and tracer movement at a field CO{sub 2} sequestration site  

SciTech Connect

Sequestration of carbon dioxide in unmineable coal seams is a potential technology mainly because of the potential for simultaneous enhanced coalbed methane production (ECBM). Several pilot tests have been performed around the globe leading to mixed results. Numerous modeling efforts have been carried out successfully to model methane production and carbon dioxide (CO{sub 2}) injection. Sensitivity analyses and history matching along with several optimization tools were used to estimate reservoir properties and to investigate reservoir performance. Geological and geophysical techniques have also been used to characterize field sequestration sites and to inspect reservoir heterogeneity. The fate and movement of injected CO{sub 2} can be determined by using several monitoring techniques. Monitoring of perfluorocarbon (PFC) tracers is one of these monitoring technologies. As a part of this monitoring technique, a small fraction of a traceable fluid is added to the injection wellhead along with the CO{sub 2} stream at different times to monitor the timing and location of the breakthrough in nearby monitoring wells or offset production wells. A reservoir modeling study was performed to simulate a pilot sequestration site located in the San Juan coal basin of northern New Mexico. Several unknown reservoir properties at the field site were estimated by modeling the coal seam as a dual porosity formation and by history matching the methane production and CO{sub 2} injection. In addition to reservoir modeling of methane production and CO{sub 2} injection, tracer injection was modeled. Tracers serve as a surrogate for determining potential leakage of CO{sub 2}. The tracer was modeled as a non-reactive gas and was injected into the reservoir as a mixture along with CO{sub 2}. Geologic and geometric details of the field site, numerical modeling details of methane production, CO{sub 2} injection, and tracer injection are presented in this paper. Moreover, the numerical predictions of the tracer arrival times were compared with the measured field data. Results show that tracer modeling is useful in investigating movement of injected CO{sub 2} into the coal seam at the field site. Also, such new modeling techniques can be utilized to determine potential leakage pathways, and to investigate reservoir anisotropy and heterogeneity.

Siriwardane, Hema J.; Bowes, Benjamin D.; Bromhal, Grant S.; Gondle, Raj K.; Wells, Arthur W.; Strazisar, Brian R.

2012-07-01T23:59:59.000Z

133

MULTI - TRACER CONTROL ROOM AIR INLEAKAGE PROTOCOL AND SIMULATED PRIMARY AND EXTENDED MULTI - ZONE RESULTS.  

SciTech Connect

The perfluorocarbon tracer (PFT) technology can be applied simultaneously to the wide range in zonal flowrates (from tens of cfms in some Control Rooms to almost 1,000,000 cfm in Turbine Buildings), to achieve the necessary uniform tagging for subsequent determination of the desired air inleakage and outleakage from all zones surrounding a plant's Control Room (CR). New types of PFT sources (Mega sources) were devised and tested to handle the unusually large flowrates in a number of HVAC zones in power stations. A review of the plans of a particular nuclear power plant and subsequent simulations of the tagging and sampling results confirm that the technology can provide the necessary concentration measurement data to allow the important ventilation pathways involving the Control Room and its air flow communications with all adjacent zones to be quantitatively determined with minimal uncertainty. Depending on need, a simple single or 3-zone scheme (involving the Control Room alone or along with the Aux. Bldg. and Turbine Bldg.) or a more complex test involving up to 7 zones simultaneously can be accommodated with the current revisions to the technology; to test all the possible flow pathways, several different combinations of up to 7 zones would need to be run. The potential exists that for an appropriate investment, in about 2 years, it would be possible to completely evaluate an entire power plant in a single extended multizone test with up to 12 to 13 separate HVAC zones. With multiple samplers in the Control Room near each of the contiguous zones, not only will the prevalent inleakage or outleakage zones be documented, but the particular location of the pathway's room of ingress can be identified. The suggested protocol is to perform a 3-zone test involving the Control Room, Aux. Bldg., and Turbine Bldg. to (1) verify CR total inleakage and (2) proportion that inleakage to distinguish that from the other 2 major buildings and any remaining untagged locations. These results would then direct the next subsequent tests. Final results would point to where mitigation steps should be initiated. Protocols for repeat testing as well as long term continual testing are suggested.

DIETZ,R.N.

2002-01-01T23:59:59.000Z

134

Desalination utilizing clathrate hydrates (LDRD final report).  

DOE Green Energy (OSTI)

Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C.

Simmons, Blake Alexander; Bradshaw, Robert W.; Dedrick, Daniel E.; Cygan, Randall Timothy (Sandia National Laboratories, Albuquerque, NM); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Majzoub, Eric H. (University of Missouri, Columbia, MO)

2008-01-01T23:59:59.000Z

135

MHD EQUILIBRIUM AND STABILITY CONSIDERATIONS FOR HIGH-ASPECT-RATIO ARIES-I TOKAMAK REACTORS  

DOE Green Energy (OSTI)

Browse > Conferences> Fusion Engineering, 1989. Pro Back to Results MHD equilibrium and stability considerations for high-aspect-ratio ARIES-I tokamak reactors .102446 searchabstract .Peng, Y.-K.M. ; Strickler, D.J. ; Hogan, J.T. ; Whitson, J.C. ; Bathke, C.G. ; Evans, K., Jr. ; Jardin, S.C. ; Klasky, M. ; Leuer, J.A. ; Oak Ridge Nat. Lab., TN This paper appears in: Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on Issue Date : 2-6 Oct 1989 On page(s): 1278 - 1282 vol.2 Meeting Date : 02 Oct 1989-06 Oct 1989 INSPEC Accession Number: 3809362 Digital Object Identifier : 10.1109/FUSION.1989.102446 Date of Current Version : 06 August 2002 Abstract The requirements of (1) an external poloidal-field coil (PFC) system with minimum stored energy, (2) double-null divertor plasmas with elongated D shape, (3) adequate passive stabilization of plasma vertical displacement by a vacuum vessel located behind the blanket zone, and (4) an enhanced plasma beta limit in the first stability regime are incorporated in the Advanced Reactor Innovation and Evaluation Study-I (ARIES-I) concept for a high-field tokamak reactor with high aspect ratio (A=4.5). The plasma current and pressure profiles are also made consistent with enhanced bootstrap current and reduced current drive power by means of ion cyclotron wave or neutral beam injection. These lead to plasmas characterized by an elongation of 1.8 to the divertor X-point, a triangularity of 0.7, a safety factor of ~1.5, a safety factor at the edge >4, a plasma beta of ~2%, and a poloidal beta of ~0.5. With a plasma current of 11 MA, a toroidal field of 13 T at the major radius of 6.5 m, and over 3.5 m of clearance between the PFCs and the plasma edge, the stored energy in the PFC system ranges from 20 GJ during plasma operation at low beta, to 12 GJ during plasma operation at high beta.

Peng, Yueng Kay Martin [ORNL; Strickler, Dennis J [ORNL

1990-01-01T23:59:59.000Z

136

Reduction of Carbon Footprint and Energy Efficiency Improvement in Aluminum Production by Use of Novel Wireless Instrumentation Integrated with Mathematical Modeling  

SciTech Connect

The work addressed the greenhouse gas emission and electrical energy consumption of the aluminum industry. The objective was to provide a means for reducing both through the application of wireless instrumentation, coupled to mathematical modeling. Worldwide the aluminum industry consumes more electrical energy than all activities in many major countries (e.g. the UK) and emits more greenhouse gasses (e.g. than France). Most of these excesses are in the 'primary production' of aluminum; that is the conversion of aluminum oxide to metal in large electrolytic cells operating at hundreds of thousands of amps. An industry-specific GHG emission has been the focus of the work. The electrolytic cells periodically, but at irregular intervals, experience an upset condition known as an 'anode effect'. During such anode effects the cells emit fluorinated hydrocarbons (PFCs, which have a high global warming potential) at a rate far greater than in normal operation. Therefore curbing anode effects will reduce GHG emissions. Prior work had indicated that the distribution of electrical current within the cell experiences significant shifts in the minutes before an anode effect. The thrust of the present work was to develop technology that could detect and report this early warning of an anode effect so that the control computer could minimize GHG emissions. A system was developed to achieve this goal and, in collaboration with Alcoa, was tested on two cells at an Alcoa plant in Malaga, Washington. The project has also pointed to the possibility of additional improvements that could result from the work. Notable among these is an improvement in efficiency that could result in an increase in cell output at little extra operating cost. Prospects for commercialization have emerged in the form of purchase orders for further installations. The work has demonstrated that a system for monitoring the current of individual anodes in an aluminum cell is practical. Furthermore the system has been installed twice on a smelter in the US without exposing workers to hazards usually associated with running signal wires in aluminum plants. The results display the early warning of an anode effect that potentially can be used to minimize such anode effects with their excessive GHG emissions. They also point to a possible, but substantial, economic benefit that could result in improved current efficiency by anode adjustment based on individual anode current measurements.

James W. Evans

2012-04-11T23:59:59.000Z

137

Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development  

SciTech Connect

Developing a reactor compatible divertor has been identified as a particularly challenging technology problem for magnetic confinement fusion. While tungsten has been identified as the most attractive solid divertor material, the NSTX/NSTX-U lithium (Li) program is investigating the viability of liquid lithium (LL) as a potential reactor compatible divertor plasma facing component (PFC) . In the near term, operation in NSTX-U is projected to provide reactor-like divertor heat loads < 40 MW/m^2 for 5 s. During the most recent NSTX campaign, ~ 0.85 kg of Li was evaporated onto the NSTX PFCs where a ~50% reduction in heat load on the Liquid Lithium Divertor (LLD) was observed, attributable to enhanced divertor bolometric radiation. This reduced divertor heat flux through radiation observed in the NSTX LLD experiment is consistent with the results from other lithium experiments and calculations. These results motivate an LL-based closed radiative divertor concept proposed here for NSTX-U and fusion reactors. With an LL coating, the Li is evaporated from the divertor strike point surface due to the intense heat. The evaporated Li is readily ionized by the plasma due to its low ionization energies, and the ionized Li ions can radiate strongly, resulting in a significant reduction in the divertor heat flux. Due to the rapid plasma transport in divertor plasma, the radiation values can be significantly enhanced up to ~ 11 MJ/cc of LL. This radiative process has the desired function of spreading the focused divertor heat load to the entire divertor chamber facilitating the divertor heat removal. The LL divertor surface can also provide a "sacrificial" surface to protect the substrate solid material from transient high heat flux such as the ones caused by the ELMs. The closed radiative LLD concept has the advantages of providing some degree of partition in terms of plasma disruption forces on the LL, Li particle divertor retention, and strong divertor pumping action from the Li-coated divertor chamber wall. By operating at a lower temperature than the first wall, the LLD can serve to purify the entire reactor chamber, as impurities generally migrate toward lower temperature Li-condensed surfaces. To maintain the LL purity, a closed LL loop system with a modest capacity (e.g., ~ 1 Liter/sec for ~ 1% level "impurities") is envisioned for a steady-state 1 GW-electric class fusion power plant.

M. Ono, et al.

2012-10-27T23:59:59.000Z

138

PROOF OF CONCEPT TEST OF A UNIQUE GASEOUS PERFLUROCARBON TRACER SYSTEM FOR VERIFICATION AND LONG TERM MONITORING OF CAPS AND COVER SYSTEMS CONDUCTED AT THE SAVANNAH RIVER SITE BENTONITE MAT TEST FACILITY.  

Science Conference Proceedings (OSTI)

Engineered covers have been placed on top of buried/subsurface wastes to minimize water infiltration and therefore, release of hazardous contaminants. In order for the cover to protect the environment it must remain free of holes and breaches throughout its service life. Covers are subject to subsidence, erosion, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. The U.S. Department of Energy Environmental Management (DOE-EM) Program 2006 Accelerated Cleanup Plan is pushing for rapid closure of many of the DOE facilities. This will require a great number of new cover systems. Some of these new covers are expected to maintain their performance for periods of up to 1000 years. Long-term stewardship will require monitoring/verification of cover performance over the course of the designed lifetime. In addition, many existing covers are approaching the end of their design life and will need validation of current performance (if continued use is desired) or replacement (if degraded). The need for a reliable method of verification and long-term monitoring is readily apparent. Currently, failure is detected through monitoring wells downstream of the waste site. This is too late as the contaminants have already left the disposal area. The proposed approach is the use of gaseous Perfluorocarbon tracers (PFT) to verify and monitor cover performance. It is believed that PFTs will provide a technology that can verify a cover meets all performance objectives upon installation, be capable of predicting changes in cover performance and failure (defined as contaminants leaving the site) before it happens, and be cost-effective in supporting stewardship needs. The PFTs are injected beneath the cover and air samples taken above (either air samples or soil gas samples) at the top of the cover. The location, concentrations, and time of arrival of the tracer(s) provide a direct measure of cover performance. PFT technology can be used as a non-invasive method (if injection ports are emplaced prior to cover emplacement) on new covers or a minimally invasive method on existing covers. PFT verification will be useful at all buried waste sites using a cover system (e.g., treated or untreated chemical waste landfills) including DOE, commercial, and private sector sites. This paper discusses the initial field trial of the PFT cover monitoring system performed at the Savannah River Site (SRS) in FY01. The experiments provided a successful proof-of-principle test of the PFT technology in monitoring caps and covers. An injection and sampling array was installed in the Bentomat test cap at the SRS Caps Test Facility. This system contained 6 feet of sandy soil beneath a 1/2 inch geosynthetic clay liner covered by an HDPE liner which was covered by 2 feet of clayey top soil. PFTs were injected into the sandy soil though a pre-existing system of access pipes below the cap and soil gas samples were taken on top of the cap. Mid-way into the injection period a series of 1 1/2 inch holes were punched into the cap (through the geomembrane) to provide a positive breach in the cap. Data will be presented that shows the initial cap was fairly tight and leak free and that the artificially induced leaks were detectable within two hours of occurrence.

HEISER,J.; SULLIVAN,T.; SERRATO,M.

2002-02-24T23:59:59.000Z