National Library of Energy BETA

Sample records for ground-level ozone limits

  1. Potential for savings in compliance costs for reducing ground-level ozone possible by instituting seasonal versus annual nitric oxide emission limits

    SciTech Connect (OSTI)

    Lookman, A.A.

    1996-12-31

    Ground-level ozone is formed in the atmosphere from its precursor emissions, namely nitric oxide (NO{sub x}) and volatile organic compounds (VOC), with its rate of formation dependent on atmospheric conditions. Since ozone levels tend to be highest during the summer months, seasonal controls of precursors have been suggested as a means of reducing the costs of decreasing ozone concentrations to acceptable levels. This paper attempts to quantify what the potential savings if seasonal control were instituted for coal-fired power plants, assuming that only commercially available NO{sub x} control technologies are used. Cost savings through seasonal control is measured by calculating the total annualized cost of NO{sub x} removal at a given amount of seasonal control for different target levels of annual control. For this study, it is assumed that trading of NO{sub x} emissions will be allowed, as has been proposed by the Ozone Transportation Commission (OTC). The problem has been posed as a binary integer linear programming problem, with decision variables being which control to use at each power plant. The results indicate that requiring annual limits which are lower than seasonal limits can substantially reduce compliance costs. These savings occur because requiring stringent compliance only on a seasonal basis allows power plants to use control methods for which the variable costs are paid for only part of the year, and through the use of gas-based controls, which are much cheaper to operate in the summer months.

  2. THE IMPACT OF OZONE ON THE LOWER FLAMMABLE LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE

    SciTech Connect (OSTI)

    Sherburne, Carol; Osterberg, Paul; Johnson, Tom; Frawely, Thomas

    2013-01-23

    The Savannah River Site, in conjunction with AREVA Federal services, has designed a process to treat dissolved radioactive waste solids with ozone. It is known that in this radioactive waste process, radionuclides radiolytically break down water into gaseous hydrogen and oxygen, which presents a well defined flammability hazard. Flammability limits have been established for both ozone and hydrogen separately; however, there is little information on mixtures of hydrogen and ozone. Therefore, testing was designed to provide critical flammability information necessary to support safety related considerations for the development of ozone treatment and potential scale-up to the commercial level. Since information was lacking on flammability issues at low levels of hydrogen and ozone, a testing program was developed to focus on filling this portion of the information gap. A 2-L vessel was used to conduct flammability tests at atmospheric pressure and temperature using a fuse wire ignition source at 1 percent ozone intervals spanning from no ozone to the Lower Flammable Limit (LFL) of ozone in the vessel, determined as 8.4%(v/v) ozone. An ozone generator and ozone detector were used to generate and measure the ozone concentration within the vessel in situ, since ozone decomposes rapidly on standing. The lower flammability limit of hydrogen in an ozone-oxygen mixture was found to decrease from the LFL of hydrogen in air, determined as 4.2 % (v/v) in this vessel. From the results of this testing, Savannah River was able to develop safety procedures and operating parameters to effectively minimize the formation of a flammable atmosphere.

  3. THE EFFECT OF THE PRESENCE OF OZONE ON THE LOWER FLAMMABILITY LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE

    SciTech Connect (OSTI)

    Sherburne, C.

    2012-01-12

    The Enhanced Chemical Cleaning (ECC) process uses ozone to effect the oxidation of metal oxalates produced during the dissolution of sludge in the Savannah River Site (SRS) waste tanks. The ozone reacts with the metal oxalates to form metal oxide and hydroxide precipitants, and the CO{sub 2}, O{sub 2}, H{sub 2}O and any unreacted O{sub 3} gases are discharged into the vapor space. In addition to the non-radioactive metals in the waste, however, the SRS radioactive waste also contains a variety of radionuclides, hence, hydrogen gas is also present in the vapor space of the ECC system. Because hydrogen is flammable, the impact of this resultant gas stream on the Lower Flammability Limit (LFL) of hydrogen must be understood for all possible operating scenarios of both normal and off-normal situations, with particular emphasis at the elevated temperatures and pressures of the typical ECC operating conditions. Oxygen is a known accelerant in combustion reactions, but while there are data associated with the behavior of hydrogen/oxygen environments, recent, relevant studies addressing the effect of ozone on the flammability limit of hydrogen proved scarce. Further, discussions with industry experts verified the absence of data in this area and indicated that laboratory testing, specific to defined operating parameters, was needed to comprehensively address the issue. Testing was thus designed and commissioned to provide the data necessary to support safety related considerations for the ECC process. A test matrix was developed to envelope the bounding conditions considered credible during ECC processing. Each test consists of combining a gas stream of high purity hydrogen with a gas stream comprised of a specified mixture of ozone and oxygen in a temperature and pressure regulated chamber such that the relative compositions of the two streams are controlled. The gases are then stirred to obtain a homogeneous mixture and ignition attempted by applying 10J of energy to a

  4. ARM - Ozone

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ozone Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Ozone In the stratosphere, ozone, is not only a greenhouse gas but also shields us from ultraviolet light. There has been a loss of stratospheric ozone, especially in the Antarctic region. During the Antarctic springtime, ozone levels

  5. GROUND LEVEL INVESTIGATION OF ANOMALOUS RADIATION LEVELS IN NIAGARA FALLS, NEW YORK

    Office of Legacy Management (LM)

    GROUND LEVEL INVESTIGATION OF ANOMALOUS RADIATION LEVELS IN NIAGARA FALLS, NEW YORK W. D. Cottrell, D. J. Christian, and F. F. Haywood ,d ;v ~ !;);;J;$ '9;) -i, - 'L." ; i--j -7,) ;3 i, Work performed by Health and Safety Research Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37630 O&J. 2,7 +, / 7&y' March 1979 \ operated by UNION CARBIDE CORPORATIOII for the DEPARTMENT OF ENERGY as part of the Formerly Utilized Sites- Remedial Action Program

  6. Limiter

    DOE Patents [OSTI]

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  7. Limiter

    DOE Patents [OSTI]

    Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  8. GROUND LEVEL ENHANCEMENT IN THE 2014 JANUARY 6 SOLAR ENERGETIC PARTICLE EVENT

    SciTech Connect (OSTI)

    Thakur, N.; Gopalswamy, N.; Xie, H.; Mkel, P.; Yashiro, S.; Akiyama, S.; Davila, J. M.

    2014-07-20

    We present a study of the 2014 January 6 solar energetic particle event which produced a small ground level enhancement (GLE), making it the second GLE of this unusual solar cycle 24. This event was primarily observed by the South Pole neutron monitors (increase of ?2.5%) while a few other neutron monitors recorded smaller increases. The associated coronal mass ejection (CME) originated behind the western limb and had a speed of 1960kms{sup 1}. The height of the CME at the start of the associated metric type II radio burst, which indicates the formation of a strong shock, was measured to be 1.61 Rs using a direct image from STEREO-A/EUVI. The CME height at the time of the GLE particle release (determined using the South Pole neutron monitor data) was directly measured as 2.96 Rs based on STEREO-A/COR1 white-light observations. These CME heights are consistent with those obtained for GLE71, the only other GLE of the current cycle, as well as cycle-23 GLEs derived using back-extrapolation. GLE72 is of special interest because it is one of only two GLEs of cycle 24, one of two behind-the-limb GLEs, and one of the two smallest GLEs of cycles 23 and 24.

  9. Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

    SciTech Connect (OSTI)

    Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit

    2015-04-24

    Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

  10. GIANT GROUND LEVEL ENHANCEMENT OF RELATIVISTIC SOLAR PROTONS ON 2005 JANUARY 20. I. SPACESHIP EARTH OBSERVATIONS

    SciTech Connect (OSTI)

    Bieber, J. W.; Clem, J.; Evenson, P.; Pyle, R.; Saiz, A.; Ruffolo, D. E-mail: clem@bartol.udel.edu E-mail: pyle@bartol.udel.edu E-mail: david.ruf@mahidol.ac.th

    2013-07-10

    A ground level enhancement (GLE) is a solar event that accelerates ions (mostly protons) to GeV range energies in such great numbers that ground-based detectors, such as neutron monitors, observe their showers in Earth's atmosphere above the Galactic cosmic ray background. GLEs are of practical interest because an enhanced relativistic ion flux poses a hazard to astronauts, air crews, and aircraft electronics, and provides the earliest direct indication of an impending space radiation storm. The giant GLE of 2005 January 20 was the second largest on record (and largest since 1956), with up to 4200% count rate enhancement at sea level. We analyzed data from the Spaceship Earth network, supplemented to comprise 13 polar neutron monitor stations with distinct asymptotic viewing directions and Polar Bare neutron counters at South Pole, to determine the time evolution of the relativistic proton density, energy spectrum, and three-dimensional directional distribution. We identify two energy-dispersive peaks, indicating two solar injections. The relativistic solar protons were initially strongly beamed, with a peak maximum-to-minimum anisotropy ratio over 1000:1. The directional distribution is characterized by an axis of symmetry, determined independently for each minute of data, whose angle from the magnetic field slowly varied from about 60 Degree-Sign to low values and then rose to about 90 Degree-Sign . The extremely high relativistic proton flux from certain directions allowed 10 s tracking of count rates, revealing fluctuations of period {approx}> 2 minutes with up to 50% fractional changes, which we attribute to fluctuations in the axis of symmetry.

  11. ARM - Measurement - Ozone Concentration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement : Ozone Concentration The atmospheric concentration or volume mixing ratio (mole fraction) of Ozone Categories Atmospheric State Instruments The above measurement is...

  12. Coordinated NO{sub x} control strategies: Phase II Title IV, ozone transport region and ozone transport assessment group

    SciTech Connect (OSTI)

    Frazier, W.F.; Dunn, R.M.; Baublis, D.C.

    1998-12-31

    Many electric utilities are faced with future nitrogen oxides (NO{sub x}) reduction requirements. In some instances, these utilities will be affected by multiple regulatory programs. For example, numerous fossil fired plants must comply with Phase II of Title IV of the Clean Air Act Amendments of 1990 (CAAA), state NO{sub x} rules as a result of the recommendations of the Ozone Transport Commission (OTC) and future requirements of the Proposed Rule for Reducing Regional Transport of Ground-Level Ozone (Ozone Transport SIP Rulemaking). This paper provides an overview of NO{sub x} regulatory programs, NO{sub x} compliance planning concepts, and NO{sub x} control technology options that could be components of an optimized compliance strategy.

  13. ARM - Instrument - ozone

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govInstrumentsozone Documentation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Ozone Monitor (OZONE) Instrument Categories Aerosols An in-situ Ozone Monitor measures atmospheric ozone concentration, typically by ultraviolet photometry in a dual absorption cell. The OZONE is part of the Aerosol Observing System (AOS). Locations Eastern North Atlantic ENA C1 Browse Data Browse Plots Graciosa Island,

  14. ARM - Campaign Instrument - ozone

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govInstrumentsozone Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Ozone Monitor (OZONE) Instrument...

  15. Ground-level spectral distribution of solar direct-normal irradiance and marine aerosol attenuation coefficients at Reunion Island

    SciTech Connect (OSTI)

    Vaxelaire, P.; Leveau, J.; Baldy, S. ); Menguy, G. )

    1991-01-01

    The ground-level spectral distribution of direct solar irradiance at Reunion Island was measured for six bands covering the spectrum of solar radiation. The measurements, distributed over one year, were made under clear sky conditions with a pyrheliometer (Eppley, NIP) and six large pass-band flat filters. Good stability of spectral irradiances as a function of solar height allows us to propose approximate relationships which significantly characterize the irradiance into each spectral band. Measurements at Reunion vary significantly from data obtained with the same apparatus in a northern hemisphere continental area (Lyon). The determination of aerosol attenuation coefficients, for different spectral bands, allows the establish of a mean curve, for these coefficients as a function of wavelength, characteristic for marine aerosols.

  16. ARM - Measurement - Ozone

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govMeasurementsOzone ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Ozone Ozone measurements are given in Dobson units and are integers with 3 significant figures. A Dobson Unit represents the physical thickness of the ozone layer if it were brought to the Earth's surface. A value of 300 Dobson units equals three millimeters. Categories Atmospheric State Instruments The above measurement is considered

  17. Ozone and acid rain

    SciTech Connect (OSTI)

    Not Available

    1987-10-09

    The roles of ozone and other oxidizing agents are discussed. The major polluting emissions are SO/sub 2/, NO, and volatile organic chemicals. In the usual ambient concentrations, these substances are relatively harmless. However, when SO/sub 2/ and NO are oxidized, they are converted into more acid, more toxic, substances. Oxidants, including OH, H/sub 2/O/sub 2/, HO/sub 2/, and organic peroxides, arise out of complex photochemistry that involves the ozone, the nitrogen oxides, and volatile organic chemicals. Were SO/sub 2/ the only pollutant, most of it would escape unchanged to the western Atlantic Ocean where it would be so diluted as to have no effect. At present about 35 percent of the SO/sub 2/ produced in the United States leaves the continent. In contrast, because of higher rates of reaction with oxidants, most of the NO is converted into nitric acid and deposited on land. The nitrogen oxides are involved in the production of ozone, some of which is naturally present. But particularly in urban settings where concentrations of NO/sub x/ are elevated and volatile organic chemicals such as those in gasoline are present, ozone concentrations may rise to levels deleterious to health. The Environmental Protection Agency has set standards for levels not to be exceeded, but nearly half of urban communities are not in compliance. The NO/sub x/ involved in the formation of urban ozone comes mostly from vehicular emissions.

  18. Tropospheric ozone in east Asia

    SciTech Connect (OSTI)

    Phadnis, M.J.

    1996-12-31

    An analysis of the observed data for the tropospheric ozone at mid latitudes in east Asia is done. There are three ways by which the tropospheric ozone is calculated, namely: (1) Ozonesonde measurements, (2) Fishman`s method of Residual Ozone and (3) TOMS measurements - an indirect method of calculating tropospheric ozone. In addition the surface ozone values at the network sites in Japan is also considered. The analysis of data is carried out for a period of twelve years from 1979 to 1991. In general it is observed that the tropospheric ozone is more in summer than winter, obviously because of the larger tropopause height in summer. On an average for the period of the analysis, the ozone values are at a high of about 60 DU (dobson units). While in winter the values go down to around 30 DU. Also a time series analysis shows an increasing trend in the values over the years. The ozonesonde values are correlated more to the TOMS tropospheric ozone values. For the stations analyzed in Japan, the TOMS tropospheric ozone values are generally greater than the ozonesonde values. The analysis of the average monthly surface ozone in Japan shows highs in spring and lows in summer. This can be attributed to movement of pollutant laden fronts towards Japan during spring. The highs for surface ozone are about 50 DU while the lows are around 20 DU.

  19. Evaluation of microporous carbon filters as catalysts for ozone decomposition

    SciTech Connect (OSTI)

    Whinnery, L.; Coutts, D.; Shen, C.; Adams, R. [Sandia National Labs., Livermore, CA (United States); Quintana, C.; Showalter, S. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    Ozone is produced in small quantities in photocopiers and laser printers in the workplace and large quantities in industrial waste water treatment facilities. Carbon filters are commonly used to decompose this unwanted ozone. The three most important factors in producing a filter for this purpose are flow properties, efficiency, and cost. Most ozone decomposition applications require very low back-pressure at modest flow rates. The tradeoff between the number of pores and the size of the pores will be discussed. Typical unfiltered emissions in the workplace are approximately 1 ppm. The maximum permissible exposure limit, PEL, for worker exposure to ozone is 0.1 ppm over 8 hours. Several methods have been examined to increase the efficiency of ozone decomposition. Carbon surfaces were modified with catalysts, the surface activated, and the surface area was increased, in attempts to decompose ozone more effectively. Methods to reduce both the processing and raw material costs were investigated. Several sources of microporous carbon were investigated as ozone decomposition catalysts. Cheaper processing routes including macropore templating, faster drying and extracting methods were also studied.

  20. Ozone decomposing filter

    DOE Patents [OSTI]

    Simandl, Ronald F.; Brown, John D.; Whinnery, Jr., LeRoy L.

    1999-01-01

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  1. Ozone Risk Assessment Utilities

    Energy Science and Technology Software Center (OSTI)

    1999-08-10

    ORAMUS is a user-friendly, menu-driven software system that calculates and displays user-selected risk estimates for health effects attributable to short-term exposure to tropospheric ozone. Inputs to the risk assessment are estimates of exposure to ozone and exposure-response relationships to produce overall risk estimates in the form of probability distributions. Three fundamental models are included: headcount risk, benchmark risk, and hospital admissions. Exposure-response relationships are based on results of controlled human exposure studies. Exposure estimates aremore » based on the EPA''s probabilistic national ambient air quality standards (NAAQS) exposure model, pNEM/Osub3, which simulates air quality associated with attainment of alternative NAAQS. Using ORAMUS, risk results for 27 air quality scenarios, air quality in 9 urban areas, 33 health endpoints, and 4 chronic health endpoints can be calculated.« less

  2. Ozone transport commission developments

    SciTech Connect (OSTI)

    Joyce, K.M.

    1995-08-01

    On September 27, 1994, the states of the Ozone Transport Commission (OTC) signed an important memorandum of understanding (MOU) agreeing to develop a regional strategy for controlling stationary sources of nitrogen oxide emissions. Specifically, the states of the Ozone Transport Region, OTR, agreed to propose regulations for the control of NOx emissions from boilers and other indirect heat exchangers with a maximum gross heat input rate of at least 250 million BTU per hour. The Ozone Transport Region was divided into Inner, Outer and Northern Zones. States in the Outer Zone agreed to reduce NOx emissions by 55%. States in the Inner Zone agreed to reduce NOx emissions 65%. Facilities in both zones have the option to emit NOx at a rate no greater than 0.2 pounds per million Btu by May 1, 1999. This option provides fairness for the gas-fired plants which already have relatively low NOx emissions. Additionally, States in the Inner and Outer Zones agreed to reduce their NOx emissions by 75% or to emit NOx at a rate no greater than 0.15 pounds per million BTU by May 1, 2003. The Northern Zone States agree to reduce their rate of NOx emissions by 55% from base year levels by May 1, 2003, or to emit NOx at a rate no greater than 0.2 pounds per million BTU. As part of this MOU, States also agreed to develop a regionwide trading mechanism to provide a cost-effective mechanism for implementing the reductions.

  3. Valuing the ozone-related health benefits of methane emission controls

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sarofim, Marcus C.; Waldhoff, Stephanie T.; Anenberg, Susan C.

    2015-06-29

    Methane is a greenhouse gas that oxidizes to form ground-level ozone, itself a greenhouse gas and a health-harmful air pollutant. Reducing methane emissions will both slow anthropogenic climate change and reduce ozone-related mortality. We estimate the benefits of reducing methane emissions anywhere in the world for ozone-related premature mortality globally and for eight geographic regions. Our methods are consistent with those used by the US Government to estimate the social cost of carbon (SCC). We find that the global short- and long-term premature mortality benefits due to reduced ozone production from methane mitigation are (2011) $790 and $1775 per tonnemore » methane, respectively. These correspond to approximately 70 and 150 % of the valuation of methane’s global climate impacts using the SCC after extrapolating from carbon dioxide to methane using global warming potential estimates. Results for monetized benefits are sensitive to a number of factors, particularly the choice of elasticity to income growth used when calculating the value of a statistical life. The benefits increase for emission years further in the future. Regionally, most of the global mortality benefits accrue in Asia, but 10 % accrue in the United States. As a result, this methodology can be used to assess the benefits of methane emission reductions anywhere in the world, including those achieved by national and multinational policies.« less

  4. Valuing the ozone-related health benefits of methane emission controls

    SciTech Connect (OSTI)

    Sarofim, Marcus C.; Waldhoff, Stephanie T.; Anenberg, Susan C.

    2015-06-29

    Methane is a greenhouse gas that oxidizes to form ground-level ozone, itself a greenhouse gas and a health-harmful air pollutant. Reducing methane emissions will both slow anthropogenic climate change and reduce ozone-related mortality. We estimate the benefits of reducing methane emissions anywhere in the world for ozone-related premature mortality globally and for eight geographic regions. Our methods are consistent with those used by the US Government to estimate the social cost of carbon (SCC). We find that the global short- and long-term premature mortality benefits due to reduced ozone production from methane mitigation are (2011) $790 and $1775 per tonne methane, respectively. These correspond to approximately 70 and 150 % of the valuation of methane’s global climate impacts using the SCC after extrapolating from carbon dioxide to methane using global warming potential estimates. Results for monetized benefits are sensitive to a number of factors, particularly the choice of elasticity to income growth used when calculating the value of a statistical life. The benefits increase for emission years further in the future. Regionally, most of the global mortality benefits accrue in Asia, but 10 % accrue in the United States. As a result, this methodology can be used to assess the benefits of methane emission reductions anywhere in the world, including those achieved by national and multinational policies.

  5. Ozone in the free atmosphere

    SciTech Connect (OSTI)

    Whitten, R.C.; Prasad, S.S.

    1985-01-01

    Experts in the field discuss the state of the ozone layer - its elements, distribution, functions, and biological and climatic effects of perturbations.

  6. Stratospheric ozone protection: The Montreal Protocol and Title VI of the Clean Air Act Amendments of 1990

    SciTech Connect (OSTI)

    Babst, C.R. III

    1993-08-01

    The stratospheric ozone layer protects the surface of the Earth from harmful ultraviolet (UV-B) radiation, which has been causally linked to skin cancer and cataracts, suppression of the human immune system, damage to crops and aquatic organisms, the formation of ground-level zone and the rapid weathering of outdoor plastics. In recent years, scientists have observed a significant deterioration of the ozone layer, particularly over the poles, but increasingly over populated regions as well. This deterioration has been attributed to the atmospheric release of certain man-made halocarbons, including chlorofluorocarbons (CFCs), halons, methyl chloroform and carbon tetrachloride. Once used extensively as propellants for aerosol sprays (but generally banned for such purposes since 1978), CFCs are widely used today as refrigerants, foams and solvents. All of these chlorinated (CFC, methyl chloroform and carbon tetrachloride) and brominated (halon) compounds are classified for regulatory purposes as Class I substances because of their significant ozone-depleting potential. Hydrochlorofluorocarbons (HCFCs), developed as alternatives to CFCs and halons for many different applications, have been classified for regulatory purposes as Class II substances because of their relatively less destructive impact on stratospheric ozone. This paper describes the following regulations to reduce destruction of the ozone layer: the Montreal Protocol; Title VI of the Clean air Act Amendments of 1990; Accelerated Phase-out schedules developed by the countries which signed the Montreal Protocol; Use restrictions; Recycling and Emission reduction requirements; Servicing of motor vehicle air conditions; ban on nonessential products; labeling requirements; safe alternatives. 6 refs.

  7. Nonaqueous ozonation of vulcanized rubber

    DOE Patents [OSTI]

    Serkiz, Steven M.

    1999-01-01

    A process and resulting product is provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  8. Promising Technology: Ozone Laundry System for Multiload Clothes Washers

    Broader source: Energy.gov [DOE]

    These laundry systems use ozone as the chemical cleaning agent. The system generates ozone by electrifying oxygen in the air, and then dissolves the ozone in water.

  9. Impacts from a fossil fuel power plant on ozone levels in Memphis, Tennessee

    SciTech Connect (OSTI)

    Mueller, S.F.; Bailey, E.M.

    1998-12-31

    The Tennessee Valley Authority (TVA) Allen power plant is located on the Mississippi River in the southwest corner of Memphis, Tennessee. Allen has three coal-fired cyclone boilers with a rated capacity of 272 MW each. It is a Phase 2 plant under Title IV of the Clean Air Act and is the largest single source of NO{sub x} in the Memphis area. TVA plans to reduce Allen NOx emissions through a combination of burning low-sulfur coal (which has the benefit of reducing NO{sub x} emissions while also reducing SO{sub 2} emissions) and installing gas re-burn technology. A modeling study using the SAI, Inc., UAM-V photochemical model was conducted to examine the potential impacts of NO{sub x} reductions on ozone levels in the Memphis area. A series of four model simulations were made in which different Allen emissions scenarios were examined. The focus period of the photochemical modeling was 11--14 July 1995 when measurements in and near Memphis indicated peak hourly ozone levels of 135--140 ppb. This analysis primarily examined computed impacts within 50 km of Memphis. Allen was computed to contribute as much as 20--30 ppb to ground ozone levels 20-50 km downwind using its NO{sub x} emission rate before Title IV compliance. After compliance it was computed to contribute only about 10--20 ppb. At the same time, maximum daily ozone reductions due to Allen NO{sub x} titration of ozone were between 30 and 60 ppb. These benefits will be reduced by 30--50% after Title IV compliance, and are expected to occur within 30 km of the plant. More model grid cells indicated dis-benefits (net ground-level ozone increases) than benefits on three of the four episode days using the Title IV compliance emission rate. Significant ozone dis-benefits were expected because of the well-documented NO titration of ozone within plumes having a high ratio of NO to volatile organic compounds.

  10. ARM - Measurement - Ozone Column Abundance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Column Abundance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Ozone Column Abundance The vertically integrated amount of ozone (commonly measured in Dobson Unit, 1 DU = 134 mmol/m^2) Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  11. Sensitivity analysis of ozone formation and transport for a Central California air pollution episode

    SciTech Connect (OSTI)

    Jin, Ling; Tonse, Shaheen; Cohan, Daniel S.; Mao, Xiaoling; Harley, Robert A.; Brown, Nancy J.

    2009-05-15

    CMAQ-HDDM is used to determine spatial and temporal variations in ozone limiting reagents and local vs upwind source contributions for an air pollution episode in Central California. We developed a first- and second- order sensitivity analysis approach with the Decoupled Direct Method to examine spatial and temporal variations of ozone-limiting reagents and the importance of local vs upwind emission sources in the San Joaquin Valley of central California for a five-day ozone episode (29th July-3rd Aug, 2000). Despite considerable spatial variations, nitrogen oxides (NO{sub x}) emission reductions are overall more effective than volatile organic compound (VOC) control for attaining the 8-hr ozone standard in this region for this episode, in contrast to the VOC control that works better for attaining the prior 1-hr ozone standard. Inter-basin source contributions of NO{sub x} emissions are limited to the northern part of the SJV, while anthropogenic VOC (AVOC) emissions, especially those emitted at night, influence ozone formation in the SJV further downwind. Among model input parameters studied here, uncertainties in emissions of NO{sub x} and AVOC, and the rate coefficient of the OH + NO{sub 2} termination reaction, have the greatest effect on first-order ozone responses to changes in NO{sub x} emissions. Uncertainties in biogenic VOC emissions only have a modest effect because they are generally not collocated with anthropogenic sources in this region.

  12. Relation between Atmospheric Ozone and Geomagnetic Disturbances...

    Office of Scientific and Technical Information (OSTI)

    This involves a decrease of ozone in the 50 to 65 deg N region and an increase south of 50 deg N. Two or three days after the storm, the ozone amount increases in the 50 to 65 deg ...

  13. Ozone Reductions Using Residential Building Envelopes

    SciTech Connect (OSTI)

    Walker, Iain S.; Sherman, Max; Nazaroff, William W.

    2009-02-01

    Ozone is an air pollutant with that can have significant health effects and a significant source of ozone in some regions of California is outdoor air. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone could lead to improved health for many California residents. Ozone is removed from indoor air by surface reactions and can also be filtered by building envelopes. The magnitude of the envelope impact depends on the specific building materials that the air flows over and the geometry of the air flow paths through the envelope that can be changes by mechanical ventilation operation. The 2008 Residential Building Standards in California include minimum requirements for mechanical ventilation by referencing ASHRAE Standard 62.2. This study examines the changes in indoor ozone depending on the mechanical ventilation system selected to meet these requirements. This study used detailed simulations of ventilation in a house to examine the impacts of different ventilation systems on indoor ozone concentrations. The simulation results showed that staying indoors reduces exposure to ozone by 80percent to 90percent, that exhaust ventilation systems lead to lower indoor ozone concentrations, that opening of windows should be avoided at times of high outdoor ozone, and that changing the time at which mechanical ventilation occurs has the ability to halve exposure to ozone. Future work should focus on the products of ozone reactions in the building envelope and the fate of these products with respect to indoor exposures.

  14. Discharge cell for ozone generator

    DOE Patents [OSTI]

    Nakatsuka, Suguru

    2000-01-01

    A discharge cell for use in an ozone generator is provided which can suppress a time-related reduction in ozone concentration without adding a catalytic gas such as nitrogen gas to oxygen gas as a raw material gas. The discharge cell includes a pair of electrodes disposed in an opposed spaced relation with a discharge space therebetween, and a dielectric layer of a three-layer structure consisting of three ceramic dielectric layers successively stacked on at least one of the electrodes, wherein a first dielectric layer of the dielectric layer contacting the one electrode contains no titanium dioxide, wherein a second dielectric layer of the dielectric layer exposed to the discharge space contains titanium dioxide in a metal element ratio of not lower than 10 wt %.

  15. Mario Molina, Chlorofluorocarbons (CFCs), and Ozone Depletion

    Office of Scientific and Technical Information (OSTI)

    Prize-winning Research, Massachusetts Institute of Technology (MIT) The Science and Policies of the Ozone Layer -- A Historical Perspective, IDEaS - Nobel Laureate Mario J....

  16. Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Ozone Formation as a Function of NOx Reductions Summary and Implications for Air Quality Impacts The Weekend Ozone Effect - The Weekly Ambient Emissions Control Experiment

  17. Ozone contactor hydraulic considerations in meeting CT disinfection...

    Office of Scientific and Technical Information (OSTI)

    Optimization of ozone dose and contact time for CT calculations was performed in the pilot ... Resource Relation: Journal Name: Ozone: Science and Engineering (The Journal of the ...

  18. Reformulated Gasoline Use Under the 8-Hour Ozone Rule

    Reports and Publications (EIA)

    2002-01-01

    This paper focuses on the impact on gasoline price and supply when additional ozone non-attainment areas come under the new 8-hour ozone standard.

  19. Reactivity of Ozone with Solid Potassium Iodide Investigated...

    Office of Scientific and Technical Information (OSTI)

    Reactivity of Ozone with Solid Potassium Iodide Investigated by Atomic Force Microscopy Citation Details In-Document Search Title: Reactivity of Ozone with Solid Potassium...

  20. Effect of Ventilation Strategies on Residential Ozone Levels...

    Office of Scientific and Technical Information (OSTI)

    Effect of Ventilation Strategies on Residential Ozone Levels Citation Details In-Document Search Title: Effect of Ventilation Strategies on Residential Ozone Levels You are...

  1. Effect of Ventilation Strategies on Residential Ozone Levels...

    Office of Scientific and Technical Information (OSTI)

    Effect of Ventilation Strategies on Residential Ozone Levels Citation Details In-Document Search Title: Effect of Ventilation Strategies on Residential Ozone Levels Authors:...

  2. Study of air pollution: Effects of ozone on neuropeptide-mediated responses in human subjects. Final report

    SciTech Connect (OSTI)

    Boushey, H.A.

    1991-11-01

    The study examined the hypothesis that ozone inactivates the enzyme, neutral endopeptidase, responsible for limiting the effects of neuropeptides released from afferent nerve endings. Cough response of capsaicin solution delivered from a nebulizer at 2 min. intervals until two or more coughs were produced. Other endpoints measured included irritative symptoms as rated by the subjects on a nonparametric scale, spirometry, of each concentration of ozone were compared to those of filtered air in a single-blind randomized sequence. The results indicate that a 2 h. exposure to 0.4 ppm of ozone with intermittent light exercise alters the sensitivity of airway nerves that mediate the cough response to inhaled materials. This dose of ozone also caused a change in FEV1. A lower level of ozone, 0.02 ppm, caused a change in neither cough threshold nor FEV1, even when the duration of exposure was extended to three hours. The findings are consistent with the author's hypothesis that ozone may sensitize nerve endings in the airways by inactivating neutral endopeptidase, an enzyme that regulates their activity, but they do not demonstrate that directly examining an effect directly mediated by airway nerves allows detection of effects of ozone at doses below those causing effects detected by standard tests of pulmonary function.

  3. The Weekend Ozone Effect - The Weekly Ambient Emissions Control Experiment

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    | Department of Energy The Weekend Ozone Effect - The Weekly Ambient Emissions Control Experiment The Weekend Ozone Effect - The Weekly Ambient Emissions Control Experiment 2003 DEER Conference Presentation: National Renewable Energy Laboratory 2003_deer_lawson.pdf (335.4 KB) More Documents & Publications Weekend/Weekday Ozone Study in the South Coast Air Basin DOE's Studies of Weekday/Weekend Ozone Pollution in Southern California Real-World Studies of Ambient Ozone Formation as a

  4. Review of atmospheric ozone and current thinking on the Antarctic ozone hole. Master's thesis

    SciTech Connect (OSTI)

    Fix, R.A.

    1987-01-01

    A general review of the formation, global distribution and concentration variations on different temporal scales of atmospheric ozone is presented. The nature and extent of the recently discovered Antarctic ozone hole is discussed, and summaries of the various theories that have been advanced to account for this phenomenon are reviewed.

  5. DOE's Studies of Weekday/Weekend Ozone Pollution in Southern...

    Broader source: Energy.gov (indexed) [DOE]

    Ozone Formation as a Function of NOx Reductions Summary and Implications for Air Quality Impacts Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S.

  6. The Weekend Ozone Effect - The Weekly Ambient Emissions Control...

    Broader source: Energy.gov (indexed) [DOE]

    More Documents & Publications WeekendWeekday Ozone Study in the South Coast Air Basin DOE's Studies of WeekdayWeekend Ozone Pollution in Southern California Real-World Studies of ...

  7. Iron Catalysis in Oxidations by Ozone - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Find More Like This Return to Search Iron Catalysis in Oxidations by Ozone Ames Laboratory Contact AMES About This Technology Technology Marketing Summary Ozone is used commercially for treatment of potable and non-potable water, and as an industrial oxidant. ISU and Ames Laboratory researchers have developed a method for using iron in ozone oxidation that significantly improves the speed of oxidation reactions. Description Ozone is recognized as potent and effective oxidizing agent, and has a

  8. Dose Limits

    Office of Energy Efficiency and Renewable Energy (EERE)

    Dose Limits ERAD (Question Posted to ERAD in May 2012) Who do you define as a member of the public for the onsite MEI? This question implies that there may be more than one maximally exposed individual (MEI), one on-site and one off-site, when demonstrating compliance with the Public Dose Limit of DOE Order 458.1. Although all potential MEIs should be considered and documented, as well as the calculated doses and pathways considered, the intent of DOE Order 458.1 is in fact to ultimately identify only one MEI, a theoretical individual who could be either on-site or off-site.

  9. Ozone Removal by Filters Containing Activated Carbon: A Pilot...

    Office of Scientific and Technical Information (OSTI)

    in a commercial building heating, ventilating, and air conditioning (HVAC) system. ... measurements of ozone concentrations in the air upstream and downstream of the filters. ...

  10. Ozone depletion, developing countries, and human rights: Seeking better ground on which to fight for protection of the ozone layer

    SciTech Connect (OSTI)

    Williams, V.

    1995-12-31

    I urge you not to take a complacent view of the situation. The state of depletion of the ozone layer continues to be alarming... In February, 1993, the ozone levels over North America and most of Europe were 20 percent below normal... Even now, millions of tons of CFC [chlorofluorocarbon] products are en route to their fatal stratospheric rendezvous... This exponential increase calls for increased reflection on the state of the ozone layer and calls for bold decisions.

  11. Exposure-Relevant Ozone Chemistry in Occupied Spaces

    SciTech Connect (OSTI)

    Coleman, Beverly Kaye

    2009-04-01

    Ozone, an ambient pollutant, is transformed into other airborne pollutants in the indoor environment. In this dissertation, the type and amount of byproducts that result from ozone reactions with common indoor surfaces, surface residues, and vapors were determined, pollutant concentrations were related to occupant exposure, and frameworks were developed to predict byproduct concentrations under various indoor conditions. In Chapter 2, an analysis is presented of secondary organic aerosol formation from the reaction of ozone with gas-phase, terpene-containing consumer products in small chamber experiments under conditions relevant for residential and commercial buildings. The full particle size distribution was continuously monitored, and ultrafine and fine particle concentrations were in the range of 10 to>300 mu g m-3. Particle nucleation and growth dynamics were characterized.Chapter 3 presents an investigation of ozone reactions with aircraft cabin surfaces including carpet, seat fabric, plastics, and laundered and worn clothing fabric. Small chamber experiments were used to determine ozone deposition velocities, ozone reaction probabilities, byproduct emission rates, and byproduct yields for each surface category. The most commonly detected byproducts included C1?C10 saturated aldehydes and skin oil oxidation products. For all materials, emission rates were higher with ozone than without. Experimental results were used to predict byproduct exposure in the cabin and compare to other environments. Byproduct levels are predicted to be similar to ozone levels in the cabin, which have been found to be tens to low hundreds of ppb in the absence of an ozone converter. In Chapter 4, a model is presented that predicts ozone uptake by and byproduct emission from residual chemicals on surfaces. The effects of input parameters (residue surface concentration, ozone concentration, reactivity of the residue and the surface, near-surface airflow conditions, and byproduct yield

  12. Experimental investigation of factors limiting slow axis beam quality in 9xx nm high power broad area diode lasers

    SciTech Connect (OSTI)

    Winterfeldt, M. Crump, P.; Wenzel, H.; Erbert, G.; Trnkle, G.

    2014-08-14

    GaAs-based broad-area diode lasers are needed with improved lateral beam parameter product (BPP{sub lat}) at high power. An experimental study of the factors limiting BPP{sub lat} is therefore presented, using extreme double-asymmetric (EDAS) vertical structures emitting at 910?nm. Continuous wave, pulsed and polarization-resolved measurements are presented and compared to thermal simulation. The importance of thermal and packaging-induced effects is determined by comparing junction -up and -down devices. Process factors are clarified by comparing diodes with and without index-guiding trenches. We show that in all cases studied, BPP{sub lat} is limited by a non-thermal BPP ground-level and a thermal BPP, which depends linearly on self-heating. Measurements as a function of pulse width confirm that self-heating rather than bias-level dominates. Diodes without trenches show low BPP ground-level, and a thermal BPP which depends strongly on mounting, due to changes in the temperature profile. The additional lateral guiding in diodes with trenches strongly increases the BPP ground-level, but optically isolates the stripe from the device edges, suppressing the influence of the thermal profile, leading to a BPP-slope that is low and independent of mounting. Trenches are also shown to initiate strain fields that cause parasitic TM-polarized emission with large BPP{sub lat}, whose influence on total BPP{sub lat} remains small, provided the overall polarization purity is >95%.

  13. Process-scale modeling of elevated wintertime ozone in Wyoming.

    SciTech Connect (OSTI)

    Kotamarthi, V. R.; Holdridge, D. J.; Environmental Science Division

    2007-12-31

    Measurements of meteorological variables and trace gas concentrations, provided by the Wyoming Department of Environmental Quality for Daniel, Jonah, and Boulder Counties in the state of Wyoming, were analyzed for this project. The data indicate that highest ozone concentrations were observed at temperatures of -10 C to 0 C, at low wind speeds of about 5 mph. The median values for nitrogen oxides (NOx) during these episodes ranged between 10 ppbv and 20 ppbv (parts per billion by volume). Measurements of volatile organic compounds (VOCs) during these periods were insufficient for quantitative analysis. The few available VOCs measurements indicated unusually high levels of alkanes and aromatics and low levels of alkenes. In addition, the column ozone concentration during one of the high-ozone episodes was low, on the order of 250 DU (Dobson unit) as compared to a normal column ozone concentration of approximately 300-325 DU during spring for this region. Analysis of this observation was outside the scope of this project. The data analysis reported here was used to establish criteria for making a large number of sensitivity calculations through use of a box photochemical model. Two different VOCs lumping schemes, RACM and SAPRC-98, were used for the calculations. Calculations based on this data analysis indicated that the ozone mixing ratios are sensitive to (a) surface albedo, (b) column ozone, (c) NOx mixing ratios, and (d) available terminal olefins. The RACM model showed a large response to an increase in lumped species containing propane that was not reproduced by the SAPRC scheme, which models propane as a nearly independent species. The rest of the VOCs produced similar changes in ozone in both schemes. In general, if one assumes that measured VOCs are fairly representative of the conditions at these locations, sufficient precursors might be available to produce ozone in the range of 60-80 ppbv under the conditions modeled.

  14. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    SciTech Connect (OSTI)

    Ketusky, E.; Subramanian, K.

    2012-02-29

    At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration) after nearing

  15. Projections of Future Summertime Ozone over the U.S.

    SciTech Connect (OSTI)

    Pfister, G. G.; Walters, Stacy; Lamarque, J. F.; Fast, Jerome D.; Barth, Mary; Wong, John; Done, James; Holland, Greg; Bruyere, Cindy

    2014-05-05

    This study uses a regional fully coupled chemistry-transport model to assess changes in surface ozone over the summertime U.S. between present and a 2050 future time period at high spatial resolution (12 km grid spacing) under the SRES A2 climate and RCP8.5 anthropogenic pre-cursor emission scenario. The impact of predicted changes in climate and global background ozone is estimated to increase surface ozone over most of the U.S; the 5th - 95th percentile range for daily 8-hour maximum surface ozone increases from 31-79 ppbV to 30-87 ppbV between the present and future time periods. The analysis of a set of meteorological drivers suggests that these mostly will add to increasing ozone, but the set of simulations conducted does not allow to separate this effect from that through enhanced global background ozone. Statistically the most robust positive feedbacks are through increased temperature, biogenic emissions and solar radiation. Stringent emission controls can counteract these feedbacks and if considered, we estimate large reductions in surface ozone with the 5th-95th percentile reduced to 27-55 ppbV. A comparison of the high-resolution projections to global model projections shows that even though the global model is biased high in surface ozone compared to the regional model and compared to observations, both the global and the regional model predict similar changes in ozone between the present and future time periods. However, on smaller spatial scales, the regional predictions show more pronounced changes between urban and rural regimes that cannot be resolved at the coarse resolution of global model. In addition, the sign of the changes in overall ozone mixing ratios can be different between the global and the regional predictions in certain regions, such as the Western U.S. This study confirms the key role of emission control strategies in future air quality predictions and demonstrates the need for considering degradation of air quality with future

  16. Morphological basis of tolerance to ozone

    SciTech Connect (OSTI)

    Evans, M.J.; Dekker, N.P.; Cabral-Anderson, L.J.; Shami, S.G.

    1985-06-01

    The purpose of this research was to study Type 1 epithelial cells in the ozone (O/sub 3/)-tolerant lung epithelium. Rats were made tolerant by exposure to 0.5 ppm O/sub 3/ for 2 days and allowed to recover in air. Reexposure to a lethal concentration of O/sub 3/ (6 ppm) at 3, 7, and 15 days of recovery revealed that tolerance was present at 3 days but almost absent at 7 and 15 days of recovery. Using Type 2 cell proliferation as a means of quantitating Type 1 cell injury, it was observed that when the preexposed rats were reexposed to 0.5 ppm at 3, 7, and 15 days, very little Type 1 cell injury occurred at 3 days. However, at 7 and 15 days the amount of Type 1 cell injury was the same as that associated with the original exposure. To determine whether there was any change in the alveolar epithelial cell populations between the periods of tolerance (3 days) and its decline (7 and 15 days), the percentage of tritiated thymidine (( /sup 3/H)TdR-labeled Type 1 and 2 cells at these times were determined. There was a significant decrease in (/sup 3/H)TdR-labeled Type 1 and 2 cells between the third and fifteenth days of recovery as excess cells were sloughed off and the tissue returned to normal. Using electron microscopic morphometry, Type 1 and 2 cells were then studied during the decline of tolerance. No change was found in the morphology of Type 2 cells; however, the morphology of Type 1 cells revealed a 58% decrease in surface area and a 25% increase in the arithmetic mean thickness when tolerance was present at 3 days. As tolerance declined (7 and 15 days), Type 1 cell morphology returned to normal. It was concluded that tolerance exists when the surface area of a cell exposed to a particular concentration of ozone is small enough so that the existing antioxidant mechanism contained within that cell volume can protect it from damage.

  17. Abiotic ozone and oxygen in atmospheres similar to prebiotic Earth

    SciTech Connect (OSTI)

    Domagal-Goldman, Shawn D.; Segura, Antígona; Claire, Mark W.; Robinson, Tyler D.; Meadows, Victoria S.

    2014-09-10

    The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely detectable potential biosignature is considered to be the detection of oxygen (O{sub 2}) or ozone (O{sub 3}) simultaneous to methane (CH{sub 4}) at levels indicating fluxes from the planetary surface in excess of those that could be produced abiotically. Here we use an altitude-dependent photochemical model with the enhanced lower boundary conditions necessary to carefully explore abiotic O{sub 2} and O{sub 3} production on lifeless planets with a wide variety of volcanic gas fluxes and stellar energy distributions. On some of these worlds, we predict limited O{sub 2} and O{sub 3} buildup, caused by fast chemical production of these gases. This results in detectable abiotic O{sub 3} and CH{sub 4} features in the UV-visible, but no detectable abiotic O{sub 2} features. Thus, simultaneous detection of O{sub 3} and CH{sub 4} by a UV-visible mission is not a strong biosignature without proper contextual information. Discrimination between biological and abiotic sources of O{sub 2} and O{sub 3} is possible through analysis of the stellar and atmospheric context—particularly redox state and O atom inventory—of the planet in question. Specifically, understanding the spectral characteristics of the star and obtaining a broad wavelength range for planetary spectra should allow more robust identification of false positives for life. This highlights the importance of wide spectral coverage for future exoplanet characterization missions. Specifically, discrimination between true and false positives may require spectral observations that extend into infrared wavelengths and provide contextual information on the planet's atmospheric chemistry.

  18. Controlling superconductivity in La2-xSrxCuO4+δ by ozone and...

    Office of Scientific and Technical Information (OSTI)

    Controlling superconductivity in La2-xSrxCuO4+ by ozone and vacuum annealing Citation Details In-Document Search Title: Controlling superconductivity in La2-xSrxCuO4+ by ozone ...

  19. Real-World Studies of Ambient Ozone Formation as a Function of...

    Broader source: Energy.gov (indexed) [DOE]

    More Documents & Publications Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S. DOE's Studies of WeekdayWeekend Ozone Pollution in Southern California ...

  20. Weekend/Weekday Ozone Study in the South Coast Air Basin | Department...

    Broader source: Energy.gov (indexed) [DOE]

    Emissions Control Experiment Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S. DOE's Studies of WeekdayWeekend Ozone Pollution in Southern California

  1. Effect of ozonation on the composition of crude coal-tar benzene

    SciTech Connect (OSTI)

    Semenova, S.A.; Patrakov, Y.F.

    2007-05-15

    The effect of ozonation on the composition of crude benzene produced by the coal-tar chemical industry was studied.

  2. DOE's Studies of Weekday/Weekend Ozone Pollution in Southern California |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Studies of Weekday/Weekend Ozone Pollution in Southern California DOE's Studies of Weekday/Weekend Ozone Pollution in Southern California 2002 DEER Conference Presentation: National Renewable Energy Laboratory 2002_deer_lawson.pdf (393.04 KB) More Documents & Publications The Weekend Ozone Effect - The Weekly Ambient Emissions Control Experiment Real-World Studies of Ambient Ozone Formation as a Function of NOx Reductions … Summary and Implications for Air Quality

  3. Report card on low level ozone in urban areas

    SciTech Connect (OSTI)

    Onischak, M.

    1994-12-31

    It has been four years since the Clean Air Act was amended in November of 1990. Much work has been done in this time, and the country is beginning to see real air quality benefits. Although these changes have not completely licked the urban ozone problem yet, they have made a lot of progress. All of the urban areas which have been required to reduce their ozone levels have done a good job of lowering their emissions. While the urban areas have not all been able to meet every federal deadline, the areas have all been able to achieve the control milestones before the mandatory Clean Air Act sanctions have taken effect. Some areas are even ready to declare their ozone problems solved.

  4. P ORNiiTM-7004 Results of Ground Level Radiation

    Office of Legacy Management (LM)

    from a program initiated in 1974 by the Atomic Energy CoNnissiOn (AEC) for ... GAMMA-RAY EXPOSURE RATES (pRhr.) Fig. 5. On-site locations and mean external exposure ...

  5. Impact of heterogeneous chemistry on model predictions of ozone changes

    SciTech Connect (OSTI)

    Granier, C.; Brasseur, G. )

    1992-11-20

    A two-dimensional chemical/transport model of the middle atmosphere is used to assess the importance of chemical heterogeneous processes in the polar regions (on polar stratospheric clouds (PSCs)) and at other latitudes (on sulfate aerosols). When conversion on type I and type II PSCs of N[sub 2]O[sub 5] into HNO[sub 3] and of CIONO[sub 2] into reactive forms of chlorine is taken into account, enhanced CIO concentrations lead to the formation of a springtime ozone hole over the Antarctic continent; no such major reduction in the ozone column is found in the Arctic region. When conversion of nitrogen and chlorine compounds is assumed to occur on sulfate particles in the lower stratosphere, significant perturbations in the chemistry are also found. For background aerosol conditions, the concentration of nitric acid is enhanced and agrees with observed values, while that of nitrogen oxides is reduced and agrees less than if heterogeneous processes are ignored in the calculations. The concentration of the OH radical is significantly increased. Ozone number density appears to become larger between 16 and 30 km but smaller below 16 km, especially at high latitudes. The ozone column is only slightly modified, except at high latitudes where it is substantially reduced if the CIONO[sub 2] conversion into reactive chlorine is considered. After a large volcanic eruption these changes are further exacerbated. The ozone budget in the lower stratrosphere becomes less affected by nitrogen oxides but is largely controlled by the CIO[sub x] and HO[sub x] chemistries. A substantial decrease in the ozone column is predicted as a result of the Pinatubo volcanic eruption, mostly in winter at middle and high latitudes. 62 refs., 18 figs., 3 tabs.

  6. Volatile organic compound emissions from usaf wastewater treatment plants in ozone nonattainment areas. Master's thesis

    SciTech Connect (OSTI)

    Ouellette, B.A.

    1994-09-01

    In accordance with the 1990 Clean Air Act Amendments (CAAA), this research conducts an evaluation of the potential emission of volatile organic compounds (VOCs) from selected Air Force wastewater treatment plants. Using a conservative mass balance analysis and process specific simulation models, volatile organic emission estimates are calculated for four individual facilities--Edwards AFB, Luke AFB, McGuire AFB, and McClellan AFB--which represent a cross section of the current inventory of USAF wastewater plants in ozone nonattainment areas. From these calculations, maximum facility emissions are determined which represent the upper limit for the potential VOC emissions from these wastewater plants. Based on the calculated emission estimates, each selected wastewater facility is evaluated as a potential major stationary source of volatile organic emissions under both Title I of the 1990 CAAA and the plant's governing Clean Air Act state implementation plan. Next, the potential impact of the specific volatile organics being emitted is discussed in terms of their relative reactivity and individual contribution to tropospheric ozone formation. Finally, a relative comparison is made between the estimated VOC emissions for the selected wastewater facilities and the total VOC emissions for their respective host installations.

  7. ARM - Field Campaign - 1999 Northeast Corridor Ozone & Particulate Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    9 Northeast Corridor Ozone & Particulate Study ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 1999 Northeast Corridor Ozone & Particulate Study 1999.07.23 - 1999.08.11 Lead Scientist : Larry Kleinman For data sets, see below. Abstract As part of the 1999 NARSTO Northeast Corridor Oxidant and Particulate Study (NEC-OPS) field campaign, the DOE G-1 aircraft sampled trace gases and aerosols in and

  8. Update of national ozone study: Where are we now?

    SciTech Connect (OSTI)

    Mathur, B.

    1996-12-31

    This paper is one of three keynote presentations given at the conference. It addresses the issue of national ozone research in focusing on the regional task force, Ozone Transport Assessment Group (OTAG). The overall objectives of the OTAG initiatives are reported. These include development of a comprehensive regional emissions inventory, selection of research models and protocols, identification of criteria for selecting emissions control strategies, and development of a framework for a NO{sub x} trading system. Findings from preliminary modeling runs and analyses are presented. 15 figs., 15 tabs.

  9. Ozone induces glucose intolerance and systemic metabolic effects in young and aged brown Norway rats

    SciTech Connect (OSTI)

    Bass, V.; Gordon, C.J.; Jarema, K.A.; MacPhail, R.C.; Cascio, W.E.; Phillips, P.M.; Ledbetter, A.D.; Schladweiler, M.C.; Andrews, D.; Miller, D.; Doerfler, D.L.; Kodavanti, U.P.

    2013-12-15

    Air pollutants have been associated with increased diabetes in humans. We hypothesized that ozone would impair glucose homeostasis by altering insulin signaling and/or endoplasmic reticular (ER) stress in young and aged rats. One, 4, 12, and 24 month old Brown Norway (BN) rats were exposed to air or ozone, 0.25 or 1.0 ppm, 6 h/day for 2 days (acute) or 2 d/week for 13 weeks (subchronic). Additionally, 4 month old rats were exposed to air or 1.0 ppm ozone, 6 h/day for 1 or 2 days (time-course). Glucose tolerance tests (GTT) were performed immediately after exposure. Serum and tissue biomarkers were analyzed 18 h after final ozone for acute and subchronic studies, and immediately after each day of exposure in the time-course study. Age-related glucose intolerance and increases in metabolic biomarkers were apparent at baseline. Acute ozone caused hyperglycemia and glucose intolerance in rats of all ages. Ozone-induced glucose intolerance was reduced in rats exposed for 13 weeks. Acute, but not subchronic ozone increased ?{sub 2}-macroglobulin, adiponectin and osteopontin. Time-course analysis indicated glucose intolerance at days 1 and 2 (2 > 1), and a recovery 18 h post ozone. Leptin increased day 1 and epinephrine at all times after ozone. Ozone tended to decrease phosphorylated insulin receptor substrate-1 in liver and adipose tissues. ER stress appeared to be the consequence of ozone induced acute metabolic impairment since transcriptional markers of ER stress increased only after 2 days of ozone. In conclusion, acute ozone exposure induces marked systemic metabolic impairments in BN rats of all ages, likely through sympathetic stimulation. - Highlights: Air pollutants have been associated with increased diabetes in humans. Acute ozone exposure produces profound metabolic alterations in rats. Age influences metabolic risk factors in aging BN rats. Acute metabolic effects are reversible and repeated exposure reduces these effects. Ozone metabolic effects

  10. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    SciTech Connect (OSTI)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  11. Meeting the New Ozone Standard: Challenges and Opportunities

    Office of Energy Efficiency and Renewable Energy (EERE)

    This presentation by Anna Garcia, executive director of the Ozone Transport Commission, was part of the July 2008 Webcast sponsored by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Weatherization and Intergovernmental Program Clean Energy and Air Quality Integration Initiative that was titled Role of Energy Efficiency and Renewable Energy in Improving Air Quality and Addressing Greenhouse Gas Reduction Goals on High Electric Demand Days.

  12. Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S.

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    | Department of Energy Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S. Weekday and Weekend Air Pollutant Levels in Ozone Problem Areas in the U.S. 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_lawson.pdf (221.69 KB) More Documents & Publications Weekend/Weekday Ozone Study in the South Coast Air Basin Real-World Studies of Ambient Ozone Formation as a Function of NOx Reductions … Summary and Implications for Air

  13. Controlling superconductivity in La2-xSrxCuO4+δ by ozone and...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Controlling superconductivity in La2-xSrxCuO4+ by ozone and vacuum annealing Citation Details In-Document Search Title: Controlling superconductivity in ...

  14. Age-dependent inhibition of pentobarbital sleeping time by ozone in mice and rats

    SciTech Connect (OSTI)

    Canada, A.T.; Calabrese, E.J.; Leonard, D.

    1986-09-01

    The effect of age on the metabolism of pentobarbital in mice and rats was investigated following exposure to 0.3 ppm of ozone for 3.75 hr. Young animals were 2.5 months of age and the mature were 18 months. The pentobarbital sleeping time was significantly prolonged following the ozone exposure in both the mice and rats when compared with an air control. No ozone effect on sleeping time was found in the young animals. The results indicate that there may be an age-related sensitivity to the occurrence of ozone-related inhibition of pentobarbital metabolism.

  15. Climatology of regional ozone: Meteorologieal effects on ozone exceedences in the southeast United States. Master`s thesis

    SciTech Connect (OSTI)

    O`Connor, J.R.

    1996-12-09

    A statistical anlysis of ozone (O3) concentrations and meterorogical parameters was performed to determine the effect of meteorological changes on ambient O3 concentrations in the urban and semi-urban environment on a regional basis in the Southeast United States. The correlation between average daily maximum O3 concentration and various meteorological varibles was analyzed on a monthly basis from April through October 1980-1994. Positive correlation was found between O3 concentration and temperature and dewpoint temperature depression, while negative correlation was found between O3 concentration and relative humidity and the minimum Pasquill Stability Index. The correlations were strongest during the summer months, particularly June, July, and August. High pressure stagnation was found to be positively correlated with O3 concentrations, although not at a statistically significant level. Regional analysis indicates that the location of areas of high pressure stagnation may play an important role in the resultant ambient concentrations of O3 throughout the region. Analysis of long term O3 concentration trends indicates increasing trends during the 1980s and decreasing trends during the 1990s. Trends for meteorological parameters that demonstrate positive (negative) correlation with O3 increase (decrease) during the 1980s, however causal relationship between these trends and those for O3 cannot be determined based on this analysis. A regional model was developed to forecast ozone concentration based on the previous day`s ozone concentration and meteorological parameters.

  16. Limited Test Ban Treaty

    National Nuclear Security Administration (NNSA)

    Detection System (USNDS), which monitors compliance with the international Limited Test Ban Treaty (LTBT). The LTBT, signed by 108 countries, prohibits nuclear testing in the...

  17. Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

    SciTech Connect (OSTI)

    Kim, Saewung; Kim, So-Young; Lee, Meehye; Shim, Heeyoun; Wolfe, Glenn; Guenther, Alex B.; He, Amy; Hong, Youdeog; Han, Jinseok

    2014-01-01

    Rapid urbanization and economic development in East Asia in past decades has led to photochemical air pollution problems such as excess photochemical ozone and aerosol formation. Asian megacities such as Seoul, Tokyo, Shanghai, Gangzhou, and Beijing are surrounded by densely forested areas and recent research has consistently demonstrated the importance of biogenic volatile organic compounds from vegetation in determining oxidation capacity in the suburban Asian megacity regions. Uncertainties in constraining tropospheric oxidation capacity, dominated by hydroxyl radical concentrations, undermine our ability to assess regional photochemical air pollution problems. We present an observational dataset of CO, NOX, SO2, ozone, HONO, and VOCs (anthropogenic and biogenic) from Taehwa Research Forest (TRF) near the Seoul Metropolitan Area (SMA) in early June 2012. The data show that TRF is influenced both by aged pollution and fresh BVOC emissions. With the dataset, we diagnose HOx (OH, HO2, and RO2) distributions calculated with the University of Washington Chemical Box Model (UWCM v 2.1). Uncertainty from unconstrained HONO sources and radical recycling processes highlighted in recent studies is examined using multiple model simulations with different model constraints. The results suggest that 1) different model simulation scenarios cause systematic differences in HOX distributions especially OH levels (up to 2.5 times) and 2) radical destruction (HO2+HO2 or HO2+RO2) could be more efficient than radical recycling (HO2+NO) especially in the afternoon. Implications of the uncertainties in radical chemistry are discussed with respect to ozone-VOC-NOX sensitivity and oxidation product formation rates. Overall, the VOC limited regime in ozone photochemistry is predicted but the degree of sensitivity can significantly vary depending on the model scenarios. The model results also suggest that RO2 levels are positively correlated with OVOCs production that is not routinely

  18. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, Duncan W.; Mattes, Benjamin R.; Koskelo, Aaron C.; Heeger, Alan J.; Robinson, Jeanne M.; Smilowitz, Laura B.; Klimov, Victor I.; Cha, Myoungsik; Sariciftci, N. Serdar; Hummelen, Jan C.

    1998-01-01

    Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

  19. CONTROL LIMITER DEVICE

    DOE Patents [OSTI]

    DeShong, J.A.

    1960-03-01

    A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

  20. Classical and alternative macrophage activation in the lung following ozone-induced oxidative stress

    SciTech Connect (OSTI)

    Sunil, Vasanthi R.; Patel-Vayas, Kinal; Shen, Jianliang; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-09-01

    Ozone is a pulmonary irritant known to cause oxidative stress, inflammation and tissue injury. Evidence suggests that macrophages play a role in the pathogenic response; however, their contribution depends on the mediators they encounter in the lung which dictate their function. In these studies we analyzed the effects of ozone-induced oxidative stress on the phenotype of alveolar macrophages (AM). Exposure of rats to ozone (2 ppm, 3 h) resulted in increased expression of 8-hydroxy-2?-deoxyguanosine (8-OHdG), as well as heme oxygenase-1 (HO-1) in AM. Whereas 8-OHdG was maximum at 24 h, expression of HO-1 was biphasic increasing after 3 h and 4872 h. Cleaved caspase-9 and beclin-1, markers of apoptosis and autophagy, were also induced in AM 24 h post-ozone. This was associated with increased bronchoalveolar lavage protein and cells, as well as matrix metalloproteinase (MMP)-2 and MMP-9, demonstrating alveolar epithelial injury. Ozone intoxication resulted in biphasic activation of the transcription factor, NF?B. This correlated with expression of monocyte chemotactic protein?1, inducible nitric oxide synthase and cyclooxygenase?2, markers of proinflammatory macrophages. Increases in arginase-1, Ym1 and galectin-3 positive anti-inflammatory/wound repair macrophages were also observed in the lung after ozone inhalation, beginning at 24 h (arginase-1, Ym1), and persisting for 72 h (galectin-3). This was associated with increased expression of pro-surfactant protein-C, a marker of Type II cell proliferation and activation, important steps in wound repair. These data suggest that both proinflammatory/cytotoxic and anti-inflammatory/wound repair macrophages are activated early in the response to ozone-induced oxidative stress and tissue injury. -- Highlights: ? Lung macrophages are highly sensitive to ozone induced oxidative stress. ? Ozone induces autophagy and apoptosis in lung macrophages. ? Proinflammatory and wound repair macrophages are activated early after ozone

  1. PEAK LIMITING AMPLIFIER

    DOE Patents [OSTI]

    Goldsworthy, W.W.; Robinson, J.B.

    1959-03-31

    A peak voltage amplitude limiting system adapted for use with a cascade type amplifier is described. In its detailed aspects, the invention includes an amplifier having at least a first triode tube and a second triode tube, the cathode of the second tube being connected to the anode of the first tube. A peak limiter triode tube has its control grid coupled to thc anode of the second tube and its anode connected to the cathode of the second tube. The operation of the limiter is controlled by a bias voltage source connected to the control grid of the limiter tube and the output of the system is taken from the anode of the second tube.

  2. Ozone-depleting-substance control and phase-out plan

    SciTech Connect (OSTI)

    Nickels, J.M.; Brown, M.J.

    1994-07-01

    Title VI of the Federal Clean Air Act Amendments of 1990 requires regulation of the use and disposal of ozone-depleting substances (ODSs) (e.g., Halon, Freon). Several important federal regulations have been promulgated that affect the use of such substances at the Hanford Site. On April 23, 1993, Executive Order (EO) 12843, Procurement Requirements and Policies for Federal Agencies for Ozone-Depleting Substances (EPA 1993) was issued for Federal facilities to conform to the new US Environmental Protection Agency (EPA) regulations implementing the Clean Air Act of 1963 (CAA), Section 613, as amended. To implement the requirements of Title VI the US Department of Energy, Richland Operations Office (RL), issued a directive to the Hanford Site contractors on May 25, 1994 (Wisness 1994). The directive assigns Westinghouse Hanford Company (WHC) the lead in coordinating the development of a sitewide comprehensive implementation plan to be drafted by July 29, 1994 and completed by September 30, 1994. The implementation plan will address several areas where immediate compliance action is required. It will identify all current uses of ODSs and inventories, document the remaining useful life of equipment that contains ODS chemicals, provide a phase-out schedule, and provide a strategy that will be implemented consistently by all the Hanford Site contractors. This plan also addresses the critical and required elements of Federal regulations, the EO, and US Department of Energy (DOE) guidance. This plan is intended to establish a sitewide management system to address the clean air requirements.

  3. Improved limited discrepancy search

    SciTech Connect (OSTI)

    Korf, R.E.

    1996-12-31

    We present an improvement to Harvey and Ginsberg`s limited discrepancy search algorithm, which eliminates much of the redundancy in the original, by generating each path from the root to the maximum search depth only once. For a complete binary tree of depth d this reduces the asymptotic complexity from O(d+2/2 2{sup d}) to O(2{sup d}). The savings is much less in a partial tree search, or in a heavily pruned tree. The overhead of the improved algorithm on a complete binary tree is only a factor of b/(b - 1) compared to depth-first search. While this constant factor is greater on a heavily pruned tree, this improvement makes limited discrepancy search a viable alternative to depth-first search, whenever the entire tree may not be searched. Finally, we present both positive and negative empirical results on the utility of limited discrepancy search, for the problem of number partitioning.

  4. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, D.W.; Mattes, B.R.; Koskelo, A.C.; Heeger, A.J.; Robinson, J.M.; Smilowitz, L.B.; Klimov, V.I.; Cha, M.; Sariciftci, N.S.; Hummelen, J.C.

    1998-04-21

    Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO{sub 2}) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400--1,100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes. 5 figs.

  5. The role of developing countries in protecting the ozone layer: An ethical analysis

    SciTech Connect (OSTI)

    Zatz, M.N.

    1994-12-31

    In an effort to reduce the depletion of the stratospheric ozone layer, the nations of the world joined together in a landmark effort to address this most important problem. Unlike many environmental issues which are localized, ozone depletion is an environmental problem which must be addressed on a global scale. In order to successfully halt the depletion of the ozone layer, it is imperative that all countries amend their current practices and reduce their consumption of ozone-depleting substances. This necessity presents an ethical dilemma when assigning responsibility for ozone layer protection among nations. This paper will address the difficulties in dealing with ozone depletion on a global scale and will discuss the ethically correct role which should be assumed by developing countries. After presenting a brief history of the problem of ozone depletion and the measures which have been taken to halt it, this paper will describe an ethical framework in which ozone layer protection policies in developing countries should be evaluated. This framework is based on the concept of balancing morally-correct policies with economically-sound policies. It illustrates, in detail, how the environmental impacts of policies must be considered in conjunction with the impacts of such policies on the lives and well-being of the country`s citizens. The paper presents an ethical analysis of three primary policy options. These options address the phaseout of ozone-depleting substances (such as CFCs) and include: the no-phaseout option, the developed country accelerated phaseout schedule, and the delayed phaseout schedule. Each option is examined within the ethical framework presented earlier in the paper. Finally, the paper concludes by addressing the ethical responsibilities of developed countries. It discusses the various ways in which developed countries should provide aid.

  6. Ozone in sea water. Part 1: Chemistry; Part 2: Corrosion of metals

    SciTech Connect (OSTI)

    Wyllie, W.E. II; Brown, B.E.; Duquette, D.J.

    1995-12-01

    Ozonation of sea water for biofouling control is being utilized in desalination processes, heat exchange systems, as well as in salt water aquariums. The chemistry of ozone in sea water is much more complex than in fresh water due to the high concentration of easily oxidizable, ozone-demanding species and the formation of secondary oxidants. The major secondary oxidant is bromine in the form of hypobromite and hypobromous acid (BrO{sup {minus}}/HOBr) which are formed by oxidation of the bromide ion (Br{sup {minus}}), naturally found in sea water in concentrations of 65 mg/L. HOBr can react again with ozone to return Br{sup {minus}}, resulting in accelerated decomposition of ozone, or to form bromate (BrO{sub 3}{sup {minus}}) The BrO ion is known to interfere with the measurement of residual ozone in sea water, so it is important that the feed gas conditions, solution pH, and the hypobromous and bromate concentrations be reported to quantify the amount of ozone introduced into a system. In 0.5 N NaCl and sea water solutions, ozone appears to stabilize the passivity of passivating metals, but susceptibility to crevice corrosion appears to increase in the same environments. The effect of BrO{sup {minus}}/HOBr on the corrosion of metals in sea water is believed to be similar to chlorine and ozone, in that it acts as a strong oxidizer. However, it is not certain whether BrO{sup {minus}}/HOBr and BrO{sub 3}{sup {minus}} have any damaging effects on protective metal films.

  7. Surface modification of nitrogen-doped carbon nanotubes by ozone via atomic layer deposition

    SciTech Connect (OSTI)

    Lushington, Andrew; Liu, Jian; Tang, Yongji; Li, Ruying; Sun, Xueliang, E-mail: xsun@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario N6A 5B9 (Canada)

    2014-01-15

    The use of ozone as an oxidizing agent for atomic layer deposition (ALD) processes is rapidly growing due to its strong oxidizing capabilities. However, the effect of ozone on nanostructured substrates such as nitrogen-doped multiwalled carbon nanotubes (NCNTs) and pristine multiwalled carbon nanotubes (PCNTs) are not very well understood and may provide an avenue toward functionalizing the carbon nanotube surface prior to deposition. The effects of ALD ozone treatment on NCNTs and PCNTs using 10?wt. % ozone at temperatures of 150, 250, and 300?C are studied. The effect of ozone pulse time and ALD cycle number on NCNTs and PCNTs was also investigated. Morphological changes to the substrate were observed by scanning electron microscopy and high resolution transmission electron microscopy. Brunauer-Emmett-Teller measurements were also conducted to determine surface area, pore size, and pore size distribution following ozone treatment. The graphitic nature of both NCNTs and PCNTs was determined using Raman analysis while x-ray photoelectron spectroscopy (XPS) was employed to probe the chemical nature of NCNTs. It was found that O{sub 3} attack occurs preferentially to the outermost geometric surface of NCNTs. Our research also revealed that the deleterious effects of ozone are found only on NCNTs while little or no damage occurs on PCNTs. Furthermore, XPS analysis indicated that ALD ozone treatment on NCNTs, at elevated temperatures, results in loss of nitrogen content. Our studies demonstrate that ALD ozone treatment is an effective avenue toward creating low nitrogen content, defect rich substrates for use in electrochemical applications and ALD of various metal/metal oxides.

  8. Heat flux limiting sleeves

    DOE Patents [OSTI]

    Harris, William G. (Tampa, FL)

    1985-01-01

    A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

  9. Influence of ozone on pentobarbital pharmacokinetics in mice

    SciTech Connect (OSTI)

    Graham, J.A.; Menzel, D.B.; Mole, M.L.; Miller, F.J.; Gardner, D.E.

    1985-01-01

    It had been shown that 3- to 5-hr exposures to ambient concentrations of ozone (O/sub 3/) increase pentobarbital-induced sleeping time in female mice, hamsters, and rats without decreasing heptatic cytochrome P-450 levels or selected mixed function oxidases. To elucidate potential mechanisms involved, clearance of pentobarbital from the blood of O/sub 3/-exposed mice was examined. Pentobarbital clearance followed first-order kinetics with a one-compartment model. Mice exposed to 1960 micrograms per cu. m. (1ppm) for 5 hr had a 71% increase in the plasma half-life of pentobarbital. It therefore appears possible that pentobarbital-induced sleeping time is increased due to a decrease in hepatic metabolism of pentobarbital.

  10. Environmental Externalities in Electric Power Markets: Acid Rain, Urban Ozone, and Climate Change

    Reports and Publications (EIA)

    1995-01-01

    This article discusses the emissions resulting from the generation of electricity by utilities and their role in contributing to the environmental problems of acid rain, urban ozone, and climate change.

  11. Improved Potential Energy Surface of Ozone Constructed Using the Fitting by Permutationally Invariant Polynomial Function

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ayouz, Mehdi; Babikov, Dmitri

    2012-01-01

    New global potential energy surface for the ground electronic state of ozone is constructed at the complete basis set level of the multireference configuration interaction theory. A method of fitting the data points by analytical permutationally invariant polynomial function is adopted. A small set of 500 points is preoptimized using the old surface of ozone. In this procedure the positions of points in the configuration space are chosen such that the RMS deviation of the fit is minimized. New ab initio calculations are carried out at these points and are used to build new surface. Additional points are addedmore » to the vicinity of the minimum energy path in order to improve accuracy of the fit, particularly in the region where the surface of ozone exhibits a shallow van der Waals well. New surface can be used to study formation of ozone at thermal energies and its spectroscopy near the dissociation threshold.« less

  12. A global analysis of the ozone deficit in the upper stratosphere and lower mesosphere

    SciTech Connect (OSTI)

    Eluszkiewicz, J.; Allen, M. )

    1993-01-20

    The global measurements of temperature, ozone, water vapor, and nitrogen dioxide acquired by the Limb Infrared Monitor of the Stratosphere (LIMS), supplemented by a precomputed distribution of chlorine monoxide, are used to test the balance between odd oxygen production and loss in the upper stratosphere and lower mesosphere. An efficient photochemical equilibrium model, validated by comparison with the results from a fully time-dependent one-dimensional model at selected latitudes, is used in the calculations. The computed ozone abundances are systematically lower than observations for May 1-7, 1979, which suggests, contrary to the conclusions of other recent studies, a problem in model simulations of stratospheric ozone. The ozone deficit' at 30[degrees]N is smaller than previous analyses of LIMS data have indicated. In the stratosphere, this reduction in the deficit is due to the fact that CIO abundances for the 1979 period utilized in this study are much lower than in earlier work, mainly as a result of lower Cl[sub y] concentrations. In the mesosphere, a correlation of the ozone deficit with the distribution of water vapor is indicated. The ozone deficit in the stratosphere can be eliminated by modifying only one model reaction rate: either by decreasing the rate of odd oxygen loss or by increasing the rate of odd oxygen production Cl[sub y] increasing the photodissociation rate of molecular oxygen primarily in the Herzberg continuum and/or invoking photolysis of vibrationally excited molecular oxygen. With the ozone abundances thus increased, a small residual deficit in the lower mesophere can be eliminated by reducing, within the recommended kinetic uncertainties, the efficiency of odd hydrogen-catalyzed odd oxygen loss. With the adjusted model, the calculated ozone abundances for the week of January 1-7. 1979, outside of winter latitudes, also agree with the LIMS observations to within 10%. 49 refs., 15 figs., 1 tab.

  13. Influence of Long-Period Variations of Total Ozone Content on Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Change in Twentieth Century Influence of Long-Period Variations of Total Ozone Content on Climate Change in Twentieth Century Zuev, V Institute of Atmospheric Optics Zueva, N. Institute of Atmospheric Optics Bondarenko, S Institute of Atmospheric Optics Category: Atmospheric State and Surface It is shown that during long-term total ozone decrease everywhere at middle and high latitudes there takes place the destruction of balance in global carbon cycle first of all due to reduction of

  14. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  15. (Limiting the greenhouse effect)

    SciTech Connect (OSTI)

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  16. Timminco Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Timminco Limited Place: Toronto, Ontario, Canada Zip: M5H 1J9 Product: Canadian manufacturer of magnesium and silicon; operates its...

  17. Confidence limits and their errors

    SciTech Connect (OSTI)

    Rajendran Raja

    2002-03-22

    Confidence limits are common place in physics analysis. Great care must be taken in their calculation and use especially in cases of limited statistics. We introduce the concept of statistical errors of confidence limits and argue that not only should limits be calculated but also their errors in order to represent the results of the analysis to the fullest. We show that comparison of two different limits from two different experiments becomes easier when their errors are also quoted. Use of errors of confidence limits will lead to abatement of the debate on which method is best suited to calculate confidence limits.

  18. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect (OSTI)

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-11-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  19. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect (OSTI)

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-01-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  20. Overview of ozone human exposure and health risk analyses used in the U.S. EPA's review of the ozone air quality standard.

    SciTech Connect (OSTI)

    Whitfield, R. G.

    1999-03-04

    This paper presents an overview of the ozone human exposure and health risk analyses developed under sponsorship of the U.S. Environmental Protection Agency (EPA). These analyses are being used in the current review of the national ambient air quality standards (NAAQS) for ozone. The analyses consist of three principal steps: (1) estimating short-term ozone exposure for particular populations (exposure model); (2) estimating population response to exposures or concentrations (exposure-response or concentration-response models); and (3) integrating concentrations or exposure with concentration-response or exposure-response models to produce overall risk estimates (risk model). The exposure model, called the probabilistic NAAQS exposure model for ozone (pNEM/03), incorporates the following factors: hourly ambient ozone concentrations; spatial distribution of concentrations; ventilation state of individuals at time of exposure; and movement of people through various microenvironments (e.g., outdoors, indoors, inside a vehicle) of varying air quality. Exposure estimates are represented by probability distributions. Exposure-response relationships have been developed for several respiratory symptom and lung function health effects, based on the results of controlled human exposure studies. These relationships also are probabilistic and reflect uncertainties associated with sample size and variability of response among subjects. The analyses also provide estimates of excess hospital admissions in the New York City area based on results from an epidemiology study. Overall risk results for selected health endpoints and recently analyzed air quality scenarios associated with alternative 8-hour NAAQS and the current 1-hour standard for outdoor children are used to illustrate application of the methodology.

  1. Post-treatment of fly ash by ozone in a fixed bed reactor

    SciTech Connect (OSTI)

    Kim Hougaard Pedersen; Merc Casanovas Meli; Anker Degn Jensen; Kim Dam-Johansen

    2009-01-15

    The residual carbon in fly ash produced from pulverized coal combustion can adsorb the air-entraining admixtures (AEAs) added to enhance air entrainment in concrete. This behavior of the ash can be suppressed by exposing the fly ash to oxidizing species, which oxidizes the carbon surface and thus prevents the AEA to be adsorbed. In the present work, two fly ashes have been ozonated in a fixed bed reactor and the results showed that ozonation is a potential post-treatment method that can lower the AEA requirements of a fly ash up to 6 times. The kinetics of the carbon oxidation by ozone was found to be fast. A kinetic model has been formulated, describing the passivation of carbon, and it includes the stoichiometry of the ozone consumption (0.8 mol of O{sub 3}/kg of C) and an ineffective ozone loss caused by catalytic decomposition. The simulated results correlated well with the experimental data. 28 refs., 7 figs., 3 tabs.

  2. COMMENTARY:Limits to adaptation

    SciTech Connect (OSTI)

    Preston, Benjamin L

    2013-01-01

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

  3. Observation of stratospheric trace gases related to ozone depletion in the Antarctic spring

    SciTech Connect (OSTI)

    De Zafra, R.L.; Parrish, A.; Solomon, P.; Barrett, J.W.; Connor, B.; Jaramillo, M. )

    1987-01-01

    During the first National Ozone Expedition (NOZE I), which ran from 21 August to early November 1986 at McMurdo Station, the authors made frequent measurements of chlorine monoxide (CIO), ozone (O{sub 3}), nitrous oxide (N{sub 2}O), and occasional measurements of hydrogen cyanide. Observations were made with a ground-based millimeters wave spectrometer capable of detecting and measuring the pressure broadened rotational emission lines of these molecules in the 260-280 gigahertz frequency range. The spectral bandpass and resolution of the instrument is sufficient to recover altitude distributions over a range of approximately 20-55 kilometers and to detect emission from as low as approximately 13-15 kilometers. Results are given and discussed on the levels of chlorine monoxide, nitrous oxide, and ozone found.

  4. Water relations of differentially irrigated cotton exposed to ozone

    SciTech Connect (OSTI)

    Temple, P.J.

    1990-01-01

    The field study was conducted to test the hypothesis that plants chronically exposed to O{sub 3} may be more susceptible to drought because O{sub 3} typically inhibits root growth and increases shoot-root ratios in plants. Cotton was grown in open-top chambers on Hanford coarse sandy loam in Riverside, CA. Plants were grown under three irrigation regimes: Optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800-2000) O{sub 3} centrations of 0.015, 0.074, 0.094, or 0.111/microLL. Leaf xylem pressure potentials Psi(sub 1) and soil water content Theta(sub v) were measured weekly from June to October. Mean seasonal Psi(sub 1) increased from -1.89 MPa to -1.72 MPa in low to high O{sub 3} treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O{sub 3} in OW and SO, but not in SS treatments. Drought-stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O{sub 3} had no apparent effect on this redistribution of roots in the soil. Since O{sub 3} had no apparent effect on the ability of drought-stressed cotton to maintain Psi(sub 1) and to increase root growth relative to shoot growth, this suggests that O{sub 3} may have little or no effect on the potential of cotton to adapt to or tolerate drought.

  5. Alternative Fuels Data Center

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    the VALE Program is to reduce ground level emissions at commercial service airports located in designated ozone and carbon monoxide air quality nonattainment and maintenance areas. ...

  6. Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

    SciTech Connect (OSTI)

    Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie; Brunner, Gregory; Zhang, Jianshun; Fisk, William J.

    2011-05-01

    Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specimens from each filter media were exposed to {approx}150 ppbv ozone in a flow tube under a constant flow of dry or humidified air (50percent RH). Ozone breakthrough was recorded for each sample over periods of {approx}1000 min; the ozone uptake rate was calculated for an initial transient period and for steady-state conditions. While ozone uptake was observed in all cases, we did not observe significant differences in the uptake rate and capacity for the various types of filter media tested. Most experiments were performed at an airflow rate of 1.3 L/min (face velocity = 0.013 m/s), and a few tests were also run at higher rates (8 to 10 L/min). Formaldehyde and acetaldehyde, two oxidation byproducts, were quantified downstream of each sample. Those aldehydes (m/z 31 and 45) and other volatile byproducts (m/z 57, 59, 61 and 101) were also detected in real-time using Proton-Transfer Reaction - Mass Spectrometry (PTR-MS). Low-ppbv byproduct emissions were consistently higher under humidified air than under dry conditions, and were higher when the filters were loaded with particles, as compared with unused filters. No significant differences were observed when ozone reacted over various types of filter media. Fiberglass filters heavily coated with impaction oil (tackifier) showed higher formaldehyde emissions than other samples. Those emissions were particularly high in the case of used filters, and were observed even in the absence of ozone, suggesting that hydrolysis of additives

  7. Solfex Limited | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Solfex Limited Address: Energy Arena Bannister Hall Works Off Shop Lane, Higher Walton Preston, Lancashire PR5 4DZ Place: Preston, United...

  8. Lysanda Limited | Open Energy Information

    Open Energy Info (EERE)

    CM8 3GA Product: US-based vehicle engineering consultancy with a technology capable of playing a role in vehicle emissions management. References: Lysanda Limited1 This...

  9. PURAC Limited | Open Energy Information

    Open Energy Info (EERE)

    technology and project management company in the environment sector and specialising in water, wastewater and municpal waste treatment. References: PURAC Limited1 This article...

  10. Narrowband filter radiometer for ground-based measurements of global ultraviolet solar irradiance and total ozone

    SciTech Connect (OSTI)

    Petkov, Boyan; Vitale, Vito; Tomasi, Claudio; Bonafe, Ubaldo; Scaglione, Salvatore; Flori, Daniele; Santaguida, Riccardo; Gausa, Michael; Hansen, Georg; Colombo, Tiziano

    2006-06-20

    The ultraviolet narrowband filter radiometer (UV-RAD) designed by the authors to take ground-based measurements of UV solar irradiance, total ozone, and biological dose rate is described, together with the main characteristics of the seven blocked filters mounted on it, all of which have full widths at half maxima that range 0.67 to 0.98 nm. We have analyzed the causes of cosine response and calibration errors carefully to define the corresponding correction terms, paying particular attention to those that are due to the spectral displacements of the filter transmittance peaks from the integer wavelength values. The influence of the ozone profile on the retrieved ozone at large solar zenith angles has also been examined by means of field measurements. The opportunity of carrying out nearly monochromatic irradiance measurements offered by the UV-RAD allowed us to improve the procedure usually followed to reconstruct the solar spectrum at the surface by fitting the computed results, using radiative transfer models with field measurements of irradiance. Two long-term comparison campaigns took place, showing that a mean discrepancy of+0.3% exists between the UV-RAD total ozone values and those given by the Brewer no. 63 spectroradiometer and that mean differences of+0.3% and-0.9% exist between the erythemal dose rates determined with the UV-RAD and those obtained with the Brewer no. 63 and the Brewer no. 104 spectroradiometers, respectively.

  11. Development of pollution reduction strategies for Mexico City: Estimating cost and ozone reduction effectiveness

    SciTech Connect (OSTI)

    Thayer, G.R.; Hardie, R.W.; Barrera-Roldan, A.

    1993-12-31

    This reports on the collection and preparation of data (costs and air quality improvement) for the strategic evaluation portion of the Mexico City Air Quality Research Initiative (MARI). Reports written for the Mexico City government by various international organizations were used to identify proposed options along with estimates of cost and emission reductions. Information from appropriate options identified by SCAQMD for Southem California were also used in the analysis. A linear optimization method was used to select a group of options or a strategy to be evaluated by decision analysis. However, the reduction of ozone levels is not a linear function of the reduction of hydrocarbon and NO{sub x} emissions. Therefore, a more detailed analysis was required for ozone. An equation for a plane on an isopleth calculated with a trajectory model was obtained using two endpoints that bracket the expected total ozone precursor reductions plus the starting concentrations for hydrocarbons and NO{sub x}. The relationship between ozone levels and the hydrocarbon and NO{sub x} concentrations was assumed to lie on this plane. This relationship was used in the linear optimization program to select the options comprising a strategy.

  12. The Impact of Emission and Climate Change on Ozone in the United States under Representative Concentration Pathways (RCPs)

    SciTech Connect (OSTI)

    Gao, Yang; Fu, Joshua S.; Drake, John B.; Lamarque, J.-F.; Liu, Yang

    2013-09-27

    Dynamical downscaling was applied in this study to link the global climate-chemistry model Community Atmosphere Model (CAM-Chem) with the regional models: Weather Research and Forecasting (WRF) Model and Community Multi-scale Air Quality (CMAQ). Two Representative Concentration Pathway (RCP) scenarios (RCP 4.5 and RCP 8.5) were used to evaluate the climate impact on ozone concentrations in 2050s. Ozone concentrations in the lower-mid troposphere (surface to ~300 hPa), from mid- to high latitudes in the Northern Hemisphere (NH), show decreasing trends in RCP 4.5 between 2000s and 2050s, with the largest decrease of 4-10 ppbv occurring in the summer and the fall; and increasing trends (2-12 ppbv) in RCP 8.5 resulting from the increased methane emissions. In RCP 8.5, methane emissions increase by ~60% by the end of 2050s, accounting for more than 90% of ozone increases in summer and fall, and 60-80% in spring and winter. Under the RCP 4.5 scenario, in the summer when photochemical reactions are the most active, the large ozone precursor emissions reduction leads to the greatest decrease of downscaled surface ozone concentrations, ranging from 6 to 10 ppbv. However, a few major cities show ozone increases of 3 to 7 ppbv due to weakened NO titration. Under the RCP 8.5 scenario, in winter, downscaled ozone concentrations increase across nearly the entire continental US in winter, ranging from 3 to 10 ppbv due to increased methane emissions and enhanced stratosphere-troposphere exchange (STE). More intense heat waves are projected to occur by the end of 2050s in RCP 8.5, leading to more than 8 ppbv of the maximum daily 8-hour daily average (MDA8) ozone during the heat wave days than other days; this indicates the dramatic impact heat waves exert on high frequency ozone events.

  13. FUEL CASK IMPACT LIMITER VULNERABILITIES

    SciTech Connect (OSTI)

    Leduc, D; Jeffery England, J; Roy Rothermel, R

    2009-02-09

    Cylindrical fuel casks often have impact limiters surrounding just the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and maintaining lower peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) impacts. Large casks are often certified by analysis only because of the costs associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 Spent Fuel Containment Cask found problems with the design of the impact limiter attachment system. Assumptions in the original Safety Analysis for Packaging (SARP) concerning the loading in the attachment bolts were found to be inaccurate in certain drop orientations. This paper documents the lessons learned and their applicability to impact limiter attachment system designs.

  14. LANSCE Beam Current Limiter (XL)

    SciTech Connect (OSTI)

    Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) is an engineered safety system that provides personnel protection from prompt radiation due to accelerated proton beams. The Beam Current Limiter (XL), as an active component of the RSS, limits the maximum average current in a beamline, thus the current available for a beam spill accident. Exceeding the pre-set limit initiates action by the RSS to mitigate the hazard (insertion of beam stoppers in the low energy beam transport). The beam limiter is an electrically isolated, toroidal transformer and associated electronics. The device was designed to continuously monitor beamline currents independent of any external timing. Fail-safe operation was a prime consideration in its development. Fail-safe operation is defined as functioning as intended (due to redundant circuitry), functioning with a more sensitive fault threshold, or generating a fault condition. This report describes the design philosophy, hardware, implementation, operation, and limitations of the device.

  15. Atomic layer deposition of tin oxide and zinc tin oxide using tetraethyltin and ozone

    SciTech Connect (OSTI)

    Warner, Ellis J.; Gladfelter, Wayne L.; Johnson, Forrest; Campbell, Stephen A.

    2015-03-15

    Silicon or glass substrates exposed to sequential pulses of tetraethyltin (TET) and ozone (O{sub 3}) were coated with thin films of SnO{sub 2}. Self-limiting deposition was found using 8 s pulse times, and a uniform thickness per cycle (TPC) of 0.2 nm/cycle was observed in a small, yet reproducible, temperature window from 290 to 320 °C. The as-deposited, stoichiometric SnO{sub 2} films were amorphous and transparent above 400 nm. Interspersing pulses of diethylzinc and O{sub 3} among the TET:O{sub 3} pulses resulted in deposition of zinc tin oxide films, where the fraction of tin, defined as [at. % Sn/(at. % Sn + at. % Zn)], was controlled by the ratio of TET pulses, specifically n{sub TET}:(n{sub TET} + n{sub DEZ}) where n{sub TET} and n{sub DEZ} are the number of precursor/O{sub 3} subcycles within each atomic layer deposition (ALD) supercycle. Based on film thickness and composition measurements, the TET pulse time required to reach saturation in the TPC of SnO{sub 2} on ZnO surfaces was increased to >30 s. Under these conditions, film stoichiometry as a function of the TET pulse ratio was consistent with the model devised by Elliott and Nilsen. The as-deposited zinc tin oxide (ZTO) films were amorphous and remained so even after annealing at 450 °C in air for 1 h. The optical bandgap of the transparent ZTO films increased as the tin concentration increased. Hall measurements established that the n-type ZTO carrier concentration was 3 × 10{sup 17} and 4 × 10{sup 18} cm{sup −3} for fractional tin concentrations of 0.28 and 0.63, respectively. The carrier mobility decreased as the concentration of tin increased. A broken gap pn junction was fabricated using ALD-deposited ZTO and a sputtered layer of cuprous oxide. The junction demonstrated ohmic behavior and low resistance consistent with similar junctions prepared using sputter-deposited ZTO.

  16. Impact Limiter Tests of Four Commonly Used Materials And Limiter...

    Office of Scientific and Technical Information (OSTI)

    ... of four impact limiter materials was tested at four different load rates, quasi-statically, 44 feet per second (ftjs), (a 9 meter drop test per lOCF71), 33 fts and 22 fts. ...

  17. Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

    SciTech Connect (OSTI)

    Kim, S.; Kim, S. -Y.; Lee, M.; Shim, H.; Wolfe, G. M.; Guenther, A. B.; He, A.; Hong, Y.; Han, J.

    2015-04-29

    Rapid urbanization and economic development in East Asia in past decades has led to photochemical air pollution problems such as excess photochemical ozone and aerosol formation. Asian megacities such as Seoul, Tokyo, Shanghai, Guangzhou, and Beijing are surrounded by densely forested areas, and recent research has consistently demonstrated the importance of biogenic volatile organic compounds (VOCs) from vegetation in determining oxidation capacity in the suburban Asian megacity regions. Uncertainties in constraining tropospheric oxidation capacity, dominated by hydroxyl radical, undermine our ability to assess regional photochemical air pollution problems. We present an observational data set of CO, NOx, SO2, ozone, HONO, and VOCs (anthropogenic and biogenic) from Taehwa research forest (TRF) near the Seoul metropolitan area in early June 2012. The data show that TRF is influenced both by aged pollution and fresh biogenic volatile organic compound emissions. With the data set, we diagnose HOx (OH, HO2, and RO2) distributions calculated using the University of Washington chemical box model (UWCM v2.1) with near-explicit VOC oxidation mechanisms from MCM v3.2 (Master Chemical Mechanism). Uncertainty from unconstrained HONO sources and radical recycling processes highlighted in recent studies is examined using multiple model simulations with different model constraints. The results suggest that (1) different model simulation scenarios cause systematic differences in HOx distributions, especially OH levels (up to 2.5 times), and (2) radical destruction (HO2 + HO2 or HO2 + RO2) could be more efficient than radical recycling (RO2 + NO), especially in the afternoon. Implications of the uncertainties in radical chemistry are discussed with respect to ozone–VOC–NOx sensitivity and VOC oxidation product

  18. Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, S.; Kim, S. -Y.; Lee, M.; Shim, H.; Wolfe, G. M.; Guenther, A. B.; He, A.; Hong, Y.; Han, J.

    2015-04-29

    Rapid urbanization and economic development in East Asia in past decades has led to photochemical air pollution problems such as excess photochemical ozone and aerosol formation. Asian megacities such as Seoul, Tokyo, Shanghai, Guangzhou, and Beijing are surrounded by densely forested areas, and recent research has consistently demonstrated the importance of biogenic volatile organic compounds (VOCs) from vegetation in determining oxidation capacity in the suburban Asian megacity regions. Uncertainties in constraining tropospheric oxidation capacity, dominated by hydroxyl radical, undermine our ability to assess regional photochemical air pollution problems. We present an observational data set of CO, NOx, SO2, ozone, HONO,more » and VOCs (anthropogenic and biogenic) from Taehwa research forest (TRF) near the Seoul metropolitan area in early June 2012. The data show that TRF is influenced both by aged pollution and fresh biogenic volatile organic compound emissions. With the data set, we diagnose HOx (OH, HO2, and RO2) distributions calculated using the University of Washington chemical box model (UWCM v2.1) with near-explicit VOC oxidation mechanisms from MCM v3.2 (Master Chemical Mechanism). Uncertainty from unconstrained HONO sources and radical recycling processes highlighted in recent studies is examined using multiple model simulations with different model constraints. The results suggest that (1) different model simulation scenarios cause systematic differences in HOx distributions, especially OH levels (up to 2.5 times), and (2) radical destruction (HO2 + HO2 or HO2 + RO2) could be more efficient than radical recycling (RO2 + NO), especially in the afternoon. Implications of the uncertainties in radical chemistry are discussed with respect to ozone–VOC–NOx sensitivity and VOC oxidation product formation rates. Overall, the NOx limited regime is assessed except for the morning hours (8 a.m. to 12 p.m. local standard time), but the degree of sensitivity

  19. Nuclear Structure at the Limits

    SciTech Connect (OSTI)

    Nazarewicz, W.

    1998-01-12

    One of the frontiers of today?s nuclear science is the ?journey to the limits? of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  20. Nuclear Structure at the Limits

    SciTech Connect (OSTI)

    Nazarewicz, Witold

    1997-12-31

    One of the frontiers of today`s nuclear science is the ``journey to the limits``: of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure at the limits are discussed from a theoretical perspective.

  1. Plaxica Limited | Open Energy Information

    Open Energy Info (EERE)

    Zip: SW7 2AZ Product: UK-based technology company developing a new generation of polymers derived from sustainable resources. References: Plaxica Limited1 This article is a...

  2. Evaluating a heated metal scrubber's effectiveness in preventing ozone monitors' anomalous behavior during hot and humid ambient sampling

    SciTech Connect (OSTI)

    Maddy, J.A.

    1999-07-01

    The purpose of this paper is to verify West Virginia's Wet/Dry test's prediction that Advanced Pollution Instrumentation's (API) ozone monitors, when using a heated metal scrubber in lieu of a standard MnO{sub 2} scrubber, would be made insensitive to sampling conditions which provoke anomalous behavior. Field trials involving two identical API model 400 ozone monitors, a Horiba APOA 360 ozone monitor, MnO{sub 2} scrubbers and API's optional heated metal scrubber would determine this. The heated metal scrubber succeeded in effectively eliminating the anomalous behavior. Evaluation results further verify the accuracy of West Virginia's Wet/Dry test. During the evaluation, a serendipitous event led to observations that confirmed previous observations by The Commonwealth of Virginia's monitoring staff, linking contamination of UV monitors' optics with anomalous behavior. Also, a partial summation of observations concerning ultraviolet ozone monitors' anomalous behavior, drawn from several sources, illustrates its complex nature.

  3. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, D.J.; Cha, Y.S.

    1999-04-06

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

  4. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  5. Regulation of ozone-induced lung inflammation and injury by the β-galactoside-binding lectin galectin-3

    SciTech Connect (OSTI)

    Sunil, Vasanthi R.; Francis, Mary; Vayas, Kinal N.; Cervelli, Jessica A.; Choi, Hyejeong; Laskin, Jeffrey D.; Laskin, Debra L.

    2015-04-15

    Macrophages play a dual role in ozone toxicity, contributing to both pro- and anti-inflammatory processes. Galectin-3 (Gal-3) is a lectin known to regulate macrophage activity. Herein, we analyzed the role of Gal-3 in the response of lung macrophages to ozone. Bronchoalveolar lavage (BAL) and lung tissue were collected 24–72 h after exposure (3 h) of WT and Gal-3{sup -/-} mice to air or 0.8 ppm ozone. In WT mice, ozone inhalation resulted in increased numbers of proinflammatory (Gal-3{sup +}, iNOS{sup +}) and anti-inflammatory (MR-1{sup +}) macrophages in the lungs. While accumulation of iNOS{sup +} macrophages was attenuated in Gal-3{sup -/-} mice, increased numbers of enlarged MR-1{sup +} macrophages were noted. This correlated with increased numbers of macrophages in BAL. Flow cytometric analysis showed that these cells were CD11b{sup +} and consisted mainly (> 97%) of mature (F4/80{sup +}CD11c{sup +}) proinflammatory (Ly6GLy6C{sup hi}) and anti-inflammatory (Ly6GLy6C{sup lo}) macrophages. Increases in both macrophage subpopulations were observed following ozone inhalation. Loss of Gal-3 resulted in a decrease in Ly6C{sup hi} macrophages, with no effect on Ly6C{sup lo} macrophages. CD11b{sup +}Ly6G{sup +}Ly6C{sup +} granulocytic (G) and monocytic (M) myeloid derived suppressor cells (MDSC) were also identified in the lung after ozone. In Gal-3{sup -/-} mice, the response of G-MDSC to ozone was attenuated, while the response of M-MDSC was heightened. Changes in inflammatory cell populations in the lung of ozone treated Gal-3{sup -/-} mice were correlated with reduced tissue injury as measured by cytochrome b5 expression. These data demonstrate that Gal-3 plays a role in promoting proinflammatory macrophage accumulation and toxicity in the lung following ozone exposure. - Highlights: • Multiple monocytic-macrophage subpopulations accumulate in the lung after ozone inhalation. • Galectin-3 plays a proinflammatory role in ozone-induced lung injury. • In the

  6. Wastewater treatment: Ozonation processes and equipment. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    The bibliography contains citations concerning the use of ozone for wastewater disinfection. The citations cover system descriptions and evaluations, comparisons with the chlorination disinfection process, reaction kinetics, and the combination of ozonation with other wastewater treatment methods. The treatment of organic and inorganic compounds in wastewater and municipal water supplies is also discussed. (Contains 250 citations and includes a subject term index and title list.)

  7. Wastewater treatment: Ozonation processes and equipment. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1993-03-01

    The bibliography contains citations concerning the use of ozone for wastewater disinfection. The citations cover system descriptions and evaluations, comparisons with the chlorination disinfection process, reaction kinetics, and the combination of ozonation with other wastewater treatment methods. The treatment of organic and inorganic compounds in wastewater and municipal water supplies is also discussed. (Contains 250 citations and includes a subject term index and title list.)

  8. Demonstration of Advanced Technologies for Multi-Load Washers in Hospitality and Healthcare -- Ozone Based Laundry Systems

    SciTech Connect (OSTI)

    Boyd, Brian K.; Parker, Graham B.; Petersen, Joseph M.; Sullivan, Greg; Goetzler, W.; Sutherland, T. A.; Foley, K. J.

    2014-08-14

    The objective of this demonstration project was to evaluate market-ready retrofit technologies for reducing the energy and water use of multi-load washers in healthcare and hospitality facilities. Specifically, this project evaluated laundry wastewater recycling technology in the hospitality sector and ozone laundry technology in both the healthcare and hospitality sectors. This report documents the demonstration of ozone laundry system installations at the Charleston Place Hotel in Charleston, South Carolina, and the Rogerson House assisted living facility in Boston, Massachusetts.

  9. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    SciTech Connect (OSTI)

    Chan, Wai Kit; Joueet, Justine; Heng, Samuel; Yeung, King Lun; Schrotter, Jean-Christophe

    2012-05-15

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: Black-Right-Pointing-Pointer Novel reactor using membranes for ozone distributor, reaction contactor and water separator. Black-Right-Pointing-Pointer Designed to achieve an order of magnitude enhancement over traditional reactor. Black-Right-Pointing-Pointer Al{sub 2}O{sub 3} and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. Black-Right-Pointing-Pointer High surface area coating prevents polarization and improves membrane separation and life.

  10. Belize Electricity Limited | Open Energy Information

    Open Energy Info (EERE)

    Belize Electricity Limited Jump to: navigation, search Logo: Belize Electricity Limited Name: Belize Electricity Limited Abbreviation: BEL Address: PO Box 327 Place: Belize City,...

  11. V Fuels Biodiesel Limited | Open Energy Information

    Open Energy Info (EERE)

    Biodiesel Limited Jump to: navigation, search Name: V-Fuels Biodiesel Limited Place: United Kingdom Product: UK-based biodiesel producers. References: V-Fuels Biodiesel Limited1...

  12. Water vapor and ozone profiles with a CO{sub 2} DIAL system in south Italy

    SciTech Connect (OSTI)

    Bellecci, C.; Caputi, G.; De Donato, F.; Gaudio, P.; Valentini, M.

    1996-12-31

    In this paper the authors present the work carried out at the University of Calabria regarding a prototype of a DIAL system. This has been realized for remote pollution monitoring. Most of the efforts have been done to perform several measurements on an horizontal path in order to scan the wide surrounding area. The concentrations of ozone and water vapor have been carried out using two different methods both related with the DIAL technique. With the integrated technique, average concentrations have been evaluated up to 5 km using topographical targets. In the range resolution technique, profiles of ozone and water vapor have been performed up to 700 m with a spatial resolution of about 30 m. Although the system needs a revision in several subsystems of its set-up, the experimentation has pointed out the performance available and the necessary improvements.

  13. Total Ozone Mapping Spectrometer (TOMS) Derived Data, Global Earth Coverage (GEC) from NASA's Earth Probe Satellite

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    This is data from an external datastream processed through the ARM External Data Center (XDC) at Brookhaven National Laboratory. The XDC identifies sources and acquires data, called "external data", to augment the data being generated within the ARM program. The external data acquired are usually converted from native format to either netCDF or HDF formats. The GEC collection contains global data derived from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Earth Probe satellite, consisting of daily values of aerosol index, ozone and reflectivity remapped into a regular 1x1.25 deg grid. Data are available from July 25, 1996 - December 31, 2005, but have been updated or replaced as of September 2007. See the explanation on the ARM web site at http://www.arm.gov/xds/static/toms.stm and the information at the NASA/TOMS web site: http://toms.gsfc.nasa.gov/ (Registration required)

  14. U.S. NO₂ trends (2005–2013): EPA air quality system (AQS) data versus improved observations from the Ozone Monitoring Instrument (OMI)

    SciTech Connect (OSTI)

    Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.; Pickering, Kenneth E.; Streets, David G.; Lu, Zifeng

    2015-06-01

    Emissions of nitrogen oxides (NOx) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence of trends and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NOx emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations

  15. U.S. NO₂ trends (2005–2013): EPA air quality system (AQS) data versus improved observations from the Ozone Monitoring Instrument (OMI)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.; Pickering, Kenneth E.; Streets, David G.; Lu, Zifeng

    2015-06-01

    Emissions of nitrogen oxides (NOx) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence of trendsmore » and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NOx emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations. The model

  16. A new feature in the internal heavy isotope distribution in ozone

    SciTech Connect (OSTI)

    Bhattacharya, S. K. Liang, Mao-Chang; Savarino, Joel; Michalski, G.

    2014-10-07

    Ozone produced by discharge or photolysis of oxygen has unusually heavy isotopic composition ({sup 18}O/{sup 16}O and {sup 17}O/{sup 16}O ratio) which does not follow normal mass fractionation rule: δ{sup 17}O ∼ 0.52{sup *}δ{sup 18}O, expressed as an anomaly Δ{sup 17}O = δ{sup 17}O − 0.52{sup *}δ{sup 18}O. Ozone molecule being an open isosceles triangle can have the heavy isotope located either in its apex or symmetric (s) position or the base or asymmetric (as) position. Correspondingly, one can define positional isotopic enrichment, written as δ{sup 18}O (s) or δ{sup 18}O (as) (and similarly for δ{sup 17}O) as well as position dependent isotope anomaly Δ{sup 17}O (s) and Δ{sup 17}O (as). Marcus and co-workers have proposed a semi-empirical model based in principle on the RRKM model of uni-molecular dissociation but with slight modification (departure from statistical randomness assumption for symmetrical molecules) which explains many features of ozone isotopic enrichment. This model predicts that the bulk isotope anomaly is contained wholly in the asymmetric position and the Δ{sup 17}O (s) is zero. Consequently, Δ{sup 17}O (as) = 1.5 {sup *} Δ{sup 17}O (bulk) (named here simply as the “1.5 rule”) which has been experimentally confirmed over a range of isotopic enrichment. We now show that a critical re-analysis of the earlier experimental data demonstrates a small but significant departure from this 1.5 rule at the highest and lowest levels of enrichments. This departure provides the first experimental proof that the dynamics of ozone formation differs from a statistical model constrained only by restriction of symmetry. We speculate over some possible causes for the departure.

  17. Tropospheric and Lower Stratospheric Ozone Profiles From AERI-X Emission Spectra

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tropospheric and Lower Stratospheric Ozone Profiles From AERI-X Emission Spectra P. F. Fogal and F. J. Murcray Department of Physics and Astronomy University of Denver Denver, Colorado Introduction The University of Denver Atmospheric Emission Radiometric Interferometer-Extended (AERI-X) has been in regular operation at the Southern Great Plains (SGP) Atmospheric Radiation Measurements (ARM) Program site, conditions permitting, since the mid-1990s. We present here the analysis of several spectra

  18. An assessment of alternatives and technologies for replacing ozone- depleting substances at DOE facilities

    SciTech Connect (OSTI)

    Purcell, C.W.; Miller, K.B.; Friedman, J.R.; Rapoport, R.D.; Conover, D.R.; Hendrickson, P.L. ); Koss, T.C. . Office of Environmental Guidance)

    1992-10-01

    Title VI of the Clean Air Act, as amended, mandates a production phase-out for ozone-depleting substances (ODSs). These requirements will have a significant impact on US Department of Energy (DOE) facilities. Currently, DOE uses ODSs in three major activities: fire suppression (halon), refrigeration and cooling (chlorofluorocarbons [CFCs]), and cleaning that requires solvents (CFCs, methyl chloroform, and carbon tetrachloride). This report provides basic information on methods and strategies to phase out use of ODSs at DOE facilities.

  19. Effects of ozone on the respiratory health, allergic sensitization, and cellular immune system in children

    SciTech Connect (OSTI)

    Zwick, H.; Popp, W.; Wagner, C.; Reiser, K.; Schmoeger, J.B.; Boeck, A.H.; Herkner, K.; Radunsky, K. )

    1991-11-01

    To investigate the lasting effects of high ozone concentrations under environmental conditions, we examined the respiratory health, pulmonary function, bronchial hyperresponsiveness to methacholine, allergic sensitization, and lymphocyte subpopulations of 10- to 14-yr-old children. A total of 218 children recruited from an area with high ozone concentrations (Group A) were tested against 281 children coming from an area with low ozone concentrations (Group B). As to subjective complaints, categorized as 'usually cough with or without phlegm,' 'breathlessness,' and 'susceptibility to chest colds,' there was no difference between the two groups. The lung function parameters were similar, but in Group A subjects' bronchial hyperresponsiveness occurred more frequently and was found to be more severe than in Group B (29.4 versus 19.9%, p less than 0.02; PD20 2,100 {plus minus} 87 versus 2,350 {plus minus} 58 micrograms, p less than 0.05). In both groups the number of children who had been suffering from allergic diseases and sensitization to aeroallergens, found by means of the skin test, was the same. Comparison of the total IgE levels showed no difference at all between the two groups. As far as the white blood cells are concerned, the total and differential cell count was the same, whereas lymphocyte subpopulations showed readily recognizable changes.

  20. Estimation of the cloud transmittance from radiometric measurements at the ground level

    SciTech Connect (OSTI)

    Costa, Dario; Mares, Oana

    2014-11-24

    The extinction of solar radiation due to the clouds is more significant than due to any other atmospheric constituent, but it is always difficult to be modeled because of the random distribution of clouds on the sky. Moreover, the transmittance of a layer of clouds is in a very complex relation with their type and depth. A method for estimating cloud transmittance was proposed in Paulescu et al. (Energ. Convers. Manage, 75 690–697, 2014). The approach is based on the hypothesis that the structure of the cloud covering the sun at a time moment does not change significantly in a short time interval (several minutes). Thus, the cloud transmittance can be calculated as the estimated coefficient of a simple linear regression for the computed versus measured solar irradiance in a time interval Δt. The aim of this paper is to optimize the length of the time interval Δt. Radiometric data measured on the Solar Platform of the West University of Timisoara during 2010 at a frequency of 1/15 seconds are used in this study.

  1. Tritium Detection Methods and Limitations

    Office of Environmental Management (EM)

    Detection Methods and Limitations Tritium Focus Group Meeting, April 2014 Tom Voss, Northern New Mexico DOE-HDBK-1105-2002 RADIOLOGICAL TRAINING FOR TRITIUM FACILITIES U.S. Department of Energy AREA TRNG Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. DOE-HDBK-1105-2002 Radiological Training for Tritium Facilities U.S. Department of Energy, Radiological Control Programs for Special Tritium Compounds, DOE-STD- draft, Washington, D.C.

  2. Summary of Dissolved Concentration Limits

    SciTech Connect (OSTI)

    Yueting Chen

    2001-06-11

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  3. Ozone and other air quality related variables affecting visibility in the southeast United States. Master`s thesis

    SciTech Connect (OSTI)

    Brittig, J.S.

    1997-07-11

    An analysis of ozone (03) concentrations and several other air quality related variables was performed to assess their relationship with visibility at five urban and semi-urban locations in the Southeast United States during the summer seasons of 1980 to 1996. The role and impact of ozone on aerosols was investigated to ascertain a relationship with visibility. Regional trend analysis of the 1980s reveals an increase in maximum ozone concentration coupled with a decrease in visibility. However, the 1990s shows a leveling off of both ozone and visibility; in both cases the results were not statistically significant at the 5% level. Site specific trends at Nashville Tennessee followed similar trends. To better ascertain the relationships and forcing mechanisms, the analysis was changed from yearly to daily and hourly averaged values. This increased resolution showed a statistically significant inverse relationship between visibility and ozone. Additionally, by performing back trajectory analysis, it was observed that the visibility degraded both by airmass migration over polluted areas and chemical kinetics.

  4. Use of North American and European air quality networks to evaluate global chemistry-climate modeling of surface ozone

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schnell, J. L.; Prather, M. J.; Josse, B.; Naik, V.; Horowitz, L. W.; Cameron-Smith, P.; Bergmann, D.; Zeng, G.; Plummer, D. A.; Sudo, K.; et al

    2015-04-16

    We test the current generation of global chemistry-climate models in their ability to simulate observed, present-day surface ozone. Models are evaluated against hourly surface ozone from 4217 stations in North America and Europe that are averaged over 1° × 1° grid cells, allowing commensurate model-measurement comparison. Models are generally biased high during all hours of the day and in all regions. Most models simulate the shape of regional summertime diurnal and annual cycles well, correctly matching the timing of hourly (~ 15:00) and monthly (mid-June) peak surface ozone abundance. The amplitude of these cycles is less successfully matched. The observedmore » summertime diurnal range (~ 25 ppb) is underestimated in all regions by about 7 ppb, and the observed seasonal range (~ 21 ppb) is underestimated by about 5 ppb except in the most polluted regions where it is overestimated by about 5 ppb. The models generally match the pattern of the observed summertime ozone enhancement, but they overestimate its magnitude in most regions. Most models capture the observed distribution of extreme episode sizes, correctly showing that about 80% of individual extreme events occur in large-scale, multi-day episodes of more than 100 grid cells. The observed linear relationship showing increases in ozone by up to 6 ppb for larger-sized episodes is also matched.« less

  5. Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

    SciTech Connect (OSTI)

    Yehia, Ashraf; Mizuno, Akira

    2013-05-14

    An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

  6. Effects of ambient ozone on respiratory function and symptoms in Mexico City schoolchildren

    SciTech Connect (OSTI)

    Castillejos, M.; Gold, D.R.; Dockery, D.; Tosteson, T.; Baum, T.; Speizer, F.E. )

    1992-02-01

    The effects of ambient ozone (O3) on respiratory function and acute respiratory symptoms were evaluated in 143 7- to 9-yr-old schoolchildren followed longitudinally at 1- to 2-wk intervals over a period of 6 months at three schools in Pedregal, Mexico City. The maximum O3 level exceeded the World Health Organization guideline of 80 ppb and the U.S. standard of 120 ppb in every week. For an increase from lowest to highest in the mean O3 level during the 48 hr before spirometry (53 ppb), logistic regression estimated relative odds of 1.7 for a child reporting cough/phlegm on the day of spirometry. For the full population, the mean O3 level during the hour before spirometry, not adjusted for temperature and humidity, predicted a significant decrement in FVC but not in FEV1 or FEF25-75. In contrast, the mean O3 level during the previous 24-, 48-, and 168-h periods predicted significant decrements in FEV1 and FEF25-75 but not in FVC. Ozone was consistently associated with a greater decrement in lung function for the 15 children with chronic phlegm as compared with the children without chronic cough, chronic phlegm, or wheeze. Ozone in the previous 24-, 48-, and 168-h periods predicted decrements in FEV1 for children of mothers who were current or former smokers, but not for children of mothers who were never smokers. Many of these effects were reduced in multiple regression analyses including temperature and humidity, as temperature and O3 were highly correlated.

  7. Detection of ocean glint and ozone absorption using LCROSS Earth observations

    SciTech Connect (OSTI)

    Robinson, Tyler D.; Ennico, Kimberly; Meadows, Victoria S.; Sparks, William; Schwieterman, Edward W.; Bussey, D. Ben J.; Breiner, Jonathan

    2014-06-01

    The Lunar CRater Observation and Sensing Satellite (LCROSS) observed the distant Earth on three occasions in 2009. These data span a range of phase angles, including a rare crescent phase view. For each epoch, the satellite acquired near-infrared and mid-infrared full-disk images, and partial-disk spectra at 0.26-0.65 μm (λ/Δλ ∼ 500) and 1.17-2.48 μm (λ/Δλ ∼ 50). Spectra show strong absorption features due to water vapor and ozone, which is a biosignature gas. We perform a significant recalibration of the UV-visible spectra and provide the first comparison of high-resolution visible Earth spectra to the NASA Astrobiology Institute's Virtual Planetary Laboratory three-dimensional spectral Earth model. We find good agreement with the observations, reproducing the absolute brightness and dynamic range at all wavelengths for all observation epochs, thus validating the model to within the ∼10% data calibration uncertainty. Data-model comparisons reveal a strong ocean glint signature in the crescent phase data set, which is well matched by our model predictions throughout the observed wavelength range. This provides the first observational test of a technique that could be used to determine exoplanet habitability from disk-integrated observations at visible and near-infrared wavelengths, where the glint signal is strongest. We examine the detection of the ozone 255 nm Hartley and 400-700 nm Chappuis bands. While the Hartley band is the strongest ozone feature in Earth's spectrum, false positives for its detection could exist. Finally, we discuss the implications of these findings for future exoplanet characterization missions.

  8. Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

    SciTech Connect (OSTI)

    Steiner, A. L.; Tawfik, A. B.; Shalaby, A.; Zakey, A. S.; Abdel Wahab, M. M.; Salah, Z.; Solmon, F.; Sillman, S.; Zaveri, Rahul A.

    2014-04-16

    An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation, and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.

  9. Highly reproducible and reliable metal/graphene contact by ultraviolet-ozone treatment

    SciTech Connect (OSTI)

    Li, Wei [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Hacker, Christina A.; Cheng, Guangjun; Hight Walker, A. R.; Richter, Curt A.; Gundlach, David J., E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn [Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Liang, Yiran; Tian, Boyuan; Liang, Xuelei, E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn; Peng, Lianmao [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China)

    2014-03-21

    Resist residue from the device fabrication process is a significant source of contamination at the metal/graphene contact interface. Ultraviolet Ozone (UVO) treatment is proven here, by X-ray photoelectron spectroscopy and Raman measurement, to be an effective way of cleaning the metal/graphene interface. Electrical measurements of devices that were fabricated by using UVO treatment of the metal/graphene contact region show that stable and reproducible low resistance metal/graphene contacts are obtained and the electrical properties of the graphene channel remain unaffected.

  10. Use of North American and European air quality networks to evaluate global chemistry–climate modeling of surface ozone

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schnell, J. L.; Prather, M. J.; Josse, B.; Naik, V.; Horowitz, L. W.; Cameron-Smith, P.; Bergmann, D.; Zeng, G.; Plummer, D. A.; Sudo, K.; et al

    2015-09-25

    We test the current generation of global chemistry–climate models in their ability to simulate observed, present-day surface ozone. Models are evaluated against hourly surface ozone from 4217 stations in North America and Europe that are averaged over 1° × 1° grid cells, allowing commensurate model–measurement comparison. Models are generally biased high during all hours of the day and in all regions. Most models simulate the shape of regional summertime diurnal and annual cycles well, correctly matching the timing of hourly (~ 15:00 local time (LT)) and monthly (mid-June) peak surface ozone abundance. The amplitude of these cycles is less successfullymore » matched. The observed summertime diurnal range (~ 25 ppb) is underestimated in all regions by about 7 ppb, and the observed seasonal range (~ 21 ppb) is underestimated by about 5 ppb except in the most polluted regions, where it is overestimated by about 5 ppb. The models generally match the pattern of the observed summertime ozone enhancement, but they overestimate its magnitude in most regions. Most models capture the observed distribution of extreme episode sizes, correctly showing that about 80 % of individual extreme events occur in large-scale, multi-day episodes of more than 100 grid cells. The models also match the observed linear relationship between episode size and a measure of episode intensity, which shows increases in ozone abundance by up to 6 ppb for larger-sized episodes. We conclude that the skill of the models evaluated here provides confidence in their projections of future surface ozone.« less

  11. Predicting tropospheric ozone and hydroxyl radical in a global, three-dimensional, chemistry, transport, and deposition model

    SciTech Connect (OSTI)

    Atherton, C.S.

    1995-01-05

    Two of the most important chemically reactive tropospheric gases are ozone (O{sub 3}) and the hydroxyl radical (OH). Although ozone in the stratosphere is a necessary protector against the sun`s radiation, tropospheric ozone is actually a pollutant which damages materials and vegetation, acts as a respiratory irritant, and is a greenhouse gas. One of the two main sources of ozone in the troposphere is photochemical production. The photochemistry is initiated when hydrocarbons and carbon monoxide (CO) react with nitrogen oxides (NO{sub x} = NO + NO{sub 2}) in the presence of sunlight. Reaction with the hydroxyl radical, OH, is the main sink for many tropospheric gases. The hydroxyl radical is highly reactive and has a lifetime on the order of seconds. Its formation is initiated by the photolysis of tropospheric ozone. Tropospheric chemistry involves a complex, non-linear set of chemical reactions between atmospheric species that vary substantially in time and space. To model these and other species on a global scale requires the use of a global, three-dimensional chemistry, transport, and deposition (CTD) model. In this work, I developed two such three dimensional CTD models. The first model incorporated the chemistry necessary to model tropospheric ozone production from the reactions of nitrogen oxides with carbon monoxide (CO) and methane (CH{sub 4}). The second also included longer-lived alkane species and the biogenic hydrocarbon isoprene, which is emitted by growing plants and trees. The models` ability to predict a number of key variables (including the concentration of O{sub 3}, OH, and other species) were evaluated. Then, several scenarios were simulated to understand the change in the chemistry of the troposphere since preindustrial times and the role of anthropogenic NO{sub x} on present day conditions.

  12. Systemic responses to inhaled ozone in mice: cachexia and down-regulation of liver xenobiotic metabolizing genes

    SciTech Connect (OSTI)

    Last, Jerold A. . E-mail: jalast@ucdavis.edu; Gohil, Kishorchandra; Mathrani, Vivek C.; Kenyon, Nicholas J.

    2005-10-15

    Rats or mice acutely exposed to high concentrations of ozone show an immediate and significant weight loss, even when allowed free access to food and water. The mechanisms underlying this systemic response to ozone have not been previously elucidated. We have applied the technique of global gene expression analysis to the livers of C57BL mice acutely exposed to ozone. Mice lost up to 14% of their original body weight, with a 42% decrease in total food consumption. We previously had found significant up-regulation of genes encoding proliferative enzymes, proteins related to acute phase reactions and cytoskeletal functions, and other biomarkers of a cachexia-like inflammatory state in lungs of mice exposed to ozone. These results are consistent with a general up-regulation of different gene families responsive to NF-{kappa}B in the lungs of the exposed mice. In the present study, we observed significant down-regulation of different families of mRNAs in the livers of the exposed mice, including genes related to lipid and fatty acid metabolism, and to carbohydrate metabolism in this tissue, consistent with a systemic cachexic response. Several interferon-dependent genes were down-regulated in the liver, suggesting a possible role for interferon as a signaling molecule between lung and liver. In addition, transcription of several mRNAs encoding enzymes of xenobiotic metabolism in the livers of mice exposed to ozone was decreased, suggesting cytokine-mediated suppression of cytochrome P450 expression. This finding may explain a previously controversial report from other investigators more than 20 years ago of prolongation of pentobarbital sleeping time in mice exposed to ozone.

  13. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, Daniel M.; Rosen, Robert S.

    2005-04-19

    A cartridge primer which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML's would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers.

  14. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, D.M.; Rosen, R.S.

    1998-06-30

    A cartridge primer is described which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML`s would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers. 10 figs.

  15. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, Daniel M.; Rosen, Robert S.

    1998-01-01

    A cartridge primer which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML's would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers.

  16. United Group Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: United Group Limited Place: Perth, Western Australia, Australia Zip: 6001 Product: The United Group Resources (UGL) division is an EPC and...

  17. Greenergy Biofuels Limited | Open Energy Information

    Open Energy Info (EERE)

    Biofuels Limited Jump to: navigation, search Name: Greenergy Biofuels Limited Place: London, Greater London, United Kingdom Zip: WC1V 7BD Sector: Biofuels Product: Imports, blends...

  18. Gujarat Ambuja Cements Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Gujarat Ambuja Cements Limited Place: Mumbai, India Zip: 400 021 Sector: Biomass Product: Indian cement company. the company...

  19. Transmission Capital Limited | Open Energy Information

    Open Energy Info (EERE)

    Transmission Capital Limited Jump to: navigation, search Name: Transmission Capital Limited Place: London, United Kingdom Zip: EC2V 7HR Sector: Renewable Energy, Services Product:...

  20. Impact Capital Partners Limited | Open Energy Information

    Open Energy Info (EERE)

    Capital Partners Limited Jump to: navigation, search Name: Impact Capital Partners Limited Place: Los Angeles, California Zip: CA 90067-1509 Product: Los Angeles-based, investment...

  1. Power Projects Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Power Projects Limited Address: PO Box 25456 Panama Street Place: Wellington Zip: 6146 Region: New Zealand Sector: Marine and Hydrokinetic...

  2. Catamount Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Catamount Energy Limited Place: United Kingdom Sector: Wind energy Product: Wind power project developer working on projects in Scotland....

  3. Central Electronics Limited CEL | Open Energy Information

    Open Energy Info (EERE)

    Electronics Limited CEL Jump to: navigation, search Name: Central Electronics Limited (CEL) Place: Sahibabad, Uttar Pradesh, India Zip: 201010 Sector: Solar Product: String...

  4. Nufcor International Limited Nufcor | Open Energy Information

    Open Energy Info (EERE)

    Limited (Nufcor) Place: United Kingdom Sector: Services Product: UK-based uranium marketing services company. References: Nufcor International Limited (Nufcor)1 This article...

  5. Mauktika Energy Limited MEL | Open Energy Information

    Open Energy Info (EERE)

    Mauktika Energy Limited MEL Jump to: navigation, search Name: Mauktika Energy Limited (MEL) Place: Hyderabad, Andhra Pradesh, India Zip: 500033 Sector: Renewable Energy Product:...

  6. Voith Hydro Wavegen Limited | Open Energy Information

    Open Energy Info (EERE)

    Voith Hydro Wavegen Limited Jump to: navigation, search Name: Voith Hydro Wavegen Limited Region: United Kingdom Sector: Marine and Hydrokinetic Website: www.wavegen.co.uk This...

  7. Cape Systems Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Cape Systems Limited Place: Rock Sound, Bahamas Sector: Services Product: Offers installation and site surveying services for clean...

  8. SRSL Ethanol Limited | Open Energy Information

    Open Energy Info (EERE)

    SRSL Ethanol Limited Jump to: navigation, search Name: SRSL Ethanol Limited Place: Mumbai, Maharashtra, India Product: Mumbai-based ethanol subsidiary of Shree Renuka Sugars...

  9. Universal Carbon Credits Limited | Open Energy Information

    Open Energy Info (EERE)

    Universal Carbon Credits Limited Jump to: navigation, search Name: Universal Carbon Credits Limited Place: London, England, United Kingdom Zip: EC3A6DF Sector: Carbon Product:...

  10. Carbon Trust Enterprises Limited | Open Energy Information

    Open Energy Info (EERE)

    Enterprises Limited Jump to: navigation, search Name: Carbon Trust Enterprises Limited Place: London, United Kingdom Zip: WC2A 2AZ Sector: Carbon Product: Carbon Trust Enterprises...

  11. Carbon Limiting Technologies | Open Energy Information

    Open Energy Info (EERE)

    Limiting Technologies Jump to: navigation, search Name: Carbon Limiting Technologies Place: London, Greater London, United Kingdom Zip: N1 8HA Sector: Carbon Product: UK-based...

  12. Clipper Windpower Europe Limited | Open Energy Information

    Open Energy Info (EERE)

    Clipper Windpower Europe Limited Jump to: navigation, search Name: Clipper Windpower Europe Limited Place: London, Greater London, United Kingdom Zip: SE1 7TJ Sector: Wind energy...

  13. Rix Biodiesel Limited | Open Energy Information

    Open Energy Info (EERE)

    Rix Biodiesel Limited Jump to: navigation, search Name: Rix Biodiesel Limited Place: Hull, United Kingdom Zip: HU8 7JR Product: Manufacture, blends and resells biodiesel....

  14. Tidal Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Tidal Energy Limited (TEL) Place: Cardiff, Wales, United Kingdom Zip: CF23 8RS Product: Tidal stream device developer. Coordinates:...

  15. Harvard Dedicated Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Harvard Dedicated Energy Limited Jump to: navigation, search Name: Harvard Dedicated Energy Limited Place: Massachusetts Phone Number: (617) 495-5560 Website: www.energyandfaciliti...

  16. BFC Solutions Limited | Open Energy Information

    Open Energy Info (EERE)

    BFC Solutions Limited Jump to: navigation, search Name: BFC Solutions Limited Place: Taunton, England, United Kingdom Zip: TA1 PEJ Sector: Carbon Product: Somerset-based...

  17. WaikatoLink Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: WaikatoLink Limited Place: New Zealand Sector: Services Product: General Financial & Legal Services ( Individual Angel network )...

  18. China Innovation Investment Limited | Open Energy Information

    Open Energy Info (EERE)

    Innovation Investment Limited Jump to: navigation, search Name: China Innovation Investment Limited Place: Hong Kong Sector: Solar Product: Hong Kong-listed alternative energy...

  19. Renewable Fuels Limited RFL | Open Energy Information

    Open Energy Info (EERE)

    Limited RFL Jump to: navigation, search Name: Renewable Fuels Limited (RFL) Place: York, United Kingdom Zip: YO19 6ET Sector: Biomass Product: Supplies various biomass fuels and...

  20. United Biofuels Private Limited | Open Energy Information

    Open Energy Info (EERE)

    United Biofuels Private Limited Jump to: navigation, search Name: United Biofuels Private Limited Place: Tamil Nadu, India Sector: Biomass Product: India-based owner and operator...

  1. Shear wall ultimate drift limits

    SciTech Connect (OSTI)

    Duffey, T.A.; Goldman, A.; Farrar, C.R.

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  2. Synthesis of MoO{sub 3} nanoparticles for azo dye degradation by catalytic ozonation

    SciTech Connect (OSTI)

    Manivel, Arumugam; Lee, Gang-Juan; Chen, Chin-Yi; Chen, Jing-Heng; Ma, Shih-Hsin; Horng, Tzzy-Leng; Wu, Jerry J.

    2015-02-15

    Highlights: • Synthesis of one-dimensional MoO{sub 3} nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO{sub 3} presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO{sub 3} nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO{sub 3} nanoparticles compared with the other approaches. All the synthesized MoO{sub 3} nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO{sub 3} catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation.

  3. Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases. Final report

    SciTech Connect (OSTI)

    Prather, Michael J.; Hsu, Juno; Nicolau, Alex; Veidenbaum, Alex; Smith, Philip Cameron; Bergmann, Dan

    2014-11-07

    Atmospheric chemistry controls the abundances and hence climate forcing of important greenhouse gases including N2O, CH4, HFCs, CFCs, and O3. Attributing climate change to human activities requires, at a minimum, accurate models of the chemistry and circulation of the atmosphere that relate emissions to abundances. This DOE-funded research provided realistic, yet computationally optimized and affordable, photochemical modules to the Community Earth System Model (CESM) that augment the CESM capability to explore the uncertainty in future stratospheric-tropospheric ozone, stratospheric circulation, and thus the lifetimes of chemically controlled greenhouse gases from climate simulations. To this end, we have successfully implemented Fast-J (radiation algorithm determining key chemical photolysis rates) and Linoz v3.0 (linearized photochemistry for interactive O3, N2O, NOy and CH4) packages in LLNL-CESM and for the first time demonstrated how change in O2 photolysis rate within its uncertainty range can significantly impact on the stratospheric climate and ozone abundances. From the UCI side, this proposal also helped LLNL develop a CAM-Superfast Chemistry model that was implemented for the IPCC AR5 and contributed chemical-climate simulations to CMIP5.

  4. Ozone-forming potential of a series of oxygenated organic compounds

    SciTech Connect (OSTI)

    Japar, S.M.; Wallington, T.J.; Rudy, S.J.; Chang, Tai Y. )

    1991-03-01

    An incremental reactivity approach has been used to assess the relative ozone-forming potentials of various important oxygenated fuels/fuel additives, i.e., tert-butyl alcohol (TBA), dimethyl ether (DME), diethyl ether (DEE), methyl tert-butyl ether (MTBE), and ethyl tert-butyl ether (ETBE), in a variety of environments. Calculations were performed using a single-cell trajectory model, combined with the Lurmann-Carter-Coyner chemical mechanism, with (NMOC)/(NO{sub x}) ratios ranging from 4 to 20. This work provides the first quantitative assessment of the air quality impact of release of these important oxygenated compounds. ETBE and DEE are the two most reactive compounds on a per carbon equivalent basis, while TBA is the least reactive species. At a (NMOC)/(NO{sub x}) ratio of 8, which is generally typical of polluted urban areas in the United States, TBA, DME, MTBE, and ETBE all have incremental reactivities less than or equal to that of the urban NMHC mix. Thus, use of these additives in fuels may have a beneficial impact on urban ozone levels.

  5. Genotypic variability in ponderosa pine responses to combined ozone and drought stresses

    SciTech Connect (OSTI)

    Temple, P.J.

    1995-06-01

    Five-year-old ponderosa (Pinus ponderosa Laws.) seedlings from 18 half-sib and one full-sib families obtained from the California Tree Improvement Program were harvested after 1, 2, and 3 growing seasons of exposure to three levels of ozone (O{sub 3}) and two levels of available soil water (ASW) in open-top chambers in the California Sierras. Seedlings were evaluated for O{sub 3} injury symptoms, biomass, and radial growth in response to these stresses. Ozone injury responses were highly variable across families, but family rankings for O{sub 3} injury were consistent across years. Family rankings for O{sub 3} injury were highly correlated with those for reductions in biomass and radial growth for trees in the high ASW treatment, but drought-stressed trees showed no consistent relation between foliar 03 injury and reductions in growth. After three seasons of exposure to 88 ppb O{sub 3}, foliar biomass of the three most susceptible families averaged 60% less than trees in the low-O{sub 3} control, while O{sub 3} had no effect on growth of the three most resistant families. Variability across families of growth responses to drought was significantly less than the variability in seedling responses to O{sub 3}.

  6. NOx Emission Reduction and its Effects on Ozone during the 2008 Olympic Games

    SciTech Connect (OSTI)

    Yang, Qing; Wang, Yuhang; Zhao, Chun; Liu, Zhen; Gustafson, William I.; Shao, Min

    2011-07-15

    We applied a daily-assimilated inversion method to estimate NOx (NO+NO2) emissions for June-September 2007 and 2008 on the basis of the Aura Ozone Monitoring Instrument (OMI) observations of nitrogen dioxide (NO2) and model simulations using the Regional chEmistry and trAnsport Model (REAM). Over urban Beijing, rural Beijing, and the Huabei Plain, OMI column NO2 reductions are approximately 45%, 33%, and 14%, respectively, while the corresponding anthropogenic NOx emission reductions are only 28%, 24%, and 6%, during the full emission control period (July 20 – Sep 20, 2008). The emission reduction began in early July and was in full force by July 20, corresponding to the scheduled implementation of emission controls over Beijing. The emissions did not appear to recover after the emission control period. Meteorological change from summer 2007 to 2008 is the main factor contributing to the column NO2 decreases not accounted for by the emission reduction. Model simulations suggest that the effect of emission reduction on ozone concentrations over Beijing is relatively minor using a standard VOC emission inventory in China. With an adjustment of the model emissions to reflect in situ observations of VOCs in Beijing, the model simulation suggests a larger effect of the emission reduction.

  7. Isotope separation of {sup 17}O by photodissociation of ozone with near-infrared laser irradiation

    SciTech Connect (OSTI)

    Hayashida, Shigeru; Kambe, Takashi; Sato, Tetsuya; Igarashi, Takehiro; Kuze, Hiroaki

    2012-04-01

    Oxygen-17 is a stable oxygen isotope useful for various diagnostics in both engineering and medical applications. Enrichment of {sup 17}O, however, has been very costly due to the lack of appropriate methods that enable efficient production of {sup 17}O on an industrial level. In this paper, we report the first {sup 17}O-selective photodissociation of ozone at a relatively high pressure, which has been achieved by irradiating a gas mixture of 10 vol% O{sub 3}-90 vol% CF{sub 4} with narrowband laser. The experiment was conducted on a pilot-plant scale. A total laser power of 1.6 W was generated by external-cavity diode lasers with all the laser wavelengths fixed at the peak of an absorption line of {sup 16}O{sup 16}O{sup 17}O around 1 {mu}m. The beams were introduced into a 25 -m long photoreaction cell under the sealed-off condition with a total pressure of 20 kPa. Lower cell temperature reduced the background decomposition of ozone, and at the temperature of 158 K, an {sup 17}O enrichment factor of 2.2 was attained.

  8. Controlling superconductivity in La2-xSrxCuO4+δ by ozone and vacuum annealing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Leng, Xiang; Bozovic, Ivan

    2014-11-21

    In this study we performed a series of ozone and vacuum annealing experiments on epitaxial La2-xSrxCuO4+δ thin films. The transition temperature after each annealing step has been measured by the mutual inductance technique. The relationship between the effective doping and the vacuum annealing time has been studied. Short-time ozone annealing at 470 °C oxidizes an underdoped film all the way to the overdoped regime. The subsequent vacuum annealing at 350 °C to 380 °C slowly brings the sample across the optimal doping point back to the undoped, non-superconducting state. Several ozone and vacuum annealing cycles have been done on themore » same sample and the effects were found to be repeatable and reversible Vacuum annealing of ozone-loaded LSCO films is a very controllable process, allowing one to tune the doping level of LSCO in small steps across the superconducting dome, which can be used for fundamental physics studies.« less

  9. Controlling superconductivity in La2-xSrxCuO4+δ by ozone and vacuum annealing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Leng, Xiang; Bozovic, Ivan

    2014-11-21

    In this study we performed a series of ozone and vacuum annealing experiments on epitaxial La2-xSrxCuO4+δ thin films. The transition temperature after each annealing step has been measured by the mutual inductance technique. The relationship between the effective doping and the vacuum annealing time has been studied. Short-time ozone annealing at 470 °C oxidizes an underdoped film all the way to the overdoped regime. The subsequent vacuum annealing at 350 °C to 380 °C slowly brings the sample across the optimal doping point back to the undoped, non-superconducting state. Several ozone and vacuum annealing cycles have been done on themore »same sample and the effects were found to be repeatable and reversible Vacuum annealing of ozone-loaded LSCO films is a very controllable process, allowing one to tune the doping level of LSCO in small steps across the superconducting dome, which can be used for fundamental physics studies.« less

  10. GenDrive Limited | Open Energy Information

    Open Energy Info (EERE)

    GenDrive Limited Jump to: navigation, search Name: GenDrive Limited Place: Cambridge, United Kingdom Zip: CB23 3GY Sector: Renewable Energy, Solar, Wind energy Product: Developing...

  11. Mistral Invest Limited | Open Energy Information

    Open Energy Info (EERE)

    Mistral Invest Limited Jump to: navigation, search Name: Mistral Invest Limited Place: London, United Kingdom Zip: W1U 7DW Sector: Wind energy Product: Private Equity Fund aiming...

  12. Zebec Biogas Limited | Open Energy Information

    Open Energy Info (EERE)

    Zebec Biogas Limited Jump to: navigation, search Name: Zebec Biogas Limited Place: Glasgow, Scotland, United Kingdom Zip: G12 9JD Product: Sotland-based biogas company. The firm is...

  13. Graduate Program Time Limits and Work Schedules

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Time Limits and Work Schedules Graduate Program Time Limits and Work Schedules Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive...

  14. Undergraduate Program Time Limits and Work Schedules

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Time Limits and Work Schedules Undergraduate Program Time Limits and Work Schedules Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive...

  15. EU Energy Wind Limited | Open Energy Information

    Open Energy Info (EERE)

    Wind Limited Jump to: navigation, search Name: EU Energy (Wind) Limited Place: Central Milton Keynes, United Kingdom Zip: K9 1LH Sector: Wind energy Product: The company will be...

  16. Lead Hero Limited | Open Energy Information

    Open Energy Info (EERE)

    Hero Limited Jump to: navigation, search Name: Lead Hero Limited Place: China Product: China-based company that holds a 100% interest in XiAn Lv Jing and a 15.05% interest in...

  17. Biodiesel Energy Trading Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Biodiesel Energy Trading Limited Place: London, United Kingdom Zip: W1J 8DY Product: London-based company focused on trading of biodiesel....

  18. IT Power Limited | Open Energy Information

    Open Energy Info (EERE)

    IT Power Limited Jump to: navigation, search Name: IT Power Limited Place: Basingstoke, England, United Kingdom Zip: RG24 8AG Sector: Renewable Energy Product: IT Power is a...

  19. Limited English Proficiency | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Limited English Proficiency Limited English Proficiency On August 11, 2000, President Clinton signed Executive Order 13166, "Improving Access to Services for Persons with Limited English Proficiency." The Executive Order requires federal agencies, including the Department of Energy, to examine the programs and services they provide, to determine whether there is a need for language assistance for persons with Limited English proficiency (LEP) related to their programs and services, and

  20. Exorka International Limited | Open Energy Information

    Open Energy Info (EERE)

    Exorka International Limited is a specialist developer of low-temperature geothermal electricity generation, incorporated in England. References: Exorka International...

  1. Undergraduate Program Time Limits and Work Schedules

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Time Limits and Work Schedules Undergraduate Program Time Limits and Work Schedules Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Student Programs (505) 665-0987 Email Time limits The length of participation in the undergraduate program is limited to a maximum of six years for students pursuing a bachelor's degree and three years for students pursuing an

  2. Primordial magnetic field limits from cosmological data

    SciTech Connect (OSTI)

    Kahniashvili, Tina [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, Ontario P3E 2C (Canada); Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Tevzadze, Alexander G. [Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Faculty of Exact and Natural Sciences, Tbilisi State University, 1 Chavchavadze Avenue, Tbilisi, GE-0128 (Georgia); Sethi, Shiv K. [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Raman Research Institute, Sadashivanagar, Bangalore 560080 (India); Pandey, Kanhaiya [Raman Research Institute, Sadashivanagar, Bangalore 560080 (India); Ratra, Bharat [Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, Kansas 66506 (United States)

    2010-10-15

    We study limits on a primordial magnetic field arising from cosmological data, including that from big bang nucleosynthesis, cosmic microwave background polarization plane Faraday rotation limits, and large-scale structure formation. We show that the physically relevant quantity is the value of the effective magnetic field, and limits on it are independent of how the magnetic field was generated.

  3. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  4. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, J.R.

    1997-02-04

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  5. Ge Interface Engineering with Ozone-oxidation for Low Interface State Density

    SciTech Connect (OSTI)

    Kuzum, Duygu; Krishnamohan, T.; Pethe, Abhijit J.; Okyay, Ali, K.; Oshima, Yasuhiro; Sun, Yun; McVittie, Jim P.; Pianetta, Piero A.; McIntyre, Paul C.; Saraswat, Krishna C.; /Stanford U., CIS

    2008-06-02

    Passivation of Ge has been a critical issue for Ge MOS applications in future technology nodes. In this letter, we introduce ozone-oxidation to engineer Ge/insulator interface. Interface states (D{sub it}) values across the bandgap and close to conduction bandedge were extracted using conductance technique at low temperatures. D{sub it} dependency on growth conditions was studied. Minimum D{sub it} of 3 x 10{sup 11} cm{sup -2} V{sup -1} was demonstrated. Physical quality of the interface was investigated through Ge 3d spectra measurements. We found that the interface and D{sub it} is strongly affected by the distribution of oxidation states and quality of the suboxide.

  6. Green Heat Solutions Limited | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: Green Heat Solutions Limited Region: Scotland Sector: Marine and Hydrokinetic Website: http: This company is listed in the Marine and Hydrokinetic...

  7. Acquasol Infrastructure Limited | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: Acquasol Infrastructure Limited Place: Adelaide, South Australia, Australia Zip: 5000 Sector: Solar Product: Adelaide based solar thermal project and...

  8. Carnegie Wave Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Address: 1 124 Stirling Highway Place: North Fremantle Zip: 6159 Region: Australia Sector: Marine and Hydrokinetic Year Founded: 1993 Website: www.carnegiewave.com...

  9. Power Paper Limited | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Power Paper Limited Place: Kiryat Arye, Petah Tikva, Israel Zip: 49130 Product: Power Paper is a developer of next-generation, printable...

  10. Maharashtra State Power Generation Company Limited MAHAGENCO...

    Open Energy Info (EERE)

    search Name: Maharashtra State Power Generation Company Limited (MAHAGENCO) Place: Mumbai, Maharashtra, India Zip: 400051 Product: Power generating firm planning to set up a...

  11. Hebei Hydroelectric Company Limited | Open Energy Information

    Open Energy Info (EERE)

    Place: Shijiazhuang, Hebei Province, China Zip: 50011 Sector: Hydro Product: China-based small hydro project developer. References: Hebei Hydroelectric Company Limited1 This...

  12. Proactive Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Energy Product: Scotland-based renewable energy company that is developing a 5MW biogas plant in South Lanarkshire. References: Proactive Energy Limited1 This article is a...

  13. Colony Mills Limited | Open Energy Information

    Open Energy Info (EERE)

    Place: Lahore, Pakistan Sector: Solar Product: Yarn manufacturer, plans to set up solar thermal plant. References: Colony Mills Limited1 This article is a stub. You can help...

  14. Optimizing areal capacities through understanding the limitations...

    Office of Scientific and Technical Information (OSTI)

    Title: Optimizing areal capacities through understanding the limitations of lithium-ion electrodes Increasing the areal capacity or electrode thickness in lithium ion batteries is ...

  15. Vihaan Networks Limited VNL | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: Vihaan Networks Limited (VNL) Place: Gurgaon, Haryana, India Zip: 122015 Sector: Solar Product: Developer of solar-powered GSM system for rural...

  16. Cumbria Wind Farms Limited | Open Energy Information

    Open Energy Info (EERE)

    United Kingdom Zip: SY16 2LW Sector: Services Product: Provides operational and maintenance services in Cumbria, Cornwall and Wales. References: Cumbria Wind Farms Limited1...

  17. Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon...

    Office of Scientific and Technical Information (OSTI)

    Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells: Preprint Bolen, M. L.; Grover, S.; Teplin, C. W.; Bobela, D.; Branz, H. M.; Stradins, P. 08 HYDROGEN; 14...

  18. 12 Voltz Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Place: Cumbria, United Kingdom Zip: LA8 9NH Sector: Renewable Energy, Solar, Wind energy Product: Selling and delivering broad range of advanced energy generating...

  19. Caldyne Automatics Limited | Open Energy Information

    Open Energy Info (EERE)

    storage product manufacturer; also makes lighting systems based on solar, wind and solar wind hybrid systems. References: Caldyne Automatics Limited1 This article is a stub....

  20. GP Batteries International Limited | Open Energy Information

    Open Energy Info (EERE)

    International Limited is principally engaged in the development, manufacture and marketing of batteries and battery-related products. References: GP Batteries International...

  1. Graduate Program Time Limits and Work Schedules

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Time Limits and Work Schedules Graduate Program Time Limits and Work Schedules Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Student Programs (505) 665-0987 Email Time Limits The length of participation in the graduate program is limited as follows: With a bachelor's pursuing a master's degree: 4 years With a bachelor's pursuing a PhD: 7 years With a master's

  2. Interim Guidance Regarding Limitations on CERCLA Liability |...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - Inner-Office Memorandum: Interim Guidance Regarding Limitations on CERCLA LiabilityPermitting...

  3. Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon...

    Office of Scientific and Technical Information (OSTI)

    Hydrogenation of Dislocation- Limited Heteroepitaxial Silicon Solar Cells Preprint Michael L. Bolen, Sachit Grover, Charles W. Teplin, Howard M. Branz, and Paul Stradins National...

  4. Wedotebary Nigeria Limited | Open Energy Information

    Open Energy Info (EERE)

    Name: Wedotebary Nigeria Limited Place: Bukuru, Nigeria Product: Nigeria-based manufacturing conglomerate. Coordinates: 9.79017, 8.85481 Show Map Loading map......

  5. Local Generation Limited | Open Energy Information

    Open Energy Info (EERE)

    United Kingdom Sector: Biomass Product: UK-based biomass firm developing anaerobic digestion plants. References: Local Generation Limited1 This article is a stub. You can help...

  6. CarbonPlan Limited | Open Energy Information

    Open Energy Info (EERE)

    as a consultant advising on renewable energy technologies, energy efficiency, & corporate social responsibility. References: CarbonPlan Limited1 This article is a stub. You can...

  7. Amperex Technology Limited ATL | Open Energy Information

    Open Energy Info (EERE)

    Technology Limited (ATL) Place: N.T., Hong Kong Product: Designer and manufacturer of Lithium Ion Polymer (LIP) battery cells and batteries for OEM customers making cell phones,...

  8. EVO Electric Limited | Open Energy Information

    Open Energy Info (EERE)

    Greater London, United Kingdom Zip: GU21 5JY Product: EVO Electric Limited develops electrical motors and generators for use in gensets, powertrains, and traction motors in...

  9. Bharat Renewable Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Energy Limited Place: Lucknow, Uttar Pradesh, India Product: Uttar Pradesh-based joint venture company for the production, procurement, cultivation and plantation of crops...

  10. PP-22 British Columbia Electric Company, Limited

    Broader source: Energy.gov [DOE]

    Presidential permit authorizing British Columbia Electric Company, Limited to construct, operate, and maintain electric transmission facilities at the U.S-Canadian border.

  11. Royal Energy Limited REL | Open Energy Information

    Open Energy Info (EERE)

    (REL) Place: Mumbai, Maharashtra, India Zip: 400 016 Product: Mumbai-based ethanol and biodiesel producer. References: Royal Energy Limited (REL)1 This article is a stub. You...

  12. EA-365 Centre Land Trading Limited | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Centre Land Trading Limited EA-365 Centre Land Trading Limited Order Authorizing Centre Land Trading Limited to export electric energy to Canada EA-365 Centre Land Trading Limited ...

  13. Removal of pollutant compounds from water supplies using ozone, ultraviolet light, and a counter, current packed column. Master's thesis

    SciTech Connect (OSTI)

    Kelly, E.L.

    1991-01-01

    Many water pollutants are determined to be carcinogenic and often appear in very low concentrations and still pose a health risk. Conventional water treatment processes cannot remove these contaminants and there is a great demand for the development of alternative removal technologies. The use of ozone and ultraviolet light in a counter current packed column could prove to be an effective treatment process to remove these contaminants.

  14. Self-triggering superconducting fault current limiter

    DOE Patents [OSTI]

    Yuan, Xing; Tekletsadik, Kasegn

    2008-10-21

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  15. Comparison of the responses of children and adults to acute ozone exposure

    SciTech Connect (OSTI)

    McDonnell, W.F.; Chapman, R.S.; Horstman, D.H.; Leigh, M.W.; Salaam, S.A.

    1986-07-01

    The purpose of the paper is to compare the results of two studies in which the respiratory responses of children and adults to acute ozone (O/sub 3/) exposure were measured. Forty-two 18-30 year old males were exposed for 2.5 hours in a controlled environmental chamber to either 0.0 or 0.12 ppm O3 while performing intermittent heavy exercise. Twenty-two 8-11 year old males were exposed in a similar manner to both air and 0.12 ppm O3. Measures of respiratory symptoms and function were made before and after exposure. Adults experienced an increase in the symptom cough and decrements in forced vital capacity and some measures of forced expiratory flow. Children experienced similar decrements in pulmonary function, but had no increase in symptoms. The authors concluded that as measured by pulmonary function children appear to be no more responsive to O3 exposure than are adults and may experience fewer symptoms.

  16. Respiratory responses of vigorously exercising children to 0. 12 ppm ozone exposure

    SciTech Connect (OSTI)

    McDonnell, W.F. 3d.; Chapman, R.S.; Leigh, M.W.; Strope, G.L.; Collier, A.M.

    1985-10-01

    Changes in respiratory function have been suggested for children exposed to less than 0.12 ppm ozone (O3) while engaged in normal activities. Because the results of these studies have been confounded by other variables, such as temperature or the presence of other pollutants or have been questioned as to the adequacy of exposure measurements, the authors determined the acute response of children exposed to 0.12 ppm O3 in a controlled chamber environment. Twenty-three white males 8 to 11 yr of age were exposed once to clean air and once to 0.12 ppm O3 in random order. Exposures were for 2.5 h and included 2 h of intermittent heavy exercise. Measures of forced expiratory volume in one second (FEV1) and the symptom cough were determined prior to and after each exposure. A significant decline in FEV1 was found after the O3 exposure compared to the air exposure, and it appeared to persist for 16 to 20 h. No significant increase in cough was found due to O3 exposure. Forced vital capacity, specific airways resistance, respiratory frequency, tidal volume, and other symptoms were measured in a secondary exploratory analysis of this study.

  17. OZONE PRODUCTION IN THE PHILADELPHIA URBAN AREA DURING NE-OPS 99.

    SciTech Connect (OSTI)

    KLEINMAN,L.I.; DAUM,P.H.; BRECHTEL,F.; LEE,Y.N.; NUNNERMACKER,L.J.; SPRINGSTON,S.R.; WEINSTEIN-LLOYD,J.

    2001-10-01

    As part of the 1999 NARSTO Northeast Oxidant and Particulate Study (NE-OPS) field campaign, the DOE G-1 aircraft sampled trace gases and aerosols in and around the Philadelphia metropolitan area. Twenty research flights were conducted between July 25 and August 11. The overall goals of these flights were to obtain a mechanistic understanding of O{sub 3} production; to characterize the spatial and temporal behavior of photo-oxidants and aerosols; and to study the evolution of aerosol size distributions, including the process of new particle formation. Within the NE-OPS program, other groups provided additional trace gas, aerosol, and meteorological observations using aircraft, balloon, remote sensing, and surface based instruments (Phillbrick et al., 2000). In this article we provide an overview of the G-1 observations related to O{sub 3} production, focusing on the vertical distribution of pollutants. Ozone production rates are calculated using a box model that is constrained by observed trace gas concentrations. Highest O{sub 3} concentrations were observed on July 31, which we present as a case study. On that day, O{sub 3} concentrations above the 1-hour 120 ppb standard were observed downwind of Philadelphia and also in the plume of a single industrial facility located on the Delaware River south of the city.

  18. Beam limiter for thermonuclear fusion devices

    DOE Patents [OSTI]

    Kaminsky, Manfred S.

    1976-01-01

    A beam limiter circumscribes the interior surface of a vacuum vessel to inhibit collisions of contained plasma and the vessel walls. The cross section of the material making up the limiter has a flatsided or slightly concave portion of increased width towards the plasma and portions of decreased width towards the interior surface of the vessel. This configuration is designed to prevent a major fraction of the material sputtered, vaporized and blistered from the limiter from reaching the plasma. It also allows adequate heat transfer from the wider to the narrower portions. The preferred materials for the beam limiter are solids of sintered, particulate materials of low atomic number with low vapor pressure and low sputtering and blistering yields.

  19. A2Wind Limited | Open Energy Information

    Open Energy Info (EERE)

    Startup with strong capability in carbon fibre design targeting the wind turbine blade space. References: A2Wind Limited1 This article is a stub. You can help OpenEI by...

  20. Greenrock Energy Services Limited | Open Energy Information

    Open Energy Info (EERE)

    Kingdom Zip: EH2 2JG Product: Scotland-based company installing ground source heat pump systems. References: Greenrock Energy Services Limited1 This article is a stub. You...

  1. EarthEnergy Limited | Open Energy Information

    Open Energy Info (EERE)

    Cornwall, United Kingdom Product: EarthEnergy Systems specialises in ground source heat pump systems. References: EarthEnergy Limited1 This article is a stub. You can help OpenEI...

  2. Adiabatic limits on Riemannian Heisenberg manifolds

    SciTech Connect (OSTI)

    Yakovlev, A A

    2008-02-28

    An asymptotic formula is obtained for the distribution function of the spectrum of the Laplace operator, in the adiabatic limit for the foliation defined by the orbits of an invariant flow on a compact Riemannian Heisenberg manifold. Bibliography: 21 titles.

  3. Eclectic Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Energy Limited Place: Nottinghamshire, United Kingdom Zip: NG21 9PR Sector: Wind energy Product: Design, manufacture D400, StealthGen micro wind, DuoGen wind and water...

  4. Principle Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Principle Energy Limited Place: Isle of Man, United Kingdom Zip: 1M1 1LB Sector: Renewable Energy Product: A UK-based renewable energy company focusing on bioethanol projects in...

  5. Crionaig Power Limited | Open Energy Information

    Open Energy Info (EERE)

    government approval for a 140MW, 39-turbine wind farm at Eisgein on the Isle of Lewis. References: Crionaig Power Limited1 This article is a stub. You can help OpenEI by...

  6. Environmental radiation standards and risk limitation

    SciTech Connect (OSTI)

    Kocher, D.C.

    1987-01-01

    The Environmental Protection Agency and Nuclear Regulatory Commission have established environmental radiation standards for specific practices which correspond to limits on risk to the public that vary by several orders of magnitude and often are much less than radiation risks that are essentially unregulated, e.g., risks from radon in homes. This paper discusses a proposed framework for environmental radiation standards that would improve the correspondence with limitation of risk. This framework includes the use of limits on annual effective dose equivalent averaged over a lifetime, rather than limits on dose equivalent to whole body or any organ for each year of exposure, and consideration of exposures of younger age groups as well as adults; limits on annual effective dose equivalent averaged over a lifetime no lower than 0.25 mSv (25 mrem) per practice; maintenance of all exposures as low as reasonably achievable (ALARA); and establishment of a generally applicable de minimis dose for public exposures. Implications of the proposed regulatory framework for the current system of standards for limiting public exposures are discussed. 20 refs.

  7. Modeling analyses of the effects of changes in nitrogen oxides emissions from the electric power sector on ozone levels in the eastern United States

    SciTech Connect (OSTI)

    Edith Gego; Alice Gilliland; James Godowitch

    2008-04-15

    In this paper, we examine the changes in ambient ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for summer 2002 under three different nitrogen oxides (NOx) emission scenarios. Two emission scenarios represent best estimates of 2002 and 2004 emissions; they allow assessment of the impact of the NOx emissions reductions imposed on the utility sector by the NOx State Implementation Plan (SIP) Call. The third scenario represents a hypothetical rendering of what NOx emissions would have been in 2002 if no emission controls had been imposed on the utility sector. Examination of the modeled median and 95th percentile daily maximum 8-hr average ozone concentrations reveals that median ozone levels estimated for the 2004 emission scenario were less than those modeled for 2002 in the region most affected by the NOx SIP Call. Comparison of the 'no-control' with the '2002' scenario revealed that ozone concentrations would have been much higher in much of the eastern United States if the utility sector had not implemented NOx emission controls; exceptions occurred in the immediate vicinity of major point sources where increased NO titration tends to lower ozone levels. 13 refs., 8 figs., 2 tabs.

  8. A brightness exceeding simulated Langmuir limit

    SciTech Connect (OSTI)

    Nakasuji, Mamoru

    2013-08-15

    When an excitation of the first lens determines a beam is parallel beam, a brightness that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured brightness is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of brightness for cathode apical radii of curvature 20, 60, 120, 240, and 480 ?m were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured brightness for three different lens excitation conditions, it is concluded that the brightness depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high brightness electron beam systems.

  9. Defining coiled tubing limits -- A new approach

    SciTech Connect (OSTI)

    Newman, K.R.; Sathuvalli, U.B.; Stone, L.R.; Wolhart, S.

    1996-12-31

    The burst, collapse and axial load operating limits for Coiled Tubing (CT) are currently established using the Von Mises incipient yield criterion. This criterion has historically been used to calculate the limits for oil country tubular goods (OCTG). The limits according to this criterion are based on the point at which the pipe material reaches a load state in which it begins to yield. Because of the bending that occurs when the CT is spooled on and off the reel, and when it is bent over the guide arch, the CT is already far beyond the yield point before it enters a well. Thus, this criterion does not really apply to CT. This paper describes a research project currently in progress. The purpose of this project is to define a new set of CT limits based on criteria other than incipient yield. This new approach to setting CT operating limits takes into account the internal residual stresses in the CT which are a consequence of repeated bending cycles and the accompanying change in material properties.

  10. PP-206 Frontera Generation Limited Partnership | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    PP-206 Frontera Generation Limited Partnership PP-206 Frontera Generation Limited Partnership Presidential permit authorizing Frontera Generation Limited Partnership to construct,...