WorldWideScience

Sample records for gases additional sources

  1. 49 CFR 173.466 - Additional tests for Type A packagings designed for liquids and gases.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Additional tests for Type A packagings designed...) Materials § 173.466 Additional tests for Type A packagings designed for liquids and gases. (a) In addition to the tests prescribed in § 173.465, Type A packagings designed for liquids and gases must be...

  2. Purification of flue gases from biofuels for use in green houses as carbon dioxide source

    International Nuclear Information System (INIS)

    Kuopanportti, H.; Rissanen, R.; Vuollet, A.; Kanniainen, T.; Tikka, A.; Ramm-Schmidt, L.; Seppaelae, R.; Piira, T.

    2007-01-01

    The objectives of the project was to develop technologies by which the flue gases from burning bio fuels and peat can be purified for used in green houses as a low cost source of carbon dioxide. Traditionally carbon dioxide has been produced by burning propane or natural gas or by injecting bottled carbon dioxide gas directly into the green house. The new methods should be more affordable than the present ones. The flue gases from burning wood and peat need cleaning, because they contain substances that are harmful to plants. Also the food use of the plants may cause additional restrictions. Harmful substances are e.g. the nitrogen oxides, sulphur compounds and heavy metals. The most complex ones are the nitrogen oxides, as they cannot be sufficiently removed by traditional cleaning methods. A pilot plant was designed for testing the influence of with new methods cleaned combustion gases on commercially important crops. The project has started 01.04.2005 and was ended 30.06.2006. During the project time, commercial solutions were in construction, thus the pilot plant was decided to be built when the commercial application had been taken in use. (orig.)

  3. A study about ions sources for solids and gases

    International Nuclear Information System (INIS)

    Perez Z, E.

    1975-01-01

    Description of the different ways of obtaining ions and the causes which limits their production is covered among the various possible combinations of parameters involved in any source in order to obtain the maximum current of ions, the following were selected: filament current against: focusing voltage and accelerating voltage, establishing also a ions current relationship between detectors. In the first pair of parameters, the increase of the accelerating voltage produced the increase of the ionization current and similarly in the second and third pair of parameters the increase of the filament current and pression respectively produced the same effect. During the separation between the discharge camera and lens it was observed that to each variation in the extraction voltage corresponded an equal variation in the focusing voltage. Finally a relationship was established in the ions current between grating and detector in order to determine the more appropriate distance between the camera and the focusing lens. The increase of the ionization current when the accelerating voltage, the magnetic field and the gas pressure are increased is interpreted as a physical fact; the efficiency of a source is considered. (author)

  4. Broad beam ion source operation with four common gases

    Science.gov (United States)

    Pak, S.; Sites, J. R.

    1980-01-01

    A Kaufman-type broad beam ion source, used for sputtering and etching purposes, has been operated with Ar, Kr, O2 and N2 gas inputs over a wide range of beam energies (200-1200 eV) and gas flow rates (1-10 sccm). The maximum ion beam current density for each gas saturates at about 2.5 mA/sq cm as gas flow is increased. The discharge threshold voltage necessary to produce a beam and the beam efficiency (beam current/molecular current), however, varied considerably. Kr had the lowest threshold and highest efficiency, Ar next, then N2 and O2. The ion beam current varied only weakly with beam energy for low gas flow rates, but showed a factor of two increase when the gas flow was higher.

  5. Halogenated source gases measured by FTIR at the Jungfraujoch station: updated trends and new target species

    Science.gov (United States)

    Mahieu, Emmanuel; Bader, Whitney; Bovy, Benoît; Franco, Bruno; Lejeune, Bernard; Servais, Christian; Notholt, Justus; Palm, Mathias; Toon, Geoffrey C.

    2015-04-01

    The atmospheric abundances of chlorine and fluorine increased very significantly during the second half of last century, following large emissions of long-lived halogenated source gases used in numerous industrial and domestic applications. Given the phase-out schedule of ozone depleting substances adopted by the Montreal Protocol, its Amendments and Adjustments, the loading of the CFCs in the Earth's atmosphere is now slowly decreasing. In contrast, their first replacement products, the HCFCs, are still on the rise, with current rates of increase substantially larger than at the beginning of the 21st century. As potent greenhouse gases, a suite of fluorinated compounds are targeted by the Kyoto Protocol. At present, they continue to accumulate in the atmosphere (Montzka et al., 2011). Given their environmental impacts, continuous monitoring of the abundances of these gases is of primary importance. In addition to the in situ networks, remote sensing techniques operated from space, balloon or from the ground provide valuable information to assess the long-term tropospheric and lower stratospheric trends of an increasing number of halogenated source gases, as well as of the reservoirs resulting from their photolysis in the stratosphere (e.g. Mahieu et al., 2014a). In this contribution, we will present decadal time series of halogenated source gases monitored at the high altitude station of the Jungfraujoch (46.5° N, 8° E, 3580 m asl) with Fourier Transform Infared (FTIR) spectrometers, within the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, see http://www.ndacc.org). Total column trends presented in previous studies for CFC-11, -12 and HCFC-22 (Zander at al., 2008), CCl4 (Rinsland et al., 2012), HCFC-142b (Mahieu et al., 2013), CF4 (Mahieu et al., 2014b) and SF6 (Zander et al., 2008) will be updated using the latest available Jungfraujoch solar observations. Investigations dealing with the definition of approaches to

  6. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    Science.gov (United States)

    Ayala, Raul E.

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  7. Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2016-02-01

    Full Text Available Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg0 to gaseous divalent mercury (Hg2+, with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp. Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g., TiO2, Fe2O3, etc. on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs, affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR system promotes mercury oxidation by 34–85 %, electrostatic precipitator (ESP and fabric filter (FF remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD captures 60–95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs. For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg0 fraction (66–82 % of total mercury in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29–90 % from non-ferrous metal

  8. Algal Biomass from Wastewater and Flue Gases as a Source of Bioenergy

    Directory of Open Access Journals (Sweden)

    Sandra Lage

    2018-03-01

    Full Text Available Algae are without doubt the most productive photosynthetic organisms on Earth; they are highly efficient in converting CO2 and nutrients into biomass. These abilities can be exploited by culturing microalgae from wastewater and flue gases for effective wastewater reclamation. Algae are known to remove nitrogen and phosphorus as well as several organic contaminants including pharmaceuticals from wastewater. Biomass production can even be enhanced by the addition of CO2 originating from flue gases. The algal biomass can then be used as a raw material to produce bioenergy; depending on its composition, various types of biofuels such as biodiesel, biogas, bioethanol, biobutanol or biohydrogen can be obtained. However, algal biomass generated in wastewater and flue gases also contains contaminants which, if not degraded, will end up in the ashes. In this review, the current knowledge on algal biomass production in wastewater and flue gases is summarized; special focus is given to the algal capacity to remove contaminants from wastewater and flue gases, and the consequences when converting this biomass into different types of biofuels.

  9. Utilisation of flue gases from biofuels in greenhouses as carbon dioxide source

    International Nuclear Information System (INIS)

    Kuopanportti, H.; Rissanen, R.; Vuollet, A.; Kanniainen, T.; Tikka, A.; Ramm-Chmidt, L.; Seppaelae, R.; Piira, T.

    2006-01-01

    The objectives of the project is to develop technologies by which the flue gases from burning bio fuels and peat can be purified for used in green houses as a low cost source of carbon dioxide. Traditionally carbon dioxide has been produced by burning propane or natural gas or by injecting bottled carbon dioxide gas directly into the green house. The new methods should be more affordable than the present ones. (orig.)

  10. A recent source modification for noble gases at the Los Alamos on-line mass analysis facility

    International Nuclear Information System (INIS)

    Balestrini, S.J.; Forman, L.

    1976-01-01

    The Los Alamos on-line mass analysis experiment at the Godiva-IV burst reactor facility has been modified to determine independent fission yields of noble gases. The gases are released from a stearate target and ionization by electron bombardment. The distance traveled by the gases from the target to the ionization chamber is 20 cm. The efficiency of the electron bombardment source is lower than that of the surface ionization source that was employed to measure the yields of Rb and Cs. But this effect is compensated by the larger quantity of target metal that is possible when using a stearate target. (Auth.)

  11. Plasma waveguides: Addition of end funnels and generation in clustered gases

    International Nuclear Information System (INIS)

    Kim, K.Y.; Alexeev, I.; Fan, J.; Parra, E.; Milchberg, H.M.

    2002-01-01

    We present results from some recent experiments: the generation of a plasma funnel for improved pump pulse input coupling to plasma waveguides, and the development of a single shot transient phase diagnostic with 15 fs temporal resolution. The phase diagnostic is used in two experiments. We first demonstrate that short pulse heated clustered gases can act as an optical guiding medium and are highly absorbing. We show that this leads to a method for plasma waveguide generation at densities substantially lower than current typical values. Second, we measure transient phase shifts generated by intense pump pulses injected into plasma waveguides

  12. LNAPL source zone delineation using soil gases in a heterogeneous silty-sand aquifer

    Science.gov (United States)

    Cohen, Grégory J. V.; Jousse, Florie; Luze, Nicolas; Höhener, Patrick; Atteia, Olivier

    2016-09-01

    Source delineation of hydrocarbon contaminated sites is of high importance for remediation work. However, traditional methods like soil core extraction and analysis or recent Membrane Interface Probe methods are time consuming and costly. Therefore, the development of an in situ method based on soil gas analysis can be interesting. This includes the direct measurement of volatile organic compounds (VOCs) in soil gas taken from gas probes using a PID (Photo Ionization Detector) and the analysis of other soil gases related to VOC degradation distribution (CH4, O2, CO2) or related to presence of Light Non-Aqueous Phase Liquid (LNAPL) as 222Rn. However, in widespread heterogeneous formations, delineation by gas measurements becomes more challenging. The objective of this study is twofold: (i) to analyse the potential of several in situ gas measurement techniques in comparison to soil coring for LNAPL source delineation at a heterogeneous contaminated site where the techniques might be limited by a low diffusion potential linked to the presence of fine sands and silts, and (ii) to analyse the effect of vertical sediment heterogeneities on the performance of these gas measurement methods. Thus, five types of gases were analysed: VOCs, their three related degradation products O2, CO2 and CH4 and 222Rn. Gas measurements were compared to independent LNAPL analysis by coring. This work was conducted at an old industrial site frequently contaminated by a Diesel-Fuel mixture located in a heterogeneous fine-grained aquifer. Results show that in such heterogeneous media migration of reactive gases like VOCs occurs only across small distances and the VOC concentrations sampled with gas probes are mainly related to local conditions rather than the presence of LNAPL below the gas probe. 222Rn is not well correlated with LNAPL because of sediment heterogeneity. Oxygen, CO2, and especially CH4, have larger lengths of diffusion and give the clearest picture for LNAPL presence at this

  13. Technical Note: A new global database of trace gases and aerosols from multiple sources of high vertical resolution measurements

    Directory of Open Access Journals (Sweden)

    G. E. Bodeker

    2008-09-01

    Full Text Available A new database of trace gases and aerosols with global coverage, derived from high vertical resolution profile measurements, has been assembled as a collection of binary data files; hereafter referred to as the "Binary DataBase of Profiles" (BDBP. Version 1.0 of the BDBP, described here, includes measurements from different satellite- (HALOE, POAM II and III, SAGE I and II and ground-based measurement systems (ozonesondes. In addition to the primary product of ozone, secondary measurements of other trace gases, aerosol extinction, and temperature are included. All data are subjected to very strict quality control and for every measurement a percentage error on the measurement is included. To facilitate analyses, each measurement is added to 3 different instances (3 different grids of the database where measurements are indexed by: (1 geographic latitude, longitude, altitude (in 1 km steps and time, (2 geographic latitude, longitude, pressure (at levels ~1 km apart and time, (3 equivalent latitude, potential temperature (8 levels from 300 K to 650 K and time.

    In contrast to existing zonal mean databases, by including a wider range of measurement sources (both satellite and ozonesondes, the BDBP is sufficiently dense to permit calculation of changes in ozone by latitude, longitude and altitude. In addition, by including other trace gases such as water vapour, this database can be used for comprehensive radiative transfer calculations. By providing the original measurements rather than derived monthly means, the BDBP is applicable to a wider range of applications than databases containing only monthly mean data. Monthly mean zonal mean ozone concentrations calculated from the BDBP are compared with the database of Randel and Wu, which has been used in many earlier analyses. As opposed to that database which is generated from regression model fits, the BDBP uses the original (quality controlled measurements with no smoothing applied in any

  14. Simultaneous control of acid gases and PAHs using a spray dryer combined with a fabric filter using different additives.

    Science.gov (United States)

    Liu, Zhen Shu; Wey, Ming Yen; Lin, Chiou Liang

    2002-04-26

    The purpose of this research was to simultaneously evaluate the removal efficiency of acid gases and PAHs from the flue gas emitted by a laboratory incinerator. This flue gas contained dust, acid gases, organics and heavy metals. A spray dryer combined with a fabric filter was used as the air pollution control device (APCD) in this study. The operating conditions investigated included different feedstock additives (polyvinyl chloride (PVC) and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3). The removal efficiency for SO2 could be enhanced by adding inorganic additives, such as SiO2, CaCl2 and NaHCO3. The presence of PVC in the incinerator feedstock also increased the removal efficiency of SO2in the spray dryer. The improved removal of PAHs could be attributed to the addition of feedstock additives (PVC and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3).

  15. On Road Study of Colorado Front Range Greenhouse Gases Distribution and Sources

    Science.gov (United States)

    Petron, G.; Hirsch, A.; Trainer, M. K.; Karion, A.; Kofler, J.; Sweeney, C.; Andrews, A.; Kolodzey, W.; Miller, B. R.; Miller, L.; Montzka, S. A.; Kitzis, D. R.; Patrick, L.; Frost, G. J.; Ryerson, T. B.; Robers, J. M.; Tans, P.

    2008-12-01

    The Global Monitoring Division and Chemical Sciences Division of the NOAA Earth System Research Laboratory have teamed up over the summer 2008 to experiment with a new measurement strategy to characterize greenhouse gases distribution and sources in the Colorado Front Range. Combining expertise in greenhouse gases measurements and in local to regional scales air quality study intensive campaigns, we have built the 'Hybrid Lab'. A continuous CO2 and CH4 cavity ring down spectroscopic analyzer (Picarro, Inc.), a CO gas-filter correlation instrument (Thermo Environmental, Inc.) and a continuous UV absorption ozone monitor (2B Technologies, Inc., model 202SC) have been installed securely onboard a 2006 Toyota Prius Hybrid vehicle with an inlet bringing in outside air from a few meters above the ground. To better characterize point and distributed sources, air samples were taken with a Portable Flask Package (PFP) for later multiple species analysis in the lab. A GPS unit hooked up to the ozone analyzer and another one installed on the PFP kept track of our location allowing us to map measured concentrations on the driving route using Google Earth. The Hybrid Lab went out for several drives in the vicinity of the NOAA Boulder Atmospheric Observatory (BAO) tall tower located in Erie, CO and covering areas from Boulder, Denver, Longmont, Fort Collins and Greeley. Enhancements in CO2, CO and destruction of ozone mainly reflect emissions from traffic. Methane enhancements however are clearly correlated with nearby point sources (landfill, feedlot, natural gas compressor ...) or with larger scale air masses advected from the NE Colorado, where oil and gas drilling operations are widespread. The multiple species analysis (hydrocarbons, CFCs, HFCs) of the air samples collected along the way bring insightful information about the methane sources at play. We will present results of the analysis and interpretation of the Hybrid Lab Front Range Study and conclude with perspectives

  16. Terrestrial Sources of Perfluorinated Gases: Excess CF4 and SF6 in Mojave Desert Groundwaters

    Science.gov (United States)

    Deeds, D. A.; Vollmer, M. K.; Kulongoski, J. T.; Miller, B. R.; Hilton, D. R.; Izbicki, J. A.; Harth, C. M.; Weiss, R. F.

    2004-12-01

    The recent discovery of perfluorinated gases in fluid inclusions of granites and fluorites suggests a geologic source for the estimated 40 parts-per-trillion (ppt) of tetrafluoromethane (CF4) and <0.006 ppt of sulfur hexafluoride (SF6) in the preindustrial atmosphere. The accumulation of these gases in groundwaters with long residence times enables the detection of even small emissions from the surrounding aquifer material. We have measured high concentrations of CF4 and SF6 in groundwaters from the Mojave Desert, California. Dissolved SF6 was extracted by a purge and trap technique and analyzed by gas chromatography with electron capture detection. Dissolved CF4 was sampled by headspace extraction, using liquid helium to cryofocus the analytes prior to injection into the Medusa gas chromatograph/quadrupole mass spectrometer analytical system. Current precisions and accuracies for these measurements are on the order of 2% for both gases. Initial measurements of dissolved CF4 concentrations range from ˜0.05 to ˜1.5 pmol kg-1, about 5 to 15 times higher than expected for water in equilibrium with the preindustrial atmosphere at the local temperature and altitude of the recharge site. SF6 concentrations range from ˜0.3 to ˜16 fmol kg-1, up to several thousand times higher than expected for air-saturated water. Taking into account the large uncertainties in the estimated preindustrial atmospheric concentration of SF6, and in the estimated atmospheric lifetimes of both SF6 and CF4, the ratio of their excess abundances in Mojave Desert groundwaters agrees within an order of magnitude with the estimated ratio of natural fluxes required to sustain their preindustrial atmospheric concentrations. Relationships among dissolved CF4 and SF6 concentrations and the other geochemical properties of the aquifer, including groundwater residence times (ages), helium abundances and isotopic ratios, and fluoride concentrations will be presented.

  17. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  18. Enhancement of P3HT organic photodiodes by the addition of a GaSe9 alloy thin layer

    Science.gov (United States)

    Siqueira, M. C.; Hoff, A.; de, C., Col; Machado, K. D.; Hümmelgen, I. A.; Serbena, J. P. M.

    2017-08-01

    We report on gallium-selenium alloy (GaSe9) thin films simultaneously functioning as both blocking layer and active layer on poly(3-hexylthiophene-2, 5-diyl) (P3HT)-based organic photodiodes in order to enhance device performance. In addition to improved transport of the photogenerated charge carriers, GaSe9 films also contribute to light absorption on a different wavelength interval than that of P3HT. Three different devices are compared: ITO/GaSe9/Al, ITO/P3HT/Al and ITO/P3HT/GaSe9/Al, with the last one presenting a lower dark current density (0.90 μA cm-2), higher ON/OFF current ratio (61) and fastest response under AM 1.5 light irradiance. The observed responsivity is 7.3 mA W-1 and is almost linearly dependent on irradiance in the range 0.6-60 W m-2. A maximum external quantum efficiency of 135% and specific detectivity of 16.7 × 1011 Jones at 390 nm incident light wavelength are obtained.

  19. Formation and migration of Natural Gases: gas composition and isotopes as monitors between source, reservoir and seep

    Science.gov (United States)

    Schoell, M.; Etiope, G.

    2015-12-01

    Natural gases form in tight source rocks at temperatures between 120ºC up to 200ºC over a time of 40 to 50my depending on the heating rate of the gas kitchen. Inferring from pyrolysis experiments, gases after primary migration, a pressure driven process, are rich in C2+ hydrocarbons (C2 to C5). This is consistent with gas compositions of oil-associated gases such as in the Bakken Shale which occur in immediate vicinity of the source with little migration distances. However, migration of gases along porous rocks over long distances (up to 200km in the case of the Troll field offshore Norway) changes the gas composition drastically as C2+ hydrocarbons tend to be retained/sequestered during migration of gas as case histories from Virginia and the North Sea will demonstrate. Similar "molecular fractionation" is observed between reservoirs and surface seeps. In contrast to gas composition, stable isotopes in gases are, in general, not affected by the migration process suggesting that gas migration is a steady state process. Changes in isotopic composition, from source to reservoir to surface seeps, is often the result of mixing of gases of different origins. Examples from various gas provinces will support this notion. Natural gas basins provide little opportunity of tracking and identifying gas phase separation. Future research on experimental phase separation and monitoring of gas composition and gas ratio changes e.g. various C2+ compound ratios over C1 or isomer ratios such as iso/n ratios in butane and pentane may be an avenue to develop tracers for phase separation that could possibly be applied to natural systems of retrograde natural condensate fields.

  20. Atmospheric observations and inverse modelling for quantifying emissions of point-source synthetic greenhouse gases in East Asia

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Muhle, Jens; Weiss, Ray

    2017-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacements that are emitted from fugitive and mobile emission sources, these gases are mostly emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane (HCFC-22) factories (HFC-23). In this work we show that atmospheric measurements can serve as a basis to calculate emissions of these gases and to highlight emission 'hotspots'. We use measurements from one Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites at Gosan on Jeju Island in the Republic of Korea. This site measures CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over seven years between 2008 and 2015. We show that our 'top-down' emission estimates for NF3 and CF4 are significantly larger than 'bottom-up' estimates in the EDGAR emissions inventory (edgar.jrc.ec.europa.eu). For example we calculate South Korean emissions of CF4 in 2010 to be 0.29±0.04 Gg/yr, which is significantly larger than the Edgar prior emissions of 0.07 Gg/yr. Further, inversions for several separate years indicate that emission hotspots can be found without prior spatial information. At present these gases make a small contribution to global radiative forcing, however, given

  1. NACP Greenhouse Gases Multi-Source Data Compilation, 2000-2009

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set is a collection of measurements of carbon dioxide (CO2) and non-CO2 greenhouse gases made across North America by nine independent atmospheric...

  2. NACP Greenhouse Gases Multi-Source Data Compilation, 2000-2009

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set is a collection of measurements of carbon dioxide (CO2) and non-CO2 greenhouse gases made across North America by nine independent...

  3. Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study

    Science.gov (United States)

    Hunt, Andrew G.; Darrah, Thomas H.; Poreda, Robert J.

    2012-01-01

    Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Therefore, efforts to understand these and other domestic and global natural gas reserves have recently increased. The suspicion of fugitive mass migration issues within current Appalachian production fields has catalyzed the need to develop a greater understanding of the genetic grouping (source) and migrational history of natural gases in this area. We introduce new noble gas data in the context of published hydrocarbon carbon (C1,C2+) (13C) data to explore the genesis of thermogenic gases in the Appalachian Basin. This study includes natural gases from two distinct genetic groups: group 1, Upper Devonian (Marcellus shale and Canadaway Group) gases generated in situ, characterized by early mature (13C[C1  C2][13C113C2]: –9), isotopically light methane, with low (4He) (average, 1  103 cc/cc) elevated 4He/40Ar and 21Ne/40Ar (where the asterisk denotes excess radiogenic or nucleogenic production beyond the atmospheric ratio), and a variable, atmospherically (air-saturated–water) derived noble gas component; and group 2, a migratory natural gas that emanated from Lower Ordovician source rocks (i.e., most likely, Middle Ordovician Trenton or Black River group) that is currently hosted primarily in Lower Silurian sands (i.e., Medina or Clinton group) characterized by isotopically heavy, mature methane (13C[C1 – C2] [13C113C2]: 3), with high (4He) (average, 1.85  103 cc/cc) 4He/40Ar and 21Ne/40Ar near crustal production levels and elevated crustal noble gas content (enriched 4He,21Ne, 40Ar). Because the release of each crustal noble gas (i.e., He, Ne, Ar

  4. Radioactive Sources in Medicine: Impact of Additional Security Measures

    International Nuclear Information System (INIS)

    Classic, K. L.; Vetter, R. J.; Nelson, K. L.

    2004-01-01

    For many years, medical centers and hospitals have utilized appropriate security measures to prevent theft or unauthorized use of radioactive materials. Recent anxiety about orphan sources and terrorism has heightened concern about diversion of radioactive sources for purposes of constructing a radiological dispersion device. Some medical centers and hospitals may have responded by conducting threat assessments and incorporating additional measures into their security plans, but uniform recommendations or regulations have not been promulgated by regulatory agencies. The International Atomic Energy Agency drafted interim guidance for the purpose of assisting member states in deciding what security measures should be taken for various radioactive sources. The recommendations are aimed at regulators, but suppliers and users also may find the recommendations to be helpful. The purpose of this paper is to describe threat assessments and additional security actions that were taken by one large and one medium-sized medical center and the impact these measures had on operations. Both medical centers possess blood bank irradiators, low-dose-rate therapy sources, and Mo-99/Tc-99m generators that are common to many health care organizations. Other medical devices that were evaluated include high-dose-rate after loaders, intravascular brachytherapy sources, a Co-60 stereotactic surgery unit, and self-shielded irradiators used in biomedical research. This paper will discuss the impact additional security has had on practices that utilize these sources, cost of various security alternatives, and the importance of a security culture in assuring the integrity of security measures without negatively impacting beneficial use of these sources. (Author) 10 refs

  5. Natural and human-related sources of ozone-forming trace gases in southern Africa

    CSIR Research Space (South Africa)

    Scholes, RJ

    1998-09-01

    Full Text Available or vehicular pollution. The cloud of tropospheric ozone which forms over southern Africa every spring probably has its main origin in natural emissions of the ozone-forming trace gases, including CO from vegetation fires, emissions of NO from soils...

  6. 75 FR 74773 - Mandatory Reporting of Greenhouse Gases: Additional Sources of Fluorinated GHGs

    Science.gov (United States)

    2010-12-01

    ... manufacturing facilities. 334413 Semiconductor, photovoltaic (solid- state) device manufacturing facilities... ICR information collection request IPCC Intergovernmental Panel on Climate Change kg kilograms LCD... Deterioration PSEF process-vent-specific emission factor PV photovoltaic cells QA quality assurance QA/QC...

  7. 75 FR 18651 - Mandatory Reporting of Greenhouse Gases: Additional Sources of Fluorinated GHGs

    Science.gov (United States)

    2010-04-12

    ... Manufacturing......... 334111 Microcomputers manufacturing facilities. 334413 Semiconductor, photovoltaic (solid... transfer fluid ICR information collection request IPCC Intergovernmental Panel on Climate Change kg... Significant Deterioration PV photovoltaic cells QA quality assurance QA/QC quality assurance/quality control R...

  8. Measurement of greenhouse gases (GHGs) and source apportionment in Bakersfield, CA during CALNEX 2010

    Science.gov (United States)

    Guha, A.; Gentner, D. R.; Goldstein, A.; Provencal, R. A.; Gardner, A.; Calnex Bakersfield Science Team

    2010-12-01

    The California Global Warming Solutions Act 2006 creates a need to validate and improve the GHG inventory of the State, which has been largely based on activity and emission factor based estimates. As part of CALNEX 2010, we conducted measurements at the Bakersfield supersite of CO2, CH4, and N2O using fast response laser analyzers (LGR Inc.) to document the ambient mixing ratios of GHGs and analyze their major sources in the region, with an emphasis on understanding emissions of methane (CH4) and nitrous oxide (N2O). The site was located downwind of the urban center during the day and usually experienced a reversal of wind direction at night. Bakersfield is an urban area with heavy industrialization including petroleum refineries, oilfields, manufacturing, and cogeneration plants, all of which can be sources of the abovementioned GHGs. The site was close to a highway and potentially subject to vehicular CH4 and N2O emissions. Hence, CO and a broad variety of VOCs, which can serve as tracers (particularly for vehicle emissions), were included in the measurements to help with source apportionment. In addition to typical urban and industrial sources, Kern County is a rich agricultural region and includes a large number of cattle feedlots, dairies, settling ponds and landfills which are assumed to be some of the largest anthropogenic sources of methane in the State. Additionally, the agricultural industry uses significant amounts of fertilizers, which can lead to production of N2O from the soils along with emissions from controlled biomass burning of agricultural waste. The three GHGs studied show a strong diurnal pattern with concentrations building up in the night-time as the planetary boundary layer (PBL) becomes smaller and reversal in wind direction causes the site to become downwind of some GHG sources like landfills and feedlots. The mean background concentrations at the site (CNO2= 323 ppb; CCO2 = 390 ppm) during the day were consistent with those from the

  9. Sources and sinks of trace gases in Amazonia and the Cerrado

    Science.gov (United States)

    M.M.C. Bustamante; Michael Keller; D.A. Silva

    2009-01-01

    Data for trace gas fluxes (NOx, N2O, and CH4) from the Amazon and cerrado region are presented with focus on the processes of production and consumption of these trace gases in soils and how they may be changed because of land use changes in both regions. Fluxes are controlled by seaonality, soil moisture, soil texture, topography, and fine-root dynamics. Compared to...

  10. Greenhouse Gases

    Science.gov (United States)

    ... Precip, and Drought Climate at a Glance Extremes Societal Impacts Snow and Ice Teleconnections GHCN Monthly Monitoring References Introduction Water Vapor CO 2 CH 4 Ozone N 2 O CFCs CO Additional Information Introduction What are greenhouse gases? Many chemical compounds ...

  11. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    Science.gov (United States)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  12. Spent yeast as natural source of functional food additives

    Science.gov (United States)

    Rakowska, Rita; Sadowska, Anna; Dybkowska, Ewa; Świderski, Franciszek

    Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are β-glucans and yeast extracts. Other like foodstuffs include dried brewer’s yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. β-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. β-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood’s lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5’-GMP and 5’-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used

  13. Source apportionment of particulate matter and trace gases near a major refinery near the Houston Ship Channel

    Science.gov (United States)

    Wallace, Henry W.; Sanchez, Nancy P.; Flynn, James H.; Erickson, Mathew H.; Lefer, Barry L.; Griffin, Robert J.

    2018-01-01

    From February 7 to 27, 2015, a mobile air quality laboratory was deployed to a location proximate to a major refinery, the Port of Houston, and several neighborhoods to conduct measurements of atmospheric trace gases and particulate matter. Two statistical models were utilized to apportion the sources of pollution impacting this site and the denizens of the nearby neighborhoods. Positive matrix factorization (PMF) was performed on the organic signal of the aerosol mass spectra, resulting in five factors totaling an average of 4.1 μg/m3 of the organic aerosol: hydrocarbon-like (0.67 μg/m3), cooking (0.35 μg/m3) biomass burning (1.14 μg/m3), low-volatility oxidized (1.15 μg/m3), and semi-volatile oxidized (0.78 μg/m3). Principal component analysis was performed on daytime and nighttime data, including concentrations from PMF output, of other PM1 components, and of trace gases. This generated five daytime and five nighttime factors that explained 74.5% and 73.0% of the variance, respectively. The most important factors impacting this site were from mobile source exhaust and petrochemical aromatic compound emissions. Together these two factors also constitute most of the observed carcinogens.

  14. Quantifying Sources and Sinks of Reactive Gases in the Lower Atmosphere Using Airborne Flux Observations

    Science.gov (United States)

    Wolfe, G. M.; Hanisco, T. F.; Arkinson, H. L.; Bui, T. P.; Crounse, J. D.; Dean-Day, J.; Goldstein, A.; Guenther, A.; Hall, S. R.; Huey, G.; hide

    2015-01-01

    Atmospheric composition is governed by the interplay of emissions, chemistry, deposition, and transport. Substantial questions surround each of these processes, especially in forested environments with strong biogenic emissions. Utilizing aircraft observations acquired over a forest in the southeast U.S., we calculate eddy covariance fluxes for a suite of reactive gases and apply the synergistic information derived from this analysis to quantify emission and deposition fluxes, oxidant concentrations, aerosol uptake coefficients, and other key parameters. Evaluation of results against state-of-the-science models and parameterizations provides insight into our current understanding of this system and frames future observational priorities. As a near-direct measurement of fundamental process rates, airborne fluxes offer a new tool to improve biogenic and anthropogenic emissions inventories, photochemical mechanisms, and deposition parameterizations.

  15. Alternative current source based Schottky contact with additional electric field

    Science.gov (United States)

    Mamedov, R. K.; Aslanova, A. R.

    2017-07-01

    Additional electric field (AEF) in the Schottky contacts (SC) that covered the peripheral contact region wide and the complete contact region narrow (as TMBS diode) SC. Under the influence of AEF is a redistribution of free electrons produced at certain temperatures of the semiconductor, and is formed the space charge region (SCR). As a result of the superposition of the electric fields SCR and AEF occurs the resulting electric field (REF). The REF is distributed along a straight line perpendicular to the contact surface, so that its intensity (and potential) has a minimum value on the metal surface and the maximum value at a great distance from the metal surface deep into the SCR. Under the influence of AEF as a sided force the metal becomes negative pole and semiconductor - positive pole, therefore, SC with AEF becomes an alternative current source (ACS). The Ni-nSi SC with different diameters (20-1000 μm) under the influence of the AEF as sided force have become ACS with electromotive force in the order of 0.1-1.0 mV, which are generated the electric current in the range of 10-9-10-7 A, flowing through the external resistance 1000 Ohm.

  16. Climate change: more than just carbon dioxide. Significance, sources and solutions for non-CO{sub 2} greenhouse gases in New zealand

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The document summarises current knowledge of the non-CO{sub 2} greenhouse gases. It describes the significance of these gases, sources of emissions in New Zealand, and some of the main ways available to reduce or control emissions. Research needed to further develop understanding of processes and reduction options for these gases is identified. New Zealand has the highest ratio of non-CO{sub 2} greenhouse gas emissions to CO{sub 2} emissions of any of the developed country Parties to the Framework Convention on Climate Change. Policy action is likely to be needed to meet New Zealand`s international commitments under the Kyoto Protocol. The greenhouse gases concerned are: methane, nitrous oxide, sulfur hexafluoride, fluorinated hydrocarbons (HFCs) and perfluorocarbons (tetrafluoromethane and hexafluoroethane).

  17. Crushing of Subglacial Lake Sediment as a Source of Bio-utilisable Gases.

    Science.gov (United States)

    Gill Olivas, B.; Telling, J.; Michaud, A. B.; Skidmore, M. L.; Priscu, J. C.; Tranter, M.

    2017-12-01

    Recent research has shown microbial ecosystems exist under glaciers and ice sheets. The sources of energy to support these ecosystems are still not fully understood, particularly beneath the Antarctic Ice Sheet, where direct access to the atmosphere and in-washed organic matter and oxidising agents does not occur. Hence, sub-ice sheet energy sources are restricted to those in subglacial environments, except for ice-margin environments. This study focuses on sediments from Subglacial Lake Whillans (SLW), the first subglacial lake to be directly and cleanly sampled. Sediment from three depths in a shallow core extracted from SLW were used to assess the possible energy contributions from mechanochemical reactions to this subglacial ecosystem. To do this, the samples were crushed under an anoxic atmosphere using a ball mill. The sediments were then transferred into serum bottles under anoxic conditions. They were wetted and the headspace gas was subsequently sampled and analysed during a 40 day incubation. Results show the release of substantial amounts of hydrogen, which could potentially serve as an abiotic source of energy to microbes, in particular, methanogenic archaea. Significant amounts of short chain hydrocarbons (including methane and ethylene), possibly from the reactivation of ancient organic carbon, were also observed. Crushed samples showed a significant concentration of hydrogen peroxide produced on contact with water, as well as significant amounts of Si radicals, showing comminution of these sediments unlocks the potential for a wide range of redox conditions and reactions to develop within glacially eroded sediment under ice. This in turn provides a previously overlooked source of nutrients and energy for microbes to utilise.

  18. Inventory preliminary of gases of greenhouse effect in Colombia. Sources and drains

    International Nuclear Information System (INIS)

    Gonzalez B, Fabio; Concha P, Ismael; Vallejo M, Jorge I.; Rodriguez M, Humberto

    1997-01-01

    This document presents a summary of the results of the national greenhouse gas emissions inventory sources sinks and reservoirs project, which has been developed within the framework of the national study to address climate change. The study was initiated by a professionals group on behalf of the Academia Colombiana de Ciencias Exactas, Fisicas y Naturales in July 1995, with financial support of the German Organization of Cooperation GTZ and the technical assistance of the Venezuelan Country Study Greenhouse gas Inventory team

  19. Intense beams from gases generated by a permanent magnet ECR ion source at PKU.

    Science.gov (United States)

    Ren, H T; Peng, S X; Lu, P N; Yan, S; Zhou, Q F; Zhao, J; Yuan, Z X; Guo, Z Y; Chen, J E

    2012-02-01

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O(+), H(+), and D(+) to N(+), Ar(+), and He(+). Up to now, about 120 mA of H(+), 83 mA of D(+), 50 mA of O(+), 63 mA of N(+), 70 mA of Ar(+), and 65 mA of He(+) extracted at 50 kV through a φ 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 π mm mrad. Tungsten samples were irradiated by H(+) or He(+) beam extracted from this ion source and H∕He holes and bubbles have been observed on the samples. A method to produce a high intensity H∕He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He(+) beam injector for coupled radio frequency quadruple and SFRFQ cavity, He(+) beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He(+) beam.

  20. Intense beams from gases generated by a permanent magnet ECR ion source at PKU

    Energy Technology Data Exchange (ETDEWEB)

    Ren, H. T.; Chen, J. E. [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y. [SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2012-02-15

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

  1. Effect of additive gases and injection methods on chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F2 remote plasmas

    International Nuclear Information System (INIS)

    Yun, Y. B.; Park, S. M.; Kim, D. J.; Lee, N.-E.; Kim, K. S.; Bae, G. H.

    2007-01-01

    The authors investigated the effects of various additive gases and different injection methods on the chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F 2 remote plasmas. N 2 and N 2 +O 2 gases in the F 2 /Ar/N 2 and F 2 /Ar/N 2 /O 2 remote plasmas effectively increased the etch rate of the layers. The addition of direct-injected NO gas increased the etch rates most significantly. NO radicals generated by the addition of N 2 and N 2 +O 2 or direct-injected NO molecules contributed to the effective removal of nitrogen and oxygen in the silicon nitride and oxide layers, by forming N 2 O and NO 2 by-products, respectively, and thereby enhancing SiF 4 formation. As a result of the effective removal of the oxygen, nitrogen, and silicon atoms in the layers, the chemical dry etch rates were enhanced significantly. The process regime for the etch rate enhancement of the layers was extended at elevated temperature

  2. Hydrogen isotopic spectral determination in inert gases with the use of light source with contracted discharge

    International Nuclear Information System (INIS)

    Nemets, V.M.; Solov'ev, A.A.

    1981-01-01

    Isotopic-spectral technique for hydrogen determination in helium, neon and argon is developed. It employs a contracted high-frequency discharge as a light source to decrease the distorting effect. of a dummy signal and the ''memory'' effect of the discharge tube. The discharge is realized in a quartz tube approximately 7 mm dia. and gas pressure in it approximately 6x10 4 Pa. The analysis technique comprises sampling of gas, dosed introduction of deuterium into the sample, selection of a mixture portion into the discharge tube, spectroscopic determination of hydrogen isotope ratio and calculation of the sought for hydrogen concentration. The lower boundary of the determined concentrations of hydrogen constitutes 7x10 - 5 , 2x10 - 4 and 4x10 - 4 volumetric per cent in helium, neon, and argon, respectively

  3. Sources and sinks of selected trace gases in the tropospheric boundary layer of the eastern United States

    Science.gov (United States)

    White, Marguerite L.

    This dissertation describes three major research projects with the common goal of characterizing sources and sinks of trace gases of strong relevance to regional air quality and global climate issues. In the first study, volatile organic compound (VOC) measurements collected at a marine and continental site in northern New England were compared and examined for evidence of regional VOC sources. Biogenic VOCs, including isoprene, monoterpenes, and oxygenated VOCs, were significant components of the total reactivity at both locations. However, very different VOC distributions were observed for each site. The impact of local anthropogenic hydrocarbon sources such as liquefied petroleum gas (LPG) leakage was also evident at both sites. During the campaign, a propane flux of 9 (+/-2) x 109 molecules cm-2 s-1 was calculated for the continental site. In the second study, three hydrocarbon sources were investigated for their potential contributions to the summertime atmospheric toluene enhancements observed at a rural location in southern New Hampshire. These sources included: (1) warm season fuel evaporation emissions, (2) local industrial emissions, and (3) local vegetative emissions. The estimated contribution of fuel evaporation emissions (16-30 pptv d-1) could not fully account for observed summertime toluene enhancements (20-50 pptv d-1). Vegetation enclosure measurements suggested biogenic toluene emissions (5 and 12 pptv d-1 for alfalfa and pine trees) made significant contributions to summertime enhancements. Industrial toluene emissions, estimated at 7 pptv d-1, most likely occurred year round rather than seasonally. Finally, controls over carbonyl sulfide (COS) uptake in a temperate loblolly pine forest grown under ambient and elevated CO2 were examined in the third study. Vegetative consumption dominated net ecosystem COS uptake (10 to 40 pmol m-2 s-1) under both CO2 regimes. Environmental controls over vegetation stomatal conductance and photosynthetic

  4. Using noble gases and 87Sr/86Sr to constrain heat sources and fluid evolution at the Los Azufres Geothermal Field, Mexico

    Science.gov (United States)

    Wen, T.; Pinti, D. L.; Castro, M. C.; Lopez Hernandez, A.; Hall, C. M.; Shouakar-Stash, O.; Sandoval-Medina, F.

    2017-12-01

    Geothermal wells and hot springs were sampled for noble gases' volume fraction and isotopic measurements and 87Sr/86Sr in the Los Azufres Geothermal Field (LAGF), Mexico, to understand the evolution of fluid circulation following three decades of exploitation and re-injection of used brines. The LAGF, divided into the Southern Production Zone (SPZ) and the Northern Production Zone (NPZ), is hosted in a Miocene to Pliocene andesitic volcanic complex covered by Quaternary rhyolitic-dacitic units. Air contamination corrected 3He/4He ratios (Rc) normalized to the atmospheric ratio (Ra=1.384 x 10-6), show a median value of 6.58 indicating a dominant mantle helium component. Contributions of crustal helium up to 53% and 18% are observed in NPZ and SPZ, respectively. Observations based on Rc/Ra and 87Sr/86Sr ratios points to the mixing of three magmatic sources supplying mantle helium to the LAGF: (1) a pure mantle He (Rc/Ra = 8) and Sr (87Sr/86Sr = 0.7035) source; (2) a pure mantle helium (Rc/Ra = 8) with some radiogenic Sr (87Sr/86Sr = 0.7049) source possibly resulting from Quaternary rhyolitic volcanism; and (3) a fossil mantle He component (Rc/Ra = 3.8) with some radiogenic Sr (87Sr/86Sr = 0.7038), corresponding possibly to the Miocene andesite reservoir. Intrusions within the last 50 kyrs from sources (1) and (2) are likely responsible for the addition of mantle volatiles and heat to the hydrothermal system of Los Azufres. He and Ar isotopes indicate that heat flow is transported by both convection and conduction. Atmospheric noble gas elemental ratios suggest that geothermal wells located closer to the western re-injection zone are beginning to be dominated by re-injection of used brines (injectate). The area affected by boiling in LAGF has further extended to the north and west since the last noble gas sampling campaign in 2009.

  5. Supporting schemes for renewable energy sources and their impact on reducing the emissions of greenhouse gases in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Tsoutsos, Theocharis [Environmental Engineering Department, Technical University of Crete (TUC), University Campus, Kounoupidiana, Chania (Greece); Papadopoulou, Eleni [Managing Authority of Operational Programme Competitiveness, Athens (Greece); Katsiri, Alexandra [Civil Engineering Department, National Technical University of Athens (NTUA) (Greece); Papadopoulos, Agis M. [Department of Mechanical Engineering, Aristotle University Thessaloniki (AUT), Thessaloniki (Greece)

    2008-09-15

    For Greece the target set by the Kyoto Protocol foresees an increase of greenhouse gases (GHG) emissions by up to 25% for the period 2008-2012, always with respect to 1990 levels. Apparently it is hard to achieve this target, because the current trend of emissions leads roughly to doubling the rate of increase, than to reducing it. Consequently, further support actions are required, in order to enhance the effort needed so that the country will manage to fulfill its commitments. The present paper aims at the evaluation of the existing situation and the suggestion of further actions required in the energy sector, and particularly in the exploitation of renewable energy technologies (RETs), in order to achieve the obligations that Greece has undertaken as far as the reduction of GHG emissions is concerned, in accordance to the European and international Greek commitments. The current analysis is based on the recent available data from official Greek institutions such as the relevant Ministries, the Managing Authority of the Operational Programme Competitiveness and related European institutions. Based on the results of the current study the implementation of RETs' investments for the period 2000-2006 is estimated to cover, at best, 50% of the share corresponding to the energy sector for the national target of reducing GHG emissions. In order to achieve to a full extent the target up to 2010, an additional investment cost of some 740 MEUR will be needed. (author)

  6. The behavior of heavy metals in the process of desulfurization of Brazilian coal combustion gases by the addition of limestone

    Directory of Open Access Journals (Sweden)

    Sebag M.G.

    2001-01-01

    Full Text Available The concentrations of heavy metals in two kinds of Brazilian coals at 100° C (acid digestion and at 850° C were studied (ashes the obtained in muffle furnace with and without addition of limestone. Data were analyzed by flame atomic absorption, using the air acetylene flame. For Pb, Zn, Ni, Mn and Cu the metal concentration obtained the acid digestion were higher than metal concentration were obtained in tests in the muffle furnace. This behavior observed in the muffle furnace occurs because these metals are fixed in stable sulfated compounds in the ashes, which are difficult to dissociate at flame temperature, and also due to the volatile character of the metals, mainly Pb and Zn. There was a constant concentration in the ashes in of Cr the acid digestion and muffle furnace tests. Results from tests using an XRD apparatus indicated, he formation of sulfated compounds in the ashes for both. coals. The analysis using microprobe electronic showed retention of metals like Ni, Mn, Cu, Fe, Ti and Ca. For both coals, the low mobility of most of the metals studied occured due to the alkaline pH of sulfated ashes. These metals in the ash from coal combustion in fluidized bed reactor were also studied and showed similar results, enabling a scale-up to pilot scale.

  7. Comparison of additives amendment for mitigation of greenhouse gases and ammonia emission during sewage sludge co-composting based on correlation analysis.

    Science.gov (United States)

    Wang, Meijing; Awasthi, Mukesh Kumar; Wang, Quan; Chen, Hongyu; Ren, Xiuna; Zhao, Junchao; Li, Ronghua; Zhang, Zengqiang

    2017-11-01

    In this study, the pilot scale co-composting of sewage sludge (SS)+wheat straw amended with 10% (dry weight ratio of basis) of three different additives (zeolite, Ca-bentonite and medical stone) was conducted for 56days to evaluate the greenhouse gases (GHGs) and nitrogen conservation efficacy and its correlation with analyzed physicochemical, gaseous and biological parameters. The results indicated that all of three additives could adequately buffer pH, considerably increase temperature, and enhance organic matter degradation as well as reduce ammonia and GHGs emission. Particularly, zeolite amended treatment showed the maximum reduction of CH 4 emission by 88.45% and less amount of nitrogen loss by 28.80%, meanwhile reduced the maturity period by 2weeks. In addition, the redundancy analysis was confirmed most significant relationship between biological, GHGs, bacterial community and nutrients concentration in 10% zeolite applied treatment than other treatments. The result suggested 10% zeolite could be a suitable additive to improve the quality of sewage sludge composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Electronegative gases

    International Nuclear Information System (INIS)

    Christophorou, L.G.

    1981-01-01

    Recent knowledge on electronegative gases essential for the effective control of the number densities of free electrons in electrically stressed gases is highlighted. This knowledge aided the discovery of new gas dielectrics and the tailoring of gas dielectric mixtures. The role of electron attachment in the choice of unitary gas dielectrics or electronegative components in dielectric gas mixtures, and the role of electron scattering at low energies in the choice of buffer gases for such mixtures is outlined

  9. Field Measurements of Trace Gases and Aerosols Emitted by Undersampled Combustion Sources Including Wood and Dung Cooking Fires, Garbage and Crop Residue Burning, and Indonesian Peat Fires

    Science.gov (United States)

    Stockwell, C.; Jayarathne, T. S.; Goetz, D.; Simpson, I. J.; Selimovic, V.; Bhave, P.; Blake, D. R.; Cochrane, M. A.; Ryan, K. C.; Putra, E. I.; Saharjo, B.; Stone, E. A.; DeCarlo, P. F.; Yokelson, R. J.

    2017-12-01

    Field measurements were conducted in Nepal and in the Indonesian province of Central Kalimantan to improve characterization of trace gases and aerosols emitted by undersampled combustion sources. The sources targeted included cooking with a variety of stoves, garbage burning, crop residue burning, and authentic peat fires. Trace gas and aerosol emissions were studied using a land-based Fourier transform infrared spectrometer, whole air sampling, photoacoustic extinctiometers (405 and 870nm), and filter samples that were analyzed off-line. These measurements were used to calculate fuel-based emission factors (EFs) for up to 90 gases, PM2.5, and PM2.5 constituents. The aerosol optical data measured included EFs for the scattering and absorption coefficients, the single scattering albedo (at 870 and 405 nm), as well as the absorption Ångström exponent. The emissions varied significantly by source, although light absorption by both brown and black carbon (BrC and BC, respectively) was important for all non-peat sources. For authentic peat combustion, the emissions of BC were negligible and absorption was dominated by organic aerosol. The field results from peat burning were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat and compare well to the limited data available from other field studies. The EFs can be used with estimates of fuel consumption to improve regional emissions inventories and assessments of the climate and health impacts of these undersampled sources.

  10. Food additives and nutrient sources added to food: developments since the creation of EFSA

    OpenAIRE

    Dusemund B; Gilbert J; Gott D; Kenigswald H; König J; Lambré C; Leblanc J-C; Mortensen A; Tobback P

    2012-01-01

    During the ten-year period since the creation of EFSA, two scientific panels of EFSA, the former Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC Panel) and the Scientific Panel on Food Additives and Nutrient Sources added to Food (ANS Panel) have been successively responsible for the safety assessment of food additives and nutrient sources added to food. They have successfully addressed a challenging number of applications and ...

  11. Long-range transport pathways of tropospheric source gases originating in Asia into the northern lower stratosphere during the Asian monsoon season 2012

    Directory of Open Access Journals (Sweden)

    B. Vogel

    2016-12-01

    Full Text Available Global simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS using artificial tracers of air mass origin are used to analyze transport mechanisms from the Asian monsoon region into the lower stratosphere. In a case study, the transport of air masses from the Asian monsoon anticyclone originating in India/China by an eastward-migrating anticyclone which broke off from the main anticyclone on 20 September 2012 and filaments separated at the northeastern flank of the anticyclone are analyzed. Enhanced contributions of young air masses (younger than 5 months are found within the separated anticyclone confined at the top by the thermal tropopause. Further, these air masses are confined by the anticyclonic circulation and, on the polar side, by the subtropical jet such that the vertical structure resembles a bubble within the upper troposphere. Subsequently, these air masses are transported eastwards along the subtropical jet and enter the lower stratosphere by quasi-horizontal transport in a region of double tropopauses most likely associated with Rossby wave breaking events. As a result, thin filaments with enhanced signatures of tropospheric trace gases were measured in the lower stratosphere over Europe during the TACTS/ESMVal campaign in September 2012 in very good agreement with CLaMS simulations. Our simulations demonstrate that source regions in Asia and in the Pacific Ocean have a significant impact on the chemical composition of the lower stratosphere of the Northern Hemisphere. Young, moist air masses, in particular at the end of the monsoon season in September/October 2012, flooded the extratropical lower stratosphere in the Northern Hemisphere with contributions of up to  ≈  30 % at 380 K (with the remaining fraction being aged air. In contrast, the contribution of young air masses to the Southern Hemisphere is much lower. At the end of October 2012, approximately 1.5 ppmv H2O is found in the lower

  12. Comparison of energy sources in terms of their full-energy-chain emission factors of greenhouse gases. Proceedings of an IAEA advisory group meeting/workshop

    International Nuclear Information System (INIS)

    1996-07-01

    Sustainable and therefore climate benign energy planning is becoming a cornerstone of national energy policies in many countries that ratified the United Nations Framework Convention on Climate Change. The ratification implies a commitment to lowering greenhouse gas emissions by the so-called Annex I countries, i.e. the developed countries. Sustainable energy planning requires comparing the advantages and disadvantages of different energy sources. Such comparison cannot be done objectively without accounting for the emissions of all greenhouse gases (GHGs) - not only CO 2 - from the whole energy chain, from ''cradle to grave''. The greenhouse gas emissions upstream and downstream of the energy conversion step are inherently associated with the production of any energy carrier, such as electricity. Therefore, analysis of the emissions of all greenhouse gases from the full energy chain FENCH is considered to be the only fair approach in comparing energy sources for climate benign energy planning. This publication reports on the IAEA Advisory Group Meeting on Analysis of Net Energy Balance and Full-Energy-Chain Greenhouse Gas Emissions for Nuclear and Other Energy Systems, held in Beijing, China, 4-7 October 1994. Refs., figs., tabs

  13. Influence of sources and meteorology on surface concentrations of gases and aerosols in a coastal industrial complex

    OpenAIRE

    Allen, Andrew G.; McGonigle, Andrew J. S.; Cardoso, Arnaldo A.; Machado, Cristine M. D.; Davison, Brian; Paterlini, Willian C.; Rocha, Gisele O. da; Andrade, Jailson Bittencourt de

    2009-01-01

    p. 214-221. Emissões industriais são as fontes principais de poluição atmosférica no parque industrial de Cubatão, no sudeste do Brasil, onde a dispersão é limitada pela extensa faixa de montanhas na região. O transporte de veículos pesados é uma fonte importante de gases e aerossóis e pode influenciar nas concentrações de poluentes atmosféricos próximos à superfície, dependendo das condições meteorológicas. Este trabalho mostra que as fontes industriais foram predominantes nos fluxos de S...

  14. Hemodynamic correction of univentricular congenital heart diseases: the role of additional sources of pulmonary blood flow

    Directory of Open Access Journals (Sweden)

    Ю. Н. Горбатых

    2015-10-01

    Full Text Available Analysis of the impact of additional sources of pulmonary blood flow on the outcomes of hemodynamic correction of univentricular congenital heart disease is presented. From 2003 to 2010 31 patients received a bidirectional cavopulmonary shunt (BCPS with/without preservation of additional pulmonary blood flow sources. The latter were preserved in 18 patients (1st group and eliminated in 13 patients (2nd group. Later on all patients had Fontan procedure. Our results showed no significant impact of additional pulmonary blood flow sources on the system ventricle function and systemic AV valve regurgitation. Preservation of adequate additional pulmonary blood flow during BCPS promotes pulmonary arterial growth and increases the degree of freedom from operative intervention, while optimizing hemodynamic features of Fontan-borderline patients.

  15. Irritant gases

    NARCIS (Netherlands)

    Meulenbelt, J

    Acute inhalation injury can result from the use of household cleaning agents (e.g. chlorine, ammonia), industrial or combustion gases (e.g. sulfur dioxide, nitrogen oxides) or bioterrorism. The severity of the injury is to a great extent determined by the circumstances of exposure. If exposure was

  16. Lattice gases

    International Nuclear Information System (INIS)

    Boghosian, B.M.

    1990-01-01

    In recent years an important class of cellular automata known as lattice gases have been successfully used to model a variety of physical systems, traditionally modeled by partial differential equations. The 2-D and 3-D Navier Stokes equations for single-phase and multiphase flow, Burgers' equation, and various types of diffusion equations are all examples. The first section of this chapter is meant to be a survey of the different ideas and techniques used in this simulations. In the second section, using lattice gases for the diffusion equation and for Burgers' equation as examples, the discrete Chapman-Enskog method is demonstrated. Beginning with rules governing particle motion on a lattice, the lattice Boltzmann equation is derived, and the Chapman-Enskog method is used to derive hydrodynamical equations for the conserved quantities. The approximations used at each step are discussed in detail. The intent is to provide an introduction to the Chapman-Enskog analysis for simple lattice gases in order to prepare the reader to better understand that for the (generally more complicated) models proposed for the simulation of the Navier-Stokes equations. 29 refs., 5 figs., 4 tabs

  17. Industrial gases

    International Nuclear Information System (INIS)

    Hunter, D.; Jackson, D.; Coeyman, M.

    1993-01-01

    Industrial gas companies have fought hard to boost sales and hold margins in the tough economic climate, and investments are well down from their 1989-'91 peak. But 'our industry is still very strong long term' says Alain Joly, CEO of industry leader L'Air Liquide (AL). By 1994, if a European and Japanese recovery follows through on one in the U.S., 'we could see major [investment] commitments starting again,' he says. 'Noncryogenic production technology is lowering the cost of gas-making possible new applications, oxygen is getting plenty of attention in the environmental area, and hydrogen also fits into the environmental thrust,' says Bob Lovett, executive v.p./gases and equipment with Air Products ampersand Chemicals (AP). Through the 1990's, 'Industrial gases could grow even faster than in the past decade,' he says. Virtually a new generation of new gases applications should become reality by the mid-1990s, says John Campbell, of industry consultants J.R. Campbell ampersand Associates (Lexington, MA). Big new oxygen volumes will be required for powder coal injection in blast furnaces-boosting a steel mill's requirement as much as 40% and coal gasification/combined cycle (CGCC). Increased oil refinery hydroprocessing needs promise hydrogen requirements

  18. Space-based Lidar Measurements of Greenhouse Gases and Their Projected Impact on Quantification of Surface Sources and Sinks

    Science.gov (United States)

    Kawa, S. R.; Baker, D. F.; Chatterjee, A.; Crowell, S.

    2016-12-01

    The measurement of atmospheric greenhouse gases (GHG), principally CO2 and CH4, from space using active (lidar) sensing techniques has several potentially significant advantages in comparison to missions using passive instrument approaches. A great deal of progress has been made in development of the active methods since the US National Academy of Sciences (NAS) 2007 Decadal Survey recommended the ASCENDS mission (Active Sensing of Carbon Emissions, Nights, Days, and Seasons) for NASA's next generation CO2 observing system. Active GHG missions remain in consideration by the current NAS Decadal Survey for Earth Science 2017. In this presentation, we update the measurement characteristics expected for active GHG sensing, test how these measurements will enhance our ability to quantify GHG surface fluxes, and examine the potential role of active sensing to address carbon cycle issues as required for confident projection of carbon-climate interactions. Over the past decade, laser CO2 instrument concepts, retrieval approaches, and measurement techniques have matured significantly, driven by technology advances and by analysis of data from airborne simulators. Performance simulations updated to match the latest developments show substantially lower random errors, better spatial resolution, and more information content for global XCO2 data than just a few years ago. Observing System Simulation Experiments using global flux inversion models show corresponding improvements in resolving surface fluxes and reducing flux uncertainties for the expected lidar data. Simulations including prospective systematic (bias) errors, which are expected to be lesser for the lidar system compared to passive measurements, provide guidance for instrument design requirements. We will comment on the impact of errors in knowledge of the atmospheric state including the need for coincident measurements of O2 column in order to normalize the column abundances to dry air mole fraction. We will also

  19. Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580 m asl): Continuous measurements and their use for regional European source allocation

    Science.gov (United States)

    Reimann, Stefan; Schaub, Daniel; Stemmler, Konrad; Folini, Doris; Hill, Matthias; Hofer, Peter; Buchmann, Brigitte; Simmonds, Peter G.; Greally, Brian R.; O'Doherty, Simon

    2004-03-01

    At the high Alpine site of Jungfraujoch (3580 m asl), 23 halogenated greenhouse gases are measured quasi-continuously by gas chromatography-mass spectrometry (GCMS). Measurement data from the years 2000-2002 are analyzed for trends and pollution events. Concentrations of the halogenated trace gases, which are already controlled in industrialized countries by the Montreal Protocol (e.g., CFCs) were at least stable or declining. Positive trends in the background concentrations were observed for substances which are used as CFC-substitutes (hydrofluorocarbons, hydrochlorofluorocarbons). Background concentrations of the hydrofluorocarbons at the Jungfraujoch increased from January 2000 until December 2002 as follows: HFC 134a (CF3CH2F) from 15 to 27 ppt, HFC 125 (CF3CHF2) from 1.4 to 2.8 ppt, and HFC 152a (CHF2CH3) from 2.3 to 3.2 ppt. For HFC 152a, a distinct increase of its concentration magnitude during pollution events was observed from 2000 to 2002, indicating rising European emissions for this compound. Background concentrations of all measured compounds were in good agreement with similar measurements at Mace Head, Ireland. On the other hand, peak concentrations were significantly higher at the Jungfraujoch. This finding is due to the proximity to potent European sources, foremost in southern Europe. The average ratio of halocarbons versus carbon monoxide (CO) concentrations above their baseline values was used to estimate source strengths for the part of Europe which most influences the Jungfraujoch during pollution events. HFCs emission estimates from Jungfraujoch tend to be higher than figures at Mace Head (Ireland) from the end of the 1990s, which either reflects the increased use of these compounds or the closer location of Jungfraujoch to major southern European sources. Transport of polluted European boundary layer air masses to the high Alpine site was observed especially during frontal passages, foehn events, and thermal lifting of air masses in summer

  20. Effect of additional carbon source on naphthalene biodegradation by Pseudomonas putida G7

    International Nuclear Information System (INIS)

    Lee, Kangtaek; Park, Jin-Won; Ahn, Ik-Sung

    2003-01-01

    Addition of a carbon source as a nutrient into soil is believed to enhance in situ bioremediation by stimulating the growth of microorganisms that are indigenous to the subsurface and are capable of degrading contaminants. However, it may inhibit the biodegradation of organic contaminants and result in diauxic growth. The objective of this work is to study the effect of pyruvate as another carbon source on the biodegradation of polynuclear aromatic hydrocarbons (PAHs). In this study, naphthalene was used as a model PAH, ammonium sulfate as a nitrogen source, and oxygen as an electron acceptor. Pseudomonas putida G7 was used as a model naphthalene-degrading microorganism. From a chemostat culture, the growth kinetics of P. putida G7 on pyruvate was determined. At concentrations of naphthalene and pyruvate giving similar growth rates of P. putida G7, diauxic growth of P. putida G7 was not observed. It is suggested that pyruvate does not inhibit naphthalene biodegradation and can be used as an additional carbon source to stimulate the growth of P. putida G7 that can degrade polynuclear aromatic hydrocarbons

  1. Shale gases

    International Nuclear Information System (INIS)

    Courme, Bruno

    2012-01-01

    This Power Point presentation comments the evolution of the World population, GDP and energy demand, the evolution of the nuclear mix by 2030, the oil and gas reserves. Then, the author defines the different hydrocarbon classes (conventional gas and oil, heavy oil, oil shale), describes how natural gas is trapped in low permeability rocks, the specific production techniques (horizontal drilling and hydraulic fracturing), and recalls the well architecture. Then, he more precisely presents the various aspects of hydraulic fracturing, outlines and comments the challenges raised by this technique regarding industry ability and means and water quality and consumption. He comments the geographical distribution of gas resources, and the share of shale gases, the impact on climate, and the European shale gas production potential

  2. Fuel gases

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    This paper gives a brief presentation of the context, perspectives of production, specificities, and the conditions required for the development of NGV (Natural Gas for Vehicle) and LPG-f (Liquefied Petroleum Gas fuel) alternative fuels. After an historical presentation of 80 years of LPG evolution in vehicle fuels, a first part describes the economical and environmental advantages of gaseous alternative fuels (cleaner combustion, longer engines life, reduced noise pollution, greater natural gas reserves, lower political-economical petroleum dependence..). The second part gives a comparative cost and environmental evaluation between the available alternative fuels: bio-fuels, electric power and fuel gases, taking into account the processes and constraints involved in the production of these fuels. (J.S.)

  3. Non-CO2 greenhouse gases and climate change.

    Science.gov (United States)

    Montzka, S A; Dlugokencky, E J; Butler, J H

    2011-08-03

    Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO(2)) from fossil fuel combustion. Anthropogenic emissions of non-CO(2) greenhouse gases, such as methane, nitrous oxide and ozone-depleting substances (largely from sources other than fossil fuels), also contribute significantly to warming. Some non-CO(2) greenhouse gases have much shorter lifetimes than CO(2), so reducing their emissions offers an additional opportunity to lessen future climate change. Although it is clear that sustainably reducing the warming influence of greenhouse gases will be possible only with substantial cuts in emissions of CO(2), reducing non-CO(2) greenhouse gas emissions would be a relatively quick way of contributing to this goal.

  4. Sources of nitrous oxide and other climate relevant gases on surface area in a dairy free stall barn with solid floor and outside slurry storage

    Science.gov (United States)

    Schmithausen, Alexander J.; Trimborn, Manfred; Büscher, Wolfgang

    2018-04-01

    Livestock production systems in agriculture are one of the major emitters of greenhouse gases. So far, the focus of research in the dairy farm sector was primarily on ruminal methane (CH4) emissions. Emissions of nitrous oxide (N2O) usually arise from solid manure or in deep litter free stall barns. Release of N2O occurs as a result of interactions between organic material, nitrogen and moisture. Data of N2O emissions from modern dairy barns and liquid manure management systems are rare. Thus, the goal of this research was to determine the main sources of trace gas emissions at the dairy farm level, including N2O. Areas such as the scraped surface area where dry and wet conditions alternate are interesting. Possible sources of trace gases within and outside the barn were localised by measuring trace gas concentration rates from different dairy farm areas (e.g., areas covered with urine and excrement or slurry storage system) via the closed chamber technique. The results indicate typical emission ratios of carbon dioxide (CO2), CH4 and N2O in the various areas to generate comparable equivalent values. Calculated on the basis of nitrogen excretion from dairy cows, total emissions of N2O were much lower from barns than typically measured in fields. However, there were also areas within the barn with individual events and unexpected release factors of N2O concentrations such as urine patches, polluted areas and cubicles. Emission factors of N2O ranged from 1.1 to 5.0 mg m-2 d-1, respectively, for cleaned areas and urine patches. By considering the release factors of these areas and their proportion of the entire barn, total emission rates of 371 CO2-eq. LU-1 a-1, 36 CO2-eq. LU-1 a-1, and 1.7 kg CO2-eq. LU-1 a-1 for CO2, CH4 and N2O, respectively, were measured for the whole barn surface area. The CH4 emissions from surface area were stronger climate relevant comparing to N2O emissions, but compared to CH4 emissions from slurry storage or ruminal fermentation (not

  5. Controlled Carbon Source Addition to an Alternating Nitrification-Denitrification Wastewater Treatment Process Including Biological P Removal

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens

    1995-01-01

    The paper investigates the effect of adding an external carbon source on the rate of denitrification in an alternating activated sludge process including biological P removal. Two carbon sources were examined, acetate and hydrolysate derived from biologically hydrolyzed sludge. Preliminary batch...... that external carbon source addition may serve as a suitable control variable to improve process performance....... process, the addition of either carbon source to the anoxic zone also resulted in an instantaneous and fairly reproducible increase in the denitrification rate. Some release of phosphate associated with the carbon source addition was observed. With respect to nitrogen removal, these results indicate...

  6. TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry. II. Additional sources

    Science.gov (United States)

    Müller, C.; Kadler, M.; Ojha, R.; Schulz, R.; Trüstedt, J.; Edwards, P. G.; Ros, E.; Carpenter, B.; Angioni, R.; Blanchard, J.; Böck, M.; Burd, P. R.; Dörr, M.; Dutka, M. S.; Eberl, T.; Gulyaev, S.; Hase, H.; Horiuchi, S.; Katz, U.; Krauß, F.; Lovell, J. E. J.; Natusch, T.; Nesci, R.; Phillips, C.; Plötz, C.; Pursimo, T.; Quick, J. F. H.; Stevens, J.; Thompson, D. J.; Tingay, S. J.; Tzioumis, A. K.; Weston, S.; Wilms, J.; Zensus, J. A.

    2018-02-01

    Context. TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of - 30° declination including high-resolution very long baseline interferometry (VLBI) imaging, radio, optical/UV, X-ray, and γ-ray studies. We have previously published first-epoch8.4 GHz VLBI images of the parsec-scale structure of the initial sample. In this paper, we present images of 39 additional sources. The full sample comprises most of the radio- and γ-ray brightest AGN in the southern quarter of the sky, overlapping with the region from which high-energy (> 100 TeV) neutrino events have been found. Aims: We characterize the parsec-scale radio properties of the jets and compare them with the quasi-simultaneous Fermi/LAT γ-ray data. Furthermore, we study the jet properties of sources which are in positional coincidence with high-energy neutrino events compared to the full sample. We test the positional agreement of high-energy neutrino events with various AGN samples. Methods: TANAMI VLBI observations at 8.4 GHz are made with southern hemisphere radio telescopes located in Australia, Antarctica, Chile, New Zealand, and South Africa. Results: Our observations yield the first images of many jets below - 30° declination at milliarcsecond resolution. We find that γ-ray loud TANAMI sources tend to be more compact on parsec-scales and have higher core brightness temperatures than γ-ray faint jets, indicating higher Doppler factors. No significant structural difference is found between sources in positional coincidence with high-energy neutrino events and other TANAMI jets. The 22 γ-ray brightest AGN in the TANAMI sky show only a weak positional agreement with high-energy neutrinos demonstrating that the > 100 TeV IceCube signal is not simply dominated by a small number of the γ-ray brightest blazars. Instead, a larger number of sources have to contribute to the signal with each individual source having only a small Poisson probability for producing an event in

  7. Styrofoam Debris as a Source of Hazardous Additives for Marine Organisms.

    Science.gov (United States)

    Jang, Mi; Shim, Won Joon; Han, Gi Myung; Rani, Manviri; Song, Young Kyoung; Hong, Sang Hee

    2016-05-17

    There is growing concern over plastic debris and their fragments as a carrier for hazardous substances in marine ecosystem. The present study was conducted to provide field evidence for the transfer of plastic-associated chemicals to marine organisms. Hexabromocyclododecanes (HBCDs), brominated flame retardants, were recently detected in expanded polystyrene (styrofoam) marine debris. We hypothesized that if styrofoam debris acts as a source of the additives in the marine environment, organisms inhabiting such debris might be directly influenced by them. Here we investigated the characteristics of HBCD accumulation by mussels inhabiting styrofoam. For comparison, mussels inhabiting different substrates, such as high-density polyethylene (HDPE), metal, and rock, were also studied. The high HBCD levels up to 5160 ng/g lipid weight and the γ-HBCD dominated isomeric profiles in mussels inhabiting styrofoam strongly supports the transfer of HBCDs from styrofoam substrate to mussels. Furthermore, microsized styrofoam particles were identified inside mussels, probably originating from their substrates.

  8. Greenhouse Gases

    Science.gov (United States)

    ... Where Our Uranium Comes From U.S. Nuclear Industry Nuclear Power & the Environment Renewable Sources Hydropower Where Hydropower Is Generated Hydropower & the Environment Tidal Power Wave Power Ocean Thermal Energy Conversion Biomass Wood and Wood Waste Waste-to-Energy (MSW) Landfill Gas and Biogas ...

  9. Fuel gases in Algeria

    International Nuclear Information System (INIS)

    Arachiche, B.; Elandaloussi, H.

    1996-01-01

    For a country like Algeria, fuel gases represent an important economical challenge. To answer the increasing energy demand in the transportation sector, the use of fuel gases allows to preserve the petroleum reserves and to create specific industrial structures devoted to LPG-f (liquefied petroleum gas-fuel) and NGV (natural gas for vehicles). This paper presents the energy policy of Algeria, its reserves, production, and exportations of hydrocarbons and the internal rational use of energy sources according to its economic and environmental policy and to its internal needs. The energy consumption of Algeria in the transportation sector represents 2/3 of the petroleum products consumed in the internal market and follows a rapid increase necessary to the socio-economic development of the country. The Algerian experience in fuel gases is analysed according to the results of two successive experimentation periods for the development of NGV before and after 1994, and the resulting transportation and distribution network is described. The development of LPG-f has followed also an experimental phase for the preparation of regulation texts and a first statement of the vehicles conversion to LPG-f is drawn with its perspectives of development according to future market and prices evolutions. (J.S.)

  10. Extracellular matrix in tumours as a source of additional neoplastic lesions - a review

    Directory of Open Access Journals (Sweden)

    Madej Janusz A.

    2014-03-01

    Full Text Available The review describes the role of cells of extracellular matrix (ECM as a source of neoplastic outgrowths additional to the original tumour. The cells undergo a spontaneous transformation or stimulation by the original tumour through intercellular signals, e.g. through Shh protein (sonic hedgehog. Additionally, cells of an inflammatory infiltrate, which frequently accompany malignant tumours and particularly carcinomas, may regulate tumour cell behaviour. This is either by restricting tumour proliferation or, inversely, by induction and stimulation of the proliferation of another tumour cell type, e.g. mesenchymal cells. The latter type of tumour may involve formation of histologically differentiated stromal tumours (GIST, which probably originate from interstitial cells of Cajal in the alimentary tract. Occasionally, e.g. in gastric carcinoma, proliferation involves lymphoid follicles and lymphocytes of GALT (gut-associated lymphoid tissue, which gives rise to lymphoma. The process is preceded by the earlier stage of intestinal metaplasia, or is induced by gastritis alone. This is an example of primary involvement of inflammatory infiltrate cells in neoplastic progression. Despite the numerous histogenetic classifications of tumours (zygotoma benignum et zygotoma malignum, or mesenchymomata maligna et mesenchymomata benigna, currently in oncological diagnosis the view prevails that the direction of tumour differentiation and its degree of histologic malignancy (grading are more important factors than the histogenesis of the tumour.

  11. Assessment of open source software for CBCT in detecting additional mental foramina

    Directory of Open Access Journals (Sweden)

    Oséas Santos Junior

    2013-04-01

    Full Text Available The purpose of this study was to evaluate which post-processing imaging protocol would be better to analyze the additional mental foramen (AMF in preoperative planning with cone-beam computed tomography (CBCT exams, and to test reproducibility of measurements, using open source software (OsiriX. The software was used to detect the cases of AMF from among 58 exams for dental implant planning in edentulous mandible areas-three cases were found. The case images were submitted to qualitative analysis using 2D orthogonal MPR, 3D-MPR and 3D volume rendering protocols by two oral and maxillofacial radiologists. Quantitative analysis used the 3D-MPR protocol; the closed polygon tool measured the mental foramen (MF and the AMF areas; the length tool measured the distance between foramina. The measurements were performed independently by the examiners, at two different times. Intra- and interexaminer agreement was assessed using the intraclass correlation coefficient. The panoramic view did not show the MF and the AMF clearly. The AMF could be detected in the parasagittal view. 2D Orthogonal MPR was effective to observe the AMF in some cases. The 3D-MPR and 3D view protocols were the most effective to locate and analyze the AMF. In conclusion, a 3D view improves visualization when anatomical points are not clearly visible. 3D-MPR was considered a more effective post-processing imaging protocol to observe foramina relationships. The high reproducibility of measurements for anatomical MF variations was established using specific tools featured in open source software for CBCT. OsiriX is realistic and recommended for preoperative planning.

  12. ADDITIONS TO THE RETROSPECTIVE BIBLIOGRAPHY OF LITHUANIAN BOOKS AND THEIR SOURCES

    Directory of Open Access Journals (Sweden)

    Kaunas, Domas

    2006-12-01

    Full Text Available The bibliographers of the Lithuanian National Martynas Maþvydas Library have written an open letter to the public asking to provide data about additions to the retrospective bibliography of oldLithuanian publications published in Vilnius in 1969. This act was inspired by the Consorcium of European Research Libraries that started a project of database of the Hand Press Books publishedin 1455–1830. Lithuanian National Library is conducting retroconversion of the retrospective bibliography and provide data to the international database. This task will also lead to the creationof an original database of books and an electronic publication of it on CD-ROM. The specialists expect that bibliophiles and collectors will help to identify the additional publications. The requestto investigate personal libraries looking for the books published before 1864 was made. The data on them should be sent to the creators of the bibliography. This article is a response to the call of bibliographers. It provides information about rare books collected in the personal library of the author. They allow to make changes of the scope of the bibliography and correct some bibliographic records. The data is organised according to the importance and subject: a additions to the retrospective bibliography of books, b copies of the books registered and described in the bibliography using sources, c additional data to some bibliographic descriptions, d unknown copies of rare books, e valuable copies of books. This article also pursues a methodological purpose. It presents the personally acquired experience of data retrieval, acquisition and classification forsuppllementing of the retrospective bibliography as well as the methods of making and arguing the assumptions inevitable in the history of a book. The author believes that the registration of oldbooks from personal libraries in bibliographies is an important task of accounting of the cultural heritage. It is very important

  13. Independent and Additive Effects of Different Sources of Fluoride and Dental Fluorosis.

    Science.gov (United States)

    Celeste, Roger Keller; Luz, Patricia Blaya

    2016-01-01

    To investigate the contribution of different sources of fluoride related to dental fluorosis. This population-based, matched, case-control study (67 pairs) used a representative sample of 271 schoolchildren. Dental fluorosis was measured using Dean's index. Children's caregivers were interviewed about nine risk factors. Data were analyzed using conditional logistic regression. The prevalence of questionable cases was 18.8 percent, and the prevalence of very mild, mild, or moderate cases of dental fluorosis was 11.5 percent, with no severe case. Age of start of toothbrushing, drinking water from wells, frequency of toothbrushing, type of tooth-paste, standard/ children's mouthrinse usage, and fluoride supplements were not significant (P>0.15). Drinking water from wells and using supplements were underpowered (N less than six). Children who frequently ate toothpaste had an odds ratio of 5.56 (95% confidence interval (CI) 1.75 to 17.73) times more fluorosis; those applying toothpaste to cover the bristles had 5.55 times more fluorosis (95% CI 1.44 to 21.42); and those using an adult size toothbrush had 3.17 times more flurosis (95% CI 1.15 to 8.71). There was a significant additive interaction (Pdental fluorosis are intentional toothpaste ingestion and tooth-paste applied on the whole toothbrush.

  14. Elite sport is not an additional source of distress for adolescents with high stress levels.

    Science.gov (United States)

    Gerber, Markus; Holsboer-Trachsler, Edith; Pühse, Uwe; Brand, Serge

    2011-04-01

    This study examined whether participation in elite sport interacts with stress in decreasing or increasing symptoms of depression and anxiety among adolescents, and further, whether the interplay between participation in high-performance sport and stress is related to the perceived quality of sleep. 434 adolescents (278 girls, 156 boys; age: M = 17.2 yr.) from 15 "Swiss Olympic Sport Classes" and 9 conventional classes answered a questionnaire and completed a 7-day sleep log. Analyses of covariance showed that heightened stress was related to more depressive symptoms and higher scores for trait-anxiety. Moreover, those classified as having poor sleep by a median split cutoff reported higher levels of depressive symptoms. No significant (multivariate) main effects were found for high-performance sport athletes. Similarly, no significant two- or three-way interaction effects were found. These results caution against exaggerated expectations concerning sport participation as a stress buffer. Nevertheless, participation in high-performance sport was not found to be an additional source of distress for adolescents who reported high stress levels despite prior research that has pointed toward such a relationship.

  15. Controlled Carbon Source Addition to an Alternating Nitrification-Denitrification Wastewater Treatment Process Including Biological P Removal

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens

    1995-01-01

    The paper investigates the effect of adding an external carbon source on the rate of denitrification in an alternating activated sludge process including biological P removal. Two carbon sources were examined, acetate and hydrolysate derived from biologically hydrolyzed sludge. Preliminary batch...... experiments performed in 5 liter bottles indicated that the denitrification rate can be instantaneously increased through the addition of either carbon source. The amount by which the rate was increased depended on the amount of carbon added. In the main experiments performed in a pilot scale alternating...... process, the addition of either carbon source to the anoxic zone also resulted in an instantaneous and fairly reproducible increase in the denitrification rate. Some release of phosphate associated with the carbon source addition was observed. With respect to nitrogen removal, these results indicate...

  16. Dissolved gases

    International Nuclear Information System (INIS)

    Heaton, T.H.E.

    1981-01-01

    The concentrations of gaseous nitrogen, argon, oxygen and helium dissolved in groundwater are often different from their concentrations in rain and surface waters. These differences reflect changes in the gas content occurring after rain or surface water, having infiltrated into the ground, become isolated from equilibrium contact with the atmosphere. A study of these changes can give insight into the origin and subsequent subsurface history of groundwater. Nitrogen and argon concentrations for many groundwaters in southern Africa indicate that excess air is added to water during infiltration. The amount of excess air is believed to reflect the physical structure of the unsaturated zone and the climate of the recharge area. Since nitrogen and argon are essentially conservative in many aquifer environments in South Africa, their concentrations can be used in distinguishing grondwaters of different recharge origins. In some areas the high helium content of the groundwater suggests that much of the helium is derived through migration from a source outside (e.g. below) the aquifer itself. Radiogenic helium concentrations nevertheless show, in two artesian aquifers, a close linear relationship to the radiocarbon age of the groundwater. This indicates a uniformity in the factors responsible for the accumulation of helium, and suggests that in these circumstances helium data can be used to give information on the age of very old groundwater. In some groundwater dissolved oxygen concentrations are found to decrease with increasing groundwater age. Whilst the rate of decrease may be very different for different aquifers, the field measurement of oxygen may be useful in preliminary surveys directed toward the location of recharge areas

  17. Addition of dietary fiber sources to shakes reduces postprandial glycemia and alters food intake.

    Science.gov (United States)

    Galvão Cândido, Flávia; Silva Ton, Winder Tadeu; Gonçalves Alfenas, Rita de Cássia

    2014-09-15

    Obesity and Type 2 diabetes may be controlled by foods capable of modulating food intake and blood glucose. We investigated whether the addition of food sources of fiber or phaseolamin to shakes can control food intake and reduce postprandial glycemia. This was a randomized, single blind, crossover design study (food intake: n=22; glycemia: n=10). Five liquid meals presenting similar amounts of macronutrients (C - control shake, OB - oat bran shake, F - flaxseed shake, WB - white bean extract shake, and UB - unripe banana flour shake) were consumed in five non-consecutive days. Participants kept dietary records during the subsequent 24 hours. Blood glucose was measured at 0 (immediately before), 15, 30, 45, 60, 90 and 120 minutes after the ingestion of each shake and the incremental areas under the curves (iAUC) were calculated. Compared to C, there was a significant increase in fiber intake after the consumption of OB (+17.9g), F (+19.1g), and UB (+12.6g), and in fat after the consumption of OB (+25,4g). There was a non-significant reduction of daily energy intake in F compared to C (1524kJ; P=0.10). There was a 43% reduction in the iAUC (P=0.03) in response to UB consumption. Unripe banana flour reduced postprandial glycemic response of shakes almost by half. The effect of oat bran and flaxseed on food intake needs further investigation in long-term studies. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  18. Non-CO2 Greenhouse Gases: International Emissions and Projections

    Science.gov (United States)

    EPA August 2011 report on global non-CO2 emissions projections (1990-2030) for emissions of non-CO2 greenhouse gases (methane, nitrous oxide, and fluorinated greenhouse gases) from more than twenty emissions sources.

  19. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    Science.gov (United States)

    Stockwell, Chelsea E.; Christian, Ted J.; Goetz, J. Douglas; Jayarathne, Thilina; Bhave, Prakash V.; Praveen, Puppala S.; Adhikari, Sagar; Maharjan, Rashmi; DeCarlo, Peter F.; Stone, Elizabeth A.; Saikawa, Eri; Blake, Donald R.; Simpson, Isobel J.; Yokelson, Robert J.; Panday, Arnico K.

    2016-09-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP) of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient) combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning), crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR) spectroscopy, whole-air sampling (WAS), and photoacoustic extinctiometers (PAX; 405 and 870 nm) based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs) for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg-1 fuel burned), single scattering albedos (SSAs), and absorption Ångström exponents (AAEs). From these data we estimate black and brown carbon (BC, BrC) emission factors (g kg-1 fuel burned). The trace gas measurements provide EFs (g kg-1) for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ˜ 80 gases in all). The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68) was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10). Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg-1), organic acids (7.66 ± 6.90 g kg-1), and HCN (2.01 ± 1.25 g kg-1), where the latter could

  20. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE: emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    Directory of Open Access Journals (Sweden)

    C. E. Stockwell

    2016-09-01

    Full Text Available The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning, crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR spectroscopy, whole-air sampling (WAS, and photoacoustic extinctiometers (PAX; 405 and 870 nm based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg−1 fuel burned, single scattering albedos (SSAs, and absorption Ångström exponents (AAEs. From these data we estimate black and brown carbon (BC, BrC emission factors (g kg−1 fuel burned. The trace gas measurements provide EFs (g kg−1 for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ∼ 80 gases in all. The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68 was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10. Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg−1, organic acids (7.66 ± 6.90 g kg−1, and HCN

  1. Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources

    Directory of Open Access Journals (Sweden)

    Anuraga Jayanegara

    2014-10-01

    Full Text Available Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (ptea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.

  2. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which...... denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source...

  3. Greenhouse effect gases sources and sinks (CO2, CH4, N2O) in grasslands and reduction strategies. Greenhouse effect gases prairies. Final report of the second part of the project. April 2004

    International Nuclear Information System (INIS)

    Soussana, J.F.

    2004-04-01

    The project 'GES-Prairies' (Greenhouse Gases - Grasslands) had two main objectives: 1. To measure more accurately the fluxes of CO 2 , CH 4 and N 2 O of French grasslands and determine the greenhouse gas (GHG) balance of these areas. 2. To calculate the net GHG emissions of cattle production farms and finally to propose and evaluate some management scenarios leading to a reduction of GHG emissions. This project deals with three different spatial scales: the field scale, the farm scale and finally, the regional scale. At the field scale, during two years, fluxes of CO 2 , CH 4 and N 2 O were measured in a mid-mountain permanent grassland, previously managed intensively by cutting and grazing (Laqueuille, Auvergne, France). Results from the first complete year of measurements show that the extensification process (reduction of the stocking rate and stopping N fertilization) allows to stock more carbon in the ecosystem. At the farm scale, We developed a model (FARMSIM, coupled to PASIM) able to simulate the GHG balance of a livestock farm. FARMSIM has been tested with data obtained from a mixed livestock farm in Lorraine (dairy and meat production, annual average stocking rate = 1.3 LU ha -1 ) of 100 ha (including 76 ha of grasslands and 21 of annual crops). The results indicate a net emission of 175 t equivalent C-CO 2 for this farm. If expressed per unit of product, it represents 1.34 t equivalent C-CO 2 per LU and per year or 0.54 kg CO 2 per kg of milk and per year. At the regional scale/. The PASIM model has been used to simulate the European grasslands with a spatial resolution of 1' (about 200 * 200 km). For each grid cell, a sensibility analysis allowed to determine the N application which correspond to 30% of the N application that would maximize the annual yield of the pasture. Simulation runs on mixed systems (combining grazing and cutting) show that almost one half of the grassland area is, on average, used for cutting. These simulations predict N 2 O

  4. Impacts of carbon source addition on denitrification and phosphorus uptake in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Begum, Shamim A; Batista, Jacimaria R

    2013-01-01

    In this study, simultaneous denitrification and phosphorus (P) removal were investigated in batch tests using nitrified mixed liquor and secondary wastewater influent from a full-scale treatment plant and different levels of acetate and propionate as supplemental carbon sources. Without supplemental carbon source, denitrification occurred at low rate and P release and P uptake was negatively affected (i.e., P removal of only 59.7%). When acetate and propionate were supplied, denitrification and P release occurred simultaneously under anoxic conditions. For acetate and propionate at a C/N stoichiometric ratio of 7.6, P release was negatively affected by denitrification. For acetate, the percent P removal and denitrification were very similar for C/N ratios of 22 (5X stoichiometric) and 59 (10X stoichiometric). For propionate, both percent P removal and denitrification deteriorated for C/N ratios of 22 (5X stoichiometric) and 45 (10X stoichiometric). It was observed that carbon source added in excess to stoichiometric ratio was consumed in the aerobic zone, but P was not taken up. This implies that PAO bacteria may utilize the excess carbon source in the aerobic zone rather than their polyhydroxyalkanoate (PHA) reserves, thereby promoting deterioration of the system.

  5. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

  6. Addition of ash on drained forested peatlands in southern Sweden. Effects on forest production, fluxes of greenhouse gases and water chemistry; Tillfoersel av aska i tallskog paa dikad torvmark i soedra Sverige. Effekter paa skogsproduktion, avgaang av vaexthusgaser och vattenkemi

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf; Jacobson, Staffan; Ring, Eva [Skogforsk, Uppsala (Sweden); Ernfors, Maria; Klemedtsson, Leif [Goeteborg Univ. (Sweden). Dept. of Plant and Environmental Sciences; Nilsson, Mats [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden)

    2006-04-15

    In Sweden, about one million tones of wood ashes are produced annually, of which about 250,000-300,000 tones originate from biofuels, e.g. forest residues. Some of the ashes produced are deposited today. One alternative use is bringing back the ashes to the forest, recycling the mineral nutrients and base compounds. In bioashes, most essential mineral nutrients for plants are included, except for N, which is gasified at combustion. On most mineral soils in Sweden, plant available nitrogen is the nutrient limiting tree growth. On organic soils, tree growth is usually increased after addition of phosphorous and potassium. Thus, there is a potential for increased forest production on peatlands after ash fertilization. This can be a profitable measure. Nutrient compensation after harvesting involve ash addition with quite low doses. This is especially important in peatlands after whole-tree harvesting in order to prevent nutrient deficiency and reduced tree growth. However, there is a need for better knowledge concerning other environmental effects before ash addition can be put into large-scale practice. The general objective of this project is to study the effects of wood-ash addition on forest production and some other environmental variables on drained, forested peatlands. The studies concern tree growth, emissions of greenhouse gases and water chemistry (ground water and run off). An important issue addressed was if an expected increased accumulation of carbon (CO{sub 2}) due to increased tree growth can compensate for an expected increased emission of greenhouse gases (e.g. CO{sub 2} and CH{sub 4}) from the peat. In addition, the very effective greenhouse gas laughing gas (N{sub 2}O), must be taken into consideration. In 2003, two field experiments were established in the county of Smaaland in southeast Sweden, where wood ashes from biofuels were applied. One experiment was designed as a randomized block experiment (273 Anderstorp) where effects on forest

  7. Addition of ash on drained forested peatlands in southern Sweden. Effects on forest production, fluxes of greenhouse gases and water chemistry; Tillfoersel av aska i tallskog paa dikad torvmark i soedra Sverige. Effekter paa skogsproduktion, avgaang av vaexthusgaser och vattenkemi

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf; Ernfors, Maria; Jacobson, Staffan; Klemedtsson, Leif; Nilsson, Mats; Ring, Eva

    2006-04-15

    In Sweden, about one million tones of wood ashes are produced annually, of which about 250,000 - 300,000 tones originate from forest residues. Some of the ashes produced are deposited today. One alternative use is bringing back the ashes to the forest, recycling the mineral nutrients and base compounds. In bioashes, most essential mineral nutrients for plants are included, except for N, which is gasified at combustion. On most mineral soils in Sweden, plant available nitrogen is the nutrient limiting tree growth. On organic soils, tree growth is usually increased after addition of phosphorous and potassium. Thus, there is a potential for increased forest production on peatlands after ash fertilization. This can be a profitable measure. Nutrient compensation after harvesting involve ash addition with quite low doses. This is especially important in peatlands after whole-tree harvesting in order to prevent nutrient deficiency and reduced tree growth. However, there is a need for better knowledge concerning other environmental effects before ash addition can be put into large-scale practice. The general objective of this project is to study the effects of wood-ash addition on forest production and some other environmental variables on drained, forested peatlands. The studies concern tree growth, emissions of greenhouse gases and water chemistry (ground water and run off). An important issue addressed was if an expected increased accumulation of carbon (CO{sub 2}) due to increased tree growth can compensate for an expected increased emission of greenhouse gases (e.g. CO{sub 2} and CH{sub 4}) from the peat. In addition, the very effective greenhouse gas laughing gas (N2O), must be taken into consideration. In 2003, two field experiments were established in the county of Smaaland in south Sweden, where wood ashes from biofuels were applied. One experiment was designed as a randomized block experiment where effects on forest production and greenhouse gases (CO{sub 2}, CH

  8. Hidden sources of phosphorus: presence of phosphorus-containing additives in processed foods.

    Science.gov (United States)

    Lou-Arnal, Luis M; Arnaudas-Casanova, Laura; Caverni-Muñoz, Alberto; Vercet-Tormo, Antonio; Caramelo-Gutiérrez, Rocío; Munguía-Navarro, Paula; Campos-Gutiérrez, Belén; García-Mena, Mercedes; Moragrera, Belén; Moreno-López, Rosario; Bielsa-Gracia, Sara; Cuberes-Izquierdo, Marta

    2014-01-01

    An increased consumption of processed foods that include phosphorus-containing additives has led us to propose the following working hypothesis: using phosphate-rich additives that can be easily absorbed in processed foods involves a significant increase in phosphorus in the diet, which may be considered as hidden phosphorus since it is not registered in the food composition tables. The quantity of phosphorus contained in 118 processed products was determined by spectrophotometry and the results were contrasted with the food composition tables of the Higher Education Centre of Nutrition and Diet, those of Morandeira and those of the BEDCA (Spanish Food Composition Database) Network. Food processing frequently involves the use of phosphoric additives. The products whose label contains these additives have higher phosphorus content and higher phosphorus-protein ratio. We observed a discrepancy with the food composition tables in terms of the amount of phosphorus determined in a sizeable proportion of the products. The phosphorus content of prepared refrigerated foods hardly appears in the tables. Product labels provide little information on phosphorus content. We observed a discrepancy in phosphorus content in certain foods with respect to the food composition tables. We should educate our patients on reviewing the additives on the labels and on the limitation of processed foods. There must be health policy actions to deal with the problem: companies should analyse the phosphorus content of their products, display the correct information on their labels and incorporate it into the food composition tables. Incentives could be established to prepare food with a low phosphorus content and alternatives to phosphorus-containing additives.

  9. A radio/optical reference frame. 5: Additional source positions in the mid-latitude southern hemisphere

    Science.gov (United States)

    Russell, J. L.; Reynolds, J. E.; Jauncey, D. L.; de Vegt, C.; Zacharias, N.; Ma, C.; Fey, A. L.; Johnston, K. J.; Hindsley, R.; Hughes, J. A.; Malin, D. F.; White, G. L.; Kawaguchi, N.; Takahashi, Y.

    1994-01-01

    We report new accurate radio position measurements for 30 sources, preliminary positions for two sources, improved radio postions for nine additional sources which had limited previous observations, and optical positions and optical-radio differences for six of the radio sources. The Very Long Baseline Interferometry (VLBI) observations are part of the continuing effort to establish a global radio reference frame of about 400 compact, flat spectrum sources, which are evenly distributed across the sky. The observations were made using Mark III data format in four separate sessions in 1988-89 with radio telescopes at Tidbinbilla, Australia, Kauai, USA, and Kashima, Japan. We observed a total of 54 sources, including ten calibrators and three which were undetected. The 32 new source positions bring the total number in the radio reference frame catalog to 319 (172 northern and 147 southern) and fill in the zone -25 deg greater than delta greater than -45 deg which, prior to this list, had the lowest source density. The VLBI positions have an average formal precision of less than 1 mas, although unknown radio structure effects of about 1-2 mas may be present. The six new optical postion measurements are part of the program to obtain positions of the optical counterparts of the radio reference frame source and to map accurately the optical on to the radio reference frames. The optical measurements were obtained from United States Naval Observatory (USNO) Black Birch astrograph plates and source plates from the AAT, and Kitt Peak National Observatory (KPNO) 4 m, and the European Southern Observatory (ESO) Schmidt. The optical positions have an average precision of 0.07 sec, mostly due to the zero point error when adjusted to the FK5 optical frame using the IRS catalog. To date we have measured optical positions for 46 sources.

  10. Common genetic variants, acting additively, are a major source of risk for autism

    Directory of Open Access Journals (Sweden)

    Klei Lambertus

    2012-10-01

    Full Text Available Abstract Background Autism spectrum disorders (ASD are early onset neurodevelopmental syndromes typified by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. While rare and especially de novo genetic variation are known to affect liability, whether common genetic polymorphism plays a substantial role is an open question and the relative contribution of genes and environment is contentious. It is probable that the relative contributions of rare and common variation, as well as environment, differs between ASD families having only a single affected individual (simplex versus multiplex families who have two or more affected individuals. Methods By using quantitative genetics techniques and the contrast of ASD subjects to controls, we estimate what portion of liability can be explained by additive genetic effects, known as narrow-sense heritability. We evaluate relatives of ASD subjects using the same methods to evaluate the assumptions of the additive model and partition families by simplex/multiplex status to determine how heritability changes with status. Results By analyzing common variation throughout the genome, we show that common genetic polymorphism exerts substantial additive genetic effects on ASD liability and that simplex/multiplex family status has an impact on the identified composition of that risk. As a fraction of the total variation in liability, the estimated narrow-sense heritability exceeds 60% for ASD individuals from multiplex families and is approximately 40% for simplex families. By analyzing parents, unaffected siblings and alleles not transmitted from parents to their affected children, we conclude that the data for simplex ASD families follow the expectation for additive models closely. The data from multiplex families deviate somewhat from an additive model, possibly due to parental assortative mating. Conclusions Our results, when viewed in the context

  11. Common genetic variants, acting additively, are a major source of risk for autism.

    Science.gov (United States)

    Klei, Lambertus; Sanders, Stephan J; Murtha, Michael T; Hus, Vanessa; Lowe, Jennifer K; Willsey, A Jeremy; Moreno-De-Luca, Daniel; Yu, Timothy W; Fombonne, Eric; Geschwind, Daniel; Grice, Dorothy E; Ledbetter, David H; Lord, Catherine; Mane, Shrikant M; Martin, Christa Lese; Martin, Donna M; Morrow, Eric M; Walsh, Christopher A; Melhem, Nadine M; Chaste, Pauline; Sutcliffe, James S; State, Matthew W; Cook, Edwin H; Roeder, Kathryn; Devlin, Bernie

    2012-10-15

    Autism spectrum disorders (ASD) are early onset neurodevelopmental syndromes typified by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. While rare and especially de novo genetic variation are known to affect liability, whether common genetic polymorphism plays a substantial role is an open question and the relative contribution of genes and environment is contentious. It is probable that the relative contributions of rare and common variation, as well as environment, differs between ASD families having only a single affected individual (simplex) versus multiplex families who have two or more affected individuals. By using quantitative genetics techniques and the contrast of ASD subjects to controls, we estimate what portion of liability can be explained by additive genetic effects, known as narrow-sense heritability. We evaluate relatives of ASD subjects using the same methods to evaluate the assumptions of the additive model and partition families by simplex/multiplex status to determine how heritability changes with status. By analyzing common variation throughout the genome, we show that common genetic polymorphism exerts substantial additive genetic effects on ASD liability and that simplex/multiplex family status has an impact on the identified composition of that risk. As a fraction of the total variation in liability, the estimated narrow-sense heritability exceeds 60% for ASD individuals from multiplex families and is approximately 40% for simplex families. By analyzing parents, unaffected siblings and alleles not transmitted from parents to their affected children, we conclude that the data for simplex ASD families follow the expectation for additive models closely. The data from multiplex families deviate somewhat from an additive model, possibly due to parental assortative mating. Our results, when viewed in the context of results from genome-wide association studies, demonstrate that a

  12. Application of an additive-type mixed probability distribution to the analysis of radiation from a mixture of radioactive sources

    Directory of Open Access Journals (Sweden)

    Dolićanin-Đekić Diana

    2013-01-01

    Full Text Available This paper investigates the possibility of distinguishing between the effects of radiation coming from two or more radioactive isotopes, by using methods of statistical mathematics. The procedure uses a mixed distribution of an additive type. Mathematical treatment is demonstrated herein on an example of analysis of composite radiation from two radioactive sources.

  13. Handbook of purified gases

    CERN Document Server

    Schoen, Helmut

    2015-01-01

    Technical gases are used in almost every field of industry, science and medicine and also as a means of control by government authorities and institutions and are regarded as indispensable means of assistance. In this complete handbook of purified gases the physical foundations of purified gases and mixtures as well as their manufacturing, purification, analysis, storage, handling and transport are presented in a comprehensive way. This important reference work is accompanied with a large number of Data Sheets dedicated to the most important purified gases.  

  14. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  15. Modeling the Influence of Process Parameters and Additional Heat Sources on Residual Stresses in Laser Cladding

    Science.gov (United States)

    Brückner, F.; Lepski, D.; Beyer, E.

    2007-09-01

    In laser cladding thermal contraction of the initially liquid coating during cooling causes residual stresses and possibly cracks. Preweld or postweld heating using inductors can reduce the thermal strain difference between coating and substrate and thus reduce the resulting stress. The aim of this work is to better understand the influence of various thermometallurgical and mechanical phenomena on stress evolution and to optimize the induction-assisted laser cladding process to get crack-free coatings of hard materials at high feed rates. First, an analytical one-dimensional model is used to visualize the most important features of stress evolution for a Stellite coating on a steel substrate. For more accurate studies, laser cladding is simulated including the powder-beam interaction, the powder catchment by the melt pool, and the self-consistent calculation of temperature field and bead shape. A three-dimensional finite element model and the required equivalent heat sources are derived from the results and used for the transient thermomechanical analysis, taking into account phase transformations and the elastic-plastic material behavior with strain hardening. Results are presented for the influence of process parameters such as feed rate, heat input, and inductor size on the residual stresses at a single bead of Stellite coatings on steel.

  16. Comparison of natural gases accumulated in Oligocene strata with hydrous pyrolysis gases from Menilite Shales of the Polish Outer Carpathians

    Science.gov (United States)

    Kotarba, M.J.; Curtis, John B.; Lewan, M.D.

    2009-01-01

    This study examined the molecular and isotopic compositions of gases generated from different kerogen types (i.e., Types I/II, II, IIS and III) in Menilite Shales by sequential hydrous pyrolysis experiments. The experiments were designed to simulate gas generation from source rocks at pre-oil-cracking thermal maturities. Initially, rock samples were heated in the presence of liquid water at 330 ??C for 72 h to simulate early gas generation dominated by the overall reaction of kerogen decomposition to bitumen. Generated gas and oil were quantitatively collected at the completion of the experiments and the reactor with its rock and water was resealed and heated at 355 ??C for 72 h. This condition simulates late petroleum generation in which the dominant overall reaction is bitumen decomposition to oil. This final heating equates to a cumulative thermal maturity of 1.6% Rr, which represents pre-oil-cracking conditions. In addition to the generated gases from these two experiments being characterized individually, they are also summed to characterize a cumulative gas product. These results are compared with natural gases produced from sandstone reservoirs within or directly overlying the Menilite Shales. The experimentally generated gases show no molecular compositions that are distinct for the different kerogen types, but on a total organic carbon (TOC) basis, oil prone kerogens (i.e., Types I/II, II and IIS) generate more hydrocarbon gas than gas prone Type III kerogen. Although the proportionality of methane to ethane in the experimental gases is lower than that observed in the natural gases, the proportionality of ethane to propane and i-butane to n-butane are similar to those observed for the natural gases. ??13C values of the experimentally generated methane, ethane and propane show distinctions among the kerogen types. This distinction is related to the ??13C of the original kerogen, with 13C enriched kerogen generating more 13C enriched hydrocarbon gases than

  17. High Temperature Thermoplastic Additive Manufacturing Using Low-Cost, Open-Source Hardware

    Science.gov (United States)

    Gardner, John M.; Stelter, Christopher J.; Yashin, Edward A.; Siochi, Emilie J.

    2016-01-01

    Additive manufacturing (or 3D printing) via Fused Filament Fabrication (FFF), also known as Fused Deposition Modeling (FDM), is a process where material is placed in specific locations layer-by-layer to create a complete part. Printers designed for FFF build parts by extruding a thermoplastic filament from a nozzle in a predetermined path. Originally developed for commercial printers, 3D printing via FFF has become accessible to a much larger community of users since the introduction of Reprap printers. These low-cost, desktop machines are typically used to print prototype parts or novelty items. As the adoption of desktop sized 3D printers broadens, there is increased demand for these machines to produce functional parts that can withstand harsher conditions such as high temperature and mechanical loads. Materials meeting these requirements tend to possess better mechanical properties and higher glass transition temperatures (Tg), thus requiring printers with high temperature printing capability. This report outlines the problems and solutions, and includes a detailed description of the machine design, printing parameters, and processes specific to high temperature thermoplastic 3D printing.

  18. Short-term nitrogen additions can shift a coastal wetland from a sink to a source of N2O

    Science.gov (United States)

    Moseman-Valtierra, Serena; Gonzalez, Rosalinda; Kroeger, Kevin D.; Tang, Jianwu; Chao, Wei Chun; Crusius, John; Bratton, John F.; Green, Adrian; Shelton, James

    2011-01-01

    Coastal salt marshes sequester carbon at high rates relative to other ecosystems and emit relatively little methane particularly compared to freshwater wetlands. However, fluxes of all major greenhouse gases (N2O, CH4, and CO2) need to be quantified for accurate assessment of the climatic roles of these ecosystems. Anthropogenic nitrogen inputs (via run-off, atmospheric deposition, and wastewater) impact coastal marshes. To test the hypothesis that a pulse of nitrogen loading may increase greenhouse gas emissions from salt marsh sediments, we compared N2O, CH4 and respiratory CO2fluxes from nitrate-enriched plots in a Spartina patens marsh (receiving single additions of NaNO3 equivalent to 1.4 g N m−2) to those from control plots (receiving only artificial seawater solutions) in three short-term experiments (July 2009, April 2010, and June 2010). In July 2009, we also compared N2O and CH4 fluxes in both opaque and transparent chambers to test the influence of light on gas flux measurements. Background fluxes of N2O in July 2009 averaged −33 μmol N2O m−2 day−1. However, within 1 h of nutrient additions, N2O fluxes were significantly greater in plots receiving nitrate additions relative to controls in July 2009. Respiratory rates and CH4 fluxes were not significantly affected. N2O fluxes were significantly higher in dark than in transparent chambers, averaging 108 and 42 μmol N2O m−2 day−1 respectively. After 2 days, when nutrient concentrations returned to background levels, none of the greenhouse gas fluxes differed from controls. In April 2010, N2O and CH4 fluxes were not significantly affected by nitrate, possibly due to higher nitrogen demands by growing S. patens plants, but in June 2010 trends of higher N2O fluxes were again found among nitrate-enriched plots, indicating that responses to nutrient pulses may be strongest during the summer. In terms of carbon equivalents, the highest average N2O and CH4 fluxes observed, exceeded half

  19. Hybrid subtractive-additive-welding microfabrication for lab-on-chip applications via single amplified femtosecond laser source

    Science.gov (United States)

    Jonušauskas, Linas; Rekštytė, Sima; Buividas, Ričardas; Butkus, Simas; Gadonas, Roaldas; Juodkazis, Saulius; Malinauskas, Mangirdas

    2017-09-01

    An approach employing ultrafast laser hybrid subtractive-additive microfabrication, which combines ablation, three-dimensional nanolithography, and welding, is proposed for the realization of a lab-on-chip (LOC) device. A single amplified Yb:KGW femtosecond (fs)-pulsed laser source is shown to be suitable for fabricating microgrooves in glass slabs, polymerization of fine-meshes microfilter out of hybrid organic-inorganic photopolymer SZ2080 inside them, and, finally, sealing the whole chip with cover glass into a single monolithic piece. The created microfluidic device proved its particle sorting function by separating 1- and 10-μm polystyrene spheres in an aqueous mixture. All together, this proves that laser microfabrication based on a single amplified fs laser source is a flexible and versatile approach for the hybrid subtractive-additive manufacturing of functional mesoscale multimaterial LOC devices.

  20. Annihilation in Gases and Galaxies

    Science.gov (United States)

    Drachman, Richard J. (Editor)

    1990-01-01

    This publication contains most of the papers, both invited and contributed, that were presented at the Workshop of Annihilation in Gases and Galaxies. This was the fifth in a biennial series associated with the International Conference on the Physics of Electronic and Atomic Collisions. Subjects covered included the scattering and annihilation of positrons and positronium atoms in various media, including those of astrophysical interest. In addition, the topics of antimatter and dark matter were covered.

  1. Using integrated noble gas and hydrocarbon geochemistry to constrain the source of hydrocarbon gases in shallow aquifers in the northern Appalachian Basin

    Science.gov (United States)

    Rising demands for domestic energy sources, mandates for cleaner burning fuels for electricity generation, and the approach of peak global hydrocarbon production are driving the transformation from coal to natural gas from unconventional energy resources.

  2. Cumulative production of gases and France parameters evaluated by the semi-automatic in vitro technique of carbohydrates sources for ruminants Produção cumulativa de gases e parâmetros de France avaliados pela técnica semiautomática in vitro de fontes de carboidratos de ruminantes

    Directory of Open Access Journals (Sweden)

    Alberto Corrêa Mendonça

    2010-06-01

    Full Text Available It was evaluated, by semi-automatic technique in vitro, the effect of the associations among different sources of carbohydrates (dent corn or flint corn or citrus pulp to forage (corn silage, sorghum silage + silage corn residue, elephant grass, sugar cane, silage corn residue on the cumulative gas production. There was a significant interaction between treatments and incubation times. The association of sorghum silage with silage corn residue + dent corn (SRDE resulted in higher cumulative gas production at all times with total production of 325.3 mL at 96 hours. The France's parameters showed that the treatment with sugar-cane (CADE, CADU and CAPC resulted in high potential gas production (322, 325 and 317mL/gMS, respectively. The associations from Elephantgrass + dent or flint corn (CEDU and CEDE resulted in high colonization times (2.21 and 1.07 hours, respectively. In general, the best results of gas production were obtained in the treatments that addressed the association of sorghum silage + silage corn residue in bulky portion (SRDE, and SRDU srpc showing the potential for using these sources in the diets of ruminants.Avaliou-se, através da técnica semiautomática in vitro, o efeito das associações entre diferentes fontes de carboidratos (milho dentado ou milho duro ou polpa cítrica e forragens (silagem de milho, silagem de sorgo + silagem de resíduo de milho, capim elefante, cana-de-açúcar, silagem de resíduo de milho, sobre a produção cumulativa de gases. Constatou-se interação significativa entre os tratamentos e tempos de incubação. A associação de silagem de sorgo com silagem de resíduo de milho + milho dentado (SRDE resultou em maior produção cumulativa de gases em todos os tempos com produção total de 325,3mL às 96 horas. Com relação aos parâmetros de France os tratamentos com cana-de-açúcar (CADE, CADU e CAPC resultaram em elevado potencial para produção de gases (322, 325 e 317mL/gMS, respectivamente

  3. Low-emission combustion and using weak gases as a source of energy - Final report; Emissionsarme Verbrennung und energetische Nutzung von Schwachgasen bis unter 2.5 MJ/m{sup 3} - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, M.

    2009-05-15

    This final report for the Swiss Federal Office of Energy (SFOE) reports on research work done on the use of weak gas such as that generated in landfill sites as a source of energy. Such gases are quoted as having only 8 per cent of the calorific value of natural gas. A project is described which is to develop a bivalent burner which can use the weak gas to help provide heating for a fermenter that can produce biogas from organic wastes. The aims of the project are discussed and figures are presented on the results obtained in laboratory tests. Field tests are stated to have shown that the new burner produces better results as far as residual methane and carbon monoxide in the exhaust fumes are concerned.

  4. Kinetic theory of gases

    CERN Document Server

    Kauzmann, Walter

    2012-01-01

    Monograph and text supplement for first-year students of physical chemistry focuses chiefly on the molecular basis of important thermodynamic properties of gases, including pressure, temperature, and thermal energy. 1966 edition.

  5. Gases in groundwater

    International Nuclear Information System (INIS)

    Vogel, J.C.; Heaton, T.H.E.

    1979-01-01

    Contributing to both economic and environmental spheres, radon and helium contained in groundwater are being used to detect uranium mineralisation and in conjunction with other gases, to locate natural gas and oil deposits; they are also helping to unravel the earth's past climatic history. Analysis of the gases dissolved in groundwater is proving useful in widely different fields ranging from uranium exploration, to earthquake prediction and the determination of palaeotemperatures [af

  6. Rating of transport and radiation source events. Draft additional guidance for the INES national officers for pilot use and feedback

    International Nuclear Information System (INIS)

    2004-09-01

    The International Nuclear Event Scale (INES) is a means for promptly communicating to the public in consistent terms the safety significance of any reported event associated with radioactive material and/or radiation and to any event occurring during the transport of radioactive material. As described in the 2001 Edition of the INES User.s Manual, events are classified on the scale at seven levels: the upper levels (4-7) are termed accidents. and the lower levels (1-3) incidents. Events which have no safety significance are classified below scale at Level 0 and termed deviations. An overview of the principles for the rating under INES together with flow charts summarizing the rating process is provided in Appendix I. The 2001 Edition of the INES User.s Manual provides some guidance for the rating of transport and radiation source events. At the technical meeting held in 2002 the INES National Officers requested the IAEA/NEA Secretariat to prepare additional guidance. Progress was reported at the Technical Meeting of the INES National Officers in March 2004 where preparation of this draft additional guidance was requested for pilot use. This note provides additional guidance on the rating of transport and radiation source events. It is for pilot use and feedback and is broadly consistent with the INES User.s Manual. It provides more detailed information and an expanded approach for the rating based on actual exposure of workers and members of the public. It is designed to be used as a self-standing document with limited need for reference to the INES User Manual. (author)

  7. Emissions, activity data, and emission factors of fluorinated greenhouse gases (F-Gases) in Germany 1995-2002

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Winfried [Oeko-Recherche, Buero fuer Umweltforschung und -beratung GmbH, Frankfurt am Main (Germany)

    2005-06-15

    Before the 1997 Kyoto Protocol on Climate Protection, the fluorinated greenhouse gases HFCs, PFCs, and SF6 (F-gases) aroused little public attention. Since then, the standards on surveying and reporting on national emissions have been rising constantly. Amongst others, the annual reporting to the UNFCCC secretariat makes detailed declarations on use and emissions of F-gases necessary, which have to be filled in specified formats for submission (Common Reporting Format = CRF). The scientific basis has been set out by the UNFCCC guidelines on reporting, in accordance with the instructions laid down in IPCC good practice guidance. Additionally, in Germany the Centralised System of Emissions (ZSE) shall provide a suitable tool to satisfy any quality needs of both activity data and emission factors. From 1995 onwards, activity data and emissions of each individual application sector shall be presented in a comprehensible and transparent way. Therefore, the way of data collection as well as the estimation methods applied must be well documented. Moreover, data has to be prepared for appropriate importation into ZSE. It is the objective of this study to provide the transparency demanded within 40 national application sectors of F-gases, for the period between 1995 and 2002. - Firstly, all the activity data as well as the emissions related to them are presented and commented. This applies to manufacturing of products, F-gases banked in operating systems, and decommissioning. - Secondly, the methodologies applied to calculate the emissions are described and all sources of information are revealed, e.g. literature, names of experts from the manufacturing industry, users, trade, and academia. - Thirdly, reliability and safety of data are discussed. - Fourthly, possible deviations from the IPCC default values are stated and given reasons for. Wherever this intensive reviewing of 40 sectors through eight years of reporting uncovers gaps or inconsistencies in previous reports

  8. Kinetic Theory of Granular Gases

    International Nuclear Information System (INIS)

    Trizac, Emmanuel

    2005-01-01

    Granular gases are composed of macroscopic bodies kept in motion by an external energy source such as a violent shaking. The behaviour of such systems is quantitatively different from that of ordinary molecular gases: due to the size of the constituents, external fields have a stronger effect on the dynamics and, more importantly, the kinetic energy of the gas is no longer a conserved quantity. The key role of the inelasticity of collisions has been correctly appreciated for about fifteen years, and the ensuing consequences in terms of phase behaviour or transport properties studied in an increasing and now vast body of literature. The purpose of this book is to help the newcomer to the field in acquiring the essential theoretical tools together with some numerical techniques. As emphasized by the authors-who were among the pioneers in the domain- the content could be covered in a one semester course for advanced undergraduates, or it could be incorporated in a more general course dealing with the statistical mechanics of dissipative systems. The book is self-contained, clear, and avoids mathematical complications. In order to elucidate the main physical ideas, heuristic points of views are sometimes preferred to a more rigorous route that would lead to a longer discussion. The 28 chapters are short; they offer exercises and worked examples, solved at the end of the book. Each part is supplemented with a relevant foreword and a useful summary including take-home messages. The editorial work is of good quality, with very few typographical errors. In spite of the title, kinetic theory stricto sensu is not the crux of the matter covered. The authors discuss the consequences of the molecular chaos assumption both at the individual particle level and in terms of collective behaviour. The first part of the book addresses the mechanics of grain collisions. It is emphasized that considering the coefficient of restitution ε -a central quantity governing the inelasticity of

  9. Effect of energy source and ruminally degradable protein addition on performance of lactating beef cows and digestion characteristics of steers.

    Science.gov (United States)

    Baumann, T A; Lardy, G P; Caton, J S; Anderson, V L

    2004-09-01

    Two trials were conducted to determine the effect of energy source (ENG) and ruminally degradable protein (RDP) on lactating cow performance and intake and digestion in beef steers. In Trial 1, 78 cow-calf pairs were used in a 2 x 2 factorial design to determine the effect of ENG (corn or soyhulls; SH) and RDP (with our without sunflower meal) to a forage diet for lactating beef cows. The basal diet consisted of 75% grass hay (11.5% CP) and 25% wheat straw (7.4% CP). Supplement treatments and predicted RDP balances were corn (-415 g of RDP/d); SH (-260 g of RDP/d); corn plus RDP (0 g of RDP/d); or SH plus RDP (0 g of RDP/d). Data were analyzed as a split-plot in time, with pen as the experimental unit (two pens per treatment). No interaction between ENG and RDP was present (P > 0.08) for any response variable. No differences (P > 0.39) due to ENG or RDP were noted for BW, BCS, or milk yield; however, final calf weight tended to increase with ENG (P = 0.06). In Trial 2, a 5 x 5 Latin square was used to determine effects of ENG and RDP on intake and digestion in steers (686 +/- 51 kg BW). Treatments were arranged as a 2 x 2 plus one factorial and comprised a control (CON; grass hay, 7% CP), grass hay plus 0.4% BW SH, grass hay plus 0.4% BW SH and 0.15% BW sunflower meal, grass hay plus 0.4% BW corn, and grass hay plus 0.4% BW corn and 0.2% BW sunflower meal. Preplanned contrasts included main effects of ENG and RDP, ENG x RDP interaction, and CON vs. supplemented (SUP) treatments. Supplementation increased total DMI compared with CON (P = 0.001), but forage DMI was greater (P = 0.001) for CON than for SUP. An ENG x RDP interaction occurred for forage DMI (P = 0.02); addition of RDP to corn decreased forage intake, whereas addition of RDP to SH had no effect. There was an ENG x RDP interaction (P = 0.001) for ruminal pH; pH tended to increase with RDP addition to SH (P = 0.07), but decreased with RDP addition to corn (P = 0.001). Supplementation increased ruminal

  10. Additively manufactured MEMS multiplexed coaxial electrospray sources for high-throughput, uniform generation of core-shell microparticles.

    Science.gov (United States)

    Olvera-Trejo, D; Velásquez-García, L F

    2016-10-18

    This study reports the first MEMS multiplexed coaxial electrospray sources in the literature. Coaxial electrospraying is a microencapsulation technology based on electrohydrodynamic jetting of two immiscible liquids, which allows precise control with low size variation of the geometry of the core-shell particles it generates, which is of great importance in numerous biomedical and engineering applications, e.g., drug delivery and self-healing composites. By implementing monolithic planar arrays of miniaturized coaxial electrospray emitters that work uniformly in parallel, the throughput of the compound microdroplet source is greatly increased, making the microencapsulation technology compatible with low-cost commercial applications. Miniaturized core-shell particle generators with up to 25 coaxial electrospray emitters (25 emitters cm -2 ) were fabricated via stereolithography, which is an additive manufacturing process that can create complex microfluidic devices at a small fraction of the cost per device and fabrication time associated with silicon-based counterparts. The characterization of devices with the same emitter structure but different array sizes demonstrates uniform array operation. Moreover, the data demonstrate that the per-emitter current is approximately proportional to the square root of the flow rate of the driving liquid, and it is independent of the flow rate of the driven liquid, as predicted by the theory. The core/shell diameters and the size distribution of the generated compound microparticles can be modulated by controlling the flow rates fed to the emitters.

  11. Hypersonics and rarefied gases

    Science.gov (United States)

    Lengrand, Jean-Claude; Allegre, Jean; Raffin, Michel

    1987-10-01

    A molecular approach to the dynamics of rarefied gases is used to solve problems in the modeling of hypersonic asymmetric flows. The microscopic, molecular, macroscopic, continuous, and hydrodynamic approaches are compared. Application of the Monte Carlo method to the simulation of intermolecular collisions, the gas-surface interaction, and hypersonic flows is considered. The use of experimental methods such as wind tunnels, flow visualizations, hot-wire techniques, laser velocimetry, and electron beam sensors for the study of real phenomena related to rarefied gases and for the validation of the calculation methods is also discussed.

  12. The greenhouse effect gases

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the greenhouse effect gases. It presents the greenhouses effect as a key component of the climate system, the impacts of the human activity, the foreseeable consequences of global warming, the Kyoto protocol and Total commitment in the domain. (A.L.B.)

  13. Improved dual-energy material discrimination for dual-source CT by means of additional spectral filtration.

    Science.gov (United States)

    Primak, A N; Ramirez Giraldo, J C; Liu, X; Yu, L; McCollough, C H

    2009-04-01

    The use of additional spectral filtration for dual-energy (DE) imaging using a dual-source CT (DSCT) system was investigated and its effect on the material-specific DE(ratio) was evaluated for several clinically relevant materials. The x-ray spectra, data acquisition, and reconstruction processes for a DSCT system (Siemens Definition) were simulated using information provided by the system manufacturer, resulting in virtual DE images. The factory-installed filtration for the 80 kV spectrum was left unchanged to avoid any further reductions in tube output, and only the filtration for the high-energy spectrum was modified. Only practical single-element filter materials within the atomic number range of 40 simulations were performed for three attenuation scenarios: Head, body, and large body. The large body scenario was evaluated for the DE acquisition mode using the 100 and 140 kV spectra. The DE(ratio) for calcium hydroxyapatite (simulating bone or calcifications), iodine, and iron were determined for CT images simulated using the modified and factory-installed filtration. Several filter materials were found to perform well at proper thicknesses, with tin being a good practical choice. When image noise was matched between the low- and high-energy images, the spectral difference in mean absorbed energy using tin was increased from 25.7 to 42.7 keV (head), from 28.6 to 44.1 keV (body), and from 20.2 to 30.2 keV (large body). The overlap of the signal spectra for energies below 80 keV was reduced from 78% to 31% (head), from 93% to 27% (body), and from 106% to 79% (large body). The DE(ratio) for the body attenuation scenario increased from 1.45 to 1.91 (calcium), from 1.84 to 3.39 (iodine), and from 1.73 to 2.93 (iron) with the additional tin filtration compared to the factory filtration. This use of additional filtration for one of the x-ray tubes used in dual-source DECT dramatically increased the difference between material-specific DE ratios, e.g., from 0.39 to 1

  14. Generation and release of radioactive gases in LLW disposal facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S. [Harvard School Public Health, Boston, MA (United States); Simonson, S.A. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-02-01

    The atmospheric release of radioactive gases from a generic engineered LLW disposal facility and its radiological impacts were examined. To quantify the generation of radioactive gases, detailed characterization of source inventory for carbon-14, tritium, iodine-129, krypton-85, and radon-222, was performed in terms of their activity concentrations; their distribution within different waste classes, waste forms and containers; and their subsequent availability for release in volatile or gaseous form. The generation of gases was investigated for the processes of microbial activity, radiolysis, and corrosion of waste containers and metallic components in wastes. The release of radionuclides within these gases to the atmosphere was analyzed under the influence of atmospheric pressure changes.

  15. Process of radioactive waste gases

    International Nuclear Information System (INIS)

    Queiser, H.; Schwarz, H.; Schroter, H.J.

    1975-01-01

    A method is described in which the radiation level of waste gases from nuclear power plants containing both activation and fission gases is controlled at or below limits permitted by applicable standards by passing such gases, prior to release to the atmosphere, through an adsorptive delay path including a body of activated carbon having the relation to the throughput and character of such gases. (U.S.)

  16. Sudden releases of gases

    Directory of Open Access Journals (Sweden)

    Chaloupecká Hana

    2014-03-01

    Full Text Available Conurbations all over the world have enlarged for numberless years. The accidental or intentional releases of gases become more frequent. Therefore, these crises situations have to be studied. The aim of this paper is to describe experiments examining these processes that were carried out in the laboratory of Environmental Aerodynamics of the Institute of Thermomechanics AS CR in Nový Knín. Results show huge puff variability from replica to replica.

  17. Addition of ash in drained peatland forests in southern Sweden - Forest yield and fluxes of greenhouse gases; Tillfoersel av aska i skog paa dikad torvmark i soedra Sverige - Skogsproduktion och emission av vaexthusgaser

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem Ulf (Skogforsk, Uppsala (Sweden)); Bjoerk, Robert G; Klemedtsson, Leif (Goeteborgs universitet (Sweden))

    2012-02-15

    The objective of the present study was to evaluate effects of wood-ash application (3.3 and 6.6 tonnes d.w. self-harden crushed wood ash ha-1) in forests on drained peatlands in southern Sweden. Tree growth (three sites) and fluxes of greenhouse gases (one site) were measured in field experiments. In the two experiments (Anderstorp and Bredaryd) in Scots pine stands (Pinus sylvestris L.) on oligotrophic mires, tree growth increased significantly during the seven-eight year long effect periods after ash application. In an earlier study in Anderstorp, the annual emissions of CO{sub 2}, CH{sub 4} and N{sub 2}O from the peat were shown to be unaffected by the ash application. In Skogaryd, a Norway spruce stand (Picea abies L. Karst.) on a minerotrophic mire, the growth was indicated to increase during the five-year effect period. In the same experiment, the previously found reduction in emissions of both CO{sub 2} and N{sub 2}O during the first two years after ash application were no longer significant, although the emissions where lower, for N{sub 2}O only in the high dose ash treatment. CH{sub 4} was unaffected during the whole observed period. During the first five years, application of 3-6 tonnes d.w. crushed wood ash ha-1 in the two studied forests on drained peatlands did not render in an increased Global Warming Potential (GWP), but rather a reduction

  18. Fate of Gases generated from Nuclear Wastes

    International Nuclear Information System (INIS)

    Srinivasulu, M.; Francis, A. J.; Francis, A. J.

    2013-01-01

    The backfill materials such as cement, bentonite or crushed rock are used as engineered barriers against groundwater infiltration and radionuclide transport. Gas generation from radioactive wastes is attributed to radiolysis, corrosion of metals, and degradation of organic materials. Corrosion of steel drums and biodegradation of organic materials in L/ILW can generate gas which causes pressure build up and has the potential to compromise the integrity of waste containers and release the radionuclides and other contaminants into the environment. Performance assessment therefore requires a detailed understanding of the source and fate of gas generation and transport within the disposal system. Here we review the sources and fate of various type of gases generated from nuclear wastes and repositories. Studies on modeling of the fate and transport of repository gases primarily deal with hydrogen and CO 2 . Although hydrogen and carbon dioxide are the major gases of concern, microbial transformations of these gases in the subterranean environments could be significant. Metabolism of hydrogen along with the carbon dioxide results in the formation of methane, low molecular weight organic compounds and cell biomass and thus could affect the total inventory in a repository environment. Modeling studies should take into consideration of both the gas generation and consumption processes over the long-term

  19. On Classical Ideal Gases

    Directory of Open Access Journals (Sweden)

    Laurent Chusseau

    2013-02-01

    Full Text Available We show that the thermodynamics of ideal gases may be derived solely from the Democritean concept of corpuscles moving in vacuum plus a principle of simplicity, namely that these laws are independent of the laws of motion, aside from the law of energy conservation. Only a single corpuscle in contact with a heat bath submitted to a z and t-invariant force is considered. Most of the end results are known but the method appears to be novel. The mathematics being elementary, the present paper should facilitate the understanding of the ideal gas law and of classical thermodynamics even though not-usually-taught concepts are being introduced.

  20. Origins of geothermal gases at Yellowstone

    Science.gov (United States)

    Lowenstern, Jacob B.; Bergfeld, Deborah; Evans, William C.; Hunt, Andrew G.

    2015-01-01

    Gas emissions at the Yellowstone Plateau Volcanic Field (YPVF) reflect open-system mixing of gas species originating from diverse rock types, magmas, and crustal fluids, all combined in varying proportions at different thermal areas. Gases are not necessarily in chemical equilibrium with the waters through which they vent, especially in acid sulfate terrain where bubbles stream through stagnant acid water. Gases in adjacent thermal areas often can be differentiated by isotopic and gas ratios, and cannot be tied to one another solely by shallow processes such as boiling-induced fractionation of a parent liquid. Instead, they inherit unique gas ratios (e.g., CH4/He) from the dominant rock reservoirs where they originate, some of which underlie the Quaternary volcanic rocks. Steam/gas ratios (essentially H2O/CO2) of Yellowstone fumaroles correlate with Ar/He and N2/CO2, strongly suggesting that H2O/CO2 is controlled by addition of steam boiled from water rich in atmospheric gases. Moreover, H2O/CO2 varies systematically with geographic location, such that boiling is more enhanced in some areas than others. The δ13C and 3He/CO2 of gases reflect a dominant mantle origin for CO2 in Yellowstone gas. The mantle signature is most evident at Mud Volcano, which hosts gases with the lowest H2O/CO2, lowest CH4 concentrations and highest He isotope ratios (~16Ra), consistent with either a young subsurface intrusion or less input of crustal and meteoric gas than any other location at Yellowstone. Across the YPVF, He isotope ratios (3He/4He) inversely vary with He concentrations, and reflect varied amounts of long- stored, radiogenic He added to the magmatic endmember within the crust. Similarly, addition of CH4 from organic-rich sediments is common in the eastern thermal areas at Yellowstone. Overall, Yellowstone gases reflect addition of deep, high-temperature magmatic gas (CO2-rich), lower-temperatures crustal gases (4He- and CH4-bearing), and those gases (N2, Ne, Ar) added

  1. Removing radioactive noble gases from nuclear process off-gases

    International Nuclear Information System (INIS)

    Lofredo, A.

    1977-01-01

    A system is claimed for separating, concentrating and storing radioactive krypton and xenon in the off-gases from a boiling water reactor, wherein adsorption and cryogenic distillation are both efficiently used for rapid and positive separation and removal of the radioactive noble gases, and for limiting such gases in circulation in the system to low inventory at all times, and wherein the system is self-regulating to eliminate operator options or attention

  2. 77 FR 12226 - Sadex Corp.; Filing of Food Additive Petition (Animal Use); Electron Beam and X-Ray Sources for...

    Science.gov (United States)

    2012-02-29

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 579 Sadex Corp.; Filing of Food Additive... Ingredients AGENCY: Food and Drug Administration, HHS. ACTION: Notice of petition. SUMMARY: The Food and Drug Administration (FDA) is announcing that Sadex Corp. has filed a petition proposing that the food additive...

  3. Glass Membrane For Controlled Diffusion Of Gases

    Science.gov (United States)

    Shelby, James E.; Kenyon, Brian E.

    2001-05-15

    A glass structure for controlled permeability of gases includes a glass vessel. The glass vessel has walls and a hollow center for receiving a gas. The glass vessel contains a metal oxide dopant formed with at least one metal selected from the group consisting of transition metals and rare earth metals for controlling diffusion of the gas through the walls of the glass vessel. The vessel releases the gas through its walls upon exposure to a radiation source.

  4. Greenhouse gases study in Amazonia

    International Nuclear Information System (INIS)

    D'Amelio, Monica Tais Siqueira

    2006-01-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO 2 sources. The Amazon forest is a significant source of N 2 O by soil process, and CH 4 by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO 2 , CH 4 , CO, H 2 , N 2 O and SF 6 have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO 2 flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO 2 flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H 2 gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO 2 sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that, in the 2004 and 2005 wet seasons and 2004 dry season comparison it was

  5. Selective noble gases monitoring

    International Nuclear Information System (INIS)

    Janecka, S.; Jancik, O.; Kapisovsky, V.; Kubik, I.; Sevecka, S.

    1995-01-01

    The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: 88 Kr(67; 22) Bq/m 3 ; 85m Kr(17; 7) Bq/m 3 ; 135m Xe(7.1; 0.5) Bq/m 3 ; 138 Xe(5.9; 0.9) Bq/m 3 . (J.K.)

  6. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  7. Biochemical methane potential from sewage sludge: Effect of an aerobic pretreatment and fly ash addition as source of trace elements.

    Science.gov (United States)

    Huiliñir, César; Pinto-Villegas, Paula; Castillo, Alejandra; Montalvo, Silvio; Guerrero, Lorna

    2017-06-01

    The effect of aerobic pretreatment and fly ash addition on the production of methane from mixed sludge is studied. Three assays with pretreated and not pretreated mixed sludge in the presence of fly ash (concentrations of 0, 10, 25, 50, 250 and 500mg/L) were run at mesophilic condition. It was found that the combined use of aerobic pretreatment and fly ash addition increases methane production up to 70% when the fly ash concentrations were lower than 50mg/L, while concentrations higher than 250mg/L cause up to 11% decrease of methane production. For the anaerobic treatment of mixed sludge without pretreatment, the fly ash improved methane generation at all the concentrations studied, with a maximum of 56%. The removal of volatile solids does not show an improvement compared to the separate use of an aerobic pre-treatment and fly ash addition. Therefore, the combined use of the aerobic pre-treatment and fly ash addition improves only the production of methane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Salted herring brine as a coating or additive for herring (Clupea harengus) products — A source of natural antioxidants?

    DEFF Research Database (Denmark)

    Albertos, Irene; Gringer, Nina; Rico, Daniel

    2016-01-01

    The objective of this study was to characterise herring brine and assess its use as natural antioxidant in herring preservation. Herring brines from different marinated products (brine from fillet-ripened spice-cured herring SC, traditional barrel-salted spice-cured herring TSp and brine from...... traditional barrel-salted herring TSa) were used without any pre-treatment or with a previous pH adjustment, and tested either as coating agents (glazing) for frozen herring or additives in fresh mince herring, in order to prevent oxidation. TSa and TSp were the most effective glazing agents, retarding lipid...... oxidation. Brines tested as additive retarded lipid and protein oxidation in a similar trend than herring mince containing salt and/or protein. SC brine was more efficient against lipid and protein oxidation when compared to the other tested brines. Using protein fractions isolated from herring marinating...

  9. Recent Additions in the Modeling Capabilities of an Open-Source Wave Energy Converter Design Tool: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tom, N.; Lawson, M.; Yu, Y. H.

    2015-04-20

    WEC-Sim is a midfidelity numerical tool for modeling wave energy conversion devices. The code uses the MATLAB SimMechanics package to solve multibody dynamics and models wave interactions using hydrodynamic coefficients derived from frequency-domain boundary-element methods. This paper presents the new modeling features introduced in the latest release of WEC-Sim. The first feature discussed conversion of the fluid memory kernel to a state-space form. This enhancement offers a substantial computational benefit after the hydrodynamic body-to-body coefficients are introduced and the number of interactions increases exponentially with each additional body. Additional features include the ability to calculate the wave-excitation forces based on the instantaneous incident wave angle, allowing the device to weathervane, as well as import a user-defined wave elevation time series. A review of the hydrodynamic theory for each feature is provided and the successful implementation is verified using test cases.

  10. Vibrationally excited oxygen in the middle atmosphere. Evaluation of its potential as an additional source of ozone

    Energy Technology Data Exchange (ETDEWEB)

    Koppers, G.A.A.

    1996-11-01

    Ozone is `the` most important trace gas in the middle atmosphere. Despite the large efforts that have been made to calculate its concentration in the middle atmosphere there is long standing discrepancy between in-situ and remote sensing measurements on one hand and model results on the other. The latter tend to be about 30% too low in the upper stratosphere and mesosphere. One of the photolysis products of ozone itself, O2({upsilon}) - an oxygen molecule with extra vibrational energy, has been suggested as an intermediate in a reaction sequence that possibly could represent the missing ozone source. A key point in model calculations that estimate the magnitude of the proposed extra ozone source is the fractional population distribution of O2({upsilon}) after ozone photodissociation. Recent statistical calculations supply the vibrational distribution of O2({upsilon}) as a function of the wavelength at which ozone is dissociated. Based on these results a 2D chemical model that includes O2({upsilon}) chemistry has been used to investigate the importance of this mechanism. The extra ozone production by this mechanism has been compared for several other vibrational distributions taken from literature, different collisional deactivation rates of the excited oxygen fragments, and including a reaction between high vibrational excited oxygen with ground state oxygen producing two odd oxygen molecules. Our results indicate that regardless of whether the high vibrational reaction is included, alternatively the deactivation rates are decreased or not, the vibrational excited oxygen mechanism can not simultaneously match the absolute amount of the difference between the model results and SAGE II data and the height distribution of this difference. 23 refs, 17 figs, 2 tabs

  11. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    1990-07-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rare gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources, in search of evidence for terrestrially elusive 244 Pu decay

  12. Emissions of greenhouse gases in the United States 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

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

  13. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  14. Cost-effectiveness in the mitigation of green house gases

    International Nuclear Information System (INIS)

    Rey, Francisco Carlos

    2009-01-01

    This paper analyzes the cost-effectiveness in the mitigation of green house gases from solar, eolic and nuclear energy sources, concluding that nuclear is, not doubt, the mos efficient. On the other hand, nuclear is the unique source that can be installed without limit in magnitude and in the proximity of the demand, and is for all these reasons that several environmental referents in the world have changed their perception on this source and defend it as the unique actual alternative to fight against the emission of green house gases. (author) [es

  15. Canonical partition functions: ideal quantum gases, interacting classical gases, and interacting quantum gases

    Science.gov (United States)

    Zhou, Chi-Chun; Dai, Wu-Sheng

    2018-02-01

    In statistical mechanics, for a system with a fixed number of particles, e.g. a finite-size system, strictly speaking, the thermodynamic quantity needs to be calculated in the canonical ensemble. Nevertheless, the calculation of the canonical partition function is difficult. In this paper, based on the mathematical theory of the symmetric function, we suggest a method for the calculation of the canonical partition function of ideal quantum gases, including ideal Bose, Fermi, and Gentile gases. Moreover, we express the canonical partition functions of interacting classical and quantum gases given by the classical and quantum cluster expansion methods in terms of the Bell polynomial in mathematics. The virial coefficients of ideal Bose, Fermi, and Gentile gases are calculated from the exact canonical partition function. The virial coefficients of interacting classical and quantum gases are calculated from the canonical partition function by using the expansion of the Bell polynomial, rather than calculated from the grand canonical potential.

  16. The preoptic area in the hypothalamus is the source of the additional respiratory drive at raised body temperature in anaesthetised rats.

    Science.gov (United States)

    Boden, A G; Harris, M C; Parkes, M J

    2000-09-01

    In mammals that use the ventilatory system as the principal means of increasing heat loss, raising body temperature causes the adoption of a specialised breathing pattern known as panting and this is mediated by the thermoregulatory system in the preoptic area of the hypothalamus. In these species an additional respiratory drive is also present at raised body temperature, since breathing can reappear at low Pa,CO2 levels, when stimulation of chemoreceptors is minimal. It is not known whether the preoptic area is also the source of this additional drive. Rats do not pant but do possess this additional respiratory drive at raised body temperatures. We have therefore tested whether the preoptic area of the hypothalamus is the source of this additional respiratory drive in rats. Urethane anaesthesia and hyperoxia were used in eleven rats to minimise behavioural and chemical drives to breathe. The presence of the additional respiratory drive was indicated if rhythmic diaphragmatic EMG activity reappeared during hypocapnia (a mean Pa,CO2 level of 21+/-2 mm Hg, n = 11), induced by mechanical ventilation. The additional respiratory drive was absent at normal body temperature (37¿C). When the temperature of the whole body was raised using an external source of radiant heat, the additional respiratory drive appeared at 40.6+/-0.5 degrees C (n = 3). In two further rats this drive was induced at normal body temperature by localised warming in the preoptic area of the intact hypothalamus. The additional respiratory drive appeared at similar temperatures to those in control rats in three rats following isolation of the hypothalamus from more rostral areas of the brain. In contrast, the additional respiratory drive failed to appear at these temperatures in three rats after isolating the hypothalamus from the caudal brainstem, by sectioning pathways medial to the medial forebrain bundle. Since the preoptic area is known to contain thermoreceptors and to receive afferents from

  17. Noble gases solubility in water

    International Nuclear Information System (INIS)

    Crovetto, Rosa; Fernandez Prini, Roberto.

    1980-07-01

    The available experimental data of solubility of noble gases in water for temperatures smaller than 330 0 C have been critically surveyed. Due to the unique structure of the solvent, the solubility of noble gases in water decreases with temperature passing through a temperature of minimum solubility which is different for each gas, and then increases at higher temperatures. As aresult of the analysis of the experimental data and of the features of the solute-solvent interaction, a generalized equation is proposed which enables thecalculation of Henry's coefficient at different temperatures for all noble gases. (author) [es

  18. Greenhouse gas emissions from deforestation and forest fires in Roraima: sources and sinks = Emissões de gases do efeito estufa por desmatamento e incêndios florestais em Roraima: fontes e sumidouros

    Directory of Open Access Journals (Sweden)

    Philip Martin Fearnside

    2013-04-01

    Full Text Available Abstract - Greenhouse gas (GHG emissions from Roraima State - Brazil are directly related to human occupation and to land-use changes in forest ecosystems. Geo-economic and political considerations were the basis for the development and consolidation of settlement areas for small farmers and for implanting large regional development projects in Roraima since the late 1970s. This increased demand for land intensified deforestation across the forest region situated along the main highways (BR-174 and BR-210. This development model resulted in the emission of large amounts of GHG to the atmosphere and increased the frequency of forest fires on the main axes of human settlement. The aim of this paper is to review the studies done to quantify GHG emissions from land-use changes and forest fires, indicating the sources and sinks, and to place Roraima in the context of climate change in Amazonia. Understanding this dynamic provides a foundation for strategic planning to change local public policies, reversing the current logic that gives greater value to unsustainable land uses as compared to forest environmental services. = Resumo - Emissões de gases do efeito estufa (GEE em Roraima – Brasil estão relacionadas diretamente à ocupação humana e as alterações do uso do solo nos sistemas florestais. Características geoeconômicas e políticas foram as bases do fomento e da sedimentação de áreas de colonização para pequenos produtores rurais e grandes projetos de desenvolvimento regional em Roraima desde o final da década de 1970. Isso incrementou a demanda por terras e intensificou o desmatamento por toda a região florestal situada ao longo dos principais eixos rodoviários (BRs 174 e 210. Este modelo de desenvolvimento implicou na emissão de grandes somas de GEE para a atmosfera, além de aumentar a frequência de incêndios florestais nos principais eixos de assentamento humano. Objetivou-se com este trabalho revisar os estudos feitos

  19. Warming Early Mars by Impact Degassing of Reduced Greenhouse Gases

    Science.gov (United States)

    Haberle, R. M.; Zahnle, K.; Barlow, N. G.

    2018-01-01

    Reducing greenhouse gases are once again the latest trend in finding solutions to the early Mars climate dilemma. In its current form collision induced absorptions (CIA) involving H2 and/or CH4 provide enough extra greenhouse power in a predominately CO2 atmosphere to raise global mean surface temperatures to the melting point of water provided the atmosphere is thick enough and the reduced gases are abundant enough. Surface pressures must be at least 500 mb and H2 and/or CH4 concentrations must be at or above the several percent level for CIA to be effective. Atmospheres with 1-2 bars of CO2 and 2- 10% H2 can sustain surface environments favorable for liquid water. Smaller concentrations of H2 are sufficient if CH4 is also present. If thick CO2 atmospheres with percent level concentrations of reduced gases are the solution to the faint young Sun paradox for Mars, then plausible mechanisms must be found to generate and sustain the gases. Possible sources of reducing gases include volcanic outgassing, serpentinization, and impact delivery; sinks include photolyis, oxidation, and escape to space. The viability of the reduced greenhouse hypothesis depends, therefore, on the strength of these sources and sinks. In this paper we focus on impact delivered reduced gases.

  20. Greenhouse gases and global warming

    International Nuclear Information System (INIS)

    1995-01-01

    From previous articles we have learned about the complexities of our environment, its atmosphere and its climate system. we have also learned that climate change and, therefore global warm and cool periods are naturally occurring phenomena. Moreover, all scientific evidence suggests that global warming, are likely to occur again naturally in the future. However, we have not yet considered the role of the rates of climate change in affecting the biosphere. It appears that how quickly the climate changes may be more important than the change itself. In light of this concern, let us now consider the possibility that, is due to human activity. We may over the next century experience global warming at rates and magnitudes unparalleled in recent geologic history. The following questions are answered; What can we learn from past climates? What do we know about global climates over the past 100 years? What causes temperature change? What are the greenhouse gases? How much have concentration of greenhouse gases increased in recent years? Why are increases in concentrations of greenhouse of concern? What is the e nhanced greenhouse effect ? How can human activity impact the global climate? What are some reasons for increased concentrations of greenhouse gases? What are fossil fuel and how do they transform into greenhouse gases? Who are the biggest emitters of greenhouse gases? Why are canada per capita emissions of greenhouse gases relatively high? (Author)

  1. Automotive industry program and strategy for control of ozone depleting substances and greenhouse gases

    International Nuclear Information System (INIS)

    Pound, F.R.; Stirling, P.J.

    1990-01-01

    This paper outlines the program status and strategy for the short and long term periods for ozone depleting substances and greenhouse gases from both stationary sources in manufacturing plants and mobile sources in motor vehicles. 5 refs

  2. Long-Term Changes of Tropospheric Trace Gases over Pakistan Derived From Multiple Satellite Instruments

    Science.gov (United States)

    Zeb, Naila; Fahim Khokhar, Muhammad; Murtaza, Rabbia; Noreen, Asma; Khalid, Tameem

    2016-07-01

    Air pollution is the expected key environmental issue of Pakistan in coming years due to its ongoing rapid economic growth and this trend suggests only worst air quality over time. In 2014, World bank reported the Pakistan's urban air quality among the most severe in the world and intimated the government to make improvement in air quality as a priority policy agenda. In addition it is recommended to strengthen the institutional and technical capacity of organizations responsible for air quality management. Therefore, the study is designed to put efforts in highlighting air quality issues. The study will provide first database for tropospheric trace gases over Pakistan. The study aims to analyse tropospheric concentrations of CO, TOC, NO2 and HCHO over Pakistan using multisensory data from January 2005 to January 2014. Spatio-temporal and seasonal variability of tropospheric trace gases is observed over the decade to explore long term trend. Hotspots are identified to see variation of species with latitude and to highlight possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over the Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60% of the Pakistan's population) sector of the country. Overall significant decreasing trend of CO is identified by MOPITT with relative change of 12.4%. Tropospheric ozone column (TOC) showed insignificant increasing trend with temporal increase of 10.4% whereas NO2 exhibited a significant temporal increase of about 28%. For formaldehyde (HCHO), an increase of about 3.8% is calculated for SCIAMACHY data. Well defined seasonal cycles for these trace gases are observed over the whole study period. CO concentrations showed peak in winter months (November/December/January/February) and dip in the months of Summer/Monsoon (June/July/August). In spite of CO, TCO increases gradually in March and peaks

  3. Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions

    Directory of Open Access Journals (Sweden)

    Kaźnica N.

    2017-12-01

    Full Text Available A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.

  4. Treatment of industrial exhaust gases by a dielectric barrier discharge

    Science.gov (United States)

    Schmidt, Michael; Hołub, Marcin; Jõgi, Indrek; Sikk, Martin

    2016-08-01

    Volatile organic compounds (VOCs) in industrial exhaust gases were treated by a dielectric barrier discharge (DBD) operated with two different mobile power supplies. Together with the plasma source various gas diagnostics were used, namely fourier transform infrared (FTIR) spectroscopy, flame ionization detector (FID) and GC-MS. The analysis revealed that some exhaust gases consist of a rather complex mixture of hydrocarbons and inorganic compounds and also vary in pollutants concentration and flow rate. Thus, analysis of removal efficiencies and byproduct concentrations is more demanding than under laboratory conditions. This contribution presents the experimental apparatus used under the harsh conditions of industrial exhaust systems as well as the mobile power source used. Selected results obtained in a shale oil processing plant, a polymer concrete production facility and a yacht hull factory are discussed. In the case of total volatile organic compounds in oil processing units, up to 60% were removed at input energy of 21-37 J/L when the concentrations were below 500 mg/m3. In the yacht hull factory up to 74% of styrene and methanol were removed at specific input energies around 300 J/L. In the polymer concrete production site 195 ppm of styrene were decomposed with the consumption of 1.8 kJ/L. These results demonstrate the feasibility of plasma assisted methods for treatment of VOCs in the investigated production processes but additional analysis is needed to improve the energy efficiency. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  5. Radioactive gases monitor system: tritium, radon, noble gases

    International Nuclear Information System (INIS)

    Egey, J.Z.; Matatagui, E.

    2015-01-01

    A system for monitoring the radioactive gases tritium, radon and noble gases is described. We present the description of the sensor and the associated electronics that have been developed to monitor the presence of radioactive gases in air or other gaseous effluents. The system has a high sensitivity and a wide range of operation. The sensor is an ionization chamber, featuring the internal circulation of the gas to monitor and the associated electronics has a resolution better than 10 E-15A (fA). It allows the detection of the individual pulses that are produced during the alpha decay of radon and its daughter elements. The measurement system is made up of a commercial data acquisition system connected to a computer. The acquired data is presented on a graphical display and it is stored for later processing and analysis. We have a system that is of simple construction and versatile. Here we present the experimental results. (authors) [es

  6. Gases and carbon in metals

    International Nuclear Information System (INIS)

    Jehn, H.; Fromm, E.; Hoerz, G.

    1978-01-01

    This issue is part of a series of data on 'gases and carbon in metals'. The present survey includes results from papers dealing with gases and carbon in actinides and recommends critically selected data for each element. Firstly data od binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility limit, dissociation pressure of compunds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas adsorption and gas desorption kinetics, compound formation, precipitation kinetics, and property changes. Following the data on binary systems, the data of ternary systems are presented, beginning with systems which contain one metal and two gases or one gas and carbon and continuing with systems with two metals and one gas or carbon. Within a ternary system the topics are arranged in the same way as in binary systems. (HB) [de

  7. BOOK REVIEW: Kinetic Theory of Granular Gases

    Science.gov (United States)

    Trizac, Emmanuel

    2005-11-01

    Granular gases are composed of macroscopic bodies kept in motion by an external energy source such as a violent shaking. The behaviour of such systems is quantitatively different from that of ordinary molecular gases: due to the size of the constituents, external fields have a stronger effect on the dynamics and, more importantly, the kinetic energy of the gas is no longer a conserved quantity. The key role of the inelasticity of collisions has been correctly appreciated for about fifteen years, and the ensuing consequences in terms of phase behaviour or transport properties studied in an increasing and now vast body of literature. The purpose of this book is to help the newcomer to the field in acquiring the essential theoretical tools together with some numerical techniques. As emphasized by the authors—who were among the pioneers in the domain— the content could be covered in a one semester course for advanced undergraduates, or it could be incorporated in a more general course dealing with the statistical mechanics of dissipative systems. The book is self-contained, clear, and avoids mathematical complications. In order to elucidate the main physical ideas, heuristic points of views are sometimes preferred to a more rigorous route that would lead to a longer discussion. The 28 chapters are short; they offer exercises and worked examples, solved at the end of the book. Each part is supplemented with a relevant foreword and a useful summary including take-home messages. The editorial work is of good quality, with very few typographical errors. In spite of the title, kinetic theory stricto sensu is not the crux of the matter covered. The authors discuss the consequences of the molecular chaos assumption both at the individual particle level and in terms of collective behaviour. The first part of the book addresses the mechanics of grain collisions. It is emphasized that considering the coefficient of restitution ɛ —a central quantity governing the

  8. Wire chamber gases

    International Nuclear Information System (INIS)

    Va'vra, J.

    1992-04-01

    In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging

  9. Desulphurization of exhaust gases in chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1981-01-01

    The sulfur content of exhaust gases can be reduced by: desulphurization of fuels; modification of processes; or treatment of resultant gases. In this paper a few selected examples from the chemical industry in the German Democratic Republic are presented. Using modified processes and treating the resultant gases, the sulphuric content of exhaust gases is effectively reduced. Methods to reduce the sulfur content of exhaust gases are described in the field of production of: sulphuric acid; viscose; fertilizers; and paraffin.

  10. Weekly cycle of minor air gases in Moscow

    Science.gov (United States)

    Lokoshchenko, Mikhail A.; Elansky, Nikolay F.; Trifanova, Alexandra V.

    2017-04-01

    The weekly cycle of the surface concentrations of five trace atmospheric gases in Moscow has been analyzed based on continuous automatic once-a-minute measurements. The data of joint ecological station of the Institute of Atmospheric Physics and Moscow State University for nine years (2002-2010) were used. This station operated in conditions of comparatively clear park zone of the University on the South-Western periphery of the city at a distance of 8 km from the city centre. Fortunately, none of the great sources of the air pollution - neither point sources, nor linear ones - are present in the vicinity of the station so that the measurements there are quite representative. Results of spectral analysis demonstrate statistically significant maximum of spectral density close to 7 days. Any clear periodicity of around seven days may be a consequence of either natural synoptic period or weekly cycle. The fact that the influence of human activity on urban air composition changes with a weekly periodicity is confirmed by statistically significant difference between concentrations of trace gases on working days and on Sunday (when emissions from both the traffic and the industrial sources are minimal). On average, both primary pollutants (nitrogen oxide and carbon oxide) and the secondary ones (NO2) show the lowest concentrations of the week on Sunday whereas ozone, by contrast, peaks on this day. Besides, usual diurnal cycle of air pollutants is transformed on Sunday - e.g., secondary nocturnal maximum of ozone in the city is absent on Sunday like at rural area. On Saturday concentrations of trace gases are in between working days and Sunday; this 'Saturday effect' is a result of a gradual clearing of the urban air. An additional effect is that in the first half of Monday (before noon) surface concentrations of NO and NO2 are generally less, whereas the concentration of O3 is, on the contrary, a bit higher than at the same time on the rest of working days. The 'Monday

  11. Deposition of Multicomponent Chromium Carbide Coatings Using a Non-Conventional Source of Chromium and Silicon with Micro-Additions of Boron

    OpenAIRE

    González Ruíz,Jesús Eduardo; Rodríguez Cristo,Alejandro; Paz Ramos,Adrian; Quintana Puchol,Rafael

    2017-01-01

    The chromium carbide coatings are widely used in the mechanical industry due to its corrosion resistance and mechanical properties. In this work, we evaluated a new source of chromium and silicon with micro-additions of boron on the deposition of multi-component coatings of chromium carbides in W108 steel. The coatings were obtained by the pack cementation method, using a simultaneous deposition at 1000 oC for 4h. The coatings were analyzed by X-ray diffraction, X-ray energy dispersive spectr...

  12. Utilization of alternative fuels and the additions to the clinker as opportunities of reductions of greenhouse gas emissions - an overview of the cement sector in Brazil; A utilizacao de combustiveis alternativos e de adicoes ao clinquer como oportunidades de reducao de emissoes de gases de efeito estufa - um panorama do setor de cimento no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Wills, William [Universidade Federal do Rio de Janeiro (PPE/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Planejamento Energetico], E-mail: wwills@lima.coppe.ufrj.br; La Rovere, Emilio Lebre; Westin, Fernanda Fortes [Universidade Federal do Rio de Janeiro (LIMA/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Lab. Interdisciplinar de Meio Ambiente], Emails: emlio@ppe.ufrj.br, fforteswestin@yahoo.com.br

    2010-07-01

    This paper analyses the energy consumption of the sector in Brazil, specially the participation of alternative sources which are growing systematically since 2001, and the addition of the clinker which is a practice that allows to reduce the CO{sub 2} emissions. These options allows to reduce the burning of fossil fuels and the pollutant emission, reducing local, regional and global impacts.

  13. A microscope for Fermi gases

    International Nuclear Information System (INIS)

    Omran, Ahmed

    2016-01-01

    This thesis reports on a novel quantum gas microscope to investigate many-body systems of fermionic atoms in optical lattices. Single-site resolved imaging of ultracold lattice gases has enabled powerful studies of bosonic quantum many-body systems. The extension of this capability to Fermi gases offers new prospects to studying complex phenomena of strongly correlated systems, for which numerical simulations are often out of reach. Using standard techniques of laser cooling, optical trapping, and evaporative cooling, ultracold Fermi gases of 6 Li are prepared and loaded into a large-scale 2D optical lattice of flexible geometry. The atomic distribution is frozen using a second, short-scaled lattice, where we perform Raman sideband cooling to induce fluorescence on each atom while maintaining its position. Together with high-resolution imaging, the fluorescence signals allow for reconstructing the initial atom distribution with single-site sensitivity and high fidelity. Magnetically driven evaporative cooling in the plane allows for producing degenerate Fermi gases with almost unity filling in the initial lattice, allowing for the first microscopic studies of ultracold gases with clear signatures of Fermi statistics. By preparing an ensemble of spin-polarised Fermi gases, we detect a flattening of the density profile towards the centre of the cloud, which is a characteristic of a band-insulating state. In one set of experiments, we demonstrate that losses of atom pairs on a single lattice site due to light-assisted collisions are circumvented. The oversampling of the second lattice allows for deterministic separation of the atom pairs into different sites. Compressing a high-density sample in a trap before loading into the lattice leads to many double occupancies of atoms populating different bands, which we can image with no evidence for pairwise losses. We therefore gain direct access to the true number statistics on each lattice site. Using this feature, we can

  14. [CFC gases in medicinal sprays].

    Science.gov (United States)

    Pedersen, P H; Svendsen, U G

    1989-03-20

    In 1987, approximately 1.18 million aerosol dispensers for medicinal use were sold in Denmark. These contained approximately 29 tons of completely halogenized CFC gases ("Freon") and the preparations were employed for the treatment of bronchial asthma and rhinitis. The possibilities of substitutes are discussed in this article. Preparations are already available which do not contain CFC. Producers of CFC are also attempting to develop new aerosol gases which do not damage the environment. Perhaps these will be found in medicinal preparations in the future.

  15. Degradabilidade e produção de gases in vitro de fontes energéticas alternativas na alimentação de ruminantes = Degradability and in vitro gas production of alternative energy sources in ruminant feed

    Directory of Open Access Journals (Sweden)

    Roberto de Camargo Wascheck

    2010-10-01

    Full Text Available O padrão fermentativo in vitro de dietas compostas por fubá de milho, farelo de arroz integral, farelo de arroz parboilizado e suas associações em diferentes proporções foi estudado, na porção concentrada da dieta de ruminantes. Até 12h de incubação, a produçãode gases foi superior (p The in vitro fermentation pattern of diets composed of corn meal, rice bran, parboiled rice bran and their associations was studied in different proportions in the concentrate portion in ruminants diets. Up to 12 hours of incubation, gas production was higher (p < 0.05 for the treatments with rice bran (FAI and parboiled rice bran (FAP; however, after 96 hours, the treatment with 100% corn meal (FMproduced more (p < 0.05 gases (379.41 mL g DM-1. Total degradability of dry matter (DM and organic matter (OM were higher (p < 0.05 for treatments FAI and FAP up to 12 hours; however, after 96 hours of incubation the total degradability of DM and OM was higher (p < 0.05 for the FM treatment (90.46 and 91.08%, respectively. The nutritional potential of rice bran or parboiled rice bran was confirmed in the diet of ruminants, as it provides a higher fractional rate of in vitro gas production (12.39 and 13.17 mL h-1 and faster degradation of DM and OM in initial times.

  16. Masses of noble gases

    CERN Multimedia

    Marx, G H; Herfurth, F; Stora, T; Blaum, K; Beck, D; Audi, G; Rosenbusch, M

    The so-called magic numbers, cornerstones of the quantum nuclear ensemble, are now known to lose their supernatural powers far from the protected valley of stability. To complement the well-established (but not yet well-understood) case of N = 20, we propose to examine the erstwhile N = 28 shell closure via a measurement of the important (but unknown) mass of the nuclide $^{48}$Ar. The quenching of a shell closure, a mechanism as mysterious as the reason for magic numbers themselves, also has important consequences in nucleosynthesis. While $^{48}$Ar is not part of the region concerned by the canonical rapid neutro-capture r-process, the question of shell strength is of great importance for heavier nuclides. The location of the r-process path would benefit from extending the succesful ISOTRAP krypton mass measurements beyond the N = 58 sub-shell to $^{96-98}$Kr. Modeling the complementary rapid proton-capture rp- process, putative source of some proton-rich species, requires the mass of $^{70}$Kr, near the e...

  17. Ionized Gas Kinematics around an Ultra-luminous X-Ray Source in NGC 5252: Additional Evidence for an Off-nuclear AGN

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjin [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Im, Myungshin [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

    2017-08-01

    The Seyfert 2 galaxy NGC 5252 contains a recently identified ultra-luminous X-ray (ULX) source that has been suggested to be a possible candidate off-nuclear low-mass active galactic nucleus. We present follow-up optical integral-field unit observations obtained using Gemini Multi-Object Spectrographs on the Gemini-North telescope. In addition to confirming that the ionized gas in the vicinity of the ULX is kinematically associated with NGC 5252, the new observations reveal ordered motions consistent with rotation around the ULX. The close coincidence of the excitation source of the line-emitting gas with the position of the ULX further suggests that ULX itself is directly responsible for the ionization of the gas. The spatially resolved measurements of [N ii] λ 6584/H α surrounding the ULX indicate a low gas-phase metallicity, consistent with those of other known low-mass active galaxies but not that of its more massive host galaxy. These findings strengthen the proposition that the ULX is not a background source but rather that it is the nucleus of a small, low-mass galaxy accreted by NGC 5252.

  18. Additive effects of CuSO4 and aromatic compounds on laccase production by Pleurotus sajor-caju PS-2001 using sucrose as a carbon source

    Directory of Open Access Journals (Sweden)

    F. Bettin

    2014-06-01

    Full Text Available Laccase enzymes are now commercially available, and a laccase/mediator combination is currently marketed for indigo dye bleaching in textile manufacturing; replacing traditional chemical-based processes with enzymatic technology reduces the need for effluent treatment. However, an inexpensive source of these enzymes will be needed to enable wider application of this technology. In the present work, the main objective was to increase laccase production by the mushroom Pleurotus sajor-caju strain PS-2001 grown on sucrose derived from sugar cane, one of most economical carbon sources known, by the addition of compounds that are known to affect laccase production. High laccase activities (45-62 U mL-1 were obtained with additions of syringaldazine, benzoic acid, gallic acid, and vanillin. When CuSO4 was used in conjunction with these aromatic compounds, the levels of laccase activity were further improved, reaching 58-80 U mL-1. These laccase activities indicate the potential of this strain as an enzyme producer, which has also been detected in media containing glucose, but with activity lower than that observed with sucrose.

  19. Origins of natural gases from marine strata in Northeastern Sichuan Basin (China) from carbon molecular moieties and isotopic data

    Science.gov (United States)

    Wang, Yunpeng; Zhao, Changyi; Wang, Hongjun; Wang, Zhaoyun; Wang, Zecheng

    2013-03-01

    To determine the origin, maturity, formation mechanism and secondary process of marine natural gases in Northeastern Sichuan area, molecular moieties and carbon isotopic data of the Carboniferous and Triassic gases have been analyzed. Typical samples of marine gas precursors including low-maturity kerogen, dispersed liquid hydrocarbons (DLHs) in source rocks, residual kerogen and oil have been examined in a closed system, and several published geochemical diagrams of gas origins have been calibrated by using laboratory data. Results show that both Carboniferous and Triassic gases in the study area have a thermogenic origin. Migration leads to stronger compositional and weak isotopic fractionation, and is path dependent. Carboniferous gases and low-H2S gases are mainly formed by secondary cracking of oil, whereas high-H2S gases are clearly related to the TSR (Thermal Sulfate Reduction) process. Gases in NE Sichuan show a mixture of heavy (13C-enriched) methane in comparison to the lower maturated ethane of Triassic gas samples, suggesting a similar source and maturity for ethane and propane of Carboniferous gases, and a mixture of heavy ethane to the propane for Triassic gases. Based on the data plotted in the diagram of Chung et al. (1988), the residual kerogen from Silurian marine shale and palaeo oil reservoirs are the main source for Carboniferous gases, and that the residual kerogen from Silurian and Permian marine rocks and Permian paleao oil reservoirs constitute the principal source of Triassic gases.

  20. μ+ charge exchange and muonium formation in low pressure gases

    International Nuclear Information System (INIS)

    Fleming, D.G.; Mikula, R.J.; Garner, D.M.

    1982-04-01

    Using the basic muon spin rotation technique, the fractions of energetic positive muons thermalizing in diamagnetic environments (fsub(μ)) or as the paramagnetic muonium atom (fsub(Mu)) have been measured in low pressure pure gases (He, Ne, Ar, Kr, Xe, H 2 , N 2 , NH 3 , and CH 4 ) as well as in several gas mixtures (Ne/Xe, Ne/Ar, Ne/NH 3 , Ne/CH 4 ). In the pure gases, the muonium fractions fsub(Mu) are generally found to be smaller than expected from analogous proton charge exchange studies, particularly in the molecular gases. This is probably due to hot atom reactions of muonium following the charge exchange regime. Comparisons with monium formation in condensed matter as well as positronium formation in gases are also presented. In the gas mixtures, the addition of only a few hundred ppm of a dopant gas, which is exothermic for muonium formation (e.g. Xe), gives rise to an fsub(Mu) characteristic of the pure dopant gas itself, demonstrating the importance of the neutralization process right down to thermal energies. In all cases, the experimental signal amplitudes are found to be strongly pressure dependent, which is interpreted in terms of the time spent by the muon as neutral muonium in the charge exchange regime: tsub(n) < 0.2 ns. This time is generally shorter in the case of molecular gases than in rare gases

  1. Controls on fluxes of trace gases from Brazilian cerrado soils

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.C. [Coll. of William and Mary, Gloucester Point, VA (United States). Virginia Inst. of Marine Science; Poth, M.A. [Dept. of Agriculture, Riverside, CA (United States)

    1998-09-01

    Tropical ecosystems play an important role in production or consumption of atmospheric trace gases including nitric oxide (NO), nitrous oxide (N{sub 2}O), carbon dioxide (CO{sub 2}), and methane (CH{sub 4}). Here the authors describe field and laboratory experiments, performed during 1994, to determine the influence of fire on processes responsible for fluxes of gases from cerrado sites burned 17 and 45 d earlier, and a control site, last burned in 1974. Burning stimulated gross N mineralization but depressed nitrification rates; however, rates were sufficient to support NO fluxes observed in a 1992 study at the same site. Extractable nutrients and fluxes of NO and N{sub 2}O from wetted and dry soils were measured prior to and for a 3-d period following burning. Over this period NO{sub 2}{sup {minus}} declined to undetectable levels; NH{sub 4}{sup +} increased, and NO fluxes remained relatively constant, suggesting that nitrifiers replaced the NO{sub 2}{sup {minus}} reduced to NO. Soils at burned and unburned sites exhibited CH{sub 4} uptake, which was inhibited by CH{sub 3}F, thereby converting soils from a strong sink to a weak source of CH{sub 4}. Carbon dioxide fluxes did not increase, and there were no detectable fluxes of N{sub 2}O following burning. In lab studies NO and N{sub 2}O emissions were inhibited by autoclaving, suggesting that nitrification was key to their production. However, addition of NO{sub 2}{sup {minus}} to autoclaved soil resulted in large fluxes of NO but no detectable N{sub 2}O, suggesting that chemodenitrification may have been responsible for NO but not N{sub 2}O production. Further research is needed to determine whether NO is produced directly by nitrifier NO{sub 2}{sup {minus}} reduction or indirectly by chemodenitrification of NO{sub 2}{sup {minus}} produced by nitrifiers.

  2. Anomalous migration of shallow groundwater and gases in the Beijing region and the 1976 Tangshan earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Shi, H.; Cai, Z.; Gao, M.

    1980-02-01

    The character and cause of blowing out of gases and emission of sound from dry wells and of water becoming muddy and changing of level in water wells of the Beijing region immediately before the 1976 Tangshan earthquake and its strong aftershocks are investigated. These phenomena, taken as possible precursors of the earthquakes as well as the motivating force, mechanism, geological background and material sources of the anomalous migration, are discussed. In addition, the paper also deals with the relation between these anomalies and the Tangshan earthquake and the significance of the study of groundwater as far as earthquake prediction is concerned. No gaseous gushing from great depth in considerable quantities appeared so that migration should be regarded only as the migration of shallow groundwater and gases. This is referred to as the consequence of the action on certain hydrogeological structures of an impulse-like extra tectonic stress field on the active faults in the Beijing region under a unified regional stress field. The present authors suppose that further studies of the anomalous migration of groundwater and gases possibly may be fruitful to earthquake prediction work.

  3. Synthetic spectra of simulated terrestrial atmospheres containing possible biomarker gases.

    Science.gov (United States)

    Schindler, T L; Kasting, J F

    2000-05-01

    NASA's proposed Terrestrial Planet Finder, a space-based interferometer, will eventually allow spectroscopic analyses of the atmospheres of extrasolar planets. Such analyses would provide information about the existence of life on these planets. One strategy in the search for life is to look for evidence of O3 (and hence O2) in a planet's atmosphere; another is to look for gases that might be present in an atmosphere analogous to that of the inhabited early Earth. In order to investigate these possibilities, we have calculated synthetic spectra for several hypothetical terrestrial-type atmospheres. The model atmospheres represent four different scenarios. The first two, representing inhabited terrestrial planets, are an Earth-like atmosphere containing variable amounts of oxygen and an early Earth-type atmosphere containing methane. In addition, two cases representing Mars-like and early Venus-like atmospheres were evaluated, to provide possible "false positive" spectra. The calculated spectra suggest that ozone could be detected by an instrument like Terrestrial Planet Finder if the O2 concentration in the planet's atmosphere is > or = 200 ppm, or 10(-3) times the present atmospheric level. Methane should be observable on an early-Earth type planet if it is present in concentrations of 100 ppm or more. Methane has both biogenic and abiogenic sources, but concentrations exceeding 1000 ppm, or 0.1% by volume, would be difficult to produce from abiogenic sources alone. High methane concentrations in a planet's atmosphere are therefore another potential indicator for extraterrestrial life.

  4. Evaluation of Near-Surface Gases in Marine Sediments to Assess Subsurface Petroleum Gas Generation and Entrapment

    Directory of Open Access Journals (Sweden)

    Michael A. Abrams

    2017-05-01

    Full Text Available Gases contained within near-surface marine sediments can be derived from multiple sources: shallow microbial activity, thermal cracking of organic matter and inorganic materials, or magmatic-mantle degassing. Each origin will display a distinctive hydrocarbon and non-hydrocarbon composition as well as compound-specific isotope signature and thus the interpretation of origin should be relatively straightforward. Unfortunately, this is not always the case due to in situ microbial alteration, non-equilibrium phase partitioning, mixing, and fractionation related to the gas extraction method. Sediment gases can reside in the interstitial spaces, bound to mineral or organic surfaces and/or entrapped in carbonate inclusions. The interstitial sediment gases are contained within the sediment pore space, either dissolved in the pore waters (solute or as free (vapour gas. The bound gases are believed to be attached to organic and/or mineral surfaces, entrapped in structured water or entrapped in authigenic carbonate inclusions. The purpose of this paper is to provide a review of the gas types found within shallow marine sediments and examine issues related to gas sampling and extraction. In addition, the paper will discuss how to recognise mixing, alteration and fractionation issues to best interpret the seabed geochemical results and determine gas origin to assess subsurface petroleum gas generation and entrapment.

  5. Emissions Of Greenhouse Gases From Rice Agriculture

    Energy Technology Data Exchange (ETDEWEB)

    M. Aslam K. Khalil

    2009-07-16

    This project produced detailed data on the processes that affect methane and nitrous oxide emissions from rice agriculture and their inter-relationships. It defines the shifting roles and potential future of these gases in causing global warming and the benefits and tradeoffs of reducing emissions. The major results include: 1). Mechanisms and Processes Leading to Methane Emissions are Delineated. Our experiments have tested the standard model of methane emissions from rice fields and found new results on the processes that control the flux. A mathematical mass balance model was used to unravel the production, oxidation and transport of methane from rice. The results suggested that when large amounts of organic matter are applied, the additional flux that is observed is due to both greater production and reduced oxidation of methane. 2). Methane Emissions From China Have Been Decreasing Over the Last Two Decades. We have calculated that methane emissions from rice fields have been falling in recent decades. This decrease is particularly large in China. While some of this is due to reduced area of rice agriculture, the bigger effect is from the reduction in the emission factor which is the annual amount of methane emitted per hectare of rice. The two most important changes that cause this decreasing emission from China are the reduced use of organic amendments which have been replaced by commercial nitrogen fertilizers, and the increased practice of intermittent flooding as greater demands are placed on water resources. 3). Global Methane Emissions Have Been Constant For More Than 20 Years. While the concentrations of methane in the atmosphere have been leveling off in recent years, our studies show that this is caused by a near constant total global source of methane for the last 20 years or more. This is probably because as some anthropogenic sources have increased, others, such as the rice agriculture source, have fallen. Changes in natural emissions appear small

  6. Determination of additivity of apparent and standardized ileal digestibility of amino acids in diets containing multiple protein sources fed to growing pigs.

    Science.gov (United States)

    Xue, P C; Ragland, D; Adeola, O

    2014-09-01

    An experiment was conducted in growing pigs to investigate the additivity of apparent ileal digestibility (AID) or standardized ileal digestibility (SID) of CP and AA in mixed diets containing multiple protein sources. Using the determined AID or SID for CP and AA in corn, soybean meal (SBM), corn distillers' dried grains with solubles (DDGS), or canola meal (CM), the AID or SID for 4 mixed diets based on corn-SBM, corn-SBM-DDGS, corn-SBM-CM, or corn-SBM-DDGS-CM were predicted and compared with determined AID or SID, respectively. Eighteen growing pigs (initial BW = 61.3 ± 5.5 kg) were surgically fitted with T-cannulas and assigned to a duplicated 9 × 4 incomplete Latin square design with 9 diets and 4 periods. The 9 experimental diets consisted of a nitrogen-free diet (NFD) to estimate basal ileal endogenous loss (BEL) of AA, 4 semipurified diets to determine the AID and SID of CP and AA in the 4 ingredients, and 4 mixed diets to test the additivity of AID and SID. Chromic oxide was added as an indigestible marker. Pigs were fed 1 of the 9 diets during each 7-d period, and ileal digesta were collected on d 6 and 7, from 0800 to 1800 h. The analyzed AA levels for the mixed diets were close to the calculated values based on the AA composition of each ingredient. The results revealed that the predicted SID were consistent with determined values, except for Leu, Thr, Asp, Cys, Pro, and Ser in the corn-SBM diet and Met and Cys in the corn-SBM-DDGS diet. The determined AID for total AA and Arg, His, Trp, Gly, and Pro in the corn-SBM diet were greater (P digestibility of AA in mixed diets containing multiple protein sources. In addition, the lack of additivity of AID in mixed diets could be attributed to the intrinsic characteristics of the feed ingredient, especially its AA content.

  7. Characterization and origin of natural gases of the Anadarko Basin

    Science.gov (United States)

    Rice, Dudley D.; Threlkeld, Charles N.; Buletich, April K.

    1989-01-01

    Natural-gas production in the Anadarko basin is from three geographically separated areas that can be differentiated by age of reservoir and by inferred nature of thermal origin of the gases. In the central basin, nonassociated gases are produced mainly from Upper Mississippian and Pennsylvanian sandstones. Gases become isotopically heavier (δ13C1 values range from -49.8 to -33.2 ppt) and chemically drier (C1/C1–5 values range from 0.74 to 0.99) with increasing level of thermal maturity. Gas samples are from depths as much as 21,600 ft. Gases were generated mainly from interbedded shales with type-III kerogen during the mature and postmature stages of hydrocarbon generation. Deviations from the trend are due to mixing and migration of gases generated at different levels of thermal maturity over the past 250 m.y. In the giant Panhandle-Hugoton field, nonassociated gases are generally produced from Permian carbonates at depths 13C1 values range from -46.4 to -39.9 ppt, C1/C1–5 values range from 0.69 to 0.96). Because organic-rich, mature source rocks are not present in the area, gases probably were generated in the central basin from Pennsylvanian or older source rocks during the mature stage of hydrocarbon generation. This implies migration over distances as much as several hundred miles. In the Sooner trend, associated gases are produced from Silurian, Devonian, and Mississippian carbonates at depths as great as 9,600 ft and were generated from type-II kerogen during the mature stage of hydrocarbon generation. Associated oil correlates with extracts of the Upper Devonian and Lower Mississippian Woodford Shale. Gases are isotopically lighter (δ13C1 values of -47.3 to -40.6 ppt) and chemically wetter (C1/C1–5 values of 0.67 to 0.99) than those derived from type-III kerogen at an equivalent level of thermal maturity.

  8. Turnover and transport of greenhouse gases in a Danish wetland

    DEFF Research Database (Denmark)

    Jørgensen, Christian Juncher

    2011-01-01

    Natural wetlands act as both sources and sinks of greenhouse gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from the soil to the atmosphere. Production and consumption of these gases in the soil are controlled by a series of highly dynamic and interrelated processes...... net N2O dynamics. Similarly, plant-mediated gas transport by the subsurface aerating macrophyte Phalaris arundinacea played a major part in regulating and facilitating emissions of greenhouse gases across the soil-atmosphere interface. It is concluded that the spatiotemporal distribution of dominating...... N2O producing and consuming processes below the surface, in combination with the variations in the diffusive exchange rates due to soil water content and apparent diffusivity, control the magnitude and timing of N2O emissions to the atmosphere in close connection with the plant-mediated gas...

  9. Sampling and analysis methods for geothermal fluids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.C.

    1978-07-01

    The sampling procedures for geothermal fluids and gases include: sampling hot springs, fumaroles, etc.; sampling condensed brine and entrained gases; sampling steam-lines; low pressure separator systems; high pressure separator systems; two-phase sampling; downhole samplers; and miscellaneous methods. The recommended analytical methods compiled here cover physical properties, dissolved solids, and dissolved and entrained gases. The sequences of methods listed for each parameter are: wet chemical, gravimetric, colorimetric, electrode, atomic absorption, flame emission, x-ray fluorescence, inductively coupled plasma-atomic emission spectroscopy, ion exchange chromatography, spark source mass spectrometry, neutron activation analysis, and emission spectrometry. Material on correction of brine component concentrations for steam loss during flashing is presented. (MHR)

  10. Soliton Gases and Generalized Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Yoshimura, Takato; Caux, Jean-Sébastien

    2018-01-01

    We show that the equations of generalized hydrodynamics (GHD), a hydrodynamic theory for integrable quantum systems at the Euler scale, emerge in full generality in a family of classical gases, which generalize the gas of hard rods. In this family, the particles, upon colliding, jump forward or backward by a distance that depends on their velocities, reminiscent of classical soliton scattering. This provides a "molecular dynamics" for GHD: a numerical solver which is efficient, flexible, and which applies to the presence of external force fields. GHD also describes the hydrodynamics of classical soliton gases. We identify the GHD of any quantum model with that of the gas of its solitonlike wave packets, thus providing a remarkable quantum-classical equivalence. The theory is directly applicable, for instance, to integrable quantum chains and to the Lieb-Liniger model realized in cold-atom experiments.

  11. Noble Gases in Lakes and Ground Waters

    OpenAIRE

    Kipfer, Rolf; Aeschbach-Hertig, Werner; Peeters, Frank; Stute, Marvin

    2002-01-01

    In contrast to most other fields of noble gas geochemistry that mostly regard atmospheric noble gases as 'contamination,' air-derived noble gases make up the far largest and hence most important contribution to the noble gas abundance in meteoric waters, such as lakes and ground waters. Atmospheric noble gases enter the meteoric water cycle by gas partitioning during air / water exchange with the atmosphere. In lakes and oceans noble gases are exchanged with the free atmosphere at the surface...

  12. Atmospheric Chemistry and Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Ehhalt, D.; Prather, M.; Dentener, F.; Derwent, R.; Dlugokencky, Edward J.; Holland, E.; Isaksen, I.; Katima, J.; Kirchhoff, V.; Matson, P.; Midgley, P.; Wang, M.; Berntsen, T.; Bey, I.; Brasseur, G.; Buja, L.; Collins, W. J.; Daniel, J. S.; DeMore, W. B.; Derek, N.; Dickerson, R.; Etheridge, D.; Feichter, J.; Fraser, P.; Friedl, R.; Fuglestvedt, J.; Gauss, M.; Grenfell, L.; Grubler, Arnulf; Harris, N.; Hauglustaine, D.; Horowitz, L.; Jackman, C.; Jacob, D.; Jaegle, L.; Jain, Atul K.; Kanakidou, M.; Karlsdottir, S.; Ko, M.; Kurylo, M.; Lawrence, M.; Logan, J. A.; Manning, M.; Mauzerall, D.; McConnell, J.; Mickley, L. J.; Montzka, S.; Muller, J. F.; Olivier, J.; Pickering, K.; Pitari, G.; Roelofs, G.-J.; Rogers, H.; Rognerud, B.; Smith, Steven J.; Solomon, S.; Staehelin, J.; Steele, P.; Stevenson, D. S.; Sundet, J.; Thompson, A.; van Weele, M.; von Kuhlmann, R.; Wang, Y.; Weisenstein, D. K.; Wigley, T. M.; Wild, O.; Wuebbles, D.J.; Yantosca, R.; Joos, Fortunat; McFarland, M.

    2001-10-01

    Chapter 4 of the IPCC Third Assessment Report Climate Change 2001: The Scientific Basis. Sections include: Executive Summary 2414.1 Introduction 2434.2 Trace Gases: Current Observations, Trends and Budgets 2484.3 Projections of Future Emissions 2664.4 Projections of Atmospheric Composition for the 21st Century 2674.5 Open Questions 2774.6 Overall Impact of Global Atmospheric Chemistry Change 279

  13. Theoretical Insight into Shocked Gases

    Energy Technology Data Exchange (ETDEWEB)

    Leiding, Jeffery Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-29

    I present the results of statistical mechanical calculations on shocked molecular gases. This work provides insight into the general behavior of shock Hugoniots of gas phase molecular targets with varying initial pressures. The dissociation behavior of the molecules is emphasized. Impedance matching calculations are performed to determine the maximum degree of dissociation accessible for a given flyer velocity as a function of initial gas pressure.

  14. Positron diffusion in noble gases

    International Nuclear Information System (INIS)

    Stromswold, D.C.; Lee, Y.K.

    1975-01-01

    Positron diffusion in helium, neon, and argon has been observed and the lifetimes of free positrons in these gases have been calculated on the basis of assumed theoretical behavior. The results are summarized for various gas pressures at room temperature. Reported lifetimes are comparable to the extrapolated values of 1.4 μsec in He and 0.2 μsec in Ar obtained at one atmosphere by Falk. (7 figures, 2 tables) (U.S.)

  15. Deposition of multicomponent chromium carbide coatings using a non-conventional source of chromium and silicon with micro-additions of boron

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Ruiz, Jesus Eduardo, E-mail: jesus.gonzalez@biomat.uh.cu [Biomaterials Center, University of Havana (Cuba); Rodriguez Cristo, Alejandro [Mechanical Plants Company, Road of the Sub-Plan, Farm La Cana, Santa Clara, Villa Clara (Cuba); Ramos, Adrian Paz [Department of Chemistry, Universite de Montreal, Quebec (Canada); Quintana Puchol, Rafael [Welding Research Center, Central University Marta Abreu of Las Villas, Villa Clara (Cuba)

    2017-01-15

    The chromium carbide coatings are widely used in the mechanical industry due to its corrosion resistance and mechanical properties. In this work, we evaluated a new source of chromium and silicon with micro-additions of boron on the deposition of multi-component coatings of chromium carbides in W108 steel. The coatings were obtained by the pack cementation method, using a simultaneous deposition at 1000 deg for 4 hours. The coatings were analyzed by X-ray diffraction, X-ray energy dispersive spectroscopy, optical microscopy, microhardness test method and pin-on-disc wear test. It was found that the coatings formed on W108 steel were mainly constituted by (Cr,Fe){sub 23}C{sub 6} , (Cr,Fe){sub 7} C{sub 3} , Cr{sub 5-x}Si{sub 3-x} C{sub x+z}, Cr{sub 3} B{sub 0,44}C{sub 1,4} and (or) Cr{sub 7} BC{sub 4} . The carbide layers showed thicknesses between 14 and 15 μm and maximum values of microhardness between 15.8 and 18.8 GPa. Also, the micro-additions of boron to the mixtures showed statistically significant influence on the thickness, microhardness and abrasive wear resistance of the carbide coatings. (author)

  16. Landfill gases and some effects on vegetation

    Science.gov (United States)

    Franklin B. Flower; Ida A. Leone; Edward F. Gilman; John J. Arthur

    1977-01-01

    Gases moving from refuse landfills through soil were studied in New Jersey. The gases, products of anaerobic decomposition of organic matter in the refuse, caused injury and death of peach trees, ornamentals, and commercial farm crops, and create possible hazards to life and property because of the entrance of combustible gases into residences. Remedial measures are...

  17. 40 CFR 1065.750 - Analytical gases.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Analytical gases. 1065.750 Section 1065.750 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS..., span, and calibration gases. For example, it may be necessary to store bottles of condensable gases in...

  18. Atmosphere-Ocean Coupling through Trace Gases

    Science.gov (United States)

    Tegtmeier, S.; Atlas, E. L.; Krüger, K.; Lennartz, S. T.; Marandino, C. A.; Patra, P. K.; Quack, B.; Schlundt, C.

    2017-12-01

    Halogen- and sulfur-containing trace gases, as well as other volatile organic compounds (VOCs, such as isoprene) from biogeochemical marine sources are important constituents of the ocean and the atmosphere. These compounds exert wide-ranging influence on atmospheric chemical processes and climate interactions, as well as on human health in coastal regions. In their reactive form, they can affect the oxidizing capacity of the air and lead to the formation of new particles or the growth of existing ones. In this contribution, marine derived halogen-, sulfur-, and oxygen-containing compounds will be discussed. Their net flux into the atmosphere and their impact on atmospheric processes is analyzed based on observations and model simulations.

  19. Canonical partition functions: ideal quantum gases, interacting classical gases, and interacting quantum gases

    OpenAIRE

    Zhou, Chi-Chun; Dai, Wu-Sheng

    2017-01-01

    In statistical mechanics, for a system with fixed number of particles, e.g., a finite-size system, strictly speaking, the thermodynamic quantity needs to be calculated in the canonical ensemble. Nevertheless, the calculation of the canonical partition function is difficult; even the canonical partition function of ideal Bose and Fermi gases cannot be obtained exactly. In this paper, based on the mathematical theory of the symmetric function and the Bell polynomial, we suggest a method for the...

  20. Greenhouse effect gases (GEI) by energy consumption; Gases efecto invernadero (GEI) por consumo de energia

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Ledo C, Ramon; Bazan N, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The purpose of this article is to present the calculation methodology of greenhouse effect gases (GEI) emissions that are produced by the power sector in Mexico, as well as to discuss its possible impact in the subject of climatic change and the possible mitigating actions to lower the amount of emissions that can be taken and, therefore, the possible climate changes. In Mexico GEI inventories have been made since 1991, year in which the National Inventory of Gases with Greenhouse Effect was obtained for year 1988. The GEI include carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), methane (CH4), nitrous oxide (NO) and volatile organic carbides that are not methane (NMVOC) and are secondary products and harmful that are obtained from the processes that turn fuels into energy (combustion). The main sources of GEI are: fixed sources (industries, residences, commerce, public services and energy transformation, such as power generation); movable sources (that include all type of transport that uses fuel). The fuels that, by their volume and efficiency, generate more emissions of GEI are crude oil, natural gas and solid biomass (firewood-cane bagasse). Any effort to reduce these emissions is very important and remarkable if it affects the consumption of these fuels. [Spanish] El proposito de este articulo es presentar la metodologia de calculo de las emisiones de los gases con efecto invernadero (GEI) que son producidos por el sector energetico en Mexico, asi como discutir su posible impacto en las cuestiones de cambio climatico y las posibles acciones de mitigacion que se pueden realizar para abatir la cantidad de emisiones y, por ende, los posibles cambios de clima. En Mexico se han realizado inventarios de GEI desde 1991, ano en que se obtuvo el Inventario Nacional de Gases con Efecto Invernadero para el ano de 1988. Los GEI comprenden al dioxido de carbono (CO2), monoxido de carbono (CO), oxidos de nitrogeno (NOx), metano (CH4), oxido nitroso (N2O) y

  1. Avaliação das silagens de capim-elefante aditivadas com nabo forrageiro, pinhão manso e tremoço, pela técnica de produção de gases Evaluation of elephant grass silages with forage radish, jatropha and lupine cakes as additives by the gas production technique

    Directory of Open Access Journals (Sweden)

    Arnaldo Prata Neiva Júnior

    2010-08-01

    Full Text Available Objetivou-se, na condução deste trabalho, a avaliação das silagens de capim-elefante aditivadas com tortas de nabo forrageiro, pinhão manso e tremoço pela técnica de produção de gás. O experimento foi desenvolvido no Laboratório de Nutrição Animal do Centro de Energia Nuclear na Agricultura da Universidade de São Paulo (LANA/CENA/USP. Como doadores de líquido de rúmen, foram utilizados 2 ovinos da raça Santa Inês, machos, adultos, castrados e providos de cânula ruminal permanente. A alimentação dos animais doadores foi constituída de forragem de gramínea cultivada e uma suplementação, ao final do dia, com feno de Tifton, concentrado comercial e sal mineral à vontade. Os substratos foram secos a 60ºC, moídos em moinho do tipo Willey, provido de peneira com perfurações de 2 mm. Os gases produzidos durante os diferentes períodos de fermentação (0, 4, 8, 12, 24, 36, 48, 72 e 96 h foram medidos com um transducer - medidor de pressão.O experimento foi instalado segundo um delineamento de blocos ao acaso em que os tratamentos foram arranjados em um esquema de parcelas subdivididas no tempo. Os maiores valores de produção de gás observados para os tratamentos em que adicionou-se torta de tremoço quando comparados com as outras tortas, decorreu do fato da torta de tremoço apresentar menor teor de fibras, propiciando assim, uma maior fermentação ruminal e, consequentemente, maior produção de gás em relação a outros alimentos com maior proporção de carboidratos estruturais (parede celular.As taxas de degradação da fração solúvel da matéria seca foi menor para NF 8% e PM 11% em relação às outras silagens estudadas. Foram encontradas diferenças significativas para as TNF, TPM e TT, nos diferentes níveis, em relação ao volume de gases em 96 h de incubação (PThe objective of this work was to evaluate elephant grass silages with forage radish, Jatropha and lupine cakes as additives by the gas

  2. Impact Delivery of Reduced Greenhouse Gases on Early Mars

    Science.gov (United States)

    Haberle, R. M.; Zahnle, K.; Barlow, N.

    2017-01-01

    Reducing greenhouse gases are once again the latest trend in finding solutions to the early Mars climate dilemma. In its current form - as proposed by Ramirez et al. [1], later refined by Wordsworth et al. [2], and confirmed by Ramirez [3] - collision induced absorptions between CO2-H2 or CO2-CH4 provide enough extra greenhouse power to raise global mean surface temperatures to the melting point of water provided the atmosphere is thick enough and the reduced gases are abundant enough. To raise surface temperatures significantly by this mechanism, surface pressures must be at least 500 mb and H2 and/or CH4 concentrations must be at or above the several percent level. Both Wordsworth et al. [2] and Ramirez [3] show that the melting point can be reached in atmospheres with 1-2 bars of CO2 and 2-10% H2; smaller concentrations of H2 will suffice if CH4 is also present. If thick weakly reducing atmospheres are the solution to the faint young Sun paradox, then plausible mechanisms must be found to generate and sustain the gases. Possible sources of reducing gases include volcanic outgassing, serpentinization, and impact delivery; sinks include photolyis, oxidation, and escape to space. The viability of the reduced greenhouse hypothesis depends, therefore, on the strength of these sources and sinks.

  3. Emission and Sink of Greenhouse Gases in Soils of Moscow

    Science.gov (United States)

    Mozharova, N. V.; Kulachkova, S. A.; Lebed'-Sharlevich, Ya. I.

    2018-03-01

    The first inventory and zoning of the emission and sink of methane and carbon dioxide in the urban structure of greenhouse gases from soils and surface technogenic formations (STFs) (Technosols) on technogenic, recrementogenic, and natural sediments have been performed with consideration for the global warming potential under conditions of different formation rate of these gases, underflooding, and sealing. From gas geochemical criteria and anthropogenic pedogenesis features, the main sources of greenhouse gases, their intensity, and mass emission were revealed. The mass fractions of emissions from the sectors of waste and land use in the inventories of greenhouse gas emissions have been determined. New sources of gas emission have been revealed in the first sector, the emissions from which add tens of percent to the literature and state reports. In the second sector, emissions exceed the available data in 70 times. Estimation criteria based on the degree of manifestation and chemical composition of soil-geochemical anomalies and barrier capacities have been proposed. The sink of greenhouse gases from the atmosphere and the internal (latent) sink of methane in soils and STFs have been determined. Ecological functions of soils and STFs have been shown, and the share of latent methane sink has been calculated. The bacterial oxidation of methane in soils and STFs exceeds its emission to the atmosphere in almost hundred times.

  4. [Underreporting of tuberculosis in the Information System on Notifiable Diseases (SINAN): primary default and case detection from additional data sources using probabilistic record linkage].

    Science.gov (United States)

    Pinheiro, Rejane Sobrino; Andrade, Vanusa de Lemos; Oliveira, Gisele Pinto de

    2012-08-01

    This study aimed to analyze underreporting of tuberculosis (TB) cases in the Information System on Notifiable Diseases (SINAN), based on the following data sources: Mortality Information System (SIM), Registry and Follow-up Book for TB Case Treatment (LPATB), and Laboratory Registry Book (LRLAB). Probabilistic record linkage was used between the SIM (2007-2008) and SINAN (2002-2008). A search was conducted in LPATB and LRLAB (2007-2008) for cases not recorded in SINAN. There were 125 deaths, of which 44.8% were not recorded in SINAN. In LPATB, 58 cases (5.1%) were in treatment and were not reported in SINAN. LRLAB showed 32 smear-positive cases not reported to SINAN and without treatment, representing primary default. Addition of the retrieved cases, led to a 14.6% increase in the incidence rate in 2007 and 11.6% in 2008. Underreporting of deaths from or with TB in the Mortality Information System and primary default revealed difficulties in access to adequate and timely treatment, calling for rethinking of strategies to detect cases for timely treatment.

  5. Method for purification of gases

    Energy Technology Data Exchange (ETDEWEB)

    Hastrup, N.E.

    1981-11-17

    The present invention is directed to a method for selective purification of gases. The method comprises feeding an exhaust gas containing a solid impurity and a gaseous impurity to a separator. A substantial portion of the solid impurity is separated. Then, the partially-purified gas is fed to a spray dryer. That gas is sprayed with an absorption agent to separate gaseous impurities. Then, the further, partially-purified gas is fed to another separator to separate remaining solid impurity. An exhaust gas which is substantially free of solid and gaseous impurities and fly ash having a desired quality are recovered.

  6. Mechanics of liquids and gases

    CERN Document Server

    Loitsyanskii, L G; Jones, W P

    1966-01-01

    Mechanics of Liquids and Gases, Second Edition is a 10-chapter text that covers significant revisions concerning the dynamics of an ideal gas, a viscous liquid and a viscous gas.After an expanded introduction to the fundamental properties and methods of the mechanics of fluids, this edition goes on dealing with the kinetics and general questions of dynamics. The next chapters describe the one-dimensional pipe flow of a gas with friction, the elementary theory of the shock tube; Riemann's theory of the wave propagation of finite intensity, and the theory of plane subsonic and supersonic flows.

  7. Ultrasonic waves in classical gases

    Science.gov (United States)

    Magner, A. G.; Gorenstein, M. I.; Grygoriev, U. V.

    2017-12-01

    The velocity and absorption coefficient for the plane sound waves in a classical gas are obtained by solving the Boltzmann kinetic equation, which describes the reaction of the single-particle distribution function to a periodic external field. Within the linear response theory, the nonperturbative dispersion equation valid for all sound frequencies is derived and solved numerically. The results are in agreement with the approximate analytical solutions found for both the frequent- and rare-collision regimes. These results are also in qualitative agreement with the experimental data for ultrasonic waves in dilute gases.

  8. Climate Change and Greenhouse Gases

    Science.gov (United States)

    Ledley, Tamara S.; Sundquist, Eric; Schwartz, Stephen; Hall, Dorothy K.; Fellows, Jack; Killeen, Timothy

    1999-01-01

    The American Geophysical Union (AGU), as a scientific organization devoted to research on the Earth and space sciences, provides current scientific information to the public on issues pertinent to geophysics. The Council of the AGU approved a position statement on Climate Change and Greenhouse Gases in December 1998. The statement, together with a short summary of the procedures that were followed in its preparation, review, and adoption were published in the February 2, 1999 issue of Eos ([AGU, 1999]. The present article reviews scientific understanding of this issue as presented in peer-reviewed publications that serves as the underlying basis of the position statement.

  9. Critical Temperature Differences of a Standing Wave Thermoacoustic Prime Mover with Various Helium-Based Binary Mixture Working Gases

    Science.gov (United States)

    Setiawan, Ikhsan; Nohtomi, Makoto; Katsuta, Masafumi

    2015-06-01

    Thermoacoustic prime movers are energy conversion devices which convert thermal energy into acoustic work. The devices are environmentally friendly because they do not produce any exhaust gases. In addition, they can utilize clean energy such as solar-thermal energy or waste heat from internal combustion engines as the heat sources. The output mechanical work of thermoacoustic prime movers are usually used to drive a thermoacoustic refrigerator or to generate electricity. A thermoacoustic prime mover with low critical temperature difference is desired when we intend to utilize low quality of heat sources such as waste heat and sun light. The critical temperature difference can be significantly influenced by the kinds of working gases inside the resonator and stack's channels of the device. Generally, helium gas is preferred as the working gas due to its high sound speed which together with high mean pressure will yield high acoustic power per unit volume of the device. Moreover, adding a small amount of a heavy gas to helium gas may improve the efficiency of thermoacoustic devices. This paper presents numerical study and estimation of the critical temperature differences of a standing wave thermoacoustic prime mover with various helium-based binary-mixture working gases. It is found that mixing helium (He) gas with other common gases, namely argon (Ar), nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), at appropriate pressures and molar compositions, reduce the critical temperature differences to lower than those of the individual components of the gas mixtures. In addition, the optimum mole fractions of Hegas which give the minimum critical temperature differences are shifted to larger values as the pressure increases, and tends to be constant at around 0.7 when the pressure increases more than 2 MPa. However, the minimum critical temperature differences slightly increase as the pressure increases to higher than 1.5 MPa. Furthermore, we found that the lowest

  10. Unmanned Aerial Systems for Monitoring Trace Tropospheric Gases

    Directory of Open Access Journals (Sweden)

    Travis J. Schuyler

    2017-10-01

    Full Text Available The emission of greenhouse gases (GHGs has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes <100 m above ground level that can achieve spatiotemporal resolution on the order of meters and seconds. Unmanned aerial systems (UASs can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the most relevant classes of UASs available and evaluates their suitability to operate three kinds of detectors for atmospheric trace gases. The three subsets of UASs discussed are: (1 micro aerial vehicles (MAVs; (2 vertical take-off and landing (VTOL; and, (3 low-altitude short endurance (LASE systems. The trace gas detectors evaluated are first the vertical cavity surface emitting laser (VCSEL, which is an infrared laser-absorption technique; second two types of metal-oxide semiconductor sensors; and, third a modified catalytic type sensor. UASs with wingspans under 3 m that can carry up to 5 kg a few hundred meters high for at least 30 min provide the best cost and convenience compromise for sensors deployment. Future efforts should be focused on the calibration and validation of lightweight analytical systems mounted on UASs for quantifying trace atmospheric gases. In conclusion, UASs offer new and exciting opportunities to study atmospheric composition and its effect on weather patterns and climate change.

  11. Estimating PM2.5 Concentrations in Xi'an City Using a Generalized Additive Model with Multi-Source Monitoring Data.

    Directory of Open Access Journals (Sweden)

    Yong-Ze Song

    Full Text Available Particulate matter with an aerodynamic diameter <2.5 μm (PM2.5 represents a severe environmental problem and is of negative impact on human health. Xi'an City, with a population of 6.5 million, is among the highest concentrations of PM2.5 in China. In 2013, in total, there were 191 days in Xi'an City on which PM2.5 concentrations were greater than 100 μg/m3. Recently, a few studies have explored the potential causes of high PM2.5 concentration using remote sensing data such as the MODIS aerosol optical thickness (AOT product. Linear regression is a commonly used method to find statistical relationships among PM2.5 concentrations and other pollutants, including CO, NO2, SO2, and O3, which can be indicative of emission sources. The relationships of these variables, however, are usually complicated and non-linear. Therefore, a generalized additive model (GAM is used to estimate the statistical relationships between potential variables and PM2.5 concentrations. This model contains linear functions of SO2 and CO, univariate smoothing non-linear functions of NO2, O3, AOT and temperature, and bivariate smoothing non-linear functions of location and wind variables. The model can explain 69.50% of PM2.5 concentrations, with R2 = 0.691, which improves the result of a stepwise linear regression (R2 = 0.582 by 18.73%. The two most significant variables, CO concentration and AOT, represent 20.65% and 19.54% of the deviance, respectively, while the three other gas-phase concentrations, SO2, NO2, and O3 account for 10.88% of the total deviance. These results show that in Xi'an City, the traffic and other industrial emissions are the primary source of PM2.5. Temperature, location, and wind variables also non-linearly related with PM2.5.

  12. Electrochemical sensor monitoring of volcanic gases

    Science.gov (United States)

    Roberts, Tjarda; Freshwater, Ray; Oppenheimer, Clive; Saffell, John; Jones, Rod; Griffiths, Paul; Braban, Christine; Mead, Iqbal

    2010-05-01

    Advances in instrumentation have fuelled a recent growth of interest in using portable sensor systems for environmental monitoring of pollution. Developments in wireless technology are enabling such systems to operate remotely and autonomously, generating a wealth of environmental data. We report here on the application of miniature Alphasense electrochemical sensors to the detection and characterisation of gases in volcanic plumes. A highly portable sensor system was developed to operate an array of 6 low cost electrochemical sensors to detect CO, H2, HCl, SO2, H2S and NO2 at 1 Hz. A miniature pump draws air over all sensors simultaneously (i.e. sensors arranged in parallel). The sensor output in these campaigns was logged on PDAs for real-time viewing, and later download (with a view to future data-streaming). The instrument was deployed at a number of volcanoes and was subject to extremely harsh conditions including highly acidic environments, low (Antarctic) temperatures, and transport over rough terrain. Analysis methods are demonstrated that consider calibration, cross-sensitivities of the sensors to multiple gases, differing sensor response times, temperature dependence, and background sensor drift with time. The analysis is applied to a range of plume field-measurements to extract gas concentrations ranging from 100's ppmv to sub-ppmv and to characterise the individual volcano emissions. Applications of similar sensor systems for real-time long-term monitoring of volcanic emissions (which may indicate and ultimately predict eruptive behavior), and UAV and balloon-borne plume sampling are now already being realised. This work focused on demonstrating the application of electrochemical sensors to monitoring of environmental pollution from volcanoes. Other applications for similar sensors include the near-source monitoring of industrial emissions, and of pollutant levels enhanced by traffic emissions in the urban environment.

  13. Greenhouse effect gases sources and sinks (CO{sub 2}, CH{sub 4}, N{sub 2}O) in grasslands and reduction strategies. Greenhouse effect gases prairies. Final report of the second part of the project. April 2004; Sources et puits de gaz a effet de serre (CO{sub 2}, CH{sub 4}, N{sub 2}O) en prairie paturee et strategies de reduction. GES-Prairies. Rapport final de la seconde tranche du projet. Avril 2004

    Energy Technology Data Exchange (ETDEWEB)

    Soussana, J.F

    2004-04-15

    The project 'GES-Prairies' (Greenhouse Gases - Grasslands) had two main objectives: 1. To measure more accurately the fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O of French grasslands and determine the greenhouse gas (GHG) balance of these areas. 2. To calculate the net GHG emissions of cattle production farms and finally to propose and evaluate some management scenarios leading to a reduction of GHG emissions. This project deals with three different spatial scales: the field scale, the farm scale and finally, the regional scale. At the field scale, during two years, fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O were measured in a mid-mountain permanent grassland, previously managed intensively by cutting and grazing (Laqueuille, Auvergne, France). Results from the first complete year of measurements show that the extensification process (reduction of the stocking rate and stopping N fertilization) allows to stock more carbon in the ecosystem. At the farm scale, We developed a model (FARMSIM, coupled to PASIM) able to simulate the GHG balance of a livestock farm. FARMSIM has been tested with data obtained from a mixed livestock farm in Lorraine (dairy and meat production, annual average stocking rate = 1.3 LU ha{sup -1}) of 100 ha (including 76 ha of grasslands and 21 of annual crops). The results indicate a net emission of 175 t equivalent C-CO{sub 2} for this farm. If expressed per unit of product, it represents 1.34 t equivalent C-CO{sub 2} per LU and per year or 0.54 kg CO{sub 2} per kg of milk and per year. At the regional scale/. The PASIM model has been used to simulate the European grasslands with a spatial resolution of 1' (about 200 * 200 km). For each grid cell, a sensibility analysis allowed to determine the N application which correspond to 30% of the N application that would maximize the annual yield of the pasture. Simulation runs on mixed systems (combining grazing and cutting) show that almost one half of the grassland area is, on

  14. Emissions of biogenic sulfur gases from northern bogs and fens

    Science.gov (United States)

    Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

    1992-01-01

    Sulfur gases are important components of the global cycle of S. They contribute to the acidity of precipitation and they influence global radiation balance and climate. The role of terrestrial sources of biogenic S and their effect on atmospheric chemistry remain as major unanswered questions in our understanding of the natural S cycle. The role of northern wetlands as sources and sinks of gaseous S by measuring rates of S gas exchange as a function of season, hydrologic conditions, and gradients in tropic status was investigated. Experiments were conducted in wetlands in New Hampshire, particularly a poor fen, and in Mire 239, a poor fen at the Experimental Lakes Area (ELA) in Ontario. Emissions were determined using Teflon enclosures, gas cryotrapping methods and gas chromatography (GC) with flame photometric detection. Dynamic (sweep flow) and static enclosures were employed which yielded similar results. Dissolved S gases and methane were determined by gas stripping followed by GC.

  15. A conceptual study on the formulation of a permeable reactive pavement with activated carbon additives for controlling the fate of non-point source environmental organic contaminants.

    Science.gov (United States)

    Huang, Shengyi; Liang, Chenju

    2018-02-01

    To take advantage of the road pavement network where non-point source (NPS) pollution such as benzene, toluene, ethyl-benzene, and xylene (BTEX) from vehicle traffic exhaust via wet and dry atmospheric deposition occurs, the asphalt pavement may be used as a media to control the NPS pollution. An experiment to prepare an adsorptive porous reactive pavement (PRP) was initiated to explore the potential to reduce environmental NPS vehicle pollution. The PRP was prepared and studied as follows: various activated carbons (AC) were initially screened to determine if they were suitable as an additive in the porous asphalt mixture; various mixtures of a selected AC were incorporated with the design of porous asphalt concrete (PAC) to produce PRP, and the PRP formulations were tested to ensure that they comply with the required specifications; qualified specimens were subsequently tested to determine their adsorption capacity for BTEX in aqueous solution, as compared to conventional PAC. The PRP08 and PRP16 samples, named for the design formulations of 0.8% and 1.6% of AC (by wt. in the formulation), exhibited low asphalt drain-down and low abrasion loss and also met all regulated specifications. The BTEX adsorption capacity measurements of PRP08 and PRP16 were 33-46%, 36-51%, 20-22%, and 6-8% respectively, higher than those obtained from PACs. Based on the test results, PRPs showed good physical performance and adsorption and may be considered as a potential method for controlling the transport of NPS vehicle pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The Multi-allelic Genetic Architecture of a Variance-Heterogeneity Locus for Molybdenum Concentration in Leaves Acts as a Source of Unexplained Additive Genetic Variance.

    Directory of Open Access Journals (Sweden)

    Simon K G Forsberg

    2015-11-01

    Full Text Available Genome-wide association (GWA analyses have generally been used to detect individual loci contributing to the phenotypic diversity in a population by the effects of these loci on the trait mean. More rarely, loci have also been detected based on variance differences between genotypes. Several hypotheses have been proposed to explain the possible genetic mechanisms leading to such variance signals. However, little is known about what causes these signals, or whether this genetic variance-heterogeneity reflects mechanisms of importance in natural populations. Previously, we identified a variance-heterogeneity GWA (vGWA signal for leaf molybdenum concentrations in Arabidopsis thaliana. Here, fine-mapping of this association reveals that the vGWA emerges from the effects of three independent genetic polymorphisms that all are in strong LD with the markers displaying the genetic variance-heterogeneity. By revealing the genetic architecture underlying this vGWA signal, we uncovered the molecular source of a significant amount of hidden additive genetic variation or "missing heritability". Two of the three polymorphisms underlying the genetic variance-heterogeneity are promoter variants for Molybdate transporter 1 (MOT1, and the third a variant located ~25 kb downstream of this gene. A fourth independent association was also detected ~600 kb upstream of MOT1. Use of a T-DNA knockout allele highlights Copper Transporter 6; COPT6 (AT2G26975 as a strong candidate gene for this association. Our results show that an extended LD across a complex locus including multiple functional alleles can lead to a variance-heterogeneity between genotypes in natural populations. Further, they provide novel insights into the genetic regulation of ion homeostasis in A. thaliana, and empirically confirm that variance-heterogeneity based GWA methods are a valuable tool to detect novel associations of biological importance in natural populations.

  17. The effectiveness of power-generating complexes constructed on the basis of nuclear power plants combined with additional sources of energy determined taking risk factors into account

    Science.gov (United States)

    Aminov, R. Z.; Khrustalev, V. A.; Portyankin, A. V.

    2015-02-01

    The effectiveness of combining nuclear power plants equipped with water-cooled water-moderated power-generating reactors (VVER) with other sources of energy within unified power-generating complexes is analyzed. The use of such power-generating complexes makes it possible to achieve the necessary load pickup capability and flexibility in performing the mandatory selective primary and emergency control of load, as well as participation in passing the night minimums of electric load curves while retaining high values of the capacity utilization factor of the entire power-generating complex at higher levels of the steam-turbine part efficiency. Versions involving combined use of nuclear power plants with hydrogen toppings and gas turbine units for generating electricity are considered. In view of the fact that hydrogen is an unsafe energy carrier, the use of which introduces additional elements of risk, a procedure for evaluating these risks under different conditions of implementing the fuel-and-hydrogen cycle at nuclear power plants is proposed. Risk accounting technique with the use of statistical data is considered, including the characteristics of hydrogen and gas pipelines, and the process pipelines equipment tightness loss occurrence rate. The expected intensities of fires and explosions at nuclear power plants fitted with hydrogen toppings and gas turbine units are calculated. In estimating the damage inflicted by events (fires and explosions) occurred in nuclear power plant turbine buildings, the US statistical data were used. Conservative scenarios of fires and explosions of hydrogen-air mixtures in nuclear power plant turbine buildings are presented. Results from calculations of the introduced annual risk to the attained net annual profit ratio in commensurable versions are given. This ratio can be used in selecting projects characterized by the most technically attainable and socially acceptable safety.

  18. Addition of ash on drained forested peatlands in southern Sweden. Effects on forest production, fluxes of greenhouse gases, peat properties, understorey vegetation and groundwater chemistry; Tillfoersel av aska i skog paa dikad torvmark i soedra Sverige. Effekter paa skogsproduktion, floeden av vaexthusgaser, torvegenskaper, markvegetation och grundvattenkemi

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf; Bjoerk, Robert G.; Ring, Eva; Ernfors, Maria; Jacobson, Staffan; Nilsson, Mats; Klemedtsson, Leif

    2009-02-15

    The objective of the present study was to evaluate effects of wood-ash addition on drained peatlands in southern Sweden. Tree growth, greenhouse gases, peat properties, microbial biomass and processes, understory vegetation and groundwater chemistry were measured in three field experiments (some variables were not measured in all experiments): (i) 168 Perstorp, an oligotrophic mire with Scotch pine (Pinus sylvestris L.), where 2.5 tonnes d.w. of wood ash/ha (2.5WA) was added in 1982; (ii) 273 Anderstorp, also an oligotrophic mire with Scots pine, where 3.3 tonnes d.w. crushed ash/ha (3.3KA) and 6.6 tonnes d.w. crushed/ha (6.6KA) was added in 2003; (iii) 278 Skogaryd, a minerotrophic mire with Norway spruce (Picea abies L. Karst.), where the same doses of crushed ash as in Anderstorp were added in 2006. Untreated controls were included in all experiments. At Anderstorp, increased tree growth was indicated, at least in the treatment with the highest ash dose during the first five years after treatment. The annual emissions of CO{sub 2}, CH4 and N{sub 2}O from the peat were unaffected. At Skogaryd, the growth was unaffected and the emissions of both CO{sub 2} and N{sub 2}O were reduced during the first two years after treatment. In general, the significant ash effects (2.5WA and 3.3KA evaluated) on peat characteristics, microbial biomass and processes were found in the upper soil (0-5 cm) at the recently treated sites (Anderstorp and Skogaryd), and at greater depths (5-30 cm) at Perstorp, where the ash was added 25 years ago. In the ash treatment at Perstorp, there was a shift in the plant community structure and a decrease in species diversity of the understory vegetation. However, at this point of time, the forest stand had become substantially denser than on the control plots. Hence, these effects on the understory vegetation may have been an indirect effect of the ash-induced altered tree stand properties. In Skogaryd, no shift in the plant community was found

  19. Low carbon fuel and chemical production from waste gases

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, S.; Liew, F.M.; Daniell, J.; Koepke, M. [LanzaTech, Ltd., Auckland (New Zealand)

    2012-07-01

    LanzaTech has developed a gas fermentation platform for the production of alter native transport fuels and commodity chemicals from carbon monoxide, hydrogen and carbon dioxide containing gases. LanzaTech technology uses these gases in place of sugars as the carbon and energy source for fermentation thereby allowing a broad spectrum of resources to be considered as an input for product synthesis. At the core of the Lanzatech process is a proprietary microbe capable of using gases as the only carbon and energy input for product synthesis. To harness this capability for the manufacture of a diverse range of commercially valuable products, the company has developed a robust synthetic biology platform to enable a variety of novel molecules to be synthesised via gas fermentation. LanzaTech initially focused on the fermentation of industrial waste gases for fuel ethanol production. The company has been operating pilot plant that uses direct feeds of steel making off gas for ethanol production for over 24 months. This platform technology has been further successfully demonstrated using a broad range of gas inputs including gasified biomass and reformed natural gas. LanzaTech has developed the fermentation, engineering and control systems necessary to efficiently convert gases to valuable products. A precommercial demonstration scale unit processing steel mill waste gases was commissioned in China during the 2{sup nd} quarter of 2012. Subsequent scale-up of this facility is projected for the 2013 and will represent the first world scale non-food based low carbon ethanol project. More recently LanzaTech has developed proprietary microbial catalysts capable of converting carbon dioxide in the presence of hydrogen directly to value added chemicals, where-in CO{sub 2} is the sole source of carbon for product synthesis. Integrating the LanzaTech technology into a number of industrial facilities, such as steel mills, oil refineries and other industries that emit Carbon bearing

  20. Granular gases under extreme driving

    Science.gov (United States)

    Kang, W.; Machta, J.; Ben-Naim, E.

    2010-08-01

    We study inelastic gases in two dimensions using event-driven molecular-dynamics simulations. Our focus is the nature of the stationary state attained by rare injection of large amounts of energy to balance the dissipation due to collisions. We find that under such extreme driving, with the injection rate much smaller than the collision rate, the velocity distribution has a power-law high-energy tail. The numerically measured exponent characterizing this tail is in excellent agreement with predictions of kinetic theory over a wide range of system parameters. We conclude that driving by rare but powerful energy injection leads to a well-mixed gas and constitutes an alternative mechanism for agitating granular matter. In this distinct nonequilibrium steady state, energy cascades from large to small scales. Our simulations also show that when the injection rate is comparable with the collision rate, the velocity distribution has a stretched exponential tail.

  1. Explorative analysis of microbes, colloids and gases

    International Nuclear Information System (INIS)

    Hallbeck, Lotta; Pedersen, Karsten

    2008-08-01

    radionuclides in groundwater. The aim of the study of colloids in the Forsmark 2.3 site investigation was to quantify and determine the composition of colloids in groundwater samples from the boreholes. There are both inorganic and organic colloids, and the site investigation measured both types. - Gases (Chapter 3): Dissolved gases in groundwater contribute to the mass of dissolved species. The distribution and composition of dissolved gases in deep groundwater are important to understand in the safety assessment of a deep geological nuclear waste repository: Micro bubbles of gas may potentially transport radionuclides from the repository to the surface. Oxygen, hydrogen sulphide and carbon dioxide are parts of fundamental redox couples that participate in several solid-aqueous phase transformations such as the precipitation of ferric iron oxides, iron sulphide and calcite. Methane and hydrogen, may serve as sources of energy to various microbiological processes

  2. Explorative analysis of microbes, colloids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Hallbeck, Lotta; Pedersen, Karsten (Microbial Analytics Sweden AB, Goeteborg (Sweden))

    2008-08-15

    potential to transport radionuclides in groundwater. The aim of the study of colloids in the Forsmark 2.3 site investigation was to quantify and determine the composition of colloids in groundwater samples from the boreholes. There are both inorganic and organic colloids, and the site investigation measured both types. - Gases (Chapter 3): Dissolved gases in groundwater contribute to the mass of dissolved species. The distribution and composition of dissolved gases in deep groundwater are important to understand in the safety assessment of a deep geological nuclear waste repository: Micro bubbles of gas may potentially transport radionuclides from the repository to the surface. Oxygen, hydrogen sulphide and carbon dioxide are parts of fundamental redox couples that participate in several solid-aqueous phase transformations such as the precipitation of ferric iron oxides, iron sulphide and calcite. Methane and hydrogen, may serve as sources of energy to various microbiological processes

  3. Lessons from geothermal gases at Yellowstone

    Science.gov (United States)

    Lowenstern, J. B.; Bergfeld, D.; Evans, W.; Hurwitz, S.

    2015-12-01

    The magma-hydrothermal system of the Yellowstone Plateau Volcanic Field encompasses over ten thousand individual springs, seeps, and fumaroles spread out over >9000 square kilometers, and produces a range of acid, neutral and alkaline waters. A prominent model (Fournier, 1989 and related papers) concludes that many neutral and alkaline fluids found in hot springs and geysers are derived from a uniform, high-enthalpy parent fluid through processes such as deep boiling and mixing with dilute meteoric groundwater. Acid waters are generally condensates of gas-bearing steam that boils off of subsurface geothermal waters. Our recent studies of gases at Yellowstone (Lowenstern et al., 2015 and references therein) are compatible with such a model, but also reveal that gases are largely decoupled from thermal waters due to open-system addition of abundant deep gas to (comparatively) shallow circulating thermal waters. Fumarole emissions at Yellowstone range from gas-rich (up to 15 mol%) composed of deeply derived CO2, He and CH4, to steam-rich emissions (16 RA) and low CH4 and He concentrations and 2) mantle-derived CO2 with much higher CH4 and/or He concentrations and abundant radiogenic He picked up from crustal degassing. Individual thermal areas have distinct CH4/He. It remains unclear whether some gas ratios mainly reflect subsurface geothermal temperatures. Instead, they may simply reflect signatures imparted by local rock types and mixing on timescales too fast for reequilibration. Overall, the gas chemistry reflects a broader view of mantle-crust dynamics than can be appreciated by studies of only dissolved solutes in the neutral and alkaline waters from Yellowstone geysers. Fournier (1989) Ann. Rev. Earth Planet. Sci. v. 17, p. 13-53. Lowenstern et al. (2015) JVGR, v. 302, 87-101.

  4. The changing role of non co2 greenhouse gases

    Science.gov (United States)

    Khalil, M. A. K.

    During the last century, the concentrations of several greenhouse gases have increased considerably - most notably, methane and nitrous oxide. In addition, new, entirely man - made gases have been put into the atmosphere that also cause the greenhouse effect; these include the chlorofluorocarbons. Calculations have shown that the during the last century the non - CO2 greenhouse gases could together be almost as effective as the increase of carbon dioxide in causing global warming. These and similar gases were therefore included in the Kyoto Protocol to develop a comprehensive plan for controlling global warming. New studies show however that the other gases, with few exceptions, are likely to play a smaller than expected role in future global warming. The most significant non - CO2 man made greenhouse gases are methane and nitrous oxide. Methane rose from 800 ppbv about 200 years ago to about 1700 ppbv in recent times, while nitrous oxide rose from about 285 ppbv to 310 ppbv over the same time. These trends made methane the most important gas for global warming next to carbon dioxide. But now, the trends of methane have declined considerably. Budget analyses suggest that we may not see major changes of concentrations in the future comparable to the trends of the last century. Thus the role of methane in future global warming may be less than expected earlier. Nitrous oxide on the other hand, has increased slowly during the last century, but now there is an indication that it may be increasing faster. The increase of nitrous oxide is still slow, but in time it is likely to become more important than previously thought. While other greenhouse gases such as the perfluorocarbons, sulfur hexafluoride and hydrochlorofluorocarbons are included in the Kyoto Protocol, these are present in such minute concentrations that it is unlikely that they will have an important role in future global warming. Recent studies on the perfluorocarbons show that the trend of the major gas

  5. Reduction of Climate Gases by Energy Efficiency

    International Nuclear Information System (INIS)

    Moe, N.

    1998-01-01

    Carbon dioxide cannot be depolluted in practice. However, there are two areas where measures can be taken to avoid CO 2 emissions: 1. Energy-efficiency. 2. Use of sustainable energy sources in energy production. It is characteristic that many measures which are good for the environment are also good from the point of view of cost efficiency, preparedness and employment. This is tru, for instance, of the greater use of biofuels instead of fossil fuels, collective heating systems as opposed to individual ones and economy measures - especially more efficient use of electricity. It is a question of thinking of the system as a whole. Methane is another factor which contributes to the greenhouse effect. Methane emissions can also be avoided, or reduced, by system-thinking. System-thinking is, for instance, not ro deposit combustible waste but to use it as an energy source. And why not produce electricity by using methane from existing landfill sites. Electrical energy is the most useful form of energy. Therefore, electricity should not, as a principal rule, be used for heating, or as process energy. The fact that energy-efficiency and emission of greenhouse gases are interrelated is shown in the following two examples. 1. Only about 25% of the energy content in extracted coal will reach the consumers as electricity when the production takes place in an ordinary, coal-fires condensing power station. 2. When district heating (room-heating and hot water) is produced in a modern heat-production plant by flue-gas condensation, about 90% of the energy is utilised for heating purposes. To obtain an overall picture of the amount of energy used for a purpose, e.g. heating or electricity, you must view the entire process from extraction to final use. Such a picture can show the energy efficiency and what losses arise. Efficiency measures can reduce the energy bill. They can also reduce pollution, greenhouse gases among other things. Examples will be given in this paper of energy

  6. High order harmonic generation in rare gases

    Energy Technology Data Exchange (ETDEWEB)

    Budil, Kimberly Susan [Univ. of California, Davis, CA (United States)

    1994-05-01

    The process of high order harmonic generation in atomic gases has shown great promise as a method of generating extremely short wavelength radiation, extending far into the extreme ultraviolet (XUV). The process is conceptually simple. A very intense laser pulse (I ~1013-1014 W/cm2) is focused into a dense (~1017 particles/cm3) atomic medium, causing the atoms to become polarized. These atomic dipoles are then coherently driven by the laser field and begin to radiate at odd harmonics of the laser field. This dissertation is a study of both the physical mechanism of harmonic generation as well as its development as a source of coherent XUV radiation. Recently, a semiclassical theory has been proposed which provides a simple, intuitive description of harmonic generation. In this picture the process is treated in two steps. The atom ionizes via tunneling after which its classical motion in the laser field is studied. Electron trajectories which return to the vicinity of the nucleus may recombine and emit a harmonic photon, while those which do not return will ionize. An experiment was performed to test the validity of this model wherein the trajectory of the electron as it orbits the nucleus or ion core is perturbed by driving the process with elliptically, rather than linearly, polarized laser radiation. The semiclassical theory predicts a rapid turn-off of harmonic production as the ellipticity of the driving field is increased. This decrease in harmonic production is observed experimentally and a simple quantum mechanical theory is used to model the data. The second major focus of this work was on development of the harmonic "source". A series of experiments were performed examining the spatial profiles of the harmonics. The quality of the spatial profile is crucial if the harmonics are to be used as the source for experiments, particularly if they must be refocused.

  7. Greenhouse Gases Concentrations in the Atmosphere Along ...

    African Journals Online (AJOL)

    This study investigated effect of vehicular emission on greenhouse gases concentrations along selected roads of different traffic densities in Abeokuta, Ogun State, Nigeria. Nine roads comprised highway, commercial and residential were selected. Greenhouse Gases (GHGs) were determined from both sides of the roads by ...

  8. 40 CFR 89.312 - Analytical gases.

    Science.gov (United States)

    2010-07-01

    ... gases must be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400... span gases. (1) Calibration gas values are to be derived from NIST Standard Reference Materials (SRM's... purified synthetic air ; (ii) C3H8 and purified nitrogen (optional for raw measurements); (iii) CO and...

  9. Study of greenhouse gases emission factor for nuclear power chain of China

    International Nuclear Information System (INIS)

    Ma Zhonghai; Pan Ziqiang; Xie Jianlun; Xiu Binglin

    2001-01-01

    The Greenhouse Gases Emission Factor (GGEF) for nuclear power chain of China is calculated based on Life Cycle Analysis method and the definition of full energy chain. There is no greenhouse gases released directly from nuclear power plant. The greenhouse gases emission from nuclear power plant is mainly from coal-fired electricity supply to nuclear power plant for its normal operation and the production of construction materials those are used in the nuclear power plant. The total GGEF of nuclear power chain in China is 13.71 g-co 2 /kWh. It is necessary to regulate un-rational power source mix and to use the energy sources in rational way for reducing the greenhouse gas effect. Nuclear power for electricity generation is one of effective ways to reduce greenhouse gases emission and retard the greenhouse effect

  10. Impact Delivery of Reduced Greenhouse Gases on Early Mars

    Science.gov (United States)

    Haberle, R. M.; Zahnle, K. J.; Barlow, N. G.

    2017-12-01

    Reducing greenhouse gases are the latest trend in finding solutions to the early Mars climate dilemma. In thick CO2 atmospheres with modest concentrations of H2 and/or CH4, collision induced absorptions can reduce the outgoing long wave radiation enough to provide a significant greenhouse effect. To raise surface temperatures significantly by this process, surface pressures must be at least 500 mb and H2 and/or CH4 concentrations must be at or above the several percent level. Volcanism, serpentinization, and impacts are possible sources for reduced gases. Here we investigate the delivery of such gases by impact degassing from comets and asteroids. We use a time-marching stochastic impactor model that reproduces the observed crater size frequency distribution of Noachian surfaces. Following each impact, reduced gases are added to the atmosphere from a production function based on gas equilibrium calculations for several classes of meteorites and comets at typical post-impact temperatures. Escape and photochemistry then remove the reduced greenhouse gases continuously in time throughout each simulation. We then conduct an ensemble of simulations with this simple model varying the surface pressure, impact history, reduced gas production and escape functions, and mix of impactor types, to determine if this could be a potentially important part of the early Mars story. Our goal is to determine the duration of impact events that elevate reduced gas concentrations to significant levels and the total time of such events throughout the Noachian. Our initial simulations indicate that large impactors can raise H2 concentrations above the 10% level - a level high enough for a very strong greenhouse effect in a 1 bar CO2 atmosphere - for millions of years, and that the total time spent at or above that level can be in the 10's of millions of years range. These are interesting results that we plan to explore more thoroughly for the meeting.

  11. Cooling of 3D granular gases in microgravity experiments

    Directory of Open Access Journals (Sweden)

    Harth Kirsten

    2017-01-01

    Full Text Available Granular gases are a most peculiar state, superficially similar to molecular gases: They are loose ensembles of moving grains, rarely interacting with each other and with container walls. The most investigated scenario is the “granular cooling”, the collective loss of energy from an initially excited state. We present an experimental study of the cooling of a 3D granular gas of rodlike grains in micro-gravity. Driven steady states of non-spherical grains are characterized by a lack of energy equipartition between the degrees of freedom of translation and rotation. Excitation by vibrating walls additionally introduces strong gradients in the direction and magnitude of translational velocities. We show that the degrees of freedom equilibrate during granular cooling in the homogeneous cooling state. The energy loss follows a t−2 scaling. In addition, the alignment of the rod axes with the excitation direction and with the instantaneous velocities are altered during this process.

  12. Chemical production from industrial by-product gases: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lyke, S.E.; Moore, R.H.

    1981-04-01

    The potential for conservation of natural gas is studied and the technical and economic feasibility and the implementation of ventures to produce such chemicals using carbon monoxide and hydrogen from byproduct gases are determined. A survey was performed of potential chemical products and byproduct gas sources. Byproduct gases from the elemental phosphorus and the iron and steel industries were selected for detailed study. Gas sampling, preliminary design, market surveys, and economic analyses were performed for specific sources in the selected industries. The study showed that production of methanol or ammonia from byproduct gas at the sites studied in the elemental phosphorus and the iron and steel industries is technically feasible but not economically viable under current conditions. Several other applications are identified as having the potential for better economics. The survey performed identified a need for an improved method of recovering carbon monoxide from dilute gases. A modest experimental program was directed toward the development of a permselective membrane to fulfill that need. A practical membrane was not developed but further investigation along the same lines is recommended. (MCW)

  13. Greenhouse gases mitigation options and strategies for Tanzania

    Energy Technology Data Exchange (ETDEWEB)

    Mwandosya, M.J.; Meena, H.E.

    1996-12-31

    Tanzania became a party to the United Nations Framework on Climate Change (UN FCCC) when she ratified the Convention in March, 1996. Now that Tanzania and other developing countries are Parties to the UN FCCC, compliance with its provisions is mandatory. The legal requirements therefore provide a basis for their participation in climate change studies and policy formulation. All parties to the Convention are required by Article 4.1 of the United Nations Convention on Climate Change (UN FCCC) to develop, periodically update, publish, and make available national inventories of anthropogenic emissions and removal of greenhouse gases that are not controlled by the Montreal Protocol. This study on possible options for the mitigation of greenhouse gases in Tanzania is a preliminary effort towards the fulfilment of the obligation. In order to fulfil their obligations under the UN FCCC and have a meaningful mitigation assessment, identification and quantification of anthropogenic sources of atmospheric emissions of greenhouse gases in the country was undertaken. In this respect, the study of anthropogenic emissions by source and removals by sink of GHGs in Tanzania was done with the main objective of increasing the quantity and quality of base-line data available in order to further scientific understanding of the relationship of greenhouse gas emissions to climate change. Furthermore, the study facilitated identification of national policy and technological options that could reduce the level of emissions in the country.

  14. Greenhouse gases and emissions trading

    International Nuclear Information System (INIS)

    LeBlanc, A.; Dudek, D.J.

    1993-01-01

    Global cooperation is essential in cutting greenhouse-gas emissions, say Alice LeBlanc and Daniel J. Dudek of the Environmental Defense in New York City. The first step, they continue, is agreement among nations on an overall global limit for all greenhouse gases, followed by an allocation of the global limit among nations. The agreements must contain effective reporting and monitoring systems and enforcement provisions, they add. The Framework Convention on Climate Change, signed by most nations of the world in Brazil in 1992, provides the foundation for such an agreement, LeBlanc and Dudek note. open-quotes International emissions trading is a way to lower costs and expand reduction options for the benefit of all,close quotes they contend. Under such an arrangement, an international agency would assign allowances, stated in tons of carbon dioxide. Countries would be free to buy and sell allowances, but no country could exceed, in a given year, the total allowances it holds. By emitting less than its allowed amount, a country would accumulate more allowances, which it could sell. The authors claim such a system would offer benefits to the world economy by saving billions of dollars in pollution-reduction costs while still achieving emission limits established in an international agreement

  15. Subnanosecond breakdown in high-pressure gases

    Science.gov (United States)

    Naidis, George V.; Tarasenko, Victor F.; Babaeva, Natalia Yu; Lomaev, Mikhail I.

    2018-01-01

    Pulsed discharges in high-pressure gases are of considerable interest as sources of nonequilibrium plasma for various technological applications: pollution control, pumping of laser media, plasma-assisted combustion, etc. Recently, attention has been attracted to the use of subnanosecond voltage fronts, producing diffuse discharges with radii of several millimeters. Such plasma structures, similar to pulsed glow discharges, are of special interest for applications due to quasi-uniformity of plasma parameters in relatively large gas volumes. This review presents the results of experimental and computational study of subnanosecond diffuse discharge formation. A description of generators of short high-voltage pulses with subnanosecond fronts and of discharge setups is given. Diagnostic methods for the measurement of various discharge parameters with high temporal and spatial resolution are described. Obtained experimental data on plasma properties for a wide range of governing factors are discussed. A review of various theoretical approaches used for computational study of the dynamics and structure of fast ionization waves is given; the applicability of conventional fluid streamer models for simulation of subnanosecond ionization waves is discussed. Calculated spatial-temporal profiles of plasma parameters during streamer propagation are presented. The efficiency of subnanosecond discharges for the production of reactive species is evaluated. On the basis of the comparison of simulation results and experimental data the effects of various factors (voltage rise time, polarity, etc.) on discharge characteristics are revealed. The major physical phenomena governing the properties of subnanosecond breakdown are analyzed.

  16. Radiative energy transfer in molecular gases

    Science.gov (United States)

    Tiwari, Surendra N.

    1992-01-01

    Basic formulations, analyses, and numerical procedures are presented to study radiative interactions in gray as well as nongray gases under different physical and flow conditions. After preliminary fluid-dynamical considerations, essential governing equations for radiative transport are presented that are applicable under local and nonlocal thermodynamic equilibrium conditions. Auxiliary relations for relaxation times and spectral absorption models are also provided. For specific applications, several simple gaseous systems are analyzed. The first system considered consists of a gas bounded by two parallel plates having the same temperature. Within the gas there is a uniform heat source per unit volume. For this system, both vibrational nonequilibrium effects and radiation conduction interactions are studied. The second system consists of fully developed laminar flow and heat transfer in a parallel plate duct under the boundary condition of a uniform surface heat flux. For this system, effects of gray surface emittance are studied. With the single exception of a circular geometry, the third system is considered identical to the second system. Here, the influence of nongray walls is also studied.

  17. Photoelectron spectrometer for attosecond spectroscopy of liquids and gases.

    Science.gov (United States)

    Jordan, I; Huppert, M; Brown, M A; van Bokhoven, J A; Wörner, H J

    2015-12-01

    A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectra for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.

  18. Catalytic dry reforming of waste plastics from different waste treatment plants for production of synthesis gases.

    Science.gov (United States)

    Saad, Juniza Md; Williams, Paul T

    2016-12-01

    Catalytic dry reforming of mixed waste plastics, from a range of different municipal, commercial and industrial sources, were processed in a two-stage fixed bed reactor. Pyrolysis of the plastics took place in the first stage and dry (CO 2 ) reforming of the evolved pyrolysis gases took place in the second stage in the presence of Ni/Al 2 O 3 and Ni-Co/Al 2 O 3 catalysts in order to improve the production of syngas from the dry reforming process. The results showed that the highest amount of syngas yield was obtained from the dry reforming of plastic waste from the agricultural industry with the Ni/Al 2 O 3 catalyst, producing 153.67mmol syngas g -1 waste . The addition of cobalt metal as a promoter to the Ni/Al 2 O 3 catalyst did not have a major influence on syngas yield. Overall, the catalytic-dry reforming of waste plastics from various waste treatment plants showed great potential towards the production of synthesis gases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Food Supplements Have a Positive Impact on Weight Gain and the Addition of Animal Source Foods Increases Lean Body Mass of Kenyan Schoolchildren

    NARCIS (Netherlands)

    Grillenberger, M.; Neumann, C.G.; Murphy, S.P.; Bwibo, N.O.; Veer, van 't P.; Hautvast, J.G.A.J.; West, C.E.

    2003-01-01

    Observational studies of dietary patterns and growth and studies with milk supplementation have shown that children consuming diets containing animal source foods grow better. This study evaluates the growth of 544 Kenyan schoolchildren (median age 7.1 y) after 23 mo of food supplementation with a

  20. Design of a multifunctional and portable detector for indoor gases

    Science.gov (United States)

    Zhang, Liping; Wang, Yutian; Li, Taishan

    2003-09-01

    With the increase of the living standards of city dwellers, home decoration has been more and more popular these years. Different kinds of material have come into people's home, which brings about beauties to the house as well as some bad effect. Because of differences in manufacturing techniques and quality, much of the material will emit poisonous gases more or less. Even if you have selected the qualified product, the toal amount of gases in you houses may not be guaranteed because of the simple reason that more than one kind of material are applied. Living in the complex environment for a long time will eventually have a bad effect on one's health. In addition the fear of the harm to be done will exert great impact psychologically. In another aspect, the coal-gas in the house-hood for cooking is also explosive and poisonous. In conclusion, the research on the indoor hazardous gases measurement and alarm device is of much economic and practical importance. The device is portable and versatile. We use rechargeable battery as the power supply. The device can detect the density of gases at the ppb level for the emission of the material and the measured value can be shown on the display. As for coal gas it can detect the percentage of LEL and make sound of alarm. We use two kinds of gas-sensors in the device, with catalytic combustion principal for coal gas detection and the PID method for the gas emissions of the decoration material. UV will destroy harmful material (such as: ammonia, dimethylamine, methyl-sulfhydrate, benzene etc.) into positive or negative ions. The sensor detects the electric charges of ionized gases and converts them into electric current signals. It is then amplified and changed into digits by amplifier and A/D. The digit signal is processed by micro-controller system of the device.

  1. Noble gases in meteorites and terrestrial planets

    Science.gov (United States)

    Wacker, J. F.

    1985-01-01

    Terrestrial planets and chondrites have noble gas platforms that are sufficiently alike, especially Ne/Ar, that they may have acquired their noble gases by similar processes. Meteorites presumably obtained their noble gases during formation in the solar nebula. Adsorption onto C - the major gas carrier in chondrites - is the likely mechanism for trapping noble gases; recent laboratory simulations support this hypothesis. The story is more complex for planets. An attractive possibility is that the planets acquired their noble gases in a late accreting veneer of chondritic material. In chondrites, noble gases correlate with C, N, H, and volatile metals; by Occam's Razor, we would expect a similar coupling in planets. Indeed, the Earth's crust and mantle contain chondritic like trace volatiles and PL group metals, respectively and the Earth's oceans resemble C chondrites in their enrichment of D (8X vs 8-10X of the galactic D/H ratio). Models have been proposed to explain some of the specific noble gas patterns in planets. These include: (1) noble gases may have been directly trapped by preplanetary material instead of arriving in a veneer; (2) for Venus, irradiation of preplanetary material, followed by diffusive loss of Ne, could explain the high concentration of AR-36; (3) the Earth and Venus may have initially had similar abundances of noble gases, but the Earth lost its share during the Moon forming event; (4) noble gases could have been captured by planetestimals, possibly leading to gravitational fractionation, particularly of Xe isotopes and (5) noble gases may have been dissolved in the hot outer portion of the Earth during contact with a primordial atmosphere.

  2. Dipolar quantum gases of erbium

    International Nuclear Information System (INIS)

    Frisch, A.

    2014-01-01

    Since the preparation of the first Bose-Einstein condensate about two decades ago and the first degenerate Fermi gas following four years later a plethora of fascinating quantum phenomena have been explored. The vast majority of experiments focused on quantum degenerate atomic gases with short-range contact interaction between particles. Atomic species with large magnetic dipole moments, such as chromium, dysprosium, and erbium, offer unique possibilities to investigate phenomena arising from dipolar interaction. This kind of interaction is not only long-range but also anisotropic in character and imprints qualitatively novel features on the system. Prominent examples are the d-wave collapse of a dipolar Bose-Einstein condensate of chromium atoms realized by the group in Stuttgart, the spin magnetization and demagnetization dynamics observed by groups in Stuttgart, Paris, and Stanford, and the deformation of the Fermi surface observed by our group in Innsbruck. This thesis reports on the creation and study of the first Bose-Einstein condensate and degenerate Fermi gas of erbium atoms. Erbium belongs to the lanthanide group of elements and has a large magnetic moment of seven Bohr magneton. In particular, this thesis describes the experimental apparatus and the sequence for producing a dipolar quantum gas. There is an emphasis on the production of the narrow-line magneto-optical trap of erbium since this represents a very efficient and robust laser-cooling scheme that greatly simplifies the experimental procedure. After describing the experimental setup this thesis focuses on several fundamental questions related to the dipolar character of erbium and to its lanthanide nature. A first set of studies centers on the scattering properties of ultracold erbium atoms, including the elastic and the inelastic cross section and the spectrum of Feshbach resonances. Specifically, we observe that identical dipolar fermions do collide and rethermalize even at low temperatures

  3. Denitrifying haloarchaea: sources and sinks of nitrogenous gases.

    Science.gov (United States)

    Torregrosa-Crespo, Javier; Bergaust, Linda; Pire, Carmen; Martínez-Espinosa, Rosa María

    2018-02-01

    Haloarchaea thrive under saline and hypersaline conditions and often dominate microbial communities in saltmarshes, salted lakes/soils and some oceanic areas. Some of the predominant species show denitrifying capabilities, although it remains unclear whether they are complete or partial denitrifiers. As complete denitrifiers, they could play important roles buffering ecosystems in which nitrate and nitrite appear as contaminants. However, partial denitrifying haloarchaea could contribute to the emission of nitrogenous gasses, thus acting as drivers of climate change and ozone depletion. In this review, we summarise some recent results on denitrification in haloarchaea, discuss the environmental implications and outline possible applications in mitigation. Finally, we list questions to be addressed in the near future, facilitating increased understanding of the role of these organisms in N turnover in arid and hypersaline environments. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes

    Science.gov (United States)

    Gerlach, Terrence

    1990-01-01

    Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.

  5. Thermodynamics of ultracold Fermi gases

    International Nuclear Information System (INIS)

    Nascimbene, Sylvain

    2010-01-01

    Complex Hamiltonians from condensed matter, such as the Fermi-Hubbard model, can be experimentally studied using ultracold gases. This thesis describes a new method for determining the equation of state of an ultracold gas, making the comparison with many-body theories straightforward. It is based on the measurement of the local pressure inside a trapped gas from the analysis of its in situ image. We first apply this method to the study of a Fermi gas with resonant interactions, a weakly-interacting 7 Li gas acting as a thermometer. Surprisingly, none of the existing many-body theories of the unitary gas accounts for the equation of state deduced from our study over its full range. The virial expansion extracted from the high-temperature data agrees with the resolution of the three-body problem. At low temperature, we observe, contrary to some previous studies, that the normal phase behaves as a Fermi liquid. Finally we obtain the critical temperature for superfluidity from a clear signature on the equation of state. We also measure the pressure of the ground state as a function of spin imbalance and interaction strength - measure directly relevant to describe the crust of neutron stars. Our data validate Monte-Carlo simulations and quantify the Lee-Huang-Yang corrections to mean-field interactions in low-density fermionic or bosonic superfluids. We show that, in most cases, the partially polarized normal phase can be described as a Fermi liquid of polarons. The polaron effective mass extracted from the equation of state is in agreement with a study of collective modes. (author)

  6. The hydrogen and carbon isotopic composition of methane from natural gases of various origins

    International Nuclear Information System (INIS)

    Schoell, M.

    1980-01-01

    The deuterium concentrations (deltaD vs SMOW) of biogenic methanes from world-wide occurrences range from -180 to -280 parts per thousand and were found to be depleted in deuterium by approx. 160 parts per thousand compared to the deuterium concentration of their associated waters. Theoretical considerations support this relationship to be the result of bacterial transformation of CO 2 to methane and is therefore indicative of the biogenic origin of methane. Thermogenic gases with high Csub(2+) concentrations (wet gases associated with crude oil) have D/H ratios from -260 to -150 parts per thousand with deuterium contents tending to increase with decreasing wetness. Dry gases which are not associated with petroleum are more enriched in deuterium (-180 to -130 parts per thousand) and show an increase in deuterium with increasing rank of the source beds as it is similarly known for carbon-13. Many dry gases in young sedimentary basins were found to contain significant amounts of Csub(2+) hydrocarbons. These gases cannot be grouped with either the biogenic of thermogenic gases and their methane is concluded to be of mixed biogenic and thermochemical origin. Using a delta 13 C/deltaD diagrammatic display of the isotope data of methanes the various genetic groups of natural gases can be defined more clearly. (author)

  7. Rayleigh scattering measurements of several fluorocarbon gases.

    Science.gov (United States)

    Zadoo, Serena; Thompson, Jonathan E

    2011-11-01

    Integrating nephelometers are commonly used to monitor airborne particulate matter. However, they must be calibrated prior to use. The Rayleigh scattering coefficients (b(RS), Mm(-1)), scattering cross sections (σ(RS), cm(2)), and Rayleigh multipliers for tetrafluoromethane (R-14), sulfur hexafluoride, pentafluoroethane (HFC-125), hexafluoropropene (HFC-216), 1,1,1,2,3,3,3,-heptafluoropropane (HFC-227ea), and octafluorocyclobutane (C-318) are reported from measurements made using a Radiance Research M903 integrating nephelometer operating at λ = 530 nm and calibration with gases of known scattering constants. Rayleigh multipliers (±90% conf. int.) were found to be 2.6 ± 0.5, 6.60 ± 0.07, 7.5 ± 1, 14.8 ± 0.9, 15.6 ± 0.5, and 22.3 ± 0.8 times that of air, respectively. To the best of our knowledge, these are the first reported values for R-14, HFC-216, HFC-125, and C-318. Experimental accuracy is supported through measurements of values for SF(6) and HFC-227ea which agree to within 3% of previous literature reports. In addition to documenting fundamental Rayleigh scattering data for the first time, the information presented within will find use for calibration of optical scattering sensors such as integrating nephelometers.

  8. Voluntary reporting of greenhouse gases, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The Voluntary Reporting Program for greenhouse gases is part of an attempt by the U.S. Government to develop innovative, low-cost, and nonregulatory approaches to limit emissions of greenhouse gases. It is one element in an array of such programs introduced in recent years as part of the effort being made by the United States to comply with its national commitment to stabilize emissions of greenhouse gases under the Framework Convention on Climate Change. The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report to the Energy Information Administration (EIA) on actions taken that have reduced or avoided emissions of greenhouse gases.

  9. Roadside management strategies to reduce greenhouse gases.

    Science.gov (United States)

    2010-06-01

    Californias Global Warming Solutions Act of 2006 (AB 32), Sustainable Communities and Climate Protection Act : (SB 375), and Executive Order S-14-08 direct Caltrans to develop actions to reduce greenhouse gases (GHGs). Air : pollution reduction is...

  10. Atomic physics: Cold gases venture into Flatland

    Science.gov (United States)

    Burnett, Keith

    2007-09-01

    Vortex structures have revealed a lot about the nature of three-dimensional Bose-Einstein condensates. They play an even bigger part in two-dimensional cold atomic gases and drive a fundamentally different phase transition.

  11. Phase space methods for degenerate quantum gases

    CERN Document Server

    Dalton, Bryan J; Barnett, Stephen M

    2015-01-01

    Recent experimental progress has enabled cold atomic gases to be studied at nano-kelvin temperatures, creating new states of matter where quantum degeneracy occurs - Bose-Einstein condensates and degenerate Fermi gases. Such quantum states are of macroscopic dimensions. This book presents the phase space theory approach for treating the physics of degenerate quantum gases, an approach already widely used in quantum optics. However, degenerate quantum gases involve massive bosonic and fermionic atoms, not massless photons. The book begins with a review of Fock states for systems of identical atoms, where large numbers of atoms occupy the various single particle states or modes. First, separate modes are considered, and here the quantum density operator is represented by a phase space distribution function of phase space variables which replace mode annihilation, creation operators, the dynamical equation for the density operator determines a Fokker-Planck equation for the distribution function, and measurable...

  12. Center for Corporate Climate Leadership: Direct Fugitive Emissions from Refrigeration, Air Conditioning, Fire Suppression, and Industrial Gases

    Science.gov (United States)

    This guidance document focuses on several fugitive emissions sources that are common for organizations in many sectors: refrigeration and air conditioningsystems, fire suppression systems, and the purchase and release of industrial gases.

  13. Food additives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002435.htm Food additives To use the sharing features on this page, please enable JavaScript. Food additives are substances that become part of a food ...

  14. Infrared (IR) remote sensing of gases

    OpenAIRE

    López Martínez, Fernando

    2008-01-01

    The IR Imaging and Remote Sensing Laboratory – LIR-UC3M of Universidad Carlos III, has developed Multi and Hyper spectral Infrared (IR) analysis techniques for gas remote sensing. Design of specific sensors for the determination of gases and their concentration are proposed. Almost all gases (CO2, CO, NO2, O3, HC o NH, …) related to industrial, environmental or military safety can be detected. Companies or centres with interest in the use of specific application sensors are required.

  15. Biological production of products from waste gases

    Science.gov (United States)

    Gaddy, James L.

    2002-01-22

    A method and apparatus are designed for converting waste gases from industrial processes such as oil refining, and carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various products, such as organic acids, alcohols, hydrogen, single cell protein, and salts of organic acids by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified.

  16. Noble Gases Trace Earth's Subducted Water Flux

    Science.gov (United States)

    Smye, A.; Jackson, C.; Konrad-Schmolke, M.; Parman, S. W.; Ballentine, C. J.

    2016-12-01

    Volatile elements are transported from Earth's surface reservoirs back into the mantle during subduction of oceanic lithosphere [e.g. 1]. Here, we investigate the degree to which the fate of slab-bound noble gases and water are linked through the subduction process. Both water and noble gases are soluble in ring-structured minerals, such as amphibole, that are common constituents of subducted oceanic lithosphere. Heating and burial during subduction liberates noble gases and water from minerals through a combination of diffusion and dissolution. Combining a kinetic model, parameterized for noble gas fractionation in amphibole [2], with thermodynamic phase equilibria calculations, we quantify the effect of subduction dehydration on the elemental composition of slab-bound noble gases. Results show that post-arc slab water and noble gas fluxes are highly correlated. Hot subduction zones, which likely dominate over geologic history, efficiently remove noble gases and water from the down-going slab; furthermore, kinetic fractionation of noble gases is predicted to occur beneath the forearc. Conversely, hydrated portions of slab mantle in cold subduction zones transport noble gases and water to depths exceeding 200 km. Preservation of seawater-like abundances of Ar, Kr and Xe in the convecting mantle [1] implies that recycling of noble gases and water occurred during cold subduction and that the subduction efficiency of these volatile elements has increased over geological time, driven by secular cooling of the mantle. [1] Holland, G. and Ballentine, C. (2006). Nature 441, 186-191. [2] Jackson et al. (2013). Nat.Geosci. 6, 562-565.

  17. Process for treating radioactive waste gases

    International Nuclear Information System (INIS)

    Yuasa, Yoshiyuki; Nagao, Hiroyuki; Takiguchi, Yukio; An, Bunzai; Tsuda, Koji.

    1975-01-01

    Object: To securely perform separation and enrichment of radioactive rare gases to store safely them for a long period of time. Structure: The wastes extracted by an air extractor are processed by a heater and a recombiner and hydrogen and oxygen are changed into water thereby and it is passed through a gas and water separator to be dewatered, after which water and carbon dioxide gas are removed by passing through a delay pipe, filter, and water- and carbon dioxide gas removing device and then fed to a lower temperature adsorbing device to adsorb and remove the radioactive rare gases. This low temperature adsorbing device is composed of two towers, one of which is designed to saturate the radioactive rare gases, which are processed by a heater and passed through a recycle line to meet raw gases. Then, it is fed to the other lower temperature adsorbing device and this cycle is repeated to enrich the radioactive rare gases. Oxygen and impurities in the enriched gases are removed by the impurity removing device and thereafter are stored in a gas holder and finally sealed in a cylinder. (Kamimura, M.)

  18. Gases and carbon in metals. Pt. 14

    International Nuclear Information System (INIS)

    Jehn, H.; Speck, H.; Hehn, W.; Fromm, E.; Hoerz, G.

    1981-01-01

    This issue is part of a series of data on 'Gases and Carbon in Metals' which supplements the data compilation in the book 'Gase und Kohlenstoff in Metallen' (Gases and Carbon in Metals), edited by E. Fromm and E. Gebhardt, Springer-Verlag, Berlin 1976. The present survey includes results from papers published after the copy deadline and recommends critically selected data. Furthermore, it comprises a bibliography of relevant literature. For each element, firstly data on binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility, solubility limit, dissociation pressure of compounds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas absorption and gas desorption kinetics, compound formation kinetics, precipitation kinetics, and property changes. Following the data on binary systems, the data of ternary systems are presented, beginning with systems which contain one metal and two gases or one gas and carbon and continuing with systems with two metals and one gas or carbon. (orig./GE)

  19. On the dissolution of vapors and gases.

    Science.gov (United States)

    Wüstneck, N; Wüstneck, R; Pison, U; Möhwald, H

    2007-02-13

    The captive bubble technique in combination with axisymmetric drop shape analysis (ADSA-CB) and with micro gas chromatography is used to study the dynamics of dissolution of different gases and vapors in water in situ. The technique yields the changes in the interfacial tension and bubble volume and surface. As examples, the dissolution of methanol and hexane vapors, inhaled anesthetic vapors, and gases, that is, diethyl ether, chloroform, isoflurane, enflurane, sevoflurane, desflurane, N2O, and xenon, and as nonimmobilizers perfluoropentane and 1,1,2-trichloro-1,2,2-trifluoro-ethane (R113) were investigated. The examination of interfacial tension-time and bubble volume-time functions permits us to distinguish between water-soluble and -insoluble substances, gases, and vapors. Vapors and gases generally differ in terms of the strength of their intermolecular interactions. The main difference between dissolution processes of gases and vapors is that, during the entire process of gas dissolution, no surface tension change occurs. In contrast, during vapor dissolution the surface tension drops immediately and decreases continuously until it reaches the equilibrium surface tension of water at the end of dissolution. The results of this study show that it is possible to discriminate anesthetic vapors from anesthetic gases and nonimmobilizers by comparing their dissolution dynamics. The nonimmobilizers have extremely low or no solubility in water and change the surface tension only negligibly. By use of newly defined molecular dissolution/diffusion coefficients, a simple model for the determination of partition coefficients is developed.

  20. Fractal gases of zero momentum with respect to all inertial frames

    Science.gov (United States)

    Moore, Guy S. M.

    1990-06-01

    Unlike gases containing molecules obeying Maxwell-Boltzmann statistics, ``fractal gases'' obey the fundamental axiom that their linear momentum is zero when resolved in any direction with respect to all inertial frames of reference. In contrast to speculation, the properties of fractal gases obeying Newtonian mechanics, or special or general relativity can be investigated in a way similar to the logic of geometry. They have the following properties: (1) An entire fractal gas cannot decay into a Maxwell-Boltzmann distribution, but is in a state of overall equilibrium. (2) Localities tend toward localized equilibrium, upset later by collision with other localities. (3) Fractal gases contain temperature differences that are a source of temporary order. (4) The appearance of a fractal gas to a hypothetical observer would suggest creation in an initial discontinuity.

  1. Iron-based alloys with corrosion resistance to oxygen-sulfur mixed gases

    Science.gov (United States)

    Natesan, Krishnamurti

    1992-01-01

    An iron-based alloy with improved performance with exposure to oxygen-sulfur mixed gases with the alloy containing about 9-30 wt. % Cr and a small amount of Nb and/or Zr implanted on the surface of the alloy to diffuse a depth into the surface portion, with the alloy exhibiting corrosion resistance to the corrosive gases without bulk addition of Nb and/or Zr and without heat treatment at temperatures of 1000.degree.-1100.degree. C.

  2. Temporal dynamics of Bose-condensed gases

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo Martinez, Mauricio

    2014-03-19

    We perform a detailed quantum dynamical study of non-equilibrium trapped, interacting Bose-condensed gases. We investigate Josephson oscillations between interacting Bose-Einstein condensates confined in a finite size double-well trap and the non-trivial time evolution of a coherent state placed at the center of a two dimensional optical lattice. For the Josephson oscillations three time scales appear. We find that Josephson junction can sustain multiple undamped oscillations up to a characteristic time scale τ{sub c} without exciting atoms out of the condensates. Beyond the characteristic time scale τ{sub c} the dynamics of the junction are governed by fast, non-condensed particles assisted Josephson tunnelling as well as the collisions between non-condensed particles. In the non-condensed particles dominated regime we observe strong damping of the oscillations due to inelastic collisions, equilibrating the system leading to an effective loss of details of the initial conditions. In addition, we predict that an initially self-trapped BEC state will be destroyed by these fast dynamics. The time evolution of a coherent state released at the center of a two dimensional optical lattice shows a ballistic expansion with a decreasing expansion velocity for increasing two-body interactions strength and particle number. Additionally, we predict that if the two-body interactions strength exceeds a certain value, a forerunner splits up from the expanding coherent state. We also observe that this system, which is prepared far from equilibrium, can evolve to a quasistationary non-equilibrium state.

  3. Apparent digestibility of simplified and semi-simplified diets, with and without addition of enzymes, and nutritional value of fibrous sources for rabbits

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Machado

    2012-07-01

    Full Text Available The objectives of this study were to evaluate the digestibility of the nutrients of simplified and semi-simplified diets, with and without inclusion of exogenous enzymes and to determine the nutritional value of the fibrous sources. The tested feedstuffs were: alfalfa hay, hay from the upper third of the cassava foliage and cassava leaf meal, using a completely randomized design with 11 diets and 8 repetitions. The treatments were constituted of 1 reference diet, 2 simplified diets and 8 semi-simplified diets (4 enzymatic inclusion. The enzymes used were carbohydrases (alpha-galactosidase, galactomanose, xylanase and beta glucanase and phytase. It was observed that the digestibility of the nutrients of the diets was influenced by the type of feed studied. Semi-simplified diets presented coefficients inferior to the reference diet and superior to the simplified diets. Exogenous enzymes promoted improvements in the digestibility of the dry matter (DM, organic matter, crude protein and gross energy. It was also observed that great part of the crude protein of the cassava leaf meal complexed, which depreciated the digestibility of diets with high inclusion of this ingredient. The nutritional value of fibrous sources was 1822.7 kcal digestible energy - DE/kgDM and 122,6 g digestible protein - DP/kg DM, for the hay from the upper third of the cassava foliage; 2232.5 kcalDE/kgDM and 155.4 gDP/kgDM for alfalfa hay and 1888.9 kcalDE/kgDM and 73.6 gDP/kgDM for the cassava leaf meal. With the exception of diets with elevated inclusion of cassava leaf meal, the semi-simplified diets presented satisfactory coefficients of digestibility improved by the enzymatic inclusion.

  4. PENAMBAHAN TEPUNG UMBI DAHLIA, KEDELAI DAN BAWANG PUTIH SEBAGAI SUMBER PREBIOTIK UNTUK ENKAPSULASI PROBIOTIK [Addition of Flours from Dahlia Tuber, Soybean and Garlic as Prebiotic Sources for Probiotic Encapsulation

    Directory of Open Access Journals (Sweden)

    Maria Ulfah

    2013-06-01

    Full Text Available The research was conducted to study the effect of addition of flours made from dahlia tuber, soybean and garlic as the sources of natural prebiotic on the encapsulation of probiotic (Lactobacillus acidophilus Dad 13 with carragenan and chitosan. Carragenan and chitosan are potential encapsulating agents that can protect bacterial cells from unfavorable conditions. It is hypothesized that addition of natural prebiotics from dahlia tuber, soybean and garlic can stimulate the growth of probiotic (L. acidophilus Dad 13 in MRS broth medium. Parameters evaluated were size and weight of capsule, number of cells in the capsule, acid and bile salt resistance of the biocapsule produced from carragenan and chitosan added with flours of dahlia tuber, soybean and garlic as the sources of natural prebiotic. The randomized complete block design was used as the experimental design with two factors. The first factor was the encapsulating agents (A1 carragenan, A2 chitosan and second factor was the sources of natural prebiotic (P1 dahlia tuber, P2 garlic, P3 soybean. The results showed that the type of encapsulating agent had an effect on weight, diameter and number of cells in the capsule but did not affect the acid and bile salt resistance. Addition of prebiotic flour to biocapsules had an effect on weight and diameter of capsules but no effect on acid and bile salt resistance and the number of cells. Addition of flour as prebiotic source from dahlia, garlic and soybean increased the cell number by 1 log cycle. Capsules made from chitosan with the addition of prebiotic source flour were lighter, had shorter diameter and lower cell reduction by acid (4.63-5.24 log cycle than those made with carragenan (6.93-7.19 log cycle. Based on the acid resistance, the best biocapsules was made with chitosan and dahlia prebiotic flour.

  5. Greenhouse gases study in Amazonia; Estudo de gases de efeito estufa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    D' Amelio, Monica Tais Siqueira

    2006-07-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO{sub 2} sources. The Amazon forest is a significant source of N{sub 2}O by soil process, and CH{sub 4} by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO{sub 2}, CH{sub 4}, CO, H{sub 2}, N{sub 2}O and SF{sub 6} have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO{sub 2} flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO{sub 2} flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H{sub 2} gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO{sub 2} sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that

  6. Iodine speciation in the hot cell effluent gases

    International Nuclear Information System (INIS)

    Lee, B.S.; Jester, W.A.; Olynyk, J.M.

    1990-01-01

    The various species of airborne radioiodine can affect the iodine source term of a severe core damage accident because of the different transport and deposition properties. also, the radiobiological hazardness may vary according to their chemical form. The purpose of the work reported in this paper was to characterize the various chemical forms of airborne radioiodine in hot cell effluent gases of a radiopharmaceutical production facility that produces medical radioisotopes from separated fission products of irradiated uranium targets. It is concluded that the methyl iodide is the youngest chemical species in terms of effective decay time age, and the hot cell filter bank is least efficient in removing the methyl iodide

  7. Decoupling of unpolluted temperate forests from rock nutrient sources revealed by natural 87Sr/86Sr and 84Sr tracer addition

    Science.gov (United States)

    Kennedy, Martin J.; Hedin, Lars O.; Derry, Louis A.

    2002-01-01

    An experimental tracer addition of 84Sr to an unpolluted temperate forest site in southern Chile, as well as the natural variation of 87Sr/86Sr within plants and soils, indicates that mechanisms in shallow soil organic horizons are of key importance for retaining and recycling atmospheric cation inputs at scales of decades or less. The dominant tree species Nothofagus nitida feeds nearly exclusively (>90%) on cations of atmospheric origin, despite strong variations in tree size and location in the forest landscape. Our results illustrate that (i) unpolluted temperate forests can become nutritionally decoupled from deeper weathering processes, virtually functioning as atmospherically fed ecosystems, and (ii) base cation turnover times are considerably more rapid than previously recognized in the plant available pool of soil. These results challenge the prevalent paradigm that plants largely feed on rock-derived cations and have important implications for understanding sensitivity of forests to air pollution. PMID:12119394

  8. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  9. Kilogram-scale production of SnO(2) yolk-shell powders by a spray-drying process using dextrin as carbon source and drying additive.

    Science.gov (United States)

    Choi, Seung Ho; Kang, Yun Chan

    2014-05-05

    A simple and general method for the large-scale production of yolk-shell powders with various compositions by a spray-drying process is reported. Metal salt/dextrin composite powders with a spherical and dense structure were obtained by spray drying and transformed into yolk-shell powders by simple combustion in air. Dextrin plays a key role in the preparation of precursor powders for fabricating yolk-shell powders by spray drying. Droplets containing metal salts and dextrin show good drying characteristics even in a severe environment of high humidity. Sucrose, glucose, and polyvinylpyrrolidone are widely used as carbon sources in the preparation of metal oxide/carbon composite powders; however, they are not appropriate for large-scale spray-drying processes because of their caramelization properties and adherence to the surface of the spray dryer. SnO2 yolk-shell powders were studied as the first target material in the spray-drying process. Combustion of tin oxalate/dextrin composite powders at 600 °C in air produced single-shelled SnO2 yolk-shell powders with the configuration SnO2 @void@SnO2 . The SnO2 yolk-shell powders prepared by the simple spray-drying process showed superior electrochemical properties, even at high current densities. The discharge capacities of the SnO2 yolk-shell powders at a current density of 2000 mA g(-1) were 645 and 570 mA h g(-1) for the second and 100th cycles, respectively; the corresponding capacity retention measured for the second cycle was 88 %. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Inhalation gases or gaseous mediators as neuroprotectants for cerebral ischaemia.

    Science.gov (United States)

    Sutherland, Brad A; Harrison, Joanne C; Nair, Shiva M; Sammut, Ivan A

    2013-01-01

    Ischaemic stroke is one of the leading causes of morbidity and mortality worldwide. While recombinant tissue plasminogen activator can be administered to produce thrombolysis and restore blood flow to the ischaemic brain, therapeutic benefit is only achieved in a fraction of the subset of patients eligible for fibrinolytic intervention. Neuroprotective therapies attempting to restrict the extent of brain injury following cerebral ischaemia have not been successfully translated into the clinic despite overwhelming pre-clinical evidence of neuroprotection. Therefore, an adequate treatment for the majority of acute ischaemic stroke patients remains elusive. In the stroke literature, the use of therapeutic gases has received relatively little attention. Gases such as hyperbaric and normobaric oxygen, xenon, hydrogen, helium and argon all possess biological effects that have shown to be neuroprotective in pre-clinical models of ischaemic stroke. There are significant advantages to using gases including their relative abundance, low cost and feasibility for administration, all of which make them ideal candidates for a translational therapy for stroke. In addition, modulating cellular gaseous mediators including nitric oxide, carbon monoxide, and hydrogen sulphide may be an attractive option for ischaemic stroke therapy. Inhalation of these gaseous mediators can also produce neuroprotection, but this strategy remains to be confirmed as a viable therapy for ischaemic stroke. This review highlights the neuroprotective potential of therapeutic gas therapy and modulation of gaseous mediators for ischaemic stroke. The therapeutic advantages of gaseous therapy offer new promising directions in breaking the translational barrier for ischaemic stroke.

  11. Trace gases and other potential perturbations to global climate

    International Nuclear Information System (INIS)

    Wang, W.; Wuebbles, D.J.; Washington, W.M.; Isaacs, R.G.; Molnar, G.

    1986-01-01

    We review the various natural and anthropogenic factors that may affect the climate. The purpose is to summarize our understanding of these factors and their potential future climatic effects so that CO 2 -induced climate change can be viewed in a proper context. The factors we discuss include trace gases, anthropogenic and volcanic aerosols, variation of solar constant, change of surface characteristics, and releases of waste heat. We discuss the origins of the various natural and anthropogenic perturbations, the physical and chemical processes and their interactions, model sensitivity calculations, and model projections of their potential future climatic effects. The discussions center on trace gases because of their potentially large climatic effects. It appears that the increases of atmospheric trace gases of other kinds in addition to CO 2 could have important climatic effects. The model calculations suggest that the combined effect of these other trace gases, and the associated change of atmospheric ozone and water vapor distributions, could potentially warm the climate by an amount comparable in magnitude to the effect of doubling the CO 2 . Aerosols of anthropogenic origins may have substantial effects on regional climate, while the volcanic aerosols may have an effect on large-scale climate for up to a few years after injection. Changes of surface characteristics and releases of waste heat may also have substantial effects on the regional climate, but these effects are most likely to be small when compared with the effect of CO 2 increase. Changes of solar constant could have an effect on the global scale, but the time scale is much longer. There is much more that needs to be learned with regard to the above mentioned natural and anthropogenic factors that may affect the climate. A brief summary of those needs is presented

  12. Broader perspectives for comparing different greenhouse gases.

    Science.gov (United States)

    Manning, Martin; Reisinger, Andy

    2011-05-28

    Over the last 20 years, different greenhouse gases have been compared, in the context of climate change, primarily through the concept of global warming potentials (GWPs). This considers the climate forcing caused by pulse emissions and integrated over a fixed time horizon. Recent studies have shown that uncertainties in GWP values are significantly larger than previously thought and, while past literature in this area has raised alternative means of comparison, there is not yet any clear alternative. We propose that a broader framework for comparing greenhouse gases has become necessary and that this cannot be addressed by using simple fixed exchange rates. From a policy perspective, the framework needs to be clearly aligned with the goal of climate stabilization, and we show that comparisons between gases can be better addressed in this context by the forcing equivalence index (FEI). From a science perspective, a framework for comparing greenhouse gases should also consider the full range of processes that affect atmospheric composition and how these may alter for climate stabilization at different levels. We cover a basis for a broader approach to comparing greenhouse gases by summarizing the uncertainties in GWPs, linking those to uncertainties in the FEIs consistent with stabilization, and then to a framework for addressing uncertainties in the corresponding biogeochemical processes. © 2011 The Royal Society

  13. Shale gases, a windfall for France?

    International Nuclear Information System (INIS)

    Tonnac, Alain de; Perves, Jean-Pierre

    2013-11-01

    After having recalled the definition and origin of shale gases, the different non conventional gases and their exploitation techniques (hydraulic fracturing and horizontal drilling) this report examines whether these gases are an opportunity for France. Some characteristics and data of the fossil and gas markets are presented and commented: world primary energy consumption, proved reserves of non conventional gases and their locations, European regions which may possess reserves of shale gases and coal-bed methane, origins of gas imports in France. The second part addresses shale gas deposits and their exploitation: discussion of the influence of the various rock parameters, evolution of production. The third part discusses the exploitation techniques and specific drilling tools. The issue of exploitation safety and security is addressed as well as the associated controversies: about the pollution of underground waters, about the fact that deep drillings result in pollution, about the risks associated with hydraulic fracturing and injections of chemical products, about the hold on ground and site degradation, about water consumption, about pollution due to gas pipeline leakage, about seismic risk, about noise drawbacks, about risks for health, about exploration and production authorization and license, and about air pollution and climate. The last part addresses the French situation and its future: status of the energy bill, recommendations made by a previous government, cancellation of authorizations, etc. Other information are provided in appendix about non conventional hydrocarbons, about shale gas exploitation in the USA, and about the Lacq gas

  14. Potential biofuel additive from renewable sources--Kinetic study of formation of butyl acetate by heterogeneously catalyzed transesterification of ethyl acetate with butanol.

    Science.gov (United States)

    Ali, Sami H; Al-Rashed, Osama; Azeez, Fadhel A; Merchant, Sabiha Q

    2011-11-01

    Butyl acetate holds great potential as a sustainable biofuel additive. Heterogeneously catalyzed transesterification of biobutanol and bioethylacetate can produce butyl acetate. This route is eco-friendly and offers several advantages over the commonly used Fischer Esterification. The Amberlite IR 120- and Amberlyst 15-catalyzed transesterification is studied in a batch reactor over a range of catalyst loading (6-12 wt.%), alcohol to ester feed ratio (1:3 to 3:1), and temperature (303.15-333.15K). A butanol mole fraction of 0.2 in the feed is found to be optimum. Amberlite IR 120 promotes faster kinetics under these conditions. The transesterifications studied are slightly exothermic. The moles of solvent sorbed per gram of catalyst decreases (ethanol>butanol>ethyl acetate>butyl acetate) with decrease in solubility parameter. The dual site models, the Langmuir Hinshelwood and Popken models, are the most successful in correlating the kinetics over Amberlite IR 120 and Amberlyst 15, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Concept of Heat Recovery from Exhaust Gases

    Science.gov (United States)

    Bukowska, Maria; Nowak, Krzysztof; Proszak-Miąsik, Danuta; Rabczak, Sławomir

    2017-10-01

    The theme of the article is to determine the possibility of waste heat recovery and use it to prepare hot water. The scope includes a description of the existing sample of coal-fired boiler plant, the analysis of working condition and heat recovery proposals. For this purpose, a series of calculations necessary to identify the energy effect of exhaust temperature decreasing and transferring recovery heat to hot water processing. Heat recover solutions from the exhaust gases channel between boiler and chimney section were proposed. Estimation for the cost-effectiveness of such a solution was made. All calculations and analysis were performed for typical Polish conditions, for coal-fired boiler plant. Typicality of this solution is manifested by the volatility of the load during the year, due to distribution of heat for heating and hot water, determining the load variation during the day. Analysed system of three boilers in case of load variation allows to operational flexibility and adaptation of the boilers load to the current heat demand. This adaptation requires changes in the operating conditions of boilers and in particular assurance of properly conditions for the combustion of fuel. These conditions have an impact on the existing thermal loss and the overall efficiency of the boiler plant. On the boiler plant efficiency affects particularly exhaust gas temperature and the excess air factor. Increasing the efficiency of boilers plant is possible to reach by following actions: limiting the excess air factor in coal combustion process in boilers and using an additional heat exchanger in the exhaust gas channel outside of boilers (economizer) intended to preheat the hot water.

  16. NGSI student activities in open source information analysis in support of the training program of the U.S. DOE laboratories for the entry into force of the additional protocol

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, M Analisa [Los Alamos National Laboratory; Uribe, Eva C [Los Alamos National Laboratory; Sandoval, Marisa N [Los Alamos National Laboratory; Boyer, Brian D [Los Alamos National Laboratory; Stevens, Rebecca S [Los Alamos National Laboratory

    2009-01-01

    In 2008 a joint team from Los Alamos National Laboratory (LANL) and Brookhaven National Laboratory (BNL) consisting of specialists in training of IAEA inspectors in the use of complementary access activities formulated a training program to prepare the U.S. Doe laboratories for the entry into force of the Additional Protocol. As a major part of the support of the activity, LANL summer interns provided open source information analysis to the LANL-BNL mock inspection team. They were a part of the Next Generation Safeguards Initiative's (NGSI) summer intern program aimed at producing the next generation of safeguards specialists. This paper describes how they used open source information to 'backstop' the LANL-BNL team's effort to construct meaningful Additional Protocol Complementary Access training scenarios for each of the three DOE laboratories, Lawrence Livermore National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory.

  17. Discovery of a Plains Caldera Complex and Extinct Lava Lake in Arabia Terra, Mars: Implications for the Discovery of Additional Highland Volcanic Source Regions

    Science.gov (United States)

    Bleacher, Jacob; Michalski, Joseph

    2012-01-01

    Several irregularly shaped topographic depressions occur near the dichotomy boundary in northern Arabia Terra, Mars. The geomorphology of these features suggests that they formed by collapse, opposed to meteor impact. At least one depression (approx.55 by 85 km) displays geologic features indicating a complex, multi-stage collapse history. Features within and around the collapse structure indicate volcanic processes. The complex occurs within Hesperian ridged plains of likely volcanic origin and displays no crater rim or evidence for ejecta. Instead the depression consists of a series of circumferential graben and down-dropped blocks which also display upper surfaces similar to ridged plain lavas. Large blocks within the depression are tilted towards the crater center, and display graben that appear to have originally been linked with circumferential graben outside of the complex related to earlier collapse events. A nearly 700 m high mound exists along a graben within the complex that might be a vent. The deepest depression displays two sets of nearly continuous terraces, which we interpret as high-stands of a drained lava lake. These features appear similar to the black ledge described during the Kilauea Iki eruption in 1959. A lacustrine origin for the terraces seems unlikely because of the paucity of channels found in or around the depression that could be linked to aqueous surface processes. In addition, there is no obvious evidence for lacustrine sediments within the basin. Together with the presence of significant faulting that is indicative of collapse we conclude that this crater complex represents a large caldera formed in the Late Noachian to Early Hesperian. Other linear and irregular depressions in the region also might be linked to ancient volcanism. If that hypothesis is correct, it suggests that northern Arabia Terra could contain a large, previously unrecognized highland igneous province. Evacuation of magma via explosive and effusive activity

  18. Equilibrium Molecular Interactions in Pure Gases

    Directory of Open Access Journals (Sweden)

    Boris I. Sedunov

    2012-01-01

    Full Text Available The equilibrium molecular interactions in pure real gases are investigated based on the chemical thermodynamics principles. The parallels between clusters in real gases and chemical compounds in equilibrium media have been used to improve understanding of the real gas structure. A new approach to the equilibrium constants for the cluster fractions and new methods to compute them and their significant parameters from the experimental thermophysical data are developed. These methods have been applied to some real gases, such as Argon and Water vapors and gaseous Alkanes. It is shown that the four-particle clusters make a noticeable contribution in the thermophysical properties of the equilibrium Water vapor. It is shown also that the effective bond energy for dimers in Alkanes linearly grows with the number of carbon atoms in the molecule.

  19. GREENHOUSE GASES AND MEANS OF PREVENTION

    Directory of Open Access Journals (Sweden)

    Dušica Stojanović

    2013-09-01

    Full Text Available The greenhouse effect can be defined as the consequence of increased heating of the Earth's surface, as well as the lower atmosphere by carbon dioxide, water vapor, and other trace amounts gases. It is well-known that human industrial activities have released large amounts of greenhouse gases in the atmosphere, about 900 billion tons of carbon dioxide, and it is estimated that up to 450 billion are still in the atmosphere. In comparison to greenhouse gases water vapor is one of the greatest contributors to the greenhouse effect on Earth. Many projects, as does the PURGE project, have tendences to build on the already conducted research and to quantify the positive and negative impacts on health and wellbeing of the population with greenhouse gas reduction strategies that are curently being implemented and should be increasingly applied in various sectors and urban areas, having offices in Europe, China and India.

  20. Bose-Einstein condensation of atomic gases

    International Nuclear Information System (INIS)

    Anglin, J. R.; Ketterle, W.

    2003-01-01

    The early experiments on Bose-Einstein condensation in dilute atomic gases accomplished three longstanding goals. First, cooling of neutral atoms into their motional state, thus subjecting them to ultimate control, limited only by Heisenberg uncertainty relation. Second, creation of a coherent sample of atoms, in which all occupy the same quantum states, and the realization of atom lasers - devices that output coherent matter waves. And third, creation of gaseous quantum fluid, with properties that are different from the quantum liquids helium-3 and helium-4. The field of Bose-Einstein condensation of atomic gases has continued to progress rapidly, driven by the combination of new experimental techniques and theoretical advances. The family of quantum degenerate gases has grown, and now includes metastable and fermionic atoms. condensates have become an ultralow-temperature laboratory for atom optics, collisional physics and many-body physics, encompassing phonons, superfluidity, quantized vortices, Josephson junctions and quantum phase transitions. (author)

  1. Indoor air pollution caused by geothermal gases

    International Nuclear Information System (INIS)

    Durand, Michael

    2006-01-01

    This paper discusses the little-known but potentially serious indoor air quality problems that may occur where buildings are constructed on geothermal ground. The main problems are related to seepage of carbon dioxide, hydrogen sulphide, radon and other gases from soil cavities directly into indoor air through perforations in the structure. These gases present a health hazard, and hydrogen sulphide, which is particularly corrosive, may cause problems electrical and electronic systems. Counter-measures are not always effective, so developments in such areas should only be undertaken with a clear understanding of site-specific issues and their possible solutions. (author)

  2. Composition of gases vented from a condenser

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, R.N.

    1980-08-01

    Designers of systems that involve condensers often need to predict the amount of process vapor that accompanies the noncondensable gases that are vented from the condensers. An approximation is given that appears to provide, in many cases, reasonably accurate values for the mole ratio of process vapor to noncondensable gases in the vented mixture. The approximation is particularly applicable to flash and direct-contact power systems for geothermal brines and ocean thermal energy conversion (OTEC). More regorous relationships are available for exceptional cases.

  3. Investigations into electrical discharges in gases

    CERN Document Server

    Klyarfel'D, B N

    2013-01-01

    Investigations into Electrical Discharges in Gases is a compilation of scientific articles that covers the advances in the investigation of the fundamental processes occurring in electrical discharges in gases and vapors. The book details the different aspects of the whole life cycle of an arc, which include the initiation of a discharge, its transition into an arc, the lateral spread of the arc column, and the recovery of electric strength after extinction of an arc. The text also discusses the methods for the dynamic measurement of vapor density in the vicinity of electrical discharges, alon

  4. NARCOSIS AND EMULSION REVERSAL BY INERT GASES

    Science.gov (United States)

    Sears, Dewey F.; Fenn, Wallace O.

    1957-01-01

    Investigations of the effect of high pressures of Na (100 to 130 atmospheres) and of Ar (60 to 80 atmospheres) showed that these gases are effective in reversing the phases of an oil in water emulsion. Nitrous oxide did not cause reversal at pressures as high as 53 atmospheres nor did helium as high as 107 atmospheres. We found CO2 most effective in reversing the emulsions and attributed this to its chemical properties. It is suggested that these observations may help to explain the narcotic effects of inert gases. PMID:13416527

  5. Flammability characteristics of combustible gases and vapors

    Energy Technology Data Exchange (ETDEWEB)

    Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)

    1964-05-01

    This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

  6. Nanoclusters and Microparticles in Gases and Vapors

    CERN Document Server

    Smirnov, Boris M

    2012-01-01

    Research of processes involving Nanoclusters and Microparticleshas been developing fastin many fields of rescent research, in particular in materials science. To stay at the cutting edge of this development, a sound understanding of the processes is needed. In this work, several processes involving small particles are described, such as transport processes in gases, charging of small particles in gases, chemical processes, atom attachment and quenching of excited atomic particles on surfaces, nucleation, coagulation, coalescence and growth processes for particles and aggregates. This work pres

  7. Gases and vacua handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 1: Gases and Vacua presents three major topics, which are the fourth to sixth parts of this volume. These topics are the remarks on units of physical quantities; kinetic theory of gases and gaseous flow; and theory of vacuum diffusion pumps. The first topic aims to present concisely the significance of units of physical quantities, catering the need and interest of those who take measurements and make calculations in different fields of vacuum sciences. The technique and applications of this particular topic are also provided. The second main topic focuses sp

  8. Interaction of gases with solid surfaces

    Science.gov (United States)

    Borisov, Sergei F.; Balakhonov, Nikifor F.; Gubanov, Vladimir A.

    Various problems related to the interaction of gases with solid surfaces are examined theoretically and experimentally. In particular, attention is given to the scattering of molecules by surfaces in the nonequilibrium system gas-solid; heat transfer in gas-solid systems over a wide range of Knudsen numbers; adsorption processes at the gas-solid interface; and thermal accommodation of gases on a controlled surface. The discussion also covers kinetic equations for the nonequilibrium heterogeneous system gas-solid; scattering nucleus and accommodation coefficients on solid surfaces; and quantum-chemical calculations of the electron states of a solid surface.

  9. Itinerant Ferromagnetism in Ultracold Fermi Gases

    DEFF Research Database (Denmark)

    Heiselberg, Henning

    2012-01-01

    Itinerant ferromagnetism in cold Fermi gases with repulsive interactions is studied applying the Jastrow-Slater approximation generalized to finite polarization and temperature. For two components at zero temperature a second order transition is found at akF ≃ 0.90 compatible with QMC. Thermodyna......Itinerant ferromagnetism in cold Fermi gases with repulsive interactions is studied applying the Jastrow-Slater approximation generalized to finite polarization and temperature. For two components at zero temperature a second order transition is found at akF ≃ 0.90 compatible with QMC...

  10. Structure and thermodynamic properties of relativistic electron gases.

    Science.gov (United States)

    Liu, Yu; Wu, Jianzhong

    2014-07-01

    Relativistic effect is important in many quantum systems but theoretically complicated from both fundamental and practical perspectives. Herein we introduce an efficient computational procedure to predict the structure and energetic properties of relativistic quantum systems by mapping the Pauli principle into an effective pairwise-additive potential such that the properties of relativistic nonquantum systems can be readily predicted from conventional liquid-state methods. We applied our theoretical procedure to relativistic uniform electron gases and compared the pair correlation functions with those for systems of nonrelativistic electrons. A simple analytical expression has been developed to correlate the exchange-correlation free energy of relativistic uniform electron systems.

  11. [Medicinal gases: oxygen and heliox].

    Science.gov (United States)

    Rodríguez Núñez, A; Martinón Sánchez, J M; Martinón Torres, F

    2003-07-01

    All forms of respiratory support involve one essential element: The gas or gas mixture administered to the patient. Oxygen is an indispensable gas for cellular metabolism and is indicated in cases of hypoxia. Oxygen therapy aims to increase the partial pressure of oxygen in arterial blood by increasing the oxygen concentration of inspired air. In addition to its therapeutic effects, the adverse effects and drawbacks of oxygen should be known. Several methods and devices for the administration of supplementary oxygen are available. Selection of the method should be individualized according to the patient's age and disease, the required inspiratory fraction and the child's possibilities of adaptation. Helium is an inert gas that has a very low specific weight and density. These properties explain its therapeutic effects, mainly in airway obstructions due to various etiologies. Breathing the helium-oxygen mixture (heliox) reduces respiratory effort and improves gas exchange, without significant adverse effects.

  12. Climate Change, Greenhouse Gases and Aerosols

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 12. Climate Change, Greenhouse Gases and Aerosols. J Srinivasan. General Article Volume 13 Issue 12 December 2008 pp 1146-1155. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Noble gases as cardioprotectants - translatability and mechanism

    NARCIS (Netherlands)

    Smit, Kirsten F.; Weber, Nina C.; Hollmann, Markus W.; Preckel, Benedikt

    2015-01-01

    Several noble gases, although classified as inert substances, exert a tissue-protective effect in different experimental models when applied before organ ischaemia as an early or late preconditioning stimulus, after ischaemia as a post-conditioning stimulus or when given in combination before,

  14. Unconventional views to generation of greenhouse gases

    Directory of Open Access Journals (Sweden)

    Buryan Petr

    2012-12-01

    Full Text Available The majority of the implemented measures lowering the amount of originating greenhouse gases derive particularly fromthe balances targeted into power industry, transportation or heavy industry. The article summarized date shoving that the dumpingof communal biodegradace wastes related to catering in many aspects competes in the creation of grenhouses gates related with the cartransportation or power industry.

  15. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    The escape rate of atmospheric molecules on the Moon is calculated.Based on the assumption that the rates of emission and escape of gases attain equilibrium, the ratio of molecular number densities during day and night, 0/0, can be explained. The plausible emission rate of helium and radioactive elements present ...

  16. Prediction of friction coefficients for gases

    Science.gov (United States)

    Taylor, M. F.

    1969-01-01

    Empirical relations are used for correlating laminar and turbulent friction coefficients for gases, with large variations in the physical properties, flowing through smooth tubes. These relations have been used to correlate friction coefficients for hydrogen, helium, nitrogen, carbon dioxide and air.

  17. Infrared scintillation in gases, liquids and crystals

    NARCIS (Netherlands)

    Belogurov, S.; Bressi, G; Carugno, G.; Conti, E; Iannuzzi, D; Meneguzzo, AT

    2000-01-01

    We report about experimental evidences of infrared scintillation in gaseous, liquid and crystal samples. We firstly studied noble gases at room temperature and near atmospheric pressure in the wavelength range between 0.7 and 1.81 mum. Ar gas emits infrared photons when irradiated by a proton beam.

  18. Eco gases for future particle gas detectors

    CERN Document Server

    Kjølbro, Jógvan Nikolaj

    2014-01-01

    Due to global regulations of non environmental refrigerants, some of the gas mixtures used in gas detectors at CERN has to be replaced. This report is a review that summarises and predicts some properties that are important when selecting new gases to operate in the gas detectors.

  19. Noble Gases in Five Rumuruti Chondrites

    Science.gov (United States)

    Weber, H. W.; Schultz, L.

    2001-03-01

    Concentration and isotopic composition have been measured in five new R-chondrites: Dar al Gani 417, Northwest Africa 053, Ouzina, Sahara 98248, and Sahara 99531. Two of these meteorites contain solar trapped gases, NWA 053 has an unusual short exposure age of 0.2 Ma.

  20. Climate Change, Greenhouse Gases and Aerosols

    Indian Academy of Sciences (India)

    user

    RESONANCE │ December 2008. GENERAL │ ARTICLE. Climate Change, Greenhouse Gases and Aerosols. J Srinivasan. Keywords. Global warming, aerosols, soot, climate models. The surface temperature of the earth is controlled by the balance between the absorbed solar radiation and the emitted infrared radiation.

  1. Anaesthetic gases: environmental impact and alternatives

    African Journals Online (AJOL)

    Review Article: Anaesthetic gases: environmental impact and alternatives. 345. 2011;17(5). South Afr J Anaesth Analg. Introduction. In recent times there has been a surge in interest in our contribution to climate change. Human activity results in increased atmospheric levels of a variety of gaseous chemicals that are able to ...

  2. Deviations from Fick's law in Lorentz gases

    NARCIS (Netherlands)

    Lowe, C.P.; Frenkel, D.; Hoef, M.A. van der

    1997-01-01

    We have calculated the self-dynamic structure factorF(k,t) for tagged particle motion in hopping Lorentz gases. We find evidence that, even at long times, the probability distribution function for the displacement of the particles is highly non-Gaussian. At very small values of the wave vector this

  3. Electron-Atom Collisions in Gases

    Science.gov (United States)

    Kraftmakher, Yaakov

    2013-01-01

    Electron-atom collisions in gases are an aspect of atomic physics. Three experiments in this field employing a thyratron are described: (i) the Ramsauer-Townsend effect, (ii) the excitation and ionization potentials of xenon and (iii) the ion-electron recombination after interrupting the electric discharge.

  4. Cold and trapped metastable noble gases

    NARCIS (Netherlands)

    Vassen, W.; Cohen-Tannoudji, C.; Leduc, M.; Boiron, D.; Westbrook, C.I.; Truscott, A.; Baldwin, K.; Birkl, G.; Cancio, P.; Trippenbach, M.

    2012-01-01

    Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general is emphasized. These aspects include detection techniques and collision processes unique to metastable atoms.

  5. Phosphazene additives

    Science.gov (United States)

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  6. Interaction and coupling in the emission of greenhouse gases from animal husbandry

    NARCIS (Netherlands)

    Monteny, G.J.; Groenestein, C.M.; Hilhorst, M.A.

    2001-01-01

    The gases methane (CH4) and nitrous oxide (N2O) contribute to global warming, while N2O also affects the ozone layer. Sources of greenhouse gas emissions in animal husbandry include animals, animal houses (indoor storage of animal excreta), outdoor storage, manure and slurry treatment (e.g.,

  7. A methodology to determine the efficiency of monitors of β emitters noble gases

    International Nuclear Information System (INIS)

    Carvalho, M.R. de; Soares, A.J.

    1996-01-01

    This work presents a methodology to determine the efficiency of air monitors used to measure the concentration of beta emitters noble gases in nuclear power stations. Efficiency values, theoretically determined, were compared with experimental data, using punctual beta sources. (author). 7 refs., 10 figs., 16 tabs

  8. 76 FR 22825 - Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems

    Science.gov (United States)

    2011-04-25

    ... AGENCY 40 CFR Parts 98 Mandatory Reporting of Greenhouse Gases: Petroleum and Natural Gas Systems AGENCY..., 2010 EPA promulgated Subpart W: Petroleum and Natural Gas Systems of the Greenhouse Gas Reporting Rule... outlined for calculating greenhouse gas emissions for the petroleum and natural gas systems source category...

  9. Variations of trace gases over the Bay of Bengal during the summer ...

    Indian Academy of Sciences (India)

    4

    As the major source of Hydroxyl radical (OH), O3 controls the self-cleaning capacity of the atmosphere. Majority of tropospheric O3 is produced by in situ photochemical reactions involving precursor gases CH4, non-CH4 hydrocarbons (NMHCs), and CO and, in presence of nitrogen oxides. (Seinfeld and Pandis, 2006).

  10. An alternative approach to establishing trade-offs among greenhouse gases.

    Science.gov (United States)

    Manne, A S; Richels, R G

    2001-04-05

    The Kyoto Protocol permits countries to meet part of their emission reduction obligations by cutting back on gases other than CO2 (ref. 1). This approach requires a definition of trade-offs among the radiatively active gases. The Intergovernmental Panel on Climate Change has suggested global warming potentials for this purpose, which use the accumulated radiative forcing of each gas by a set time horizon to establish emission equivalence. But it has been suggested that this approach has serious shortcomings: damages or abatement costs are not considered and the choice of time horizon for calculating cumulative radiative force is critical, but arbitrary. Here we describe an alternative framework for determining emission equivalence between radiatively active gases that addresses these weaknesses. We focus on limiting temperature change and rate of temperature change, but our framework is also applicable to other objectives. For a proposed ceiling, we calculate how much one should be willing to pay for emitting an additional unit of each gas. The relative prices then determine the trade-off between gases at each point in time, taking into account economical as well as physical considerations. Our analysis shows that the relative prices are sensitive to the lifetime of the gases, the choice of target and the proximity of the target, making short-lived gases more expensive to emit as we approach the prescribed ceiling.

  11. Trends and temporal variations of major greenhouse gases at a rural site in Central Europe

    Science.gov (United States)

    Haszpra, L.; Barcza, Z.; Hidy, D.; Szilágyi, I.; Dlugokencky, E.; Tans, P.

    In this study the trends and temporal variations of four major greenhouse gases (CO 2, CH 4, N 2O, SF 6) measured at Hegyhátsál, Hungary, are analyzed. The long term trends observed closely follow the global tendencies. The relatively small positive offset can be attributed to the European anthropogenic sources. The seasonal cycles are basically governed by that in the atmospheric mixing, however, in the case of CO 2 and N 2O it is also modulated by the temporal variation in the biological activity. A secondary maximum in SF 6 mixing ratio in summer may indicate the additional contribution of the seasonally changing circulation pattern. The daily cycles are dominated by the diurnal variation in the vertical mixing of the atmosphere. However, in the case of CO 2 the diurnal cycle in the biospheric uptake/release is the governing process, especially in the growing season. The lack of diurnal cycle in the mixing ratio of the exclusively anthropogenic SF 6 indicates that there is no notable anthropogenic activity in the influence area of the station, which also means that Hegyhátsál can be considered to be a rural monitoring site as free from direct anthropogenic pollution as it is possible in Central Europe. It is demonstrated that the diurnal covariance between the mixing ratios and the vertical mixing at a mid-continental, low elevation site has to be taken into account, and properly handled, in the dispersion models, otherwise the results may be distorted. The collocated measurement of greenhouse gases of different origin could potentially help modelers to improve the boundary layer representation and horizontal diffusion simulation in the three dimensional atmospheric transport models.

  12. Sectoral emission inventories of greenhouse gases for 1990 on a per country basis as well as on 1°×1°

    NARCIS (Netherlands)

    Olivier, J.G.J.; Bouwman, A.F.; Berdowski, J.J.M.; Veldt, C.; Bloos, J.P.J.; Visschedijk, A.J.H.; Maas, C.W.M. van der; Zandveld, P.Y.J.

    1999-01-01

    A set of global greenhouse gas emission inventories has been compiled per source category for the 1990 annual emissions of the direct greenhouse gases CO2, CH4 and N2O, as well as of the indirect greenhouse gases (ozone precursors) CO, NOx and NMVOC, and of SO2. The inventories are available by

  13. Petroleum Gases Market in Turkey

    International Nuclear Information System (INIS)

    Bumin, S.; Ozyoruk, B.

    2007-01-01

    We are at the beginning of a new millennium. At this stage, we are observing economic and social liberalization efforts and regional alliance projects throughout the world. In this very same process, we are also experiencing a more holistic concept called globalization, which covers rapid and simultaneous dissemination and integration of capital, labor, information and technology, world-wide. This globalization opened a new era where national market economies and local companies went into competition in the international arena. In this era, it became a necessity for the non-liberal economies to catch up with the developments in the international markets and be open to economic and political changes. These developments have brought along many radical economic and social changes throughout the world. Policies adopted in Turkey, with respect to the energy reform process, display a general tendency towards putting in place a legal framework that will support the implementation of good governance principles, and providing conformity with the relevant legislative infrastructure of both OECD and EU countries. Turkey has only limited reserves of oil and natural gas, but substantial reserves of coal, particularly lignite. Energy demand has grown at 4-5 % per annum over the past three decades and will continue to grow rapidly, which will require enormous investments in 2000 and 2020, with the most significant increase being that of natural gas. Because of its limited energy resources, Turkey is heavily dependent on imported oil and gas. There are major oil and gas pipelines going through Turkey and additional pipelines are being constructed or are being planned. There is some production of lignite which is used in power plants and industry. 73 % of the world's proven oil reserves and 72 % of the world's proven gas reserves are located in the surrounding regions of Turkey: Middle East, Caspian Region and Russia. This makes Turkey a crucial bridge between energy rich regions

  14. Sampling of contaminants from product gases of biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Staahlberg, P.; Lappi, M.; Kurkela, E.; Simell, P.; Oesch, P.; Nieminen, M. [VTT Energy, Espoo (Finland). New Energy Technologies

    1998-12-01

    Reliable sampling and analysis of products from biomass gasification are essential for the successful process development and economical operation of commercial gasifiers. One of the most important and most difficult analytical tasks is to characterise the emissions from the gasifiers. This report presents a review of the sampling and analytical systems employed and developed when doing research on coal and biomass gasification. In addition to the sampling systems published in the literature, experiences obtained in various biomass gasification R and D projects of VTT in 1985-1995 are described. The present sampling methods used for different gas contaminants at VTT are also briefly presented. This report focuses mainly on the measurement of tars, nitrogen compounds and sulphur gases. Isokinetic and non-isokinetic sampling train systems are described and, in addition, special sampling apparatus based on liquid-quenched probe and gas dilution is briefly outlined. Sampling of tars with impinger systems and sampling of heavy tars with filter techniques are described in detail. Separate sampling of particulates is briefly discussed. From inorganic compounds the sampling systems used for H{sub 2}S and other sulphur gases, NH{sub 3} and HCN and HCl are presented. Proper storage of the samples is also included in the report. (orig.) 90 refs.

  15. Fuel saving, carbon dioxide emission avoidance, and syngas production by tri-reforming of flue gases from coal- and gas-fired power stations, and by the carbothermic reduction of iron oxide

    International Nuclear Information System (INIS)

    Halmann, M.; Steinfeld, A.

    2006-01-01

    Flue gases from coal, gas, or oil-fired power stations, as well as from several heavy industries, such as the production of iron, lime and cement, are major anthropogenic sources of global CO 2 emissions. The newly proposed process for syngas production based on the tri-reforming of such flue gases with natural gas could be an important route for CO 2 emission avoidance. In addition, by combining the carbothermic reduction of iron oxide with the partial oxidation of the carbon source, an overall thermoneutral process can be designed for the co-production of iron and syngas rich in CO. Water-gas shift (WGS) of CO to H 2 enables the production of useful syngas. The reaction process heat, or the conditions for thermoneutrality, are derived by thermochemical equilibrium calculations. The thermodynamic constraints are determined for the production of syngas suitable for methanol, hydrogen, or ammonia synthesis. The environmental and economic consequences are assessed for large-scale commercial production of these chemical commodities. Preliminary evaluations with natural gas, coke, or coal as carbon source indicate that such combined processes should be economically competitive, as well as promising significant fuel saving and CO 2 emission avoidance. The production of ammonia in the above processes seems particularly attractive, as it consumes the nitrogen in the flue gases

  16. Micrometeorological flux measurements of aerosol and gases above Beijing

    Science.gov (United States)

    Nemitz, Eiko; Langford, Ben; Mullinger, Neil; Cowan, Nicholas; Coyle, Mhairi; Acton, William Joe; Lee, James; Fu, Pingqing

    2017-04-01

    Air pollution is estimated to cause 1.6 million premature deaths in China every year and in the winter 2016/17 Beijing had to issue health alerts and put in place ad hoc limitations on industrial and vehicular activity. Much of this pollution is attributed to emissions from industrial processes and in particular coal combustion. By contrast, the diffuse pollutant sources within the city are less well understood. This includes, e.g., emissions from the Beijing traffic fleet, the sewage system, food preparation, solid fuel combustion in the streets and small industrial processes. Within the framework of a major UK-Chinese collaboration to study air pollution and its impact on human health in Beijing, we therefore measured fluxes of a large range of pollutants from a height of 102 m on the 325 m meteorological tower at the Institute of Atmospheric Physics. Several instruments were mounted at 102 m: fluxes of CO2 and H2O were measured with an infrared gas analyser (LiCOR 7500) and fluxes of ozone with a combination of a relative fast-response ozone analyser (ROFI) and a 2B absolute O3 instrument. Total particle number fluxes were measured with a condensation particle counter (TSI CPC 3785), and size-segregated fluxes over the size range 0.06 to 20 μm with a combination of an optical Ultrafine High Sensitivity Aerosol Spectrometer (UHSAS) and an Aerodynamic Particle Sizer Spectrometer (TSI APS3321). Ammonia (NH3) fluxes were measured for the first time above the urban environment using an Aerodyne compact quantum cascade laser (QCL). In addition, composition resolved aerosol fluxes were measured with an Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS), operated in a measurement container at the bottom of the tower, which subsampled from a 120 m long copper tube (15 mm OD). The analysis so far suggests that, due to often low wind speeds, fluxes were at times de-coupled from the surface. Fluxes normalised by CO2, a tracer for the amount of fossil fuel consumed, should be

  17. Effect of cooling the recirculated exhaust gases on diesel engine emissions

    International Nuclear Information System (INIS)

    Abu-Hamdeh, Nidal H.

    2003-01-01

    Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NO x ), carbon dioxide (CO 2 ) and carbon monoxide (CO). In addition, O 2 concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NO x ) and carbon dioxide (CO 2 ) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O 2 ) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NO x gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NO x but increased the particulate matter concentrations in the exhaust gases

  18. Evaluation of the correlation between concentration of volatile organic compounds and temperature of the exhaust gases in motor vehicles

    Science.gov (United States)

    Skrętowicz, Maria; Wróbel, Radosław; Andrych-Zalewska, Monika

    2017-11-01

    Volatile organic compounds (VOCs) are the group of organic compounds which are one of the most important air pollutants. One of the main sources of VOCs are combustion processes including fuel combustion is internal combustion engines. Volatile organic compounds are very dangerous pollution, because even in very low concentrations they have significant harmful effect on human health. A lot of that compounds are mutagenic and carcinogenic, in addition they could cause asthma, intoxication or allergy. The measurements of VOCs are quite problematic, because it is required using the specialist analytical apparatus, ex. chromatograph. However, not always it is need to measure the content of that compounds in engine exhaust with high precision and sometimes it is enough only to estimate the level of the concentration. Emission of the VOCs mainly depends on the combustion process in the engine and this determines the temperature of the exhaust gases. In this paper authors tried to determine if the correlation between temperature of exhaust gases and VOCs' concentration exist and is able to determine.

  19. Monitoring organic volatiles and flammable gases with a holographic sensor

    Science.gov (United States)

    Martínez-Hurtado, J. L.; Davidson, C. A. B.; Lowe, C. R.

    2011-05-01

    There is an increasing preoccupation regarding the effects of organic volatiles or explosive gases in human welfare and society. A holographic sensor for gaseous and volatile compounds was produced by diffusion of silver salts in a silicon elastomer (PDMS). The salts were reduced to produce silver particles, which upon ablation with a pulsed laser form fringes of nano-sized silver grains. The fringes are separated by about half of the wavelength of the laser (266nm) producing a photonic effect that can be measured as a colorful reflection. A CCD spectrophotometer was used to detect the reflected wavelength of the hologram illuminated with a white light source. The molecular affinity of PDMS for organic molecules can be expressed as intermolecular forces in terms of the cohesive energy density. This parameter is used to predict with great accuracy the sensor performance. Hydrocarbon gases at different concentrations were tested for 3 sets of temperatures. Alkanes, alkenes and alkynes containing 2 to 4 carbon atoms were detected. The sensor responds in less than 5s to the hydrocarbon gas presence in a range of concentrations from 0% to 100% (v/v). Liquid organic compounds exhibit a slower response; however, the results agree with the prediction imposed by the cohesive energy densities. The capabilities of the sensor make it ideal for applications in indoor environment monitoring or dangerous environments enriched with such organic compounds.

  20. Conversion of South African Coal Fly Ash into High-Purity ZSM-5 Zeolite without Additional Source of Silica or Alumina and Its Application as a Methanol-to-Olefins Catalyst

    OpenAIRE

    Roland N. M. Missengue; Pit Losch; Nicholas M. Musyoka; Benoit Louis; Patrick Pale; Leslie F. Petrik

    2018-01-01

    Characteristics of ZSM-5 synthesized from H2SO4-treated coal fly ash and fused coal fly ash extracts are compared in this study. In the synthesis process, fused coal fly ash extract (without an additional silica source) was used in the synthesis of ZSM-5. The effect of the structure-directing agent (tetrapropylammonium bromide, 1,6-hexanediamine or 1-propylamine) on the properties and methanol-to-olefins (MTO) effectiveness of the fly ash-based ZSM-5 was also investigated. A pure ZSM-5 synthe...

  1. AIR POLLUTION FROM ANIMAL AND MUNICIPAL WASTEWATER: ASSESSMENT OF PRODUCTION AND RELEASE OF NOXIOUS GASES

    DEFF Research Database (Denmark)

    Dai, Xiaorong

    Airborne contaminants and odor from animal manure and municipal wastewater can affect human physical and psychological health, and the environment. The estimation of gas emission rates and development of technologies to reduce the release of noxious gases from wastewater is limited by current...... knowledge on the production pathways of gases and the release mechanisms from various sources. The overall objective of this PhD project was to assess the production and release of noxious gases from animal manure and municipal wastewater by giving emphasis on the effects of waste management (such as......, surface disturbances during storage, acidification and aeration), the hydrolysis of urea by bacteria, the waste types and wastes physicochemical characteristics. Animal wastewater stored in under-floor deep pit is characterized by the frequent occurrence of surface liquid disturbances caused by the urine...

  2. High-pressure plastic scintillation detector for measuring radiogenic gases in flow systems

    CERN Document Server

    Schell, W R; Yoon, S R; Tobin, M J

    1999-01-01

    Radioactive gases are emitted into the atmosphere from nuclear electric power and nuclear fuel reprocessing plants, from hospitals discarding xenon used in diagnostic medicine, as well as from nuclear weapons tests. A high-pressure plastic scintillation detector was constructed to measure atmospheric levels of such radioactive gases by detecting the beta and internal conversion (IC) electron decays. Operational tests and calibrations were made that permit integration of the flow detectors into a portable Gas Analysis, Separation and Purification system (GASP). The equipment developed can be used for measuring fission gases released from nuclear reactor sources and/or as part of monitoring equipment for enforcing the Comprehensive Test Ban Treaty. The detector is being used routinely for in-line gas separation efficiency measurements, at the elevated operational pressures used for the high-pressure swing analysis system (2070 kPa) and at flow rates of 5-15 l/min . This paper presents the design features, opera...

  3. Properties of quantum self-gravitating gases

    International Nuclear Information System (INIS)

    Rumyantseva, E.N.

    1981-01-01

    Ways of development of the quantum field theory in the general relativity theory are under consideration. A direction, where consideration of quantum fields in strong nonstatic gravitational fields leads to such effects as particle production, is found out. Authors managed to explain properties of quantum self-gravitating gases on the base of an expansion the fugacity in power series for bose- and fermi gases. Expressions for fluctuations in statistical models of the Fridmann universe are presented. The spectrum density of relict neutrinos in Fridmann models is calculated. A characteristic low boundary of the neutrino energy spectrum constitutes 1 MeV. A number of neutrinos with such energies practically is equal to zero. A great number of neutrinos has energies 0 . It is precisely these neurinos, which are responsible for the closed state of the universe according to the built up model

  4. Thermodynamics of dilute gases in shear flow

    Science.gov (United States)

    Jou, D.; Criado-Sancho, M.

    2001-03-01

    We consider the effect of shear and normal viscous pressures on the non-equilibrium entropy of ideal gases in Couette flow. These results extend the previous ones (Bidar et al., Physica A 233 (1996) 163), where normal pressure effects were ignored. Furthermore, we analyze the non-equilibrium contributions to the chemical potential, which may be useful in the analysis of shear-induced effects on colligative properties and chemical equilibrium.

  5. Effect of Greenhouse Gases Dissolved in Seawater.

    Science.gov (United States)

    Matsunaga, Shigeki

    2015-12-30

    A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  6. Strongly Interacting Fermi Gases in Two Dimensions

    Science.gov (United States)

    2012-07-17

    Phys. 82, 3045 (2010). [4] M. Inguscio, W. Ketterle, C. Salomon, eds., Ultracold Fermi gases, Proceedings of the International School of Physics Enrico ... Enrico Fermi ,” Course CLXIV, Varenna, 2006, edited by M. Inguscio, W. Ketterle, and C. Salomon (IOS, Amsterdam, 2008). [3] W. Ketterle and M...International School of Physics ‘‘ Enrico Fermi ,’’ Course CLXIV, edited by M. Inguscio, W. Ketterle, and C. Salomon (Elsevier, Amsterdam, 2008). [4] S

  7. Noble Gases in the Chelyabinsk Meteorites

    Science.gov (United States)

    Haba, Makiko K.; Sumino, Hirochika; Nagao, Keisuke; Mikouchi, Takashi; Komatsu, Mutsumi; Zolensky, Michael E.

    2014-01-01

    The Chelyabinsk meteorite fell in Russia on February 15, 2013 and was classified as LL5 chondrite. The diameter before it entered the atmosphere has been estimated to be about 20 m [1]. Up to now, numerous fragments weighing much greater than 100 kg in total have been collected. In this study, all noble gases were measured for 13 fragments to investigate the exposure history of the Chelyabinsk meteorite and the thermal history of its parent asteroid.

  8. Paschen's law studies in cold gases

    Science.gov (United States)

    Massarczyk, R.; Chu, P.; Dugger, C.; Elliott, S. R.; Rielage, K.; Xu, W.

    2017-06-01

    The break-through voltage behavior over small gaps has been investigated for differing gap distances, gas pressures, and gas temperatures in nitrogen, neon, argon and xenon gases. A deviation from Paschen's law at micro gap distances has been found. At lower temperatures, a significant shift of the curve relative to the results at room temperature was observed. This behavior can be explained by combining Paschen's law and the ideal gas law.

  9. Paschen's law studies in cold gases

    OpenAIRE

    Massarczyk, R.; Chu, P.; Elliott, S. R.; Rielage, K.; Dugger, C.; Xu, W.

    2016-01-01

    The break-through voltage over small gaps has been investigated for differing gap distances, gas pressures, and gas temperatures in nitrogen, neon, argon and xenon gases. A deviation from Paschen's law at micro gap distances has been found. The breakthrough behavior of the fill gas in colder environments was tested as well. A significant shift of the curve relative to the results at room temperature was observed. The results can be explained by combining Paschen's law and the ideal gas law.

  10. High field optical nonlinearities in gases

    Science.gov (United States)

    Cheng, Yu-Hsiang

    Optical femtosecond self-channeling in gases, also called femtosecond filamentation, has become an important area of research in high field nonlinear optics. Filamentation occurs when laser light self-focuses in a gas owing to self-induced nonlinearity, and then defocuses in the plasma generated by the self-focused beam. The result of this process repeating itself multiple times is an extended region of plasma formation. Filamentation studies have been motivated by the extremely broad range of applications, especially in air, including pulse compression, supercontinuum generation, broadband high power terahertz pulse generation, discharge triggering and guiding, and remote sensing. Despite the worldwide work in filamentation, the fundamental gas nonlinearities governing self-focusing had never been directly measured in the range of laser intensity up to and including the ionization threshold. This dissertation presents the first such measurements. We absolutely measured the temporal refractive index change of O2, N2, Ar, H2, D2 and N2O caused by highfield ultrashort optical pulses with single-shot supercontinuum spectral interferometry, cleanly separating for the first time the instantaneous electronic and delayed rotational nonlinear response in diatomic gases. We conclusively showed that a recent claim by several European groups that the optical bound electron nonlinearity saturates and goes negative is not correct. Such a phenomenon would preclude the need for plasma to provide the defocusing contribution for filamentation. Our results show that the 'standard model of filamentation', where the defocusing is provided by plasma, is correct. Finally, we demonstrated that high repetition rate femtosecond laser pulses filamenting in gases can generate long-lived gas density `holes' which persist on millisecond timescales, long after the plasma has recombined. Gas density decrements up to ~20% have been measured. The density hole refilling is dominated by thermal

  11. Role of buffer gases in optoacoustic spectroscopy

    International Nuclear Information System (INIS)

    Thomas III, L.J.; Kelly, M.J.; Amer, N.M.

    1978-01-01

    The dependence of an acoustically resonant optoacoustic signal on the molecular weight and thermodynamic and transport properpties of the buffer gas is reported. Our results show that careful selection of such gases can significantly increase the sensitivity and flexibility of optoacoustic spectroscopy. We also demonstrate that such thermodynamic quantities as γ (equivalentC/sub p//C/sub v/) and sound velocity can now be measured readily and accurately. Other potential applications are suggested

  12. Emissions of ammonia and greenhouse gases during combined pre-composting and vermicomposting of duck manure.

    Science.gov (United States)

    Wang, Jinzhi; Hu, Zhengyi; Xu, Xingkai; Jiang, Xia; Zheng, Binghui; Liu, Xiaoning; Pan, Xubin; Kardol, Paul

    2014-08-01

    Combined pre-composting and vermicomposting has shown potential for reclamation of solid wastes, which is a significant source of ammonia (NH3), and greenhouse gases (GHG), including nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2). Earthworms and amendments may both affect physico-chemical characteristics that control gas-producing processes, and thus affect NH3 and GHG emissions. Here, we used two-way ANOVA to test the effects of addition of reed straw and combined addition of reed straw and zeolite on NH3 and GHG emissions during pre-composting of duck manure, either with or without a follow-up phase of vermicomposting. Results showed that cumulative N2O, CH4, and CO2 emissions during pre-composting and vermicomposting ranged from 92.8, 5.8, and 260.6 mg kg(-)(1) DM to 274.2, 30.4, and 314.0 mg kg(-1) DM, respectively. Earthworms and amendments significantly decreased N2O and CH4 emissions. Emission of CO2 was not affected by earthworms, but increased in responses to addition of reed straw. Cumulative NH3 emission ranged from 3.0 to 8.1 g kg(-1) DM, and was significantly decreased by reed straw and zeolite addition. In conclusion, combined pre-composting and vermicomposting with reed straw and zeolite addition would be strongly recommended in mitigating emissions of N2O, CH4, and NH3 from duck manure. Moreover, this method also provides nutrient-rich products that can be used as a fertilizer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Agreements on emission of greenhouse gases

    International Nuclear Information System (INIS)

    Aulstad, Johan Greger

    2001-01-01

    Agreements on emission of greenhouse gases is one of the instruments used by Norwegian authorities to meet their obligations with respect to the Climate Convention and the Kyoto Protocol. This book discusses the legal issues raised by these agreements. A main topic is how the industrial emissions conform to the Pollution Act. Does the Pollution Act apply to these emissions? What is the impact of the sanction rules in this act on the emissions? The book also deals with the following general questions that arise in connection with the application of public authority: (1) Can the administration grant concessions and permits in the form of agreements? (2) What commitments can be imposed on a private party by the administration by agreement? (3) Should the procedures set down in the Pollution Act and in the Public Administration Act be followed fully when the pollution authorities make agreements? Is the opportunity of the administration to reverse more restricted when they make agreements than when they make one-sided decisions? Although this discussion primarily deals with the emission of greenhouse gases, the reasoning and conclusions are relevant in many other types of agreements in which the public administration is one of the parties. The agreement that regulates the emissions of greenhouse gases from the Norwegian aluminium industry is described in a special section. The book also gives a brief account of how agreements are used in the Danish climate policy

  14. Thermodynamics of Quantum Gases for the Entire Range of Temperature

    Science.gov (United States)

    Biswas, Shyamal; Jana, Debnarayan

    2012-01-01

    We have analytically explored the thermodynamics of free Bose and Fermi gases for the entire range of temperature, and have extended the same for harmonically trapped cases. We have obtained approximate chemical potentials for the quantum gases in closed forms of temperature so that the thermodynamic properties of the quantum gases become…

  15. Liquid chromatography coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry and post-column addition of metal salt solutions as a powerful tool for the metabolic profiling of Fusarium oxysporum.

    Science.gov (United States)

    Cirigliano, Adriana M; Rodriguez, M Alejandra; Gagliano, M Laura; Bertinetti, Brenda V; Godeas, Alicia M; Cabrera, Gabriela M

    2016-03-25

    Fusarium oxysporum L11 is a non-pathogenic soil-borne fungal strain that yielded an extract that showed antifungal activity against phytopathogens. In this study, reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry (API-QTOF-MS) was applied for the comprehensive profiling of the metabolites from the extract. The employed sources were electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Post-column addition of metal solutions of Ca, Cu and Zn(II) was also tested using ESI. A total of 137 compounds were identified or tentatively identified by matching their accurate mass signals, suggested molecular formulae and MS/MS analysis with previously reported data. Some compounds were isolated and identified by NMR. The extract was rich in cyclic peptides like cyclosporins, diketopiperazines and sansalvamides, most of which were new, and are reported here for the first time. The use of post-column addition of metals resulted in a useful strategy for the discrimination of compound classes since specific adducts were observed for the different compound families. This technique also allowed the screening for compounds with metal binding properties. Thus, the applied methodology is a useful choice for the metabolic profiling of extracts and also for the selection of metabolites with potential biological activities related to interactions with metal ions. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Local sources of global climate forcing from different categories of land use activities

    OpenAIRE

    D. S. Ward; N. M. Mahowald

    2015-01-01

    Identifying and quantifying the sources of climate impacts from land use and land cover change (LULCC) is necessary to optimize policies regarding LULCC for climate change mitigation. These climate impacts are typically defined relative to emissions of CO2, or sometimes emissions of other long-lived greenhouse gases. Here we use previously published estimates of the radiative forcing (RF) of LULCC that include the short-lived forcing agents O3 and aerosols, in addition to lo...

  17. Greenhouse gases mitigation policies in the agriculture of Aragon, Spain

    Directory of Open Access Journals (Sweden)

    Mohamed Taher Kahil

    2013-05-01

    Full Text Available Climate change is an important threat to human society. Agriculture is a source of greenhouse gases (GHG, but it also provides alternatives to confront climate change. The expansion of intensive agriculture around the world during recent decades has generated significant environmental damages from pollution emissions. The spatial distribution of emissions is important for the design of local abatement measures. This study makes an assessment of GHG emissions in an intensive agricultural area of Aragon (Spain, and then an economic optimization model is developed to analyze several GHG mitigation measures. The results indicate that adequate management of manure, emissions limits, and animal production restrictions are appropriate measures to abate pollution. Economic instruments such as input and emission taxes could be only ancillary measures to address nonpoint pollution problems. Suitable pollution abatement policies should be based on institutional instruments adapted to local conditions, and involve the cooperation of stakeholders.

  18. [In-situ monitoring algorithm of gases poisonous elements concentration with ultraviolet optical absorption spectroscopy based on recursion iterative method].

    Science.gov (United States)

    Wang, Hui-feng; Jiang, Xu-qian

    2012-01-01

    The key and challenge problem of in-situ monitoring poisonous elements of gases is how to separate the various gases absorption signal from mixed gases absorption spectroscopy and compute it's accuracy concentration? Here we present a new algorithms in return recursion iteration based on Lambert-Beer principle. In the algorithms, recurred by the character of absorption peak of various gases in the band of 190-290 nm UV rays continuous spectroscopy and the character of twin element fold for absorbance are used. Firstly, the authors suppose that there is no absorption for others gases in the character absorption band for a certain gas, the authors can inference the initial concentration of the gas. Then the authors switch to another character spectroscopy, and put the photons that gases absorption out of the total number of absorbed photons that are measured. So we could get the initial concentration of another gas. By analogy the authros can get the initial concentration of all kinds of other poisonous elements. Then come back to the character spectroscopy of the first gas, the authors can get a new concentration of the first gas from the difference between the total number of absorbed photons and the photons that other gases absorption. By analogy the authors can get the iterative concentration of other gases, by irterating this process repeatly for some times until the measurement error of the adjacent gas concentration is smaller than a certain numerical value. Finally the authors can get the real and accurate concentration of all kinds of gases. Experiment shows that the authors can get the accurate concentration of all kinds of gases with the algorithm. The accuracy can be within 2%, and at the same time, it is easy enough to satisfy the necessity of real-time requirement. In addition it could be used to measure the concentration of many kinds of gas at a time. It is robust and suitable to be taken into practice.

  19. Technical papers 2: regional evaluation of the greenhouse gases emissions bound to the energy; Cahiers techniques 2: bilan regional des emissions de gaz a effet de serre liees a l'energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The regional evaluation of the greenhouse gases emissions is realized in the framework of the climatic change fight. This technical paper aims to give regions information on the greenhouse gases emissions bound the the energy consumption. It provides a sectoral analysis in function of the energy sources and pollution sources. (A.L.B.)

  20. Thermodynamic model for swelling of unconfined coal due to adsorption of mixed gases

    NARCIS (Netherlands)

    Liu, J.; Peach, C.J.; Zhou, Hongwei; Spiers, C.J.

    2015-01-01

    Permeability evolution in coal seams during CO2-Enhanced Coalbed Methane (ECBM) production is strongly influenced by swelling/shrinkage effects related to sorption and desorption of both CO2 and CH4. Other gases, such as N2, have also been proposed for injection in ECBM operations. In addition,

  1. Tendências no desenvolvimento de gases de proteção utilizados na soldagem MIG/MAG Trends in the development of protective gases used in GMAW welding

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Soares Tatagiba

    2012-09-01

    Full Text Available Este trabalho tem como objetivo apresentar uma revisão do estado da arte sobre os gases de proteção usados nos processos de soldagem a arco elétrico, com ênfase na soldagem MIG/MAG do aço. São apresentados os principais conceitos da física do arco e as propriedades relacionadas aos gases de proteção. O modelo de atmosfera ligeiramente oxidante para os gases de proteção é discutido, sendo mostradas as formulações dos gases estudados em artigos científicos e em patentes depositadas, bem como as reivindicações (vantagens requeridas. Também são mencionados alguns poucos estudos usando adições de gases não convencionais. Foi observado que no desenvolvimento de gases de proteção para soldagem MIG/MAG do aço predomina o modelo da formação de atmosfera ligeiramente oxidante. A maioria das formulações propostas envolve o uso de misturas binárias, ternárias e até quaternárias dos gases Ar, He, CO2 e O2. Em aplicações específicas, adições de N2 e H2 foram usadas. Neste sentido, pouca inovação foi identificada, sendo atribuídas possíveis razões a este fato. A tendência observada para o desenvolvimento de gases de proteção parece ser o uso de misturas ricas em gases inertes, com adições calibradas de elementos oxidantes, sempre atendendo a aplicações específicas.This paper has as objective to present a state of the art review on the shielding gases used in the electric arc welding processes, with emphasis on GMAW welding of steel. There are shown the main concepts of arc physics and properties related to shielding gases. The model of slightly oxidizing atmosphere for shielding gases is discussed, and the formulations of the gases studied in scientific articles and in deposited patents, as well as the claims (benefits required. It also mentions some few studies using additions of non-conventional gases. It was observed that for the development of shielding gases for the GMAW steel welding the model of

  2. Kinetic theory of nonideal gases and nonideal plasmas

    CERN Document Server

    Klimontovich, Yu L

    2013-01-01

    Kinetic Theory of Nonideal Gases and Nonideal Plasmas presents the fundamental aspects of the kinetic theory of gases and plasmas. The book consists of three parts, which attempts to present some of the ideas, methods and applications in the study of the kinetic processes in nonideal gases and plasmas. The first part focuses on the classical kinetic theory of nonideal gases. The second part discusses the classical kinetic theory of fully ionized plasmas. The last part is devoted to the quantum kinetic theory of nonideal gases and plasmas. A concluding chapter is included, which presents a shor

  3. Method for carrying out endothermic chemical reactions with the use of nuclear reactor cooling gases

    International Nuclear Information System (INIS)

    Haese, E.

    1977-01-01

    A process is disclosed for carrying out an endothermic chemical reaction, such as the water-gas reaction, wherein heat is supplied to the reaction from nuclear reactor cooling gases. The invention is characterized in that water vapor and fuel, for example, are passed through a series of heat exchangers and reaction chambers in series, the heat exchangers being disposed within a conduit through which cooling gases from a nuclear reactor flow. When a fuel such as methane, for example, is being dissociated in the endothermic reaction, additional fuel is added to each reaction chamber where heat is supplied from the nuclear reactor cooling medium via a separate heat exchanger for that chamber

  4. Enhanced Boiling-Metal Cooling Of Vanes Exposed To Hot Gases

    Science.gov (United States)

    Osofsky, I. B.

    1995-01-01

    Incorporation of automatic, self-powered jet pumps proposed to enhance boiling-liquid-metal cooling of vanes exposed to hot gases. In original intended application, vanes and probes thrust-vector-control devices inserted in supersonic flows of hot gases in rocket-engine nozzles; this cooling concept also applicable to vanes and blades in high-performance turbine engines. In further improvement, additional axial and transverse slots added to coolant passages in vane or probe and to coolant reservoir. Slots reduce stresses caused by thermal expansion and contraction of solid coolant.

  5. Evaluation of gases, condensates, and SO2 emissions from Augustine volcano, Alaska: the degassing of a Cl-rich volcanic system

    Science.gov (United States)

    Symonds, R.B.; Rose, William I.; Gerlach, T.M.; Briggs, P.H.; Harmon, R.S.

    1990-01-01

    After the March-April 1986 explosive eruption a comprehensive gas study at Augustine was undertaken in the summers of 1986 and 1987. Airborne COSPEC measurements indicate that passive SO2 emission rates declined exponentially during this period from 380??45 metric tons/day (T/D) on 7/24/86 to 27??6 T/D on 8/24/87. These data are consistent with the hypothesis that the Augustine magma reservoir has become more degassed as volcanic activity decreased after the spring 1986 eruption. Gas samples collected in 1987 from an 870??C fumarole on the andesitic lava dome show various degrees of disequilibrium due to oxidation of reduced gas species and condensation (and loss) of H2O in the intake tube of the sampling apparatus. Thermochemical restoration of the data permits removal of these effects to infer an equilibrium composition of the gases. Although not conclusive, this restoration is consistent with the idea that the gases were in equilibrium at 870??C with an oxygen fugacity near the Ni-NiO buffer. These restored gas compositions show that, relative to other convergent plate volcanoes, the Augustine gases are very HCl rich (5.3-6.0 mol% HCl), S rich (7.1 mol% total S), and H2O poor (83.9-84.8 mol% H2O). Values of ??D and ??18O suggest that the H2O in the dome gases is a mixture of primary magmatic water (PMW) and local seawater. Part of the Cl in the Augustine volcanic gases probably comes from this shallow seawater source. Additional Cl may come from subducted oceanic crust because data by Johnston (1978) show that Cl-rich glass inclusions in olivine crystals contain hornblende, which is evidence for a deep source (>25km) for part of the Cl. Gas samples collected in 1986 from 390??-642??C fumaroles on a ramp surrounding the inner summit crater have been oxidized so severely that restoration to an equilibrium composition is not possible. H and O isotope data suggest that these gases are variable mixtures of seawater, FMW, and meteoric steam. These samples are much

  6. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Science.gov (United States)

    2010-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons...

  7. Methodology to determine the efficiency of a beta emitter gases monitor; Metodologia para determinacao da eficiencia de um monitor de gases emissores de particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Marcos Rodrigues de

    1995-07-01

    This work presents a methodology developed to determinate the efficiency of air monitors used to measure the concentration of beta emitters noble gases in nuclear power stations. Efficiency values, obtained by means of theoretical computation are compared with experimental values. The experimental part of the work was performed using three different point beta source, to simulate small amounts of gas uniformly distributed in small volume. The comparison shows that theoretical an experimental values agree within 4,2 % for {sup 90}Sr + {sup 90}Y, {sup 204}Tl and {sup 45}Ca beta sources. (author)

  8. Conversion of South African Coal Fly Ash into High-Purity ZSM-5 Zeolite without Additional Source of Silica or Alumina and Its Application as a Methanol-to-Olefins Catalyst

    Directory of Open Access Journals (Sweden)

    Roland N. M. Missengue

    2018-03-01

    Full Text Available Characteristics of ZSM-5 synthesized from H2SO4-treated coal fly ash and fused coal fly ash extracts are compared in this study. In the synthesis process, fused coal fly ash extract (without an additional silica source was used in the synthesis of ZSM-5. The effect of the structure-directing agent (tetrapropylammonium bromide, 1,6-hexanediamine or 1-propylamine on the properties and methanol-to-olefins (MTO effectiveness of the fly ash-based ZSM-5 was also investigated. A pure ZSM-5 synthesized from the fused coal fly ash extract led to a methanol conversion higher than 90% after 5 h on stream. The template 1,6-hexanediamine led to the synthesis of the most stable fly ash-based catalyst keeping a 44% methanol conversion after 24 h on stream.

  9. Screening of additives in plastics with high resolution time-of-flight mass spectrometry and different ionization sources: direct probe injection (DIP)-APCI, LC-APCI, and LC-ion booster ESI.

    Science.gov (United States)

    Ballesteros-Gómez, Ana; Jonkers, Tim; Covaci, Adrian; de Boer, Jacob

    2016-04-01

    Plastics are complex mixtures consisting of a polymer and additives with different physico-chemical properties. We developed a broad screening method to elucidate the nature of compounds present in plastics used in electrical/electronic equipment commonly found at homes (e.g., electrical adaptors, computer casings, heaters). The analysis was done by (a) solvent extraction followed by liquid chromatography coupled to high accuracy/resolution time-of-flight mass spectrometry (TOFMS) with different ionization sources or (b) direct analysis of the solid by ambient mass spectrometry high accuracy/resolution TOFMS. The different ionization methods showed different selectivity and sensitivity for the different compound classes and were complementary. A variety of antioxidants, phthalates, UV filters, and flame retardants were found in most samples. Furthermore, some recently reported impurities or degradation products derived from flame retardants were identified, such as hydroxylated triphenyl phosphate and tetrabromobisphenol A monoglycidyl ether.

  10. Characteristic of combustion of Colombian gases

    International Nuclear Information System (INIS)

    Gil B, Edison; Maya, Ruben; Andres, Amel A.

    1996-01-01

    The variety of gas locations in the country, makes that the gas that will be distributed by the net of present gas pipeline a very different composition, what bears to that these they behave in a different way during its use. In this work the main characteristics of the combustion are calculated for the Colombian gases, basically the properties of the combustion and the characteristics of the smoke, as basic information for the design and operation of the gas teams and their certification. These properties were calculated with the special help software for combustion developed by the authors

  11. Method for detecting trace impurities in gases

    Science.gov (United States)

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  12. Effect of Greenhouse Gases Dissolved in Seawater

    Directory of Open Access Journals (Sweden)

    Shigeki Matsunaga

    2015-12-01

    Full Text Available A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  13. Mean free path in soccer and gases

    Energy Technology Data Exchange (ETDEWEB)

    Luzuriaga, J, E-mail: luzuriag@cab.cnea.gov.a [Centro Atomico Bariloche - CNEA, Instituto Balseiro UNC (8400), Bariloche (Argentina)

    2010-09-15

    The trajectories of the molecules in an ideal gas and of the ball in a soccer game are compared. The great difference between these motions and some similarities are discussed. This example could be suitable for discussing many concepts in kinetic theory in a way that can be pictured by students for getting a more intuitive understanding. It could be suitable for an introductory course in vacuum techniques or undergraduate courses in kinetic theory of gases. Without going into the slightly harder quantitative results, the analysis presented might be used for introducing some ideas of kinetic theory qualitatively to high school students.

  14. Gases and vacua handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 1: Gases and Vacua provides information on the many aspects of vacuum technology, from material on the quantum theoretical aspects of the complex semi-conductors used for thermionic and photo-electric emission to data on the performance of commercially available pumps, gauges, and high-vacuum materials. The handbook satisfies the need of workers using vacuum apparatuses or works on the diverse applications of high-vacuum technology in research and industry. The book is a compilation of long articles prepared by experts in vacuum technology. Sufficient theoret

  15. Positron scattering from noble gases future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A C L; Caradonna, P; Makochekanwa, C; Slaughter, D S; Sullivan, J P; Buckman, S J [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra, ACT (Australia); Mitroy, J, E-mail: acj107@rsphysse.anu.edu.a [Faculty of Education Health and Science, Charles Darwin University, NT (Australia)

    2009-11-01

    Recent results for positron scattering from noble gases over an energy range from 0.5 to 60eV are presented. Measurements include the grand total ({sigma}{sub GT}), Ps formation ({sigma}{sub Ps}) and Grand total - Ps formation (({sigma}{sub GT}-P{sub s}) cross sections. Some preliminary DCS results will also be presented. Work on a formulation of modified effective range theory (MERT) is being undertaken to determine the value of the scattering length which may be useful for identifying a bound state. Plans for experiments on metal atoms will be outlined.

  16. Green House Gases Measurement At Maitri, Antarctica

    Science.gov (United States)

    Jain, S. L.; Ghude, S. D.; Arya, B. C.

    The earth's environment is constantly changing. The scientific evidence indicates that these changes are result of a complex interplay among a number of natural and human related systems. Therefore in the recent times, concern has grown about global change - which is related to natural and anthropogenic alteration of the Earth's environment. Among them the important issues, which are dangerous for the survival of life on the earth, are global green house warming, urban and regional atmospheric pollution, regional increases in tropospheric ozone, the decrease in stratospheric ozone in general and ozone hole over Antarctica in particular, acid rain etc. The monitoring of green house gases has an important role in the understanding of global change. The green house effect of CO_2 increase which has been the subject of scientific studies since later half of the nineteenth century but the CO_2 problem gained tremendous momentum during last two decades. Now it has been recognized that the green house effect due to trace gases such as CFC's, CH_4, O_3, N_2O, H_2O etc. is as much as that due to CO_2 while it was only due to CO_2 during pre industrial era to 1950's. In view of the above various state of art systems have been set up at Maitri, Antarctica for measurements of various green house gases, column ozone, water vapour, UV-B radiation, aerosol optical depth and vertical profiles of ozone which in turn will go a long way to fill in the gaps and provide valuable data for modeling studies. An automated gas chromatograph based experiment was setup in January 2002 at Maitri, for the measurements of green house gases, such as Carbon Dioxide (CO_2), Methane (CH_4) etc. The average concentration of CO_2 during the year 2002 is found out to be 367.42 ppm and average concentration of CH_4 from February to May 2003 is found out to be 1.69 ppm. An increase of about 1.6 ppm of CO_2 concentration was observed during the year 2002. The hourly mean mixing ratios of CO was found in

  17. Surface dependency in thermodynamics of ideal gases

    International Nuclear Information System (INIS)

    Sisman, Altug

    2004-01-01

    The Casimir-like size effect rises in ideal gases confined in a finite domain due to the wave character of atoms. By considering this effect, thermodynamic properties of an ideal gas confined in spherical and cylindrical geometries are derived and compared with those in rectangular geometry. It is seen that an ideal gas exhibits an unavoidable quantum surface free energy and surface over volume ratio becomes a control variable on thermodynamic state functions in microscale. Thermodynamics turns into non-extensive thermodynamics and geometry difference becomes a driving force since the surface over volume ratio depends on the geometry

  18. Multi-layer Retrievals of Greenhouse Gases from a Combined Use of GOSAT TANSO-FTS SWIR and TIR

    Science.gov (United States)

    Kikuchi, N.; Kuze, A.; Kataoka, F.; Shiomi, K.; Hashimoto, M.; Suto, H.; Knuteson, R. O.; Iraci, L. T.; Yates, E. L.; Gore, W.; Tanaka, T.; Yokota, T.

    2016-12-01

    The TANSO-FTS sensor onboard GOSAT has three frequency bands in the shortwave infrared (SWIR) and the fourth band in the thermal infrared (TIR). Observations of high-resolution spectra of reflected sunlight in the SWIR are extensively utilized to retrieve column-averaged concentrations of the major greenhouse gases such as carbon dioxide (XCO2) and methane (XCH4). Although global XCO2 and XCH4 distribution retrieved from SWIR data can reduce the uncertainty in the current knowledge about sources and sinks of these gases, information on the vertical profiles would be more useful to constrain the surface flux and also to identify the local emission sources. Based on the degrees of freedom for signal, Kulawik et al. (2016, IWGGMS-12 presentation) shows that 2-layer information on the concentration of CO2 can be extracted from TANSO-FTS SWIR measurements, and the retrieval error is predicted to be about 5 ppm in the lower troposphere. In this study, we present multi-layer retrievals of CO2 and CH4 from a combined use of measurements of TANSO-FTS SWIR and TIR. We selected GOSAT observations at Railroad Valley Playa in Nevada, USA, which is a vicarious calibration site for TANSO-FTS, as we have various ancillary data including atmospheric temperature and humidity taken by a radiosonde, surface temperature, and surface emissivity with a ground based FTS. All of these data are useful especially for retrievals using TIR spectra. Currently, we use the 700-800 cm-1 and 1200-1300 cm-1 TIR windows for CO2 and CH4 retrievals, respectively, in addition to the SWIR bands. We found that by adding TIR windows, 3-layer information can be extracted, and the predicted retrieval error in the CO2 concentration was reduced about 1 ppm in the lower troposphere. We expect that the retrieval error could be further reduced by optimizing TIR windows and by reducing systematic forward model errors.

  19. Vapour-phase crystallisation of silica from SiF4-bearing volcanic gases

    Directory of Open Access Journals (Sweden)

    M. H. G. Jacobs

    2005-06-01

    Full Text Available Thermodynamic modelling of magmatic gases shows that SiF4 may be an important F-bearing species at the high pressures typical of magma reservoirs. Upon decompression during degassing, SiF4 will react with water vapour to form HF and silica. Common magmatic gases of high-T fumaroles seem to contain too little SiF4 to be a significant source of silica, except if extremely large amounts of gas percolate through a small volume of rock, as is the case in lava domes. Only if fluorine contents of the gases exceed 1 mol% detectable amounts of silica may be formed, but such high fluorine contents have not yet been observed in natural gases. Alternatively, silica may be formed by heating of cool SiF4-rich gases circulating in cooling lava bodies. We suggest that these mechanisms may be responsible for the deposition of crystalline silica, most probably cristobalite, observed in vesicles in lavas from Lewotolo volcano (Eastern Sunda Arc, Indonesia. Silica occurs as vapour-crystallised patches in vesicles, and is sometimes associated with F-phlogopite, which further supports F-rich conditions during deposition. Because of the connection between F-rich conditions and high-K volcanism, we propose that late-stage gaseous transport and deposition of silica may be more widespread in K-rich volcanoes than elsewhere, and long-term exposure to ash from eruptions of such volcanoes could therefore carry an increased risk for respiratory diseases. The dependence of SiF4/HF on temperature reported here differs from the current calibration used for temperature measurements of fumarolic gases by remote sensing techniques, and we suggest an updated calibration.

  20. The electricity cogeneration in sugar mills and alcohol and the reduction of emissions of greenhouse gases

    International Nuclear Information System (INIS)

    Valdés Delgado, Antonio

    2015-01-01

    Electric power in Cuba currently produces -in high proportion- plants employing fossil fuel. The price of fossil fuels and the negative influence on the environment by emissions of greenhouse gases, has indicated the need to develop other energy sources. Biomass sugarcane provides ample opportunities to produce this energy with positive economic and environmental results. The technological process for the production of sugar requires the use of mechanical energy, low power consumption compared to thermal energy requirements and their use at low pressures determine the possibility of implementing a cogeneration system of mechanical, thermal and electrical energy. The power consumption for the driving equipment of a factory is about 15-30 kw-kr / ton rod. The amount of electrical energy generated in a sugar cane factory is sufficient to meet their own needs, being able to obtain an additional amount for supply to the public network and meet the needs of other productions as is alcohol. Agricultural crop residues (RAC) and sugarcane bagasse and a liquid fuel: alcohol and gaseous fuel: different energy possibilities derived from the sugar industry reflected in the disposal of solid fuels such as is the biogas. The preparation of solid, liquid and gaseous fuels from sugar and alcohol production avoids the use of fossil fuels such as gasoline and fuel oil and gas enables not be sent into the atmosphere that impact on the greenhouse effect. (full text)

  1. Air-sea gas transfer for gases of varying solubility

    Science.gov (United States)

    Rutgersson, Anna; Sahlee, Erik; Andersson, Andreas; Podgrajsek, Eva

    2014-05-01

    CombiCombination of surface water cooling and a deep ocean mixed layer generates convective eddies scaling with the depth of a mixed layer that enhances the efficiency of the air-sea gas transfer. This enhancement is explained by the convective eddies disturbing the molecular diffusion layer and inducing increased turbulent mixing in the water (Rutgersson et al 2011). The enhancement can be introduced into existing formulations for calculating the air-sea exchange of gases by using an additional resistance, due to large-scale convection acting in parallel with other processes. The additional resistance is expressed by the convective velocity scale of the water and the friction velocity and characterizes the relative role of surface shear and buoyancy forces. We use direct flux measurements by the Eddy-Covariance method (EC), we use gases of varying solubility (carbon dioxide, methane and water vapor). New methodology allows also to introduce EC measurements of oxygen (Andersson et al., 2014). Water-side convection is of particular interest for the low to moderate wind-speed regime, when spray and bubbles have less dominance of the efficiency of the transfer. It is also possible that gases of different solubility shows a different response to various forcing mechanisms. Lake data of methane fluxes exhibits a stronger diurnal cycle than CO2 as a response to the strong diurnal cycle of water-side convection (Podgrajsek et al., 2014). Calculated fluxes from the Baltic Sea basin shows an altered diurnal cycle when introducing the convection. The potential need of taking processes into account generating turbulence of a larger scale, such as water-side convection or Langmuir circulation introduced larger requirements on the remote sensing products used for air-sea gas flux climatologies. Andersson, A. Rutgersson A. and Sahlee, E. Using a high frequency fluorescent oxygen probe in atmospheric eddy covariance applications. Submitted 2014. Podgrajsek, E., E. Sahlée and A

  2. Method for monitoring stack gases for uranium activity

    International Nuclear Information System (INIS)

    Beverly, C.R.; Ernstberger, H.G.

    1988-01-01

    A method for sampling stack gases emanating from the purge cascade of a gaseous diffusion cascade system utilized to enrich uranium for determining the presence and extent of uranium in the stack gases in the form of gaseous uranium hexafluoride, is described comprising the steps of removing a side stream of gases from the stack gases, contacting the side stream of the stack gases with a stream of air sufficiently saturated with moisture for reacting with and converting any gaseous uranium hexafluroide contracted thereby in the side stream of stack gases to particulate uranyl fluoride. Thereafter contacting the side stream of stack gases containing the particulate uranyl fluoride with moving filter means for continuously intercepting and conveying the intercepted particulate uranyl fluoride away from the side stream of stack gases, and continually scanning the moving filter means with radiation monitoring means for sensing the presence and extent of particulate uranyl fluoride on the moving filter means which is indicative of the extent of particulate uranyl fluoride in the side stream of stack gases which in turn is indicative of the presence and extent of uranium hexafluoride in the stack gases

  3. Evidence for a mantle component shown by rare gases, C and N isotopes in polycrystalline diamonds from Orapa (Botswana) [rapid communication

    Science.gov (United States)

    Gautheron, Cécile; Cartigny, Pierre; Moreira, Manuel; Harris, Jeff. W.; Allègre, Claude J.

    2005-12-01

    In an attempt to constrain the origin of polycrystalline diamond, combined analyses of rare gases and carbon and nitrogen isotopes were performed on six such diamonds from Orapa (Botswana). Helium shows radiogenic isotopic ratios of R/Ra = 0.14-1.29, while the neon ratios ( 21Ne/ 22Ne of up to 0.0534) reflect a component from mantle, nucleogenic and atmospheric sources. 40Ar/ 36Ar ratios of between 477 and 6056 are consistent with this interpretation. The ( 129Xe/ 130Xe) isotopic ratios range between 6.54 and 6.91 and the lower values indicate an atmospheric component. The He, Ne, Ar and Xe isotopic compositions and the Xe isotopic pattern are clear evidence for a mantle component rather than a crustal one in the source of the polycrystalline diamonds from Orapa. The δ 13C and δ 15N isotopic values of - 1.04 to - 9.79‰ and + 4.5 to + 15.5‰ respectively, lie within the range of values obtained from the monocrystalline diamonds at that mine. Additionally, this work reveals that polycrystalline diamonds may not be the most appropriate samples to study if the aim is to consider the compositional evolution of rare gases through time. Our data shows that after crystallization, the polycrystalline diamonds undergo both gas loss (that is more significant for the lighter rare gases such as He and Ne) and secondary processes (such as radiogenic, nucleogenic and fissiogenic, as well as atmospheric contamination). Finally, if polycrystalline diamonds sampled an old mantle (1-3.2 Ga), the determined Xe isotopic signatures, which are similar to present MORB mantle - no fissiogenic Xe from fission of 238U being detectable - imply either that Xe isotopic ratios have not evolved within the convective mantle since diamond crystallization, or that these diamonds are actually much younger.

  4. Treatment of tritiated exhaust gases at the Tritium Laboratory Karlsruhe

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, E.; Besserer, U. [Kernforschungszentrum Karlsruhe GmbH (Germany); Jacqmin, G. [NUKEM GmbH, Industreistr, Alzenau (Germany)

    1995-02-01

    The Tritium Laboratory Karlsruhe (TLK) accomplished commissioning; tritium involving activities will start this year. The laboratory is destined mainly to investigating processing of fusion reactor fuel and to developing analytic devices for determination of tritium and tritiated species in view of control and accountancy requirements. The area for experimental work in the laboratory is about 800 m{sup 2}. The tritium infrastructure including systems for tritium storage, transfer within the laboratory and processing by cleanup and isotope separation methods has been installed on an additional 400 m{sup 2} area. All tritium processing systems (=primary systems), either of the tritium infrastructure or of the experiments, are enclosed in secondary containments which consist of gloveboxes, each of them connected to the central depressurization system, a part integrated in the central detritiation system. The atmosphere of each glovebox is cleaned in a closed cycle by local detritiation units controlled by two tritium monitors. Additionally, the TLK is equipped with a central detritiation system in which all gases discharged from the primary systems and the secondary systems are processed. All detritiation units consist of a catalyst for oxidizing gaseous tritium or tritiated hydrocarbons to water, a heat exchanger for cooling the catalyst reactor exhaust gas to room temperature, and a molecular sieve bed for adsorbing the water. Experiments with tracer amounts of tritium have shown that decontamination factors >3000 can be achieved with the TLK detritiation units. The central detritiation system was carefully tested and adjusted under normal and abnormal operation conditions. Test results and the behavior of the tritium barrier preventing tritiated exhaust gases from escaping into the atmosphere will be reported.

  5. Corrosion by cooling gases in nuclear reactors

    International Nuclear Information System (INIS)

    Darras, R.

    1960-01-01

    This article begins with a review of the various materials which can be used and the cooling gases in which they may be heated, emphasis being placed on the importance of reaching temperatures as high as possible. This is followed by a few general remarks on the dry oxidation of metals and alloys, particularly with regard to diffusion phenomena and their various possible mechanisms, and also the methods of investigation employed. Finally, the behaviour of the chief nuclear materials heated in the various gases is studied successively. Materials used for fuel (metallic uranium, uranium oxide, carbides and silicides), canning materials (magnesium, aluminium, zirconium, beryllium, stainless and refractory steels), structural materials (ordinary or slightly alloyed steels), and finally moderators (graphite, beryllium oxide) are deal with in this way. This account is backed up both by the results obtained at the CEA and by work published outside or abroad up to the present day. In conclusion, every effort has been made to direct future research on the basis of the foregoing. Reprint of a paper published in Industries Atomiques - no. 9/10, 1959, p. 3-23 [fr

  6. Subcooled boiling effect on dissolved gases behaviour

    International Nuclear Information System (INIS)

    Zmitko, M.; Sinkule, J.; Linek, V.

    1999-01-01

    A model describing dissolved gasses (hydrogen, nitrogen) and ammonia behaviour in subcooled boiling conditions of WWERs was developed. Main objective of the study was to analyse conditions and mechanisms leading to formation of a zone with different concentration of dissolved gases, eg. a zone depleted in dissolved hydrogen in relation to the bulk of coolant. Both, an equilibrium and dynamic approaches were used to describe a depletion of the liquid surrounding a steam bubble in the gas components. The obtained results show that locally different water chemistry conditions can be met in the subcooled boiling conditions, especially, in the developed subcooled boiling regime. For example, a 70% hydrogen depletion in relation to the bulk of coolant takes about 1 ms and concerns a liquid layer of 1 μn surrounding the steam bubble. The locally different concentration of dissolved gases can influence physic-chemical and radiolytic processes in the reactor system, eg. Zr cladding corrosion, radioactivity transport and determination of the critical hydrogen concentration. (author)

  7. Positron Cooling and Annihilation in Noble Gases.

    Science.gov (United States)

    Green, D G

    2017-11-17

    Positron cooling and annihilation in room temperature noble gases is simulated using accurate scattering and annihilation cross sections calculated with many-body theory, enabling the first simultaneous probing of the energy dependence of the scattering and annihilation cross sections. A strikingly small fraction of positrons is shown to survive to thermalization: ∼0.1 in He, ∼0 in Ne, ∼0.15 in Ar, ∼0.05 in Kr, and ∼0.01 in Xe. For Xe, the time-varying annihilation rate Z[over ¯]_{eff}(τ) is shown to be highly sensitive to the depletion of the momentum distribution due to annihilation, conclusively explaining the long-standing discrepancy between gas-cell and trap-based measurements. Overall, the use of the accurate atomic data gives Z[over ¯]_{eff}(τ) in close agreement with experiment for all noble gases except Ne, the experiment for which is proffered to have suffered from incomplete knowledge of the fraction of positrons surviving to thermalization and/or the presence of impurities.

  8. 46 CFR 194.15-17 - Compressed gases other than inert gases.

    Science.gov (United States)

    2010-10-01

    ... particular operation, compressed gases are needed within the laboratory, the cylinders may be temporarily installed in the laboratory, provided no more than one (1) cylinder of each gas is in the laboratory simultaneously. When transporting compressed gas cylinders to, from, or within the vessel, the cylinder valves...

  9. From additivity to synergism

    DEFF Research Database (Denmark)

    Ritz, Christian; Streibig, Jens Carl

    2014-01-01

    Interest in synergistic or antagonistic effects through mixture experiments has grown immensely over the past two decades, not the least within in pharmacology and toxicology. Several definitions of reference models exist; one commonly used reference model is concentration or dose addition, which...... assumes compounds, when administrated simultaneously, do not interfere with each other at the site of action. We focus on statistical modelling that allows evaluation of dose addition. We will describe several statistical approaches that are suitable for analysis mixture data where synergistic...... or antagonistic effects may be present. The statistical models are defined and explained and some of the approaches exemplified. Code in open-source software is provided....

  10. International collaboration on capture, storage and utilization of greenhouse gases

    International Nuclear Information System (INIS)

    Freund, P.

    1998-01-01

    Climate change will have world-wide implications. So it is highly appropriate that there should be international collaboration to investigate technologies for reducing emissions of greenhouse gases, the root cause of the problem. Sixteen countries, as well as three industrial sponsors, support the IEA Greenhouse Gas R and D Program and, in many cases, industry is also involved indirectly, through the national memberships. This provides a broad range of interest and expertise to guide the management of the Program, as well as ensuring that the results reach a wide audience. The IEA Greenhouse Gas R and D Program has three main activities: (1) evaluation of technologies for mitigation of greenhouse gas emissions from use of fossil fuels; (2) dissemination of the results of these studies; (3) identification of targets for research, development and demonstration and promotion of these findings. In its first five years of operation, the Program has studied the major greenhouse gases, carbon dioxide and methane, and various means of reducing their emissions. The main emphasis has been placed on capture, storage and utilization of CO 2 from power generation. This option is now much better understood and can be compared with more established measures, such as fuel switching, energy efficiency improvements and use of renewable energy. As well as studying abatement of CO 2 emissions, the Program has conducted a series of studies of technologies for reducing CH 4 emissions from man-made sources. The Program's activities are carried out by the Operating Agent, who develops and manages a series of technical studies to meet members' requirements

  11. Efeito de fontes e de aditivos na absorção de 35S via foliar pelo feijoeiro Sources and additive effects on 35S foliar uptake by bean plants

    Directory of Open Access Journals (Sweden)

    J.A. de Oliveira Jr.

    1995-12-01

    Full Text Available Foi conduzido em casa de vegetação um experimento com o objetivo de avaliar o efeito de fontes de enxofre, na presença ou não de aditivos (uréia e glicose, sobre a absorção do demento pelas folhas de feijoeiro. Os tratamentos: soluções de ácido sulfúrico e de sulfates de amonio, potássio, magnésio, manganês e zinco marcadas com 35S, contendo ou não os aditivos, foram aplicados ao primeiro trifólio das plantas para avaliar a absorção e translocação de enxofre. Os resultados permitiram concluir que 33% do S adicionado foi absorvido, e desse total 27% foi translocado, não havendo influência dos aditivos sobre esses processos. O ácido sulfúrico e o sulfato de amonio destacaram-se como os melhores fornecedores de enxofre, via foliar, para o feijoeiro.A greenhouse experiment was carried out with the aim of evaluating the effect of sulphur sources, in the presence or absence of additives (urea and glucose, on the sulphur uptake by bean leaves. The treatments: solutions of sulphuric acid, ammonium, potassium, magnesium, manganese and zinc sulphates labelled with 35S, containing or not the additives, were applied to the first trifoliate of the plants to assess the sulphur uptake and translocation. The results enable to conclude that 33% of the added sulphur was absorved, and 27% out of this total was translocated. The additives did not have any influence on uptake and translocation. The sulphuric acid and ammonium sulphate solutions were the best sulphur suppliers for the bean plant.

  12. The Effect of Firearm Muzzle Gases on the Backspatter of Blood

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, M.C.; Laber, T.L.; Epstein, B.P.; Zamzow, D.S.; Baldwin, D.P.

    2010-05-12

    Injuries caused by gunshots can produce what bloodstain pattern analysts know as 'backspatter.' Observations about the presence or absence of backspatter on an individual may be used in court as evidence of guilt or innocence. The discharge of three firearms (.22 caliber revolver, .38 caliber revolver, and .308 caliber rifle) and the resulting impact of bullets on a blood source were recorded using high-speed digital video imaging. Blood droplets, firearm muzzle gases, and ballistic shock waves were visualized using standard reflected light and shadowgraphy imaging techniques. A significant interaction between air currents, muzzle gases, and particulate material emanating from the firearms upon discharge with backspattered blood was observed. Blood droplets, initially spattered back toward the firearm and the shooter, were observed to change direction under the influence of firearm-induced air currents and were blown forward toward and beyond their original source location. Implications for experts testifying in court and for bloodstain pattern instructors are discussed.

  13. Renewable energies in electricity generation for reduction of greenhouse gases in Mexico 2025.

    Science.gov (United States)

    Islas, Jorge; Manzini, Fabio; Martínez, Manuel

    2002-02-01

    This study presents 4 scenarios relating to the environmental futures of electricity generation in Mexico up to the year 2025. The first scenario emphasizes the use of oil products, particularly fuel oil, and represents the historic path of Mexico's energy policy. The second scenario prioritizes the use of natural gas, reflecting the energy consumption pattern that arose in the mid-1990s as a result of reforms in the energy sector. In the third scenario, the high participation of renewable sources of energy is considered feasible from a technical and economic point of view. The fourth scenario takes into account the present- and medium-term use of natural-gas technologies that the energy reform has produced, but after 2007 a high and feasible participation of renewable sources of energy is considered. The 4 scenarios are evaluated up to the year 2025 in terms of greenhouse gases (GHG) and acid rain precursor gases (ARPG).

  14. Remote Sensing of Spatial Distributions of Greenhouse Gases in the Los Angles Basin

    Science.gov (United States)

    Fu, Dejian; Pongetti, Thomas J.; Sander, Stanley P.; Cheung, Ross; Stutz, Jochen; Park, Chang Hyoun; Li, Qinbin

    2011-01-01

    The Los Angeles air basin is a significant anthropogenic source of greenhouse gases and pollutants including CO2, CH4, N2O, and CO, contributing significantly to regional and global climate change. Recent legislation in California, the California Global Warming Solutions Act (AB32), established a statewide cap for greenhouse gas emissions for 2020 based on 1990 emissions. Verifying the effectiveness of regional greenhouse gas emissions controls requires high-precision, regional-scale measurement methods combined with models that capture the principal anthropogenic and biogenic sources and sinks. We present a novel approach for monitoring the spatial distributions of greenhouse gases in the Los Angeles basin using high resolution remote sensing spectroscopy. We participated in the CalNex 2010 campaign to provide greenhouse gas distributions for comparison between top-down and bottom-up emission estimates.

  15. Reducing the Livestock related green house gases emission

    Directory of Open Access Journals (Sweden)

    D Indira

    2012-08-01

    Full Text Available Cattle rearing generate more global warming green house gases than driving cars. These green house gases leads to changes in the climate. This climate change affects the livestock, man and natural environment continuously. For this reason it is important for livestock farmers to find the ways which minimize these gases emission. In this article the causes of climate change and effects, measures to be taken by farmers and their efficiency in reducing green house gases emission were reviewed briefly to make the farmers and students aware of the reduction of global warming green house gases and measures to be taken for reducing these gases. [Vet. World 2012; 5(4.000: 244-247

  16. [Regulations on gases for medical use in France].

    Science.gov (United States)

    Poitou, P; Fouret, C; Duffau, E

    2002-09-01

    In 1989, a European directive extended the definition of proprietary medicinal products, and consequently the necessity to hold a marketing authorization (MA), for all industrially manufactured products, including medicinal gases. In France, the directive 89/341/CEE was transposed in the French law on December 8(th), 1992 and France was the first Member State to implement provisions for the obtention of MAs for gases for medical use. Since then, France has stayed at the forefront in this area. Following the inclusion of gases in the scope of pharmaceutical products, gases require on MA obtained following the same methods as for drugs and be manufactured and distributed in authorized sites. Moreover, the European directive has led the French authorities to classify gases according to their use. Gases for medical use are thus considered either as medicinal products or as medical devices.

  17. Soil greenhouse gases emissions reduce the benefit of mangrove plant to mitigating atmospheric warming effect

    OpenAIRE

    Chen, Guangcheng; Chen, Bin; Yu, Dan; Ye, Yong; Tam, Nora F. Y.; Chen, Shunyang

    2016-01-01

    Mangrove soils have been recognized as sources of atmospheric greenhouse gases but the atmospheric fluxes are poorly characterized, and their adverse warming effect has scarcely been considered with respect to the role of mangrove wetlands in mitigating global warming. The present study balanced the warming effect of soil greenhouse gas emissions with plant carbon dioxide (CO2) sequestration rate in a highly productive mangrove wetland in South China to assess the role of mangrove wetland in ...

  18. PROSPECTS FOR USE OF CONDENSED GASES AND SUPERCRITICAL FLUIDS IN PHYTOCHEMICAL PRODUCTION

    OpenAIRE

    Demyanenko DV; Breusova SV; Karpenko LA

    2017-01-01

    In the given review article analysis of the literature and patent sources concerning main methods for intensification of extraction processes of medicinal vegetative raw materials – use of condensed gases and supercritical fluids (SCF) on more acceptable extractants has been carried out for last 20 years. Urgency of the specified technologies consists in need for replacement of traditional extraction methods on power- and time-saving ones, and also in use of nontoxic, fire-proof and low-boili...

  19. Offsets : An innovative approach to reducing greenhouse gases

    International Nuclear Information System (INIS)

    Steward, B.

    1998-01-01

    One of the most innovative ways to address climate change is the use of offsets, which refers to actions taken outside of a company's operations, domestically and internationally, to reduce greenhouse gas emissions. This paper is devoted to a discussion of Suncor Energy's action plan for greenhouse gases which include offsets, and to an explanation of the reasons why offsets are fundamental to successful greenhouse gas management. Suncor Energy Inc., has developed a plan with seven elements to meet their target of stabilizing their greenhouse gas emissions at 1990 levels by year 2000. The seven elements include: (1) energy efficiency and process improvements at their oil sands facility, (2) the development of alternative and renewable sources of energy, such as ethanol blended gasolines and the use of wind turbines to generate electricity, (3) promoting environmental and economic research to develop more advanced oil and gas technology to reduce greenhouse gas emissions, (4) implementing a constructive public policy input in support of sustainable development, (5) educating employees, customers and communities on global climate change, (6) measuring and reporting the company's environmental progress, and (7) pursuing domestic and international offset opportunities such as transfer of technology to developing countries, cogeneration of energy using natural gas, energy efficiency, renewable energy sources, emission reduction purchases and forest conservation. Of these proposed measures, offsets are the critical element which could spell the difference between success and failure in managing greenhouse gas emissions and the difference between economic hardship and economic opportunity

  20. Greenhouse gases: How does heavy oil stack up?

    International Nuclear Information System (INIS)

    Ottenbreit, R.J.

    1991-01-01

    Life-cycle emissions of direct greenhouse gases (GHG) have been calculated to elucidate the global warming impacts of various fossil fuel feedstocks. Calculations were made for the transportation sector using five fossil fuel sources: natural gas, light crude oil, conventional heavy oil, crude bitumen recovered through in-situ steam stimulation, and crude bitumen recovered through mining. Results suggest that fuels sourced from light crude oil have the lowest GHG emissions, while conventional heavy oil has the highest GHG emission levels for this application. Emissions of methane can constitute a significant portion of the life-cycle GHG emissions of a fossil fuel. For all the fossil fuels examined, except conventional heavy oil, GHG emissions associated with their production, transport, processing, and distribution are less than one third of their total life-cycle emissions. The remainder is associated with end use. This confirms that consumers of fossil fuel products, rather than fossil fuel producers, have the most leverage to reduce GHG emissions. 2 figs

  1. Dry additives-reduction catalysts for flue waste gases originating from the combustion of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Hard coal is the basic energy generating raw material in Poland. In 1990, 60% of electricity and thermal energy was totally obtained from it. It means that 100 million tons of coal were burned. The second position is held by lignite - generating 38% of electricity and heat (67.3 million tons). It is to be underlined that coal combustion is particularly noxious to the environment. The coal composition appreciably influences the volume of pollution emitted in the air. The contents of incombustible mineral parts - ashes - oscillates from 2 to 30%; only 0.02 comes from plants that had once originated coal and cannot be separated in any way. All the rest, viz. the so-called external mineral substance enters the fuel while being won. The most indesirable hard coal ingredient is sulfur whose level depends on coal sorts and its origin. The worse the fuel quality, the more sulfur it contains. In the utilization process of this fuel, its combustible part is burnt: therefore, sulfur dioxide is produced. At the present coal consumption, the SO{sub 2} emission reaches the level of 3.2 million per year. The intensifies the pressure on working out new coal utilization technologies, improving old and developing of pollution limiting methods. Research is also directed towards such an adaptation of technologies in order that individual users may also make use thereof (household furnaces) as their share in the pollution emission is considerable.

  2. 49 CFR 173.302a - Additional requirements for shipment of nonliquefied (permanent) compressed gases in...

    Science.gov (United States)

    2010-10-01

    ...; d = D-2t, where t=minimum wall thickness determined by a suitable method. (iii) Compliance with.... A DOT 3AL cylinder is authorized only when transported by motor vehicle, rail car, or cargo-only...

  3. Calibration of new measuring systems to detect emissions of radioactive noble gases

    International Nuclear Information System (INIS)

    Winkelmann, I.; Kreiner, H.J.

    1977-12-01

    This report describes the calibration of different systems for the integral measurement of radioactive noble gases and the calibration of a measuring chamber for the detection of individual nuclides of radioactive noble gases in the gaseous effluent of nuclear power plants. For these measuring chambers the calibration factors for Kr-85 and Xe-133 are given as well as the detection limits to be obtained with these measuring systems for several radioactive noble gases present in the gaseous effluent at the stack of nuclear power plants. Calibration factors for Kr-85 and Xe-133 and the detection limits of this measuring method for the detections of individual nuclides of radioactive noble gases in air samples are defined taken wirh a high pressure compressor in pressure flasks an measured on a Ge(Li)-semiconductor spectrometer (pressure flask measuring method). A measuring equipment is described and calibrated which allows simultaneous measurement of activity concentration of radioactive noble gases and radioactive aerosols with a sensitivity of 2 x 10 -7 Ci/m 3 for radioactive gases and 1 x 10 -9 Ci/m 3 for radioactive particulates at a background radiation of 1 R/h. This paper is an additional report to our STH-Bericht 3/76, 'Calibration of measuring equipment for monitoring of gaseous effluents from nuclear power plants', which specifies a procedure for the calibration of measuring chambers for monitoring of gaseous radioactive effluents from nuclear power plants /1/. The calibration system used here makes it possible to simultaneously calibrate several noble gas measuring devices. (orig.) [de

  4. Temporal variations of atmospheric greenhouse gases and their related gases at Syowa Station, Antarctica and Ny-Alesund, Svalbard.

    Directory of Open Access Journals (Sweden)

    Shinji Morimoto

    2010-12-01

    Full Text Available To elucidate temporal variations of greenhouse gases and their related gases in the Arctic and Antarctic regions and to investigate their sources and sinks, systematic measurements of atmospheric CO_2, CH_4CO, N_2O, O_2 and tropospheric O_3 concentrations have been carried out at Syowa Station, Antarctica and Ny-Alesund, Svalbard. The CO_2 concentrations at both polar sites have increased at a rate of about 1.9 ppmv yr^, reflecting fossil fuel combustion and land use change. The CH_4 concentrations also showed clear seasonal cycles superimposed on complex secular trends. The increase rate of the CH_4 concentration varied with time. CH_4 increases were observed until 1999, the concentrations remained steady from 2000 to 2006 and then rapid increases were observed in 2007. Stable isotope data of CH_4 revealed causes of the seasonal cycles and the secular variations of the CH_4 concentrations. The O_2 concentrations (δ(O_2 N_2 at both polar sites showed prominent seasonal cycles and secular decreasing trends. From analyses of the Atmospheric Potential Oxygen (APO and CO_2 concentrations, the CO_2 uptake rates by the terrestrial biosphere and the ocean were estimated to be 1.1 and 2.7 GtC yr^, respectively. By comparing the N_2O concentrations observed at Ny-Alesund and numerical model results, it was suggested that the observed seasonal N_2O cycle could be enlarged by intrusion of a stratospheric air mass with low N_2O concentration into the troposphere in summer. With an analysis using a three dimensional chemical-transport model and the CO concentration at Syowa Station, sporadic increases of CO concentration observed in February-March, 2003 and February, 2007 were ascribed to CO release by large-scale forest fires in Australia. Surface ozone depletion events were observed more than 40 times at Syowa Station from 1988 to 2007.

  5. Microscopy of 2D Fermi gases. Exploring excitations and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Morgener, Kai Henning

    2014-12-08

    This thesis presents experiments on three-dimensional (3D) and two-dimensional (2D) ultracold fermionic {sup 6}Li gases providing local access to microscopic quantum many-body physics. A broad magnetic Feshbach resonance is used to tune the interparticle interaction strength freely to address the entire crossover between the Bose-Einstein-Condensate (BEC) and Bardeen-Cooper-Schrieffer (BCS) regime. We map out the critical velocity in the crossover from BEC to BCS superfluidity by moving a small attractive potential through the 3D cloud. We compare the results with theoretical predictions and achieve quantitative understanding in the BEC regime by performing numerical simulations. Of particular interest is the regime of strong correlations, where no theoretical predictions exist. In the BEC regime, the critical velocity should be closely related to the speed of sound, according to the Landau criterion and Bogolyubov theory. We measure the sound velocity by exciting a density wave and tracking its propagation. The focus of this thesis is on our first experiments on general properties of quasi-2D Fermi gases. We realize strong vertical confinement by generating a 1D optical lattice by intersecting two blue-detuned laser beams under a steep angle. The large resulting lattice spacing enables us to prepare a single planar quantum gas deeply in the 2D regime. The first measurements of the speed of sound in quasi-2D gases in the BEC-BCS crossover are presented. In addition, we present preliminary results on the pressure equation of state, which is extracted from in-situ density profiles. Since the sound velocity is directly connected to the equation of state, the results provide a crosscheck of the speed of sound. Moreover, we benchmark the derived sound from available equation of state predictions, find very good agreement with recent numerical calculations, and disprove a sophisticated mean field approach. These studies are carried out with a novel apparatus which has

  6. Properties of gases, liquids, and solutions principles and methods

    CERN Document Server

    Mason, Warren P

    2013-01-01

    Physical Acoustics: Principles and Methods, Volume ll-Part A: Properties of Gases, Liquids, and Solutions ponders on high frequency sound waves in gases, liquids, and solids that have been proven as effective tools in examining the molecular, domain wall, and other types of motions. The selection first offers information on the transmission of sound waves in gases at very low pressures and the phenomenological theory of the relaxation phenomena in gases. Topics include free molecule propagation, phenomenological thermodynamics of irreversible processes, and simultaneous multiple relaxation pro

  7. Hydrogen Peroxide Enhances Removal of NOx from Flue Gases

    Science.gov (United States)

    Collins, Michelle M.

    2005-01-01

    Pilot scale experiments have demonstrated a method of reducing the amounts of oxides of nitrogen (NOx) emitted by industrial boilers and powerplant combustors that involves (1) injection of H2O2 into flue gases and (2) treatment of the flue gases by caustic wet scrubbing like that commonly used to remove SO2 from combustion flue gases. Heretofore, the method most commonly used for removing NOx from flue gases has been selective catalytic reduction (SCR), in which the costs of both installation and operation are very high. After further development, the present method may prove to be an economically attractive alternative to SCR.

  8. Valorisation of CO2-rich off-gases to biopolymers through biotechnological process.

    Science.gov (United States)

    Garcia-Gonzalez, Linsey; De Wever, Heleen

    2017-11-01

    As one of the key enabling technologies, industrial biotechnology has a high potential to tackle harmful CO2 emissions and to turn CO2 into a valuable commodity. So far, experimental work mainly focused on the bioconversion of pure CO2 to chemicals and plastics and little is known about the tolerance of the bioprocesses to the presence of impurities. This work is the first to investigate the impact of real CO2-rich off-gases on autotrophic production of polyhydroxybutyrate. To this end, two-phase heterotrophic-autotrophic fermentation experiments were set up, consisting of heterothrophic cell mass growth using glucose as substrate followed by autotrophic biopolymer production using either pure synthetic CO2 or industrial off-gases sampled at two point sources. The use of real off-gases did not affect the bacterial performance. High biopolymer content (up to 73%) and productivities (up to 0.227 g/lh) were obtained. Characterisation of the polymers showed that all biopolymers had similar properties, independent of the CO2 source. Moreover, the CO2-derived biopolymers' properties were comparable to commercial ones and biopolymers reported in literature, which are all produced from organic carbon sources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. 1988 Pilot Institute on Global Change on trace gases and the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, J.A.; Moore, B. III

    1998-07-01

    This proposal seeks multi-agency funding to conduct an international, multidisciplinary 1988 Pilot Institute on Global Change to take place from August 7 through 21, 1988, on the topic: Trace Gases and the Biosphere. The institute, to be held in Snowmass, Colorado, is envisioned as a pilot version of a continuing series of institutes on Global Change (IGC). This proposal seeks support for the 1988 pilot institute only. The concept and structure for the continuing series, and the definition of the 1988 pilot institute, were developed at an intensive and multidisciplinary Summer Institute Planning Meeting in Boulder, Colorado, on August 24--25, 1987. The theme for the 1988 PIGC, Trace Gases and the Biosphere, will focus a concerted, high-level multidisciplinary effort on a scientific problem central to the Global Change Program. Dramatic year-to-year increases in the global concentrations of radiatively-active trace gases such as methane and carbon dioxide are now well documented. The predicted climatic effects of these changes lend special urgency to efforts to study the biospheric sources and sinks of these gases and to clarify their interactions and role in the geosphere-biosphere system.

  10. Renewable energies for reduction of greenhouse gases in the Mexican electricity generation in 2025

    Energy Technology Data Exchange (ETDEWEB)

    Islas, J; Manzini, F; Martinez, M [Centre for Energy Research, UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    This study presents three scenarios relating to the environmental futures of electricity generation in Mexico up to the year 2025. The first scenario emphasizes the use of oil products, particularly fuel oil, and represents the energy policy path that was in effect until 1990. The second scenario prioritizes the use of natural gas, reflecting the energy consumption pattern that arose in the mid-90's as a result of reforms in the energy sector. In the third scenario, the high participation of renewable sources of energy is considered feasible from a technical and economic point of view. The three scenarios are evaluated up to the year 2025 in terms of greenhouse gases (GHG) and acid rain precursor gases (ARPG). [Spanish] Este estudio presenta tres escenarios relacionados de los futuros ambientales de generacion de electricidad en Mexico hasta el ano 2025. El primer escenario enfatiza la utilizacion de productos del petroleo, particularmente el combustoleo, y representa el curso de la politica de energia vigente hasta 1990. El segundo escenario da prioridad al uso de gas natural, reflejando el patron de consumo de energia que surgio a mediados de los 90's como resultado de reformas en el sector energetico. En el tercer escenario, la alta participacion de las fuentes renovables de energia es considerada factible desde los puntos de vista tecnico y economico. Los tres escenarios son evaluados hasta el ano 2025 en terminos de los gases de efecto invernadero (GHG) y de gases precursores de lluvia acida (ARPG).

  11. Greenhouse gases disclosure by listed UK companies

    Directory of Open Access Journals (Sweden)

    Jan Michalak

    2016-12-01

    Full Text Available The article aims to present the issue of voluntary and mandatory disclosure of greenhouse gas emissions in UK companies’ reports and factors influencing it. In order to do it, CDP, CDSB, FRC and DEFRA guidelines are analysed. The article also investigates greenhouse gases disclosures by companies included in the FTSE4Good UK 50 index and factors affecting the amount of the disclosures. The research meth-ods used in the article are content analysis and multiple regression. The results of the research show thatthe vast majority of companies disclose information on the direct and indirect emissions resulting from the purchase of energy (scope 1 and 2 as well as different intensity indicators. Factors influencing signif-icantly the amount of disclosure of greenhouse gas emissions are emissions intensity and company size.

  12. Retention of nitrous gases in scrubber columns

    International Nuclear Information System (INIS)

    Nakazone, A.K.; Costa, R.C.; Lobao, A.S.T.; Matsuda, H.T.; Araujo, B.F. de

    1988-01-01

    During the UO 2 dissolution in nitric acid, some different species of NO (sub)x are released. The off gas can either be refluxed to the dissolver or be released and retained on special colums. The final composition of the solution is the main parameter to take in account. A process for nitrous gases retention using scrubber colums containing H 2 O or diluted HNO 3 is presented. Chemiluminescence measurement was employed to NO x evaluation before and after scrubing. Gas flow, temperature, residence time are the main parameters considered in this paper. For the dissolution of 100g UO 2 in 8M nitric acid, a 6NL/h O 2 flow was the best condition for the NO/NO 2 oxidation with maximum absorption in the scrubber columns. (author) [pt

  13. Monolayer adsorption of noble gases on graphene

    Science.gov (United States)

    Maiga, Sidi M.; Gatica, Silvina M.

    2018-02-01

    We report our results of simulations of the adsorption of noble gases (Kr, Ar, Xe) on graphene. For Kr, we consider two configurations: supported and free-standing graphene, where atoms are adsorbed only on one or two sides of the graphene. For Ar and Xe, we studied only the case of supported graphene. For the single-side adsorption, we calculated the two-dimensional gas-liquid critical temperature for each adsorbate. We determined the different phases of the monolayers and constructed the phase diagrams. We found two-dimensional incommensurate solid phases for krypton, argon and xenon, and a two-dimensional commensurate solid phase for krypton. For double side adsorption of Kr, we do not see evidence of an ordering transition driven by the interlayer forces.

  14. A New Perspective on Classical Ideal Gases

    Directory of Open Access Journals (Sweden)

    Fabrice Philippe

    2013-08-01

    Full Text Available The ideal-gas barometric and pressure laws are derived from the Democritian concept of independent corpuscles moving in vacuum, plus a principle of simplicity, namely that these laws are independent of the kinetic part of the Hamiltonian. A single corpuscle in contact with a heat bath in a cylinder and submitted to a constant force (weight is considered. The paper importantly supplements a previously published paper: First, the stability of ideal gases is established. Second, we show that when walls separate the cylinder into parts and are later removed, the entropy is unaffected. We obtain full agreement with Landsberg’s and others’ (1994 classical thermodynamic result for the entropy of a column of gas submitted to gravity.

  15. Human activities affecting trace gases and climate

    International Nuclear Information System (INIS)

    Braatz, B.; Ebert, C.

    1990-01-01

    The Earth's climate has been in a constant state of change throughout geologic time due to natural perturbations in the global geobiosphere. However, various human activities have the potential to cause future global warming over a relatively short amount of time. These activities, which affect the Earth's climate by altering the concentrations of trace gases in the atmosphere, include energy consumption, particularly fossil-fuel consumption; industrial processes (production and use of chlorofluorocarbons, halons, and chlorocarbons, landfilling of wastes, and cement manufacture); changes in land use patterns, particularly deforestation and biomass burning; and agricultural practices (waste burning, fertilizer usage, rice production, and animal husbandry). Population growth is an important underlying factor affecting the level of growth in each activity. This paper describes how the human activities listed above contribute to atmospheric change, the current pattern of each activity, and how levels of each activity have changed since the early part of this century

  16. Gender and Boyle's law of gases

    CERN Document Server

    Potter, Elizabeth

    2001-01-01

    Gender and Boyle''s Law of GasesElizabeth PotterRe-examines the assumptions and experimental evidence behind Boyle''s Law.Boyle''s Law, which describes the relation between the pressure and volume of a gas, was worked out by Robert Boyle in the mid-1600s. His experiments are still considered examples of good scientific work and continue to be studied along with their historical and intellectual contexts by philosophers, historians, and sociologists. Now there is controversy over whether Boyle''s work was based only on experimental evidence or whether it was influenced by the politics and religious controversies of the time, including especially class and gender politics.Elizabeth Potter argues that even good science is sometimes influenced by such issues, and she shows that the work leading to the Gas Law, while certainly based on physical evidenc...

  17. Voluntary reporting of greenhouse gases 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Voluntary Reporting of Greenhouse Gases Program, required by Section 1605(b) of the Energy Policy Act of 1992, records the results of voluntary measures to reduce, avoid, or sequester greenhouse gas emissions. In 1998, 156 US companies and other organizations reported to the Energy information Administration that, during 1997, they had achieved greenhouse gas emission reductions and carbon sequestration equivalent to 166 million tons of carbon dioxide, or about 2.5% of total US emissions for the year. For the 1,229 emission reduction projects reported, reductions usually were measured by comparing an estimate of actual emissions with an estimate of what emissions would have been had the project not been implemented.

  18. Dosimetry of the radioactive noble gases

    International Nuclear Information System (INIS)

    Soldat, J.K.; Bramson, P.E.; Parker, H.M.

    1973-01-01

    Methods are described that were used for estimations of the radiation dose rate to various human tissues from the radioactive gases of Ar, Kr, and Xe following inhalation or immersion in a semi-infinite cloud. Dose rates to the whole-body, lungs, adipose tissues, and testes were calculated following inhalation; and dose rates to the skin, whole-body, lungs, and testes from a semi-infinite cloud were calculated for 39 Ar, 41 Ar, 83 Kr, 85 Kr, 87 Kr, 88 Kr, 131 Xe, 133 Xe, 135 Xe, 137 Xe, 138 Xe, and also 88 Rb found in equilibrium with its parent 88 Kr and 138 Cs found in equilibrium with its parent 138 Xe. (U.S.)

  19. Kinetic studies of ion - recombination in gases

    Energy Technology Data Exchange (ETDEWEB)

    Caulfield, K.J.; Bhave, R.N.; Cooper, R. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry

    1996-12-31

    Full text: Subsequent to primary ionisation/excitation and dissociation events in irradiated systems, the medium relaxes by various secondary processes which may also be precursors to lasting chemical and physical changes in the system. Pulse radiolysis techniques can be successfully utilised to directly observe such processes so that kinetic parameters may be determined to subsequently accurately model these processes in irradiated systems. Time resolved microwave absorption techniques on a Febetron 706 pulsed electron beam system have been used to study ion recombination in simple gas systems. The microwave absorption method relies on the mobility of charged species within the system and effectively measures an ac-conductivity of the irradiated medium. The technique has a time resolution of about one nanosecond. The decay of conductivity in irradiated gases over the pressure range 50 to 1500 torr has been measured on time scales from 10 nanoseconds to 10 microseconds. Bulk gas pressure and ion densities were such that measurements yielded recombination coefficients for dimeric rare gas cations with thermal electrons. The recombination rate constant, {alpha}{sub T}, is shown to be both independent and dependent on the total pressure in the system ({alpha}{sub T} = {alpha}{sub 2} + {alpha}{sub 3} [M]; {alpha}{sub T} has values up to approx 10{sup +14} L. M{sup -1} s{sup -1} ). Total recombination coefficients {alpha}{sub T} have been measured for the noble gases helium, neon, argon, krypton and xenon. Measurements have also been made for the simple diatomic molecules nitrogen and hydrogen. All the systems studied, except for argon, show both two and three body processes occurring. The three body or assisted process requires the thermalisation of electrons in the neighborhood of the positive ion prior capture. The two body effect is thought to be a radiative or dissociative process. The mechanistic implications of the pulse radiolysis results will be discussed in

  20. Measuring Gases Using Drones at Turrialba Volcano, Costa Rica

    Science.gov (United States)

    Stix, J.; Alan, A., Jr.; Corrales, E.; D'Arcy, F.; de Moor, M. J.; Diaz, J. A.

    2016-12-01

    We are currently developing a series of drones and associated instrumentation to study Turrialba volcano in Costa Rica. This volcano has shown increasing activity during the last 20 years, and the volcano is currently in a state of heightened unrest as exemplified by recent explosive activity in May-August 2016. The eruptive activity has made the summit area inaccessible to normal gas monitoring activities, prompting development of new techniques to measure gas compositions. We have been using two drones, a DJI Spreading Wings S1000 octocopter and a Turbo Ace Matrix-i quadcopter, to airlift a series of instruments to measure volcanic gases in the plume of the volcano. These instruments comprise optical and electrochemical sensors to measure CO2, SO2, and H2S concentrations which are considered the most significant species to help forecast explosive eruptions and determine the relative proportions of magmatic and hydrothermal components in the volcanic gas. Additionally, cameras and sensors to measure air temperature, relative humidity, atmospheric pressure, and GPS location are included in the package to provide meteorological and geo-referenced information to complement the concentration data and provide a better picture of the volcano from a remote location. The integrated payloads weigh 1-2 kg, which can typically be flown by the drones in 10-20 minutes at altitudes of 2000-4000 meters. Preliminary tests at Turrialba in May 2016 have been very encouraging, and we are in the process of refining both the drones and the instrumentation packages for future flights. Our broader goals are to map gases in detail with the drones in order to make flux measurements of each species, and to apply this approach at other volcanoes.

  1. Spatial Patterns of Greenhouse Gases Across an Urbanization Gradient in a Suburban River Network

    Science.gov (United States)

    Robison, A.; Balch, E.; Wollheim, W. M.

    2017-12-01

    River networks are important components of the global carbon cycle, processing significant quantities of terrestrial carbon and are most often sources of greenhouse gases (GHGs) to the atmosphere. While recent investigations have begun to incorporate aquatic systems into continental carbon budgets, our understanding of what drives the variability in space and time of these dynamics is poorly constrained. Meanwhile, urban areas continue to expand rapidly across the globe, with wide ranging effects on aquatic systems. A better understanding of the effect of human activities on aquatic carbon and GHG dynamics at both local and global scales is needed. We address the question: How does urbanization affect GHG dynamics in river networks? To address this question, we conducted a synoptic survey of 45 sites in a suburban river network in New England (Ipswich River, MA), analyzing samples for physical and chemical characteristics, including dissolved GHGs, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Sampling sites were selected across an urbanization gradient (1.4-90% developed) and included headwater streams, major tributaries, the basin mouth, and additional sites along the main stem. Initial results indicate dissolved N2O concentration in headwater streams is related to catchment development, while CO2 and CH4 are not correlated to land use generally. CO2 and CH4 signals from urban areas are likely modified by fluvial wetlands that are abundant along larger tributaries and the mainstem. Developed watersheds are inherently altered and heterogeneous landscapes. To fully quantify the role of urbanized waters in the larger carbon cycle, GHG dynamics must be considered at the river network scale. The work presented here begins this process, allowing for an examination of the interaction between land use and GHG concentrations. Additional analyses will focus on further constraining GHG patterns across the river network, and modeling gas transport through and

  2. Revised accident source terms for light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soffer, L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  3. 49 CFR 229.43 - Exhaust and battery gases.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Exhaust and battery gases. 229.43 Section 229.43... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside the... conditions. (b) Battery containers shall be vented and batteries kept from gassing excessively. ...

  4. Concentrations of pollutant gases in female hostels of the Federal ...

    African Journals Online (AJOL)

    The overall mean values of these gases significantly exceeded Federal Environmental Protection Agency (FEPA) ambient air quality standards, indicating that air quality in the hostels may constitute health risks to the students. Keywords: pollutant gases, female hostile, Nigeria International Journal of Natural and Applied ...

  5. 78 Greenhouse Gases Concentrations in the Atmosphere Along ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    Abstract. This study investigated effect of vehicular emission on greenhouse gases concentrations along selected roads of different traffic densities in Abeokuta, Ogun State, Nigeria. Nine roads comprised highway, commercial and residential were selected. Greenhouse Gases (GHGs) were determined from both sides of the ...

  6. 40 CFR 86.114-94 - Analytical gases.

    Science.gov (United States)

    2010-07-01

    ...) Optionally, for response factor determination, single blends of methanol using air as the diluent. (3) Gases... precision blending devices (gas dividers) to obtain the required calibration, as defined below, is... gases (not including methanol) shall be traceable to within one percent of NIST (formerly NBS) gas...

  7. Solubility of non-polar gases in electrolyte solutions

    Science.gov (United States)

    Walker, R. L., Jr.

    1970-01-01

    Solubility theory describes the effects of both concentration and temperature on solute activity coefficients. It predicts the salting-out effect and the decrease in solubility of non-polar gases with increased electrolyte concentration, and can be used to calculate heats of solution, entropies, and partial molal volumes of dissolved gases

  8. A Simple Experiment to Demonstrate the Effects of Greenhouse Gases

    Science.gov (United States)

    Keating, C. F.

    2007-01-01

    The role of greenhouse gases in our atmosphere is the subject of considerable discussion and debate. Global warming is well-documented, as is the continually increasing amount of greenhouse gases that human activity puts in the air. Is there a relationship between the two? The simple experiment described in this paper provides a good demonstration…

  9. The challenges of the greenhouse gases emissions reduction in buildings

    International Nuclear Information System (INIS)

    Arnaud, E.

    2005-09-01

    The building sector is responsible of 18% of the greenhouse gases emissions in France. This document aims to evaluate the greenhouse gases emissions of the sector and then defines technical and financial avenues worth exploring to reduce them. (A.L.B.)

  10. 30 CFR 75.322 - Harmful quantities of noxious gases.

    Science.gov (United States)

    2010-07-01

    ... Section 75.322 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.322 Harmful quantities of noxious gases. Concentrations of noxious or poisonous gases, other than carbon dioxide, shall...

  11. [Simulation of polluted atmospheres for animal experimentation: toxic gases].

    Science.gov (United States)

    Godin, J; Boudène, C

    1976-09-20

    A process for the generation of standardized polluted atmospheres usable for animal exposure is described. It is based on the diffusion of compressed gases across a silicone membrane. This device has been tested with four gases of particular importance in the field of atmospheric pollution (sulfur dioxide, nitrogen oxide, carbon monoxide and ammoniac).

  12. Energy scenarios and greenhouse effect gases emissions model for Mexico; Modelo de escenarios energeticos y de emisiones de gases de efecto invernadero para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum Pardo, Claudia; Rodriguez Viqueira, Luis [Instituto de Ingenieria de la UNAM, Mexico, D. F. (Mexico)

    1998-12-31

    This paper presents the bases for the Model of Energy and Greenhouse Emission Scenarios (MEEEM) developed by the Instituto de Ingenieria de la UNAM (Universidad Nacional Autonoma de Mexico`s Engineering Institute). This model was built with the objective of analyzing the different technological options for the mitigation of the greenhouse gases effect on Mexico. The MEEEM is a model for the end uses that simulate in a simple way the energy demand, transformation and supply and calculates the differential leveled costs among a basic scenario and several mitigation scenarios of the greenhouse emissions. The article also presents some of the results in evaluating three technologies of renewable energy sources. Although the model is perfectible, its development shows its usefulness in this type of models in the decision taking for the energy and environmental planning of the country. [Espanol] Este articulo presenta las bases del Modelo de Escenarios Energeticos y de Emisiones de Gases de Efecto Invernadero para Mexico (MEEEM), desarrollado por el Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM). Este modelo fue construido con el objetivo de analizar las diversas opciones tecnologicas de mitigacion de gases de efecto invernadero para Mexico. El MEEEM es un modelo de usos finales que simula de una manera sencilla, la demanda, transformacion y oferta de la energia y calcula la diferencia de costos nivelados entre un escenario base y diversos escenarios de mitigacion de emisiones de gases de efecto invernadero. El articulo presenta tambien algunos resultados obtenidos al evaluar tres tecnologias de fuentes renovables de energia. Aun cuando el modelo es perfectible, su desarrollo demuestra la utilidad de este tipo de modelos en la toma de decisiones para planeacion energetica y ambiental del pais.

  13. Use of sulfide-containing liquors for removing mercury from flue gases

    Science.gov (United States)

    Nolan, Paul S.; Downs, William; Bailey, Ralph T.; Vecci, Stanley J.

    2006-05-02

    A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

  14. Methodology to determine the efficiency of a beta emitter gases monitor

    International Nuclear Information System (INIS)

    Carvalho, Marcos Rodrigues de

    1995-01-01

    This work presents a methodology developed to determinate the efficiency of air monitors used to measure the concentration of beta emitters noble gases in nuclear power stations. Efficiency values, obtained by means of theoretical computation are compared with experimental values. The experimental part of the work was performed using three different point beta source, to simulate small amounts of gas uniformly distributed in small volume. The comparison shows that theoretical an experimental values agree within 4,2 % for 90 Sr + 90 Y, 204 Tl and 45 Ca beta sources. (author)

  15. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from fuels common in the US

    Science.gov (United States)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-12-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern US. A gas chromatograph-mass spectrometry (GC-MS) instrument provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectroscopy (OP-FTIR) instrument and three different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the US Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana and were used as the basis for a number of emission factors reported by Yokelson et al. (2013). The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the three geographic fuel regions being simulated. Discrete emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 % ± 0.12 % of emissions by mole and less than 0.95 % × 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 41-54 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde

  16. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States

    Science.gov (United States)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-08-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern United States. A gas chromatograph-mass spectrometer (GC-MS) provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectrometer (OP-FTIR) and 3 different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the U.S. Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana. The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the 3 geographic fuel regions being simulated. Emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 ± 0.12 % of emissions by mole and less than 0.95 ± 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 42-57 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde were the dominant potential SOA precursors. In addition, ambient air measurements of emissions from the Fourmile Canyon Fire

  17. Characterization of ISOLDE ion source and ion source chemistry

    CERN Document Server

    Barbeau, Marion

    2014-01-01

    This report presents results of measurements made with the ISOLDE OFF-LINE mass separator [1]. The first part shows measurements of the ionization characteristics of noble gases in a VADIS ion source. The goal of the measurements was to determine the dependency of the extractable current of first and second noble gases ions with the electron energy. In the second part, investigation on in-target chemistry are presented. Here, the effect of injected sulfur hexafluoride ($SF_6$) on the release of oxygen from aluminium oxide ($Al_2 O_3$) was studied.

  18. Detecting and Identifying Industrial Gases by a Method Based on Olfactory Machine at Different Concentrations

    Directory of Open Access Journals (Sweden)

    Yunlong Sun

    2018-01-01

    Full Text Available Gas sensors have been widely reported for industrial gas detection and monitoring. However, the rapid detection and identification of industrial gases are still a challenge. In this work, we measure four typical industrial gases including CO2, CH4, NH3, and volatile organic compounds (VOCs based on electronic nose (EN at different concentrations. To solve the problem of effective classification and identification of different industrial gases, we propose an algorithm based on the selective local linear embedding (SLLE to reduce the dimensionality and extract the features of high-dimensional data. Combining the Euclidean distance (ED formula with the proposed algorithm, we can achieve better classification and identification of four kinds of gases. We compared the classification and recognition results of classical principal component analysis (PCA, linear discriminate analysis (LDA, and PCA + LDA algorithms with the proposed SLLE algorithm after selecting the original data and performing feature extraction. The experimental results show that the recognition accuracy rate of the SLLE reaches 91.36%, which is better than the other three algorithms. In addition, the SLLE algorithm provides more efficient and accurate responses to high-dimensional industrial gas data. It can be used in real-time industrial gas detection and monitoring combined with gas sensor networks.

  19. Electric energy auctions in Brazil and its effect on emissions of greenhouse gases by the electric sector; Leiloes de energia eletrica no Brasil e sua influencia nas emissoes de gases de efeito estufa pelo setor eletrico

    Energy Technology Data Exchange (ETDEWEB)

    Alpire, Ricardo; Pereira, Osvaldo Livio Soliano [Universidade Salvador (UNIFACS), BA (Brazil)

    2010-07-01

    The result of the auctions of electricity, after the new regulatory framework in 2004, has shown the increased participation of fossil sources of thermal generation, contributing to increased emission of greenhouse gases by the Brazilian Electricity Sector. This article aims to analyze the correlation between growth in electric generation sector and rising greenhouse gases, especially through the study of the winning projects of electric power auctions conducted with the advent of the New Institutional Model of the Power Sector from 2004, comparing with the existing policies and prospects of the next auction of the electric sector. (author)

  20. Deep Inelastic Scattering on Ultracold Gases

    Directory of Open Access Journals (Sweden)

    Johannes Hofmann

    2017-03-01

    Full Text Available We discuss Bragg scattering on both Bose and Fermi gases with strong short-range interactions in the deep inelastic regime of large wave vector transfer q, where the dynamic structure factor is dominated by a resonance near the free-particle energy ℏω=ϵ_{q}=ℏ^{2}q^{2}/2m. Using a systematic short-distance expansion, the structure factor at high momentum is shown to exhibit a nontrivial dependence on frequency characterized by two separate scaling regimes. First, for frequencies that differ from the single-particle energy by terms of order O(q (i.e., small deviations compared to the single-particle energy, the dynamic structure factor is described by the impulse approximation of Hohenberg and Platzman. Second, deviations of order O(q^{2} (i.e., of the same order or larger than the single-particle energy are described by the operator product expansion, with a universal crossover connecting both regimes. The scaling is consistent with the leading asymptotics for a number of sum rules in the large momentum limit. Furthermore, we derive an exact expression for the shift and width of the single-particle peak at large momentum due to interactions, thus extending a result by Beliaev [J. Exp. Theor. Phys. 7, 299 (19580044-4510] for the low-density Bose gas to arbitrary values of the scattering length a. The shift exhibits a maximum around qa≃1, which is connected with a maximum in the static structure factor due to strong short-range correlations. For Bose gases with moderate interaction strengths, the theoretically predicted shift is consistent with the value observed by Papp et al. [Phys. Rev. Lett. 101, 135301 (2008PRLTAO0031-900710.1103/PhysRevLett.101.135301]. Finally, we develop a diagrammatic theory for the dynamic structure factor which accounts for the correlations beyond Bogoliubov theory. It covers the full range of momenta and frequencies and provides an explicit example for the emergence of asymptotic scaling at large momentum.

  1. Analytical methods for toxic gases from thermal degradation of polymers

    Science.gov (United States)

    Hsu, M.-T. S.

    1977-01-01

    Toxic gases evolved from the thermal oxidative degradation of synthetic or natural polymers in small laboratory chambers or in large scale fire tests are measured by several different analytical methods. Gas detector tubes are used for fast on-site detection of suspect toxic gases. The infrared spectroscopic method is an excellent qualitative and quantitative analysis for some toxic gases. Permanent gases such as carbon monoxide, carbon dioxide, methane and ethylene, can be quantitatively determined by gas chromatography. Highly toxic and corrosive gases such as nitrogen oxides, hydrogen cyanide, hydrogen fluoride, hydrogen chloride and sulfur dioxide should be passed into a scrubbing solution for subsequent analysis by either specific ion electrodes or spectrophotometric methods. Low-concentration toxic organic vapors can be concentrated in a cold trap and then analyzed by gas chromatography and mass spectrometry. The limitations of different methods are discussed.

  2. Solubility of gases in water at high temperature

    International Nuclear Information System (INIS)

    Crovetto, Rosa; Fernandez Prini, R.J.; Japas, M.L.

    1981-01-01

    In the primary circuits of the PWR, it is usual to find apolar gases such as the noble gases like, nitrogen, hydrogen (deuterium) and oxygen. These gases enter into the circuit partly due to failures in the fuel elements, accidental entries of air into the system and corrosion processes and radiolisis in the coolant media. For the operation of several auxiliary systems in the primary circuit, it is important to know the solubility of these gases in the flux of the circuit and the evaluation of physicochemical processes that take place. A cell has been built that allows to carry out determinations of solubility in the range of 350 deg C and 100 Mega Pascal. Three alternative experimental techniques have been developed to determine the solubility of the gases which are compared to each other. Measures of solubility of argon in H2O and D2O have been made in a wide range of temperatures. (V.B.) [es

  3. Contribution of the renewable energies to the decrease of the greenhouse gases emission for 2010; Contribution des EnR a la reduction des emissions de gaz a effet de serre a l'horizon 2010

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-03-01

    To illustrate the renewable energies contribution to the decrease of the greenhouse gases emission in 2010 (19 Mt of CO{sub 2} per year, of greenhouse gases emission avoided), this document presents the different renewable energies sources and the international context of their implementation. Today data and estimations for 2010 are provided. (A.L.B.)

  4. Sorption pumps and storage for gases

    Science.gov (United States)

    Haaland, Peter; Bethel, Dylan

    2016-08-16

    A method and system for filling gas storage vessels from a source operates by cooling a sorbent, opening a valve to transfer gas by physisorption, regulating the sorbent temperature to achieve the desired degree of filling, closing the valve connecting to the gas source, and warming the tank, sorbent, and gas to provide a predetermined pressure at room temperature.

  5. Rating of transport and radiation source events. Draft additional guidance for the INES national officers for pilot use and feedback; Echelle de classement des incidents de radioprotection: document d'application du systeme international propose par l'AIEA pour les sources radioactives et les transports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-15

    The International Nuclear Event Scale (INES) is a means for promptly communicating to the public in consistent terms the safety significance of any reported event associated with radioactive material and/or radiation and to any event occurring during the transport of radioactive material. As described in the 2001 Edition of the INES User.s Manual, events are classified on the scale at seven levels: the upper levels (4-7) are termed accidents. and the lower levels (1-3) incidents. Events which have no safety significance are classified below scale at Level 0 and termed deviations. An overview of the principles for the rating under INES together with flow charts summarizing the rating process is provided in Appendix I. The 2001 Edition of the INES User.s Manual provides some guidance for the rating of transport and radiation source events. At the technical meeting held in 2002 the INES National Officers requested the IAEA/NEA Secretariat to prepare additional guidance. Progress was reported at the Technical Meeting of the INES National Officers in March 2004 where preparation of this draft additional guidance was requested for pilot use. This note provides additional guidance on the rating of transport and radiation source events. It is for pilot use and feedback and is broadly consistent with the INES User.s Manual. It provides more detailed information and an expanded approach for the rating based on actual exposure of workers and members of the public. It is designed to be used as a self-standing document with limited need for reference to the INES User Manual. (author)

  6. Degradabilidade e produção de gases in vitro de fontes energéticas alternativas na alimentação de ruminantes - doi: 10.4025/actascianimsci.v32i4.8835 Degradability and in vitro gas production of alternative energy sources in ruminant feed - doi: 10.4025/actascianimsci.v32i4.8835

    Directory of Open Access Journals (Sweden)

    Sergio Renato Artiaga da Rosa

    2010-10-01

    Full Text Available O padrão fermentativo in vitro de dietas compostas por fubá de milho, farelo de arroz integral, farelo de arroz parboilizado e suas associações em diferentes proporções foi estudado, na porção concentrada da dieta de ruminantes. Até 12h de incubação, a produção de gases foi superior (p -1. As degradabilidades totais da matéria seca (MS e matéria orgânica (MO foram superiores (p in vitro (12,39 e 13,17 mL h-1 e maior degradação da MS e MO nos tempos iniciais.The in vitro fermentation pattern of diets composed of corn meal, rice bran, parboiled rice bran and their associations was studied in different proportions in the concentrate portion in ruminants diets. Up to 12 hours of incubation, gas production was higher (p -1. Total degradability of dry matter (DM and organic matter (OM were higher (p in vitro gas production (12.39 and 13.17 mL h-1 and faster degradation of DM and OM in initial times.

  7. Emissions of greenhouse gases from the use of transportation fuels and electricity. Volume 2: Appendixes A--S

    Energy Technology Data Exchange (ETDEWEB)

    DeLuchi, M.A. [Argonne National Lab., IL (United States)]|[Univ. of California, Davis, CA (United States). Inst. of Transportation Studies

    1993-11-01

    This volume contains the appendices to the report on Emission of Greenhouse Gases from the Use of Transportation Fuels and Electricity. Emissions of methane, nitrous oxide, carbon monoxide, and other greenhouse gases are discussed. Sources of emission including vehicles, natural gas operations, oil production, coal mines, and power plants are covered. The various energy industries are examined in terms of greenhouse gas production and emissions. Those industries include electricity generation, transport of goods via trains, trucks, ships and pipelines, coal, natural gas and natural gas liquids, petroleum, nuclear energy, and biofuels.

  8. Landau damping in trapped Bose condensed gases

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, B; Zaremba, E [Department of Physics, Queen' s University, Kingston, ON K7L 3N6 (Canada)

    2003-07-01

    We study Landau damping in dilute Bose-Einstein condensed gases in both spherical and prolate ellipsoidal harmonic traps. We solve the Bogoliubov equations for the mode spectrum in both of these cases, and calculate the damping by summing over transitions between excited quasiparticle states. The results for the spherical case are compared to those obtained in the Hartree-Fock (HF) approximation, where the excitations take on a single-particle character, and excellent agreement between the two approaches is found. We have also taken the semiclassical limit of the HF approximation and obtain a novel expression for the Landau damping rate involving the time-dependent self-diffusion function of the thermal cloud. As a final approach, we study the decay of a condensate mode by making use of dynamical simulations in which both the condensate and thermal cloud are evolved explicitly as a function of time. A detailed comparison of all these methods over a wide range of sample sizes and trap geometries is presented.

  9. Measuring non-condensable gases in steam.

    Science.gov (United States)

    van Doornmalen, J P C M; Kopinga, K

    2013-11-01

    In surgery, medical devices that are used should be sterilized. To obtain surface steam sterilization conditions, not only in the sterilizer chamber itself but also in the loads to be sterilized, the amount of non-condensable gases (NCGs), for instance air, should be very low. Even rather small fractions of NCGs (below 1%) seriously hamper steam penetration in porous materials or devices with hollow channels (e.g., endoscopes). A recently developed instrument which might detect the presence of residual NCGs in a reliable and reproducible way is the 3M(TM) Electronic Test System (ETS). In this paper, a physical model is presented that describes the behavior of this instrument. This model has been validated by experiments in which known fractions of NCGs were introduced in a sterilizer chamber in which an ETS was placed. Despite several approximations made in the model, a good agreement is found between the model predictions and the experimental results. The basic principle of the ETS, measuring the heat transfer by condensation on a cooled surface, permits a very sensitive detection of NCGs in harsh environments like water vapor at high temperatures and pressures. Our model may serve to develop adapted and optimized versions of this instrument for use outside the field of sterilization, e.g., in heat exchangers based on steam condensation.

  10. Collision Statistics of Driven Polydisperse Granular Gases

    International Nuclear Information System (INIS)

    Chen Zhiyuan; Zhang Duanming; Yang Fengxia; Guo Xinping; Li Zhongming

    2008-01-01

    We present a dynamical model of two-dimensional polydisperse granular gases with fractal size distribution, in which the disks are subject to inelastic mutual collisions and driven by standard white noise. The inhomogeneity of the disk size distribution can be measured by a fractal dimension d f . By Monte Carlo simulations, we have mainly investigated the effect of the inhomogeneity on the statistical properties of the system in the same inelasticity case. Some novel results are found that the average energy of the system decays exponentially with a tendency to achieve a stable asymptotic value, and the system finally reaches a nonequilibrium steady state after a long evolution time. Furthermore, the inhomogeneity has great influence on the steady-state statistical properties. With the increase of the fractal dimension d f , the distributions of path lengths and free times between collisions deviate more obviously from expected theoretical forms for elastic spheres and have an overpopulation of short distances and time bins. The collision rate increases with d f , but it is independent of time. Meanwhile, the velocity distribution deviates more strongly from the Gaussian one, but does not demonstrate any apparent universal behavior

  11. Beneficial Effects of Environmental Gases: Health Prospective

    International Nuclear Information System (INIS)

    Hussein, A.Z.; IBrahim, M.S.; Zakaria, Kh.M.

    2009-01-01

    Radioactive radon gas is widely considered to be a health hazard by environmental agencies in the United States and in Europe. Yet despite the warnings of these agencies, thousands of people annually expose themselves to radon for therapeutic purposes, in facilities ranging from rustic old mines, to upscale spas and clinics. The inert natural radioactive gas radon has been used since the beginning of the century in the treatment of rheumatic diseases. In many places in the world, radon is used for therapeutic purposes for various diseases. Radon inhalation is applied in a thermal gallery with atmospheric radon concentrations up to 100 kBq/m3, elevated temperature up to 41 EC , and humidity close to 100%, or in the form of radon baths where Rn is emanated from water with high natural Rn activity. Frequently, a combination of both treatment procedures is applied. Evidence from empirical experience and from clinical observational studies suggests that radon has analgesic, anti inflammatory and immune-stimulating effects. Ozone is one of nature's most powerful oxidants. It increases the effectiveness of the antioxidant enzyme system, which scavenge excess free radicals in the body. It is used in water purification and sewage treatment and is now being applied medically to treat many diseases from wounds and colitis to cancer, stroke and AIDS. According to the dosage and concentration range, medical ozone is a pharmaceutical agent that exerts specific properties and a well-defined range of efficacy. This paper describes the medical application of environmental gases: radon and ozone

  12. Hydropower may produce more greenhouse gases

    International Nuclear Information System (INIS)

    Kolshus, Hans H.; Folkestad, Tonje

    2002-01-01

    According to this article, dam projects in hydropower development may lead to increased emission of greenhouse gases and may create great inconveniences for the local community. Hence it is not without problems to sponsor such projects through the Clean Development Mechanism (CDM) of the Kyoto Protocol. In many countries the great era of hydroelectric development is over and the potential is now in the developing countries. The aim of the CDM is two-fold: sustainable development in the developing countries, and cheap reduction of greenhouse gas emission from developed nations. It has been agreed upon in the climate negotiations that it is the developing country receiving the investments that shall document that the projects conform to the goal of sustainable development of that country. The concept of sustain ability is a vague one, and it is a great challenge to make it more precise so that requirements may be posed on CDM projects. This is important as projects that are suitable from a climate point of view may have undesirable environmental or social effects, which may be in conflict with the goal of sustainable development. This also pertains to hydropower. It also appears that water reservoirs are not always as clean as has been assumed

  13. EB technology for the purification of flue gases

    International Nuclear Information System (INIS)

    Kojima, Takuji

    2003-01-01

    Sulfur oxides and nitrogen oxides in flue gas from coal-combustion boilers in power plants, dioxins in flue gas from municipal waste incineration facilities and toxic volatile organic compounds (VOCs) in off-gas from painting or cleaning factories are among air pollutants for which emission is regulated by a law in Japan. Electron beam is the effective and easy controllable radiation source for treatment of these flue gases. This report describes outline of the results so far obtained at JAERI on electron beam treatment of flue gas. The removal performance higher than 90% at 10 kGy for flue gas containing 800 ppm SOx and 225 ppm NOx were achieved and being applied to real-scale power plants in Poland and China with expectation of cost reduction of 20% compared to conventional plants. Decomposition of dioxins in flue gas from solid waste incinerators is another project. Using an accelerator of 300 keV and 40 mA for treatment of real incineration gas at 200degC, we obtain 90% decomposition of dioxins at 15 kGy irradiation. Expansion of these flue gas purification technologies combined with low-energy electron accelerators is expected. (S. Ohno)

  14. A 3-D radiation model for non-grey gases

    International Nuclear Information System (INIS)

    Selcuk, Nevin; Doner, Nimeti

    2009-01-01

    A three-dimensional radiation code based on method of lines (MOL) solution of discrete ordinates method (DOM) coupled with spectral line-based weighted sum of grey gases (SLW) model for radiative heat transfer in non-grey absorbing-emitting media for use in conjunction with a computational fluid dynamics (CFD) code based on the same approach was developed. The code was applied to three test problems: two containing isothermal homogenous/non-homogenous water vapor and one non-isothermal water vapor/carbon dioxide mixture. Predictive accuracy of the code was evaluated by benchmarking its steady-state predictions against accurate results, calculated by ray tracing method with statistical narrow band model, available in the literature. Comparative testing with solutions of other methods is also provided. Comparisons reveal that MOL solution of DOM with SLW model provides accurate solutions for radiative heat fluxes and source terms and can be used with confidence in conjunction with CFD codes based on MOL

  15. Impact of greenhouse gases on agricultural productivity in Pakistan

    International Nuclear Information System (INIS)

    Valasai, G.D; Harijan, K.; Uqaili, M.S.; Memon, H.R

    2005-01-01

    Pakistan is an agricultural developing country. About 68% of the country's population resides in rural areas and is mostly linked with agriculture. Agricultural sector contributes more than 25% to GDP, employees about 45% of the labour force and contributes significantly to export earnings of the country. Energy sector is the major source (80%) of emissions of Greenhouse Gases (GHGs). Agriculture and livestock sectors are also responsible for GHGs emissions. The emissions of GHGs results in acid rain and earth's temperature rise (global warming). The destabilization of the global climate destroys natural ecosystem and increases natural disasters, such as violent storms, floods, droughts etc. The acid rain and these natural disasters affect the agricultural productivity. The study indicates that the agricultural productivity per capita in Pakistan decreased continuously during the last two decades. The paper concludes that due to emissions of GHGs, the agricultural productivity is significantly affected in the country. The government should take concrete measures to minimize the emissions of GHGs for increasing the agricultural productivity and reducing other harmful impacts in the country. This paper presents the review and analysis of the effects of GHGs emissions on the agricultural productivity in Pakistan. (author)

  16. Tracking Oxidation During Transport of Trace Gases in Air from the Northern to Southern Hemisphere

    Science.gov (United States)

    Montzka, S. A.; Moore, F. L.; Atlas, E. L.; Parrish, D. D.; Miller, B. R.; Sweeney, C.; McKain, K.; Hall, B. D.; Siso, C.; Crotwell, M.; Hintsa, E. J.; Elkins, J. W.; Blake, D. R.; Barletta, B.; Meinardi, S.; Claxton, T.; Hossaini, R.

    2017-12-01

    Trace gas mole fractions contain the imprint of recent influences on an air mass such as sources, transport, and oxidation. Covariations among the many gases measured from flasks during ATom and HIPPO, and from the ongoing NOAA cooperative air sampling program enable recent influences to be identified from a wide range of sources including industrial activity, biomass burning, emissions from wetlands, and uptake by terrestrial ecosystems. In this work we explore the evolution of trace gas concentrations owing to atmospheric oxidation as air masses pass through the tropics, the atmospheric region with the highest concentrations of the hydroxyl radical. Variations in C2-C5 hydrocarbon concentrations downwind of source regions provide a measure of photochemical ageing in an air mass since emission, but they become less useful when tracking photochemical ageing as air is transported from the NH into the SH owing to their low mixing ratios, lifetimes that are very short relative to transport times, non-industrial sources in the tropics (e.g., biomass burning), and southern hemispheric sources. Instead, we consider a range of trace gases and trace gas pairs that provide a measure of photochemical processing as air transits the tropics. To be useful in this analysis, these trace gases would have lifetimes comparable to interhemispheric transport times, emissions arising from only the NH at constant relative magnitudes, and concentrations sufficient to allow precise and accurate measurements in both hemispheres. Some anthropogenically-emitted chlorinated hydrocarbons meet these requirements and have been measured during ATom, HIPPO, and from NOAA's ongoing surface sampling efforts. Consideration of these results and their implications for tracking photochemical processing in air as it is transported across the tropics will be presented.

  17. Integrated Modeling & Development of Emission Scenarios for Methane and Key Indirect Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Atul K.

    2005-09-30

    This report outlines main accomplishments on the development of Emission inventories and Scenarios for Key Indirect Greenhouse Gases (CO, VOCs, NOx) and methane supported by Office of Science (BER), US Department of Energy. This research produced 3 journal articles, 1 book chapter, and 4 research articles/abstracts in conference proceedings. In addition, this grant supported two PhD students and one undergraduate student at UIUC.

  18. Emissions of ammonia and greenhouse gases during combined pre-composting and vermicomposting of duck manure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jinzhi [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environment Sciences, Beijing 100012 (China); College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049 (China); Hu, Zhengyi, E-mail: zhyhu@ucas.ac.cn [College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Xingkai [State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 (China); Jiang, Xia; Zheng, Binghui [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environment Sciences, Beijing 100012 (China); Liu, Xiaoning [College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049 (China); Pan, Xubin [Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100029 (China); Kardol, Paul [Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S 90183 Umeå (Sweden)

    2014-08-15

    Highlights: • Earthworms significantly decreased emissions of N{sub 2}O and CH{sub 4}, but had a marginal effect on CO{sub 2} emission. • NH{sub 3}, N{sub 2}O, and CH{sub 4} emissions were significantly reduced by reed straw and zeolite, CO{sub 2} emission was increased by reed straw. • Combined pre-composting and vermicomposting with reed straw and zeolite would be recommended for disposal of duck manure. - Abstract: Combined pre-composting and vermicomposting has shown potential for reclamation of solid wastes, which is a significant source of ammonia (NH{sub 3}), and greenhouse gases (GHG), including nitrous oxide (N{sub 2}O), methane (CH{sub 4}), and carbon dioxide (CO{sub 2}). Earthworms and amendments may both affect physico-chemical characteristics that control gas-producing processes, and thus affect NH{sub 3} and GHG emissions. Here, we used two-way ANOVA to test the effects of addition of reed straw and combined addition of reed straw and zeolite on NH{sub 3} and GHG emissions during pre-composting of duck manure, either with or without a follow-up phase of vermicomposting. Results showed that cumulative N{sub 2}O, CH{sub 4}, and CO{sub 2} emissions during pre-composting and vermicomposting ranged from 92.8, 5.8, and 260.6 mg kg{sup −1} DM to 274.2, 30.4, and 314.0 mg kg{sup −1} DM, respectively. Earthworms and amendments significantly decreased N{sub 2}O and CH{sub 4} emissions. Emission of CO{sub 2} was not affected by earthworms, but increased in responses to addition of reed straw. Cumulative NH{sub 3} emission ranged from 3.0 to 8.1 g kg{sup −1} DM, and was significantly decreased by reed straw and zeolite addition. In conclusion, combined pre-composting and vermicomposting with reed straw and zeolite addition would be strongly recommended in mitigating emissions of N{sub 2}O, CH{sub 4}, and NH{sub 3} from duck manure. Moreover, this method also provides nutrient-rich products that can be used as a fertilizer.

  19. Prospects of electron beam treatment of flue gases in the Philippines

    International Nuclear Information System (INIS)

    Cabalfin, Estelita G.

    2005-01-01

    Coal-fired and oil-based power plants operated in Philippines are totally 11 and 58 units respectively. The government recognizes the threat of air pollution, because more than one third of the electricity generation is fueled by coal. The Philippines Congress therefore enacted Republic Act 8749 (Clean Air Act of 1999) under which sulfur and nitrogen oxides concentration at the point of emission from stationary sources shall be strictly regulated. Under the UNDP/IAEA regional project on industrial application of radiation, the Philippine Nuclear Research Institute (PNRI) in cooperation with the National Power Corporation hosted two national executive management seminars on electron beam treatment of flue gases in 1990 and 1994. The Philippine Smelting and Refining Corporation (PASAR) has interest in this technology of reducing 90% SO 2 removal efficiency with EB power of 380 kW. PNRI promotes, through training courses and seminars, the applications of nuclear technology and radiation including EB treatment of flue gases. (S. Ohno)

  20. Noble gases, nitrogen, and methane from the deep interior to the atmosphere of Titan

    Science.gov (United States)

    Glein, Christopher R.

    2015-04-01

    this picture. As for the isotopes in CH4, I show that their observed relative abundances can be explained by low-temperature (∼20 °C) equilibria with liquid water (D/H) and the expected aqueous alteration mineral calcite (12C/13C), provided that nickel was present to catalyze isotopic exchange over geologic timescales. The present hypothesis is chemically and isotopically consistent with the Cassini-Huygens data, and it implies that the formation of Titan's atmosphere would have been an unavoidable consequence of volatile processing that was driven by the geophysical evolution of the interior. If all of the atmospheric N2 and CH4 have an endogenic origin, then no more than ∼1.6 times the present amount of N2 can be lost by photochemistry and escape over the history of the atmosphere; and the D/H ratio in Titan's water should be much lower than that in Enceladus' plume. Given its important implications to the origin and evolution of volatiles in the outer Solar System, we must go back to Titan to acquire additional isotopic data that will allow more rigorous tests of models of the origin of its atmosphere. I predict the following isotopic ratios: 20Ne/22Ne ≈ 8.9, 36Ar/38Ar ≈ 5.3, (14N/15N)NH3 ≈ 130-170 , (12C/13C)CO2 ≈ 84 , (D/H)H2O ≈ 1.7 ×10-4 ; and recommend that future in situ instrumentation have the capability to measure the rare isotopologues of N2 and CH4, which represent previously unconsidered but potentially valuable sources of geochemical information on the origin and evolution of Titan's atmosphere.

  1. Radioactive wastes: sources, treatment, and disposal

    International Nuclear Information System (INIS)

    Wymer, R.G.; Blomeke, J.O.

    1975-01-01

    Sources, treatment, and disposal of radioactive wastes are analyzed in an attempt to place a consideration of the problem of permanent disposal at the level of established or easily attainable technology. In addition to citing the natural radioactivity present in the biosphere, the radioactive waste generated at each phase of the fuel cycle (mills, fabrication plants, reactors, reprocessing plants) is evaluated. The three treatment processes discussed are preliminary storage to permit decay of the short-lived radioisotopes, solidification of aqueous wastes, and partitioning the long-lived α emitters for separate and long-term storage. Dispersion of radioactive gases to the atmosphere is already being done, and storage in geologically stable structures such as salt mines is under active study. The transmutation of high-level wastes appears feasible in principle, but exceedingly difficult to develop

  2. Long Term Association of Tropospheric Trace gases over Pakistan by exploiting satellite observations and development of Econometric Regression based Model

    Science.gov (United States)

    Zeb, Naila; Fahim Khokhar, Muhammad; Khan, Saud Ahmed; Noreen, Asma; Murtaza, Rabbia

    2017-04-01

    Air pollution is the expected key environmental issue of Pakistan as it is ranked among top polluted countries in the region. Ongoing rapid economic growth without any adequate measures is leading to worst air quality over time. The study aims to monitor long term atmospheric composition and association of trace gases over Pakistan. Tropospheric concentrations of CO, TOC, NO2 and HCHO derived from multiple satellite instruments are used for study from year 2005 to 2014. The study will provide first database for tropospheric trace gases over Pakistan. Spatio-temporal assessment identified hotspots and possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60 % of the Pakistan's population) sector of the country. The expected sources are the agricultural fires, biomass/fossil fuel burning for heating purposes, urbanization, industrialization and meteorological variations. Seasonal variability is observed to explore seasonal patterns over the decade. Well defined seasonal cycles of trace gases are observed over the whole study period. The observed seasonal patterns also showed some noteworthy association among trace gases, which is further explored by different statistical tests. Seasonal Mann Kendall test is applied to test the significance of trend in series whereas correlation is carried out to measure the strength of association among trace gases. Strong correlation is observed for trace gases especially between CO and TOC. Partial Mann Kendall test is used to ideally identify the impact of each covariate on long term trend of CO and TOC by partialling out each correlating trace gas (covariate). It is observed that TOC, NO2 and HCHO has significant impact on long term trend of CO whereas, TOC critically depends on NO2 concentrations for long term increase over the region

  3. Action plan for response to abnormal conditions in Hanford high level radioactive liquid waste storage tanks containing flammable gases

    International Nuclear Information System (INIS)

    Sherwood, D.J.

    1994-03-01

    Radioactive liquid waste tends to produce hydrogen as a result of the interaction of gamma radiation and water. In tanks containing organic chelating agents, additional hydrogen gas as well as nitrous oxide and ammonia can be produced by thermal and radiolytic decomposition of these organics. Several high-level radioactive liquid waste storage tanks, located underground at the Hanford Site, contain waste that retains the gases produced in them until large quantities are released rapidly to the tank vapor space. Tanks filled to near capacity have relatively little vapor space; therefore, if the waste suddenly releases a large amount of hydrogen and nitrous oxide, a flammable gas mixture may result. The most notable waste tank with a flammable gas problem is tank 241-SY-101. Waste in this tank has occasionally released enough flammable gas to burn if an ignition source had been present inside of the tank. Several other waste tanks exhibit similar behavior to a lesser magnitude. Administrative controls have been developed to assure that these Flammable Gas Watch List tanks are safely maintained. Responses have also been developed for off-normal conditions which might develop in these tanks. In addition, scientific and engineering studies are underway to further understand and mitigate the behavior of the Flammable Gas Watch List tanks

  4. Oxygen buffering of Kilauea volcanic gases and the oxygen fugacity of Kilauea basalt

    Science.gov (United States)

    Gerlach, T.M.

    1993-01-01

    Volcanic gases collected during episode 1 of the Puu Oo eruption along the east rift zone of Kilauea Volcano, Hawaii, have uniform C-O-H-S-Cl-F compositions that are sharply depleted in CO2. The CO2-poor gases are typical of Type II volcanic gases (gerlach and Graeber, 1985) and were emitted from evolved magma stored for a prolonged period of time in the east rift zone after releasing CO2-rich gases during an earlier period of temporary residence in the summit magma chamber. The samples are remarkably free of contamination by atmospheric gases and meteoric water. Thermodynamic evaluation of the analytical data shows that the episode 1 gases have equilibrium compositions appropriate for temperatures between 935 and 1032??C. Open- and closed-system equilibrium models of species distributions for the episode 1 gases show unequivocally that coexisting lavas buffered the gas oxygen fugacities during cooling. These models indicate that the fO2 buffering process occurs by transfer of oxygen from the major species in the gas phase (H2O, CO2, SO2) to the lava during cooling and that the transfer of oxygen also controls the fugacities of several minor and trace species (H2, CO, H2S, S2, Cl2, F2), in addition to O2 during cooling. Gas/lava exchanges of other components are apparently insignificant and exert little influence, compared to oxygen exchange, during cooling. Oxygen transfer during cooling is variable, presumably reflecting short-term fluctuations in gas flow rates. Higher flow rates restrict the time available for gas/lava oxygen transfer and result in gases with higher equilibrium temperatures. Lower flow rates favor fO2-constrained equilibration by oxygen transfer down to lower temperatures. Thus, the chemical equilibrium preserved in these gases is a heterogeneous equilibrium constrained by oxygen fugacity, and the equilibrium temperatures implied by the compositions of the gases reflect the temperatures at which gas/lava oxygen exchange ceased. This conclusion

  5. Injection of gases into the stratosphere by explosive volcanic eruptions

    Science.gov (United States)

    Textor, Christiane; Graf, Hans-F.; Herzog, Michael; Oberhuber, J. M.

    2003-10-01

    Explosive eruptions can inject large amounts of volcanic gases into the stratosphere. These gases may be scavenged by hydrometeors within the eruption column, and high uncertainties remain regarding the proportion of volcanic gases, which eventually reach the stratosphere. These are caused by the difficulties of directly sampling explosive volcanic eruption columns and by the lack of laboratory studies in the extreme parameter regime characterizing them. Using the nonhydrostatic nonsteady state plume model Active Tracer High Resolution Atmospheric Model (ATHAM), we simulated an explosive volcanic eruption. We examined the scavenging efficiency for the climatically relevant gases within the eruption column. The low concentration of water in the plume results in the formation of relatively dry aggregates. More than 99% of these are frozen because of their fast ascent to low-temperature regions. Consideration of the salinity effect increases the amount of liquid water by one order of magnitude, but the ice phase is still highly dominant. Consequently, the scavenging efficiency for HCl is very low, and only 1% is dissolved in liquid water. However, scavenging by ice particles via direct gas incorporation during diffusional growth is a significant process. The salinity effect increases the total scavenging efficiency for HCl from about 50% to about 90%. The sulfur-containing gases SO2 and H2S are only slightly soluble in liquid water; however, these gases are incorporated into ice particles with an efficiency of 10 to 30%. Despite scavenging, more than 25% of the HCl and 80% of the sulfur gases reach the stratosphere because most of the particles containing these species are lifted there. Sedimentation of the particles would remove the volcanic gases from the stratosphere. Hence the final quantity of volcanic gases injected in a particular eruption depends on the fate of the particles containing them, which is in turn dependent on the volcanic and environmental

  6. BIOSIGNATURE GASES IN H2-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS

    International Nuclear Information System (INIS)

    Seager, S.; Bains, W.; Hu, R.

    2013-01-01

    Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H 2 -dominated atmospheres. We study biosignature gases on exoplanets with thin H 2 atmospheres and habitable surface temperatures, using a model atmosphere with photochemistry and a biomass estimate framework for evaluating the plausibility of a range of biosignature gas candidates. We find that photochemically produced H atoms are the most abundant reactive species in H 2 atmospheres. In atmospheres with high CO 2 levels, atomic O is the major destructive species for some molecules. In Sun-Earth-like UV radiation environments, H (and in some cases O) will rapidly destroy nearly all biosignature gases of interest. The lower UV fluxes from UV-quiet M stars would produce a lower concentration of H (or O) for the same scenario, enabling some biosignature gases to accumulate. The favorability of low-UV radiation environments to accumulate detectable biosignature gases in an H 2 atmosphere is closely analogous to the case of oxidized atmospheres, where photochemically produced OH is the major destructive species. Most potential biosignature gases, such as dimethylsulfide and CH 3 Cl, are therefore more favorable in low-UV, as compared with solar-like UV, environments. A few promising biosignature gas candidates, including NH 3 and N 2 O, are favorable even in solar-like UV environments, as these gases are destroyed directly by photolysis and not by H (or O). A more subtle finding is that most gases produced by life that are fully hydrogenated forms of an element, such as CH 4 and H 2 S, are not effective signs of life in an H 2 -rich atmosphere because the dominant atmospheric chemistry will generate such gases abiologically, through photochemistry or geochemistry. Suitable biosignature gases in H 2 -rich atmospheres for super-Earth exoplanets transiting M stars could potentially be detected in transmission spectra with the James Webb Space Telescope

  7. Biogenic gases in tropical floodplain river

    Directory of Open Access Journals (Sweden)

    Maria Victória Ramos Ballester

    2001-06-01

    Full Text Available Analysis of the distribution of biogenic gases in the floodplain of the Mogi-Guaçu River (São Paulo, Brazil enabled the establishment of a "redox hierarchy", in which the main channel was the most oxidizing environment, followed by Diogo Lake, with Infernão Lake having the most reducing conditions of the subsystems evaluated. Diogo Lake exported about 853.4 g C.m-2.year-1, of which, 14.6% was generated from methanogenesis and 36.7% by aerobic respiration. For Infernão Lake, these values were 2016 g C.m-2.year-1, 1.8 % and 41.5 %, respectively. Carbon export by these systems was predominantly in the form of CO2, which was responsible for the release of 728.78 g C.m-2.year-1 at Diogo Lake and 1979.72 g C.m-2. year-1 at Infernão Lake. Such patterns may result from the nature of the hydrological conditions, the action of the hydroperiod, and morphological characteristics of the environment.A análise da distribuição de gases biogênicos na planície de inundação do Rio Mogi Guaçu (São Paulo, Brasil possibilitou o estabelecimento de um gradiente redox para os sistemas aquáticos avaliados, em que o canal principal do rio apresentou-se como o ambiente mais oxidado, seguido da Lagoa do Diogo, e a Lagoa do Infernão apresentando as condições mais redutoras entre os ambientes em questão. A Lagoa do Diogo exporta um total de 853,4 g C.m-2.ano-1, do qual 14,6% é produzido pela metanogênese e 36,7% pela respiração aeróbia. Para a Lagoa do Infernão estes valores foram respectivamente de 2.016 g C.m-2.ano-1, 1,8% e de 41,5%. A exportação de carbono por estes sistemas é realizada, predominantemente na forma de CO2, nos valores de 728,78 g C.m-2.ano-1 para a Lagoa do Diogo e 1.979,72 g C.m-2.ano-1 para a Lagoa do Infernão. Estes padrões parecem estar relacionados com a natureza das condições hidrológicas, com a ação do hidroperíodo e com as características morfológicas do ambiente.

  8. A novel solution for reducing the transfer of particles and gases among adjacent apartments

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza

    2016-01-01

    A unique type of fabric membrane has been developed by a Swedish company. That membrane is design to trap the emission from surfaces. To test the performance of the said membrane for trapping particles and gases, a study was conducted by the Danish Building Research Institute (SBi). The study...... is based on the laboratory experiments as well as in situ measurements. Laboratory tests were performed in the laboratory of SBi where two adjacent apartments were simulated. One apartment was the source apartment which generated the particles and the second apartment was the exposed apartment which...... was exposed to the particles generated by the source apartment. Exposed apartment was situated over the source apartments. Both apartments had the same plan area and height. The simulated apartments were separated by wooden flooring. When the ultra-fine particles (UFP) were generated in the source apartment...

  9. Universal Bose Gases Near Resonance: A Rigorous Solution

    OpenAIRE

    Jiang, Shao-Jian; Liu, Wu-Ming; Semenoff, Gordon W.; Zhou, Fei

    2013-01-01

    We obtain a rigorous solution of universal Bose gases near resonance and offer an answer to one of the long-standing challenges of quantum gases at large scattering lengths, where the standard dilute theory breaks down. The solution was obtained by using an $\\epsilon$ expansion near four spatial dimension. In dimension $d = 4 - \\epsilon$, the chemical potential of Bose gases near resonances is shown to approach the universal value $\\epsilon^{(2/(4-\\epsilon))} \\epsilon_F \\sqrt{2/3} (1 + 0.474 ...

  10. Non-equilibrium effects of diatomic and polyatomic gases on the shock-vortex interaction based on the second-order constitutive model of the Boltzmann-Curtiss equation

    Science.gov (United States)

    Singh, S.; Karchani, A.; Myong, R. S.

    2018-01-01

    The rotational mode of molecules plays a critical role in the behavior of diatomic and polyatomic gases away from equilibrium. In order to investigate the essence of the non-equilibrium effects, the shock-vortex interaction problem was investigated by employing an explicit modal discontinuous Galerkin method. In particular, the first- and second-order constitutive models for diatomic and polyatomic gases derived rigorously from the Boltzmann-Curtiss kinetic equation were solved in conjunction with the physical conservation laws. As compared with a monatomic gas, the non-equilibrium effects result in a substantial change in flow fields in both macroscale and microscale shock-vortex interactions. Specifically, the computational results showed three major effects of diatomic and polyatomic gases on the shock-vortex interaction: (i) the generation of the third sound waves and additional reflected shock waves with strong and enlarged expansion, (ii) the dominance of viscous vorticity generation, and (iii) an increase in enstrophy with increasing bulk viscosity, related to the rotational mode of gas molecules. Moreover, it was shown that there is a significant discrepancy in flow fields between the microscale and macroscale shock-vortex interactions in diatomic and polyatomic gases. The quadrupolar acoustic wave source structures, which are typically observed in macroscale shock-vortex interactions, were not found in any microscale shock-vortex interactions. The physics of the shock-vortex interaction was also investigated in detail to examine vortex deformation and evolution dynamics over an incident shock wave. A comparative study of first- and second-order constitutive models was also conducted for the enstrophy and dissipation rate. Finally, the study was extended to the shock-vortex pair interaction case to examine the effects of pair interaction on vortex deformation and evolution dynamics.

  11. Desulfurization of chemical waste gases and flue gases with economic utilization of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1983-09-01

    The technological state of recovery of sulfur dioxide from waste and flue gases in the GDR is discussed. Two examples of plants are presented: a pyrosulfuric acid plant in Coswig, recovering sulfur dioxide from gases by absorption with sodium hydroxide, followed by catalytic oxidation to sulfur trioxide, and a plant for waste sulfuric acid recovery from paraffin refining, where the diluted waste acid is sprayed into a furnace and recovered by an ammonium-sulfite-bisulfite solution from the combustion gas (with 4 to 10% sulfur dioxide content). Investment and operation costs as well as profits of both plants are given. Methods employed for power plant flue gas desulfurization in major industrial countries are further assessed: about 90% of these methods uses wet flue gas scrubbing with lime. In the USA flue gas from 25,000 MW of power plant capacity is desulfurized. In the USSR, a 35,000 m/sup 3//h trial plant at Severo-Donetzk is operating using lime, alkali and magnesite. At the 150 MW Dorogobush power plant in the USSR a desulfurization plant using a cyclic ammonia process is under construction.

  12. Light crystals for ultracold quantum degenerate bosonic gases

    International Nuclear Information System (INIS)

    Arimondo, E.

    2009-01-01

    Full text follows. The experimental realization of quantum degenerate states in ultracold atomic gases has opened the possibility to realize few body systems isolated from external perturbations and at temperatures close to absolute zero. Under these conditions counterintuitive phenomena characteristic of the quantum mechanical evolution may be assessed experimentally. Matter quantum-mechanical waves inside periodic potentials investigated in solid-state physics, where electrons propagate within a crystal lattice. Interfering laser beams create a light-induced spatial periodic potential for ultracold atoms called an 'optical lattice'. Atoms hopping between the lattice periodic potential minima emulate the motion of electrons in a crystal. The creation of one-, two-, and three-dimensional periodic structures in which atoms can be trapped and accelerated, with the possibility of switching or modulating the lattice at will, gives a great flexibility. In addition atomic physicists can tune the lattice's geometry, the rate of hopping, and the push and pull between atoms within the light crystals. So they hope to map the various behaviors of solid-state models. On the basis of the research work performed at Pisa, several processes of quantum mechanics evolution within a spatial periodic potential and associated to the solid-state physics will be presented

  13. Two Catalysts for Selective Oxidation of Contaminant Gases

    Science.gov (United States)

    Wright, John D.

    2011-01-01

    Two catalysts for the selective oxidation of trace amounts of contaminant gases in air have been developed for use aboard the International Space Station. These catalysts might also be useful for reducing concentrations of fumes in terrestrial industrial facilities especially facilities that use halocarbons as solvents, refrigerant liquids, and foaming agents, as well as facilities that generate or utilize ammonia. The first catalyst is of the supported-precious-metal type. This catalyst is highly active for the oxidation of halocarbons, hydrocarbons, and oxygenates at low concentrations in air. This catalyst is more active for the oxidation of hydrocarbons and halocarbons than are competing catalysts developed in recent years. This catalyst completely converts these airborne contaminant gases to carbon dioxide, water, and mineral acids that can be easily removed from the air, and does not make any chlorine gas in the process. The catalyst is thermally stable and is not poisoned by chlorine or fluorine atoms produced on its surface during the destruction of a halocarbon. In addition, the catalyst can selectively oxidize ammonia to nitrogen at a temperature between 200 and 260 C, without making nitrogen oxides, which are toxic. The temperature of 260 C is higher than the operational temperature of any other precious-metal catalyst that can selectively oxidize ammonia. The purpose of the platinum in this catalyst is to oxidize hydrocarbons and to ensure that the oxidation of halocarbons goes to completion. However, the platinum exhibits little or no activity for initiating the destruction of halocarbons. Instead, the attack on the halocarbons is initiated by the support. The support also provides a high surface area for exposure of the platinum. Moreover, the support resists deactivation or destruction by halogens released during the destruction of halocarbons. The second catalyst is of the supported- metal-oxide type. This catalyst can selectively oxidize ammonia to

  14. Noble gases in Mars atmosphere: new precise analysis with Paloma

    Science.gov (United States)

    Sarda, Ph.; Paloma Team

    2003-04-01

    The Viking mission embarked a mass spectrometer designed by Alfred O. Nier that yielded the first determination of the elemental and isotopic composition of noble gases in Mars atmosphere. For example, the 40Ar/36Ar ratio in martian air is roughly 10 fold that in terrestrial air. This extraordinary accomplishment, however, has furnished only partial results with large analytical uncertainties. For example, we do not know the isotopic composition of helium, and only very poorly that of Ne, Kr and Xe. In planetary science, it is fundamental to have a good knowledge of the atmosphere because this serves as a reference for all further studies of volatiles. In addition, part of our present knowledge of Mars atmosphere is based on the SNC meteorites, and again points to important differences between the atmospheres of Earth and Mars. For example the 129Xe/132Xe ratio of martian atmosphere would be twice that of terrestrial air and the 36Ar/38Ar ratio strongly different from the terrestrial or solar value. There is a need for confirming that the atmospheric components found in SNC meteorites actually represents the atmosphere of Mars, or to determine how different they are. Paloma is an instrument designed to generate elemental and isotopic data for He, Ne, Ar, Kr and Xe (and other gases) using a mass spectrometer with a purification and separation line. Gas purification and separation did not exist on the Vicking instrument. Because Paloma includes purification and separation, we expect strong improvement in precision. Ne, Ar and Xe isotope ratios should be obtained with an accuracy of better than 1%. Determination of the presently unknown ^3He/^4He ratio is also awaited from this experiment. Knowledge of noble gas isotopes in Mars atmosphere will allow some insight into major planetary processes such as degassing (^3He/^4He, 40Ar/36Ar, 129Xe/130Xe, 136Xe/130Xe), gravitational escape to space (^3He/^4He, 20Ne/22Ne), hydrodynamic escape and/or impact erosion of the

  15. Band structure engineering for ultracold quantum gases in optical lattices

    International Nuclear Information System (INIS)

    Weinberg, Malte

    2014-01-01

    the same system maps onto a quantum spin-1/2 XY model. Owing to the quantum nature of the pseudospins, geometrical frustration leads to a highly degenerate ground state which can result in exotic valence bond spin-liquid phases. First signatures of an order-by-disorder effect emerge in this regime. A complementary approach to the manipulation of the band structure is investigated in a honeycomb potential. By rotating the quantization field of the system, the statedependent energy offset between the twofold atomic basis of the hexagonal Bravais lattice can be adjusted. This purposeful breaking of inversion symmetry enables the continuous opening of an energy gap at the Dirac points of the honeycomb band structure. In addition, a striking influence of the band gap onto the lifetimes for atoms in the first excited energy band is observed. In the last part of the thesis, both experimental manipulation techniques are discussed with respect to future applications for ultracold quantum gases in non-cubic optical lattices.

  16. Request for Correction 10008 Endangerment Findings for Greenhouse Gases

    Science.gov (United States)

    Request for correction by Peabody Energy Company for the EPA to correct temperature data in Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act

  17. The application of isotope techniques to the analysis of gases

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Grosse, H.J.; Popp, P.; Thuemmel, H.W.

    1978-01-01

    The development of devices for the detection of nuclear radiation has also led to systems permitting concentrations of gaseous components in gases or mixtures of gases to be determined with the aid of ionizing radiation. Such systems, which use either the ionization of gases in connection with recombination processes or the multiplication of charged particles, or the excitation of gases by means of α,β,γ or X-rays, are described. The most frequently used ionization detectors (electron capture detectors, aerosol ionization analysers, cross-section detectors, noble gas detectors and electron mobility detectors) are characterized with reference to their properties and main fields of application. It is shown that as a result of the development of sensitive energy-resolving detectors the possibilities for the utilization of excitation processes for gas analysis are increasing. The prospects for ionization detectors and systems based on the excitation of characteristic X-rays are discussed. (author)

  18. THE USE OF BIOFILTERS FOR DEODORISATION OF THE NOXIOUS GASES

    Directory of Open Access Journals (Sweden)

    Monika Wierzbińska

    2015-01-01

    Full Text Available One of the methods of deodorization of noxious gases is biofiltration. This method consists of pollutants biodegradation by using micro-organisms, what leads to the formation of nontoxic and innoxious compounds. In comparison with conventional techniques, bio-filtration requires lower investments and exploitation costs, moreover it is nature friendly. This technique is still developing. Scientists have carried out research on the optimization of biofiltration process, biofilters and selecting parameters of purified gases or improving the method of efficiency. However, industrial application of biofilters is still difficult for many reasons. In this paper we present the mechanism of biofiltration process, the parameters and conditions which have to be fulfilled by purified gases, installation structure for gases biofiltration, application field of this method and specific example of exploited biofilters, including practical operational guidelines.

  19. Quantum gases finite temperature and non-equilibrium dynamics

    CERN Document Server

    Szymanska, Marzena; Davis, Matthew; Gardiner, Simon

    2013-01-01

    The 1995 observation of Bose-Einstein condensation in dilute atomic vapours spawned the field of ultracold, degenerate quantum gases. Unprecedented developments in experimental design and precision control have led to quantum gases becoming the preferred playground for designer quantum many-body systems. This self-contained volume provides a broad overview of the principal theoretical techniques applied to non-equilibrium and finite temperature quantum gases. Covering Bose-Einstein condensates, degenerate Fermi gases, and the more recently realised exciton-polariton condensates, it fills a gap by linking between different methods with origins in condensed matter physics, quantum field theory, quantum optics, atomic physics, and statistical mechanics. Thematically organised chapters on different methodologies, contributed by key researchers using a unified notation, provide the first integrated view of the relative merits of individual approaches, aided by pertinent introductory chapters and the guidance of ed...

  20. ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides information on greenhouse gases and human-produced air pollution, including atmospheric concentrations of carbon dioxide (CO2), methane (CH4),...

  1. Trace Gases, CO2, Climate, and the Greenhouse Effect.

    Science.gov (United States)

    Aubrecht, Gordon J., II

    1988-01-01

    Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

  2. Solubilities of gases in ionic liquids using a corresponding-states approach to Kirkwood-Buff solution theory

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2011-01-01

    The solubilities of gases in ionic liquids and compressed liquid densities have been successfully described over a wide range of conditions using a reformulated corresponding-states formulation for direct correlation function integrals. In addition, comparisons with experimental data show reliable...... prediction of ionic liquid characteristic properties from simple rules....

  3. Remote measurements of volcanic gases: Applications of open-path Fourier transform infrared spectroscopy

    Science.gov (United States)

    Maciejewski, Adam John Henry

    The composition of volcanic gas plumes depends largely on the chemistry of the degassing magma, the depth of volatile exsolution, and the level of volcanic activity. The ratios between the most common volcanic gases: CO 2, H2O, SO2, HCl and HF, as measured at the surface, can be used to provide information on the evolution of the magma body. My research on volcanic gases has centred on the use of open-path Fourier transform IR spectroscopy (OP-FTIR) and correlation spectroscopy (COSPEC). Remote-sensing techniques rely on the characteristic IR or UV absorbances of natural and/or artificial radiation by different gases. Direct-sampling techniques rely on gases being trapped, dissolved or adsorbed before being analysed by traditional methods, e.g. wet-chemistry, colourimetry, and gas chromatography. The capture of gases is best achieved as close to the source as possible and the suitability of an individual technique depends on: the type of gas to be measured; the location of vent or fumarole; the level of volcanic activity; and the environment in which data are collected. I used OP-FTIR on La Fossa di Vulcano to measure the SO2:HCl mass ratios of gases emitted from the rim and central crater fumaroles, ~4.3-6.1 and 0.9-2.6 respectively. At Mt. Etna, analysis showed that, in 1994, SO2:HCl mass ratios were ~4.9-5.8. A comparative study of lava effusion rates and COSPEC-derived SO2 fluxes for the 1991-1993 Etna eruption showed that variations were generally synchronous. Analyses on Montserrat in June 1996 to show the gas plume to be relatively SO 2 poor, with SO2:HCl mass ratios of HF-SiF4 ratios to estimate gas equilibrium temperatures at La Fossa and Mt. Etna to be ~200°C and ~250-290°C respectively. Historic activity has centred on the twin massifs of Volcán Masaya and Volcán Santiago and is dominated by pit-crater collapses. I propose that the degassing episodes, which occur with no increase in eruptive activity, are related to the convective overturn of magma

  4. Pulsed TEA CO2 Laser Irradiation of Titanium in Nitrogen and Carbon Dioxide Gases

    Science.gov (United States)

    Ciganovic, J.; Matavulj, P.; Trtica, M.; Stasic, J.; Savovic, J.; Zivkovic, S.; Momcilovic, M.

    2017-12-01

    Surface changes created by interaction of transversely excited atmospheric carbon dioxide (TEA CO2) laser with titanium target/implant in nitrogen and carbon dioxide gas were studied. TEA CO2 laser operated at 10.6 μm, pulse length of 100 ns and fluence of ˜17 J/cm2 which was sufficient for inducing surface modifications. Induced changes depend on the gas used. In both gases the grain structure was produced (central irradiated zone) but its forms were diverse, (N2: irregular shape; CO2: hill-like forms). Hydrodynamic features at peripheral zone, like resolidified droplets, were recorded only in CO2 gas. Elemental analysis of the titanium target surface indicated that under a nitrogen atmosphere surface nitridation occurred. In addition, irradiation in both gases was followed by appearance of plasma in front of the target. The existence of plasma indicates relatively high temperatures created above the target surface offering a sterilizing effect.

  5. Three toxic gases meet in the mitochondria

    Science.gov (United States)

    Decréau, Richard A.; Collman, James P.

    2015-01-01

    The rationale of the study was two-fold: (i) develop a functional synthetic model of the Cytochrome c oxidase (CcO) active site, (ii) use it as a convenient tool to understand or predict the outcome of the reaction of CcO with ligands (physiologically relevant gases and other ligands). At physiological pH and potential, the model catalyzes the 4-electron reduction of oxygen. This model was immobilized on self-assembled-monolayer (SAM) modified electrode. During catalytic oxygen reduction, electron delivery through SAMs is rate limiting, similar to the situation in CcO. This model contains all three redox-active components in CcO's active site, which are required to minimize the production of partially-reduced-oxygen-species (PROS): Fe-heme (“heme a3”) in a myoglobin-like model fitted with a proximal imidazole ligand, and a distal tris-imidazole Copper (“CuB”) complex, where one imidazole is cross-linked to a phenol (mimicking “Tyr244”). This functional CcO model demonstrates how CcO itself might tolerate the hormone NO (which diffuses through the mitochondria). It is proposed that CuB delivers superoxide to NO bound to Fe-heme forming peroxynitrite, then nitrate that diffuses away. Another toxic gas, H2S, has exceptional biological effects: at ~80 ppm, H2S induces a state similar to hibernation in mice, lowering the animal's temperature and slowing respiration. Using our functional CcO model, we have demonstrated that at the same concentration range H2S can reversibly inhibit catalytic oxygen reduction. Such a reversible catalytic process on the model was also demonstrated with an organic compound, tetrazole (TZ). Following studies showed that TZ reversibly inhibits respiration in isolated mitochondria, and induces deactivation of platelets, a mitochondria-rich key component of blood coagulation. Hence, this program is a rare example illustrating the use of a functional model to understand and predict physiologically important reactions at the active

  6. Three Toxic Gases Meet in the Mitochondria

    Directory of Open Access Journals (Sweden)

    Richard A Decreau

    2015-08-01

    Full Text Available The rationale of the study was two-fold : (i develop a functional synthetic model of the Cytochrome c oxidase (CcO active site, (ii use it as a convenient tool to understand or predict the outcome of the reaction of CcO with ligands (physiologically relevant gases and other ligands. At physiological pH and potential, the model catalyzes the 4-electron reduction of oxygen. This model was immobilized on self-assembled-monolayer (SAM modified electrode. During catalytic oxygen reduction, electron delivery through SAMs is rate limiting, similar to the situation in CcO. This model contains all three redox-active components in CcO’s active site, which are required to minimize the production of partially-reduced-oxygen-species (PROS: Fe¬-heme (heme a3 in a myoglobin-like model fitted with a proximal imidazole ligand, and a distal tris-imidazole Copper (CuB complex, where one imidazole is cross-linked to a phenol (mimicking Tyr244. This functional CcO model demonstrates how CcO itself might tolerate the hormone NO (which diffuses through the mitochondria. It is proposed that CuB delivers superoxide to NO bound to Fe-heme forming peroxynitrite, then nitrate that diffuses away. Another toxic gas, H2S, has exceptional biological effects: at ~80 ppm, H2S induces a state similar to hibernation in mice, lowering the animal's temperature and slowing respiration. Using our functional CcO model, we have demonstrated that at the same concentration range H2S can reversibly inhibit catalytic oxygen reduction. Such a reversible catalytic process on the model was also demonstrated with an organic compound, tetrazole (TZ. Following studies showed that TZ reversibly inhibits respiration in isolated mitochondria, and induces deactivation of platelets, a mitochondria-rich key component of blood coagulation. Hence, this program is a rare example illustrating the use of a functional model to understand and predict physiologically important reactions at the active site

  7. Cost effective method for valuation of impacts caused by greenhouse gases emissions for oil and gas companies; Metodo de custo-efetividade para avaliacao de impactos causados pelas emissoes de gases de efeito estufa em empresas de oleo e gas

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Elisa Vieira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Barros, Sergio Ricardo da Silveira [Universidade Federal Fluminense (LATEC/UFF), Niteroi, RJ (Brazil). Mestrado em Sistemas de Gestao

    2012-07-01

    The objective of this work is to apply the method of cost-effectiveness in economic evaluation of new investment projects, based on information about reducing greenhouse gases emissions. In the context of the commitment of companies with the Climate Change and Sustainability, this work is important and contributes to the oil and gas industry, because it integrates information on reducing emissions of greenhouse gases in negative Net Present Value (NPV) projects, helping the portfolio manager on decision making between alternative projects. In this article, examples are given of two investment projects, in which the cost effectiveness methodology is applied, considering the reduction of emission of greenhouse gases such as additional environmental benefit, or cost avoidance, in an adjusted model of the economic viability analysis of meritorious projects. (author)

  8. Biological production of ethanol from waste gases with Clostridium ljungdahlii

    Science.gov (United States)

    Gaddy, James L.

    2000-01-01

    A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products is disclosed. The method includes introducing the waste gases into a bioreactor where they are fermented to various product, such as organic acids, alcohols H.sub.2, SCP, and salts of organic acids by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified.

  9. High-resolution spectroscopy of gases for industrial applications

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    High-resolution spectroscopy of gases is a powerful technique which has various fundamental and practical applications: in situ simultaneous measurements of gas temperature and gas composition, radiative transfer modeling, validation of existing and developing of new databases and etc. Existing...... to, for example, atmospheric research, combustion and gasification. Some high-temperature, high-resolution IR/UV absorption/transmission measurements gases (e.g. CO2, SO2, SO3 and phenol) are presented....

  10. Observation of the Efimovian Expansion in Scale Invariant Fermi Gases

    OpenAIRE

    Deng, Shujin; Shi, Zhe-Yu; Diao, Pengpeng; Yu, Qianli; Zhai, Hui; Qi, Ran; Wu, Haibin

    2015-01-01

    Scale invariance emerges and plays an important role in strongly correlated many-body systems such as critical regimes nearby phase transitions and the unitary Fermi gases. Discrete scaling symmetry also manifests itself in quantum few-body systems such as the Efimov effect. Here we report both theoretical predication and experimental observation of a novel type expansion dynamics for scale invariant quantum gases. When the frequency of the harmonic trap holding the gas decreases continuously...

  11. Anomalous migration of shallow groundwater and gases in the Beijing region and the 1976 Tangshan earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Shi, H. (Seismological Brigade of Beijing, China); Cai, Z.; Gao, M.

    1980-02-01

    The character and cause of blowing out of gases and emission of sound from dry wells and of water becoming muddy and changing of level in water wells of the Beijing region immediately before the 1976 Tangshan earthquake and its strong aftershocks are investigated. These phenomena, taken as possible precursors of the earthquakes as well as the motivating force, mechanism, geological background and material sources of the anomalous migration are discussed. Besides, the paper also deals with the relation between these anomalies and the Tangshan earthquake and the significance of the study of groundwater as far as earthquake prediction is concerned. No gaseous gushing from great depth in considerable quantities appeared so that migration should be regarded only as the migration of shallow groundwater and gases. This is referred to the consequence of the action on certain hydrogeological structures of an impulse-like extra tectonic stress field on the active faults in the Beijing region under a unified regional stress field. The present authors suppose that further studies of the anomalous migration of groundwater and gases possibly may be fruitful to earthquake prediction work.

  12. GREENHOUSE GASES REDUCTION THROUGH WASTE MANAGEMENT IN CROATIA

    Directory of Open Access Journals (Sweden)

    Aleksandra Anić Vučinić

    2010-01-01

    Full Text Available The climate change policy is one of the key factors in the achievement of sustainable development in the Republic of Croatia. Control and mitigation of green house gases is correlated with all economy activities. Waste management is one of the main tasks of environmental protection in Croatia. The Waste Management Strategy of the Republic of Croatia and the Waste Management Plan in the Republic of Croatia define the concept of waste management hierarchy and direct and indirect measures as criteria for sustainable waste management establishment. The main constituent of this system is avoiding and minimizing waste, as well as increasing the recycling and recovery level of waste and land fill gas, which also represent green house gases mitigation measures. The Waste Management Plan consists of several direct and indirect measures for green house gases emission reduction and their implementation also affects the green house gases emissions. The contribution of the methane emission from land fills amounts to about 2% of the total green house gases emissions in Croatia. The climate change control and mitigation measures as an integral part of waste management sector strategies represent the measures of achieving the national objectives to wards green house gases emission reduction which Croatia has accepted in the frame work of the Kyoto Protocol.

  13. Dissolved Gases as Indicators for Stream-Ground Water Interactions

    Science.gov (United States)

    Werner, S. F.; Browne, B. A.; Wallschlaeger, C. W.; Wyss, J. R.; Bowling, J. M.

    2007-12-01

    The connection between groundwater and surface water varies along stream corridors, but these hydrologic changes are typically difficult to observe or measure. Many dissolved gases entering streams via groundwater discharge are either undersaturated or supersaturated with respect to atmospheric equilibrium due to physical or biological mechanisms. Because such gases behave non-conservatively (e.g., via losses to the atmosphere) within the stream channel, their longitudinal patterns can potentially help identify where groundwater enters or exits a stream system. Such information can be very useful for understanding stream water quality and the impacts of land management. Unfortunately, dissolved gases (other than oxygen) have not been frequently employed in studies of stream systems, and their full potential as hydrologic tools has not been established. A better understanding of how dissolved gases can be used to study the groundwater/surface water connection is needed. In this study we present and interpret longitudinal patterns of several gases along an 8 km stretch of a baseflow dominated stream located in a predominantly agricultural sand plain watershed of central Wisconsin. Dissolved gas measurements included oxygen, carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and noble gases. Major and minor ions were also measured. Sampling locations were sited at 350-m intervals along the thalweg of the stream into headwater tributaries. Losing stream sections had CFCs, nitrous oxide, and methane concentrations near atmospheric equilibrium. Gaining stream sections were supersaturated with nitrous oxide, methane, and carbon dioxide and undersaturated with CFCs and oxygen. High concentrations of nitrous oxide accompanied nitrate entering the stream.

  14. Implementation of non-condensable gases condensation suppression model into the WCOBRA/TRAC-TF2 LOCA safety evaluation code

    International Nuclear Information System (INIS)

    Liao, J.; Cao, L.; Ohkawa, K.; Frepoli, C.

    2012-01-01

    The non-condensable gases condensation suppression model is important for a realistic LOCA safety analysis code. A condensation suppression model for direct contact condensation was previously developed by Westinghouse using first principles. The model is believed to be an accurate description of the direct contact condensation process in the presence of non-condensable gases. The Westinghouse condensation suppression model is further revised by applying a more physical model. The revised condensation suppression model is thus implemented into the WCOBRA/TRAC-TF2 LOCA safety evaluation code for both 3-D module (COBRA-TF) and 1-D module (TRAC-PF1). Parametric study using the revised Westinghouse condensation suppression model is conducted. Additionally, the performance of non-condensable gases condensation suppression model is examined in the ACHILLES (ISP-25) separate effects test and LOFT L2-5 (ISP-13) integral effects test. (authors)

  15. Energy Sources Management and Future Automotive Technologies: Environmental Impact

    Directory of Open Access Journals (Sweden)

    Florin Mariasiu

    2012-01-01

    Full Text Available The paper presents the environmental impact created through the introduction of introducing new technologies in transportation domain. New electric vehicles are considered zero-emission vehicles (ZEV. However, electricity produced in power plants is still predominantly based on fossil fuel usage (required for recharge electric vehicle batteries and thus directly affects the quantity of pollutant emissions and greenhouse gases (CO2, NOx and SOx. Given the structure of EU-wide energy sources used for electricity generation, the potential pollutant emissions stemming from these energy sources, related to energy consumption of an electric vehicle, was determined under the projected environmental impact of specific market penetration of electric vehicles. In addition to the overall impact at the EU level, were identified the countries for which the use of electric vehicles is (or not feasible in terms of reaching the lower values ​​of future emissions compared to the present and future European standards.

  16. Removal of ethylene oxide from waste gases by absorption

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana Lj.

    2011-01-01

    Full Text Available Ethylene oxide (EtO is an organic compound, which is used as starting material in the production of polymers and as sterilizing agent for thermolabile materials. Although ethylene oxide is not common as an organic pollutant, its removal from numerous emission sources (e.g. ethylene oxide production plants or food and pharmaceutical sterilizing units is of the crucial importance because of its mutagenic, teratogenic and cancerogenic effect on human health. The objective of this paper is the experimental investigation of ethylene oxide (EtO absorption in diluted aqueous solution of sulfuric acid in order to evaluate the applicability of this procedure as well as to obtain project parameters for industrial plant realization. It was found that absorption is suitable as the fist step in the purification treatment of high EtO concentrations in the emission gases. According to the literature data, the basic parameter that defines the scrubber efficiency is the contact time, i.e. the ratio of packing height in scrubber and velocity of gas mixture. To investigate the characteristics of wet treatment in a broad range of contact time, part of experimental studies were conducted in the system with two and with three scrubbers in series. The obtained experimental results show that the high degree of EtO removal can be achieved (>98% when the contact time is sufficiently long (about 25 s. The process is effective until the concentration of formed glycol in the solution reaches value of about 20%. The process is safe and there is no danger of ignition and explosion of air and EtO mixture, although at the entrance to the scrubber EtO concentrations are significantly above the lower explosive limit.

  17. Search for impurities of counting gases in ionization chambers

    International Nuclear Information System (INIS)

    Hofmann, T.

    1992-03-01

    In order to reach for the gas detectors applied at the ALADIN spectrometer of the GSI an as good as possible and timely remaining gas purity, a study on the kind and effects of impurities in different counting gases was performed. The gas purity was observed via the signal height of an α source after a drift path of the electrons of 50 cm. A steady decrease of the α-signals was measures, the steepness of which decreases slowly as function of the time. The half-life lies in the range of weeks, which lets conclude on a slow outgassing from the materials of the arrangement. By a gas chromatography and mass spectroscopy these impurities could be determined. Beside impurities by polar molecules as water and oxygen from the atmosphere, which are deposed in microscopical capillaries of the chamber materials and then outgassed in the samples after several days so-called softeners could be observed. Because these impurities in the arrangement at the ALADIN spectrometer cannot be avoided, a purification system in the flow-through operation was constructed and its effect tested. The gas quality can by this over several days be kept in the mean constant. In this dynamical process the fluctuations of the signal heights lie at ±0.7%. A ionization chamber as monitor for the gas purity was constructed and tested with different gas mixtures concerning observables like signal height and drift time. By this calibrated monitor in the experiment at the ALADIN spectrometer the gas quality can be independently determined. (orig.) [de

  18. Monitoring of air pollutants and greenhouse gases. Monitoring Krypton-85

    International Nuclear Information System (INIS)

    Novitchkov, V.

    1996-01-01

    Krypton-85 is an anthropogenic radioactive noble gas, a gaseous fission product which builds up in the atmosphere. The World Meteorological Organization (WMO) Global Atmospheric Watch (GAW) integrates many monitoring and research activities involving the measurements of atmospheric composition. Kr-85 represents one of the gases recommended by the WMO for monitoring. The collaborative program of the Moscow State Engineering Physics Institute (MEPI) and the US Air Resources Laboratory (ARL) NOAA activities is aimed at determining the possible future consequences of Krypton-85 content (trend) increasing in the earth's atmosphere. The research is conducted at the MEPI to study the character of KR-85 release into the atmosphere and its distribution in the atmosphere, to determine Kr-85 possible sources. If only the question of the direct impact of Kr-85 on climate would be considered, only the order of magnitude of the atmospheric concentration would be of interest. In this case almost any available detection method and a precision as low as some 10% would be acceptable. If however, Kr-85 is to be applied as a tracer for the improvement of our present knowledge of local, regional and global transport and mixing processes and the validation of global-scale transport and mixing models, a much higher precision is required (order of +1%). This high standard cannot be met without a permanent quality assurance programmer. It is within the framework of the WMO that MEPI and the Air Resources Laboratory NOAA USA proposes collaboration of Kr-85 scientific findings. The project MEPI open-quotes Monitoring Krypton-85close quotes is being financed through the International Science and Technology Center

  19. Realization of effective super Tonks-Girardeau gases via strongly attractive one-dimensional Fermi gases

    International Nuclear Information System (INIS)

    Chen Shu; Yin Xiangguo; Guan Liming; Guan Xiwen; Batchelor, M. T.

    2010-01-01

    A significant feature of the one-dimensional super Tonks-Girardeau gas is its metastable gas-like state with a stronger Fermi-like pressure than for free fermions which prevents a collapse of atoms. This naturally suggests a way to search for such strongly correlated behavior in systems of interacting fermions in one dimension. We thus show that the strongly attractive Fermi gas without polarization can be effectively described by a super Tonks-Girardeau gas composed of bosonic Fermi pairs with attractive pair-pair interaction. A natural description of such super Tonks-Girardeau gases is provided by Haldane generalized exclusion statistics. In particular, they are equivalent to ideal particles obeying more exclusive statistics than Fermi-Dirac statistics.

  20. Development of Optical Parametric Amplifier for Lidar Measurements of Trace Gases on Earth and Mars

    Science.gov (United States)

    Numata, Kenji; Riris, Haris; Li, Steve; Wu, Stewart; Kawa, Stephen R.; Krainak, Michael; Abshire, James

    2011-01-01

    Trace gases in planetary atmospheres offer important clues as to the origins of the planet's hydrology, geology. atmosphere. and potential for biology. Wc report on the development effort of a nanosecond-pulsed optical parametric amplifier (OPA) for remote trace gas measurements for Mars and Earth. The OP A output light is single frequency with high spectral purity and is widely tunable both at 1600 nm and 3300 nm with an optical-optical conversion efficiency of approximately 40%. We demonstrated open-path atmospheric measurements ofCH4 (3291 nm and 1651 nm). CO2 (1573 nm), H20 (1652 nm) with this laser source.

  1. Norwegian environmental policy: From continued increase of the emission of greenhouse gases to decrease

    International Nuclear Information System (INIS)

    2002-01-01

    According to Norway's Minister of the Environment, Norway will be one of the first among the industrialized countries to ratify the Kyoto Protocol on the emission of greenhouse gases. The tax on carbon dioxide will be continued and from 2005 there will be a national quota system for emission from sources not previously included. Several other measures have also been proposed. The current regulations admit 16 percent increase in the emissions up to 2008, while the measures proposed by the government and listed in this article may give a reduction of 12 percent

  2. Overview of the Flammability of Gases Generated in Hanford Waste Tanks

    International Nuclear Information System (INIS)

    Mahoney, L.A.; Huckaby, J.L.; Bryan, S.A.; Johnson, G.D.

    2000-01-01

    This report presents an overview of what is known about the flammability of the gases generated and retained in Hanford waste tanks in terms of the gas composition, the flammability and detonability limits of the gas constituents, and the availability of ignition sources. The intrinsic flammability (or nonflammability) of waste gas mixtures is one major determinant of whether a flammable region develops in the tank headspace; other factors are the rate, surface area, volume of the release, and the tank ventilation rate, which are not covered in this report

  3. Explorative analysis of microbes, colloids and gases together with microbial modelling. Site description model SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Hallbeck, Lotta; Pedersen, Karsten

    2008-08-01

    The work has involved the development of descriptive and mathematical models for groundwaters in relation to rock domains, fracture domains and deformation zones. Past climate changes are the major driving force for hydrogeochemical changes and therefore of fundamental importance for understanding the palaeohydrogeological, palaeohydrogeochemical and present evolution of groundwater in the crystalline bedrock of the Fennoscandian Shield. Understanding current undisturbed hydrochemical conditions at the proposed repository site is important when predicting future changes in groundwater chemistry. The causes of copper corrosion and/or bentonite degradation are of particular interest as they may jeopardise the long-term integrity of the planned SKB repository system. Thus, the following variables are considered for the hydrogeochemical site descriptive modelling: pH, Eh, sulphur species, iron, manganese, carbonate, phosphate, nitrogen species, total dissolved solids (TDS), isotopes, colloids, fulvic and humic acids and microorganisms. In addition, dissolved gases (e.g. carbon dioxide, methane and hydrogen) are of interest because of their likely participation in microbial reactions. In this series of reports, the final hydrogeochemical evaluation work of the site investigation at the Laxemar site, is presented. The work was conducted by SKB's hydrogeochemical project group, ChemNet, which consists of independent consultants and Univ. researchers with expertise in geochemistry, hydrochemistry, hydrogeochemistry, microbiology, geomicrobiology, analytical chemistry etc. The resulting site descriptive model version, mainly based on available primary data from the extended data freeze L2.3 (Nov 2007). This report focuses on microbiology, colloids and gases. Several methods must be used to characterise active microbial communities in groundwater. Microbial parameters of interest are the total number of cells (TNC) and the presence of various metabolic groups of

  4. Explorative analysis of microbes, colloids and gases together with microbial modelling. Site description model SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Hallbeck, Lotta; Pedersen, Karsten (Microbial Analytics Sweden AB, Goeteborg (Sweden))

    2008-08-15

    The work has involved the development of descriptive and mathematical models for groundwaters in relation to rock domains, fracture domains and deformation zones. Past climate changes are the major driving force for hydrogeochemical changes and therefore of fundamental importance for understanding the palaeohydrogeological, palaeohydrogeochemical and present evolution of groundwater in the crystalline bedrock of the Fennoscandian Shield. Understanding current undisturbed hydrochemical conditions at the proposed repository site is important when predicting future changes in groundwater chemistry. The causes of copper corrosion and/or bentonite degradation are of particular interest as they may jeopardise the long-term integrity of the planned SKB repository system. Thus, the following variables are considered for the hydrogeochemical site descriptive modelling: pH, Eh, sulphur species, iron, manganese, carbonate, phosphate, nitrogen species, total dissolved solids (TDS), isotopes, colloids, fulvic and humic acids and microorganisms. In addition, dissolved gases (e.g. carbon dioxide, methane and hydrogen) are of interest because of their likely participation in microbial reactions. In this series of reports, the final hydrogeochemical evaluation work of the site investigation at the Laxemar site, is presented. The work was conducted by SKB's hydrogeochemical project group, ChemNet, which consists of independent consultants and Univ. researchers with expertise in geochemistry, hydrochemistry, hydrogeochemistry, microbiology, geomicrobiology, analytical chemistry etc. The resulting site descriptive model version, mainly based on available primary data from the extended data freeze L2.3 (Nov 2007). This report focuses on microbiology, colloids and gases. Several methods must be used to characterise active microbial communities in groundwater. Microbial parameters of interest are the total number of cells (TNC) and the presence of various metabolic groups of

  5. Low-power, open-path mobile sensing platform for high-resolution measurements of greenhouse gases and air pollutants

    Science.gov (United States)

    Tao, Lei; Sun, Kang; Miller, David J.; Pan, Dan; Golston, Levi M.; Zondlo, Mark A.

    2015-04-01

    A low-power mobile sensing platform has been developed with multiple open-path gas sensors to measure the ambient concentrations of greenhouse gases and air pollutants with high temporal and spatial resolutions over extensive spatial domains. The sensing system consists of four trace gas sensors including two custom quantum cascade laser-based open-path sensors and two LICOR open-path sensors to measure CO2, CO, CH4, N2O, NH3, and H2O mixing ratios simultaneously at 10 Hz. In addition, sensors for meteorological and geolocation data are incorporated into the system. The system is powered by car batteries with a low total power consumption (~200 W) and is easily transportable due to its low total mass (35 kg). Multiple measures have been taken to ensure robust performance of the custom, open-path sensors located on top of the vehicle where the optics are exposed to the harsh on-road environment. The mobile sensing system has been integrated and installed on top of common passenger vehicles and participated in extensive field campaigns (>400 h on-road time with >18,000 km total distance) in both the USA and China. The simultaneous detection of multiple trace gas species makes the mobile sensing platform a unique and powerful tool to identify and quantify different emission sources through mobile mapping.

  6. Characterization and control of odorous gases at a landfill site: a case study in Hangzhou, China.

    Science.gov (United States)

    Ying, Ding; Chuanyu, Cai; Bin, Hu; Yueen, Xu; Xuejuan, Zheng; Yingxu, Chen; Weixiang, Wu

    2012-02-01

    Municipal solid waste (MSW) landfills are one of the major sources of offensive odors potentially creating annoyance in adjacent communities. At the end of May 2007, an odor pollution incident occurred at the Tianziling landfill site, Hangzhou, China, where the residents lodged complaints about the intense odor from the landfill, which drew a significant attention from the government. In this study, ambient air monitoring was conducted at the Tianziling landfill site. The main odor composition of the gas samples collected on June 1st 2007 and the reduction of various odorous gases from the samples collected on June 1st 2009 due to the applied odor control techniques were determined using gas chromatography-mass spectrometry (GC-MS). In addition, variations of primary odorous gaseous (NH(3) and H(2)S) concentrations at different locations in the landfill site from July 2007 to June 2009 were also investigated by using classical spectrophotometric methods. Results showed that a total of 68 volatile compounds were identified among which H(2)S (56.58-579.84 μg/m(3)) and NH(3) (520-4460 μg/m(3)) were the notable odor components contributing to 4.47-10.92% and 83.91-93.94% of total concentrations, respectively. Similar spatial and temporal shifts of H(2)S and NH(3) concentrations were observed and were significantly affected by environmental factors including temperature, air pressure and wind direction. Odor pollution was worse when high temperature, high humidity, low air pressure, and southeast, northeast or east wind appeared. Moreover, the environmental sampling points of the dumping area and the leachate treatment plant were found to be the main odor sources at the Tianziling landfill site. The odor control technologies used in this project had a good mitigating effect on the primary odorous compounds. This study provides long-term valuable information concerning the characteristics and control of odors at landfill sites in a long run. Copyright © 2011 Elsevier

  7. Monitoring system for industrial gases pollutants

    International Nuclear Information System (INIS)

    Iliescu, M.; Culcer, M.; Curuia, M.; Anghel, N.M.; Stefanescu, I.

    2003-01-01

    The system is designed for monitoring gas pollutants in air, in a chemical plant. It consists of gas detectors with transmitter and modules for environmental conditions measurement, data loggers and a central monitoring station which role is to collect data, generate alarms if pollutants concentration becomes over limit and create database. A dedicated software permits data collecting and processing in order to get solutions for minimising human and technological risks. The system role is monitoring the pollution sources and the surrounded areas that might be affected, for keeping gas pollutants concentration at an acceptable level and to minimise the pollution effects. (author)

  8. Trace water vapor determination in nitrogen and corrosive gases using infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, L.H.; Niemczyk, T.M. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemistry; Stallard, B.R.; Garcia, M.J. [Sandia National Labs., Albuquerque, NM (United States)

    1997-06-01

    The generation of particles in gas handling systems as a result of corrosion is a major concern in the microelectronics industry. The corrosion can be caused by the presence of trace quantities of water in corrosive gases such as HCl or HBr. FTIR spectroscopy has been shown to be a method that can be made compatible with corrosive gases and is capable of detecting low ppb levels of water vapor. In this report, the application of FTIR spectroscopy combined with classical least squares multivariate calibration to detect trace H{sub 2}O in N{sub 2}, HCl and HBr is discussed. Chapter 2 discusses the gas handling system and instrumentation required to handle corrosive gases. A method of generating a background spectrum useful to the measurements discussed in this report, as well as in other application areas such as gas phase environmental monitoring, is discussed in Chapter 3. Experimental results obtained with the first system are presented in Chapter 4. Those results made it possible to optimize the design options for the construction of a dedicate system for low ppb water vapor determination. These designs options are discussed in Chapter 5. An FTIR prototype accessory was built. In addition, a commercially available evacuable FTIR system was obtained for evaluation. Test results obtained with both systems are discussed in Chapter 6. Experiments dealing with the interaction between H{sub 2}O-HCl and potential improvements to the detection system are discussed in Chapter 7.

  9. Effect of pressure on the structural properties and electronic band structure of GaSe

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, U.; Olguin, D.; Syassen, K. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Cantarero, A. [Department of Materials Sciences, University of Valencia, 46000 Burjasot (Spain); Hanfland, M. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

    2007-01-15

    The structural properties of GaSe have been investigated up to 38 GPa by monochromatic X-ray diffraction. The onset of the phase transition from the {epsilon}-GaSe to a disordered NaCl-type structural motif is observed near 21 GPa. Using the experimentally determined lattice parameters of the layered {epsilon}-phase as input, constrained ab-initio total energy calculations were performed in order to optimize the internal structural parameters at different pressures. The results obtained for the nearest-neighbor Ga-Se distance agree with those derived from recent EXAFS measurements. In addition, information is obtained on the changes of Ga-Ga and Se-Se bond lengths which were not accessible to a direct experimental determination yet. Based on the optimized structural parameters, we report calculations of band gap changes of {epsilon}-GaSe under pressure. The optical response and electronic band structure of the metallic high-pressure phase of GaSe are discussed briefly. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Knudsen temperature jump and the Navier-Stokes hydrodynamics of granular gases driven by thermal walls.

    Science.gov (United States)

    Khain, Evgeniy; Meerson, Baruch; Sasorov, Pavel V

    2008-10-01

    Thermal wall is a convenient idealization of a rapidly vibrating plate used for vibrofluidization of granular materials. The objective of this work is to incorporate the Knudsen temperature jump at thermal wall in the Navier-Stokes hydrodynamic modeling of dilute granular gases of monodisperse particles that collide nearly elastically. The Knudsen temperature jump manifests itself as an additional term, proportional to the temperature gradient, in the boundary condition for the temperature. Up to a numerical prefactor O(1) , this term is known from kinetic theory of elastic gases. We determine the previously unknown numerical prefactor by measuring, in a series of molecular dynamics (MD) simulations, steady-state temperature profiles of a gas of elastically colliding hard disks, confined between two thermal walls kept at different temperatures, and comparing the results with the predictions of a hydrodynamic calculation employing the modified boundary condition. The modified boundary condition is then applied, without any adjustable parameters, to a hydrodynamic calculation of the temperature profile of a gas of inelastic hard disks driven by a thermal wall. We find the hydrodynamic prediction to be in very good agreement with MD simulations of the same system. The results of this work pave the way to a more accurate hydrodynamic modeling of driven granular gases.

  11. Implementation of experimental CRDS and DOAS systems for determination of gases with direct green house effect

    Science.gov (United States)

    Cotirlan, C.; Negrila, C. C.; Ristici, V.; Balin, I.

    2009-04-01

    The implementation of the experimental spectroscopic systems address stringent problems related to the control of gases emissions with direct green house effect as: CO2, CH4,NOx. CRDS (Cavity Ring - Down Spectroscopy) and DOAS (Differential Optical Absorption Spectroscopy) are versatile, fast-response techniques and can contribute to the improving of the quality of air, especially in large cities and industrial areas as well as the improving the meteorological prognosis. Firstly, we describe an CRD system for measurements of the optical absorption of water and for determination of the optical properties of gases with direct green house effect from ambient air. Secondly, a DOAS system provides measurements for the detection and characterization of atmospheric pollutants. The data obtained in the two systems: CRDS and DOAS are correlated in the aim of pollutant concentrations monitoring in different humidity conditions. The humidity is a main factor in the concentration and the dispersion of atmospheric pollutants. The analysis of how different compositions of pollutants answer to humidity have a significant impact upon the uncertainties regarding the modeling of pollutants impact on the climate. The potential of CRDS and DOAS techniques in the study of the environmental pollution and in the laboratory fundamental research is proved by their sensitivity better than 1 ppm. In addition to DOAS system, gases standards and calibrated established point monitors for SO2, NOx and O3 are integrated in the measurement approach and tests in order to validate our CRDS first experimental set-up.

  12. Noble Gases in the LEW 88663 L7 Chondrite

    Science.gov (United States)

    Miura, Y. N.; Sugiura, N.; Nagao, K.

    1995-09-01

    LEW88663 and some meteorites (e.g. Shaw) are the most highly metamorphosed meteorites among L group chondrites. Although the abundances of lithophile elements and oxygen isotopic compositions of the L7 chondrite LEW88663 (total recovered mass: 14.5g) are close to those of the range for L chondrites [1,2], metallic iron is absent and concentrations of siderophile elements are about half of typical values for L chondrites [3,4]. Petrographical and geochemical observation suggested that this meteorite has experienced partial melting [5]. As a part of our study on differentiated meteorites, we also investigated noble gases in this meteorite. We present here noble gas compositions of LEW88663 and discuss history of this meteorite. In addition, we will consider whether there is any evidence for bridging between chondrites and achondrites. Noble gases were extracted from a whole rock sample weighing 66.31 mg by total fusion, and all stable noble gas isotopes as well as cosmogenic radioactive 81Kr were analyzed using a mass spectrometer at ISEI, Okayama University. The results are summarized in the table. The concentrations of cosmogenic ^3He, ^21Ne, and ^38Ar are 7.3, 1.6 and 3.1x10^-8 cm^3STP/g, respectively. The cosmic-ray exposure ages based on them are calculated to be 4.7, 6.9 and 8.8 m.y., respectively, using the production rates proposed by [6, 7] and mean chemical compositions of L chondrites. The shorter cosmic-ray exposure ages T(sub)3 and T(sub)21 than T(sub)38 would be due to diffusive loss of lighter noble gases from the meteorite. The concentrations of trapped Kr and Xe in LEW88663 are lower than those for L6 chondrites [8], supporting thermal metamorphism for the meteorite higher than that for L6 chondrites. The Kr and Xe are isotopically close to those of the terrestrial atmospheric Kr and Xe, and elemental abundance ratios for Ar, Kr and Xe suggest adsorbed noble gas patterns of the terrestrial atmosphere. The terrestrial atmospheric Ar, Kr and Xe (most

  13. 40 CFR 52.22 - Enforceable commitments for further actions addressing the pollutant greenhouse gases (GHGs).

    Science.gov (United States)

    2010-07-01

    ... actions addressing the pollutant greenhouse gases (GHGs). 52.22 Section 52.22 Protection of Environment... greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases (GHGs) means the air pollutant as defined in § 86.1818-12(a) of this chapter as the aggregate group of six greenhouse gases: Carbon dioxide, nitrous...

  14. Emissions of Greenhouse gases in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Evers, C.W.A. [Ministry of Housing, The Hague (Netherlands). Inspectorate for Environmental Protection; Berdowski, J.J.M.; Pulles, T.P.J. [TNO Inst. for Environmental Sciences, Delft (Netherlands)

    1995-12-31

    The Dutch emission inventory system enables the registration, analysis and localization of emission data of both industrial and non-industrial sources in the Netherlands. The results can be used to test the effectiveness of governmental environmental policy. These activities are part of the policy evaluation tasks of the Inspectorate General for Environmental Protection (IGEP) and of the Ministry of Transport, Public Works and Water Management. The emission inventory takes place in cycles of one year. Recently, the most relevant results of the Dutch emission inventory for 1992 have been published. In that cycle the emissions in 1992 to air and water from about 800 major companies have been registered. These 800 companies are the most important contributors to the total industrial emissions in the Netherlands. The emissions of these companies are registered within the individual inventory system. The emissions from the smaller enterprises and from diffuse non-industrial sources are stored in the collective emission inventory system. The data collected in the 1992 inventory have been established for the first time in close cooperation between the IGEP, TNO, the Central Bureau of Statistics and the National Institute of Public Health and Environmental Protection. This implies that the data presented here have to be considered as the official data for the emissions in the Netherlands for the year 1992. (author)

  15. Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams.

    Science.gov (United States)

    Coutts, Janelle L.; Lunn, Griffin Michael; Meyer, Caitlin E.

    2015-01-01

    In membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center's sub-scale MABRs, as well as Johnson Space Center's full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need

  16. Contraction of the positive column of discharges in noble gases

    International Nuclear Information System (INIS)

    Golubovskii, Yu B; Nekuchaev, V; Gorchakov, S; Uhrlandt, D

    2011-01-01

    This review describes the experimental studies of contraction in neon, argon and helium, discussing the basic regularities of the phenomenon. These studies, extended over a long time, are still urgent. For pressures that are not too high a noticeable contraction of the plasma glow and a smooth non-monotonic dependence of the degree of contraction on the current are observed. Above a critical pressure the plasma immediately contracts into a bright thin cord, if the current reaches a critical value. A hysteresis phenomenon is observed during the transition from the diffuse state to the contracted state and vice versa. Experiments that show the secondary role of non-homogeneous gas heating for contraction in neon and argon, and the main role for contraction in helium, are described. Studies of the ionization waves (the strata), which propagate as pulses of the current cord area, are reviewed showing the close relationship between contraction and stratification. The roles of various mechanisms leading to the contraction and describing the general picture of the observed phenomena are analysed. For heavy noble gases the main role is played by ionization non-linearity as a function of electron concentration, which is related to the competition of electron-atom and electron-electron collisions. This non-linearity leads to plasma shrinkage and the development of ionization instability in the radial (contraction) and longitudinal (stratification) directions. For helium such non-linearity does not play a leading role, since the frequency of the elastic electron-atom collisions is considered to be constant over a large energy range, and this yields a Maxwellian distribution function. The contraction in helium is defined by thermal effects. In addition, recent studies on the numerical modelling of the contraction are discussed. (topical review)

  17. LIDAR technology for measuring trace gases on Mars and Earth

    Science.gov (United States)

    Riris, H.; Abshire, J. B.; Graham, Allan; Hasselbrack, William; Rodriguez, Mike; Sun, Xiaoli; Weaver, Clark; Mao, Jianping; Kawa, Randy; Li, Steve; Numata, Kenji; Wu, Stewart

    2017-11-01

    Trace gases and their isotopic ratios in planetary atmospheres offer important but subtle clues as to the origins of a planet's atmosphere, hydrology, geology, and potential for biology. An orbiting laser remote sensing instrument is capable of measuring trace gases on a global scale with unprecedented accuracy, and higher spatial resolution that can be obtained by passive instruments. For Earth we have developed laser technique for the remote measurement of the tropospheric CO2, O2, and CH4 concentrations from space. Our goal is to develop a space instrument and mission approach for active CO2 measurements. Our technique uses several on and off-line wavelengths tuned to the CO2 and O2 absorption lines. This exploits the atmospheric pressure broadening of the gas lines to weigh the measurement sensitivity to the atmospheric column below 5 km and maximizes sensitivity to CO2 changes in the boundary layer where variations caused by surface sources and sinks are largest. Simultaneous measurements of O2 column use a selected region in the Oxygen A-band. Laser altimetry and atmospheric backscatter can also be measured simultaneously, which permits determining the surface height and measurements made to thick cloud tops and through aerosol layers. We use the same technique but with a different transmitter at 1.65 um to measure methane concentrations. Methane is also a very important trace gas on earth, and a stronger greenhouse gas than CO2 on a per molecule basis. Accurate, global observations are needed in order to better understand climate change and reduce the uncertainty in the carbon budget. Although carbon dioxide is currently the primary greenhouse gas of interest, methane can have a much larger impact on climate change. Methane levels have remained relatively constant over the last decade but recent observations in the Arctic have indicated that levels may be on the rise due to permafrost thawing. NASA's Decadal Survey underscored the importance of Methane as a

  18. Development and test of a Stirling engine driven by waste gases for the micro-CHP system

    International Nuclear Information System (INIS)

    Li Tie; Tang Dawei; Li Zhigang; Du Jinglong; Zhou Tian; Jia Yu

    2012-01-01

    In recent years, micro-CHP systems are attracting world attention. As one kind of external heating engines, Stirling engines could be applied to the micro-CHP systems driven by solar, biogas, mid-high temperature waste gases and many other heat sources. The development of a Stirling engine driven by mid-high temperature waste gases is presented first. The thermodynamic design method, the key parameters of the designed Stirling engine and its combustion chamber adapted for waste gases are described in detail. Then the performance test of the Stirling engine is carried out. During the test, the temperature of the heater head is monitored by thermocouples, and the pressure of the working fluid helium in the Stirling engine is monitored by pressure sensors. The relationships among the output shaft power, torque and speed are studied, and the pressure losses of the working fluid in the heat exchanger system are also analyzed. The test results demonstrate that the output shaft power could reach 3476 W at 1248 RPM, which is in good agreement with the predicted value of 3901 W at 1500 RPM. The test results confirm the fact that Stirling engines driven by mid-high temperature waste gases are able to achieve a valuable output power for engineering application. - Highlights: ► A β-type Stirling engine whose output power could reach about 3.5 kW is developed by ourselves. ► Waste gases are used as the heat source to drive the Stirling engine. ► Test on the relationship among the power, torque, and speed are presented. ► The pressure changing process of the working fluid in the heat exchanger system during the test is recorded and analyzed.

  19. 40 CFR 98.410 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.410 Definition of the source category. (a) The industrial gas supplier source category consists of any facility that... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Definition of the source category. 98...

  20. The addition of sugar beet to ethanol pathway in GHGenius

    International Nuclear Information System (INIS)

    2007-01-01

    Developed by Natural Resources Canada, the GHGenius model is used to estimate the life cycle emissions of primary greenhouse gases (GHGs) as well as the criteria pollutants from combustion sources. The model can be used to analyze the emissions from conventional and alternatively fuelled combustion engines and fuel cell powered trucks and vehicles, as well as light duty powered electric vehicles. Over 140 vehicle and fuel combinations can be used. This paper examined the effects of adding energy used to produce materials consumed in the production of alternative fuels in GHGenius energy balance calculations, as well as vehicle emission calculations on a carbon dioxide (CO 2 ) eq/GJ of fuel consumed basis. This paper also examined the addition of sugar beet ethanol pathways to GHGenius. Energy balances were obtained and a number of process improvements to sugar beet ethanol processing were examined as sensitivity cases. GHGenius was used to calculate the energy consumption of each stage in the production cycle. Estimates included the energy required to produce the chemicals used in the ethanol processing procedure. Results were then compared with results obtained from gasoline, corn and wheat ethanols. Results of the study showed that energy balances were lower than corn or wheat ethanol. Feedstock transmission and processing requirements were also higher due to the higher moisture content of the feedstock. The results of several European studies considering the use of sugar beet ethanol were also included. 17 tabs., 9 figs

  1. Isotope aided studies of atmospheric carbon dioxide and other greenhouse gases. Phase II

    International Nuclear Information System (INIS)

    2002-01-01

    The substantial increase in atmospheric greenhouse gas concentrations and their role in global warming have become major concerns of world governments. Application of isotope techniques to label sources and sinks of CO 2 and other greenhouse gases has emerged as a potentially powerful method for reducing uncertainties in the global CO 2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. As with CO 2 concentration measurements, meaningful integration of isotopes in global models requires careful attention to quality assurance, quality control and inter-comparability of measurements made by a number of networks and laboratories. To support improvements in isotope measurement capabilities, the IAEA began implementing Co-ordinated Research Projects (CRPs) in 1992. The first project, entitled Isotope Variations of Carbon Dioxide and other Trace Gases in the Atmosphere, was implemented from 1992 to 1994. A significant contribution was made towards a better understanding of the global carbon cycle and especially of the sources and sinks of carbon with data on the 14 C and 13 C content of atmospheric CO 2 , pointing to a better understanding of the problem of the 'missing sink' in the global carbon cycle. Important methodological developments in the field of high precision stable isotope mass spectrometry and improved data acquisition procedures emerged from work carried out within the framework of this programme. The development of pressurized gas standards and planning for an associated interlaboratory calibration were initiated. Due to the good progress and long standing nature of the required work a second CRP was initiated and implemented from 1996 to 1999. It was entitled Isotope aided Studies of Atmospheric Carbon Dioxide and Other Trace Gases - Phase II, to document the close relationship of both programmes. This publication provides an overview of the scientific outcomes of the studies conducted within Phase

  2. Desulphurisation of waste gases in Czech Republic

    Directory of Open Access Journals (Sweden)

    Svrèek Peter

    1998-09-01

    Full Text Available The paper deals with the problem of the decreasing sulphur dioxide emission in the Czech Republic. In 1991 a new Cean Air Act has been accepted. Emission limit values based on the best available technology not entailing cost. All sources of pollution will have to comply the emission limit values up to December 31, 1998 at the latest. At the present time the last units in the power plants and heating plants are under construction, many of them are on the scale. The prevailing system is the wet limestone technology producing gypsum. Differences in the installed systems, in particular power plants, are described. In a lesser extent the wet dry lime technology will be used. Old boilers are replaced by the atmospheric fluidized bed combustion. At the end of the paper the proposal of the amendment to the Europe Union Directive 608/87 EEC, is discussed. Differences in the systems in the particular power plants are described.

  3. Ozone depletion, greenhouse gases, and climate change

    Science.gov (United States)

    Mooney, Harold A.; Baker, D. James, Jr.; Bretherton, Francis P.; Burke, Kevin C.; Clark, William C.; Davis, Margaret B.; Dickinson, Robert E.; Imbrie, John; Malone, Thomas F.; Mcelroy, Michael B.

    1989-01-01

    This symposium was organized to study the unusual convergence of a number of observations, both short and long term that defy an integrated explanation. Of particular importance are surface temperature observations and observations of upper atmospheric temperatures, which have declined significantly in parts of the stratosphere. There has also been a dramatic decline in ozone concentration over Antarctica that was not predicted. Significant changes in precipitation that seem to be latitude dependent have occurred. There has been a threefold increase in methane in the last 100 years; this is a problem because a source does not appear to exist for methane of the right isotopic composition to explain the increase. These and other meteorological global climate changes are examined in detail.

  4. Screening of additives in plastics with high resolution time-of-flight mass spectrometry and different ionization sources: direct probe injection (DIP)-APCI, LC-APCI and LC-ion booster ESI

    NARCIS (Netherlands)

    Ballesteros-Gomez, A.M.; Jonkers, T.; Covaci, A.; de Boer, J.

    2016-01-01

    Plastics are complex mixtures consisting of a polymer and additives with different physico-chemical properties. We developed a broad screening method to elucidate the nature of compounds present in plastics used in electrical/electronic equipment commonly found at homes (e.g., electrical adaptors,

  5. Reference on Thermophysical Properties: Density and Viscosity of Several Gases by Using Macro Excel (RSSDFIUSK vs. 1

    Directory of Open Access Journals (Sweden)

    Elin Yusibani

    2015-09-01

    Full Text Available A source code for calculating reference on thermophysical properties: density and viscosity for several gases (nitrogen, helium, hydrogen, argon and air has been developed under Visual Basic for Applications (VBA programming in MS Excel (as a macros. Selected density and viscosity equations have been chosen as a basic equation in the VBA programming as a user-defined function. This macro is very useful for engineers and researchers due to enhance their experimental and/or theoretical studies.

  6. Reference on Thermophysical Properties: Density and Viscosity of Several Gases by Using Macro Excel (RSSDFIUSK Vs. 1)

    OpenAIRE

    Yusibani, Elin

    2015-01-01

    A source code for calculating reference on thermophysical properties: density and viscosity for several gases (nitrogen, helium, hydrogen, argon and air) has been developed under Visual Basic for Applications (VBA) programming in MS Excel (as a macros). Selected density and viscosity equations have been chosen as a basic equation in the VBA programming as a user-defined function. This macro is very useful for engineers and researchers due to enhance their experimental and/or theoretical studies.

  7. Radon in fumarolic gases from vulcano island (Sicily, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Cioni, R.; Corazza, E.; D' Amore, F.

    1984-01-01

    In this study, Radon-222 activity was measured sporadically in fumarolic gases from the island of Vulcano (Italy) between 1978 and 1980. Rn variations in the crater fumaroles (300/sup 0/C) were found to be correlated with microseismic activity; they also correlate positively with water and negatively with the S/C1 ratio. On the basis of a geochemical model, the fumarolic gases at Vulcano are assumed to be a mixture of deep magmatic gases and fluids from shallow aquifers. Rn is carried by these fluids (an average of 500 nCi per kg of fluid). Circulating water can strip Rn from the U-rich rocks on Vulcano. At present it is impossible to determine whether microseismicity is producing composition changes, or vice versa, or whether both are the consequence of a main volcano-tectonic event.

  8. Global warming description using Daisyworld model with greenhouse gases.

    Science.gov (United States)

    Paiva, Susana L D; Savi, Marcelo A; Viola, Flavio M; Leiroz, Albino J K

    2014-11-01

    Daisyworld is an archetypal model of the earth that is able to describe the global regulation that can emerge from the interaction between life and environment. This article proposes a model based on the original Daisyworld considering greenhouse gases emission and absorption, allowing the description of the global warming phenomenon. Global and local analyses are discussed evaluating the influence of greenhouse gases in the planet dynamics. Numerical simulations are carried out showing the general qualitative behavior of the Daisyworld for different scenarios that includes solar luminosity variations and greenhouse gases effect. Nonlinear dynamics perspective is of concern discussing a way that helps the comprehension of the global warming phenomenon. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Emissions of greenhouse gases in the United States 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    This is the sixth annual report on aggregate US national emissions of greenhouse gases. It covers emissions over the period 1990--1996, with preliminary estimates of emissions for 1997. Chapter one summarizes some background information about global climate change and the greenhouse effect. Important recent developments in global climate change activities are discussed, especially the third Conference of the Parties to the Framework Convention on Climate Change, which was held in December of 1997 in Kyoto, Japan. Chapters two through five cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons and related gases, respectively. Chapter six describes potential sequestration and emissions of greenhouse gases as a result of land use changes. Six appendices are included in the report. 96 refs., 38 tabs.

  10. Multisensor system for toxic gases detection generated on indoor environments

    Science.gov (United States)

    Durán, C. M.; Monsalve, P. A. G.; Mosquera, C. J.

    2016-11-01

    This work describes a wireless multisensory system for different toxic gases detection generated on indoor environments (i.e., Underground coal mines, etc.). The artificial multisensory system proposed in this study was developed through a set of six chemical gas sensors (MQ) of low cost with overlapping sensitivities to detect hazardous gases in the air. A statistical parameter was implemented to the data set and two pattern recognition methods such as Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) were used for feature selection. The toxic gases categories were classified with a Probabilistic Neural Network (PNN) in order to validate the results previously obtained. The tests were carried out to verify feasibility of the application through a wireless communication model which allowed to monitor and store the information of the sensor signals for the appropriate analysis. The success rate in the measures discrimination was 100%, using an artificial neural network where leave-one-out was used as cross validation method.

  11. A route to ultrathin quantum gases at polar perovskite heterointerfaces

    KAUST Repository

    Nazir, Safdar

    2012-09-07

    Oxide interfaces are attracting interest in recent years due to special functionalities of two-dimensional quantum gases. However, with typical thicknesses of at least 10-12 Å the gases still extend considerably in the third dimension, which compromises the size of quantum effects. To overcome this limitation, we propose incorporation of highly electronegative cations, such as Ag. By ab initio calculations, we demonstrate the formation of a mobile two-dimensional hole gas in AgNbO 3/SrTiO 3 that is confined to an ultrathin slab of only 5.6 Å thickness. Electronegative cations therefore are a promising way to enhance the quantum nature of hole gases. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Molecular Dynamics Simulation Study of Transport Properties of Diatomic Gases

    International Nuclear Information System (INIS)

    Lee, Song Hi; Kim, Ja Hun

    2014-01-01

    In this paper, we report thermodynamic and transport properties (diffusion coefficient, viscosity, and thermal conductivity) of diatomic gases (H 2 , N 2 , O 2 , and Cl 2 ) at 273.15 K and 1.00 atm by performing molecular dynamics simulations using Lennard-Jones intermolecular potential and modified Green-Kubo formulas. The results of self-diffusion coefficients of diatomic gases obtained from velocity auto-correlation functions by Green-Kubo relation are in good agreement with those obtained from mean square displacements by Einstein relation. While the results for viscosities of diatomic gases obtained from stress auto-correlation functions underestimate the experimental results, those for thermal conductivities obtained from heat flux autocorrelation functions overestimate the experimental data except H 2

  13. High-resolution spectroscopy of gases for industrial applications

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    databases (e.g. HITRAN, HITEMP or CDSD) can normally be used for absorption spectra calculations at limited temperature/pressure ranges. Therefore experimental measurements of absorption/transmission spectra gases (e.g. CO2, H2O or SO2) at high-resolution and elevated temperatures are essential both......High-resolution spectroscopy of gases is a powerful technique which has various fundamental and practical applications: in situ simultaneous measurements of gas temperature and gas composition, radiative transfer modeling, validation of existing and developing of new databases and etc. Existing...... for analysis of complex experimental data and further development of the databases. High-temperature gas cell facilities available at DTU Chemical Engineering are presented and described. The gas cells and high-resolution spectrometers allow us to perform high-quality reference measurements of gases relevant...

  14. Opportunity to reduce the exhaust gases with engine adjust

    International Nuclear Information System (INIS)

    Dimitrovski, Mile; Mucevski, Kiril

    2002-01-01

    According to statistics in the Republic of Macedonia, the number of old vehicles is about 90%. These are vehicles produced between 1975 and 1990 with classical systems for forming and burning the fuel mixture. The most of them do not have system for processing exhaust gases (catalytic converter) and are serious air pollutants of carbon monoxide (CO). In this article we try to make an attempt to reduce exhaust gases in some kinds of these vehicles with adjusting to the system for burning fuel mixture and with adjusting to the system for forming fuel mixture (carburetor). At the same time the changes on the rotate bending moment and engine power are followed. It is noticed that with a proper adjustment the emission of exhaust gases can be reduced without a serious depreciation of the rotate bending moment and the engine power. (Author)

  15. Spherically symmetric high-velocity plasma expansions into background gases

    Science.gov (United States)

    Tan, T.-H.; Borovsky, J. E.

    1986-01-01

    Spherically symmetric plasmas with high expansion velocities have been produced by irradiating targets with eight beams from the Helios CO2 laser in the presence of gases at various pressures. Attention was given to the properties of the target-emitted ions in order to obtain information about the ion-acceleration mechanisms in plasma expansions. Photoionization of the ambient gases by the soft X-ray emission from the laser-irradiated targets produced background plasmas, permitting plasma counterstreaming experiments to be performed in spherical geometry. Successful laser-target coupling in the presence of back-ground gases is obtained; modification of the ion acceleration in accordance with isothermal-expansion models is observed; and an absence of collective coupling between collisionless counterstreaming plasmas is found.

  16. Source rock hydrocarbons. Present status

    International Nuclear Information System (INIS)

    Vially, R.; Maisonnier, G.; Rouaud, T.

    2013-01-01

    This report first presents the characteristics of conventional oil and gas system, and the classification of liquid and gaseous non conventional hydrocarbons, with the peculiar case of coal-bed methane. The authors then describe how source rock hydrocarbons are produced: production of shale oils and gases (horizontal drilling, hydraulic fracturing, exploitation) and of coal-bed methane and coal mine methane. In the next part, they address and discuss the environmental impact of source rock hydrocarbon production: installation footprint, water resource management, drilling fluids, fracturing fluids composition, toxicity and recycling, air pollution, induced seismicity, pollutions from other exploitation and production activities. They propose an overview of the exploitation and production of source rock gas, coal-bed gas and other non conventional gases in the world. They describe the current development and discuss their economic impacts: world oil context and trends in the USA, in Canada and other countries, impacts on the North American market, on the world oil industry, on refining industries, on the world oil balance. They analyse the economic impacts of non conventional gases: development potential, stakes for the world gas trade, consequence for gas prices, development opportunities for oil companies and for the transport sector, impact on CO 2 emissions, macro-economic impact in the case of the USA

  17. Radiolytic and thermal generation of gases from Hanford grout samples

    Energy Technology Data Exchange (ETDEWEB)

    Meisel, D.; Jonah, C.D.; Kapoor, S.; Matheson, M.S.; Mulac, W.A.

    1993-10-01

    Gamma irradiation of WHC-supplied samples of grouted Tank 102-AP simulated nonradioactive waste has been carried out at three dose rates, 0.25, 0.63, and 130 krad/hr. The low dose rate corresponds to that in the actual grout vaults; with the high dose rate, doses equivalent to more than 40 years in the grout vault were achieved. An average G(H{sub 2}) = 0.047 molecules/100 eV was found, independent of dose rate. The rate of H2 production decreases above 80 Mrad. For other gases, G(N{sub 2}) = 0.12, G(O{sub 2}) = 0.026, G(N{sub 2}O) = 0.011 and G(CO) = 0.0042 at 130 krad/hr were determined. At lower dose rates, N{sub 2} and O{sub 2} could not be measured because of interference by trapped air. The value of G(H{sub 2}) is higher than expected, suggesting segregation of water from nitrate and nitrite salts in the grout. The total pressure generated by the radiolysis at 130 krad/h has been independently measured, and total amounts of gases generated were calculated from this measurement. Good agreement between this measurement and the sum of all the gases that were independently determined was obtained. Therefore, the individual gas measurements account for most of the major components that are generated by the radiolysis. At 90 {degree}C, H{sub 2}, N{sub 2}, and N{sub 2}O were generated at a rate that could be described by exponential formation of each of the gases. Gases measured at the lower temperatures were probably residual trapped gases. An as yet unknown product interfered with oxygen determinations at temperatures above ambient. The thermal results do not affect the radiolytic findings.

  18. Novel System for Continuous Measurements of Dissolved Gases in Liquids

    Science.gov (United States)

    Baer, D. S.; Liem, J.; Owano, T. G.; Gupta, M.

    2014-12-01

    Measurements of dissolved gases in lakes, rivers and oceans may be used to quantify underwater greenhouse gas generation, air-surface exchange, and pollution migration. Studies involving quantification of dissolved gases typically require obtaining water samples (from streams, lakes, or ocean water) and transporting them to a laboratory, where they are degased. The gases obtained are then generally measured using gas chromatography and isotope ratio mass spectrometry for concentrations and isotope ratios, respectively. This conventional, off-line, discrete-sample methodology is time consuming and labor intensive, and thus severely inhibits detailed spatial and temporal mapping of dissolved gases. In this work, we describe the commercial development of a new portable membrane-based gas extraction system (18.75" x 18.88" x 10.69", 16 kg, 85 watts) that interfaces directly to our cavity enhanced laser absorption based (or Off-Axis ICOS) gas analyzers to continuously and quickly measure concentrations and isotope ratios of dissolved gases. By accurately controlling the water flow rate through the membrane contactor, gas pressure on the outside and water pressure on the inside of the membrane, the system can generate precise and highly reproducible results. Furthermore, the gas-phase mole fractions (parts per million, ppm) may be converted into dissolved gas concentrations (nM), by accurately measuring the gas flow rates in and out of the extraction system. We will present detailed laboratory test data that quantifies the performance (linearity, precision, and dynamic range) of the system for measurements of the concentrations and isotope ratios of dissolved greenhouse gases (methane, carbon dioxide, and nitrous oxide) continuously and in real time.

  19. A biological model of tamponade gases following pneumatic retinopexy.

    Science.gov (United States)

    Hutter, Joseph; Luu, Hoan; Schroeder, LeRoy

    2002-10-01

    Predict the persistence and expansion of intra-ocular tamponade gases used in retinal detachment surgery. Quantify factors that contribute to elevations in the intraocular pressure. We developed a non-equilibrium physiological model of intraocular gas transfer in vitreoretinal surgery. The model was calibrated using published volumetric decay measurements for four perfluorocarbon gases (CF(4), C(2)F(6), C(3)F(8), C( 4)F(10)) injected into the New Zealand red rabbit. We validated the model by comparing predicted and experimental results at different conditions in the rabbit. Using the rabbit results, the model was scaled up to humans. Predictions of gas expansion, half-life, and intraocular pressure in humans were found to correlate very well with clinical results. Gas transfer in the eye was controlled by diffusion through plasma and membranes. Although intraocular pressure depended on several complicating factors such as the physiological condition of the eye as well as the medications being used, prediction of conditions that favor elevations in intraocular pressure were identified based on the transport and thermodynamic properties of the gases. The biological model accurately predicted the dynamics of intraocular gases in the human eye. The major factor affecting the intraocular pressure was the aqueous humor dynamics, which is highly dependent on the physiological conditions in the eye. However, for long duration gases such as perfluoropropane, elevations in intraocular pressure are possible following an increase in volume and/or purity of the injected gas. By injecting a mixture of air with an expansive gas, it is possible to reduce elevations in intraocular pressure in patients with the trade off of a reduced longevity of the gas bubble. For gases that diffuse faster than perfluoropropane, there are minimal effects on intraocular pressure due to these changes.

  20. Observations of mass fractionation of noble gases in synthetic methane hydrate

    Science.gov (United States)

    Hunt, Andrew G.; Pohlman, John; Stern, Laura A.; Ruppel, Carolyn D.; Moscati, Richard J.; Landis, Gary P.; Pinkston, John C.

    2011-01-01

    As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings are presently dissociating and releasing methane and other gases to the oceanatmosphere system. A key challenge in assessing the susceptibility of gas hydrates to warming climate is the lack of a technique able to distinguish between methane recently released from gas hydrates and methane emitted from leaky thermogenic reservoirs, shallow sublake and subseafloor sediments, coalbeds, and other sources. Carbon and deuterium stable isotopic data provide only a first-order characterization of methane sources, while gas hydrate can sequester any type of methane. Here, we investigate the possibility of exploiting the pattern of noble gas fractionation within the gas hydrate lattice to fingerprint methane released from gas hydrates. Starting with synthetic gas hydrate formed under careful laboratory conditions, we document complex noble gas fractionation patterns in the gases liberated during dissociation and explore the effects of aging and storage (e.g., in liquid nitrogen), as well as sampling and preservation procedures. The laboratory results confirm a unique noble gas fractionation pattern for gas hydrates, one that shows promise in evaluating modern natural gas seeps for a signature associated with gas hydrate dissociation.