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Sample records for gases determination des

  1. Dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques Depolluting Exhaust Gases from Diesel Engines by Catalytic Mufflers

    Directory of Open Access Journals (Sweden)

    Goldenberg E.

    2006-11-01

    Full Text Available On présente dans cet article les résultats d'une première série de recherches sur la dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques. L'efficacité des catalyseurs à base de platine pour l'oxydation du monoxyde de carbone et des hydrocarbures imbrûlés a pu être établie par des essais sur banc moteur et sur véhicule. L'emploi de certaines phases actives à base de métaux non nobles permet d'autre part d'abaisser la température de début d'oxydation des particules de suie de 380 à 250 °C environ, avec, entre 250 et 350 °C, élimination de 15 à 20 % des produits piégés. L'essai de divers media filtrants a mis en évidence l'importance des phénomènes d'adsorption des revêtements en alumine et a orienté la recherche vers de nouveaux supports pour filtres catalytiques. This article describes the results of a first series of research on the depollution of exhaust gases from diesel engines by catalytic mufflers. The effectiveness of platinum-base catalysts for the oxidation of carbon monoxide and unburned hydrocarbons was determined by test on an engine test bed and on vehicles on the road. The use of some active non-noble metal phases reduced on the other hand the starting oxidation temperature of soot particulates from 380°C to about 250°C, eliminating 15 to 20% of the trapped products between 250 and 350° C. Tests of different filtering media revealed the importance of adsorption phenomena on alumina coatings and directed research toward new supports for catalytic filters.

  2. The method of determination of mercury adsorption from flue gases

    Directory of Open Access Journals (Sweden)

    Budzyń Stanisław

    2017-01-01

    Full Text Available For several recent years Faculty of Energy and Fuels of the AGH University of Science and Technology in Krakow conduct intensive studies on the occurrence of mercury contained in thermal and coking coals, as well as on the possible reduction of fossil-fuel mercury emissions. This research focuses, among others, on application of sorbents for removal of mercury from flue gases. In this paper we present the methodology for testing mercury adsorption using various types of sorbents, in laboratory conditions. Our model assumes burning a coal sample, with a specific mercury content, in a strictly determined time period and temperature conditions, oxygen or air flow rates, and the flow of flue gases through sorbent in a specific temperature. It was developed for particular projects concerning the possibilities of applying different sorbents to remove mercury from flue gases. Test stand itself is composed of a vertical pipe furnace inside which a quartz tube was mounted for sample burning purposes. At the furnace outlet, there is a heated glass vessel with a sorbent sample through which flue gases are passing. Furnace allows burning at a defined temperature. The exhaust gas flow path is heated to prevent condensation of the mercury vapor prior to contact with a sorbent. The sorbent container is positioned in the heating element, with controlled and stabilized temperature, which allows for testing mercury sorption in various temperatures. Determination of mercury content is determined before (coal and sorbent, as well as after the process (sorbent and ash. The mercury balance is calculated based on the Hg content determination results. This testing method allows to study sorbent efficiency, depending on sorption temperature, sorbent grain size, and flue-gas rates.

  3. Determination experimentale des principales caracteristiques ...

    African Journals Online (AJOL)

    Through the present research work, usual scientific parameters and characteristics of Borassus palm wood from Benin, are determined. Specifically, infradensity, shrinkage coefficient and behaviour, breaking stress in the direction of the fibbers at pulling, compression and bending, are known as well as Young modulus at ...

  4. Recent Experimental Advances to Determine (noble) Gases in Waters

    Science.gov (United States)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (doi:10:4319/lom.2011.9.42. [2] Vogel et al. (2013) Geochem. Geophys. Geosyst., 14, doi:10.1002/ggge.20164. [3] Brennwald et al. (2013) Environ. Sci. Technol., Article ASAP, DOI: 10.1021/es401698p. [4] Mächler et al. (2012) Environ. Sci. Technol., 47, 7060-7066. [5] Huxol et al. Environ. Sci. Technol., in revision.

  5. Study of gases contained in an Antarctica glacier; Etude des gaz contenus dans un glacier antarctique

    Energy Technology Data Exchange (ETDEWEB)

    Raynaud, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-15

    This report presents a study of gases contained in ice samples taken from a drilling 97.8 meters deep in the coastal zone of Adelie Land (Antarctica). Simultaneously, a study has been made of the composition of the atmospheric air and of the gases extracted in situ from the firn. Carbon dioxyde was analysed by means of gas-phase chromatography and argon, oxygen and nitrogen by means of mass spectrometry. The results obtained show that for the most part the oxygen concentration decreases with an increase in the depth of the drilling. The values range from a maximum of 20,83 per cent of the volume at the surface to a minimum of 19,46 per cent of the volume at a depth of 87 meters. The results also show that the distribution of carbon dioxide concentration does not vary with the depth. These concentrations are either in the same range as or lower than the concentration of CO{sub 2} found in atmospheric air. The different results are discussed. (author) [French] Le present travail rend compte d'analyses de gaz contenus dans des echantillons de glace provenant d'un forage de 97,8 m de profondeur, realise dans la zone cotiere de la Terre Adelie (Antarctique). Parallelement, la composition d'air atmospherique et de gaz extraits in situ du neve a ete etudiee. La chromatographie en phase gazeuse a ete utilisee pour analyser le CO{sub 2} et la spectrometrie de masse pour analyser l'argon, l'oxygene et l'azote. Les resultats obtenus indiquent essentiellement le long du forage: - une decroissance de la teneur en oxygene avec la profondeur, les valeurs extremes etant de 20.83 pour cent en volume a la surface et de 19,46 pour cent en volume a - 87 metres, - une repartition des teneurs en CO{sub 2} sans correlation nette avec la profondeur, ces teneurs etant de l'ordre ou inferieures a la teneur atmospherique. Les differents resultats sont discutes. (auteur)

  6. Using Thermal Infrared Absorption and Emission to Determine Trace Gases

    Science.gov (United States)

    Clerbaux, Cathy; Drummond, James R.; Flaud, Jean-Marie; Orphal, Johannes

    The light emerging from the top of the atmosphere in the greater part of the infrared region is thermal radiation from the Earth's surface. The resultant spectra obtained depend on the temperature difference between the emitting feature and absorbing gas. In this region the greenhouse gases, carbon dioxide, CO2, methane, CH4, ozone, O3, and water, H2O, are observed as well as carbon monoxide, CO, a product indicative of fossil fuel combustion, methanol, CH3OH, from biomass burning, and ammonia, NH3, from agriclulture. Chapter 3 describes the techniques for retrieving atmospheric abundances of these and other species from a number of satellite instruments, and concludes with suggestions for future developments.

  7. Methodology to determining the efficiency of a rare gases monitor

    International Nuclear Information System (INIS)

    Carvalho, Marcos R. de; Soares, Adalberto J.

    1996-01-01

    This work presents a methodology to determinate the efficiency of air monitors used to measure the concentration of noble gas in nuclear power stations. Efficiency values, theoretically determined, were compared with experimental data, using punctual β sources. (author)

  8. 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

  9. Determining the Speed of Sound and Heat Capacity Ratios of Gases by Acoustic Interferometry

    Science.gov (United States)

    Varberg, Thomas D.; Pearlman, Bradley W.; Wyse, Ian A.; Gleason, Samuel P.; Kellett, Dalir H. P.; Moffett, Kenneth L.

    2017-01-01

    In this paper, we describe an experiment for the undergraduate physical chemistry laboratory in which students determine the speed of sound in the gases He, N[subscript 2], CO[subscript 2], and CF[subscript 3]CH[subscript 2]F. The experimental apparatus consists of a closed acrylic tube containing the gas under study. White audio noise is injected…

  10. Comparison of two standard test methods for determining explosion limits of gases at atmospheric conditions.

    Science.gov (United States)

    De Smedt, G; de Corte, F; Notelé, R; Berghmans, J

    1999-12-31

    A comparison is made between two internationally accepted methods to determine the explosion limits of gases at atmospheric pressure and room temperature (20 l sphere - DIN 51649). Significant differences (about 1 vol.%) in the upper explosion limits (UEL) values are found for four hydrocarbons tested. A new criterion is proposed which leads to close agreement between the UEL values obtained by the two methods.

  11. The optical method for determining the thermodynamic parameters of hot gases

    International Nuclear Information System (INIS)

    Egorov, O.V.; Voitsekhovskaya, O.K.; Kashirskii, D.E.; Tsvyk, R.Sh.; Sazanovich, V.M.; Sherstobitov, M.V.

    2014-01-01

    The research conducted on the thermodynamic parameters of a flame was based on its experimental transmission spectra in the 2.7 μm and 4.3 μm ranges. To produce the flame, alcohol was burned under atmospheric conditions. The hot gases resulting from the burning of ethanol (H 2 O, CO, and CO 2 ) were accelerated and spun by the rotation of an impeller. The optical method developed by the authors was employed for predicting the temperature and partial pressure of the hot gases. The results demonstrate the practical significance of the method suggested. The spectroscopic database HITEMP 2010 was used for all line-by-line calculations presented in the article. - Highlights: • We report an optical method for determining the thermodynamic parameters of hot gases. • This method was tested in an experiment by burning alcohol at surface level atmospheric pressure. • The results of this research indicate the practical application of the suggested method

  12. La socialisation comme determinant des inegalites de reussite en ...

    African Journals Online (AJOL)

    La socialisation comme determinant des inegalites de reussite en education physique et sportive entre filles et garçons musulmans au Senegal. ... de leur capital en matière de socialisation et d'expériences de pratique au cours d'EPS ; d'autre part, du fait entre-autre de la recherche de performance et du caractère objectif ...

  13. Dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques Depolluting Exhaust Gases from Diesel Engines by Catalytic Mufflers

    OpenAIRE

    Goldenberg E.; Prigent M.; Caillod J.

    2006-01-01

    On présente dans cet article les résultats d'une première série de recherches sur la dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques. L'efficacité des catalyseurs à base de platine pour l'oxydation du monoxyde de carbone et des hydrocarbures imbrûlés a pu être établie par des essais sur banc moteur et sur véhicule. L'emploi de certaines phases actives à base de métaux non nobles permet d'autre part d'abaisser la température de début d'oxydation des particule...

  14. Agriculture and greenhouse gases emissions reduction; Agriculture et reduction des emissions de gaz a effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Leguet, B.

    2005-09-15

    In France, the agriculture is the third sector of greenhouse gases emitter. Meanwhile since 1990 this sector poorly reduces its greenhouse gases. It is necessary to find mechanisms which allow the valorization of emissions reduction. In this framework the author presents the specificities of the greenhouse gases emissions of the agricultural sector, the possible incentives of emissions reduction, the reduction projects in France and abroad. (A.L.B.)

  15. 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.

  16. 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.

  17. 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)

  18. DETERMINATION OF CO2 MASSES IN THE EXHAUST GASES OF THE MARINE DIESEL ENGINES

    Directory of Open Access Journals (Sweden)

    Doru COSOFRET

    2016-05-01

    Full Text Available Currently, reducing CO2 emissions that contribute to the greenhouse effect is currently under attention of the relevant international bodies. In the field of maritime transport, in 2011 International Maritime Organization (IMO has taken steps to reduce emissions of CO2 from the exhaust gases of marine diesel engines on ships, by imposing their energy efficiency standards. In this regard, we conducted a laboratory study on a 4-stroke diesel engine naturally aspirated by using to power it diesel and different blends of biodiesel with diesel fuel. The purpose of the study was to determine the formulas for calculating the mass flow rates of CO2 from exhaust gases’ concentrations experimentally determined. Determining the mass flow of CO2 is necessary to calculate the energy efficiency coefficient of the ship to assess the energy efficiency of the board of the limits imposed by the IMO.

  19. The suitability of using dissolved gases to determine groundwater discharge to high gradient streams

    Science.gov (United States)

    Gleeson, Tom; Manning, Andrew H.; Popp, Andrea; Zane, Mathew; Clark, Jordan F.

    2018-01-01

    Determining groundwater discharge to streams using dissolved gases is known to be useful over a wide range of streamflow rates but the suitability of dissolved gas methods to determine discharge rates in high gradient mountain streams has not been sufficiently tested, even though headwater streams are critical as ecological habitats and water resources. The aim of this study is to test the suitability of using dissolved gases to determine groundwater discharge rates to high gradient streams by field experiments in a well-characterized, high gradient mountain stream and a literature review. At a reach scale (550 m) we combined stream and groundwater radon activity measurements with an in-stream SF6 tracer test. By means of numerical modeling we determined gas exchange velocities and derived very low groundwater discharge rates (∼15% of streamflow). These groundwater discharge rates are below the uncertainty range of physical streamflow measurements and consistent with temperature, specific conductance and streamflow measured at multiple locations along the reach. At a watershed-scale (4 km), we measured CFC-12 and δ18O concentrations and determined gas exchange velocities and groundwater discharge rates with the same numerical model. The groundwater discharge rates along the 4 km stream reach were highly variable, but were consistent with the values derived in the detailed study reach. Additionally, we synthesized literature values of gas exchange velocities for different stream gradients which show an empirical relationship that will be valuable in planning future dissolved gas studies on streams with various gradients. In sum, we show that multiple dissolved gas tracers can be used to determine groundwater discharge to high gradient mountain streams from reach to watershed scales.

  20. The suitability of using dissolved gases to determine groundwater discharge to high gradient streams

    Science.gov (United States)

    Gleeson, Tom; Manning, Andrew H.; Popp, Andrea; Zane, Matthew; Clark, Jordan F.

    2018-02-01

    Determining groundwater discharge to streams using dissolved gases is known to be useful over a wide range of streamflow rates but the suitability of dissolved gas methods to determine discharge rates in high gradient mountain streams has not been sufficiently tested, even though headwater streams are critical as ecological habitats and water resources. The aim of this study is to test the suitability of using dissolved gases to determine groundwater discharge rates to high gradient streams by field experiments in a well-characterized, high gradient mountain stream and a literature review. At a reach scale (550 m) we combined stream and groundwater radon activity measurements with an in-stream SF6 tracer test. By means of numerical modeling we determined gas exchange velocities and derived very low groundwater discharge rates (∼15% of streamflow). These groundwater discharge rates are below the uncertainty range of physical streamflow measurements and consistent with temperature, specific conductance and streamflow measured at multiple locations along the reach. At a watershed-scale (4 km), we measured CFC-12 and δ18O concentrations and determined gas exchange velocities and groundwater discharge rates with the same numerical model. The groundwater discharge rates along the 4 km stream reach were highly variable, but were consistent with the values derived in the detailed study reach. Additionally, we synthesized literature values of gas exchange velocities for different stream gradients which show an empirical relationship that will be valuable in planning future dissolved gas studies on streams with various gradients. In sum, we show that multiple dissolved gas tracers can be used to determine groundwater discharge to high gradient mountain streams from reach to watershed scales.

  1. LA RECHERCHE DES DETERMINANTS DE LA PERFORMANCE : APPLICATION A L'ORGANISATION SPATIALE DES BUREAUX

    OpenAIRE

    Véronique Malleret

    2003-01-01

    International audience; Cette communication examine les liens qui peuvent exister entre l'organisation spatiale des bureaux et la performance des entreprises. Elle propose un cadre d'analyse articulant les différentes variables du problème et l'illustre ensuite par une étude de cas.

  2. Determination of low molecular weight monocarboxylic Acid gases in the atmosphere by parallel plate diffusion scrubber-ion chromatography.

    Science.gov (United States)

    Lee, Bokyoung; Hwangbo, Yown; Lee, Dong Soo

    2009-08-01

    A method has been developed for the determination of the concentration of low molecular weight monocarboxylic acid gases in the atmosphere. The method involves quantitative collection of analyte gases using a parallel plate diffusion scrubber and subsequent ion analysis by ion chromatography. Among the gases are formic acid, acetic acid, propionic acid, n-butyric acid, and n-valeric acid. Method detection limits are on the order of sub to low parts-per-trillion by volume. The method has been successfully applied to ambient air analysis.

  3. 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)

  4. Comparison of different methods of assessing the tar content of gases from wood gasification; Vergleich verschiedener Methoden zur Bestimmung des Teergehalts in Gasen aus der Holzvergasung

    Energy Technology Data Exchange (ETDEWEB)

    Moersch, O.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

    1998-09-01

    The authors present a method developed at the Institute of Chemical Engineering and Steam Boiler Technology (IVD) of Stuttgart University for quasi-continuous online measurement of tar concentrations in gases from biomass gasification. The method is compared with other methods in terms of time requirements, accuracy, and cost: Gravimetry, wet chemical analysis, solid phase amino-adsorption (SPA), and online process gas chromatography. The measurements were carried out on the fluidized-bed combustion system of the IVD. Wood was gasified at 800 degrees centigrade with a fuel/air ratio of 0.25. The measured tar concentrations differed widely, i.e. between 0.8 and 6.8 g per cubic metre. (orig.) [Deutsch] In dieser Arbeit wird ein am Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) entwickeltes Verfahren zur quasikontinuierlichen Online-Messung des Teergehalts im Gas aus der Biomassevergasung vorgestellt und mit anderen Methoden aus der Literatur im Hinblick auf Zeitaufwand, Genauigkeit und Kosten verglichen. Untersucht wurden dabei eine gravimetrische Methode, die nasschemische Bestimmung, das Solid-Phase-Amino Adsorptionsverfahren (SPA), sowie die Online Analyse mittels Prozess-Gaschromatograph. Die Messungen wurden an der Wirbelschichtvergasungsanlage des IVD durchgefuehrt. Vergast wurde Holz bei 800 C und einer Luftzahl von 0.25. Der mit den verschiedenen Verfahren ermittelte Teergehalt unterscheidet sich zum Teil erheblich. Es ergaben sich Werte zwischen 0.8 und 6.8 g/m{sup 3}. (orig.)

  5. Determination of viscous pressure losssand resistance upstream from the choke point from breathing gases of different physical properties

    DEFF Research Database (Denmark)

    Pedersen, O.F.

    2007-01-01

      Determination of viscous pressure loss and resistance upstream from the choke point from breathing gases of different physical properties Ole F. Pedersen, Institute of Public Health, University of Aarhus, Denmark. AIM. To determine viscous pressure losses and resistances  upstream to CP...

  6. 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

  7. Experimental and simulation determination of minimum miscibility pressure for a Bakken tight oil and different injection gases

    Directory of Open Access Journals (Sweden)

    Sheng Li

    2017-03-01

    Full Text Available The effective development of unconventional tight oil formations, such as Bakken, could include CO2 enhanced oil recovery (EOR technologies with associated benefits of capturing and storing large quantities of CO2. It is important to conduct the gas injection at miscible condition so as to reach maximum recovery efficiency. Therefore, determination of the minimum miscibility pressure (MMP of reservoir live oil–injection gas system is critical in a miscible gas flooding project design. In this work, five candidate injection gases, namely CO2, CO2-enriched flue gas, natural gas, nitrogen, and CO2-enriched natural gas, were selected and their MMPs with a Bakken live oil were determined experimentally and numerically. At first, phase behaviour tests were conducted for the reconstituted Bakken live oil and the gases. CO2 outperformed other gases in terms of viscosity reduction and oil swelling. Rising bubble apparatus (RBA determined live oil–CO2 MMP as 11.9 MPa and all other gases higher than 30 MPa. The measured phase behaviour data were used to build and tune an equation-of-state (EOS model, which calculated the MMPs for different live oil-gas systems. The EOS-based calculations indicated that CO2 had the lowest MMP with live oil among the five gases in the study. At last, the commonly-accepted Alston et al. equation was used to calculate live oil–pure CO2 MMP and effect of impurities in the gas phase on MMP change. The Bakken oil–CO2 had a calculated MMP of 10.3 MPa from the Alston equation, and sensitivity analysis showed that slight addition of volatile impurities, particularly N2, can increase MMP significantly.

  8. Determinants de l'adoption des semences certifiees de varietes ...

    African Journals Online (AJOL)

    Au Bénin, la diffusion des variétés à haut rendement de riz s'est accélérée en réponse à une demande croissante de cette denrée. Ces variétés évaluées par la recherche, favorisent l'augmentation du rendement de la production rizicole. Pour cela, la semence de ces variétés nécessite un renouvellement périodique dans ...

  9. The Adiabatic Expansion of Gases and the Determination of Heat Capacity Ratios: A Physical Chemistry Experiment.

    Science.gov (United States)

    Moore, William M.

    1984-01-01

    Describes the procedures and equipment for an experiment on the adiabatic expansion of gases suitable for demonstration and discussion in the physical chemical laboratory. The expansion produced shows how the process can change temperature and still return to a different location on an isotherm. (JN)

  10. [Determination of partition coefficient of dissolved gases in transformer oil using phase ratio variation method and static headspace gas chromatography].

    Science.gov (United States)

    Zhao, Jinghong; Wang, Hailong; Liu, Wenmin; Zhou, Yansheng; Guan, Yafeng

    2004-05-01

    The partition coefficients of dissolved gases in transformer oil were determined using a phase ratio variation method and static headspace gas chromatography (GC). A pressure balancing and gas volume-metering device was connected to the vent of a sample loop on a six-port injection valve of the GC. The gas phase sample from the headspace vial of 25 mL was transferred to an 80 microL sample-loop through a fused silica capillary of 0.53 mm i.d., and then separated and determined quantitatively by GC. A 2 m x 1 mm i.d. GDX502 micro-packed column was used for the separation. Five different gas-liquid volume ratios in the headspace vials were measured at different equilibrium concentrations. The partition coefficients of hydrocarbon gases including methane, acetylene, ethylene, ethane and propane dissolved in transformer oil were determined by using linear regression analysis at 20 degrees C and 50 degrees C separately. The errors between the real values and regression values from experimental data were less than 4.14% except methane. Fundamental data for on-line measurement of dissolved gases in transformer oil are provided by GC.

  11. Determination of the energy potential of gases produced in the pyrolysis processes of the vegetal carbon manufacture industry.

    Science.gov (United States)

    Gañan, J; González, J F; González-García, C M; Cuerda-Correa, E M; Macías-García, A

    2006-03-01

    In this work, a pyrolysis plant located in Valverde de Leganes, Badajoz (SW Spain) was studied. At present, only the solid phase obtained by pyrolysis finds an application as domestic fuel. In order to analyze the feasibility of a further energetic exploitation of the plant under study, the gases flowing through the chimneys were collected at different times throughout the pyrolysis process. Next, they were characterized and quantified by gas chromatography, the energy potential of each of the gases being determined. According to the results obtained in this study, a total energy potential of 5.6 x 10(7) MJ (i.e., 1.78 MW(t)) might be generated yearly. Hence, considering an overall process yield equal to 20%, up to 358 KW(e) would be produced. This power would supply enough electric energy to the industry, the remaining being added to the common electric network.

  12. Use of DES Modeling for Determining Launch Availability for SLS

    Science.gov (United States)

    Staton, Eric; Cates, Grant; Finn, Ronald; Altino, Karen M.; Burns, K. Lee; Watson, Michael D.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) is developing new capabilities for human and scientific exploration beyond Earth's orbit. This effort includes the Space Shuttle derived Space Launch System (SLS), the Orion Multi-Purpose Crew Vehicle (MPCV), and the Ground Systems Development and Operations (GSDO). There are several requirements and Technical Performance Measures (TPMs) that have been levied by the Exploration Systems Development (ESD) upon the SLS, Orion, and GSDO Programs including an integrated Launch Availability (LA) TPM. The LA TPM is used to drive into the SLS, Orion and GSDO designs a high confidence of successfully launching exploration missions that have narrow Earth departure windows. The LA TPM takes into consideration the reliability of the overall system (SLS, Orion and GSDO), natural environments, likelihood of a failure, and the time required to recover from an anomaly. A challenge with the LA TPM is the interrelationships between SLS, Orion, GSDO and the natural environments during launch countdown and launch delays that makes it impossible to develop an analytical solution for calculating the integrated launch probability. This paper provides an overview of how Discrete Event Simulation (DES) modeling was used to develop the LA TPM, how it was allocated down to the individual programs, and how the LA analysis is being used to inform and drive the SLS, Orion, and GSDO designs to ensure adequate launch availability for future human exploration.

  13. Analysis of odorous gases with simultaneous GC-MS and sensory determination

    Energy Technology Data Exchange (ETDEWEB)

    Orko, I.; Lehtomaeki, J.; Sandell, E.; Arnold, M. [VTT Chemical Technology, Espoo (Finland). Environmental Technology

    1995-12-31

    Industrial odorous off-gases can consist of hundreds of different compounds giving cause to odour annoyance in the vicinity of the odour-emitting plant. For the identification of the odorous components in the gas, traditional analytical methods are not always sufficient since the odour threshold values cannot often be found in literature. This report describes the development of a GC-MS sniffing port method for identifying odorous compounds in off-gases. In the method the sample is injected into a gas chromatograph and divided into two flows. The compounds in these sample flows are separated in two identical columns and detected simultaneously in a mass spectrometer and by sensory means. The olfactory detections are marked in the iongram and the odorous compounds are identified. Tenax TA adsorbent is generally used for collecting the odorous sample for analysis. The compounds are released from the adsorbent for analysis by thermal desorption. The report also describes a case study where the GC-MS sniffing port method was applied to a gaseous emission from a food factory. Over ten odorous compounds could be identified. (author)

  14. 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.)

  15. 77 FR 5514 - Mandatory Reporting of Greenhouse Gases: Notice of Preliminary Determinations Regarding Requests...

    Science.gov (United States)

    2012-02-03

    ... To Use Provisional Global Warming Potentials Under the Fluorinated Gas Production Category of the... preliminary determinations regarding requests to use provisional global warming potentials for eight...-1742. FOR FURTHER INFORMATION CONTACT: Deborah Ottinger, Climate Change Division, Office of Atmospheric...

  16. 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

  17. The Determination of Total Nitrogen Oxides in Stack Gases. Phenoldisulfonic Acid Method.

    Science.gov (United States)

    Thorpe, Charles J. D.

    The well known Saltzman method for oxides of nitrogen is intended for the determination of these constituents in the ambient atmosphere in the range of a few parts per billion to about 5ppm. However, when sulfur dioxide is present in the gas to be sampled and/or the concentration range of the oxides of nitrogen is from five to several thousand…

  18. The Determination of Hydrogen Sulfide in Stack Gases, Iodometric Titration After Sulfite Removal.

    Science.gov (United States)

    Robles, E. G.

    The determination of hydrogen sulfide in effluents from coal-fired furnaces and incinerators is complicated by the presence of sulfur oxides (which form acids). Organic compounds also may interfere with or prevent the formation of the cadmium sulfide precipitate or give false positive results because of reaction with iodine. The report presents a…

  19. 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

  20. Determination of maximal amount of minor gases adsorbed in a shale sample by headspace gas chromatography.

    Science.gov (United States)

    Zhang, Chun-Yun; Hu, Hui-Chao; Chai, Xin-Sheng; Pan, Lei; Xiao, Xian-Ming

    2014-02-07

    In this paper, we present a novel method for determining the maximal amount of ethane, a minor gas species, adsorbed in a shale sample. The method is based on the time-dependent release of ethane from shale samples measured by headspace gas chromatography (HS-GC). The study includes a mathematical model for fitting the experimental data, calculating the maximal amount gas adsorbed, and predicting results at other temperatures. The method is a more efficient alternative to the isothermal adsorption method that is in widespread use today. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Effect of variation in argon content of calibration gases on determination of atmospheric carbon dioxide.

    Science.gov (United States)

    Min, Deullae; Kang, Namgoo; Moon, Dong Min; Lee, Jin Bok; Lee, Dong Soo; Kim, Jin Seog

    2009-12-15

    Carbon dioxide (CO(2)) is a greenhouse gas that makes by far the largest contribution to the global warming of the Earth's atmosphere. For the measurements of atmospheric CO(2) a non-dispersive infrared analyzer (NDIR) and gas chromatography are conventionally being used. We explored whether and to what degree argon content can influence the determination of atmospheric CO(2) using the comparison of CO(2) concentrations between the sample gas mixtures with varying Ar amounts at 0 and 18.6 mmol mol(-1) and the calibration gas mixtures with Ar at 8.4, 9.1, and 9.3 mmol mol(-1). We newly discovered that variation of Ar content in calibration gas mixtures could undermine accuracy for precise and accurate determination of atmospheric CO(2) in background air. The differences in CO(2) concentration due to the variation of Ar content in the calibration gas mixtures were negligible (<+/-0.03 micromol mol(-1)) for NDIR systems whereas they noticeably increased (<+/-1.09 micromol mol(-1)) especially for the modified GC systems to enhance instrumental sensitivity. We found that the thermal mass flow controller is the main source of the differences although such differences appeared only in the presence of a flow restrictor in GC systems. For reliable monitoring of real atmospheric CO(2) samples, one should use calibration gas mixtures that contain Ar content close to the level (9.332 mmol mol(-1)) in the ambient air as possible. Practical guidelines were highlighted relating to selection of appropriate analytical approaches for the accurate and precise measurements of atmospheric CO(2). In addition, theoretical implications from the findings were addressed.

  2. Influence of atmospheric 14CO2 on determination of the ratio of biogenic carbon to fossil one in exhaust gases using accelerator mass spectrometry. Experimental evaluation for industrial flue gases

    International Nuclear Information System (INIS)

    Yunoki, Shunji; Saito, Masaaki; Nagakawa, Yoshiyasu

    2012-01-01

    The influence of atmospheric 14 CO 2 was evaluated on the determination of biogenic carbon ratios in industrial flue gases using accelerated mass spectrometry(AMS). Bioethanol, n-hexane, and their mixtures were combusted with a four-stroke engine, and 14 CO 2 in exhaust gases was analyzed by AMS. The experimental biogenic carbon ratio determined by ASTM D6866 method was 1.2 times higher than the theoretical value of mixed fuel containing 3.18% biogenic carbons. In general, the influence of atmospheric 14 CO 2 taken in combustion gases is neglected. It seems that the error cannot be neglected under international trading of emission allowances, where a large amount of carbons in the fuel were evaluated. The experimental value became to be the theoretical value by subtracting the amount of atmospheric 14 C from that of the samples. As the contents of biofuel increased, the experimental biogenic carbon ratios reached the theoretical values and the influence of atmospheric 14 CO 2 decreased. We recommend that the influence of atmospheric 14 CO 2 should be corrected when fuel samples contain low amounts of 14 C. (author)

  3. Element-specific determination of chlorine in gases by Laser-Induced-Breakdown-Spectroscopy (LIBS).

    Science.gov (United States)

    Haisch, C; Niessner, R; Matveev, O I; Panne, U; Omenetto, N

    1996-08-01

    An experimental set-up for the detection of elemental chlorine in chlorinated hydrocarbons (CHCs) is described based on a miniaturized system, which could be used for on-line monitoring of chlorinated compounds. With an optimized time-resolved detection chlorine from CHCs like CCl(4) can be determined by Laser-Induced-Breakdown-Spectroscopy (LIBS) with microg/g-detection limits in the gas phase. The application of a miniaturized Nd : YAG laser resulted only in a minor loss in performance, hence it could be used for designing a rugged and small on-line sensor. In addition, preliminary results for the detection of chlorine via the formation of CuCl in the plasma formed by focussing the laser on a copper surface are reported. Utilizing the luminescence of the CuCl D-system at 440 nm, a tenfold improvement in the detection limits was obtained. It appears that the formation of "ad hoc" selected, small molecules in a laser plasma could be a promising alternative for the selective and sensitive analysis of gaseous chlorinated and other species.

  4. A Gas Chromatographic Method for the Determination of Bicarbonate and Dissolved Gases

    Directory of Open Access Journals (Sweden)

    John H. Loughrin

    2017-11-01

    Full Text Available A gas chromatographic method for the rapid determination of aqueous carbon dioxide and its speciation into solvated carbon dioxide and bicarbonate is presented. One-half mL samples are injected through a rubber septum into 20-mL vials that are filled with 9.5 mL of 0.1 N HCl. A one mL portion of the headspace is withdrawn and injected onto a gas chromatograph equipped with a thermal conductivity detector. Using the dimensionless Henry's constant for carbon dioxide and an adaptation of the Henderson-Hasselbalch equation, carbon dioxide in the samples can be categorized among solvated, bicarbonate, and carbonate forms. Natural water samples as well as wastewater from a municipal sewage treatment plant and a swine rearing operation were analyzed by this method and the results compared favorably to those obtained by titration. Samples stored for up to 5 weeks showed no significant changes in carbon dioxide concentrations. In addition, using flame ionization and electron capture detectors, methane and nitrous oxide concentrations in the samples were also measured.

  5. Determination of carbon monoxide, methane and carbon dioxide in refinery hydrogen gases and air by gas chromatography.

    Science.gov (United States)

    Kamiński, Marian; Kartanowicz, Rafal; Jastrzebski, Daniel; Kamiński, Marcin M

    2003-03-14

    This paper illustrates a method for determining trace amounts of CO, CH4 and CO2 with the detection limit of 0.15, 0.15 and 0.20 microg/l, respectively, in refinery hydrogen gases or in air. A simple modification of a gas chromatograph equipped with a flame-ionization detector is presented. A Porapak Q column, additionally connected with a short molecular sieve 5A packed column and a catalytic hydrogenation reactor on the Ni catalyst have been applied. The principle of the analytical method proposed is the separation of CO from O2 before the introduction of CO to the methanizer. The analytical procedure and examples of the results obtained have been presented. The modification applied makes it possible to use the GC instrument for other determinations, requiring utilization of the Porapak Q column and the flame-ionization detector. In such cases, the short molecular sieve 5A column and the methanizer can be by-passed.

  6. An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-03-01

    Full Text Available A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a and a hydrochlorofluorocarbon (HCFC-22 for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively from 2005 to 2006 were found for China, whereas the emission changes in North America (−9%, 23%, 17%, respectively and Europe (11%, 11%, −4%, respectively were mostly smaller and less systematic. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC. For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2 higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP. Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported time of the HCFC-22 consumption and the actual time of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a

  7. Elements for a policy of greenhouse effect gases reduction; Elements pour une politique de reduction des emissions de gaz a effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-01-15

    In the framework of the ''Grenelle de l'environnement'' on the fight against the greenhouse effect gases, the authors aim to offer propositions and recommendations for the future energy policy. They explain the possible confusions. They discuss the economic efficiency of propositions of CO{sub 2} emissions reduction, the actions propositions in the different sectors and the axis of research and development. (A.L.B.)

  8. Determination of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls by gas chromatography/mass spectrometry in the negative chemical ionization mode with different reagent gases.

    Science.gov (United States)

    Chernetsova, Elena S; Revelsky, Alexander I; Revelsky, Igor A; Mikhasenko, Ilya A; Sobolevsky, Tim G

    2002-01-01

    Reagent gases that are used in mass spectrometry in the NCI mode for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) are discussed. Ion-molecule reactions and respective characteristic ions that form while using reagent gases (CH(4), O(2), i-C(4)H(10), NH(3), H(2), He, Ar, Xe, SF(6)) or gas mixtures (CH(4)/O(2), Ar/CH(4), CH(4)/H(2)O, Ar/O(2), i-C(4)H(10)/CH(2)Cl(2)/O(2)) are reviewed. It is shown that only CH(4), O(2), CH(4)/O(2), and CH(4)/N(2)O are widely used and well studied, even though-in the case of these reagent gases-there are contradictions between the publications of various authors. Such reagent gases as NH(3) and He are not well studied, but further investigations of their use for the determination of organochlorine pollutants could be of interest. The possibilities of more sensitive and selective determination of PCDDs, PCDFs, and PCBs are discussed. Copyright 2003 Wiley Periodicals, Inc.

  9. 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

  10. New on-line methods for determining the deuterium/hydrogen composition of water and hydrocarbon gases using O(2-) ion-conducting solid electrolyte reactor.

    Science.gov (United States)

    Sevastyanov, Vyacheslav S; Pedentchouk, Nikolai; Babulevich, Nataliya E; Galimov, Eric M

    2012-11-30

    The deuterium/hydrogen (D/H) composition of water and hydrocarbon gases is widely used in geological, environmental and petroleum studies. The aim of this work was to develop a simple reduction zirconium dioxide solid electrolyte reactor (SER) for water decomposition and new methods for measuring hydrogen isotope ratios in water and hydrocarbon gases. δ(2)H(VSMOW) values were determined using two new different on-line methods: solid electrolyte reactor isotope ratio mass spectrometry (SER-IRMS) for water and gas chromatography combustion solid electrolyte reactor isotope ratio mass spectrometry (GC-C-SER-IRMS) for hydrocarbon gases. We have designed a solid electrolyte reactor based on oxygen ion-conducting zirconium dioxide stabilized by yttria (Y(2)O(3)). The reactor was used for catalytic electrochemical decomposition of water in a helium carrier gas. The solid electrolyte reactor has a small internal volume of 0.1 cm(3). It was operated at a temperature of ~950 °C. The total time of analysis for determining the hydrogen isotope ratio in water was 150 s. A typical water sample volume was about 0.2 μL (split ratio 500:1). The precision of the δ(2) H(VSMOW) measurements for water was better than or equal to 2.2‰ and that for hydrocarbon gases was within 0.5-3.0‰. Fast, simple and accurate on-line methods (SER-IRMS and GC-C-SER-IRMS) were developed. The SER-IRMS method makes it possible to work with small water samples. Although the GC-C-SER-IRMS method was developed for hydrocarbons, it can also be used for other organic gases and their mixtures. The new solid electrolyte reactor for water decomposition is low cost and the ceramic tube is inexpensive. Copyright © 2012 John Wiley & Sons, Ltd.

  11. 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

  12. determinants de l'adoption et impact des varietes ameliorees sur la ...

    African Journals Online (AJOL)

    ACSS

    C'est ainsi que la recherche a créé des nouvelles variétés ... La recherche en économie de la production agricole a montré que les taux d'adoption et les facteurs influençant la décision des agriculteurs d'adopter une technologie agricole varient fortement entre ..... des agriculteurs sur l'innovation sont fortement liées aux ...

  13. Late production of hydrocarbon gases in sedimentary basins: kinetic and isotopic study; Genese tardive des gaz hydrocarbures dans les bassins sedimentaires: etude cinetique et isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Lorant, F.

    1999-06-23

    the mechanisms of cracking and the isotopic processes. Following this concept, a general class-compound model for the production and the degradation of oil and gas, including the calculation of the isotopic compositions, was set up. The kinetic scheme, based on that proposed by Behar et at. (1992), comprises 10 first-order reactions whose pre exponential factors (A) are not all the same. The various kinetic and isotopic parameters were determined on the basis of pyrolysis experiments performed on an immature Type II kerogen. The first simulations at low temperature show that this model can reproduce isotopic trends that are consistent with natural observations. However the current uncertainty on the isotopic parameters does not yet allow a confident utilization of the model to predict the {delta}{sup 13}C of hydrocarbon gases is the geological conditions. (author)

  14. Greenhouse gases regional fluxes estimated from atmospheric measurements; Estimation des flux de gaz a effet de serre a l'echelle regionale a partir de mesures atmospheriques

    Energy Technology Data Exchange (ETDEWEB)

    Messager, C

    2007-07-15

    build up a new system to measure continuously CO{sub 2} (or CO), CH{sub 4}, N{sub 2}O and SF{sub 6} mixing ratios. It is based on a commercial gas chromatograph (Agilent 6890N) which have been modified to reach better precision. Reproducibility computed with a target gas on a 24 hours time step gives: 0.06 ppm for CO{sub 2}, 1.4 ppb for CO, 0.7 ppb for CH{sub 4}, 0.2 ppb for N{sub 2}O and 0.05 ppt for SF{sub 6}. The instrument's run is fully automated, an air sample analysis takes about 5 minutes. In July 2006, I install instrumentation on a telecommunication tall tower (200 m) situated near Orleans forest in Trainou, to monitor continuously greenhouse gases (CO{sub 2}, CH{sub 4}, N{sub 2}O, SF{sub 6}), atmospheric tracers (CO, Radon-222) and meteorological parameters. Intake lines were installed at 3 levels (50, 100 and 180 m) and allow us to sample air masses along the vertical. Continuous measurement started in January 2007. I used Mace Head (Ireland) and Gif-sur-Yvette continuous measurements to estimate major greenhouse gases emission fluxes at regional scale. To make the link between atmospheric measurements and surface fluxes, we need to quantify dilution due to atmospheric transport. I used Radon-222 as tracer (radon tracer method) and planetary boundary layer heights estimates from ECMWF model (boundary layer budget method) to parameterize atmospheric transport. In both cases I compared results to available emission inventories. (author)

  15. 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 ...

  16. Inventory of greenhouse effect gases in France under the united nation framework convention on climatic change; Inventaire des emissions de gaz a effet de serre en France au titre de la convention cadre des nations unies sur le changement climatique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    The present report supplies emission data, for France and for the period 1990 - 2000 concerning all the substances involved in the increase in the greenhouse effect and covered under the United Nations' Framework Convention on Climate Change (UNFCCC). The substances are the six direct greenhouse gases covered by the Kyoto protocol: carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), the two species of halogenous substances - hydro-fluorocarbons (HFCs) and per-fluorocarbons (PFCs), and sulphur hexafluoride (SF{sub 6}). Emissions of sulphur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), non methane volatile organic compounds (NMVOCs), and carbon monoxide (CO), gases which indirectly make a significant contribution to the greenhouse effect, are reported under the Convention. For the period 1990 - 1999 as a whole, estimates provided in the previous inventories have been reviewed and corrected to take into account updated statistics, improved knowledge, possible changes in methodology and specifications contained in the guidelines (FCCC/CP/1999/7) defined by the UNFCCC on reporting for inventories of emissions, in particular the use of the Common Reporting Format (CRF). (author)

  17. 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

  18. 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

  19. New determination of the vapour pressures of the isotopes of neon; Nouvelles determinations des tensions de vapeur des isotopes du neon

    Energy Technology Data Exchange (ETDEWEB)

    Roth, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-03-15

    We have undertaken an experimental reinvestigation of the vapor pressures of the neon isotopes over the temperature range 16.30-30.1 deg. K. Measurements were made by differential manometry in a Giauque-Johnston type cryostat modified for temperature stability. The New sample contained 99.9 % Ne{sup 20} and the Ne{sup 22} sample contained 72,2 % Ne{sup 22}. Extrapolation to pure Ne{sup 20} and Ne{sup 22} can be made with sufficient accuracy by the use of Raoult's law. Our results are in substantial agreement with those of Keesom and Haantjes. At 20 deg. K, where the scatter in our data is an order of magnitude smaller than in the data of Keesom and Haantjes, we find In P{sub Ne{sup 2}{sup 0}}/P{sub Ne{sup 2}{sup 2}} is 6 % larger than the smoothed line given by them. For solid neon, our data can be represented to a high accuracy by a Debye harmonic lattice with {theta}{sub D} (Ne{sup 20}) = 74.6 deg. K. The result may be compared with the value obtained by Henshaw from the Debye-Waller temperature factor, {theta}{sub D} = 73 deg. K, and with the recent calculation of the zero point energy of Ne by Bernardes, from which he obtains {theta}{sub D} 8E{sub {theta}}/9R = 73 deg.. K. (author) [French] On a construit un appareillage dont le principe est derive de celui des instruments decrits par GIAUQUE et EGAN ou par H.L. JOHNSTON qui a permis d'etendre le domaine des mesures de tension de vapeur des isotopes du Neon entre 16,30 et 32 deg. K environ. Le rapport des pressions extremes atteintes est ainsi multiplie par plus de 40 pour le neon ordinaire qui servait de reference et de thermometre. L'appareil, adapte en particulier au travail sous pressions elevees, permet, de plus, de travailler sur de relativement petites quantites totales de gaz - environ 500 cm{sup 3} suffisent dans l'intervalle de pression evoque. La stabilite de temperature obtenue peut etre tres bonne surtout lorsque l'on travaille dans la phase liquide; dans ce cas, les

  20. 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

  1. 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.)

  2. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Energy Technology Data Exchange (ETDEWEB)

    Veyrie, P. [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  3. Isotopic correlations in fission gases applied to light water reactors

    International Nuclear Information System (INIS)

    Rousset, Pierre.

    1978-01-01

    The study of stable fission gases, released from irradiated fuel elements, allows not only the kinetics of release to be determined as a function of the irradiation conditions, but also very useful experimental correlations to be laid down in view of specifying irradiation parameters: specific burn-up and linear power. The LECI (Laboratoire d'Etude des Combustibles Irradies) at Saclay has effected for many years qualitative and quantitative analysis of the stable fission gases released from enriched UO 2 based fuels in the framework of quality control of the fuels for light water reactors (especially PWR). The use of the numerous results obtained in various conditions allowed a detail study of the isotope ratio for Xe and Kr, which may be applied to test elements and power assemblies [fr

  4. Use of Molecular Modeling to Determine the Interaction and Competition of Gases within Coal for Carbon Dioxide Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey D. Evanseck; Jeffry D. Madura

    2003-02-23

    A 3-dimensional coal structural model for the Argonne Premium Coal Pocahontas No. 3 has been generated. The model was constructed based on the wealth of structural information available in the literature with the enhancement that the structural diversity within the structure was represented implicitly (for the first time) based on image analysis of HRTEM in combination with LDMS data. The complex and large structural model (>10,000 carbon atoms) will serve as a basis for examining the interaction of gases within this low volatile bituminous coal. Simulations are of interest to permit reasonable simulations of the host-guest interactions with regard to carbon dioxide sequestration within coal and methane displacement from coal. The molecular structure will also prove useful in examining other coal related behavior such as solvent swelling, liquefaction and other properties. Molecular models of CO{sub 2} have been evaluated with water to analyze which classical molecular force-field parameters are the most reasonable to predict the interactions of CO{sub 2} with water. The comparison of the molecular force field models was for a single CO{sub 2}-H{sub 2}O complex and was compared against first principles quantum mechanical calculations. The interaction energies and the electrostatic interaction distances were used as criteria in the comparison. The ab initio calculations included Hartree-Fock, B3LYP, and Moeller-Plesset 2nd, 3rd, and 4th order perturbation theories with basis sets up to the aug-cc-pvtz basis set. The Steele model was the best literature model, when compared to the ab initio data, however, our new CO{sub 2} model reproduces the QM data significantly better than the Steele force-field model.

  5. Rare gases adsorption and separation on silver doped adsorbent

    International Nuclear Information System (INIS)

    Deliere, Ludovic

    2015-01-01

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) implements means for detecting nuclear tests in an International Monitoring System (IMS). The Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA) has developed in the mid-90's, the SPALAX system (Systeme de Prelevement d'Air en Ligne avec l'Analyse des radioXenons). Xenon analysis, including radioactive isotopes from the fission reaction during the explosion, requires the development of highly efficient process for xenon concentration. In this work, the adsorption and diffusion phenomena of noble gases are studied in silver exchanged ZSM-5 zeolite. The 'experience/Monte Carlo simulation' coupling is used to determine the essential thermodynamic data on the adsorption of noble gases and to characterize the adsorption sites. The presence of a strong adsorption site, identified as silver nanoparticles and intervening at low concentration of noble gases (including xenon and radon) in some silver exchanged zeolites, achieves adsorption and selectivity performance to date unrivaled. These results allow considering their use in many critical applications in the field of capture and separation of rare gases: rare gas industrial production, reprocessing of spent fuel from gas, radon in air pollution control. (author) [fr

  6. A novel method for the determination of adsorption partition coefficients of minor gases in a shale sample by headspace gas chromatography.

    Science.gov (United States)

    Zhang, Chun-Yun; Hu, Hui-Chao; Chai, Xin-Sheng; Pan, Lei; Xiao, Xian-Ming

    2013-10-04

    A novel method has been developed for the determination of adsorption partition coefficient (Kd) of minor gases in shale. The method uses samples of two different sizes (masses) of the same material, from which the partition coefficient of the gas can be determined from two independent headspace gas chromatographic (HS-GC) measurements. The equilibrium for the model gas (ethane) was achieved in 5h at 120°C. The method also involves establishing an equation based on the Kd at higher equilibrium temperature, from which the Kd at lower temperature can be calculated. Although the HS-GC method requires some time and effort, it is simpler and quicker than the isothermal adsorption method that is in widespread use today. As a result, the method is simple and practical and can be a valuable tool for shale gas-related research and applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Visualisation of Gasoline and Exhaust Gases Distribution in a 4-Valve Si Engine; Effects of Stratification on Combustion and Pollutants Visualisation de la répartition du carburant et des gaz brûlés dans un moteur à 4 soupapes à allumage commandé ; effet de la stratification sur la combustion et les polluants

    Directory of Open Access Journals (Sweden)

    Deschamps B.

    2006-12-01

    Full Text Available sAn indirect method to map the burned gases in SI engine has been developed. It is based on visualisation by Laser Induced Fluorescence of the unburned mixture seeded with biacetyl. Both internally and externally recirculated burned gases are monitored. This diagnostic is complementary to the LIF technique applied to measure the gasoline distribution. These LIF gasoline and burned gases measurements are applied in a 4-valve optical access SI engine for a large range of operating conditions. These include variations of both fuel injection and burned gas recirculation modes causing different types of stratification leading to very distinct heat release and exhaust emissions characteristics. Tumble level and spark location are also modified. The observation of the actual stratification in the engine forms a sound basis explanation of the engine performance. Parameters allowing an optimisation of NOx and HC levels can be inferred, and in particular the effectiveness of recirculation and fuel injection strategies. The conclusions are confirmed by measurements in a single engine cylinder conventional head with the same geometry. Une méthode indirecte pour cartographier les gaz brûlés dans un moteur à allumage commandé a été développée. Elle est fondée sur une visualisation à partir de la fluorescence induite par laser (LIF du mélange air-carburant non brûlé et ensemencé avec du biacétyl. Les gaz brûlés provenant à la fois des recirculations internes et externes sont observés. Ce type de diagnostic est complémentaire des techniques de LIF utilisées pour observer la distribution du carburant. Ces mesures de concentration sont réalisées dans un moteur à 4 soupapes avec accès optiques, pour une gamme étendue de conditions opératoires. Celles-ci comprennent des variations des modes d'injection du carburant et des modes de recirculation des gaz brûlés, provoquant ainsi différents types de stratifications qui correspondent

  8. Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1951-01-15

    M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

  9. Determination of the concentration of {alpha} emitting radioactive aerosols; Mesure de la concentration des aerosols radioactifs emetteurs {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Labeyrie, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-06-15

    In the first part of this work the techniques used for the quantitative measurement of the concentrations of aerosols carrying short lived (radon or thoron daughters) or long lived (uranium) {alpha} radioactive emitters are described. In the second part the author investigates the problem of the determination of radon concentration in air by means of activity determinations on airborne dusts. Special reference is made to the measurement of the radon active deposit on two types of dusts (iron oxide (yellow) and uranium oxide) in small chambers (6 liters). In the third part are given data resulting from determinations of radon and thoron concentrations in atmospheric air in the south of Paris area using this method. (author) [French] Dans la premiere partie de ce travail on expose les techniques utilisees pour la mesure quantitative des concentrations d'aerosols contenant des emetteurs radioactifs {alpha}, tant pour ceux a vie courte (derives du radon ou du thoron) que pour ceux a vie longue (uranium). Dans la seconde partie on traite le probleme de la determination de la concentration de l'air en radon par la mesure de l'activite des poussieres ayant sejourne dans cet air. En particulier, on indique pour de petits volumes (6 litres) la proportion de depot actif du radon qui est fixee sur deux types de poussieres (limonite et oxyde d'uranium) en fonction de la concentration de celles-ci. Dans la troisieme partie on donne quelques exemples de mesure par cette methode de la concentration en radon et en thoron de l'atmosphere de la region parisienne. (auteur)

  10. An improved back-flush-to-vent gas chromatographic method for determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia.

    Science.gov (United States)

    Trubyanov, Maxim M; Mochalov, Georgy M; Vorotyntsev, Ilya V; Vorotyntsev, Andrey V; Suvorov, Sergey S; Smirnov, Konstantin Y; Vorotyntsev, Vladimir M

    2016-05-20

    A novel method for rapid, quantitative determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia by dual-channel two-dimensional GC-PDHID is presented. An improved matrix back-flush-to-vent approach combining back-flush column switching technique with auxiliary NaHSO4 ammonia trap is described. The NaHSO4 trap prevents traces of ammonia from entering the analytical column and is shown not to affect the impurity content of the sample. The approach allows shortening the analysis time and increasing the amount of measurements without extensive maintenance of the GC-system. The performance of the configuration has been evaluated utilizing ammonia- and helium-based calibration standards. The method has been applied for the analysis of 99.9999+% ammonia purified by high-pressure distillation at the production site. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 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.)

  12. The anisotropic potential of molecular hydrogen determined from the scattering of oriented H2 on inert gases

    International Nuclear Information System (INIS)

    Zandee, A.P.L.M.

    1977-01-01

    This thesis deals with an experiment aimed at determining the angle dependence of an intermolecular potential between H 2 molecule and a rare gas atom. The small relative difference in total collision cross section for beams of differently oriented H 2 molecules colliding with inert gas atoms in a scattering box is measured (anisotropy A). Through variation of the orientation and by studying its influence on the total collision cross sections, the angle dependence of the intermolecular potential can be arrived at

  13. Evaluation of a hand-held blood gas analyzer for rapid determination of blood gases, electrolytes and metabolites in intensive care setting.

    Science.gov (United States)

    Luukkonen, Antti A M; Lehto, Tiina M; Hedberg, Pirjo S M; Vaskivuo, Tommy E

    2016-04-01

    Intensive care units, operating rooms, emergency departments, and neonatology units need rapid measurements of blood gases, electrolytes, and metabolites. These analyses can be performed in a central laboratory or at the clinic with traditional or compact cassette-type blood gas analyzers such as the epoc blood gas testing system for analyzing whole blood samples at the bedside. In this study, the performance and interchangeability of a hand-held epoc blood gas analyzer was evaluated. The analytical performance of the epoc analyzer was evaluated by determining within-and between-run precisions. The accuracy of the epoc analyzer was assessed by comparing patient results from the device with those obtained with the Siemens Rapidlab 1265 and Rapidpoint RP500 and Siemens Dimension Vista and Sysmex XE-2100 analyzers. The following parameters were measured: pH, pCO2, pO2, Hb (calc), Na+, K+, iCa2+, glucose, and lactate. The CV% of the epoc's between-day imprecision for the various parameters varied from 0.4 to 8.6. The within-run imprecision CV% varied from 0.6 to 5.2. The squared regression coefficient (R2) between the epoc and RL1265 varied from 0.94 to 0.99, with the exception of Na+ and Ca2+ (R2≥0.82). The correlation (R2) of Na+ and K+ between epoc and Dimension Vista was 0.73 and 0.89, respectively. The correlation (R2) of Hb between the epoc and the XE-2100 analyzer was 0.94. With most of the measured blood gas parameters, the epoc analyzer correlated well with reference techniques. The epoc analyzer is suitable for rapid measurement of the blood gases, the electrolytes, and the metabolites in the ICU.

  14. Measuring probe and method for determining the oxygen content in gases, vapors, and liquids, especially in liquid metals

    International Nuclear Information System (INIS)

    Sundermann, H.; Andrae, U.

    1978-01-01

    The invention is concerned with the improvement of the measuring probe described in the main patent no. 1798002 with which the oxygen content in liquid metals, e.g. Na, is to be determined. In order to avoid the glass stopper shutting off the reference space having to be ground out it is proposed to connect the solid electrolyte firmly and hermetically with a metallic mounting support (e.g. Fe-Co-Ni alloy), having got the same thermal coefficient of expansion as the solid electrolyte (e.g. zirconium dioxide stabilized with ythium oxide or thorium dioxide). Further details of the design are very explicitly described. (HP) [de

  15. Detection of carbon dioxide in the gases evolved during the hot extraction determination of hydrogen in uranium ingots

    International Nuclear Information System (INIS)

    Jursik, M.L.; Pope, J.D.

    1977-08-01

    The hot extraction method was used at the National Lead Company of Ohio to determine hydrogen in uranium metal at the 2 ppM level. The volume of gas evolved from the heated sample was assumed to be hydrogen. When a liquid nitrogen trap was placed into the system the hydrogen values were reduced 5 to 10%. The gas retained by the nitrogen trap was identified by mass spectrometry as predominantly carbon dioxide. Low hydrogen values were observed only when the nitrogen trap was used in the analysis of high-carbon (300 to 600 ppM) uranium from NLO production ingots. However, hydrogen values for low-carbon (30 to 50 ppM) uranium were unaffected by the nitrogen trap. The formation of carbon dioxide appears to be associated with the carbon content of the uranium metal. Comparisons of hydrogen values obtained with the hot extraction method and with an inert fusion--thermal conductivity method are also presented. 3 tables, 4 figures

  16. Clay stones of the deep Namur as potental sources of nitrogen of Northwest-German natural gases - first indications from the pyrolisis tests; Tonsteine des tiefen Namur als potentielle Stickstoffquellen nordwestdeutscher Erdgase - erste Indizien aus Pyrolyseuntersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Krooss, B.M. [Forschungszentrum Juelich (Germany). Inst. fuer Erdoel und organische Geochemie; Karg, H. [RWTH Aachen (Germany)

    1998-12-31

    The content of molecular nitrogen in the natural gas deposits of the Northwest-German basin can show values of up to 100 volume percent (nitrogen province) and therefore carry a high exploration risk. Analysis of the generation of the gas from carboniferous clay stone by means of open pyrolysis shows that the nitrogen generation potential is relatively high when compared to coal (according to TOC standards). This analysis enabled the determination of generation graphs for nitrogen, partly also for methane, from Namur clay stones of a maturity between 2.81 and 3.86 volume percent. (orig.). [Deutsch] Die Gehalte an molekularem Stickstoff (N{sub 2}) in Erdgaslagerstaetten des Nordwestdeutschen Beckens koennen Werte von nahezu 100 Vol.-% (Stickstoffprovinz) erreichen und stellen somit ein hohes Explorationsrisiko dar. Die Untersuchung der Gasgenese aus karbonischen Tonsteinen mit der Methode der offenen Pyrolyse zeigt ein im Vergleich zu Kohlen hohes Stickstoff-Genesepotential (TOC-normiert). Mit Hilfe der verwendeten Analysenmethode konnten Genesekurven fuer Stickstoff, sowie teilweise fuer Methan, aus Namur Tonsteinen in einem Reifebereich von 2.81 bis 3.86% VR{sub r} bestimmt werden. (orig.)

  17. Determination of the food consumption in eleven regions of the european community with a view to studying the radioactive contamination level: Methods used. Results of family enquiries; Determination des regimes alimentaires des populations de onze regions de la communaute europeenne en vue de l'etude des niveaux de contamination radioactive: Methodologie. Resultats des enquetes familiales

    Energy Technology Data Exchange (ETDEWEB)

    Cresta, M.; Lacourly, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    In the present report are given the results obtained from food surveys carried out during the period 1963-1965 and involving 9000 families living in eleven regions spread out over the six European Community countries. A partial analysis of the results obtained covers a reduced sample of 3725 families; it makes it possible to fix the composition of the mean individual, monthly and annual food consumptions for each of the eleven regions. Details of the organisation of the survey, of the data processing methods and of the method of presenting the results are given in the first part of the report. the second part presents, in numerical table form, the consumption of various foodstuffs and the feeding principles for each region covered by the survey. Tables summarizing the data make it possible to compare the mean individual consumptions in the various regions studied. (author) [French] Dans le present rapport sont rassembles les premiers resultats des enquetes alimentaires effectuees pendant la periode 1963-1965, aupres de 9000 familles, dans onze regions reparties dans les six pays de la Communaute Europeenne. L'exploitation partielle des donnees obtenues porte sur un echantillon reduit a 3725 familles et permet d'etablir la composition du regime alimentaire moyen individuel, mensuel et annuel de chacune des onze regions. L'organisation des enquetes, la methode de traitement des donnees et l'expression des resultats sont exposees dans la premiere partie du rapport. La seconde reunit, sous forme de tableaux numeriques, les consommations des differents aliments et principes alimentaires par region d'enquetes. Des tableaux recapitulatifs permettent, en outre, une comparaison des consommations moyennes, individuelles des differentes regions etudiees. (auteur)

  18. Quantification of the greenhouse effect gases at the territorial scale. Final report; Quantification des emissions de gaz a effet de serre a l'echelle territoriale. Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Magnin, G.; Lacassagne, S

    2003-07-01

    An efficient action against the greenhouse effect needs the implication of the local collectivities. To implement appropriate energy policies, deciders need information and tools to quantify the greenhouse gases and evaluate the obtained results of their greenhouse gases reduction policies. This study is a feasibility study of the tools realization, adapted to the french context. It was done in three steps: analysis of the existing tools, application to the french context and elaboration of the requirements of appropriate tools. This report presents the study methodology, the information analysis and the conclusions. (A.L.B.)

  19. Determination of the 20 MeV linear accelerator, new injector for the synchrotron Saturne. Choice of the electrical and dynamical particle parameters; Determination de l'accelerateur lineaire de 20 MeV, nouvel injecteur du synchrotron Saturne. Choix des parametres electriques, dynamique des particules

    Energy Technology Data Exchange (ETDEWEB)

    Prome, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-12-15

    This report takes place in the general determination of the 20 MeV linear accelerator which will be the new Saturne injector; it deals with particle dynamics. Starting from beam requirements at the output of the linac, cells lengths with variable synchronous phase angle, buncher and de-buncher parameters, beam emittances at the output in several phase spaces are successively determined. (author) [French] Dans le contexte general de la determination de l'accelerateur lineaire de 20 MeV, nouvel injecteur du synchrotron Saturne, ce rapport traite de la partie relative au mecanisme de l'acceleration des particules; a partir des caracteristiques souhaitees pour le faisceau a la sortie de cet accelerateur, on determine successivement les longueurs des cellules, compte tenu du choix d'un angle de phase synchrone variable, les caracteristiques du groupeur et du degroupeur et les emittances du faisceau en sortie dans les differents plans de phase. (auteur)

  20. Greenhouse effect gases inventory in France during the years 1990-1999; Inventaire des emissions de gaz a effet de serre en France au cours de la periode 1990-1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The present report supplies emission data, for France and for the period 1990-1999, concerning all the substances involved in the increase in the greenhouse effect and covered under the United Nations' Framework Convention on Climate Change (UNFCCC). The substances are the six direct greenhouse gases covered by the Kyoto protocol: carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), the two species of halogenous substances - hydro-fluorocarbons (HFCs) and per-fluorocarbons (PFCs), and sulphur hexafluoride (SF{sub 6}). Emissions of sulphur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), non methane volatile organic compounds (NMVOCs), and carbon monoxide (CO), gases which indirectly make a significant contribution to the greenhouse effect, are reported under the Convention. The emissions of the six gases that directly contribute to the greenhouse effect are expressed in terms of Global Warming Potential (GWP) which decreased by 2.1 % in 1999 compared to 1990. The emissions of the four gases that indirectly contribute to the greenhouse effect are moving towards decrease: this is by 17% for NO{sub x}, 23% as regards NMVOCs, 33% for CO and by 44% regarding SO{sub 2}. Out of the six greenhouse gases covered by the Kyoto Protocol, CO{sub 2} accounts for the largest share in total GWP emissions (70 %), followed by N{sub 2}O (16 %), CH{sub 4} (12 %), HFCs (0.99 %), SF{sub 6} (0.5 %), and PFCs (0.39 %). (author)

  1. 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 ...

  2. Determination of the free enthalpies of formation of borosilicate glasses; Determination des enthalpies libres de formation des verres borosilicates. Application a l'etude de l'alteration des verres de confinement de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Y

    2000-07-01

    This work contributes to the study of the thermochemical properties of nuclear waste glasses. Results are used to discuss mechanisms and parameters integrated in alteration models of conditioning materials. Glass is a disordered material defined thermodynamically as a non-equilibrium state. Taking into account one order parameter to characterise its configurational state, the metastable equilibrium for the glass was considered and the main thermochemical properties were determined. Calorimetric techniques were used to measure heat capacities and formation enthalpies of borosilicate glasses (from 3 to 8 constitutive oxides). Formation Entropies were measured too, using the entropy theory of relaxation processes proposed by Adam and Gibbs (1965). The configurational entropy contribution were determined from viscosity measurements. This set of data has allowed the calculation of Gibb's free energies of dissolution of glasses in pure water. By comparison with leaching experiments, it has been demonstrated that the decreasing of the dissolution rate at high reaction progress cannot be associated to the approach of an equilibrium between the sound glass and the aqueous solution. The composition changes of the reaction area at the glass surface need to be considered too. To achieve a complete description of the thermodynamic stability, the equilibrium between hydrated de-alkalinized glass and/or the gel layer with the aqueous solution should also be evaluated. (author)

  3. 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.  

  4. 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.

  5. Modeling of radiant heat transfers in non-grey gases using the discrete ordinate method in association with a narrow bands statistical model; Modelisation des transferts radiatifs dans des gaz non gris par la methode des ordonnees discretes associee a un modele statistique a bandes etroites

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, A.B. de; Delmas, A.; Sacadura, J.F. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1996-12-31

    A formulation based on the use of the discrete ordinate method applied to the integral form of the radiant heat transfer equation is proposed for non-grey gases. The correlations between transmittances are neglected and no explicit wall reflexion is considered. The configuration analyzed consists in a flat layer of non-isothermal steam-nitrogen mixture. Cavity walls are grey with diffuse reflexion and emission. A narrow band statistical model is used to represent the radiative properties of the gas. The distribution of the radiative source term inside the cavity is calculated along two temperature profiles in a uniform steam concentration. Results obtained using this simplified approach are in good agreement with those found in the literature for the same temperature and concentration distributions. This preliminary study seems to indicate that the algorithm based on the integration of radiant heat transfer along the luminance path is less sensitive to de-correlation effects than formulations based on the differential form the the radiant heat transfer. Thus, a more systematic study of the influence of the neglecting of correlations on the integral approach is analyzed in this work. (J.S.) 16 refs.

  6. Mass measurement project by determination of Q{sub {beta}} for neutron-rich nuclei; Projet de mesure des masses par determination des Q{sub {beta}} pour des noyaux tres riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pautrat, M.; Lagrange, J.M.; Petizon, L. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vanhorenbeeck, J.; Duhamel, P. [Brussels Univ. (Belgium). Inst. d`Astronomie et d`Astrophysique; Binon, F. [Universite Libre de Bruxelles (Belgium)

    1993-12-31

    The aim of the project described hereafter is to collect new data on the exotic neutron rich nuclei of the Fe to Zn region, and in particular to determine their masses, for both nuclear physics and astrophysics purposes. These isotopes will be produced through projectile fragmentation at the GANIL facility and selected by the LISE3 spectrometer. Their half-lives will be measured as well as the energy of their main {gamma} rays; {gamma} - {gamma} coincidences will then allow to build a preliminary level scheme. The analysis of {beta} spectra and {beta} - {gamma} coincidences will finally provide the maximum {beta} decay energies of the studied nuclei leading to their masses. The difficulties arising from the low production rates, the {beta} detection, the data handling are discussed together with the solutions proposed to overcome them. (authors). 17 refs.

  7. Theoretical investigations on the determination of cavitation-free primary flow after compacting the reactor FRG-1; Theoretische Untersuchungen zur Bestimmung des kavitationsfreien Primaerdurchsatzes nach Kernkompaktierung des Reaktors FRG-1

    Energy Technology Data Exchange (ETDEWEB)

    Pihowicz, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Zentralabteilung Forschungsreaktoren

    1997-12-31

    Basing on an extensive analysis of the influence of compacting the FRG-1 reactor core upon the change in flow, heat exchange, as well as cavitation behavior of the primary circuit the underlying principles of the determination procedure for a cavitations-free primary flow have been developed theoretically. It was found that the problem has to be treated in a complex manner, i.e. considering the coupled flow, temperature, as well as cavitation fields, and that for a successful solution of the problem it is absolutely necessary to simultaneously induce an optimized fixation of the main primary coolant pump. (orig.) [Deutsch] Auf der Basis einer umfangreichen Analyse des Einflusses einer Kernkompaktierung des Reaktors FRG-1 auf die Aenderung der Stroemungs-, Waermeaustausch- und Kavitationsverhaeltnisse im Reaktorkuehlkreislauf wurden theoretische Grundlagen der Vorgehensweise zur Bestimmung des kavitationsfreien Primaerdurchsatzes entwickelt. Es wurde nachgewiesen, dass das Problem komplex, d.h. unter Beruecksichtigung der gegenseitigen Kopplung von Stroemungs-, Temperatur- und Kavitationsfeldern betrachtet werden muss und, dass es zur erfolgreichen Loesung der Aufgabe noch unbedingt erforderlich ist, parallel eine optimale Festlegung der Hauptprimaerumwaelzpumpe herbeizufuehren. (orig.)

  8. For a better control of the greenhouse gases emissions of the international maritime and aerial baggage holds: evaluation and possible actions; Pour une maitrise des emissions de gaz a effet de serre des soutes internationales aeriennes et maritimes: constat et actions possibles

    Energy Technology Data Exchange (ETDEWEB)

    Sassi, O. [Ecole Nationale des Ponts et Chaussees, 77 - Marne la Vallee (France)

    2003-07-01

    The greenhouse gases emissions resulting from the aerial and marine baggage holds, are not taken into account in the national objectives of greenhouse gases reduction, defined by the Kyoto protocol. Thus they have to be controlled separately by each country concerned by the Kyoto protocol and urgent actions to reduce the greenhouse gases emissions are necessary. This study brings in first parts information on the context (legislation, traffic), the emission inventories and the options of allocation. It proposes then control methods and analyzes the possible measures. (A.L.B.)

  9. Hydration of swelling clays: multi-scale sequence of hydration and determination of macroscopic energies from microscopic properties; Hydratation des argiles gonflantes: sequence d'hydratation multi-echelle determination des energies macroscopiques a partir des proprietes microscopiques

    Energy Technology Data Exchange (ETDEWEB)

    Salles, F

    2006-10-15

    Smectites have interesting properties which make them potential candidates for engineered barriers in deep geological nuclear waste repository: low permeability, swelling and cations retention. The subject of this thesis consists in the determination of the relationship between hydration properties, swelling properties and cations mobility in relation with confinement properties of clayey materials. The aim is to understand and to predict the behaviour of water in smectites, following two research orientations: the mechanistic aspects and the energetic aspects of the hydration of smectites. We worked on the Na-Ca montmorillonite contained in the MX80 bentonite, with the exchanged homo ionic structure (saturated with alkaline cations and calcium cations). The approach crosses the various scales (microscopic, mesoscopic and macroscopic) and implied the study of the various components of the system (layer-cation-water), by using original experimental methods (thermo-poro-metry and electric conductivity for various relative humidities (RH) and electrostatic calculations. Initially, the dry state is defined by SCTA (scanning calorimetry thermal analysis). Then a classical characterization of the smectite porosity for the dry state is carried out using mercury intrusion and nitrogen adsorption. We evidenced the existence of a meso-porosity which radius varies from 2 to 10 nm depending on the compensating cation. The thermo-poro-metry and conductivity experiments performed at various hydration states made it possible to follow the increase in the pore sizes and the cations mobility as a function of the hydration state. We highlight in particular the existence of an osmotic mesoscopic swelling for low RH (approximately 50-60%RH for Li and Na). By combining the results of thermo-poro-metry, X-ray diffraction and electric conductivity, we are able to propose a complete hydration sequence for each cation, showing the crucial role of the compensating cation in the hydration of

  10. A Determination of Air-Sea Gas Exchange and Upper Ocean Biological Production From Five Noble Gases and Tritiugenic Helium-3

    Science.gov (United States)

    2007-09-01

    02. Oxygen signatures in the ocean are a result of physics and biology . Argon mimics the physics and thus the difference between 02 and Ar can be a...Zashu, and H. Sakai. Noble-gases in submarine glasses from mido- ceanic ridges and Loihi seamount : Constraints on the early history of the earth...Massachusetts 02139 and Woods Hole Oceanographic Institution Woods Hole, Massachusetts 02543 September 2007 DOCTORAL DISSERTATION Funding was provided by the

  11. Fission product determination in irradiated fuel processing waste (electrophoresis); Dosage des produits de fission dans les effluents de traitement des combustibles irradies (electrophorese)

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, J.M.; Tret, J. [Commissariat a l' Energie Atomique, Centre de Marcoule, 30 - Bagnols-sur-Ceze (France). Centre de Production de Plutonium de Marcoule. Services d' Extraction du Plutonium

    1966-07-01

    This dosage method concerns fission products present in the waste produced from the processing of cooled irradiated fuels. - Sr, Cs, Ce, Y, Ru by quantitative analysis; - Zr, Nb by qualitative analysis. It includes electrophoresis on paper strips one meter long which is then analysed between two window-less Geiger counters. For an activity of 10{sup -2} {mu}Ci of any cation in a 10 {mu}l spot, the standard error {sigma} if 3 to 4 per cent. complete analysis lasts about 5 hours. (authors) [French] Cette methode de dosage concerne les produits de fission presents dans les effluents de traitement des combustibles irradies refroidis: - Sr, Cs, Ce, Y, Ru en analyse quantitative; - Zr, Nb en analyse qualitative. Elle comporte une electrophorese sur bande de papier de un metre de longueur suivie d'un depouillement entre deux compteurs Geiger sans fenetre. Pour une activite de 10{sup -2} {mu}Ci d'un cation quelconque dans une tache de 10 {mu}l l'erreur standard {sigma} est de 3 a 4 pour cent. L'analyse complete demande environ 5 heures. (auteurs)

  12. 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.

  13. 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.

  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. Contribution to the activation analysis of the rare gases. Contribution to the analysis of carbon monoxide and water vapour in gases (1963); Contribution a l'analyse par activation des gaz rares. Contribution a l'analyse de l'oxyde de carbone et de la vapeur d'eau dans les gaz (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Diebolt, J. [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-15

    In the present work, we have applied radioactive analysis to the general technique of rare gas separation. This separation is carried out on active charcoal, at constant pressure. The desorption of the gas is caused by an increase in the initial temperature of adsorption. These separations are quantitative and can be confirmed by chemical analysis. The volumes of desorbed gas are measured by radioactive counting. We have also used radioactivation to study the reduction of palladous chloride by carbon monoxide. Since this reduction is quantitative, we can have a knowledge of the mass of palladium reduced by measuring its activity. We have used the property which have organic chlorides of being hydrolysed by water vapour and of liberating hydrochloric acid to study quantitatively the amount of water vapour which a gas contains. The hydrochloric acid formed is measured by activation of the chlorine in the acid. (author) [French] Dans les travaux que nous presentons, nous avons applique l'analyse par radioactivation, a la technique generale de separation des gaz rares. Cette separation est faite sur charbon active, a pression constante. La desorption des gaz est provoquee par une augmentation de la temperature initiale d'adsorption. Ces separations sont quantitatives, et peuvent etre exploitees par l'analyse chimique. Les volumes de gaz dedorbes sont mesures par comptage de la radioactivite. Nous avons egalement utilise la radioactivation pour l'etude de la reduction du chlorure palladeux par l'oxyde de carbone. Cette reduction etant quantitative, nous pouvons connaitre la masse de palladium reduit par la mesure de son activite. Nous avons exploite la propriete que possede un chlorure organique d'etre hydrolise par la vapeur d'eau et de liberer de l'acide chlorhydrique pour etudier quantitativement la vapeur d'eau contenue dans un gaz. L'acide chlorhydrique forme est mesure par l'activation du chlore de l

  16. 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...

  17. 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.

  18. Chemical and isotopic fractionations of natural gases during their migration. Importance of methane solubilization and diffusion during geological times; Fractionnements chimiques et isotopiques des gaz naturels lors de leur migration. Importance de la solubilisation et de la diffusion du methane au cours des temps geologiques

    Energy Technology Data Exchange (ETDEWEB)

    Pernaton, E.

    1998-09-09

    Two experimental devices have been elaborated in the purpose of simulating in laboratory the solubilization of methane in water and the migration by solubilization/diffusion of some gas species (methane, ethane, propane and nitrogen) through porous media saturated with water. Significant shifts in isotopic ratios of diffused methane (carbon and hydrogen) have been observed. Those fractionations for carbon isotopes, which in most cases are characterised by a {sup 12}C-enriched diffused methane, have fundamental consequences about the interpretation of the origin of methane in sedimentary basins and, in a more general way, about the genetic characterisation of hydrocarbon gases in reservoirs. Indeed, this gives an ambiguous origin for any gas having {sup 12}C-enriched methane, two different interpretations are possible: mixing between thermogenic and bacterial hydrocarbon gases and a diffusive trend during migration. Using a diagram C2/C1 versus {delta}{sup 13}C1, we have shown that in some geological cases, these two processes, mixing and diffusion, exist and that it is possible to discern them.The chemical and isotopic compositions of natural gases do not only reflect genetic processes but are also an indication of their migration. Moreover, the experiments have shown that the gas transport by solubilization/diffusion is a potential operator of gas leakage from natural accumulations. In consequence, a numerical model of gas migration through cap rocks of reservoirs has been elaborated and will be integrated into sedimentary basin models. (author)

  19. 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.)

  20. Reduction of greenhouse gases from electrolysis; Die Reduktion von Treibhausgasen in der Elektrolyse

    Energy Technology Data Exchange (ETDEWEB)

    Iffert, M.; Ganther, R.; Opgen-Rhein, J. [Trimet Aluminium AG, Essen (Germany)

    2002-07-01

    Perfluorcarbon (PFC, e.g. tetrafluoromethane and hexafluoro-ethane) emissions are harmful to the environment because of their global warming potential and, therefore, it is a challenge for the aluminium industry to reduce the generation of such gases. Before this background, two measurement campaigns of CF{sub 4} emissions were carried out at Trimet Aluminium AG during the spring of 2001. In the first campaign, the current level of emissions was determined and different strategies of automatic anode effect treatment were analysed and compared. Afterwards, the most successful method with the lowest mount of emissions was implemented in all process computers. In the second campaign the improvements obtained were verified. (orig.) [German] Perfluorierte Kohlenwasserstoffe (PFC) wie z.B. Tetrafluormethan (CF{sub 4}) und Hexafluorethan (C{sub 2}F{sub 6}) sind klimarelevante Gase, welche den Treibhauseffekt verstaerken. Daher ist es eine Herausforderung fuer die Aluminiumindustrie, die Generierung dieser Gase zu reduzieren. Vor diesem Hintergrund wurden im Fruehjahr 2001 zwei Messkampagnen der CF{sub 4}-Emissionen von der Trimet Aluminium AG durchgefuehrt. Ziel der ersten Kampagne war eine Statusaufnahme der bisherigen CF{sub 4}-Emissionen und, verschiedene Strategien zum Loeschen des automatischen Anodeneffekts zu analysieren und zu vergleichen. Anschliessend wurde die erfolgreichste Methode mit den niedrigsten CF{sub 4}-Emissionen in allen Ofenrechnern installiert. In der zweiten Messkampagne wurden dann die erzielten Verbesserungen verifiziert. (orig.)

  1. Rheological online determination of the organic dry substance concentration of sewage sludge; Rheologische online Bestimmung des oTS-Gehalts von Klaerschlamm

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, P.; Boehm, A.; Fessler, J.; Liebelt, U. [BASF AG, Ludwigshafen am Rhein (Germany); Traegner, U. [Fachhochschule fuer Technik, Mannheim (Germany)

    1999-07-01

    In order to adjust the filter cake to a certain calorific value and to enhance the dehydratability of sludge, ash, carbon and flocculation agents are added to the latter prior to filtration. Dosage of the additives depends on the sludge's content of organic solids, determined in the form of the so-called organic dry substance concentration. In bench-scale and technical-scale experiments on the rheological properties of sewage sludge, a correlation between organic dry substance concentration and rheological properties, especially the liquid limit of sewage sludge, was established. This knowledge was used to develop a measuring technique for online determination of organic dry substance concentration by means of rheology. (orig.) [German] Zur Einstellung eines bestimmten Heizwertes des Filterkuchens und zur Verbesserung der Entwaesserbarkeit werden dem Schlamm vor der Filtration Asche, Kohle und Flockungsmittel zugegeben. Die Dosierung der Zuschlagsstoffe erfolgt in Abhaengigkeit vom Gehalt des Schlamms an organischem Feststoff, bestimmt in Form der sog. oTS-Konzentration. In Labor- und Betriebsversuchen zum rheologischen Verhalten von Klaerschlamm konnte eine Korrelation zwischen der oTS-Konzentration und den Fliesseigenschaften, insbesondere der Fliessgrenze von Klaerschlamm ermittelt werden. Diese Erkenntnis wurde in ein Messverfahren zur online-Bestimmung der oTS-Konzentration mittels Rheologie umgesetzt. (orig.)

  2. 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.

  3. Remarks concerning the determination of burn-out in research reactors; Remarques sur la determination des echauffements critiques dans les reacteurs de recherche

    Energy Technology Data Exchange (ETDEWEB)

    Fabrega, S.; Lafay, J.; Vernier, P. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    The operation of reactors cooled by water at low pressure is quite safe as long as the margin existing between nominal conditions and certain conditions leading to burn-out is known. The phenomena which can cause such an effect are defined here. A distinction is made between primary burnout, which is completely localized, and secondary burn-up. This latter can be the result either of a flow reduction, or of the onset of a hydrodynamic oscillation, or again of the attainment of sonic flow conditions. Once the planner is aware of the varied nature of these phenomena, it is shown which are the precautions to be taken during the construction and operation of an out-of-pile test-loop so that such phenomena may subsequently be detected. In the first experiment on a loop with a 600 x 53 x 2 mm rectangular channel, there resulted either primary (critical) burn-out (down-stream pressurization), or secondary critical burn-out (up-stream pressurization) resulting from instability. Another experiment has shown that in the case of the reactor PEGASE, critical burn-out was due to flow reduction in nominal and steady-state operational conditions. (authors) [French] Le fonctionnement des reacteurs refroidis a l'eau a basse pression est sur si la marge entre les conditions nominales et certaines conditions pour lesquelles apparaissent des echauffements critiques (burn out) est connue. On definit les phenomenes qui peuvent entrainer de tels echauffements. On distingue l'echauffement critique primaire, purement local, de l'echauffement critique secondaire. Celui-ci peut etre la consequence, soit d'une redistribution de debit, soit de l'apparition d'une oscillation hydrodynamique, soit de l'atteinte des conditions de vitesse sonique. Le projeteur etant averti de la nature variee de ces phenomenes, on montre quelles sont les precautions a prendre pour construire et exploiter une boucle d'essais hors pile, afin de pouvoir creer et ensuite

  4. 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.)

  5. 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.

  6. 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.)

  7. 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

  8. Unified fit of solar and atmospheric neutrinos: towards the MNSP matrix; Ajustements globaux des resultats des experiences de neutrinos solaires et atmospheriques: vers la determination de la matrice de melange des neutrinos (dite MNSP)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    Present solar and atmospheric neutrino give a strong indication that neutrinos oscillate between the three active species. This is the first step towards the determination of their mass. But we have also to determine the 3 x 3 neutrino mixing matrix (3 angles and one or several phases linked to CP violation), called MNSP (Maki-Nakagawa-Suzuki-Pontecorvo) and similar to the quark mixing matrix, called CKM (Cabibbo-Kobayashi-Maskawa). The purpose of the colloquium (one day) is to give an overview of the present situation and what progresses are expected in the forthcoming years. 3 guidelines: pedagogical approach, critical review of the experimental situation and of the different analyses, lookout to the future. (author)

  9. Grain scale stresses and strains determination by X-ray diffraction; Contribution a l'analyse par diffractometrie X des deformations et des contraintes a l'echelle des grains

    Energy Technology Data Exchange (ETDEWEB)

    Huang, W

    2007-03-15

    A new methodology for strain and stress analysis by X ray diffraction (XRD) in single crystal was developed. It can be applied to determine the second order stress (in grain scale) in single and multi-crystal material with non-cubic lattice. This method is based on the method Ortner I. It has introduced the metric tensor G which is deduced from the lattice space measured by XRD. In the developed method, when the crystal reference is non-orthonormal, an orthonormal reference associated with the crystal basis is defined, so all calculation could be done with usual calculation laws. The use of the least square method allows the acquisition of many more measurements than the six absolute necessary. Then a better metric tensor G is calculated and the statistical error is obtained. This developed method was applied in a bi crystal copper. The experimental results have shown that this method is also effective. The second order residuals stresses for coarse Zn grains in a galvanized coating were determined after annealing. The four coarse grains with different orientations were also characterized and demonstrated the elastic and plastic deformation mechanism in a grain or between the grains during in situ tensile loading. So this method is well able to determine the strains and stresses in grain scale in a mono crystal or multi crystal with any crystalline structure. (author)

  10. 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.

  11. Validation of a multi-residue method for the determination of residuals pesticides in cabbage (Brassica Oleracea var. Capitata) for gases chromatography

    International Nuclear Information System (INIS)

    Moreno, Milton Leonardo; Guerrero Dallos, Jairo Arturo

    2002-01-01

    This study describes the validation of a multi-residue method for the determination of most used organo chlorine, organophosphorus and organonitrogen pesticides in cabbage in the Cundinamarca Department (Colombia). The extraction process includes blending of small sample quantity with ethyl acetate in presence of Na 2 SO 4 and NaHCO 3 , filtration and concentration. The clean up steps include GPC and mini-column chromatography using silica gel. Final determination was carried out by gas chromatography with: pulsed splitless injection, HP-5 capillary column, and a parallel detection system with micro electron capture detection (μ - ECD) and Nitrogen-Phosphorus Detection (NPD). The methodology is specific, selective, accurate and robust. Recovery values of majority of pesticides were in the range 70-120% at spiking levels ranging 0.05-10.73 mg/kg. Limits of detection were less than 0.10 mg/kg for most of the studied compounds. The distribution of the analyses in the laboratory sample was evaluated and it was found its homogeneity. The evaluation of pesticide residues was made in a specific area of municipality of Madrid-Cundinamarca, (Colombia). No residues of the studied analyses were founded

  12. Optimization of conditions to produce nitrous gases by electrochemical reduction of nitric acid; Optimisation des conditions operatoires de production de vapeurs nitreuses par reduction electrochimique d`acide nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Lemaire, M. [CEA Centre d`Etudes Nucleaires de Saclay, 91 -Gif-sur-Yvette (France)]|[CEA Centre d`Etudes de la Vallee du Rhone, 30 -Marcoule (France). Direction du Cycle du Combustible

    1996-11-22

    Gaseous nitrogen oxides (NO and NO{sub 2}) involved as oxidizing agents in nuclear fuel reprocessing can be an produced by electrochemical reduction of nitric acid. This could be an interesting alternative to the usual process because no wastes are generated. Voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0.05 V{sub S}HE and 0.3 V{sub S}HE and O.5 V{sub S}HE and 1 V{sub S}HE. The highest potential region reduction mechanism was studies by: classical micro-electrolysis methods; macro-electrolysis methods; infra-red spectroscopy couplet to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric acid reduction can also be explained by an other chemical reaction. In the potential value of platinum electrode is above 0.8 V{sub S}HE, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author). 91 refs.

  13. 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 ...

  14. 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...

  15. 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

  16. Simple and rapid determination of PCDD/Fs in flue gases from various waste incinerators in China using DR-EcoScreen cells.

    Science.gov (United States)

    Zhou, Zhiguang; Zhao, Bin; Kojima, Hiroyuki; Takeuchi, Shinji; Takagi, Yoko; Tateishi, Norio; Iida, Mitsuru; Shiozaki, Takuya; Xu, Pengjun; Qi, Li; Ren, Yue; Li, Nan; Zheng, Sen; Zhao, Hu; Fan, Shuang; Zhang, Ting; Liu, Aimin; Huang, Yeru

    2014-05-01

    In developing countries such as China, there is a strong need for simple and rapid bioassays for the determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in environmental samples; i.e., flue gas and fly ash from waste incinerators. In this study, we applied the DR-EcoScreen cell (DR-cell) assay to determination of PCDD/Fs in 78 flue gas samples obtained from various waste incinerators in China between 2009 and 2011. The flue gas samples were obtained from four kinds of incinerators, classified into hazardous, medical and municipal-solid waste, and iron ore sintering, and the flue gas extracts were cleaned up using an SPD-600 automated-sample preparation device for DR-cell assay. The PCDD/Fs values obtained from the DR-cell assay were compared with those obtained from conventional high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) analysis. The bioanalytical equivalent (BEQ) values obtained from the DR-cell assay were very closely correlated with the international toxicity equivalent (I-TEQ) values from HRGC-HRMS analysis (r2=0.98, n=78), while the BEQ values were 5.52-fold higher than the I-TEQ values, as the PCDFs, which account for 80% of the total I-TEQ value, were overestimated by DR cell-assay. Therefore, we multiplied the BEQ values from the DR-cell assay by a conversion coefficient (0.181, the reciprocal of 5.52), and could approximate the TEQ values from the HRGC-HRMS analysis. These results suggest that the DR-cell assay combined with SPD-600 cleanup provides a promising method for the simple and rapid screening of PCDD/Fs levels in flue gas samples, such as those from various waste incinerators in China. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Method by chromatography of gases for the determination of made up of alcoholic fermentation in pineapple fruits (Ananas comosus [L.] Merr)

    International Nuclear Information System (INIS)

    Murillo Williams, A.

    2001-01-01

    The pineapple (Ananas comosus) it is used in the entire world for the fresh consumption or for processed products (canned, frozen, dehydrated). it is cultivated in a wide range of countries and in extreme latitudes.The factors of quality include: maturity, stability, size uniformity, absence of microbial deterioration, absence of burns for the sun, absence of blows, damage for insects and breaking, crowns, color, longitude and integrity. The factors that determine the longevity of a product can be physiologic or pathological. The physiologic conditions refer to the processes of degradation of the fabrics after the crop, while the pathological ones involve the attack of mushrooms and bacteria. In the case of the pineapple, a physiologic problem exists, called black heart, internal brewing (IB), brown endogenic stain ( m ancha cafe endogena , MCE) or chilling injury (CI) that can happen in any part of the world where it is cultivated. This problem has associated to the exhibition from the pineapple to low temperatures, so it is a challenge to manage a fruit like the pineapple that it cannot tolerate low temperatures without problems. In studies made about the physiologic changes that happen during the storage in controlled atmospheres in fruits, it has been observed that the ethanol and the acetaldehyde are volatile compounds associated with metabolic post-crop changes and that they have implication in the quality of the product. (author) [es

  18. An introduction to the Boltzmann equation and transport processes in gases

    CERN Document Server

    Kremer, Gilberto M; Colton, David

    2010-01-01

    This book covers classical kinetic theory of gases, presenting basic principles in a self-contained framework and from a more rigorous approach based on the Boltzmann equation. Uses methods in kinetic theory for determining the transport coefficients of gases.

  19. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    International Nuclear Information System (INIS)

    Hofmann, Martin Alexander

    2012-01-01

    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, θ 13 , has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti ν e 's by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of ∝ 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71±0.08).10 -14 (g)/(g) for uranium and (8.16±0.49).10 -14 (g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10 -13 (g)/(g)). Both gamma spectroscopy measurements and

  20. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Martin Alexander

    2012-11-27

    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, {theta}{sub 13}, has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti {nu}{sub e}'s by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of {proportional_to} 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71{+-}0.08).10{sup -14}(g)/(g) for uranium and (8.16{+-}0.49).10{sup -14}(g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10{sup -13

  1. Experimental determination of unsteady flow forces on turbine blades by hydraulic analogy; Determination experimentale, par analogie hydraulique, des efforts instationnaires sur les aubages d`une turbine

    Energy Technology Data Exchange (ETDEWEB)

    Verdonk, G. [GEC Alsthom Rateau, 93 - La Courneuve (France); Naudin, M. [Framatome Thermodyn, 71 - Le Creusot (France); Pluviose, M. [CNAM, 75 - Paris (France); Sankale, H. [CETIM, 44 - Nantes (France)

    1998-06-01

    The blades of turbomachinery undergo unsteady flow forces, created principally by the presence of a series of stator or diffuser blades prior to a series of rotor blades. The stage geometry is the main factor which defines the magnitude of these forces. The influence of both geometric and thermodynamic parameters is currently being analysed using a model representing the turbine blades and by applying the hydraulic analogy technique. The study is being conducted at CETIM in Nantes amongst a working group including manufacturers, research organisms, and technical center. Work is in progress and initial results have proved sufficiently encouraging for presentation at the forthcoming Symposium on multidisciplinary turbomachinery issues organised by the Societe Francaise des Mecaniciens. The study should eventually facilitate the optimisation of rotor blade dimensioning for total and partial injection turbine applications and furthermore to reduce the risk of blade failure. Following quantitative study, results obtained for a given geometry of total injection turbine are presented in this paper. (authors) 16 refs.

  2. Procedure to determine the optimal main primary coolant pump parameters of the FRG-1 reactor. P.1: Development concept, optimization criteria and general logical structure of the procedure; Verfahren zur Bestimmung der optimalen Kenndaten der Hauptprimaerumwaelzpumpe nach der Kernkompaktierung des Reaktors FRG-1. T.1: Entwicklungskonzept, Optimierungskriterien und allgemeine logische Struktur des Verfahrens

    Energy Technology Data Exchange (ETDEWEB)

    Pihowicz, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Zentralabteilung Forschungsreaktoren

    1998-12-31

    First a development concept of the procedure was derived. Following this concept the procedure has to be derived stepwise, i.e. on subsequent logical levels. Furthermore, the report contains the results of the first two logical levels. On the first (basic) level the optimization criteria had been formulated. The general logical structure of the procedure results from the second logical level (macro level) of the evaluation process. This structure consists of four determination blocks, one identification unit and some determination elements as well as their logical interconnections in the form of decision and result units. The blocks serve for the realization of the closed and composed partial tasks of the procedure. They themselves form the complicated but not yet deviced partial structures, which again are the logical connections of the determination elements. In contrast to the blocks all determination elements are simple enough, so that their direct mathematical determination becomes possible. They serve for the solution of simple partial tasks. (orig.) [Deutsch] Zuerst wurde ein Konzept zur Entwicklung des Verfahrens erstellt. Nach dem Konzept soll das Verfahren stufenweise, auf nacheinander folgenden logischen Ebenen abgeleitet werden. Ausserdem enthaelt die Abhandlung noch die auf den zwei anfaenglichen logischen Ebenen des Entwicklungsprozesses erzielten Resultate. Auf der ersten Ebene (Grundebene) wurden die Optimierungskriterien formuliert. Die allgemeine logische Struktur des Verfahrens ergibt sich als Resultat der zweiten logischen Ebene (Makroebene) des Entwicklungsprozesses. Diese Struktur setzt sich aus vier Bestimmungsbloecken, einer Identifikationseinheit und einigen Bestimmungselementen sowie ihrer logischen Verknuepfung in Form der Entscheidungs- und Ergebniseinheiten zusammen. Die Bloecke dienen zur Realisierung der geschlossenen und zusammengesetzten Teilaufgaben des Verfahrens. Sie bilden selbst die komplizierten, jedoch noch nicht abgeleiteten

  3. 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

  4. 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.)

  5. Evaluation des dommages des punaisese( Heteroptera ) et des ...

    African Journals Online (AJOL)

    L'analyse statistique des résultats dans les blocs témoins montre que les punaises occasionnent plus de dommages aux boutons floraux et aux capsules vertes immatures que les chenilles. Sur les jeunes capsules, la moyenne des dommages des punaises et des chenilles reste statistiquement identique. Les traitements ...

  6. Auto-ignition modelling: analysis of the dilution effects by the unburnt gases and of the interactions with turbulence for diesel homogeneous charge compression ignition (HCCI) engines; Modelisation de l'auto-inflammation: analyse des effets de la dilution par les gaz brules et des interactions avec la turbulence dediee aux moteurs Diesel a charge homogene

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, G.

    2005-09-15

    Homogeneous Charge Compression Ignition (HCCI) is an alternative engine combustion process that offers the potential for substantial reductions in both NO{sub x} and particulate matter still providing high Diesel-like efficiencies. Combustion in HCCI mode takes place essentially by auto-ignition. It is mainly controlled by the chemical kinetics. It is therefore necessary to introduce detailed chemistry effects in combustion CFD codes in order to properly model the HCCI combustion process. The objective of this work is to develop an auto-ignition model including detailed chemical kinetics and its interactions with turbulence. Also, a comprehensive study has been performed to analyze the chemical influence of CO and H{sub 2} residual species on auto-ignition, which can be present in the exhaust gases. A new auto-ignition model, TKI-PDF (Tabulated Kinetics for Ignition - with turbulent mixing interactions through a pdf approach) dedicated to RANS 3D engine combustion CFD calculations is proposed. The TKI-PDF model is formulated in order to accommodate the detailed chemical kinetics of auto-ignition coupled with turbulence/chemistry interactions. The complete model development and its validation against experimental results are presented in two parts. The first part of this work describes the detailed chemistry input to the model. The second part is dedicated to the turbulent mixing description. A method based on a progress variable reaction rate tabulation is used. A look-up table for the progress variable reaction rates has been built through constant volume complex chemistry simulations. Instantaneous local reaction rates inside the CFD computational cell are then calculated by linear interpolation inside the look-up table depending on the local thermodynamic conditions. In order to introduce the turbulent mixing effects on auto-ignition, a presumed pdf approach is used. The model has been validated in different levels. First, the detailed kinetic approach was

  7. Recommandations pour la détermination expérimentale de la capacité d'échange de cations des milieux argileux Recommendations for Experimentally Determining the Cation-Exchange Capacity of Shaly Media

    Directory of Open Access Journals (Sweden)

    Chambre Syndicale du Pétrole$

    2006-11-01

    Full Text Available Cet article présente une méthode relativement simple et précise destinée à la détermination de la capacité d'échanges de cations des milieux argileux qui permet de caractériser la réactivité des argiles. Cette mesure présente une certaine importance en raison des problèmes posés par les réservoirs argileux (interprétation des diagraphies, efficacité des méthodes de récupération améliorée par voie chimique. . . . Après avoir brièvement rappelé les propriétés fondamentales des argiles, la capacité d'échanges de cations (CEC est définie et la méthode recommandée de mesure de celle-ci (dosage par le chlorure de cobaltihexammine est décrite. Trois exemples viennent ensuite illustrer cette méthode dans le cas d'une argile pure, d'un sable argileux et d'un échantillon de grès argileux consolidé. This article describes a relatively simple and accurate method for determining the cation-exchange capacity of shaly media, which enables the characterization of the clay reactivity. This measurement is of some importance because of the problems posed by shaly reservoirs (interpreting well logs, effectiveness of improved-recovery methods by chemical means, etc. . After a brief review of the fondamental properties of shales, the cation-exchange capacity (CEC is defined, and the recommended measurement method by using cobaltihexammine chloride is described. Three examples are then given to illustrate this method for pure clay, for a shaly Band and for a consolidated shaly sandstone.

  8. Determination de la Distribution Granulometrique des Particules par la Mesure de la Transmission d’un Aerosol Sedimentant (Aerosol Size Distribution Using the Extinction-Sedimentation Inversion Technique),

    Science.gov (United States)

    1982-11-01

    l’ajustement d’une fonction mathematique aux valeurs mesuries de la densite optique. L’appendice B traite de l’aspect informatique de l’etude. Ce travail a...selon l’expresslon mathematique 17. Les details relatifs au calcul des coefficients de la meilleure courbe sont donnSs en appen- dlce A. Les fig. 6...expressions mathematiques des meilleures courbes de la densitS optique. Les fonctlons de distribution initiale des poudres avant dissemination de’termine’es

  9. 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.

  10. 75 FR 70254 - PSD and Title V Permitting Guidance for Greenhouse Gases

    Science.gov (United States)

    2010-11-17

    ... AGENCY PSD and Title V Permitting Guidance for Greenhouse Gases AGENCY: Environmental Protection Agency... the EPA has posted its guidance titled, ``PSD and Title V Permitting Guidance for Greenhouse Gases... for Greenhouse Gases.'' This document has been determined to be an EPA Significant Guidance Document...

  11. 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.

  12. 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

  13. Experimental determination and evaluation of the friction behavior of geosynthetics; Experimentelle Ermittlung und Bewertung des Reibungsverhaltens von Geokunststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, Maik

    2016-08-17

    In many fields of geotechnical engineering geosynthetics have established itself as an alternative to common used earth materials. Particularly in landfill sealing systems many different types of geosynthetics are used together. In embankments geosynthetics form inclined planes. The safety against sliding must be proved for all contact surfaces. For this purpose, the knowledge of the friction behavior of the geosynthetics is required. Normally, the friction behavior is modeled analytically with the Coulomb failure criterion. The Coulomb friction parameters usually must be determined experimentally. In spite of the good state of the art and numerous studies into geosynthetics, in detail, there are still issues relating to the determination of friction behavior of geosynthetics, to the application of the Coulomb failure criterion and to the assessment of the friction parameters with a view to the time- and temperature-dependent behavior of synthetics. The main objective of this work is to contribute to a reliable determination of the friction behavior and to a correct assessment of the evaluated test results as the basis for a reliable and economical dimensioning of structures with geosynthetics. For this, the measurement technique of a standard large direct shear box was upgraded by the author, so that the effective normal stress can be measured below the test surface. Also tests with very small normal stresses can be carried out with this modification. Furthermore, a force-controlled test device was designed for studies of the influences arising from long-term combined compressive and shear loads and temperature. Based on experimental investigations inadequacies in the current experimental procedure are identified. In addition, the impact of factors are quantified, which are often ignored or considered to be marginal in practice. With further experimental investigations it is demonstrated that the linear Coulomb failure criterion is valid for limited normal stress

  14. Evaluation of the greenhouse effect gases (CO{sub 2}, CH{sub 4}, N{sub 2}O) in grass land and in the grass breeding. Greenhouse effect gases prairies. report of the first part of the project December 2002; Bilan des emissions de gaz a effet de serre (CO{sub 2}, CH{sub 4}, N{sub 2}O) en prairie paturee et dans des exploitations d'elevage herbager. GES-Prairies. Rapport de la premiere tranche du projet Decembre 2002

    Energy Technology Data Exchange (ETDEWEB)

    Soussana, J.F

    2002-12-15

    In the framework of the Kyoto protocol on the greenhouse effect gases reduction, many ecosystems as the prairies can play a main role for the carbon sequestration in soils. The conservation of french prairies and their management adaptation could allow the possibility of carbon sequestration in the soils but also could generate emissions of CO{sub 2} and CH{sub 4} (by the breeding animals on grass) and N{sub 2}O (by the soils). This project aims to establish a detailed evaluation of the contribution of the french prairies to the the greenhouse effect gases flux and evaluate the possibilities of reduction of the emissions by adaptation of breeding systems. (A.L.B.)

  15. 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)

  16. New experimental determination of the neutron resonance parameters of {sup 99}Tc; Nouvelle determination experimentale des parametres de resonances neutroniques de {sup 99}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Brienne-Raepsaet, C. [CEA Bruyeres-le-Chatel, 91 (France). Dept. de Physique Theorique et Appliquee]|[Aix-Marseille-1 Univ., 13 - Marseille (France)

    1999-04-01

    In order to improve nuclear data for nuclear waste transmutation cross-sections of Tc{sup 99} in the resonance energy region have been performed using the time-of-flight method at the pulsed white neutron source GELINA of the Institute for Reference Materials and Measurements, Geel, Belgium. The energy range studied spreads from 3 eV to 100 KeV. 2 kinds of measurements have been performed: capture and transmission measurements. In the energy range between 0 and 2 KeV, more than 220 resonances have been analyzed. About 130 resonances which had stayed previously undiscovered, have been detected and analyzed. Because of instability problems concerning the process of measuring itself, the systematic error is not yet determined. The accuracy which takes into account statistical and systematic errors is expected to be between 4 and 5%.

  17. Determination of detection limits for a VPD ICPMS method of analysis; Determination des limites de detection d'une methode d'analyse VPD ICPMS

    Energy Technology Data Exchange (ETDEWEB)

    Badard, M.; Veillerot, M

    2007-07-01

    This training course report presents the different methods of detection and quantifying of metallic impurities in semiconductors. One of the most precise technique is the collection of metal impurities by vapor phase decomposition (VPD) followed by their analysis by ICPMS (inductively coupled plasma mass spectrometry). The study shows the importance of detection limits in the domain of chemical analysis and the way to determine them for the ICPMS analysis. The results found on detection limits are excellent. Even if the detection limits reached with ICPMS performed after manual or automatic VPD are much higher than detection limits of ICPMS alone, this method remains one of the most sensible for ultra-traces analysis. (J.S.)

  18. 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

  19. 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

  20. Pulse radiolysis of gases

    International Nuclear Information System (INIS)

    Nielsen, O.J.

    1984-04-01

    The pulse radiolysis equipment and technique are described and its relevance to atmospheric chemistry is discussed. Pulse radiolysis of a number of different chemical systems have been used to check the validity of the proposed mechanisms: 1) The hydrogen atom yield in the pulse radiolysis of H 2 was measured by four independent calibration techniques, using reactions of H with O 2 , C1NO, and HI. The H atom yield was compared with O 2 yields in pure O 2 and in O 2 /SF 6 mixtures which lead to a value G(H) = 17.6. The rate constants at room temperature of several reactions were determined. 2) OH radical reactions with tetraalkyllead at room temperature and with ethane, methane, and a series of C1- and F-substituted methanes at 300-400 K were studied. Arrhenius parameters, A and Esub(a), were determined for several reactions. The lifetime of Pb(CH 3 ) 4 and Pb(C 2 H 5 ) 4 in ambient air is estimated. CF 2 C1 2 was found to be a very efficient third body, M, in the reaction OH + OH + M arrow H 2 O 2 + M. 3) In the H 2 S systems the HS extinction coefficient at 3242 AA was determined to 9.5 x 10 2 cm -1 mol -1 . Four rate constants at room temperature were determined. (author)

  1. 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)

  2. 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.

  3. 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)

  4. 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

  5. [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.

  6. Synergic chemical analysis - the coupling of TG with FTIR, MS and GC-MS; 1. The determination of the gases released during the thermal oxidation of a printed circuit board

    International Nuclear Information System (INIS)

    Webb, M.; Last, P.M.; Breen, C.

    1999-01-01

    This contribution reports the coupling of TG with FTIR, MS and GC-MS (Synergic chemical analysis). During thermogravimetric analysis the gases evolved are analysed using 'real-time' FTIR and MS. Simultaneously the gases are collected on an absorbent trap (organic trap module, OTM) for subsequent analysis using GC-MS. As an example the technique has been used to identify the products evolved from a printed circuit board during thermal oxidation. The use of TG-FTIR-MS-OTM-GC-MS provided information that could not be available through single techniques alone. For example, it was possible to ascertain the temperature range over which bromophenol was released. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Working group results on the division by four of the greenhouse gases emissions in France, at 2050, called factor four; Les travaux du groupe de travail sur la division par quatre des emissions de gaz a effet de serre de la France, a l'horizon 2050, dit facteur 4

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This working group aims to evaluate and propose different ways to divide by four the greenhouse gases emissions at 2050 in France. This objective was decided by the Government and fixed in the Climate Plan and in the Program law of 13 July 2005. In this framework, this meeting presents studies of the working group, concerning the following topics: buildings and greenhouse gases, a scenario for the UE25 realized by Greenpeace, the agriculture and the forests facing the climate, the biomass the nature the agriculture and the silviculture facing the climate. (A.L.B.)

  8. Des Connaissances Aux Politiques

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dans beaucoup de pays en développement, la faible capacité du gouvernement est pratiquement la définition des problèmes de développement du pays. ...... Promouvoir l'échange des connaissances émanant des recherches ainsi que des outils et des résultats, et le dialogue entre les pays, institutions et donateurs.

  9. Development of a test system for the determination of biodegradability in surface waters; Entwicklung eines Testsystems fuer die Pruefung des biologischen Abbaus in Oberflaechengewaessern

    Energy Technology Data Exchange (ETDEWEB)

    Kalsch, W.; Knacker, T.; Robertz, M.; Schallnass, H.J.

    1997-04-01

    The study presented here describes the development of a laboratory test system for the determination of aerobic biodegradability of substances at low concentrations in surface water. It was aimed to prepare a draft guideline for a biodegradation simulation test according to OECD format. The experimental approach was based on a literature study conducted within the frame of this project. Further useful information on the possible test design was derived from the German BBA guideline 5-1. Natural water and sediments were collected. Radiolabelled Lindane or 4-Nitrophenol was added. The test vessels (reactors) were aerated and incubated under controlled conditions for up to 92 days. The results showed biological stability of the sediment/water systems even without addition of nutrients and adherence to non-reducing conditions. Mineralisation of 4-Nitrophenol was influenced by the sediment type, the method of aeration and temperature. Factors affecting the mineralisation of Lindane were the method of application and again, the sediment type and temperature. Considerable amounts of the radioactivity were bound to the sediment and were to a large extent unextractable. The potential of a reactor to mineralise a test substance could not be correlated with the biological parameters measured. (orig.) [Deutsch] Die vorliegende Studie beschreibt die Entwicklung eines Labortestverfahrens zur Pruefung des aeroben Abbaus niedrig konzentrierter Stoffe in Oberflaechengewaessern. Dabei war es ein Ziel, das Verfahren so weit abzusichern, dass ein Entwurf fuer eine Pruefrichtlinie als Simulationstest im Format der OECD-Richtlinien abgefasst werden konnte. Grundlage fuer die Konzeption war eine zuvoerderst durchgefuehrte Literaturstudie. Hinweise auf ein moegliches Testdesign ergaben sich auch aus der BBA-Richtlinie 5-1. Wasser und Sediment wurden der Natur entnommen und nach Zugabe der radioaktiven Pruefsubstanz Lindan oder 4-Nitrophenol in einem beluefteten Gefaess unter

  10. Variabilite des productions et des revenus des exploitations ...

    African Journals Online (AJOL)

    ... sont à dominance céréale et coton avec environ 75 % des assolements. Les revenus nets des EAF montrent en moyenne une prédominance des productions végétales (1 394 976 Fcfa) et animales, (1 420 430 Fcfa) sur les activités de diversification (358 449 Fcfa). Mots clés : production, revenu, économie, performance, ...

  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. 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.

  13. Presentation of conclusions of the 9. meeting of the working group on the division by four of the greenhouse gases emissions in France for 2050, called factor 4; Releve de conclusions de la 9. reunion du groupe de travail sur la division par quatre des emissions de gaz a effet de serre de la France a l'horizon 2050, dit Facteur 4

    Energy Technology Data Exchange (ETDEWEB)

    Lamblin, V

    2006-05-15

    This document provides opinions and recommendations of the working group on the factor 4. It deals with the individual behaviors and their positive evolution, the part of the public policies, the actions of the CITEPA, the scientific context about the greenhouse gases decrease objectives, the works of the factor 4 and the long dated reduction aboard. (A.L.B.)

  14. Modelisation des effets physico-techniques pour la conception des ...

    African Journals Online (AJOL)

    automatisation dans les installations industrielles a besoin d'une régulation automatique des commandes des processus technologiques pour lesquelles certaines contraintes sont à relever compte tenu des exigences des innovations scientifiques de ...

  15. variabilite des productions et des revenus des exploitations

    African Journals Online (AJOL)

    3Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR Innovation,. Montpellier, France. Doubangolo COULIBALY, Email kone_b@yahoo.fr. RESUME. La durabilité des systèmes de production à base de coton dans un contexte de variabilité des prix aux producteurs et de ...

  16. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    Science.gov (United States)

    Amrani, Salah

    La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

  17. La metamorphose des cypris femelles des Rhizocephales

    NARCIS (Netherlands)

    Veillet, A.

    1964-01-01

    Depuis la découverte de la métamorphose des cypris de Sacculina carcini Thompson par Delage, peu de biologistes se sont intéressés au développement des Rhizocéphales. On admet aujourd'hui que tous les Cirripèdes parasites ont, comme Sacculina carcini, une forme kentrogone qui inocule le parasite au

  18. 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.

  19. 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...

  20. 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

  1. 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.)

  2. 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.

  3. 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...

  4. 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...

  5. Etude dynamique des apports en éléments majeurs et nutritifs des ...

    African Journals Online (AJOL)

    Afin dfevaluer le niveau trophique de la lagune qui expliquerait la proliferation des algues sur la lagune, les nutriments (NTK et phosphore total) et la Demande Chimique en Oxygene (DCO) des eaux de la lagune. Porto-Novo ont ete determines suivant les quatre saisons de lfannee. Lfetude a egalement permis dfanalyser ...

  6. Determination of Thermodynamical Data of Calcium Hydroxichloride Détermination des données thermodynamiques de l'hydroxychlorure de calcium

    Directory of Open Access Journals (Sweden)

    Allal K. M.

    2006-12-01

    Full Text Available The reaction of hydrochloric acid with dry alkaline sorbents such as hydrated lime in the incineration units leads to the formation of not only calcium chloride but calcium hydroxichloride as well. A thermodynamic study of the chemical reactions involved in the dechlorination process is required in order to show if such a product is theoretically possible to be formed. However, the data of CaCIOH necessary to carry out such a study are not available in the literature. Hence, a method of predicting these data is developed in the present work. Predicted values of Gibbs energy and entropy of formation of CaCIOH at different temperatures are compared to values calculated by Mostafa's model and satisfactory results were obtained. La réaction de l'acide chlorhydrique avec des adsorbants alcalins tels que la chaux au niveau de stations d'incinération entraîne la formation de chlorure ainsi que de l'hydroxychlorure de calcium. Une étude thermodynamique des différentes réactions mises en jeu dans le procédé de déchloruration serait nécessaire, afin de montrer qu'un tel produit serait théoriquement susceptible d'être formé. Cependant, les données thermodynamiques de CaCIOH permettant de mener à bien une telle étude ne sont pas disponibles dans la littérature. Par conséquent, une méthode permettant de prédire ces données a été développée dans ce présent travail. Des valeurs d'énergie de Gibbs et d'entropie de formation de CaCIOH prédites par cette méthode à différentes températures ont été comparées à celles déterminées à l'aide du modèle de Mostafa, et des résultats satisfaisants ont été obtenus.

  7. 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...

  8. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    37. Taux des lipides et des protéines et composition en acides gras du tissu comestible des crustacés et des mollusques pêchés en Algérie : Effet du halofénozide (RH-0345) sur la composition en acides gras de. Penaeus kerathurus (Crustacé, Décapode). Samira Gheid. 1. , Safia Nadji. 2 et Mohamed El Hadi Khebbeb. 3.

  9. Methoden Des Fremdsprachenunterrichts

    Directory of Open Access Journals (Sweden)

    Rasa Sklizmantaitė

    2011-04-01

    Full Text Available Beim Unterrichten einer Fremdsprache ist es wichtig, Methoden des Fremdsprachenunterrichts zu kennen, um eine Methode des Unterrichts nach dem Niveau und Bedürfnissen der entsprechenden Gruppe opti-mal zu wählen. Im Artikel wird der Überblick des Fremdsprachenunterrichts im Hinblick auf historische Entwicklung dargeboten sowie die Hauptmerkmale einiger Methoden des Fremdsprachenunterrichts aufgezählt.

  10. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of

  11. Effect of adding Te to layered GaSe crystals to increase the van der Waals bonding force

    Science.gov (United States)

    Tanabe, Tadao; Zhao, Shu; Sato, Yohei; Oyama, Yutaka

    2017-10-01

    The interplanar binding strength of layered GaSe1-xTex crystals was directly measured using a tensile testing machine. The GaSe1-xTex crystals were grown by a low temperature liquid phase solution method under a controlled Se vapor pressure. The stoichiometry-controlled GaSe1-xTex crystal has the ɛ-polytype structure of GaSe, where the Te atoms are substituted for some of the Se atoms in the GaSe crystal. The effect of adding Te on the bonding strength between the GaSe layers was determined from direct measurements of the van der Waals bonding energy. The bonding energy was increased from 0.023 × 106 N/m2 for GaSe to 0.16 × 106 N/m2 for GaSe1-xTex (x = 0.106).

  12. Analyses and quantitative determination of the strontium radioisotopes 89 and 90 in milk powder; Recherche et dosage des isotopes radioactifs 89 et 90 du strontium dans le lait en poudre

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmaire, L.; Michon, G. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    The authors describe a procedure for the determination of the strontium radioisotopes 89 and 90. The concentration of strontium is made possible by the insolubility of its nitrate salt in strong nitric acid which allows the removal of greatest part of calcium. The purification is performed on a cation exchange column. The amount of radioisotope 90 is determined by means of its daughter product yttrium 90 necessary calibrations and computations are treated in special paragraphs. With regard to the reproducibility of the measurements, the fluctuations are less than 20 per cent. This seems satisfaction for such a technique which have great sensibility while being long and necessitative great carefulness. (author) [French] Les auteurs decrivent une technique de dosage des isotopes 89 et 90 du strontium. La concentration du strontium est assuree grace a l'insolubilite de son nitrate dans l'acide nitrique concentre, ce qui permet d'eliminer la plus grande partie du Ca. La purification se fait sur une colonne echangeuse de cations. L'isotope 90 est dose grace a son descendant l'yttrium 90. Les etalonnages et calculs necessaires font l'objet de paragraphes detailles. En ce qui concerne la reproductibilite des mesures, les fluctuations sont inferieures a 20 pour cent, ce qui semble satisfaisant devant la grande sensibilite de la methode qui reste cependant longue et delicate. (auteur)

  13. Civili, langue des Baloango

    DEFF Research Database (Denmark)

    Mavoungou, Paul Achille; Ndinga-Koumba-Binza, Hugues Steve

    , Congo, Angola, etc.) issus de la décolonisation. Il présente de façon succincte quelques phénomènes historiques, phonologiques, morphosyntaxiques, homonymiques et analogiques de la langue. Des faits sémantiques des emprunts linguistiques y sont également décrits dans le cadre des changements...

  14. ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

    African Journals Online (AJOL)

    AISA

    haies vives) et la valorisation des produits forestiers tels que l'utilisation des tourteaux comme engrais organiques (Francis et al.,. 2005). Plusieurs études ont montré que les perceptions paysannes d'une technologie ou d'une innovation sont déterminantes pour son adoption. (Adesina et Baidu-forson, 1996). Les travaux.

  15. 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)

  16. 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.

  17. Determination of neutron resonance parameters of Neptunium 237 between 0 and 500 eV. The covariance matrices of statistical and of systematic origin, relating the resonance parameters, are also given; Determination des parametres des resonances neutroniques du neptunium 237, en dessous de 500eV, et obtention des matrices de covariances statistiques et systematiques entre les parametres de ces resonances

    Energy Technology Data Exchange (ETDEWEB)

    Lepretre, A.; Herault, N. [CEA Saclay, Dept. d' Astrophysique de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Brusegan, A.; Noguere, G.; Siegler, P. [Institut des Materiaux et des Metrologies - IRMM, Joint Research Centre, Gell (Belgium)

    2002-12-01

    This report is a follow up of the report CEA DAPNIA/SPHN-99-04T of Vincent Gressier. In the frame of a collaboration between the 'Commissariat a l'Energie Atomique (CEA)' and the Institute for Reference Materials and Measurement (IRMM, Geel, Belgique), the resonance parameters of neptunium 237 have been determined in the energy interval between 0 and 500 eV. These parameters have been obtained by using the Refit code in analysing simultaneously three transmission experiments. The covariance matrix of statistical origin is provided. A new method, based on various sensitivity studies is proposed for determining also the covariance matrix of systematic origin, relating the resonance parameters. From an experimental viewpoint, the study indicated that, with a large probability, the background spectrum has structure. A two dimensional profiler for the neutron density has been proved feasible. Such a profiler could, among others, demonstrate the existence of the structured background. (authors)

  18. Determination of the contributions of the waste management sector to increasing resource productivity and of the share recycling takes in the value-added chain displaying the paths of recovery of relevant waste; Ermittlung des Beitrages der Abfallwirtschaft zur Steigerung der Ressourcenproduktivitaet sowie des Anteils des Recyclings an der Wertschoepfung unter Darstellung der Verwertungs- und Beseitigungspfade des ressourcenrelevanten Abfallaufkommens

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Joerg; Heidrich, Kerstin; Baumann, Janett; Kuegler, Thomas; Reichenbach, Jan [INTECUS GmbH Abfallwirtschaft und umweltintegratives Management, Dresden (Germany)

    2012-05-15

    The degree of substitution of primary raw materials by secondary raw materials cannot explicitly be seen in the resource productivity indicator of the national sustainability strategy. To incorporate the effects of substitution of primary raw materials, secondary raw materials should be considered in addition as a separate category. In the present study a reproducible and continuously adaptable presentation of material flows of recyclable wastes has been developed and the contributions of the waste management sector to resource productivity have been described on that basis. The material flows of metal, plastics, construction and demolition waste as well as for the biodegradable waste were mapped at a low level of detail using German waste statistics. With the help of in-depth studies the material flows of iron and steel, copper, gold, polyethylene (HD- /LDPE), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) could be displayed in more detail. The amounts of waste and secondary raw materials determined in this way led to a quantification of the feedstock, energy and economic savings from recycling by means of a comparison with the primary commodities substituted. Without considering preceding steps of processing and production abroad the raw material and energetic substitution was set into relation with the consumption of primary materials by the German economy to establish the socalled DERec parameter (Direct Effect of Recovery). The total DERec, determined for all material flows considered in the study amounts to 49.525 million tons, which, in the absence of recycling and energy recovery, would additionally be necessary to generate the substituted raw materials and energy. This would mean a significant increase in material inputs to the economy. Only this amount already corresponds to 3.7% of DMI (Direct Material Input), which in 2007 made up a total of 1.35 billion tons of domestic and imported abiotic resources. This underlines the importance of

  19. Kinetic theory the Chapman-Enskog solution of the transport equation for moderately dense gases

    CERN Document Server

    Brush, S G

    1972-01-01

    Kinetic Theory, Volume 3: The Chapman-Enskog Solution of the Transport Equation for Moderately Dense Gases describes the Chapman-Enskog solution of the transport equation for moderately dense gases. Topics covered range from the propagation of sound in monatomic gases to the kinetic theory of simple and composite monatomic gases and generalizations of the theory to higher densities. The application of kinetic theory to the determination of intermolecular forces is also discussed. This volume is divided into two sections and begins with an introduction to the work of Hilbert, Chapman, and Ensko

  20. 40 CFR 86.514-78 - Analytical gases.

    Science.gov (United States)

    2010-07-01

    ...; and (ii) Optionally, for response factor determination, single blends of methanol using air as the... 18 and 21 mole percent. (7) The use of proportioning and precision blending devices to obtain the... Administrator. (b) Calibration gases (not including methanol) shall be known to within 2 percent of true values...

  1. Metastability in spin polarised Fermi gases and quasiparticle decays

    DEFF Research Database (Denmark)

    Sadeghzadeh, Kayvan; Bruun, Georg; Lobo, Carlos

    2011-01-01

    We investigate the metastability associated with the first order transition from normal to superfluid phases in the phase diagram of two-component polarised Fermi gases.We begin by detailing the dominant decay processes of single quasiparticles.Having determined the momentum thresholds of each pr...

  2. Measuring the Speed of Sound through Gases Using Nitrocellulose

    Science.gov (United States)

    Molek, Karen Sinclair; Reyes, Karl A.; Burnette, Brandon A.; Stepherson, Jacob R.

    2015-01-01

    Measuring the heat capacity ratios, ?, of gases either through adiabatic expansion or sound velocity is a well established physical chemistry experiment. The most accurate experiments depend on an exact determination of sound origin, which necessitates the use of lasers or a wave generator, where time zero is based on an electrical trigger. Other…

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances; Analyse des modalites de fixation des valeurs limites d'exposition et d'emission pour les substances chimiques et radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, C.; Schneider, T

    2002-08-01

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  8. 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.

  9. Mécanique des fluides fondamentale

    CERN Document Server

    Zeytounian, Radyadour K

    1991-01-01

    Ce cours de mecanique des fluides est avant tout un cours theorique qui repond aux questions fondamentales de ce sujet de recherche. Les quatre premiers chapitres presentent les equations propres a determiner l'ecoulement de fluide considere et diverses solutions. Les chapitres 5 et 6sont consacres aux problemes lies la stabilite, aux bifurcations et aux comportements chaotiques. Le livre donne un vision globale des questions traitees en mecanique des fluides qui sont a la base de toute la recherche, de la modelisation et de toutes les applications dans ce domaine.

  10. Geometric parameters determination of a single vapor bubble growth and heat transfer associated: non condensable influence on the onset of convective instabilities; Determination des caracteristiques geometriques de la croissance d'une bulle de vapeur et des transferts de chaleur associes: influence des incondensables sur le declenchement d'instabilites convectives

    Energy Technology Data Exchange (ETDEWEB)

    Barthes, M.; Reynard, Ch.; Santini, R.; Tadrist, L. [Laboratoire Institut Universitaire des Systemes Thermiques Industriels (IUSTI), CNRS UMR 6595, DME, 13 - Marseille (France)

    2005-06-01

    We present here an experimental work of a single vapor bubble growth in a subcooled liquid bulk (FC-72) at atmospheric pressure. The vapor bubble grows on a downward facing heating element (at constant heating power) on an artificial nucleation site located in the centre of the heated surface. Bubble dynamics are studied thanks to image proceeding. The temporal evolution of geometric parameters, such as diameter, height, volume and shape, are measured. The analysis of some parameters enables us to determine the influence of the heating power on the heat and mass transfers. Moreover an observation, using a shadowgraphy method, of the different modes of convective instabilities is presented. The non condensable gas influence on the occurrence of the instability is discussed. (authors)

  11. Détermination de paramètres de fracturation hydraulique par inversion des courbes de pression Determining Hydraulic Fracturing Parameters by Inverting Pressure Curves

    Directory of Open Access Journals (Sweden)

    Herail R.

    2006-11-01

    Full Text Available Une nouvelle méthode d'interprétation des minifracsest présentée dans cet article, en considérant la contrainte principale mineure et le coefficient de filtration comme seules inconnues du problème. Tout d'abord, le problème direct est défini en appliquant le modèle confiné de Nordgren Nolte (à la fois phases de propagation et de fermeture. La sensibilité du modèle est étudiée et montre que la contrainte et la viscosité du fluide ont une grande influence sur la propagation tandis que le coefficient de filtration a une grande influence sur la fermeture. Deuxièmement, une méthode inverse qui consiste à minimiser une fonction dans l'espace des paramètres est proposée. La méthode inverse est ensuite appliquée à un cas réel et montre qu'une très bonne approximation de bêta3 et Cw peut être obtenue. This article describes a new method of interpreting minifracsby considering the minor principal stress and the fluid loss coefficient as the only unknowns of the problem. First of all, the direct problem is defined by applying Nordgren-Nolte's contained model (both propagation and closure phases. The sensitivity of the model is examined, and it shows that the stress and viscosity of the fluid have great influence on propagation, while the fluid loss coefficient has great influence on the closure. Secondly, an inverse method consisting in minimizing a function in the parameter space is proposed. The inverse method is then applied to an actual case and shows that a very good approximation of beta3 and Cw can be obtained.

  12. 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.

  13. The Gaseous Explosive Reaction : The Effect of Inert Gases

    Science.gov (United States)

    Stevens, F W

    1928-01-01

    Attention is called in this report to previous investigations of gaseous explosive reactions carried out under constant volume conditions, where the effect of inert gases on the thermodynamic equilibrium was determined. The advantage of constant pressure methods over those of constant volume as applied to studies of the gaseous explosive reaction is pointed out and the possibility of realizing for this purpose a constant pressure bomb mentioned. The application of constant pressure methods to the study of gaseous explosive reactions, made possible by the use of a constant pressure bomb, led to the discovery of an important kinetic relation connecting the rate of propagation of the zone of explosive reaction within the active gases, with the initial concentrations of those gases: s = K(sub 1)(A)(sup n1)(B)(sup n2)(C)(sup n3)------. By a method analogous to that followed in determining the effect of inert gases on the equilibrium constant K, the present paper records an attempt to determine their kinetic effect upon the expression given above.

  14. Appropriation des Tic et performance des entreprises

    OpenAIRE

    Lethiais , Virginie; Smati , Wided

    2009-01-01

    Quatre pages Marsouin; L'utilisation des TIC (Technologies de l'information et de la Communication) se développe dans les entreprises pour assurer des tâches de plus en plus nombreuses : la communication, la recherche d'informations, la commercialisation des produits et services, le travail en groupe, la gestion de l'entreprise, la prospection, etc. Les équipements en TIC ainsi que l'usage qui en est fait diffèrent d'une entreprise à une autre selon de nombreux critères. L'objet de ce quatre ...

  15. 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.

  16. 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.

  17. Cartographie des directions dominantes des vents au Benin : Outil ...

    African Journals Online (AJOL)

    Cartographie des directions dominantes des vents au Benin : Outil de conception et de dimensionnement des ouvrages. ... nous avons, après la collecte des informations météorologiques, procédé : - à l'analyse des données (directions) des six stations météorologiques principales conformément aux méthodes statistiques.

  18. Comparaison de diverses méthodes de dosage des argiles d'un sable de gisement. Dosage des argiles Comparison of Different Methods of Determining Clays in a Reservoir Sand. Quantitative Analysis of Clays

    Directory of Open Access Journals (Sweden)

    Yvon J.

    2006-11-01

    Full Text Available Les argiles d'un sable de gisement, concentrées dans la fraction de diamètre Phi Oil, gas and geothermal reservoirs all contain clayey fractions no matter how small they may be. This has been blamed whenever operating or producing problems arise. It may be revealed by phenomena of mechanical resistance, permeability or interfacial properties (ion exchange, adsorption, etc. . Tests to understand such phenomena then go via the quantitative mineralogical analysis of the clays present. This analysis must also be looked at in terms of methods. It is subjected to constraints of cost, instrumentation, competence or deadlines. This article proposes:(a A so-called conventional route (Dejou et al, 1977 based on chemical and weighted analyses. (b An overall assessment method of the clay phase by difference (determination of two nonclay species. (c A method based on the statistical processing of microanalytic data obtained by an electronic microprobe. The material examined was a quartzose arenite made up mainly of quartz, jarosite, orthoclase, plagioclases, calcite, dolomite, muscovite, kaolinite, illite, montmorillonite, interstratified illite-montmorillionite, iron oxyhydroxides and accessory minerals such as rutile, zircon, garnet, tourmaline and hydroxylapatite. The arenite was subjected to an ultrasonic treatment (Letelier, 1986 to recover pellicular or weakly cemented clays. After this treatment, all the free clays were found in the < 40 m fraction which were used for the measurements. The so-called conventionalmethod is based on the associating of multiple techniques that are normally used for analyzing clays. They include X-ray diffraction, TDA, TGA, selective dissolution, CEC, adsorption of various reagents and gravimetric separations. They have been reviewed by Dejou et al (1977. The results they give depend on the grain size, chrystallochemistry, presence of amorphous elements and especially the typical chemical compositions assigned to the

  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. Applications biotechnologiques des mycorhizes

    OpenAIRE

    Redecker, Dirk

    2012-01-01

    La symbiose mycorhizienne est une association entre un champignon mycorhizogène et une racine de plante-hôte. La mycorrhize à arbuscules (MA) est extrêmement ancienne puisqu’elle est datée de la même époque que l’apparition des plantes terrestres, il y a 460 millions d’années. Elle s’effectue entre un champignon mycorhizogène à arbuscules (CMA, phylum Glomeromycota) et plus de 80% des plantes terrestres. Les CMA sont des microorganismes ubiquitaires du sol et sont des biotrophes obligatoires ...

  1. 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

    kerogen less enriched in 13C. The typically assumed linear trend for ??13C of methane, ethane and propane versus their reciprocal carbon number for a single sourced natural gas is not observed in the experimental gases. Instead, the so-called "dogleg" trend, exemplified by relatively 13C depleted methane and enriched propane as compared to ethane, is observed for all the kerogen types and at both experimental conditions. Three of the natural gases from the same thrust unit had similar "dogleg" trends indicative of Menilite source rocks with Type III kerogen. These natural gases also contained varying amounts of a microbial gas component that was approximated using the ????13C for methane and propane determined from the experiments. These approximations gave microbial methane components that ranged from 13-84%. The high input of microbial gas was reflected in the higher gas:oil ratios for Outer Carpathian production (115-1568 Nm3/t) compared with those determined from the experiments (65-302 Nm3/t). Two natural gas samples in the far western part of the study area had more linear trends that suggest a different organic facies of the Menilite Shales or a completely different source. This situation emphasizes the importance of conducting hydrous pyrolysis on samples representing the complete stratigraphic and lateral extent of potential source rocks in determining specific genetic gas correlations. ?? 2009 Elsevier Ltd.

  2. A Geochemical Approach for Monitoring a CO2 Pilot Site: Rousse, France. A Major gases, CO2-Carbon Isotopes and Noble Gases Combined Approach Une méthode géochimique pour la surveillance d’un site pilote de stockage de CO2 : Rousse, France. Approche combinant les gaz majeurs, l’isotopie du carbone du CO2 et les gaz rares

    Directory of Open Access Journals (Sweden)

    Garcia B.

    2012-02-01

    Full Text Available This paper presents the geochemical characterization of various gas end-members involved in a depleted gas field CO2 storage pilot (Rousse, France. In this pilot, CO2 is produced by oxycombustion from natural gas transformed into fuel gas at the Lacq plant, and transported in a pipeline 30 km away to the depleted gas reservoir of Rousse. Gases produced at Rousse before CO2 injection, the Lacq fuel gas and the CO2 resulting from the oxy-fuel combustion were sampled, together with gases from a –45 m monitoring well and from soils in the vicinity of the Rousse structure. For all samples, the bulk gas composition, the carbon isotopic compositions and the abundance and isotopic signatures of the noble gases were determined. The bulk gas compositions of the Rousse natural gas are comparable to the Lacq fuel gas with methane as the main compound with residual C2-C5 and CO2. Soil gases are typical mixtures of air with biogenic CO2 (up to 9-10%, while the monitoring well gases display typical air compositions with no excess CO2 The Rousse gas and the Lacq fuel gas have δ13CCH4 values of –41.0‰ and –43.0‰ respectively. The injected CO2 out of the oxycombustion chamber has a δ13CCO2 of –40.0‰, whereas δ13CCO2 value for soils samples is comprised between –15 and –25‰. The Rousse natural gas and the Lacq fuel gas are both characterized by a high He enrichment, and depletion in Ne, Ar and Kr compared to the air values. The oxyfuel combustion process provides a CO2 with the He enrichment of the Lacq fuel gas, and a Ne, Ar and Kr composition reflecting that of the oxygen produced at the Air Separation Unit (ASU. Indeed, Ne is depleted relatively to the air, while Kr is enriched up to tenfold, which results from the cryogenic separation of the air noble gases within the ASU. Soil samples noble gas compositions are equivalent to that of the air. In the light of these results, the compositions of the various end-members involved in this CO2

  3. 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...

  4. 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

  5. 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

  6. Elaboration of fiber-reinforced metallic materials; Elaboration des materiaux metalliques renforces par des fibres

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.M. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-08-01

    A bibliographic study on the elaboration of fiber reinforced metallic materials is presented in three parts: the theory of fiber reinforcement of metals in summarized, with emphasis on the mechanical and geometric factors which govern the behaviour and the performances to be expected from a given composite material; a second part is devoted to the study of the physical and chemical factors related to the structural stability of the material. Finally, the various processes of fabrication of such composites are presented and discussed. (author) [French] Cette etude bibliographique de l'elaboration des materiaux metalliques renforces par des fibres, comprend trois parties. Dans la premiere partie, la theorie du renforcement des metaux par des fibres est resumee de maniere a mettre en lumiere les facteurs mecaniques et geometriques qui determinent le comportement et les performances que l'on peut attendre d'un composite donne. La seconde partie est consacree a l'etude des facteurs physico-chimiques qui determinent la stabilite structurale d'un composite. Enfin, la troisieme partie est constituee par l'expose des differentes methodes d'elaboration des composites. (auteur)

  7. 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.

  8. 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.

  9. Use of geothermal heat by means of energetic geostructures. Methodology to identify potential zones of application; Exploitation de la chaleur terrestre par des geostructures energetiques. Methodologie de determination des zones potentielles

    Energy Technology Data Exchange (ETDEWEB)

    Joliquin, P.

    2002-07-01

    This study focuses on the realisation of earth heat exchangers by means of so-called geostructures. These geostructures are works of concrete being in close contact with the ground and which are used for foundation or as retaining structures. The three main types of geostructures are piles, the walls and the foundation slabs. These structures can be equipped with a network of tubes where a liquid circulates to permit a heat exchange with the ground. In this case, they can be called energetic geostructures. To date, the use of this technology is rather limited in Switzerland. Therefore, the aim of this study is to increase its development, and a methodology to identify potential zones of application will be given for the purpose of energy planning. The correct land planning and the geotechnical properties of the ground are the two basic criteria to select the type of geostructure and its foundation conditions. Additional criteria like the thermal properties of the ground and the presence of groundwater will determine whether geostructures can be equipped with heat exchangers. Finally, the protection of the groundwater and thermal ground disturbances are possible criteria which could limit the application of energetic geostructures. To validate this methodology, six sites were selected in the canton of Geneva. Two of them ('La Chapelle - Les Sciers' and 'Frontenex - Gradelle'), were investigated by applying the above mentioned criteria. The conclusion is that the two sites represent potential zones for using energetic geostructures. Nevertheless, within the site 'La Chapelle - Les Sciers', the presence of an important groundwater resource was identified. To protect it, it is not permitted to pierce the impermeable layer above the aquifer, and therefore foundation depths must carefully be chosen by controlling the lengths of piles. (author)

  10. 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

  11. 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

  12. Stress analysis of the O-element pipe during the process of flue gases purification

    Directory of Open Access Journals (Sweden)

    Nekvasil R.

    2008-11-01

    Full Text Available Equipment for flue gases purification from undesired substances is used throughout power and other types of industry. This paper deals with damaging of the O-element pipe designed to remove sulphur from the flue gases, i.e. damaging of the pipe during flue gases purification. This purification is conducted by spraying the water into the O-shaped pipe where the flue gases flow. Thus the sulphur binds itself onto the water and gets removed from the flue gas. Injection of cold water into hot flue gases, however, causes high stress on the inside of the pipe, which can gradually damage the O-element pipe. In this paper initial injection of water into hot pipe all the way to stabilization of temperature fields will be analyzed and the most dangerous places which shall be considered for fatigue will be determined.

  13. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

    Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

  14. Physical replicas and the Bose glass in cold atomic gases

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, S; Kantian, A; Daley, A J; Zoller, P [Institute for Theoretical Physics, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck (Austria); Katzgraber, H G [Theoretische Physik, ETH Zurich, CH-8093 Zuerich (Switzerland); Lewenstein, M [ICAO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Castelldefels, Barcelona (Spain); Buechler, H P [Institute for Theoretical Physics III, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)], E-mail: sarah.morrison@uibk.ac.at

    2008-07-15

    We study cold atomic gases in a disorder potential and analyse the correlations between different systems subjected to the same disorder landscape. Such independent copies with the same disorder landscape are known as replicas. While, in general, these are not accessible experimentally in condensed matter systems, they can be realized using standard tools for controlling cold atomic gases in an optical lattice. Of special interest is the overlap function which represents a natural order parameter for disordered systems and is a correlation function between the atoms of two independent replicas with the same disorder. We demonstrate an efficient measurement scheme for the determination of this disorder-induced correlation function. As an application, we focus on the disordered Bose-Hubbard model and determine the overlap function within the perturbation theory and a numerical analysis. We find that the measurement of the overlap function allows for the identification of the Bose-glass phase in certain parameter regimes.

  15. Physical replicas and the Bose glass in cold atomic gases

    International Nuclear Information System (INIS)

    Morrison, S; Kantian, A; Daley, A J; Zoller, P; Katzgraber, H G; Lewenstein, M; Buechler, H P

    2008-01-01

    We study cold atomic gases in a disorder potential and analyse the correlations between different systems subjected to the same disorder landscape. Such independent copies with the same disorder landscape are known as replicas. While, in general, these are not accessible experimentally in condensed matter systems, they can be realized using standard tools for controlling cold atomic gases in an optical lattice. Of special interest is the overlap function which represents a natural order parameter for disordered systems and is a correlation function between the atoms of two independent replicas with the same disorder. We demonstrate an efficient measurement scheme for the determination of this disorder-induced correlation function. As an application, we focus on the disordered Bose-Hubbard model and determine the overlap function within the perturbation theory and a numerical analysis. We find that the measurement of the overlap function allows for the identification of the Bose-glass phase in certain parameter regimes

  16. 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.

  17. La gouvernance des risques naturels et la problematique des ...

    African Journals Online (AJOL)

    Depuis quelques années, la gouvernance des risques naturels dus aux inondations remet en cause les processus de mise en oeuvre des politiques urbaines et la qualité de la structure des aménagements dans les grandes villes du Golfe de Guinée. La perception de la gouvernance et l'application des politiques de ...

  18. 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.

  19. 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

  20. 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

  1. Noble gases in ten stone meteorites from Antarctica

    International Nuclear Information System (INIS)

    Weber, H.W.; Schultz, L.

    1980-01-01

    The concentrations and isotopic composition of noble gases have been determined in all ten stone meteorites recovered in Antarctica during 1976-1977 by a U.S.-Japanese expedition. From a comparison of spallogenic and radiogenic gas components it is concluded that the chondrites Mt. Baldr (a) and Mt. Baldr (b) belong to the same fall but that all other stone meteorites are individual finds. (orig.)

  2. Quelques aspects de la géochimie organique dans la prospection des hydrocarbures Several Aspects of Organic Geochemistry in Prospection for Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Kubler B.

    2006-10-01

    know whether origins are similar or different. In some cases, correlations not only between shows and accumulations, but also between source rocks and accumulations, have become certain. Study along logical lines of the development of living, dead, fossilized and then diagenized organic matter compounds, has made it possible to define the organic origin of petroleum and also to associate its composition with the dominant types of organic matter in sedimentary basins, and hence to determine sedimentation conditions and the most favourable environment for the accumulation and preservation of petroligenic organic matter. However, the greatest contribution of organic geochemistry to exploration has certainly been its ability to determine, in the initial stage, a range of temperature, and then of temperature and duration: the heat-time factor generating maximum production and then conservation of liquid hydrocarbons: the potential ail window. More recently, geochemistry of hydrocarbon gases was able to demonstrate that thisoil windowwas surrounded by the generation of light gases. This recent development has refocused attention on prospecting objectives which had been abandoned or deemed without interest. However, organic geochemistry by its very nature and like most laboratory-based sciences, yieldsspotresults; these will not be fully significant unless the geological specimens are properly situated in the geological configuration to which they belong.

  3. Determination of low concentrations of pyridine in piperidine by gas chromatography and infrared spectroscopy; Determinacion de bajas concentraciones de piperidina en piridina por cromatografia de gases y espectroscopia infrarroja

    Energy Technology Data Exchange (ETDEWEB)

    Perez Garcia, M. M.; Parellada Bellod, R.

    1979-07-01

    This paper describes the determination of low amounts of piperidine in pyridine in the concentration range of 0-5%. After an exhausting review of the bibliography on the column selection, the chromatographic separation and determination are made on the following column: 27% Pennwalt- 223; 4% KOH on Gas-Chrom R; 80-100 mesh with flame ionization detector. The retention indexes of both compounds and tho Rohrschneider constants of the phase used are calculated. The minimum detection limit achieved for piperidine is 0,25%. (Author) 25 refs.

  4. Determination of consumption biogenic solid fuels in the commercial sector, trade, services (tertiary sector). Final report; Ermittlung des Verbrauchs biogener Festbrennstoffe im Sektor Gewerbe, Handel, Dienstleistungen (GHD-Sektor). Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Viehmann, Cornelia; Westerkamp, Tanja; Schwenker, Andre; Schenker, Marian; Thraen, Daniela; Lenz, Volker [DBFZ Deutsches BiomasseForschungsZentrum gemeinnuetzige GmbH, Leipzig (Germany); Ebert, Marcel [Leipziger Institut fuer Energie GmbH (Ireland), Leipzig (DE)

    2012-07-01

    . While in the energy balance of fossil fuels for the tertiary sector is determined by residual definition, this is not possible with biogenic solid fuels, since the sum of the total energy-recycled wood (and straw) is not known. Reasons for this are that only a fraction of the fuel are sold through the official fuel trade, while at the same time a considerable variety of usable biogenic solid fuels and their sources of supply are available. For this reason, in this project, the bottom-up approach, that is the consideration of the individual selected sectors of the tertiary sector, is used for the extrapolation. The tertiary sector comprises a wide variety of different industries, but not all are suitable for using solid fuels. Therefore, first, the identification of relevant sectors for this project is necessary. In addition to the group of relevant and irrelevant industries, potentially relevant industries are reported, which despite of currently low use of solid fuels can gain important in the future. The input data of classified relevant sectors are collected in a literature review and through interviews. These are processed accordingly and entered into the part of the project to be developed extrapolation method. For a holistic view of the tertiary sector, the extrapolation method is able to include data of potentially relevant or not relevant industries. In conclusion, in this study, the extrapolation results are presented and discussed. [German] Die Politik hat sich sowohl auf nationaler als auch auf europaeischer Ebene ambitionierte Ziele zum Ausbau erneuerbarer Energien und zur Minderung der Treibhausgasemissionen gesetzt. Im Nationalen Aktionsplan fuer Erneuerbare Energien der Bundesrepublik Deutschland sind diese Ziele bis zum Jahr 2020 definiert. Der Anteil erneuerbarer Energien bei der Bereitstellung von Waerme und Kaelte soll demnach von 6,6 % auf 15,5 % des Bruttoendenergieverbrauches steigen. Entsprechend der zunehmenden Bedeutung der solarthermischen

  5. Holographic determination of the Soret-coefficient of some mixtures under microgravity. Final report; Holographische Bestimmung des Soret-Koeffizienten von ausgewaehlten binaeren Gemischen unter Weltraumbedingungen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Richter, J.; Luenskens, S.; Brinkmann, B.

    1994-12-01

    A measurement apparatus to determinate Soret-Coefficients of molten salt mixtures with holographic interferometry was developed. The soret-Coefficient of KNO{sub 3}-AgNO{sub 3} was measured in dependence of temperature and mole fraction. The dependence of the refractive index on temperature and composition was determined wit a self developed device especially suitable for high temperatures. (orig.)

  6. L'amelioration potentielle des sciages d'epinette noire en tenant compte des noeuds

    Science.gov (United States)

    Lemieux, Hugo

    Cette recherche a pour but de determiner l'amelioration potentielle de la resistance mecanique des sciages d'epinette noire. Un echantillon de billes a ete mesure afin de caracteriser les noeuds en surface. Un sous-echantillon a ete disseque afin de caracteriser les noeuds. Ces mesures ont servi dans un modele de debitage de billes et de classement des planches qui prend en compte les noeuds. Des simulations de sciage et de classement ont ete effectuees sur toutes les billes en faisant des rotations de celles-ci. Les simulations ont determine les positions qui donnent un meilleur et un pire rendement au niveau du classement. La moitie des billes a ensuite ete sciee par rapport a une meilleure position et l'autre moitie par rapport a la pire solution. Les sciages ont ete classes visuellement par rapport aux noeuds seulement et par rapport a tous les defauts. Ils ont ensuite ete testees a destruction. L'analyse a determine que les noeuds n'ont pas d'effet sur le classement visuel des sciages mais qu'ils ont eu un effet marque sur la resistance mecanique.

  7. determination des parametres influents de la dynamique des forets

    African Journals Online (AJOL)

    Administrateur

    Chev. Leguminoseae-Mim. LOL. Loloti. Lannea welwitschii (Hiern) Engl. Anacardiaceae. LON. Lohonfé. Celtis adolphi-frederici Engl. Ulmaceae. LOT. Lotofa. Sterculia rhinopetala K.Schum. Sterculiaceae. MEL. Mélégba. Berlinia confusa Hoyle.

  8. determination des parametres influents de la dynamique des forets ...

    African Journals Online (AJOL)

    Administrateur

    shown out by many researchers in evergreen forest (permanent plots of Irobo) and in semi-deciduous forest. (permanent plots of Mopri). The results of this study confirm the positive effect of the selective thinning on the timber resources increase of the both forest types. Indeed, the increment rate of the commercial stand ...

  9. Analyse Des Perceptions Locales Et Des Facteurs Determinant L ...

    African Journals Online (AJOL)

    Mots clés : Jatropha curcas L., ethnobotanique, perceptions locales, groupes socioprofessionnels, Bénin. This study analyzed local perceptions of Jatropha curcas L. (Euphorbiaceae) cultivation and the various organs and products used according to the age ; the sex and the socio-linguistic groups. A sample of 704 people ...

  10. Equilibrium phase experimental determination of petroleum + gas systems at supercritical condition using ultrasonic technology; Estudo experimental do equilibrio de fases de sistemas de fracoes de petroleo e gases em condicoes supercriticas utilizando tecnicas de ultra-som: aparato experimental

    Energy Technology Data Exchange (ETDEWEB)

    Mehl, Ana; Pessoa, Fernando L.P.; Silva, Silvia M.C. da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Feiteira, Jose F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Escola de Engenharia

    2008-07-01

    In separation process of multicomponent systems based on phase equilibrium is essential know the phase behavior and the critical points of the system for determination and optimization of the operational conditions. The experimental apparatus presents the challenge of determine the equilibrium phase dates of a system composed by petroleum residua and supercritical solvent. The used method, named acoustic method, allows the composition identification of the phases in equilibrium also in cloudy systems as they are the systems formed by residues of crude oil. For this reason, the acoustic methodology, based on the ultra-sound technology will be used in the study of the phase equilibrium and experimental characterization of the system, in benches scale, operating in severe conditions of temperature and pressure.The acoustic method is one not invasive and not subjective technique, what becomes the work in high pressures safer. (author)

  11. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

    La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

  12. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

    Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. Terminologie des indices boursiers

    OpenAIRE

    Van der Yeught, Michel

    2013-01-01

    Les indices boursiers sont omniprésents en anglais financier. Les plus importants sont universellement familiers mais leur nature et leur fonctionnement restent largement méconnus. Des distinctions (average/index, narrow index/broad index, price-weighted/market value-weighted, all share/ composite/ subindex) permettront à l’angliciste de spécialité d’adapter à chaque indice la terminologie française ou anglaise qui lui correspond. Des remarques sur des erreurs courantes, un mini-glossaire, un...

  19. Combustion of low calorific value gases in porous burners; Verbrennung von niederkalorischen Gasen in Porenbrennern

    Energy Technology Data Exchange (ETDEWEB)

    Diezinger, S.; Talukdar, P.; Issendorff, F. von; Trimis, D. [Lehrstuhl fuer Stroemungsmechanik Friedrich-Alexander-Univ., Erlangen-Nuernberg (Germany)

    2005-04-01

    By the use of low calorific value gases significant energy amounts can be saved, emissions can be reduced and system efficients can be increased. These mixtures are generated in different fields like waste sites and fuel cell systems with reformation of hydrocarbons. Conventional combustion techniques are not suited for the combustion of this kind of gases. Due to its high internal heat recuperation the porous burner technology has great potential for the combustion of low calorific value gases. In this work the influence of the combustion zone properties, the surface load and the educt temperature were determined by numerical simulations and experiments. (orig.)

  20. 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.)

  1. 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)

  2. Tin dioxide: synthesis, characterization and study of the interactions with different polluting gases - application to DeNOx catalysis; Dioxyde d'etain: synthese, caracterisation et etude des interactions avec differents gaz polluants - application a la catalyse DeNOx

    Energy Technology Data Exchange (ETDEWEB)

    Sergent, N.

    2003-01-01

    Two high specific surface area tin dioxides after calcination at 600 degrees C under O{sub 2} have been synthesized: SnO{sub 2}-HNO{sub 3} (24 m{sup 2} g{sup -1}) and SnO{sub 2}-N{sub 2}H{sub 4} (101 m{sup 2} g{sup -1}). The surface of the 600 degrees C - calcined SnO{sub 2}-N{sub 2}H{sub 4} sample was found to be more hydroxylated than the 600 degrees C - calcined SnO{sub 2}-HNO{sub 3} one. The thermal treatment under O{sub 2} involves the formation of mono-ionized oxygen vacancies, leading to non-stoichiometric tin dioxides. A specific treatment like outgassing at temperatures above 300-400 degrees C, was found to be necessary to extract surface oxygen atoms. The CO adsorption at liquid N{sub 2} temperature on the SnO{sub 2}-N{sub 2}H{sub 4} sample has shown the existence of two cationic Sn{sup 4+} sites, having different Lewis acidities. Concerning the surface OH groups, it has been observed: i) hydroxyl which are inaccessible to CO, ii) weakly acidic surface hydroxyl and iii) surface hydroxyl having a weak Broensted acidity. Then, a study of the interactions between the 600 degrees C - calcined SnO{sub 2}-N{sub 2}H{sub 4} sample and various pollutant gases has been carried out by transmission FTIR spectroscopy. Carbon dioxide interacts with SnO{sub 2} surface, leading to CO{sub 2} species adsorbed on cationic sites together with carbonates and bicarbonates ad-species. Carbon monoxide involves the partial reduction of SnO{sub 2} surface by reaction of CO with surface oxygens to form carbonate species and CO{sub 2}. Interactions of SnO{sub 2} surface with NO{sub 2} have shown the formation of NO{sup +}, nitrite and nitrate ad-species. The NO adsorption on SnO{sub 2}-N{sub 2}H{sub 4} have shown the formation of electron donor species (nitrite and nitrate species) together with electron acceptor species (nitrosyl species). Finally, in the Selective Catalytic Reduction (SCR) of NO{sub x} by propene in oxygen excess, SnO{sub 2} was found to be active at high

  3. Few-body physics in resonantly interacting ultracold quantum gases

    Science.gov (United States)

    D’Incao, José P.

    2018-02-01

    We provide a general discussion on the importance of three-body Efimov physics for strongly interacting ultracold quantum gases. Using the adiabatic hyperspherical representation, we discuss a universal classification of three-body systems in terms of the attractive or repulsive character of the effective interactions. The hyperspherical representation leads to a simple and conceptually clear picture for the bound and scattering properties of three-body systems with strong s-wave interactions. Using our universal classification scheme, we present a detailed discussion of all relevant ultracold three-body scattering processes using a pathway analysis that makes evident the importance of Efimov physics in determining the energy and scattering length dependence of such processes. This article provides a general overview of the current status of the field and a discussion of various issues relevant to the lifetime and stability of ultracold quantum gases along with universal properties of ultracold, resonantly interacting, few-body systems.

  4. Measurement of biocarbon in flue gases using 14C

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, K.M.; Jungner, H.; Antson, O.; Rasanen, J.; Tormonen, K.; Roine, J. [University of Helsinki, Helsinki (Finland). Radiocarbon Dating Laboratory

    2007-07-01

    A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil- and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The C-14 content in CO{sub 2} was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that C-14 measurement provides the possibility to determine the ratio of bio and fossil fuel burned in power plants.

  5. Noble gases and the early history of the Earth: Inappropriate paradigms and assumptions inhibit research and communication

    Science.gov (United States)

    Huss, G. R.; Alexander, E. C., Jr.

    1985-01-01

    The development of models as tracers of nobel gases through the Earth's evolution is discussed. A new set of paradigms embodying present knowledge was developed. Several important areas for future research are: (1) measurement of the elemental and isotopic compositions of the five noble gases in a large number of terrestrial materials, thus better defining the composition and distribution of terrestrial noble gases; (2) determinations of relative diffusive behavior, chemical behavior, and the distribution between solid and melt of noble gases under mantle conditions are urgently needed; (3) disequilibrium behavior in the nebula needs investigation, and the behavior of plasmas and possible cryotrapping on cold nebular solids are considered.

  6. Use of the effective heat of formation model to determine phase formation sequences of In-Se, Ga-Se, Cu-Se, and Ga-In multilayer thin films

    International Nuclear Information System (INIS)

    Moore, H.J.; Olson, D.L.; Noufi, R.

    1998-01-01

    Multilayer thin films of indium-selenium, gallium-selenium, copper-selenium, and gallium-indium have been analyzed for the purpose of understanding thin film phase transformations that are relevant to the production of Cu(In,Ga)Se 2 photovoltaic solar cells. For example, the intermetallic phases that are present during selenization of precursor films will affect film microstructure and the resulting film properties. Throughout this research, the effective heat of formation model has been used to predict phase formation sequences. The accuracy of these predictions was explored experimentally. By using differential thermal analysis, the reactions of product film formation were examined. X-ray diffraction was used to determine reactant and product phases

  7. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  8. Die Wahrheit des Holocaust

    Directory of Open Access Journals (Sweden)

    Michael Stolleis

    2003-01-01

    Full Text Available Rezensiertes Werk: Raul Hilberg, Die Quellen des Holocaust. Entschlüsseln und Interpretieren. Deutsch von Udo Rennert, Frankfurt am Main: S. Fischer 2002, 256 S., ISBN 3-10-033626-7

  9. 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.

  10. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Key words: cathode sputtering magnetron; thin films; nanostructure; corrosion; alloys Fe-Si. 1. INTRODUCTION. Les alliages de fer–Silicium (FexSiy) sont des matériaux importants, largement répandus dans des circuits électroniques et magnétiques, et jouissent d‟un excellent rapport qualité/prix. Ce succès est lie aux.

  11. typologie des parcs agroforestiers

    African Journals Online (AJOL)

    AISA

    AU SENEGAL : TYPOLOGIE DES PARCS AGROFORESTIERS. I. COLY1, L. E. AKPO1, D. SARR1, R. MALOU2, H. DACOSTA3 et F. DIOME4. 1Faculté des Sciences et ... Mots clés : Agro-écologie, parcs agro forestiers, typologie, Bas fonds de la Néma, Sénégal. .... afin d'en distinguer les sous unités, et d'en établir.

  12. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    1 mai 2011 ... microscopie électronique à balayage (MEB) et la diffraction des rayons X (DRX). Nous avons effectué des essais d‟oxydation à haute température sur trois alliages binaires FeAl à 1 000 oC, dans une atmosphère d'air de laboratoire et à pression atmosphérique. Les essais d‟oxydation menés à 1000 °C ...

  13. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    déclin avec le développement de la chimie de synthèse, toutefois les effets indésirables des médicaments ont ravivé l‟intérêt des scientifiques pour les plantes médicinales. C‟est ainsi que de nouvelles recherches ont vu le jour, notamment de l‟espoir de traiter certaines maladies infectieuses par les huiles essentielles.

  14. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    profondes aux fosses abyssales représentant ainsi un important réservoir de biodiversité. .... des animaux menacés de l‟IUCN (Union. Internationale pour la Conservation de la. Nature) comporte plus de 100 ..... lacunes de notre compréhension des capacités de réponses et d‟adaptation de la biodiversité. Jackson et al.

  15. Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

    Science.gov (United States)

    Gerrish, Harold C; Tessmann, Arthur M

    1935-01-01

    The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

  16. Influence of the gray gases number in the weighted sum of gray gases model on the radiative heat exchange calculation inside pulverized coal-fired furnaces

    Directory of Open Access Journals (Sweden)

    Crnomarković Nenad Đ.

    2016-01-01

    Full Text Available The influence of the number of gray gases in the weighted sum in the gray gases model on the calculation of the radiative heat transfer is discussed in the paper. A computer code which solved the set of equations of the mathematical model describing the reactive two-phase turbulent flow with radiative heat exchange and with thermal equilibrium between phases inside the pulverized coal-fired furnace was used. Gas-phase radiative properties were determined by the simple gray gas model and two combinations of the weighted sum of the gray gases models: one gray gas plus a clear gas and two gray gases plus a clear gas. Investigation was carried out for two values of the total extinction coefficient of the dispersed phase, for the clean furnace walls and furnace walls covered by an ash layer deposit, and for three levels of the approximation accuracy of the weighting coefficients. The influence of the number of gray gases was analyzed through the relative differences of the wall fluxes, wall temperatures, medium temperatures, and heat transfer rate through all furnace walls. The investigation showed that there were conditions of the numerical investigations for which the relative differences of the variables describing the radiative heat exchange decrease with the increase in the number of gray gases. The results of this investigation show that if the weighted sum of the gray gases model is used, the complexity of the computer code and calculation time can be reduced by optimizing the number of gray gases. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in-house developed software tools

  17. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  18. Evaluation of the Giggenbach bottle method using artificial fumarolic gases

    Science.gov (United States)

    Lee, S.; Jeong, H. Y.

    2013-12-01

    Volcanic eruption is one of the most dangerous natural disasters. Mt. Baekdu, located on the border between North Korea and China, has been recently showing multiple signs of its eruption. The magmatic activity of a volcano strongly affects the composition of volcanic gases, which can provide a useful tool for predicting the eruption. Among various volcanic gas monitoring methods, the Giggenbach bottle method involves the on-site sampling of volcanic gases and the subsequent laboratory analysis, thus making it possible to detect a range of volcanic gases at low levels. In this study, we aim to evaluate the effectiveness of the Giggenbach bottle method and develop the associated analytical tools using artificial fumarolic gases with known compositions. The artificial fumarolic gases are generated by mixing CO2, CO, H2S, SO2, Ar, and H2 gas streams with a N2 stream sparged through an acidic medium containing HCl and HF. The target compositions of the fumarolic gases are selected to cover those reported for various volcanoes under different tectonic environments as follows: CO2 (2-12 mol %), CO (0.3-1 mol %), H2S (0.7-2 mol %), SO2 (0.6-4 mol %), Ar (0.3-0.7 mol %), H2 (0.3-0.7 mol %), HCl (0.2-1 mol %), and HF (HF dissolve into the alkaline solution. In case of H2S, it reacts with dissolved Cd2+ to precipitate as CdS(s). The gas accumulated in the headspace can be analyzed for CO, Ar, H2, and N2 on a gas chromatography. The alkaline solution is first separated from yellowish CdS precipitates by filtration, and then pretreated with hydrogen peroxide to oxidize dissolved SO2 (H2SO3) to SO42-. The resultant solution can be analyzed for SO2 as SO42-, HCl as Cl-, and HF as F- on an ion chromatography and CO2 on an ionic carbon analyzer. Also, the amount of H2S can be determined by measuring the remaining dissolved Cd2+ on an inductively coupled plasma-mass spectrometry.

  19. Dosage direct des alcools dans les carburols par chromatographie en phase gazeuse Direct Gas Chromatographie Determination of Alcohols in Gasolines Blended by Oxygenated Compounds

    Directory of Open Access Journals (Sweden)

    Petroff N.

    2006-11-01

    Full Text Available Dans cette étude, on décrit une méthode de chromatographie en phase gazeuse utilisant une colonne remplie ; elle permet de doser, sans préfractionnement, les alcools jusqu'aux butanols dans les carburols (carburants additionnés de composés oxygénés. La phase stationnaire sélectionnée est le glycérol. This report describes a gas chromatographie method using a packed column. It allows the direct determination of alcohols up to butanols in gasolines blended with oxygenated compounds without prefractionation. Glycerol has been selected as stationary phase.

  20. Combined novel methods for the determination of the humidification conditions of polymer electrolyte fuel cells; Kombination neuer Methoden zur Bestimmung des Wasserhaushaltes von Polymer-Elektrolyt-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Robert Martin

    2011-05-02

    The water management is one of the key factors for the performance of a low temperature PEM fuel cell. With respect to the optimization of the fuel cell operation it is important to detect and differentiate water in the membrane, in the gas diffusion layer (GDL) and excess water in the flow field channel. The water content of each component influences the performance in different ways and adapted operation modes have to be kept. This work entitled 'Combined novel methods for the determination of the humidification conditions of PEM fuel cells' provides techniques and guidelines for fuel cell operation and will conclude in a straightforward control and operation strategy. Based on a combination of electrochemical impedance spectroscopy (EIS), locally resolved current distribution measurements and neutron radiography an informative basis for the determination of the water content of an operating PEM fuel cell is created. Special attention has been paid to the reproducibility and comparability in order to set up a consistent investigation and control strategy. (orig.)

  1. 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

  2. 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

  3. Spin Transport in Bose Gases

    NARCIS (Netherlands)

    van Driel, H.J.

    2012-01-01

    In this Thesis, we show that in a rotating two-component Bose mixture, the spin drag between the two different spin species shows a Hall effect. This spin drag Hall effect can be observed experimentally by studying the out-of-phase dipole mode of the mixture. We determine the damping of this mode

  4. 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)

  5. Development of techniques and models for the determination of redox potentials of saline solutions; Entwicklung von Methoden und Modellen zur Bestimmung des Redoxpotentials salinarer Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Sven; Bischofer, Barbara; Scharge, Tina; Schoenwiese, Dagmar

    2014-03-15

    The mobility of radionuclides and heavy metals in aqueous systems depends significantly on their oxidation state. Under saline conditions the measurement of pH values and redox potential are distorted/falsified by solution-specific and hardly assessable ion diffusion effects at the reference electrode. The secure prognosis of redox properties is an essential prerequisite for the calculation of the expected heavy metal and radionuclide concentrations in case of a hypothetical solution ingress in an underground disposal facility. The evaluation of the existing data base shows that there are large uncertainties even for the solubility of widespread oxides and oxy-hydroxides like goethite or hematite. The redox properties of natural systems are determined by the solubility of metastable ferrous intermediate products like ferrihydrite, ''green rust'' or jarosite. The work is aimed to establish a consistent data base with information on these phases and ferrous solute species.

  6. Gas Well Testing Analysis Using Finite-Difference Models and Optimization Techniques Analyse d'essais de puits de gaz par des modèles utilisant la méthode des différences finies et par des techniques d'optimisation

    Directory of Open Access Journals (Sweden)

    Darderes E. A.

    2006-11-01

    Full Text Available In reservoir engineering studies of gas fields, three important parameters are needed: the permeability-thickness product, the skin factor, and the inertial-turbulent factor. Several methods have been proposed to determine these parameters from gas well tests. The most powerful one is the pseudo-steady state analysis, where a linear dependence on a semilogarithmic plot is found between the real gas pseudo-pressure and time. Another one is the type-curve matching. Both have drawbacks because they can be rigorously applied only to specific cases. An automated type-curve match, which provides a general method to analyze well test data, is presented in this paper. It is based on the adjustment of a numerical model to gas well test data, by means of optimization techniques. The numerical model is the solution of the second order strongly non-linear partial differential equation which rules the radial flow of real gases towards a well. The differential equation is solved by finite-differences, taking into account the variation of gas properties with pressure. In order to simulate any gas well test, appropriate initial and boundary conditions are imposed. The least squares method is used to minimize residual differences between actual pressures measured during test and computed pressures. Two optimization techniques are applied to obtain the best estimate of parameters that minimize the sum of the square of the residuals: the univariate method of Fibonacci [1] and the multivariate method of Marquardt [1, 2]. This procedure is applied to a single-rate and a two-rate drawdown test. Numerical results showed excellent agreement with well test data. Les études de gisements de gaz rendent indispensables la connaissance de trois paramètres importants : la capacité de flux (produit de la perméabilité par l'épaisseur de la couche productrice, l'effet de peau et le facteur d'inertie et de turbulence. On connaît plusieurs méthodes pour déterminer ces

  7. Determination of the uncertainties of air pollutant emissions of land bound traffic in Germany, computed with the models TREMOD and TREMOD MM; Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Knoerr, Wofram [ifeu - Institut fuer Energie- und Umweltforschung Heidelberg gGmbH, Heidelberg (Germany); Heldstab, Juerg; Kasser, Florian; Keller, Mario [INFRAS, Zuerich (Switzerland)

    2010-05-15

    Germany is obligated to the implementation of emission inventories for climatic gases and air pollutants. This requires the proof and documentation of the data quality and uncertainties. In the project under consideration the uncertainties of the ZSE data records (ZSE = central system emissions) of the source groups road traffic, rail traffic, inland navigation traffic and residual traffic of the emission inventory are to be determined for all fuel methods, greenhouse gases and air pollutants. The basis of the ZSE data records are the programs TREMOD and TREMOD MM as well as the sales figures of fuels. Provisional results of the actual mineral oil statistics, updated road performances and stocks of vehicles as well as the actual emission factor data base of traffic are used as a fundament for the determination of uncertainties.

  8. Etude des comportements rheologiques des melanges de farine ble ...

    African Journals Online (AJOL)

    Etude des comportements rheologiques des melanges de farine ble/sorgho sans tanins issue de trois nouvelles varietes cultivees au Senegal et mise au point de pains a base de farines composees (ble/sorgho)

  9. Effets des biomasses vertes de Tithonia diversifolia et des engrais ...

    African Journals Online (AJOL)

    Effets des biomasses vertes de Tithonia diversifolia et des engrais minéraux sur la croissance, le développement et le rendement du manioc ( Manihot esculenta Crantz) en zone forestière du Cameroun.

  10. Measurements of waste tank passive ventilation rates using tracer gases

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Olsen, K.B.; Sklarew, D.S.; Evans, J.C.; Remund, K.M.

    1997-09-01

    This report presents the results of ventilation rate studies of eight passively ventilated high-level radioactive waste tanks using tracer gases. Head space ventilation rates were determined for Tanks A-101, AX-102, AX-103, BY-105, C-107, S-102, U-103, and U-105 using sulfur hexafluoride (SF 6 ) and/or helium (He) as tracer gases. Passive ventilation rates are needed for the resolution of several key safety issues. These safety issues are associated with the rates of flammable gas production and ventilation, the rates at which organic salt-nitrate salt mixtures dry out, and the estimation of organic solvent waste surface areas. This tracer gas study involves injecting a tracer gas into the tank headspace and measuring its concentration at different times to establish the rate at which the tracer is removed by ventilation. Tracer gas injection and sample collection were performed by SGN Eurisys Service Corporation and/or Lockheed Martin Hanford Corporation, Characterization Project Operations. Headspace samples were analyzed for He and SF 6 by Pacific Northwest National Laboratory (PNNL). The tracer gas method was first demonstrated on Tank S-102. Tests were conducted on Tank S-102 to verify that the tracer gas was uniformly distributed throughout the tank headspace before baseline samples were collected, and that mixing was sufficiently vigorous to maintain an approximately uniform distribution of tracer gas in the headspace during the course of the study. Headspace samples, collected from a location about 4 in away from the injection point and 15, 30, and 60 minutes after the injection of He and SF 6 , indicated that both tracer gases were rapidly mixed. The samples were found to have the same concentration of tracer gases after 1 hour as after 24 hours, suggesting that mixing of the tracer gas was essentially complete within 1 hour

  11. À propos des occasionnalismes

    Directory of Open Access Journals (Sweden)

    Dal Georgette

    2016-01-01

    Full Text Available Les occasionnalismes (nonce formations ou contextual formations dans la terminologie anglo-saxonne, qu’on définira provisoirement comme de “new complex word[s] created by a speaker/writer on the spur of the moment to cover some immediate need” (Bauer, 1983 : 45 ont, à notre connaissance, peu retenu l’attention des morphologues du domaine francophone. Pourtant, toutes les conditions sont désormais réunies pour que cet objet, invisible lorsqu’il s’agissait de décrire le système morphologique du français (ou d’autres langues à partir de ressources dictionnairiques, émerge en tant qu’observable dans une morphologie puisant ses données dans le réel langagier des locuteurs. Par définition en effet, on s’attend à ce qu’un occasionalisme soit absent des dictionnaires (nous verrons que, dans les faits, la situation est plus complexe que cela, et que ces contextual formations ne puissent pas être étudiées en dehors du contexte dans lequel elles ont été produites. À cet égard, la Toile et les produits qui en dérivent constituent des ressources de choix. C’est particulièrement vrai des forums, dans lesquels les internautes s’expriment librement, laissant libre cours à leur potentiel créatif (ou ce qu’ils pensent tel. Dans la présente communication, après avoir défini la notion d’occasionalisme, nous utiliserons un corpus constitué au fil d’autres recherches pour dégager des motifs récurrents propices à leur apparition, autrement dit pour établir une grammaire des occasionnalismes.

  12. Results of the working group on the division by four of greenhouse gases emissions in France, at the horizon of 2050, called ''factor 4''. DGEMP- Observatory of the energy; Les travaux du groupe de travail sur la division par quatre des emissions de gaz a effet de serre de la france, a l'horizon 2050, dit ''facteur 4''. DGEMP-Observatoire de l'Energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This group, created by the french Government in march 2005, aims to evaluate the different possibilities to reach the objective of division by four the greenhouse gases emissions. This document presents some recalls on the climatic change and the situation today, the positions of the France and the foreign and the conclusions and the recommendations of the group. (A.L.B.)

  13. 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.

  14. 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.

  15. 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)

  16. Reseau des polygones de bord des indicateurs de performance d ...

    African Journals Online (AJOL)

    La fonction maintenance hospitalière a des composantes spécifiques qui la rendent de plus en plus complexe et fastidieuse. La politique d'une maintenance biomédicale repose sur des piliers et des leviers propres à une meilleure exploitation des dispositifs médicaux dans un système de santé. Trois niveaux de leviers ...

  17. Impact des microcredits sur les conditions sociosanitaires des ...

    African Journals Online (AJOL)

    Cependant, très peu d'étude se focalisent sur leurs impacts réels sur les conditions de vies des bénéficiaires de leurs services. C'est à ce propos que la présente recherche se donne comme objectif de contribuer à une meilleure connaissance des impacts des microcrédits - un des services offert par les IMF - sur les ...

  18. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le projet vise à analyser la contribution réelle et potentielle de l'entrepreneuriat inclusif au bien-être des jeunes et des femmes en Côte d'Ivoire, au Burkina Faso et au Kenya. Après un état des lieux de la pratique de l'entrepreneuriat inclusif dans chacun des pays ciblés, l'équipe de recherche étudiera son incidence sur ...

  19. Electron beam process for SO2 removal from flue gases with high SO2 content

    International Nuclear Information System (INIS)

    Licki, J.; Chmielewski, A.G.; Zimek, Z.; Tyminski, B.; Bulka, S.

    2002-01-01

    Flue gases with high SO 2 concentration are emitted from different industrial processes, e.g. combustion of coal with high sulfur content, copper smelting and sintering plant. The application of the electron beam process for SO 2 removal from such flue gases was investigated. A parametric study was carried out to determine the removal efficiency as a function of temperature and humidity of irradiated gases, dose and ammonia stoichiometry. At the dose 11.5 kGy 95% SO 2 removal efficiency was obtained when the temperature and humidity of irradiated flue gases and ammonia stoichiometry were properly adjusted. The synergistic effect of high SO 2 concentration on NO x removal was observed. The collected by-product was the mixture of (NH 4 ) 2 SO 4 and NH 4 NO 3 . The content of heavy metals in the by-product was many times lower than the values acceptable for commercial fertilizer

  20. La fabrique des sciences des institutions aux pratiques

    CERN Document Server

    Benninghoff, Martin; Crettaz von Roten, Fabienne; Merz, Martina

    2006-01-01

    Aujourd'hui, les façons de produire, d'organiser, d'évaluer et d'utiliser les savoirs sont en profond débat. De plus en plus, l'Etat, la société civile et l'économie tentent d'influencer les activités des universités et des laboratoires de recherche. Ces développements mettent à l'épreuve tout à la fois les fondements des systèmes d'enseignement supérieur et de recherche, l'autonomie des institutions scientifiques, la définition des frontières des savoirs et l'acceptation des sciences. Dans des contextes suisses et européens, cet ouvrage s'intéresse aux manières dont les sciences et les technologies sont fabriquées, en analysant leurs institutions et les pratiques. A partir d'une approche relationnelle, les sciences et les technologies sont conçues comme des phénomènes profondément sociaux, culturels et politiques. Une telle démarche déstabilise les visions parfois idéalisées et stéréotypées de la construction des savoirs. Des études de cas détaillées décrivent des phénomè...

  1. Effets des extraits vegetaux sur la dynamique de populations des ...

    African Journals Online (AJOL)

    La présente étude se propose de trouver une alternative de l'utilisation des pesticides chimiques en testant l'effet insecticide des extraits aqueux des feuilles de Hyptis suaveolens, graines de Ricinus communis et de Azadirachta indica contre les ravageurs du niébé en conditions de champ en utilisant le cyperméthrine ...

  2. Determination of the thermal radiation effect on an optical strontium lattice clock; Bestimmung des Einflusses thermischer Strahlung auf eine optische Strontium-Gitteruhr

    Energy Technology Data Exchange (ETDEWEB)

    Middelmann, Thomas

    2013-05-31

    Optical clocks have the potential to be 100 times more accurate than current best cesium atomic clocks within a fraction of the averaging time. This corresponds to a fractional uncertainty of the clock frequency on the level of 10{sup -18} and requires highaccuracy knowledge of systematic frequency shifts, such that they can be avoided or corrected for. In strontium optical lattice clocks an ensemble of ultracold strontium atoms is confined in an optical lattice, to allow for spectroscopy of the reference transition 5s{sup 2} {sup 1}S{sub 0}-5s5p {sup 3}P{sub 0} in the Lamb-Dicke regime. The by far largest systematic frequency shift of the strontium clock transition is caused by its high sensitivity to blackbody radiation (BBR). The knowledge of the resulting frequency shift limited the achievable clock uncertainty to about 1 x 10{sup -16}. In this thesis for the first time an experimental approach was followed, to determine the sensitivity of the strontium clock transition to blackbody radiation. At an environmental temperature of 300 K the resulting frequency shift corresponds to 2.277 8(23) Hz. The achieved uncertainty contributes with 5 x 10{sup -18} to the fractional systematic uncertainty of the clock frequency. The determination is based on a precision measurement of the difference of static polarizabilities of the two clock states {Delta}{alpha}{sub dc} = {alpha}(5s5p {sup 3}P{sub 0})-{alpha}(5s{sup 2} {sup 1}S{sub 0}) = 4.078 73(11) x 10{sup -39} Cm{sup 2} /V. For this the de Stark shift of the clock transition has been measured in the accurately known electric field of a precision plate capacitor, which has been developed in this work. The attained static polarizability difference {Delta}{alpha}{sub dc} corresponds to the first term of a power series of the sensitivity to BBR. Higher orders are accumulated as dynamic part of the BBR shift. Which has been modelled using {Delta}{alpha}{sub dc} and experimental data for other atomic properties. To

  3. 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)

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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...

  13. 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.

  14. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  15. Nouvelle méthode expérimentale pour déterminer le gonflement libre des sols argileux Novel experimental method to determine clay soil free swelling

    Directory of Open Access Journals (Sweden)

    Essaaidi M.

    2012-09-01

    Full Text Available Le dispositif est un interferometre de Michelson modifie. En effet sur le miroir mobile est colle un echantillon d’fargile cylindrique, seche, de longueur L, de rayon R et faconnee de maniere a retenir les gouttes d’feau a sa surface pour controler la teneur en eau. Lorsqu’fon injecte un volume d’feau distillee (quelques gouttes a la surface de l’fechantillon, celui-ci se gonfle et le miroir se deplace. On observe le defilement des franges et on procede au comptage de leur nombre durant le temps t que dure le gonflement (environ 40 mn. On peut ainsi mesurer le deplacement libre du miroir et determiner: la valeur du gonflement exprime en % ou g/cm3, le gonflement sous contrainte σ (pour comparer avec l’foedometre et sa vitesse au cours du temps t. The propose device is based on Michelson interferometer. In fact, we put the a sample of cylindrical shape dry clay of length L and radius R on the mobile mirror, This sample can retain a drop of water on its surface in order to monitor water content. When injecting a volume of distilled water (a few drops to the surface of the sample, it swells and moves the mirror. Consequently, we see scrolling fringes and we proceed to count their number during the time t during this swelling (about 40 min. We can measure the free displacement of the mirror and to establish the value of swelling expressed in% or g/cm3, the swelling under stress σ (to compare with the oedometer and speed during a time t.

  16. Screening phytochimique et identification spectroscopique des ...

    African Journals Online (AJOL)

    Le screening phytochimique des feuilles et des fleurs de cette plante, effectuée pour la première fois, a révélé la présence des alcaloïdes, des flavonoïdes, des tanins catéchiques, des terpènes, des coumarines et des composés cyanogénétiques. Quant aux saponines et les quinones libres, ils sont présents chez les fleurs ...

  17. 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:

  18. 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,

  19. 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.

  20. 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 ...

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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 ...

  8. 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

  9. 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.

  10. 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.

  11. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Résumé. Dans ce travail, on s‟intéresse à l‟effet des concentrations du xanthane, du caséinate de sodium et du tween 20 sur les propriétés rhéologiques, ... macromolécules des deux biopolymères, par effet du volume exclu, auquel cas, les ..... 25 (4), 743-749. [8] Gast A.P., Hall C.K., Russel W.B.,. 1983. Polymer-induced ...

  12. Liste des tableaux

    OpenAIRE

    2014-01-01

    1 – Importations en charbon américain en Europe de l’Ouest de 1946 à 1958 .47 2 – Organisation des demandes d’allocations de charbon allemand auprès de l’eco. 75 3 – Consommations de charbon allemand dans les zones occidentales de l’Allemagne d’octobre à décembre 1945. 86 4 – Production, exportations et consommation nationale apparente du charbon allemand dans la zone britannique en 1945 et 1946. 90 5 – Total des importations de charbons allemand et américain de janvier à avril 1946. 99 6 – I...

  13. Table des tableaux

    OpenAIRE

    2018-01-01

    Tableau 1 : Production nationale d'alcool avant 1919 68 Tableau 2 : Production nationale d'alcool après 1939 (Source : Martraire, 1955, A.D. 77 : Az 7086) 71 Tableau 3 : Les surfaces agricoles disponibles en France en 2004 123 Tableau 4 : Le régime fiscal des carburants et des biocarburants en 2005 et 2006 (source : ADEME) 175 Tableau 5 : Exemple de coût de production de biocarburants (Source : Stéphane His (IFP), Les biocarburants en Europe, 2004) 176 Tableau 6 : L’application de la directiv...

  14. Wall shear stress hot film sensor for use in gases

    International Nuclear Information System (INIS)

    Osorio, O D; Silin, N

    2011-01-01

    The purpose of this work is to present the construction and characterization of a wall shear stress hot film sensor for use in gases made with MEMS technology. For this purpose, several associated devices were used, including a constant temperature feedback bridge and a shear stress calibration device that allows the sensor performance evaluation. The sensor design adopted here is simple, economical and is manufactured on a flexible substrate allowing its application to curved surfaces. Stationary and transient wall shear stress tests were carried on by means of the calibration device, determining its performance for different conditions.

  15. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    Face à ce constat, le défi de la recherche serait la détermination du niveau actuel de contamination des légumes feuilles et des eaux du barrage et celui de l'État serait l'initiation de programmes de sensibilisation des producteurs par rapport à une gestion plus rigoureuse des pesticides. Mots-clés : pratiques paysannes, ...

  16. Etude theorique et experimentale des evaporateurs de dioxyde de carbone operant dans des conditions de givrage

    Science.gov (United States)

    Bendaoud, Adlane Larbi

    frigorifique moyenne superieures de 20 % par rapport a celle du cas de base. 3. la diminution de la temperature de l'air a l'entree du serpentin entraine une diminution du temps de fonctionnement et augmente la frequence de degivrage alors que la diminution de l'humidite relative de l'air a l'entree augmente le temps de fonctionnement et reduis la frequence de degivrage. 4. le debit massique de l'air est un parametre tres important qu'il faut choisir et determiner avec beaucoup de soin afin de ne pas serieusement affecter le temps de fonctionnement du serpentin. Les resultats issus de ce travail de recherche ont fait l'objet de trois publications dans des revues internationales [4-6] et de deux presentations dans des conferences specialisees [7,8]. (Abstract shortened by UMI.)

  17. Identification et surveillance des individus

    OpenAIRE

    Aghroum, Christian; Alberganti, Michel; Bonelli, Laurent; Ceyhan, Ayse; Denis, Vincent; Dufief, Vincent; Laurent, Sébastien; Piazza, Pierre; Preuss-Laussinotte, Sylvia; Rousselin, Thierry; Thorel, Jérôme; Tsoukala, Anastassia; Vitran, Jean-Claude; Alberganti, Michel; Alberganti, Michel

    2014-01-01

    « Big Brother is watching you ! » Cet avertissement placardé sur les murs de la cité imaginaire d'Océania dans le roman 1984 de Georges Orwell peut-il s'appliquer à nos sociétés contemporaines ? Passeport biométrique, fichage informatisé des individus, multiplication des caméras de surveillance, utilisation de puce dans des objets de la vie quotidienne, ou pour suivre les criminels en liberté surveillée, les mesures d'identification, de fichage et de surveillance des individus par des techniq...

  18. Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Jurain, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources

  19. Physics of phenomena in the zone close to an underground nuclear explosion; Physique des phenomenes en zone proche des explosions nucleaires souterraines

    Energy Technology Data Exchange (ETDEWEB)

    Maury, J.; Levret, C. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    After a description of the phenomenology of underground explosions, the basic laws governing the propagation in the ground of the energy produced by the explosion are given. The reports considers hydrodynamics, the mechanics of solids, the equations of state for solids and gases in the case of very high and medium pressures, and the dynamical strength of solids. These various elements make it possible to draw up a system of equations which define completely the changes with time of the shock-wave produced in the ground by the explosion. (authors) [French] Apres une description de la phenomenologie des explosions souterraines, on expose les lois fondamentales regissant la propagation dans le sol de l'energie degagee par l'explosion. L'expose comprend des developpements sur l'hydrodynamique, la mecanique des solides, les equations d'etat des solides et des gaz, aux tres fortes et moyennes pressions, et sur la resistance dynamique des solides. Ces differents elements permettent d'ecrire un systeme d'equations qui definissent completement l'evolution dans le temps de l'onde de choc emise dans le sol par l'explosion. (auteurs)

  20. La structure des solutions aqueuses

    Science.gov (United States)

    Powell, D. H.

    2003-09-01

    En commençant par l'étude par diffraction neutronique de la structure des liquides moléculaires puis de l'hydratation des ions en solution, ce cours montrera comment les principes présentés lors des cours précédents peuvent être appliqués à des systèmes aqueux. Des exemples tirés de la littérature seront utilisés pour illustrer les considérations expérimentales propre à ce domaine et le genre d'informations que nous pouvons obtenir. Ce cours montrera également l'applicaton de la diffraction neutronique à des systèmes d'intérêt biologique et environnemental et se terminera par un examen de la complémentarité fournie par la diffraction des rayons X, l'EXAFS et la RMN.

  1. peste des petits ruminants

    African Journals Online (AJOL)

    HP USER

    Diallo A, Minet C, Le Goff C, Berhe G, Albina E, Libeau. G, Barrett T (2007). The threat of peste des petits ruminants: progress in vaccine development for disease control. Vaccine. 25:5591–5597. Esuruoso GO (1995). The practice of preventive veterinary medicine in a devastated national economy. Being the text of an.

  2. Investir dan des solutions

    International Development Research Centre (IDRC) Digital Library (Canada)

    Gestion du risque. La gestion du risque est une responsabilité partagée entre les gestionnaires du Centre qui est intégrée à tous les processus administratifs importants. .... que préconisent les Normes internationales d'information financière (normes IFRS). TABLEAU 2. RÉPARTITION DES PRODUITS. Crédit parlementaire.

  3. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Plusieurs études cliniques et épidémiologiques ont montré que le diabète est associé à cette ... CMLs responsables de la modulation des fibroblastes en ..... Pagano P.J., 2004. Gene transfer of. NAD(P)H oxidase inhibitor to the vascular adventitia attenuates medial smooth muscle hypertrophy. Circ. Res., 95, 587-. 594.

  4. Praxis des Klebens

    CERN Document Server

    Theuerkauff, Petra

    1989-01-01

    Bei diesem Buch handelt es sich um einen Leitfaden fur Klebepraktiker. Es werden die verschiedenen Einzelschritte beim kleben beschrieben, als auch die vorbereitenden Massnahmen und anschliessenden Prufverfahren auf Festigkeit behandelt. Das Buch sollte an keinem Arbeitsplatz fehlen, wo man sich mit Problemen der Fugetechnik des Klebens beschaftigt.

  5. La physique des infinis

    CERN Document Server

    Bernardeau, Francis; Laplace, Sandrine; Spiro, Michel

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  6. REPRISE DES COURS - Yoga

    CERN Multimedia

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  7. Development of speciation analysis for selenium in nutritional supplements by the determination of the seleno-methionine; Developpement de l'analyse de speciation du selenium dans des complements alimentaires par la determination de la selenomethionine

    Energy Technology Data Exchange (ETDEWEB)

    Sannac, S.; Labarraque, G.; Fisicaro, P. [Laboratoire National de Metrologie et d' Essai (LNE), 75 - Paris (France); Sannac, S.; Pannier, F.; Potin-Gautier, M. [Pau Univ. et des Pays de l' Adour, CNRS/UMR 5254, Lab. de Chimie Analytique, Bio-Inorganique et Environnement (IPREM), 64 (France)

    2009-07-01

    The development of a reference method in analytical chemistry is presented. Liquid chromatography with inductively coupled plasma mass spectrometry is employed to perform in speciation analysis. Applications are developed for the determination of seleno-methionine in nutritional supplements. The use of isotope dilution, a primary method, is required to enable measurement traceability. Method validation is ensured by the study of a certified reference material. (authors)

  8. Determination of anisotropic velocity model by reflection tomography of compression and shear modes; Determination de modele de vitesse anisotrope par tomographie de reflexion des modes de compression et de cisaillement

    Energy Technology Data Exchange (ETDEWEB)

    Stopin, A.

    2001-12-01

    As the jump from 2D to 3D, seismic exploration lives a new revolution with the use of converted PS waves. Indeed PS converted waves are proving their potential as a tool for imaging through gas; lithology discrimination; structural confirmation; and more. Nevertheless, processing converted shear data and in particular determining accurate P and S velocity models for depth imaging of these data is still a challenging problem, especially when the subsurface is anisotropic. To solve this velocity model determination problem we propose to use reflection travel time tomography. In a first step, we derive a new approximation of the exact phase velocity equation of the SV wave in anisotropic (TI) media. This new approximation is valid for non-weak anisotropy and is mathematically simpler to handle than the exact equation. Then, starting from an isotropic reflection tomography tool developed at Lt-'P, we extend the isotropic bending ray tracing method to the anisotropic case and we implement the quantities necessary for the determination of the anisotropy parameters from the travel time data. Using synthetic data we then study the influence of the different anisotropy parameters on the travel times. From this analysis we propose a methodology to determine a complete anisotropic subsurface model (P and S layer velocities, interface geometries, anisotropy parameters). Finally, on a real data set from the Gulf of Mexico we demonstrate that this new anisotropic reflection tomography tool allows us to obtain a reliable subsurface model yielding kinematically correct and mutually coherent PP and PS images in depth; such a result could not be obtained with an isotropic velocity model. Similar results are obtained on a North Sea data set. (author)

  9. Permeation, diffusion and dissolution of hydrogen isotopes, methane and inert gases through/in a tetrafluoroethylene film

    International Nuclear Information System (INIS)

    Matsuyama, M.; Miyake, H.; Ashida, K.; Watanabe, K.

    1982-01-01

    Tetrafluoroethylene (TFE) is widely used for conventional tritium handling systems such as vacuum seals, tubing and so on. We measured the permeation of the three hydrogen isotopes, methane and the inert gases through a TFE film at room temperature by means of the time-lag method in order to establish the physicochemical properties which determine the solubility and diffusivity of those gases. It was found that the diffusion constant of the inert gases changed exponentially with the heat of vaporization and the solubility was an exponential function of the Lennard-Jones force constant of the gases. On the other hand, hydrogen isotopes and methane deviated from these relations. It is concluded that chemical interactions between the solute and the solvent play an important role for the dissolution and the diffusion of these gases in TFE. (orig.)

  10. Standard model parameters determination and validity tests in Z{sup 0} hadronic disintegrations; Determination des parametres du modele standard et tests de sa validite dans les desintegrations hadroniques du Z{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, T.

    1993-05-01

    This thesis describes the determination of the electroweak parameters from the measurements of the total hadronic cross-section by the DELPHI experiment at LEP-I. The analysed data was taken in the years 1991 and 1992; a previous analysis of the data taken in 1990 is included in the final fits. The first part of the thesis describes the interest of the measurement of the Z{sup 0} resonance parameters in the framework of the Standard Model as well as their implications for alternative models. The Standard Model predictions are described in some detail, and their precision is estimated. Then follows a brief description of the LEP collider, of the measurement of the collision energy, and of the experimental setup. A chapter is devoted to the description of the luminosity measurement, essential for the determination of total cross-sections. The measurement of the hadronic cross-section (event selection, study of backgrounds, study of sources of systematic uncertainties) is described in detail in the next chapter. Then follows a description of the method of the extraction of the resonance parameters, and a discussion of the uncertainties in their determination. The values obtained are interpreted in the framework of the Standard Model, as well as in the framework of some more general theories. Finally, the event generator for hadron production in two-photon collisions is described in the appendix. (author). 69 refs., 51 figs., 9 tabs., 1 ann.

  11. Recevabilité des communications par la Commission africaine des droits de l’homme et des peuples

    OpenAIRE

    Nguema, Nisrine Eba

    2014-01-01

    La Commission africaine des droits de l’homme et des peuples constitue le principal organe de protection des droits de l’homme en Afrique. Mise en place en 1987, elle a pour mission principale de recevoir les communications des victimes des violations des droits de l’homme. L’ouverture de la procédure de traitement des communications individuelles devant la Commission africaine est conditionnée par le respect des conditions posée par l’article 56 de la Charte africaine des droits de l’homme e...

  12. Injectabilite des coulis de ciment dans des milieux fissures

    Science.gov (United States)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  13. 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.

  14. 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

  15. 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

  16. Utilisation des cahiers d'activites dans l'enseignement des sciences ...

    African Journals Online (AJOL)

    Les résultats des entretiens ont mis en exergue des sujets comme l'utilisation abusive des CA par certains enseignants, l'imposition des CA aux apprenants et leur coût, la qualité des contenus des CA et le maintien ou la suppression de la production des CA. D'autre part, le rendement scolaire des apprenants a été ...

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le ...

    African Journals Online (AJOL)

    Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le foreur des tiges du cacaoyer ( Eulophonotus myrmeleon Felder : Lepidoptera, Cossidae). Implications dans la stratégie de protection de la cacaoculture en Côte d'Ivoire.

  7. 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

  8. 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…

  9. Dopage et protection des jeunes sportifs : Loin des affaires

    OpenAIRE

    Guy, Daniel

    2002-01-01

    National audience; Loin des affaires et des révélations polémiques de la presse, les jeunes plébiscitent massivement les activités sportives. Sport compétition, sport participation, sport détente... Pourtant, quand la pratique devient intense, que les entraînements et les compétitions s'enchaînent à un rythme soutenu, l'ombre des conduites dopantes vient déchirer la quiétude des uns et des autres. Or, que savons-nous réellement de la pratique des jeunes sportifs ? Comment préparent-ils les co...

  10. Efficiency of utilization of heat of moisture from exhaust gases of heat HRSG of CCGT

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2017-01-01

    Full Text Available The paper discusses the technology of utilizing the heat of exhaust gas moisture from heat recovery steam gases (HRSG of combined-cycle gas turbine (CCGT. Particular attention focused on the influence of the excess air factor on the trapping of the moisture of the exhaust gases, as in the HRSG of the CCGT its value varies over a wider range than in the steam boilers of the TPP. For the research, has been developed a mathematical model that allows to determine the volumes of combustion products and the amount of water vapor produced according to a given composition of the burned gas and determine the amount of moisture that will be obtained as a result of condensation at a given temperature of the flue gases at the outlet of the condensation heat exchanger (CHE. To calculate the efficiency of the HRSG taking into account the heat of condensation of moisture in the CHE an equation is derived.

  11. Détermination automatique de l'indice d'octane et de la composition des reformats par chromatographie en phase gazeuse Automatic Determination of Reformate Octane Number and Composition by Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Petroff N.

    2006-11-01

    Full Text Available Utilisant des analyses par chromatographie en phase gazeuse, diverses méthodes ont été testées pour calculer l'indice d'octane de reformats. L'une d'elles s'est imposée par la simplicité de l'appareillage, ses possibilités d'automatisation et son adéquation à des échantillons provenant de charges différentes. Cette étude décrit les conditions opératoires de la méthode chromatographique optimisées pour les réformes, en vue d'obtenir des valeurs calculées de l'indice d'octane (IO dit Recherche différant de moins de un point des valeurs mesurées sur un moteur CFR selon la norme ASTM/D2699 (NF MO7026. L'analyse chromatographique est faite sur une colonne capillaire fonctionnant en température programmée. Le traitement des données est réalisé par un logiciel qui assure àla fois l'identification des constituants et le calcul de l'indice d'octane, à partir des données chromatographiques standard (temps de rétention et surface des pics. Les résultats obtenus portent sur une soixantaine de reformats divers. La fiabilité de la méthode d'identification, la répétabilité et la reproductibilité des valeurs de IO calculés sont démontrées. Ces résultats permettent d'envisager l'exploitation de la méthode en sortie d'unité. Various methods were tested by gas chromatography analysis for calculating the octane number of reformates. One of them was superior because of the simplicity of its equipment, its possibilities of automation and its suitability for samples coming from different feeds. This article describes the operating conditions of the optimized chromatographic method for reformates with a view to obtaining calculated values of the so-called Researchoctane number (RON different by at least one point from the values measured with a CFR engine according to the ASTM/D2699 standard. Chromatographic analysis is performed in a capillary column operating with programmedtemperature. Data processing is done with a software

  12. Aspects des Onychomycoses chez des patients camerounais de ...

    African Journals Online (AJOL)

    ... biologiques et évolutifs des onychomycoses chez des patients camerounais. Méthode : Il s'agit d'une étude rétrospective et descriptive menée de mars 2011 à mars 2014 dans l'unité de dermatologie de l'hôpital général de Douala (HGD), incluant des patients chez lesquels le diagnostic d'onychomycose avait été posé.

  13. Des dispositions responsables à prendre pour la protection des ...

    African Journals Online (AJOL)

    En considérant l'effet néfaste des maladies, des parasites, du changement climatique et d'autres facteurs environnementaux (les OGM par exemple) sur la survie des abeilles, la baisse de leurs populations dans certaines parties du monde ne saurait être attribuée aux seules pesticides. En plus, l'impact de ces derniers sur ...

  14. Collection d'entretiens avec des chercheurs participant à des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2014-07-07

    Jul 7, 2014 ... Entretien avec…propose des entrevues vidéos avec des chercheurs participant à des projets portant sur l'adaptation aux changements climatiques réalisés en Afrique, en Asie ainsi qu'en Amérique latine et dans les Caraïbes que le CRDI subventionne par le truchement de son programme Changements ...

  15. Etat des controverses des approches cognitive et ecologique en ...

    African Journals Online (AJOL)

    Cette revue de question vise à présenter dans le champ de l'apprentissage moteur, le sens des postulats des approches cognitive et écologique de même que les critiques formulées à leur encontre. Des documents scientifiques et articles de revues indexées et publiés dans la banque de données MEDLINE, ont été ...

  16. Méthode rapide de caractérisation des roches mètres, de leur potentiel pétrolier et de leur degré d'évolution Rapid Method for Source Rocks Characrerysation and for Determination of Petroleum Potential and Degree of Evolution

    Directory of Open Access Journals (Sweden)

    Espitalié J.

    2006-11-01

    Full Text Available Les études fondamentales réalisées sur les kérogènes à l'aide de diverses méthodes physico-chimiques d'analyse ont permis de mettre au point une méthode et un appareillage adaptés à l'exploration pétrolière. On expose dans cet article la mise au point de cette méthode et on montre, à l'aide des paramètres qu'elle permet d'obtenir, ses applications dans le domaine de l'exploration pétrolière - reconnaissance des différents types de roche mère et de leur potentiel pétrolier; - caractérisation de leur degré d'évolution (zone à huile - zone à gaz. On montre aussi que cette méthode convient particulièrement bien à l'estimation du rendement en huile des roches bitumineuses et à l'étude de la qualité et du rang des charbons. Fundamental research on kerogens by different physico-chemical analysis methods have led to the development of a method and equipment suited for petroleum exploration. This article describes the development of this method and, by means of the parameters it determines, shows how it con be applied in the field of petroleum exploration - exploring different types of source rock and their petroleum potential ; - characterizing their degree of evolution (ail zone/gas zone. This method is also shown ta be particularly suited for estimating the oil yield of cil shales and investigating the quality and classification of cool.

  17. New experimental determination of the neutronic resonance parameters of {sup 237}Np below 500 eV; Nouvelle determination experimentale des parametres de resonances neutroniques de {sup 237}Np en dessous de 500 eV

    Energy Technology Data Exchange (ETDEWEB)

    Gressier, V

    1999-10-01

    For studies of future nuclear reactors dedicated to nuclear waste transmutation, an improvement of the accuracy of the neutron radiative capture cross section of {sup 237}Np appears necessary. In the framework of a collaboration between the Commissariat a l'Energie atomique (CEA) and Institute for Reference Materials and Measurement (IRMM, Geel, Bergium), a new determination of the resonance parameters of {sup 237}Np has been performed. Two types of experiments are carried out at GELINA, the IRMM pulsed neutron source, using the time of flight method: a transmission experiment which is related to the neutron total cross section and a capture experiment which gives the neutron radiative capture cross section. The resonance parameters presented in this work are extracted from the transmission data between 0 and 500 eV with the least square code REFIT, using the Reich-Moore formalism. In parallel, the Doppler effect is investigated. The commonly used free gas model appears inadequate below 20 eV for neptunium dioxide at room temperature. By the use of the program DOPUSH, which calculates the Doppler broadening with a harmonic crystal model according to Lamb's theory, we are able to produce abetter fit of the experimental data for the resonances of {sup 237}Np in NpO{sub 2} at low energy or temperatures. In addition to the resonance parameters, a study of their mean value and distribution is included in this work. (authors)

  18. Photovoltaic system at Lac des Sables; Systeme photovoltaique du Lac des Sables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    The Societe des etablissements de plein air du Quebec (SEPAQ) has adopted a photovoltaic system coupled with an in-house generator to provide power to its buildings located at Lac des Sables in a remote area of Mont Tremblant Park, Quebec. The Societe came to this decision after analysing the costs associated with buying land, materials for an electric transmission line, followed by an analysis of the cost of fuel and the use of a power plant. The advantages include a reduction in fuel consumption, extends the life of the generator, reduces the emissions of greenhouse gases reduces exposition to noise. The photovoltaic system was provided by Energie Matrix Inc. and incorporates well with the building architecture. The data used to select the proper dimension of the photovoltaic system were: a theoretical maximum daily energy requirement of 8.9 kilowatt hour from May to mid-October, operation period of the photovoltaic from May to mid-October, and an autonomy of 5 to 6 days considering that the batteries would be kept at a temperature below 15 Celsius. The characteristics of the system were briefly described. The system has been in operation since September 2002. 2 figs.

  19. Fourrages ligneux des savanes du Tchad : Etat actuel des ...

    African Journals Online (AJOL)

    Une meilleure méthode d'aménagement et de gestion des ligneux fourragers en vue de leur utilisation optimale a été proposée. Mots clés ...... Toutefois, la présence massive des rejets de souches observée au niveau des classes supérieures à [0-0,5 m[ est une forme d'adaptation et une stratégie de survie des espèces ...

  20. Possibilities for using a temperature-controlled pyrolysis method in order to determine the bonding form of mecury in soils and sediments; Moeglichkeiten der Anwendung eines temperaturgesteuerten Pyrolyseverfahrens zur Bestimmung der Bindungsform des Quecksilbers in Boeden und Sedimenten

    Energy Technology Data Exchange (ETDEWEB)

    Biester, H.

    1994-12-31

    The bonding behaviour of mercury in solids was investigated by means of a temperature-controlled pyrolysis method. Starting from the special property of elemental mercury to evaporate already at room temperature, a method was developed which permits to characterize different mercury bonding forms on the basis of Hg evaporation behaviour from solids at continuously increased temperature. The method starts from the assumption that it is possible to thermally reduce compounded mercury and release it in elemental form. The focus of the work was on the study of Hg bonding behaviour in soils and sediments. The soil samples used were from the areas of two mercury deposits, different kyanizing sites, some former mirror factories, and a chlor-alkali electrolysis workshop. The investigated sediments are a collection of mercury-polluted samples from the rivers Elbe, Rhine, Murg, the Rio Sao Joao de Meriti (Brazil) and some brooks and rivers of the Saar-Nahe depression. (orig./EF) [Deutsch] In der vorliegenden Arbeit wurde das Bindungsverhalten von Quecksilber in Feststoffen mittels eines temperaturgesteuerten Pyrolyseverfahrens untersucht. Ausgehend von der besonderen Eigenschaften des elementaren Quecksilbers, bereits bei Zimmertemperatur zu verdampfen, wurde ein Verfahren entwickelt, das eine Charakterisierung verschiedener Quecksilberbindungsformen aufgrund des Abdampfverhaltens des Hg aus dem Feststoff unter kontinuierlicher Temperaturerhoehung zulaesst. Dem Verfahren liegt dabei die Annahme zugrunde, dass sich das Quecksilber in seinen Verbindungen thermisch reduzieren und in elementarer Form freisetzen laesst. Durch den kontinuierlichen Aufheizprozess erfolgt die Freisetzung des Quecksilbers in Abhaengigkeit von der Bindungsstaerke in unterschiedlichen Temperaturbereichen. Die Darstellung der Ergebnisse erfolgte in Form von Abdampfkurven, die die Extinktion in Abhaengigkeit von der Temperatur darstellen. Der Schwerpunkt dieser Arbeit lag auf der Untersuchung des

  1. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Unité de Recherche des Matériaux et des Energies Renouvelables (U.R.M.E.R). Université Abou –Baker Belkaid B.p : 119 Tlemcen 13000 Algerie. 2. Unité de Développement de la Technologie Du Silicium. UDTS, BP 399, Alger, Algérie. Accepté le : 08/06/2011. صخلم. داوﻣﻟا نﻣ ﻲﺗﻟا ﺔﺻﺎﺧو ،ﺔﻋﺎﻧﺻ يأ رﯾوطﺗ ﻲﻓ ﺎﯾﺳﯾﺋر ﻼﻣﺎﻋ ةرﯾﺧﻷا تاوﻧﺳﻟا ...

  2. Table des tableaux

    OpenAIRE

    2017-01-01

    1. District de l’Inquisition de Tolède. Distances depuis le siège 19 2. District de l’Inquisition de Tolède. Répartition de la population par régions géographiques en 1591 24 3. District de l’Inquisition de Tolède. Évolution de la population au XVIe siècle par régions géographiques 25 4. Inquisition de Tolède. Origine des étrangers vieux-chrétiens jugés par le tribunal 27 5. Inquisition de Tolède. Répartition des clercs selon le type d’agglomération 55 6. District de l’Inquisition de Tolède, ...

  3. X-ray magnetic dichroism: from quantitative determination of magnetic moments to imaging of magnetization dynamics; Dichroisme magnetique des rayons X: de la determination quantitative des moments magnetiques a l'imagerie de la dynamique de l'aimantation

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J

    2006-03-15

    In this document, I use some results of my research activities of the last ten years to show the power of x-ray magnetic dichroism for determining magnetic properties of thin layers, multilayers and nano-structures. The use of sum rules for x-ray dichroism allows a quantitative determination of the spin and orbital contributions to the magnetic moment, for each element of a heterogeneous material separately. Used in a qualitative way, x-ray dichroism allows monitoring the magnetization of the different layers in a multilayer material as a function of applied field. In combination with the temporal structure of synchrotron radiation, it is possible to study fast magnetization reversal with element selectivity, which is important for devices like spin valves and magnetic tunnel junctions. Adding the spatial resolution of a photoelectron emission microscope (PEEM), it becomes possible to study all the details of the fast magnetization reversal in complex magnetic systems. (author)

  4. Liste des figures

    OpenAIRE

    2015-01-01

    Claudine Fabre-Vassas, Identification d'un rite 1. Ordonnance de 1779 interdisant «la méthode de guérir les hernies par la castration» 66 Christian Bromberger, Pour une ethnologie du spectacle sportif 1. La popularité relative de deux vedettes de l'Olympique de Marseille 228 2. Répartition des spectateurs marseillais dans le stade d'après leur origine résidentielle 232

  5. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    7 sept. 2011 ... D‟autre part une approche statistique sera menée à partir de l‟analyse en composantes principales (ACP) afin de déterminer les processus géochimiques responsables de l‟évolution de la salinité des sols. 2. Matériel et méthodes. 2.1 Cadre physique. Le lac Fetzara est situé à 18 km au Sud-. Ouest de ...

  6. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Notre objectif est d‟élaborer des couches minces en Fe-Si par copulvérisation cathodique magnétron à différent pourcentage de silicium dans une atmosphère inerte d‟Argon et de les caractériser du point de vue physique. (composition chimique, microstructure…). Ces couches peuvent servir comme capteur magnétique.

  7. Des Ogle's old stump

    International Nuclear Information System (INIS)

    Jones, M.; Sutton, D.; Wallace, R.

    1998-01-01

    On 17 October 1997 Sylvia Bryan of RD4 Kaitaia wrote to 'Dear Somebody-Everybody' at the Anthropology Department, University of Auckland, urging further examination of an adzed stump found by Des Ogle during planting out of the Te Aupouri forest. The authors have since sought out relevant information and present it here for the interests of our readers. (author). 7 refs., 1 fig

  8. Wave speeds in the macroscopic extended model for ultrarelativistic gases

    Energy Technology Data Exchange (ETDEWEB)

    Borghero, F., E-mail: borghero@unica.it [Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy); Demontis, F., E-mail: fdemontis@unica.it [Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); Pennisi, S., E-mail: spennisi@unica.it [Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)

    2013-11-15

    Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.

  9. 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

  10. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  11. Administrateur de programme, Application des connaissances ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Supervision. Supervision directe : Consultants et personnel temporaire, au besoin. Supervision indirecte : Consultants chargés de préparer des sommaires des résultats de recherche et des communications internes, et personnel temporaire au besoin.

  12. 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.)

  13. Germination et accumulation des métabolites chez les plantules de ...

    African Journals Online (AJOL)

    Le taux de germination et l\\'accumulation des protéines et proline au niveau des feuilles pourraient être utilisés comme critères précoces de sélection des légumineuses tolérantes à la salinité. In order to determine physiological criteria of early selection for salt tolerant leguminous plants, effects of NaCl concentrations on ...

  14. Influence of impurity gases and operating conditions on PAFC performance

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, K.; Iwasa, N.; Suzuki, M.; Okada, O. [Osaka Gas Co., Ltd. (Japan)] [and others

    1996-12-31

    On-site Phosphoric Acid Fuel Cell (PAFC) Cogeneration system is installed at various test sites, such as at underground parking lot, within chemical plant premises and near urban streets. Since in the current PAFC system, cathode air is supplied to the cell with no particular pretreatment, impurity gases in the air might influence on cell performance. We have investigated the influence of various impurity gases in the cathode gas, on sub-scale single cells, and have found that NO{sub 2}, SO{sub 2} and toluene affect negatively on cell performance. The results of these experiments and the conceivable mechanism of these effects on cell degradation are reported. We have also investigated the influence of other operating parameters, such as temperature, current density, fuel utilization on cell performance. From these experiments, we have found that operating temperature is a significant factor, which mainly determines cell voltage decline rate. The results of sub-scale single cell tests and a short-stack verification test are also reported.

  15. CFD simulations in the nuclear containment using the DES turbulence models

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Peng [School of Engineering, Sun Yat-Sen University, Guangzhou (China); Chen, Meilan [China Nuclear Power Technology Research Institute, Shenzhen (China); Li, Wanai, E-mail: liwai@mail.sysu.edu.cn [Sino-French Institute of Nuclear Engineering & Technology, Sun Yat-Sen University, Guangzhou (China); Liu, Yulan [School of Engineering, Sun Yat-Sen University, Guangzhou (China); Wang, Biao [Sino-French Institute of Nuclear Engineering & Technology, Sun Yat-Sen University, Guangzhou (China)

    2015-06-15

    Highlights: • The k-ε based DES model is used in the nuclear containment simulation. • The comparison of results between different turbulent models is obtained. • The superiority of DES models is analyzed. • The computational efficiency with the DES turbulence models is explained. - Abstract: Different species of gases would be released into the containment and cause unpredicted disasters during the nuclear severe accidents. It is important to accurately predict the transportation and stratification phenomena of these gas mixtures. CFD simulations of these thermal hydraulic issues in nuclear containment are investigated in this paper. The main work is to study the influence of turbulence model on the calculation of gas transportation and heat transfer. The k-ε based DES and other frequently used turbulence models are used in the steam and helium release simulation in THAI series experiment. This paper will show the superiority of the DES turbulence model in terms of computational efficiency and accuracy with the experimental results, and analyze the necessities of DES model to simulate the large-scale containment flows with both laminar and turbulence regions.

  16. CFD simulations in the nuclear containment using the DES turbulence models

    International Nuclear Information System (INIS)

    Ding, Peng; Chen, Meilan; Li, Wanai; Liu, Yulan; Wang, Biao

    2015-01-01

    Highlights: • The k-ε based DES model is used in the nuclear containment simulation. • The comparison of results between different turbulent models is obtained. • The superiority of DES models is analyzed. • The computational efficiency with the DES turbulence models is explained. - Abstract: Different species of gases would be released into the containment and cause unpredicted disasters during the nuclear severe accidents. It is important to accurately predict the transportation and stratification phenomena of these gas mixtures. CFD simulations of these thermal hydraulic issues in nuclear containment are investigated in this paper. The main work is to study the influence of turbulence model on the calculation of gas transportation and heat transfer. The k-ε based DES and other frequently used turbulence models are used in the steam and helium release simulation in THAI series experiment. This paper will show the superiority of the DES turbulence model in terms of computational efficiency and accuracy with the experimental results, and analyze the necessities of DES model to simulate the large-scale containment flows with both laminar and turbulence regions

  17. Projektmanagement in Zeiten des Wandels

    OpenAIRE

    Papesch, Gerti

    2003-01-01

    Projektmanagement in Zeiten des Wandels : 2. Fachtagung Projektmanagement, 1. Oktober 2003 / ZWW, Zentrum für Weiterbildung und Wissenstransfer. Gerhard Wilhems ... - Augsburg : ZWW, 2003. - VI, 190 S.

  18. Mechanisms of impact of greenhouse gases on the Earth's ozone layer in the Polar Regions

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    A numerical 2-D zonally averaged interactive dynamical radiative-photochemical model of the atmosphere including aerosol physics is used to examine the impact of the greenhouse gases CO2, CH4, and N2O on the future long-term changes of the Earth's ozone layer, in particular on its expected recovery after reduction of anthropogenic discharges of chlorine and bromine compounds into the atmosphere. The model allows calculating self-consistently diabatic circu-lation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the North to South Poles, as well as distribution of sulphate aerosol particles and polar strato-spheric clouds (PSCs) of types I and II. The scenarios of expected changes of the anthropogenic pollutants for the period from 1980 through 2050 are taken from Climate Change 2001. The processes, which determine the influence of anthropogenic growth of atmospheric abun-dance of the greenhouse gases on the long-term changes of the Earth's ozone layer in the Polar Regions, have been studied in details. Expected cooling of the stratosphere caused by increases of greenhouse gases, most importantly CO2, essentially influences the ozone layer by two ways: through temperature dependencies of the gas phase reaction rates and through enhancement of polar ozone depletion via increased PSC formation. The model calculations show that a weak-ness in efficiencies of all gas phase catalytic cycles of the ozone destruction due to cooling of the stratosphere is a dominant mechanism of the impact of the greenhouse gases on the ozone layer in Antarctic as well as at the lower latitudes. This mechanism leads to a significant acceleration of the ozone layer recovery here because of the greenhouse gases growth. On the contrary, the mechanism of the impact of the greenhouse gases on the ozone through PSC modification be-gins to be more effective in Arctic in comparison with the gas phase mechanism in springs after about 2020, which leads to retard

  19. 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...

  20. Efficiency of utilization of heat of moisture from exhaust gases of heat HRSG of CCGT

    OpenAIRE

    Galashov Nikolay; Tsibulskiy Svyatoslav; Mel’nikov Denis; Kiselev Alexandr; Gabdullina Al’bina

    2017-01-01

    The paper discusses the technology of utilizing the heat of exhaust gas moisture from heat recovery steam gases (HRSG) of combined-cycle gas turbine (CCGT). Particular attention focused on the influence of the excess air factor on the trapping of the moisture of the exhaust gases, as in the HRSG of the CCGT its value varies over a wider range than in the steam boilers of the TPP. For the research, has been developed a mathematical model that allows to determine the volumes of combustion produ...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Meconnaissance des traumatismes des voies urinaires dans un ...

    African Journals Online (AJOL)

    Meconnaissance des traumatismes des voies urinaires dans un contexte de poly traumatisme: a propos de deux observations. ... They insist on good clinical assessment of abdominal trauma doubled the achievement of imaging tests to not overlook lesions of the urinary tract that can put patient's life threatening. Keywords: ...

  8. Composition chimique et effet Acaricide des huiles essentielles des ...

    African Journals Online (AJOL)

    La composition chimique et l\\'effet acaricide des huiles essentielles des feuilles de Chenopodium ambrosioides et Eucalyptus saligna vis-à-vis de Rhipicephalus lunulatus ont été évalués au Laboratoire de Chimie Appliquée et Environnementale de l\\'Université de Dschang dans l\\'Ouest du Cameroun. Cinq doses de ...

  9. Culture du bambou : diversification des moyens de subsistance des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

  10. Diversification des moyens de subsistance des petits producteurs de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' Association of Malawi (NASFAM), le tabac est la seule et unique source de revenus. Les cultivateurs de tabac, au Malawi ...

  11. Etude des interactions entre les differents acteurs des interventions ...

    African Journals Online (AJOL)

    Etude des interactions entre les differents acteurs des interventions sous directives communautaires et changements obtenus au Benin et au Togo. P.V. Malou Adom, Ch. P. Makoutode, T Gnaro, A.R. Ouro-Koura, E.M. Ouendo, G Napo-Koura, M Makoutode ...

  12. Effets des biomasses vertes de Tithonia diversifolia et des engrais ...

    African Journals Online (AJOL)

    Innovation (MINRESI) pour avoir financé l'intégralité des activités relatives à cette étude. RESUME. L'amélioration de la productivité des sols ferralitiques en zone forestière peut être possible grâce aux intrants locaux en complément à la fertilisation ...

  13. Gestion des ressources naturelles : des solutions avantageuses à ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    environnement et l'accès aux ressources naturelles est un enjeu crucial. Ces 40 dernières années, des chercheurs appuyés par le CRDI ont trouvé des moyens novateurs de réduire la pauvreté tout en protégeant les ressources naturelles dont ...

  14. La recherche en action : des solutions locales, des effets durables ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    15 déc. 2010 ... Le Centre de recherches pour le développement international (CRDI) appuie la production et l'application de connaissances qui améliorent de façon notable la situation des habitants des pays en développement.

  15. Roles et taches des accompagnateurs des patients hospitalises ...

    African Journals Online (AJOL)

    Roles et taches des accompagnateurs des patients hospitalises dans le service de pneumo-phtysiologie au Centre Hospitalier Universitaire Yalgado Ouedraogo de ... Logistical support represented by material support, drug supply, cleaning of premises, and littering occupied respectively 100%, 91%, 42% and 73%.

  16. Perspectives d'amélioration du rendement à très faible charge des moteurs d'automobile Prospects for Lmprovinq the Very-Low-Load Efficiency of Automotive Engines

    Directory of Open Access Journals (Sweden)

    Douaud A.

    2006-11-01

    Full Text Available Le mauvais rendement énergétique des véhicules utilisés à très faible charge (circulation urbaine, vitesses limitées provient entre autres des combustions non optimales. Celles-ci sont de plusieurs types : combustion lente et/ou tardive, ratés de propagation. L'acquisition de cycles de pression au moyen du système DIGITAP développé à l'In-titut Français du Pétrole (IFP est décrite et le calcul instantané du travail cycle-à-cycle permet de définir un critère de stabilité de fonctionnement du moteur. L'analyse thermodynamique des cycles montre que la composition du mélange air + carburant + gaz résiduels, trop proche des limites de propagabilité de flamme, est à l'origine des phénomènes observés. Des voies d'action portant sur les gaz résiduels, la turbulence et les paramètres du système d'allumage sont dégagées et permettent des améliorations importantes du rendement. The poor energy efficiency of vehicles used at very low engine load (urban traffic, limited speeds comes from non-optimum combustion, among other causes. Such combustion may be of several types, i. e. slow and/or late combustion, propagation misfiring. The recording of pressure cycles by the DIGITAP system developed at Institut Français du Pétrole (IFP is described, and the instantaneous computing of the cycle-to-cycle work enables a stability criterion for engine operating to be described. The thermodynamic analysis of the cycles shows that the composition of the air + fuel + residuel gas mixture which is too close to flame propagation limits is at the origin of the phenomena observed. Methods of action concerning residual gases, turbulence and the parameters of the ignition system are determined and make for great improvements in efficiency and stability for such types of running.

  17. La diffraction des neutrons et des rayons X pour l'étude structurale des liquides et des verres

    Science.gov (United States)

    Fischer, H. E.; Salmon, P. S.; Barnes, A. C.

    2003-02-01

    La compréhension de mainte propriété physique d'un verre ou d'un liquide nécessite la connaissance des facteurs de structure partiels (PSFs) qui décrivent chacun la distribution d'une espèce atomique autour d'une autre. La technique de diffraction des neutrons avec substitution isotopique (NDIS) [1,2,3], ayant bien réussi a déterminer les PSFs de certains composés [4,5], est pourtant restreinte aux isotopes présentant un contraste suffisant en longueur de diffusion. D'un autre cote, la technique de diffusion anomale des rayons X (AXS ou AXD) [6] permet de faire varier la longueur de diffusion d'une espèce atomique pourvu que son énergie d'absorption soit à la fois accessible et suffisamment élevée pour donner un assez grand transfert du moment. La combinaison des techniques de diffraction des neutrons (avec ou sans substitution isotopique) et de diffraction des rayons X (avec ou sans diffusion anomale) peut donc permettre d'obtenir un meilleur contraste en longueurs de diffusion pour un système donné, mais exige une analyse de données plus soignée pour pouvoir bien tenir compte des erreurs systématiques qui sont différentes pour les 2 techniques [7]. Pour les atomes ayant des distributions électroniques quasi-sphériques, e.g. dans le cas d'un alliage liquide, la combinaison des techniques de NDIS et de diffraction des rayons X s'est déjà montrée très avantageuse pour la détermination des PSFs [8,9]. Dans le cas des verres ayant d'importantes liaisons covalentes, l'effective combinaison des 2 techniques peut être moins directe mais facilitée lorsqu'il s'agit des atomes de grand Z [10,11]. Nous présentons ici un sommaire du méthode et quelques exemples des résultats.

  18. Study of radiation-induced desorption of gases out of graphite materials

    International Nuclear Information System (INIS)

    Vorob'ev, A.E.; Katrich, N.P.; Sidel'nikova, N.S.; Fedorenko, A.I.

    1987-01-01

    The study results of radiative stimulated desorption of dissolved gases and helium from GMZ and GSP graphites under irradiation by 4 He + ions (E=31 keV) at T=78 K and in backout process after iradiation (T up to 400 K) are presented in paper. It have been studied the initial samples and the samples preliminary irradiated by electrons (E=1.5 MeV) by thermal and fast neutrons and by clusters of hydrogen and helium plasmas (E10 keV). It has been shown that the desorption of impurity pases (CO, C 2 H 4 , N 2 , H 2 ) is minimum for GSP samples and is of order more for GMZ samples. The all types of preliminary irradiation result in the increasing of impurity gases desorption. The activation energies for impurity gases and helium have been determined from thermodesorbtion data

  19. Greenhouse gases - an up-date on the contribution of automotive fuels

    International Nuclear Information System (INIS)

    Williams, M.L.

    1992-01-01

    This paper examines the contribution to global emissions of greenhouse gases from automotive fuels. The Greenhouse Effect and Climate Change are explained briefly. Data is presented on the global warming potential of automobile emissions, actual measured emission rates and greenhouse gas emissions as CO 2 equivalents. It is concluded that insufficient data exists to assess accurately the contribution of automotive fuel use to all the important greenhouse gases. Over short timescales (say 20 years) low emission technologies do show significant reductions in CO 2 equivalent emissions compared with current technology vehicles. However, in the longer term, fuel economy rather than emissions of non-CO 2 gases, is likely to become the determining factor. (UK)

  20. Control of Self Burning in Coal, Piles by Detection of the generated gases; Control de autoencendidos en Parvas de Carbon por Deteccion de los Gases Producidos

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    The purpose of this Research Project is to find the most appropriate method for immediate and remote detection of the phenomena that take place in Thermic Power Plant coal piles, due to the piling up of great quantities of this fuel and its large surface area. These phenomena are: Slow self-oxidation of the coal, producing loss of its calorific power, with its consequent financial loss. Self-combustion of the coal caused when the gases produced by self-oxidation and temperature conditions combine, and they reach a critical point (that of ignition). One of the most recent and novel methods for detection is the Formation of images of Gases, based on the use of laser turned into the vibration wavelengths of the molecules in the gases. This technique, coupled with Thermography, would give as a spatial map of thus distribution and temperatures of gave. It is necessary, in order to extend the use of this equipment to Thermic Power Plant coal piles, to accurately determine which different gases are emanated as well as the minimum concentration of each one of these and the temperature distribution in space. (Author)

  1. 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

  2. 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.

  3. La cogestion des Ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Comprend des réf. bibliogr. ISBN 1-55250-329-1. 1. Cogestion des ressources naturelles—Pays en voie de développement—Cas, Études de. 2. Conservation ...... De fait, les villageois en imputaient la faute aux fonctionnaires nationaux et locaux qui n'avaient pas su mettre efficacement en oeuvre les politiques forestières.

  4. 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...

  5. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    diabète et le tabagisme sont des facteurs de risque reconnus [2-4]. Les données épidémiologiques recueillies au cours de ces trente dernières années laissent ... réduction d‟expression du gène LOX-1 et de la libération de TNFα stimulée par les. LDL-oxydées [22]. Chez l‟homme, in vivo, Voutilainen et al. [23] ont mis en ...

  6. COMPLICATIONS CHIRURGICALES DES AVORTEMENTS ...

    African Journals Online (AJOL)

    1 janv. 2004 ... liquide purulent, sérosanguinolent, ou fécaloïde. Les lésions retrouvées étaient classées en lésions utérines et annexielles (Tableau I), lésions ... femmes par an dans le Monde d'après l'Organisation. Mondiale de la Santé [15]. Leur fréquence élevée dans notre série impose une prise systématique des ...

  7. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Revue Synthèse N° 22, Décembre 2010. N. Benrachou et al. 19. Tableau 3. Composition en triglycérides des trois huiles d'olive). Blanquette. Limli. Bouricha. Variétés. Triglycérides. N° pic. NCE. 3,24 ± 0,01. 2,86± 0,02. 1,06 ± 0,03. LLL. 1. 42. 2,97 ± 0,01. 2,15 ± 0,07. 1,71 ± 0,06. OLLn +PoLL. 2. 0,21 ± 0,01. 0,66 ± 0,02.

  8. Liste des auteurs

    OpenAIRE

    2016-01-01

    Garry Apgar The Voltair Society of America, New York Jean Balcou Université de Bretagne occidentale, Brest Annie Becq Université de Caen Paul Benhamou. Purdue University, West Lafayette, Indiana Reed Benhamou Indiana University, Bloomington, Indiana Jacqueline Biard-Millerioux Université de Poitiers Françoise Bléchet Bibliothèque nationale de France, département des manuscrits, Paris Nicolas Brucker Université de Metz Else-Marie Bukdahl The Royal Danish Academy of Fine Art, Copenhague Christo...

  9. Gestion des ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Mais la situation évolue grâce aux travaux du Réseau international sur le bam- bou et le rotin (INBAR), créé par le CRDI dans les années 1990. À Allahabad, en Inde, la culture du bam- bou a permis de rétablir la fertilité des sols dégradés par l'extraction de l'argile nécessaire à la fabrication de briques, et les agriculteurs.

  10. Emission of Gases during Composting of Solid Waste

    Directory of Open Access Journals (Sweden)

    Dajana Kučić

    2017-10-01

    Full Text Available Composting is a biochemical process converting organic components into stable compost with release of heat, water, CO2 and NH3. The objective of this work was to determine the amount of CO2 and NH3 in the exhaust gases during composting of tobacco waste (TW and mixture of tobacco and grape waste (TGW. The cumulative evolved CO2 during 21 days of composting of TW and TGW, per mass of volatile matter, was 94.01 g kg−1 and 208.18 g kg−1, respectively, and cumulative evolved NH3 during composting of TW and TGW, per mass of volatile matter, was 504.81 mg kg−1 and 122.45 mg kg−1, respectively.

  11. Probing Positron Cooling in Noble Gases via Annihilation γ Spectra.

    Science.gov (United States)

    Green, D G

    2017-11-17

    γ spectra for positron annihilation in noble-gas atoms are calculated using many-body theory for positron momenta up to the positronium-formation threshold. These data are used, together with time-evolving positron-momentum distributions determined in the preceding Letter [Phys. Rev. Lett. 119, 203403 (2017)PRLTAO0031-9007], to calculate the time-varying γ spectra produced during positron cooling in noble gases. The γ spectra and their S[over ¯] and W[over ¯] shape parameters are shown to be sensitive probes of the time evolution of the positron momentum distribution and thus provide a means of studying positron cooling that is complementary to positron lifetime spectroscopy.

  12. Projections of global emissions of fluorinated greenhouse gases in 2050

    Energy Technology Data Exchange (ETDEWEB)

    Gschrey, Barbara; Schwarz, Winfried [Oeko-Recherche Buero fuer Umweltforschung und -beratung GmbH, Frankfurt/Main (Germany)

    2009-11-15

    Emissions of fluorinated greenhouse gases are currently covered under the Montreal Protocol, which focuses on ozone-depleting substances such as CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons), and under the Kyoto Protocol, which controls emissions of HFCs (hydrofluorocarbons), PFCs (perfluorocarbons) and SF{sub 6} (sulfur hexafluoride). This study bridges the gap between political regimes and their reporting systems by giving an overview of banks and emissions of all fluorinated gases in 2005, and projections of banks and emissions of fluorinated gases in 2050. The Montreal Protocol and its amendments will eventually result in the full phase out of CFCs and HCFCs. Developed countries have already completed the phase out of CFCs and will reach full phase out of HCFCs by 2020. Developing countries, in contrast, will phase out CFCs by 2010 and HCFCs by 2030. Although climate-friendly technology is available for most applications, the risk occurs that substitutes for ozone-depleting substances rely on HFCs, which cause global warming. This study determines global emissions of HFCs, PFCs and SF{sub 6} (Kyoto F-gases) in 2050 in a ''business-as-usual'' scenario. The global population is expected to increase to ca. 8.7 billion people, and high economic growth of 3.5% per year is assumed. Emissions in 2050 are quantified for each sector of application as well as for developed and developing countries based on growth rates of each sector. In 2050, total global emissions of fluorinated greenhouse gases are projected to amount to 4 GT CO{sub 2} eq. which equals ca. 5.9% of the total greenhouse gas emissions at this time. Compared to a relatively small share of F-gas emissions ranging around 1.3% of total greenhouse gas emissions in 2004, this percentage reflects an enormous increase. Relative to projected direct CO{sub 2} emissions alone, the 2050 F-gas emissions will even account for ca. 7.9%. In case of CO{sub 2} mitigation, this share

  13. Utilisation sans risque des eaux usées, des excréta et des eaux ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les responsables de ce projet piloteront l'application et l'adaptation des principes directeurs relatifs à l'utilisation sans risque des eaux usées, des excreta et des eaux grises en agriculture et en aquaculture (Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture), que ...

  14. 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.

  15. Measurement and Prediction of Volumetric and Transport Properties of Reservoir Fluids At High Pressure Mesure et prédiction des propriétés volumétriques et des propriétés de transport des fluides de gisement à haute pression

    Directory of Open Access Journals (Sweden)

    De Sant'ana H. B.

    2006-12-01

    Full Text Available Discoveries of oil and gas fields under severe conditions of temperature (above 150°C or pressure (in excess of 50 MPa have been made in various regions of the world. In the North Sea, production is scheduled from deep reservoirs at 190°C and 110 MPa. This brings with it important challenges for predicting the properties of reservoir fluids, both from an experimental and a theoretical standpoint. In order to perform fluid studies for these reservoir conditions, IFP has developed a specific mercury-free high pressure apparatus with sapphire windows, a phase sampling device and viscosity determination by the capillary tube method. Its application is illustrated here using examples of real fluids and model mixtures. This equipment was first used to measure volumetric properties for gases. It has been shown that very high compressibility factors can be found with HP-HT gas condensates. This has a strong influence on recovery factors during primary depletion. In order to predict more accurately the volumetric properties of mixtures under these conditions, we propose to use a conventional equation of state, such as Peng-Robinson, with two improvements :- a modified temperature-dependent volume translation method, calibrated for high pressure density data; the method is simple, more accurate than other volume translation methods and fully consistent with lumping procedures;- a quadratic mixing rule on the covolume. Specific phase behavior can also be found. At low temperatures, wax crystallization can occur from a fluid which is a gas condensate at reservoir temperature. This feature is due to the simultaneous presence of abundant methane and heavy paraffins. A study of model fluids in a sapphire cell has allowed us to identify the possible types of phase diagrams. Although generally not considered to be an important parameter, gas viscosity may have some importance in the production of HP-HT accumulations, because of high flow rates. Viscosity

  16. 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

  17. [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.

  18. Determination of the Effect of Geological Reservoir Variability on Carbon Dioxide Storage Using Numerical Experiments Détermination de la variabilité des réservoirs géologiques sur le stockage du CO2 par la méthodologie des plans d’expériences

    Directory of Open Access Journals (Sweden)

    Diedro F.

    2013-06-01

    Full Text Available The simulations of carbon dioxide storage in sedimentary reservoirs model the fluid and gas flow and the chemical reactions which occur between the minerals (calcite and dolomite and the injected CO2 [André et al. (2007 Energy Convers. Manage. 48, 17821797; Gunter et al. (1999 Appl. Geochem. 4, 1-111. However because of the lack of data, these reservoirs are always partially known and the fitted variograms of petrophysical and mineralogical quantities are approximate. The aim is to quantify the impact of uncertainties on reservoir characteristics on the storage predictions. We focus on two operational parameters: the quantity of the stored carbon dioxide and the mean variation of the porosity. Two sources of uncertainties are examined: the draw dispersion and the approximation on the variogram parameters. To study the influence of the draw dispersion, variogram parameters are kept fixed and different simulations are run; the associated variance on the operational parameters then has the meaning of a repeatability error. In the second case, a sensibility analysis is carried out to study the influence of variogram parameters variations (sill, range, nugget effect on the CO2 storage. The chosen methodology is the designs of experiments. The simulations are carried out using reactive transport software. The studied carbonated reservoir is built in reference to the Dogger formation of Paris Basin (France [Diedro (2009 Thèse, École Nationale Supérieure des Mines de St- Étienne. This reservoir is composed of several minerals, some of them being disposed in spots. The results show that the impact of the draw dispersion remains lower than the impact of the variogram parameters. The effect of the size of the dolomite spots within the rock on the stored carbon dioxide is to be noticed. Larger spots of the dolomite field with low concentration lead to a greater precipitation of carbonate and reduction of porosity than little ,spots with higher

  19. Chirurgie des grassmanniennes

    CERN Document Server

    Lafforgue, Laurent

    2003-01-01

    Les compactifications diverses de variétés de modules sont un thème important et récurrent des mathématiques modernes, et elles connaissent un grand nombre d'applications. Ce livre traite le cas de cellules de Schubert minces, qui sont de sous-variétés naturelles de grassmanniennes. L'auteur a été amené à traiter ces questions par un cas particulier lié à ses travaux sur le programme de Langlands. Dans cette monographie, il en développe une théorie plus systématique, présentant le fortes similarités avec celle des modules du courbes stables. The various compactifications of moduli spaces are an important recurrent theme of modern mathematics, and they have a large number of applications. This book treats the case of thin Schubert varieties, which are natural subvarieties of Grassmannians. The author was led to these questions by a particular case linked to his work on the Langlands program. In this monograph, he develops the theory in a more systematic way, which exhibits strong similarities...

  20. Mécanique des sols et des roches

    CERN Document Server

    Vullier, Laurent; Zhao, Jian

    2016-01-01

    La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

  1. Perception des producteurs sur l'utilisation des déjections de ...

    African Journals Online (AJOL)

    Objectif: L'étude vise à analyser la perception des producteurs sur la contribution des chenilles dans la gestion de la fertilité des sols et dans la production des ... Les producteurs enquêtés ont par ailleurs, identifié les facteurs anthropiques, climatiques et édaphiques comme les facteurs pouvant influencer la dynamique des ...

  2. La Flore Des Adventices Des Cultures Cotonnieres De La Region ...

    African Journals Online (AJOL)

    A partir de relevés itinérants réalisés dans des cultures cotonnières de la région du Worodougou, en Côte d\\'Ivoire, précisement à Mankono, Dianra et Séguéla, 230 espèces d\\'adventices ont été recensées. Dans chacune des trois localités inventoriées, il apparaît que les familles des Poaceae, Fabaceae et Asteraceae ...

  3. Evaluation de la gestion des dechets issus des activites de ...

    African Journals Online (AJOL)

    Le moyen d'élimination des déchets utilisé est l'incinération. Tous les agents impliqués dans la vaccination ont une connaissance des risques de contamination liés aux déchets vaccinaux. La gestion des déchets reste un système global dont tous les aspects méritent d'être considérés. Chaque étape de l'élimination est ...

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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.)

  14. 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.

  15. 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.

  16. 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.

  17. Assessing the DICE model: uncertainty associated with the emission and retention of greenhouse gases

    International Nuclear Information System (INIS)

    Kaufmann, R.K.

    1997-01-01

    Analysis of the DICE model indicates that it contains unsupported assumptions, simple extrapolations, and mis-specifications that cause it to understate the rate at which economic activity emits greenhouse gases and the rate at which the atmosphere retains greenhouse gases. The model assumes a world population that is 2 billion people lower than the 'base case' projected by demographers. The model extrapolates a decline in the quantity of greenhouse gases emitted per unit of economic activity that is possible only if there is a structural break in the economic and engineering factors have determined this ratio over the last century. The model uses a single equation to simulate the rate at which greenhouse gases accumulate in the atmosphere. The forecast for the airborne fraction generated by this equation contradicts forecasts generated by models that represent the physical and chemical processes which determine the movement of carbon from the atmosphere to the ocean. When these unsupported assumptions, simple extrapolations, and misspecifications are remedied with simple fixes, the economic impact of global climate change increases several fold. Similarly, these remedies increase the impact of uncertainty on estimates for the economic impact of global climate change. Together, these results indicate that considerable scientific and economic research is needed before the threat of climate change can be dismissed with any degree of certainty. 23 refs., 3 figs

  18. Evaluation des activites antihyperglycemiantes d'extraits aqueux de ...

    African Journals Online (AJOL)

    écorce de Casuarina equisetifolia révèle la présence des alcaloïdes, des tanins, des flavonoïdes, des leucoanthocyanes, des dérivés anthracéniques, des coumarines et des composés réducteurs, composés aux propriétés médicales multiples, ...

  19. Gases for establishing pneumoperitoneum during laparoscopic abdominal surgery.

    Science.gov (United States)

    Yu, Tianwu; Cheng, Yao; Wang, Xiaomei; Tu, Bing; Cheng, Nansheng; Gong, Jianping; Bai, Lian

    2017-06-21

    mean difference (SMD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence, MAIN RESULTS: We included nine RCTs, randomising 519 participants, comparing different gases for establishing pneumoperitoneum: nitrous oxide (three trials), helium (five trials), or room air (one trial) was compared to carbon dioxide. Three trials randomised participants to nitrous oxide pneumoperitoneum (100 participants) or carbon dioxide pneumoperitoneum (96 participants). None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of nitrous oxide and carbon dioxide on cardiopulmonary complications (RR 2.00, 95% CI 0.38 to 10.43; two studies; 140 participants; very low quality of evidence), or surgical morbidity (RR 1.01, 95% CI 0.18 to 5.71; two studies; 143 participants; very low quality of evidence). There were no serious adverse events related to either nitrous oxide or carbon dioxide pneumoperitoneum (three studies; 196 participants; very low quality of evidence). We could not combine data from two trials (140 participants) which individually showed lower pain scores (a difference of about one visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain) with nitrous oxide pneumoperitoneum at various time points on the first postoperative day, and this was rated asvery low quality .Four trials randomised participants to helium pneumoperitoneum (69 participants) or carbon dioxide pneumoperitoneum (75 participants) and one trial involving 33 participants did not state the number of participants in each group. None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of helium or carbon dioxide on cardiopulmonary complications (RR 1.46, 95% CI 0.35 to 6.12; three studies; 128 participants; very low quality of evidence) or pain scores (visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain; MD 0.49 cm

  20. Engagements contractuels et performances des organisations de ...

    African Journals Online (AJOL)

    amélioration des performances des organisations des producteurs (OP) à l'Ouest Cameroun. Il est basé sur des enquêtes par questionnaires auprès des délégués de 33 OP de maïs bénéficiaires de l'encadrement du Programme d'Amélioration de la ...

  1. Médecine des voyages

    Science.gov (United States)

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  2. 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.

  3. 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.

  4. Les reseaux de politique publique comme facteur d'influence du choix des instruments de politique energetique canadienne a des fins environnementales de 1993 a nos jours

    Science.gov (United States)

    Fathy El Dessouky, Naglaa

    l'agenda politique du pays. Notre projet de recherche, par le truchement de l'approche des reseaux de politique publique, s'attarde a decrire et a expliquer le processus de la formulation d'une politique particuliere, soit la politique energetique a des fins de protection de l'environnement, elaboree en 1993. Il s'agit de mettre en evidence les facteurs affectant le choix des instruments de ces politiques publiques dans leur contexte national. Ainsi, la question generale de cette recherche est: Comment les phases evolutives de la formation d'un reseau de politique, en l'occurrence le Conseil canadien de l'energie (CCE), menent a des caracteristiques particulieres a ce reseau; et comment celles-ci determinent-elles les types des instruments de politique publique choisis, particulierement ceux de la recente orientation des politiques energetiques canadiennes a des fins environnementales elaborees en 1993? Afin d'atteindre l'objectif de notre recherche, deux facteurs primordiaux sont utilises, soit la circulation de l'information et l'exercice du controle sur les ressources des acteurs. L'analyse des caracteristiques du reseau en fonction des liens forts et des liens faibles autant que la presence ou l'absence des trous structuraux nous permettent de bien identifier les positions des differents acteurs, etatiques et non etatiques, sur le plan de l'information et du controle, qui a leur tour, nous semble-t-il, constituent des facteurs affectant les types des instruments des politiques publiques choisis: instruments substantifs, qui indiquent le degre de l'intervention du gouvernement, et instruments proceduraux, qui mettent plutot l'accent sur le degre de l'influence du gouvernement sur les acteurs non etatiques. L'etude soutient que l'approche des reseaux se distingue notamment par son potentiel a expliquer l'interrelation relative entre idees, interets et institutions, ce qui a son tour est susceptible de permettre une meilleure comprehension des processus de l

  5. Influence des facteurs agro-écologiques et des herbicides sur le ...

    African Journals Online (AJOL)

    Influence des facteurs agro-écologiques et des herbicides sur le rendement et les caractéristiques technologiques des grains et farines de blés tendres ( Triticum aestivum L.) et durs ( Triticum durum Desf.)

  6. Evaluation des pratiques de gestion des adventices en riziculture ...

    African Journals Online (AJOL)

    Le riz est l'aliment principal pour la quasi-totalité des populations vivant en Côte d'Ivoire. Cependant, les adventices sont considérées comme la contrainte biologique la plus importante faisant obstacle à la production rizicole. L'objectif de cette étude menée en 2015 était d'évaluer différentes techniques de gestion des ...

  7. Des agriculteurs trouvent des moyens d'exploiter les avantages ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    19 sept. 2013 ... Le tout dernier prototype sera adapté en vue de son utilisation dans les collectivités et les villages. On continuera d'y apporter des améliorations pour lui permettre de moudre d'autres mils (le pied de coq et l'herbe à épée ou kodo). Des chercheurs de la Tamil Nadu Agricultural University s'emploient aussi ...

  8. Modernisation des marchés agroalimentaires - inclusion des petits ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les marchés agroalimentaires connaissent de rapides changements dans les pays en développement et les pays en transition. Sous l'influence de la libéralisation du commerce et des nouvelles technologies de transformation des aliments et de commerce de détail, les marchés agroalimentaires évoluent vers une plus ...

  9. Therapie des Harnwegsinfekts

    Directory of Open Access Journals (Sweden)

    Stoiser B

    2010-01-01

    Full Text Available Harnwegsinfektionen gehören zu den häufigsten entzündlichen Erkrankungen im niedergelassenen Bereich. Eine intelligente Therapiestrategie stellt damit nicht nur eine klinische Herausforderung dar, sondern ermöglicht rasche Heilung, Vermeidung von Resistenzbildungen sowie oft unnötiger, teurer diagnostischer Schritte. Der erste entscheidende Schritt ist die genaue Klassifizierung des Harnweginfektes – asymptomatische Bakteriurie bis zur komplizierten Pyelonephritis. Hier entscheiden sich bereits Aggressivität der Behandlung sowie diagnostischer Aufwand. Für die Entwicklung einer empirischen antimikrobiellen Therapie ist die Kenntnis der häufigsten Erreger sowie lokaler Resistenzmuster wichtig. Bei gezieltem Vorgehen können die meisten Harnwegsinfekte ohne erhöhten diagnostischen Aufwand therapiert werden.

  10. Code des baux 2018

    CERN Document Server

    Vial-Pedroletti, Béatrice; Kendérian, Fabien; Chavance, Emmanuelle; Coutan-Lapalus, Christelle

    2017-01-01

    Le code des baux 2018 vous offre un contenu extrêmement pratique, fiable et à jour au 1er août 2017. Cette 16e édition intègre notamment : le décret du 27 juillet 2017 relatif à l’évolution de certains loyers dans le cadre d’une nouvelle location ou d’un renouvellement de bail, pris en application de l’article 18 de la loi n° 89-462 du 6 juillet 1989 ; la loi du 27 janvier 2017 relative à l’égalité et à la citoyenneté ; la loi du 9 décembre 2016 relative à la transparence, à la lutte contre la corruption et à la modernisation de la vie économique ; la loi du 18 novembre 2016 de modernisation de la justice du xxie siècle

  11. Methanol production from steel-work off-gases and biomass based synthesis gas

    International Nuclear Information System (INIS)

    Lundgren, J.; Ekbom, T.; Hulteberg, C.; Larsson, M.; Grip, C.-E.; Nilsson, L.; Tunå, P.

    2013-01-01

    Highlights: • The integration of a methanol synthesis process in steel plants increases the gas utilization efficiency. • Methanol produced by off-gases from steelmaking combined with biomass show competitive production costs versus petrol. • The integration of a methanol synthesis process in steel plants may reduce the specific CO 2 -emissions of the plant. - Abstract: Off-gases generated during steelmaking are to a large extent used as fuels in process units within the plant. The surplus gases are commonly supplied to a plant for combined heat and power production. The main objective of this study has been to techno-economically investigate the feasibility of an innovative way of producing methanol from these off-gases, thereby upgrading the economic value of the gases. Cases analyzed have included both off-gases only and mixes with synthesis gas, based on 300 MW th of biomass. The SSAB steel plant in the town of Luleå, Sweden has been used as a basis. The studied biomass gasification technology is based on a fluidized-bed gasification technology, where the production capacity is determined from case to case coupled to the heat production required to satisfy the local district heating demand. Critical factors are the integration of the gases with availability to the synthesis unit, to balance the steam system of the biorefinery and to meet the district heat demand of Luleå. The annual production potential of methanol, the overall energy efficiency, the methanol production cost and the environmental effect have been assessed for each case. Depending on case, in the range of 102,000–287,000 ton of methanol can be produced per year at production costs in the range of 0.80–1.1 EUR per liter petrol equivalent at assumed conditions. The overall energy efficiency of the plant increases in all the cases, up to nearly 14%-units on an annual average, due to a more effective utilization of the off-gases. The main conclusion is that integrating methanol

  12. 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. ...

  13. 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 ...

  14. 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

  15. 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…

  16. 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.)

  17. 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...

  18. [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).

  19. Prise en compte du gonflement des terrains dans le dimensionnement des revêtements des tunnels

    OpenAIRE

    Bultel, Frédéric

    2001-01-01

    Travail préparé au Laboratoire Central des Ponts et Chaussées (LCPC-Paris) dans le cadre d'une convention CIFRE avec la société Scetauroute,Composition du jury : MM. R. KASTNER professeur à l'Institut National des Sciences Appliquées de Lyon (rapporteur),I. SHAHROUR professeur à l'Ecole Universitaire Des Ingénieurs de Lille (rapporteur), P. EGGER professeur à l'Ecole Polytechnique Fédérale de Lausanne (Examinateur), B. GAUDIN expert géotechnique à Scetauroute-DTTS (Examinateur), J.P. MAGNAN D...

  20. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland.

  1. 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

  2. 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.

  3. La cogestion des Ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Liban — les conflits sur les ressources et la modification des moyens de subsistance à Arsaal . 71. Chapitre ..... Ainsi, un seul arbre d'une forêt peut fournir des fruits, du bois de chauffage, du fourrage et de l'ombrage; constituer un stabilisateur du sol et un habitat faunique et représenter un lien avec l'identité ancestrale.

  4. CONTRAINTES INSTITUTIONNELLES ET LABELLISATION DES ...

    African Journals Online (AJOL)

    de labellisation des produits algériens (particulièrement le vin et les dattes) par le biais des indications géographiques et les contraintes institutionnels et territoriales qui contrarient ce processus. Le contexte algérien, très marqué par une économie mono-ex- portatrice et très dépendante à l'égard d'un seul type de produit, ...

  5. 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

  6. Electrically tunable magnetic configuration on vacancy-doped GaSe monolayer

    Science.gov (United States)

    Tang, Weiqing; Ke, Congming; Fu, Mingming; Wu, Yaping; Zhang, Chunmiao; Lin, Wei; Lu, Shiqiang; Wu, Zhiming; Yang, Weihuang; Kang, Junyong

    2018-03-01

    Group-IIIA metal-monochalcogenides with the enticing properties have attracted tremendous attention across various scientific disciplines. With the aim to satisfy the multiple demands of device applications, here we report a design framework on GaSe monolayer in an effort to tune the electronic and magnetic properties through a dual modulation of vacancy doping and electric field. A half-metallicity with a 100% spin polarization is generated in a Ga vacancy doped GaSe monolayer due to the nonbonding 4p electronic orbital of the surrounding Se atoms. The stability of magnetic moment is found to be determined by the direction of applied electric field. A switchable magnetic configuration in Ga vacancy doped GaSe monolayer is achieved under a critical electric field of 0.6 V/Å. Electric field induces redistribution of the electronic states. Finally, charge transfers are found to be responsible for the controllable magnetic structure in this system. The magnetic modulation on GaSe monolayer in this work offers some references for the design and fabrication of tunable two-dimensional spintronic device.

  7. Pollution atmospherique par emission de gaz d'echappement des ...

    African Journals Online (AJOL)

    The objective of the present work is to study the air pollution generated by the gases of exhaust in the city of Porto-Novo to Benin. The quantification of the different pollutants or particles given out on the one hand by the vehicles, and the determination of the level of the pollution of every particle on the other hand, allowed us ...

  8. Géochimie des gaz naturels et origine des gisements de gaz en Europe occidentale Geochemistry of Natural Gas and Origins of Gas Fields in Western Europe

    Directory of Open Access Journals (Sweden)

    Tissot B.

    2006-11-01

    Full Text Available De nombreux gisements de gaz sont connus en Europe, dans des conditions géologiques très diverses et dans des terrains d'âge Paléozoïque à Pleistocène. Le problème de leur origine peut être élucidé par l'étude de la composition chimique et isotopique des gaz associée à la connaissance de l'histoire géologique. On rappellera d'abord le schéma général de formation de l'huile et du gaz dans les bassins sédimentaires, puis on discutera les conditions particulières de formation des divers types de gaz. Enfin, on passera en revue, à titre d'exemple, un certain nombre de gisements de gaz d'Europe occidentale. A great many gas fields are known in Europe, having a wide variety of geological conditions and in formations ranging in age from the Paleozoic to the Pleistocene. The problem of their origin can be explained by analyzing the chemical and isotopic composition of the gases combined with knowing the geological history. This article first reviews the general pattern of oil and gas formation in sedimentary basins and then goes on to discuss the specific conditions for the formation of different types of gas. It concludes with a review of various gas fields in Western Europe.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    SARAH

    30 sept. 2017 ... sont le barrage, les puits à faible profondeur (1 à 2 m) et les tranchées creusées dans la cuvette par les maraîchers. 22 % des producteurs utilisent l'eau du barrage directement, 60 % l'eau des puits (figure 2) uniquement et 18 % utilisent les deux types de ressources (figure 3). Toutes les cultures en saison ...

  19. Étude des caractéristiques des peuplements et des noix de Cocos ...

    African Journals Online (AJOL)

    Cocos nucifera est l'un des arbres cultivés le plus répandu. Il se propage par graine avec un long cycle biologique. Cette étude qui avait pour objectif de caractériser les populations naturelles de cocotiers des Niayes (Sénégal), notamment leur structure et leur fruit, a montré que les arbres sont âgés et leur régénération ...

  20. L'accumulation des métaux lourds au niveau des cultures : Cas des ...

    African Journals Online (AJOL)

    Le Bassin de Sebou présente une importance socio-économique pour le Maroc. En effet, il est sujet de diverses utilisations ; eau potable, eau d'irrigation et eau industrielle. Toutefois, ce bassin subit des pressions multiples, notamment par la pollution métallique. Considérant le risque de bioaccumulation des métaux par ...

  1. Efficacy of homologous peste des petits ruminants vaccine on sheep ...

    African Journals Online (AJOL)

    The effect of homologous peste des petits ruminants vaccine (HPPRV) on flock size, morbidity and mortality in sheep and goats was determined in five locations, Unguwan Goje, Bayan Fada, Lowcost, Kyamsangi, and Bagyar, in Dengi, Kanam Local Government Area of Plateau State. Enzyme-linked Immunosorbent Assay ...

  2. Modelisation des emissions de particules microniques et nanometriques en usinage

    Science.gov (United States)

    Khettabi, Riad

    La mise en forme des pieces par usinage emet des particules, de tailles microscopiques et nanometriques, qui peuvent etre dangereuses pour la sante. Le but de ce travail est d'etudier les emissions de ces particules pour fins de prevention et reduction a la source. L'approche retenue est experimentale et theorique, aux deux echelles microscopique et macroscopique. Le travail commence par des essais permettant de determiner les influences du materiau, de l'outil et des parametres d'usinage sur les emissions de particules. E nsuite un nouveau parametre caracterisant les emissions, nomme Dust unit , est developpe et un modele predictif est propose. Ce modele est base sur une nouvelle theorie hybride qui integre les approches energetiques, tribologiques et deformation plastique, et inclut la geometrie de l'outil, les proprietes du materiau, les conditions de coupe et la segmentation des copeaux. Il ete valide au tournage sur quatre materiaux: A16061-T6, AISI1018, AISI4140 et fonte grise.

  3. Apparatus for production, measurement and reaction studies of dissociated gases at elevated temperatures

    Science.gov (United States)

    Christian, J. D.; Gilbreath, W. P.

    1975-01-01

    An apparatus is described which is used for the controlled production, characterization, and study of dissociated gases in a microwave discharge at elevated temperatures. A unique feature is the ability to produce and study a microwave discharge plasma in the heated zone. This allows elevated temperature reactions to be studied in high concentrations of dissociated gases. Further, the system permits weight change measurements of specimens in the plasma, thus facilitating reaction rate determinations. Included is a description of a cavity for use on a 50-mm diameter cylindrical reactor. The effects of flow rate, pressure, temperature, power, metal sample, and sampling position on dissociation percentage of oxygen in the apparatus are described as well as a technique for sample temperature measurements in the plasma which permits determination of high temperature recombination coefficients and reaction rates.

  4. Effect of photocurrent amplification in In sub 2 O sub 3 -GaSe heterostructure

    CERN Document Server

    Drapak, S I

    2001-01-01

    The experimentally determined effects of originating the photocurrent amplification in the In sub 2 O sub 3 -GaSe heterostructure with localization of the barrier plane perpendicular to the semiconductor layers are described. The value of the amplification coefficient by the reverse displacement U = 10 V reached M approx = 82 and the absolute value of the current sensitivity - 30-32 A/W. The mechanism of the current transfer through the dielectric, inevitable originating on the gallium monoselenide surface, is determined on the basis of the volt-ampere characteristics study. The supposition is made on the change in the conductivity mechanisms by transferring the barrier plane from the parallel to the perpendicular one to the GaSe layers

  5. 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

  6. Poissons Characoïdes des Guyanes. I. Généralités. II. Famille des Serrasalmidae

    NARCIS (Netherlands)

    Géry, J.

    1972-01-01

    TABLE DES MATIÈ RES ENGLISH PREFACE AND SUMMARY......... 5 AVANT-PROPOS................. 8 RESUME ................... 9 PREMIERE PARTIE : GENERALITES SUR LES GUYANES ET LES POISSONS CHARACOÏDES................. 12 Chapitre 1. Introduction 1-1. Historique.................. 12 1- 2. Sources et

  7. Onlinespieler abseits des Mainstreams

    Directory of Open Access Journals (Sweden)

    Harald Baumgartlinger

    2012-12-01

    Full Text Available MMO(RPGs „Massively Multiplayer Online (Role-Playing Games“ nehmen einen Sonderstatus unter den Onlinespielen ein, welcher durch den wachsenden wirtschaftlichen Erfolg, insbesondere durch den „breakthrough hit“ (Duchenaut et al. 2006: 407 World of Warcraft (WoW, auch an Bedeutung für die Medien- und Kommunikationswissenschaft gewinnt (vgl. Inderst 2009: 15; vgl. Seifert/Jöckel 2008: 297. Der Primus des Genres, WoW, repräsentiert gemeinsam mit einigen nahezu identen Titeln insgesamt 85 Prozent der gespielten MMOGs (vgl. Williams et al. 2008: 999. Daher befasst sich auch die Mehrheit der vorliegenden Studien mit eben diesen Spielen. Neue Formen von MMO(Gs können jedoch zu ebenso neuartigen Spielerfahrungen führen und damit unterschiedliche Nutzungsmotive befriedigen (vgl. Seifert/Jöckel 2008: 309 und folglich zu einem gänzlich anderen Spielerleben führen. Während im Mainstream die kooperativen Spielerbeziehungen überwiegen, dominiert in Darkfall Online der soziale Wettbewerb. Der von Williams et al. 2008 verwendete Fragebogen diente als Rohling für die Kreation eines für die speziellen Anforderungen adaptierten Erhebungstools zur Erforschung der Spielertypologie und der Motive der Darkfall-Online-SpielerInnen. Die in der Onlinebefragung (N = 506 gesammelten Daten belegen, dass sich sowohl die Spielerdemographie, als auch die Motive der Spieler von den Mainstream MMOs unterscheiden. Zudem konnten realweltliche Eigenschaften der Spieler als signifikante Einflussfaktoren für die Spielzuwendung identifiziert werden.

  8. Terre des hommes

    CERN Multimedia

    Staff Association

    2012-01-01

    Transformez votre téléphone portable en geste de solidarité ! Collecte du 12 au 23 novembre 2012   Faites un geste simple et utile en déposant vos téléphones portables inutilisés dans les urnes installées dans les trois restaurants du CERN. En Suisse, une personne change tous les 12 à 18 mois de téléphone portable. La plupart de nos vieux appareils sont simplement laissés à l’abandon avec comme seule fonction de parer une éventuelle panne à venir. On  estime ainsi que 8 millions de portables sont inutilisés, alors qu'entre 30 et 50% peuvent être réutilisés. L'action Solidarcomm leur offre une deuxième vie ! Terre des Hommes Suisse, dans le cadre de la campagne Solidarcomm, collecte et valorise vos téléphones inutilis&...

  9. 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

  10. 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

  11. 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.

  12. Metal-organic frameworks with high capacity and selectivity for harmful gases

    OpenAIRE

    Britt, David; Tranchemontagne, David; Yaghi, Omar M.

    2008-01-01

    Benchmarks have been established for the performance of six metal-organic frameworks (MOFs) and isoreticular MOFs (IRMOFs, which have the same underlying topology as MOF-5), MOF-5, IRMOF-3, MOF-74, MOF-177, MOF-199, and IRMOF-62, as selective adsorbents for eight harmful gases: sulfur dioxide, ammonia, chlorine, tetrahydrothiophene, benzene, dichloromethane, ethylene oxide, and carbon monoxide. Kinetic breakthrough measurements are used to determine the calculated dynamic adsorption capacity ...

  13. 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.

  14. 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.

  15. Minimisation des inductances propres des condensateurs à film métallisé

    Science.gov (United States)

    Joubert, Ch.; Rojat, G.; Béroual, A.

    1995-07-01

    In this article, we examine the different factors responsible for the equivalent series inductance in metallized capacitors and we propose structures for capacitors that reduce this inductance. After recalling the structure of metallized capacitors we compare, by experimental measurements, the inductance due to the winding and that one added by the connections. The latter can become preponderant. In order to explain the experimental evolution of the winding impedance vs. frequency, we describe an analytical model which gives the current density in the winding and its impedance. This model enables us to determine the self resonant frequency for different types of capacitors. From where, we can infer the influence of the height of capacitors and their internal and external radius upon performances, It appears that to reduce the equivalent series inductance, it is better to use flat windings and annular windings. Dans cet article nous examinons les différents facteurs responsables de l'inductance équivalente série dans les condensateurs à film métallisé et proposons des géométries de condensateurs qui réduisent cette inductance. Après avoir rappelé la structure des condensateurs à film métallisé, nous comparons, par des mesures expérimentales, l'inductance due au bobinage et l'inductance ajoutée par les connexions. Cette dernière peut devenir prépondérante. Afin d'expliquer l'évolution de l'impédance du bobinage en fonction de la fréquence, nous décrivons un modèle analytique qui donne la densité du courant dans le bobinage et l'impédance de ce dernier. En outre, ce modèle permet de déterminer la fréquence de résonance série de divers types de condensateurs ce qui permet de déduire l'influence de la hauteur des condensateurs et de leurs rayons interne et externe sur les performances. Il apparaît ainsi que, pour diminuer l'inductance équivalente série, il vaut mieux employer des bobinages plats et des bobinages annulaires.

  16. Recoupement des politiques: renforcer les initiatives de reddition de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Au cours des dernières années, les acquisitions massives (achats, locations ou autres arrangements) de terres agricoles dans les pays en développement par des particuliers, des entreprises et des gouvernements étrangers ont eu des effets économiques positifs tout comme des effets négatifs sur les moyens de ...

  17. 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.

  18. 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 ...

  19. 107 Etude des facteurs de variation des prix d'intérêt des matières ...

    African Journals Online (AJOL)

    DELL

    Imen BELHADJ SLIMEN et Taha NAJAR. Etude des facteurs de variation des prix d'intérêt des matières premières de substitution utilisées dans les aliments concentrés des animaux d'élevage. Imen BELHADJ SLIMEN1,2* et Taha NAJAR1,2. 1Institut National Agronomique de Tunisie, Département Ressources Animales, ...

  20. Gyrodactylidae et Gyrodactylose des Salmonidae

    Directory of Open Access Journals (Sweden)

    MALMBERG G.

    1993-01-01

    Full Text Available Vingt et une espèces de Gyrodactylus de Salmonidae arrangées en six groupes sont présentées. Les observations concernant ces espèces dans les milieux naturels et en pisciculture sont résumées. Sur la base de données générales relatives aux espèces de Gyrodactylus en milieu naturel en Scandinavie et Baltique, les observations biologiques, écologiques et comportementales de G. salaris Malmberg, 1957 et G. derjavini MALMBERG et MALMBERG (1987 des salmonidae sauvages des rivières norvégiennes et suédoises sont présentées. La viviparité unique, la reproduction asexuée et sexuée et le pouvoir de reproduction chez les Gyrodactylus sont développés. La Gyrodactylose à G. salaris est abordée en milieu naturel, dans les rivières norvégiennes et en pisciculture, en Suède et au Danemark. L'étude ultrastructurale des blessures causées par G. salaris ainsi que les résultats expérimentaux sur les espèces norvégiennes et canadiennes sont présentés. La distribution géographique naturelle des Salmonidae, les modifications liées à l'homme et à l'activité économique ainsi que les Salmonidae élevés sont revus. La présence de six groupes d'espèces de Gyrodactylus en Amérique du Nord et Eurasie est discutée en fonction de la distribution géographique des espèces hôtes. Il est souligné qu'une propagation intercontinentale des espèces de Gyrodactylus de Salmonidae a dû être impossible à cause de leur origine limnique d'une part et de la salinité élevée des océans atlantique et pacifique d'autre part. Les exigences micro et macro environnementales des espèces sont discutées dans les conditions naturelles et les variations saisonnières, préférendums et tolérances du parasitisme sont signalés. L'effet des conditions de pisciculture sur les espèces de Gyrocactylus sont discutées : la capacité reproductrice et de propagation ainsi que la spécificité — stricte dans la nature — peuvent être influenc