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Sample records for forecasting dissolved gases

  1. Effect of Greenhouse Gases Dissolved in Seawater.

    PubMed

    Matsunaga, Shigeki

    2016-01-01

    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. PMID:26729101

  2. Effect of Greenhouse Gases Dissolved in Seawater

    PubMed Central

    Matsunaga, Shigeki

    2015-01-01

    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. PMID:26729101

  3. Novel System for Continuous Measurements of Dissolved Gases in Liquids

    NASA Astrophysics Data System (ADS)

    Baer, D. S.; Liem, J.; Owano, T. G.; Gupta, M.

    2014-12-01

    Measurements of dissolved gases in lakes, rivers and oceans may be used to quantify underwater greenhouse gas generation, air-surface exchange, and pollution migration. Studies involving quantification of dissolved gases typically require obtaining water samples (from streams, lakes, or ocean water) and transporting them to a laboratory, where they are degased. The gases obtained are then generally measured using gas chromatography and isotope ratio mass spectrometry for concentrations and isotope ratios, respectively. This conventional, off-line, discrete-sample methodology is time consuming and labor intensive, and thus severely inhibits detailed spatial and temporal mapping of dissolved gases. In this work, we describe the commercial development of a new portable membrane-based gas extraction system (18.75" x 18.88" x 10.69", 16 kg, 85 watts) that interfaces directly to our cavity enhanced laser absorption based (or Off-Axis ICOS) gas analyzers to continuously and quickly measure concentrations and isotope ratios of dissolved gases. By accurately controlling the water flow rate through the membrane contactor, gas pressure on the outside and water pressure on the inside of the membrane, the system can generate precise and highly reproducible results. Furthermore, the gas-phase mole fractions (parts per million, ppm) may be converted into dissolved gas concentrations (nM), by accurately measuring the gas flow rates in and out of the extraction system. We will present detailed laboratory test data that quantifies the performance (linearity, precision, and dynamic range) of the system for measurements of the concentrations and isotope ratios of dissolved greenhouse gases (methane, carbon dioxide, and nitrous oxide) continuously and in real time.

  4. Thermodynamic properties of gases dissolved in electrolyte solutions.

    NASA Technical Reports Server (NTRS)

    Tiepel, E. W.; Gubbins, K. E.

    1973-01-01

    A method based on perturbation theory for mixtures is applied to the prediction of thermodynamic properties of gases dissolved in electrolyte solutions. The theory is compared with experimental data for the dependence of the solute activity coefficient on concentration, temperature, and pressure; calculations are included for partial molal enthalpy and volume of the dissolved gas. The theory is also compared with previous theories for salt effects and found to be superior. The calculations are best for salting-out systems. The qualitative feature of salting-in is predicted by the theory, but quantitative predictions are not satisfactory for such systems; this is attributed to approximations made in evaluating the perturbation terms.

  5. [Quantitative analysis of transformer oil dissolved gases using FTIR].

    PubMed

    Zhao, An-xin; Tang, Xiao-jun; Wang, Er-zhen; Zhang, Zhong-hua; Liu, Jun-hua

    2013-09-01

    For the defects of requiring carrier gas and regular calibration, and low safety using chromatography to on line monitor transformer dissolved gases, it was attempted to establish a dissolved gas analysis system based on Fourier transform infrared spectroscopy. Taking into account the small amount of characteristic gases, many components, detection limit and safety requirements and the difficulty of degasser to put an end to the presence of interference gas, the quantitative analysis model was established based on sparse partial least squares, piecewise section correction and feature variable extraction algorithm using improvement TR regularization. With the characteristic gas of CH4, C2H6, C2H6, and CO2, the results show that using FTIR meets DGA requirements with the spectrum wave number resolution of 1 cm(-1) and optical path of 10 cm. PMID:24369641

  6. Validation of aerosols, reactive gases and greenhouse gases in the CAMS forecasts, analyses and reanalyses

    NASA Astrophysics Data System (ADS)

    Eskes, Henk; Basart, Sara; Blechschmidt, Anne; Chabrillat, Simon; Clark, Hannah; Cuevas, Emilio; Engelen, Richard; Kapsomenakis, John; Katragkou, Eleni; Mantzius Hansen, Kaj; Niemeijer, Sander; Ramonet, Michel; Schulz, Michael; Sudarchikova, Natalia; Wagner, Annette; Warneke, Thorsten

    2016-04-01

    The Atmosphere Monitoring Service of the European Copernicus Programme (CAMS) is an operational service providing analyses, reanalyses and daily forecasts of aerosols, reactive gases and greenhouse gases on a global scale, and air quality forecasts and reanalyses on a regional scale. CAMS is based on the systems developed during the European MACC I-II-III (Monitoring Atmospheric Composition and Climate) research projects. In CAMS data assimilation techniques are applied to combine in-situ and remote sensing observations with global and European-scale models of atmospheric reactive gases, aerosols and greenhouse gases. The global component is based on the Integrated Forecast System of the ECMWF, and the regional component on an ensemble of 7 European air quality models. CAMS is implemented by ECMWF, and the transition from MACC to CAMS is currently being implemented (2015-2016). CAMS has a dedicated validation activity, a partnership of 13 institutes co-ordinated by KNMI, to document the quality of the atmospheric composition products. In our contribution we discuss this validation activity, including the measurement data sets, validation requirements, the operational aspects, the upgrade procedure, the validation reports and scoring methods, and the model configurations and assimilation systems validated. Of special concern are the forecasts of high pollution concentration events (fires, dust storms, air pollution events, volcano ash and SO2). A few interesting validation results will be shown.

  7. Simultaneous analysis of noble gases, sulfur hexafluoride, and other dissolved gases in water.

    PubMed

    Brennwald, Matthias S; Hofer, Markus; Kipfer, Rolf

    2013-08-01

    We developed an analytical method for the simultaneous measurement of dissolved He, Ne, Ar, Kr, Xe, SF6, N2, and O2 concentrations in a single water sample. The gases are extracted from the water using a head space technique and are transferred into a vacuum system for purification and separation into different fractions using a series of cold traps. Helium is analyzed using a quadrupole mass spectrometer (QMS). The remaining gas species are analyzed using a gas chromatograph equipped with a mass spectrometer (GC-MS) for analysis of Ne, Ar, Kr, Xe, N2, and O2 and an electron capture detector (GC-ECD) for SF6 analysis. Standard errors of the gas concentrations are approximately 8% for He and 2-5% for the remaining gas species. The method can be extended to also measure concentrations of chlorofluorocarbons (CFCs). Tests of the method in Lake Lucerne (Switzerland) showed that dissolved gas concentrations agree with measurements from other methods and concentrations of air saturated water. In a small artificial pond, we observed systematic gas supersaturations, which seem to be linked to adsorption of solar irradiation in the pond and to water circulation through a gravel bed. PMID:23826704

  8. Process for coal liquefaction by separation of entrained gases from slurry exiting staged dissolvers

    DOEpatents

    Givens, Edwin N.; Ying, David H. S.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a solvent, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals are separated from the condensed dissolver effluent. In accordance with the improved process, fresh hydrogen is fed to each dissolver and the entrained gas from each dissolver is separated from the slurry phase and removed from the reactor system before the condensed phase is passed to the next dissolver in the series. In accordance with another process, the feeds to the dissolvers are such that the top of each downstream dissolver is used as a gas-liquid separator.

  9. Pumping-induced ebullition: a unified and simplified method for measuring multiple dissolved gases.

    PubMed

    Browne, Bryant A

    2004-11-01

    The incorporation of multiple dissolved gas measurements in biogeochemical studies remains a difficult and expensive challenge. Incompatibilities in collection, handling, and storage procedures generally force the application of multiple sampling procedures for multiple gases. This paper introduces the concept and application of pumping-induced ebullition (PIE), a unified approach for routine measurement of multiple dissolved gases in natural waters and establishes a new platform for development of in situ real-time dissolved gas monitoring tools. Ebullition (spontaneous formation of bubbles) is induced by pumping a water sample through a narrow-diametertube (a "restrictor") to decrease hydrostatic pressure (PH) below total dissolved gas pressure (PT). Buoyancy is used to trap bubbles within a collection tower where gas accumulates rapidly (1 mL/min) to support multiple chemical analyses. Providing for field collection of an essentially unlimited and unified volume of gas sample, PIE afforded accurate and precise measurements of major (N2, 02, Ar), trace (CO2, N20, CH4) and ultratrace (CFC11, CFC12, CFC113, SF6) dissolved gases in Wisconsin groundwater, revealing interrelationships between denitrification, apparent recharge age-dates, and historical land use. Compared to conventional approaches, PIE eliminates multiple gas-specific sampling methods, reduces data computations, simplifies laboratory instrumentation, and avoids aqueous production and consumption of biogenic gases during sample storage. A lake depth profile for CO2 demonstrates PIE's flexibility as an in situ real-time platform for dissolved gas measurements. The apparent departures of some gases (SF6, H2, N2O, CO2) from solubility equilibrium behavior warrant further confirmation and theoretical investigation. PMID:15575293

  10. Dissolved Gases in Seawater and Sediments (Paper 7R0315)

    NASA Astrophysics Data System (ADS)

    Key, R. M.

    1987-07-01

    Certainly the most controversial results derived from the study of any dissolved gas concerned oxygen utilization rates in the North Atlantic. Jenkins (1982) estimated a net oxy-gen utilization rate (OUR) for the Beta triangle region of the North Atlantic (apices 26.5°N x 38.5°W, 32.5°N x 30.0°W, and 22.5°N x 28.5°W) of 5.7 moles of oxygen consumed m-2 yr-1 for the zone below 100m. He assumed that the oxygen distribution below the euphotic zone was stationary and steady state and therfore that the in situ oxygen consumption must be balanced by physical transport of oxygen into the area. His estimates were based on measured distributions of dissolved oxygen and the tracers 3He and 3H and a simple model which assumed lateral advection was small. The derived value or OUR was several times higher that previous estimates based on 14C and 15N incubation techniques. The OUR requires a downward flux of carbon from the photic zone of approximately 50 gCm-2yr-1 , which is again much higher that previous results. Jenkins and Goldman (1985) amplified the arguments in a study of seasonal oxygen cycling and primary production based on a ten year time series of measurements from the Panulirus station near Bermuda. Considering insolation, heat budgets and 3He/3H data they estimated a vertically integrated oxygen production rate of 5 Mm-2yr-1 and a subsequent new production of 50 gCm-2yr-1. The results were supported by calculations based on a second order turbulence closure model (Klein and Coste, 1984). These results have been challenged primarily on the basis of the spatial variability of the phenomenon!. Whatever the final outcome Jenkins has clearly demonstrated that the time has come to take a fresh look at oxygen utilization rates and primary productivity given the tools and modelling capabilities now at hand. The TTO data set will go a long way toward providing the necessary data set for the North Atlantic when the analyses are complete. Other studies have dealt with

  11. A simple device for the collection of water and dissolved gases at defined depths

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A device, consisting of a jar fitted with an inlet comprised of a gas-tight check valve and 2-way ball valve outlet connected via tubing to a portable peristaltic pump, was constructed to collect water samples without atmospheric contamination or loss of dissolved gases. A headspace void for dissol...

  12. Geochemistry of dissolved gases in the hypersaline Orca basin. Technical report

    SciTech Connect

    Wiesenburg, D.A.

    1980-12-01

    Hypersaline, anoxic waters significantly affect the biogeochemistry of dissolved gases in the Orca Basin (Northern Gulf of Mexico). The high stability of the Orca brine pool makes it an ideal laboratory for studying production and consumption of dissolved gases during anaerobic decomposition. Depth distributions were determined for nitrogen, oxygen, argon, methane, ethane, propane, ammonia, hydrogen sulfide, and nitrous oxide. Physical stratification of the water column strongly influences Orca Basin gas distributions. The high salinity brine (approx. 250%) is internally well mixed due to convective overturning, but transfer across the brine-sea water interface is controlled by molecular diffusion. With a molecular diffusivity of 0.00001 sq cm/sec, it will take 1,000,000 years for all salts to diffuse from the basin. Heat diffuses faster than salt and is lost from the basin at a rate of 0.5 microcal sq cm/sec. If geothermal heat input from the sediments is slightly higher, this input could account for the higher temperature in the brine (5.6C) compared to the deep Gulf waters (4.2 C). This study has shown the utility of dissolved gases in examining water chemistry of unusual areas. Since sources of dissolved gases are independent of the sources of major ions in solution, calculations of gas distributions on a salt-free basis are useful in examining production and consumption processes.

  13. A Ni-Doped Carbon Nanotube Sensor for Detecting Oil-Dissolved Gases in Transformers

    PubMed Central

    Lu, Jia; Zhang, Xiaoxing; Wu, Xiaoqing; Dai, Ziqiang; Zhang, Jinbin

    2015-01-01

    C2H2, C2H4, and C2H6 are important oil-dissolved gases in power transformers. Detection of the composition and content of oil-dissolved gases in transformers is very significant in the diagnosis and assessment of the state of transformer operations. The commonly used oil-gas analysis methods have many disadvantages, so this paper proposes a Ni-doped carbon nanotube (Ni-CNT) gas sensor to effectively detect oil-dissolved gases in a transformer. The gas-sensing properties of the sensor to C2H2, C2H4, and C2H6 were studied using the test device. Based on the density functional theory (DFT) the adsorption behaviors of the three gases on intrinsic carbon nanotubes (CNTs) and Ni-CNTs were calculated. The adsorption energy, charge transfer, and molecular frontier orbital of the adsorption system were also analyzed. Results showed that the sensitivity of the CNT sensor to the three kinds of gases was in the following order: C2H2 > C2H4 > C2H6. Moreover, the doped Ni improved the sensor response, and the sensor response and gas concentration have a good linear relationship. PMID:26066989

  14. A Ni-Doped Carbon Nanotube Sensor for Detecting Oil-Dissolved Gases in Transformers.

    PubMed

    Lu, Jia; Zhang, Xiaoxing; Wu, Xiaoqing; Dai, Ziqiang; Zhang, Jinbin

    2015-01-01

    C2H2, C2H4, and C2H6 are important oil-dissolved gases in power transformers. Detection of the composition and content of oil-dissolved gases in transformers is very significant in the diagnosis and assessment of the state of transformer operations. The commonly used oil-gas analysis methods have many disadvantages, so this paper proposes a Ni-doped carbon nanotube (Ni-CNT) gas sensor to effectively detect oil-dissolved gases in a transformer. The gas-sensing properties of the sensor to C2H2, C2H4, and C2H6 were studied using the test device. Based on the density functional theory (DFT) the adsorption behaviors of the three gases on intrinsic carbon nanotubes (CNTs) and Ni-CNTs were calculated. The adsorption energy, charge transfer, and molecular frontier orbital of the adsorption system were also analyzed. Results showed that the sensitivity of the CNT sensor to the three kinds of gases was in the following order: C2H2 > C2H4 > C2H6. Moreover, the doped Ni improved the sensor response, and the sensor response and gas concentration have a good linear relationship. PMID:26066989

  15. Characterizing spatial and temporal variability of dissolved gases in aquatic environments with in situ mass spectrometry.

    PubMed

    Camilli, Richard; Duryea, Anthony N

    2009-07-01

    The TETHYS mass spectrometer is intended for long-term in situ observation of dissolved gases and volatile organic compounds in aquatic environments. Its design maintains excellent low mass range sensitivity and stability during long-term operations, enabling characterization of low-frequency variability in many trace dissolved gases. Results are presented from laboratory trials and a 300-h in situ trial in a shallow marine embayment in Massachusetts, U.S.A. This time series consists of over 15000 sample measurements and represents the longest continuous record made by an in situ mass spectrometer in an aquatic environment. These measurements possess sufficient sampling density and duration to apply frequency analysis techniques for study of temporal variability in dissolved gases. Results reveal correlations with specific environmental periodicities. Numerical methods are presented for converting mass spectrometer ion peak ratios to absolute-scale dissolved gas concentrations across wide temperature regimes irrespective of ambient pressure, during vertical water column profiles in a hypoxic deep marine basin off the coast of California, U.S.A. Dissolved oxygen concentration values obtained with the TETHYS instrument indicate close correlation with polarographic oxygen sensor data across the entire depth range. These methods and technology enable observation of aquatic environmental chemical distributions and dynamics at appropriate scales of resolution. PMID:19673300

  16. Distribution patterns of water-dissolved gases in oil-gas-bearing sediments

    SciTech Connect

    Panchenko, A.S.

    1982-07-01

    The prospecting significance of water-dissolved gases is dependent on processes of diffusion in the pool-water system, as a result of which gas halos (methane, ethane, propane, butane, pentane, CO/sub 2/, N/sub 2/, H/sub 2/S, He, Ar) are formed around the hydrocarbon accumulations. In the study presented, the authors identify a pattern previously unknown in the distribution of water-dissolved gases accompanying hydrocarbon pools. In this pattern, the concentration and partial pressure of the gaseous hydrocarbons in the water may increase, or at first decrease and then increase. The presence of such gas halos around pools is explained by the peculiarities of formation of hydrocarbon deposits, and should be considered when prospecting for hydrocarbon deposits. (JMT)

  17. Dissolved gases in hydrothermal (phreatic) and geyser eruptions at Yellowstone National Park, USA

    USGS Publications Warehouse

    Hurwitz, Shaul; Clor, Laura; McCleskey, R. Blaine; Nordstrom, D Kirk; Hunt, Andrew G.; Evans, William C.

    2016-01-01

    Multiphase and multicomponent fluid flow in the shallow continental crust plays a significant role in a variety of processes over a broad range of temperatures and pressures. The presence of dissolved gases in aqueous fluids reduces the liquid stability field toward lower temperatures and enhances the explosivity potential with respect to pure water. Therefore, in areas where magma is actively degassing into a hydrothermal system, gas-rich aqueous fluids can exert a major control on geothermal energy production, can be propellants in hazardous hydrothermal (phreatic) eruptions, and can modulate the dynamics of geyser eruptions. We collected pressurized samples of thermal water that preserved dissolved gases in conjunction with precise temperature measurements with depth in research well Y-7 (maximum depth of 70.1 m; casing to 31 m) and five thermal pools (maximum depth of 11.3 m) in the Upper Geyser Basin of Yellowstone National Park, USA. Based on the dissolved gas concentrations, we demonstrate that CO2 mainly derived from magma and N2 from air-saturated meteoric water reduce the near-surface saturation temperature, consistent with some previous observations in geyser conduits. Thermodynamic calculations suggest that the dissolved CO2 and N2 modulate the dynamics of geyser eruptions and are likely triggers of hydrothermal eruptions when recharged into shallow reservoirs at high concentrations. Therefore, monitoring changes in gas emission rate and composition in areas with neutral and alkaline chlorine thermal features could provide important information on the natural resources (geysers) and hazards (eruptions) in these areas.

  18. Dissolved Gases and Ice Fracturing During the Freezing of a Multicellular Organism: Lessons from Tardigrades

    PubMed Central

    Kletetschka, Gunther; Hruba, Jolana

    2015-01-01

    Abstract Three issues are critical for successful cryopreservation of multicellular material: gases dissolved in liquid, thermal conductivity of the tissue, and localization of microstructures. Here we show that heat distribution is controlled by the gas amount dissolved in liquids and that when changing the liquid into solid, the dissolved gases either form bubbles due to the absence of space in the lattice of solids and/or are migrated toward the concentrated salt and sugar solution at the cost of amount of heat required to be removed to complete a solid-state transition. These factors affect the heat distribution in the organs to be cryopreserved. We show that the gas concentration issue controls fracturing of ice when freezing. There are volumetric changes not only when changing the liquid into solid (volume increases) but also reduction of the volume when reaching lower temperatures (volume decreases). We discuss these issues parallel with observations of the cryosurvivability of multicellular organisms, tardigrades, and discuss their analogy for cryopreservation of large organs. PMID:26309797

  19. Dissolved Gases and Ice Fracturing During the Freezing of a Multicellular Organism: Lessons from Tardigrades.

    PubMed

    Kletetschka, Gunther; Hruba, Jolana

    2015-01-01

    Three issues are critical for successful cryopreservation of multicellular material: gases dissolved in liquid, thermal conductivity of the tissue, and localization of microstructures. Here we show that heat distribution is controlled by the gas amount dissolved in liquids and that when changing the liquid into solid, the dissolved gases either form bubbles due to the absence of space in the lattice of solids and/or are migrated toward the concentrated salt and sugar solution at the cost of amount of heat required to be removed to complete a solid-state transition. These factors affect the heat distribution in the organs to be cryopreserved. We show that the gas concentration issue controls fracturing of ice when freezing. There are volumetric changes not only when changing the liquid into solid (volume increases) but also reduction of the volume when reaching lower temperatures (volume decreases). We discuss these issues parallel with observations of the cryosurvivability of multicellular organisms, tardigrades, and discuss their analogy for cryopreservation of large organs. PMID:26309797

  20. Upper ocean model of dissolved atmospheric gases. Annual report, 1 August 1991--31 July 1992

    SciTech Connect

    Schudlich, R.; Emerson, S.

    1992-12-31

    The goal of this project is to estimate the rate of biological oxygen production at Hawaiian Ocean Time-series station ALOHA in the central North Pacific ocean. Our approach is to use an upper ocean model together with measurements to interpret an annual cycle of temperature, salinity, dissolved oxygen, argon, nitrogen, and the stable isotope ratio of oxygen at station ALOHA. This project represents the first upper ocean geochemical study in which model predictions are verifiable by independent measurements. Using the model, we will be able to assess the relative roles played by physical processes (air-sea gas exchange, air injection by bubbles, temperature-induced changes in gas solubility, trapping below the mixed layer, and diffusion) and biological processes (photosynthesis, respiration, and nutrient recycling) in producing the observed distribution of dissolved atmospheric gases. The long term goal of this project is to understand the utility of chemical tracers for quantifying biological processes in the ocean.

  1. Gasometer: An inexpensive device for continuous monitoring of dissolved gases and supersaturation

    USGS Publications Warehouse

    Bouck, G.R.

    1982-01-01

    The “gasometer” is a device that measures differential dissolved-gas pressures (δP) in water relative to barometric pressure (as does the “Weiss saturometer”), but operates continuously without human attention. The gasometer can be plumbed into a water-supply system and requires 8 liters/minute of water or more at 60 kilopascals. The gasometer's surfaces are nontoxic, and flow-through water can be used for fish culture. The gasometer may be connected to a small submersible pump and operated as a portable unit. The gasometer can activate an alarm system and thus protect fish from hyperbaric (supersaturation) or hypobaric gas pressures (usually due to low dissolved oxygen). Instructions are included for calculating and reporting data including the pressure and saturation of individual gases. Construction and performance standards are given for the gasometer. Occasional cleaning is required to remove biofouling from the gas-permeable tubing.PDF

  2. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    NASA Astrophysics Data System (ADS)

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-08-01

    To maintain local pH levels near the electrode during electrochemical reactions, the use of buffer solutions is effective. Nevertheless, the critical effects of the buffer concentration on electrocatalytic performances have not been discussed in detail. In this study, two fundamental electrochemical reactions, oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), on a platinum rotating disk electrode are chosen as model gas-related aqueous electrochemical reactions at various phosphate concentrations. Our detailed investigations revealed that the kinetic and limiting diffusion current densities for both the ORR and HOR logarithmically decrease with increasing solute concentration (log |jORR | = - 0.39 c + 0.92 , log |jHOR | = - 0.35 c + 0.73) . To clarify the physical aspects of this phenomenon, the electrolyte characteristics are addressed: with increasing phosphate concentration, the gas solubility decrease, the kinematic viscosity of the solution increase and the diffusion coefficient of the dissolved gases decrease. The simulated limiting diffusion currents using the aforementioned parameters match the measured ones very well (log |jORR | = - 0.43 c + 0.99 , log |jHOR | = - 0.40 c + 0.54) , accurately describing the consequences of the electrolyte concentration. These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases.

  3. Method for Extraction of Dissolved Gases From Groundwater for Radiokrypton Analysis

    NASA Astrophysics Data System (ADS)

    Probst, P.; Yokochi, R.; Sturchio, N. C.

    2006-12-01

    Two radioactive isotopes of krypton (Kr) have proven to be valuable tools for dating groundwater. ^{81}Kr (half life of 229,000 years) is an excellent tracer for groundwater flow on the 50,000 to 1,000,000 year time scale. ^{85}Kr (half life of 10.8 years) can be used to study groundwater less than 50 years old. The recent application of Atom Trap Trace Analysis (ATTA) on Kr at Argonne National Laboratory enabled the quantification of those low abundance isotopes (~ 10^{-12} for ^{81}Kr)in natural samples. ATTA analyses currently need 50 μL of krypton, which requires over 700 L of groundwater to be processed. A new system, EDGAR (Extraction of Dissolved Gases for Analysis of Radiokrypton), has been developed at the University of Illinois at Chicago for a simple and rapid extraction of dissolved gases from groundwater. The key component of EDGAR is a hydrophobic semi-permeable membrane contactor that transports gases across the membrane material as water flows through it. A vacuum compressor applies vacuum to the outer side of the membrane and then compresses the extracted gas into a size 80 gas cylinder. The extraction apparatus is housed in a rolling steel-frame cart that weighs about 180 kg and requires a 120VAC/20 amp power source. Electronic sensors monitor the membrane vacuum, sample tank pressure, water temperature and total water flow. A data logger records all of the sensor signals. Laboratory testing of the membrane extraction was conducted using tap water derived from Lake Michigan. Dissolved oxygen (DO_2) measurements before and after the membrane were used as a benchmark. DO_2 dropped from the initial value of 12-15 mg/L to 1.6-3.7 mg/L after the membrane extraction, indicating an extraction of 67 to 88 % of dissolved oxygen. The amount of oxygen removed from the water was proportional to the vacuum applied to the membrane. Field testing of EDGAR was performed on a local anoxic groundwater well. The compositions of the extracted gas and the dissolved

  4. Validation of reactive gases and aerosols in the MACC global analysis and forecast system

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Huijnen, V.; Arola, A.; Benedictow, A.; Blechschmidt, A.-M.; Botek, E.; Boucher, O.; Bouarar, I.; Chabrillat, S.; Cuevas, E.; Engelen, R.; Flentje, H.; Gaudel, A.; Griesfeller, J.; Jones, L.; Kapsomenakis, J.; Katragkou, E.; Kinne, S.; Langerock, B.; Razinger, M.; Richter, A.; Schultz, M.; Schulz, M.; Sudarchikova, N.; Thouret, V.; Vrekoussis, M.; Wagner, A.; Zerefos, C.

    2015-11-01

    The European MACC (Monitoring Atmospheric Composition and Climate) project is preparing the operational Copernicus Atmosphere Monitoring Service (CAMS), one of the services of the European Copernicus Programme on Earth observation and environmental services. MACC uses data assimilation to combine in situ and remote sensing observations with global and regional models of atmospheric reactive gases, aerosols, and greenhouse gases, and is based on the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF). The global component of the MACC service has a dedicated validation activity to document the quality of the atmospheric composition products. In this paper we discuss the approach to validation that has been developed over the past 3 years. Topics discussed are the validation requirements, the operational aspects, the measurement data sets used, the structure of the validation reports, the models and assimilation systems validated, the procedure to introduce new upgrades, and the scoring methods. One specific target of the MACC system concerns forecasting special events with high-pollution concentrations. Such events receive extra attention in the validation process. Finally, a summary is provided of the results from the validation of the latest set of daily global analysis and forecast products from the MACC system reported in November 2014.

  5. Forecasting models for flow and total dissolved solids in Karoun river-Iran

    NASA Astrophysics Data System (ADS)

    Salmani, Mohammad Hassan; Salmani Jajaei, Efat

    2016-04-01

    Water quality is one of the most important factors contributing to a healthy life. From the water quality management point of view, TDS (total dissolved solids) is the most important factor and many water developing plans have been implemented in recognition of this factor. However, these plans have not been perfect and very successful in overcoming the poor water quality problem, so there are a good volume of related studies in the literature. We study TDS and the water flow of the Karoun river in southwest Iran. We collected the necessary time series data from the Harmaleh station located in the river. We present two Univariate Seasonal Autoregressive Integrated Movement Average (ARIMA) models to forecast TDS and water flow in this river. Then, we build up a Transfer Function (TF) model to formulate the TDS as a function of water flow volume. A performance comparison between the Seasonal ARIMA and the TF models are presented.

  6. Dissolved inert gases (He, Ne, N2) as marker of groundwater flow-lines and degassing sources in Etnean area

    NASA Astrophysics Data System (ADS)

    Paonita, A.; Longo, M.; Bellomo, S.; Brusca, L.; D'Alessandro, W.

    2015-12-01

    Several studies in the past three decades have demonstrated the role played by monitoring chemical and isotopic composition of dissolved gases in groundwaters hosted in volcanic area, which represents by now a powerful tool to evaluate the state of activity of volcanoes and its evolution. The first step to make it possible, is a comprehensive understanding of fluids circulation inside the volcano edifice, starting from groundwaters characterization up to the identification of the underground pathways and their relationships with tectonic structures, that enhance interactions between waters and magmatic gases. In this work, we focussed on chemical composition of inert dissolved gases (He, Ne, N2) and He isotope abundances coming from groundwaters circulating in Mt Etna, as having great contrast between magmatic and shallow sources and no chemical interaction with rocks. We identified waters which intersect anomalous degassing areas, such as well evident or buried tectonic structures. These waters show both nearly magmatic He isotopic composition and high ratios of dissolved magmatic gases (He, CO2) versus the atmospherics ones (N2). Along the hydrologic flow-lines and faraway from the degassing structures, we found waters with lower He isotopic ratios and consequently richer of atmospheric-derived gases (Ne, N2). On this basis, we set-up a model of unidimensional dispersion-advection, coupled to a two-layer dynamic exchange of volatiles between the aquifer surface and atmosphere. The model is able to quantitatively explain the progressive "dilution" of the magmatic signal through several kilometres-long distances, from the source point of the anomaly towards the final stage of flow-lines at the coast. Typical hydro geological parameters, such as rock permeability, could be constrained by this approach. Moreover, anomalous compositions found along water flow-lines could represent possible new sources of degassing, allowing to detect hidden degassing structures.

  7. Carbon dioxide and helium dissolved gases in groundwater at central Tenerife Island, Canary Islands: chemical and isotopic characterization

    NASA Astrophysics Data System (ADS)

    Marrero-Diaz, Rayco; López, Dina; Perez, Nemesio M.; Custodio, Emilio; Sumino, Hirochika; Melián, Gladys V.; Padrón, Eleazar; Hernandez, Pedro A.; Calvo, David; Barrancos, José; Padilla, Germán; Sortino, Francesco

    2015-10-01

    Seismic-volcanic unrest was detected between 2004 and 2005 in the central and northwest zones of Tenerife Island (Canary Islands, Spain). With the aim of strengthening the program of geochemical and seismic-volcanic surveillance, a study of the origin, characteristics, and spatial distribution of dissolved carbon dioxide (CO2) and helium (He) gases in the volcanic aquifer of central Tenerife Island and around Teide volcano was carried out. This work also improves the hydrogeological and hydrogeochemical conceptual model of groundwater flow. Dissolved CO2 concentrations in sampled groundwater are several orders of magnitude higher than that of air-saturated water (ASW) suggesting a significant contribution of non-atmospheric CO2, mainly magmatic, confirmed through measurement of isotopic compositions (δ13CTDIC) and total dissolved inorganic carbon (TDIC) concentrations. A vertical stratification of dissolved CO2 and δ13CTDIC values was observed in the volcanic aquifer at the eastern region of Las Cañadas Caldera. Stratification seems to be controlled by both degree of magmatic CO2-water interaction and CO2 degassing and the original δ13Cco2(g) isotopic composition. The highest dissolved helium (4He) concentrations in groundwater seem to be related to radiogenic contributions resulting from water-rock interactions, and increase with residence time, instead of with endogenous magmatic inputs. Isotopic systematics show that the dissolved gases in groundwater of central Tenerife are variable mixtures of CO2-3He-rich fluids of volcanic-hydrothermal origin with both organic and atmospheric components. The results suggest that the eastern area of Las Cañadas Caldera, the South Volcanic Ridge, and the Teide summit cone are the areas most affected by degassing of the volcanic-hydrothermal system, and they are therefore the most suitable zones for future geochemical monitoring.

  8. Continuous in-situ monitoring of dissolved gases for the characterization of the Critical Zone with a MIMS

    NASA Astrophysics Data System (ADS)

    Chatton, Eliot; Labasque, Thierry; Aquilina, Luc; de la Bernardie, Jérôme; Guihéneuf, Nicolas

    2016-04-01

    In the perspective of a temporal and spatial exploration of the Critical Zone, we developed an in situ monitoring instrument for continuous dissolved gas analysis (N2, O2, CO2, CH4, He, Ne, Ar, Kr, Xe). With a large resolution (5 orders of magnitude) and a capability of high frequency multi-tracer analysis (1 gas every 1.5 seconds), the MIMS (Membrane Inlet Mass Spectrometer) is an innovative tool allowing the investigation of a large panel of physical and biogeochemical processes. First of all, this study presents the results of groundwater tracer tests using dissolved gases in order to evaluate transport properties of a fractured media in Brittany, France (Ploemeur, ORE H+). The tracer test experiment showed that the MIMS is perfectly suitable for field work. The instrument provides precise measurements accurate enough to produce breakthrough curves during groundwater tracer tests. The results derived from 4He data gives transport parameters in good agreement with the results obtained with a fluorescent tracer. Combined with a pump and a multi-parameter probe, the MIMS is also capable to perform accurate dissolved gases well-logs allowing a real-time estimation of recharge conditions (temperature, excess air), aquifer stratification, redox conditions and groundwater residence time by 4He dating. Therefore, the MIMS is a valuable tool for in situ characterization of biogeochemical reactivity in aquatic systems, the determination of aquifer transport properties, the monitoring of groundwater recharge conditions and the characterization of aquifer-river exchanges.

  9. Tracing a past thermal event by using atmospheric noble gases dissolved in deep Michigan Basin brines

    NASA Astrophysics Data System (ADS)

    Ma, L.; Castro, M. C.; Hall, C. M.

    2008-12-01

    Atmospheric noble gases (e.g., 22Ne, 36Ar, 84Kr, 130Xe) are introduced into the subsurface by recharge water in solubility equilibrium with the atmosphere (Air Saturated Water - ASW). Because noble gases are chemically inert and stable in nature, they are only sensitive to subsurface physical processes. More specifically, depletion of this component in sedimentary systems commonly suggests loss to an oil or natural gas phase in the subsurface, which is originally free of atmospheric noble gases. This has been traditionally used to identify and quantify subsurface oil, gas, and water phase interactions. Alternatively, depletion of atmospheric noble gases due to subsurface boiling and steam phase separation has also been previously recorded in tectonically active areas (hydrothermal systems). Such depletion is thus indicative of the occurrence of a thermal event and can be used to trace the thermal history of stable tectonic regions. Here, we present noble gas concentrations of 38 deep brines (~0.5-3.6km) from the Michigan Basin. The atmospheric noble gas component shows a strong depletion pattern with respect to air saturated water. Depletion of lighter gases (22Ne and 36Ar) is stronger compared to the heavier ones (84Kr and 130Xe). To understand the mechanisms responsible for this overall atmospheric noble gas depletion, phase interaction models were tested. We show that this atmospheric noble gas depletion pattern is best explained by a model involving subsurface boiling and steam separation, and thus, consistent with the occurrence of a past thermal event of mantle origin as previously indicated by both high 4He/heat flux ratios and the presence of primordial mantle He and Ne signatures in the basin. Such a conceptual model is also consistent with the presence of past elevated temperatures in the Michigan Basin (e.g., ~80- 260°C) at shallow depths as suggested by previous thermal studies in the basin. We suggest that recent reactivation of the ancient mid

  10. Dissolved Noble Gases in Rainwater, Southern Michigan - Evidence for Lack of Rainwater Equilibration with the Atmosphere at Surface Conditions

    NASA Astrophysics Data System (ADS)

    Warrier, R. B.; Castro, M.; Hall, C. M.

    2012-12-01

    Atmospheric noble gases dissolved in groundwater have been extensively used to reconstruct the past climate. A key assumption of the noble gas thermometer is that rainwater is in equilibrium with ground air when it reaches the water table. However, our recent study conducted in the Galapagos Islands showed that dissolved atmospheric noble gas concentrations in high-altitude spring samples display high apparent recharge altitudes, cold apparent temperatures and a unique, previously unknown noble gas pattern. In addition to atmospheric He excesses, this pattern displays Ne, Kr, and Xe depletion together with relative Ar enrichment. We hypothesized that this unexpected noble gas pattern resulted from the combined effect of a lack of rainwater equilibration at high altitudes in the atmosphere and the impact of fog droplets on noble gas concentrations in groundwater. To understand the origin of this previously unknown noble gas pattern, we analyzed He, Ne, Ar, Kr and Xe dissolved in 12 rainwater samples resulting from the passage of both warm and cold fronts in southern Michigan. Preliminary results show that all samples present atmospheric He excesses, ranging between 1% and 29% with respect to air saturated water (ASW) for corresponding measured temperature and altitude values at the time and location of sampling. In addition, these samples can be subdivided into two groups with distinct patterns. The first group displays a pattern remarkably similar to the unique anomalous pattern observed in high-altitude spring samples in the Galapagos Islands with relative Ar enrichment and Ne, Kr, and Xe depletion. The second group displays a mass-dependent pattern with greater depletion of the heavier noble gases Kr and Xe as compared to the lighter noble gases Ne and Ar. The first group of rainwater samples was mostly collected during the passage of warm fronts, which are typically associated with light, steady precipitation and gradual adiabatic uplift of air masses as

  11. A Portable Membrane-based Gas Sampler for Gases Dissolved in Groundwater

    NASA Astrophysics Data System (ADS)

    Alexander, P.; Loose, B.; Stute, M.

    2007-12-01

    The complications that arise while collecting, transporting and storing groundwater for trace gas analysis have prompted a new approach, which uses membrane technology to obtain a gas sample from the water stream, in the field. This portable groundwater sampler uses a microporous hydrophobic membrane to collect a finite volume of gas, which is in solubility equilibrium with a time-invariant stream of water. Samples of the gas volume can be analyzed to determine original water concentrations for virtually any dissolved gas. The sampler does not require the use of compressed inert gas and its power consumption is minimal. During the development stages, N2, Ar, O2, CO2 and SF6 were sampled and measured using gas chromatography to evaluate the equilibrium condition and confirm the equilibration time, which was initially gauged using a pressure transducer. Equilibration studies were conducted in the laboratory and at Black Rock Forest, a field site near the Lamont Campus of Columbia University. The time required to achieve solubility equilibrium depends on the dissolved gas content and the water flow rate; 100 cc of gas can be collected, from water in equilibrium with the atmosphere, at low flow (ca. 2 L min-1) in less than 1 hour. The initial results demonstrate that gauge pressure is a good proxy for solubility equilibrium, and that diffusion can fractionate the gas ratios during rapid mass transfer as indicated by rapid pressure changes.

  12. Dating base flow in streams using dissolved gases and diurnal temperature changes

    NASA Astrophysics Data System (ADS)

    Sanford, Ward E.; Casile, Gerolamo; Haase, Karl B.

    2015-12-01

    A method is presented for using dissolved CFCs or SF6 to estimate the apparent age of stream base flow by indirectly estimating the mean concentration of the tracer in the inflowing groundwater. The mean value is estimated simultaneously with the mean residence times of the gas and water in the stream by sampling the stream for one or both age tracers, along with dissolved nitrogen and argon at a single location over a period of approximately 12-14 h. The data are fitted to an equation representing the temporal in-stream gas exchange as it responds to the diurnal temperature fluctuation. The efficacy of the method is demonstrated by collecting and analyzing samples at six different stream locations across parts of northern Virginia, USA. The studied streams drain watersheds with areas of between 2 and 122 km2 during periods when the diurnal stream temperature ranged between 2 and 5°C. The method has the advantage of estimating the mean groundwater residence time of discharge from the watershed to the stream without the need for the collection of groundwater infiltrating to streambeds or local groundwater sampled from shallow observation wells near the stream.

  13. Use of dissolved and vapor-phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface

    USGS Publications Warehouse

    Amos, R.T.; Mayer, K.U.; Bekins, B.A.; Delin, G.N.; Williams, R.L.

    2005-01-01

    [1] At many sites contaminated with petroleum hydrocarbons, methanogenesis is a significant degradation pathway. Techniques to estimate CH4 production, consumption, and transport processes are needed to understand the geochemical system, provide a complete carbon mass balance, and quantify the hydrocarbon degradation rate. Dissolved and vapor-phase gas data collected at a petroleum hydrocarbon contaminated site near Bemidji, Minnesota, demonstrate that naturally occurring nonreactive or relatively inert gases such as Ar and N2 can be effectively used to better understand and quantify physical and chemical processes related to methanogenic activity in the subsurface. In the vadose zone, regions of Ar and N2 depletion and enrichment are indicative of methanogenic and methanotrophic zones, and concentration gradients between the regions suggest that reaction-induced advection can be an important gas transport process. In the saturated zone, dissolved Ar and N2 concentrations are used to quantify degassing driven by methanogenesis and also suggest that attenuation of methane along the flow path, into the downgradient aquifer, is largely controlled by physical processes. Slight but discernable preferential depletion of N2 over Ar, in both the saturated and unsaturated zones near the free-phase oil, suggests reactivity of N2 and is consistent with other evidence indicating that nitrogen fixation by microbial activity is taking place at this site. Copyright 2005 by the American Geophysical Union.

  14. Influence of dissolved gases on sonochemistry and sonoluminescence in a flow reactor.

    PubMed

    Gielen, B; Marchal, S; Jordens, J; Thomassen, L C J; Braeken, L; Van Gerven, T

    2016-07-01

    In the present work, the influence of gas addition is investigated on both sonoluminescence (SL) and radical formation at 47 and 248 kHz. The frequencies chosen in this study generate two distinct bubble types, allowing to generalize the conclusions for other ultrasonic reactors. In this case, 47 kHz provides transient bubbles, while stable ones dominate at 248 kHz. For both bubble types, the hydroxyl radical and SL yield under gas addition followed the sequence: Ar>Air>N2>CO2. A comprehensive interpretation is given for these results, based on a combination of thermal gas properties, chemical reactions occurring within the cavitation bubble, and the amount of bubbles. Furthermore, in the cases where argon, air and nitrogen were bubbled, a reasonable correlation existed between the OH-radical yield and the SL signal, being most pronounced under stable cavitation at 248 kHz. Presuming that SL and OH originate from different bubble populations, the results indicate that both populations respond similarly to a change in acoustic power and dissolved gas. Consequently, in the presence of non-volatile pollutants that do not quench SL, sonoluminescence can be used as an online tool to qualitatively monitor radical formation. PMID:26964973

  15. Upper ocean model of dissolved atmospheric gases. Final report for the period 1 August 1991--31 May 1995

    SciTech Connect

    Schudlich, R.; Emerson, S.

    1996-05-01

    This report summarizes results from three years of funding for a modelling study of processes controlling the distribution of metabolic chemical tracers in surface waters. We determined concentrations of the gases O{sub 2}, Ar, N{sub 2}, and the stable isotope ratio ({sup 18}O/{sup 16}O) of molecular oxygen in surface waters at Station ALOHA in conjunction with the Global Ocean Flux Study (GOFS) Hawaiian Ocean Time-series project during the years 1989- 90 and 1992-93. Under this contract we have incorporated chemical tracers into an existing ocean mixed-layer model to simulate the physical processes controlling the distribution and seasonal cycle of dissolved gases in the upper ocean. The broad background of concurrent chemical, physical, and biological measurements at Station ALOHA provides enough redundancy of ``ground truth`` to assess the model`s accuracy. Biological oxygen production estimated from modelled chemical tracers agrees with estimates based on measurement of carbon fluxes into the deep ocean and nitrate fluxes into the upper ocean during 1989-90 and 1992-93, verifying for the first time the utility of chemical tracers for determining biological fluxes in the ocean. Our results suggest that in the euphotic zone (the upper 100 m of the ocean), the net biological O{sub 2} production is 1.0-2. 0 moles m{sup -2}yr{sup - 1}. Inert gas (Ar, N{sub 2}) supersaturation levels show that air and bubble injection are important modes of air-sea gas transfer in the Station ALOHA region.

  16. AIRS: Improving Weather Forecasting and Providing New Data on Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Chahine, Moustafa T.; Pagano, Thomas S.; Aumann, Hartmut H.; Atlas, Robert; Barnet, Christopher; Blaisdell, John; Chen, Luke; Divakarla, Murty; Fetzer, Eric J.; Goldberg, Mitch; Gautier, Catherine; Granger, Stephanie; Hannon, Scott; Irion, Fredrick W; Kakar, Ramesh; Kalnay, Eugenia; Lambrigtsen, Bjorn H.; Lee, Sung-Yung; Marshall, John Le; McMillan, W. Wallace; McMillin, Larry; Olsen, Edward T.; Revercomb, Henry; Rosenkranz, Philip; Smith, William L.

    2006-01-01

    This paper discusses the performance of AIRS and examines how it is meeting its operational and research objectives based on the experience of more than 2 yr with AIRS data. We describe the science background and the performance of AIRS in terms of the accuracy and stability of its observed spectral radiances. We examine the validation of the retrieved temperature and water vapor profiles against collocated operational radiosondes, and then we assess the impact thereof on numerical weather forecasting of the assimilation of the AIRS spectra and the retrieved temperature. We close the paper with a discussion on the retrieval of several minor tropospheric constituents from AIRS spectra.

  17. Mutual and Self-Diffusivities in Binary Mixtures of [EMIM][B(CN)4] with Dissolved Gases by Using Dynamic Light Scattering and Molecular Dynamics Simulations.

    PubMed

    Koller, Thomas M; Heller, Andreas; Rausch, Michael H; Wasserscheid, Peter; Economou, Ioannis G; Fröba, Andreas P

    2015-07-01

    Ionic liquids (ILs) are possible working fluids for the separation of carbon dioxide (CO2) from flue gases. For evaluating their performance in such processes, reliable mutual-diffusivity data are required for mixtures of ILs with relevant flue gas components. In the present study, dynamic light scattering (DLS) and molecular dynamics (MD) simulations were used for the investigation of the molecular diffusion in binary mixtures of the IL 1-ethyl-3-methylimidazolium tetracyanoborate ([EMIM][B(CN)4]) with the dissolved gases carbon dioxide, nitrogen, carbon monoxide, hydrogen, methane, oxygen, and hydrogen sulfide at temperatures from 298.15 to 363.15 K and pressures up to 63 bar. At conditions approaching infinite dilution of a gas, the Fick mutual diffusivity of the mixture measured by DLS and the self-diffusivity of the corresponding gas calculated by MD simulations match, which could be generally found within combined uncertainties. The obtained diffusivities are in agreement with literature data for the same or comparable systems as well as with the general trend of increasing diffusivities for decreasing IL viscosities. The DLS and MD results reveal distinctly larger molecular diffusivities for [EMIM][B(CN)4]-hydrogen mixtures compared to mixtures with all other gases. This behavior results in the failure of an empirical correlation with the molar volumes of the gases at their normal boiling points. The DLS experiments also showed that there is no noticeable influence of the dissolved gas and temperature on the thermal diffusivity of the studied systems. PMID:26075680

  18. Molecular and isotopic composition of hydrate-bound and dissolved gases in the southern basin of Lake Baikal, based on an improved headspace gas method

    NASA Astrophysics Data System (ADS)

    Sakagami, Hirotoshi; Takahashi, Nobuo; Hachikubo, Akihiro; Minami, Hirotsugu; Yamashita, Satoshi; Shoji, Hitoshi; Khlystov, Oleg; Kalmychkov, Gennadiy; Grachev, Mikhail; De Batist, Marc

    2012-12-01

    Assessments of the molecular and isotopic composition of hydrate-bound and dissolved gases in pore water were conducted during the multi-phase gas hydrate project (MHP-09) cruise VER09-03 to the southern basin of Lake Baikal in September 2009. To avoid changes in gas composition during core sampling and transport, various headspace methods were investigated aimed at preserving the dissolved gases in pore water. When distilled water was added to the sediment samples, the concentrations of carbon dioxide and oxygen decreased because of dissolution into the water and/or microbial consumption. When the headspace was not flushed with inert gases, trace levels of hydrogen and ethylene were detected. The findings suggest that best preparation is achieved by flushing the headspace with helium, and adding a saturated aqueous solution of sodium chloride. This improved headspace method served to examine the molecular and isotopic compositions of gas samples retrieved at several new sites in the southern basin. Methane was the major component, and the proportion of ethane ranged widely from 0.0009 to 1.67 mol% of the total hydrocarbon gases. The proportions of propane and higher hydrocarbons were small or less than their detection limits. The carbon isotope signatures suggest that microbial-sourced methane and ethane were dominant in the Peschanka study area, whereas ethane was of thermogenic origin at all other study sites in the southern basin of Lake Baikal.

  19. Modeling and forecasting riverine dissolved inorganic nitrogen export using anthropogenic nitrogen inputs, hydroclimate, and land-use change

    NASA Astrophysics Data System (ADS)

    Huang, Hong; Chen, Dingjiang; Zhang, Baifa; Zeng, Lingzao; Dahlgren, Randy A.

    2014-09-01

    A quantitative understanding of riverine nitrogen (N) export in response to human activities and climate change is critical for developing effective watershed N pollution control measures. This study quantified net anthropogenic N inputs (NANI) and riverine dissolved inorganic N (DIN = NO3-N + NH4-N + NO2-N) export for the upper Jiaojiang River catchment in eastern China over the 1980-2010 time period and examined how NANI, hydroclimate, and land-use practices influenced riverine DIN export. Over the 31-yr study period, riverine DIN yield increased by 1.6-fold, which mainly results from a ∼77% increase in NANI and increasing fractional delivery of NANI due to a ∼55% increase in developed land area. An empirical model that utilizes an exponential function of NANI and a power function of combining annual water discharge and developed land area percentage could account for 89% of the variation in annual riverine DIN yields in 1980-2010. Applying this model, annual NANI, catchment storage, and natural background sources were estimated to contribute 57%, 22%, and 21%, respectively, of annual riverine DIN exports on average. Forecasting based on a likely future climate change scenario predicted a 19.6% increase in riverine DIN yield by 2030 due to a 4% increase in annual discharge with no changes in NANI and land-use compared to the 2000-2010 baseline condition. Anthropogenic activities have increased both the N inputs available for export and the fractional export of N inputs, while climate change can further enhance riverine N export. An integrated N management strategy that considers the influence of anthropogenic N inputs, land-use and climate change is required to effectively control N inputs to coastal areas.

  20. Sensitivity of free radicals production in acoustically driven bubble to the ultrasonic frequency and nature of dissolved gases.

    PubMed

    Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud

    2015-01-01

    Central events of ultrasonic action are the bubbles of cavitation that can be considered as powered microreactors within which high-energy chemistry occurs. This work presents the results of a comprehensive numerical assessment of frequency and saturating gases effects on single bubble sonochemistry. Computer simulations of chemical reactions occurring inside a bubble oscillating in liquid water irradiated by an ultrasonic wave have been performed for a wide range of ultrasonic frequencies (213-1100kHz) under different saturating gases (O2, air, N2 and H2). For O2 and H2 bubbles, reactions mechanism consisting in 25 reversible chemical reactions were proposed for studying the internal bubble-chemistry whereas 73 reversible reactions were taken into account for air and N2 bubbles. The numerical simulations have indicated that radicals such as OH, H, HO2 and O are created in the bubble during the strong collapse. In all cases, hydroxyl radical (OH) is the main oxidant created in the bubble. The production rate of the oxidants decreases as the driving ultrasonic frequency increases. The production rate of OH radical followed the order O2>air>N2>H2 and the order becomes more remarkable at higher ultrasonic frequencies. The effect of ultrasonic frequency on single bubble sonochemistry was attributed to its significant impact on the cavitation process whereas the effects of gases were attributed to the nature of the chemistry produced in the bubble at the strong collapse. It was concluded that, in addition to the gas solubility, the nature of the internal bubble chemistry is another parameter of a paramount importance that controls the overall sonochemical activity in aqueous solutions. PMID:25112684

  1. Attractive forces between hydrophobic solid surfaces measured by AFM on the first approach in salt solutions and in the presence of dissolved gases.

    PubMed

    Azadi, Mehdi; Nguyen, Anh V; Yakubov, Gleb E

    2015-02-17

    Interfacial gas enrichment of dissolved gases (IGE) has been shown to cover hydrophobic solid surfaces in water. The atomic force microscopy (AFM) data has recently been supported by molecular dynamics simulation. It was demonstrated that IGE is responsible for the unexpected stability and large contact angle of gaseous nanobubbles at the hydrophobic solid-water interface. Here we provide further evidence of the significant effect of IGE on an attractive force between hydrophobic solid surfaces in water. The force in the presence of dissolved gas, i.e., in aerated and nonaerated NaCl solutions (up to 4 M), was measured by the AFM colloidal probe technique. The effect of nanobubble bridging on the attractive force was minimized or eliminated by measuring forces on the first approach of the AFM probe toward the flat hydrophobic surface and by using high salt concentrations to reduce gas solubility. Our results confirm the presence of three types of forces, two of which are long-range attractive forces of capillary bridging origin as caused by either surface nanobubbles or gap-induced cavitation. The third type is a short-range attractive force observed in the absence of interfacial nanobubbles that is attributed to the IGE in the form of a dense gas layer (DGL) at hydrophobic surfaces. Such a force was found to increase with increasing gas saturation and to decrease with decreasing gas solubility. PMID:25627159

  2. The hyporheic zone as a source of dissolved organic carbon and carbon gases to a temperate forested stream

    USGS Publications Warehouse

    Schindler, J.E.; Krabbenhoft, D.P.

    1998-01-01

    The objective of this study was to examine chemical changes in porewaters that occur over small scales (cm) as groundwater flows through the hyporheic zone and discharges to a stream in a temperate forest of northern Wisconsin. Hyporheic-zone porewaters were sampled at discrete depths of 2, 10, 15, 61, and 183 cm at three study sites in the study basin. Chemical profiles of dissolved organic carbon (DOC), CO2, CH4, and pH show dramatic changes between 61 cm sediment depth and the water-sediment interface. Unless discrete samples at small depth intervals are taken, these chemical profiles are not accounted for. Similar trends were observed at the three study locations, despite each site having very different hydraulic-flow regimes. Increases in DOC concentration by an order of magnitude from 61 to 15 cm depth with a corresponding decrease in pH and rapid decreases in the molecular weight of the DOC suggest that aliphatic compounds (likely organic acids) are being generated in the hyporheic zone. Estimated efflux rates of DOC, CO2, and CH4 to the stream are 6.2, 0.79, 0.13 moles m2 d-1, respectively, with the vast majority of these materials produced in the hyporheic zone. Very little of these materials are accounted for by sampling stream water, suggesting rapid uptake and/or volatilization.

  3. Chlorofluorocarbons, sulfur hexafluoride, and dissolved permanent gases in ground water from selected sites in and near the Idaho National Engineering and Environmental Laboratory, Idaho, 1994-97

    USGS Publications Warehouse

    Busenberg, Eurybiades; Plummer, L. Niel; Bartholomay, Roy C.; Wayland, Julian E.

    1998-01-01

    From July 1994 through May 1997, the U.S. Geological Survey in cooperation with the Department of Energy, sampled 86 wells completed in the Snake River Plain aquifer at and near the Idaho N ationa1 Engineering and Environmental Laboratory (INEEL). The wells were sampled for a variety of constituents including one- and two-carbon halocarbons. Concentrations of dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11) and trichlorotrifluororoethane (CFC-113) were determined. The samples for halocarbon analysis were collected in 62-milliliter flame sealed borosilicate glass ampoules in the field. The data will be used to evaluate the ages of ground waters at INEEL. The ages of the ground water will be used to determine recharge rates, residence time, and travel time of water in the Snake River Plain aquifer in and near INEEL. The chromatograms of 139 ground waters are presented showing a large number of halomethanes, haloethanes, and haloethenes present in the ground waters underlying the INEEL. The chromatograms can be used to qualitatively evaluate a large number of contaminants at parts per trillion to parts per billion concentrations. The data can be used to study temporal and spatial distribution of contaminants in the Snake River Plain aquifer. Representative compressed chromatograms for all ground waters sampled in this study are available on two 3.5-inch high density computer disks. The data and the program required to decompress the data can be obtained from the U.S. Geological Survey office at Idaho Falls, Idaho. Sulfur hexafluoride (SF6) concentrations were measured in selected wells to determine the feasibility of using this environmental tracer as an age dating tool of ground water. Concentrations of dissolved nitrogen, argon, carbon dioxide, oxygen, and methane were measured in 79 ground waters. Concentrations of dissolved permanent gases are tabulated and will be used to evaluate the temperature of recharge of ground water in and near the INEEL.

  4. Chlorofluorocarbons, Sulfur Hexafluoride, and Dissolved Permanent Gases in Ground Water from Selected Sites In and Near the Idaho National Engineering and Environmental Laboratory, Idaho, 1994 - 1997

    SciTech Connect

    Busenberg, E.; Plummer, L.N.; Bartholomay, R.C.; Wayland, J.E.

    1998-08-01

    From July 1994 through May 1997, the U.S. Geological Survey, in cooperations with the Department of Energy, sampled 86 wells completed in the Snake River Plain aquifer at and near the Idaho National Engineering and Environmental Laboratory (INEEL). The wells were sampled for a variety of constituents including one- and two-carbon halocarbons. Concentrations of dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and trichlorotrifluororoethane (CFC-113) were determined. The data will be used to evaluate the ages of ground waters at INEEL. The ages of the ground water will be used to determine recharge rates, residence time, and travel time of water in the Snake River Plain aquifer in and near INEEL. The chromatograms of 139 ground waters are presented showing a large number of halomethanes, haloethanes, and haloethenes present in the ground waters underlying the INEEL. The chromatograms can be used to qualitatively evaluate a large number of contaminants at parts per trillion to parts per billion concentrations. The data can be used to study temporal and spatial distribution of contaminants in the Snake River Plain aquifer. Representative compressed chromatograms for all ground waters sampled in this study are available on two 3.5-inch high density computer disks. The data and the program required to decompress the data can be obtained from the U.S. Geological Survey office at Idaho Falls, Idaho. Sulfur hexafluoride (SF6) concentrations were measured in selected wells to determine the feasibility of using this environmental tracer as an age dating tool of ground water. Concentrations of dissolved nitrogen, argon, carbon dioxide, oxygen, and methane were measured in 79 ground waters. Concentrations of dissolved permanent gases are tabulated and will be used to evaluate the temperature of recharge of ground water in and near the INEEL.

  5. Gas transport below artificial recharge ponds: insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment.

    PubMed

    Clark, Jordan F; Hudson, G Bryant; Avisar, Dror

    2005-06-01

    A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable. PMID:15984768

  6. Evaluation of the MACC operational forecast system - potential and challenges of global near-real-time modelling with respect to reactive gases in the troposphere

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Blechschmidt, A.-M.; Bouarar, I.; Brunke, E.-G.; Clerbaux, C.; Cupeiro, M.; Cristofanelli, P.; Eskes, H.; Flemming, J.; Flentje, H.; George, M.; Gilge, S.; Hilboll, A.; Inness, A.; Kapsomenakis, J.; Richter, A.; Ries, L.; Spangl, W.; Stein, O.; Weller, R.; Zerefos, C.

    2015-03-01

    Monitoring Atmospheric Composition and Climate (MACC/MACCII) currently represents the European Union's Copernicus Atmosphere Monitoring Service (CAMS) (http://www.copernicus.eu), which will become fully operational in the course of 2015. The global near-real-time MACC model production run for aerosol and reactive gases provides daily analyses and 5 day forecasts of atmospheric composition fields. It is the only assimilation system world-wide that is operational to produce global analyses and forecasts of reactive gases and aerosol fields. We have investigated the ability of the MACC analysis system to simulate tropospheric concentrations of reactive gases (CO, O3, and NO2) covering the period between 2009 and 2012. A validation was performed based on CO and O3 surface observations from the Global Atmosphere Watch (GAW) network, O3 surface observations from the European Monitoring and Evaluation Programme (EMEP) and furthermore, NO2 tropospheric columns derived from the satellite sensors SCIAMACHY and GOME-2, and CO total columns derived from the satellite sensor MOPITT. The MACC system proved capable of reproducing reactive gas concentrations in consistent quality, however, with a seasonally dependent bias compared to surface and satellite observations: for northern hemispheric surface O3 mixing ratios, positive biases appear during the warm seasons and negative biases during the cold parts of the years, with monthly Modified Normalised Mean Biases (MNMBs) ranging between -30 and 30% at the surface. Model biases are likely to result from difficulties in the simulation of vertical mixing at night and deficiencies in the model's dry deposition parameterization. Observed tropospheric columns of NO2 and CO could be reproduced correctly during the warm seasons, but are mostly underestimated by the model during the cold seasons, when anthropogenic emissions are at a highest, especially over the US, Europe and Asia

  7. Evaluation of the MACC operational forecast system - potential and challenges of global near-real-time modelling with respect to reactive gases in the troposphere

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Blechschmidt, A.-M.; Bouarar, I.; Brunke, E.-G.; Clerbaux, C.; Cupeiro, M.; Cristofanelli, P.; Eskes, H.; Flemming, J.; Flentje, H.; George, M.; Gilge, S.; Hilboll, A.; Inness, A.; Kapsomenakis, J.; Richter, A.; Ries, L.; Spangl, W.; Stein, O.; Weller, R.; Zerefos, C.

    2015-12-01

    The Monitoring Atmospheric Composition and Climate (MACC) project represents the European Union's Copernicus Atmosphere Monitoring Service (CAMS) (http://www.copernicus.eu/), which became fully operational during 2015. The global near-real-time MACC model production run for aerosol and reactive gases provides daily analyses and 5-day forecasts of atmospheric composition fields. It is the only assimilation system worldwide that is operational to produce global analyses and forecasts of reactive gases and aerosol fields. We have investigated the ability of the MACC analysis system to simulate tropospheric concentrations of reactive gases covering the period between 2009 and 2012. A validation was performed based on carbon monoxide (CO), nitrogen dioxide (NO2) and ozone (O3) surface observations from the Global Atmosphere Watch (GAW) network, the O3 surface observations from the European Monitoring and Evaluation Programme (EMEP) and, furthermore, NO2 tropospheric columns, as well as CO total columns, derived from satellite sensors. The MACC system proved capable of reproducing reactive gas concentrations with consistent quality; however, with a seasonally dependent bias compared to surface and satellite observations - for northern hemispheric surface O3 mixing ratios, positive biases appear during the warm seasons and negative biases during the cold parts of the year, with monthly modified normalised mean biases (MNMBs) ranging between -30 and 30 % at the surface. Model biases are likely to result from difficulties in the simulation of vertical mixing at night and deficiencies in the model's dry deposition parameterisation. Observed tropospheric columns of NO2 and CO could be reproduced correctly during the warm seasons, but are mostly underestimated by the model during the cold seasons, when anthropogenic emissions are at their highest level, especially over the US, Europe and Asia. Monthly MNMBs of the satellite data

  8. Responses of dissolved trace gases (CH4, N2O, CO, NMHCs, CH3Cl) to phytoplankton bloom during in situ iron enrichment (SEEDII) in the western subarctic Pacific

    NASA Astrophysics Data System (ADS)

    Kameyama, S.; Nakagawa, F.; Sasakawa, M.; Yamaguchi, J.; Komatsu, D. D.; Ijiri, A.; Tsunogai, U.; Horiguchi, T.; Kawamura, H.; Tsuda, A.

    2006-12-01

    Biogeochemical processes in ocean surface are known to play important roles in the global circulation of many trace gases: not only CO2 but also non-CO2 gases, such as CH4, N2O, CO, NMHCs and CH3Cl. The mixing ratios of these components in air are highly responsible for controlling global warming, stratospheric and tropospheric O3, tropospheric OH, organic aerosols, and peroxides. While future global changes could alter air-sea fluxes of these components in ocean surface, the detailed processes to produce/consume these components, as well as the range of the variations, are not clarified as yet. The iron fertilization experiment offers us a wonderful chance to quantify the effect of phytoplankton bloom to the production of the trace gases. During 2004 iron-enrichment experiment in the northwest subarctic Pacific (SEEDSII), we monitored mixing ratios of the trace gases (CH4, N2O, CO, NMHCs and CH3Cl) within the phytoplankton bloom. Besides, the stable isotopic ratios were also monitored to clarify the processes that are responsible for the variations. Both the mixing ratios and the stable isotopic ratios of dissolved CH4, N2O and CH3Cl exhibit little changes during the 23 days observation. On the other hand, dissolved CO exhibit remarkable change in the carbon isotopic composition as phytoplankton bloomed. The maximum variation reached to about 25‰ depletion in δ13C. We conclude that the enrichment of the CO precursor must be responsible for the variation. Furthermore, in accordance with the phytoplankton bloomed, the concentration of NMHCs, especially alkane, exhibit remarkable enrichment in the mixing rations: 3 times for ethane, 4 times for propane, 13 times for butane compared with those prior to the bloom. In accordance with the enrichment, the stable carbon isotopic composition of ethane and propane increased, while that of butane decreased. To clarify the source of alkane during the bloom, we determined both concentration and δ13C of alkane emitted from

  9. Dissolved greenhouse gases (nitrous oxide and methane) associated with the natural iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Farías, L.; Florez-Leiva, L.; Besoain, V.; Fernández, C.

    2014-08-01

    The concentrations of greenhouse gases (GHGs) like nitrous oxide (N2O) and methane (CH4) were measured in the Kerguelen Plateau Region (KPR), an area with annual microalgal bloom caused by natural Fe fertilization, which may stimulate microbes involved in GHG cycling. This study was carried out during the KEOPS 2 cruise during the austral spring of 2011. Two transects were sampled along and across the KRP, the north-south (N-S) transect (46-51° S, 72° E meridian) and the west-east (W-E) transect (66-75° E, 48.3° S latitude), both associated with the presence of a plateau, polar fronts and other mesoscale features. The W-E transect had N2O levels ranging from equilibrium (105%) to light supersaturation (120%) with respect to the atmosphere. CH4 levels fluctuated dramatically, with intense supersaturations (120-970%) in areas close to the coastal waters of Kerguelen Island and in the polar front (PF). There, Fe and nutrient fertilization seem to promote high total chlorophyll a (TChl a) levels. The distribution of both gases was more homogenous in the N-S transect, but CH4 peaked at southeastern stations of the KPR (A3 stations), where phytoplankton bloom was observed. Both gases responded significantly to the patchy distribution of particulate matter as Chl a, stimulated by Fe supply by complex mesoscale circulation. While CH4 appears to be produced mainly at the pycnoclines, N2O seems to be consumed superficially. Air-sea fluxes for N2O (from -10.5 to 8.65, mean 1.71 μmol m-2d-1), and for CH4 (from 0.32 to 38.1, mean 10.07 μmol m-2d-1) reflected sink and source behavior for N2O and source behavior for CH4, with considerable variability associated with a highly fluctuating wind regime and, in the case of CH4, due to its high superficial levels that had not been reported before in the Southern Ocean and may be caused by an intense microbial CH4 cycling.

  10. Dissolved greenhouse gases (nitrous oxide and methane) associated with the naturally iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Farías, L.; Florez-Leiva, L.; Besoain, V.; Sarthou, G.; Fernández, C.

    2015-03-01

    The concentrations of greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), were measured in the Kerguelen Plateau region (KPR). The KPR is affected by an annual microalgal bloom caused by natural iron fertilization, and this may stimulate the microbes involved in GHG cycling. This study was carried out during the KEOPS 2 cruise during the austral spring of 2011. Oceanographic variables, including N2O and CH4, were sampled (from the surface to 500 m depth) in two transects along and across the KRP, the north-south (TNS) transect (46°-51° S, ~ 72° E) and the east-west (TEW) transect (66°-75° E, ~ 48.3° S), both associated with the presence of a plateau, polar front (PF) and other mesoscale features. The TEW presented N2O levels ranging from equilibrium (105%) to slightly supersaturated (120%) with respect to the atmosphere, whereas CH4 levels fluctuated dramatically, being highly supersaturated (120-970%) in areas close to the coastal waters of the Kerguelen Islands and in the PF. The TNS showed a more homogenous distribution for both gases, with N2O and CH4 levels ranging from 88 to 171% and 45 to 666% saturation, respectively. Surface CH4 peaked at southeastern stations of the KPR (A3 stations), where a phytoplankton bloom was observed. Both gases responded significantly, but in contrasting ways (CH4 accumulation and N2O depletion), to the patchy distribution of chlorophyll a. This seems to be associated to the supply of iron from various sources. Air-sea fluxes for N2O (from -10.5 to 8.65, mean 1.25 ± 4.04 μmol m-2 d-1) and for CH4 (from 0.32 to 38.1, mean 10.01 ± 9.97 μmol-2 d-1) indicated that the KPR is both a sink and a source for N2O, as well as a considerable and variable source of CH4. This appears to be associated with biological factors, as well as the transport of water masses enriched with Fe and CH4 from the coastal area of the Kerguelen Islands. These previously unreported results for the Southern Ocean suggest an intense

  11. In situ measurements of dissolved gases (CO2 and CH4) in a wide range of concentrations in a tropical reservoir using an equilibrator.

    PubMed

    Abril, Gwenaël; Richard, Sandrine; Guérin, Frédéric

    2006-02-01

    An equilibrator system connected to an infrared photo acoustic gas analyzer was used in order to measure directly in situ the concentrations of dissolved CO2 and CH4 in waters of a tropical reservoir (Petit Saut, French Guiana). The performance of the system was tested both on a vertical profile in the stratified water body of the reservoir and in the surface waters of the river downstream the dam. Results agreed with conventional GC analysis at +/-15% in a wide range of concentrations (CO2:50-400 micromol l-1 and CH4:0.5-350 micromol l-1 corresponding to gas partial pressures of respectively 1700-13,000 and 12-8800 microatm). The time needed for in situ measurements was equivalent to water sampling, time for GC analysis in the laboratory being suppressed. The continuous monitoring of gas concentrations for 24 h in the reservoir surface waters revealed rapid changes in concentrations highly significant in the daily emission budget. The system opens new perspectives for the monitoring of gas concentrations in highly dynamic systems like tropical reservoirs. PMID:16398998

  12. Forecasting forecast skill

    NASA Technical Reports Server (NTRS)

    Kalnay, Eugenia; Dalcher, Amnon

    1987-01-01

    It is shown that it is possible to predict the skill of numerical weather forecasts - a quantity which is variable from day to day and region to region. This has been accomplished using as predictor the dispersion (measured by the average correlation) between members of an ensemble of forecasts started from five different analyses. The analyses had been previously derived for satellite-data-impact studies and included, in the Northern Hemisphere, moderate perturbations associated with the use of different observing systems. When the Northern Hemisphere was used as a verification region, the prediction of skill was rather poor. This is due to the fact that such a large area usually contains regions with excellent forecasts as well as regions with poor forecasts, and does not allow for discrimination between them. However, when regional verifications were used, the ensemble forecast dispersion provided a very good prediction of the quality of the individual forecasts.

  13. Electrolytic dissolver

    DOEpatents

    Wheelwright, E.J.; Fox, R.D.

    1975-08-26

    This patent related to an electrolytic dissolver wherein dissolution occurs by solution contact including a vessel of electrically insulative material, a fixed first electrode, a movable second electrode, means for insulating the electrodes from the material to be dissolved while permitting a free flow of electrolyte therebetween, means for passing a direct current between the electrodes and means for circulating electrolyte through the dissolver. (auth)

  14. NOBLE GASES

    EPA Science Inventory

    The Noble Gases symposium, on which this report is based, provided comprehensive coverage of the noble gases. The coverage included, but was not limited to, the properties, biokinetics, bioeffects, production and release to the environment, detection techniques, standards, and ap...

  15. Greenhouse Gases

    MedlinePlus

    ... Greenhouse Gases Come From Outlook for Future Emissions Recycling and Energy Nonrenewable Sources Oil and Petroleum Products ... Power Wave Power Ocean Thermal Energy Conversion Biomass Wood and Wood Waste Waste-to-Energy (MSW) Landfill ...

  16. Thermodynamics of Trapping Gases for Underwater Superhydrophobicity.

    PubMed

    Patankar, Neelesh A

    2016-07-12

    Rough surfaces submerged in a liquid can remain almost dry if the liquid does not fully wet the roughness, and gases are sustained in roughness grooves. Such partially dry surfaces can help reduce drag, enhance boiling, and reduce biofouling. Gases sustained in roughness grooves would be composed of air and the vapor phase of the liquid itself. In this work, the thermodynamics of sustaining gases (e.g., air) is considered. Governing equations are presented along with a solution methodology to determine a critical condition to sustain gases. The critical roughness scale to sustain gases is estimated for different degrees of saturation of gases dissolved in the liquid. It is shown that roughness spacings of less than a micron are essential to sustain gases on surfaces submerged in water at atmospheric pressure. This is consistent with prior empirical data. PMID:27276525

  17. Toxic gases.

    PubMed Central

    Matthews, G.

    1989-01-01

    An overview of the widespread use of gases and some volatile solvents in modern society is given. The usual circumstances in which undue exposure may occur are described. The most prominent symptoms and general principles of diagnosis and treatment are given and are followed by more specific information on the commoner, more toxic materials. While acute poisonings constitute the greater part of the paper, some indication of chronic disorders arising from repeated or prolonged exposure is also given. PMID:2687827

  18. Noble Gases

    NASA Astrophysics Data System (ADS)

    Podosek, F. A.

    2003-12-01

    The noble gases are the group of elements - helium, neon, argon, krypton, xenon - in the rightmost column of the periodic table of the elements, those which have "filled" outermost shells of electrons (two for helium, eight for the others). This configuration of electrons results in a neutral atom that has relatively low electron affinity and relatively high ionization energy. In consequence, in most natural circumstances these elements do not form chemical compounds, whence they are called "noble." Similarly, much more so than other elements in most circumstances, they partition strongly into a gas phase (as monatomic gas), so that they are called the "noble gases" (also, "inert gases"). (It should be noted, of course, that there is a sixth noble gas, radon, but all isotopes of radon are radioactive, with maximum half-life a few days, so that radon occurs in nature only because of recent production in the U-Th decay chains. The factors that govern the distribution of radon isotopes are thus quite different from those for the five gases cited. There are interesting stories about radon, but they are very different from those about the first five noble gases, and are thus outside the scope of this chapter.)In the nuclear fires in which the elements are forged, the creation and destruction of a given nuclear species depends on its nuclear properties, not on whether it will have a filled outermost shell when things cool off and nuclei begin to gather electrons. The numerology of nuclear physics is different from that of chemistry, so that in the cosmos at large there is nothing systematically special about the abundances of the noble gases as compared to other elements. We live in a very nonrepresentative part of the cosmos, however. As is discussed elsewhere in this volume, the outstanding generalization about the geo-/cosmochemistry of the terrestrial planets is that at some point thermodynamic conditions dictated phase separation of solids from gases, and that the

  19. Managing biogeochemical cycles to reduce greenhouse gases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This special issue focuses on terrestrial biogeochemical cycles and their roles in determining current continental-scale budgets and future trends in biogenic greenhouse gases (GHGs) for North America. Understanding the current magnitude and forecasting future trajectories of atmospheric GHG concent...

  20. Fishing Forecasts

    NASA Technical Reports Server (NTRS)

    1988-01-01

    ROFFS stands for Roffer's Ocean Fishing Forecasting Service, Inc. Roffer combines satellite and computer technology with oceanographic information from several sources to produce frequently updated charts sometimes as often as 30 times a day showing clues to the location of marlin, sailfish, tuna, swordfish and a variety of other types. Also provides customized forecasts for racing boats and the shipping industry along with seasonal forecasts that allow the marine industry to formulate fishing strategies based on foreknowledge of the arrival and departure times of different fish. Roffs service exemplifies the potential for benefits to marine industries from satellite observations. Most notable results are reduced search time and substantial fuel savings.

  1. Global Reactive Gases in the MACC project

    NASA Astrophysics Data System (ADS)

    Schultz, M. G.

    2012-04-01

    In preparation for the planned atmospheric service component of the European Global Monitoring for Environment and Security (GMES) initiative, the EU FP7 project Monitoring of Atmospheric Composition and Climate (MACC) developed a preoperational data assimilation and modelling system for monitoring and forecasting of reactive gases, greenhouse gases and aerosols. The project is coordinated by the European Centre for Medium-Range Weather Forecast (ECMWF) and the system is built on ECMWF's Integrated Forecasting System (IFS) which has been coupled to the chemistry transport models MOZART-3 and TM5. In order to provide daily forecasts of up to 96 hours for global reactive gases, various satellite retrieval products for ozone (total column and profile data), CO, NO2, CH2O and SO2 are either actively assimilated or passively monitored. The MACC system is routinely evaluated with in-situ data from ground-based stations, ozone sondes and aircraft measurements, and with independent satellite retrievals. Global MACC reactive gases forecasts are used in the planning and analysis of large international field campaigns and to provide dynamical chemical boundary conditions to regional air quality models worldwide. Several case studies of outstanding air pollution events have been performed, and they demonstrate the strengths and weaknesses of chemical data assimilation based on current satellite data products. Besides the regular analyses and forecasts of the tropospheric chemical composition, the MACC system is also used to monitor the evolution of stratospheric ozone. A comprehensive reanalysis simulation from 2003 to 2010 provides new insights into the interannual variability of the atmospheric chemical composition.

  2. Solubility of non-polar gases in electrolyte solutions

    NASA Technical Reports Server (NTRS)

    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

  3. Colorimetric Detection Of Substances In Liquids And Gases

    NASA Technical Reports Server (NTRS)

    Harris, J. Milton; Mcgill, R. Andrew; Paley, Mark S.

    1992-01-01

    Thin polymer films containing solvatochromic dyes used as sensing elements to detect substances dissolved in liquids and gases. Dyes do not react with liquids in which dissolved, but do respond to changes in chemical compositions by changing color. Concentration determined visually by comparison of color with predetermined standard chart, or spectrophotometrically.

  4. Forecasting Future Social Needs

    ERIC Educational Resources Information Center

    Abt, Clark C.

    1971-01-01

    Describes briefly why social forecasting is easier than technological forecasting, offers four approaches to social forecasting (judgment, extrapolation, speculation, analysis), and suggests a procedure recommended for social forecasting. (CJ)

  5. Reasonable Forecasts

    ERIC Educational Resources Information Center

    Taylor, Kelley R.

    2010-01-01

    This article presents a sample legal battle that illustrates school officials' "reasonable forecasts" of substantial disruption in the school environment. In 2006, two students from a Texas high school came to school carrying purses decorated with images of the Confederate flag. The school district has a zero-tolerance policy for clothing or…

  6. TRAVEL FORECASTER

    NASA Technical Reports Server (NTRS)

    Mauldin, L. E.

    1994-01-01

    Business travel planning within an organization is often a time-consuming task. Travel Forecaster is a menu-driven, easy-to-use program which plans, forecasts cost, and tracks actual vs. planned cost for business-related travel of a division or branch of an organization and compiles this information into a database to aid the travel planner. The program's ability to handle multiple trip entries makes it a valuable time-saving device. Travel Forecaster takes full advantage of relational data base properties so that information that remains constant, such as per diem rates and airline fares (which are unique for each city), needs entering only once. A typical entry would include selection with the mouse of the traveler's name and destination city from pop-up lists, and typed entries for number of travel days and purpose of the trip. Multiple persons can be selected from the pop-up lists and multiple trips are accommodated by entering the number of days by each appropriate month on the entry form. An estimated travel cost is not required of the user as it is calculated by a Fourth Dimension formula. With this information, the program can produce output of trips by month with subtotal and total cost for either organization or sub-entity of an organization; or produce outputs of trips by month with subtotal and total cost for international-only travel. It will also provide monthly and cumulative formats of planned vs. actual outputs in data or graph form. Travel Forecaster users can do custom queries to search and sort information in the database, and it can create custom reports with the user-friendly report generator. Travel Forecaster 1.1 is a database program for use with Fourth Dimension Runtime 2.1.1. It requires a Macintosh Plus running System 6.0.3 or later, 2Mb of RAM and a hard disk. The standard distribution medium for this package is one 3.5 inch 800K Macintosh format diskette. Travel Forecaster was developed in 1991. Macintosh is a registered trademark of

  7. [Influence of dissolved gases on highly diluted aqueous media].

    PubMed

    Belovolova, L V; Glushkov, M V; Vinogradov, E A

    2014-01-01

    In the experiments on redox potential measurement for a series of identical samples of purified and presettled water it was found that the response to ultraviolet irradiation varies appreciably within a few days after treatment, including stepwise changes. In a few hours after exposure, leading to a higher content of reactive oxygen species as compared with the equilibrium values, long-term changes including variations in redox potential and optical system parameters are recorded in water and diluted aqueous media. We propose a heuristic organization model of the water-gas system with an increased content of reactive oxygen species. PMID:25707230

  8. Process for coal liquefaction in staged dissolvers

    DOEpatents

    Roberts, George W.; Givens, Edwin N.; Skinner, Ronald W.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a pasting oil, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals, are separated from the condensed reactor effluent. In accordance with the improved process, the first dissolver is operated at a higher temperature than the second dissolver. This temperature sequence produces improved product selectivity and permits the incorporation of sufficient hydrogen in the solvent for adequate recycle operations.

  9. Forecaster's dilemma: Extreme events and forecast evaluation

    NASA Astrophysics Data System (ADS)

    Lerch, Sebastian; Thorarinsdottir, Thordis; Ravazzolo, Francesco; Gneiting, Tilmann

    2015-04-01

    In discussions of the quality of forecasts in the media and public, attention often focuses on the predictive performance in the case of extreme events. Intuitively, accurate predictions on the subset of extreme events seem to suggest better predictive ability. However, it can be demonstrated that restricting conventional forecast verification methods to subsets of observations might have unexpected and undesired effects and may discredit even the most skillful forecasters. Hand-picking extreme events is incompatible with the theoretical assumptions of established forecast verification methods, thus confronting forecasters with what we refer to as the forecaster's dilemma. For probabilistic forecasts, weighted proper scoring rules provide suitable alternatives for forecast evaluation with an emphasis on extreme events. Using theoretical arguments, simulation experiments and a case study on probabilistic forecasts of wind speed over Germany, we illustrate the forecaster's dilemma and the use of weighted proper scoring rules.

  10. Noble gases in meteorites and terrestrial planets

    NASA Technical Reports Server (NTRS)

    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.

  11. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, S.; Kulkarni, S.S.

    1986-08-26

    Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

  12. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.

    1986-01-01

    Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

  13. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, S.

    1986-08-19

    The separation of polar gases from nonpolar gases may be effected by passing a mixture of nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

  14. Separation of polar gases from nonpolar gases

    DOEpatents

    Kulprathipanja, Santi

    1986-01-01

    The separation of polar gases from nonpolar gases may be effected by passing a mixture of nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

  15. Forecast Mekong

    USGS Publications Warehouse

    Turnipseed, D. Phil

    2011-01-01

    Forecast Mekong is part of the U.S. Department of State's Lower Mekong Initiative, which was launched in 2009 by Secretary Hillary Clinton and the Foreign Ministers of Cambodia, Laos, Thailand, and Vietnam to enhance partnerships between the U.S. and the Lower Mekong River countries in the areas of environment, health, education, and infrastructure. The U.S. Geological Survey (USGS) is working in close cooperation with the U.S. Department of State to use research and data from the Lower Mekong Basin to provide hands-on results that will help decision makers in Lower Mekong River countries in the planning and design for restoration, conservation, and management efforts in the basin.

  16. Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

    SciTech Connect

    Ho, C.S.; Smith, M.D.

    1986-01-01

    The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

  17. Dissolver vessel bottom assembly

    DOEpatents

    Kilian, Douglas C.

    1976-01-01

    An improved bottom assembly is provided for a nuclear reactor fuel reprocessing dissolver vessel wherein fuel elements are dissolved as the initial step in recovering fissile material from spent fuel rods. A shock-absorbing crash plate with a convex upper surface is disposed at the bottom of the dissolver vessel so as to provide an annular space between the crash plate and the dissolver vessel wall. A sparging ring is disposed within the annular space to enable a fluid discharged from the sparging ring to agitate the solids which deposit on the bottom of the dissolver vessel and accumulate in the annular space. An inlet tangential to the annular space permits a fluid pumped into the annular space through the inlet to flush these solids from the dissolver vessel through tangential outlets oppositely facing the inlet. The sparging ring is protected against damage from the impact of fuel elements being charged to the dissolver vessel by making the crash plate of such a diameter that the width of the annular space between the crash plate and the vessel wall is less than the diameter of the fuel elements.

  18. Method to Estimate the Dissolved Air Content in Hydraulic Fluid

    NASA Technical Reports Server (NTRS)

    Hauser, Daniel M.

    2011-01-01

    In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The current methods used to measure the dissolved air content require the fluid to be drawn from the hydraulic system, and additional offline laboratory processing time is involved. During laboratory processing, there is a potential for contamination to occur, especially when subsaturated fluid is to be analyzed. A new method measures the amount of dissolved air in hydraulic fluid through the use of a dissolved oxygen meter. The device measures the dissolved air content through an in situ, real-time process that requires no additional offline laboratory processing time. The method utilizes an instrument that measures the partial pressure of oxygen in the hydraulic fluid. By using a standardized calculation procedure that relates the oxygen partial pressure to the volume of dissolved air in solution, the dissolved air content is estimated. The technique employs luminescent quenching technology to determine the partial pressure of oxygen in the hydraulic fluid. An estimated Henry s law coefficient for oxygen and nitrogen in hydraulic fluid is calculated using a standard method to estimate the solubility of gases in lubricants. The amount of dissolved oxygen in the hydraulic fluid is estimated using the Henry s solubility coefficient and the measured partial pressure of oxygen in solution. The amount of dissolved nitrogen that is in solution is estimated by assuming that the ratio of dissolved nitrogen to dissolved oxygen is equal to the ratio of the gas solubility of nitrogen to oxygen at atmospheric pressure and temperature. The technique was performed at atmospheric pressure and room temperature. The technique could be theoretically carried out at higher pressures and elevated

  19. Transport of Trace Gases

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2005-01-01

    Trace gases measurements are used to diagnose both the chemistry and transport of the atmosphere. These lectures emphasize the interpretation of trace gases measurements and techniques used to untangle chemistry and transport effects. I will discuss PV transform, trajectory techniques, and age-of-air as far as the circulation of the stratosphere.

  20. Improved Anvil Forecasting

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred C.

    2000-01-01

    This report describes the outcome of Phase 1 of the AMU's Improved Anvil Forecasting task. Forecasters in the 45th Weather Squadron and the Spaceflight Meteorology Group have found that anvil forecasting is a difficult task when predicting LCC and FR violations. The purpose of this task is to determine the technical feasibility of creating an anvil-forecasting tool. Work on this study was separated into three steps: literature search, forecaster discussions, and determination of technical feasibility. The literature search revealed no existing anvil-forecasting techniques. However, there appears to be growing interest in anvils in recent years. If this interest continues to grow, more information will be available to aid in developing a reliable anvil-forecasting tool. The forecaster discussion step revealed an array of methods on how better forecasting techniques could be developed. The forecasters have ideas based on sound meteorological principles and personal experience in forecasting and analyzing anvils. Based on the information gathered in the discussions with the forecasters, the conclusion of this report is that it is technically feasible at this time to develop an anvil forecasting technique that will significantly contribute to the confidence in anvil forecasts.

  1. Role of metabolic gases in bubble formation during hypobaric exposures

    NASA Technical Reports Server (NTRS)

    Foster, P. P.; Conkin, J.; Powell, M. R.; Waligora, J. M.; Chhikara, R. S.

    1998-01-01

    Our hypothesis is that metabolic gases play a role in the initial explosive growth phase of bubble formation during hypobaric exposures. Models that account for optimal internal tensions of dissolved gases to predict the probability of occurrence of venous gas emboli were statistically fitted to 426 hypobaric exposures from National Aeronautics and Space Administration tests. The presence of venous gas emboli in the pulmonary artery was detected with an ultrasound Doppler detector. The model fit and parameter estimation were done by using the statistical method of maximum likelihood. The analysis results were as follows. 1) For the model without an input of noninert dissolved gas tissue tension, the log likelihood (in absolute value) was 255.01. 2) When an additional parameter was added to the model to account for the dissolved noninert gas tissue tension, the log likelihood was 251.70. The significance of the additional parameter was established based on the likelihood ratio test (P < 0.012). 3) The parameter estimate for the dissolved noninert gas tissue tension participating in bubble formation was 19. 1 kPa (143 mmHg). 4) The additional gas tissue tension, supposedly due to noninert gases, did not show an exponential decay as a function of time during denitrogenation, but it remained constant. 5) The positive sign for this parameter term in the model is characteristic of an outward radial pressure of gases in the bubble. This analysis suggests that dissolved gases other than N2 in tissues may facilitate the initial explosive bubble-growth phase.

  2. Computers and Technological Forecasting

    ERIC Educational Resources Information Center

    Martino, Joseph P.

    1971-01-01

    Forecasting is becoming increasingly automated, thanks in large measure to the computer. It is now possible for a forecaster to submit his data to a computation center and call for the appropriate program. (No knowledge of statistics is required.) (Author)

  3. Forecasting Artificial Intelligence Demand

    NASA Astrophysics Data System (ADS)

    Wheeler, David R.; Shelley, Charles

    1986-03-01

    Forecasts are major components of the decision analysis process. When accurate, estimates of future economic activity associated with specific courses of action can correctly set corporate strategy in an uncertain environment. When inaccurate, they can lead to bankruptcy. The basic trouble with most forecasts is that they are not made by forecasters.

  4. Photochemistry of biogenic gases

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1989-01-01

    The relationship between the biosphere and the atmosphere is examined, emphasizing the composition and photochemistry and chemistry of the troposphere and stratosphere. The reactions of oxygen, ozone, and hydroxyl are reviewed and the fate of the biogenic gases ammonia, methane, reduced sulfur species, reduced halogen species, carbon monoxide, nitric oxide, nitrous oxide, nitrogen, and carbon dioxide are described. A list is given of the concentration and sources of the various gases.

  5. Planetary noble gases

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin

    1993-01-01

    An overview of the history and current status of research on planetary noble gases is presented. The discovery that neon and argon are vastly more abundant on Venus than on earth points to the solar wind rather than condensation as the fundamental process for placing noble gases in the atmospheres of the terrestrial planets; however, solar wind implantation may not be able to fully reproduce the observed gradient, nor does it obviously account for similar planetary Ne/Ar ratios and dissimilar planetary Ar/Kr ratios. More recent studies have emphasized escape rather than accretion. Hydrodynamic escape, which is fractionating, readily accounts for the difference between atmospheric neon and isotopically light mantle neon. Atmospheric cratering, which is nearly nonfractionating, can account for the extreme scarcity of nonradiogenic noble gases (and other volatiles) on Mars.

  6. Forecaster priorities for improving probabilistic flood forecasts

    NASA Astrophysics Data System (ADS)

    Wetterhall, Fredrik; Pappenberger, Florian; Alfieri, Lorenzo; Cloke, Hannah; Thielen, Jutta

    2014-05-01

    Hydrological ensemble prediction systems (HEPS) have in recent years been increasingly used for the operational forecasting of floods by European hydrometeorological agencies. The most obvious advantage of HEPS is that more of the uncertainty in the modelling system can be assessed. In addition, ensemble prediction systems generally have better skill than deterministic systems both in the terms of the mean forecast performance and the potential forecasting of extreme events. Research efforts have so far mostly been devoted to the improvement of the physical and technical aspects of the model systems, such as increased resolution in time and space and better description of physical processes. Developments like these are certainly needed; however, in this paper we argue that there are other areas of HEPS that need urgent attention. This was also the result from a group exercise and a survey conducted to operational forecasters within the European Flood Awareness System (EFAS) to identify the top priorities of improvement regarding their own system. They turned out to span a range of areas, the most popular being to include verification of an assessment of past forecast performance, a multi-model approach for hydrological modelling, to increase the forecast skill on the medium range (>3 days) and more focus on education and training on the interpretation of forecasts. In light of limited resources, we suggest a simple model to classify the identified priorities in terms of their cost and complexity to decide in which order to tackle them. This model is then used to create an action plan of short-, medium- and long-term research priorities with the ultimate goal of an optimal improvement of EFAS in particular and to spur the development of operational HEPS in general.

  7. Removal of sulfur and nitrogen containing pollutants from discharge gases

    DOEpatents

    Joubert, James I.

    1986-01-01

    Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

  8. Weather forecasting expert system study

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Weather forecasting is critical to both the Space Transportation System (STS) ground operations and the launch/landing activities at NASA Kennedy Space Center (KSC). The current launch frequency places significant demands on the USAF weather forecasters at the Cape Canaveral Forecasting Facility (CCFF), who currently provide the weather forecasting for all STS operations. As launch frequency increases, KSC's weather forecasting problems will be great magnified. The single most important problem is the shortage of highly skilled forecasting personnel. The development of forecasting expertise is difficult and requires several years of experience. Frequent personnel changes within the forecasting staff jeopardize the accumulation and retention of experience-based weather forecasting expertise. The primary purpose of this project was to assess the feasibility of using Artificial Intelligence (AI) techniques to ameliorate this shortage of experts by capturing aria incorporating the forecasting knowledge of current expert forecasters into a Weather Forecasting Expert System (WFES) which would then be made available to less experienced duty forecasters.

  9. Weather assessment and forecasting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Data management program activities centered around the analyses of selected far-term Office of Applications (OA) objectives, with the intent of determining if significant data-related problems would be encountered and if so what alternative solutions would be possible. Three far-term (1985 and beyond) OA objectives selected for analyses as having potential significant data problems were large-scale weather forecasting, local weather and severe storms forecasting, and global marine weather forecasting. An overview of general weather forecasting activities and their implications upon the ground based data system is provided. Selected topics were specifically oriented to the use of satellites.

  10. Gases in Tektite Bubbles.

    PubMed

    O'keefe, J A; Lowman, P D; Dunning, K L

    1962-07-20

    Spectroscopic analysis of light produced by electrodeless discharge in a tektite bubble showed the main gases in the bubble to be neon, helium, and oxygen. The neon and helium have probably diffused in from the atmosphere, while the oxygen may be atmospheric gas incorporated in the tektite during its formation. PMID:17801113

  11. Dissolved gas and isotopic tracers of denitrification

    SciTech Connect

    Singleton, M J; Moran, J E; Esser, B K; McNab, W W; Carle, S F; Cey, B D

    2008-02-28

    We present results from field studies in California (USA) where tritium-helium age dating is used in conjunction with major gases (N{sub 2}, O{sub 2}, CH{sub 4}, CO{sub 2}), noble gases (He, Ne, Ar, Kr, Xe), and stable isotopes ({sup 15}N/{sup 14}N, {sup 18}O/{sup 16}O) in order to document nitrate loading and denitrification associated with confined animal agricultural operations and septic systems. Preliminary results show that in-field extraction of the full suite of dissolved gases will be possible using a new Gas Extraction System under development to augment the current Noble Gas Mass Spectrometry and Membrane Inlet Mass Spectrometry techniques. Ascribing observed groundwater nitrate levels to specific current and past land use practices is often complicated by uncertainty in groundwater age and the degree and locus of dentrification. Groundwater age dating at dairy field sites using the {sup 3}H-{sup 3}He method indicates that the highest nitrate concentrations (150-260 mg/L-NO3) occur in waters with apparent ages of <5 yrs, whereas older waters contain excess N{sub 2} from saturated zone denitrification [1]. At a residential septic system site in Livermore, CA, waters with young apparent ages (<1 yr) proximal to leach line drainage have lower nitrate concentrations and elevated nitrate {delta}{sup 15}N and {delta}{sup 18}O values consistent with denitrification, but little evidence for excess N{sub 2}, indicating that denitrification is occurring in the unsaturated zone. Degassing of groundwater can complicate efforts to calculate travel times [2] and to quantify denitrification. Degassed groundwater underlying dairy operations is formed by two distinct mechanisms: (1) recharge of manure lagoon water affected by biogenic gas ebullition [3] and (2) saturated zone denitrification producing N{sub 2} gas above solubility in groundwater. Gas loss due to both mechanisms is evident in the concentrations of noble gases and major gases in dairy groundwater samples.

  12. Forecasting Future Trends in Education

    ERIC Educational Resources Information Center

    Collazo, Andres; And Others

    1977-01-01

    Describes a forecasting model sensitive to the major factors influencing educational outcomes, presents several forecasts based on alternative sets of assumptions, and discusses the implications of these forecasts, including ways to subvert them. (Author/JG)

  13. Aviation Forecasting in ICAO

    NASA Technical Reports Server (NTRS)

    Mcmahon, J.

    1972-01-01

    Opinions or plans of qualified experts in the field are used for forecasting future requirements for air navigational facilities and services of international civil aviation. ICAO periodically collects information from Stators and operates on anticipated future operations, consolidates this information, and forecasts the future level of activity at different airports.

  14. Congressional Election Forecasting.

    ERIC Educational Resources Information Center

    Lewis-Beck, Michael S.; Rice, Tom W.

    1988-01-01

    Reviews the growing literature on the forecasting of elections, providing an example in the form of 1988 congressional election predictions. Briefly discusses the history of election outcome prediction and outlines two scientific forecasting models which, the authors state, are appropriate for use in the classroom. (GEA)

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

    NASA Astrophysics Data System (ADS)

    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 (< 0.015 mol %). The artificial fumarolic gases are collected into an evacuated bottle partially filled with 4 M NaOH solution containing 0.5 mM Cd(CH3COO)2. While non-condensable components such as CO, Ar, H2, and N2 accumulate in the headspace of the bottle, acidic components including CO2, SO2, HCl, and 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

  16. Method for dissolving plutonium dioxide

    DOEpatents

    Tallent, Othar K.

    1978-01-01

    The fluoride-catalyzed, non-oxidative dissolution of plutonium dioxide in HNO.sub.3 is significantly enhanced in rate by oxidizing dissolved plutonium ions. It is believed that the oxidation of dissolved plutonium releases fluoride ions from a soluble plutonium-fluoride complex for further catalytic action.

  17. Statistical evaluation of forecasts

    NASA Astrophysics Data System (ADS)

    Mader, Malenka; Mader, Wolfgang; Gluckman, Bruce J.; Timmer, Jens; Schelter, Björn

    2014-08-01

    Reliable forecasts of extreme but rare events, such as earthquakes, financial crashes, and epileptic seizures, would render interventions and precautions possible. Therefore, forecasting methods have been developed which intend to raise an alarm if an extreme event is about to occur. In order to statistically validate the performance of a prediction system, it must be compared to the performance of a random predictor, which raises alarms independent of the events. Such a random predictor can be obtained by bootstrapping or analytically. We propose an analytic statistical framework which, in contrast to conventional methods, allows for validating independently the sensitivity and specificity of a forecasting method. Moreover, our method accounts for the periods during which an event has to remain absent or occur after a respective forecast.

  18. SSUSI Aurora Forecast Model

    NASA Astrophysics Data System (ADS)

    Hsieh, S. W.; Zhang, Y.; Schaefer, R. K.; Romeo, G.; Paxton, L.

    2013-12-01

    A new capability has been developed at JHU/APL for forecasting the global aurora quantities based on the DMSP SSUSI data and the TIMED/GUVI Global Aurora Model. The SSUSI Aurora Forecast Model predicts the electron energy flux, mean energy, and equatorward boundary in the auroral oval for up to 1 day or 15 DMSP orbits in advance. In our presentation, we will demonstrate this newly implemented capability and its results. The future improvement plan will be discussed too.

  19. Precipitation and temperature ensemble forecasts from single-value forecasts

    NASA Astrophysics Data System (ADS)

    Schaake, J.; Demargne, J.; Hartman, R.; Mullusky, M.; Welles, E.; Wu, L.; Herr, H.; Fan, X.; Seo, D. J.

    2007-04-01

    A procedure is presented to construct ensemble forecasts from single-value forecasts of precipitation and temperature. This involves dividing the spatial forecast domain and total forecast period into a number of parts that are treated as separate forecast events. The spatial domain is divided into hydrologic sub-basins. The total forecast period is divided into time periods, one for each model time step. For each event archived values of forecasts and corresponding observations are used to model the joint distribution of forecasts and observations. The conditional distribution of observations for a given single-value forecast is used to represent the corresponding probability distribution of events that may occur for that forecast. This conditional forecast distribution subsequently is used to create ensemble members that vary in space and time using the "Schaake Shuffle" (Clark et al, 2004). The resulting ensemble members have the same space-time patterns as historical observations so that space-time joint relationships between events that have a significant effect on hydrological response tend to be preserved. Forecast uncertainty is space and time-scale dependent. For a given lead time to the beginning of the valid period of an event, forecast uncertainty depends on the length of the forecast valid time period and the spatial area to which the forecast applies. Although the "Schaake Shuffle" procedure, when applied to construct ensemble members from a time-series of single value forecasts, may preserve some of this scale dependency, it may not be sufficient without additional constraint. To account more fully for the time-dependent structure of forecast uncertainty, events for additional "aggregate" forecast periods are defined as accumulations of different "base" forecast periods. The generated ensemble members can be ingested by an Ensemble Streamflow Prediction system to produce ensemble forecasts of streamflow and other hydrological variables that reflect

  20. [Prospects for Application of Gases and Gas Hydrates to Cryopreservation].

    PubMed

    Shishova, N V; Fesenko, E E

    2015-01-01

    In the present review, we tried to evaluate the known properties of gas hydrates and gases participating in the formation of gas hydrates from the point of view of the mechanisms of cryoinjury and cryoprotection, to consider the papers on freezing biological materials in the presence of inert gases, and to analyze the perspectives for the development of this direction. For the purpose, we searched for the information on the physical properties of gases and gas hydrates, compared processes occured during the formation of gas hydrates and water ice, analyzed the influence of the formation and growth of gas hydrates on the structure of biological objects. We prepared a short review on the biological effects of xenon, krypton, argon, carbon dioxide, hydrogen sulfide, and carbon monoxide especially on hypothermal conditions and probable application of these properties in cryopreservation technologies. The description of the existing experiments on cryopreservation of biological objects with the use of gases was analyzed. On the basis of the information we found, the most perspective directions of work in the field of cryopreservation of biological objects with the use of gases were outlined. An attempt was made to forecast the potential problems in this field. PMID:26591607

  1. Equilibration of quantum gases

    NASA Astrophysics Data System (ADS)

    Farrelly, Terry

    2016-07-01

    Finding equilibration times is a major unsolved problem in physics with few analytical results. Here we look at equilibration times for quantum gases of bosons and fermions in the regime of negligibly weak interactions, a setting which not only includes paradigmatic systems such as gases confined to boxes, but also Luttinger liquids and the free superfluid Hubbard model. To do this, we focus on two classes of measurements: (i) coarse-grained observables, such as the number of particles in a region of space, and (ii) few-mode measurements, such as phase correlators. We show that, in this setting, equilibration occurs quite generally despite the fact that the particles are not interacting. Furthermore, for coarse-grained measurements the timescale is generally at most polynomial in the number of particles N, which is much faster than previous general upper bounds, which were exponential in N. For local measurements on lattice systems, the timescale is typically linear in the number of lattice sites. In fact, for one-dimensional lattices, the scaling is generally linear in the length of the lattice, which is optimal. Additionally, we look at a few specific examples, one of which consists of N fermions initially confined on one side of a partition in a box. The partition is removed and the fermions equilibrate extremely quickly in time O(1/N).

  2. ANALYSIS OF DISSOLVED METHANE, ETHANE, AND ETHYLENE IN GROUND WATER BY A STANDARD GAS CHROMATOGRAPHIC TECHNIQUE

    EPA Science Inventory

    The measurement of dissolved gases such as methane, ethane, and ethylene in ground water is important in determining whether intrinsic bioremediation is occurring in a fuel- or solvent-contaminated aquifer. A simple procedure is described for the collection and subsequent analys...

  3. DISSOLVED OXYGEN AND METHANE IN WATER BY A GC HEADSPACE EQUILIBRATION TECHNIQUE

    EPA Science Inventory

    An analytical procedure is described for the determination of dissolved oxygen and methane in groundwater samples. The method consists of generating a helium gas headspace in a water filled bottle, and analysis of the headspace by gas chromatography. Other permanent gases such as...

  4. Calibration of Dissolved Noble Gas Mass Spectrometric Measurements by an Air-Water Equilibration System

    NASA Astrophysics Data System (ADS)

    Hillegonds, Darren; Matsumoto, Takuya; Jaklitsch, Manfred; Han, Liang-Feng; Klaus, Philipp; Wassenaar, Leonard; Aggarwal, Pradeep

    2013-04-01

    Precise measurements by mass spectrometry of dissolved noble gases (He, Ar, Ne, Kr, Xe) in water samples require careful calibration against laboratory standards with known concentrations. Currently, air pipettes are used for day-to-day calibrations, making estimation of overall analytical uncertainties for dissolved noble gas measurements in water difficult. Air equilibrated water (AEW) is often used as a matrix-equivalent laboratory standard for dissolved gases in groundwater, because of the well-known and constant fractions of noble gases in the atmosphere. AEW standards, however, are only useful if the temperature and pressure of the gas-water equilibrium can be controlled and measured precisely (i.e., to better than 0.5%); contamination and partial sample degassing must also be prevented during sampling. Here we present the details of a new custom air-water equilibration system which consists of an insulated 600 liter tank filled with deionized water, held isothermally at a precise target temperature (<0.05 °C) through the use of a heat exchanger. The temperature and total dissolved gas of the water in the tank are monitored continually, as are atmospheric pressure and air temperature in the laboratory. Different noble gas concentration standards can be reliably produced by accurately controlling the water temperature of the equilibration system. Equilibration characteristics and reproducibility of this system for production of copper tubes containing known amounts of noble gases will be presented.

  5. DISSOLVED OXYGEN AND METHANE IN WATER BY A GC HEADSPACE EQUILIBRATION TECHNIQUE

    EPA Science Inventory

    An analytical procedure is described for the determination of dissolved oxygen and methane in groundwater samples. he method consists of generating a helium gas headspace in a water filled bottle, and analysis of the headspace by gas chromatography. ther permanent gases such as n...

  6. An overview of health forecasting.

    PubMed

    Soyiri, Ireneous N; Reidpath, Daniel D

    2013-01-01

    Health forecasting is a novel area of forecasting, and a valuable tool for predicting future health events or situations such as demands for health services and healthcare needs. It facilitates preventive medicine and health care intervention strategies, by pre-informing health service providers to take appropriate mitigating actions to minimize risks and manage demand. Health forecasting requires reliable data, information and appropriate analytical tools for the prediction of specific health conditions or situations. There is no single approach to health forecasting, and so various methods have often been adopted to forecast aggregate or specific health conditions. Meanwhile, there are no defined health forecasting horizons (time frames) to match the choices of health forecasting methods/approaches that are often applied. The key principles of health forecasting have not also been adequately described to guide the process. This paper provides a brief introduction and theoretical analysis of health forecasting. It describes the key issues that are important for health forecasting, including: definitions, principles of health forecasting, and the properties of health data, which influence the choices of health forecasting methods. Other matters related to the value of health forecasting, and the general challenges associated with developing and using health forecasting services are discussed. This overview is a stimulus for further discussions on standardizing health forecasting approaches and methods that will facilitate health care and health services delivery. PMID:22949173

  7. The Measurement of Dissolved Oxygen

    ERIC Educational Resources Information Center

    Thistlethwayte, D.; And Others

    1974-01-01

    Describes an experiment in environmental chemistry which serves to determine the dissolved oxygen concentration in both fresh and saline water. Applications of the method at the undergraduate and secondary school levels are recommended. (CC)

  8. METHOD OF DISSOLVING URANIUM METAL

    DOEpatents

    Slotin, L.A.

    1958-02-18

    This patent relates to an economicai means of dissolving metallic uranium. It has been found that the addition of a small amount of perchloric acid to the concentrated nitric acid in which the uranium is being dissolved greatly shortens the time necessary for dissolution of the metal. Thus the use of about 1 or 2 percent of perchioric acid based on the weight of the nitric acid used, reduces the time of dissolution of uranium by a factor of about 100.

  9. Carbon isotopic composition of deep carbon gases in an ombrogenous peatland, northwestern Ontario, Canada

    SciTech Connect

    Aravena, R. . Center for Groundwater Research and Wetlands Research Center); Warner, B.G. . Wetlands Research Center and Dept. of Geography); Charman, D.J. . Dept. of Geographical Sciences); Belyea, L.R. . School of Biological Sciences); Mathur, S.P. ); Dinel, H. )

    1993-01-01

    Radiocarbon dating and carbon isotope analyses of deep peat and gases in a small ombrogenous peatland in northwestern Ontario reveals the presence of old gases at depth that are 1000-2000 yr younger than the enclosing peat. The authors suggest that the most likely explanation to account for this age discrepancy is the downward movement by advection of younger dissolved organic carbon for use by fermentation and methanogens bacteria. This study identifies a potentially large supply of old carbon gases in peatlands that should be considered in global carbon models of the terrestrial biosphere.

  10. Forecasting digital microcircuit obsolescence

    NASA Astrophysics Data System (ADS)

    Balwally, Nandakumar M.

    1991-03-01

    This report documents a procedure for forecasting digital microcircuit obsolescence at the Defense Electronics Supply Center, Dayton, OH. Obsolescence is caused by rapid advancement in digital technology and decrease in commercial demand while military demand still continues. In logistics parlance, parts obsolescence is known as a diminishing manufacturing source (DMS) problem. Continued supply of an obsolete DMS item is assured via substitution, alternate sourcing or a one time buy equal to the lifetime requirements of the item. Emulation is a recent alternative which explores the possibility of replacing obsolete digital microcircuits with state of the art devices which can be manufactured and supplied on demand. The report recommends use of a statistical model which forecasts DMS items from a population of presently non-DMS items belonging to obsolete digital microcircuit technologies. The items forecast by the model should be evaluated for their emulation potential.

  11. Gases in Seawater

    NASA Astrophysics Data System (ADS)

    Nightingale, P. D.; Liss, P. S.

    2003-12-01

    The annual gross and net primary productivity of the surface oceans is similar in size to that on land (IPCC, 2001). Marine productivity drives the cycling of gases such as oxygen (O2), dimethyl sulfide (DMS), carbon monoxide (CO), carbon dioxide (CO2), and methyl iodide (CH3I) which are of fundamental importance in studies of marine productivity, biogeochemical cycles, atmospheric chemistry, climate, and human health, respectively. For example, ˜30% of the world's population (1,570 million) is thought to be at risk of iodine-deficiency disorders that impair mental development (WHO, 1996). The main source of iodine to land is the supply of volatile iodine compounds produced in the ocean and then transferred to the atmosphere via the air-surface interface. The flux of these marine iodine species to the atmosphere is also thought to be important in the oxidation capacity of the troposphere by the production of the iodine oxide radical ( Alicke et al., 1999). A further example is that the net flux of CO2 from the atmosphere to the ocean, ˜1.7±0.5 Gt C yr-1, represents ˜30% of the annual release of anthropogenic CO2 to the atmosphere (IPCC, 2001). This net flux is superimposed on a huge annual flux (90 Gt C yr-1) of CO2 that is cycled "naturally" between the ocean and the atmosphere. The long-term sink for anthropogenic CO2 is recognized as transfer to the ocean from the atmosphere. A final example is the emission of volatile sulfur, in the form of DMS, from the oceans. Not only is an oceanic flux from the oceans needed to balance the loss of sulfur (a bioessential element) from the land via weathering, it has also been proposed as having a major control on climate due to the formation of cloud condensation nuclei (Charlson et al., 1987). Indeed, the existence of DMS and CH3I has been used as evidence in support of the Gaia hypothesis (Lovelock, 1979).There are at least four main processes that affect the concentration of gases in the water column: biological

  12. Solubilities of nitrogen and noble gases in basalt melt

    NASA Technical Reports Server (NTRS)

    Miyazaki, A.; Hiyagon, H.; Sugiura, N.

    1994-01-01

    Nitrogen and noble gases are important tracers in geochemistry and chosmochemistry. Compared to noble gases, however, physicochemical properties of nitrogen, such as solubility in melt or melt/silicate partition, are not well known. Solubility of nitrogen in basalt melt depends on redox condition of the atmosphere. For example, solubility of nitrogen in E chondrite melt under reducing conditions is as high as 2 mol percent at 1500 C, suggesting that nitrogen is chemically dissolved in silicate melts, i.e., being dissolved as free anions or replacing oxygen sites in silicate network. However, the solubility and the dissolution mechanism of nitrogen under oxidizing conditions are not well investigated. To obtain nitrogen solubility in silicate melts under various redox conditions and to understand its mechanism, we are conducting experiments by using (15)N(15)N-labeled nitrogen gas. This makes it easy to distinguish dissolved nitrogen from later contamination of atmospheric nitrogen, and hence enables us to measure the nitrogen solubility accurately. As a preliminary experiment, we have measured solubility of nitrogen in basalt melt under the atmospheric oxygen pressure.

  13. Forecasters of earthquakes

    NASA Astrophysics Data System (ADS)

    Maximova, Lyudmila

    1987-07-01

    For the first time Soviet scientists have set up a bioseismological proving ground which will stage a systematic extensive experiment of using birds, ants, mountain rodents including marmots, which can dig holes in the Earth's interior to a depth of 50 meters, for the purpose of earthquake forecasting. Biologists have accumulated extensive experimental data on the impact of various electromagnetic fields, including fields of weak intensity, on living organisms. As far as mammals are concerned, electromagnetic waves with frequencies close to the brain's biorhythms have the strongest effect. How these observations can be used to forecast earthquakes is discussed.

  14. Route based forecasting

    NASA Astrophysics Data System (ADS)

    Zuurendonk, I. W.; Wokke, M. J. J.

    2009-09-01

    Road surface temperatures can differ several degrees on a very short distance due to local effects. In order to get more insight in the local temperature differences and to develop safer gritting routes, Meteogroup has developed a system for route based temperature forecasting. The standard version of the road model is addressed to forecast road surface temperature and condition for a specific location. This model consists of two parts. First a physical part, based on the energy balance equations. The second part of the model performs a statistical correction on the calculated physical road surface temperature. The road model is able to create a forecast for one specific location. From infrared measurements, we know that large local differences in road surface temperature exist on a route. Differences can be up to 5 degrees Celsius over a distance of several hundreds of meters. Based on those measurements, the idea came up to develop a system that forecasts road surface temperature and condition for an entire route: route based forecasting. The route is split up in sections with equal properties. For each section a temperature and condition will be calculated. The main factors that influence the road surface temperature are modelled in this forecasting system: •The local weather conditions: temperature, dew point temperature, wind, precipitation, weather type, cloudiness. •The sky view: A very sheltered place will receive less radiation during daytime and emit less radiation during nighttime. For a very open spot, the effects are reversed. •The solar view: A road section with trees on the southern side, will receive less solar radiation during daytime than a section with tress on the southern side. The route based forecast shows by means of a clear Google Maps presentation which sections will be slippery at what time of the coming night. The final goal of this type of forecast, is to make dynamical gritting possible: a variable salt amount and a different

  15. Online dissolved methane and total dissolved sulfide measurement in sewers.

    PubMed

    Liu, Yiwen; Sharma, Keshab R; Fluggen, Markus; O'Halloran, Kelly; Murthy, Sudhir; Yuan, Zhiguo

    2015-01-01

    Recent studies using short-term manual sampling of sewage followed by off-line laboratory gas chromatography (GC) measurement have shown that a substantial amount of dissolved methane is produced in sewer systems. However, only limited data has been acquired to date due to the low frequency and short span of this method, which cannot capture the dynamic variations of in-sewer dissolved methane concentrations. In this study, a newly developed online measuring device was used to monitor dissolved methane concentrations at the end of a rising main sewer network, over two periods of three weeks each, in summer and early winter, respectively. This device uses an online gas-phase methane sensor to measure methane under equilibrium conditions after being stripped from the sewage. The data are then converted to liquid-phase methane concentrations according to Henry's Law. The detection limit and range are suitable for sewer application and can be adjusted by varying the ratio of liquid-to-gas phase volume settings. The measurement presented good linearity (R² > 0.95) during field application, when compared to off-line measurements. The overall data set showed a wide variation in dissolved methane concentration of 5-15 mg/L in summer and 3.5-12 mg/L in winter, resulting in a significant average daily production of 24.6 and 19.0 kg-CH₄/d, respectively, from the network with a daily average sewage flow of 2840 m³/day. The dissolved methane concentration demonstrated a clear diurnal pattern coinciding with flow and sulfide fluctuation, implying a relationship with the wastewater hydraulic retention time (HRT). The total dissolved sulfide (TDS) concentration in sewers can be determined simultaneously with the same principle. PMID:25462721

  16. Reducing emissions from uranium dissolving

    SciTech Connect

    Griffith, W.L.; Compere, A.L.; Huxtable, W.P.; Googin, J.M.

    1992-10-01

    This study was designed to assess the feasibility of decreasing NO{sub x} emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO{sub x} fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO{sub x} emissions. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO{sub 2} which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  17. Reducing emissions from uranium dissolving

    SciTech Connect

    Griffith, W.L.; Compere, A.L.; Huxtable, W.P.; Googin, J.M.

    1992-10-01

    This study was designed to assess the feasibility of decreasing NO[sub x] emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO[sub x] fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO[sub x] emissions. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO[sub 2] which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  18. Dissolving Polymers in Ionic Liquids.

    NASA Astrophysics Data System (ADS)

    Hoagland, David; Harner, John

    2009-03-01

    Dissolution and phase behavior of polymers in ionic liquids have been assessed by solution characterization techniques such as intrinsic viscosity and light scattering (static and dynamic). Elevated viscosity proved the greatest obstacle. As yet, whether principles standard to conventional polymer solutions apply to ionic liquid solutions is uncertain, especially for polymers such as polyelectrolytes and hydrophilic block copolymers that may specifically interact with ionic liquid anions or cations. For flexible polyelectrolytes (polymers releasing counterions into high dielectric solvents), characterization in ionic liquids suggests behaviors more typical of neutral polymer. Coil sizes and conformations are approximately the same as in aqueous buffer. Further, several globular proteins dissolve in a hydrophilic ionic liquid with conformations analogous to those in buffer. General principles of solubility, however, remain unclear, making predictions of which polymer dissolves in which ionic liquid difficult; several otherwise intractable polymers (e.g., cellulose, polyvinyl alcohol) dissolve and can be efficiently functionalized in ionic liquids.

  19. Developing air quality forecasts

    NASA Astrophysics Data System (ADS)

    Lee, Pius; Saylor, Rick; Meagher, James

    2012-05-01

    Third International Workshop on Air Quality Forecasting Research; Potomac, Maryland, 29 November to 1 December 2011 Elevated concentrations of both near-surface ozone (O3) and fine particulate matter smaller than 2.5 micrometers in diameter have been implicated in increased mortality and other human health impacts. In light of these known influences on human health, many governments around the world have instituted air quality forecasting systems to provide their citizens with advance warning of impending poor air quality so that they can take actions to limit exposure. In an effort to improve the performance of air quality forecasting systems and provide a forum for the exchange of the latest research in air quality modeling, the International Workshop on Air Quality Forecasting Research (IWAQFR) was established in 2009 and is cosponsored by the U.S. National Oceanic and Atmospheric Administration (NOAA), Environment Canada (EC), and the World Meteorological Organization (WMO). The steering committee for IWAQFR's establishment was composed of Véronique Bouchet, Mike Howe, and Craig Stoud (EC); Greg Carmichael (University of Iowa); Paula Davidson and Jim Meagher (NOAA); and Liisa Jalkanen (WMO). The most recent workshop took place in Maryland.

  20. Survival Sales Forecasting.

    ERIC Educational Resources Information Center

    Paradiso, James; Stair, Kenneth

    Intended to provide insight into the dynamics of demand analysis, this paper presents an eight-step method for forecasting sales. Focusing on sales levels that must be achieved to enjoy targeted profits in favor of the usual approach of emphasizing how much will be sold within a given period, a sample situation is provided to illustrate this…

  1. Forecasting Scientific - Technical Information.

    ERIC Educational Resources Information Center

    Vvedenskiy, T. A.; And Others

    This document contains three selections from the Russian-language journal "Nauchno-Teknicheskaya Informatsiya," Moscow. The first article is "Documentation for Technical Forecasts" by T. A. Vvedenskiy (Series 1, Number 11, 1969, submitted for publication 9 July 1968, p3-5). This article deals with the transformation of the method of scientific…

  2. Improving operational plume forecasts

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-04-01

    Forecasting how plumes of particles, such as radioactive particles from a nuclear disaster, will be transported and dispersed in the atmosphere is an important but computationally challenging task. During the Fukushima nuclear disaster in Japan, operational plume forecasts were produced each day, but as the emissions continued, previous emissions were not included in the simulations used for forecasts because it became impractical to rerun the simulations each day from the beginning of the accident. Draxler and Rolph examine whether it is possible to improve plume simulation speed and flexibility as conditions and input data change. The authors use a method known as a transfer coefficient matrix approach that allows them to simulate many radionuclides using only a few generic species for the computation. Their simulations work faster by dividing the computation into separate independent segments in such a way that the most computationally time consuming pieces of the calculation need to be done only once. This makes it possible to provide real-time operational plume forecasts by continuously updating the previous simulations as new data become available. They tested their method using data from the Fukushima incident to show that it performed well. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2011JD017205, 2012)

  3. Forecasting Mass Communication.

    ERIC Educational Resources Information Center

    Dailey, Joseph M.

    In sorting through predictions about future communications, it should be kept in mind that if one can think of a communication technology in the future, then that communication technology will stand a very good chance of becoming a reality. In other words, the forecasting of invention is not separate from invention itself. Secondly, the inventions…

  4. External Environmental Forecast.

    ERIC Educational Resources Information Center

    Lapin, Joel D.

    Representing current viewpoints of academics, futures experts, and social observers, this external environmental forecast presents projections and information of particular relevance to the future of Catonsville Community College. The following topics are examined: (1) population changes and implications for higher education; (2) state and local…

  5. Federal Forecasters Directory, 1995.

    ERIC Educational Resources Information Center

    National Center for Education Statistics (ED), Washington, DC.

    This directory lists employees of the federal government who are involved in forecasting for policy formation and trend prediction purposes. Job title, agency, business address, phone or e-mail number, and specialty areas are listed for each employee. Employees are listed for the following agencies: (1) Bureau of the Census; (2) Bureau of Economic…

  6. Forecasting Credit Hours.

    ERIC Educational Resources Information Center

    Bivin, David; Rooney, Patrick Michael

    1999-01-01

    This study used Tobit analysis to estimate retention probabilities and credit hours at two universities. Tobit was judged as appropriate for this problem because it recognizes the lower bound of zero on credit hours and incorporates this bound into parameter estimates and forecasts. Models are estimated for credit hours in a single year and…

  7. Reducing Emissions from Uranium Dissolving

    SciTech Connect

    Griffith, W.L.

    1992-01-01

    This study was designed to assess the feasibility of decreasing NO{sub x} emissions from the current uranium alloy scrap tray dissolving facility. In the current process, uranium scrap is dissolved in boiling nitric acid in shallow stainless-steel trays. As scrap dissolves, more metal and more nitric acid are added to the tray by operating personnel. Safe geometry is assured by keeping liquid level at or below 5 cm, the depth of a safe infinite slab. The accountability batch control system provides additional protection against criticality. The trays are steam coil heated. The process has operated satisfactorily, with few difficulties, for decades. Both uranium and uranium alloys are dissolved. Nitric acid is recovered from the vapors for reuse. Metal nitrates are sent to uranium recovery. Brown NO{sub x} fumes evolved during dissolving have occasionally resulted in a visible plume from the trays. The fuming is most noticeable during startup and after addition of fresh acid to a tray. Present environmental regulations are expected to require control of brown NO{sub x} emissions. Because NO{sub x} is hazardous, fumes should be suppressed whenever the electric blower system is inoperable. Because the tray dissolving process has worked well for decades, as much of the current capital equipment and operating procedures as possible were preserved. A detailed review of the literature, indicated the feasibility of slightly altering process chemistry to favor the production of NO{sub 2}, which can be scrubbed and recycled as nitric acid. Methods for controlling the process to manage offgas product distribution and to minimize chemical reaction hazards were also considered.

  8. Corporate Forecasting: Promise and Reality

    ERIC Educational Resources Information Center

    Wheelwright, Steven C.; Clarke, Darral G.

    1976-01-01

    Discusses a survey of forecast preparers and users in 127 major companies in an attempt to assess underlying problems and identify areas for improvement. Concludes that forecasting responsibilities and tasks must be better defined and that forecast preparers and users must become better informed about one another's roles. (Author/JG)

  9. Process for the removal of acid forming gases from exhaust gases and production of phosphoric acid

    DOEpatents

    Chang, Shih-Ger; Liu, David K.

    1992-01-01

    Exhaust gases are treated to remove NO or NO.sub.x and SO.sub.2 by contacting the gases with an aqueous emulsion or suspension of yellow phosphorous preferably in a wet scrubber. The addition of yellow phosphorous in the system induces the production of O.sub.3 which subsequently oxidizes NO to NO.sub.2. The resulting NO.sub.2 dissolves readily and can be reduced to form ammonium ions by dissolved SO.sub.2 under appropriate conditions. In a 20 acfm system, yellow phosphorous is oxidized to yield P.sub.2 O.sub.5 which picks up water to form H.sub.3 PO.sub.4 mists and can be collected as a valuable product. The pressure is not critical, and ambient pressures are used. Hot water temperatures are best, but economics suggest about 50.degree. C. The amount of yellow phosphorus used will vary with the composition of the exhaust gas, less than 3% for small concentrations of NO, and 10% or higher for concentrations above say 1000 ppm. Similarly, the pH will vary with the composition being treated, and it is adjusted with a suitable alkali. For mixtures of NO.sub.x and SO.sub.2, alkalis that are used for flue gas desulfurization are preferred. With this process, better than 90% of SO.sub.2 and NO in simulated flue gas can be removed. Stoichiometric ratios (P/NO) ranging between 0.6 and 1.5 were obtained.

  10. Physics of Hyperpolarized Noble Gases

    NASA Astrophysics Data System (ADS)

    Happer, William

    1999-11-01

    The production of highly spin-polarized (hyperpolarized) gases by optical pumping with lasers involves spin-dependent interactions of atoms in gases, liquids, solids and on surfaces. Although enough is understood about these interactions to allow large quantities of hyperpolarized gas to be prepared, some of the basic physics is still mysterious. A better understanding of the physics would lead to worthwhile improvements in the performance of polarization systems. The most important physics involved in the production of hyperpolarized gases will be reviewed, with particular emphasis on areas where the physics is still not understood.

  11. Environmental implications of anesthetic gases.

    PubMed

    Yasny, Jeffrey S; White, Jennifer

    2012-01-01

    For several decades, anesthetic gases have greatly enhanced the comfort and outcome for patients during surgery. The benefits of these agents have heavily outweighed the risks. In recent years, the attention towards their overall contribution to global climate change and the environment has increased. Anesthesia providers have a responsibility to minimize unnecessary atmospheric pollution by utilizing techniques that can lessen any adverse effects of these gases on the environment. Moreover, health care facilities that use anesthetic gases are accountable for ensuring that all anesthesia equipment, including the scavenging system, is effective and routinely maintained. Implementing preventive practices and simple strategies can promote the safest and most healthy environment. PMID:23241038

  12. Feshbach resonances in ultracold gases

    SciTech Connect

    Chin Cheng; Grimm, Rudolf; Julienne, Paul; Tiesinga, Eite

    2010-04-15

    Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.

  13. Noble gases in the moon

    NASA Technical Reports Server (NTRS)

    Manuel, O. K.; Srinivasan, B.; Hennecke, E. W.; Sinclair, D. E.

    1972-01-01

    The abundance and isotopic composition of helium, neon, argon, krypton, and xenon which were released by stepwise heating of lunar fines (15601.64) and (15271.65) were measured spectrometrically. The results of a composition of noble gases released from the lunar fines with noble gases in meteorites and in the earth are presented along with the isotopic composition of noble gases in lunar fines, in meteorites, and in the atmosphere. A study of two isotopically distinct components of trapped xenon in carbonaceous chondrites is also included.

  14. Dissolved oxygen content prediction in crab culture using a hybrid intelligent method.

    PubMed

    Yu, Huihui; Chen, Yingyi; Hassan, ShahbazGul; Li, Daoliang

    2016-01-01

    A precise predictive model is needed to obtain a clear understanding of the changing dissolved oxygen content in outdoor crab ponds, to assess how to reduce risk and to optimize water quality management. The uncertainties in the data from multiple sensors are a significant factor when building a dissolved oxygen content prediction model. To increase prediction accuracy, a new hybrid dissolved oxygen content forecasting model based on the radial basis function neural networks (RBFNN) data fusion method and a least squares support vector machine (LSSVM) with an optimal improved particle swarm optimization(IPSO) is developed. In the modelling process, the RBFNN data fusion method is used to improve information accuracy and provide more trustworthy training samples for the IPSO-LSSVM prediction model. The LSSVM is a powerful tool for achieving nonlinear dissolved oxygen content forecasting. In addition, an improved particle swarm optimization algorithm is developed to determine the optimal parameters for the LSSVM with high accuracy and generalizability. In this study, the comparison of the prediction results of different traditional models validates the effectiveness and accuracy of the proposed hybrid RBFNN-IPSO-LSSVM model for dissolved oxygen content prediction in outdoor crab ponds. PMID:27270206

  15. Dissolved oxygen content prediction in crab culture using a hybrid intelligent method

    NASA Astrophysics Data System (ADS)

    Yu, Huihui; Chen, Yingyi; Hassan, Shahbazgul; Li, Daoliang

    2016-06-01

    A precise predictive model is needed to obtain a clear understanding of the changing dissolved oxygen content in outdoor crab ponds, to assess how to reduce risk and to optimize water quality management. The uncertainties in the data from multiple sensors are a significant factor when building a dissolved oxygen content prediction model. To increase prediction accuracy, a new hybrid dissolved oxygen content forecasting model based on the radial basis function neural networks (RBFNN) data fusion method and a least squares support vector machine (LSSVM) with an optimal improved particle swarm optimization(IPSO) is developed. In the modelling process, the RBFNN data fusion method is used to improve information accuracy and provide more trustworthy training samples for the IPSO-LSSVM prediction model. The LSSVM is a powerful tool for achieving nonlinear dissolved oxygen content forecasting. In addition, an improved particle swarm optimization algorithm is developed to determine the optimal parameters for the LSSVM with high accuracy and generalizability. In this study, the comparison of the prediction results of different traditional models validates the effectiveness and accuracy of the proposed hybrid RBFNN-IPSO-LSSVM model for dissolved oxygen content prediction in outdoor crab ponds.

  16. Dissolved oxygen content prediction in crab culture using a hybrid intelligent method

    PubMed Central

    Yu, Huihui; Chen, Yingyi; Hassan, ShahbazGul; Li, Daoliang

    2016-01-01

    A precise predictive model is needed to obtain a clear understanding of the changing dissolved oxygen content in outdoor crab ponds, to assess how to reduce risk and to optimize water quality management. The uncertainties in the data from multiple sensors are a significant factor when building a dissolved oxygen content prediction model. To increase prediction accuracy, a new hybrid dissolved oxygen content forecasting model based on the radial basis function neural networks (RBFNN) data fusion method and a least squares support vector machine (LSSVM) with an optimal improved particle swarm optimization(IPSO) is developed. In the modelling process, the RBFNN data fusion method is used to improve information accuracy and provide more trustworthy training samples for the IPSO-LSSVM prediction model. The LSSVM is a powerful tool for achieving nonlinear dissolved oxygen content forecasting. In addition, an improved particle swarm optimization algorithm is developed to determine the optimal parameters for the LSSVM with high accuracy and generalizability. In this study, the comparison of the prediction results of different traditional models validates the effectiveness and accuracy of the proposed hybrid RBFNN-IPSO-LSSVM model for dissolved oxygen content prediction in outdoor crab ponds. PMID:27270206

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

    NASA Technical Reports Server (NTRS)

    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.

  18. METHOD OF DISSOLVING METALLIC URANIUM

    DOEpatents

    Schulz, W.W.

    1959-07-28

    A process is presented for more rapidly dissolving metallic uranium which comprises contacting the uranium with a mixture of nitric and phosphoric acids. The preferred concentration is a mixture which is about 10 M in nitric acid and between 0.1 to 0.15 M in phosphoric acid.

  19. Dissolved gas - the hidden saboteur

    SciTech Connect

    Magorien, V.G.

    1993-12-31

    Almost all hydraulic power components, to properly perform their tasks, rely on one basic, physical property, i.e., the incompressibility of the working fluid. Unfortunately, a frequently overlooked fluid property which frustrates this requirement is its ability to absorb, i.e., dissolve, store and give off gas. The gas is, most often but not always, air. This property is a complex one because it is a function not only of the fluid`s chemical make-up but temperature, pressure, exposed area, depth and time. In its relationshiop to aircraft landing-gear, where energy is absorbed hydraulically, this multi-faceted fluid property can be detrimental in two ways: dynamically, i.e., loss of energy absorption ability and statically, i.e., improper aircraft attitude on the ground. The pupose of this paper is to bring an awareness to this property by presenting: (1) examples of these manifestations with some empirical and practical solutions to them, (2) illustrations of this normally `hidden saboteur` at work, (3) Henry`s Dissolved Gas Law, (4) room-temperature, saturated values of dissolved gas for a number of different working fluids, (5) a description of the instrument used to obtain them, (6) some `missing elements` of the Dissolved Gas Law pertaining to absoption, (7) how static and dynamic conditions effect gas absorption and (8) some recommended solutions to prevent becoming a victim of this `hidden saboteur`

  20. Dissolving pulp from jute stick.

    PubMed

    Matin, Mhafuza; Rahaman, M Mostafizur; Nayeem, Jannatun; Sarkar, Mamon; Jahan, M Sarwar

    2015-01-22

    Jute stick is woody portion of jute plant, which remain as leftover after extracting bast fibre. Presently, it is being used for fencing in the rural area. In this investigation, biorefinery concept was initiated in producing dissolving pulp from jute stick by pre-hydrolysis kraft process. At 170°C for 1h of pre-hydrolysis, 70% of hemicelluloses was dissolved with negligible loss of α-cellulose. At this condition, 75% of dissolved sugars in the pre-hydrolysis liquor were in the oligomeric form. The pre-hydrolysed jute stick was subsequently pulped by kraft process with the variation of active alkali. The pulp yield was 36.2% with kappa number 18.5 at the conditions of 16% active alkali for 2h of cooking at 170°C. Final pulp was produced with 92% α-cellulose and 89% brightness after D0EpD1EpD1 bleaching. The produced dissolving pulp can be used in rayon production. PMID:25439866

  1. Generating Water-Soluble Noxious Gases: An Overhead Projector Demonstration

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Oliver-Hoyo, Maria; Hur, Chinhyu

    1998-12-01

    A simple, inexpensive apparatus to generate and collect water-soluble noxious gases as an overhead projector demonstration can be made from two small beakers and a Petri dish. The detection and generation of sulfur dioxide and nitrogen dioxide are described. Sulfur dioxide dissolved in water is detected using an acid-base indicator, decolorizing of anthocyanin, or reduction of permanganate. The SO2 is generated by addition of sulfite or bisulfite to a strong acid or by the addition of concentrated sulfuric acid to sugars. Nitrogen dioxide is generated by mixing copper and nitric acid and detected using an acid-base indicator.

  2. Erosion patterns on dissolving blocks

    NASA Astrophysics Data System (ADS)

    Courrech du Pont, Sylvain; Cohen, Caroline; Derr, Julien; Berhanu, Michael

    2016-04-01

    Patterns in nature are shaped under water flows and wind action, and the understanding of their morphodynamics goes through the identification of the physical mechanisms at play. When a dissoluble body is exposed to a water flow, typical patterns with scallop-like shapes may appear [1,2]. These shapes are observed on the walls of underground rivers or icebergs. We experimentally study the erosion of dissolving bodies made of salt, caramel or ice into water solutions without external flow. The dissolving mixture, which is created at the solid/liquid interface, undergoes a buoyancy-driven instability comparable to a Rayleigh-Bénard instability so that the dissolving front destabilizes into filaments. This mechanism yields to spatial variations of solute concentration and to differential dissolution of the dissolving block. We first observe longitudinal stripes with a well defined wavelength, which evolve towards chevrons and scallops that interact and move again the dissolving current. Thanks to a careful analysis of the competing physical mechanisms, we propose scaling laws, which account for the characteristic lengths and times of the early regime in experiments. The long-term evolution of patterns is understood qualitatively. A close related mechanism has been proposed to explain structures observed on the basal boundary of ice cover on brakish lakes [3] and we suggest that our experiments are analogous and explain the scallop-like patterns on iceberg walls. [1] P. Meakin and B. Jamtveit, Geological pattern formation by growth and dissolution in aqueous systems, Proc. R. Soc. A 466, 659-694 (2010). [2] P.N. Blumberg and R.L. Curl, Experimental and theoretical studies of dissolution roughness, J. Fluid Mech. 65, 735-751 (1974). [3] L. Solari and G. Parker, Morphodynamic modelling of the basal boundary of ice cover on brakish lakes, J.G.R. 118, 1432-1442 (2013).

  3. Origin, speciation, and fluxes of trace-element gases at Augustine volcano, Alaska: Insights into magma degassing and fumarolic processes

    SciTech Connect

    Symonds, R.B.; Rose, W.I. ); Reed, M.H. )

    1992-02-01

    Thermochemical modeling predicts that trace elements in the Augustine gas are transported from near-surface magma as simple chloride, oxychloride, sulfide, and elemental gas species. However, Si, Ca, Al, Mg, Ti, V, and Cr are actually more concentrated in solids, beta-quartz (SiO{sub 2}), wollastonite (CaSiO{sub 3}), anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}), diopside (CaMgSi{sub 2}O{sub 6}), sphene (CaTiSiO{sub 5}), V{sub 2}O{sub 3}(c), and Cr{sub 2}O{sub 3}(c), respectively, than in their most abundant gaseous species, SiF{sub 4}, CaCl{sub 2}, AlF{sub 2}O, MgCl{sub 2}, TiCl{sub 4}, VOCl{sub 3}, and CrO{sub 2}Cl{sub 2}. Using the calculated distribution of gas species and the COSPEC SO{sub 2} fluxes, the authors have estimated the emission rates for many species. Such forecasts could be useful to evaluate the effects of these trace species on atmospheric chemistry. Because of the high volatility of metal chlorides, the extremely HCl-rich Augustine volcanic gases are favorable for transporting metals from magma. Thermochemical modeling shows that equilibrium degassing of magma near 870C can account for the concentrations of Fe, Na, K, Mn, Cu, Ni, and part of the Mg in the gases escaping from the dome fumaroles on the 1986 lava dome. Nonvolatile elements in the gas condensates came from eroded rock particles that dissolved in the authors' samples or, for Si, from contamination from the silica sampling tube. Erosion is more prevalent in the pyroclastic flow fumaroles than in the summit vents, reflecting physical differences in the fumarole walls: ash vs. lava. Trace element contents of volcanic gases show enormous variability because of differences in the intensive parameters of degassing magma and variable amounts of wall rock erosion in volcanic fumaroles.

  4. Forecasting Infectious Disease Outbreaks

    NASA Astrophysics Data System (ADS)

    Shaman, J. L.

    2015-12-01

    Dynamic models of infectious disease systems abound and are used to study the epidemiological characteristics of disease outbreaks, the ecological mechanisms affecting transmission, and the suitability of various control and intervention strategies. The dynamics of disease transmission are non-linear and consequently difficult to forecast. Here, we describe combined model-inference frameworks developed for the prediction of infectious diseases. We show that accurate and reliable predictions of seasonal influenza outbreaks can be made using a mathematical model representing population-level influenza transmission dynamics that has been recursively optimized using ensemble data assimilation techniques and real-time estimates of influenza incidence. Operational real-time forecasts of influenza and other infectious diseases have been and are currently being generated.

  5. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. PMID:26081307

  6. The forecaster's added value

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2009-09-01

    To the authors' knowledge there are relatively few studies that try to answer this topic: "Are humans able to add value to computer-generated forecasts and warnings ?". Moreover, the answers are not always positive. In particular some postprocessing method is competitive or superior to human forecast (see for instance Baars et al., 2005, Charba et al., 2002, Doswell C., 2003, Roebber et al., 1996, Sanders F., 1986). Within the alert system of ARPA Piemonte it is possible to study in an objective manner if the human forecaster is able to add value with respect to computer-generated forecasts. Every day the meteorology group of the Centro Funzionale of Regione Piemonte produces the HQPF (Human QPF) in terms of an areal average for each of the 13 regional warning areas, which have been created according to meteo-hydrological criteria. This allows the decision makers to produce an evaluation of the expected effects by comparing these HQPFs with predefined rainfall thresholds. Another important ingredient in this study is the very dense non-GTS network of rain gauges available that makes possible a high resolution verification. In this context the most useful verification approach is the measure of the QPF and HQPF skills by first converting precipitation expressed as continuous amounts into ‘‘exceedance'' categories (yes-no statements indicating whether precipitation equals or exceeds selected thresholds) and then computing the performances for each threshold. In particular in this work we compare the performances of the latest three years of QPF derived from two meteorological models COSMO-I7 (the Italian version of the COSMO Model, a mesoscale model developed in the framework of the COSMO Consortium) and IFS (the ECMWF global model) with the HQPF. In this analysis it is possible to introduce the hypothesis test developed by Hamill (1999), in which a confidence interval is calculated with the bootstrap method in order to establish the real difference between the

  7. Satellite freeze forecast system

    NASA Technical Reports Server (NTRS)

    Martsolf, J. D. (Principal Investigator)

    1983-01-01

    Provisions for back-up operations for the satellite freeze forecast system are discussed including software and hardware maintenance and DS/1000-1V linkage; troubleshooting; and digitized radar usage. The documentation developed; dissemination of data products via television and the IFAS computer network; data base management; predictive models; the installation of and progress towards the operational status of key stations; and digital data acquisition are also considered. The d addition of dew point temperature into the P-model is outlined.

  8. Uranium price forecasting methods

    SciTech Connect

    Fuller, D.M.

    1994-03-01

    This article reviews a number of forecasting methods that have been applied to uranium prices and compares their relative strengths and weaknesses. The methods reviewed are: (1) judgemental methods, (2) technical analysis, (3) time-series methods, (4) fundamental analysis, and (5) econometric methods. Historically, none of these methods has performed very well, but a well-thought-out model is still useful as a basis from which to adjust to new circumstances and try again.

  9. Frost Forecasting for Fruitgrowers

    NASA Technical Reports Server (NTRS)

    Martsolf, J. D.; Chen, E.

    1983-01-01

    Progress in forecasting from satellite data reviewed. University study found data from satellites displayed in color and used to predict frost are valuable aid to agriculture. Study evaluated scheme to use Earth-temperature data from Geostationary Operational Environmental Satellite in computer model that determines when and where freezing temperatures endanger developing fruit crops, such as apples, peaches and cherries in spring and citrus crops in winter.

  10. Land-Breeze Forecasting

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Wheeler, Mark M.; Merceret, Francis J. (Technical Monitor)

    2002-01-01

    The nocturnal land breeze at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) is both operationally significant and challenging to forecast. The occurrence and timing of land breezes impact low-level winds, atmospheric stability, low temperatures, and fog development. Accurate predictions of the land breeze are critical for toxic material dispersion forecasts associated with space launch missions, since wind direction and low-level stability can change noticeably with the onset of a land breeze. This report presents a seven-year observational study of land breezes over east-central Florida from 1995 to 2001. This comprehensive analysis was enabled by the high-resolution tower observations over KSC/CCAFS. Five-minute observations of winds, temperature, and moisture along with 9 15-MHz Doppler Radar Wind Profiler data were used to analyze specific land-breeze cases, while the tower data were used to construct a composite climatology. Utilities derived from this climatology were developed to assist forecasters in determining the land-breeze occurrence, timing, and movement based on predicted meteorological conditions.

  11. Global crop forecasting

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.; Hall, F. G.

    1980-01-01

    The needs for and remote sensing means of global crop forecasting are discussed, and key results of the Large Area Crop Inventory Experiment (LACIE) are presented. Current crop production estimates provided by foreign countries are shown often to be inadequate, and the basic elements of crop production forecasts are reviewed. The LACIE project is introduced as a proof-of-concept experiment designed to assimilate remote sensing technology, monitor global wheat production, evaluate key technical problems, modify the technique accordingly and demonstrate the feasibility of a global agricultural monitoring system. The global meteorological data, sampling and aggregation techniques, Landsat data analysis procedures and yield forecast procedures used in the experiment are outlined. Accuracy assessment procedures employed to evaluate LACIE technology performance are presented, and improvements in system efficiency and capacity during the three years of operation are pointed out. Results of LACIE estimates of Soviet, U.S. and Canadian wheat production are presented which demonstrate the feasibility and accuracy of the remote-sensing approach for global food and fiber monitoring.

  12. Kp forecast models

    NASA Astrophysics Data System (ADS)

    Meng, C.; Wing, S.; Johnson, J. R.; Jen, J.; Carr, S.; Sibeck, D. G.; Costello, K.; Freeman, J.; Balikhin, M.; Bechtold, K.; Vandegriff, J.

    2004-12-01

    Magnetically active times, e.g., Kp > 5, are notoriously difficult to predict, precisely when the predictions are crucial to the space weather users. Taking advantage of the routinely available solar wind measurements at Langrangian point (L1) and nowcast Kps, Kp forecast models based on neural networks were developed with the focus on improving the forecast for active times. In order to satisfy different needs and operational constraints, three models were developed: (1) model that inputs nowcast Kp, solar wind parameters, and predict Kp 1 hr ahead; (2) model with the same input as (1) and predict Kp 4 hr ahead; and (3) model that inputs only solar wind parameters and predict Kp 1 hr ahead (the exact prediction lead time depends on the solar wind speed and the location of the solar wind monitor). Extensive evaluations of these models and other major operational Kp forecast models show that while the new models can predict Kps more accurately for all activities, the most dramatic improvements occur for moderate and active times. The evaluations of the models over 2 solar cycles, 1975-2001, show that solar wind driven models predict Kp more accurately during solar maximum than solar minimum. This result, as well as information dynamics analysis of Kp, suggests that geospace is more dominated by internal dynamics during solar minimum than solar maximum, when it is more directly driven by external inputs, namely solar wind and IMF.

  13. Kp forecast models

    NASA Astrophysics Data System (ADS)

    Wing, S.; Johnson, J. R.; Jen, J.; Meng, C.-I.; Sibeck, D. G.; Bechtold, K.; Freeman, J.; Costello, K.; Balikhin, M.; Takahashi, K.

    2005-04-01

    Magnetically active times, e.g., Kp > 5, are notoriously difficult to predict, precisely the times when such predictions are crucial to the space weather users. Taking advantage of the routinely available solar wind measurements at Langrangian point (L1) and nowcast Kps, Kp forecast models based on neural networks were developed with the focus on improving the forecast for active times. To satisfy different needs and operational constraints, three models were developed: (1) a model that inputs nowcast Kp and solar wind parameters and predicts Kp 1 hour ahead; (2) a model with the same input as model 1 and predicts Kp 4 hour ahead; and (3) a model that inputs only solar wind parameters and predicts Kp 1 hour ahead (the exact prediction lead time depends on the solar wind speed and the location of the solar wind monitor). Extensive evaluations of these models and other major operational Kp forecast models show that while the new models can predict Kps more accurately for all activities, the most dramatic improvements occur for moderate and active times. Information dynamics analysis of Kp suggests that geospace is more dominated by internal dynamics near solar minimum than near solar maximum, when it is more directly driven by external inputs, namely solar wind and interplanetary magnetic field (IMF).

  14. Kp forecast models

    NASA Astrophysics Data System (ADS)

    Wing, S.; Johnson, J. R.; Meng, C.; Takahashi, K.

    2005-05-01

    Magnetically active times, e.g., Kp > 5, are notoriously difficult to predict, precisely the times when such predictions are crucial to the space weather users. Taking advantage of the routinely available solar wind measurements at Langrangian point (L1) and nowcast Kps, Kp forecast models based on neural networks were developed with the focus on improving the forecast for active times. To satisfy different needs and operational constraints, three models were developed: (1) a model that inputs nowcast Kp and solar wind parameters and predicts Kp 1 hr ahead; (2) a model with the same input as model 1 and predicts Kp 4 hr ahead; and (3) a model that inputs only solar wind parameters and predicts Kp 1 hr ahead (the exact prediction lead time depends on the solar wind speed and the location of the solar wind monitor.) Extensive evaluations of these models and other major operational Kp forecast models show that, while the new models can predict Kps more accurately for all activities, the most dramatic improvements occur for moderate and active times. Information dynamics analysis of Kp, suggests that geospace is more dominated by internal dynamics near solar minimum than near solar maximum, when it is more directly driven by external inputs, namely solar wind and interplanetary magnetic field (IMF).

  15. Forecasting geomagnetic activity indices

    NASA Astrophysics Data System (ADS)

    Schofield, J.; Wing, S.; Johnson, J. R.

    2007-12-01

    Magnetically active times, e.g., Kp > 5, are notoriously difficult to predict, precisely the times when such predictions are crucial to the space weather users. Taking advantage of the routinely available solar wind measurements at Langrangian point (L1) and nowcast Kps, Kp and Dst forecast models based on neural networks were developed with the focus on improving the forecast for active times. To satisfy different needs and operational constraints, three models were developed: (1) a model that inputs nowcast Kp and solar wind parameters and predicts Kp 1 hr ahead; (2) a model with the same input as model 1 and predicts Kp 4 hr ahead; and (3) a model that inputs only solar wind parameters and predicts Kp 1 hr ahead (the exact prediction lead time depends on the solar wind speed and the location of the solar wind monitor.) Extensive evaluations of these models and other major operational Kp forecast models show that, while the new models can predict Kps more accurately for all activities, the most dramatic improvements occur for moderate and active times. Similar Dst models were developed. Information dynamics analysis of Kp, suggests that geospace is more dominated by internal dynamics near solar minimum than near solar maximum, when it is more directly driven by external inputs, namely solar wind and interplanetary magnetic field (IMF).

  16. The Influence of Dissolved Carbon Dioxide on Cavitation Intensity in Ultrasound Cleaning Systems

    NASA Astrophysics Data System (ADS)

    Brems, Steven; Hauptmann, Marc; Camerotto, Elisabeth; Pacco, Antoine; Struyf, Herbert; Mertens, Paul; Gottschalk, Christiane; De Gendt, Stefan

    2013-06-01

    A study is made of the effect of dissolved CO2 on cavitation inception and activity in an ultrasound system with a sound frequency of 928 kHz. It is shown that measurable cavitation activity is completely absent at moderate acoustic power densities (≤1.7 W cm-2) when only CO2 is dissolved in ultra pure water. It is suggested that the enhanced stability of CO2 bubbles against coalescence might be the origin of the delayed cavitation inception when compared to other dissolved gases. A combination of dissolved O2 and CO2 can lead to a measurable cavitation activity at an acoustic power of 420 mW cm-2, but an increase of the dissolved CO2 level reduces, in general, the observed cavitation activity. In order to compare results with different dissolved gas concentrations, measurements are performed with acoustic pulses and the pulse off time is varied. An optimal pulse-off time exists, where a maximum of cavitation activity is observed. However, the pulse-off time interval with enhanced cavitation activity is narrowed with increasing dissolved CO2 concentrations. Again, a decrease in bubble coalescence might explain the narrowing of the “enhancement peak”.

  17. Investigation of spray characteristics for flashing injection of fuels containing dissolved air and superheated fuels

    NASA Technical Reports Server (NTRS)

    Solomon, A. S. P.; Chen, L. D.; Faeth, G. M.

    1982-01-01

    The flow, atomization and spreading of flashing injector flowing liquids containing dissolved gases (jet/air) as well as superheated liquids (Freon II) were considered. The use of a two stage expansion process separated by an expansion chamber, ws found to be beneficial for flashing injection particularly for dissolved gas systems. Both locally homogeneous and separated flow models provided good predictions of injector flow properties. Conventional correlations for drop sizes from pressure atomized and airblast injectors were successfully modified, using the separated flow model to prescribe injector exit conditions, to correlate drop size measurements. Additional experimental results are provided for spray angle and combustion properties of sprays from flashing injectors.

  18. EU pharmaceutical expenditure forecast

    PubMed Central

    Urbinati, Duccio; Rémuzat, Cécile; Kornfeld, Åsa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aballéa, Samuel; Mzoughi, Olfa; Toumi, Mondher

    2014-01-01

    Background and Objectives With constant incentives for healthcare payers to contain their pharmaceutical budgets, forecasting has become critically important. Some countries have, for instance, developed pharmaceutical horizon scanning units. The objective of this project was to build a model to assess the net effect of the entrance of new patented medicinal products versus medicinal products going off-patent, with a defined forecast horizon, on selected European Union (EU) Member States’ pharmaceutical budgets. This model took into account population ageing, as well as current and future country-specific pricing, reimbursement, and market access policies (the project was performed for the European Commission; see http://ec.europa.eu/health/healthcare/key_documents/index_en.htm). Method In order to have a representative heterogeneity of EU Member States, the following countries were selected for the analysis: France, Germany, Greece, Hungary, Poland, Portugal, and the United Kingdom. A forecasting period of 5 years (2012–2016) was chosen to assess the net pharmaceutical budget impact. A model for generics and biosimilars was developed for each country. The model estimated a separate and combined effect of the direct and indirect impacts of the patent cliff. A second model, estimating the sales development and the risk of development failure, was developed for new drugs. New drugs were reviewed individually to assess their clinical potential and translate it into commercial potential. The forecast was carried out according to three perspectives (healthcare public payer, society, and manufacturer), and several types of distribution chains (retail, hospital, and combined retail and hospital). Probabilistic and deterministic sensitivity analyses were carried out. Results According to the model, all countries experienced drug budget reductions except Poland (+€41 million). Savings were expected to be the highest in the United Kingdom (−€9,367 million), France

  19. Scavenging dissolved oxygen via acoustic droplet vaporization.

    PubMed

    Radhakrishnan, Kirthi; Holland, Christy K; Haworth, Kevin J

    2016-07-01

    Acoustic droplet vaporization (ADV) of perfluorocarbon emulsions has been explored for diagnostic and therapeutic applications. Previous studies have demonstrated that vaporization of a liquid droplet results in a gas microbubble with a diameter 5-6 times larger than the initial droplet diameter. The expansion factor can increase to a factor of 10 in gassy fluids as a result of air diffusing from the surrounding fluid into the microbubble. This study investigates the potential of this process to serve as an ultrasound-mediated gas scavenging technology. Perfluoropentane droplets diluted in phosphate-buffered saline (PBS) were insonified by a 2 MHz transducer at peak rarefactional pressures lower than and greater than the ADV pressure amplitude threshold in an in vitro flow phantom. The change in dissolved oxygen (DO) of the PBS before and after ADV was measured. A numerical model of gas scavenging, based on conservation of mass and equal partial pressures of gases at equilibrium, was developed. At insonation pressures exceeding the ADV threshold, the DO of air-saturated PBS decreased with increasing insonation pressures, dropping as low as 25% of air saturation within 20s. The decrease in DO of the PBS during ADV was dependent on the volumetric size distribution of the droplets and the fraction of droplets transitioned during ultrasound exposure. Numerically predicted changes in DO from the model agreed with the experimentally measured DO, indicating that concentration gradients can explain this phenomenon. Using computationally modified droplet size distributions that would be suitable for in vivo applications, the DO of the PBS was found to decrease with increasing concentrations. This study demonstrates that ADV can significantly decrease the DO in an aqueous fluid, which may have direct therapeutic applications and should be considered for ADV-based diagnostic or therapeutic applications. PMID:26964964

  20. Hydrological Forecasting Practices in Brazil

    NASA Astrophysics Data System (ADS)

    Fan, Fernando; Paiva, Rodrigo; Collischonn, Walter; Ramos, Maria-Helena

    2016-04-01

    This work brings a review on current hydrological and flood forecasting practices in Brazil, including the main forecasts applications, the different kinds of techniques that are currently being employed and the institutions involved on forecasts generation. A brief overview of Brazil is provided, including aspects related to its geography, climate, hydrology and flood hazards. A general discussion about the Brazilian practices on hydrological short and medium range forecasting is presented. Detailed examples of some hydrological forecasting systems that are operational or in a research/pre-operational phase using the large scale hydrological model MGB-IPH are also presented. Finally, some suggestions are given about how the forecasting practices in Brazil can be understood nowadays, and what are the perspectives for the future.

  1. Operational hydrological forecasting in Bavaria. Part I: Forecast uncertainty

    NASA Astrophysics Data System (ADS)

    Ehret, U.; Vogelbacher, A.; Moritz, K.; Laurent, S.; Meyer, I.; Haag, I.

    2009-04-01

    In Bavaria, operational flood forecasting has been established since the disastrous flood of 1999. Nowadays, forecasts based on rainfall information from about 700 raingauges and 600 rivergauges are calculated and issued for nearly 100 rivergauges. With the added experience of the 2002 and 2005 floods, awareness grew that the standard deterministic forecast, neglecting the uncertainty associated with each forecast is misleading, creating a false feeling of unambiguousness. As a consequence, a system to identify, quantify and communicate the sources and magnitude of forecast uncertainty has been developed, which will be presented in part I of this study. In this system, the use of ensemble meteorological forecasts plays a key role which will be presented in part II. Developing the system, several constraints stemming from the range of hydrological regimes and operational requirements had to be met: Firstly, operational time constraints obviate the variation of all components of the modeling chain as would be done in a full Monte Carlo simulation. Therefore, an approach was chosen where only the most relevant sources of uncertainty were dynamically considered while the others were jointly accounted for by static error distributions from offline analysis. Secondly, the dominant sources of uncertainty vary over the wide range of forecasted catchments: In alpine headwater catchments, typically of a few hundred square kilometers in size, rainfall forecast uncertainty is the key factor for forecast uncertainty, with a magnitude dynamically changing with the prevailing predictability of the atmosphere. In lowland catchments encompassing several thousands of square kilometers, forecast uncertainty in the desired range (usually up to two days) is mainly dependent on upstream gauge observation quality, routing and unpredictable human impact such as reservoir operation. The determination of forecast uncertainty comprised the following steps: a) From comparison of gauge

  2. Process for removing sulfur dioxide from flue gases

    SciTech Connect

    Stowe, D.H. Jr.; Benson, L.B.

    1991-02-26

    This patent describes improvement in a process for removing sulfur dioxide from flue gases in a wet scrubber, wherein an aqueous slurry formed from calcium hydroxide and magnesium hydroxide is contacted in the wet scrubber with the flue gases, and the slurry, after the contact, contains calcium sulfite solids and dissolved magnesium sulfite, and is discharged from the wet scrubber and passed to a thickener wherein a thickened aqueous sludge containing calcium sulfite solids is separated from an overflow liquor. The improvement comprises: returning at least a portion of the overflow liquor to the wet scrubber; concentrating the thickened aqueous sludge by removal of a sulfite solution, comprising water containing dissolved magnesium sulfite, therefrom; returning a first portion of the sulfite solution to the thickener; oxidizing magnesium sulfite in a second portion of the sulfite solution to form a sulfate solution containing magnesium sulfate; adding lime to the sulfate solution following the oxidation, to precipitate calcium sulfate and form an aqueous magnesium hydroxide suspension; and separating precipitated calcium sulfate from the aqueous magnesium hydroxide suspension.

  3. Abating environmentally harmful waste gases

    NASA Astrophysics Data System (ADS)

    Sridhar, S.; Sichen, Du; Pal, U. B.; Seetharaman, S.

    2002-05-01

    A gas-purification method, based on the condensation of nitrogen, sulfur, and carbon-containing environmentally hazardous gases produced from industrial processes, is proposed in this article. The method, which utilizes the cooling capacity of waste nitrogen in the oxygen plant to condense the hazardous gases, is capable of removing hazardous impurities up to 99.98%. Theoretical calculations underlying the condensation process are presented employing gases produced in a blast furnace and coke oven in an integrated steel plant. The cooling power required for the condensation process is calculated using the waste nitrogen generated from an oxygen plant that generates captive oxygen for the steel plant. Design modifications that need to be made to the oxygen plant in order to utilize the cooling power of the waste nitrogen gas are also presented. As a case study, the advantages of the method are illustrated with purification of coke-oven gas. The economic impact and the investment aspects are also discussed.

  4. Solar Indices Forecasting Tool

    NASA Astrophysics Data System (ADS)

    Henney, Carl John; Shurkin, Kathleen; Arge, Charles; Hill, Frank

    2016-05-01

    Progress to forecast key space weather parameters using SIFT (Solar Indices Forecasting Tool) with the ADAPT (Air Force Data Assimilative Photospheric flux Transport) model is highlighted in this presentation. Using a magnetic flux transport model, ADAPT, we estimate the solar near-side field distribution that is used as input into empirical models for predicting F10.7(solar 10.7 cm, 2.8 GHz, radio flux), the Mg II core-to-wing ratio, and selected bands of solar far ultraviolet (FUV) and extreme ultraviolet (EUV) irradiance. Input to the ADAPT model includes the inferred photospheric magnetic field from the NISP ground-based instruments, GONG & VSM. Besides a status update regarding ADAPT and SIFT models, we will summarize the findings that: 1) the sum of the absolute value of strong magnetic fields, associated with sunspots, is shown to correlate well with the observed daily F10.7 variability (Henney et al. 2012); and 2) the sum of the absolute value of weak magnetic fields, associated with plage regions, is shown to correlate well with EUV and FUV irradiance variability (Henney et al. 2015). This work utilizes data produced collaboratively between Air Force Research Laboratory (AFRL) and the National Solar Observatory (NSO). The ADAPT model development is supported by AFRL. The input data utilized by ADAPT is obtained by NISP (NSO Integrated Synoptic Program). NSO is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under a cooperative agreement with the National Science Foundation (NSF). The 10.7 cm solar radio flux data service, utilized by the ADAPT/SIFT F10.7 forecasting model, is operated by the National Research Council of Canada and National Resources Canada, with the support of the Canadian Space Agency.

  5. Forecast Mekong: 2011 update

    USGS Publications Warehouse

    Turnipseed, D. Phil

    2011-01-01

    In 2009, U.S. Secretary of State Hillary R. Clinton joined with the Foreign Ministers of Cambodia, Laos, Thailand, and Vietnam in launching the Lower Mekong Initiative to enhance U.S. engagement with the Lower Mekong countries in the areas of environment, health, education, and infrastructure. Part of the Lower Mekong Initiative, the U.S. Geological Survey's Forecast Mekong project is engaging the United States in scientific research relevant to environmental issues in the Lower Mekong River countries and is staying the course in support of the Mekong Nations with a suite of new projects for 2011.

  6. Forecasting in Complex Systems

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Holliday, J. R.; Graves, W. R.; Turcotte, D. L.; Donnellan, A.

    2014-12-01

    Complex nonlinear systems are typically characterized by many degrees of freedom, as well as interactions between the elements. Interesting examples can be found in the areas of earthquakes and finance. In these two systems, fat tails play an important role in the statistical dynamics. For earthquake systems, the Gutenberg-Richter magnitude-frequency is applicable, whereas for daily returns for the securities in the financial markets are known to be characterized by leptokurtotic statistics in which the tails are power law. Very large fluctuations are present in both systems. In earthquake systems, one has the example of great earthquakes such as the M9.1, March 11, 2011 Tohoku event. In financial systems, one has the example of the market crash of October 19, 1987. Both were largely unexpected events that severely impacted the earth and financial systems systemically. Other examples include the M9.3 Andaman earthquake of December 26, 2004, and the Great Recession which began with the fall of Lehman Brothers investment bank on September 12, 2013. Forecasting the occurrence of these damaging events has great societal importance. In recent years, national funding agencies in a variety of countries have emphasized the importance of societal relevance in research, and in particular, the goal of improved forecasting technology. Previous work has shown that both earthquakes and financial crashes can be described by a common Landau-Ginzburg-type free energy model. These metastable systems are characterized by fat tail statistics near the classical spinodal. Correlations in these systems can grow and recede, but do not imply causation, a common source of misunderstanding. In both systems, a common set of techniques can be used to compute the probabilities of future earthquakes or crashes. In this talk, we describe the basic phenomenology of these systems and emphasize their similarities and differences. We also consider the problem of forecast validation and verification

  7. Weather Forecasting Aid

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Weather forecasters are usually very precise in reporting such conditions as temperature, wind velocity and humidity. They also provide exact information on barometric pressure at a given moment, and whether the barometer is "rising" or "falling"- but not how rapidly or how slowly it is rising or falling. Until now, there has not been available an instrument which measures precisely the current rate of change of barometric pressure. A meteorological instrument called a barograph traces the historical ups and downs of barometric pressure and plots a rising or falling curve, but, updated every three hours, it is only momentarily accurate at each updating.

  8. Isothermal compressors for process gases

    SciTech Connect

    Wiederuh, E.; Meinhart, D. )

    1992-09-01

    This paper reports on isothermal compressors which are more efficient for all gases. The study of several representative gases considered stage efficiencies, pressure ratios and pressure losses of the intercoolers. Generally there are two ways to reduce power consumption of a gas compression process: minimize losses of the compressor or improve the thermodynamics of the process. But there are some new ways to reduce losses of turbocompressors. Losses of the impeller labyrinth seals and the balance piston labyrinth seal can be reduced by optimizing the labyrinth geometry and minimizing labyrinth clearances. Therefore, conventional labyrinth seals are still being studied and will be improved.

  9. Conduction of Electricity through Gases

    NASA Astrophysics Data System (ADS)

    Thomson, J. J.; Thomson, G. P.

    2013-06-01

    1. Electrical conductivity of gases in a normal state; 2. Properties of a gas when in a conducting state; 3. Mobility of ions; 4. Mathematical theory of the conduction of electricity through a gas containing ions; 5. Effect produced by a magnetic field on the motion of the ions; 6. Determination of the ratio of the charge to the mass of an ion; 7. Determination of the charge carried by the negative ion; 8. On some physical properties of gaseous ions; 9. Ionisation by incandescent solids; 10. Ionisation in gases from flames; 11. Ionisation by light. Photo-electric effects; Name index; Subject index.

  10. Quantum Gases in Optical Lattices

    NASA Astrophysics Data System (ADS)

    Barmettler, Peter; Kollath, Corinna

    2015-09-01

    The experimental realization of correlated quantum phases with ultracold gases in optical lattices and their theoretical understanding has witnessed remarkable progress during the last decade. In this review we introduce basic concepts and tools to describe the many-body physics of quantum gases in optical lattices. This includes the derivation of effective lattice Hamiltonians from first principles and an overview of the emerging quantum phases. Additionally, state-of-the-art numerical tools to quantitatively treat bosons or fermions on different lattices are introduced.

  11. Interactive Forecasting with the National Weather Service River Forecast System

    NASA Technical Reports Server (NTRS)

    Smith, George F.; Page, Donna

    1993-01-01

    The National Weather Service River Forecast System (NWSRFS) consists of several major hydrometeorologic subcomponents to model the physics of the flow of water through the hydrologic cycle. The entire NWSRFS currently runs in both mainframe and minicomputer environments, using command oriented text input to control the system computations. As computationally powerful and graphically sophisticated scientific workstations became available, the National Weather Service (NWS) recognized that a graphically based, interactive environment would enhance the accuracy and timeliness of NWS river and flood forecasts. Consequently, the operational forecasting portion of the NWSRFS has been ported to run under a UNIX operating system, with X windows as the display environment on a system of networked scientific workstations. In addition, the NWSRFS Interactive Forecast Program was developed to provide a graphical user interface to allow the forecaster to control NWSRFS program flow and to make adjustments to forecasts as necessary. The potential market for water resources forecasting is immense and largely untapped. Any private company able to market the river forecasting technologies currently developed by the NWS Office of Hydrology could provide benefits to many information users and profit from providing these services.

  12. Microbial metabolism and the geochemistry of bioactive gases in Kamchatka and Lassen hot springs

    NASA Astrophysics Data System (ADS)

    He, B.; Robb, F. T.; Colman, A. S.

    2013-12-01

    Thermophilic and hyperthermophilic metabolisms include several pathways that involve dissolved gases as carbon sources, energy sources, and/or waste products. In hot springs, dissolved gas concentrations are often compared with concentrations predicted based upon equilibration with free phase gases bubbling up in the same springs. This comparison guides the inference of metabolic modes in the subsurface, spring vents, and outflow channels. Supersaturation is invoked as a signal of a biogenic source for the gas, while undersaturation is interpreted to indicate microbial consumption. However, these conventional interpretations of disequilibria between dissolved and free phase gases can be misleading. They ignore the decoupling of water and free phase gas transport in terrestrial hot springs and the effects on gas solubility of thermal and pressure gradients that exist as fluids travel from depth to vent. We have surveyed two significant geothermal regions: Lassen Volcanic National Park (LVNP), California, USA (July, 2009), and Uzon Caldera, Kamchatka, Russia (August, 2010) in past years. We collected and analyzed both free phase and dissolved gas composition from a number of hot springs in each region. We used Henry's Law to calculate apparent saturation state of the dissolved gases with respect to the free phases gases bubbling up in the springs. We then constructed a 1-D gas exchange-transport model to examine the thermodynamic drivers and potential kinetic hindrances to gas exchange and equilibration in water and gases ascending continental hot spring systems. Specifically, this model takes into account: (1) the vertical gradient in temperature and pressure, (2) interaction between the bioactive gases via water gas shift reaction, and (3) fluid transport from subsurface to vent. We have modeled several end-member transport-exchange scenarios: (1) gas and spring water co-ascend in a closed system, with instantaneous equilibration between free phase and dissolved

  13. Novel Apparatus for the Real-Time Quantification of Dissolved Gas Concentrations and Isotope Ratios

    NASA Astrophysics Data System (ADS)

    Gupta, M.; Leen, J.; Baer, D. S.; Owano, T. G.; Liem, J.

    2013-12-01

    Measurements of dissolved gases and their isotopic composition are critical in studying a variety of phenomena, including underwater greenhouse gas generation, air-surface exchange, and pollution migration. These studies typically involve obtaining water samples from streams, lakes, or ocean water and transporting them to a laboratory, where they are degased. The gases obtained are then generally measured using gas chromatography and isotope ratio mass spectrometry for concentrations and isotope ratios, respectively. This conventional, off-line methodology is time consuming, significantly limits the number of the samples that can be measured and thus severely inhibits detailed spatial and temporal mapping of gas concentrations and isotope ratios. In this work, we describe the development of a new membrane-based degassing device that interfaces directly to Los Gatos Research (cavity enhanced laser absorption or Off-Axis ICOS) gas analyzers (cavity enhanced laser absorption or Off-Axis ICOS analyzers) to create an autonomous system that can continuously and quickly measure concentrations and isotope ratios of dissolved gases in real time in the field. By accurately controlling the water flow rate through the membrane degasser, gas pressure on the outside of the membrane, and water pressure on the inside of the membrane, the system is able to generate precise and highly reproducible results. Moreover, by accurately measuring the gas flow rates in and out of the degasser, the gas-phase concentrations (ppm) could be converted into dissolved gas concentrations (nM). We will present detailed laboratory test data that quantifies the linearity, precision, and dynamic range of the system for the concentrations and isotope ratios of dissolved methane, carbon dioxide, and nitrous oxide. By interfacing the degassing device to a novel cavity-enhanced spectrometer (developed by LGR), preliminary data will also be presented for dissolved volatile organics (VOC) and other

  14. Mass transport phenomena between bubbles and dissolved gases in liquids under reduced gravity conditions

    NASA Technical Reports Server (NTRS)

    Dewitt, Kenneth J.; Brockwell, Jonathan L.; Yung, Chain-Nan; Chai, An-Ti; Mcquillen, John B.; Sotos, Raymond G.; Neumann, Eric S.

    1988-01-01

    This paper will describe the experimental and analytical work that has been done to establish justification and feasibility for a Shuttle mid-deck experiment involving mass transfer between a gas bubble and a liquid. The experiment involves the observation and measurement of the dissolution of an isolated, immobile gas bubble of specified size and composition in a thermostatted solvent liquid of known concentration in the reduced gravity environment of earth orbit. Methods to generate and deploy the bubble have been successful both in normal gravity using mutually buoyant fluids and under reduced gravity conditions in the NASA Lear Jet. Initialization of the experiment with a bubble of a prescribed size and composition in a liquid of known concentration has been accomplished using the concept of unstable equilibrium. Subsequent bubble dissolution or growth is obtained by a step increase or decrease in the liquid pressure. A numerical model has been developed which simulates the bubble dynamics and can be used to determine molecular parameters by comparison with the experimental data. The primary objective of the experiment is the elimination of convective effects that occur in normal gravity. The results will yield information on transport under conditions of pure diffusion.

  15. Mass transport phenomena between bubbles and dissolved gases in liquids under reduced gravity conditions

    NASA Technical Reports Server (NTRS)

    Dewitt, Kenneth J.; Brockwell, Jonathan L.; Yung, Chain-Nan; Chai, An-Ti; Mcquillen, John B.; Sotos, Raymond G.; Neumann, Eric S.

    1988-01-01

    The experimental and analytical work that was done to establish justification and feasibility for a shuttle middeck experiment involving mass transfer between a gas bubble and a liquid is described. The experiment involves the observation and measurement of the dissolution of an isolated immobile gas bubble of specified size and composition in a thermostatted solvent liquid of known concentration in the reduced gravity environment of earth orbit. Methods to generate and deploy the bubble were successful both in normal gravity using mutually buoyant fluids and under reduced gravity conditions in the NASA Lear Jet. Initialization of the experiment with a bubble of a prescribed size and composition in a liquid of known concentration was accomplished using the concept of unstable equilibrium. Subsequent bubble dissolution or growth is obtained by a step increase or decrease in the liquid pressure. A numerical model was developed which simulates the bubble dynamics and can be used to determine molecular parameters by comparison with the experimental data. The primary objective of the experiment is the elimination of convective effects that occur in normal gravity.

  16. Mass Transport Phenomena Between Bubbles and Dissolved Gases in Liquids Under Reduced Gravity Conditions

    NASA Technical Reports Server (NTRS)

    Dewitt, K. J.; Brockwell, J. L.

    1985-01-01

    The long term objective of the experiment is to observe the dissolution of isolated, immobile gas bubbles of specified size and composition in a solvent liquid of known concentration in the reduced gravity environment of earth orbit. Preliminary bubble dissolution experiment conducted both in the NASA Lewis 2.2 sec drop tower and in normal gravity using SO2 - Toluene system were not completely successful in their objective. The method of gas injection and lack of bubble interface stabiliy experienced due to the extreme solubility of SO in Toluene has the effects of changing the problem from that of bubble dissolution to one of bubble formation stability and subsequent dissolution in a liquid of unknown initial solute concentration. Current work involves further experimentation in order to refine the bubble injection system and to investigate the concept of having a bubble with a critical radius in a state of unstable equilibrium.

  17. Dissolved atmospheric gas in xylem sap measured with membrane inlet mass spectrometry.

    PubMed

    Schenk, H Jochen; Espino, Susana; Visser, Ate; Esser, Bradley K

    2016-04-01

    A new method is described for measuring dissolved gas concentrations in small volumes of xylem sap using membrane inlet mass spectrometry. The technique can be used to determine concentrations of atmospheric gases, such as argon, as reported here, or for any dissolved gases and their isotopes for a variety of applications, such as rapid detection of trace gases from groundwater only hours after they were taken up by trees and rooting depth estimation. Atmospheric gas content in xylem sap directly affects the conditions and mechanisms that allow for gas removal from xylem embolisms, because gas can dissolve into saturated or supersaturated sap only under gas pressure that is above atmospheric pressure. The method was tested for red trumpet vine, Distictis buccinatoria (Bignoniaceae), by measuring atmospheric gas concentrations in sap collected at times of minimum and maximum daily temperature and during temperature increase and decline. Mean argon concentration in xylem sap did not differ significantly from saturation levels for the temperature and pressure conditions at any time of collection, but more than 40% of all samples were supersaturated, especially during the warm parts of day. There was no significant diurnal pattern, due to high variability between samples. PMID:26868162

  18. PROCESS OF DISSOLVING ZIRCONIUM ALLOYS

    DOEpatents

    Shor, R.S.; Vogler, S.

    1958-01-21

    A process is described for dissolving binary zirconium-uranium alloys where the uranium content is about 2%. In prior dissolution procedures for these alloys, an oxidizing agent was added to prevent the precipitation of uranium tetrafluoride. In the present method complete dissolution is accomplished without the use of the oxidizing agent by using only the stoichiometric amount or slight excess of HF required by the zirconium. The concentration of the acid may range from 2M to 10M and the dissolution is advatageously carried out at a temperature of 80 deg C.

  19. Origin, speciation, and fluxes of trace-element gases at Augustine volcano, Alaska: Insights into magma degassing and fumarolic processes

    NASA Astrophysics Data System (ADS)

    Symonds, Robert B.; Reed, Mark H.; Rose, William I.

    1992-02-01

    Thermochemical modeling predicts that trace elements in the Augustine gas are transported from near-surface magma as simple chloride (NaCl, KCl, FeCl 2, ZnCl 2, PbCl 2, CuCl, SbCl 3, LiCl, MnCl 2, NiCl 2, BiCl, SrCl 2), oxychloride (MoO 2Cl 2), sulfide (AsS), and elemental (Cd) gas species. However, Si, Ca, Al, Mg, Ti, V, and Cr are actually more concentrated in solids, beta-quartz (SiO 2), wollastonite (CaSiO 3), anorthite (CaAl 2Si 2O 8), diopside (CaMgSi 2O 6), sphene (CaTiSiO 5), V 2O 3(c), and Cr 2O 3(c), respectively, than in their most abundant gaseous species, SiF 4, CaCl 2, AlF 2O, MgCl 2 TiCl 4, VOCl 3, and CrO 2Cl 2. These computed solids are not degassing products, but reflect contaminants in our gas condensates or possible problems with our modeling due to "missing" gas species in the thermochemical data base. Using the calculated distribution of gas species and the COSPEC SO 2 fluxes, we have estimated the emission rates for many species (e.g., COS, NaCl, KCl, HBr, AsS, CuCl). Such forecasts could be useful to evaluate the effects of these trace species on atmospheric chemistry. Because of the high volatility of metal chlorides (e.g., FeCl 2, NaCl, KCl, MnCl 2, CuCl), the extremely HCl-rich Augustine volcanic gases are favorable for transporting metals from magma. Thermochemical modeling shows that equilibrium degassing of magma near 870°C can account for the concentrations of Fe, Na, K, Mn, Cu, Ni and part of the Mg in the gases escaping from the dome fumaroles on the 1986 lava dome. These calculations also explain why gases escaping from the lower temperature but highly oxidized moat vents on the 1976 lava dome should transport less Fe, Na, K, Mn and Ni, but more Cu; oxidation may also account for the larger concentrations of Zn and Mo in the moat gases. Nonvolatile elements (e.g., Al, Ca, Ti, Si) in the gas condensates came from eroded rock particles that dissolved in our samples or, for Si, from contamination from the silica sampling tube. Only a

  20. Interaction quenches of Fermi gases

    SciTech Connect

    Uhrig, Goetz S.

    2009-12-15

    It is shown that the jump in the momentum distribution of Fermi gases evolves smoothly for small and intermediate times once an interaction between the fermions is suddenly switched on. The jump does not vanish abruptly. The loci in momentum space where the jumps occur are those of the noninteracting Fermi sea. No relaxation of the Fermi surface geometry takes place.

  1. Social Indicators and Social Forecasting.

    ERIC Educational Resources Information Center

    Johnston, Denis F.

    The paper identifies major types of social indicators and explains how they can be used in social forecasting. Social indicators are defined as statistical measures relating to major areas of social concern and/or individual well being. Examples of social indicators are projections, forecasts, outlook statements, time-series statistics, and…

  2. Regional-seasonal weather forecasting

    SciTech Connect

    Abarbanel, H.; Foley, H.; MacDonald, G.; Rothaus, O.; Rudermann, M.; Vesecky, J.

    1980-08-01

    In the interest of allocating heating fuels optimally, the state-of-the-art for seasonal weather forecasting is reviewed. A model using an enormous data base of past weather data is contemplated to improve seasonal forecasts, but present skills do not make that practicable. 90 references. (PSB)

  3. Forecasting School District Fiscal Health.

    ERIC Educational Resources Information Center

    Smith, Curtis A.

    1986-01-01

    This paper's goal is to redefine fiscal health by broadening its predictive function and to determine which fiscal indicators are useful for forecasting fiscal health for one, two, and three years. Results indicate that school district fiscal health forecasts are potentially great planning tools for local for local decision makers. Includes 11…

  4. The pioneers of weather forecasting

    NASA Astrophysics Data System (ADS)

    Ballard, Susan

    2016-01-01

    In The Weather Experiment author Peter Moore takes us on a compelling journey through the early history of weather forecasting, bringing to life the personalities, lives and achievements of the men who put in place the building blocks required for forecasts to be possible.

  5. Statistical Earthquake Focal Mechanism Forecasts

    NASA Astrophysics Data System (ADS)

    Kagan, Y. Y.; Jackson, D. D.

    2013-12-01

    The new whole Earth focal mechanism forecast, based on the GCMT catalog, has been created. In the present forecast, the sum of normalized seismic moment tensors within 1000 km radius is calculated and the P- and T-axes for the focal mechanism are evaluated on the basis of the sum. Simultaneously we calculate an average rotation angle between the forecasted mechanism and all the surrounding mechanisms. This average angle shows tectonic complexity of a region and indicates the accuracy of the prediction. The method was originally proposed by Kagan and Jackson (1994, JGR). Recent interest by CSEP and GEM has motivated some improvements, particularly to extend the previous forecast to polar and near-polar regions. The major problem in extending the forecast is the focal mechanism calculation on a spherical surface. In the previous forecast as our average focal mechanism was computed, it was assumed that longitude lines are approximately parallel within 1000 km radius. This is largely accurate in the equatorial and near-equatorial areas. However, when one approaches the 75 degree latitude, the longitude lines are no longer parallel: the bearing (azimuthal) difference at points separated by 1000 km reach about 35 degrees. In most situations a forecast point where we calculate an average focal mechanism is surrounded by earthquakes, so a bias should not be strong due to the difference effect cancellation. But if we move into polar regions, the bearing difference could approach 180 degrees. In a modified program focal mechanisms have been projected on a plane tangent to a sphere at a forecast point. New longitude axes which are parallel in the tangent plane are corrected for the bearing difference. A comparison with the old 75S-75N forecast shows that in equatorial regions the forecasted focal mechanisms are almost the same, and the difference in the forecasted focal mechanisms rotation angle is close to zero. However, though the forecasted focal mechanisms are similar

  6. Erosion Patterns on Dissolving Surfaces

    NASA Astrophysics Data System (ADS)

    Cohen, Caroline; Polizzi, Stefano; Berhanu, Michael; Derr, Julien; Courrech Du Pont, Sylvain

    2015-11-01

    The shaping of landscapes results from water or wind erosional processes. Here we focus on dissolution processes. We perform laboratory experiments on hard caramel bodies, which dissolve on a short timescale, compared to geological material such as limestone. We highlight the spontaneous appearance of a dissolution pattern with no external flow. When a tilted hard caramel block dissolves, the syrup (denser than water) sinks in the bath and induces a flow, which results in a pattern on the bottom of the block. First parallel stripes appear, which evolve to transversal scallops in about one hour. The whole pattern moves upstream at a slow velocity. The stripes appearance is due to a buoyancy-driven instability. By varying the density and the viscosity of the bath, we show that the initial wavelengths of the pattern are in agreement with those given by the solutal Rayleigh-Benard number. Later pattern evolution to scallops results from complex interactions between the flow and the topography. Finally we emphasize that similar mechanism of patterns formation can occur in the dissolution of minerals like salt, but also in the shaping of the bottom face of melting icebergs in the cold seas.

  7. Weather Forecasting Systems and Methods

    NASA Technical Reports Server (NTRS)

    Mecikalski, John (Inventor); MacKenzie, Wayne M., Jr. (Inventor); Walker, John Robert (Inventor)

    2014-01-01

    A weather forecasting system has weather forecasting logic that receives raw image data from a satellite. The raw image data has values indicative of light and radiance data from the Earth as measured by the satellite, and the weather forecasting logic processes such data to identify cumulus clouds within the satellite images. For each identified cumulus cloud, the weather forecasting logic applies interest field tests to determine a score indicating the likelihood of the cumulus cloud forming precipitation and/or lightning in the future within a certain time period. Based on such scores, the weather forecasting logic predicts in which geographic regions the identified cumulus clouds will produce precipitation and/or lighting within during the time period. Such predictions may then be used to provide a weather map thereby providing users with a graphical illustration of the areas predicted to be affected by precipitation within the time period.

  8. EDITORIAL: Cold Quantum GasesEditorial: Cold Quantum Gases

    NASA Astrophysics Data System (ADS)

    Vassen, W.; Hemmerich, A.; Arimondo, E.

    2003-04-01

    This Special Issue of Journal of Optics B: Quantum and Semiclassical Optics brings together the contributions of various researchers working on theoretical and experimental aspects of cold quantum gases. Different aspects of atom optics, matter wave interferometry, laser manipulation of atoms and molecules, and production of very cold and degenerate gases are presented. The variety of subjects demonstrates the steadily expanding role associated with this research area. The topics discussed in this issue, extending from basic physics to applications of atom optics and of cold atomic samples, include: bulletBose--Einstein condensation bulletFermi degenerate gases bulletCharacterization and manipulation of quantum gases bulletCoherent and nonlinear cold matter wave optics bulletNew schemes for laser cooling bulletCoherent cold molecular gases bulletUltra-precise atomic clocks bulletApplications of cold quantum gases to metrology and spectroscopy bulletApplications of cold quantum gases to quantum computing bulletNanoprobes and nanolithography. This special issue is published in connection with the 7th International Workshop on Atom Optics and Interferometry, held in Lunteren, The Netherlands, from 28 September to 2 October 2002. This was the last in a series of Workshops organized with the support of the European Community that have greatly contributed to progress in this area. The scientific part of the Workshop was managed by A Hemmerich, W Hogervorst, W Vassen and J T M Walraven, with input from members of the International Programme Committee who are listed below. The practical aspects of the organization were ably handled by Petra de Gijsel from the Vrije Universiteit in Amsterdam. The Workshop was funded by the European Science Foundation (programme BEC2000+), the European Networks 'Cold Quantum Gases (CQG)', coordinated by E Arimondo, and 'Cold Atoms and Ultraprecise Atomic Clocks (CAUAC)', coordinated by J Henningsen, by the German Physical Society (DFG), by

  9. Lessons from geothermal gases at Yellowstone

    NASA Astrophysics Data System (ADS)

    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 (<0.01% gas) dominated by N2 and Ar. The clear implication is that deep gas is diluted with atmospheric gas boiled off of geothermal liquids. The general trend is antithetical to that predicted by progressive boiling of a parent fluid (Rayleigh or batch degassing), where decreasing gas content should correlate with increasing proportions of soluble gas (i.e., CO2). Deep gas at Yellowstone fits into two general categories: 1) mantle-derived CO2 with a hotspot He isotope signature (>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

  10. METHOD OF DISSOLVING REFRACTORY ALLOYS

    DOEpatents

    Helton, D.M.; Savolainen, J.K.

    1963-04-23

    This patent relates to the dissolution of alloys of uranium with zirconium, thorium, molybdenum, or niobium. The alloy is contacted with an anhydrous solution of mercuric chloride in a low-molecular-weight monohydric alcohol to produce a mercury-containing alcohol slurry. The slurry is then converted to an aqueous system by adding water and driving off the alcohol. The resulting aqueous slurry is electrolyzed in the presence of a mercury cathode to remove the mercury and produce a uranium-bearing aqueous solution. This process is useful for dissolving irradiated nuclear reactor fuels for radiochemical reprocessing by solvent extraction. In addition, zirconium-alloy cladding is selectively removed from uranium dioxide fuel compacts by this means. (AEC)

  11. Atmospheric composition forecasting in Europe

    NASA Astrophysics Data System (ADS)

    Menut, L.; Bessagnet, B.

    2010-01-01

    The atmospheric composition is a societal issue and, following new European directives, its forecast is now recommended to quantify the air quality. It concerns both gaseous and particles species, identified as potential problems for health. In Europe, numerical systems providing daily air quality forecasts are numerous and, mostly, operated by universities. Following recent European research projects (GEMS, PROMOTE), an organization of the air quality forecast is currently under development. But for the moment, many platforms exist, each of them with strengths and weaknesses. This overview paper presents all existing systems in Europe and try to identify the main remaining gaps in the air quality forecast knowledge. As modeling systems are now able to reasonably forecast gaseous species, and in a lesser extent aerosols, the future directions would concern the use of these systems with ensemble approaches and satellite data assimilation. If numerous improvements were recently done on emissions and chemistry knowledge, improvements are still needed especially concerning meteorology, which remains a weak point of forecast systems. Future directions will also concern the use of these forecast tools to better understand and quantify the air pollution impact on health.

  12. Forecasts of geomagnetic secular variation

    NASA Astrophysics Data System (ADS)

    Wardinski, Ingo

    2014-05-01

    We attempt to forecast the geomagnetic secular variation based on stochastic models, non-parametric regression and singular spectrum analysis of the observed past field changes. Although this modelling approach is meant to be phenomenological, it may provide some insight into the mechanisms underlying typical time scales of geomagnetic field changes. We follow two strategies to forecast secular variation: Firstly, by applying time series models, and secondly, by using time-dependent kinematic models of the advected secular variation. These forecasts can span decades, to longer periods. This depends on the length of the past observations used as input, with different input models leading to different details in the forecasts. These forecasts become more uncertain over longer forecasting periods. One appealing reason is the disregard of magnetic diffusion in the kinematic modelling. But also the interactions of unobservable small scale core field with core flow at all scale unsettle the kinematic forecasting scheme. A further (obvious) reason is that geomagnetic secular variation can not be mimicked by linear time series models as the dynamo action itself is highly non-linear. Whether the dynamo action can be represented by a simple low-dimensional system requires further analysis.

  13. Progress in dissolving modified LEU Cintichem targets

    SciTech Connect

    Leonard, R.A.; Chen, L.; Mertz, C.J.; Vandegrift, G.F.

    1996-12-31

    A process is under development to use low-enriched uranium (LEU) metal targets for production of {sup 99}Mo. The first step is to dissolve the irradiated foil. In past work, this has been done by heating a closed (sealed) vessel containing the foil and a solution of nitric and sulfuric acids. In this work, the authors have demonstrated that (1) the dissolver solution can contain nitric acid alone, (2) uranium dioxide is also dissolved by nitric acid alone, and (3) barrier metals of Cu, Fe, or Ni on the U foil are also dissolved by nitric acid. Changes to the dissolver design and operation needed to accommodate the uranium foil are discussed, including (1) simple operations that are easy to do in a remote-maintenance facility, (2) heat removal from the irradiated LEU foil, and (3) cold trap operation with high dissolver pressures.

  14. Dissolved air-flotation processes. Technical report

    SciTech Connect

    Krofta, M.; Wang, L.K.

    1986-11-05

    The theories and applications of various dissolved-air-flotation clarifiers (Supracell, Sandfloat, Floatpress, and Sedifloat) are presented. Supracell is a high-rate dissolved-air-flotation clarifier with only 3 to 5 minutes of detention time. Major application of Supracell is industrial-effluent treatment. Sandfloat is a package plant consisting of flocculation, dissolved-air floatation and automatic backwash filtration, and designed for either potable water treatment or tertiary wastewater-treatment. Sedifloat is a wastewater-treatment package plant consisting of both sedimentation and dissolved-air flotation. Floatpress consists of both dissolved air flotation and filter press and is specifically designed for sludge thickening. A Krofta Bargefloat is a floating lake-water clarification plant designed for acid-rain neutralization, phosphorus removal, algae removal and lake-water purification. Bargefloat has built-in chemical feeders, flocculator, dissolved-air-flotation clarifier and sand filter on a barge.

  15. Dissolved Gas Composition of Groundwater in Taipei Basin and its implications

    NASA Astrophysics Data System (ADS)

    Cheung, Nga-Chi; Yang, Tsanyao Frank; Chen, Ai-Ti; Chen, Wen-Fu; Wang, Yun-Shuen

    2015-04-01

    This study is the first comprehensive analysis for dissolved gases of groundwater in Taipei Basin, northern Taiwan. In addition to conventional water chemistry, the dissolved-gas compositions of groundwater from 34 observation wells have been systematically analyzed. The relationship between dissolved gases and geological environment, and probable sources of the gases are discussed in this study. According to the water chemistry data of Piper plot, most of the groundwater samples in this study can be classified as Ca(HCO3)2 and NaHCO3 types. Several samples exhibit NaCl type characteristic which reveals the mix with seawater. Isotopic compositions of hydrogen and oxygen for groundwater, surface water and meteoric water in Taipei Basin are aligned with Local Meteoric Water Line (LMWL), which indicates that they are influenced by meteoric water. Composition of groundwater in the southern part of the basin has similar characteristics with surface water. However, stratifications occurred in the observation wells from northern part of the basin. It reveals different recharge sources for groundwater samples in northern basin with the southern basin. Based on the major dissolved gases compositions, three major components are identified which are CH4, N2 and CO2. The d13C of dissolved inorganic carbon (DIC) indicates microbial activities are dominant in the studied area. Dissolved radon concentrations are in the range of 200 - 20,667 Bq/m3 in the studied area and the deeper well usually exhibits a higher radon value than the shallow one from the same site. Several sites with high radon values are correlated with the locations of fault zones, which may provide the conduit for deeper gas migrate to shallower aquifers. The groundwater samples from northern part of the basin exhibit unexpectedly high helium isotopic ratios (RA >2, where RA is the 3He/4He ratio of air). Samples from five observation wells have RA values more than 3 RA and the highest one is 4.2 RA, which

  16. Isotopic Analysis and Evolved Gases

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.; Boynton, William V.; Chutjian, Ara; Hoffman, John H.; Jordan, Jim L.; Kargel, Jeffrey S.; McEntire, Richard W.; Nyquist, Larry

    1996-01-01

    Precise measurements of the chemical, elemental, and isotopic composition of planetary surface material and gases, and observed variations in these compositions, can contribute significantly to our knowledge of the source(s), ages, and evolution of solar system materials. The analyses discussed in this paper are mostly made by mass spectrometers or some other type of mass analyzer, and address three broad areas of interest: (1) atmospheric composition - isotopic, elemental, and molecular, (2) gases evolved from solids, and (3) solids. Current isotopic data on nine elements, mostly from in situ analysis, but also from meteorites and telescopic observations are summarized. Potential instruments for isotopic analysis of lunar, Martian, Venusian, Mercury, and Pluto surfaces, along with asteroid, cometary and icy satellites, surfaces are discussed.

  17. Strongly Interacting Homogeneous Fermi Gases

    NASA Astrophysics Data System (ADS)

    Mukherjee, Biswaroop; Patel, Parth; Yan, Zhenjie; Struck, Julian; Zwierlein, Martin

    2016-05-01

    We present a homogeneous box potential for strongly interacting Fermi gases. The local density approximation (LDA) allows measurements on traditional inhomogeneous traps to observe a continuous distribution of Fermi gases in a single shot, but also suffer from a broadened response due to line-of-sight averaging over varying densities. We trap ultracold Fermionic (6 Li) in an optical homogeneous potential and characterize its flatness through in-situ tomography. A hybrid approach combining a cylindrical optical potential with a harmonic magnetic trap allows us to exploit the LDA and measure local RF spectra without requiring significant image reconstruction. We extract various quantities from the RF spectra such as the Tan's contact, and discuss further measurements of homogeneous Fermi systems under spin imbalance and finite temperature.

  18. Annihilation in Gases and Galaxies

    NASA Technical Reports Server (NTRS)

    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.

  19. Atmospheric Chemistry and Greenhouse Gases

    SciTech Connect

    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

  20. 40 CFR 92.112 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Analytical gases. 92.112 Section 92...) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.112 Analytical gases. (a) Gases for the CO and CO2 analyzers shall be single blends of CO and CO2, respectively, using...

  1. Lagrangian Aerosol and Ozone Precursor Forecasts Utilizing NASA Aura OMI NO2 and NOAA GOES-GASP AOD Observations

    EPA Science Inventory

    Over the past decade, the remote sensing of trace gases and aerosols from space has dramatically improved. The emergence and application of these measurements adds a new dimension to air quality Management and forecasting by enabling consistent observations of pollutants over l...

  2. Characterizing the uncertainty in river stage forecasts conditional on point forecast values

    NASA Astrophysics Data System (ADS)

    Yan, Jun; Liao, Gong-Yi; Gebremichael, Mekonnen; Shedd, Robert; Vallee, David R.

    2012-12-01

    Uncertainty information about river level forecast is as important as the forecast itself for forecast users. This paper presents a flexible, statistical approach that processes deterministic forecasts into probabilistic forecasts. The model is a smoothly changing conditional distribution of river stage given point forecast and other information available, such as lagged river level at the time of forecasting. The parametric distribution is a four-parameter skewt distribution, with each parameter modeled as a smooth function of the point forecast and the 1 day ago observed river level. The model was applied to 9 years of daily 6 h lead forecasts and 24 h lead forecasts in the warm season and their matching observations at the Plymouth station on the Pemigewasset River in New Hampshire. For each point forecast, the conditional distribution and resulting prediction intervals provide uncertainty information that are potentially very important to forecast users and algorithm developers in decision making and improvement of forecast quality.

  3. In situ Measurements of Dissolved Gas Dynamics and Root Uptake in the Wetland Rhizosphere

    NASA Astrophysics Data System (ADS)

    Reid, Matthew; Jaffe, Peter

    2013-04-01

    Anaerobic wetland soils are important natural sources of various atmospheric trace gases that are detrimental to the environment, including methane (CH4), nitrous oxide, elemental mercury (Hg°), and halomethanes. The balance between production and uptake in soils depends, in part, on mass transfer within the soil and between soil and the atmosphere. Observed volatilization rates of trace gases are highly variable and poorly described by models, however, so there is a clear need for new process measurements to clarify the rates of these transport mechanisms. Here we present results from mesocosm push-pull tests intended to quantify transport processes of dissolved gases in wetland sediments, with a focus on uptake by wetland plant roots and partitioning into trapped gas bubbles. This technique uses a suite of nonreactive volatile tracers to pinpoint transport mechanisms without the confounding influence of biochemical transformations. Mass balance approaches are used to determine transport kinetics, and a new analytical method to interpret dissolved gas push-pull test data is presented and compared to traditional analytical techniques. Results confirm the key role of vegetation in dramatically enhancing removal rates of dissolved gases from wetland soils. Root uptake is shown to be diffusion-limited and relative root uptake rates are modeled as an empirical function of molecular size. We use the porewater removal rates measured here to estimate potential volatilization fluxes of CH4, methyl chloride, and Hg° from wetlands vegetated with Typha latifolia and Scirpus acutus. The implementation of this new push-pull test methodology to field settings will be discussed.

  4. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    NASA Astrophysics Data System (ADS)

    Tao, P.; Tie-Yuan, S.; Zhi-Yuan, Y.; Jun-Chao, W.

    2015-05-01

    The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period. Hydrological forecast based on Ensemble Precipitation prediction gives better hydrological forecast information, better satisfying the need for risk information for flood prevention and disaster reduction, and has broad development opportunities.

  5. Investigation of arterial gas occlusions. [effect of noncondensable gases on high performance heat pipes

    NASA Technical Reports Server (NTRS)

    Saaski, E. W.

    1974-01-01

    The effect of noncondensable gases on high-performance arterial heat pipes was investigated both analytically and experimentally. Models have been generated which characterize the dissolution of gases in condensate, and the diffusional loss of dissolved gases from condensate in arterial flow. These processes, and others, were used to postulate stability criteria for arterial heat pipes under isothermal and non-isothermal condensate flow conditions. A rigorous second-order gas-loaded heat pipe model, incorporating axial conduction and one-dimensional vapor transport, was produced and used for thermal and gas studies. A Freon-22 (CHCIF2) heat pipe was used with helium and xenon to validate modeling. With helium, experimental data compared well with theory. Unusual gas-control effects with xenon were attributed to high solubility.

  6. Value of Wind Power Forecasting

    SciTech Connect

    Lew, D.; Milligan, M.; Jordan, G.; Piwko, R.

    2011-04-01

    This study, building on the extensive models developed for the Western Wind and Solar Integration Study (WWSIS), uses these WECC models to evaluate the operating cost impacts of improved day-ahead wind forecasts.

  7. Method Forecasts Global Energy Substitution

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Describes a model developed to forecast energy demands and determine trends in demand for primary fuels. The energy model essentially considers primary energy sources as competing commodities in a market. (MLH)

  8. Practical Meteor Stream Forecasting

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; Suggs, Robert M.

    2003-01-01

    Inspired by the recent Leonid meteor storms, researchers have made great strides in our ability to predict enhanced meteor activity. However, the necessary calibration of the meteor stream models with Earth-based ZHRs (Zenith Hourly Rates) has placed emphasis on the terran observer and meteor activity predictions are published in such a manner to reflect this emphasis. As a consequence, many predictions are often unusable by the satellite community, which has the most at stake and the greatest interest in meteor forecasting. This paper suggests that stream modelers need to pay more attention to the needs of this community and publish not just durations and times of maxima for Earth, but everything needed to characterize the meteor stream in and out of the plane of the ecliptic, which, at a minimum, consists of the location of maximum stream density (ZHR) and the functional form of the density decay with distance from this point. It is also suggested that some of the terminology associated with meteor showers may need to be more strictly defined in order to eliminate the perception of crying wolf by meteor scientists. An outburst is especially problematic, as it usually denotes an enhancement by a factor of 2 or more to researchers, but conveys the notion of a sky filled with meteors to satellite operators and the public. Experience has also taught that predicted ZHRs often lead to public disappointment, as these values vastly overestimate what is seen.

  9. Preparing for an Uncertain Forecast

    ERIC Educational Resources Information Center

    Karolak, Eric

    2011-01-01

    Navigating the world of government relations and public policy can be a little like predicting the weather. One can't always be sure what's in store or how it will affect him/her down the road. But there are common patterns and a few basic steps that can help one best prepare for a change in the forecast. Though the forecast is uncertain, early…

  10. Municipal water consumption forecast accuracy

    NASA Astrophysics Data System (ADS)

    Fullerton, Thomas M.; Molina, Angel L.

    2010-06-01

    Municipal water consumption planning is an active area of research because of infrastructure construction and maintenance costs, supply constraints, and water quality assurance. In spite of that, relatively few water forecast accuracy assessments have been completed to date, although some internal documentation may exist as part of the proprietary "grey literature." This study utilizes a data set of previously published municipal consumption forecasts to partially fill that gap in the empirical water economics literature. Previously published municipal water econometric forecasts for three public utilities are examined for predictive accuracy against two random walk benchmarks commonly used in regional analyses. Descriptive metrics used to quantify forecast accuracy include root-mean-square error and Theil inequality statistics. Formal statistical assessments are completed using four-pronged error differential regression F tests. Similar to studies for other metropolitan econometric forecasts in areas with similar demographic and labor market characteristics, model predictive performances for the municipal water aggregates in this effort are mixed for each of the municipalities included in the sample. Given the competitiveness of the benchmarks, analysts should employ care when utilizing econometric forecasts of municipal water consumption for planning purposes, comparing them to recent historical observations and trends to insure reliability. Comparative results using data from other markets, including regions facing differing labor and demographic conditions, would also be helpful.

  11. Survey of air cargo forecasting techniques

    NASA Technical Reports Server (NTRS)

    Kuhlthan, A. R.; Vermuri, R. S.

    1978-01-01

    Forecasting techniques currently in use in estimating or predicting the demand for air cargo in various markets are discussed with emphasis on the fundamentals of the different forecasting approaches. References to specific studies are cited when appropriate. The effectiveness of current methods is evaluated and several prospects for future activities or approaches are suggested. Appendices contain summary type analyses of about 50 specific publications on forecasting, and selected bibliographies on air cargo forecasting, air passenger demand forecasting, and general demand and modalsplit modeling.

  12. Investigating Students' Understanding of the Dissolving Process

    ERIC Educational Resources Information Center

    Naah, Basil M.; Sanger, Michael J.

    2013-01-01

    In a previous study, the authors identified several student misconceptions regarding the process of dissolving ionic compounds in water. The present study used multiple-choice questions whose distractors were derived from these misconceptions to assess students' understanding of the dissolving process at the symbolic and particulate levels. The…

  13. Dissolved Oxygen Data for Coos Estuary (Oregon)

    EPA Science Inventory

    The purpose of this product is the transmittal of dissolved oxygen data collected in the Coos Estuary, Oregon to Ms. Molly O'Neill (University of Oregon), for use in her studies on the factors influencing spatial and temporal patterns in dissolved oxygen in this estuary. These d...

  14. HESS Opinions "Forecaster priorities for improving probabilistic flood forecasts"

    NASA Astrophysics Data System (ADS)

    Wetterhall, F.; Pappenberger, F.; Alfieri, L.; Cloke, H. L.; Thielen-del Pozo, J.; Balabanova, S.; Daňhelka, J.; Vogelbacher, A.; Salamon, P.; Carrasco, I.; Cabrera-Tordera, A. J.; Corzo-Toscano, M.; Garcia-Padilla, M.; Garcia-Sanchez, R. J.; Ardilouze, C.; Jurela, S.; Terek, B.; Csik, A.; Casey, J.; Stankūnavičius, G.; Ceres, V.; Sprokkereef, E.; Stam, J.; Anghel, E.; Vladikovic, D.; Alionte Eklund, C.; Hjerdt, N.; Djerv, H.; Holmberg, F.; Nilsson, J.; Nyström, K.; Sušnik, M.; Hazlinger, M.; Holubecka, M.

    2013-11-01

    Hydrological ensemble prediction systems (HEPS) have in recent years been increasingly used for the operational forecasting of floods by European hydrometeorological agencies. The most obvious advantage of HEPS is that more of the uncertainty in the modelling system can be assessed. In addition, ensemble prediction systems generally have better skill than deterministic systems both in the terms of the mean forecast performance and the potential forecasting of extreme events. Research efforts have so far mostly been devoted to the improvement of the physical and technical aspects of the model systems, such as increased resolution in time and space and better description of physical processes. Developments like these are certainly needed; however, in this paper we argue that there are other areas of HEPS that need urgent attention. This was also the result from a group exercise and a survey conducted to operational forecasters within the European Flood Awareness System (EFAS) to identify the top priorities of improvement regarding their own system. They turned out to span a range of areas, the most popular being to include verification of an assessment of past forecast performance, a multi-model approach for hydrological modelling, to increase the forecast skill on the medium range (>3 days) and more focus on education and training on the interpretation of forecasts. In light of limited resources, we suggest a simple model to classify the identified priorities in terms of their cost and complexity to decide in which order to tackle them. This model is then used to create an action plan of short-, medium- and long-term research priorities with the ultimate goal of an optimal improvement of EFAS in particular and to spur the development of operational HEPS in general.

  15. Tunneling in degenerate atomic gases

    NASA Astrophysics Data System (ADS)

    Paraoanu, Gheorghe-Sorin

    The experimental achievement of Bose-Einstein condensation in cold alkali atomic gases in 1995 has started a period of fertile research at the intersection of atomic physics, quantum optics, and condensed matter. In this thesis, various tunneling effects in both bosonic and fermionic gases are investigated. The first part of this work deals with bosons in different Josephson-type experimental setups. After a brief general introduction we establish, in Chapter 2, a mapping between the phase and the Bogoliubov representation for the Josephson oscillations; in Chapter 3 we calculate the Josephson coupling constant for the condensate in the external Josephson effect. Chapter 4 deals with Josephson effects at the level of depletion: we describe in detail the oscillatory dynamics of the virtual quasiparticles. The next Chapter is a stability analysis for the formation of vortices in the Kibble Zurek scenario. Finally, Chapter 6 contains a discussion on the time-evolution of the many-body states in the absence of tunneling. The second part of the thesis (Chapter 7--Chapter 9) deals with fermionic systems below the BCS critical temperature. The first two of these Chapters explore the possibility of driving transitions between hyperfine states with lasers. In Chapter 7 we show that these transitions could be used to investigate the coherence of the Cooper pairs. In Chapter 8 we imagine an internal Josephson experiment which uses a pair of lasers to drive transitions between two superfluids. Finally, in Chapter 9 we examine the properties of vortices formed in trapped Cooper-paired fermionic gases.

  16. Climate Change and Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    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.

  17. Spark ignition of flowing gases

    NASA Technical Reports Server (NTRS)

    Swett, Clyde C , Jr

    1956-01-01

    Research conducted at the NACA Lewis Laboratory on ignition of flowing gases by means of long-duration discharges is summarized and analyzed. Data showing the effect of a flowing combustible mixture on the physical and electrical characteristics of spark discharges and data showing the effects of variables on the spark energy required for ignition that has been developed to predict the effect of many of the gas-stream and spark variables is described and applied to a limited amount of experimental data.

  18. Magnetism in ultracold quantum gases

    NASA Astrophysics Data System (ADS)

    Schmaljohann, H.; Erhard, M.; Kronjäger, J.; Kottke, M.; van Staa, S.; Arlt, J. J.; Bongs, K.; Sengstock, K.

    2004-12-01

    We study the static and dynamic magnetic properties of ultracold quantum gases, in particular the spinor physics of F = 1 and F = 2 Bose-Einstein condensates of 87Rb atoms. Our data lead to the conclusion, that the F = 2 ground state of 87Rb is polar, while we find the F = 1 ground state to be ferromagnetic. The dynamics of spinor systems is linked to an interplay between coherent mean-field interactions, losses and interactions with atoms in the thermal cloud. Within this rich parameter space we observe indications for coherent spinor dynamics and novel thermalization regimes.

  19. Medical Imaging of Hyperpolarized Gases

    NASA Astrophysics Data System (ADS)

    Miller, G. Wilson

    2009-08-01

    Since the introduction of hyperpolarized 3He and 129Xe as gaseous MRI contrast agents more than a decade ago, a rich variety of imaging techniques and medical applications have been developed. Magnetic resonance imaging of the inhaled gas depicts ventilated lung airspaces with unprecedented detail, and allows one to track airflow and pulmonary mechanics during respiration. Information about lung structure and function can also be obtained using the physical properties of the gas, including spin relaxation in the presence of oxygen, restricted diffusion inside the alveolar airspaces, and the NMR frequency shift of xenon dissolved in blood and tissue.

  20. Fields, Flares, And Forecasts

    NASA Astrophysics Data System (ADS)

    Boucheron, L.; Al-Ghraibah, Amani; McAteer, J.; Cao, H.; Jackiewicz, J.; McNamara, B.; Voelz, D.; Calabro, B.; DeGrave, K.; Kirk, M.; Madadi, A.; Petsov, A.; Taylor, G.

    2011-05-01

    Solar active regions are the source of many energetic and geo-effective events such as solar flares and coronal mass ejections (CMEs). Understanding how these complex source regions evolve and produce these events is of fundamental importance, not only to solar physics, but also to the demands of space weather forecasting. We propose to investigate the physical properties of active region magnetic fields using fractal-, gradient-, neutral line-, emerging flux-, wavelet- and general image-based techniques, and to correlate them to solar activity. The combination of these projects with solarmonitor.org and the international Max Millenium Campaign presents an opportunity for accurate and timely flare predictions for the first time. Many studies have attempted to relate solar flares to their concomitant magnetic field distributions. However, a consistent, causal relationship between the magnetic field on the photosphere and the production of solar flares is unknown. Often the local properties of the active region magnetic field - critical in many theories of activity - are lost in the global definition of their diagnostics, in effect smoothing out variations that occur on small spatial scales. Mindful of this, our overall goal is to create measures that are sensitive to both the global and the small-scale nature of energy storage and release in the solar atmosphere in order to study solar flare prediction. This set of active region characteristics will be automatically explored for discriminating features through the use of feature selection methods. Such methods search a feature space while optimizing a criterion - the prediction of a flare in this case. The large size of the datasets used in this project make it well suited for an exploration of a large feature space. This work is funded through a New Mexico State University Interdisciplinary Research Grant.

  1. Statistical earthquake focal mechanism forecasts

    NASA Astrophysics Data System (ADS)

    Kagan, Yan Y.; Jackson, David D.

    2014-04-01

    Forecasts of the focal mechanisms of future shallow (depth 0-70 km) earthquakes are important for seismic hazard estimates and Coulomb stress, and other models of earthquake occurrence. Here we report on a high-resolution global forecast of earthquake rate density as a function of location, magnitude and focal mechanism. In previous publications we reported forecasts of 0.5° spatial resolution, covering the latitude range from -75° to +75°, based on the Global Central Moment Tensor earthquake catalogue. In the new forecasts we have improved the spatial resolution to 0.1° and the latitude range from pole to pole. Our focal mechanism estimates require distance-weighted combinations of observed focal mechanisms within 1000 km of each gridpoint. Simultaneously, we calculate an average rotation angle between the forecasted mechanism and all the surrounding mechanisms, using the method of Kagan & Jackson proposed in 1994. This average angle reveals the level of tectonic complexity of a region and indicates the accuracy of the prediction. The procedure becomes problematical where longitude lines are not approximately parallel, and where shallow earthquakes are so sparse that an adequate sample spans very large distances. North or south of 75°, the azimuths of points 1000 km away may vary by about 35°. We solved this problem by calculating focal mechanisms on a plane tangent to the Earth's surface at each forecast point, correcting for the rotation of the longitude lines at the locations of earthquakes included in the averaging. The corrections are negligible between -30° and +30° latitude, but outside that band uncorrected rotations can be significantly off. Improved forecasts at 0.5° and 0.1° resolution are posted at http://eq.ess.ucla.edu/kagan/glob_gcmt_index.html.

  2. Filter for cleaning hot gases

    SciTech Connect

    Gresch, H.; Holter, H.; Hubner, K.; Igelbuscher, H.; Weber, E.

    1981-10-20

    In an apparatus for cleaning hot gases a filter housing has an inlet for unfiltered gas and an outlet for filtered gas. A plurality of filtered inserts are placed within the housing in a manner capable of filtering undesirable components from the gas feed stream. Each filter insert is made of a fibrous filter material. Silicic-acid glass fibers have a silicic acid content of at least 90%. Coated upon the fibers and absorbed into their pores is a metal oxide of aluminum, titanium, zirconium, cromium, nickle or cobalt. A honeycombed cage filled with high temperature resistant perlite is located within the housing between the gas inlet and the fiber inserts. The cage has an inlet and outlet external to the housing for replacing the perlite. A combustion chamber mounted in the housing has a discharge nozzle located so that the nozzle is directed at the filter inserts. Combusting materials in the chamber causes an explosive backflow of gases through the filter inserts.

  3. Predicting Flows of Rarefied Gases

    NASA Technical Reports Server (NTRS)

    LeBeau, Gerald J.; Wilmoth, Richard G.

    2005-01-01

    DSMC Analysis Code (DAC) is a flexible, highly automated, easy-to-use computer program for predicting flows of rarefied gases -- especially flows of upper-atmospheric, propulsion, and vented gases impinging on spacecraft surfaces. DAC implements the direct simulation Monte Carlo (DSMC) method, which is widely recognized as standard for simulating flows at densities so low that the continuum-based equations of computational fluid dynamics are invalid. DAC enables users to model complex surface shapes and boundary conditions quickly and easily. The discretization of a flow field into computational grids is automated, thereby relieving the user of a traditionally time-consuming task while ensuring (1) appropriate refinement of grids throughout the computational domain, (2) determination of optimal settings for temporal discretization and other simulation parameters, and (3) satisfaction of the fundamental constraints of the method. In so doing, DAC ensures an accurate and efficient simulation. In addition, DAC can utilize parallel processing to reduce computation time. The domain decomposition needed for parallel processing is completely automated, and the software employs a dynamic load-balancing mechanism to ensure optimal parallel efficiency throughout the simulation.

  4. Supersaturation of Dissolved Hydrogen and Methane in Rumen of Tibetan Sheep

    PubMed Central

    Wang, Min; Ungerfeld, Emilio M.; Wang, Rong; Zhou, Chuan She; Basang, Zhu Zha; Ao, Si Man; Tan, Zhi Liang

    2016-01-01

    Hydrogen (H2) is an essential substrate for methanogens to produce methane (CH4), and also influences pathways of volatile fatty acids (VFA) production in the rumen. Dissolved H2 (H2 (aq)) is the form of H2 available to microbes, and dissolved CH4 (CH4 (aq)) is important for indicating methanogens activity. Rumen H2 (aq) concentration has been estimated by assuming equilibrium with headspace gaseous H2 (H2 (g)) concentration using Henry's law, and has also been directly measured in the liquid phase in some in vitro and in vivo experiments. In this in vivo study, H2 (aq) and CH4 (aq) concentration measured directly in rumen fluid and their corresponding concentrations estimated from their gaseous phase concentrations, were compared to investigate the existence of equilibrium between the gas and liquid phases. Twenty-four Tibetan sheep were randomly assigned to two mixed diets containing the same concentrate mixed with oat grass (OG diet) or barley straw (BS diet). Rumen gaseous phase and contents were sampled using rumenocentesis and oral stomach tubing, respectively. Rumen H2 (aq) and CH4 (aq) concentration and VFA profile differed between sheep fed OG and BS diets. Measured H2 (aq) and CH4 (aq) concentration were greater than H2 (aq) and CH4 (aq) concentrations estimated using gas concentrations, indicating lack of equilibrium between gas and liquid phase and supersaturation of H2 and CH4 in rumen fluid. As a consequence, Gibbs energy changes (ΔG) estimated for various metabolic pathways were different when calculated using dissolved gases concentrations directly measured and when using dissolved gases concentrations assuming equilibrium with the gaseous phase. Dissolved CH4, but not CH4 (g), was positively correlated with H2 (aq). Both H2 (aq) and H2 (g) concentrations were positively correlated with the molar percentage of butyrate and negatively correlated with the molar percentage of acetate. In summary, rumen fluid was supersaturated with both H2 and CH4

  5. Solubility of inert gases in dog blood and skeletal muscle.

    PubMed

    Meyer, M; Tebbe, U; Piiper, J

    1980-03-01

    Solubility of H2, Ar, CH4 and SF6 was determined at 310 K (37 degrees C) in water, in saline (0.154 mol NaCl/l H2O), in plasma and whole blood of dogs, and in homogenates of the dog gastrocnemius muscle. The liquids were equilibrated with pure gases, and the dissolved gases were extracted and measured by gas chromatography as described previously (Meyer, M.: Pflügers Arch. 375, 161--165, 1978). In saline, the solubilities were 4% (SF6) to 15% (Ar) lower than in water. For dog blood the following mean values for the solubility coefficient (in mumol . 1(-1) . kPa-1) were found: for H2, 6.44; for Ar, 9.94; for CH4, 11.44; for SF6, 2.62. The red cell/plasma and the muscle/blood solubility ratios were near unity for H2, Ar and CH4 (ranging from 0.9 to 1.3); for SF6, however, they were much higher (about 2.1), apparently due to the high solubility of SF6 in hydrophobic substances (lipids). PMID:6247698

  6. CME Ensemble Forecasting - A Primer

    NASA Astrophysics Data System (ADS)

    Pizzo, V. J.; de Koning, C. A.; Cash, M. D.; Millward, G. H.; Biesecker, D. A.; Codrescu, M.; Puga, L.; Odstrcil, D.

    2014-12-01

    SWPC has been evaluating various approaches for ensemble forecasting of Earth-directed CMEs. We have developed the software infrastructure needed to support broad-ranging CME ensemble modeling, including composing, interpreting, and making intelligent use of ensemble simulations. The first step is to determine whether the physics of the interplanetary propagation of CMEs is better described as chaotic (like terrestrial weather) or deterministic (as in tsunami propagation). This is important, since different ensemble strategies are to be pursued under the two scenarios. We present the findings of a comprehensive study of CME ensembles in uniform and structured backgrounds that reveals systematic relationships between input cone parameters and ambient flow states and resulting transit times and velocity/density amplitudes at Earth. These results clearly indicate that the propagation of single CMEs to 1 AU is a deterministic process. Thus, the accuracy with which one can forecast the gross properties (such as arrival time) of CMEs at 1 AU is determined primarily by the accuracy of the inputs. This is no tautology - it means specifically that efforts to improve forecast accuracy should focus upon obtaining better inputs, as opposed to developing better propagation models. In a companion paper (deKoning et al., this conference), we compare in situ solar wind data with forecast events in the SWPC operational archive to show how the qualitative and quantitative findings presented here are entirely consistent with the observations and may lead to improved forecasts of arrival time at Earth.

  7. Advances in Solar Power Forecasting

    NASA Astrophysics Data System (ADS)

    Haupt, S. E.; Kosovic, B.; Drobot, S.

    2014-12-01

    The National Center for Atmospheric Research and partners are building a blended SunCast Solar Power Forecasting system. This system includes several short-range nowcasting models and improves upon longer range numerical weather prediction (NWP) models as part of the "Public-Private-Academic Partnership to Advance Solar Power Forecasting." The nowcasting models being built include statistical learning models that include cloud regime prediction, multiple sky imager-based advection models, satellite image-based advection models, and rapid update NWP models with cloud assimilation. The team has also integrated new modules into the Weather Research and Forecasting Model (WRF) to better predict clouds, aerosols, and irradiance. The modules include a new shallow convection scheme; upgraded physics parameterizations of clouds; new radiative transfer modules that specify GHI, DNI, and DIF prediction; better satellite assimilation methods; and new aerosol estimation methods. These new physical models are incorporated into WRF-Solar, which is then integrated with publically available NWP models via the Dynamic Integrated Forecast (DICast) system as well as the Nowcast Blender to provide seamless forecasts at partner utility and balancing authority commercial solar farms. The improvements will be described and results to date discussed.

  8. Automation of energy demand forecasting

    NASA Astrophysics Data System (ADS)

    Siddique, Sanzad

    Automation of energy demand forecasting saves time and effort by searching automatically for an appropriate model in a candidate model space without manual intervention. This thesis introduces a search-based approach that improves the performance of the model searching process for econometrics models. Further improvements in the accuracy of the energy demand forecasting are achieved by integrating nonlinear transformations within the models. This thesis introduces machine learning techniques that are capable of modeling such nonlinearity. Algorithms for learning domain knowledge from time series data using the machine learning methods are also presented. The novel search based approach and the machine learning models are tested with synthetic data as well as with natural gas and electricity demand signals. Experimental results show that the model searching technique is capable of finding an appropriate forecasting model. Further experimental results demonstrate an improved forecasting accuracy achieved by using the novel machine learning techniques introduced in this thesis. This thesis presents an analysis of how the machine learning techniques learn domain knowledge. The learned domain knowledge is used to improve the forecast accuracy.

  9. Dynamic SEP event probability forecasts

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.; Ling, A.

    2015-10-01

    The forecasting of solar energetic particle (SEP) event probabilities at Earth has been based primarily on the estimates of magnetic free energy in active regions and on the observations of peak fluxes and fluences of large (≥ M2) solar X-ray flares. These forecasts are typically issued for the next 24 h or with no definite expiration time, which can be deficient for time-critical operations when no SEP event appears following a large X-ray flare. It is therefore important to decrease the event probability forecast with time as a SEP event fails to appear. We use the NOAA listing of major (≥10 pfu) SEP events from 1976 to 2014 to plot the delay times from X-ray peaks to SEP threshold onsets as a function of solar source longitude. An algorithm is derived to decrease the SEP event probabilities with time when no event is observed to reach the 10 pfu threshold. In addition, we use known SEP event size distributions to modify probability forecasts when SEP intensity increases occur below the 10 pfu event threshold. An algorithm to provide a dynamic SEP event forecast, Pd, for both situations of SEP intensities following a large flare is derived.

  10. Communicating Storm Surge Forecast Uncertainty

    NASA Astrophysics Data System (ADS)

    Troutman, J. A.; Rhome, J.

    2015-12-01

    When it comes to tropical cyclones, storm surge is often the greatest threat to life and property along the coastal United States. The coastal population density has dramatically increased over the past 20 years, putting more people at risk. Informing emergency managers, decision-makers and the public about the potential for wind driven storm surge, however, has been extremely difficult. Recently, the Storm Surge Unit at the National Hurricane Center in Miami, Florida has developed a prototype experimental storm surge watch/warning graphic to help communicate this threat more effectively by identifying areas most at risk for life-threatening storm surge. This prototype is the initial step in the transition toward a NWS storm surge watch/warning system and highlights the inundation levels that have a 10% chance of being exceeded. The guidance for this product is the Probabilistic Hurricane Storm Surge (P-Surge) model, which predicts the probability of various storm surge heights by statistically evaluating numerous SLOSH model simulations. Questions remain, however, if exceedance values in addition to the 10% may be of equal importance to forecasters. P-Surge data from 2014 Hurricane Arthur is used to ascertain the practicality of incorporating other exceedance data into storm surge forecasts. Extracting forecast uncertainty information through analyzing P-surge exceedances overlaid with track and wind intensity forecasts proves to be beneficial for forecasters and decision support.

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

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  12. The NCEP Climate Forecast System Reanalysis (Invited)

    NASA Astrophysics Data System (ADS)

    Kistler, R.

    2010-12-01

    The NCEP Climate Forecast System Reanalysis (CFSR) was completed for the 31-year period from 1979 to 2009, in January 2010. The CFSR was designed and executed as a global, high resolution, coupled atmosphere-ocean-land surface-sea ice system to provide the best estimate of the state of these coupled domains over this period. The current CFSR will be extended as an operational, real time product into the future. New features of the CFSR include (1) coupling of atmosphere and ocean during the generation of the 6 hour guess field, (2) an interactive sea-ice model, and (3) assimilation of satellite radiances by the Grid-point Statistical Interpolation (GSI) scheme over the entire period. The CFSR global atmosphere resolution is ~38 km (T382) with 64 levels extending from the surface to 0.26 hPa. The global ocean’s latitudinal spacing is 0.25 deg at the equator, extending to a global 0.5 deg beyond the tropics, with 40 levels to a depth of 4737m. The global land surface model has 4 soil levels and the global sea ice model has 3 layers. The CFSR atmospheric model has observed variations in carbon dioxide (CO2) over the 1979-2009 period, together with changes in aerosols and other trace gases and solar variations. Most available in-situ and satellite observations were included in the CFSR. Satellite observations were used in radiance form, rather than retrieved values, and were bias corrected with “spin up” runs at full resolution, taking into account variable CO2 concentrations. This procedure enabled smooth transitions of the climate record due to evolutionary changes in the satellite observing system. CFSR atmospheric, oceanic and land surface output products are available at an hourly time resolution and a horizontal resolution of 0.5 deg x 0.5 deg in latitude and longitude. The CFSR data will be distributed by NCDC and NCAR. This reanalysis will serve many purposes, including providing the basis for most of NCEP Climate Prediction Center’s operational climate

  13. Medium Range Forecasts Representation (and Long Range Forecasts?)

    NASA Astrophysics Data System (ADS)

    Vincendon, J.-C.

    2009-09-01

    The progress of the numerical forecasts urges us to interest us in more and more distant ranges. We thus supply more and more forecasts with term of some days. Nevertheless, precautions of use are necessary to give the most reliable and the most relevant possible information. Available in a TV bulletin or on quite other support (Internet, mobile phone), the interpretation and the representation of a medium range forecast (5 - 15 days) must be different from those of a short range forecast. Indeed, the "foresee-ability” of a meteorological phenomenon decreases gradually in the course of the ranges, it decreases all the more quickly that the phenomenon is of small scale. So, at the end of some days, the probability character of a forecast becomes very widely dominating. That is why in Meteo-France the forecasts of D+4 to D+7 are accompanied with a confidence index since around ten years. It is a figure between 1 and 5: the more we approach 5, the more the confidence in the supplied forecast is good. In the practice, an indication is supplied for period D+4 / D+5, the other one for period D+6 / D+7, every day being able to benefit from a different forecast, that is be represented in a independent way. We thus supply a global tendency over 24 hours with less and less precise symbols as the range goes away. Concrete examples will be presented. From now on two years, we also publish forecasts to D+8 / J+9, accompanied with a sign of confidence (" good reliability " or " to confirm "). These two days are grouped together on a single map because for us, the described tendency to this term is relevant on a duration about 48 hours with a spatial scale slightly superior to the synoptic scale. So, we avoid producing more than two zones of types of weather over France and we content with giving an evolution for the temperatures (still, in increase or in decline). Newspapers began to publish this information, it should soon be the case of televisions. It is particularly

  14. Forecasting the Beginning, Middle, and End of Eruptions

    NASA Astrophysics Data System (ADS)

    Pallister, J. S.; McCausland, W. A.; Ogburn, S. E.; White, R. A.; Wright, H. M. N.

    2015-12-01

    Volcanic eruptions are triggered either by "bottom-up" processes such as magmatic intrusion and recharge or by "top-down" processes such as unloading by flank failure. Eruptions end when conduit pressure drops below lithostatic pressure because of depletion of magmatic gases or cessation of magmatic replenishment, or alternatively, as a consequence of plugging of the conduit by crystallization. Examples from the Volcano Disaster Assistance Program (VDAP) show that it is possible to forecast the beginning, changes during, and the end of eruptions using a combination of multi-parametric monitoring, geologic constraints and applicable information from global databases. Beginning: Magmatic intrusions can be detected from patterns of precursory seismicity, CO2 emissions, and inflation. The probability that a particular intrusive episode leads to eruption can be estimated from global data modified by the local history of past eruptions and by characteristic progressions in monitoring parameters. Middle: Increased probability of a more explosive phase during a long-lived dome-forming eruption may be forecast on the basis of high extrusion rates and recurrence of deep or distal VT earthquakes; both indicate more rapid magma ascent and increased gas pressure. Alternatively, increased seismicity coincident with a rapid decrease in gas emission and extrusion rate may signal conduit plugging, which can also lead to an explosive phase. End: The end of long-lived eruptions may be forecast using a combination of: 1) global data on duration of similar eruptions, 2) comparison of eruptive volumes to those of past eruptions, 3) projection of effusion rate trends to zero, 4) reversal of regional deflation to inflation and near-vent inflation to deflation, and 5) change in morphology or composition indicative of more viscous crystalline magma. We find that forecasting using the criteria such as described above is best conducted by multidisciplinary teams using probabilistic event

  15. Decadal Prediction Skill in the GEOS-5 Forecast System

    NASA Technical Reports Server (NTRS)

    Ham, Yoo-Geun; Rienecker, Michele M.; Suarez, Max J.; Vikhliaev, Yury; Zhao, Bin; Marshak, Jelena; Vernieres, Guillaume; Schubert, Siegfried D.

    2013-01-01

    A suite of decadal predictions has been conducted with the NASA Global Modeling and Assimilation Office's (GMAO's) GEOS-5 Atmosphere-Ocean general circulation model. The hind casts are initialized every December 1st from 1959 to 2010, following the CMIP5 experimental protocol for decadal predictions. The initial conditions are from a multivariate ensemble optimal interpolation ocean and sea-ice reanalysis, and from GMAO's atmospheric reanalysis, the modern-era retrospective analysis for research and applications. The mean forecast skill of a three-member-ensemble is compared to that of an experiment without initialization but also forced with observed greenhouse gases. The results show that initialization increases the forecast skill of North Atlantic sea surface temperature compared to the uninitialized runs, with the increase in skill maintained for almost a decade over the subtropical and mid-latitude Atlantic. On the other hand, the initialization reduces the skill in predicting the warming trend over some regions outside the Atlantic. The annual-mean Atlantic meridional overturning circulation index, which is defined here as the maximum of the zonally-integrated overturning stream function at mid-latitude, is predictable up to a 4-year lead time, consistent with the predictable signal in upper ocean heat content over the North Atlantic. While the 6- to 9-year forecast skill measured by mean squared skill score shows 50 percent improvement in the upper ocean heat content over the subtropical and mid-latitude Atlantic, prediction skill is relatively low in the sub-polar gyre. This low skill is due in part to features in the spatial pattern of the dominant simulated decadal mode in upper ocean heat content over this region that differ from observations. An analysis of the large-scale temperature budget shows that this is the result of a model bias, implying that realistic simulation of the climatological fields is crucial for skillful decadal forecasts.

  16. Smooth Sailing for Weather Forecasting

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Through a cooperative venture with NASA's Stennis Space Center, WorldWinds, Inc., developed a unique weather and wave vector map using space-based radar satellite information and traditional weather observations. Called WorldWinds, the product provides accurate, near real-time, high-resolution weather forecasts. It was developed for commercial and scientific users. In addition to weather forecasting, the product's applications include maritime and terrestrial transportation, aviation operations, precision farming, offshore oil and gas operations, and coastal hazard response support. Target commercial markets include the operational maritime and aviation communities, oil and gas providers, and recreational yachting interests. Science applications include global long-term prediction and climate change, land-cover and land-use change, and natural hazard issues. Commercial airlines have expressed interest in the product, as it can provide forecasts over remote areas. WorldWinds, Inc., is currently providing its product to commercial weather outlets.

  17. Aggregate vehicle travel forecasting model

    SciTech Connect

    Greene, D.L.; Chin, Shih-Miao; Gibson, R.

    1995-05-01

    This report describes a model for forecasting total US highway travel by all vehicle types, and its implementation in the form of a personal computer program. The model comprises a short-run, econometrically-based module for forecasting through the year 2000, as well as a structural, scenario-based longer term module for forecasting through 2030. The short-term module is driven primarily by economic variables. It includes a detailed vehicle stock model and permits the estimation of fuel use as well as vehicle travel. The longer-tenn module depends on demographic factors to a greater extent, but also on trends in key parameters such as vehicle load factors, and the dematerialization of GNP. Both passenger and freight vehicle movements are accounted for in both modules. The model has been implemented as a compiled program in the Fox-Pro database management system operating in the Windows environment.

  18. Forecasting improves for polar lows

    NASA Astrophysics Data System (ADS)

    Thanks to a 3-year research program recently concluded by the Norwegian Meteorological Institute in Oslo, Norwegian meteorologists are better able to forecast the intense low-pressure phenomena that threaten the safety of the country's coastal areas during the winter season.During the course of the program, meteorologists developed and tested “objective forecasting methods,” as well as a numerical model suitable for small-scale weather phenomena. They also improved the processing of satellite data, and gained experience with the observing systems used, according to a bulletin prepared by the institute. The monitoring and forecasting systems should improve as the observation network improves and as the mesoscale numerical model is refined, explained Arne Grammeltvedt, director of the institute.

  19. Angular correlation studies in noble gases

    NASA Technical Reports Server (NTRS)

    Coleman, P. G.

    1990-01-01

    There has been a recent revival of interest in the measurement of angular correlation of annihilation photons from the decay of positrons and positronium in gases. This revival has been stimulated by the possibility offered by the technique to shed new light on the apparently low positronium formation fraction in the heavier noble gases and to provide information on positronium quenching processes in gases such as oxygen. There is also the potential for learning about positronium slowing down in gases. This review focuses on experimental noble gas work and considers what new information has been, and may be, gained from these studies.

  20. Cooling Atomic Gases With Disorder

    NASA Astrophysics Data System (ADS)

    Paiva, Thereza; Khatami, Ehsan; Yang, Shuxiang; Rousseau, Valéry; Jarrell, Mark; Moreno, Juana; Hulet, Randall G.; Scalettar, Richard T.

    2015-12-01

    Cold atomic gases have proven capable of emulating a number of fundamental condensed matter phenomena including Bose-Einstein condensation, the Mott transition, Fulde-Ferrell-Larkin-Ovchinnikov pairing, and the quantum Hall effect. Cooling to a low enough temperature to explore magnetism and exotic superconductivity in lattices of fermionic atoms remains a challenge. We propose a method to produce a low temperature gas by preparing it in a disordered potential and following a constant entropy trajectory to deliver the gas into a nondisordered state which exhibits these incompletely understood phases. We show, using quantum Monte Carlo simulations, that we can approach the Néel temperature of the three-dimensional Hubbard model for experimentally achievable parameters. Recent experimental estimates suggest the randomness required lies in a regime where atom transport and equilibration are still robust.

  1. Modeling photoelectron currents through gases

    NASA Astrophysics Data System (ADS)

    Wyatt, A. F. G.

    2007-06-01

    We reexamine the processes involved in a current flowing from a photocathode, through a gas, to a collector at a positive voltage. The current is determined by the electrons being scattered back to the photocathode as well as by the transport through the gas. We find that the current, as a function of gas pressure and applied electric field, is reasonably well described by Thomson’s equation if the velocities of the electrons are correctly defined and the measured scattering cross sections are used. At low pressures, the relevant electron energy is the emitted energy from the photocathode, as suggested by Loeb [The Kinetic Theory of Gases (McGraw-Hill, New York, 1934), p. 625]. At high pressures, the electrons that return to the photocathode are thermalized; while in the gas, the electrons have an extra energy from the electric field.

  2. Cooling Atomic Gases With Disorder.

    PubMed

    Paiva, Thereza; Khatami, Ehsan; Yang, Shuxiang; Rousseau, Valéry; Jarrell, Mark; Moreno, Juana; Hulet, Randall G; Scalettar, Richard T

    2015-12-11

    Cold atomic gases have proven capable of emulating a number of fundamental condensed matter phenomena including Bose-Einstein condensation, the Mott transition, Fulde-Ferrell-Larkin-Ovchinnikov pairing, and the quantum Hall effect. Cooling to a low enough temperature to explore magnetism and exotic superconductivity in lattices of fermionic atoms remains a challenge. We propose a method to produce a low temperature gas by preparing it in a disordered potential and following a constant entropy trajectory to deliver the gas into a nondisordered state which exhibits these incompletely understood phases. We show, using quantum Monte Carlo simulations, that we can approach the Néel temperature of the three-dimensional Hubbard model for experimentally achievable parameters. Recent experimental estimates suggest the randomness required lies in a regime where atom transport and equilibration are still robust. PMID:26705614

  3. APPARATUS FOR CATALYTICALLY COMBINING GASES

    DOEpatents

    Busey, H.M.

    1958-08-12

    A convection type recombiner is described for catalytically recombining hydrogen and oxygen which have been radiolytically decomposed in an aqueous homogeneous nuclear reactor. The device is so designed that the energy of recombination is used to circulate the gas mixture over the catalyst. The device consists of a vertical cylinder having baffles at its lower enda above these coarse screens having platinum and alumina pellets cemented thereon, and an annular passage for the return of recombined, condensed water to the reactor moderator system. This devicea having no moving parts, provides a simple and efficient means of removing the danger of accumulated hot radioactive, explosive gases, and restoring them to the moderator system for reuse.

  4. Continuous Processing With Mars Gases

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde; Jennings, Paul

    2000-01-01

    Current Martian missions call for the production of oxygen for breathing, and fuel and oxygen for propulsion to be produced from atmospheric carbon dioxide (CO2). Adsorption and freezing are the two methods considered for capturing CO2 from the atmosphere. However, the nitrogen (N2) and argon (Ar), which make up less than 5 percent of the atmosphere, cause difficulties with both of these processes by blocking the CO2. This results in the capture process rapidly changing from a pressure driven process to a diffusion controlled process. To increase the CO2 capture rates, some type of mechanical pump is usually proposed to remove the N2 and Ar. The N2 and Ar are useful and have been proposed for blanketing and pressurizing fuel tanks and as buffer gas for breathing air for manned missions. Separation of the Martian gases with the required purity can be accomplished with a combination of membranes. These membrane systems do not require a high feed pressure and provide suitable separation. Therefore, by use of the appropriate membrane combination with the Martian atmosphere supplied by a compressor a continuous Supply Of CO2 for fuel and oxygen production can be supplied. This phase of our program has focused on the selection of the membrane system. Since permeation data for membranes did not exist for Martian atmospheric pressures and temperatures, this information had to be compiled. The general trend as the temperature was lowered was for the membranes to become more selective. In addition, the relative permeation rates between the three gases changed with temperature. The end result was to provide design parameters that could be used to separate CO2 from N2 and Ar. This paper will present the membrane data, provide the design requirements for a compressor, and compare the results with adsorption and freezer methods.

  5. GEM: Statistical weather forecasting procedure

    NASA Technical Reports Server (NTRS)

    Miller, R. G.

    1983-01-01

    The objective of the Generalized Exponential Markov (GEM) Program was to develop a weather forecast guidance system that would: predict between 0 to 6 hours all elements in the airways observations; respond instantly to the latest observed conditions of the surface weather; process these observations at local sites on minicomputing equipment; exceed the accuracy of current persistence predictions at the shortest prediction of one hour and beyond; exceed the accuracy of current forecast model output statistics inside eight hours; and be capable of making predictions at one location for all locations where weather information is available.

  6. Acquisition forecast: Fiscal year 1995

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This volume includes projections of all anticipated FY95, and beyond, NASA contract actions above $25,000 that small and small disadvantaged businesses may be able to perform under direct contract with the government or as subcontractors. The forecast consolidates anticipated procurements at each NASA center into an agencywide report, with the aim of increasing industries' advance knowledge of NASA requirements and enhancing competition in contracting. Each center forecast report is divided into three principal categories of procurement: research and development, services, and supplies and equipment.

  7. FDA Approves First Fully Dissolvable Stent

    MedlinePlus

    ... fullstory_159721.html FDA Approves First Fully Dissolvable Stent Device is absorbed by the body after about ... July 5, 2016 (HealthDay News) -- The first coronary stent to be gradually absorbed by the body has ...

  8. Dissolved gas transport in the presence of a trapped gas phase: Experimental evaluation of a two-dimensional kinetic model

    SciTech Connect

    Donaldson, J.H.; Istok, J.D.; O`Reilly, K.T.

    1998-01-01

    Quantitative information on dissolved gas transport in ground water aquifers is needed for a variety of site characterization and remedial design applications. The objective of this study was to gain further understanding of dissolved gas transport in the presence of trapped gas in the pore space of an otherwise water saturated porous medium, using a combination of laboratory experiments and numerical modeling. Transport experiments were conducted in a large-scale laboratory physical aquifer model containing a homogeneous sandpack. Tracer (Br{sup {minus}}) and dissolved gas (O{sub 2} or H{sub 2}) plumes were created using a two-well injection/extraction scheme and then were allowed to drift in a uniform flow field. Plume locations and shapes were monitored by measuring tracer and dissolved gas concentrations as a function of position within the sandpack and time. In all experiments, partitioning of the dissolved gases between the mobile ground water and stationary trapped gas phases resulted in substantial retardation and tailing of the dissolved O{sub 2} and H{sub 2} plumes relative to the Br{sup {minus}} plumes. Most observed plume features could be reproduced in simulations performed with a numerical model that combined the advection-dispersion equation with diffusion controlled mass transfer of dissolved gas between the mobile aqueous and stationary trapped gas phases. Fitted values of the volumetric trapped gas content and mass transfer coefficient ranged from 0.04 to 0.08 and from 10{sup {minus}6} to 10{sup {minus}5} sec{sup {minus}1}, respectively. Sensitivity analyses were used to examine how systematic variations in these parameters would be expected to affect dissolved gas transport under a range of potential field conditions. The experimental and modeling results indicate that diffusion controlled mass transfer should be considered when predicting dissolved gas transport in ground water aquifers in the presence of trapped gas.

  9. Forecast communication through the newspaper Part 1: Framing the forecaster

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.

    2015-04-01

    This review is split into two parts both of which address issues of forecast communication of an environmental disaster through the newspaper during a period of crisis. The first part explores the process by which information passes from the scientist or forecaster, through the media filter, to the public. As part of this filter preference, omission, selection of data, source, quote and story, as well as placement of the same information within an individual piece or within the newspaper itself, can serve to distort the message. The result is the introduction of bias and slant—that is, the message becomes distorted so as to favor one side of the argument against another as it passes through the filter. Bias can be used to support spin or agenda setting, so that a particular emphasis becomes placed on the story which exerts an influence on the reader's judgment. The net result of the filter components is either a negative (contrary) or positive (supportive) frame. Tabloidization of the news has also resulted in the use of strong, evocative, exaggerated words, headlines and images to support a frame. I illustrate these various elements of the media filter using coverage of the air space closure due to the April 2010 eruption of Eyjafjallajökull (Iceland). Using the British press coverage of this event it is not difficult to find examples of all media filter elements, application of which resulted in bias against the forecast and forecaster. These actors then became named and blamed. Within this logic, it becomes only too easy for forecasters and scientists to be framed in a negative way through blame culture. The result is that forecast is framed in such a way so as to cause the forecaster to be blamed for all losses associated with the loss-causing event. Within the social amplification of risk framework (SARF), this can amplify a negative impression of the risk, the event and the response. However, actions can be taken to avoid such an outcome. These actions

  10. Accuracy of forecasts in strategic intelligence

    PubMed Central

    Mandel, David R.; Barnes, Alan

    2014-01-01

    The accuracy of 1,514 strategic intelligence forecasts abstracted from intelligence reports was assessed. The results show that both discrimination and calibration of forecasts was very good. Discrimination was better for senior (versus junior) analysts and for easier (versus harder) forecasts. Miscalibration was mainly due to underconfidence such that analysts assigned more uncertainty than needed given their high level of discrimination. Underconfidence was more pronounced for harder (versus easier) forecasts and for forecasts deemed more (versus less) important for policy decision making. Despite the observed underconfidence, there was a paucity of forecasts in the least informative 0.4–0.6 probability range. Recalibrating the forecasts substantially reduced underconfidence. The findings offer cause for tempered optimism about the accuracy of strategic intelligence forecasts and indicate that intelligence producers aim to promote informativeness while avoiding overstatement. PMID:25024176

  11. A Delphi forecast of technology in education

    NASA Technical Reports Server (NTRS)

    Robinson, B. E.

    1973-01-01

    The results are reported of a Delphi forecast of the utilization and social impacts of large-scale educational telecommunications technology. The focus is on both forecasting methodology and educational technology. The various methods of forecasting used by futurists are analyzed from the perspective of the most appropriate method for a prognosticator of educational technology, and review and critical analysis are presented of previous forecasts and studies. Graphic responses, summarized comments, and a scenario of education in 1990 are presented.

  12. Forecasting Consumer Adoption of Information Technology and Services--Lessons from Home Video Forecasting.

    ERIC Educational Resources Information Center

    Klopfenstein, Bruce C.

    1989-01-01

    Describes research that examined the strengths and weaknesses of technological forecasting methods by analyzing forecasting studies made for home video players. The discussion covers assessments and explications of correct and incorrect forecasting assumptions, and their implications for forecasting the adoption of home information technologies…

  13. Facilitating Conceptual Change in Gases Concepts

    ERIC Educational Resources Information Center

    Cetin, Pinar Seda; Kaya, Ebru; Geban, Omer

    2009-01-01

    The aim of this study is to investigate the effectiveness of conceptual change oriented instruction (CCOI) over traditionally designed chemistry instruction (TDCI) on overcoming 10th grade students' misconceptions on gases concepts. In addition, the effect of gender difference on students' understanding of gases concepts was investigated. The…

  14. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 1065.750 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... with calibration gases. Use gases with contamination no higher than the highest of the following values in the gas cylinder or at the outlet of a zero-gas generator: (i) 2% contamination, measured...

  15. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 1065.750 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... with calibration gases. Use gases with contamination no higher than the highest of the following values in the gas cylinder or at the outlet of a zero-gas generator: (i) 2% contamination, measured...

  16. 40 CFR 86.1514 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... on a dry basis. (b) If the raw CO sampling system specified in 40 CFR part 1065 is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used. (c) If a CVS sampling system is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used....

  17. 40 CFR 86.1514 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... carbon monoxide on a dry basis. (b) If the raw CO sampling system specified in 40 CFR part 1065 is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used. (c) If a CVS sampling system is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used....

  18. 40 CFR 86.1514 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... carbon monoxide on a dry basis. (b) If the raw CO sampling system specified in 40 CFR part 1065 is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used. (c) If a CVS sampling system is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used....

  19. 40 CFR 86.1514 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbon monoxide on a dry basis. (b) If the raw CO sampling system specified in 40 CFR part 1065 is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used. (c) If a CVS sampling system is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used....

  20. 40 CFR 86.1514 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... carbon monoxide on a dry basis. (b) If the raw CO sampling system specified in 40 CFR part 1065 is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used. (c) If a CVS sampling system is used, the analytical gases specified in 40 CFR part 1065, subpart H, shall be used....

  1. 40 CFR 90.312 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Analytical gases. 90.312 Section 90.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Emission Test Equipment Provisions § 90.312 Analytical gases. (a)...

  2. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration... ≤ 31 ppm C, ≤ 400 ppm CO) (4) Purified synthetic air (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm... having the following chemical compositions shall be available: (i) C3H8 and purified synthetic air ;...

  3. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The...) (Contamination ≤ 31 ppm C, ≤ 400 ppm CO) (4) Purified synthetic air (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400... having the following chemical compositions shall be available: (i) C3H8 and purified synthetic air ;...

  4. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The...) (Contamination ≤ 31 ppm C, ≤ 400 ppm CO) (4) Purified synthetic air (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400... having the following chemical compositions shall be available: (i) C3H8 and purified synthetic air ;...

  5. 40 CFR 91.312 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Analytical gases. 91.312 Section 91.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.312 Analytical gases. (a) The shelf life of a...

  6. 40 CFR 91.312 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) (Oxygen content between 18-21 percent vol.) (c) Calibration and span gases. (1) Calibration gas values are... purified nitrogen. Note: For the HFID or FID, the manufacturer may choose to use as a diluent span gas and... calibration and span gases. If a manufacturer chooses to use C3 H8 and purified nitrogen for the...

  7. 40 CFR 90.312 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and span gases. (1) Calibration gas values are to be derived from NIST “Standard Reference Materials... or FID the manufacturer may choose to use as a diluent span gas and the calibration gas either... choice of diluent (zero air or purified nitrogen) between the calibration and span gases. If...

  8. Analyzing Gases From Decomposing Electrical Insulation

    NASA Technical Reports Server (NTRS)

    Moffett, Gary; Shelley, Timothy J.; Morelli, John J.

    1995-01-01

    Test fixture holds insulated wire and traps gases emitted by heating of wire. Used with gas chromatograph and/or mass spectrometer, to analyze gases emitted by insulation on wire when wire heated with controlled current in controlled atmosphere to simulate pyrolysis, combustion, and arc tracking. Small, inexpensive, easily maintained, and relatively nonreactive to organic compounds produced during breakdown of insulation.

  9. Newsletter. Social and Human Forecasting.

    ERIC Educational Resources Information Center

    Istituto Ricerche Applicate Documentazione e Studi, Rome (Italy).

    The newsletter is not only a means of information on social and human forecasting but, moreover, a way of world intercommunication on the topic. Typical issues include current announcements and information (written primarily in English but also in other languages with English translations provided) on: 1) aims, intentions, and activities of…

  10. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  11. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark

    2005-01-01

    The Applied Meteorology Unit developed a forecast tool that provides an assessment of the likelihood of local convective severe weather for the day in order to enhance protection of personnel and material assets of the 45th Space Wing Cape Canaveral Air Force Station (CCAFS), and Kennedy Space Center (KSC).

  12. Worldwide satellite market demand forecast

    NASA Technical Reports Server (NTRS)

    Bowyer, J. M.; Frankfort, M.; Steinnagel, K. M.

    1981-01-01

    The forecast is for the years 1981 - 2000 with benchmark years at 1985, 1990 and 2000. Two typs of markets are considered for this study: Hardware (worldwide total) - satellites, earth stations and control facilities (includes replacements and spares); and non-hardware (addressable by U.S. industry) - planning, launch, turnkey systems and operations. These markets were examined for the INTELSAT System (international systems and domestic and regional systems using leased transponders) and domestic and regional systems. Forecasts were determined for six worldwide regions encompassing 185 countries using actual costs for existing equipment and engineering estimates of costs for advanced systems. Most likely (conservative growth rate estimates) and optimistic (mid range growth rate estimates) scenarios were employed for arriving at the forecasts which are presented in constant 1980 U.S. dollars. The worldwide satellite market demand forecast predicts that the market between 181 and 2000 will range from $35 to $50 billion. Approximately one-half of the world market, $16 to $20 billion, will be generated in the United States.

  13. An Experiment in Probabilistic Forecasting.

    ERIC Educational Resources Information Center

    Brown, Thomas A.

    Students were asked to make forecasts of fourteen quantities where true values would not become known for five or six months. The quantities were selected to be typical of the subjects which would be of interest to a decisionmaker in business or government, and included GNP, consumer prices, draft calls, deaths in South Vietnam, and election…

  14. Understanding and Forecasting Ethnolinguistic Vitality

    ERIC Educational Resources Information Center

    Karan, Mark E.

    2011-01-01

    Forecasting of ethnolinguistic vitality can only be done within a well-functioning descriptive and explanatory model of the dynamics of language stability and shift. It is proposed that the Perceived Benefit Model of Language Shift, used with a taxonomy of language shift motivations, provides that model. The model, based on individual language…

  15. Military needs and forecast, 2

    NASA Technical Reports Server (NTRS)

    Goldstayn, Alan B.

    1986-01-01

    FORECAST 2 has accomplished its objectives of identifying high leverage technologies for corporate Air Force review. Implementation is underway with emphasis on restructuring existing programs and programming resources in the FY88 BES/FY89 POM. Many joint service/agency opportunities exist.

  16. In Brief: Forecasting meningitis threats

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-12-01

    The University Corporation for Atmospheric Research (UCAR), in conjunction with a team of health and weather organizations, has launched a project to provide weather forecasts to medical officials in Africa to help reduce outbreaks of meningitis. The forecasts will enable local health care providers to target vaccination programs more effectively. In 2009, meteorologists with the National Center for Atmospheric Research, which is managed by UCAR, will begin issuing 14-day forecasts of atmospheric conditions in Ghana. Later, UCAR plans to work closely with health experts from several African countries to design and test a decision support system to provide health officials with useful meteorological information. ``By targeting forecasts in regions where meningitis is a threat, we may be able to help vulnerable populations. Ultimately, we hope to build on this project and provide information to public health programs battling weather-related diseases in other parts of the world,'' said Rajul Pandya, director of UCAR's Community Building Program. Funding for the project comes from a $900,000 grant from Google.org, the philanthropic arm of the Internet search company.

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

    NASA Astrophysics Data System (ADS)

    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 (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial

  18. Attractive surface force in the presence of dissolved gas: a molecular approach.

    PubMed

    Bratko, Dusan; Luzar, Alenka

    2008-02-19

    Despite widespread evidence of the influence of dissolved air on hydrophobic interaction, the mechanisms of observed effects are still unknown. Although some experiments indicate that adsorbed gases can modify the structure of water next to hydrophobic surfaces, gas effects on measured forces have been observed only at large surface separations. Gas-specific depletion of water at a hydrophobic surface has been detected but was not reproduced in subsequent measurements. We use computer simulations to study short-ranged hydrophobic attraction in the absence and presence of dissolved gas and monitor gas adsorption at molecular resolution inaccessible in experiments. Although we observe a significant accumulation of dissolved gases at hydrophobic surfaces, even in supersaturated gas solutions surface concentrations remain too low to induce any significant change in the local structure of water and short-range surface forces. We present direct calculations of the hydrophobic force between model hydrocarbon plates at separations between 1.5 and 4 nm. Although stronger, the calculated solvation force has a similar decay rate as deduced from recent surface force apparatus measurements at a somewhat lower contact angle. Within the statistical uncertainty, short-range attraction is not affected by the presence of dissolved nitrogen, even in supersaturated solution with a gas fugacity as high as 30 atm. Comparisons of the adsorption behavior of N2, O2, CO2, and Ar reveal similar features in contrast to the peculiar suppression of water depletion reported for an Ar solution in a neutron reflectivity experiment. Our calculations reveal a notable difference between pathways to the capillary evaporation of pure water and gas-phase nucleation in confined supersaturated gas solutions. PMID:17979305

  19. Possible future directions in crop yield forecasting

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.

    1979-01-01

    This paper examines present and future possible applications of remote sensing to crop yield forecasting. It is concluded that there are ways in which Landsat data could be used to assist in crop yield forecasting using present technology. A framework for global crop yield forecasting which uses remote sensing, meteorological, field and ancillary data, as available, is proposed for the future.

  20. Beat the Instructor: An Introductory Forecasting Game

    ERIC Educational Resources Information Center

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  1. Methodological Problems in the Forecasting of Education

    ERIC Educational Resources Information Center

    Kostanian, S. L.

    1978-01-01

    Examines how forecasting of educational development in the Soviet Union can be coordinated with forecasts of scientific and technical progress. Predicts that the efficiency of social forecasting will increase when more empirical data on macro- and micro-processes is collected. (Author/DB)

  2. Can Business Students Forecast Their Own Grade?

    ERIC Educational Resources Information Center

    Hossain, Belayet; Tsigaris, Panagiotis

    2013-01-01

    This study examines grade expectations of two groups of business students for their final course mark. We separate students that are on average "better" forecasters on the basis of them not making significant forecast errors during the semester from those students that are poor forecasters of their final grade. We find that the better…

  3. Use of Financial Forecasting in Educational Retrenchment.

    ERIC Educational Resources Information Center

    Chabotar, Kent John

    1987-01-01

    Demonstrates local government's use of alternative forecasting techniques in school planning and retrenchment. Argues that forecasting is an art blending academic and political concerns. While statistical techniques and historical data are useful forecasting tools, the most significant influence should be school officials' plans and preferences.…

  4. Facilitating Conceptual Change in Gases Concepts

    NASA Astrophysics Data System (ADS)

    Çetin, Pinar Seda; Kaya, Ebru; Geban, Ömer

    2009-04-01

    The aim of this study is to investigate the effectiveness of conceptual change oriented instruction (CCOI) over traditionally designed chemistry instruction (TDCI) on overcoming 10th grade students' misconceptions on gases concepts. In addition, the effect of gender difference on students' understanding of gases concepts was investigated. The subjects of this study consisted of 74 10th grade students from two chemistry classes. One of the classes was assigned as experimental group and the other group was assigned as control group. The experimental group was instructed with CCOI and the control group was instructed by TDCI. Gases Concept Test (GCT) was administered to both groups as pre- and post-tests to measure the students' conceptual understanding. The results showed that students in the experimental group got higher average scores from Gases Concept Test. Also, a significant difference was found between the performance of females and that of males in terms of understanding gases concepts in favor of males.

  5. Research of medical gases in Poland

    PubMed Central

    2013-01-01

    Research of medical gases is well established in Poland and has been marked with the foundation of several professional societies. Numerous academic centers including those dealing with hyperbaric and diving medicine conduct studies of medical gases, in vast majority supported with intramural funds. In general, Polish research of medical gases is very much clinical in nature, covering new applications and safety of medical gases in medicine; on the other hand there are several academic centers pursuing preclinical studies, and elaborating basic theories of gas physiology and mathematical modeling of gas exchange. What dominates is research dealing with oxygen and ozone as well as studies of anesthetic gases and their applications. Finally, several research directions involving noble gas, hydrogen and hydrogen sulfide for cell protection, only begin to gain recognition of basic scientists and clinicians. However, further developments require more monetary spending on research and clinical testing as well as formation of new collective bodies for coordinating efforts in this matter. PMID:23916016

  6. Isotopic composition of gases from mud volcanoes

    SciTech Connect

    Valysaev, B.M.; Erokhin, V.E.; Grinchenko, Y.I.; Prokhorov, V.S.; Titkov, G.A.

    1985-09-01

    A study has been made of the isotopic composition of the carbon in methane and carbon dioxide, as well as hydrogen in the methane, in the gases of mud volcanoes, for all main mud volcano areas in the USSR. The isotopic composition of carbon and hydrogen in methane shows that the gases resemble those of oil and gas deposits, while carbon dioxide of these volcanoes has a heavier isotopic composition with a greater presence of ''ultraheavy'' carbon dioxide. By the chemical and isotopic composition of gases, Azerbaidzhan and South Sakhalin types of mud volcano gases have been identified, as well as Bulganak subtypes and Akhtala and Kobystan varieties. Correlations are seen between the isotopic composition of gases and the geological build of mud volcano areas.

  7. Richardson's Barotropic Forecast: A Reappraisal.

    NASA Astrophysics Data System (ADS)

    Lynch, Peter

    1992-01-01

    To elucidate his numerical technique and to examine the effectiveness of geostrophic initial winds, Lewis Fry Richardson carried out an idealized forecast using the linear shallow-water equations and simple analytical pressure and velocity fields. This barotropic forecast has been repeated and extended using a global numerical model, and the results are presented in this paper. Richardson's conclusions regarding the use of geostrophic winds as initial data are reconsidered.An analysis of Richardson's data into normal modes shows that almost 85% of the energy is accounted for by a single eigenmode, the gravest symmetric rotational Hough mode, which travels westward with a period of about five days. This five-day wave has been detected in analyses of stratospheric data. It is striking that the fields chosen by Richardson on considerations of smoothness should so closely resemble a natural oscillation of the atmosphere.The numerical model employed in this study uses an implicit differencing technique, which is stable for large time steps. The numerical instability that would have destroyed Richardson's barotropic forecast, had it been extended, is thereby circumvented. It is sometimes said that computational instability was the cause of the failure of Richardson's baroclinic forecast, for which he obtained a pressure tendency value two orders of magnitude too large. However, the initial tendency is independent of the time step (at least for the explicit scheme used by Richardson). In fact, the spurious tendency resulted from the presence of unrealistically large high-frequency gravity-wave components in the initial fields.High-frequency oscillations are also found in the evolution starting from the idealized data in the barotropic forecast. They are shown to be due to the gravity-wave components of the initial data. These oscillations may be removed by a slight modification of the initial fields. This initialization is effected by means of a simple digital filtering

  8. 40 CFR 86.514-78 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Analytical gases. 86.514-78 Section 86... Later New Motorcycles; Test Procedures § 86.514-78 Analytical gases. (a) Analyzer gases. (1) Gases for... diluent. (2) Gases for the THC analyzer shall be: (i) Single blends of propane using air as the...

  9. 40 CFR 86.514-78 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Analytical gases. 86.514-78 Section 86... Later New Motorcycles; Test Procedures § 86.514-78 Analytical gases. (a) Analyzer gases. (1) Gases for... diluent. (2) Gases for the THC analyzer shall be: (i) Single blends of propane using air as the...

  10. 40 CFR 86.514-78 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Analytical gases. 86.514-78 Section 86... Later New Motorcycles; Test Procedures § 86.514-78 Analytical gases. (a) Analyzer gases. (1) Gases for... diluent. (2) Gases for the THC analyzer shall be: (i) Single blends of propane using air as the...

  11. Method of concurrently filtering particles and collecting gases

    SciTech Connect

    Mitchell, Mark A; Meike, Annemarie; Anderson, Brian L

    2015-04-28

    A system for concurrently filtering particles and collecting gases. Materials are be added (e.g., via coating the ceramic substrate, use of loose powder(s), or other means) to a HEPA filter (ceramic, metal, or otherwise) to collect gases (e.g., radioactive gases such as iodine). The gases could be radioactive, hazardous, or valuable gases.

  12. Model sensitivity to MACC anthropogenic and biogenic emissions: Global simulations and evaluation for reactive gases

    NASA Astrophysics Data System (ADS)

    Stein, O.; Schultz, M. G.; Bouarar, I.; Clark, H.; Katragkou, E.; Leitao, J.; Heil, A.

    2012-04-01

    The EU projects MACC (Monitoring Atmospheric Composition and Climate, 2009-2011) and MACC-II (2011-2014) prepare for the operational Global Monitoring for Environment and Security (GMES) atmospheric core service which is envisaged to start in 2014. Besides global service lines for greenhouse gases and aerosols, emphasis is put also on global monitoring and forecasting of reactive gases. The MACC reanalysis and forecast simulations benefit from the multi-sensor approach for data assimilation of ozone, CO and NO2 observations. Currently the Integrated Forecast System (IFS) of the European Centre for Medium-range Weather Forecasts (ECMWF) is coupled to the chemical transport model MOZART-3 to represent in detail the chemical conversion as well as major source and sink processes. A global emission inventory for reactive gases has been developed as part of the MACC project. Based upon the ACCMIP emissions for the year 2000 these emissions are extrapolated for years after 2000 with the Representative Concentration Pathway RCP8.5 scenario and extended for VOCs and several other species. This inventory composes the MACCity anthropogenic emission inventory (Granier et al. 2011). During the MACC project it became apparent that using the MACCity emissions in reanalysis simulations for recent years led to an underestimation of CO concentrations in the Northern Hemisphere when compared to independent observations. In order to give insight into the reasons for this behavior we conducted MOZART offline simulations for the year 2008 to test the sensitivity of the chemical transport model to the varying emissions. Therefore we ran MOZART with different sets of emissions: 1. MACCity emissions, 2. The GEMS/RETRO emission inventory, 3. MACCity emissions, but with increased traffic CO emissions. While using the emission inventory developed in the RETRO and GEMS projects gives quite reasonable tropospheric concentrations for the key species, the MACCity emissions are too low

  13. Study of transient jet gases

    NASA Astrophysics Data System (ADS)

    Saber, Aaron Jaan

    1988-03-01

    This work involves the use of flash lamp schlieren and the development of flash lamp light slicing (planar imaging) and their employment in visualization of transient gas jets discharging into the atmosphere and the mixing that ensues. Details of the flash lamp light slicing system design are provided. Visualization of flows from a pulsed valve discharge system and a shock tube open at the downstream end of the driven section are used to simulate real discharges. Gas flow Mach numbers for discharges of air into the atmosphere range to about 0.4. Axial light slicing images show development of the starting jets, including the formation of the starting vortex and coherent structures that form along the jet shaft. Transverse light slicing images reveal the development of scallops and cusps inside the head of the jet. Voids in the jet were observed at about 4 to 6 diameters from the exit plane. This may imply that ambient and jet gases differentiate at some points downstream. These features suggest cyclic development of jet features. The results can also be used to validate and calibrate computational fluid dynamic (CFD) computer codes used to predict the behavior of fluids under varying initial and boundary conditions.

  14. Cooling Atomic Gases With Disorder

    NASA Astrophysics Data System (ADS)

    Scalettar, Richard

    Cold atomic gases have proven capable of emulating a number of fundamental condensed matter phenomena including Bose-Einstein condensation, the Mott transition, Fulde-Ferrell-Larkin-Ovchinnikov pairing and the quantum Hall effect. Cooling to a low enough temperature to explore magnetism and exotic superconductivity in lattices of fermionic atoms remains a challenge. We propose a method to produce a low temperature gas by preparing it in a disordered potential and following a constant entropy trajectory to deliver the gas into a non-disordered state which exhibits these incompletely understood phases. We show, using quantum Monte Carlo simulations, that we can approach the Neél temperature of the three-dimensional Hubbard model for experimentally achievable parameters. Recent experimental estimates suggest the randomness required lies in a regime where atom transport and equilibration are still robust. Thereza Paiva, Ehsan Khatami, Shuxiang Yang, Valery Rousseau, Mark Jarrell, Juana Moreno, Randall G. Hulet, and Richard T. Scalettar, arXiv:1508.02613 This work was supported by the NNSA SSAA program.

  15. Atomtronics with Ultracold Bose Gases

    NASA Astrophysics Data System (ADS)

    Ott, Herwig

    Neutral atom systems can exhibit similar transport properties like solid state devices. For instance, a neutral atom current is induced by a difference in chemical potential very much in the same way as a voltage drives an electric current. Employing Bose-Einstein condensed atomic gases allows observing superfluid transport phenomena, thus drawing connections to superconductivity. With help of light fields, the atomic current can additionally be guided in engineered potential landscapes in which one can also incorporate tunneling junctions. Eventually, the different components and elements can be integrated in atomtronic circuits which shed light on fundamental transport properties of many-body quantum systems. In this talk, I will present two fundamental atomtronic devices. The first is the observation of negative differential conductivity, which occurs at a multimode tunneling junction for ultracold atoms. The second is the appearance of a DC Josephson current in a biased tunneling junction, which features bistable transport characteristics. I will discuss the prospects of these basic elements for more complex atomtronic circuits.

  16. Greenhouse Trace Gases in Deadwood

    NASA Astrophysics Data System (ADS)

    Covey, Kristofer; Bueno de Mesquita, Cliff; Oberle, Brad; Maynard, Dan; Bettigole, Charles; Crowther, Thomas; Duguid, Marlyse; Steven, Blaire; Zanne, Amy; Lapin, Marc; Ashton, Mark; Oliver, Chad; Lee, Xuhui; Bradford, Mark

    2016-04-01

    Deadwood, long recognized as playing an important role in carbon cycling in forest ecosystems, is more recently drawing attention for its potential role in the cycling of other greenhouse trace gases. We report data from four independent studies measuring internal gas concentrations in deadwood in in three Quercus dominated upland forest systems in the Northeastern and Central United States. Mean methane concentrations in deadwood were 23 times atmospheric levels, indicating a lower bound, mean radial wood surface area flux of ~6 x 10-4 μmol CH4 m-2 s-1. Site, decay class, diameter, and species were all highly significant predictors of methane abundance in deadwood, and log diameter and decay stage interacted as important controls limiting methane concentrations in the smallest and most decayed logs. Nitrous oxide concentrations were negatively correlated with methane and on average ~25% lower than ambient, indicating net consumption of nitrous oxide. These data suggest nonstructural carbohydrates fuel archaeal methanogens and confirm the potential for widespread in situ methanogenesis in both living and deadwood. Applying this understanding to estimate methane emissions from microbial activity in living trees implies a potential global flux of 65.6±12.0 Tg CH4 yr-1, more than 20 times greater than currently considered.

  17. ADDING REALISM TO NUCLEAR MATERIAL DISSOLVING ANALYSIS

    SciTech Connect

    Williamson, B.

    2011-08-15

    Two new criticality modeling approaches have greatly increased the efficiency of dissolver operations in H-Canyon. The first new approach takes credit for the linear, physical distribution of the mass throughout the entire length of the fuel assembly. This distribution of mass is referred to as the linear density. Crediting the linear density of the fuel bundles results in using lower fissile concentrations, which allows higher masses to be charged to the dissolver. Also, this approach takes credit for the fact that only part of the fissile mass is wetted at a time. There are multiple assemblies stacked on top of each other in a bundle. On average, only 50-75% of the mass (the bottom two or three assemblies) is wetted at a time. This means that only 50-75% (depending on operating level) of the mass is moderated and is contributing to the reactivity of the system. The second new approach takes credit for the progression of the dissolving process. Previously, dissolving analysis looked at a snapshot in time where the same fissile material existed both in the wells and in the bulk solution at the same time. The second new approach models multiple consecutive phases that simulate the fissile material moving from a high concentration in the wells to a low concentration in the bulk solution. This approach is more realistic and allows higher fissile masses to be charged to the dissolver.

  18. On the reliability of seasonal climate forecasts

    PubMed Central

    Weisheimer, A.; Palmer, T. N.

    2014-01-01

    Seasonal climate forecasts are being used increasingly across a range of application sectors. A recent UK governmental report asked: how good are seasonal forecasts on a scale of 1–5 (where 5 is very good), and how good can we expect them to be in 30 years time? Seasonal forecasts are made from ensembles of integrations of numerical models of climate. We argue that ‘goodness’ should be assessed first and foremost in terms of the probabilistic reliability of these ensemble-based forecasts; reliable inputs are essential for any forecast-based decision-making. We propose that a ‘5’ should be reserved for systems that are not only reliable overall, but where, in particular, small ensemble spread is a reliable indicator of low ensemble forecast error. We study the reliability of regional temperature and precipitation forecasts of the current operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts, universally regarded as one of the world-leading operational institutes producing seasonal climate forecasts. A wide range of ‘goodness’ rankings, depending on region and variable (with summer forecasts of rainfall over Northern Europe performing exceptionally poorly) is found. Finally, we discuss the prospects of reaching ‘5’ across all regions and variables in 30 years time. PMID:24789559

  19. ECMWF SSW forecast evaluation using infrasound

    NASA Astrophysics Data System (ADS)

    Smets, P. S. M.; Assink, J. D.; Le Pichon, A.; Evers, L. G.

    2016-05-01

    Accurate prediction of Sudden Stratospheric Warming (SSW) events is important for the performance of numerical weather prediction due to significant stratosphere-troposphere coupling. In this study, for the first time middle atmospheric numerical weather forecasts are evaluated using infrasound. A year of near-continuous infrasound from the volcano Mount Tolbachik (Kamchatka, Russian Federation) is compared with simulations using high-resolution deterministic forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF). For the entire time span the nowcast generally performs best, indicated by a higher continuity of the predicted wavefront characteristics with a minimal back azimuth difference. Best performance for all forecasts is obtained in summer. The difference between the infrasound observations and the predictions based on the forecasts is significantly larger during the 2013 SSW period for all forecasts. Simulations show that the SSW onset is better captured by the 10 day forecast while the recovery is better captured by the nowcast.

  20. Climate Time Series Analysis and Forecasting

    NASA Astrophysics Data System (ADS)

    Young, P. C.; Fildes, R.

    2009-04-01

    This paper will discuss various aspects of climate time series data analysis, modelling and forecasting being carried out at Lancaster. This will include state-dependent parameter, nonlinear, stochastic modelling of globally averaged atmospheric carbon dioxide; the computation of emission strategies based on modern control theory; and extrapolative time series benchmark forecasts of annual average temperature, both global and local. The key to the forecasting evaluation will be the iterative estimation of forecast error based on rolling origin comparisons, as recommended in the forecasting research literature. The presentation will conclude with with a comparison of the time series forecasts with forecasts produced from global circulation models and a discussion of the implications for climate modelling research.

  1. Univariate time series forecasting algorithm validation

    NASA Astrophysics Data System (ADS)

    Ismail, Suzilah; Zakaria, Rohaiza; Muda, Tuan Zalizam Tuan

    2014-12-01

    Forecasting is a complex process which requires expert tacit knowledge in producing accurate forecast values. This complexity contributes to the gaps between end users and expert. Automating this process by using algorithm can act as a bridge between them. Algorithm is a well-defined rule for solving a problem. In this study a univariate time series forecasting algorithm was developed in JAVA and validated using SPSS and Excel. Two set of simulated data (yearly and non-yearly); several univariate forecasting techniques (i.e. Moving Average, Decomposition, Exponential Smoothing, Time Series Regressions and ARIMA) and recent forecasting process (such as data partition, several error measures, recursive evaluation and etc.) were employed. Successfully, the results of the algorithm tally with the results of SPSS and Excel. This algorithm will not just benefit forecaster but also end users that lacking in depth knowledge of forecasting process.

  2. Model documentation report: Short-term Integrated Forecasting System demand model 1985. [(STIFS)

    SciTech Connect

    Not Available

    1985-07-01

    The Short-Term Integrated Forecasting System (STIFS) Demand Model consists of a set of energy demand and price models that are used to forecast monthly demand and prices of various energy products up to eight quarters in the future. The STIFS demand model is based on monthly data (unless otherwise noted), but the forecast is published on a quarterly basis. All of the forecasts are presented at the national level, and no regional detail is available. The model discussed in this report is the April 1985 version of the STIFS demand model. The relationships described by this model include: the specification of retail energy prices as a function of input prices, seasonal factors, and other significant variables; and the specification of energy demand by product as a function of price, a measure of economic activity, and other appropriate variables. The STIFS demand model is actually a collection of 18 individual models representing the demand for each type of fuel. The individual fuel models are listed below: motor gasoline; nonutility distillate fuel oil, (a) diesel, (b) nondiesel; nonutility residual fuel oil; jet fuel, kerosene-type and naphtha-type; liquefied petroleum gases; petrochemical feedstocks and ethane; kerosene; road oil and asphalt; still gas; petroleum coke; miscellaneous products; coking coal; electric utility coal; retail and general industry coal; electricity generation; nonutility natural gas; and utility petroleum. The demand estimates produced by these models are used in the STIFS integrating model to produce a full energy balance of energy supply, demand, and stock change. These forecasts are published quarterly in the Outlook. Details of the major changes in the forecasting methodology and an evaluation of previous forecast errors are presented once a year in Volume 2 of the Outlook, the Methodology publication.

  3. Incorporation of Solar Noble Gases from a Nebula-Derived Atmosphere During Magma Ocean Cooling

    NASA Technical Reports Server (NTRS)

    Woolum, D. S.; Cassen, P.; Wasserburg, G. J.; Porcelli, D.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    The presence of solar noble gases in the deep interior of the Earth is inferred from the Ne isotopic compositions of MORB (Mid-ocean Ridge Basalts) and OIB (Oceanic Island Basalt); Ar data may also consistent with a solar component in the deep mantle. Models of the transport and distribution of noble gases in the earth's mantle allow for the presence of solar Ar/Ne and Xe/Ne ratios and permit the calculation of lower mantle noble gas concentrations. These mantle data and models also indicate that the Earth suffered early (0.7 to 2 x 10(exp 8) yr) and large (greater than 99 percent) losses of noble gases from the interior, a result previously concluded for atmospheric Xe. We have pursued the suggestion that solar noble gases were incorporated in the forming Earth from a massive, nebula-derived atmosphere which promoted large-scale melting, so that gases from this atmosphere dissolved in the magma ocean and were mixed downward. Models of a primitive atmosphere captured from the solar nebula and supported by accretion luminosity indicate that pressures at the Earth's surface were adequate (and largely more than the required 100 Atm) to dissolve sufficient gases. We have calculated the coupled evolution of the magma ocean and the overlying atmosphere under conditions corresponding to the cessation (or severe attenuation) of the sustaining accretion luminosity, prior to the complete removal of the solar nebula. Such a condition was likely to obtain, for instance, when most of the unaccumulated mass resided in large bodies which were only sporadically accreted. The luminosity supporting the atmosphere is then that provided by the cooling Earth, consideration of which sets a lower limit to the time required to solidify the mantle and terminate the incorporation of atmospheric gases within it. In our initial calculations, we have fixed the nebula temperature at To = 300K, a value likely to be appropriate for nebular temperatures at lAU in the early planet-building epoch

  4. Simulation of a continuous rotary dissolver

    SciTech Connect

    Carnal, C.L.; Hardy, J.E.; Lewis, B.E.

    1989-01-01

    This paper describes the simulation of a rotating, multistage chemical reactor that dissolves spent nuclear fuel for reprocessing in a breeder cycle. The continuous, time-dependent process model of a dissolver was developed using the Advanced Continuous Simulation Language (ACSL) to calculate various temperatures and the masses of the chemical constituents of the solution in each stage. The Gear integration algorithm (Gear 1971) was used to accommodate the stiff dynamics. An arrangement of interacting discrete sections was employed to cause fresh fuel to be added and dissolver rotations to occur at appropriate times. By changing various constants, the model can simulate the effect of different fuel compositions and operational scenarios. The model code is a valuable tool for analysis of the performance of the dissolution system and has been instrumental in its design. 5 refs., 7 figs.

  5. Wastewater treatment with zero dissolved oxygen

    SciTech Connect

    Hirl, P.J.

    1998-07-01

    Many wastewater treatment plants operate their biological reactors inefficiently because the aeration is not adjusted so that the oxygen supply rate equals the microbial oxygen demand in real times. Tapered aeration systems vary aeration based on the oxygen demand profile but these systems are static. Dynamic oxygen control systems have been successful but do not operate at low dissolved oxygen concentrations. The purpose of the research described is to develop a control system and reactor operating strategies to dynamically change the aeration rate to match the oxygen uptake rate while maintaining the dissolve oxygen concentration less than 0.5 mg/L. Though, low dissolved oxygen operation can reduce the rate of carbon degradation and/or promote filamentous bulking, it also maximizes the oxygen transfer rate and can promote simultaneous nitrification and denitrification. Development and testing of a control system and operating strategies at the bench scale is in progress.

  6. A Quantitative Evaluation of Dissolved Oxygen Instrumentation

    NASA Technical Reports Server (NTRS)

    Pijanowski, Barbara S.

    1971-01-01

    The implications of the presence of dissolved oxygen in water are discussed in terms of its deleterious or beneficial effects, depending on the functional consequences to those affected, e.g., the industrialist, the oceanographer, and the ecologist. The paper is devoted primarily to an examination of the performance of five commercially available dissolved oxygen meters. The design of each is briefly reviewed and ease or difficulty of use in the field described. Specifically, the evaluation program treated a number of parameters and user considerations including an initial check and trial calibration for each instrument and a discussion of the measurement methodology employed. Detailed test results are given relating to the effects of primary power variation, water-flow sensitivity, response time, relative accuracy of dissolved-oxygen readout, temperature accuracy (for those instruments which included this feature), error and repeatability, stability, pressure and other environmental effects, and test results obtained in the field. Overall instrument performance is summarized comparatively by chart.

  7. Analysis of dissolved gas and fluid chemistry in mountainous region of Goaping river watershed in southern Taiwan

    NASA Astrophysics Data System (ADS)

    Tang, Kai-Wen; Chen, Cheng-Hong; Liu, Tsung-Kwei

    2016-04-01

    Annual rainfall in Taiwan is up to 2500 mm, about 2.5 times the average value of the world. However due to high topographic relief of the Central Mountain Range in Taiwan, groundwater storage is critical for water supply. Mountain region of the Goaping river watershed in southern Taiwan is one of the potential areas to develop groundwater recharge model. Therefore the target of this study is to understand sources of groundwater and surface water using dissolved gas and fluid chemistry. Four groundwater and 6 surface water samples were collected from watershed, 5 groundwater and 13 surface water samples were collected from downstream. All samples were analyzed for stable isotopes (hydrogen and oxygen), dissolved gases (including nitrogen, oxygen, argon, methane and carbon dioxide), noble gases (helium and radon) and major ions. Hydrogen and oxygen isotopic ratios of surface water and groundwater samples aligned along meteoric water line. For surface water, dissolved gases are abundant in N2 (>80%) and O2 (>10%); helium isotopic ratio is approximately equal to 1 RA (RA is 3He/4He ratio of air); radon-222 concentration is below the detection limit (<200 Bq/m3); and concentrations of major anions and cations are low (Na+ <20 ppm, Ca2+ < 60 ppm, Cl‑ <2 ppm). All these features indicate that surface waters are predominately recharged by precipitation. For groundwater, helium isotopic ratios (0.9˜0.23 RA) are lower and radon-222 concentrations (300˜6000 Bq/m3) are much higher than the surface water. Some samples have high amounts of dissolved gases, such as CH4 (>20%) or CO2 (>10%), most likely contributed by biogenic or geogenic sources. On the other hand, few samples that have temperature 5° higher than the average of other samples, show significantly high Na+ (>1000 ppm), Ca2+ (>150 ppm) and Cl‑ (>80 ppm) concentrations. An interaction between such groundwater and local hot springs is inferred. Watershed and downstream samples differ in dissolved gas species and

  8. Light Collection in Liquid Noble Gases

    SciTech Connect

    McKinsey, Dan

    2013-05-29

    Liquid noble gases are increasingly used as active detector materials in particle and nuclear physics. Applications include calorimeters and neutrino oscillation experiments as well as searches for neutrinoless double beta decay, direct dark matter, muon electron conversion, and the neutron electric dipole moment. One of the great advantages of liquid noble gases is their copious production of ultraviolet scintillation light, which contains information about event energy and particle type. I will review the scintillation properties of the various liquid noble gases and the means used to collect their scintillation light, including recent advances in photomultiplier technology and wavelength shifters.

  9. The future of energy gases

    SciTech Connect

    Howell, D.G.

    1995-04-01

    Natural gas, mainly methane, produces lower CO {sub 2}, CO, NO{sub x}, SO {sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce each 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the above rates of recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions stemming from the need to drill an enormous number of wells, many in ecologically sensitive areas. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane is known to exist in the mantle and lower crust. Near the Earth`s surface, methane occurs in enormous oil and/or gas reservoirs in rock, and is absorbed in coal, dissolved in water, and trapped in a latticework of ice-like material called gas hydrate. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, methane accounts for roughly 25 percent of current U.S. consumption, but its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.

  10. Airfreight forecasting methodology and results

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A series of econometric behavioral equations was developed to explain and forecast the evolution of airfreight traffic demand for the total U.S. domestic airfreight system, the total U.S. international airfreight system, and the total scheduled international cargo traffic carried by the top 44 foreign airlines. The basic explanatory variables used in these macromodels were the real gross national products of the countries involved and a measure of relative transportation costs. The results of the econometric analysis reveal that the models explain more than 99 percent of the historical evolution of freight traffic. The long term traffic forecasts generated with these models are based on scenarios of the likely economic outlook in the United States and 31 major foreign countries.

  11. Errors in Moral Forecasting: Perceptions of Affect Shape the Gap Between Moral Behaviors and Moral Forecasts.

    PubMed

    Teper, Rimma; Tullett, Alexa M; Page-Gould, Elizabeth; Inzlicht, Michael

    2015-07-01

    Research in moral decision making has shown that there may not be a one-to-one relationship between peoples' moral forecasts and behaviors. Although past work suggests that physiological arousal may account for part of the behavior-forecasting discrepancy, whether or not perceptions of affect play an important determinant remains unclear. Here, we investigate whether this discrepancy may arise because people fail to anticipate how they will feel in morally significant situations. In Study 1, forecasters predicted cheating significantly more on a test than participants in a behavior condition actually cheated. Importantly, forecasters who received false somatic feedback, indicative of high arousal, produced forecasts that aligned more closely with behaviors. In Study 2, forecasters who misattributed their arousal to an extraneous source forecasted cheating significantly more. In Study 3, higher dispositional emotional awareness was related to less forecasted cheating. These findings suggest that perceptions of affect play a key role in the behavior-forecasting dissociation. PMID:25900823

  12. Probabilistic Downscaling Methods for Developing Categorical Streamflow Forecasts using Climate Forecasts

    NASA Astrophysics Data System (ADS)

    Mazrooei, A. H.

    2015-12-01

    Statistical information from climate forecast ensembles can be utilized in developing probabilistic streamflow forecasts for providing the uncertainty in streamflow forecast potential. This study examines the use of Multinomial Logistic Regression (MLR) in downscaling the probabilistic information from the large-scale climate forecast ensembles into a point-scale categorical streamflow forecasts. Performance of MLR in developing one-month lead categorical forecasts is evaluated for various river basins over the US Sunbelt. Comparison of MLR with the estimated categorical forecasts from Principle Component Regression (PCR) method under both cross-validation and split-sampling validation reveals that in general the forecasts from MLR has better performance and lower Rank Probability Score (RPS) compared to the PCR forecasts. In addition, MLR performs better than PCR method particularly in arid basins that exhibit strong skewness in seasonal flows with records of distinct dry years. A theoretical underpinning for this improved performance of MLR is also provided.

  13. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C.J.; Mackenzie, P.D.

    1982-09-03

    Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  14. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C. Judson; MacKenzie, Patricia D.

    1985-01-01

    Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  15. [What you should know of the arterial blood gases during the watch].

    PubMed

    Márquez-González, Horacio; Pámanes-González, Jesús; Márquez-Flores, Horacio; Gómez-Negrete, Alonso; Muñoz-Ramírez, Mireya C; Villa-Romero, Antonio Rafael

    2012-01-01

    Gasometry is the measurement of dissolved gases in the blood, by measuring pH, carbon dioxide pressure (pCO(2)), serum bicarbonate (HCO(3-)), and lactate and serum electrolytes: sodium, potassium and chlorine you can make a diagnosis, etiology and treatment in the critically ill patient. The aim is to provide five steps for the interpretation of blood gases by: 1. The definition of acidemia or acidosis, or alkalemia or alkalosis. 2. Defining the metabolic component or respiratory. 3. To determine the anion gap; levels above 15 ± 2 determine other likely causes of excess anions (methanol, uremia, diabetic ketoacidosis, paraldehyde, ionized, lactic acidosis, ethylene glycol and salicylates. 4. Compensation, using the Winter formula. 5. The delta gap, with the formula for determining intrinsic and metabolic alkalosis. When anion gap is normal, is calculated urinary anion gap; the value is negative if the loss is extrarenal, contrary to the positive result is renal etiology. PMID:23234742

  16. Vesicles in Apollo 15 Green Glasses: The Nature of Ancient Lunar Gases

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; Clemett, S. J.; Berger, E. L.; Rahman, Z.; McKay, D. S.; Gibson, E. K.; Wentworth, S. J.

    2014-01-01

    Detailed studies of Apollo 15 green glass and related beads have shown they were formed in gas-rich fire fountains.. As the magmatic fluid became super-saturated in volatile gas, bubbles or vesicles formed within the magma. These exsolved gases became trapped within vesicles as the glasses were ejected from the fire-fountain and subsequently quenched. One of the keys to understanding formation processes on the ancient moon includes determining the composition of volatile species and elements, including metals, dissolved in magmatic gases. Here we report the nature of mineral phases spatially associated with vesicles in a green glass bead from Apollo sample 15411,42. The phases reflect the composition of the cooling/degassing magmatic vapors and fluids present at the time of bead formation approx, 3 Ga ago

  17. Improving Forecasts for Water Management

    NASA Astrophysics Data System (ADS)

    Arumugam, Sankar; Wood, Andy; Rajagopalan, Balaji; Schaake, John

    2014-01-01

    Recent advances in seasonal to interannual hydroclimate predictions provide an opportunity for developing a proactive approach toward water management. This motivated a recent AGU Chapman Conference (see program details at http://chapman.agu.org/watermanagement/). Approximately 85 participants from the United States, Oceania, Asia, Europe, and South America presented and discussed the current state of successes, challenges, and opportunities in seasonal to interannual hydroclimate forecasts and water management, and a number of key messages emerged.

  18. Post Processing Numerical Weather Prediction Model Rainfall Forecasts for Use in Ensemble Streamflow Forecasting in Australia

    NASA Astrophysics Data System (ADS)

    Shrestha, D. L.; Robertson, D.; Bennett, J.; Ward, P.; Wang, Q. J.

    2012-12-01

    Through the water information research and development alliance (WIRADA) project, CSIRO is conducting research to improve flood and short-term streamflow forecasting services delivered by the Australian Bureau of Meteorology. WIRADA aims to build and test systems to generate ensemble flood and short-term streamflow forecasts with lead times of up to 10 days by integrating rainfall forecasts from Numerical Weather Prediction (NWP) models and hydrological modelling. Here we present an overview of the latest progress towards developing this system. Rainfall during the forecast period is a major source of uncertainty in streamflow forecasting. Ensemble rainfall forecasts are used in streamflow forecasting to characterise the rainfall uncertainty. In Australia, NWP models provide forecasts of rainfall and other weather conditions for lead times of up to 10 days. However, rainfall forecasts from Australian NWP models are deterministic and often contain systematic errors. We use a simplified Bayesian joint probability (BJP) method to post-process rainfall forecasts from the latest generation of Australian NWP models. The BJP method generates reliable and skilful ensemble rainfall forecasts. The post-processed rainfall ensembles are then used to force a semi-distributed conceptual rainfall runoff model to produce ensemble streamflow forecasts. The performance of the ensemble streamflow forecasts is evaluated on a number of Australian catchments and the benefits of using post processed rainfall forecasts are demonstrated.

  19. Short-term ensemble streamflow forecasting using operationally-produced single-valued streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Regonda, Satish; Seo, Dong-Jun; Lawrence, Bill

    2010-05-01

    We present a statistical procedure that generates short-term streamflow ensemble forecasts from single-valued, or deterministic, forecasts operationally produced by the National Weather Service (NWS) River Forecast Centers (RFC). The resulting ensemble forecast provides an estimate of the uncertainty in the single-valued forecast to aid risk-based decision making by the emergency managers and by the users of the forecast products and services. The single-valued forecasts are produced at a 6-hr time step for 5 days into the future, and reflect single-valued short-term quantitative precipitation and temperature forecasts (QPF, QTF) and various run-time modifications (MOD), or manual data assimilation, by human forecasters to reduce various sources of error in the end-to-end forecast process. The proposed procedure generates 5 day-ahead ensemble traces of streamflow from a very parsimonious approximation of the conditional multivariate probability distribution of future streamflow given the single-valued streamflow forecasts, QPF and recent streamflow observations. For parameter estimation and evaluation, we used a 10-year archive of the single-valued river stage forecasts for six forecast points in Oklahoma produced operationally by the Arkansas-Red River Basin River Forecast Center (ABRFC). To evaluate the procedure, we carried out dependent and leave-one-year-out cross validation. The resulting ensemble hindcasts are then verified using the Ensemble Verification System (EVS) developed at the NWS Office of Hydrologic Development (OHD).

  20. Scorecard on winter weather forecast

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    A comparison of the observed temperatures and precipitation for this past winter (maps on left) with predicted temperatures and precipitation (maps on right) shows that the National Weather Service (NWS) temperature prediction was below par, but that the NWS precipitation forecast was ‘quite good,’ according to Don L. Gilman, chief of the NWS long-range forecast branch. The predictions, issued November 29, 1982 (Eos, December 14, 1982, p. 1211), covered December, January, and February.NWS long-range forecasters had thought that frigid Arctic air would swoop far south to bring below-normal temperatures to the western United States. Instead, an east Pacific trough, which may have been the strongest since 1900, brought a strong influx of air from the west, according to Gilman. The intense, low-pressure anomaly in the east Pacific, with the strong westerly winds, teamed with heavy rains south and southwest of Hawaii and warm equatorial Pacific waters to bring warm, wet air to the western United States. The results (see maps): Throughout most of the country, observed temperatures were above normal (A) or normal (N), while observed precipitation was heavy (H) o r normal (no code). Below-normal temperatures (B) occurred only in a portion of the southcentral U.S. and the Florida Keys. Light precipitation (L) fell over two patches in the northern plains, in the Appalachian region, and along the Maine coast.

  1. Forecast of iceberg ensemble drift

    SciTech Connect

    El-Tahan, M.S.; El-Tahan, H.W.; Venkatesh, S.

    1983-05-01

    The objectives of the study are to gain a better understanding of the characteristics of iceberg motion and the factors controlling iceberg drift, and to develop an iceberg ensemble drift forecast system to be operated by the Canadian Atmospheric Environment Service. An extensive review of field and theoretical studies on iceberg behaviour, and the factors controlling iceberg motion has been carried out. Long term and short term behaviour of icebergs are critically examined. A quantitative assessment of the effects of the factors controlling iceberg motion is presented. The study indicated that wind and currents are the primary driving forces. Coriolis Force and ocean surface slope also have significant effects. As for waves, only the higher waves have a significant effect. Iceberg drift is also affected by iceberg size characteristics. Based on the findings of the study a comprehensive computerized forecast system to predict the drift of iceberg ensembles off Canada's east coast has been designed. The expected accuracy of the forecast system is discussed and recommendations are made for future improvements to the system.

  2. Communicating uncertainty in hydrological forecasts: mission impossible?

    NASA Astrophysics Data System (ADS)

    Ramos, Maria-Helena; Mathevet, Thibault; Thielen, Jutta; Pappenberger, Florian

    2010-05-01

    Cascading uncertainty in meteo-hydrological modelling chains for forecasting and integrated flood risk assessment is an essential step to improve the quality of hydrological forecasts. Although the best methodology to quantify the total predictive uncertainty in hydrology is still debated, there is a common agreement that one must avoid uncertainty misrepresentation and miscommunication, as well as misinterpretation of information by users. Several recent studies point out that uncertainty, when properly explained and defined, is no longer unwelcome among emergence response organizations, users of flood risk information and the general public. However, efficient communication of uncertain hydro-meteorological forecasts is far from being a resolved issue. This study focuses on the interpretation and communication of uncertain hydrological forecasts based on (uncertain) meteorological forecasts and (uncertain) rainfall-runoff modelling approaches to decision-makers such as operational hydrologists and water managers in charge of flood warning and scenario-based reservoir operation. An overview of the typical flow of uncertainties and risk-based decisions in hydrological forecasting systems is presented. The challenges related to the extraction of meaningful information from probabilistic forecasts and the test of its usefulness in assisting operational flood forecasting are illustrated with the help of two case-studies: 1) a study on the use and communication of probabilistic flood forecasting within the European Flood Alert System; 2) a case-study on the use of probabilistic forecasts by operational forecasters from the hydroelectricity company EDF in France. These examples show that attention must be paid to initiatives that promote or reinforce the active participation of expert forecasters in the forecasting chain. The practice of face-to-face forecast briefings, focusing on sharing how forecasters interpret, describe and perceive the model output forecasted

  3. Ultrasonic propagation in gases at high temperatures

    NASA Technical Reports Server (NTRS)

    Carey, C.; Carnevale, E. H.; Lynworth, L. C.; Uva, S.

    1970-01-01

    Ultrasonic pulse method /1 to 3 MHz/ measures both sound speed and absorption in monatomic and polyatomic gases in a temperature range of 300 to 20000 degrees K at atmospheric pressure. Helium, nitrogen, oxygen, and argon are investigated.

  4. REGIONAL DEPOSITION OF INHALED REACTIVE GASES

    EPA Science Inventory

    A critical concept in inhalation toxicology involves the determination of dose as the first component for providing a perspective to judge the applicability of various toxicological results to human exposure conditions. Available experimental data for reactive gases were reviewed...

  5. Voluntary reporting of greenhouse gases, 1995

    SciTech Connect

    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.

  6. Denitrification of combustion gases. [Patent application

    DOEpatents

    Yang, R.T.

    1980-10-09

    A method for treating waste combustion gas to remove the nitrogen oxygen gases therefrom is disclosed wherein the waste gas is first contacted with calcium oxide which absorbs and chemically reacts with the nitrogen oxide gases therein at a temperature from about 100/sup 0/ to 430/sup 0/C. The thus reacted calcium oxide (now calcium nitrate) is then heated at a temperature range between about 430/sup 0/ and 900/sup 0/C, resulting in regeneration of the calcium oxide and production of the decomposition gas composed of nitrogen and nitrogen oxide gas. The decomposition gases can be recycled to the calcium oxide contacting step to minimize the amount of nitrogen oxide gases in the final product gas.

  7. Silicon Carbide Transistor For Detecting Hydrocarbon Gases

    NASA Technical Reports Server (NTRS)

    Shields, Virgil B.; Ryan, Margaret A.; Williams, Roger M.

    1996-01-01

    Proposed silicon carbide variable-potential insulated-gate field-effect transistor specially designed for use in measuring concentrations of hydrocarbon gases. Devices like this prove useful numerous automotive, industrial, aeronautical, and environmental monitoring applications.

  8. Quantum gases: The high-symmetry switch

    NASA Astrophysics Data System (ADS)

    Gorshkov, Alexey V.

    2014-10-01

    Accessing orbital exchange between highly symmetric many-component spins may hold the key to a number of exotic, strongly correlated quantum phenomena, but probing such exchange is far from easy. An experiment with ultracold gases takes on the task.

  9. Export of Dissolved Methane and Carbon Dioxide with Effluents from Municipal Wastewater Treatment Plants.

    PubMed

    Alshboul, Zeyad; Encinas-Fernández, Jorge; Hofmann, Hilmar; Lorke, Andreas

    2016-06-01

    Inland waters play an important role for regional and global scale carbon cycling and are significant sources of the atmospheric greenhouse gases methane (CH4) and carbon dioxide (CO2). Although most studies considered the input of terrestrially derived organic and inorganic carbon as the main sources for these emissions, anthropogenic sources have rarely been investigated. Municipal wastewater treatment plants (WWTPs) could be additional sources of carbon by discharging the treated wastewater into the surrounding aquatic ecosystems. Here we analyze seasonally resolved measurements of dissolved CH4 and CO2 concentrations in effluents and receiving streams at nine WWTPs in Germany. We found that effluent addition significantly altered the physicochemical properties of the streamwater. Downstream of the WWTPs, the concentrations of dissolved CH4 and CO2 were enhanced and the atmospheric fluxes of both gases increased by a factor of 1.2 and 8.6, respectively. The CH4 exported with discharged effluent, however, accounted for only a negligible fraction (0.02%) of the estimated total CH4 emissions during the treatment process. The CH4 concentration in the effluent water was linearly related to the organic load of the wastewater, which can provide an empirical basis for future attempts to add WWTPs inputs to regional-scale models for inland water-carbon fluxes. PMID:27160023

  10. Improved Arterial Blood Oxygenation Following Intravenous Infusion of Cold Supersaturated Dissolved Oxygen Solution

    PubMed Central

    Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

    2014-01-01

    BACKGROUND One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. METHODS Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer’s lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. RESULTS Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. CONCLUSIONS A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model. PMID:25249764

  11. Assessment of reservoir system variable forecasts

    NASA Astrophysics Data System (ADS)

    Kistenmacher, Martin; Georgakakos, Aris P.

    2015-05-01

    Forecast ensembles are a convenient means to model water resources uncertainties and to inform planning and management processes. For multipurpose reservoir systems, forecast types include (i) forecasts of upcoming inflows and (ii) forecasts of system variables and outputs such as reservoir levels, releases, flood damage risks, hydropower production, water supply withdrawals, water quality conditions, navigation opportunities, and environmental flows, among others. Forecasts of system variables and outputs are conditional on forecasted inflows as well as on specific management policies and can provide useful information for decision-making processes. Unlike inflow forecasts (in ensemble or other forms), which have been the subject of many previous studies, reservoir system variable and output forecasts are not formally assessed in water resources management theory or practice. This article addresses this gap and develops methods to rectify potential reservoir system forecast inconsistencies and improve the quality of management-relevant information provided to stakeholders and managers. The overarching conclusion is that system variable and output forecast consistency is critical for robust reservoir management and needs to be routinely assessed for any management model used to inform planning and management processes. The above are demonstrated through an application from the Sacramento-American-San Joaquin reservoir system in northern California.

  12. Forecasting Space Weather from Magnetograms

    NASA Technical Reports Server (NTRS)

    Falconer, David A.; Moore, Ronald L.; Barghouty, Abdulnasser F.; Khazanov, Igor

    2012-01-01

    Large flares and fast CMEs are the drivers of the most severe space weather including Solar Energetic Particle Events (SEP Events). Large flares and their co-produced CMEs are powered by the explosive release of free magnetic energy stored in non-potential magnetic fields of sunspot active regions. The free energy is stored in and released from the low-beta regime of the active region s magnetic field above the photosphere, in the chromosphere and low corona. From our work over the past decade and from similar work of several other groups, it is now well established that (1) a proxy of the free magnetic energy stored above the photosphere can be measured from photospheric magnetograms, maps of the measured field in the photosphere, and (2) an active region s rate of production of major CME/flare eruptions in the coming day or so is strongly correlated with its present measured value of the free-energy proxy. These results have led us to use the large database of SOHO/MDI full-disk magnetograms spanning Solar Cycle 23 to obtain empirical forecasting curves that from an active region s present measured value of the free-energy proxy give the active region s expected rates of production of major flares, CMEs, fast CMEs, and SEP Events in the coming day or so (Falconer et al 2011, Space Weather, 9, S04003). For each type of event, the expected rate is readily converted to the chance that the active region will produce such an event in any given forward time window of a day or so. If the chance is small enough (e.g. <5%), the forecast is All Clear for that type of event. We will present these forecasting curves and demonstrate the accuracy of their forecasts. In addition, we will show that the forecasts for major flares and fast CMEs can be made significantly more accurate by taking into account not only the value of the free energy proxy but also the active region s recent productivity of major flares; specifically, whether the active region has produced a major flare

  13. Biological production of products from waste gases

    DOEpatents

    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.

  14. DISSOLVED OXYGEN IMPACT FROM URBAN STORM RUNOFF

    EPA Science Inventory

    The primary objective of the research reported here is to determine if on a national basis a correlation exists between strength of dissolved oxygen (DO) deficits and the presence of rainfall and/or storm runoff downstream of urban areas. A secondary objective is to estimate the ...

  15. Modeling Fish Growth in Low Dissolved Oxygen

    ERIC Educational Resources Information Center

    Neilan, Rachael Miller

    2013-01-01

    This article describes a computational project designed for undergraduate students as an introduction to mathematical modeling. Students use an ordinary differential equation to describe fish weight and assume the instantaneous growth rate depends on the concentration of dissolved oxygen. Published laboratory experiments suggest that continuous…

  16. Dissolving microneedles for transdermal drug delivery.

    PubMed

    Lee, Jeong W; Park, Jung-Hwan; Prausnitz, Mark R

    2008-05-01

    Microfabrication technology has been adapted to produce micron-scale needles as a safer and painless alternative to hypodermic needle injection, especially for protein biotherapeutics and vaccines. This study presents a design that encapsulates molecules within microneedles that dissolve within the skin for bolus or sustained delivery and leave behind no biohazardous sharp medical waste. A fabrication process was developed based on casting a viscous aqueous solution during centrifugation to fill a micro-fabricated mold with biocompatible carboxymethylcellulose or amylopectin formulations. This process encapsulated sulforhodamine B, bovine serum albumin, and lysozyme; lysozyme was shown to retain full enzymatic activity after encapsulation and to remain 96% active after storage for 2 months at room temperature. Microneedles were also shown to be strong enough to insert into cadaver skin and then to dissolve within minutes. Bolus delivery was achieved by encapsulating molecules just within microneedle shafts. For the first time, sustained delivery over hours to days was achieved by encapsulating molecules within the microneedle backing, which served as a controlled release reservoir that delivered molecules by a combination of swelling the backing with interstitial fluid drawn out of the skin and molecule diffusion into the skin via channels formed by dissolved microneedles. We conclude that dissolving microneedles can be designed to gently encapsulate molecules, insert into skin, and enable bolus or sustained release delivery. PMID:18261792

  17. REMOVING DISSOLVED INORGANIC CONTAMINANTS FROM WATER

    EPA Science Inventory

    Dissolved inorganic contaminants in water can be cationic, anionic, or neutral forms of ions, atoms, or molecules of any element in the periodic table. The article describes the physicochemical treatment processes typically used to remove the more common inorganic contaminants fr...

  18. Abiotic uptake of gases by organic soils

    NASA Astrophysics Data System (ADS)

    Smagin, A. V.

    2007-12-01

    Methodological and experimental studies of the abiotic uptake of gaseous substances by organic soils were performed. The static adsorption method of closed vessels for assessing the interaction of gases with the solid and liquid soil phases and the dynamic method of determining the sorption isotherms of gases by soils were analyzed. The theoretical substantiation of the methods and their practical implementations on the basis of a PGA-7 portable gas analyzer (Russia) were considered. Good agreement between the equilibrium sorption isotherms of the gases and the Langmuir model was revealed; for the real ranges of natural gas concentrations, this model can be reduced to the linear Henry equation. The limit values of the gas sorption (Langmuir monolayer capacity) are typical for dry samples; they vary from 670 4000 g/m3 for methane and oxygen to 20 000 25 000 g/m3 for carbon dioxide. The linear distribution coefficients of gases between the solid and gas phases of organic soils (Henry constants) are 8 18 units for poorly sorbed gases (O2, CH4) and 40 60 units for CO2. The kinetics of the chemicophysical uptake of gases by the soil studied is linear in character and obeys the relaxation kinetic model of the first order with the corresponding relaxation constants, which vary from 1 h -1 in wet samples to 10 h -1 in dry samples.

  19. Source gases: Concentrations, emissions, and trends

    NASA Technical Reports Server (NTRS)

    Fraser, Paul J.; Harriss, Robert; Penkett, Stuart A.; Makide, Yoshihiro; Sanhueza, Eugenio; Alyea, Fred N.; Rowland, F. Sherwood; Blake, Don; Sasaki, Toru; Cunnold, Derek M.

    1991-01-01

    Source gases are defined as those gases that influence levels of stratospheric ozone (O3) by transporting species containing halogen, hydrogen, and nitrogen to the stratosphere. Examples are the CFC's, methane (CH4), and nitrous oxide (N2O). Other source gases that also come under consideration in an atmospheric O3 context are those that are involved in the O3 or hydroxyl (OH) radical chemistry of the troposphere. Examples are CH4, carbon monoxide (CO), and nonmethane hydrocarbons (NMHC's). Most of the source gases, along with carbon dioxide (CO2) and water vapor (H2O), are climatically significant and thus affect stratospheric O3 levels by their influence on stratospheric temperatures. Carbonyl sulphide (COS) could affect stratospheric O3 through maintenance of the stratospheric sulphate aerosol layer, which may be involved in heterogeneous chlorine-catalyzed O3 destruction. The previous reviews of trends and emissions of source gases, either from the context of their influence on atmospheric O3 or global climate change, are updated. The current global abundances and concentration trends of the trace gases are given in tabular format.

  20. Classification and generation of terrestrial rare gases

    NASA Technical Reports Server (NTRS)

    Saito, K.

    1978-01-01

    A Kr-84/Xe-130 versus Ne-20/Ar-36 diagram is a very useful format with which to study the elemental ratios of rare gases from terrestrial materials. It can separate not only the three types of rare gases which Ozima and Alexander (1976) classified but also the 'planetary' type rare gases from the other three types of rare gases. When all the available terrestrial rare gas data are plotted in a Kr-84/Xe-130 versus Ne-20/Ar-36 diagram, several observations can be made. First, most of the analyses of rare gases from shales yield Kr-84/Xe-130 ratios between the 'planetary' and atmospheric values. If, however, the atmosphere's high Kr-84/Xe-130 ratio was produced by the selective adsorption of xenon onto shales from an initially 'planetary' atmosphere, as is widely accepted, then the Kr-84/Xe-130 ratio in shales should be even lower than the 'planetary' value. Second, the rare gas pattern in the quenched rims of submarine basalts may be explained as fractionated samples of the rare gases in sea water.

  1. Evaluation of seasonal forecast skill over China

    NASA Astrophysics Data System (ADS)

    Roads, John O.; Chen, Shyh-Chin

    2003-06-01

    Since Sept. 26, 1997, the Scripps Experimental Climate Prediction Center (ECPC) has been making experimental, near real-time seasonal global forecasts. Images of these forecasts, at daily to seasonal time scales, are provided on the World Wide Web, and experimental digital forecast products are made available to international collaborators. Over Asia, these experimental forecasts are now being used to drive regional prediction and various application models at National Taiwan University (NTU) and the Hong Kong Observatory. Roads et al. [Bull. Am. Meteorol. Soc. 82 (2001) 639] and Terra Chen et al. [Atmos. Oceanogr. Sci. 12 (2003a) 377] previously discussed the basic forecast and analysis system. The purpose of this paper is to discuss specific synoptic characteristics of recent seasonal forecasts as a guide to further application and development.

  2. ECMWF SSW forecast evaluation using infrasound

    NASA Astrophysics Data System (ADS)

    Smets, Pieter; Assink, Jelle; Le Pichon, Alexis; Evers, Läslo

    2016-04-01

    Accurate prediction of Sudden Stratospheric Warming (SSW) events is important for the performance of numerical weather prediction due to significant stratosphere--troposphere coupling. In this study, for the first time middle atmospheric numerical weather forecasts are evaluated using infrasound. A year of near continuous infrasound from Mt. Tolbachik (Kamchatka, Russian Federation) is compared with simulations using high resolution deterministic forecasts of the European Centre for Medium-range Weather Forecasts (ECMWF). For the entire timespan the nowcast generally performs best, indicated by a higher continuity and and smaller bearing difference. However, focussing on the period around the 2013 major SSW shows that while the SSW onset is better captured by the ten day forecast, the recovery is better captured by the nowcast. As such, this study demonstrates the use of infrasound in the evaluation of middle atmospheric weather forecasts and therefore its potential in the assessment of tropospheric forecast skill.

  3. Dissolver Off-gas Hot Operations Authorization (AFCI CETE Milestone Report)

    SciTech Connect

    Jubin, Robert Thomas

    2009-06-01

    The head-end processing of the Coupled-End-to-End (CETE) Demonstration includes fuel receipt, fuel disassembly, exposure of fuel (e.g., by segmenting the fuel pins), voloxidation of the fuel to separate tritium, and fuel dissolution. All of these processing steps with the exception of the dissolution step will be accomplished in the Irradiated Fuels Examination Laboratory (IFEL) (Building 3525). The final headend step will be performed in the Radiochemical Engineering Development Center (Building 7920). The primary purpose of the fuel dissolution step is to prepare the solid fuel for subsequent liquid separations steps. This is accomplished by dissolving the fuel solids using nitric acid. During the dissolution process gases are evolved. Oxides of nitrogen are the primary off-gas components generated by the reactions of nitric acid and the fuel oxides however, during the dissolution and sparging of the resulting solution, iodine, C-14 as carbon dioxide, xenon, and krypton gasses are also released to the off-gas stream. The Dissolver Off-gas treatment rack provides a means of trapping these volatile fission products and other gases via various trapping media. Specifically the rack will recover iodine on a solid sorbent bed, scrub NOx in a water/acid column, scrub CO{sub 2} in a caustic scrubber column, remove moisture with solid sorbent drier beds and recover Xe and Kr using solid absorbent beds. The primary purpose of this experimental rack and the off-gas rack associated with the voloxidation equipment located at IFEL is to close the material balances around the volatile gases and to provide an understanding of the impacts of specific processing conditions on the fractions of the volatile components released from the various head-end processing steps.

  4. How rolling forecasting facilitates dynamic, agile planning.

    PubMed

    Miller, Debra; Allen, Michael; Schnittger, Stephanie; Hackman, Theresa

    2013-11-01

    Rolling forecasting may be used to replace or supplement the annual budget process. The rolling forecast typically builds on the organization's strategic financial plan, focusing on the first three years of plan projections and comparing the strategic financial plan assumptions with the organization's expected trajectory. Leaders can then identify and respond to gaps between the rolling forecast and the strategic financial plan on an ongoing basis. PMID:24340653

  5. Seasonal hydrological ensemble forecasts over Europe

    NASA Astrophysics Data System (ADS)

    Arnal, Louise; Wetterhall, Fredrik; Pappenberger, Florian

    2015-04-01

    Seasonal forecasts have an important socio-economic value in hydro-meteorological forecasting. The applications are for example hydropower management, spring flood prediction and water resources management. The latter includes prediction of low flows, primordial for navigation, water quality assessment, droughts and agricultural water needs. Traditionally, seasonal hydrological forecasts are done using the observed discharge from previous years, so called Ensemble Streamflow Prediction (ESP). With the recent increasing development of seasonal meteorological forecasts, the incentive for developing and improving seasonal hydrological forecasts is great. In this study, a seasonal hydrological forecast, driven by the ECMWF's System 4 (SEA), was compared with an ESP of modelled discharge using observations. The hydrological model used for both forecasts was the LISFLOOD model, run over a European domain with a spatial resolution of 5 km. The forecasts were produced from 1990 until the present time, with a daily time step. They were issued once a month with a lead time of seven months. The SEA forecasts are constituted of 15 ensemble members, extended to 51 members every three months. The ESP forecasts comprise 20 ensembles and served as a benchmark for this comparative study. The forecast systems were compared using a diverse set of verification metrics, such as continuous ranked probability scores, ROC curves, anomaly correlation coefficients and Nash-Sutcliffe efficiency coefficients. These metrics were computed over several time-scales, ranging from a weekly to a six-months basis, for each season. The evaluation enabled the investigation of several aspects of seasonal forecasting, such as limits of predictability, timing of high and low flows, as well as exceedance of percentiles. The analysis aimed at exploring the spatial distribution and timely evolution of the limits of predictability.

  6. Operational Short-Term Flood Forecasting for Bangladesh: Application of ECMWF Ensemble Precipitation Forecasts

    NASA Astrophysics Data System (ADS)

    Hopson, T. M.; Webster, P. J.

    2004-12-01

    The country of Bangladesh frequently experiences severe catchment-scale flooding from the combined discharges of the Ganges and Brahmaputra rivers. Beginning in 2003, we have been disseminating upper-catchment discharge forecasts for this country to provide advanced warning for evacuation and relief measures. These forecasts are being generated using the European Centre for Medium-Range Weather Forecasting (ECMWF) shortterm ensemble weather forecasts and a combination of distributed and data-based modeling techniques. The forecasts from each of these models are combined using the multi-ensemble technique commonly employed in numerical weather prediction. This leads to a reduction in the overall forecast error and capitalizes on the strengths of each model during different periods of the monsoon season. In addition, the models are combined such that the probabilistic nature of the ensemble precipitation forecasts is retained while being combined with the discharge modeling error to produce true probabilistic forecasts of discharge that are being employed operationally.

  7. Geothermal wells: a forecast of drilling activity

    SciTech Connect

    Brown, G.L.; Mansure, A.J.; Miewald, J.N.

    1981-07-01

    Numbers and problems for geothermal wells expected to be drilled in the United States between 1981 and 2000 AD are forecasted. The 3800 wells forecasted for major electric power projects (totaling 6 GWe of capacity) are categorized by type (production, etc.), and by location (The Geysers, etc.). 6000 wells are forecasted for direct heat projects (totaling 0.02 Quads per year). Equations are developed for forecasting the number of wells, and data is presented. Drilling and completion problems in The Geysers, The Imperial Valley, Roosevelt Hot Springs, the Valles Caldera, northern Nevada, Klamath Falls, Reno, Alaska, and Pagosa Springs are discussed. Likely areas for near term direct heat projects are identified.

  8. Combining forecast weights: Why and how?

    NASA Astrophysics Data System (ADS)

    Yin, Yip Chee; Kok-Haur, Ng; Hock-Eam, Lim

    2012-09-01

    This paper proposes a procedure called forecast weight averaging which is a specific combination of forecast weights obtained from different methods of constructing forecast weights for the purpose of improving the accuracy of pseudo out of sample forecasting. It is found that under certain specified conditions, forecast weight averaging can lower the mean squared forecast error obtained from model averaging. In addition, we show that in a linear and homoskedastic environment, this superior predictive ability of forecast weight averaging holds true irrespective whether the coefficients are tested by t statistic or z statistic provided the significant level is within the 10% range. By theoretical proofs and simulation study, we have shown that model averaging like, variance model averaging, simple model averaging and standard error model averaging, each produces mean squared forecast error larger than that of forecast weight averaging. Finally, this result also holds true marginally when applied to business and economic empirical data sets, Gross Domestic Product (GDP growth rate), Consumer Price Index (CPI) and Average Lending Rate (ALR) of Malaysia.

  9. Wheat yield forecasts using LANDSAT data

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.; Rice, D. P.; Nalepka, R. F.

    1977-01-01

    Several considerations of winter wheat yield prediction using LANDSAT data were discussed. In addition, a simple technique which permits direct early season forecasts of wheat production was described.

  10. Optimized Flood Forecasts Using a Statistical Enemble

    NASA Astrophysics Data System (ADS)

    Silver, Micha; Fredj, Erick

    2016-04-01

    The method presented here assembles an optimized flood forecast from a set of consecutive WRF-Hydro simulations by applying coefficients which we derive from straightforward statistical procedures. Several government and research institutions that produce climate data offer ensemble forecasts, which merge predictions from different models to gain a more accurate fit to observed data. Existing ensemble forecasts present climate and weather predictions only. In this research we propose a novel approach to constructing hydrological ensembles for flood forecasting. The ensemble flood forecast is created by combining predictions from the same model, but initiated at different times. An operative flood forecasting system, run by the Israeli Hydrological Service, produces flood forecasts twice daily with a 72 hour forecast period. By collating the output from consecutive simulation runs we have access to multiple overlapping forecasts. We then apply two statistical procedures to blend these consecutive forecasts, resulting in a very close fit to observed flood runoff. We first employ cross-correlation with a time lag to determine a time shift for each of the original, consecutive forecasts. This shift corrects for two possible sources of error: slow or fast moving weather fronts in the base climate data; and mis-calibrations of the WRF-Hydro model in determining the rate of flow of surface runoff and in channels. We apply this time shift to all consecutive forecasts, then run a linear regression with the observed runoff data as the dependent variable and all shifted forecasts as the predictor variables. The solution to the linear regression equation is a set of coefficients that corrects the amplitude errors in the forecasts. These resulting regression coefficients are then applied to the consecutive forecasts producing a statistical ensemble which, by design, closely matches the observed runoff. After performing this procedure over many storm events in the Negev region

  11. The Economic Value of Air Quality Forecasting

    NASA Astrophysics Data System (ADS)

    Anderson-Sumo, Tasha

    Both long-term and daily air quality forecasts provide an essential component to human health and impact costs. According the American Lung Association, the estimated current annual cost of air pollution related illness in the United States, adjusted for inflation (3% per year), is approximately $152 billion. Many of the risks such as hospital visits and morality are associated with poor air quality days (where the Air Quality Index is greater than 100). Groups such as sensitive groups become more susceptible to the resulting conditions and more accurate forecasts would help to take more appropriate precautions. This research focuses on evaluating the utility of air quality forecasting in terms of its potential impacts by building on air quality forecasting and economical metrics. Our analysis includes data collected during the summertime ozone seasons between 2010 and 2012 from air quality models for the Washington, DC/Baltimore, MD region. The metrics that are relevant to our analysis include: (1) The number of times that a high ozone or particulate matter (PM) episode is correctly forecasted, (2) the number of times that high ozone or PM episode is forecasted when it does not occur and (3) the number of times when the air quality forecast predicts a cleaner air episode when the air was observed to have high ozone or PM. Our collection of data included available air quality model forecasts of ozone and particulate matter data from the U.S. Environmental Protection Agency (EPA)'s AIRNOW as well as observational data of ozone and particulate matter from Clean Air Partners. We evaluated the performance of the air quality forecasts with that of the observational data and found that the forecast models perform well for the Baltimore/Washington region and the time interval observed. We estimate the potential amount for the Baltimore/Washington region accrues to a savings of up to 5,905 lives and 5.9 billion dollars per year. This total assumes perfect compliance with

  12. 1992 five year battery forecast

    SciTech Connect

    Amistadi, D.

    1992-12-01

    Five-year trends for automotive and industrial batteries are projected. Topic covered include: SLI shipments; lead consumption; automotive batteries (5-year annual growth rates); industrial batteries (standby power and motive power); estimated average battery life by area/country for 1989; US motor vehicle registrations; replacement battery shipments; potential lead consumption in electric vehicles; BCI recycling rates for lead-acid batteries; US average car/light truck battery life; channels of distribution; replacement battery inventory end July; 2nd US battery shipment forecast.

  13. Forecasting California’s earthquakes

    USGS Publications Warehouse

    Kerr, R. A.

    1988-01-01

    For the first time, researchers have reached to a consensus on the threat of large earthquakes to California, things look no worse for Los Angles than before. It still has about a 60 percent chance of being shaken by a large earthquake sometime during the next 30 years. But other heavily populated areas of California, such as San Bernardino and the East Bay area of San Francisco, are now getting their fair share of attention. The new consensus also points up the considerable uncertainties invloved in earthquake forecasting

  14. Forecast Mekong: navigating changing waters

    USGS Publications Warehouse

    Powell, Janine

    2011-01-01

    The U.S. Geological Survey (USGS) is using research and data from the Mekong River Delta in Southeast Asia to compare restoration, conservation, and management efforts there with those done in other major river deltas, such as the Mississippi River Delta in the United States. The project provides a forum to engage regional partners in the Mekong Basin countries to share data and support local research efforts. Ultimately, Forecast Mekong will lead to more informed decisions about how to make the Mekong and Mississippi Deltas resilient in the face of climate change, economic stresses, and other impacts.

  15. Mental Models of Software Forecasting

    NASA Technical Reports Server (NTRS)

    Hihn, J.; Griesel, A.; Bruno, K.; Fouser, T.; Tausworthe, R.

    1993-01-01

    The majority of software engineers resist the use of the currently available cost models. One problem is that the mathematical and statistical models that are currently available do not correspond with the mental models of the software engineers. In an earlier JPL funded study (Hihn and Habib-agahi, 1991) it was found that software engineers prefer to use analogical or analogy-like techniques to derive size and cost estimates, whereas curren CER's hide any analogy in the regression equations. In addition, the currently available models depend upon information which is not available during early planning when the most important forecasts must be made.

  16. 41 CFR 50-204.70 - Compressed gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Compressed gases. 50-204... Gases, Vapors, Fumes, Dusts, and Mists § 50-204.70 Compressed gases. The in-plant handling, storage, and utilization of all compressed gases in cylinders, portable tanks, rail tankcars, or motor vehicle cargo...

  17. 41 CFR 50-204.70 - Compressed gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Compressed gases. 50-204... Gases, Vapors, Fumes, Dusts, and Mists § 50-204.70 Compressed gases. The in-plant handling, storage, and utilization of all compressed gases in cylinders, portable tanks, rail tankcars, or motor vehicle cargo...

  18. 41 CFR 50-204.70 - Compressed gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Compressed gases. 50-204... Gases, Vapors, Fumes, Dusts, and Mists § 50-204.70 Compressed gases. The in-plant handling, storage, and utilization of all compressed gases in cylinders, portable tanks, rail tankcars, or motor vehicle cargo...

  19. 41 CFR 50-204.70 - Compressed gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Compressed gases. 50-204... Gases, Vapors, Fumes, Dusts, and Mists § 50-204.70 Compressed gases. The in-plant handling, storage, and utilization of all compressed gases in cylinders, portable tanks, rail tankcars, or motor vehicle cargo...

  20. 40 CFR 86.514-78 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Analytical gases. 86.514-78 Section 86.514-78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Later New Motorcycles; Test Procedures § 86.514-78 Analytical gases. (a) Analyzer gases. (1) Gases...

  1. Seasonal forecast skill of Arctic sea ice area in a dynamical forecast system

    NASA Astrophysics Data System (ADS)

    Sigmond, M.; Fyfe, J. C.; Flato, G. M.; Kharin, V. V.; Merryfield, W. J.

    2013-02-01

    AbstractWe assess the seasonal <span class="hlt">forecast</span> skill of pan-Arctic sea ice area in a dynamical <span class="hlt">forecast</span> system that includes interactive atmosphere, ocean, and sea ice components. <span class="hlt">Forecast</span> skill is quantified by the correlation skill score computed from 12 month ensemble <span class="hlt">forecasts</span> initialized in each month between January 1979 to December 2009. We find that <span class="hlt">forecast</span> skill is substantial for all lead times and predicted seasons except spring but is mainly due to the strong downward trend in observations for lead times of about 4 months and longer. Skill is higher when evaluated against an observation-based dataset with larger trends. The <span class="hlt">forecast</span> skill when linear trends are removed from the <span class="hlt">forecasts</span> and verifying observations is small and generally not statistically significant at lead times greater than 2 to 3 months, except for January/February when <span class="hlt">forecast</span> skill is moderately high up to an 11 month lead time. For short lead times, high trend-independent <span class="hlt">forecast</span> skill is found for October, while low skill is found for November/December. This is consistent with the seasonal variation of observed lag correlations. For most predicted months and lead times, trend-independent <span class="hlt">forecast</span> skill exceeds that of an anomaly persistence <span class="hlt">forecast</span>, highlighting the potential for dynamical <span class="hlt">forecast</span> systems to provide valuable seasonal predictions of Arctic sea ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011NHESS..11.1529V&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011NHESS..11.1529V&link_type=ABSTRACT"><span id="translatedtitle">Perturbation of convection-permitting NWP <span class="hlt">forecasts</span> for flash-flood ensemble <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vincendon, B.; Ducrocq, V.; Nuissier, O.; Vié, B.</p> <p>2011-05-01</p> <p>Mediterranean intense weather events often lead to devastating flash-floods. Extending the <span class="hlt">forecasting</span> lead times further than the watershed response times, implies the use of numerical weather prediction (NWP) to drive hydrological models. However, the nature of the precipitating events and the temporal and spatial scales of the watershed response make them difficult to <span class="hlt">forecast</span>, even using a high-resolution convection-permitting NWP deterministic <span class="hlt">forecasting</span>. This study proposes a new method to sample the uncertainties of high-resolution NWP precipitation <span class="hlt">forecasts</span> in order to quantify the predictability of the streamflow <span class="hlt">forecasts</span>. We have developed a perturbation method based on convection-permitting NWP-model error statistics. It produces short-term precipitation ensemble <span class="hlt">forecasts</span> from single-value meteorological <span class="hlt">forecasts</span>. These rainfall ensemble <span class="hlt">forecasts</span> are then fed into a hydrological model dedicated to flash-flood <span class="hlt">forecasting</span> to produce ensemble streamflow <span class="hlt">forecasts</span>. The verification on two flash-flood events shows that this <span class="hlt">forecasting</span> ensemble performs better than the deterministic <span class="hlt">forecast</span>. The performance of the precipitation perturbation method has also been found to be broadly as good as that obtained using a state-of-the-art research convection-permitting NWP ensemble, while requiring less computing time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ESASP.688E...7K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ESASP.688E...7K"><span id="translatedtitle">From Fire Observations to Smoke Plume <span class="hlt">Forecasting</span> in the MACC Services</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaiser, Johannes W.; Benedetti, A.; Flemming, J.; Morcrette, J.-J.; Heil, A.; Schultz, M. G.; van der Werf, G. R.; Wooster, M. J.</p> <p>2011-01-01</p> <p>The MACC project is implementing atmospheric monitoring and <span class="hlt">forecasting</span> services for the global and Euro- pean domains as part of the GMES programme. Smoke plumes are monitored by assimilating observations of aerosol optical depth and various trace <span class="hlt">gases</span>. Biomass burning is monitored in real time by assimilating observations of fire radiative power (FRP) from five satellite- based instruments. The global monitoring capability is demonstrated with a near real time fire and smoke analysis for South America, where a threefold increase of biomass burning has been detected in 2010 compared to 2009. Furthermore, an anomalously flat diurnal cycle has been recorded for the Russian wildfires of July and August 2010. This can be interpreted as a characteristic of peaty soil burning, which entails particularly large emissions. The global aerosol service was able to <span class="hlt">forecast</span>, with three days lead time, an air quality threshold transgression in Finland that resulted from the Russian fires.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....11169B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....11169B"><span id="translatedtitle">Distribution of <span class="hlt">dissolved</span> silver in marine waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barriada, J. L.; Achterberg, E. P.; Tappin, A.; Truscott, J.</p> <p>2003-04-01</p> <p>Silver is one of the most toxic heavy metals, surpassed only by mercury [1-3]. Monitoring of <span class="hlt">dissolved</span> silver concentrations in natural waters is therefore of great importance. The determination of <span class="hlt">dissolved</span> silver in waters is not without challenges, because of its low (picomolar) concentrations. Consequently, there are only a few reported studies in marine waters, which have been performed in USA [4-6] and Japan [7]. The analytical techniques used in the reported studies for the determination of silver in seawater were Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) after solvent extraction [2,4,5], and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after solvent extraction or solid phase extraction [7,8]. In this contribution, we will present an optimised Magnetic Sector (MS) ICP-MS technique for the determination of <span class="hlt">dissolved</span> silver in marine waters. The MS-ICP-MS method used anion exchange column to preconcentrate silver from saline waters, and to remove the saline matrix. The ICP-MS method has been used successfully to determine total <span class="hlt">dissolved</span> silver in estuarine and oceanic samples. Bibliography 1. H. T. Ratte, Environ. Toxicol. Chem. 1999, 18: p. 89-108. 2. R. T. Herrin, A. W. Andren and D. E. Armstrong, Environ. Sci. Technol. 2001, 35: 1953-1958. 3. D. E. Schildkraut, P. T. Dao, J. P. Twist, A. T. Davis and K. A. Robillard, Environ. Toxicol. Chem. 1998, 17: 642-649. 4. E. Breuer, S. A. Sanudo-Wilhelmy and R. C. Aller, Estuaries. 1999, 22:603-615. 5. A. R. Flegal, S. A. Sanudowilhelmy and G. M. Scelfo, Mar. Chem. 1995, 49: 315-320. 6. S. N. Luoma, Y. B. Ho and G. W. Bryan, Mar. Pollut. Bull. 1995, 31: 44-54. 7. Y. Zhang, H. Amakawa and Y. Nozaki, Mar. Chem. 2001, 75: 151-163. 8. L. Yang and R. E. Sturgeon, J. Anal. At. Spectrom. 2002, 17: 88-93.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992JApMe..31..465Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992JApMe..31..465Y"><span id="translatedtitle">A Streamflow <span class="hlt">Forecast</span> Model for Central Arizona.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Young, Kenneth C.; Gall, Robert L.</p> <p>1992-05-01</p> <p>A spring-runoff <span class="hlt">forecast</span> model for central Arizona was developed based on multiple discriminant analysis. More than 6500 potential predictor variables were analyzed, including local precipitation and temperature variables, as well as global sea level pressure variables. The <span class="hlt">forecast</span> model was evaluated on nine years exclusive of the years on which the model was based. <span class="hlt">Forecasts</span> are provided in the form of a cumulative distribution function (cdf) of the expected runoff, based on analogs. A ranked probability score to evaluate <span class="hlt">forecast</span> skill for the cdf <span class="hlt">forecasts</span> was developed. Ranked probability skill scores ranged from 25% to 45%.Local and global <span class="hlt">forecast</span> models were developed and compared to the combined data source model. The global <span class="hlt">forecast</span> model was equivalent in skill to the local <span class="hlt">forecast</span> model. The combined model exhibited a marked improvement in skill over either the local or global models.Three recurrent patterns in the predictor variables used by the <span class="hlt">forecast</span> model are analyzed in some depth. Above-normal pressure at Raoul Island northeast of New Zealand 14 to 18 months prior to the event <span class="hlt">forecast</span> was found to be associated with above-normal runoff. A westward shift of the Bermuda high, as evidenced by the pressure change at Charleston, South Carolina, from December to August of the preceding year, was found to be associated with above-normal runoff. Above-normal pressure at Port Moresby, New Guinea coupled with below-normal pressure at San Diego, California, the month prior to the <span class="hlt">forecast</span>, was found to be associated with above-normal runoff.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ems..confE..68W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ems..confE..68W"><span id="translatedtitle">Improved low visibility <span class="hlt">forecasts</span> at Amsterdam Airport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wijngaard, J.; Vogelezang, D.; Maat, N.; van Bruggen, H.</p> <p>2009-09-01</p> <p>Accurate, reliable and unambiguous information concerning the actual and expected (low) visibility conditions at Amsterdam Airport Schiphol is very important for the available operational flow capacity. Therefore visibility <span class="hlt">forecast</span> errors can have a negative impact on safety and operational expenses. KNMI has performed an update of the visibility <span class="hlt">forecast</span> system in close collaboration with the main users of the <span class="hlt">forecasts</span> (Air Traffic Control, the airport authorities and KLM airlines). This automatic <span class="hlt">forecasting</span> system consists of a Numerical Weather Prediction Model (Hirlam) with a statistical post processing module on top of it. Output of both components is supplied to a human <span class="hlt">forecaster</span> who issues a special probabilistic <span class="hlt">forecast</span> bulletin. This bulletin is tailored to the specific requirements of the airport community. The improvements made to the <span class="hlt">forecast</span> system are twofold: 1) In addition to the Meteorological Optical Range (MOR) values, RVR (Runway Visual Range) is <span class="hlt">forecasted</span>. Since RVR depends on both MOR and the local Background Luminance, a (deterministic) statistical <span class="hlt">forecast</span> for the latter has been developed. 2) Another improvement was achieved by calculating joint probabilities for specific combinations of visibility and cloud base height for thresholds which have direct impact on the flow capacity at the airport. The development of this new visibility <span class="hlt">forecast</span> will be presented briefly. Also a few verification results will be shown to demonstrate the improvements made. Finally, the importance of explaining the user the use of the <span class="hlt">forecast</span> information, in relation to their decision making process, will be discussed. For that reason, a simple guideline model to make a cost-optimal choice will be introduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1194334','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1194334"><span id="translatedtitle">Ecological <span class="hlt">Forecasting</span> in Chesapeake Bay: Using a Mechanistic-Empirical Modelling Approach</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brown, C. W.; Hood, Raleigh R.; Long, Wen; Jacobs, John M.; Ramers, D. L.; Wazniak, C.; Wiggert, J. D.; Wood, R.; Xu, J.</p> <p>2013-09-01</p> <p>The Chesapeake Bay Ecological Prediction System (CBEPS) automatically generates daily nowcasts and three-day <span class="hlt">forecasts</span> of several environmental variables, such as sea-surface temperature and salinity, the concentrations of chlorophyll, nitrate, and <span class="hlt">dissolved</span> oxygen, and the likelihood of encountering several noxious species, including harmful algal blooms and water-borne pathogens, for the purpose of monitoring the Bay's ecosystem. While the physical and biogeochemical variables are <span class="hlt">forecast</span> mechanistically using the Regional Ocean Modeling System configured for the Chesapeake Bay, the species predictions are generated using a novel mechanistic empirical approach, whereby real-time output from the coupled physical biogeochemical model drives multivariate empirical habitat models of the target species. The predictions, in the form of digital images, are available via the World Wide Web to interested groups to guide recreational, management, and research activities. Though full validation of the integrated <span class="hlt">forecasts</span> for all species is still a work in progress, we argue that the mechanistic–empirical approach can be used to generate a wide variety of short-term ecological <span class="hlt">forecasts</span>, and that it can be applied in any marine system where sufficient data exist to develop empirical habitat models. This paper provides an overview of this system, its predictions, and the approach taken.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHyd..538..754M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHyd..538..754M"><span id="translatedtitle">Streamflow <span class="hlt">forecasting</span> using functional regression</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Masselot, Pierre; Dabo-Niang, Sophie; Chebana, Fateh; Ouarda, Taha B. M. J.</p> <p>2016-07-01</p> <p>Streamflow, as a natural phenomenon, is continuous in time and so are the meteorological variables which influence its variability. In practice, it can be of interest to <span class="hlt">forecast</span> the whole flow curve instead of points (daily or hourly). To this end, this paper introduces the functional linear models and adapts it to hydrological <span class="hlt">forecasting</span>. More precisely, functional linear models are regression models based on curves instead of single values. They allow to consider the whole process instead of a limited number of time points or features. We apply these models to analyse the flow volume and the whole streamflow curve during a given period by using precipitations curves. The functional model is shown to lead to encouraging results. The potential of functional linear models to detect special features that would have been hard to see otherwise is pointed out. The functional model is also compared to the artificial neural network approach and the advantages and disadvantages of both models are discussed. Finally, future research directions involving the functional model in hydrology are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJBm...57..813A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJBm...57..813A"><span id="translatedtitle">Phantosmia as a meteorological <span class="hlt">forecaster</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aiello, S. R.; Hirsch, A. R.</p> <p>2013-09-01</p> <p>In normosmics, olfactory ability has been found to vary with ambient humidity, barometric pressure, and season. While hallucinated sensations of phantom pain associated with changes in weather have been described, a linkage to chemosensory hallucinations has heretofore not been reported. A 64-year-old white male with Parkinson's disease presents with 5 years of phantosmia of a smoky burnt wood which changed to onion-gas and then to a noxious skunk-onion excrement odor. Absent upon waking it increases over the day and persists for hours. When severe, there appears a phantom taste with the same qualities as the odor. It is exacerbated by factors that manipulate intranasal pressure, such as coughing. When eating or sniffing, the actual flavors replace the phantosmia. Since onset, he noted the intensity and frequency of the phantosmia <span class="hlt">forecasted</span> the weather. Two to 3 h before a storm, the phantosmia intensifies from a level 0 to a 7-10, which persists through the entire thunderstorm. Twenty years prior, he reported the ability to <span class="hlt">forecast</span> the weather, based on pain in a torn meniscus, which vanished after surgical repair. Extensive olfactory testing demonstrates underlying hyposmia. Possible mechanisms for such chemosensory-meteorological linkage includes: air pressure induced synesthesia, disinhibition of spontaneous olfactory discharge, exacerbation of ectopic discharge, affect mediated somatic sensory amplification, and misattribution error with expectation and recall bias. This is the first reported case of weather-induced exacerbation of phantosmia. Further investigation of the connection between chemosensory complaints and ambient weather is warranted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.2307T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.2307T"><span id="translatedtitle">Earthquakes - Volcanoes (Causes and <span class="hlt">Forecast</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsiapas, E.</p> <p>2009-04-01</p> <p>EARTHQUAKES - VOLCANOES (CAUSES AND <span class="hlt">FORECAST</span>) ELIAS TSIAPAS RESEARCHER NEA STYRA, EVIA,GREECE TEL.0302224041057 tsiapas@hol.gr The earthquakes are caused by large quantities of liquids (e.g. H2O, H2S, SO2, ect.) moving through lithosphere and pyrosphere (MOHO discontinuity) till they meet projections (mountains negative projections or projections coming from sinking lithosphere). The liquids are moved from West Eastward carried away by the pyrosphere because of differential speed of rotation of the pyrosphere by the lithosphere. With starting point an earthquake which was noticed at an area and from statistical studies, we know when, where and what rate an earthquake may be, which earthquake is caused by the same quantity of liquids, at the next east region. The <span class="hlt">forecast</span> of an earthquake ceases to be valid if these components meet a crack in the lithosphere (e.g. limits of lithosphere plates) or a volcano crater. In this case the liquids come out into the atmosphere by the form of gasses carrying small quantities of lava with them (volcano explosion).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JSEdT..22..103N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JSEdT..22..103N"><span id="translatedtitle">Investigating Students' Understanding of the <span class="hlt">Dissolving</span> Process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Naah, Basil M.; Sanger, Michael J.</p> <p>2013-04-01</p> <p>In a previous study, the authors identified several student misconceptions regarding the process of <span class="hlt">dissolving</span> ionic compounds in water. The present study used multiple-choice questions whose distractors were derived from these misconceptions to assess students' understanding of the <span class="hlt">dissolving</span> process at the symbolic and particulate levels. The symbolic-level questions were based on balanced equations, and the particulate-level questions used multiple-choice questions involving dynamic animations or static pictures. This paper analyzes students' responses to these questions to look for associations among four variables—Answer (the correct answer and three misconceptions), Representation (symbolic or particulate question), Visualization (static or animated pictures), and Representation Order (symbolic questions before or after the particulate questions). The results indicate that the correct answer and the acid-base misconception were more popular than the ion-pair or subscript error misconceptions, the ion-pair misconception was more popular for the particulate questions than the symbolic questions, and that participants were more likely to select the correct answer when viewing static particulate questions compared to animated particulate questions, especially if the particulate questions are seen first. These results suggest that the animated motion of <span class="hlt">dissolving</span> these compounds in water may be distracting for students.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26ES...35a2017M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26ES...35a2017M"><span id="translatedtitle">Quantifying air-sea gas exchange using noble <span class="hlt">gases</span> in a coastal upwelling zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manning, C. C.; Stanley, R. H. R.; Nicholson, D. P.; Squibb, M. E.</p> <p>2016-05-01</p> <p>The diffusive and bubble-mediated components of air-sea gas exchange can be quantified separately using time-series measurements of a suite of <span class="hlt">dissolved</span> inert <span class="hlt">gases</span>. We have evaluated the performance of four published air-sea gas exchange parameterizations using a five-day time-series of <span class="hlt">dissolved</span> He, Ne, Ar, Kr, and Xe concentration in Monterey Bay, CA. We constructed a vertical model including surface air-sea gas exchange and vertical diffusion. Diffusivity was measured throughout the cruise from profiles of turbulent microstructure. We corrected the mixed layer gas concentrations for an upwelling event that occurred partway through the cruise. All tested parameterizations gave similar results for Ar, Kr, and Xe; their air-sea fluxes were dominated by diffusive gas exchange during our study. For He and Ne, which are less soluble, and therefore more sensitive to differences in the treatment of bubble-mediated exchange, the parameterizations gave widely different results with respect to the net gas exchange flux and the bubble flux. This study demonstrates the value of using a suite of inert <span class="hlt">gases</span>, especially the lower solubility ones, to parameterize air-sea gas exchange.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFD.L3010B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFD.L3010B"><span id="translatedtitle">Numerical simulation of cavitating channel flows including non-condensable <span class="hlt">gases</span> effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Battistoni, Michele; Som, Sibendu; Longman, Douglas E.</p> <p>2013-11-01</p> <p>Fuel injectors often feature cavitation because of large pressure gradients which in some regions lead to extremely low pressure levels. Numerical results are assessed against quantitative high resolution experimental data collected at Argonne National Laboratory using synchrotron x-ray radiography on real-size fuel nozzles. Simulation are performed on structured embedded grids using finite volume method and second-order discretization schemes in space and time. A single fluid homogeneous mixture model is compared to a multi-fluid non-homogeneous model. Two mass transfer models for predicting cavitation are also studied. RANS and LES cases are presented. The presence of <span class="hlt">dissolved</span> <span class="hlt">gases</span> in the multi-phase flow is addressed and their effect has been accounted for by running compressible three-phase flow simulations. The study highlights the importance of accounting for <span class="hlt">dissolved</span> <span class="hlt">gases</span> in the liquid, since some void formations, which could be attributed to cavitation, are actually due to non-condensable gas expansion. A discussion about the effect of turbulent pressure fluctuations on cavitation inception is also presented. Visiting Scholar at Argonne National Laboratory, Chicago IL; Assistant Professor at University of Perugia, Italy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AdG....29...77S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AdG....29...77S"><span id="translatedtitle">The use of MOGREPS ensemble rainfall <span class="hlt">forecasts</span> in operational flood <span class="hlt">forecasting</span> systems across England and Wales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schellekens, J.; Weerts, A. H.; Moore, R. J.; Pierce, C. E.; Hildon, S.</p> <p>2011-03-01</p> <p>Operational flood <span class="hlt">forecasting</span> systems share a fundamental challenge: <span class="hlt">forecast</span> uncertainty which needs to be considered when making a flood warning decision. One way of representing this uncertainty is through employing an ensemble approach. This paper presents research funded by the Environment Agency in which ensemble rainfall <span class="hlt">forecasts</span> are utilised and tested for operational use. The form of ensemble rainfall <span class="hlt">forecast</span> used is the Met Office short-range product called MOGREPS. It is tested for operational use within the Environment Agency's National Flood <span class="hlt">Forecasting</span> System (NFFS) for England and Wales. Currently, the NFFS uses deterministic <span class="hlt">forecasts</span> only. The operational configuration of the NFFS for Thames Region is extended to trial the use of the new ensemble rainfall <span class="hlt">forecasts</span> in support of probabilistic flood <span class="hlt">forecasting</span>. Evaluation includes considering issues of model performance, configuration (how to fit the ensemble <span class="hlt">forecasts</span> within the current configurations), data volumes, run times and options for displaying probabilistic <span class="hlt">forecasts</span>. Although ensemble rainfall <span class="hlt">forecasts</span> available from MOGREPS are not extensive enough to fully verify product performance, it is concluded that their use within current Environment Agency regional flood <span class="hlt">forecasting</span> systems can provide better information to the <span class="hlt">forecaster</span> than use of the deterministic <span class="hlt">forecasts</span> alone. Of note are the small number of false alarms of river flow exceedance generated when using MOGREPS as input and that small flow events are also <span class="hlt">forecasted</span> rather well, notwithstanding the rather coarse resolution of the MOGREPS grid (24 km) compared to the studied catchments. In addition, it is concluded that, with careful configuration in NFFS, MOGREPS can be used in existing systems without a significant increase in system load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMGC11H1110M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMGC11H1110M&link_type=ABSTRACT"><span id="translatedtitle">Modeled <span class="hlt">Forecasts</span> of Dengue Fever in San Juan, Puerto Rico Using NASA Satellite Enhanced Weather <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morin, C.; Quattrochi, D. A.; Zavodsky, B.; Case, J.</p> <p>2015-12-01</p> <p>Dengue fever (DF) is an important mosquito transmitted disease that is strongly influenced by meteorological and environmental conditions. Recent research has focused on <span class="hlt">forecasting</span> DF case numbers based on meteorological data. However, these <span class="hlt">forecasting</span> tools have generally relied on empirical models that require long DF time series to train. Additionally, their accuracy has been tested retrospectively, using past meteorological data. Consequently, the operational utility of the <span class="hlt">forecasts</span> are still in question because the error associated with weather and climate <span class="hlt">forecasts</span> are not reflected in the results. Using up-to-date weekly dengue case numbers for model parameterization and weather <span class="hlt">forecast</span> data as meteorological input, we produced weekly <span class="hlt">forecasts</span> of DF cases in San Juan, Puerto Rico. Each week, the past weeks' case counts were used to re-parameterize a process-based DF model driven with updated weather <span class="hlt">forecast</span> data to generate <span class="hlt">forecasts</span> of DF case numbers. Real-time weather <span class="hlt">forecast</span> data was produced using the Weather Research and <span class="hlt">Forecasting</span> (WRF) numerical weather prediction (NWP) system enhanced using additional high-resolution NASA satellite data. This methodology was conducted in a weekly iterative process with each DF <span class="hlt">forecast</span> being evaluated using county-level DF cases reported by the Puerto Rico Department of Health. The one week DF <span class="hlt">forecasts</span> were accurate especially considering the two sources of model error. First, weather <span class="hlt">forecasts</span> were sometimes inaccurate and generally produced lower than observed temperatures. Second, the DF model was often overly influenced by the previous weeks DF case numbers, though this phenomenon could be lessened by increasing the number of simulations included in the <span class="hlt">forecast</span>. Although these results are promising, we would like to develop a methodology to produce longer range <span class="hlt">forecasts</span> so that public health workers can better prepare for dengue epidemics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=44948&keyword=affect+AND+photosynthetic+AND+organisms+AND+water&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74681076&CFTOKEN=37965430','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=44948&keyword=affect+AND+photosynthetic+AND+organisms+AND+water&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74681076&CFTOKEN=37965430"><span id="translatedtitle">SUSPENDED AND <span class="hlt">DISSOLVED</span> SOLIDS EFFECTS ON FRESHWATER BIOTA: A REVIEW</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>It is widely recognized that suspended and <span class="hlt">dissolved</span> solids in lakes, rivers, streams, and reservoirs affect water quality. In this report the research needs appropriate to setting freshwater quality criteria or standards for suspended solids (not including bedload) and <span class="hlt">dissolved</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol7/pdf/CFR-2010-title7-vol7-sec760-908.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol7/pdf/CFR-2010-title7-vol7-sec760-908.pdf"><span id="translatedtitle">7 CFR 760.908 - Deceased individuals or <span class="hlt">dissolved</span> entities.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... <span class="hlt">dissolved</span> entity must be provided. (c) If a participant is now a <span class="hlt">dissolved</span> general partnership or joint venture, all members of the general partnership or joint venture at the time of dissolution or their...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol7/pdf/CFR-2011-title7-vol7-sec760-908.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol7/pdf/CFR-2011-title7-vol7-sec760-908.pdf"><span id="translatedtitle">7 CFR 760.908 - Deceased individuals or <span class="hlt">dissolved</span> entities.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... <span class="hlt">dissolved</span> entity must be provided. (c) If a participant is now a <span class="hlt">dissolved</span> general partnership or joint venture, all members of the general partnership or joint venture at the time of dissolution or their...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982csu..rept.....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982csu..rept.....D"><span id="translatedtitle">Methanol production from fermentor off-<span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dale, B. E.; Moreira, A. R.</p> <p></p> <p>The off <span class="hlt">gases</span> from an acetone butanol fermentation facility are composed mainly of CO2 and H2. Such a gas stream is an ideal candidate as a feed to a methanol synthesis plant utilizing modern technology recently developed and known as the CDH-methanol process. A detailed economic analysis for the incremental cost of a methanol synthesis plant utilizing the off <span class="hlt">gases</span> from an acetone butanol fermentation indicates a profitable rate of return of 25 to 30% under the most likely production conditions. Bench scale studies at different fermentor mixing rates indicate that the volume of <span class="hlt">gases</span> released during the fermentation is a strong function of the agitation rate and point to a potential interaction between the volume of H2 evolved and the levels of butanol present in the final fermented broth. Such interaction may require establishing optimum operating conditions for an integrated butanol fermentation methanol synthesis plant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840064033&hterms=Tourmaline&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTourmaline','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840064033&hterms=Tourmaline&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DTourmaline"><span id="translatedtitle">Rare <span class="hlt">gases</span> in cyclosilicates and cogenetic minerals</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Saito, K.; Alexander, E. C., Jr.; Dragon, J. C.; Zashu, S.</p> <p>1984-01-01</p> <p>The cyclosilicate minerals, beryl, tourmaline, and cordierite, typically contain large amounts of He-4 and Ar-40 which are not in situ radiogenic products. In the study of excess rare <span class="hlt">gases</span> in cyclosilicates, one of the most enigmatic observations is the age effect, a qualitative tendency for geologically older samples to contain more excess He-4 and Ar-40 than younger samples. The present investigation is concerned with measurements regarding the abundance and isotopic composition of all five rare <span class="hlt">gases</span> in a number of cyclosilicates as well as in their cogenetic minerals. The significance of the obtained data is discussed. The data indicate that cyclosilicates sample the rare <span class="hlt">gases</span> present in the environment in which they crystallize. This 'sampling' involves major elemental fractionations which are variable but mineral specific. Cyclosilicates can, therefore, be used to probe the isotopic ratios and elemental compositions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1047261','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1047261"><span id="translatedtitle">Where do California's greenhouse <span class="hlt">gases</span> come from?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a></p> <p>Fischer, Marc</p> <p>2013-05-29</p> <p>Last March, more than two years after California passed legislation to slash greenhouse gas emissions 25 percent by 2020, Lawrence Berkeley National Laboratory scientist Marc Fischer boarded a Cessna loaded with air monitoring equipment and crisscrossed the skies above Sacramento and the Bay Area. Instruments aboard the aircraft measured a cocktail of greenhouse <span class="hlt">gases</span>: carbon dioxide from fossil fuel use, methane from livestock and landfills, CO2 from refineries and power plants, traces of nitrous oxide from agriculture and fuel use, and industrially produced other <span class="hlt">gases</span> like refrigerants. The flight was part of the Airborne Greenhouse Gas Emissions Survey, a collaboration between Berkeley Lab, the National Oceanic and Atmospheric Administration, and the University of California, and UC Davis to pinpoint the sources of greenhouse <span class="hlt">gases</span> in central California. The survey is intended to improve inventories of the states greenhouse gas emissions, which in turn will help scientists verify the emission reductions mandated by AB-32, the legislation enacted by California in 2006.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6863090','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6863090"><span id="translatedtitle">Bromine-containing source <span class="hlt">gases</span> during EASOE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fabian, P. ); Borchers, R.; Kourtidis, K. )</p> <p>1994-06-22</p> <p>The authors report three different vertical profile measurements of three bromine containing <span class="hlt">gases</span> which are thought to be the major sources of active bromine in the stratosphere. These <span class="hlt">gases</span> are CBrClF[sub 2] (Halon-1211), CBrF[sub 3] (Halon-1301) and methyl bromide (CH[sub 3]Br). They were sampled using cryogenic samplers from balloon borne flights from Kiruna during January, February and March 1992. The two halons are of anthropogenic origin, while methyl bromide is thought to have a relatively large natural origin. Consistent with the decrease in concentration of these <span class="hlt">gases</span> with altitude was an increase in the density of BrO[sub x] with altitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020018869','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020018869"><span id="translatedtitle">Advanced Global Atmospheric <span class="hlt">Gases</span> Experiment (AGAGE)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Prinn, Ronald G.</p> <p>2001-01-01</p> <p>AGAGE comprises continuous high frequency in-situ gas chromatographic FID/ECD measurements of two biogenic/anthropogenic <span class="hlt">gases</span> (CH4, N2O) and five anthropogenic <span class="hlt">gases</span> (CFCl3, CF2Cl2, CH3CCl3, CF2ClCFCl2, CCl4) which are carried out at five globally distributed sites (Ireland, California, Barbados, Samoa, Tasmania). Also, high frequency in-situ gas-chromatographic mass spectrometric measurements of about 30 species including chlorofluorocarbon replacements and many natural halocarbons are made at two sites (Ireland, Tasmania), and will soon begin at the other three sites. Finally, high frequency in-situ gas chromatographic HgO-RD measurements of CO and H2 are performed at two sites (Ireland, Tasmania). The goal is quantitative determination of the sources, sinks, and circulation of these environmentally important <span class="hlt">gases</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1047261','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1047261"><span id="translatedtitle">Where do California's greenhouse <span class="hlt">gases</span> come from?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fischer, Marc</p> <p>2009-01-01</p> <p>Last March, more than two years after California passed legislation to slash greenhouse gas emissions 25 percent by 2020, Lawrence Berkeley National Laboratory scientist Marc Fischer boarded a Cessna loaded with air monitoring equipment and crisscrossed the skies above Sacramento and the Bay Area. Instruments aboard the aircraft measured a cocktail of greenhouse <span class="hlt">gases</span>: carbon dioxide from fossil fuel use, methane from livestock and landfills, CO2 from refineries and power plants, traces of nitrous oxide from agriculture and fuel use, and industrially produced other <span class="hlt">gases</span> like refrigerants. The flight was part of the Airborne Greenhouse Gas Emissions Survey, a collaboration between Berkeley Lab, the National Oceanic and Atmospheric Administration, and the University of California, and UC Davis to pinpoint the sources of greenhouse <span class="hlt">gases</span> in central California. The survey is intended to improve inventories of the states greenhouse gas emissions, which in turn will help scientists verify the emission reductions mandated by AB-32, the legislation enacted by California in 2006.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/141365','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/141365"><span id="translatedtitle">Bioprocessing of organic <span class="hlt">gases</span> in waste air</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bohn, H.L.</p> <p>1993-12-31</p> <p>Natural porous media (soils, compost, peat, wood bark chips) in biofilters effectively, safely, and inexpensively remove organic <span class="hlt">gases</span> from air by adsorbing then and oxidizing them to CO{sub 2}. The sorption capacities of the media are low: their effectiveness is due to oxidation by the active microbial population which disposes the gas and continuously regenerates the sorption capacity. O-, N-, and S-containing organic <span class="hlt">gases</span> generally oxidize rapidly and {>=}95% removal efficiency is routine. Aromatic and halogenated organic <span class="hlt">gases</span> oxidize slowly and require correspondingly larger biofilter beds and reaction times to achieve high removal efficiencies. Installation costs of biofilters vary widely, operating costs are low because no fuel or oxidant is required, and no secondary pollution is created.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ChPhB..21k5202X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ChPhB..21k5202X"><span id="translatedtitle">Dark lump excitations in superfluid Fermi <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Yan-Xia; Duan, Wen-Shan</p> <p>2012-11-01</p> <p>We study the linear and nonlinear properties of two-dimensional matter-wave pulses in disk-shaped superfluid Fermi <span class="hlt">gases</span>. A Kadomtsev—Petviashvili I (KPI) solitary wave has been realized for superfluid Fermi <span class="hlt">gases</span> in the limited cases of Bardeen—Cooper—Schrieffer (BCS) regime, Bose—Einstein condensate (BEC) regime, and unitarity regime. One-lump solution as well as one-line soliton solutions for the KPI equation are obtained, and two-line soliton solutions with the same amplitude are also studied in the limited cases. The dependence of the lump propagating velocity and the sound speed of two-dimensional superfluid Fermi <span class="hlt">gases</span> on the interaction parameter are investigated for the limited cases of BEC and unitarity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT.......178C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT.......178C"><span id="translatedtitle">NMR studies and applications of perfluorocarbon <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Yulin</p> <p></p> <p>Hyperpolarized 3He has been very successful in magnetic resonance imaging (MRI) of the lungs. It provides ways to study the physiological properties of the lungs and lung function. However, the high costs of the polarizing apparatus and the complicated polarizing procedure are preventing this technique from being clinically used routinely. Recent developments have shown that several fluorinated <span class="hlt">gases</span> have the potential to replace 3He in some of its applications. This thesis presents some preliminary results of human excised lung imaging using C2F6 and C3F8. These two fluorinated <span class="hlt">gases</span> were able to yield images with good signal-to-noise ratio and reasonable resolutions in a 1.5 T magnet. Using diffusion MRI of these two <span class="hlt">gases</span> can distinguish emphysematous lungs from healthy ones. An important application of these <span class="hlt">gases</span> would be to determine local lung surface-to-volume (S/V) ratio in vivo, which requires the unrestricted (free) diffusivity in each pixel to be known. We present data in this thesis which allow free diffusivities to be calculated from the relaxation time T1. Samples of pure C 2F6 and C3F8 at different pressures and in mixtures with oxygen at different concentrations were made. Measurements were done at two different magnetic fields and temperature was regulated to study the temperature dependence over a small range. These two <span class="hlt">gases</span> were also used in studies of carbon-block filters, where the strong adsorption of the <span class="hlt">gases</span> to the high surface-area carbon is beneficial. A brief review of our work on mouse lung imaging using hyperpolarized 3He is presented in Appendix A; Appendix B is a study of the longitudinal spin magnetization in the presence of a strong magnetic field gradient; the construction of the pulsed field gradient waveform measurement coils and some experimental results using these coils are contained in Appendix C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=wind&pg=5&id=EJ1064476','ERIC'); return false;" href="http://eric.ed.gov/?q=wind&pg=5&id=EJ1064476"><span id="translatedtitle">School Science Inspired by Improving Weather <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Reid, Heather; Renfrew, Ian A.; Vaughan, Geraint</p> <p>2014-01-01</p> <p>High winds and heavy rain are regular features of the British weather, and <span class="hlt">forecasting</span> these events accurately is a major priority for the Met Office and other <span class="hlt">forecast</span> providers. This is the challenge facing DIAMET, a project involving university groups from Manchester, Leeds, Reading, and East Anglia, together with the Met Office. DIAMET is part…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......268A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......268A"><span id="translatedtitle">Solar power deployment: <span class="hlt">Forecasting</span> and planning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alanazi, Mohana</p> <p></p> <p>The rapid growth of Photovoltaic (PV) technology has been very visible over the past decade. Recently, the penetration of PV plants to the existing grid has significantly increased. Such increase in the integration of solar energy has brought attention to the solar irradiance <span class="hlt">forecasting</span>. This thesis presents a thorough research of PV technology, how solar power can be <span class="hlt">forecasted</span>, and PV planning under uncertainty. Over the last decade, the PV was one of the fastest growing renewable energy technologies. However, the PV system output varies based on weather conditions. Due to the variability and the uncertainty of solar power, the integration of the electricity generated by PV system is considered one of the challenges that have confronted the PV system. This thesis proposes a new <span class="hlt">forecasting</span> method to reduce the uncertainty of the PV output so the power operator will be able to accommodate its variability. The new <span class="hlt">forecasting</span> method proposes different processes to be undertaken before the data is fed to the <span class="hlt">forecasting</span> model. The method converts the data sets included in the <span class="hlt">forecasting</span> from non-stationary data to a stationary data by applying different processes including: removing the offset, removing night time solar values, and normalization. The new <span class="hlt">forecasting</span> method aims to reduce the <span class="hlt">forecasting</span> error and analyzes the error effect on the long term planning through calculating the payback period considering different errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nonli..29.2888Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Nonli..29.2888Z&link_type=ABSTRACT"><span id="translatedtitle">Analog <span class="hlt">forecasting</span> with dynamics-adapted kernels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Zhizhen; Giannakis, Dimitrios</p> <p>2016-09-01</p> <p>Analog <span class="hlt">forecasting</span> is a nonparametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of <span class="hlt">forecasting</span> methods which improve traditional analog <span class="hlt">forecasting</span> by combining ideas from kernel methods developed in harmonic analysis and machine learning and state-space reconstruction for dynamical systems. A key ingredient of our approach is to replace single-analog <span class="hlt">forecasting</span> with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve <span class="hlt">forecast</span> skill, including Takens’ delay-coordinate maps (to recover information in the initial data lost through partial observations) and a directional dependence on the dynamical vector field generating the data. Mathematically, our approach is closely related to kernel methods for out-of-sample extension of functions, and we discuss alternative strategies based on the Nyström method and the multiscale Laplacian pyramids technique. We illustrate these techniques in applications to <span class="hlt">forecasting</span> in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale <span class="hlt">forecasting</span> in the North Pacific sector of a comprehensive climate model. We find that <span class="hlt">forecasts</span> based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED082497.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED082497.pdf"><span id="translatedtitle">A Delphi <span class="hlt">Forecast</span> of Technology in Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Robinson, Burke E.</p> <p></p> <p>The <span class="hlt">forecast</span> reported here surveys expected utilization levels, organizational structures, and values concerning technology in education in 1990. The focus is upon educational technology and <span class="hlt">forecasting</span> methodology; televised instruction, computer-assisted instruction (CAI), and information services are considered. The methodology employed…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=300991','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=300991"><span id="translatedtitle">Climate <span class="hlt">forecasts</span> for corn producer decision making</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Corn is the most widely grown crop in the Americas, with annual production in the United States of approximately 332 million metric tons. Improved climate <span class="hlt">forecasts</span>, together with climate-related decision tools for corn producers based on these improved <span class="hlt">forecasts</span>, could substantially reduce uncertai...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70046866','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70046866"><span id="translatedtitle">Chesapeake Bay hypoxic volume <span class="hlt">forecasts</span> and results</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Scavia, Donald; Evans, Mary Anne</p> <p>2013-01-01</p> <p>The 2013 <span class="hlt">Forecast</span> - Given the average Jan-May 2013 total nitrogen load of 162,028 kg/day, this summer’s hypoxia volume <span class="hlt">forecast</span> is 6.1 km3, slightly smaller than average size for the period of record and almost the same as 2012. The late July 2013 measured volume was 6.92 km3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ARIMA&id=EJ842702','ERIC'); return false;" href="http://eric.ed.gov/?q=ARIMA&id=EJ842702"><span id="translatedtitle">Some Initiatives in a Business <span class="hlt">Forecasting</span> Course</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chu, Singfat</p> <p>2007-01-01</p> <p>The paper reports some initiatives to freshen up the typical undergraduate business <span class="hlt">forecasting</span> course. These include (1) students doing research and presentations on contemporary tools and industry practices such as neural networks and collaborative <span class="hlt">forecasting</span> (2) insertion of Logistic Regression in the curriculum (3) productive use of applets…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=social+AND+forecasting&pg=4&id=EJ547715','ERIC'); return false;" href="http://eric.ed.gov/?q=social+AND+forecasting&pg=4&id=EJ547715"><span id="translatedtitle">Methods and Techniques of Revenue <span class="hlt">Forecasting</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Caruthers, J. Kent; Wentworth, Cathi L.</p> <p>1997-01-01</p> <p>Revenue <span class="hlt">forecasting</span> is the critical first step in most college and university budget-planning processes. While it seems a straightforward exercise, effective <span class="hlt">forecasting</span> requires consideration of a number of interacting internal and external variables, including demographic trends, economic conditions, and broad social priorities. The challenge…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713443H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713443H"><span id="translatedtitle">Flood <span class="hlt">Forecasting</span> in Wales: Challenges and Solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>How, Andrew; Williams, Christopher</p> <p>2015-04-01</p> <p>With steep, fast-responding river catchments, exposed coastal reaches with large tidal ranges and large population densities in some of the most at-risk areas; flood <span class="hlt">forecasting</span> in Wales presents many varied challenges. Utilising advances in computing power and learning from best practice within the United Kingdom and abroad have seen significant improvements in recent years - however, many challenges still remain. Developments in computing and increased processing power comes with a significant price tag; greater numbers of data sources and ensemble feeds brings a better understanding of uncertainty but the wealth of data needs careful management to ensure a clear message of risk is disseminated; new modelling techniques utilise better and faster computation, but lack the history of record and experience gained from the continued use of more established <span class="hlt">forecasting</span> models. As a flood <span class="hlt">forecasting</span> team we work to develop coastal and fluvial <span class="hlt">forecasting</span> models, set them up for operational use and manage the duty role that runs the models in real time. An overview of our current operational flood <span class="hlt">forecasting</span> system will be presented, along with a discussion on some of the solutions we have in place to address the challenges we face. These include: • real-time updating of fluvial models • rainfall <span class="hlt">forecasting</span> verification • ensemble <span class="hlt">forecast</span> data • longer range <span class="hlt">forecast</span> data • contingency models • offshore to nearshore wave transformation • calculation of wave overtopping</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AGUFM.H12G..03W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AGUFM.H12G..03W&link_type=ABSTRACT"><span id="translatedtitle">Streamflow Ensemble Generation using Climate <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watkins, D. W.; O'Connell, S.; Wei, W.; Nykanen, D.; Mahmoud, M.</p> <p>2002-12-01</p> <p>Although significant progress has been made in understanding the correlation between large-scale atmospheric circulation patterns and regional streamflow anomalies, there is a general perception that seasonal climate <span class="hlt">forecasts</span> are not being used to the fullest extent possible for optimal water resources management. Possible contributing factors are limited knowledge and understanding of climate processes and prediction capabilities, noise in climate signals and inaccuracies in <span class="hlt">forecasts</span>, and hesitancy on the part of water managers to apply new information or methods that could expose them to greater liability. This work involves a decision support model based on streamflow ensembles developed for the Lower Colorado River Authority in Central Texas. Predicative skill is added to ensemble <span class="hlt">forecasts</span> that are based on climatology by conditioning the ensembles on observable climate indicators, including streamflow (persistence), soil moisture, land surface temperatures, and large-scale recurrent patterns such as the El Ni¤o-Southern Oscillation, Pacific Decadal Oscillation, and the North Atlantic Oscillation. A Bayesian procedure for updating ensemble probabilities is outlined, and various skill scores are reviewed for evaluating <span class="hlt">forecast</span> performance. Verification of the ensemble <span class="hlt">forecasts</span> using a resampling procedure indicates a small but potentially significant improvement in <span class="hlt">forecast</span> skill that could be exploited in seasonal water management decisions. The ultimate goal of this work will be explicit incorporation of climate <span class="hlt">forecasts</span> in reservoir operating rules and estimation of the value of the <span class="hlt">forecasts</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010GeoJI.181..382Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010GeoJI.181..382Z"><span id="translatedtitle">Gambling scores for earthquake predictions and <span class="hlt">forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhuang, Jiancang</p> <p>2010-04-01</p> <p>This paper presents a new method, namely the gambling score, for scoring the performance earthquake <span class="hlt">forecasts</span> or predictions. Unlike most other scoring procedures that require a regular scheme of <span class="hlt">forecast</span> and treat each earthquake equally, regardless their magnitude, this new scoring method compensates the risk that the <span class="hlt">forecaster</span> has taken. Starting with a certain number of reputation points, once a <span class="hlt">forecaster</span> makes a prediction or <span class="hlt">forecast</span>, he is assumed to have betted some points of his reputation. The reference model, which plays the role of the house, determines how many reputation points the <span class="hlt">forecaster</span> can gain if he succeeds, according to a fair rule, and also takes away the reputation points betted by the <span class="hlt">forecaster</span> if he loses. This method is also extended to the continuous case of point process models, where the reputation points betted by the <span class="hlt">forecaster</span> become a continuous mass on the space-time-magnitude range of interest. We also calculate the upper bound of the gambling score when the true model is a renewal process, the stress release model or the ETAS model and when the reference model is the Poisson model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5347900','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5347900"><span id="translatedtitle"><span class="hlt">Forecast</span> of geothermal-drilling activity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mansure, A.J.; Brown, G.L.</p> <p>1982-07-01</p> <p>The number of geothermal wells that will be drilled to support electric power production in the United States through 2000 A.D. are <span class="hlt">forecasted</span>. Results of the <span class="hlt">forecast</span> are presented by 5-year periods for the five most significant geothermal resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED340733.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED340733.pdf"><span id="translatedtitle"><span class="hlt">Forecasting</span> Enrollments with Fuzzy Time Series.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Song, Qiang; Chissom, Brad S.</p> <p></p> <p>The concept of fuzzy time series is introduced and used to <span class="hlt">forecast</span> the enrollment of a university. Fuzzy time series, an aspect of fuzzy set theory, <span class="hlt">forecasts</span> enrollment using a first-order time-invariant model. To evaluate the model, the conventional linear regression technique is applied and the predicted values obtained are compared to the…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Overpopulation&pg=3&id=EJ078615','ERIC'); return false;" href="http://eric.ed.gov/?q=Overpopulation&pg=3&id=EJ078615"><span id="translatedtitle">Resources and Long-Range <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Smith, Waldo E.</p> <p>1973-01-01</p> <p>The author argues that <span class="hlt">forecasts</span> of quick depletion of resources in the environment as a result of overpopulation and increased usage may not be free from error. Ignorance still exists in understanding the recovery mechanisms of nature. Long-range <span class="hlt">forecasts</span> are likely to be wrong in such situations. (PS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730024131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730024131"><span id="translatedtitle">Techniques for <span class="hlt">Forecasting</span> Air Passenger Traffic</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Taneja, N.</p> <p>1972-01-01</p> <p>The basic techniques of <span class="hlt">forecasting</span> the air passenger traffic are outlined. These techniques can be broadly classified into four categories: judgmental, time-series analysis, market analysis and analytical. The differences between these methods exist, in part, due to the degree of formalization of the <span class="hlt">forecasting</span> procedure. Emphasis is placed on describing the analytical method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870000478&hterms=Atmospheric+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Atmospheric%2Bpressure%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870000478&hterms=Atmospheric+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Atmospheric%2Bpressure%2529"><span id="translatedtitle">Measuring Viscosities of <span class="hlt">Gases</span> at Atmospheric Pressure</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini</p> <p>1987-01-01</p> <p>Variant of general capillary method for measuring viscosities of unknown <span class="hlt">gases</span> based on use of thermal mass-flowmeter section for direct measurement of pressure drops. In technique, flowmeter serves dual role, providing data for determining volume flow rates and serving as well-characterized capillary-tube section for measurement of differential pressures across it. New method simple, sensitive, and adaptable for absolute or relative viscosity measurements of low-pressure <span class="hlt">gases</span>. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21313336','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21313336"><span id="translatedtitle">Stationary light in cold-atomic <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nikoghosyan, Gor; Fleischhauer, Michael</p> <p>2009-07-15</p> <p>We discuss stationary light created by a pair of counterpropagating control fields in {lambda}-type atomic <span class="hlt">gases</span> with electromagnetically induced transparency for the case of negligible Doppler broadening. In this case, the secular approximation used in the discussion of stationary light in hot vapors is no longer valid. We discuss the quality of the effective light-trapping system and show that in contrast to previous claims it is finite even for vanishing ground-state dephasing. The dynamics of the photon loss is in general nonexponential and can be faster or slower than in hot <span class="hlt">gases</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5263171','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5263171"><span id="translatedtitle">Composition of <span class="hlt">gases</span> vented from a condenser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lyon, R.N.</p> <p>1980-08-01</p> <p>Designers of systems that involve condensers often need to predict the amount of process vapor that accompanies the noncondensable <span class="hlt">gases</span> 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 <span class="hlt">gases</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ApPhB..79.1001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ApPhB..79.1001S"><span id="translatedtitle">Dynamics and thermodynamics in spinor quantum <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmaljohann, H.; Erhard, M.; Kronjäger, J.; Sengstock, K.; Bongs, K.</p> <p>2004-12-01</p> <p>We discuss magnetism in spinor quantum <span class="hlt">gases</span> theoretically and experimentally with emphasis on temporal dynamics of the spinor order parameter in the presence of an external magnetic field. In a simple coupled Gross Pitaevskii picture we observe a dramatic suppression of spin dynamics due to quadratic Zeeman “dephasing”. In view of an inhomogeneous density profile of the trapped condensate we present evidence of spatial variations of spin dynamics. In addition we study spinor quantum <span class="hlt">gases</span> as a model system for thermodynamics of Bose Einstein condensation. As a particular example we present measurements on condensate magnetisation due to the interaction with a thermal bath.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.V23C0645B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.V23C0645B"><span id="translatedtitle">Noble <span class="hlt">Gases</span> in Carbonatite Magmatism: Oldonyo Lengai</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burnard, P.; Marty, B.; Fischer, T.; Hilton, D.; Mangasini, F.; Makene, C.</p> <p>2006-12-01</p> <p>Oldonyo Lengai,Tanzania, is the only volcano on Earth that is actively erupting carbonatitic lavas. In order to further constrain the origin of the Oldonyo Lengai magmas, an expedition to Oldonyo Lengai in July 2005 sampled to volcanic <span class="hlt">gases</span>. Two fumaroles were sampled, one with a discharging temperature of 124 °C, the other more than 168 °C. The chemical composition of discharging <span class="hlt">gases</span> is dominated by H2O (approx77 mol%) and CO2 (approx 22 mol%), SO2, H2S and HCl make up less than 1 mol%, combined. The inert <span class="hlt">gases</span> (N2, He, He/Ne) show that these samples contain virtually no air. He/Ne ratios are between 2000 and 6500 and He/Ar ratios are up to 0.3 [Fischer et al, 2006, this volume]. The 3He/4He ratio of 6.7 - 6.8 Ra is consistent with an upper mantle origin of these <span class="hlt">gases</span>. We have also measured Ne and Xe isotopic compositions of several aliquots of the sampled <span class="hlt">gases</span> using a multicollector noble gas mass spectrometer (HELIX-MC). The additional precision afforded by multicollection allows us to identify noble gas isotopic anomalies at the sub 5 per mil level. Despite the excellent purity (low atmospheric content) of the <span class="hlt">gases</span>, as evidenced by extremely high He/Ne ratios, the isotopic compositions of both Ne and Xe are very close to those of the atmosphere: a 2 per mil excess in 129Xe/130Xe ratio was observed (the remaining Xe isotope ratios being indistinguishable from air) and 20Ne/22Ne up to 10.3 was measured (50 per mil higher than air) in a split of the sample that has He/Ne = 6500. Although isotolically anomalous Ne was observed, it is not possible to determine if this is indeed mantle - derived Ne or if the 20Ne excesses result from kinetic fractionationed air entrained within the volcano's plumbing system: the composition of the three Ne isotopes (20Ne, 21Ne and 22Ne) are consistent with mass fractionation processes. Our results are most readily interpreted as atmospheric entrainment prior to sampling. However, further measurements of the remaining noble</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1236224','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1236224"><span id="translatedtitle">Oxidation of ultrathin <span class="hlt">GaSe</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.</p> <p>2015-10-26</p> <p>Oxidation of exfoliated gallium selenide (<span class="hlt">GaSe</span>) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of <span class="hlt">GaSe</span> are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga<sub>2</sub>Se<sub>3</sub> and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22485972','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22485972"><span id="translatedtitle">Oxidation of ultrathin <span class="hlt">GaSe</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Beechem, Thomas E. Brumbach, Michael T.; McDonald, Anthony E.; Howell, Stephen W.; Ohta, Taisuke; Kowalski, Brian M.; Pask, Jesse A.; Kalugin, Nikolai G.; Spataru, Catalin D.</p> <p>2015-10-26</p> <p>Oxidation of exfoliated gallium selenide (<span class="hlt">GaSe</span>) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of <span class="hlt">GaSe</span> are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga{sub 2}Se{sub 3} and amorphous Se. Photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/9293061','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/9293061"><span id="translatedtitle">Measurement and interpretation of arterial blood <span class="hlt">gases</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Syabbalo, N</p> <p>1997-01-01</p> <p>Arterial blood <span class="hlt">gases</span> and pH are routinely being measured in clinical practice, both to provide diagnosis and to guide therapy in critically ill patients. Oximetry is clinically useful in establishing the presence of hypoxaemia in patients with respiratory diseases. Oximetry is also a simple and reliable method for monitoring patients undergoing anaesthesia, sleep studies and cardiopulmonary exercise testing. The search continues for new innovative techniques for continuous transcutaneous and intra-arterial blood gas monitoring. This is essential in the management of critically ill patients because blood analysers provide only intermittent monitoring of arterial blood <span class="hlt">gases</span>. PMID:9293061</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015famr.book...61S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015famr.book...61S"><span id="translatedtitle">Seeing Spin Dynamics in Atomic <span class="hlt">Gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stamper-Kurn, Dan M.</p> <p>2015-06-01</p> <p>The dynamics of internal spin, electronic orbital, and nuclear motion states of atoms and molecules have preoccupied the atomic and molecular physics community for decades. Increasingly, such dynamics are being examined within many-body systems composed of atomic and molecular <span class="hlt">gases</span>. Our findings sometimes bear close relation to phenomena observed in condensed-matter systems, while on other occasions they represent truly new areas of investigation. I discuss several examples of spin dynamics that occur within spinor Bose-Einstein <span class="hlt">gases</span>, highlighting the advantages of spin-sensitive imaging for understanding and utilizing such dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1236224-oxidation-ultrathin-gase','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1236224-oxidation-ultrathin-gase"><span id="translatedtitle">Oxidation of ultrathin <span class="hlt">GaSe</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.</p> <p>2015-10-26</p> <p>Oxidation of exfoliated gallium selenide (<span class="hlt">GaSe</span>) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of <span class="hlt">GaSe</span> are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga2Se3 and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1096278','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1096278"><span id="translatedtitle">Managing biogeochemical cycles to reduce greenhouse <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Post, Wilfred M; Venterea, Rodney</p> <p>2012-01-01</p> <p>This special issue focuses on terrestrial biogeochemical cycles as they relate to North America-wide budgeting and future projection of biogenic greenhouse <span class="hlt">gases</span> (GHGs). Understanding the current magnitude and providing guidance on the future trajectories of atmospheric concentrations of these <span class="hlt">gases</span> requires investigation of their (i) biogeochemical origins, (ii) response to climate feedbacks and other environmental factors, and (iii) susceptibility to management practices. This special issue provides a group of articles that present the current state of continental scale sources and sinks of biogenic GHGs and the potential to better manage them in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70155840','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70155840"><span id="translatedtitle">Origins of geothermal <span class="hlt">gases</span> at Yellowstone</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lowenstern, Jacob B.; Bergfeld, D.; Evans, William C.; Hunt, Andrew G.</p> <p>2015-01-01</p> <p>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. <span class="hlt">Gases</span> 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. <span class="hlt">Gases</span> 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 <span class="hlt">gases</span>. 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 <span class="hlt">gases</span> reflect a dominant mantle origin for CO2 in Yellowstone gas. The mantle signature is most evident at Mud Volcano, which hosts <span class="hlt">gases</span> 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 <span class="hlt">gases</span> reflect addition of deep, high-temperature magmatic gas (CO2-rich), lower-temperatures crustal <span class="hlt">gases</span> (4He- and CH4-bearing), and those <span class="hlt">gases</span> (N2, Ne, Ar) added</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JVGR..302...87L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JVGR..302...87L"><span id="translatedtitle">Origins of geothermal <span class="hlt">gases</span> at Yellowstone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lowenstern, Jacob B.; Bergfeld, Deborah; Evans, William C.; Hunt, Andrew G.</p> <p>2015-09-01</p> <p>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. <span class="hlt">Gases</span> 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. <span class="hlt">Gases</span> 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 <span class="hlt">gases</span>. 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 <span class="hlt">gases</span> reflect a dominant mantle origin for CO2 in Yellowstone gas. The mantle signature is most evident at Mud Volcano, which hosts <span class="hlt">gases</span> 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 <span class="hlt">gases</span> reflect addition of deep, high-temperature magmatic gas (CO2-rich), lower-temperatures crustal <span class="hlt">gases</span> (4He- and CH4-bearing), and those <span class="hlt">gases</span> (N2, Ne, Ar) added</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930093929','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930093929"><span id="translatedtitle">The Flow of <span class="hlt">Gases</span> in Narrow Channels</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rasmussen, R E H</p> <p>1951-01-01</p> <p>Measurements were made of the flow of <span class="hlt">gases</span> through various narrow channels a few microns wide at average pressures from 0.00003 to 40 cm. Hg. The flow rate, defined as the product of pressure and volume rate of flow at unit pressure difference, first decreased linearly with decrease in mean pressure in the channel, in agreement with laminar-flow theory, reached a minimum when the mean path length was approximately equal to the channel width, and then increased to a constant value. The product of flow rate and square root of molecular number was approximately the same function of mean path length for all <span class="hlt">gases</span> for a given channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816659F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816659F&link_type=ABSTRACT"><span id="translatedtitle">Evaluation and first <span class="hlt">forecasts</span> of the German Climate <span class="hlt">Forecast</span> System 1 (GCFS1)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fröhlich, Kristina; Baehr, Johanna; Müller, Wolfgang; Bunzel, Felix; Pohlmann, Holger; Dobrynin, Mikhail</p> <p>2016-04-01</p> <p>We present the near-operational seasonal <span class="hlt">forecast</span> system GCFS1 (German Climate <span class="hlt">Forecast</span> System version 1), based on the CMIP5 version of the global coupled climate model MPI-ESM-LR. For GCFS1 we also present a detailed assessment on the predictive skill of the model. GCFS1 has been developed in cooperation between the Max Planck Institute for Meteorology, University of Hamburg and German Meteorological Service (DWD), the <span class="hlt">forecasts</span> are conducted by DWD. The system is running at ECMWF with a re-<span class="hlt">forecast</span> ensemble of 15 member and a <span class="hlt">forecast</span> ensemble of 30 member. The re-<span class="hlt">forecasts</span> are initialised with full field nudging in the atmosphere (using ERA Interim), in the ocean (using ORAS4) and in the sea-ice component (using NSIDC sea-ice concentration). For the initialization of the <span class="hlt">forecasts</span> analyses from the ECMWF NWP model and recent ORAS4 analyses are taken. The ensemble perturbations are, for both re-<span class="hlt">forecasts</span> and <span class="hlt">forecasts</span>, generated through bred vectors in the ocean which provide initial perturbations for the ensemble in combination with simple physics perturbations in the atmosphere. Evaluation of the re-<span class="hlt">forecasted</span> climatologies will be presented for different variables, start dates and regions. The first winter <span class="hlt">forecast</span> during the strong El Niño phase is also subject of evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2892H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2892H"><span id="translatedtitle">Monthly <span class="hlt">forecasting</span> of agricultural pests in Switzerland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirschi, M.; Dubrovsky, M.; Spirig, C.; Samietz, J.; Calanca, P.; Weigel, A. P.; Fischer, A. M.; Rotach, M. W.</p> <p>2012-04-01</p> <p>Given the repercussions of pests and diseases on agricultural production, detailed <span class="hlt">forecasting</span> tools have been developed to simulate the degree of infestation depending on actual weather conditions. The life cycle of pests is most successfully predicted if the micro-climate of the immediate environment (habitat) of the causative organisms can be simulated. Sub-seasonal pest <span class="hlt">forecasts</span> therefore require weather information for the relevant habitats and the appropriate time scale. The pest <span class="hlt">forecasting</span> system SOPRA (www.sopra.info) currently in operation in Switzerland relies on such detailed weather information, using hourly weather observations up to the day the <span class="hlt">forecast</span> is issued, but only a climatology for the <span class="hlt">forecasting</span> period. Here, we aim at improving the skill of SOPRA <span class="hlt">forecasts</span> by transforming the weekly information provided by ECMWF monthly <span class="hlt">forecasts</span> (MOFCs) into hourly weather series as required for the prediction of upcoming life phases of the codling moth, the major insect pest in apple orchards worldwide. Due to the probabilistic nature of operational monthly <span class="hlt">forecasts</span> and the limited spatial and temporal resolution, their information needs to be post-processed for use in a pest model. In this study, we developed a statistical downscaling approach for MOFCs that includes the following steps: (i) application of a stochastic weather generator to generate a large pool of daily weather series consistent with the climate at a specific location, (ii) a subsequent re-sampling of weather series from this pool to optimally represent the evolution of the weekly MOFC anomalies, and (iii) a final extension to hourly weather series suitable for the pest <span class="hlt">forecasting</span> model. Results show a clear improvement in the <span class="hlt">forecast</span> skill of occurrences of upcoming codling moth life phases when incorporating MOFCs as compared to the operational pest <span class="hlt">forecasting</span> system. This is true both in terms of root mean squared errors and of the continuous rank probability scores of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997evwc.book.....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997evwc.book.....K"><span id="translatedtitle">Economic Value of Weather and Climate <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katz, Richard W.; Murphy, Allan H.</p> <p>1997-06-01</p> <p>Weather and climate extremes can significantly impact the economics of a region. This book examines how weather and climate <span class="hlt">forecasts</span> can be used to mitigate the impact of the weather on the economy. Interdisciplinary in scope, it explores the meteorological, economic, psychological, and statistical aspects of weather prediction. Chapters by area specialists provide a comprehensive view of this timely topic. They encompass <span class="hlt">forecasts</span> over a wide range of temporal scales, from weather over the next few hours to the climate months or seasons ahead, and address the impact of these <span class="hlt">forecasts</span> on human behavior. Economic Value of Weather and Climate <span class="hlt">Forecasts</span> seeks to determine the economic benefits of existing weather <span class="hlt">forecasting</span> systems and the incremental benefits of improving these systems, and will be an interesting and essential text for economists, statisticians, and meteorologists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/103301','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/103301"><span id="translatedtitle">Load <span class="hlt">forecast</span> and need for power</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>1995-10-01</p> <p>This portion of the Energy Vision 2020 draft report discusses the models used for <span class="hlt">forecasting</span> the load growth over the period of this report. To deal with uncertainties in load growth, TVA has used a range of <span class="hlt">forecasts</span>: low, medium, and high. Based on the medium <span class="hlt">forecast</span>, TVA has determined that an additional 800 MWe will be required by 1998 and 16,500 MWe by 2020. based on the high growth <span class="hlt">forecast</span>, additional power will be needed in 1997 and increasing thereafter. Based on the low growth <span class="hlt">forecast</span>, no additional capacity would be needed during the period of this report. These estimates include a reserve margin of 15% through 1997, 13% average through the period 1998 to 2010, and 12% average during the remainder of the reporting period.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/13795','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/13795"><span id="translatedtitle">Uncertainty in dispersion <span class="hlt">forecasts</span> using meteorological ensembles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chin, H N; Leach, M J</p> <p>1999-07-12</p> <p>The usefulness of dispersion <span class="hlt">forecasts</span> depends on proper interpretation of results. Understanding the uncertainty in model predictions and the range of possible outcomes is critical for determining the optimal course of action in response to terrorist attacks. One of the objectives for the Modeling and Prediction initiative is creating tools for emergency planning for special events such as the upcoming the Olympics. Meteorological <span class="hlt">forecasts</span> hours to days in advance are used to estimate the dispersion at the time of the event. However, there is uncertainty in any meteorological <span class="hlt">forecast</span>, arising from both errors in the data (both initial conditions and boundary conditions) and from errors in the model. We use ensemble <span class="hlt">forecasts</span> to estimate the uncertainty in the <span class="hlt">forecasts</span> and the range of possible outcomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012HESSD...913569R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012HESSD...913569R"><span id="translatedtitle">Do probabilistic <span class="hlt">forecasts</span> lead to better decisions?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramos, M. H.; van Andel, S. J.; Pappenberger, F.</p> <p>2012-12-01</p> <p>The last decade has seen growing research in producing probabilistic hydro-meteorological <span class="hlt">forecasts</span> and increasing their reliability. This followed the promise that, supplied with information about uncertainty, people would take better risk-based decisions. In recent years, therefore, research and operational developments have also start putting attention to ways of communicating the probabilistic <span class="hlt">forecasts</span> to decision makers. Communicating probabilistic <span class="hlt">forecasts</span> includes preparing tools and products for visualization, but also requires understanding how decision makers perceive and use uncertainty information in real-time. At the EGU General Assembly 2012, we conducted a laboratory-style experiment in which several cases of flood <span class="hlt">forecasts</span> and a choice of actions to take were presented as part of a game to participants, who acted as decision makers. Answers were collected and analyzed. In this paper, we present the results of this exercise and discuss if indeed we make better decisions on the basis of probabilistic <span class="hlt">forecasts</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/698698','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/698698"><span id="translatedtitle">Guideline for developing an ozone <span class="hlt">forecasting</span> program</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dye, T.S.; MacDonald, C.P.; Anderson, C.B.</p> <p>1999-07-01</p> <p>The purpose of this document is to provide guidance to help air quality agencies develop, operate, and evaluate ozone <span class="hlt">forecasting</span> programs. This guidance document provides: Background information about ozone and the weather`s effect on ozone; A list of how ozone <span class="hlt">forecasts</span> are currently used; A summary and evaluation of methods currently used to <span class="hlt">forecast</span> ozone; and Steps you can follow to develop and operate an ozone <span class="hlt">forecasting</span> program. The intended audience of this document is project managers, meteorologists, air quality analysts, and data analysts. Project managers can learn about the level of effort needed to set up and operate a <span class="hlt">forecasting</span> program. Meteorologists can learn about the various methods to predict ozone and the steps needed to create a program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006SPIE.6358E..54C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006SPIE.6358E..54C&link_type=ABSTRACT"><span id="translatedtitle">Demand <span class="hlt">forecast</span> model based on CRM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, Yuancui; Chen, Lichao</p> <p>2006-11-01</p> <p>With interiorizing day by day management thought that regarding customer as the centre, <span class="hlt">forecasting</span> customer demand becomes more and more important. In the demand <span class="hlt">forecast</span> of customer relationship management, the traditional <span class="hlt">forecast</span> methods have very great limitation because much uncertainty of the demand, these all require new modeling to meet the demands of development. In this paper, the notion is that <span class="hlt">forecasting</span> the demand according to characteristics of the potential customer, then modeling by it. The model first depicts customer adopting uniform multiple indexes. Secondly, the model acquires characteristic customers on the basis of data warehouse and the technology of data mining. The last, there get the most similar characteristic customer by their comparing and <span class="hlt">forecast</span> the demands of new customer by the most similar characteristic customer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013HESS...17.2219R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013HESS...17.2219R&link_type=ABSTRACT"><span id="translatedtitle">Do probabilistic <span class="hlt">forecasts</span> lead to better decisions?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramos, M. H.; van Andel, S. J.; Pappenberger, F.</p> <p>2013-06-01</p> <p>The last decade has seen growing research in producing probabilistic hydro-meteorological <span class="hlt">forecasts</span> and increasing their reliability. This followed the promise that, supplied with information about uncertainty, people would take better risk-based decisions. In recent years, therefore, research and operational developments have also started focusing attention on ways of communicating the probabilistic <span class="hlt">forecasts</span> to decision-makers. Communicating probabilistic <span class="hlt">forecasts</span> includes preparing tools and products for visualisation, but also requires understanding how decision-makers perceive and use uncertainty information in real time. At the EGU General Assembly 2012, we conducted a laboratory-style experiment in which several cases of flood <span class="hlt">forecasts</span> and a choice of actions to take were presented as part of a game to participants, who acted as decision-makers. Answers were collected and analysed. In this paper, we present the results of this exercise and discuss if we indeed make better decisions on the basis of probabilistic <span class="hlt">forecasts</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.G33A0831S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.G33A0831S"><span id="translatedtitle"><span class="hlt">Forecasting</span> the Chilean Tsunami, February 27 2010</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sterling, K.; Knight, W.; Whitmore, P.</p> <p>2010-12-01</p> <p>The West Coast and Alaska Tsunami Warning Center (WC/ATWC) is responsible for issuing tsunami warnings, advisories, and watches for the United States and Canadian coastlines. Utilizing well defined criteria related to earthquake magnitude and location an initial alert message is transmitted. The situation is monitored closely and analyzed using <span class="hlt">forecast</span> models and real-time sea level observations. If a tsunami is detected then a tsunami warning, advisory, or watch is issued. On February 27, 2010 at 06:34:14 UTC, a M8.8 earthquake occurred off the coast of Maule, Chile, initiating a tsunami that propagated throughout the Pacific Ocean. With approximately 13 hours before the tsunami arrived on the US west coast, the WC/ATWC utilized all available <span class="hlt">forecasting</span> tools to refine predicted tsunami amplitudes and inundation estimates, thereby providing the best possible estimates to emergency managers and the public. The guidance from the tsunami <span class="hlt">forecast</span> models, used in concurrence with sea-level observations, resulted in a tsunami advisory being issued for the Pacific coastal regions of the United States and Canada, the extent of which was expanded and then decreased as the event evolved. The WC/ATWC used two tsunami <span class="hlt">forecast</span> models: the Alaska Tsunami <span class="hlt">Forecast</span> Model (ATFM) and the Short-term Inundation <span class="hlt">Forecasting</span> for Tsunamis (SIFT) to formulate a solution. Each model provided an initial tsunami <span class="hlt">forecast</span> based on the earthquake magnitude and location that was subsequently refined over the following hours as Deep-ocean Assessment and Reporting of Tsunamis (DART) observations became available. After the DART data was assimilated into the models, the two <span class="hlt">forecasts</span> were used in conjunction to publicly issue predicted maximum amplitudes for 77 locations along the US west coast and in Alaska. As the tsunami reached the US coastline, tide gauge observations were used in scaling the <span class="hlt">forecasted</span> maximum amplitudes from the ATFM, thereby increasing the <span class="hlt">forecast</span> accuracy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26938320','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26938320"><span id="translatedtitle">Carbon dynamics and their link to <span class="hlt">dissolved</span> organic matter quality across contrasting stream ecosystems.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bodmer, Pascal; Heinz, Marlen; Pusch, Martin; Singer, Gabriel; Premke, Katrin</p> <p>2016-05-15</p> <p>Streams represent active components of the carbon cycle as emitters of carbon dioxide (CO2) and methane to the atmosphere at a global scale. However, the mechanisms and governing factors of these emissions are still largely unknown, especially concerning the effect of land use. We compared <span class="hlt">dissolved</span> and gaseous carbon dynamics in streams bordered by contrasting types of land use, specifically agriculture and forest. Carbon dioxide and methane partial pressures (pCO2 and pCH4, respectively) in the water body and carbon emissions via both <span class="hlt">gases</span> were studied for 24h during four field expeditions. pCH4 did not differ between the two system types. pCO2 was constantly oversaturated in all streams and significantly higher in agricultural streams (annual mean 4282ppm) compared to forest streams (annual mean 2189ppm) during all seasons. However, emissions of CO2 were not significantly different between the stream types due to significantly higher gas transfer velocity in forest compared to agricultural streams. pCO2 was significantly positively correlated to the concentrations of <span class="hlt">dissolved</span> organic carbon, <span class="hlt">dissolved</span> nitrogen and soluble reactive phosphorus in the water. Furthermore, pCO2 was correlated to optical parameters of <span class="hlt">dissolved</span> organic matter (DOM) quality, e.g., it increased with indicators of molecular size and an allochthonous fluorescent component identified by Parallel Factor Analysis (PARAFAC). This study demonstrates that different forms of land use may trigger a cascade of effects on the carbon production and emission of streams linked to changes in DOM quality. PMID:26938320</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM22D..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM22D..08S"><span id="translatedtitle">Space Weather <span class="hlt">Forecasting</span>: An Enigma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sojka, J. J.</p> <p>2012-12-01</p> <p>-pipe" disciplines. The perceived progress in space weather understanding differs significantly depending upon which community (scientific, technology, <span class="hlt">forecaster</span>, society) is addressing the question. Even more divergent are these thoughts when the question is how valuable is the scientific capability of <span class="hlt">forecasting</span> space weather. This talk will discuss present day as well as future potential for <span class="hlt">forecasting</span> space weather for a few selected examples. The author will attempt to straddle the divergent community opinions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........83L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........83L"><span id="translatedtitle">Wind speed <span class="hlt">forecasting</span> for wind energy applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Hong</p> <p></p> <p>With more wind energy being integrated into our grid systems, <span class="hlt">forecasting</span> wind energy has become a necessity for all market participants. Recognizing the market demands, a physical approach to site-specific hub-height wind speed <span class="hlt">forecasting</span> system has been developed. This system is driven by the outputs from the Canadian Global Environmental Multiscale (GEM) model. A simple interpolation approach benchmarks the <span class="hlt">forecasting</span> accuracy inherited from GEM. Local, site specific winds are affected on a local scale by a variety of factors including representation of the land surface and local boundary-layer process over heterogeneous terrain which have been a continuing challenge in NWP models like GEM with typical horizontal resolution of order 15-km. In order to resolve these small scale effects, a wind energy industry standard model, WAsP, is coupled with GEM to improve the <span class="hlt">forecast</span>. Coupling the WAsP model with GEM improves the overall <span class="hlt">forecasts</span>, but remains unsatisfactory for <span class="hlt">forecasting</span> winds with abrupt surface condition changes. Subsequently in this study, a new coupler that uses a 2-D RANS model of boundary-layer flow over surface condition changes with improved physics has been developed to further improve the <span class="hlt">forecasts</span> when winds coming from a water surface to land experience abrupt changes in surface conditions. It has been demonstrated that using vertically averaged wind speeds to represent geostrophic winds for input into the micro-scale models could reduce <span class="hlt">forecast</span> errors. The hub-height wind speed <span class="hlt">forecasts</span> could be further improved using a linear MOS approach. The <span class="hlt">forecasting</span> system has been evaluated, using a wind energy standard evaluation matrix, against data from an 80-m mast located near the north shore of Lake Erie. Coupling with GEM-LAM and a power conversion model using a theoretical power curve have also been investigated. For hub-height wind speeds GEM appears to perform better with a 15-Ian grid than the high resolution GEM-2.5Ian version at the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010WRR....46.3532B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010WRR....46.3532B"><span id="translatedtitle">A multisite seasonal ensemble streamflow <span class="hlt">forecasting</span> technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bracken, Cameron; Rajagopalan, Balaji; Prairie, James</p> <p>2010-03-01</p> <p>We present a technique for providing seasonal ensemble streamflow <span class="hlt">forecasts</span> at several locations simultaneously on a river network. The framework is an integration of two recent approaches: the nonparametric multimodel ensemble <span class="hlt">forecast</span> technique and the nonparametric space-time disaggregation technique. The four main components of the proposed framework are as follows: (1) an index gauge streamflow is constructed as the sum of flows at all the desired spatial locations; (2) potential predictors of the spring season (April-July) streamflow at this index gauge are identified from the large-scale ocean-atmosphere-land system, including snow water equivalent; (3) the multimodel ensemble <span class="hlt">forecast</span> approach is used to generate the ensemble flow <span class="hlt">forecast</span> at the index gauge; and (4) the ensembles are disaggregated using a nonparametric space-time disaggregation technique resulting in <span class="hlt">forecast</span> ensembles at the desired locations and for all the months within the season. We demonstrate the utility of this technique in skillful <span class="hlt">forecast</span> of spring seasonal streamflows at four locations in the Upper Colorado River Basin at different lead times. Where applicable, we compare the <span class="hlt">forecasts</span> to the Colorado Basin River <span class="hlt">Forecast</span> Center's Ensemble Streamflow Prediction (ESP) and the National Resource Conservation Service "coordinated" <span class="hlt">forecast</span>, which is a combination of the ESP, Statistical Water Supply, a principal component regression technique, and modeler knowledge. We find that overall, the proposed method is equally skillful to existing operational models while tending to better predict wet years. The <span class="hlt">forecasts</span> from this approach can be a valuable input for efficient planning and management of water resources in the basin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013HESS...17.1913S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013HESS...17.1913S"><span id="translatedtitle">Evaluation of numerical weather prediction model precipitation <span class="hlt">forecasts</span> for short-term streamflow <span class="hlt">forecasting</span> purpose</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shrestha, D. L.; Robertson, D. E.; Wang, Q. J.; Pagano, T. C.; Hapuarachchi, H. A. P.</p> <p>2013-05-01</p> <p>The quality of precipitation <span class="hlt">forecasts</span> from four Numerical Weather Prediction (NWP) models is evaluated over the Ovens catchment in Southeast Australia. Precipitation <span class="hlt">forecasts</span> are compared with observed precipitation at point and catchment scales and at different temporal resolutions. The four models evaluated are the Australian Community Climate Earth-System Simulator (ACCESS) including ACCESS-G with a 80 km resolution, ACCESS-R 37.5 km, ACCESS-A 12 km, and ACCESS-VT 5 km. The skill of the NWP precipitation <span class="hlt">forecasts</span> varies considerably between rain gauging stations. In general, high spatial resolution (ACCESS-A and ACCESS-VT) and regional (ACCESS-R) NWP models overestimate precipitation in dry, low elevation areas and underestimate in wet, high elevation areas. The global model (ACCESS-G) consistently underestimates the precipitation at all stations and the bias increases with station elevation. The skill varies with <span class="hlt">forecast</span> lead time and, in general, it decreases with the increasing lead time. When evaluated at finer spatial and temporal resolution (e.g. 5 km, hourly), the precipitation <span class="hlt">forecasts</span> appear to have very little skill. There is moderate skill at short lead times when the <span class="hlt">forecasts</span> are averaged up to daily and/or catchment scale. The precipitation <span class="hlt">forecasts</span> fail to produce a diurnal cycle shown in observed precipitation. Significant sampling uncertainty in the skill scores suggests that more data are required to get a reliable evaluation of the <span class="hlt">forecasts</span>. The non-smooth decay of skill with <span class="hlt">forecast</span> lead time can be attributed to diurnal cycle in the observation and sampling uncertainty. Future work is planned to assess the benefits of using the NWP rainfall <span class="hlt">forecasts</span> for short-term streamflow <span class="hlt">forecasting</span>. Our findings here suggest that it is necessary to remove the systematic biases in rainfall <span class="hlt">forecasts</span>, particularly those from low resolution models, before the rainfall <span class="hlt">forecasts</span> can be used for streamflow <span class="hlt">forecasting</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6854525','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6854525"><span id="translatedtitle">Decision support for financial <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jairam, B.N.; Morris, J.D.; Emrich, M.L.; Hardee, H.K.</p> <p>1988-10-01</p> <p>A primary mission of the Budget Management Division of the Air Force is fiscal analysis. This involves formulating, justifying, and tracking financial data during budget preparation and execution. An essential requirement of this process is the ready availability and easy manipulation of past and current budget data. This necessitates the decentralization of the data. A prototypical system, BAFS (Budget Analysis and <span class="hlt">Forecasting</span> System), that provides such a capability is presented. In its current state, the system is designed to be a decision support tool. A brief report of the budget decisions and activities is presented. The system structure and its major components are discussed. An insight into the implementation strategies and the tool used is provided. The paper concludes with a discussion of future enhancements and the system's evolution into an expert system. 4 refs., 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70035688','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70035688"><span id="translatedtitle">Real-time flood <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lai, C.; Tsay, T.-K.; Chien, C.-H.; Wu, I.-L.</p> <p>2009-01-01</p> <p>Researchers at the Hydroinformatic Research and Development Team (HIRDT) of the National Taiwan University undertook a project to create a real time flood <span class="hlt">forecasting</span> model, with an aim to predict the current in the Tamsui River Basin. The model was designed based on deterministic approach with mathematic modeling of complex phenomenon, and specific parameter values operated to produce a discrete result. The project also devised a rainfall-stage model that relates the rate of rainfall upland directly to the change of the state of river, and is further related to another typhoon-rainfall model. The geographic information system (GIS) data, based on precise contour model of the terrain, estimate the regions that were perilous to flooding. The HIRDT, in response to the project's progress, also devoted their application of a deterministic model to unsteady flow of thermodynamics to help predict river authorities issue timely warnings and take other emergency measures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.9176C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9176C"><span id="translatedtitle">Emulation for probabilistic weather <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornford, Dan; Barillec, Remi</p> <p>2010-05-01</p> <p>Numerical weather prediction models are typically very expensive to run due to their complexity and resolution. Characterising the sensitivity of the model to its initial condition and/or to its parameters requires numerous runs of the model, which is impractical for all but the simplest models. To produce probabilistic <span class="hlt">forecasts</span> requires knowledge of the distribution of the model outputs, given the distribution over the inputs, where the inputs include the initial conditions, boundary conditions and model parameters. Such uncertainty analysis for complex weather prediction models seems a long way off, given current computing power, with ensembles providing only a partial answer. One possible way forward that we develop in this work is the use of statistical emulators. Emulators provide an efficient statistical approximation to the model (or simulator) while quantifying the uncertainty introduced. In the emulator framework, a Gaussian process is fitted to the simulator response as a function of the simulator inputs using some training data. The emulator is essentially an interpolator of the simulator output and the response in unobserved areas is dictated by the choice of covariance structure and parameters in the Gaussian process. Suitable parameters are inferred from the data in a maximum likelihood, or Bayesian framework. Once trained, the emulator allows operations such as sensitivity analysis or uncertainty analysis to be performed at a much lower computational cost. The efficiency of emulators can be further improved by exploiting the redundancy in the simulator output through appropriate dimension reduction techniques. We demonstrate this using both Principal Component Analysis on the model output and a new reduced-rank emulator in which an optimal linear projection operator is estimated jointly with other parameters, in the context of simple low order models, such as the Lorenz 40D system. We present the application of emulators to probabilistic weather</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/911928','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/911928"><span id="translatedtitle">Construction Safety <span class="hlt">Forecast</span> for ITER</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>cadwallader, lee charles</p> <p>2006-11-01</p> <p>The International Thermonuclear Experimental Reactor (ITER) project is poised to begin its construction activity. This paper gives an estimate of construction safety as if the experiment was being built in the United States. This estimate of construction injuries and potential fatalities serves as a useful <span class="hlt">forecast</span> of what can be expected for construction of such a major facility in any country. These data should be considered by the ITER International Team as it plans for safety during the construction phase. Based on average U.S. construction rates, ITER may expect a lost workday case rate of < 4.0 and a fatality count of 0.5 to 0.9 persons per year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860061198&hterms=nino+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnino%2Bforecasting','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860061198&hterms=nino+forecasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnino%2Bforecasting"><span id="translatedtitle">Experimental <span class="hlt">forecasts</span> of El Nino</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cane, M. A.; Zebiak, S. E.; Dolan, S. C.</p> <p>1986-01-01</p> <p>A deterministic numerical model of the coupled evolution of the tropical ocean and atmosphere was used to <span class="hlt">forecast</span> all El Nino/Southern Oscillation (ENSO) events from 1970 to 1986. More particularly, the model, originally developed for studying large-scale ocean-atmosphere interactions in the tropics, successfully predicted the characteristics of the spatial and temporal structure of ENSO observed in the study interval. The model indicated that rainfall moving eastward over the Pacific slackens the surface winds that would otherwise cool the eastern Pacific by drawing up cooler subsurface waters. The oceanic thermocline increases, a poleward flow of westerly flowing warn waters deplets the equatorial warm water reservoir, and sea surface temperatures decline. These ENSO conditions are statistically tractable with the model several months in advance, provided upper ocean layer thermal data are available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23456373','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23456373"><span id="translatedtitle">Phantosmia as a meteorological <span class="hlt">forecaster</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aiello, S R; Hirsch, A R</p> <p>2013-09-01</p> <p>In normosmics, olfactory ability has been found to vary with ambient humidity, barometric pressure, and season. While hallucinated sensations of phantom pain associated with changes in weather have been described, a linkage to chemosensory hallucinations has heretofore not been reported. A 64-year-old white male with Parkinson's disease presents with 5 years of phantosmia of a smoky burnt wood which changed to onion-gas and then to a noxious skunk-onion excrement odor. Absent upon waking it increases over the day and persists for hours. When severe, there appears a phantom taste with the same qualities as the odor. It is exacerbated by factors that manipulate intranasal pressure, such as coughing. When eating or sniffing, the actual flavors replace the phantosmia. Since onset, he noted the intensity and frequency of the phantosmia <span class="hlt">forecasted</span> the weather. Two to 3 h before a storm, the phantosmia intensifies from a level 0 to a 7-10, which persists through the entire thunderstorm. Twenty years prior, he reported the ability to <span class="hlt">forecast</span> the weather, based on pain in a torn meniscus, which vanished after surgical repair. Extensive olfactory testing demonstrates underlying hyposmia. Possible mechanisms for such chemosensory-meteorological linkage includes: air pressure induced synesthesia, disinhibition of spontaneous olfactory discharge, exacerbation of ectopic discharge, affect mediated somatic sensory amplification, and misattribution error with expectation and recall bias. This is the first reported case of weather-induced exacerbation of phantosmia. Further investigation of the connection between chemosensory complaints and ambient weather is warranted. PMID:23456373</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....111201L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....111201L"><span id="translatedtitle">Challenges in <span class="hlt">Forecasting</span> SEP Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhmann, Janet; Mays, M. Leila; Odstrcil, Dusan; Bain, Hazel; Li, Yan; Leske, Richard; Cohen, Christina</p> <p>2015-04-01</p> <p>A long-standing desire of space weather prediction providers has been the ability to <span class="hlt">forecast</span> SEP (Solar Energetic Particle) events as a part of their offerings. SEPs can have deleterious effects on the space environment and space hardware, that also impact human exploration missions. Developments of observationally driven, physics based models in the last solar cycle have made it possible to use solar magnetograms and coronagraph images to simulate, up to a month in advance for solar wind structure, and up to days in advance for interplanetary Coronal Mass Ejection (ICME) driven shocks, time series of upstream parameters similar in content to those obtained by L1 spacecraft. However, SEPs have been missing from these predictions. Because SEP event modeling requires different physical considerations it has typically been approached with cosmic ray transport concepts and treatments. However, many extra complications arise because of the moving, evolving nature of the ICME shock source of the largest events. In general, a realistic SEP event model for these so-called 'gradual' events requires an accurate description of the time-dependent 3D heliosphere as an underlying framework. We describe some applications of an approach to SEP event simulations that uses the widely-applied ENLIL heliospheric model to describe both underlying solar wind and ICME shock characteristics. Experimentation with this set-up illustrates the importance of knowing the shock connectivity to the observer, and of the need to include even non-observer-impacting CMEs in the heliospheric model. It also provides a possible path forward toward the goal of having routine SEP <span class="hlt">forecasts</span> together with the other heliospheric predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V43E4945L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V43E4945L"><span id="translatedtitle">Comparison of sampling methods for the determination of sulfur species in volcanic <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, S.; Park, M.; Jeong, H. Y.</p> <p>2014-12-01</p> <p>We aimed to evaluate three methods for the determination of sulfur species in volcanic <span class="hlt">gases</span> using an artificial fumarole. Among three methods, both cadmium sulfide and silver sulfide precipitation methods utilized the NaOH solutions containing Cd2+ and Ag+, respectively, in pre-evacuated bottles. Sulfur <span class="hlt">gases</span> (H2S + SO2) from the artificial fumarole were <span class="hlt">dissolved</span> into the NaOH solutions, and then H2S reacted with either Cd2+ or Ag+ to precipitate as CdS and Ag2S. Subsequently, the alkaline solutions were filtered to separate the precipitates from the solution. While the filtrate was analyzed on an ion chromatograph (IC) for SO2 concentrations, the precipitate was oxidized by H2O2 solutions and analyzed on an IC for H2S concentrations. In the third method (the iodine method), KI-KIO3 solutions in falcon tubes were employed in addition to NaOH solutions in pre-evacuated bottles. Once sulfur <span class="hlt">gases</span> were collected by the NaOH solution, they were also sampled into the KI-KIO3 solution. In the iodine solution, H2S was oxidized and precipitated as elemental sulfur, whereas SO2 was <span class="hlt">dissolved</span> as sulfate. Once both sampling were done, the total sulfur in the NaOH solution was determined on an IC. The KI-KIO3 solution was centrifuged to separate elemental sulfur from the solution. Following the oxidation of elemental sulfur into sulfate, the resultant solution was analyzed on an IC for H2S concentrations. For all methods, the H2S concentrations determined from the fumarolic <span class="hlt">gases</span> at low H2S flow rates were lower than expected. Notably, the H2S concentrations determined by silver sulfide precipitation method were lower than those by cadmium sulfide precipitation method. This is because Ag2S(s) is more soluble than CdS(s) under our experimental conditions. Also, the H2S determination by cadmium sulfide precipitation led to the similar results to the iodine method. However, the measured SO2 concentrations from the fumarolic <span class="hlt">gases</span> were in good agreement with the expected ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/919208','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/919208"><span id="translatedtitle">Final Report on California Regional Wind Energy <span class="hlt">Forecasting</span> Project:Application of NARAC Wind Prediction System</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chin, H S</p> <p>2005-07-26</p> <p>Wind power is the fastest growing renewable energy technology and electric power source (AWEA, 2004a). This renewable energy has demonstrated its readiness to become a more significant contributor to the electricity supply in the western U.S. and help ease the power shortage (AWEA, 2000). The practical exercise of this alternative energy supply also showed its function in stabilizing electricity prices and reducing the emissions of pollution and greenhouse <span class="hlt">gases</span> from other natural gas-fired power plants. According to the U.S. Department of Energy (DOE), the world's winds could theoretically supply the equivalent of 5800 quadrillion BTUs of energy each year, which is 15 times current world energy demand (AWEA, 2004b). Archer and Jacobson (2005) also reported an estimation of the global wind energy potential with the magnitude near half of DOE's quote. Wind energy has been widely used in Europe; it currently supplies 20% and 6% of Denmark's and Germany's electric power, respectively, while less than 1% of U.S. electricity is generated from wind (AWEA, 2004a). The production of wind energy in California ({approx}1.2% of total power) is slightly higher than the national average (CEC & EPRI, 2003). With the recently enacted Renewable Portfolio Standards calling for 20% of renewables in California's power generation mix by 2010, the growth of wind energy would become an important resource on the electricity network. Based on recent wind energy research (Roulston et al., 2003), accurate weather <span class="hlt">forecasting</span> has been recognized as an important factor to further improve the wind energy <span class="hlt">forecast</span> for effective power management. To this end, UC-Davis (UCD) and LLNL proposed a joint effort through the use of UCD's wind tunnel facility and LLNL's real-time weather <span class="hlt">forecasting</span> capability to develop an improved regional wind energy <span class="hlt">forecasting</span> system. The current effort of UC-Davis is aimed at developing a database of wind turbine power curves as a function of wind speed and</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HydJ...24...99G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HydJ...24...99G"><span id="translatedtitle"><span class="hlt">Dissolved</span> noble <span class="hlt">gases</span> and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gumm, L. P.; Bense, V. F.; Dennis, P. F.; Hiscock, K. M.; Cremer, N.; Simon, S.</p> <p>2016-02-01</p> <p>Groundwater in shallow unconsolidated sedimentary aquifers close to the Bornheim fault in the Lower Rhine Embayment (LRE), Germany, has relatively low δ2H and δ18O values in comparison to regional modern groundwater recharge, and 4He concentrations up to 1.7 × 10-4 cm3 (STP) g-1 ± 2.2 % which is approximately four orders of magnitude higher than expected due to solubility equilibrium with the atmosphere. Groundwater age dating based on estimated in situ production and terrigenic flux of helium provides a groundwater residence time of ˜107 years. Although fluid exchange between the deep basal aquifer system and the upper aquifer layers is generally impeded by confining clay layers and lignite, this study's geochemical data suggest, for the first time, that deep circulating fluids penetrate shallow aquifers in the locality of fault zones, implying that sub-vertical fluid flow occurs along faults in the LRE. However, large hydraulic-head gradients observed across many faults suggest that they act as barriers to lateral groundwater flow. Therefore, the geochemical data reported here also substantiate a conduit-barrier model of fault-zone hydrogeology in unconsolidated sedimentary deposits, as well as corroborating the concept that faults in unconsolidated aquifer systems can act as loci for hydraulic connectivity between deep and shallow aquifers. The implications of fluid flow along faults in sedimentary basins worldwide are far reaching and of particular concern for carbon capture and storage (CCS) programmes, impacts of deep shale gas recovery for shallow groundwater aquifers, and nuclear waste storage sites where fault zones could act as potential leakage pathways for hazardous fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880015678','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880015678"><span id="translatedtitle">Oxidation and reduction rates for organic carbon in the Amazon mainstream tributary and floodplain, inferred from distributions of <span class="hlt">dissolved</span> <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richey, Jeffrey E.; Devol, Allan H.; Wofsy, Steven C.; Victoria, Reynaldo; Riberio, Maria N. G.</p> <p>1986-01-01</p> <p>Concentrations of CO2, O2, CH4, and N2O in the Amazon River system reflect an oxidation-reduction sequence in combination with physical mixing between the floodplain and the mainstem. Concentrations of CO2 ranged from 150 microM in the Amazon mainstem to 200 to 300 microM in aerobic waters of the floodplain, and up to 1000 microM in oxygen-depleted environments. Apparent oxygen utilization (AOU) ranged from 80 to 250 microM. Methane was highly supersaturated, with concentrations ranging from 0.06 microM in the mainstem to 100 microM on the floodplain. Concentrations of N2O were slightly supersaturated in the mainstem, but were undersaturated on the floodplain. Fluxes calculated from these concentrations indicated decomposition of 1600 g C sq m y(-1) of organic carbon in Amazon floodplain waters. Analysis of relationships between CH4, O2, and CO2 concentrations indicated that approximately 50 percent of carbon mineralization on the floodplain is anaerobic, with 20 percent lost to the atmoshphere as CH4. The predominance of anaerobic metabolism leads to consumption of N2O on the flood plane. Elevated concentrations of CH4 in the mainstem probably reflect imput from the floodplain, while high levels of CO2 in the mainstem are derived from a combination of varzea drainage and in situ respiration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.431..206S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.431..206S"><span id="translatedtitle">Mean annual temperature in New Zealand during the last glacial maximum derived from <span class="hlt">dissolved</span> noble <span class="hlt">gases</span> in groundwater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seltzer, A. M.; Stute, M.; Morgenstern, U.; Stewart, M. K.; Schaefer, J. M.</p> <p>2015-12-01</p> <p>This study presents a reconstruction of mean annual surface temperature in New Zealand over the last glacial period using groundwater noble gas paleothermometry. Low resolution 14C-derived mean recharge ages of groundwater from the Deep Moutere, Deep Wairau, and Taranaki aquifers range from roughly 41,500 yr to present, including the last glacial maximum (LGM). Modeled noble gas temperatures of probable glacial-age samples range from roughly 3.7-6.2 °C cooler than present. We present an error-weighted mean cooling of 4.6 ± 0.5°C relative to present during last glacial period. The screened depth intervals of some wells sampled in this study allow for a degree of mixing during extraction between groundwater layers of different recharge age. Mixing with modern groundwater may slightly elevate the noble gas temperatures (NGTs) of glacial-age samples while making them appear substantially younger. Given the uncertainty in dating, we cannot rule out a larger LGM temperature depression of up to ∼6 °C. The ∼4.6 °C cooling estimate agrees with a number of terrestrial paleoclimate reconstructions near the study area as well as the majority of nearby paleoceanographic temperature studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EGUGA..1614288L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EGUGA..1614288L&link_type=ABSTRACT"><span id="translatedtitle">Inter-comparison exercises on <span class="hlt">dissolved</span> <span class="hlt">gases</span> for groundwater dating (GDAT 2012) : analytical uncertainties, apparent ages and other derived parameters.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Labasque, Thierry; Aquilina, Luc; Visser, Ate; Vergnaud, Virginie</p> <p>2014-05-01</p> <p>An inter-laboratory comparison exercise dedicated to environmental tracers used for groundwater dating was organized in 2012 in France. The goal was to compare sampling and analytical protocols through results obtained by the community of groundwater dating laboratories. Sampling and analytical protocols were compared through three different exercises on various supports : (1) on groundwater from a homogeneous aquifer, (2) on groundwater from a fractured heterogeneous aquifer and (3) on an air standard. The two tests allowed 31 Laboratories from 14 countries to compare their protocols for both sampling and analyses. It allows discussing the uncertainties related to sampling protocols issuing from each laboratory methods. The results show a good agreement between laboratories on the aquifers and the air standard. The dispersion of SF6 results in air standard is low (rsd 2%) compared to CFCs (rsd 3 to 7%), even if its concentration is two orders of magnitude lower. Results obtained in recent groundwater (recharge after 1980) show that the uncertainty on groundwater dating with SF6 is between 3 and 4 years. This large uncertainty is mainly due to sampling and/or analytical problems. For CFCs, uncertainties obtained over all the laboratories are less than 2 years for groundwater with recharge between 1965 and 1996. The goal of the inter-laboratory comparison exercise was also to quantify the analytical uncertainty of the 3H and noble gas measurements and to assess whether they meet the requirements for 3H/3He dating and noble gas paleotemperature reconstruction. The reproducibility of the tritium measurements was 13.5%. The reproducibility of the 3He/4He ratio and 4He, Ne, Ar, Kr and Xe concentrations was 1.4%, 1.8%, 1.5%, 2.2%, 2.9%, and 2.4%. The propagated uncertainty of the tritium and noble gas measurements meets the desired precision for typical 3H/3He dating applications. However, the measurement uncertainties for the noble gas concentrations are insufficient to distinguish the appropriate excess air model if the measured helium concentration is not included. While the analytical uncertainty introduces an unavoidable source of uncertainty in the 3H/3He apparent age estimate, other sources of uncertainty are often much greater and less well defined than the analytical uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6464612','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6464612"><span id="translatedtitle">Catalytic desulfurization of industrial waste <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dupin, Th.</p> <p>1985-07-30</p> <p>Industrial waste <span class="hlt">gases</span> containing objectionable/polluting compounds of sulfur, e.g., H/sub 2/S, SO/sub 2/ and such organosulfur derivatives as COS, CS/sub 2/ and mercaptans, are catalytically desulfurized, e.g., by Claus process, employing an improved catalyst comprising titanium dioxide and calcium, barium, strontium or magnesium sulfate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ions&pg=2&id=EJ1037244','ERIC'); return false;" href="http://eric.ed.gov/?q=ions&pg=2&id=EJ1037244"><span id="translatedtitle">Electron-Atom Collisions in <span class="hlt">Gases</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kraftmakher, Yaakov</p> <p>2013-01-01</p> <p>Electron-atom collisions in <span class="hlt">gases</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22373592','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22373592"><span id="translatedtitle">Collective modes in cold paramagnetic <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Andreeva, T L; Rubin, P L</p> <p>2014-02-28</p> <p>We have obtained a condition for the emergence of spin waves in paramagnetic <span class="hlt">gases</span> Re >> ImÂ, which is fulfilled only at temperatures of the order of 1 μK. (laser applications and other topics in quantum electronics)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=interferometer&pg=2&id=EJ136811','ERIC'); return false;" href="http://eric.ed.gov/?q=interferometer&pg=2&id=EJ136811"><span id="translatedtitle">Refractive Indices of <span class="hlt">Gases</span> at Microwave Frequencies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goodhead, D. T.; And Others</p> <p>1976-01-01</p> <p>Describes a simple microwave interferometer capable of measuring small phase shifts. Proposes laboratory exercises involving the use of the interferometer in the determination of refractive indices of <span class="hlt">gases</span> and the analysis of the reflection in a test chamber. (Author/CP)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19700000440','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19700000440"><span id="translatedtitle">Elimination of <span class="hlt">gases</span> and contamination from water</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buck, A. P.</p> <p>1970-01-01</p> <p>Filtration system with membrane type hydrophilic and hydrophobic filters gives absolute filtration with automatic venting of freed <span class="hlt">gases</span>, and prevents backward transmission of contamination with no bacterial growth through the filters. Filter aids in degassing industrial solutions and in removing oxygen from sea water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec90-312.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec90-312.pdf"><span id="translatedtitle">40 CFR 90.312 - Analytical <span class="hlt">gases</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... § 90.312 Analytical <span class="hlt">gases</span>. (a) The shelf life of a calibration gas may not be exceeded. The expiration...); (4) Purified synthetic air, also referred to as “zero air” or “zero gas” (Contamination ≤ 1 ppm C... following chemical compositions must be available: C3 H8 and purified synthetic air and/or C3 H8...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED200391.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED200391.pdf"><span id="translatedtitle">Teacher's Guide for Balloons and <span class="hlt">Gases</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Griffith, Joe H.; And Others</p> <p></p> <p>This guide was developed to provide children with an opportunity to prepare and collect several common <span class="hlt">gases</span> and to discover and work with some of their properties. The guide is divided into five major sections: (1) introduction, (2) materials, (3) activities, (4) balloons aloft, and (5) an appendix. The introduction provides information…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790052592&hterms=pyrolysis+equipment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpyrolysis%2Bequipment','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790052592&hterms=pyrolysis+equipment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpyrolysis%2Bequipment"><span id="translatedtitle">Toxicity of pyrolysis <span class="hlt">gases</span> from polyether sulfone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hilado, C. J.; Olcomendy, E. M.</p> <p>1979-01-01</p> <p>A sample of polyether sulfone was evaluated for toxicity of pyrolysis <span class="hlt">gases</span>, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Sulfur&pg=6&id=EJ071358','ERIC'); return false;" href="http://eric.ed.gov/?q=Sulfur&pg=6&id=EJ071358"><span id="translatedtitle">Removing Sulphur Dioxide From Stack <span class="hlt">Gases</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Slack, A. V.</p> <p>1973-01-01</p> <p>Process types, process concepts, claims and counterclaims, cost factors, and the level of developed technology for sulfur dioxide control in stack <span class="hlt">gases</span> are focused upon and evaluated. Wet and dry processes as well as recovery and throwaway processes are compared. (BL)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030106652&hterms=Thermochemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DThermochemistry','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030106652&hterms=Thermochemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DThermochemistry"><span id="translatedtitle">Residual <span class="hlt">Gases</span> in Crystal Growth Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Palosz, W.</p> <p>2003-01-01</p> <p>Residual <span class="hlt">gases</span> present in closed ampoules may affect different crystal growth processes. That seems to be particularly true under microgravity conditions where, due to weightlessness of the melt, the <span class="hlt">gases</span> may lead to detached solidification and/or formation of voids and bubbles, as observed in the past. For that reason a good understanding and control of formation of residual <span class="hlt">gases</span> is important for an optimum design and meaningful interpretation of crystal growth experiments. Our extensive experimental and theoretical studies of the subject, summarized in this paper, include degassing of silica glass and generation of <span class="hlt">gases</span> from different source materials. Different materials processing conditions, like outgassing under vacuum, annealing in hydrogen, resublimation, different material preparation procedures, multiple annealings, different processing times, and others were applied and their effect on the amount and composition of gas were analyzed. The experimental results were interpreted based on theoretical calculations on diffusion in silica glass and source materials and thermochemistry of the system. Procedures for a reduction of the amount of gas are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030110980&hterms=Nature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DNature','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030110980&hterms=Nature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DNature"><span id="translatedtitle">Fullerenes and the Nature of Planetary <span class="hlt">Gases</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Becker, Luann; Poreda, Robert J.; Nuth, Joe</p> <p>2003-01-01</p> <p>Over the past several decades, two issues have dominated the discussion of planetary noble gas patterns: 1) the general resemblance of the noble gas abundances in carbonaceous chondrites to those measured in the Earth s atmosphere and; 2) atmospheric inventories of argon and neon that fall off significantly with increasing distance from the Sun. The recognition of the latter has led to the conclusion that the planetary component is not found on planets. In particular, the inability to explain the missing xenon reservoir, once thought to be sequestered in crustal rocks has been extremely troublesome. Some models have focused on various fractionations of solar wind rather than condensation as the process for the evolution of noble <span class="hlt">gases</span> in the terrestrial planets. However, these models cannot explain the observed gradient of the <span class="hlt">gases</span>, nor do they account for the similar Ne/Ar ratios and the dissimilar planetary Ar/Kr ratios. More recent studies have focused on hydrodynamic escape to explain the fractionation of <span class="hlt">gases</span>, like neon, in the atmosphere and the mantle. Escape theory also seems to explain, in part, the isotopically heavy argon on Mars, however, it does not explain the discrepancies observed for the abundances of argon and neon on Venus and the Earth. This has led to the assumption that some combination of solar wind implantation, absorption and escape are needed to explain the nature of planetary noble <span class="hlt">gases</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.S21C..08J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.S21C..08J"><span id="translatedtitle">Prospective Tests of Southern California Earthquake <span class="hlt">Forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jackson, D. D.; Schorlemmer, D.; Gerstenberger, M.; Kagan, Y. Y.; Helmstetter, A.; Wiemer, S.; Field, N.</p> <p>2004-12-01</p> <p>We are testing earthquake <span class="hlt">forecast</span> models prospectively using likelihood ratios. Several investigators have developed such models as part of the Southern California Earthquake Center's project called Regional Earthquake Likelihood Models (RELM). Various models are based on fault geometry and slip rates, seismicity, geodetic strain, and stress interactions. Here we describe the testing procedure and present preliminary results. <span class="hlt">Forecasts</span> are expressed as the yearly rate of earthquakes within pre-specified bins of longitude, latitude, magnitude, and focal mechanism parameters. We test models against each other in pairs, which requires that both <span class="hlt">forecasts</span> in a pair be defined over the same set of bins. For this reason we specify a standard "menu" of bins and ground rules to guide <span class="hlt">forecasters</span> in using common descriptions. One menu category includes five-year <span class="hlt">forecasts</span> of magnitude 5.0 and larger. Contributors will be requested to submit <span class="hlt">forecasts</span> in the form of a vector of yearly earthquake rates on a 0.1 degree grid at the beginning of the test. Focal mechanism <span class="hlt">forecasts</span>, when available, are also archived and used in the tests. Interim progress will be evaluated yearly, but final conclusions would be made on the basis of cumulative five-year performance. The second category includes <span class="hlt">forecasts</span> of earthquakes above magnitude 4.0 on a 0.1 degree grid, evaluated and renewed daily. Final evaluation would be based on cumulative performance over five years. Other types of <span class="hlt">forecasts</span> with different magnitude, space, and time sampling are welcome and will be tested against other models with shared characteristics. Tests are based on the log likelihood scores derived from the probability that future earthquakes would occur where they do if a given <span class="hlt">forecast</span> were true [Kagan and Jackson, J. Geophys. Res.,100, 3,943-3,959, 1995]. For each pair of <span class="hlt">forecasts</span>, we compute alpha, the probability that the first would be wrongly rejected in favor of the second, and beta, the probability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8844F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8844F"><span id="translatedtitle">Evaluation and comparison of O3 <span class="hlt">forecasts</span> of ALARO-CAMx and WRF-Chem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flandorfer, Claudia; Hirtl, Marcus</p> <p>2015-04-01</p> <p>ZAMG runs two models for Air-Quality <span class="hlt">forecasts</span> operationally: ALARO-CAMx and WRF-Chem. ALARO-CAMx is a combination of the meteorological model ALARO and the photochemical dispersion model CAMx and is operated at ZAMG by order of the regional governments since 2005. The emphasis of this modeling system is on predicting ozone peaks in the north-east Austrian flatlands. Two modeling domains are used with the highest resolution (5 km) in the alpine region. Various extensions with external data sources have been conducted in the past to improve the daily <span class="hlt">forecasts</span> of the model, e.g. data assimilation of O3- and PM10 observations from the Austrian measurement network (with optimum interpolation technique); MACC-II boundary conditions; combination of high resolved emission inventories for Austria with TNO and EMEP data. The biogenic emissions are provided by the SMOKE model. The model runs 2 times per day for a period of 48 hours. The second model which is operational is the on-line coupled model WRF-Chem. Meteorology is simulated simultaneously with the emission, turbulent mixing, transport, transformation, and fate of trace <span class="hlt">gases</span> and aerosols. 2 domains are used for the simulations. The mother domain covers Europe with a resolution of 12 km. The inner domain includes the alpine region with a horizontal resolution of 4km. 45 model levels are used in the vertical. The model runs 2 times per day for a period of 72 hours and is initialized with ECMWF <span class="hlt">forecasts</span>. The evaluation of both models is conducted for summer 2014 with the main focus on the <span class="hlt">forecasts</span> of ozone. The measurements of the Air-Quality stations are compared with the punctual <span class="hlt">forecasts</span> at the sites of the stations and with the area <span class="hlt">forecasts</span> for every province of Austria. Beside the evaluation a comparison of the <span class="hlt">forecasts</span> of ALARO-CAMx and WRF-Chem is done. The summer 2014 was the coldest and the dullest in the last 9 years. Due to this only two exceedances of the information threshold were measured (June</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4085D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010EGUGA..12.4085D&link_type=ABSTRACT"><span id="translatedtitle">Evaluation of Flood <span class="hlt">Forecast</span> and Warning in Elbe river basin - Impact of <span class="hlt">Forecaster</span>'s Strategy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Danhelka, Jan; Vlasak, Tomas</p> <p>2010-05-01</p> <p>Czech Hydrometeorological Institute (CHMI) is responsible for flood <span class="hlt">forecasting</span> and warning in the Czech Republic. To meet that issue CHMI operates hydrological <span class="hlt">forecasting</span> systems and publish flow <span class="hlt">forecast</span> in selected profiles. Flood <span class="hlt">forecast</span> and warning is an output of system that links observation (flow and atmosphere), data processing, weather <span class="hlt">forecast</span> (especially NWP's QPF), hydrological modeling and modeled outputs evaluation and interpretation by <span class="hlt">forecaster</span>. <span class="hlt">Forecast</span> users are interested in final output without separating uncertainties of separate steps of described process. Therefore an evaluation of final operational <span class="hlt">forecasts</span> was done for profiles within Elbe river basin produced by AquaLog <span class="hlt">forecasting</span> system during period 2002 to 2008. Effects of uncertainties of observation, data processing and especially meteorological <span class="hlt">forecasts</span> were not accounted separately. <span class="hlt">Forecast</span> of flood levels exceedance (peak over the threshold) during <span class="hlt">forecasting</span> period was the main criterion as flow increase <span class="hlt">forecast</span> is of the highest importance. Other evaluation criteria included peak flow and volume difference. In addition Nash-Sutcliffe was computed separately for each time step (1 to 48 h) of <span class="hlt">forecasting</span> period to identify its change with the lead time. Textual flood warnings are issued for administrative regions to initiate flood protection actions in danger of flood. Flood warning hit rate was evaluated at regions level and national level. Evaluation found significant differences of model <span class="hlt">forecast</span> skill between <span class="hlt">forecasting</span> profiles, particularly less skill was evaluated at small headwater basins due to domination of QPF uncertainty in these basins. The average hit rate was 0.34 (miss rate = 0.33, false alarm rate = 0.32). However its explored spatial difference is likely to be influenced also by different fit of parameters sets (due to different basin characteristics) and importantly by different impact of human factor. Results suggest that the practice of interactive</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeCoA.162...66C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeCoA.162...66C"><span id="translatedtitle">Total <span class="hlt">dissolvable</span> and <span class="hlt">dissolved</span> iron isotopes in the water column of the Peru upwelling regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chever, Fanny; Rouxel, Olivier J.; Croot, Peter L.; Ponzevera, Emmanuel; Wuttig, Kathrin; Auro, Maureen</p> <p>2015-08-01</p> <p>Vertical distributions of iron (Fe) concentrations and isotopes were determined in the total <span class="hlt">dissolvable</span> and <span class="hlt">dissolved</span> pools in the water column at three coastal stations located along the Peruvian margin, in the core of the Oxygen Minimum Zone (OMZ). The shallowest station 121 (161 m total water depth) was characterized by lithogenic input from the continental plateau, yielding concentrations as high as 456 nM in the total <span class="hlt">dissolvable</span> pool. At the 2 other stations (stations 122 and 123), Fe concentrations of <span class="hlt">dissolved</span> and total <span class="hlt">dissolvable</span> pools exhibited maxima in both surface and deep layers. Fe isotopic composition (δ56Fe) showed a fractionation toward lighter values for both physical pools throughout the water column for all stations with minimum values observed for the surface layer (between -0.64 and -0.97‰ at 10-20 m depth) and deep layer (between -0.03 and -1.25‰ at 160-300 m depth). An Fe isotope budget was established to determine the isotopic composition of the particulate pool. We observed a range of δ56Fe values for particulate Fe from +0.02 to -0.87‰, with lightest values obtained at water depth above 50 m. Such light values in the both particulate and <span class="hlt">dissolved</span> pools suggest sources other than atmospheric dust deposition in the surface ocean, including lateral transport of isotopically light Fe. Samples collected at station 122 closest to the sediment show the lightest isotope composition in the <span class="hlt">dissolved</span> and the particulate pools (-1.25 and -0.53‰ respectively) and high Fe(II) concentrations (14.2 ± 2.1 nM) consistent with a major reductive benthic Fe sources that is transferred to the ocean water column. A simple isotopic model is proposed to link the extent of Fe(II) oxidation and the Fe isotope composition of both particulate and <span class="hlt">dissolved</span> Fe pools. This study demonstrates that Fe isotopic composition in OMZ regions is not only affected by the relative contribution of reductive and non-reductive shelf sediment input but also by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267129','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4267129"><span id="translatedtitle">Testing the Value of Probability <span class="hlt">Forecasts</span> for Calibrated Combining</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lahiri, Kajal; Peng, Huaming; Zhao, Yongchen</p> <p>2014-01-01</p> <p>We combine the probability <span class="hlt">forecasts</span> of a real GDP decline from the U.S. Survey of Professional <span class="hlt">Forecasters</span>, after trimming the <span class="hlt">forecasts</span> that do not have “value”, as measured by the Kuiper Skill Score and in the sense of Merton (1981). For this purpose, we use a simple test to evaluate the probability <span class="hlt">forecasts</span>. The proposed test does not require the probabilities to be converted to binary <span class="hlt">forecasts</span> before testing, and it accommodates serial correlation and skewness in the <span class="hlt">forecasts</span>. We find that the number of <span class="hlt">forecasters</span> making valuable <span class="hlt">forecasts</span> decreases sharply as the horizon increases. The beta-transformed linear pool combination scheme, based on the valuable individual <span class="hlt">forecasts</span>, is shown to outperform the simple average for all horizons on a number of performance measures, including calibration and sharpness. The test helps to identify the good <span class="hlt">forecasters</span> ex ante, and therefore contributes to the accuracy of the combined <span class="hlt">forecasts</span>. PMID:25530646</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.7343R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.7343R"><span id="translatedtitle"><span class="hlt">Dissolved</span> gas dynamics in wetland soils: Root-mediated gas transfer kinetics determined via push-pull tracer tests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reid, Matthew C.; Pal, David S.; Jaffé, Peter R.</p> <p>2015-09-01</p> <p>Gas transfer processes are fundamental to the biogeochemical and water quality functions of wetlands, yet there is limited knowledge of the rates and pathways of soil-atmosphere exchange for <span class="hlt">gases</span> other than oxygen and methane (CH4). In this study, we use a novel push-pull technique with sulfur hexafluoride (SF6) and helium (He) as <span class="hlt">dissolved</span> gas tracers to quantify the kinetics of root-mediated gas transfer, which is a critical efflux pathway for <span class="hlt">gases</span> from wetland soils. This tracer approach disentangles the effects of physical transport from simultaneous reaction in saturated, vegetated wetland soils. We measured significant seasonal variation in first-order gas exchange rate constants, with smaller spatial variations between different soil depths and vegetation zones in a New Jersey tidal marsh. Gas transfer rates for most biogeochemical trace <span class="hlt">gases</span> are expected to be bracketed by the rate constants for SF6 and He, which ranged from ˜10-2 to 2 × 10-1 h-1 at our site. A modified Damköhler number analysis is used to evaluate the balance between biochemical reaction and root-driven gas exchange in governing the fate of environmental trace <span class="hlt">gases</span> in rooted, anaerobic soils. This approach confirmed the importance of plant gas transport for CH4, and showed that root-driven transport may affect nitrous oxide (N2O) balances in settings where N2O reduction rates are slow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T51B2026J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T51B2026J"><span id="translatedtitle">Performance of aftershock <span class="hlt">forecasts</span>: problem and formulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, C.; Wu, Z.; Li, L.</p> <p>2010-12-01</p> <p>WFSD project deals with the problems of earthquake physics, in which one of the important designed aims is the <span class="hlt">forecast</span> of the on-going aftershock activity of the Wenchuan earthquake, taking the advantage of the fast response to great earthquakes. Correlation between fluid measurements and aftershocks provided heuristic clues to the <span class="hlt">forecast</span> of aftershocks, invoking the discussion on the performance of such ‘precursory anomalies’, even if in a retrospective perspective. In statistical seismology, one of the critical issues is how to test the statistical significance of an earthquake <span class="hlt">forecast</span> scheme against real seismic activity. Due to the special characteristics of aftershock series and the feature of aftershock <span class="hlt">forecasts</span> that it deals with a limited spatial range and specific temporal duration, the test of the performance of aftershock <span class="hlt">forecasts</span> has to be different from the standard tests for main shock series. In this presentation we address and discuss the possible schemes for testing the performance of aftershock <span class="hlt">forecasts</span> - a seemingly simple but practically important issue in statistical seismology. As a simple and preliminary approach, we use an alternative form of Receiver Operating Characteristic (ROC) test, as well as other similar tests, considering the properties of aftershock series by using Omori law, ETAS model, and/or CFS calculation. We also discussed the lessons and experiences of the Wenchuan aftershock <span class="hlt">forecasts</span>, exploring how to make full use of the present knowledge of the regularity of aftershocks to serve the earthquake rescue and relief endeavor as well as the post-earthquake reconstruction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986SPIE..566..102M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986SPIE..566..102M"><span id="translatedtitle">Precision Fiber Optic Sensor Market <span class="hlt">Forecast</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montgomery, Jeff D.; Glasco, Jon; Dixon, Frank W.</p> <p>1986-01-01</p> <p>The worldwide market for precision fiber optic sensors is <span class="hlt">forecasted</span>, 1984-1994. The <span class="hlt">forecast</span> is based upon o Analysis of fiber optic sensor and related component current technology, and a <span class="hlt">forecast</span> of technology advancement o Review and projection of demand for precision sensing, and the penetration which fiber optics will make into this market The analysis and projections are based mainly on interviews conducted worldwide with research teams, government agencies, systems contractors, medical and industrial laboratories, component suppliers and others. The worldwide market for precision (interferometric) fiber optic sensing systems is <span class="hlt">forecasted</span> to exceed $0.8 billion by 1994. The <span class="hlt">forecast</span> is segmented by geographical region (Europe, Japan and North America) and by function; o Gyroscope o Sonar o Gradiometer/Magnetometer o Other - Chemical Composition - Atmospheric Acoustic - Temperature - Position - Pressure Requirements for components are reviewed. These include special fiber, emitters and detectors, modulators, couplers, switches, integrated optical circuits and integrated optoelectronics. The advancement in component performance is <span class="hlt">forecasted</span>. The major driving forces creating fiber optic sensor markets are reviewed. These include fiber optic sensor technical and economic advantages, increasingly stringent operational requirements, and technology evolution. The leading fiber optic sensor and related component development programs are reviewed. Component sources are listed. Funding sources for sensor and component development are outlined, and trends <span class="hlt">forecasted</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H43B1227B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H43B1227B"><span id="translatedtitle">Toward Improving Streamflow <span class="hlt">Forecasts</span> Using SNODAS Products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barth, C.; Boyle, D. P.; Lamorey, G. W.; Bassett, S. D.</p> <p>2007-12-01</p> <p>As part of the Water 2025 initiative, researchers at the Desert Research Institute in collaboration with the U.S. Bureau of Reclamation are developing and improving water decision support system (DSS) tools to make seasonal streamflow <span class="hlt">forecasts</span> for management and operations of water resources in the mountainous western United States. Streamflow <span class="hlt">forecasts</span> in these areas may have errors that are directly related to uncertainties resulting from the lack of direct high resolution snow water equivalent (SWE) measurements. The purpose of this study is to investigate the possibility of improving the accuracy of streamflow <span class="hlt">forecasts</span> through the use of Snow Data Assimilation System (SNODAS) products, which are high-resolution daily estimates of snow cover and associated hydrologic variables such as SWE and snowmelt runoff that are available for the coterminous United States. To evaluate the benefit of incorporating the SNODAS product into streamflow <span class="hlt">forecasts</span>, a variety of Ensemble Streamflow Predictions (ESP) are generated using the Precipitation-Runoff Modeling System (PRMS). A series of manual and automatic calibrations of PRMS to different combinations of measured (streamflow) and estimated (SNODAS SWE) hydrologic variables is performed for several watersheds at various scales of spatial resolution. This study, which is embedded in the constant effort to improve streamflow <span class="hlt">forecasts</span> and hence water operations DSS, shows the potential of using a product such as SNODAS SWE estimates to decrease parameter uncertainty related to snow variables and enhance <span class="hlt">forecast</span> skills early in the <span class="hlt">forecast</span> season.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23826222','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23826222"><span id="translatedtitle">A Simulation Optimization Approach to Epidemic <span class="hlt">Forecasting</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nsoesie, Elaine O; Beckman, Richard J; Shashaani, Sara; Nagaraj, Kalyani S; Marathe, Madhav V</p> <p>2013-01-01</p> <p>Reliable <span class="hlt">forecasts</span> of influenza can aid in the control of both seasonal and pandemic outbreaks. We introduce a simulation optimization (SIMOP) approach for <span class="hlt">forecasting</span> the influenza epidemic curve. This study represents the final step of a project aimed at using a combination of simulation, classification, statistical and optimization techniques to <span class="hlt">forecast</span> the epidemic curve and infer underlying model parameters during an influenza outbreak. The SIMOP procedure combines an individual-based model and the Nelder-Mead simplex optimization method. The method is used to <span class="hlt">forecast</span> epidemics simulated over synthetic social networks representing Montgomery County in Virginia, Miami, Seattle and surrounding metropolitan regions. The results are presented for the first four weeks. Depending on the synthetic network, the peak time could be predicted within a 95% CI as early as seven weeks before the actual peak. The peak infected and total infected were also accurately <span class="hlt">forecasted</span> for Montgomery County in Virginia within the <span class="hlt">forecasting</span> period. <span class="hlt">Forecasting</span> of the epidemic curve for both seasonal and pandemic influenza outbreaks is a complex problem, however this is a preliminary step and the results suggest that more can be achieved in this area. PMID:23826222</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H21A1012O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H21A1012O"><span id="translatedtitle">National Weather Service <span class="hlt">Forecast</span> Reference Evapotranspiration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Osborne, H. D.; Palmer, C. K.; Krone-Davis, P.; Melton, F. S.; Hobbins, M.</p> <p>2013-12-01</p> <p>The National Weather Service (NWS), Weather <span class="hlt">Forecasting</span> Offices (WFOs) are producing daily reference evapotranspiration (ETrc) <span class="hlt">forecasts</span> or FRET across the Western Region and in other selected locations since 2009, using the Penman - Monteith Reference Evapotranspiration equation for a short canopy (12 cm grasses), adopted by the Environmental Water Resources Institute of the American Society of Civil Engineers (ASCE-EWRI, 2004). The sensitivity of these daily calculations to fluctuations in temperatures, humidity, winds, and sky cover allows <span class="hlt">forecasters</span> with knowledge of local terrain and weather patterns to better <span class="hlt">forecast</span> in the ETrc inputs. The daily FRET product then evolved into a suite of products, including a weekly ETrc <span class="hlt">forecast</span> for better water planning and a tabular point <span class="hlt">forecast</span> for easy ingest into local water management-models. The ETrc <span class="hlt">forecast</span> product suite allows water managers, the agricultural community, and the public to make more informed water-use decisions. These products permit operational planning, especially with the impending drought across much of the West. For example, the California Department of Water Resources not only ingests the FRET into their soil moisture models, but uses the FRET calculations when determining the reservoir releases in the Sacramento and American Rivers. We will also focus on the expansion of FRET verification, which compares the daily FRET to the observations of ETo from the California Irrigation Management Information System (CIMIS) across California's Central Valley for the 2012 water year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3120P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3120P"><span id="translatedtitle">Urban Air Quality <span class="hlt">Forecasting</span> in Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlovic, Radenko; Menard, Sylvain; Cousineau, Sophie; Stroud, Craig; Moran, Michael</p> <p>2016-04-01</p> <p>Environment and Climate Change Canada has been providing air quality (AQ) <span class="hlt">forecasts</span> for major Canadian urban centers since 2001. Over this period, the Canadian AQ <span class="hlt">Forecast</span> Program has expanded and evolved. It currently uses the Regional Air Quality Deterministic Prediction System (RAQDPS) modelling framework. At the heart of the RAQDPS is the GEM-MACH model, an on-line coupled meteorology‒chemistry model configured for a North American domain with 10 km horizontal grid spacing and 80 vertical levels. A statistical post-processing model (UMOS-AQ) is then applied to the RAQDPS hourly <span class="hlt">forecasts</span> for locations with AQ monitors to reduce point <span class="hlt">forecast</span> bias and error. These outputs provide the primary guidance from which operational meteorologists disseminate Air Quality Health Index (AQHI) <span class="hlt">forecasts</span> to the public for major urban centres across Canada. During the 2015 summer Pan Am and Parapan Am Games, which were held in Ontario, Canada, an experimental version of the RAQDPS at 2.5 km horizontal grid spacing was run for a domain over the greater Toronto area. Currently, there is ongoing research to develop and assess AQ systems run at 1 km resolution. This presentation will show analyses of operational AQ <span class="hlt">forecast</span> performance for several pollutants over the last few years in major Canadian urban centres such as Toronto, Montreal, Vancouver, Ottawa, and Calgary. Trends in observed pollution along with short- and long-term development plans for urban AQ <span class="hlt">forecasting</span> will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9161M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9161M"><span id="translatedtitle">Tropical ocean initialisation strategies for seasonal <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mulholland, David; Haines, Keith</p> <p>2016-04-01</p> <p>Operational seasonal ENSO <span class="hlt">forecasts</span> show substantial skill in tropical regions, but are sensitive to the initialisation procedure used in the ocean. Due to errors in wind stress forcing and in modelling the vertical transfer of momentum, a bias correction method is often used during ocean data assimilation in order to assimilate hydrographic data, e.g. from the TOGA/TAO array. While this improves the ocean state, particularly the circulation, during the analysis, it leads to an inconsistency at the beginning of a coupled <span class="hlt">forecast</span>, since the bias correction term is generally not retained during the <span class="hlt">forecast</span> itself. We present results from a number of ensemble simulations carried out with the European Centre for Medium-range Weather <span class="hlt">Forecasts</span> (ECMWF) coupled <span class="hlt">forecast</span> system, comparing different initialisation strategies for the equatorial ocean. Rapid adjustments in the ocean at the beginning of the <span class="hlt">forecast</span> are found to induce additional variability in the thermocline. We then show that this spurious variability can be substantially reduced by persisting or more slowly adjusting the bias correction term during the first month, and that this leads to significant improvements in ENSO SST <span class="hlt">forecast</span> skill, at lead times of 3-7 months. The results highlight the importance of ocean initialisation in maximising the skill of ENSO predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010E%26ES...11a2009K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010E%26ES...11a2009K"><span id="translatedtitle">Improving weather <span class="hlt">forecasts</span> for wind energy applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kay, Merlinde; MacGill, Iain</p> <p>2010-08-01</p> <p>Weather <span class="hlt">forecasts</span> play an important role in the energy industry particularly because of the impact of temperature on electrical demand. Power system operation requires that this variable and somewhat unpredictable demand be precisely met at all times and locations from available generation. As wind generation makes up a growing component of electricity supply around the world, it has become increasingly important to be able to provide useful <span class="hlt">forecasting</span> for this highly variable and uncertain energy resource. Of particular interest are <span class="hlt">forecasts</span> of weather events that rapidly change wind energy production from one or more wind farms. In this paper we describe work underway to improve the wind <span class="hlt">forecasts</span> currently available from standard Numerical Weather Prediction (NWP) through a bias correction methodology. Our study has used the Australian Bureau of Meteorology MesoLAPS 5 km limited domain model over the Victoria/Tasmania region, providing <span class="hlt">forecasts</span> for the Woolnorth wind farm, situated in Tasmania, Australia. The accuracy of these <span class="hlt">forecasts</span> has been investigated, concentrating on the key wind speed ranges 5 - 15 ms-1 and around 25 ms-1. A bias correction methodology was applied to the NWP hourly <span class="hlt">forecasts</span> to help account for systematic issues such as the NWP grid point not being at the exact location of the wind farm. An additional correction was applied for timing issues by using meteorological data from the wind farm. Results to date show a reduction in spread of <span class="hlt">forecast</span> error for hour ahead <span class="hlt">forecasts</span> by as much as half using this double correction methodology - a combination of both bias correction and timing correction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18..991A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18..991A&link_type=ABSTRACT"><span id="translatedtitle">Seasonal hydrological ensemble <span class="hlt">forecasts</span> over Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arnal, Louise; Wetterhall, Fredrik; Stephens, Elisabeth; Cloke, Hannah; Pappenberger, Florian</p> <p>2016-04-01</p> <p>This study investigates the limits of predictability in dynamical seasonal discharge <span class="hlt">forecasting</span>, in both space and time, over Europe. Seasonal <span class="hlt">forecasts</span> have an important socioeconomic value. Applications are numerous and cover hydropower management, spring flood prediction, low flow prediction for navigation and agricultural water demands. Additionally, the constant increase in NWP skill for longer lead times and the predicted increase in the intensity and frequency of hydro-meteorological extremes, have amplified the incentive to promote and further improve hydrological <span class="hlt">forecasts</span> on sub-seasonal to seasonal timescales. In this study, seasonal hydrological <span class="hlt">forecasts</span> (SEA), driven by the ECMWF's System 4 in hindcast mode, were analysed against an Ensemble Streamflow Prediction (ESP) benchmark. The ESP was forced with an ensemble of resampled historical meteorological observations and started with perfect initial conditions. Both <span class="hlt">forecasts</span> were produced by the LISFLOOD model, run on the pan-European scale with a spatial resolution of 5 by 5 km. The <span class="hlt">forecasts</span> were issued monthly on a daily time step, from 1990 until the current time, up to a lead time of 7 months. The seasonal discharge <span class="hlt">forecasts</span> were analysed against the ESP on a catchment scale in terms of their accuracy, skill and sharpness, using a diverse set of verification metrics (e.g. KGE, CRPSS and ROC). Additionally, a reverse-ESP was constructed by forcing the LISFLOOD model with a single perfect meteorological set of observations and initiated from an ensemble of resampled historical initial conditions. The comparison of the ESP with the reverse-ESP approach enabled the identification of the respective contribution of meteorological forcings and hydrologic initial conditions errors to seasonal discharge <span class="hlt">forecasting</span> uncertainties in Europe. These results could help pinpoint target elements of the <span class="hlt">forecasting</span> chain which, after being improved, could lead to substantial increase in discharge predictability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994smog.symp..311S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994smog.symp..311S"><span id="translatedtitle">Accuracy analysis of TDRSS demand <span class="hlt">forecasts</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stern, Daniel C.; Levine, Allen J.; Pitt, Karl J.</p> <p>1994-11-01</p> <p>This paper reviews Space Network (SN) demand <span class="hlt">forecasting</span> experience over the past 16 years and describes methods used in the <span class="hlt">forecasts</span>. The paper focuses on the Single Access (SA) service, the most sought-after resource in the Space Network. Of the ten years of actual demand data available, only the last five years (1989 to 1993) were considered predictive due to the extensive impact of the Challenger accident of 1986. NASA's Space Network provides tracking and communications services to user spacecraft such as the Shuttle and the Hubble Space Telescope. <span class="hlt">Forecasting</span> the customer requirements is essential to planning network resources and to establishing service commitments to future customers. The lead time to procure Tracking and Data Relay Satellites (TDRS's) requires demand <span class="hlt">forecasts</span> ten years in the future a planning horizon beyond the funding commitments for missions to be supported. The long range <span class="hlt">forecasts</span> are shown to have had a bias toward underestimation in the 1991 -1992 period. The trend of underestimation can be expected to be replaced by overestimation for a number of years starting with 1998. At that time demand from new missions slated for launch will be larger than the demand from ongoing missions, making the potential for delay the dominant factor. If the new missions appear as scheduled, the <span class="hlt">forecasts</span> are likely to be moderately underestimated. The SN commitment to meet the negotiated customer's requirements calls for conservatism in the <span class="hlt">forecasting</span>. Modification of the <span class="hlt">forecasting</span> procedure to account for a delay bias is, therefore, not advised. Fine tuning the mission model to more accurately reflect the current actual demand is recommended as it may marginally improve the first year <span class="hlt">forecasting</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H31J..01F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H31J..01F"><span id="translatedtitle">Using <span class="hlt">Forecast</span> Information in Reservoir Operation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faber, B.</p> <p>2011-12-01</p> <p>Reservoir operation is a series of decisions made over time. We choose whether to release water for various downstream purposes, or store it for later use. We choose whether to detain high flows to protect downstream areas, or pass that flow to retain space to store imminent higher flows. These decisions are driven by current and future inflows to the reservoir, and yet those inflows are uncertain and extremely variable. Conceptually, more information provides opportunity for better decisions, and so information about future inflows can improve reservoir operations. However, uncertain information must be used carefully, with awareness of the uncertainty and the likely consequence of "wrong" decisions (i.e., those with consequences worse than decisions that might otherwise have been made.) The historical streamflow record offers one source of information on the range and timing of streamflows. Streamflow <span class="hlt">forecasting</span> provides additional valuable information on coming reservoir inflows, both at short and longer time scales. For example, 5-day flow <span class="hlt">forecasts</span> based on <span class="hlt">forecasted</span> precipitation can inform rain-flood operations, while seasonal snowmelt <span class="hlt">forecasts</span> can aid snowmelt-flood operation, reservoir refill, and seasonal allocation of water supply. <span class="hlt">Forecast</span> information can aid our decision-making greatly, but too much reliance on an incorrect <span class="hlt">forecast</span> can make operation worse. Informed use of <span class="hlt">forecasts</span> requires an understanding of the expected range of the actual streamflow (the error distribution). <span class="hlt">Forecast</span> products must therefore be provided with a description of skill and error distribution understood by the producers and users of that information. Using <span class="hlt">forecasts</span> wisely, with an understanding of their uncertainty, is an important aspect of the operation of our nation's Federal reservoirs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950010799','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950010799"><span id="translatedtitle">Accuracy analysis of TDRSS demand <span class="hlt">forecasts</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stern, Daniel C.; Levine, Allen J.; Pitt, Karl J.</p> <p>1994-01-01</p> <p>This paper reviews Space Network (SN) demand <span class="hlt">forecasting</span> experience over the past 16 years and describes methods used in the <span class="hlt">forecasts</span>. The paper focuses on the Single Access (SA) service, the most sought-after resource in the Space Network. Of the ten years of actual demand data available, only the last five years (1989 to 1993) were considered predictive due to the extensive impact of the Challenger accident of 1986. NASA's Space Network provides tracking and communications services to user spacecraft such as the Shuttle and the Hubble Space Telescope. <span class="hlt">Forecasting</span> the customer requirements is essential to planning network resources and to establishing service commitments to future customers. The lead time to procure Tracking and Data Relay Satellites (TDRS's) requires demand <span class="hlt">forecasts</span> ten years in the future a planning horizon beyond the funding commitments for missions to be supported. The long range <span class="hlt">forecasts</span> are shown to have had a bias toward underestimation in the 1991 -1992 period. The trend of underestimation can be expected to be replaced by overestimation for a number of years starting with 1998. At that time demand from new missions slated for launch will be larger than the demand from ongoing missions, making the potential for delay the dominant factor. If the new missions appear as scheduled, the <span class="hlt">forecasts</span> are likely to be moderately underestimated. The SN commitment to meet the negotiated customer's requirements calls for conservatism in the <span class="hlt">forecasting</span>. Modification of the <span class="hlt">forecasting</span> procedure to account for a delay bias is, therefore, not advised. Fine tuning the mission model to more accurately reflect the current actual demand is recommended as it may marginally improve the first year <span class="hlt">forecasting</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AAS...21544204M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AAS...21544204M"><span id="translatedtitle">Accurate Weather <span class="hlt">Forecasting</span> for Radio Astronomy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maddalena, Ronald J.</p> <p>2010-01-01</p> <p>The NRAO Green Bank Telescope routinely observes at wavelengths from 3 mm to 1 m. As with all mm-wave telescopes, observing conditions depend upon the variable atmospheric water content. The site provides over 100 days/yr when opacities are low enough for good observing at 3 mm, but winds on the open-air structure reduce the time suitable for 3-mm observing where pointing is critical. Thus, to maximum productivity the observing wavelength needs to match weather conditions. For 6 years the telescope has used a dynamic scheduling system (recently upgraded; www.gb.nrao.edu/DSS) that requires accurate multi-day <span class="hlt">forecasts</span> for winds and opacities. Since opacity <span class="hlt">forecasts</span> are not provided by the National Weather Services (NWS), I have developed an automated system that takes available <span class="hlt">forecasts</span>, derives <span class="hlt">forecasted</span> opacities, and deploys the results on the web in user-friendly graphical overviews (www.gb.nrao.edu/ rmaddale/Weather). The system relies on the "North American Mesoscale" models, which are updated by the NWS every 6 hrs, have a 12 km horizontal resolution, 1 hr temporal resolution, run to 84 hrs, and have 60 vertical layers that extend to 20 km. Each <span class="hlt">forecast</span> consists of a time series of ground conditions, cloud coverage, etc, and, most importantly, temperature, pressure, humidity as a function of height. I use the Liebe's MWP model (Radio Science, 20, 1069, 1985) to determine the absorption in each layer for each hour for 30 observing wavelengths. Radiative transfer provides, for each hour and wavelength, the total opacity and the radio brightness of the atmosphere, which contributes substantially at some wavelengths to Tsys and the observational noise. Comparisons of measured and <span class="hlt">forecasted</span> Tsys at 22.2 and 44 GHz imply that the <span class="hlt">forecasted</span> opacities are good to about 0.01 Nepers, which is sufficient for <span class="hlt">forecasting</span> and accurate calibration. Reliability is high out to 2 days and degrades slowly for longer-range <span class="hlt">forecasts</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.H53G1497C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.H53G1497C&link_type=ABSTRACT"><span id="translatedtitle">Seasonal streamflow <span class="hlt">forecasting</span> with the global hydrological <span class="hlt">forecasting</span> system FEWS-World</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Candogan Yossef, N.; Van Beek, L. P.; Winsemius, H.; Bierkens, M. F.</p> <p>2011-12-01</p> <p>The year-to-year variability of river discharge brings about risks and opportunities in water resources management. Reliable hydrological <span class="hlt">forecasts</span> and effective communication allow several sectors to make more informed management decisions. In many developing regions of the world, there are no efficient hydrological <span class="hlt">forecasting</span> systems. For these regions, a global <span class="hlt">forecasting</span> system which indicates increased probabilities of streamflow excesses or shortages over long lead-times can be of great value. FEWS-World is developed for this purpose. The system incorporates the global hydrological model PCR-GLOBWB and delivers streamflow <span class="hlt">forecasts</span> on a global scale. This study investigates the skill and value of FEWS-World. Skill is defined as the ability of the system to <span class="hlt">forecast</span> discharge extremes; and value is its usefulness for possible users and ultimately for affected populations. Skill is assessed in historical simulation mode as well as retroactive <span class="hlt">forecasting</span> mode. The eventual goal is to transfer FEWS-World to operational <span class="hlt">forecasting</span> mode, where the system will use operational seasonal <span class="hlt">forecasts</span> from the European Center for Medium-Range Weather <span class="hlt">Forecasts</span> (ECMWF). The results will be disseminated on the internet to provide valuable information for users in data and model-poor regions of the world. The preliminary skill assessment of PCR-GLOBWB in reproducing flow extremes is carried out for a selection of 20 large rivers of the world. The model is run for a historical period, with a meteorological forcing data set based on observations from the Climate Research Unit of the University of East Anglia, and the ERA-40 reanalysis of ECMWF. Model skill in reproducing monthly anomalies as well as floods and droughts is assessed by applying verification measures developed for deterministic meteorological <span class="hlt">forecasts</span>. The results of this preliminary analysis shows that even where the simulated hydrographs are biased, higher skills can be attained in reproducing monthly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10135022','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10135022"><span id="translatedtitle">1993 Pacific Northwest Loads and Resources Study, Pacific Northwest Economic and Electricity Use <span class="hlt">Forecast</span>, Technical Appendix: Volume 1.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>United States. Bonneville Power Administration.</p> <p>1994-02-01</p> <p>This publication documents the load <span class="hlt">forecast</span> scenarios and assumptions used to prepare BPA`s Whitebook. It is divided into: intoduction, summary of 1993 Whitebook electricity demand <span class="hlt">forecast</span>, conservation in the load <span class="hlt">forecast</span>, projection of medium case electricity sales and underlying drivers, residential sector <span class="hlt">forecast</span>, commercial sector <span class="hlt">forecast</span>, industrial sector <span class="hlt">forecast</span>, non-DSI industrial <span class="hlt">forecast</span>, direct service industry <span class="hlt">forecast</span>, and irrigation <span class="hlt">forecast</span>. Four appendices are included: long-term <span class="hlt">forecasts</span>, LTOUT <span class="hlt">forecast</span>, rates and fuel price <span class="hlt">forecasts</span>, and <span class="hlt">forecast</span> ranges-calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140002701','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140002701"><span id="translatedtitle">How MAG4 Improves Space Weather <span class="hlt">Forecasting</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Falconer, David; Khazanov, Igor; Barghouty, Nasser</p> <p>2013-01-01</p> <p>Dangerous space weather is driven by solar flares and Coronal Mass Ejection (CMEs). <span class="hlt">Forecasting</span> flares and CMEs is the first step to <span class="hlt">forecasting</span> either dangerous space weather or All Clear. MAG4 (Magnetogram <span class="hlt">Forecast</span>), developed originally for NASA/SRAG (Space Radiation Analysis Group), is an automated program that analyzes magnetograms from the HMI (Helioseismic and Magnetic Imager) instrument on NASA SDO (Solar Dynamics Observatory), and automatically converts the rate (or probability) of major flares (M- and X-class), Coronal Mass Ejections (CMEs), and Solar Energetic Particle Events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10177378','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10177378"><span id="translatedtitle">1993 Solid Waste Reference <span class="hlt">Forecast</span> Summary</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Valero, O.J.; Blackburn, C.L.; Kaae, P.S.; Armacost, L.L.; Garrett, S.M.K.</p> <p>1993-08-01</p> <p>This report, which updates WHC-EP-0567, 1992 Solid Waste Reference <span class="hlt">Forecast</span> Summary, (WHC 1992) <span class="hlt">forecasts</span> the volumes of solid wastes to be generated or received at the US Department of Energy Hanford Site during the 30-year period from FY 1993 through FY 2022. The data used in this document were collected from Westinghouse Hanford Company <span class="hlt">forecasts</span> as well as from surveys of waste generators at other US Department of Energy sites who are now shipping or plan to ship solid wastes to the Hanford Site for disposal. These wastes include low-level and low-level mixed waste, transuranic and transuranic mixed waste, and nonradioactive hazardous waste.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5693663','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5693663"><span id="translatedtitle">Combustion control system adding a liquid, exhaust <span class="hlt">gases</span>, and PCV <span class="hlt">gases</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lindberg, J.E.</p> <p>1980-01-15</p> <p>A combustion control system is disclosed that adds a fluid and heat energy to the air-fuel mixture of the induction system of an internal combustion engine in response to engine need to improve combustion, to increase power, to improve efficiency, and to reduce emissions. The system incorporates fluidic control mechanisms which provide the control functions without any moving parts. The system incorporates one or more variable impedance flow control mechanisms, each of which produces an impedance to flow through the control mechanism which varies in a controlled relationship to the pressure differential across the control mechanism. In one embodiment, the main variable impedance control mechanism is a vortex chamber. The outlet of the vortex chamber is connected to the positive crankcase ventilation (PCV) inlet to intake manifold downstream of the butterfly valve. The vortex chamber has inputs for supplying air, the liquid, exhaust <span class="hlt">gases</span>, and PCV <span class="hlt">gases</span> for mixing within the vortex chamber. The incoming liquid, air, exhaust <span class="hlt">gases</span>, and PCV <span class="hlt">gases</span> are transmitted into the main vortex chamber by input constructions which, in themselves, provide for controlled regulation of both the relative proportions and total amounts of the incoming liquid and <span class="hlt">gases</span>. In a specific embodiment, the input constructions include a liquid-exhaust gas acceleration chamber for mixing liquid with exhaust <span class="hlt">gases</span> and a PCV-exhaust gas vortex chamber for mixing exhaust <span class="hlt">gases</span> with PCV <span class="hlt">gases</span> and air and swirl producing devices for causing controlled choking of the inlets of one or more of the vortex chambers. The system also incorporates a variable impedance syphon break in the line connecting the liquid source with the liquid-exhaust gas acceleration chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25553683','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25553683"><span id="translatedtitle">Novel approach of aceclofenac fast <span class="hlt">dissolving</span> tablet.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dave, Vivek; Yadav, Sachdev; Sharma, Swapnil; Vishwakarma, Pushpendra; Ali, Nasir</p> <p>2015-01-01</p> <p>Fast disintegrating tablets (FDTs) have received ever increasing demand during the last decade, and the field has become a hastily growing area in the pharmaceutical industry. Upon introduction into the mouth, these tablets <span class="hlt">dissolve</span> or disintegrate in the mouth in the absence of additional water for easy administration of active pharmaceutical ingredients. Aceclofenac, an NSAID, has been recommended orally for the treatment of bone and connective tissue disorder and thus the formulation of the same resulted in development of several FDT technologies. The present aim is to formulate a tablet which disintegrate and <span class="hlt">dissolve</span> rapidly and give its rapid onset of action: analgesic, antipyretic and anti-inflammatory action. Besides, the conventional tablets also show poor patient compliance an attempt had been made to formulate for FDT of aceclofenac by using various super disintegrants like sodium starch glycolate, croscarmellose sodium and crosspovidone (polyplasdone XL) and PEG 6000 followed by novel technique. The tablets were evaluated for friability, hardness, weight variation, disintegration time, wetting time, in vitro dissolution studies and drug content studies. It was concluded that the batch which was prepared by using combination of crosspovidone and sodium starch glycolate as a super disintegrant shows excellent disintegration time, enhance dissolution rate, taste masking and hence lead to improve efficacy and bioavailability of drug. PMID:25553683</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20364240','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20364240"><span id="translatedtitle">Photoluminescent detection of <span class="hlt">dissolved</span> underwater trace explosives.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Langston, Tye</p> <p>2010-01-01</p> <p>A portable, rapid, and economical method for in situ trace explosive detection in aqueous solutions was demonstrated using photoluminescence. Using europium/ thenoyltrifluoroacetone as the reagent, <span class="hlt">dissolved</span> nitroglycerin was fluorescently tagged and detected in seawater solutions without sample preparation, drying, or preconcentration. The chemical method was developed in a laboratory setting and demonstrated in a flow-through configuration using lightweight, inexpensive, commercial components by directly injecting the reagents into a continually flowing seawater stream using a small amount of organic solvent (approximately 8% of the total solution). Europium's vulnerability to vibrational fluorescence quenching by water provided the mode of detection. Without nitroglycerin in the seawater solution, the reagent's fluorescence was quenched, but when <span class="hlt">dissolved</span> nitroglycerin was present, it displaced the water molecules from the europium/thenoyltrifluoroacetone compound and restored fluorescence. This effort focused on developing a seawater sensor, but performance comparisons were made to freshwater. The method was found to perform better in freshwater and it was shown that certain seawater constituents (such as calcium) have an adverse impact. However, the concentrations of these constituents are not expected to vary significantly from the natural seawater used herein. PMID:20364240</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/859259','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/859259"><span id="translatedtitle"><span class="hlt">DISSOLVED</span> CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>NA</p> <p>2004-11-22</p> <p>The purpose of this study is to evaluate <span class="hlt">dissolved</span> concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict <span class="hlt">dissolved</span> concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H41A1148C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H41A1148C"><span id="translatedtitle">Seasonal Runoff <span class="hlt">Forecasts</span> Based on the Climate <span class="hlt">Forecast</span> System Version 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, L.; Mo, K. C.; Shukla, S.; Lettenmaier, D. P.</p> <p>2012-12-01</p> <p>Seasonal runoff <span class="hlt">forecasts</span> are needed for many hydroclimatological applications, such as drought outlook, agricultural planning, seasonal hydrologic prediction, and multi-purpose reservoir management. Recently, NOAA National Centers for Environmental Prediction (NCEP) has transitioned to their second generation of the Climate <span class="hlt">Forecast</span> System (CFSv2) in operation. CFSv2 is a coupled ocean-atmosphere-land model with advanced physics, increased resolution, refined initialization, and improved land surface model, and provides <span class="hlt">forecasts</span> up to nine months in advance. Information on the accuracy and skill of the CFSv2 <span class="hlt">forecasts</span> is sought for the daily operation of many applications. In this study, we conduct an assessment of the prediction skill of seasonal runoff <span class="hlt">forecasts</span> from CFSv2 using its retrospective <span class="hlt">forecasts</span> from 1982 to 2009. <span class="hlt">Forecast</span> skill of spatially aggregated cumulative runoff (CR) from direct CFSv2 <span class="hlt">forecasts</span> and those obtained from the Variable Infiltration Capacity (VIC) model driven by daily precipitation, temperature, and wind <span class="hlt">forecasts</span> from CFSv2 (i.e., hydroclimate <span class="hlt">forecasts</span>) are compared with <span class="hlt">forecasts</span> based on the ensemble streamflow prediction (ESP) technique. All <span class="hlt">forecasts</span> are verified against historical VIC simulations with input forcing of precipitation and temperature derived from a set of 2131 high-quality index stations selected from the National Climatic Data Center's (NCDC's) Cooperative Observer stations across the contiguous United States. The monthly CR is spatially aggregated to 48 sub-regions created by merging the 221 U.S. Geological Survey (USGS) hydrologic sub-regions in order to evaluate regional characteristics. Preliminary results suggest that <span class="hlt">forecast</span> skill of CR is seasonally and regionally dependent. Direct runoff <span class="hlt">forecasts</span> from CFSv2 have the lowest skill on average, indicating limited use for hydrological drought prediction. Month-1 CR prediction from hydroclimate <span class="hlt">forecasts</span> is superior than that from the other two <span class="hlt">forecast</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016763','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016763"><span id="translatedtitle">Hydrocarbon Rocket Technology Impact <span class="hlt">Forecasting</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stuber, Eric; Prasadh, Nishant; Edwards, Stephen; Mavris, Dimitri N.</p> <p>2012-01-01</p> <p>Ever since the Apollo program ended, the development of launch propulsion systems in the US has fallen drastically, with only two new booster engine developments, the SSME and the RS-68, occurring in the past few decades.1 In recent years, however, there has been an increased interest in pursuing more effective launch propulsion technologies in the U.S., exemplified by the NASA Office of the Chief Technologist s inclusion of Launch Propulsion Systems as the first technological area in the Space Technology Roadmaps2. One area of particular interest to both government agencies and commercial entities has been the development of hydrocarbon engines; NASA and the Air Force Research Lab3 have expressed interest in the use of hydrocarbon fuels for their respective SLS Booster and Reusable Booster System concepts, and two major commercially-developed launch vehicles SpaceX s Falcon 9 and Orbital Sciences Antares feature engines that use RP-1 kerosene fuel. Compared to engines powered by liquid hydrogen, hydrocarbon-fueled engines have a greater propellant density (usually resulting in a lighter overall engine), produce greater propulsive force, possess easier fuel handling and loading, and for reusable vehicle concepts can provide a shorter turnaround time between launches. These benefits suggest that a hydrocarbon-fueled launch vehicle would allow for a cheap and frequent means of access to space.1 However, the time and money required for the development of a new engine still presents a major challenge. Long and costly design, development, testing and evaluation (DDT&E) programs underscore the importance of identifying critical technologies and prioritizing investment efforts. Trade studies must be performed on engine concepts examining the affordability, operability, and reliability of each concept, and quantifying the impacts of proposed technologies. These studies can be performed through use of the Technology Impact <span class="hlt">Forecasting</span> (TIF) method. The Technology Impact</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26521000','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26521000"><span id="translatedtitle">Note: <span class="hlt">Dissolved</span> hydrogen detection in power transformer oil based on chemically etched fiber Bragg grating.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiang, Jun; Ma, Guo-ming; Song, Hong-tu; Zhou, Hong-yang; Li, Cheng-rong; Luo, Ying-ting; Wang, Hong-bin</p> <p>2015-10-01</p> <p>A fiber Bragg grating (FBG) sensor based on chemically etched cladding to detect <span class="hlt">dissolved</span> hydrogen is proposed and studied in this paper. Low hydrogen concentration tests have been carried out in mixed <span class="hlt">gases</span> and transformer oil to investigate the repeatability and sensitivity. Moreover, to estimate the influence of etched cladding thickness, a physical model of FBG-based hydrogen sensor is analyzed. Experimental results prove that thin cladding chemically etched by HF acid solution improves the response to hydrogen detection in oil effectively. At last, the sensitivity of FBG sensor chemically etched 16 μm could be as high as 0.060 pm/(μl/l), increased by more than 30% in comparison to un-etched FBG. PMID:26521000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86j6103J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86j6103J"><span id="translatedtitle">Note: <span class="hlt">Dissolved</span> hydrogen detection in power transformer oil based on chemically etched fiber Bragg grating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Jun; Ma, Guo-ming; Song, Hong-tu; Zhou, Hong-yang; Li, Cheng-rong; Luo, Ying-ting; Wang, Hong-bin</p> <p>2015-10-01</p> <p>A fiber Bragg grating (FBG) sensor based on chemically etched cladding to detect <span class="hlt">dissolved</span> hydrogen is proposed and studied in this paper. Low hydrogen concentration tests have been carried out in mixed <span class="hlt">gases</span> and transformer oil to investigate the repeatability and sensitivity. Moreover, to estimate the influence of etched cladding thickness, a physical model of FBG-based hydrogen sensor is analyzed. Experimental results prove that thin cladding chemically etched by HF acid solution improves the response to hydrogen detection in oil effectively. At last, the sensitivity of FBG sensor chemically etched 16 μm could be as high as 0.060 pm/(μl/l), increased by more than 30% in comparison to un-etched FBG.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHyd..512..506T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHyd..512..506T"><span id="translatedtitle">Understanding and modelling <span class="hlt">dissolved</span> gas transport in the bedrock of three Fennoscandian sites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trinchero, Paolo; Delos, Anne; Molinero, Jorge; Dentz, Marco; Pitkänen, Petteri</p> <p>2014-05-01</p> <p>The origin and transport of <span class="hlt">dissolved</span> <span class="hlt">gases</span> in the geosphere is of interest for assessment studies of nuclear waste repositories. In this paper, we analyse available field measurements of helium, methane and hydrogen at three Fennoscandian sites: Forsmark and Laxemar in Sweden and Olkiluoto in Finland. The field data are interpreted using different analytical models all based on the one-dimensional diffusion equation. The results of the different models provide estimates about the amount of deep gas flux, the in situ production and the groundwater residence time of the considered sites. The computed helium fluxes, which fall within the lower range of crustal degassing fluxes reported by Torgersen (2010), are strictly related with the high tightness of the considered fracture media. The very high estimates of groundwater residence time indicate that, at the considered depths, there are only very few flowing fractures while in the rest of the fractured domain groundwater has been almost motionless during a whole glacial cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol30/pdf/CFR-2011-title40-vol30-sec430-40.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol30/pdf/CFR-2011-title40-vol30-sec430-40.pdf"><span id="translatedtitle">40 CFR 430.40 - Applicability; description of the <span class="hlt">dissolving</span> sulfite subcategory.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... <span class="hlt">dissolving</span> sulfite subcategory. 430.40 Section 430.40 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY <span class="hlt">Dissolving</span> Sulfite Subcategory § 430.40 Applicability; description of the <span class="hlt">dissolving</span> sulfite... at <span class="hlt">dissolving</span> sulfite mills....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol29/pdf/CFR-2010-title40-vol29-sec430-40.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol29/pdf/CFR-2010-title40-vol29-sec430-40.pdf"><span id="translatedtitle">40 CFR 430.40 - Applicability; description of the <span class="hlt">dissolving</span> sulfite subcategory.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... <span class="hlt">dissolving</span> sulfite subcategory. 430.40 Section 430.40 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY <span class="hlt">Dissolving</span> Sulfite Subcategory § 430.40 Applicability; description of the <span class="hlt">dissolving</span> sulfite... at <span class="hlt">dissolving</span> sulfite mills....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126153&keyword=TAX&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64964693&CFTOKEN=74044533','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=126153&keyword=TAX&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64964693&CFTOKEN=74044533"><span id="translatedtitle">EVALUATION OF SIGNIFICANT ANTHROPOGENIC SOURCES OF RADIATIVELY IMPORTANT TRACE <span class="hlt">GASES</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The report is an initial evaluation of significant anthropogenic sources of radiatively important trace <span class="hlt">gases</span>. missions of greenhouse <span class="hlt">gases</span> from human activities--including fossil fuel combustion, industrial/agricultural activities, and transportation--contribute to the increasin...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012HESSD...912563S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012HESSD...912563S"><span id="translatedtitle">Evaluation of numerical weather prediction model precipitation <span class="hlt">forecasts</span> for use in short-term streamflow <span class="hlt">forecasting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shrestha, D. L.; Robertson, D. E.; Wang, Q. J.; Pagano, T. C.; Hapuarachchi, P.</p> <p>2012-11-01</p> <p>The quality of precipitation <span class="hlt">forecasts</span> from four Numerical Weather Prediction (NWP) models is evaluated over the Ovens catchment in southeast Australia. Precipitation <span class="hlt">forecasts</span> are compared with observed precipitation at point and catchment scales and at different temporal resolutions. The four models evaluated are the Australian Community Climate Earth-System Simulator (ACCESS) including ACCESS-G with a 80 km resolution, ACCESS-R 37.5 km, ACCESS-A 12 km, and ACCESS-VT 5 km. The high spatial resolution NWP models (ACCESS-A and ACCESS-VT) appear to be relatively free of bias (i.e. <30%) for 24 h total precipitation <span class="hlt">forecasts</span>. The low resolution models (ACCESS-R and ACCESS-G) have widespread systematic biases as large as 70%. When evaluated at finer spatial and temporal resolution (e.g. 5 km, hourly) against station observations, the precipitation <span class="hlt">forecasts</span> appear to have very little skill. There is moderate skill at short lead times when the <span class="hlt">forecasts</span> are averaged up to daily and/or catchment scale. The skill decreases with increasing lead times and the global model ACCESS-G does not have significant skill beyond 7 days. The precipitation <span class="hlt">forecasts</span> fail to produce a diurnal cycle shown in observed precipitation. Significant sampling uncertainty in the skill scores suggests that more data are required to get a reliable evaluation of the <span class="hlt">forecasts</span>. Future work is planned to assess the benefits of using the NWP rainfall <span class="hlt">forecasts</span> for short-term streamflow <span class="hlt">forecasting</span>. Our findings here suggest that it is necessary to remove the systematic biases in rainfall <span class="hlt">forecasts</span>, particularly those from low resolution models, before the rainfall <span class="hlt">forecasts</span> can be used for streamflow <span class="hlt">forecasting</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/ofr80754','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/ofr80754"><span id="translatedtitle">Weather <span class="hlt">forecast</span> needs from the viewpoint of hydrology</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Thomas, Donald M.; Buchanan, Thomas J.</p> <p>1980-01-01</p> <p>Hydrologists now depend on directly observed data in their <span class="hlt">forecasting</span> and only infrequently use meteorological <span class="hlt">forecasts</span>. Case studies show how reliable meteorological <span class="hlt">forecasts</span> could be beneficial in flood and drought situations. Hydrologists need meteorological <span class="hlt">forecasts</span> that recognize spatial variability, that are unbiased, and that have a specified degree of uncertainty. (USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFMED42A1205D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFMED42A1205D"><span id="translatedtitle">Comparison of Five Weather <span class="hlt">Forecast</span> Methods at Four California Locations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dempsey, D. P.; Garcia, O.; Frieberg, E.; Tidwell, W.; Chow, B.; Daquigan, D.; Long, D.; Tan, K.</p> <p>2003-12-01</p> <p>In this project we compare five methods of <span class="hlt">forecasting</span> maximum and minimum temperature and probability of precipitation at four California locations: California Academy of Sciences in San Francisco, Oakland Museum, Sacramento Executive Airport, and Truckee Airport. The five methods are applied to make 24-hour <span class="hlt">forecasts</span> twice weekly during the period from August 18 to December 2, 2003. The five <span class="hlt">forecast</span> methods include: (1) Persistence. A persistence <span class="hlt">forecast</span> assumes that tomorrow's weather will be the same as today's. (2) Climatology. Our climatology-based <span class="hlt">forecasts</span> use weather conditions for the day at or very near each of the four locations, averaged over the 30-year period from 1971 to 2000. (3) Official National Weather Service (NWS) <span class="hlt">forecasts</span>. We use the official NWS <span class="hlt">forecasts</span> for Oakland Museum, Sacramento Executive Airport, and Truckee Airport. For The California Academy of Sciences (CAS) we use the NWS's new Prototype Digital <span class="hlt">Forecast</span> for the CAS's latitude and longitude. (4) Individual student <span class="hlt">forecasts</span>, made by four 10th grade students from San Francisco's Burton High School. They consulted the most recent meteograms, satellite images, soundings, synoptic analyses, and computer model <span class="hlt">forecasts</span>, as well as climatology, persistence, and NWS <span class="hlt">forecasts</span>. (5) A consensus of student <span class="hlt">forecasts</span>, comprising the average of the four student <span class="hlt">forecasts</span>. We calculate <span class="hlt">forecast</span> error by squaring the difference between a <span class="hlt">forecast</span> and the verifying observation, and compare the <span class="hlt">forecast</span> methods based on these errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol3/pdf/CFR-2011-title48-vol3-sec232-072-3.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol3/pdf/CFR-2011-title48-vol3-sec232-072-3.pdf"><span id="translatedtitle">48 CFR 232.072-3 - Cash flow <span class="hlt">forecasts</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... problems. (c) Single or one-time cash flow <span class="hlt">forecasts</span> are of limited <span class="hlt">forecasting</span> power. As such, they should... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Cash flow <span class="hlt">forecasts</span>. 232..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING 232.072-3 Cash flow <span class="hlt">forecasts</span>....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol3/pdf/CFR-2012-title48-vol3-sec232-072-3.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol3/pdf/CFR-2012-title48-vol3-sec232-072-3.pdf"><span id="translatedtitle">48 CFR 232.072-3 - Cash flow <span class="hlt">forecasts</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... problems. (c) Single or one-time cash flow <span class="hlt">forecasts</span> are of limited <span class="hlt">forecasting</span> power. As such, they should... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Cash flow <span class="hlt">forecasts</span>. 232..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING 232.072-3 Cash flow <span class="hlt">forecasts</span>....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol3/pdf/CFR-2014-title48-vol3-sec232-072-3.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol3/pdf/CFR-2014-title48-vol3-sec232-072-3.pdf"><span id="translatedtitle">48 CFR 232.072-3 - Cash flow <span class="hlt">forecasts</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... problems. (c) Single or one-time cash flow <span class="hlt">forecasts</span> are of limited <span class="hlt">forecasting</span> power. As such, they should... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Cash flow <span class="hlt">forecasts</span>. 232..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING 232.072-3 Cash flow <span class="hlt">forecasts</span>....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol3/pdf/CFR-2013-title48-vol3-sec232-072-3.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol3/pdf/CFR-2013-title48-vol3-sec232-072-3.pdf"><span id="translatedtitle">48 CFR 232.072-3 - Cash flow <span class="hlt">forecasts</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... problems. (c) Single or one-time cash flow <span class="hlt">forecasts</span> are of limited <span class="hlt">forecasting</span> power. As such, they should... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Cash flow <span class="hlt">forecasts</span>. 232..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING 232.072-3 Cash flow <span class="hlt">forecasts</span>....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20643469','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20643469"><span id="translatedtitle">Effluent <span class="hlt">dissolved</span> organic nitrogen and <span class="hlt">dissolved</span> phosphorus removal by enhanced coagulation and microfiltration.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arnaldos, Marina; Pagilla, Krishna</p> <p>2010-10-01</p> <p>Plants aiming to achieve very low effluent nutrient levels (<3 mg N/L for N, and <0.1 mg P/L for P) need to consider removal of effluent fractions hitherto not taken into account. Two of these fractions are <span class="hlt">dissolved</span> organic nitrogen (DON) and <span class="hlt">dissolved</span> non-reactive phosphorus (DNRP) (mainly composed of organic phosphorus). In this research, enhanced coagulation using alum (at doses commonly employed in tertiary phosphorus removal) followed by microfiltration (using 0.22 μm pore size filters) was investigated for simultaneous effluent DON and <span class="hlt">dissolved</span> phosphorus (DP) fractions removal. At an approximate dose of 3.2 mg Al(III)/L, corresponding to 1.5 Al(III)/initial DON-N and 3.8 Al(III)/initial DP-P molar ratios, maximum simultaneous removal of DON and DP was achieved (69% for DON and 72% for DP). At this dose, residual DON and DP concentrations were found to be 0.3 mg N/L and 0.25 mg P/L, respectively. Analysis of the trends of removal revealed that the DNRP removal pattern was similar to that commonly reported for <span class="hlt">dissolved</span> reactive phosphorus. Since this study involved intensive analytical work, a secondary objective was to develop a simple and accurate measurement protocol for determining <span class="hlt">dissolved</span> N and P species at very low levels in wastewater effluents. The protocol developed in this study, involving simultaneous digestion for DON and DNRP species, was found to be very reliable and accurate based on the results. PMID:20643469</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E2185Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E2185Z&link_type=ABSTRACT"><span id="translatedtitle">Prediction Techniques in Operational Space Weather <span class="hlt">Forecasting</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhukov, Andrei</p> <p>2016-07-01</p> <p>The importance of <span class="hlt">forecasting</span> space weather conditions is steadily increasing as our society is becoming more and more dependent on advanced technologies that may be affected by disturbed space weather. Operational space weather <span class="hlt">forecasting</span> is still a difficult task that requires the real-time availability of input data and specific prediction techniques that are reviewed in this presentation, with an emphasis on solar and interplanetary weather. Key observations that are essential for operational space weather <span class="hlt">forecasting</span> are listed. Predictions made on the base of empirical and statistical methods, as well as physical models, are described. Their validation, accuracy, and limitations are discussed in the context of operational <span class="hlt">forecasting</span>. Several important problems in the scientific basis of predicting space weather are described, and possible ways to overcome them are discussed, including novel space-borne observations that could be available in future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC51G..06A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC51G..06A"><span id="translatedtitle">Impact of Seasonal <span class="hlt">Forecasts</span> on Agriculture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aldor-Noiman, S. C.</p> <p>2014-12-01</p> <p>More extreme and volatile weather conditions are a threat to U.S. agricultural productivity today, as multiple environmental conditions during the growing season impact crop yields. That's why farmers' agronomic management decisions are dominated by consideration for near, medium and seasonal <span class="hlt">forecasts</span> of climate. The Climate Corporation aims to help farmers around the world protect and improve their farming operations by providing agronomic decision support tools that leverage <span class="hlt">forecasts</span> on multiple timescales to provide valuable insights directly to farmers. In this talk, we will discuss the impact of accurate seasonal <span class="hlt">forecasts</span> on major decisions growers face each season. We will also discuss assessment and evaluation of seasonal <span class="hlt">forecasts</span> in the context of agricultural applications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. Their policies may differ from this site.</small> </div> </center> <div id="footer-wrapper"> <div class="footer-content"> <div id="footerOSTI" class=""> <div class="row"> <div class="col-md-4 text-center col-md-push-4 footer-content-center"><small><a href="http://www.science.gov/disclaimer.html">Privacy and Security</a></small> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center col-md-pull-4 footer-content-left"> <img src="http://www.osti.gov/images/DOE_SC31.png" alt="U.S. Department of Energy" usemap="#doe" height="31" width="177"><map style="display:none;" name="doe" id="doe"><area shape="rect" coords="1,3,107,30" href="http://www.energy.gov" alt="U.S. Deparment of Energy"><area shape="rect" coords="114,3,165,30" href="http://www.science.energy.gov" alt="Office of Science"></map> <a ref="http://www.osti.gov" style="margin-left: 15px;"><img src="http://www.osti.gov/images/footerimages/ostigov53.png" alt="Office of Scientific and Technical Information" height="31" width="53"></a> <div class="visible-sm visible-xs push_footer"></div> </div> <div class="col-md-4 text-center footer-content-right"> <a href="http://www.osti.gov/nle"><img src="http://www.osti.gov/images/footerimages/NLElogo31.png" alt="National Library of Energy" height="31" width="79"></a> <a href="http://www.science.gov"><img src="http://www.osti.gov/images/footerimages/scigov77.png" alt="science.gov" height="31" width="98"></a> <a href="http://worldwidescience.org"><img src="http://www.osti.gov/images/footerimages/wws82.png" alt="WorldWideScience.org" height="31" width="90"></a> </div> </div> </div> </div> </div> <p><br></p> </div><!-- container --> </body> </html>