Science.gov

Sample records for forecasting dissolved gases

  1. Effect of Greenhouse Gases Dissolved in Seawater.

    PubMed

    Matsunaga, Shigeki

    2015-12-30

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

  2. 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.

  3. Greenhouse gases dissolved in soil solution - often ignored, but important?

    NASA Astrophysics Data System (ADS)

    Weymann, Daniel; Brueggemann, Nicolas; Puetz, Thomas; Vereecken, Harry

    2014-05-01

    Flux measurements of climate-relevant trace gases from soils are frequently undertaken in contemporary ecosystem studies and substantially contribute to our understanding of greenhouse gas balances of the biosphere. While the great majority of such investigations builds on closed chamber and eddy covariance measurements, where upward gas fluxes to the atmosphere are measured, fewest concurrently consider greenhouse gas dissolution in the seepage and leaching of dissolved gases via the vadose zone to the groundwater. Here we present annual leaching losses of dissolved N2O and CO2 from arable, grassland, and forest lysimeter soils from three sites differing in altitude and climate. We aim to assess their importance in comparison to direct N2O emission, soil respiration, and further leaching parameters of the C- and N cycle. The lysimeters are part of the Germany-wide lysimeter network initiative TERENO-SoilCan, which investigates feedbacks of climate change to the pedosphere on a long-term scale. Soil water samples were collected weekly from different depths of the profiles by means of suction cups. A laboratory pre-experiment proved that no degassing occurred under those sampling conditions. We applied the headspace equilibration technique to determine dissolved gas concentrations by gas chromatography. The seepage water of all lysimeters was consistently supersaturated with N2O and CO2 compared to water equilibrated ambient air. In terms of N2O, leaching losses increased in the ascending order forest, grassland, and arable soils, respectively. In case of the latter soils, we observed a strong variability of N2O, with dissolved concentrations up to 23 μg N L-1. However, since seepage discharge of the arable lysimeters was comparatively small and mostly limited to the hydrological winter season, leached N2O appeared to be less important than direct N2O emissions. In terms of dissolved CO2,our measurements revealed considerable leaching losses from the mountainous

  4. 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.

  5. 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

  6. Influence of Gases Dissolved in Water to the Emergence of Ice Crystals

    NASA Astrophysics Data System (ADS)

    Mikula, V.

    2010-04-01

    Composition of gases dissolved in the body determines if the organism survives hypothermia or not. My work could have a major impact in terms of freezing and thawing of tissues, organs or whole organisms for their survival.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. Distribution and origin of dissolved gases of groundwaters at Las Cañadas aquifer, Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Marrero, R.; Melian, G.; Padron, E.; Sortino, F.; Hernandez Perez, P. A.; Lopez, D. L.; Perez, N.

    2009-12-01

    Volcanic aquifers commonly trap an important fraction of the main soluble components of fluids released from volcanic-hydrothermal system (CO2, SO2, H2S, HCl, HF, etc.). In particular, the interactions between volcanic gases and volcanic aquifers have been studied through hydrogeochemical parameters, as major and minor ions contents and dissolved gases in groundwaters. In the context of hydrogeochemical studies applied to active volcanic areas, studies of dissolved gases species in groundwater could be a useful tool to better understand the subsurface processes as gas-water-rock interaction or to strengthen the geochemical seismic-volcanic surveillance programs. In this work, we report the results of the geochemical characterization of dissolved gases (N2, O2, Ar, CO2, CH4, CO, H2, He, 222Rn, δ13CTDIC) in 96 groundwater samples from Las Cañadas aquifer (around Teide volcano) between May and October, 2006. The main aims of this work are: (1) to determine the background level of magmatic gas input in the aquifer during quiescent periods, (2) to better define the origin of dissolved gases in Las Cañadas aquifer, specially CO2, (3) to evaluate the gas-water-rock interaction processes occurring at depth, and (4) to delineate high permeable pathway of upward migration of volcanic-hydrothermal gases. In general, the dissolved gas phase in groundwaters of Las Cañadas aquifer is relatively enriched in endogenous gases (CO2, He and H2) while it is relatively depleted in atmospheric gases (N2, O2 and Ar). N2-O2-CO2 triangular diagram shows that dissolved gases in most of analyzed groundwater are variable mixtures of CO2-rich fluids from the volcanic-hydrothermal system (as represent the Teide fumaroles) with dissolved air. The relatively high N2/O2 ratio in some groundwater compared to the air saturated water suggests an O2 consumption during gas-water-rock interactions occurring at depth. Spatial distribution maps show anomalous concentration of 222Rn CH4, H2 and CO2

  15. 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.

  16. 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

  17. Impact of artificial recharge on dissolved noble gases in groundwater in California.

    PubMed

    Cey, Bradley D; Hudson, G Bryant; Moran, Jean E; Scanlon, Bridget R

    2008-02-15

    Dissolved noble gas concentrations in groundwater can provide valuable information on recharge temperatures and enable 3H-3He age-dating with the use of physically based interpretive models. This study presents a large (905 samples) data set of dissolved noble gas concentrations from drinking water supply wells throughout California, representing a range of physiographic, climatic, and water management conditions. Three common interpretive models (unfractionated air, UA; partial re-equilibration, PR; and closed system equilibrium, CE) produce systematically different recharge temperatures or ages; however, the ability of the different models to fit measured data within measurement uncertainty indicates that goodness-of-fit is not a robust indicator for model appropriateness. Therefore caution is necessary when interpreting model results. Samples from multiple locations contained significantly higher Ne and excess air concentrations than reported in the literature, with maximum excess air tending toward 0.05 cm3 STP g(-1) (deltaNe approximately 400%). Artificial recharge is the most plausible cause of the high excess air concentrations. The ability of artificial recharge to dissolve greater amounts of atmospheric gases has important implications for oxidation-reduction dependent chemical reactions. Measured gas concentration ratios suggest that diffusive degassing may have occurred. Understanding the physical processes controlling gas dissolution during groundwater recharge is critical for optimal management of artificial recharge and for predicting changes in water quality that can occur following artificial recharge.

  18. Daily air quality forecast (gases and aerosols) over Switzerland. Modeling tool description and first results analysis.

    NASA Astrophysics Data System (ADS)

    Couach, O.; Kirchner, F.; Porchet, P.; Balin, I.; Parlange, M.; Balin, D.

    2009-04-01

    Map3D, the acronym for "Mesoscale Air Pollution 3D modelling", was developed at the EFLUM laboratory (EPFL) and received an INNOGRANTS awards in Summer 2007 in order to move from a research phase to a professional product giving daily air quality forecast. It is intended to give an objective base for political decisions addressing the improvement of regional air quality. This tool is a permanent modelling system which provides daily forecast of the local meteorology and the air pollutant (gases and particles) concentrations. Map3D has been successfully developed and calculates each day at the EPFL site a three days air quality forecast over Europe and the Alps with 50 km and 15 km resolution, respectively (see http://map3d.epfl.ch). The Map3D user interface is a web-based application with a PostgreSQL database. It is written in object-oriented PHP5 on a MVC (Model-View-Controller) architecture. Our prediction system is operational since August 2008. A first validation of the calculations for Switzerland is performed for the period of August 2008 - January 2009 comparing the model results for O3, NO2 and particulates with the results of the Nabel measurements stations. The subject of air pollution regimes (NOX/VOC) and specific indicators application with the forecast will be also addressed.

  19. 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.

  20. A paleotemperature record derived from dissolved noble gases in groundwater of the Aquia Aquifer (Maryland, USA)

    NASA Astrophysics Data System (ADS)

    Aeschbach-Hertig, Werner; Stute, Martin; Clark, Jordan F.; Reuter, Robert F.; Schlosser, Peter

    2002-03-01

    Low 14C activities in groundwater of the confined part of the Aquia aquifer in southeastern Maryland suggest that most of this water infiltrated at least 30,000 years ago. However, radiocarbon contents of the dissolved inorganic carbon seem to be affected by isotopic exchange, possibly with secondary calcite deposits in the formation, leading to overestimated 14C ages. Whereas the geochemistry of the Aquia aquifer complicates the application of the widely used 14C dating method, the accumulation of radiogenic He seems to provide a viable alternative for establishing a chronology. The quasi-linear increase of He concentrations with flow distance observed in the Aquia aquifer can be explained entirely by accumulation of in situ produced radiogenic He. U and Th concentrations in Aquia sand were measured in order to determine the accumulation rate of 4He with sufficient confidence to establish a He time scale. Concentrations of dissolved atmospheric noble gases were used to derive mean annual ground temperatures at the time of infiltration. These noble gas temperatures (NGTs) clearly show the presence of water that infiltrated under much cooler conditions than at present. NGTs are correlated with chloride concentrations, corroborating the hypothesis that chloride variations in this aquifer constitute a climate signal. In contrast, the stable isotope ratios δ 180 and δD do not provide a clear record of past climatic changes in the Aquia aquifer and the correlation between NGTs and stable isotope ratios is weak. The NGT record suggests that mean annual temperatures in this midlatitude coastal site during the last glacial maximum (LGM) were (9.0 ± 0.6) °C colder than during the Holocene. This difference is slightly lower than estimates derived from pollen data for this region, but considerably larger than the rather uniform cooling of about 5°C indicated by noble gas studies in more southern locations of North America. The larger cooling is ascribed to the influence

  1. 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.

  2. 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.

  3. The 2011 El Hierro submarine eruption, Canary Islands: chemical and isotopic evidence in dissolved gases of seawater

    NASA Astrophysics Data System (ADS)

    Nolasco, D.; Padrón, E.; Melián, G.; Dionis, S.; Rodríguez, F.; Padilla, G.; Hernández, P. A.; Pérez, N. M.; Sumino, H.

    2012-04-01

    El Hierro is the smallest of the Canary Islands and is located in the southwest extreme of the archipelago. Since 16 July, an anomalous seismicity at El Hierro Island was recorded by IGN seismic network. After the occurrence of more than 10,000 seismic events, volcanic tremor started at 05:15 on October 10, 2011, followed by a green discolouration of seawater and strong degassing on October 12, 2011, indicating the occurrence of a submarine eruption at the south of El Hierro island. Further episodes of volcanic activity had occurred during November, December 2011 and January 2012, with turbulent water, foam rings, and volcanic material again reaching the sea surface. Colour of the discoloured area has changed frequently from light green to dark brown, depending on the eruptive activity. To provide additional information about the 2011 El Hierro submarine eruption, a chemical and isotopic study of the dissolved gases in the seawater affected by the eruptive event was conducted one week after the eruption started. Sea water samples were collected by the Ignacio Lozano Oceanographic Research Vessel (ICCM). Three vertical geochemical profiles of dissolved gases were carried out near the location of the submarine eruption. Depths of the sea water samples ranged from 10 to 400 meters. Dissolved CO2, He, N2, O2 and Ar as well as the isotopic composition of CO2, Ar and He were analyzed. Relatively high 3He/4He ratio were observed at most of the sea water samples reaching values up to 5.8 RA (RA the 3He/4He ratio on air) at 100 meters depth of the geochemical vertical profile closest to the eruption site, suggesting a significant volcanic-magmatic-hydrothermal discharge through the submarine eruption vent. Other dissolved gas geochemical parameters such as N2/36Ar, N2/O2 and CO2/O2 ratios clearly suggest a strong presence of a submarine volcanic plume around 100 meters depth associated to this submarine eruption. The He and CO2 isotopes systematics confirmed also clearly a

  4. 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

  5. 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.

  6. 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.

  7. Effect of dissolved gases in water on acoustic cavitation and bubble growth rate in 0.83 MHz megasonic of interest to wafer cleaning.

    PubMed

    Kang, Bong-Kyun; Kim, Min-Su; Park, Jin-Goo

    2014-07-01

    Changes in the cavitation intensity of gases dissolved in water, including H2, N2, and Ar, have been established in studies of acoustic bubble growth rates under ultrasonic fields. Variations in the acoustic properties of dissolved gases in water affect the cavitation intensity at a high frequency (0.83 MHz) due to changes in the rectified diffusion and bubble coalescence rate. It has been proposed that acoustic bubble growth rates rapidly increase when water contains a gas, such as hydrogen faster single bubble growth due to rectified diffusion, and a higher rate of coalescence under Bjerknes forces. The change of acoustic bubble growth rate in rectified diffusion has an effect on the damping constant and diffusivity of gas at the acoustic bubble and liquid interface. It has been suggested that the coalescence reaction of bubbles under Bjerknes forces is a reaction determined by the compressibility and density of dissolved gas in water associated with sound velocity and density in acoustic bubbles. High acoustic bubble growth rates also contribute to enhanced cavitation effects in terms of dissolved gas in water. On the other hand, when Ar gas dissolves into water under ultrasound field, cavitation behavior was reduced remarkably due to its lower acoustic bubble growth rate. It is shown that change of cavitation intensity in various dissolved gases were verified through cleaning experiments in the single type of cleaning tool such as particle removal and pattern damage based on numerically calculated acoustic bubble growth rates.

  8. Dissolved gases in perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica

    NASA Technical Reports Server (NTRS)

    Andersen, D. T.; McKay, C. P.; Wharton, R. A. Jr; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Measurements of dissolved N2, O2, Ar, CO2, and CH4 were made in perennially ice-covered Lake Hoare. Results confirm previous reports that O2 concentrations in the upper water column exceed atmospheric equilibrium and that N2 and Ar are supersaturated throughout the water column. The mean supersaturation of N2 was found to be 2.0 (+/- 0.37) and Ar was 3.8 (+/- 1.1). The ratios of N2/Ar (20.3 +/- 13.8), and O2/Ar (22.5 +/- 4.0) at the ice-water interface are consistent with those previously measured, suggesting that bubble formation is the main process for removing gas from the lake. However, the saturations of N2 and Ar greatly exceed those previously predicted for degassing by bubble formation only at the ice-water interface. The data support the hypothesis that removal of gas by bubbles occurs in the water column to a depth of 11 m in Lake Hoare. CO2 concentration increases from near zero at the ice-water interface to 80-100 times saturation at and below the chemocline at c. 28 m. There is considerable variability in the gas concentrations throughout the water column; samples separated in depth by one metre may vary by more than 50% in gas content. It is likely that this phenomenon results from the lack of turbulent mixing in the water column. Methane (c. 2 micrograms l-1) was detected below the chemocline and immediately above the sediment/water interface at a depth of 30 m. Samples from lakes Vanda, Joyce, and Miers, also show supersaturations of O2, N2, and Ar at levels similar to levels found in Lake Hoare.

  9. Dissolved gases in perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica.

    PubMed

    Andersen, D T; McKay, C P; Wharton, R A

    1998-06-01

    Measurements of dissolved N2, O2, Ar, CO2, and CH4 were made in perennially ice-covered Lake Hoare. Results confirm previous reports that O2 concentrations in the upper water column exceed atmospheric equilibrium and that N2 and Ar are supersaturated throughout the water column. The mean supersaturation of N2 was found to be 2.0 (+/- 0.37) and Ar was 3.8 (+/- 1.1). The ratios of N2/Ar (20.3 +/- 13.8), and O2/Ar (22.5 +/- 4.0) at the ice-water interface are consistent with those previously measured, suggesting that bubble formation is the main process for removing gas from the lake. However, the saturations of N2 and Ar greatly exceed those previously predicted for degassing by bubble formation only at the ice-water interface. The data support the hypothesis that removal of gas by bubbles occurs in the water column to a depth of 11 m in Lake Hoare. CO2 concentration increases from near zero at the ice-water interface to 80-100 times saturation at and below the chemocline at c. 28 m. There is considerable variability in the gas concentrations throughout the water column; samples separated in depth by one metre may vary by more than 50% in gas content. It is likely that this phenomenon results from the lack of turbulent mixing in the water column. Methane (c. 2 micrograms l-1) was detected below the chemocline and immediately above the sediment/water interface at a depth of 30 m. Samples from lakes Vanda, Joyce, and Miers, also show supersaturations of O2, N2, and Ar at levels similar to levels found in Lake Hoare. PMID:11541288

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    USGS Publications Warehouse

    Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

    2014-01-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  16. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    NASA Astrophysics Data System (ADS)

    Porubsky, W. P.; Weston, N. B.; Moore, W. S.; Ruppel, C.; Joye, S. B.

    2014-04-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  17. 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

  18. 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.

  19. Calibration of membrane inlet mass spectrometric measurements of dissolved gases: differences in the responses of polymer and nano-composite membranes to variations in ionic strength.

    PubMed

    Miranda, L D; Byrne, R H; Short, R T; Bell, R J

    2013-11-15

    This work examines the transmission behavior of aqueous dissolved methane, nitrogen, argon and carbon dioxide through two types of membranes: a polysiloxane nano-composite (PNC) membrane and a conventional polydimethylsiloxane (PDMS) membrane. Transmission properties at 30 °C were examined by membrane introduction mass spectrometry (MIMS) at nearly constant gas partial pressures in NaCl solutions over a range of ionic strength (0-1 molal). Gas flow rates were examined as a function of dissolved gas concentrations using the Setschenow equation. Although MIMS measurements with PDMS and PNC membranes produced signal responses that were directly proportional to aqueous dissolved gas concentrations, the proportionalities varied with ionic strength and were distinctly different for the two types of membranes. With the exception of carbon dioxide, the PNC membrane had membrane salting coefficients quite similar to Setschenow coefficients reported for gases in aqueous solution. In contrast, the PDMS membrane had membrane salting coefficients that were generally smaller than the corresponding Setschenow gas coefficient for each gas. Differences between Setschenow coefficients and membrane salting coefficients lead to MIMS calibrations (gas-flow vs. gas-concentration proportionalities) that vary with ionic strength. Accordingly, gas-flow vs. gas-concentration relationships for MIMS measurements with PDMS membranes are significantly dependent on ionic strength. In contrast, for PNC membranes, flow vs. concentration relationships are independent (argon, methane, nitrogen) or weakly dependent (CO2) on ionic strength. Comparisons of gas Setschenow and membrane salting coefficients can be used to quantitatively describe the dependence of membrane gas-flow on gas-concentrations and ionic strength for both PDMS and PNC membranes.

  20. 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.

  1. Using dissolved gases to observe the evolution of groundwater age in a mountain watershed over a period of thirteen years

    USGS Publications Warehouse

    Manning, Andrew H.

    2011-01-01

    Baseflows in snowmelt-dominated mountain streams are critical for sustaining ecosystems and water resources during periods of greatest demand. Future climate predictions for mountainous areas throughout much of the western U.S. include increasing temperatures, declining snowpacks, and earlier snowmelt periods. The degree to and rate at which these changes will affect baseflows in mountain streams remains unknown, largely because baseflows are groundwater-fed and the relationship between climate and groundwater recharge/discharge rates in mountain watersheds is uncertain. We use groundwater age determinations from multiple dissolved gas tracers (CFCs, SF6, and 3H/3He) to track changes in groundwater age over a period of thirteen years in the Sagehen Creek watershed, Sierra Nevada Mountains, CA. Data were collected from springs and wells in 2009 and 2010 and combined with those obtained in prior studies from 1997 to 2003. Apparent ages range from 0 to >60 years. Comparison between variations in age and variations in snow water equivalent (SWE) and mean annual air temperature reveals the degree of correlation between these climate variables and recharge rate. Further, comparison of apparent ages from individual springs obtained at different times and using different tracers helps constrain the age distribution in the sampled waters. The age data are generally more consistent with an exponential age distribution than with piston-flow. However, many samples, even those with relatively old mean ages, must have a disproportionately large very young fraction that responds directly to annual SWE variations. These findings have important implications for how future baseflows may respond to decreasing SWE.

  2. 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.

  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 - 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.

  4. Geologic and geochemical systematics of the occurrence of nonhydrocarbon gases: Towards working models to forecast CO{sub 2}, H{sub 2}S and N{sub 2} in natural gas

    SciTech Connect

    Imbus, S.W.; Bissada, K.K.; Urwongse, T.

    1995-12-31

    Despite recent progress towards understanding the mechanisms responsible for generation of many of the naturally occurring non-hydrocarbon gases, no globally applicable set of geologic or geochemical criteria has been developed to elucidate their origin or forecast their abundance in natural gas systems. The present study attempts to identify empirical relationships between the occurrence of these non-hydrocarbon gases and specific geological conditions including tectonic/structural setting; prevalent lithostratigraphy: present and paleo-geothermal and hydrothermal conditions; source rock type and thermal maturity; reservoir lithology and temperature; etc. The use of geochemical data (molecular and isotopic compositions) to assess the relative importance of the diverse controls (in terms of {open_quotes}basin{close_quotes} vs. {open_quotes}reservoir{close_quotes}, organic vs. inorganic, chemical vs. physicochemical factors) will also be examined in the context of the observations. The incorporation of more detailed geologic observations into this basic framework should provide the basis for working-out the geologic/geochemical systematics. This is a most critical step in developing the ultimate forecasting model.

  5. 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

  6. 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.

  7. Electronegative gases

    SciTech Connect

    Christophorou, L.G.

    1981-01-01

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

  8. 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)

  9. 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 ...

  10. 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

  11. New perspectives for noble gases in oceanography

    NASA Astrophysics Data System (ADS)

    Aeschbach, Werner

    2016-08-01

    Conditions prevailing in regions of deep water formation imprint their signature in the concentrations of dissolved noble gases, which are conserved in the deep ocean. Such "recharge conditions" including temperature, salinity, and interactions with sea ice are important in view of ocean-atmosphere CO2 partitioning. Noble gases, especially the temperature sensitive Kr and Xe, are well-established tracers to reconstruct groundwater recharge conditions. In contrast, tracer oceanography has traditionally focused on He isotopes and the light noble gases Ne and Ar, which could be analyzed at the required high precision. Recent developments of analytical and data interpretation methods now provide fresh perspectives for noble gases in oceanography.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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…

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Dissolved gas concentrations of the geothermal fluids in Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Ai-Ti; Yang, Tsanyao Frank

    2010-05-01

    Taiwan, a geologically active island, is located on the boundary of the Philippine Sea Plate and the Eurasian Plate. High heat flow and geothermal gradient generated by the complex collision and orogeny, warm up the meteoric water and/or the ground water. The heated water becomes geothermal fluids. In previous studies, researchers tried to categorize hot springs based on the appearance, chemical compositions and lithological areas. Because of the chemical inertness, the concentrations and isotopic composition of dissolved noble gases are good indicators of the mantle degassing, geothermal conditions, and so on. In this study, 55 hot springs were collected from different tectonic units. It is the first time to systematically study the hot springs in Taiwan in terms of dissolved gases. Hot spring water is sampled and stored in pre-evacuated glass bottles for analyzing gas compositions. The abundances of noble gases were determined by a quadrupole mass spectrometer based on the isotope dilution technique. Samples with glass vials are introduced to RAD 7 and GC for dissolved Rn and major dissolved gases analyses. Furthermore, helium isotopic ratios and helium-neon ratios are measured on a conventional noble gas mass spectrometer. For hydrochemistry analysis, water samples are analyzed by IC, ICP-MS and titration. We can classify the hot springs samples into three major groups from main anion concentration data; and then, subdivide them into nine minor groups by cation concentration data. Moreover, according to major dissolved gases compositions, three major gas components: CH4, N2 and CO2, are identified. Dissolved noble gases provided more detailed clues about hot springs sources in Taiwan, such as the degree of mixing between meteoric water and deep-source water, which will be further discussed in this study.

  5. 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.

  6. 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.

  7. Modeling dissolved and free phase gas dynamics under decompression.

    PubMed

    Wienke, B R

    1990-04-01

    Dissolved and free gases do not behave the same way in tissue under pressure, and their interaction is complex. Differences are highlighted, particularly with respect to time scales, gradients and transport. Impacts of free phases on diving are described, contrasting increased off-gassing pressures, slower ascent rates, safety stops and reduced repetitive exposures as consistent practical measures within Haldane models (limited supersaturation) which can be played off against buildup of dissolved gas. Simple computations illustrate the points.

  8. Trends in source gases

    NASA Technical Reports Server (NTRS)

    Ehhalt, D. H.; Fraser, P. J.; Albritton, D.; Cicerone, R. J.; Khalil, M. A. K.; Legrand, M.; Makide, Y.; Rowland, F. S.; Steele, L. P.; Zander, R.

    1989-01-01

    Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form.

  9. 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.

  10. An advanced passive diffusion sampler for the determination of dissolved gas concentrations

    NASA Astrophysics Data System (ADS)

    Gardner, P.; Solomon, D. K.

    2009-06-01

    We have designed and tested a passive headspace sampler for the collection of noble gases that allows for the precise calculation of dissolved gas concentrations from measured gas mixing ratios. Gas permeable silicon tubing allows for gas exchange between the headspace in the sampler volume and the dissolved gases in the adjacent water. After reaching equilibrium, the aqueous-phase concentration is related to the headspace concentration by Henry's law. Gas exchange between the water and headspace can be shut off in situ, preserving the total dissolved gas pressure upon retrieval. Gas samples are then sealed in an all metal container, retaining even highly mobile helium. Dissolved noble gas concentrations measured in these diffusion samplers are in good agreement with traditional copper tube aqueous-phase samples. These significantly reduce the laboratory labor in extracting the gases from a water sample and provide a simple and robust method for collecting dissolved gas concentrations in a variety of aqueous environments.

  11. 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.

  12. 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.

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

    PubMed

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

    1998-03-01

    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.

  14. 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.

  15. 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.

  16. 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

  17. Load forecasting by ANN

    SciTech Connect

    Highley, D.D.; Hilmes, T.J. )

    1993-07-01

    This article discusses the use and training of artificial neural networks (ANNs) for load forecasting. The topics of the article include a brief overview of neural networks, interest in ANNs, training of neural networks, a case study in load forecasting, and the potential for using an artificial neural network to perform short-term load forecasting.

  18. 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.

  19. Strongly correlated Bose gases

    NASA Astrophysics Data System (ADS)

    Chevy, F.; Salomon, C.

    2016-10-01

    The strongly interacting Bose gas is one of the most fundamental paradigms of quantum many-body physics and the subject of many experimental and theoretical investigations. We review recent progress on strongly correlated Bose gases, starting with a description of beyond mean-field corrections. We show that the Efimov effect leads to non universal phenomena and to a metastability of the low temperature Bose gas through three-body recombination to deeply bound molecular states. We outline differences and similarities with ultracold Fermi gases, discuss recent experiments on the unitary Bose gas, and finally present a few perspectives for future research.

  20. 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.

  1. Noxious gases in greenhouses.

    PubMed

    Likas, C; Exarchou, V; Gourgoulianis, K; Giaglaras, P; Gemptos, T; Kittas, K; Molyvdas, P A

    2001-01-01

    The concentration of NO(2) and SO(2) was measured in a commercial greenhouse from 23/9/1999 25/01/2000. The measurements showed that the level of the two gases is very high in the greenhouse atmosphere. Lung function tests in 42 workers showed that temporary work did not influence significantly the respiratory health status. PMID:11426932

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Advanced chaos forecasting

    NASA Astrophysics Data System (ADS)

    Doerner, R.; Hübinger, B.; Martienssen, W.

    1994-07-01

    The exponential separation of initially adjacent trajectories restricts the predictability of deterministic chaotic motions. The predictability depends on the initial state from where the trajectory starts that shall be forecasted. By calculating the predictability simultaneously with the forecast, we are able to reject forecasts with low reliability immediately, thereby decreasing drastically the average forecast error. We test this scheme experimentally on Chua's circuit [Komuro, Tokunaga, Matsumoto, Chua, and Hotta, Int. J. Bifurc. Chaos 1, 139 (1991)], basing all calculations only on a time series of a single scalar variable.

  8. Kinetic Theory of Gases

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The theory, developed in the nineteenth century, notably by Rudolf Clausius (1822-88) and James Clerk Maxwell (1831-79), that the properties of a gas (temperature, pressure, etc) could be described in terms of the motions (and kinetic energy) of the molecules comprising the gases. The theory has wide implications in astrophysics. In particular, the perfect gas law, which relates the pressure, vol...

  9. Toxic gases from fires.

    PubMed

    Terrill, J B; Montgomery, R R; Reinhardt, C F

    1978-06-23

    The major lethal factors in uncontrolled fires are toxic gases, heat, and oxygen deficiency. The predominant toxic gas is carbon monoxide, which is readily generated from the combusion of wood and other cellulosic materials. Increasing use of a variety of synthetic polymers has stimulated interest in screening tests to evaluated the toxicity of polymeric materials when thermally decomposed. As yet, this country lacks a standardized fire toxicity test protocol. PMID:208143

  10. 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.

  11. 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

  12. Consumption trend analysis in the industrial sector: Existing forecasts

    NASA Astrophysics Data System (ADS)

    1981-08-01

    The Gas Research Institute (GRI) is engaged in medium- to long-range research and development in various sectors of the economy that depend on gasing technologies and equipment. To assess the potential demand for natural gas in the industrial sector, forecasts available from private and public sources were compared and analyzed. More than 20 projections were examined, and 10 of the most appropriate long-range demand forecasts were analyzed and compared with respect to the various assumptions, methodologies and criteria on which each was based.

  13. Dynamics of dissolved gas in a cavitating fluid

    NASA Astrophysics Data System (ADS)

    Mastikhin, Igor V.; Newling, Benedict

    2008-12-01

    A strong acoustic field in a liquid separates the liquid and dissolved gases by the formation of bubbles (cavitation). Bubble growth and collapse is the result of active exchange of gas and vapor through the bubble walls with the surrounding liquid. This paper details a new approach to the study of cavitation, not as an evolution of discrete bubbles, but as the dynamics of molecules constituting both the bubbles and the fluid. We show, by direct, independent measurement of the liquid and the dissolved gas, that the motions of dissolved gas (freon-22, CHClF2 ) and liquid (water) can be quite different during acoustic cavitation and are strongly affected by filtration or previous cavitation of the solvent. Our observations suggest that bubbles can completely refresh their content within two acoustic cycles and that long-lived (˜minutes) microbubbles act as nucleation sites for cavitation. This technique is complementary to the traditional optical and acoustical techniques.

  14. 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).

  15. [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

  16. 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.

  17. 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.

  18. Probabilistic river forecast methodology

    NASA Astrophysics Data System (ADS)

    Kelly, Karen Suzanne

    1997-09-01

    The National Weather Service (NWS) operates deterministic conceptual models to predict the hydrologic response of a river basin to precipitation. The output from these models are forecasted hydrographs (time series of the future river stage) at certain locations along a river. In order for the forecasts to be useful for optimal decision making, the uncertainty associated with them must be quantified. A methodology is developed for this purpose that (i) can be implemented with any deterministic hydrologic model, (ii) receives a probabilistic forecast of precipitation as input, (iii) quantifies all sources of uncertainty, (iv) operates in real-time and within computing constraints, and (v) produces probability distributions of future river stages. The Bayesian theory which supports the methodology involves transformation of a distribution of future precipitation into one of future river stage, and statistical characterization of the uncertainty in the hydrologic model. This is accomplished by decomposing total uncertainty into that associated with future precipitation and that associated with the hydrologic transformations. These are processed independently and then integrated into a predictive distribution which constitutes a probabilistic river stage forecast. A variety of models are presented for implementation of the methodology. In the most general model, a probability of exceedance associated with a given future hydrograph specified. In the simplest model, a probability of exceedance associated with a given future river stage is specified. In conjunction with the Ohio River Forecast Center of the NWS, the simplest model is used to demonstrate the feasibility of producing probabilistic river stage forecasts for a river basin located in headwaters. Previous efforts to quantify uncertainty in river forecasting have only considered selected sources of uncertainty, been specific to a particular hydrologic model, or have not obtained an entire probability

  19. Quantitation of dissolved gas content in emulsions and in blood using mass spectrometric detection.

    PubMed

    Grimley, Everett; Turner, Nicole; Newell, Clayton; Simpkins, Cuthbert; Rodriguez, Juan

    2011-06-01

    Quantitation of dissolved gases in blood or in other biological media is essential for understanding the dynamics of metabolic processes. Current detection techniques, while enabling rapid and convenient assessment of dissolved gases, provide only direct information on the partial pressure of gases dissolved in the aqueous fraction of the fluid. The more relevant quantity known as gas content, which refers to the total amount of the gas in all fractions of the sample, can be inferred from those partial pressures, but only indirectly through mathematical modeling. Here we describe a simple mass spectrometric technique for rapid and direct quantitation of gas content for a wide range of gases. The technique is based on a mass spectrometer detector that continuously monitors gases that are rapidly extracted from samples injected into a purge vessel. The accuracy and sample processing speed of the system is demonstrated with experiments that reproduce within minutes literature values for the solubility of various gases in water. The capability of the technique is further demonstrated through accurate determination of O(2) content in a lipid emulsion and in whole blood, using as little as 20 μL of sample. The approach to gas content quantitation described here should greatly expand the range of animals and conditions that may be used in studies of metabolic gas exchange, and facilitate the development of artificial oxygen carriers and resuscitation fluids.

  20. Trapped noble gases in meteorites

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.

    1988-01-01

    The trapped noble gases in meteorites come in two main varieties, usually referred to as solar and planetary. The solar noble gases are implanted solar-wind or solar-flare materials, and thus their relative elemental abundances provide a good estimate of those of the sun. The planetary noble gases have relative elemental abundances similar to those in the terrestrial atmosphere, but there are also important distinctions. At least one other elemental pattern (subsolar) and several isotopic patterns have also been identified.

  1. 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.

  2. Phase transitions in real gases and ideal Bose gases

    NASA Astrophysics Data System (ADS)

    Maslov, V. P.

    2011-05-01

    Based on number theory, we present a new concept of gas without the particle interaction taken into account in which there are first-order phase transitions for T < T cr on isotherms. We present formulas for new ideal gases, solving the Gibbs paradox, and also formulas for the transition to real gases based on the concept of the Zeno line.

  3. 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.

  4. 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

  5. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Analytical gases. 89.312 Section 89.312....312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration date of the calibration gases stated by the gas manufacturer shall be recorded. (b) Pure gases....

  6. 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.

  7. 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.

  8. 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.

  9. US industrial battery forecast

    SciTech Connect

    Hollingsworth, V. III

    1996-09-01

    Last year was strong year for the US industrial battery market with growth in all segments. Sales of industrial batteries in North America grew 19.2% in 1995, exceeding last year`s forecasted growth rate of 11.6%. The results of the recently completed BCI Membership Survey forecast 1996 sales to be up 10.5%, and to continue to increase at a 10.4% compound annual rate through the year 2000. This year`s survey includes further detail on the stationary battery market with the inclusion of less than 25 Ampere-Hour batteries for the first time.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. 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…

  15. Education Planning: Pupil Forecasting.

    ERIC Educational Resources Information Center

    Royal Inst. of Public Administration, Reading (England). Local Government Operational Research Unit.

    This computer-based system of enrollment projection predicts up to seven years ahead the number of school children of each age and sex who will be in school. The main distinguishing feature of the system is the ability to detect well in advance small changes in the geographical distribution of children. Forecasts are made for zones that will yield…

  16. 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…

  17. 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…

  18. Evolving forecasting classifications and applications in health forecasting

    PubMed Central

    Soyiri, Ireneous N; Reidpath, Daniel D

    2012-01-01

    Health forecasting forewarns the health community about future health situations and disease episodes so that health systems can better allocate resources and manage demand. The tools used for developing and measuring the accuracy and validity of health forecasts commonly are not defined although they are usually adapted forms of statistical procedures. This review identifies previous typologies used in classifying the forecasting methods commonly used in forecasting health conditions or situations. It then discusses the strengths and weaknesses of these methods and presents the choices available for measuring the accuracy of health-forecasting models, including a note on the discrepancies in the modes of validation. PMID:22615533

  19. 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.

  20. 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.

  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. 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)

  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. 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.

  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.

  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. 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.

  8. 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

  9. Technology 2005 : Reviews & Forecasts

    NASA Astrophysics Data System (ADS)

    Kimura, Ken

    Nine Technical Committees (TC's) of the Fundamentals and Materials Society of IEE Japan have contributed their Review & Forecast articles to the present. Special Issue of the IEEJ Transaction on Fundamentals and Materials. So you can survey the state-of-the-art of the 9 different technical fields with these articles. The series of reviews were submitted in reply to the request by experts in the respective fields.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 40 CFR 89.312 - 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. 89.312 Section 89... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration date of the calibration gases stated by the gas manufacturer shall be recorded. (b) Pure...

  15. 40 CFR 91.312 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Analytical gases. 91.312 Section 91... Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. Record the expiration date stated by the gas supplier for each calibration gas. (b) Pure gases. The required purity of the gases...

  16. 40 CFR 91.312 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Analytical gases. 91.312 Section 91... Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. Record the expiration date stated by the gas supplier for each calibration gas. (b) Pure gases. The required purity of the gases...

  17. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Analytical gases. 1065.750 Section... ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.750 Analytical gases. Analytical gases must meet the accuracy and purity specifications of...

  18. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Analytical gases. 1065.750 Section... ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.750 Analytical gases. Analytical gases must meet the accuracy and purity specifications of...

  19. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Analytical gases. 1065.750 Section... ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.750 Analytical gases. Analytical gases must meet the accuracy and purity specifications of...

  20. 40 CFR 89.312 - 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. 89.312 Section 89... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration date of the calibration gases stated by the gas manufacturer shall be recorded. (b) Pure...

  1. 40 CFR 91.312 - 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. 91.312 Section 91... Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. Record the expiration date stated by the gas supplier for each calibration gas. (b) Pure gases. The required purity of the gases...

  2. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Analytical gases. 89.312 Section 89... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration date of the calibration gases stated by the gas manufacturer shall be recorded. (b) Pure...

  3. 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... Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. Record the expiration date stated by the gas supplier for each calibration gas. (b) Pure gases. The required purity of the gases...

  4. 40 CFR 92.112 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Analytical gases. 92.112 Section 92.112... POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.112 Analytical gases. (a) Gases for... as the diluent. (b) Gases for the hydrocarbon analyzer shall be single blends of propane using...

  5. 40 CFR 89.312 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Analytical gases. 89.312 Section 89... Provisions § 89.312 Analytical gases. (a) The shelf life of all calibration gases must not be exceeded. The expiration date of the calibration gases stated by the gas manufacturer shall be recorded. (b) Pure...

  6. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Analytical gases. 1065.750 Section... ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.750 Analytical gases. Analytical gases must meet the accuracy and purity specifications of...

  7. 40 CFR 90.312 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Analytical gases. 90.312 Section 90.312... § 90.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. The expiration date stated by the gas supplier must be recorded. (b) Pure gases. The required purity of the gases...

  8. 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

  9. 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.

  10. 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.

  11. Evaluation of headspace equilibration methods for quantifying greenhouse gases in groundwater.

    PubMed

    Jahangir, M M R; Johnston, P; Khalil, M I; Grant, J; Somers, C; Richards, K G

    2012-11-30

    The objective of the study was to evaluate the different headspace equilibration methods for the quantification of dissolved greenhouse gases in groundwater. Groundwater samples were collected from wells with contrasting hydrogeochemical properties and degassed using the headspace equilibration method. One hundred samples from each well were randomly selected, treatments were applied and headspace gases analysed by gas chromatography. Headspace equilibration treatments varied helium (He):water ratio, shaking time and standing time. Mean groundwater N(2)O, CO(2) and CH(4) concentrations were 0.024 mg N L(-1), 13.71 mg C L(-1) and 1.63 μg C L(-1), respectively. All treatments were found to significantly influence dissolved gas concentrations. Considerable differences in the optimal He:water ratio and standing time were observed between the three gases. For N(2)O, CO(2) and CH(4) the optimum operating points for He:water ratio was 4.4:1, 3:1 and 3.4:1; shaking time was 13, 12 and 13 min; and standing time was 63, 17 and 108 min, respectively. The headspace equilibration method needs to be harmonised to ensure comparability between studies. The experiment reveals that He:water ratio 3:1 and shaking time 13 min give better estimation of dissolved gases than any lower or higher ratios and shaking times. The standing time 63, 17 and 108 min should be applied for N(2)O, CO(2) and CH(4), respectively.

  12. 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.

  13. 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

  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. 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.

  16. Measuring and understanding total dissolved gas pressure in groundwater

    NASA Astrophysics Data System (ADS)

    Ryan, C.; Roy, J. W.; Randell, J.; Castellon, L.

    2009-05-01

    Since dissolved gases are important to a number of aspects of groundwater (e.g. age dating, active or passive bioremediation, greenhouse gas fluxes, understanding biogeochemical processes involving gases, assessing potential impacts of coal bed methane activities), accurate concentration measurements, and understanding of their subsurface behaviour are important. Researchers have recently begun using total dissolved gas pressure (TGP) sensor measurements, more commonly applied for surface water monitoring, in concert with gas composition analyses to estimate more accurate groundwater gas concentrations in wells. We have used hydraulic packers to isolate the well screens where TDP is being measured, and pump tests to indicate that in-well degassing may reduce TDG below background groundwater levels. Thus, in gas-charged groundwater zones, TGPs can be considerably underestimated in the absence of pumping or screen isolation. We have also observed transient decreased TGPs during pumping that are thought to result from ebullition induced when the water table or water level in the well is lowered below a critical hydrostatic pressure.

  17. 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.

  18. Forecasting droughts in East Africa

    NASA Astrophysics Data System (ADS)

    Mwangi, E.; Wetterhall, F.; Dutra, E.; Di Giuseppe, F.; Pappenberger, F.

    2014-02-01

    The humanitarian crises caused by the recent droughts (2008-2009 and 2010-2011) in East Africa have illustrated that the ability to make accurate drought forecasts with sufficient lead time is essential. The use of dynamical model precipitation forecasts in combination with drought indices, such as the Standardized Precipitation Index (SPI), can potentially lead to a better description of drought duration, magnitude and spatial extent. This study evaluates the use of the European Centre for Medium-Range Weather Forecasts (ECMWF) products in forecasting droughts in East Africa. ECMWF seasonal precipitation shows significant skill for March-May and October-December rain seasons when evaluated against measurements from the available in situ stations from East Africa. The forecast for October-December rain season has higher skill than for the March-May season. ECMWF forecasts add value to the consensus forecasts produced during the Greater Horn of Africa Climate Outlook Forum (GHACOF), which is the present operational product for precipitation forecast over East Africa. Complementing the original ECMWF precipitation forecasts with SPI provides additional information on the spatial extent and intensity of the drought event.

  19. Hydrologic Forecasting and Hydropower Production

    NASA Astrophysics Data System (ADS)

    Wigmosta, M. S.; Voisin, N.; Lettenmaier, D. P.; Coleman, A.; Mishra, V.; Schaner, N. A.

    2011-12-01

    Hydroelectric power production is one of many competing demands for available water along with other priority uses such as irrigation, thermoelectric cooling, municipal, recreation, and environmental performance. Increasingly, hydroelectric generation is being used to offset the intermittent nature of some renewable energy sources such as wind-generated power. An accurate forecast of the magnitude and timing of water supply assists managers in integrated planning and operations to balance competing water uses against current and future supply while protecting against the possibility of water or energy shortages and excesses with real-time actions. We present a medium-range to seasonal ensemble streamflow forecasting system where uncertainty in forecasts is addressed explicitly. The integrated forecast system makes use of remotely-sensed data and automated spatial and temporal data assimilation. Remotely-sensed snow cover, observed snow water equivalent, and observed streamflow data are used to update the hydrologic model state prior to the forecast. In forecast mode, the hydrology model is forced by calibrated ensemble weather/climate forecasts. This system will be fully integrated into a water optimization toolset to inform reservoir and power operations, and guide environmental performance decision making. This flow forecast system development is carried out in agreement with the National Weather Service so that the system can later be incorporated into the NOAA eXperimental Ensemble Forecast Service (XEFS).

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. New frontiers with ultracold gases

    SciTech Connect

    Ketterle, Wolfgang

    2005-05-05

    This article summarizes recent work at MIT, which was presented at ICAP 2004. These examples demonstrate the broad range of topics, which are covered by research on quantum-degenerate gases: boson and fermion mixtures, cold molecules, vortices, and interactions with surfaces.

  6. Flexible hose for liquefied gases

    SciTech Connect

    Mead, H.B.

    1984-05-01

    Flexible hose for liquefied gases, comprising a tubular body of biaxially oriented polypropylene film (2) arranged between an inner helically wound wire (3) and an outer helically wound wire (4), said wires being wound at the same pitch but having the windings displaced by half a pitch width from each other.

  7. 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.

  8. 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

  9. 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.

  10. 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`

  11. 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

  12. 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.

  13. 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

  14. On the siting of noble gases in E-chondrites

    NASA Technical Reports Server (NTRS)

    Crabb, J.; Anders, E.

    1982-01-01

    Fractions of six E-chondrites were separated by density, grain size, and chemical resistance to determine the siting of noble gases. The samples were taken from the Qingzhen (E3), Indarch (E4), Abee and Saint Saveur (E4-5), and Yilmia and North West Forrest (E6) meteorites. The Ar-rich component of the E6s was concentrated in the enstatite-rich fraction. This subsolar component was resistant to HCl and HNO3 treatment, but could be partially dissolved by HF, implying that the subsolar component is located in the enstatite. The noble gases were transported there by metamorphism. Xe-129 was found in the same regions in the E6s, but was in areas associated with chondrules in the E4s. Additionally, the carbon-rich fraction of the E4 sample displayed Xe and Ne/CCF-Xe isotopic ratios similar to that found in C-chondrites. E3 and E4 primordial gases were analogous, with no subsolar contribution.

  15. 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.

  16. Measurement of Relative Dissolved Gas Concentrations Using Underwater Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bell, R. J.; Toler, S.; van Amerom, F. H.; Wenner, P.; Hall, M.; Edkins, J.; Gassig, S.; Short, R.; Byrne, R.

    2004-12-01

    The deployment of underwater mass spectrometer (UMS) systems in marine and lacustrine environments has provided chemical data of exceptional temporal and spatial resolution. UMS instruments operate moored, tethered, remotely, or autonomously, allowing users to customize deployments to suit a wide variety of situations. The ability to collect and analyze real-time data enables prompt, intelligent sampling decisions based on observed analyte distributions. UMS systems can simultaneously detect a wide variety of analytes generated by biological, chemical, physical, geothermal and anthropogenic activities. A polydimethylsiloxane (PDMS) membrane separates the sample-stream from the spectrometer's vacuum chamber. This membrane is selective against water and charged species, yet highly permeable to volatile organic compounds (VOC) and simple gases. Current detection limits for dissolved gases and VOCs are on the order of ppm and ppb respectively. Semi-quantitative proof-of-concept applications have included horizontal mapping of gas gradients, characterization of geothermal vent water, and observation of dissolved gas profiles. Horizontal gradients in dissolved gas concentrations were determined in Lake Maggiore, St Petersburg, Florida. The UMS was positioned on a remotely-guided surface vehicle, and real-time gas concentration data were transmitted to shore via wireless ethernet. Real-time observations allowed intensive sampling of areas with strong gas gradients. Oxygen and CO2 exhibited patchy distributions and their concentrations varied inversely, presumably in response to biological activity. The UMS signal for methane depended on the instrument's proximity to organic rich sediments. Geothermal vent water was characterized while the UMS was deployed in Yellowstone Lake, Wyoming, on a tethered Eastern Oceanics remotely operated vehicle (ROV). Observations of dissolved vent-gas compositions were obtained to depths of 30m. Distinct differences in dissolved vent

  17. 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).

  18. 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)

  19. 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.

  20. 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.

  1. 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

  2. Solar Noble Gases from ACFER 111 Metal Etched in Vacuo

    NASA Astrophysics Data System (ADS)

    Pedroni, A.; Begemann, F.

    1992-07-01

    Regolith grains dissolved by stepwise etching release a mixture of near-surface implanted Solar Wind gases (SW) and a deeper- sited, isotopically heavier component attributed to Solar Energetic Particles (SEP) (1,2,3). In all regolith materials examined so far the elemental abundance ratios in both components are distinctly different from the canonical solar values (4). The differences are generally explained to be owing to diffusive elemental fractionation although there is no strong evidence that upon their implantation the composition of the gases was indeed solar. In contrast, the solar noble gases present in the H3-H6 chondritic regolith breccia Acfer 111 appear to be nearly unfractionated and thus offer a unique chance for more accurate analyses. A magnetic fraction of Acfer 111 matrix, consisting of approx. 80% metal and 20% silicates, was etched with a 60 g/mol aqueous solution of HNO3 in a high-vacuum extraction line similar to that in (1). The gases released were drawn off in steps and analyzed; the experiment was stopped when ~97% of the metal and ~50% of the silicates were dissolved. As etching proceeds, the isotopic composition of the released gases changes in a pattern similar to that observed previously in other regolithic materials. The isotopic composition of solar neon decreases from ^20Ne/^22Ne=13.1 in the first step to ^20Ne/^22Ne=11.6, which can be interpreted as a change of the mixing ratio of SW (^20Ne/^22Ne=13.7) and SEP (^20Ne/^22Ne=11.3) neon. The isotopic compositions of solar He, Ar, and Kr are consistent with their also being mixtures of SW and SEP having compositions reported previously (2,3), although our data are compromised to some extent by the presence of planetary gases extracted from the silicates and, in the first steps, by atmospheric contamination probably present in terrestrial weathering products (mostly rust). The elemental composition of noble gases released from Acfer 111 was distinct from previous experiments: The (^4He

  3. Reliable probabilistic forecasts from an ensemble reservoir inflow forecasting system

    NASA Astrophysics Data System (ADS)

    Bourdin, Dominique R.; Nipen, Thomas N.; Stull, Roland B.

    2014-04-01

    This paper describes a probabilistic reservoir inflow forecasting system that explicitly attempts to sample from major sources of uncertainty in the modeling chain. Uncertainty in hydrologic forecasts arises due to errors in the hydrologic models themselves, their parameterizations, and in the initial and boundary conditions (e.g., meteorological observations or forecasts) used to drive the forecasts. The Member-to-Member (M2M) ensemble presented herein uses individual members of a numerical weather model ensemble to drive two different distributed hydrologic models, each of which is calibrated using three different objective functions. An ensemble of deterministic hydrologic states is generated by spinning up the daily simulated state using each model and parameterization. To produce probabilistic forecasts, uncertainty models are used to fit probability distribution functions (PDF) to the bias-corrected ensemble. The parameters of the distribution are estimated based on statistical properties of the ensemble and past verifying observations. The uncertainty model is able to produce reliable probability forecasts by matching the shape of the PDF to the shape of the empirical distribution of forecast errors. This shape is found to vary seasonally in the case-study watershed. We present an "intelligent" adaptation to a Probability Integral Transform (PIT)-based probability calibration scheme that relabels raw cumulative probabilities into calibrated cumulative probabilities based on recent past forecast performance. As expected, the intelligent scheme, which applies calibration corrections only when probability forecasts are deemed sufficiently unreliable, improves reliability without the inflation of ignorance exhibited in certain cases by the original PIT-based scheme.

  4. 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.

  5. Gases in ice cores

    PubMed Central

    Bender, Michael; Sowers, Todd; Brook, Edward

    1997-01-01

    Air trapped in glacial ice offers a means of reconstructing variations in the concentrations of atmospheric gases over time scales ranging from anthropogenic (last 200 yr) to glacial/interglacial (hundreds of thousands of years). In this paper, we review the glaciological processes by which air is trapped in the ice and discuss processes that fractionate gases in ice cores relative to the contemporaneous atmosphere. We then summarize concentration–time records for CO2 and CH4 over the last 200 yr. Finally, we summarize concentration–time records for CO2 and CH4 during the last two glacial–interglacial cycles, and their relation to records of global climate change. PMID:11607743

  6. The sloping alveolar plateau of tracer gases washed out from mixed venous blood in man.

    PubMed

    Schrikker, A C; de Vries, W R; Zwart, A; Luijendijk, S C

    1989-03-01

    We have investigated the slope of the alveolar plateau for inert tracer gases that were washed out from mixed venous blood. Two pairs of tracer gases were used (He, SF6) and (C2H2, Freon 22). The gases of each pair share almost the same blood-gas partition coefficient but they have different diffusive properties in the gas phase. The experiments were performed in healthy subjects at rest and at three levels of exercise (75, 150, 225 W). Each experiment started with the alveolar washin of the tracer gases by adding these gases to inspired air. This washin was continued for several minutes in order to dissolve sufficient amounts of the tracer gases in the body tissues. Subsequently, the tracer gases were washed out. In this paper, the slopes of the alveolar plateaus are defined as the relative increase of the concentration per second. Steeper slopes were found for the heavier gases (SF6 and Freon 22) in comparison with those for the lighter gases of the two pairs (He and C2H2). This finding may be ascribed to the contribution of diffusion-limited gas mixing in the lung to the slope of the alveolar plateau. For each gas, the slope for the first expiration during washout (alveolar washout) was considerably smaller than that for the later part of washout (mixed venous washout), and the difference amounts to about 56% and 76% of the slope during mixed venous washout at rest and at the highest level of exercise, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. 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.

  8. 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.

  9. 40 CFR 92.112 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 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...

  10. 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... Provisions § 90.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. The expiration date stated by the gas supplier must be recorded. (b) Pure gases. The required purity of the...

  11. 40 CFR 90.312 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Analytical gases. 90.312 Section 90... Provisions § 90.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. The expiration date stated by the gas supplier must be recorded. (b) Pure gases. The required purity of the...

  12. 40 CFR 92.112 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 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...

  13. 40 CFR 90.312 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Analytical gases. 90.312 Section 90... Provisions § 90.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. The expiration date stated by the gas supplier must be recorded. (b) Pure gases. The required purity of the...

  14. 40 CFR 90.312 - 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. 90.312 Section 90... Provisions § 90.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. The expiration date stated by the gas supplier must be recorded. (b) Pure gases. The required purity of the...

  15. 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...

  16. 40 CFR 92.112 - 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. 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...

  17. Toxicity of pyrolysis gases from polypropylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. F.

    1979-01-01

    A sample of polypropylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. The gases from this sample appeared to be equivalent or less toxic than the gases from a sample of polyethylene under these particular test conditions. Carbon monoxide appeared to be the principal toxicant.

  18. 46 CFR 194.15-17 - Compressed gases other than inert gases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shall be capped or otherwise protected in accordance with 49 CFR 173.301(g). (b) Cylinders temporarily... 46 Shipping 7 2012-10-01 2012-10-01 false Compressed gases other than inert gases. 194.15-17... Scientific Laboratory § 194.15-17 Compressed gases other than inert gases. (a) When, in consideration for...

  19. 46 CFR 194.15-17 - Compressed gases other than inert gases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shall be capped or otherwise protected in accordance with 49 CFR 173.301(g). (b) Cylinders temporarily... 46 Shipping 7 2011-10-01 2011-10-01 false Compressed gases other than inert gases. 194.15-17... Scientific Laboratory § 194.15-17 Compressed gases other than inert gases. (a) When, in consideration for...

  20. 46 CFR 194.15-17 - Compressed gases other than inert gases.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shall be capped or otherwise protected in accordance with 49 CFR 173.301(g). (b) Cylinders temporarily... 46 Shipping 7 2014-10-01 2014-10-01 false Compressed gases other than inert gases. 194.15-17... Scientific Laboratory § 194.15-17 Compressed gases other than inert gases. (a) When, in consideration for...

  1. Forecasting droughts in East Africa

    NASA Astrophysics Data System (ADS)

    Mwangi, Emmah; Wetterhall, Fredrik; Dutra, Emanuel; Di Giuseppe, Francesca; Pappenberger, Florian

    2014-05-01

    The humanitarian crisis caused by the recent droughts (2008-2009 and 2010-2011) in East Africa have illustrated that the ability to make accurate drought predictions with sufficient lead time is essential. The use of dynamical model forecasts in combination with drought indices, such as the Standardized Precipitation Index (SPI), can potentially to lead to a better description of drought duration, magnitude and spatial extent. This study evaluates the use of the European Centre for Medium-Range Weather Forecasts (ECMWF) products in forecasting droughts in East Africa. ECMWF seasonal precipitation shows significant skill for both rain seasons when evaluated against measurements from the available in-situ stations from East Africa. The forecast for October-December rain season has higher skill than for the March-May season. ECMWF forecasts add value to the statistical forecasts produced during the Greater Horn of Africa Climate Outlook Forums (GHACOF), which is the present operational product. Complementing the raw precipitation forecasts with SPI provides additional information on the spatial extent and intensity of the drought event.

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. 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

  7. A portable membrane contactor sampler for analysis of noble gases in groundwater.

    PubMed

    Matsumoto, Takuya; Han, Liang-Feng; Jaklitsch, Manfred; Aggarwal, Pradeep K

    2013-01-01

    To enable a wider use of dissolved noble gas concentrations and isotope ratios in groundwater studies, we have developed an efficient and portable sampling device using a commercially available membrane contactor. The device separates dissolved gases from a stream of water and collects them in a small copper tube (6 mm in diameter and 100 mm in length with two pinch-off clamps) for noble gas analysis by mass spectrometry. We have examined the performance of the sampler using a tank of homogeneous water prepared in the laboratory and by field testing. We find that our sampling device can extract heavier noble gases (Ar, Kr, and Xe) more efficiently than the lighter ones (He and Ne). An extraction time of about 60 min at a flow rate of 3 L/min is sufficient for all noble gases extracted in the sampler to attain equilibrium with the dissolved phase. The extracted gas sample did not indicate fractionation of helium ((3) He/(4) He) isotopes or other noble gas isotopes. Field performance of the sampling device was tested using a groundwater well in Vienna and results were in excellent agreement with those obtained from the conventional copper tube sampling method.

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. Latin American Battery Forecast Report

    SciTech Connect

    Malacon, S.

    1995-12-31

    A forecast of battery production in Latin America is described. The economic influence and political difficulties which have influenced the market are discussed. Data is presented for original equipment shipments and replacement batteries.

  13. 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.

  14. Adiabatic processes in monatomic gases

    NASA Astrophysics Data System (ADS)

    Carrera-Patiño, Martin E.

    1988-08-01

    A kinetic model is used to predict the temperature evolution of a monatomic ideal gas undergoing an adiabatic expansion or compression at a constant finite rate, and it is then generalized to treat real gases. The effects of interatomic forces are considered, using as examples the gas with the square-well potential and the van der Waals gas. The model is integrated into a Carnot cycle operating at a finite rate to compare the efficiency's rate-dependent behavior with the reversible result. Limitations of the model, rate penalties, and their importance are discussed.

  15. Method for transporting impellent gases

    NASA Technical Reports Server (NTRS)

    Papst, H.

    1975-01-01

    The described system DAL comprises a method and a device for transportation of buoyant impellent gases, without the need for expensive pipes and liquid tankers. The gas is self air-lifted from its source to a consignment point by means of voluminous, light, hollow bodies. Upon release of the gas at the consignment point, the bodies are filled with another cheap buoyant gas (steam or heated air) for the return trip to the source. In both directions substantial quantities of supplementary freight goods can be transported. Requirements and advantages are presented.

  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. 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…

  18. Forecasting droughts in East Africa

    NASA Astrophysics Data System (ADS)

    Mwangi, E.; Wetterhall, F.; Dutra, E.; Di Giuseppe, F.; Pappenberger, F.

    2013-08-01

    The humanitarian crisis caused by the recent droughts (2008-2009 and 2010-2011) in the East African region have illustrated that the ability to make accurate drought predictions with adequate lead time is essential. The use of dynamical model forecasts and drought indices, such as Standardized Precipitation Index (SPI), promises to lead to a better description of drought duration, magnitude and spatial extent. This study evaluates the use of the European Centre for Medium-Range Weather Forecasts (ECMWF) products in forecasting droughts in East Africa. ECMWF seasonal precipitation shows significant skill for both rain seasons when evaluated against measurements from the available in-situ stations from East Africa. The October-December rain season has higher skill that the March-May season. ECMWF forecasts add value to the statistical forecasts produced during the Greater Horn of Africa Climate Outlook Forums (GHACOF) which is the present operational product. Complementing the raw precipitation forecasts with SPI provides additional information on the spatial extend and intensity of the drought event.

  19. 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.

  20. 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.

  1. 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.

  2. Disposal of acid gases with oilfield produced water

    SciTech Connect

    Duckworth, G.L.; Kopperson, D.; Horne, S.; Kohn, G.; Romansky, D.; Chan, C.

    1998-12-31

    With tightening environmental policies, many companies are investigating alternatives to atmospheric sulfur and greenhouse gas emissions. The oil and gas industry of Alberta, Canada typically recovers a high percentage of sulfur in large sour gas processing plants, but is often looking for a more cost effective approach to dealing with small volume plants. PanCanadian Petroleum Limited and DPH Engineering Inc. have developed a disposal scheme that makes low volume sour gas processing more affordable and easier to operate by disposing of acid gases in an aqueous phase to a disposal well. The development of this scheme utilized the results of reservoir studies, computer simulations, laboratory tests and field tests. This work has further resulted in the implementation of two full scale schemes to dissolve acid gas in produced water and inject it into deep subsurface formations. These schemes have operated with minimal problems and have met their environmental requirements.

  3. Medical Imaging of Hyperpolarized Gases

    SciTech Connect

    Miller, G. Wilson

    2009-08-04

    Since the introduction of hyperpolarized {sup 3}He and {sup 129}Xe 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.

  4. 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.

  5. 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.

  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. 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.

  8. 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.

  9. A preliminary survey of noble gases at Dixie Valley, Nevada

    SciTech Connect

    Kennedy, B.M.; Benoit, D.; Truesdell, A.H.

    1996-12-31

    A preliminary survey of noble gas abundances and isotopic compositions in production fluids from four high pressure separator stations providing steam to the dual flash Dixie Valley Geothermal Plant has been completed. The atmospheric noble gases are dominated by dissolved gases introduced with the injection fluid, a mixture of flashed degassed brine and condensate equilibrated with air in the cooling tower. Excess helium, however, represents a primary reservoir fluid and variations in the amount of excess can be used to monitor the changing proportion of injectate in the production fluid. The helium component associated with the reservoir fluid has an isotopic composition (0.70 - 0.76 Ra) implying that {approximately}7.5% of the helium in the 1995 Dixie Valley reservoir fluid is mantle-derived. The Dixie Valley geothermal field is closely related to the range-front normal fault of the Stillwater Range. Assuming fluid transport along the fault from deeper sources and using a one-dimensional steady-state advection model, the helium content and isotopic composition of the reservoir fluid predicts an average fluid flow rate of virgin fluid from depth of {approximately} 7 mm/yr. This is significantly less than injectate flow rates within the reservoir estimated from tracer tests (i.e. 5 - 120 m/day).

  10. Highly sensitive Raman system for dissolved gas analysis in water.

    PubMed

    Yang, Dewang; Guo, Jinjia; Liu, Qingsheng; Luo, Zhao; Yan, Jingwen; Zheng, Ronger

    2016-09-20

    The detection of dissolved gases in seawater plays an important role in ocean observation and exploration. As a potential technique for oceanic applications, Raman spectroscopy has already proved its advantages in the simultaneous detection of multiple species during previous deep-sea explorations. Due to the low sensitivity of conventional Raman measurements, there have been many reports of Raman applications on direct seawater detection in high-concentration areas, but few on undersea dissolved gas detection. In this work, we have presented a highly sensitive Raman spectroscopy (HSRS) system with a special designed gas chamber for small amounts of underwater gas extraction. Systematic experiments have been carried out for system evaluation, and the results have shown that the Raman signals obtained by the innovation of a near-concentric cavity was about 21 times stronger than those of conventional side-scattering Raman measurements. Based on this system, we have achieved a low limit of detection of 2.32 and 0.44  μmol/L for CO2 and CH4, respectively, in the lab. A test-out experiment has also been accomplished with a gas-liquid separator coupled to the Raman system, and signals of O2 and CO2 were detected after 1 h of degasification. This system may show potential for gas detection in water, and further work would be done for the improvement of in situ detection.

  11. Highly sensitive Raman system for dissolved gas analysis in water.

    PubMed

    Yang, Dewang; Guo, Jinjia; Liu, Qingsheng; Luo, Zhao; Yan, Jingwen; Zheng, Ronger

    2016-09-20

    The detection of dissolved gases in seawater plays an important role in ocean observation and exploration. As a potential technique for oceanic applications, Raman spectroscopy has already proved its advantages in the simultaneous detection of multiple species during previous deep-sea explorations. Due to the low sensitivity of conventional Raman measurements, there have been many reports of Raman applications on direct seawater detection in high-concentration areas, but few on undersea dissolved gas detection. In this work, we have presented a highly sensitive Raman spectroscopy (HSRS) system with a special designed gas chamber for small amounts of underwater gas extraction. Systematic experiments have been carried out for system evaluation, and the results have shown that the Raman signals obtained by the innovation of a near-concentric cavity was about 21 times stronger than those of conventional side-scattering Raman measurements. Based on this system, we have achieved a low limit of detection of 2.32 and 0.44  μmol/L for CO2 and CH4, respectively, in the lab. A test-out experiment has also been accomplished with a gas-liquid separator coupled to the Raman system, and signals of O2 and CO2 were detected after 1 h of degasification. This system may show potential for gas detection in water, and further work would be done for the improvement of in situ detection. PMID:27661606

  12. 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.

  13. Large N model of bose gases

    NASA Astrophysics Data System (ADS)

    Ke, Ke; Radzihovsky, Leo

    2009-10-01

    We construct the large N model of bose gases. Using an artificial parameter 1/N to do the perturbative analysis to study two models: U(N) bose gases and U(1) xO(N) bose gases. We find that for the U(N) model we get the same Bogoliubov spectrum and LHY thermal dynamical relations with ordinary bose gases. For the U(1) xO(N) model, however, we calculate dispersion relation, chemical potential and free energy when N goes to infinity and find that every quantities depends on the ration of two scattering length and √(na^3).

  14. Evaluation of persulfate oxidative wet scrubber for removing BTEX gases.

    PubMed

    Liang, Chenju; Chen, Yan-Jyun; Chang, Keng-Jung

    2009-05-30

    Soil vapor extraction (SVE) coupled with air sparging of groundwater is a method commonly used to remediate soil and groundwater contaminated with volatile organic petroleum contaminants such as gasoline. These hazardous contaminants are mainly attributable to the compounds-benzene, toluene, ethylbenzene, and xylenes (known collectively as BTEX). Exhaust gas from SVE may contain BTEX, and therefore must be treated before being discharged. This study evaluated the use of iron-activated persulfate chemical oxidation in conjunction with a wet scrubbing system, i.e., a persulfate oxidative scrubber (POS) system, to destroy BTEX gases. The persulfate anions can be activated by citric acid (CA) chelated Fe(2+) to generate sulfate radicals (SO(4)(*-), E degrees =2.4V), which may rapidly degrade BTEX in the aqueous phase and result in continuous destruction of the BTEX gases. The results show that persulfate activation occurred as a result of continuous addition of the citric acid chelated Fe(2+) activator, which readily oxidized the dissolved BTEX. Based on initial results from the aqueous phase, a suitable Fe(2+)/CA molar ratio of 5/3 was determined and used to initiate activation in the subsequent POS system tests. In the POS system, using persulfate as a scrubber solution and with activation by injecting Fe(2+)/CA activators under two testing conditions, varying iron concentrations and pumping rates, resulted in an approximate 50% removal of BTEX gases. During the course of the tests which in corporate activation, a complete destruction of BTEX was achieved in the aqueous phase. It is noted that no removal of BTEX occurred in the control tests which did not include activation. The results of this study would serve as a reference for future studies into the practical chemical oxidation of waste gas streams.

  15. 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.

  16. 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.

  17. Granular gases under extreme driving

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

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

  18. 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.

  19. 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.

  20. Forecasting seasonal outbreaks of influenza.

    PubMed

    Shaman, Jeffrey; Karspeck, Alicia

    2012-12-11

    Influenza recurs seasonally in temperate regions of the world; however, our ability to predict the timing, duration, and magnitude of local seasonal outbreaks of influenza remains limited. Here we develop a framework for initializing real-time forecasts of seasonal influenza outbreaks, using a data assimilation technique commonly applied in numerical weather prediction. The availability of real-time, web-based estimates of local influenza infection rates makes this type of quantitative forecasting possible. Retrospective ensemble forecasts are generated on a weekly basis following assimilation of these web-based estimates for the 2003-2008 influenza seasons in New York City. The findings indicate that real-time skillful predictions of peak timing can be made more than 7 wk in advance of the actual peak. In addition, confidence in those predictions can be inferred from the spread of the forecast ensemble. This work represents an initial step in the development of a statistically rigorous system for real-time forecast of seasonal influenza.

  1. 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.

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. ALFA: Automated load forecasting assistant

    SciTech Connect

    Jabbour, K.; Riveros, J.F.V.; Landsbergen, D.; Meyer, W.

    1988-08-01

    ALFA, an expert system for forecasting short term demand for electricity is presented. ALFA is in operation at the new Energy Management System center at Niagara Mohawk Power Corporation in Upstate New York, generating the real time hourly load forecasts up to 48 hours in advance. ALFA uses an extensive 10 year historical data base of hourly observations of 12 weather variables and load, and a rule base that takes into account daily, weekly, and seasonal variations of load, as well as holidays, special events, and load growth. A satellite interface for the real-time acquisition of weather data, and the machine-operator interface are also discussed.

  9. 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.

  10. 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.

  11. The solubility of noble gases in crude oil at 25-100°C

    USGS Publications Warehouse

    Kharaka, Yousif K.; Specht, Daniel J.

    1988-01-01

    The solubility of the noble gases He, Ne, Ar, Kr and Xe was measured in two typical crude oils at temperatures of 25–100°C. The oil samples were obtained from the Elk Hills oil field located in southern San Joaquin Valley, California. The experimental procedure consisted of placing a known amount of gas with a known volume of crude oil in a stainless steel hydrothermal pressure vessel. The vessel was housed inside an oven and the entire unit rotates providing continuous mixing. The amount of gas dissolved in oil at a measured temperature and partial pressure of gas was used to calculate the solubility constants for these gases. Results show that the solubility of He and Ne in both oils is approximately the same; solubility then increases with atomic mass, with the solubility of Xe at 25°C being two orders of magnitude higher than that of He. The gas solubilities are somewhat higher in the lower density (higher API gravity) oil. The solubility of Ar is approximately constant in the range of temperatures of this study. The solubilities of He and Ne increase, but those of Kr and Xe decrease with increasing temperatures. Solubilities of noble gases in crude oil are significantly higher than their solubilities in water. For example, the solubilities of He and Xe at 25°C in the light oil of this study are, respectively, 3 and 24 times higher than their solubilities in pure water, and they are 15 and 300 times higher than in a brine with a salinity of 350,000 mg/l dissolved solids. These large and variable differences in the solubilities of noble gases in oil and water indicate that, in sedimentary basins with oil, these gases must be partitioned between oil, water and natural gas before they are used to deduce the origin and residence time of these fluids.

  12. 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....

  13. 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....

  14. 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....

  15. 40 CFR 91.312 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Analytical gases. 91.312 Section 91.312... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.312 Analytical gases. (a) The shelf life of a calibration gas may not be exceeded. Record the expiration date stated by...

  16. 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....

  17. 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....

  18. 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…

  19. Toxicity of pyrolysis gases from polyoxymethylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. P.

    1979-01-01

    A sample of polyoxymethylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Under several test conditions, this material gave shorter times to death than many other synthetic polymers. Carbon monoxide appeared to be the principal toxicant in the pyrolysis gases.

  20. Recognizing and Dealing with Dangerous Gases.

    ERIC Educational Resources Information Center

    Bove, Robert A.

    1978-01-01

    When handling hazardous gases, it is necessary to know their properties, precautions that can be taken to protect workers, and proper first aid. This article gives everyday rules for handling gas cylinders, and a brief first aid guide for 12 common toxic gases and vapors. (BB)

  1. 40 CFR 1065.750 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  2. 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

  3. 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

  4. Analysis of gases in the Earth's crust

    NASA Astrophysics Data System (ADS)

    Jenden, P. D.

    1986-05-01

    To investigate the origin and fate of natural gas in the Earth's crust, approximately 700 gas samples have been analyzed for chemical composition and stable isotopic ratios of carbon, hydrogen, nitrogen, sulfur and oxygen. During the current reporting period, helium isotope measurements confirmed the presence of mantle volatiles in the Sacramento basin, a dry gas province in northern California. Methane carbon isotope ratios and N2/Ar ratios suggest that Sacramento basin commercial gases with up to 88% nitrogen are derived from metasedimentary rocks. Studies of seep gases in Los Angeles indicate that ethane and higher hydrocarbons may be retarded during natural gas migration and the propane is selectively attacked during bacterial alteration. Carbon dioxide reduction and acetate dissimilation, the two main pathways for microbial methane formation, are characterized by different methane hydrogen isotope ratios. Hydrogen isotope ratios of methane and carbon isotope ratios of carbon dioxide and ethane help to distinguish microbial gases, thermogenic gases, and mixed gases.

  5. 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

  6. Error growth in operational ECMWF forecasts

    NASA Technical Reports Server (NTRS)

    Kalnay, E.; Dalcher, A.

    1985-01-01

    A parameterization scheme used at the European Centre for Medium Range Forecasting to model the average growth of the difference between forecasts on consecutive days was extended by including the effect of error growth on forecast model deficiencies. Error was defined as the difference between the forecast and analysis fields during the verification time. Systematic and random errors were considered separately in calculating the error variance for a 10 day operational forecast. A good fit was obtained with measured forecast errors and a satisfactory trend was achieved in the difference between forecasts. Fitting six parameters to forecast errors and differences that were performed separately for each wavenumber revealed that the error growth rate grew with wavenumber. The saturation error decreased with the total wavenumber and the limit of predictability, i.e., when error variance reaches 95 percent of saturation, decreased monotonically with the total wavenumber.

  7. 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

  8. 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.

  9. Forecasting for energy and chemical decision analysis

    SciTech Connect

    Cazalet, E.G.

    1984-08-01

    This paper focuses on uncertainty and bias in forecasts used for major energy and chemical investment decisions. Probability methods for characterizing uncertainty in the forecast are reviewed. Sources of forecasting bias are classified based on the results of relevant psychology research. Examples are drawn from the energy and chemical industry to illustrate the value of explicit characterization of uncertainty and reduction of bias in forecasts.

  10. 40 CFR 86.514-78 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 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. 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...

  12. 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...

  13. 40 CFR 86.114-94 - 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. 86.114-94 Section 86...-Duty Vehicles; Test Procedures § 86.114-94 Analytical gases. (a) Analyzer gases. (1) Gases for the CO...) Gases for the THC analyzer shall be: (i) Single blends of propane using air as the diluent; and...

  14. 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... 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...

  15. 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...

  16. 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.

  17. 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…

  18. 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…

  19. 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...

  20. 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.

  1. 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…

  2. 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.

  3. Forecasting phenology under global warming.

    PubMed

    Ibáñez, Inés; Primack, Richard B; Miller-Rushing, Abraham J; Ellwood, Elizabeth; Higuchi, Hiroyoshi; Lee, Sang Don; Kobori, Hiromi; Silander, John A

    2010-10-12

    As a consequence of warming temperatures around the world, spring and autumn phenologies have been shifting, with corresponding changes in the length of the growing season. Our understanding of the spatial and interspecific variation of these changes, however, is limited. Not all species are responding similarly, and there is significant spatial variation in responses even within species. This spatial and interspecific variation complicates efforts to predict phenological responses to ongoing climate change, but must be incorporated in order to build reliable forecasts. Here, we use a long-term dataset (1953-2005) of plant phenological events in spring (flowering and leaf out) and autumn (leaf colouring and leaf fall) throughout Japan and South Korea to build forecasts that account for these sources of variability. Specifically, we used hierarchical models to incorporate the spatial variability in phenological responses to temperature to then forecast species' overall and site-specific responses to global warming. We found that for most species, spring phenology is advancing and autumn phenology is getting later, with the timing of events changing more quickly in autumn compared with the spring. Temporal trends and phenological responses to temperature in East Asia contrasted with results from comparable studies in Europe, where spring events are changing more rapidly than are autumn events. Our results emphasize the need to study multiple species at many sites to understand and forecast regional changes in phenology. PMID:20819816

  4. 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…

  5. Premier Forecasting Center Avoids Ax

    NASA Astrophysics Data System (ADS)

    Simpson, Sarah

    2004-03-01

    Last fall, the U.S. Senate proposed eliminating all 2004 funding for NOAA's Space Environment Center (SEC), but fortunately for the world's premier space weather forecasting center and its myriad customers, the Senate did not get its way. When the full Congress passed the final budget on 22 January, the center's budget for the year was at least restored-at least partially.

  6. Wavelet-based Evapotranspiration Forecasts

    NASA Astrophysics Data System (ADS)

    Bachour, R.; Maslova, I.; Ticlavilca, A. M.; McKee, M.; Walker, W.

    2012-12-01

    Providing a reliable short-term forecast of evapotranspiration (ET) could be a valuable element for improving the efficiency of irrigation water delivery systems. In the last decade, wavelet transform has become a useful technique for analyzing the frequency domain of hydrological time series. This study shows how wavelet transform can be used to access statistical properties of evapotranspiration. The objective of the research reported here is to use wavelet-based techniques to forecast ET up to 16 days ahead, which corresponds to the LANDSAT 7 overpass cycle. The properties of the ET time series, both physical and statistical, are examined in the time and frequency domains. We use the information about the energy decomposition in the wavelet domain to extract meaningful components that are used as inputs for ET forecasting models. Seasonal autoregressive integrated moving average (SARIMA) and multivariate relevance vector machine (MVRVM) models are coupled with the wavelet-based multiresolution analysis (MRA) results and used to generate short-term ET forecasts. Accuracy of the models is estimated and model robustness is evaluated using the bootstrap approach.

  7. 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.

  8. Volcanic forcing in decadal forecasts

    NASA Astrophysics Data System (ADS)

    Ménégoz, Martin; Doblas-Reyes, Francisco; Guemas, Virginie; Asif, Muhammad; Prodhomme, chloe

    2016-04-01

    Volcanic eruptions can significantly impact the climate system, by injecting large amounts of particles into the stratosphere. By reflecting backward the solar radiation, these particles cool the troposphere, and by absorbing the longwave radiation, they warm the stratosphere. As a consequence of this radiative forcing, the global mean surface temperature can decrease by several tenths of degrees. However, large eruptions are also associated to a complex dynamical response of the climate system that is particularly tricky do understand regarding the low number of available observations. Observations seem to show an increase of the positive phases of the Northern Atlantic Oscillation (NAO) the two winters following large eruptions, associated to positive temperature anomalies over the Eurasian continent. The summers following large eruptions are generally particularly cold, especially over the continents of the Northern Hemisphere. Overall, it is really challenging to forecast the climate response to large eruptions, as it is both modulated by, and superimposed to the climate background conditions, largely driven themselves by internal variability at seasonal to decadal scales. This work describes the additional skill of a forecast system used for seasonal and decadal predictions when it includes observed volcanic forcing over the last decades. An idealized volcanic forcing that could be used for real-time forecasts is also evaluated. This work consists in a base for forecasts that will be performed in the context of the next large volcanic eruption.

  9. 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.

  10. 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).

  11. 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.

  12. Dissolved air flotation and me.

    PubMed

    Edzwald, James K

    2010-04-01

    This paper is mainly a critical review of the literature and an assessment of what we know about dissolved air flotation (DAF). A few remarks are made at the outset about the author's personal journey in DAF research, his start and its progression. DAF has been used for several decades in drinking water treatment as an alternative clarification method to sedimentation. DAF is particularly effective in treating reservoir water supplies; those supplies containing algae, natural color or natural organic matter; and those with low mineral turbidity. It is more efficient than sedimentation in removing turbidity and particles for these type supplies. Furthermore, it is more efficient in removing Giardia cysts and Cryptosporidium oocysts. In the last 20 years, fundamental models were developed that provide a basis for understanding the process, optimizing it, and integrating it into water treatment plants. The theories were tested through laboratory and pilot-plant studies. Consequently, there have been trends in which DAF pretreatment has been optimized resulting in better coagulation and a decrease in the size of flocculation tanks. In addition, the hydraulic loading rates have increased reducing the size of DAF processes. While DAF has been used mainly in conventional type water plants, there is now interest in the technology as a pretreatment step in ultrafiltration membrane plants and in desalination reverse osmosis plants.

  13. Seasonal Streamflow Forecasts for African Basins

    NASA Astrophysics Data System (ADS)

    Serrat-Capdevila, A.; Valdes, J. B.; Wi, S.; Roy, T.; Roberts, J. B.; Robertson, F. R.; Demaria, E. M.

    2015-12-01

    Using high resolution downscaled seasonal meteorological forecasts we present the development and evaluation of seasonal hydrologic forecasts with Stakeholder Agencies for selected African basins. The meteorological forecasts are produced using the Bias Correction and Spatial Disaggregation (BCSD) methodology applied to NMME hindcasts (North American Multi-Model Ensemble prediction system) to generate a bootstrap resampling of plausible weather forecasts from historical observational data. This set of downscaled forecasts is then used to drive hydrologic models to produce a range of forecasts with uncertainty estimates suitable for water resources planning in African pilot basins (i.e. Upper Zambezi, Mara Basin). In an effort to characterize the utility of these forecasts, we will present an evaluation of these forecast ensembles over the pilot basins, and discuss insights as to their operational applicability by regional actors. Further, these forecasts will be contrasted with those from a standard Ensemble Streamflow Prediction (ESP) approach to seasonal forecasting. The case studies presented here have been developed in the setting of the NASA SERVIR Applied Sciences Team and within the broader context of operational seasonal forecasting in Africa. These efforts are part of a dialogue with relevant planning and management agencies and institutions in Africa, which are in turn exploring how to best use uncertain forecasts for decision making.

  14. Student Enrollment Forecasting in Georgia: Lessons Learned.

    ERIC Educational Resources Information Center

    Chan, Tak Cheung; Pool, Harbison; Davidson, Ronald

    2002-01-01

    Study of school district enrollment forecasting in Georgia finds, for example, differences in forecasting accuracy between large and small school districts, the widespread use of the Cohort Survival Technique, a lag in small school districts' use of sophisticated, computer-based enrollment forecasting models. (Contains 34 references.) (PKP)

  15. 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…

  16. 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…

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

    PubMed

    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

  18. 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

  19. A Wind Forecasting System for Energy Application

    NASA Astrophysics Data System (ADS)

    Courtney, Jennifer; Lynch, Peter; Sweeney, Conor

    2010-05-01

    Accurate forecasting of available energy is crucial for the efficient management and use of wind power in the national power grid. With energy output critically dependent upon wind strength there is a need to reduce the errors associated wind forecasting. The objective of this research is to get the best possible wind forecasts for the wind energy industry. To achieve this goal, three methods are being applied. First, a mesoscale numerical weather prediction (NWP) model called WRF (Weather Research and Forecasting) is being used to predict wind values over Ireland. Currently, a gird resolution of 10km is used and higher model resolutions are being evaluated to establish whether they are economically viable given the forecast skill improvement they produce. Second, the WRF model is being used in conjunction with ECMWF (European Centre for Medium-Range Weather Forecasts) ensemble forecasts to produce a probabilistic weather forecasting product. Due to the chaotic nature of the atmosphere, a single, deterministic weather forecast can only have limited skill. The ECMWF ensemble methods produce an ensemble of 51 global forecasts, twice a day, by perturbing initial conditions of a 'control' forecast which is the best estimate of the initial state of the atmosphere. This method provides an indication of the reliability of the forecast and a quantitative basis for probabilistic forecasting. The limitation of ensemble forecasting lies in the fact that the perturbed model runs behave differently under different weather patterns and each model run is equally likely to be closest to the observed weather situation. Models have biases, and involve assumptions about physical processes and forcing factors such as underlying topography. Third, Bayesian Model Averaging (BMA) is being applied to the output from the ensemble forecasts in order to statistically post-process the results and achieve a better wind forecasting system. BMA is a promising technique that will offer calibrated

  20. The COMESEP SEP forecast tool

    NASA Astrophysics Data System (ADS)

    Dierckxsens, Mark; Tziotziou, Kostas; Dalla, Silvia; Patsou, Ioanna; Marsh, Mike; Crosby, Norma; Malandraki, Olga; Lygeros, Nik

    2014-05-01

    The FP7 COMESEP (COronal Mass Ejections and Solar Energetic Particles: forecasting the space weather impact) project developed tools for forecasting geomagnetic storms and solar energetic particle (SEP) radiation storms. Here we present the SEP forecast tool which provides a prediction of the probability for an SEP event to occur near Earth following the real-time observation of an X-ray flare, and estimates the most likely impact if such an event would occur. The tool has been operational on the COMESEP alert system (http://www.comesep.eu/alert) since November 2013. Alerts are provided for proton storms with E>10 MeV and E>60 MeV in the form of a risk level, combining the probability and expected impact. The predictions are based on a statistical analysis of SEP events and their parent solar activity during Solar Cycle 23. The input parameters are the flare intensity and longitude location, as well as the CME speed and width, if an observed CME can be associated with the flare. This information is also received through the COMESEP system. Alerts are based on the available information when triggered and are subsequently updated if more information becomes available. The forecast for the probability, the impact and risk level are evaluated on events from solar cycles 22 and 24. The effect of including flare location and CME parameters is also studied. The performance of the SEP forecast tool within the COMESEP alert system will be described. This work has received funding from the European Commission FP7 Project COMESEP (263252)

  1. A Course in Economic Forecasting: Rationale and Content.

    ERIC Educational Resources Information Center

    Loomis, David G.; Cox, James E., Jr.

    2000-01-01

    Discusses four reasons why economic forecasting courses are important: (1) forecasting skills are in demand by businesses; (2) forecasters are in demand; (3) forecasting courses have positive externalities; (4) and forecasting provides a real-world context. Describes what should be taught in an economic forecasting course. (CMK)

  2. Forecasting long-range atmospheric pollutant transport and dispersion: Approaches and issues

    SciTech Connect

    Griggs, D.P.; Addis, R.P.

    1996-01-11

    The ability to forecast the transport and diffusion of airborne contaminants over long distances is vital when responding to nuclear emergencies. Increases in computing capabilities and ready access to large-scale model output make it possible to employ advanced three-dimensional prognostic models to forecast the long-range transport of toxic or radioactive gases for emergency response. The Savannah River Technology Center (SRTC) of the U.S. Department of Energy`s Savannah River Site demonstrated this during the European Tracer EXperiment (ETEX). ETEX, conducted in the Fall of 1994, is designed to evaluate the performance of models for long-range atmospheric pollutant transport and dispersion. ETEX involved two tracer experiments as well as a multinational real-time modeling exercise. The real-time modeling component tested the ability of participants to provide timely long-range forecasts of the tracer plume transport and diffusion. Notification of the time, location and amount of tracer occurred after the start of the release. Participants provided 60-hour forecasts of tracer surface concentration within 6 hours of being notified, and updated forecasts every 12 hours thereafter. The two tracer experiments were conducted near Rennes, France on October 23, 1994 and November 14, 1994.

  3. Collisions of ions in gases

    NASA Astrophysics Data System (ADS)

    Bailey, T. L.

    1982-03-01

    This report is a summary description of research carried out under the ONR Project 'Collisions of Ions in Gases'. The work consisted of experimental studies of collisions of low-energy ions (4 < or = E sub L < or = 500 eV) with atoms and molecules, using the ion-beam gas-target technique, and of theoretical and computational studies done in support of the experiments. Three types of experiments were carried out: (a) measurements of relative differential cross-sections for elastic and inelastic (i.e., charge transfer) scattering in collisions of the He(++) ions with Ne, Ar, and Kr atoms, over the ion energy range 8 < or = E sub L < or = 60 eV; (b) kinematical studies of charge transfer in collisions of 30 < or = E sub L < or = 373 eV Ne(+), Ar(+), and Kr(+) ions with H2, D2, O2, and N2 molecules, in which the KE-distributions of the product H2(+), etc., were measured; and (c) measurements of the absolute total cross-sections for the charge transfer process He(++) + R = He(+) + R(+), where R = Ne, Ar, Kr, over the energy range 4 < or = E sub L < or = 500 eV. The experimental results, and their interpretations in terms of appropriate quantum scattering theory (where the latter was feasible) are discussed briefly. The effects of the thermal motions of collision participants (i.e., thermal broadening) in ion-atom and similar scattering experiments were investigated in computational studies, and a new crossed ion-supersonic atom/molecule beams apparatus, designed to remove the thermal broadening effect and to give high resolution in energy and angle, is discussed.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. On the reliability of seasonal climate forecasts.

    PubMed

    Weisheimer, A; Palmer, T N

    2014-07-01

    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.

  9. Statistical calibration of seasonal ensemble streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Wood, A. W.; Wiley, M.; Nijssen, B.

    2008-12-01

    Model-based streamflow forecast ensembles routinely exhibit errors due to input forecast uncertainty, initial condition uncertainty and hydrologic modeling error, and such errors can undermine the suitability of raw model forecast output for use in follow-on applications such as reservoir management. This presentation evaluates the use of quantile regression for modeling and correcting streamflow prediction errors at seasonal lead times. Quantile regression has been used rarely in the hydrologic forecasting area, yet its insensitivity to outliers and avoidance of parametric assumptions about forecast errors makes it suitable for representing quantiles of datasets (such as streamflow) that often have skewed or otherwise irregular distributions. For illustration, a local linear quantile regression framework is applied to seasonal streamflow hindcasts in the Pacific Northwest and elsewhere in the western US, and found to reduce forecast bias and improve reliability, albeit with a slight loss of forecast resolution.

  10. 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.

  11. 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.

  12. Using Climate Forecasts for Drought Management

    NASA Astrophysics Data System (ADS)

    Steinemann, Anne C.

    2006-10-01

    Drought hazards, and the ability to mitigate them with advance warning, offer potentially valuable applications of climate forecast products. Yet the value is often untapped, owing to the gap between climate science and societal decisions. This study bridged that gap; it determined forecast needs among water managers, translated forecasts to meet those needs, and shaped drought decision making to take advantage of forecasts. NOAA Climate Prediction Center (CPC) seasonal precipitation outlooks were converted into a forecast precipitation index (FPI) tailored for water managers in the southeastern United States. The FPI expresses forecasts as a departure from the climatological normal and is consistent with other drought indicators. Evaluations of CPC seasonal forecasts issued during 1995 2000 demonstrated positive skill for drought seasons in the Southeast. In addition, using evaluation criteria of water managers, 88% of forecasts for drought seasons would have appropriately prompted drought responses. Encouraged by these evaluations, and the understandability of the FPI, state water managers started using the forecasts in 2001 for deciding whether to pay farmers to suspend irrigation. Economic benefits of this forecast information were estimated at $100 $350 million in a state-declared drought year (2001, 2002) and $5 $30 million in the other years (2003, 2004). This study provides four main contributions: 1) an investigation of the needs and potential benefits of seasonal forecast information for water management, 2) a method for translating the CPC forecasts into a format needed by water managers, 3) the integration of forecast information into agency decision making, and 4) the economic valuation of that forecast information.

  13. 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.

  14. 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.

  15. 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.

  16. [Roles of soil dissolved organic carbon in carbon cycling of terrestrial ecosystems: a review].

    PubMed

    Li, Ling; Qiu, Shao-Jun; Liu, Jing-Tao; Liu, Qing; Lu, Zhao-Hua

    2012-05-01

    Soil dissolved organic carbon (DOC) is an active fraction of soil organic carbon pool, playing an important role in the carbon cycling of terrestrial ecosystems. In view of the importance of the carbon cycling, this paper summarized the roles of soil DOC in the soil carbon sequestration and greenhouse gases emission, and in considering of our present ecological and environmental problems such as soil acidification and climate warming, discussed the effects of soil properties, environmental factors, and human activities on the soil DOC as well as the response mechanisms of the DOC. This review could be helpful to the further understanding of the importance of soil DOC in the carbon cycling of terrestrial ecosystems and the reduction of greenhouse gases emission.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. An artificial neutral network hourly temperature forecaster with applications in load forecasting

    SciTech Connect

    Khotanzad, A.; Davis, M.H.; Abaye, A.; Maratukulam, D.J.

    1996-05-01

    Many short term load forecasting techniques use forecast hourly temperatures in generating a load forecast. Some utility companies, however, do not have access to a weather service that provides these forecasts. To fill this need, a temperature forecaster, based on artificial neural networks, has been developed that predicts hourly temperatures up to seven days in the future. The prediction is based on forecast daily high and low temperatures and other information that would be readily available to any utility. The forecaster has been evaluated using data from eight utilities in the US. The mean absolute error of one day ahead forecasts for these utilities is 1.48{degree}F. The forecaster is implemented at several electric utilities and is being used in production environments.

  2. 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.

  3. 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.

  4. Quantum Polarization Spectroscopy of Ultracold Spinor Gases

    SciTech Connect

    Eckert, K.; Zawitkowski, L.; Sanpera, A.; Lewenstein, M.; Polzik, E. S.

    2007-03-09

    We propose a method for the detection of ground state quantum phases of spinor gases through a series of two quantum nondemolition measurements performed by sending off-resonant, polarized light pulses through the gas. Signatures of various mean-field as well as strongly correlated phases of F=1 and F=2 spinor gases obtained by detecting quantum fluctuations and mean values of polarization of transmitted light are identified.

  5. 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.

  6. Nonhydrodynamic Transport in Trapped Unitary Fermi Gases

    NASA Astrophysics Data System (ADS)

    Brewer, Jasmine; Romatschke, Paul

    2015-11-01

    Many strongly coupled fluids are known to share similar hydrodynamic transport properties. In this work we argue that this similarity could extend beyond hydrodynamics to transient dynamics through the presence of nonhydrodynamic modes. We review nonhydrodynamic modes in kinetic theory and gauge-gravity duality and discuss their signatures in trapped Fermi gases close to unitarity. Reanalyzing previously published experimental data we find hints of nonhydrodynamic modes in cold Fermi gases in two and three dimensions.

  7. 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.

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. Dissolved organic matter photolysis in Canadian arctic thaw ponds

    NASA Astrophysics Data System (ADS)

    Laurion, Isabelle; Mladenov, Natalie

    2013-09-01

    The abundant thaw lakes and ponds in the circumarctic receive a new pool of organic carbon as permafrost peat soils degrade, which can be exposed to significant irradiance that potentially increases as climate warms and ice cover shortens. Exposure to sunlight is known to accelerate the transformation of dissolved organic matter (DOM) into molecules that can be more readily used by microbes. We sampled the water from two common classes of ponds found in the ice-wedge system of continuous permafrost regions of Canada, polygonal and runnel ponds, and followed the transformation of DOM over 12 days by looking at dissolved organic carbon (DOC) concentration and DOM absorption and fluorescence properties. The results indicate a relatively fast decay of color (3.4 and 1.6% loss d-1 of absorption at 320 nm for the polygonal and runnel pond, respectively) and fluorescence (6.1 and 8.3% loss d-1 of total fluorescent components, respectively) at the pond surface, faster in the case of humic-like components, but insignificant losses of DOC over the observed period. This result indicates that direct DOM mineralization (photochemical production of CO2) is apparently minor in thaw ponds compared to the photochemical transformation of DOM into less chromophoric and likely more labile molecules with a greater potential for microbial mineralization. Therefore, DOM photolysis in arctic thaw ponds can be considered as a catalytic mechanism, accelerating the microbial turnover of mobilized organic matter from thawing permafrost and the production of greenhouse gases, especially in the most shallow ponds. Under a warming climate, this mechanism will intensify as summers lengthen.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Dissolved Fe(II) in a river-estuary system rich in dissolved organic matter

    NASA Astrophysics Data System (ADS)

    Hopwood, Mark J.; Statham, Peter J.; Milani, Ambra

    2014-12-01

    Reduced iron, Fe(II), accounts for a significant fraction of dissolved Fe across many natural surface waters despite its rapid oxidation under oxic conditions. Here we investigate the temporal and spatial variation in dissolved Fe redox state in a high dissolved organic matter (DOM) estuarine system, the River Beaulieu. We couple manual sample collection with the deployment of an autonomous in situ analyser, designed to simultaneously measure dissolved Fe(II) and total dissolved Fe, in order to investigate processes operating on the diurnal timescale and to evaluate the performance of the analyser in a high DOM environment. Concentrations of dissolved Fe available to the ligand ferrozine are elevated throughout the estuary (up to 21 μM in freshwater) and notably higher than those previously reported likely due to seasonal variation. Fe(II) is observed to account for a large, varying fraction of the dissolved Fe available to ferrozine (25.5 ± 12.5%) and this fraction decreases with increasing salinity. We demonstrate that the very high DOM concentration in this environment and association of this DOM with dissolved Fe, prevents the accurate measurement of dissolved Fe concentrations in situ using a sensor reliant on rapid competitive ligand exchange.

  18. 40 CFR 86.1214-85 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Analytical gases. 86.1214-85 Section... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1214-85 Analytical gases. (a) Analyzer gases. (1) Gases for...

  19. 40 CFR 86.1214-85 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Analytical gases. 86.1214-85 Section... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1214-85 Analytical gases. (a) Analyzer gases. (1) Gases for...

  20. 40 CFR 86.1214-85 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Analytical gases. 86.1214-85 Section... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1214-85 Analytical gases. (a) Analyzer gases. (1) Gases for...

  1. 41 CFR 50-204.70 - Compressed gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 40 CFR 86.1214-85 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Analytical gases. 86.1214-85 Section... Emission Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1214-85 Analytical gases. (a) Analyzer gases. (1) Gases for...

  7. 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.

  8. 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.

  9. [Application of phenological pattern recognition in ecological dynamic forecasting].

    PubMed

    Pei, Tiefan; Jin, Changiie

    2005-09-01

    This paper described the principles, methods, and procedures of ecological dynamic forecasting by the automation techniques of pattern recognition and mathematical logic judgment on the basis of phenological data and model output maps from T42L9 numerical weather prediction model. This new forecasting method proposed on the basis of modern meteorology and automation techniques enables the classic phenology to apply to a new field ecological forecasting. It enables phenological forecasting to develop from single-station forecasting stage to regional forecasting stage, which is greatly corresponded to the development stage from single station forecasting stage to synoptic stage in weather forecasting, and enables agro-meteorological forecasting to develop from qualitative and statistical forecasting stage to ecological dynamic forecasting stage. With this new qualitative forecasting method, both the predicted objective and predictors are of considerable bio-physical interests. The ecological dynamic forecasting method could be applied to crop sowing, crop growth, irrigation and fertilization, and diseases and pests

  10. Broader perspectives for comparing different greenhouse gases.

    PubMed

    Manning, Martin; Reisinger, Andy

    2011-05-28

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

  11. 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

  12. Empirical seasonal forecasts of the NAO

    NASA Astrophysics Data System (ADS)

    Sanchezgomez, E.; Ortizbevia, M.

    2003-04-01

    We present here seasonal forecasts of the North Atlantic Oscillation (NAO) issued from ocean predictors with an empirical procedure. The Singular Values Decomposition (SVD) of the cross-correlation matrix between predictor and predictand fields at the lag used for the forecast lead is at the core of the empirical model. The main predictor field are sea surface temperature anomalies, although sea ice cover anomalies are also used. Forecasts are issued in probabilistic form. The model is an improvement over a previous version (1), where Sea Level Pressure Anomalies were first forecast, and the NAO Index built from this forecast field. Both correlation skill between forecast and observed field, and number of forecasts that hit the correct NAO sign, are used to assess the forecast performance , usually above those values found in the case of forecasts issued assuming persistence. For certain seasons and/or leads, values of the skill are above the .7 usefulness treshold. References (1) SanchezGomez, E. and Ortiz Bevia M., 2002, Estimacion de la evolucion pluviometrica de la Espana Seca atendiendo a diversos pronosticos empiricos de la NAO, in 'El Agua y el Clima', Publicaciones de la AEC, Serie A, N 3, pp 63-73, Palma de Mallorca, Spain

  13. 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.

  14. Visualization of ocean forecast in BYTHOS

    NASA Astrophysics Data System (ADS)

    Zhuk, E.; Zodiatis, G.; Nikolaidis, A.; Stylianou, S.; Karaolia, A.

    2016-08-01

    The Cyprus Oceanography Center has been constantly searching for new ideas for developing and implementing innovative methods and new developments concerning the use of Information Systems in Oceanography, to suit both the Center's monitoring and forecasting products. Within the frame of this scope two major online managing and visualizing data systems have been developed and utilized, those of CYCOFOS and BYTHOS. The Cyprus Coastal Ocean Forecasting and Observing System - CYCOFOS provides a variety of operational predictions such as ultra high, high and medium resolution ocean forecasts in the Levantine Basin, offshore and coastal sea state forecasts in the Mediterranean and Black Sea, tide forecasting in the Mediterranean, ocean remote sensing in the Eastern Mediterranean and coastal and offshore monitoring. As a rich internet application, BYTHOS enables scientists to search, visualize and download oceanographic data online and in real time. The recent improving of BYTHOS system is the extension with access and visualization of CYCOFOS data and overlay forecast fields and observing data. The CYCOFOS data are stored at OPENDAP Server in netCDF format. To search, process and visualize it the php and python scripts were developed. Data visualization is achieved through Mapserver. The BYTHOS forecast access interface allows to search necessary forecasting field by recognizing type, parameter, region, level and time. Also it provides opportunity to overlay different forecast and observing data that can be used for complex analyze of sea basin aspects.

  15. Assessing probabilistic forecasts of volcanic eruption onsets

    NASA Astrophysics Data System (ADS)

    Bebbington, Mark S.

    2013-12-01

    A method for assessing prospectively the quality of a suite of eruption forecasts is proposed. Any forecast of the next eruption onset from a polygenetic volcano can be converted into a probability distribution for the elapsed time since the forecast is made. This probability distribution, which effectively becomes a statistical P value when the observation is "plugged in," will thus itself have a uniform distribution under the null hypothesis that the forecast correctly describes the process. Given sufficient realizations, which may be on the same or different volcanoes, we can use standard statistical tests, such as the Kolmogorov-Smirnov test, to determine if the forecasts are consistent with the model(s). The use of the Kolmogorov-Smirnov test enables currently open forecasts to be included via the Kaplan-Meier product-limit estimator. While consistent underestimates (or overestimates) of the repose length will result in a median greater (or less) than , the method also assesses whether the method assigns the correct degree of aleatory variability to the forecast. Note that it is possible for the forecasts to be less precise than claimed. This would be indicated by the median of the sample being around , but the quartiles being well outside the interval, for example. The method is illustrated on the author's library of forecasts dating back to 1994, including renewal models and other point processes, on a gallery of approximately 20 volcanoes including Etna, Aso, and Ruapehu.

  16. 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

  17. 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.

  18. 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

  19. Intermediate-term forecasting of aftershocks from an early aftershock sequence: Bayesian and ensemble forecasting approaches

    NASA Astrophysics Data System (ADS)

    Omi, Takahiro; Ogata, Yosihiko; Hirata, Yoshito; Aihara, Kazuyuki

    2015-04-01

    Because aftershock occurrences can cause significant seismic risks for a considerable time after the main shock, prospective forecasting of the intermediate-term aftershock activity as soon as possible is important. The epidemic-type aftershock sequence (ETAS) model with the maximum likelihood estimate effectively reproduces general aftershock activity including secondary or higher-order aftershocks and can be employed for the forecasting. However, because we cannot always expect the accurate parameter estimation from incomplete early aftershock data where many events are missing, such forecasting using only a single estimated parameter set (plug-in forecasting) can frequently perform poorly. Therefore, we here propose Bayesian forecasting that combines the forecasts by the ETAS model with various probable parameter sets given the data. By conducting forecasting tests of 1 month period aftershocks based on the first 1 day data after the main shock as an example of the early intermediate-term forecasting, we show that the Bayesian forecasting performs better than the plug-in forecasting on average in terms of the log-likelihood score. Furthermore, to improve forecasting of large aftershocks, we apply a nonparametric (NP) model using magnitude data during the learning period and compare its forecasting performance with that of the Gutenberg-Richter (G-R) formula. We show that the NP forecast performs better than the G-R formula in some cases but worse in other cases. Therefore, robust forecasting can be obtained by employing an ensemble forecast that combines the two complementary forecasts. Our proposed method is useful for a stable unbiased intermediate-term assessment of aftershock probabilities.

  20. Bias correcting precipitation forecasts to improve the skill of seasonal streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Crochemore, Louise; Ramos, Maria-Helena; Pappenberger, Florian

    2016-09-01

    Meteorological centres make sustained efforts to provide seasonal forecasts that are increasingly skilful, which has the potential to benefit streamflow forecasting. Seasonal streamflow forecasts can help to take anticipatory measures for a range of applications, such as water supply or hydropower reservoir operation and drought risk management. This study assesses the skill of seasonal precipitation and streamflow forecasts in France to provide insights into the way bias correcting precipitation forecasts can improve the skill of streamflow forecasts at extended lead times. We apply eight variants of bias correction approaches to the precipitation forecasts prior to generating the streamflow forecasts. The approaches are based on the linear scaling and the distribution mapping methods. A daily hydrological model is applied at the catchment scale to transform precipitation into streamflow. We then evaluate the skill of raw (without bias correction) and bias-corrected precipitation and streamflow ensemble forecasts in 16 catchments in France. The skill of the ensemble forecasts is assessed in reliability, sharpness, accuracy and overall performance. A reference prediction system, based on historical observed precipitation and catchment initial conditions at the time of forecast (i.e. ESP method) is used as benchmark in the computation of the skill. The results show that, in most catchments, raw seasonal precipitation and streamflow forecasts are often more skilful than the conventional ESP method in terms of sharpness. However, they are not significantly better in terms of reliability. Forecast skill is generally improved when applying bias correction. Two bias correction methods show the best performance for the studied catchments, each method being more successful in improving specific attributes of the forecasts: the simple linear scaling of monthly values contributes mainly to increasing forecast sharpness and accuracy, while the empirical distribution mapping

  1. National Severe Storms Forecast Center

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The principal mission of the National Severe Storms Forecast Center (NSSFC) is to maintain a continuous watch of weather developments that are capable of producing severe local storms, including tornadoes, and to prepare and issue messages designated as either Weather Outlooks or Tornado or Severe Thunderstorm Watches for dissemination to the public and aviation services. In addition to its assigned responsibility at the national level, the NSSFC is involved in a number of programs at the regional and local levels. Subsequent subsections and paragraphs describe the NSSFC, its users, inputs, outputs, interfaces, capabilities, workload, problem areas, and future plans in more detail.

  2. Earthquake Scaling, Simulation and Forecasting

    NASA Astrophysics Data System (ADS)

    Sachs, Michael Karl

    Earthquakes are among the most devastating natural events faced by society. In 2011, just two events, the magnitude 6.3 earthquake in Christcurch New Zealand on February 22, and the magnitude 9.0 Tohoku earthquake off the coast of Japan on March 11, caused a combined total of $226 billion in economic losses. Over the last decade, 791,721 deaths were caused by earthquakes. Yet, despite their impact, our ability to accurately predict when earthquakes will occur is limited. This is due, in large part, to the fact that the fault systems that produce earthquakes are non-linear. The result being that very small differences in the systems now result in very big differences in the future, making forecasting difficult. In spite of this, there are patterns that exist in earthquake data. These patterns are often in the form of frequency-magnitude scaling relations that relate the number of smaller events observed to the number of larger events observed. In many cases these scaling relations show consistent behavior over a wide range of scales. This consistency forms the basis of most forecasting techniques. However, the utility of these scaling relations is limited by the size of the earthquake catalogs which, especially in the case of large events, are fairly small and limited to a few 100 years of events. In this dissertation I discuss three areas of earthquake science. The first is an overview of scaling behavior in a variety of complex systems, both models and natural systems. The focus of this area is to understand how this scaling behavior breaks down. The second is a description of the development and testing of an earthquake simulator called Virtual California designed to extend the observed catalog of earthquakes in California. This simulator uses novel techniques borrowed from statistical physics to enable the modeling of large fault systems over long periods of time. The third is an evaluation of existing earthquake forecasts, which focuses on the Regional

  3. 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.

  4. 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.

  5. Uncertainty forecasts improve weather-related decisions and attenuate the effects of forecast error.

    PubMed

    Joslyn, Susan L; LeClerc, Jared E

    2012-03-01

    Although uncertainty is inherent in weather forecasts, explicit numeric uncertainty estimates are rarely included in public forecasts for fear that they will be misunderstood. Of particular concern are situations in which precautionary action is required at low probabilities, often the case with severe events. At present, a categorical weather warning system is used. The work reported here tested the relative benefits of several forecast formats, comparing decisions made with and without uncertainty forecasts. In three experiments, participants assumed the role of a manager of a road maintenance company in charge of deciding whether to pay to salt the roads and avoid a potential penalty associated with icy conditions. Participants used overnight low temperature forecasts accompanied in some conditions by uncertainty estimates and in others by decision advice comparable to categorical warnings. Results suggested that uncertainty information improved decision quality overall and increased trust in the forecast. Participants with uncertainty forecasts took appropriate precautionary action and withheld unnecessary action more often than did participants using deterministic forecasts. When error in the forecast increased, participants with conventional forecasts were reluctant to act. However, this effect was attenuated by uncertainty forecasts. Providing categorical decision advice alone did not improve decisions. However, combining decision advice with uncertainty estimates resulted in the best performance overall. The results reported here have important implications for the development of forecast formats to increase compliance with severe weather warnings as well as other domains in which one must act in the face of uncertainty.

  6. Perturbation of convection-permitting NWP forecasts for flash-flood ensemble forecasting

    NASA Astrophysics Data System (ADS)

    Vincendon, B.; Ducrocq, V.; Nuissier, O.; Vié, B.

    2011-05-01

    Mediterranean intense weather events often lead to devastating flash-floods. Extending the forecasting 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 forecast, even using a high-resolution convection-permitting NWP deterministic forecasting. This study proposes a new method to sample the uncertainties of high-resolution NWP precipitation forecasts in order to quantify the predictability of the streamflow forecasts. We have developed a perturbation method based on convection-permitting NWP-model error statistics. It produces short-term precipitation ensemble forecasts from single-value meteorological forecasts. These rainfall ensemble forecasts are then fed into a hydrological model dedicated to flash-flood forecasting to produce ensemble streamflow forecasts. The verification on two flash-flood events shows that this forecasting ensemble performs better than the deterministic forecast. 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.

  7. Uncertainty forecasts improve weather-related decisions and attenuate the effects of forecast error.

    PubMed

    Joslyn, Susan L; LeClerc, Jared E

    2012-03-01

    Although uncertainty is inherent in weather forecasts, explicit numeric uncertainty estimates are rarely included in public forecasts for fear that they will be misunderstood. Of particular concern are situations in which precautionary action is required at low probabilities, often the case with severe events. At present, a categorical weather warning system is used. The work reported here tested the relative benefits of several forecast formats, comparing decisions made with and without uncertainty forecasts. In three experiments, participants assumed the role of a manager of a road maintenance company in charge of deciding whether to pay to salt the roads and avoid a potential penalty associated with icy conditions. Participants used overnight low temperature forecasts accompanied in some conditions by uncertainty estimates and in others by decision advice comparable to categorical warnings. Results suggested that uncertainty information improved decision quality overall and increased trust in the forecast. Participants with uncertainty forecasts took appropriate precautionary action and withheld unnecessary action more often than did participants using deterministic forecasts. When error in the forecast increased, participants with conventional forecasts were reluctant to act. However, this effect was attenuated by uncertainty forecasts. Providing categorical decision advice alone did not improve decisions. However, combining decision advice with uncertainty estimates resulted in the best performance overall. The results reported here have important implications for the development of forecast formats to increase compliance with severe weather warnings as well as other domains in which one must act in the face of uncertainty. PMID:21875244

  8. 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.

  9. Bromine-containing source gases during EASOE

    SciTech Connect

    Fabian, P. ); Borchers, R.; Kourtidis, K. )

    1994-06-22

    The authors report three different vertical profile measurements of three bromine containing gases which are thought to be the major sources of active bromine in the stratosphere. These gases 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 gases with altitude was an increase in the density of BrO[sub x] with altitude.

  10. Where do California's greenhouse gases come from?

    SciTech Connect

    Fischer, Marc

    2009-01-01

    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 gases: 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 gases 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 gases 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.

  11. Advanced Global Atmospheric Gases Experiment (AGAGE)

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.

    2001-01-01

    AGAGE comprises continuous high frequency in-situ gas chromatographic FID/ECD measurements of two biogenic/anthropogenic gases (CH4, N2O) and five anthropogenic gases (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 gases.

  12. Density Fluctuations in Uniform Quantum Gases

    SciTech Connect

    Bosse, J.; Pathak, K. N.; Singh, G. S.

    2011-12-12

    Analytical expressions are given for the static structure factor S(k) and the pair correlation function g(r) for uniform ideal Bose-Einstein and Fermi-Dirac gases for all temperatures. In the vicinity of Bose Einstein condensation (BEC) temperature, g(r) becomes long ranged and remains so in the condensed phase. In the dilute gas limit, g(r) of bosons and fermions do not coincide with Maxwell-Boltzmann gas but exhibit bunching and anti-bunching effect respectively. The width of these functions depends on the temperature and is scaled as {radical}(inverse atomic mass). Our numerical results provide the precise quantitative values of suppression/increase (antibunching and bunching) of the density fluctuations at small distances in ideal quantum gases in qualitative agreement with the experimental observation for almost non-trapped dilute gases.

  13. Rare gases in cyclosilicates and cogenetic minerals

    NASA Technical Reports Server (NTRS)

    Saito, K.; Alexander, E. C., Jr.; Dragon, J. C.; Zashu, S.

    1984-01-01

    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 gases 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 gases 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 gases 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.

  14. Where do California's greenhouse gases come from?

    ScienceCinema

    Fischer, Marc

    2016-07-12

    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 gases: 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 gases 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 gases 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.

  15. From Fire Observations to Smoke Plume Forecasting in the MACC Services

    NASA Astrophysics Data System (ADS)

    Kaiser, Johannes W.; Benedetti, A.; Flemming, J.; Morcrette, J.-J.; Heil, A.; Schultz, M. G.; van der Werf, G. R.; Wooster, M. J.

    2011-01-01

    The MACC project is implementing atmospheric monitoring and forecasting 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 gases. 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 forecast, with three days lead time, an air quality threshold transgression in Finland that resulted from the Russian fires.

  16. Forecasting volcanic air pollution in Hawaii: Tests of time series models

    NASA Astrophysics Data System (ADS)

    Reikard, Gordon

    2012-12-01

    Volcanic air pollution, known as vog (volcanic smog) has recently become a major issue in the Hawaiian islands. Vog is caused when volcanic gases react with oxygen and water vapor. It consists of a mixture of gases and aerosols, which include sulfur dioxide and other sulfates. The source of the volcanic gases is the continuing eruption of Mount Kilauea. This paper studies predicting vog using statistical methods. The data sets include time series for SO2 and SO4, over locations spanning the west, south and southeast coasts of Hawaii, and the city of Hilo. The forecasting models include regressions and neural networks, and a frequency domain algorithm. The most typical pattern for the SO2 data is for the frequency domain method to yield the most accurate forecasts over the first few hours, and at the 24 h horizon. The neural net places second. For the SO4 data, the results are less consistent. At two sites, the neural net generally yields the most accurate forecasts, except at the 1 and 24 h horizons, where the frequency domain technique wins narrowly. At one site, the neural net and the frequency domain algorithm yield comparable errors over the first 5 h, after which the neural net dominates. At the remaining site, the frequency domain method is more accurate over the first 4 h, after which the neural net achieves smaller errors. For all the series, the average errors are well within one standard deviation of the actual data at all the horizons. However, the errors also show irregular outliers. In essence, the models capture the central tendency of the data, but are less effective in predicting the extreme events.

  17. NMR studies and applications of perfluorocarbon gases

    NASA Astrophysics Data System (ADS)

    Chang, Yulin

    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 gases 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 gases 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 gases can distinguish emphysematous lungs from healthy ones. An important application of these gases 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 gases were also used in studies of carbon-block filters, where the strong adsorption of the gases 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.

  18. Temporally multiplexed quantum repeaters with atomic gases

    SciTech Connect

    Simon, Christoph; Riedmatten, Hugues de; Afzelius, Mikael

    2010-07-15

    We propose a temporally multiplexed version of the Duan-Lukin-Cirac-Zoller (DLCZ) quantum-repeater protocol using controlled inhomogeneous spin broadening in atomic gases. A first analysis suggests that the advantage of multiplexing is negated by noise due to spin-wave excitations corresponding to unobserved directions of Stokes photon emission. However, this problem can be overcome with the help of a moderate-finesse cavity which is in resonance with Stokes photons, but invisible to the anti-Stokes photons. Our proposal promises greatly enhanced quantum repeater performance with atomic gases.

  19. Oxidation of ultrathin GaSe

    SciTech Connect

    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.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe 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.

  20. Measuring Viscosities of Gases at Atmospheric Pressure

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini

    1987-01-01

    Variant of general capillary method for measuring viscosities of unknown gases 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 gases. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.

  1. Xenon and other noble gases in shergottites

    NASA Technical Reports Server (NTRS)

    Swindle, T. D.; Caffee, M. W.; Hohenberg, C. M.

    1986-01-01

    The isotopic composition of the xenon component trapped in EETA 79001's lithologies B and C has been determined, and other noble gases were measured in some samples. The Xe component was found to have light isotope ratios indistinguishable from those of the terrestrial atmosphere. The trapped component has a Xe-129/Xe-132 ratio of about 2.4, and is enhanced in Xe-134 and Xe-136 relative to the terrestrial atmosphere or the average carbonaceous chondrite. Similarities between values for Ar-40/Ar-36, Xe-129/Xe-132, and N-15/N-14 and the corresponding Martian atmospheric values suggest Martian origin of the trapped gases.

  2. Oxidation of ultrathin GaSe

    DOE PAGES

    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.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe 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.

  3. Origins of geothermal gases at Yellowstone

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  4. Measurement and interpretation of arterial blood gases.

    PubMed

    Syabbalo, N

    1997-01-01

    Arterial blood gases 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 gases. PMID:9293061

  5. Stationary light in cold-atomic gases

    SciTech Connect

    Nikoghosyan, Gor; Fleischhauer, Michael

    2009-07-15

    We discuss stationary light created by a pair of counterpropagating control fields in {lambda}-type atomic gases 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 gases.

  6. Origins of geothermal gases at Yellowstone

    USGS Publications Warehouse

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

    2015-01-01

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

  7. Managing biogeochemical cycles to reduce greenhouse gases

    SciTech Connect

    Post, Wilfred M; Venterea, Rodney

    2012-01-01

    This special issue focuses on terrestrial biogeochemical cycles as they relate to North America-wide budgeting and future projection of biogenic greenhouse gases (GHGs). Understanding the current magnitude and providing guidance on the future trajectories of atmospheric concentrations of these gases 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.

  8. Atomic Fermi gases in optical lattices

    SciTech Connect

    Modugno, G.; De Mirandes, E.; Ferlando, F.; Ott, H.; Roati, G.; Inguscio, M.

    2005-05-05

    We report on the first experiments with atomic Fermi gases in optical lattices. We have studied the properties of non interacting fermions and of an interacting boson-fermion mixture in a 1D lattice in presence of additional linear or harmonic potentials. These systems have allowed to study for the first time the fundamental quantum transport properties of a perfect crystal and to confirm the role of interactions in real crystals. We have found that the combination of Fermi gases and optical lattices can also have important applications, such as high-resolution force sensing.

  9. Oxidation of ultrathin GaSe

    SciTech Connect

    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.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe 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.

  10. 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

  11. Dissolved Oxygen Levels in Lake Chabot

    NASA Astrophysics Data System (ADS)

    Sharma, D.; Pica, R.

    2014-12-01

    Dissolved oxygen levels are crucial in every aquatic ecosystem; it allows for the fish to breathe and it is the best indicator of water quality. Lake Chabot is the main backup water source for Castro Valley, making it crucial that the lake stays in good health. Last year, research determined that the water in Lake Chabot was of good quality and not eutrophic. This year, an experiment was conducted using Lake Chabot's dissolved oxygen levels to ensure the quality of the water and to support the findings of the previous team. After testing three specifically chosen sites at the lake using a dissolved oxygen meter, results showed that the oxygen levels in the lake were within the healthy range. It was then determined that Lake Chabot is a suitable backup water source and it continues to remain a healthy habitat.

  12. 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.

  13. Earthquakes - Volcanoes (Causes and Forecast)

    NASA Astrophysics Data System (ADS)

    Tsiapas, E.

    2009-04-01

    EARTHQUAKES - VOLCANOES (CAUSES AND FORECAST) 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 forecast 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).

  14. Streamflow forecasting using functional regression

    NASA Astrophysics Data System (ADS)

    Masselot, Pierre; Dabo-Niang, Sophie; Chebana, Fateh; Ouarda, Taha B. M. J.

    2016-07-01

    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 forecast 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 forecasting. 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.

  15. Phantosmia as a meteorological forecaster

    NASA Astrophysics Data System (ADS)

    Aiello, S. R.; Hirsch, A. R.

    2013-09-01

    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 forecasted 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 forecast 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.

  16. Quantifying air-sea gas exchange using noble gases in a coastal upwelling zone

    NASA Astrophysics Data System (ADS)

    Manning, C. C.; Stanley, R. H. R.; Nicholson, D. P.; Squibb, M. E.

    2016-05-01

    The diffusive and bubble-mediated components of air-sea gas exchange can be quantified separately using time-series measurements of a suite of dissolved inert gases. We have evaluated the performance of four published air-sea gas exchange parameterizations using a five-day time-series of dissolved 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 gases, especially the lower solubility ones, to parameterize air-sea gas exchange.

  17. Modeled Forecasts of Dengue Fever in San Juan, Puerto Rico Using NASA Satellite Enhanced Weather Forecasts

    NASA Astrophysics Data System (ADS)

    Morin, C.; Quattrochi, D. A.; Zavodsky, B.; Case, J.

    2015-12-01

    Dengue fever (DF) is an important mosquito transmitted disease that is strongly influenced by meteorological and environmental conditions. Recent research has focused on forecasting DF case numbers based on meteorological data. However, these forecasting 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 forecasts are still in question because the error associated with weather and climate forecasts are not reflected in the results. Using up-to-date weekly dengue case numbers for model parameterization and weather forecast data as meteorological input, we produced weekly forecasts 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 forecast data to generate forecasts of DF case numbers. Real-time weather forecast data was produced using the Weather Research and Forecasting (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 forecast being evaluated using county-level DF cases reported by the Puerto Rico Department of Health. The one week DF forecasts were accurate especially considering the two sources of model error. First, weather forecasts 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 forecast. Although these results are promising, we would like to develop a methodology to produce longer range forecasts so that public health workers can better prepare for dengue epidemics.

  18. 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

  19. Ecological forecasting in Chesapeake Bay: Using a mechanistic-empirical modeling approach

    NASA Astrophysics Data System (ADS)

    Brown, C. W.; Hood, R. R.; Long, W.; Jacobs, J.; Ramers, D. L.; Wazniak, C.; Wiggert, J. D.; Wood, R.; Xu, J.

    2013-09-01

    The Chesapeake Bay Ecological Prediction System (CBEPS) automatically generates daily nowcasts and three-day forecasts of several environmental variables, such as sea-surface temperature and salinity, the concentrations of chlorophyll, nitrate, and dissolved 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 forecast 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 forecasts 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 forecasts, 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.

  20. Ecological Forecasting in Chesapeake Bay: Using a Mechanistic-Empirical Modelling Approach

    SciTech Connect

    Brown, C. W.; Hood, Raleigh R.; Long, Wen; Jacobs, John M.; Ramers, D. L.; Wazniak, C.; Wiggert, J. D.; Wood, R.; Xu, J.

    2013-09-01

    The Chesapeake Bay Ecological Prediction System (CBEPS) automatically generates daily nowcasts and three-day forecasts of several environmental variables, such as sea-surface temperature and salinity, the concentrations of chlorophyll, nitrate, and dissolved 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 forecast 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 forecasts 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 forecasts, 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.

  1. Some Initiatives in a Business Forecasting Course

    ERIC Educational Resources Information Center

    Chu, Singfat

    2007-01-01

    The paper reports some initiatives to freshen up the typical undergraduate business forecasting course. These include (1) students doing research and presentations on contemporary tools and industry practices such as neural networks and collaborative forecasting (2) insertion of Logistic Regression in the curriculum (3) productive use of applets…

  2. Flood Forecasting in Wales: Challenges and Solutions

    NASA Astrophysics Data System (ADS)

    How, Andrew; Williams, Christopher

    2015-04-01

    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 forecasting 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 forecasting models. As a flood forecasting team we work to develop coastal and fluvial forecasting 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 forecasting 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 forecasting verification • ensemble forecast data • longer range forecast data • contingency models • offshore to nearshore wave transformation • calculation of wave overtopping

  3. Forecasting Popularity of Videos Using Social Media

    NASA Astrophysics Data System (ADS)

    Xu, Jie; van der Schaar, Mihaela; Liu, Jiangchuan; Li, Haitao

    2015-03-01

    This paper presents a systematic online prediction method (Social-Forecast) that is capable to accurately forecast the popularity of videos promoted by social media. Social-Forecast explicitly considers the dynamically changing and evolving propagation patterns of videos in social media when making popularity forecasts, thereby being situation and context aware. Social-Forecast aims to maximize the forecast reward, which is defined as a tradeoff between the popularity prediction accuracy and the timeliness with which a prediction is issued. The forecasting is performed online and requires no training phase or a priori knowledge. We analytically bound the prediction performance loss of Social-Forecast as compared to that obtained by an omniscient oracle and prove that the bound is sublinear in the number of video arrivals, thereby guaranteeing its short-term performance as well as its asymptotic convergence to the optimal performance. In addition, we conduct extensive experiments using real-world data traces collected from the videos shared in RenRen, one of the largest online social networks in China. These experiments show that our proposed method outperforms existing view-based approaches for popularity prediction (which are not context-aware) by more than 30% in terms of prediction rewards.

  4. Climate forecasts for corn producer decision making

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 forecasts, together with climate-related decision tools for corn producers based on these improved forecasts, could substantially reduce uncertai...

  5. Intermediate range forecasting - observational requirements and techniques

    NASA Astrophysics Data System (ADS)

    Hayden, Christopher M.

    1992-07-01

    The 1990s will witness a significant increase in meteorological observations, both traditional and innovative. Numerical weather forecast models will improve in terms of scale definition and physics. The role the observations, especially those from space, may play in improving the intermediater range forecast is presented. The greatest challenge is to insure that the modeler and the observationalist exploit their opportunities together.

  6. Resources and Long-Range Forecasts

    ERIC Educational Resources Information Center

    Smith, Waldo E.

    1973-01-01

    The author argues that forecasts 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 forecasts are likely to be wrong in such situations. (PS)

  7. Chesapeake Bay hypoxic volume forecasts and results

    USGS Publications Warehouse

    Scavia, Donald; Evans, Mary Anne

    2013-01-01

    The 2013 Forecast - Given the average Jan-May 2013 total nitrogen load of 162,028 kg/day, this summer’s hypoxia volume forecast 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.

  8. Ozone ensemble forecast with machine learning algorithms

    NASA Astrophysics Data System (ADS)

    Mallet, Vivien; Stoltz, Gilles; Mauricette, Boris

    2009-03-01

    We apply machine learning algorithms to perform sequential aggregation of ozone forecasts. The latter rely on a multimodel ensemble built for ozone forecasting with the modeling system Polyphemus. The ensemble simulations are obtained by changes in the physical parameterizations, the numerical schemes, and the input data to the models. The simulations are carried out for summer 2001 over western Europe in order to forecast ozone daily peaks and ozone hourly concentrations. On the basis of past observations and past model forecasts, the learning algorithms produce a weight for each model. A convex or linear combination of the model forecasts is then formed with these weights. This process is repeated for each round of forecasting and is therefore called sequential aggregation. The aggregated forecasts demonstrate good results; for instance, they always show better performance than the best model in the ensemble and they even compete against the best constant linear combination. In addition, the machine learning algorithms come with theoretical guarantees with respect to their performance, that hold for all possible sequences of observations, even nonstochastic ones. Our study also demonstrates the robustness of the methods. We therefore conclude that these aggregation methods are very relevant for operational forecasts.

  9. Techniques for Forecasting Air Passenger Traffic

    NASA Technical Reports Server (NTRS)

    Taneja, N.

    1972-01-01

    The basic techniques of forecasting 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 forecasting procedure. Emphasis is placed on describing the analytical method.

  10. Forecasting Enrollments with Fuzzy Time Series.

    ERIC Educational Resources Information Center

    Song, Qiang; Chissom, Brad S.

    The concept of fuzzy time series is introduced and used to forecast the enrollment of a university. Fuzzy time series, an aspect of fuzzy set theory, forecasts 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…

  11. Analog forecasting with dynamics-adapted kernels

    NASA Astrophysics Data System (ADS)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

    Analog forecasting 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 forecasting methods which improve traditional analog forecasting 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 forecasting with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve forecast 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 forecasting in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale forecasting in the North Pacific sector of a comprehensive climate model. We find that forecasts based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.

  12. Streamflow Ensemble Generation using Climate Forecasts

    NASA Astrophysics Data System (ADS)

    Watkins, D. W.; O'Connell, S.; Wei, W.; Nykanen, D.; Mahmoud, M.

    2002-12-01

    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 forecasts 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 forecasts, 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 forecasts 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 forecast performance. Verification of the ensemble forecasts using a resampling procedure indicates a small but potentially significant improvement in forecast skill that could be exploited in seasonal water management decisions. The ultimate goal of this work will be explicit incorporation of climate forecasts in reservoir operating rules and estimation of the value of the forecasts.

  13. School Science Inspired by Improving Weather Forecasts

    ERIC Educational Resources Information Center

    Reid, Heather; Renfrew, Ian A.; Vaughan, Geraint

    2014-01-01

    High winds and heavy rain are regular features of the British weather, and forecasting these events accurately is a major priority for the Met Office and other forecast 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…

  14. Why preferring parametric forecasting to nonparametric methods?

    PubMed

    Jabot, Franck

    2015-05-01

    A recent series of papers by Charles T. Perretti and collaborators have shown that nonparametric forecasting methods can outperform parametric methods in noisy nonlinear systems. Such a situation can arise because of two main reasons: the instability of parametric inference procedures in chaotic systems which can lead to biased parameter estimates, and the discrepancy between the real system dynamics and the modeled one, a problem that Perretti and collaborators call "the true model myth". Should ecologists go on using the demanding parametric machinery when trying to forecast the dynamics of complex ecosystems? Or should they rely on the elegant nonparametric approach that appears so promising? It will be here argued that ecological forecasting based on parametric models presents two key comparative advantages over nonparametric approaches. First, the likelihood of parametric forecasting failure can be diagnosed thanks to simple Bayesian model checking procedures. Second, when parametric forecasting is diagnosed to be reliable, forecasting uncertainty can be estimated on virtual data generated with the fitted to data parametric model. In contrast, nonparametric techniques provide forecasts with unknown reliability. This argumentation is illustrated with the simple theta-logistic model that was previously used by Perretti and collaborators to make their point. It should convince ecologists to stick to standard parametric approaches, until methods have been developed to assess the reliability of nonparametric forecasting.

  15. Solar power deployment: Forecasting and planning

    NASA Astrophysics Data System (ADS)

    Alanazi, Mohana

    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 forecasting. This thesis presents a thorough research of PV technology, how solar power can be forecasted, 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 forecasting method to reduce the uncertainty of the PV output so the power operator will be able to accommodate its variability. The new forecasting method proposes different processes to be undertaken before the data is fed to the forecasting model. The method converts the data sets included in the forecasting 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 forecasting method aims to reduce the forecasting error and analyzes the error effect on the long term planning through calculating the payback period considering different errors.

  16. Evaluation and first forecasts of the German Climate Forecast System 1 (GCFS1)

    NASA Astrophysics Data System (ADS)

    Fröhlich, Kristina; Baehr, Johanna; Müller, Wolfgang; Bunzel, Felix; Pohlmann, Holger; Dobrynin, Mikhail

    2016-04-01

    We present the near-operational seasonal forecast system GCFS1 (German Climate Forecast 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 forecasts are conducted by DWD. The system is running at ECMWF with a re-forecast ensemble of 15 member and a forecast ensemble of 30 member. The re-forecasts 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 forecasts analyses from the ECMWF NWP model and recent ORAS4 analyses are taken. The ensemble perturbations are, for both re-forecasts and forecasts, 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-forecasted climatologies will be presented for different variables, start dates and regions. The first winter forecast during the strong El Niño phase is also subject of evaluation.

  17. Monthly forecasting of agricultural pests in Switzerland

    NASA Astrophysics Data System (ADS)

    Hirschi, M.; Dubrovsky, M.; Spirig, C.; Samietz, J.; Calanca, P.; Weigel, A. P.; Fischer, A. M.; Rotach, M. W.

    2012-04-01

    Given the repercussions of pests and diseases on agricultural production, detailed forecasting 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 forecasts therefore require weather information for the relevant habitats and the appropriate time scale. The pest forecasting 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 forecast is issued, but only a climatology for the forecasting period. Here, we aim at improving the skill of SOPRA forecasts by transforming the weekly information provided by ECMWF monthly forecasts (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 forecasts 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 forecasting model. Results show a clear improvement in the forecast skill of occurrences of upcoming codling moth life phases when incorporating MOFCs as compared to the operational pest forecasting system. This is true both in terms of root mean squared errors and of the continuous rank probability scores of the

  18. Catalytic desulfurization of industrial waste gases

    SciTech Connect

    Dupin, Th.

    1985-07-30

    Industrial waste gases 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.

  19. Elimination of gases and contamination from water

    NASA Technical Reports Server (NTRS)

    Buck, A. P.

    1970-01-01

    Filtration system with membrane type hydrophilic and hydrophobic filters gives absolute filtration with automatic venting of freed gases, 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.

  20. Electron-Atom Collisions in Gases

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2013-01-01

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

  1. Refractive Indices of Gases at Microwave Frequencies

    ERIC Educational Resources Information Center

    Goodhead, D. T.; And Others

    1976-01-01

    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 gases and the analysis of the reflection in a test chamber. (Author/CP)

  2. Collective modes in cold paramagnetic gases

    SciTech Connect

    Andreeva, T L; Rubin, P L

    2014-02-28

    We have obtained a condition for the emergence of spin waves in paramagnetic gases Re >> ImÂ, which is fulfilled only at temperatures of the order of 1 μK. (laser applications and other topics in quantum electronics)

  3. Removing Sulphur Dioxide From Stack Gases

    ERIC Educational Resources Information Center

    Slack, A. V.

    1973-01-01

    Process types, process concepts, claims and counterclaims, cost factors, and the level of developed technology for sulfur dioxide control in stack gases are focused upon and evaluated. Wet and dry processes as well as recovery and throwaway processes are compared. (BL)

  4. Toxicity of pyrolysis gases from foam plastics

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Casey, C. J.

    1980-01-01

    Twenty-three samples of flexible foams and twelve samples of rigid foams were evaluated for toxicity of pyrolysis gases, using the USF toxicity screening test method. Polychloroprene among the flexible foams, and polystyrene among the rigid foams, appeared to exhibit the least toxicity under these particular test conditions.

  5. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, 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.

  6. Residual Gases in Crystal Growth Systems

    NASA Technical Reports Server (NTRS)

    Palosz, W.

    2003-01-01

    Residual gases 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 gases 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 gases 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 gases 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.

  7. Fullerenes and the Nature of Planetary Gases

    NASA Technical Reports Server (NTRS)

    Becker, Luann; Poreda, Robert J.; Nuth, Joe

    2003-01-01

    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 gases in the terrestrial planets. However, these models cannot explain the observed gradient of the gases, 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 gases, 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 gases.

  8. Demand forecast model based on CRM

    NASA Astrophysics Data System (ADS)

    Cai, Yuancui; Chen, Lichao

    2006-11-01

    With interiorizing day by day management thought that regarding customer as the centre, forecasting customer demand becomes more and more important. In the demand forecast of customer relationship management, the traditional forecast 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 forecasting 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 forecast the demands of new customer by the most similar characteristic customer.

  9. PV production forecast in La Reunion Island

    NASA Astrophysics Data System (ADS)

    Dubus, L.; Leboucher, V.; Garo, M.

    2010-09-01

    Photovoltaic power production is developing quickly in La Reunion (Indian Ocean). In order to integrate this fluctuating energy source into the network, reliable production forecasts are necessary from real time to day+3. Weather forecasts from standard models are in general inadequate, in particular due to too coarse resolution in this complex orography area. In this study, we use observations (Météo-France) and reanalysis (ERAinterim) fields to evaluate the potential predictability of PV production, for individual solar power plants and from the island aggregated point of view. This in particular allows to select the best weather predictors for PV production. The forecast quality of the selected fields was then established, in order to use only the interesting ones. Finally, NWPs are used to estimate which part of PV production predictability is accessible with state of the art weather forecasting models. This leads to requirements on temporal and spatial resolution of NWP to improve the forecast quality.

  10. Uncertainty in dispersion forecasts using meteorological ensembles

    SciTech Connect

    Chin, H N; Leach, M J

    1999-07-12

    The usefulness of dispersion forecasts 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 forecasts hours to days in advance are used to estimate the dispersion at the time of the event. However, there is uncertainty in any meteorological forecast, arising from both errors in the data (both initial conditions and boundary conditions) and from errors in the model. We use ensemble forecasts to estimate the uncertainty in the forecasts and the range of possible outcomes.

  11. Do probabilistic forecasts lead to better decisions?

    NASA Astrophysics Data System (ADS)

    Ramos, M. H.; van Andel, S. J.; Pappenberger, F.

    2013-06-01

    The last decade has seen growing research in producing probabilistic hydro-meteorological forecasts 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 forecasts to decision-makers. Communicating probabilistic forecasts 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 forecasts 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 forecasts.

  12. Guideline for developing an ozone forecasting program

    SciTech Connect

    Dye, T.S.; MacDonald, C.P.; Anderson, C.B.

    1999-07-01

    The purpose of this document is to provide guidance to help air quality agencies develop, operate, and evaluate ozone forecasting programs. This guidance document provides: Background information about ozone and the weather`s effect on ozone; A list of how ozone forecasts are currently used; A summary and evaluation of methods currently used to forecast ozone; and Steps you can follow to develop and operate an ozone forecasting 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 forecasting program. Meteorologists can learn about the various methods to predict ozone and the steps needed to create a program.

  13. Space Weather Forecasting: An Enigma

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.

    2012-12-01

    -pipe" disciplines. The perceived progress in space weather understanding differs significantly depending upon which community (scientific, technology, forecaster, society) is addressing the question. Even more divergent are these thoughts when the question is how valuable is the scientific capability of forecasting space weather. This talk will discuss present day as well as future potential for forecasting space weather for a few selected examples. The author will attempt to straddle the divergent community opinions.

  14. 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.

  15. Wind speed forecasting for wind energy applications

    NASA Astrophysics Data System (ADS)

    Liu, Hong

    With more wind energy being integrated into our grid systems, forecasting wind energy has become a necessity for all market participants. Recognizing the market demands, a physical approach to site-specific hub-height wind speed forecasting 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 forecasting 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 forecast. Coupling the WAsP model with GEM improves the overall forecasts, but remains unsatisfactory for forecasting 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 forecasts 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 forecast errors. The hub-height wind speed forecasts could be further improved using a linear MOS approach. The forecasting 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

  16. IUPAC-NIST Solubility Data Series 70. The Solubility of Gases in Glassy Polymers

    NASA Astrophysics Data System (ADS)

    Paterson, Russell; Yampol'Skii, Yuri P.; Fogg, Peter G. T.; Bokarev, Alexandre; Bondar, Valerii; Ilinich, Oleg; Shishatskii, Sergey

    1999-09-01

    Solubility of gases in polymers is an important property of polymeric materials relevant to many practical applications. Sorption of small molecules in polymers is a fundamental concern in such areas as food packaging, beverage storage, and polymer processing. However, by far the main interest in the solubility of gases in polymers, and especially in glassy polymers, is related to development of novel advanced materials for gas separation membranes. This is because the concentration gradient of a dissolved gas is the driving force of membrane processes. Development of these novel separation methods resulted in a rapid accumulation, in the recent literature, of thermodynamic data related to the solubility of gases in polymers at different temperatures and pressures. Polymers can be regarded as special cases of media intermediate between liquids and solids. As a consequence, modeling of gas sorption in polymers is very difficult and presents a permanent challenge to theoreticians and experimenters. The collection and critical evaluation of solubility data for various gas-polymer systems is relevant to both practical aspects of polymer applications and to fundamental studies of polymer behavior. This volume of the IUPAC-NIST Solubility Data Series summarizes the compilations and critical evaluations of the data on solubility of gases in glassy polymers. It is implied in this edition that "gases" are the components that are either permanent gases (supercitical fluids) or have saturated vapor pressure more than 1 atm at ambient conditions (298 K). The polymeric components of compilations and critical evaluations are primarily high molecular mass, amorphous, linear (noncross-linked) compounds that have the glass transition temperatures above ambient temperature. The data for each gas-polymer system have been evaluated, if the results of at least three independent and reliable studies have been reported. Where the data of sufficient accuracy and reliability are available

  17. The impact of seasonality and elevation on dissolved greenhouse gas concentrations in a northeastern Wyoming watershed

    NASA Astrophysics Data System (ADS)

    Kuhn, C.; Bettigole, C.; Raymond, P. A.; Glick, H.; Seegmiller, L.; Oliver, C.; Khadka, A.; Routh, D.

    2014-12-01

    Quantification of river and stream contributions to global carbon emission budgets using field-based measurements is key to understanding how freshwater streams act as conduits between terrestrial and atmospheric carbon pools. In order to better characterize drivers of this process, this study quantifies: a) emissions of carbon dioxide and methane from a semi-arid, high plains riverine system with montaine headwaters in order to establish baseline data for the watershed; b) the impact of stream order, seasonality and elevation on dissolved gas concentrations to better understand the spatial and temporal heterogeneity of dissolved carbon gases. To achieve the latter objective, we conducted field surveys in first and second order streams in the Clear Creek drainage of the Powder River Basin watershed. We took direct measurements of stream gases using headspace sampling at thirty sites along an elevation gradient ranging from 1,203-3,346 meters. We also intensely monitored five transects throughout the descending limb of spring runoff (June 8th-August 12th) to investigate how temperature and discharge volume impact greenhouse gas concentrations. Clear Creek, located in northeastern Wyoming, is approximately 118.4 km long with a drainage area of 2,968 km2. The creek flows east out of Bighorn National Forest where it turns northeast to converge with the Powder River about ten miles before the Montana border. The stream straddles the Middle Rockies and Northwestern Great Plains ecoregions and experiences an abrupt shift in soil type, riparian vegetation, underlying geology and stream geometry as the stream exits the mountains and enters the agricultural alluvial floodplain. These site specific biological and physical changes along the elevation gradient affect dissolved greenhouse gas concentrations.

  18. 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…

  19. Dissolving Microneedles for Transdermal Drug Delivery

    PubMed Central

    Lee, Jeong Woo; Park, Jung-Hwan; Prausnitz, Mark R.

    2008-01-01

    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 two 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

  20. Comparison of sampling methods for the determination of sulfur species in volcanic gases

    NASA Astrophysics Data System (ADS)

    Lee, S.; Park, M.; Jeong, H. Y.

    2014-12-01

    We aimed to evaluate three methods for the determination of sulfur species in volcanic gases 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 gases (H2S + SO2) from the artificial fumarole were dissolved 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 gases 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 dissolved 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 gases 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 gases were in good agreement with the expected ones.

  1. Final Report on California Regional Wind Energy Forecasting Project:Application of NARAC Wind Prediction System

    SciTech Connect

    Chin, H S

    2005-07-26

    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 gases 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 forecasting has been recognized as an important factor to further improve the wind energy forecast 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 forecasting capability to develop an improved regional wind energy forecasting 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

  2. Construction Safety Forecast for ITER

    SciTech Connect

    cadwallader, lee charles

    2006-11-01

    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 forecast 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.

  3. Real-time flood forecasting

    USGS Publications Warehouse

    Lai, C.; Tsay, T.-K.; Chien, C.-H.; Wu, I.-L.

    2009-01-01

    Researchers at the Hydroinformatic Research and Development Team (HIRDT) of the National Taiwan University undertook a project to create a real time flood forecasting 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.

  4. Decision support for financial forecasting

    SciTech Connect

    Jairam, B.N.; Morris, J.D.; Emrich, M.L.; Hardee, H.K.

    1988-10-01

    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 Forecasting 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.

  5. Challenges in Forecasting SEP Events

    NASA Astrophysics Data System (ADS)

    Luhmann, Janet; Mays, M. Leila; Odstrcil, Dusan; Bain, Hazel; Li, Yan; Leske, Richard; Cohen, Christina

    2015-04-01

    A long-standing desire of space weather prediction providers has been the ability to forecast 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 forecasts together with the other heliospheric predictions.

  6. MSSM forecast for the LHC

    NASA Astrophysics Data System (ADS)

    Cabrera, Maria Eugenia; Casas, J. Alberto; de Austri, Roberto Ruiz

    2010-05-01

    We perform a forecast of the MSSM with universal soft terms (CMSSM) for the LHC, based on an improved Bayesian analysis. We do not incorporate ad hoc measures of the fine-tuning to penalize unnatural possibilities: such penalization arises from the Bayesian analysis itself when the experimental value of M Z is considered. This allows to scan the whole parameter space, allowing arbitrarily large soft terms. Still the low-energy region is statistically favoured (even before including dark matter or g-2 constraints). Contrary to other studies, the results are almost unaffected by changing the upper limits taken for the soft terms. The results are also remarkable stable when using flat or logarithmic priors, a fact that arises from the larger statistical weight of the low-energy region in both cases. Then we incorporate all the important experimental constrains to the analysis, obtaining a map of the probability density of the MSSM parameter space, i.e. the forecast of the MSSM. Since not all the experimental information is equally robust, we perform separate analyses depending on the group of observables used. When only the most robust ones are used, the favoured region of the parameter space contains a significant portion outside the LHC reach. This effect gets reinforced if the Higgs mass is not close to its present experimental limit and persits when dark matter constraints are included. Only when the g-2 constraint (based on e + e - data) is considered, the preferred region (for μ > 0) is well inside the LHC scope. We also perform a Bayesian comparison of the positive- and negative- μ possibilities.

  7. Phantosmia as a meteorological forecaster.

    PubMed

    Aiello, S R; Hirsch, A R

    2013-09-01

    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 forecasted 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 forecast 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

  8. Phantosmia as a meteorological forecaster.

    PubMed

    Aiello, S R; Hirsch, A R

    2013-09-01

    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 forecasted 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 forecast 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.

  9. Tested Demonstrations: Diffusion of Gases--Kinetic Molecular Theory of Gases.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1984-01-01

    Provided are procedures and list of materials needed to demonstrate that the pressure inside a container with a porous surface can be changed due to the rate of diffusion of low molecular weight gases. Typical results obtained are included. (JN)

  10. Evaluation and comparison of O3 forecasts of ALARO-CAMx and WRF-Chem

    NASA Astrophysics Data System (ADS)

    Flandorfer, Claudia; Hirtl, Marcus

    2015-04-01

    ZAMG runs two models for Air-Quality forecasts 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 forecasts 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 gases 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 forecasts. The evaluation of both models is conducted for summer 2014 with the main focus on the forecasts of ozone. The measurements of the Air-Quality stations are compared with the punctual forecasts at the sites of the stations and with the area forecasts for every province of Austria. Beside the evaluation a comparison of the forecasts 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

  11. Combustion control system adding a liquid, exhaust gases, and PCV gases

    SciTech Connect

    Lindberg, J.E.

    1980-01-15

    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 gases, and PCV gases for mixing within the vortex chamber. The incoming liquid, air, exhaust gases, and PCV gases 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 gases. In a specific embodiment, the input constructions include a liquid-exhaust gas acceleration chamber for mixing liquid with exhaust gases and a PCV-exhaust gas vortex chamber for mixing exhaust gases with PCV gases 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.

  12. Evaluation of Flood Forecast and Warning in Elbe river basin - Impact of Forecaster's Strategy

    NASA Astrophysics Data System (ADS)

    Danhelka, Jan; Vlasak, Tomas

    2010-05-01

    Czech Hydrometeorological Institute (CHMI) is responsible for flood forecasting and warning in the Czech Republic. To meet that issue CHMI operates hydrological forecasting systems and publish flow forecast in selected profiles. Flood forecast and warning is an output of system that links observation (flow and atmosphere), data processing, weather forecast (especially NWP's QPF), hydrological modeling and modeled outputs evaluation and interpretation by forecaster. Forecast users are interested in final output without separating uncertainties of separate steps of described process. Therefore an evaluation of final operational forecasts was done for profiles within Elbe river basin produced by AquaLog forecasting system during period 2002 to 2008. Effects of uncertainties of observation, data processing and especially meteorological forecasts were not accounted separately. Forecast of flood levels exceedance (peak over the threshold) during forecasting period was the main criterion as flow increase forecast 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 forecasting 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 forecast skill between forecasting 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

  13. Testing the Value of Probability Forecasts for Calibrated Combining

    PubMed Central

    Lahiri, Kajal; Peng, Huaming; Zhao, Yongchen

    2014-01-01

    We combine the probability forecasts of a real GDP decline from the U.S. Survey of Professional Forecasters, after trimming the forecasts 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 forecasts. The proposed test does not require the probabilities to be converted to binary forecasts before testing, and it accommodates serial correlation and skewness in the forecasts. We find that the number of forecasters making valuable forecasts decreases sharply as the horizon increases. The beta-transformed linear pool combination scheme, based on the valuable individual forecasts, 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 forecasters ex ante, and therefore contributes to the accuracy of the combined forecasts. PMID:25530646

  14. Performance of aftershock forecasts: problem and formulation

    NASA Astrophysics Data System (ADS)

    Jiang, C.; Wu, Z.; Li, L.

    2010-12-01

    WFSD project deals with the problems of earthquake physics, in which one of the important designed aims is the forecast 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 forecast 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 forecast scheme against real seismic activity. Due to the special characteristics of aftershock series and the feature of aftershock forecasts that it deals with a limited spatial range and specific temporal duration, the test of the performance of aftershock forecasts 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 forecasts - 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 forecasts, 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.

  15. Urban Air Quality Forecasting in Canada

    NASA Astrophysics Data System (ADS)

    Pavlovic, Radenko; Menard, Sylvain; Cousineau, Sophie; Stroud, Craig; Moran, Michael

    2016-04-01

    Environment and Climate Change Canada has been providing air quality (AQ) forecasts for major Canadian urban centers since 2001. Over this period, the Canadian AQ Forecast 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 forecasts for locations with AQ monitors to reduce point forecast bias and error. These outputs provide the primary guidance from which operational meteorologists disseminate Air Quality Health Index (AQHI) forecasts 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 forecast 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 forecasting will also be presented.

  16. National Weather Service Forecast Reference Evapotranspiration

    NASA Astrophysics Data System (ADS)

    Osborne, H. D.; Palmer, C. K.; Krone-Davis, P.; Melton, F. S.; Hobbins, M.

    2013-12-01

    The National Weather Service (NWS), Weather Forecasting Offices (WFOs) are producing daily reference evapotranspiration (ETrc) forecasts 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 forecasters with knowledge of local terrain and weather patterns to better forecast in the ETrc inputs. The daily FRET product then evolved into a suite of products, including a weekly ETrc forecast for better water planning and a tabular point forecast for easy ingest into local water management-models. The ETrc forecast 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.

  17. Tropical ocean initialisation strategies for seasonal forecasting

    NASA Astrophysics Data System (ADS)

    Mulholland, David; Haines, Keith

    2016-04-01

    Operational seasonal ENSO forecasts 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 forecast, since the bias correction term is generally not retained during the forecast itself. We present results from a number of ensemble simulations carried out with the European Centre for Medium-range Weather Forecasts (ECMWF) coupled forecast system, comparing different initialisation strategies for the equatorial ocean. Rapid adjustments in the ocean at the beginning of the forecast 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 forecast skill, at lead times of 3-7 months. The results highlight the importance of ocean initialisation in maximising the skill of ENSO predictions.

  18. Seasonal hydrological ensemble forecasts over Europe

    NASA Astrophysics Data System (ADS)

    Arnal, Louise; Wetterhall, Fredrik; Stephens, Elisabeth; Cloke, Hannah; Pappenberger, Florian

    2016-04-01

    This study investigates the limits of predictability in dynamical seasonal discharge forecasting, in both space and time, over Europe. Seasonal forecasts 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 forecasts on sub-seasonal to seasonal timescales. In this study, seasonal hydrological forecasts (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 forecasts were produced by the LISFLOOD model, run on the pan-European scale with a spatial resolution of 5 by 5 km. The forecasts 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 forecasts 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 forecasting uncertainties in Europe. These results could help pinpoint target elements of the forecasting chain which, after being improved, could lead to substantial increase in discharge predictability

  19. Accurate Weather Forecasting for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Maddalena, Ronald J.

    2010-01-01

    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 forecasts for winds and opacities. Since opacity forecasts are not provided by the National Weather Services (NWS), I have developed an automated system that takes available forecasts, derives forecasted 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 forecast 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 forecasted Tsys at 22.2 and 44 GHz imply that the forecasted opacities are good to about 0.01 Nepers, which is sufficient for forecasting and accurate calibration. Reliability is high out to 2 days and degrades slowly for longer-range forecasts.

  20. Accuracy analysis of TDRSS demand forecasts

    NASA Technical Reports Server (NTRS)

    Stern, Daniel C.; Levine, Allen J.; Pitt, Karl J.

    1994-01-01

    This paper reviews Space Network (SN) demand forecasting experience over the past 16 years and describes methods used in the forecasts. 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. Forecasting 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 forecasts ten years in the future a planning horizon beyond the funding commitments for missions to be supported. The long range forecasts 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 forecasts are likely to be moderately underestimated. The SN commitment to meet the negotiated customer's requirements calls for conservatism in the forecasting. Modification of the forecasting 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 forecasting.

  1. Acquisition and Early Losses of Rare Gases from the Deep Earth

    NASA Technical Reports Server (NTRS)

    Porcelli, D.; Cassen, P.; Woolum, D.; Wasserburg, G. J.

    1998-01-01

    Direct observations show that the deep Earth contains rare gases of solar composition distinct from those in the atmosphere. We examine the implications of mantle rare gas characteristics on acquisition of rare gases from the solar nebula and subsequent losses due to a large impact. Deep mantle rare gas concentrations and isotopic compositions can be obtained from a model of transport and distribution of mantle rare gases. This model assumes the lower mantle closed early, while the upper mantle is open to subduction from the atmosphere and mass transfer from the lower mantle. Constraints are derived that can be incorporated into models for terrestrial volatile acquisition: (1) Calculated lower-mantle Xe-isotopic ratios indicate that the fraction of radiogenic Xe produced by I-129 and Pu-244 during the first about 10(exp 8) yr was lost, a conclusion also drawn for atmospheric Xe. Thus, either the Earth was made from materials that had lost >99% of rare gases about (0.7-2) x 10(exp 8) yr after the solar system formed, or gases were then lost from the fully formed Earth. (2) Concentrations of 3He and 20Ne in the lower mantle were established after these losses. (3) Neon-isotopic data indicates that mantle Ne has solar composition. The model allows for solar Ar/Ne and Xe/Ne in the lower mantle if a dominant fraction of upper mantle Ar and Xe are subduction-derived. If Earth formed in the presence of the solar nebula, it could have been melted by accretional energy and the blanketing effect of a massive, nebula-derived atmosphere. Gases from this atmosphere would have been sequestered within the molten Earth by dissolution at the surface and downward mixing. It was found that too much Ne would be dissolved in the Earth unless the atmosphere began to escape when the Earth was only partially assembled. Here we consider conditions required to initially dissolve sufficient rare gases to account for the present lower mantle concentrations after subsequent losses at 10(exp 8

  2. 1993 Pacific Northwest Loads and Resources Study, Pacific Northwest Economic and Electricity Use Forecast. Technical Appendix: Volume 1.

    SciTech Connect

    1994-02-01

    This publication documents the load forecast scenarios and assumptions used to prepare BPA's Whitebook. It is divided into: intoduction, summary of 1993 Whitebook electricity demand forecast, conservation in the load forecast, projection of medium case electricity sales and underlying drivers, residential sector forecast, commercial sector forecast, industrial sector forecast, non-DSI industrial forecast, direct service industry forecast, and irrigation forecast. Four appendices are included: long-term forecasts, LTOUT forecast, rates and fuel price forecasts, and forecast ranges-calculations.

  3. Seasonal streamflow forecasting with the global hydrological forecasting system FEWS-World

    NASA Astrophysics Data System (ADS)

    Candogan Yossef, N.; Van Beek, L. P.; Winsemius, H.; Bierkens, M. F.

    2011-12-01

    The year-to-year variability of river discharge brings about risks and opportunities in water resources management. Reliable hydrological forecasts and effective communication allow several sectors to make more informed management decisions. In many developing regions of the world, there are no efficient hydrological forecasting systems. For these regions, a global forecasting 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 forecasts on a global scale. This study investigates the skill and value of FEWS-World. Skill is defined as the ability of the system to forecast 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 forecasting mode. The eventual goal is to transfer FEWS-World to operational forecasting mode, where the system will use operational seasonal forecasts from the European Center for Medium-Range Weather Forecasts (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 forecasts. The results of this preliminary analysis shows that even where the simulated hydrographs are biased, higher skills can be attained in reproducing monthly

  4. EVALUATION OF SIGNIFICANT ANTHROPOGENIC SOURCES OF RADIATIVELY IMPORTANT TRACE GASES

    EPA Science Inventory

    The report is an initial evaluation of significant anthropogenic sources of radiatively important trace gases. missions of greenhouse gases from human activities--including fossil fuel combustion, industrial/agricultural activities, and transportation--contribute to the increasin...

  5. How MAG4 Improves Space Weather Forecasting

    NASA Technical Reports Server (NTRS)

    Falconer, David; Khazanov, Igor; Barghouty, Nasser

    2013-01-01

    Dangerous space weather is driven by solar flares and Coronal Mass Ejection (CMEs). Forecasting flares and CMEs is the first step to forecasting either dangerous space weather or All Clear. MAG4 (Magnetogram Forecast), 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.

  6. Method for enhancing microbial utilization rates of gases using perfluorocarbons

    DOEpatents

    Turick, Charles E.

    1997-01-01

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

  7. Method for enhancing microbial utilization rates of gases using perfluorocarbons

    DOEpatents

    Turick, C.E.

    1997-06-10

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

  8. Study of electron transport in hydrocarbon gases

    NASA Astrophysics Data System (ADS)

    Hasegawa, H.; Date, H.

    2015-04-01

    The drift velocity and the effective ionization coefficient of electrons in the organic gases, C2H2, C2H4, C2H6, CH3OH, C2H5OH, C6H6, and C6H5CH3, have been measured over relatively wide ranges of density-reduced electric fields (E/N) at room temperature (around 300 K). The drift velocity was measured, based on the arrival-time spectra of electrons by using a double-shutter drift tube over the E/N range from 300 to 2800 Td, and the effective ionization coefficient (α - η) was determined by the steady-state Townsend method from 150 to 3000 Td. Whenever possible, these parameters were compared with those available in the literature. It has been shown that the swarm parameters for these gases have specific tendencies, depending on their molecular configurations.

  9. Quantum fluctuations in dipolar Bose gases

    SciTech Connect

    Lima, Aristeu R. P.; Pelster, Axel

    2011-10-15

    We investigate the influence of quantum fluctuations upon dipolar Bose gases by means of the Bogoliubov-de Gennes theory. Thereby, we make use of the local density approximation to evaluate the dipolar exchange interaction between the condensate and the excited particles. This allows to obtain the Bogoliubov spectrum analytically in the limit of large particle numbers. After discussing the condensate depletion and the ground-state energy correction, we derive quantum-corrected equations of motion for harmonically trapped dipolar Bose gases by using superfluid hydrodynamics. These equations are subsequently applied to analyze the equilibrium configuration, the low-lying oscillation frequencies, and the time-of-flight dynamics. We find that both atomic magnetic and molecular electric dipolar systems offer promising scenarios for detecting beyond mean-field effects.

  10. Efimov Resonances in Ultracold Quantum Gases

    NASA Astrophysics Data System (ADS)

    Ferlaino, F.; Zenesini, A.; Berninger, M.; Huang, B.; Nägerl, H.-C.; Grimm, R.

    2011-11-01

    Ultracold atomic gases have developed into prime systems for experimental studies of Efimov three-body physics and related few-body phenomena, which occur in the universal regime of resonant interactions. In the last few years, many important breakthroughs have been achieved, confirming basic predictions of universal few-body theory and deepening our understanding of such systems. We review the basic ideas along with the fast experimental developments of the field, focussing on ultracold cesium gases as a well-investigated model system. Triatomic Efimov resonances, atom-dimer Efimov resonances, and related four-body resonances are discussed as central observables. We also present some new observations of such resonances, supporting and complementing the set of available data.

  11. Itinerant ferromagnetism in ultracold Fermi gases

    SciTech Connect

    Heiselberg, H.

    2011-05-15

    Itinerant ferromagnetism in cold Fermi gases with repulsive interactions is studied applying the Jastrow-Slater approximation generalized to finite polarization and temperature. For two components at zero temperature, a second-order transition is found at ak{sub F}{approx_equal}0.90 compatible with results of quantum-Monte-Carlo (QMC) calculations. Thermodynamic functions and observables, such as the compressibility and spin susceptibility and the resulting fluctuations in number and spin, are calculated. For trapped gases, the resulting cloud radii and kinetic energies are calculated and compared to recent experiments. Spin-polarized systems are recommended for effective separation of large ferromagnetic domains. Collective modes are predicted and tricritical points are calculated for multicomponent systems.

  12. Advanced Global Atmospheric Gases Experiment (AGAGE)

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.; Kurylo, Michael (Technical Monitor)

    2004-01-01

    We seek funding from NASA for the third year (2005) of the four-year period January 1, 2003 - December 31, 2006 for continued support of the MIT contributions to the multi-national global atmospheric trace species measurement program entitled Advanced Global Atmospheric Gases Experiment (AGAGE). The case for real-time high-frequency measurement networks like AGAGE is very strong and the observations and their interpretation are widely recognized for their importance to ozone depletion and climate change studies and to verification issues arising from the Montreal Protocol (ozone) and Kyoto Protocol (climate). The proposed AGAGE program is distinguished by its capability to measure over the globe at high frequency almost all of the important species in the Montreal Protocol and almost all of the significant non-CO2 gases in the Kyoto Protocol.

  13. Dilute spin-orbit Fermi gases

    NASA Astrophysics Data System (ADS)

    Maldonado-Mundo, Daniel; He, Lianyi; Öhberg, Patrik; Valiente, Manuel

    2014-03-01

    We study repulsive Fermi gases with Rashba spin-orbit coupling in two and three dimensions when they are dilute enough that a single branch of the spectrum is occupied in the non-interacting ground state. We develop an effective renormalizable theory for fermions in the lower branch and obtain the energy of the system in three dimensions to second order in the renormalized coupling constant. We then exploit the non-Galilean-relativistic nature of spin-orbit coupled gases. We find that at finite momentum, the two-dimensional Fermi sea is deformed in a non-trivial way. Using mean-field theory to include interactions, we show that the ground-state of the system acquires a finite momentum, and is consequently deformed, when the interaction is stronger than a critical value. Heriot-Watt University. CM-DTC. SUPA. EPSRC.

  14. Fitter apparatus for purifying exhaust gases

    SciTech Connect

    Oyobe, K.; Fukutani, M.; Ito, K.; Matsui, K.; Miwa, N.; Nomura, E.

    1985-05-28

    Filter apparatus having a honeycomb structure and a heater for purifying exhaust gases consists of cells or passages defined by porous partition walls. Alternate passages are provided respectively with upstream plugs and downstream plugs. Particulates in exhaust gases are trapped in the honeycomb structure and ignited by the heater. The upstream plugs define spaces upstream thereof in which particulates are trapped in addition to those trapped in the passages having downstream plugs. The heat of burning of the particulates trapped in the spaces facilitates the burning of the particulates trapped in the passages having downstream plugs. Therefore, the exhaust gas particualtes trapped and collected in the downstream portion of the structure can also be easily burned to regenerate the structure over its entire length.

  15. Method for introduction of gases into microspheres

    DOEpatents

    Hendricks, Charles D.; Koo, Jackson C.; Rosencwaig, Allan

    1981-01-01

    A method for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500.mu. with both thin walls (0.5 to 4.mu.) and thick walls (5 to 20.mu.) that contain various fill gases, such as Ar, Kr, Xe, Br, DT, H.sub.2, D.sub.2, He, N.sub.2, Ne, CO.sub.2, etc. in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace. Almost any gas can be introduced into the inner cavity of a glass microsphere by this method during the formation of the microsphere provided that the gas is diffused into the gel membrane or microsphere prior to its transformation into glass. The process of this invention provides a significant savings of time and related expense of filling glass microspheres with various gases. For example, the time for filling a glass microballoon with 1 atmosphere of DT is reduced from about two hours to a few seconds.

  16. Glass Membrane For Controlled Diffusion Of Gases

    DOEpatents

    Shelby, James E.; Kenyon, Brian E.

    2001-05-15

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

  17. Thermodynamics of dilute gases in shear flow

    NASA Astrophysics Data System (ADS)

    Jou, D.; Criado-Sancho, M.

    2001-03-01

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

  18. Toxicity of Pyrolysis Gases from Elastomers

    NASA Technical Reports Server (NTRS)

    Hilado, Carlos J.; Kosola, Kay L.; Solis, Alida N.; Kourtides, Demetrius A.; Parker, John A.

    1977-01-01

    The toxicity of the pyrolysis gases from six elastomers was investigated. The elastomers were polyisoprene (natural rubber), styrene-butadiene rubber (SBR), ethylene propylene diene terpolymer (EPDM), acrylonitrile rubber, chlorosulfonated polyethylene rubber, and polychloroprene. The rising temperature and fixed temperature programs produced exactly the same rank order of materials based on time to death. Acryltonitrile rubber exhibited the greatest toxicity under these test conditions; carbon monoxide was not found in sufficient concentrations to be the primary cause of death.

  19. Current fluctuations in stochastic lattice gases.

    PubMed

    Bertini, L; De Sole, A; Gabrielli, D; Jona-Lasinio, G; Landim, C

    2005-01-28

    We study current fluctuations in lattice gases in the macroscopic limit extending the dynamic approach for density fluctuations developed in previous articles. More precisely, we establish a large deviation theory for the space-time fluctuations of the empirical current which include the previous results. We then estimate the probability of a fluctuation of the average current over a large time interval. It turns out that recent results by Bodineau and Derrida [Phys. Rev. Lett. 92, 180601 (2004)

  20. Noble Gases in the Chelyabinsk Meteorites

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  1. Splitting of inviscid fluxes for real gases

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Vanleer, Bram; Shuen, Jian-Shun

    1988-01-01

    Flux-vector and flux-difference splittings for the inviscid terms of the compressible flow equations are derived under the assumption of a general equation of state for a real gas in equilibrium. No necessary assumptions, approximations or auxiliary quantities are introduced. The formulas derived include several particular cases known for ideal gases and readily apply to curvilinear coordinates. Applications of the formulas in a TVD algorithm to one-dimensional shock-tube and nozzle problems show their quality and robustness.

  2. Hydrocarbon Rocket Technology Impact Forecasting

    NASA Technical Reports Server (NTRS)

    Stuber, Eric; Prasadh, Nishant; Edwards, Stephen; Mavris, Dimitri N.

    2012-01-01

    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 Forecasting (TIF) method. The Technology Impact

  3. Ninth electric utility forecasting symposium: Proceedings. Forecasting and DSM -- Organizing for success

    SciTech Connect

    1995-05-01

    EPRI and the San Diego Gas and Electric Company (SDG and E) hosted a two-and-one-half day symposium in San Diego, California on September 8--10, 1993. Plenary presentations, topical paper sessions, and demonstrations covered a wide variety of topics, ranging from traditional forecasting topics to the changing nature of customers in the next century. The objectives of the symposium were to: exchange information and ideas about new forecasting methods, tools, and data sources; promote an exchange of views between those who produce forecasts and those who use forecasts; explore the relationship between forecasting and DSM; and discuss possible future trends for the electric utility industry and to consider the future role of forecasting. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  4. Mean annual temperature in New Zealand during the last glacial maximum derived from dissolved noble gases in groundwater

    NASA Astrophysics Data System (ADS)

    Seltzer, A. M.; Stute, M.; Morgenstern, U.; Stewart, M. K.; Schaefer, J. M.

    2015-12-01

    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.

  5. Dissolved noble gases and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany

    NASA Astrophysics Data System (ADS)

    Gumm, L. P.; Bense, V. F.; Dennis, P. F.; Hiscock, K. M.; Cremer, N.; Simon, S.

    2016-02-01

    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.

  6. Oxidation and reduction rates for organic carbon in the Amazon mainstream tributary and floodplain, inferred from distributions of dissolved gases

    NASA Technical Reports Server (NTRS)

    Richey, Jeffrey E.; Devol, Allan H.; Wofsy, Steven C.; Victoria, Reynaldo; Riberio, Maria N. G.

    1986-01-01

    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.

  7. Inter-comparison exercises on dissolved gases for groundwater dating (GDAT 2012) : analytical uncertainties, apparent ages and other derived parameters.

    NASA Astrophysics Data System (ADS)

    Labasque, Thierry; Aquilina, Luc; Visser, Ate; Vergnaud, Virginie

    2014-05-01

    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.

  8. 40 CFR 600.108-08 - Analytical gases.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Analytical gases. 600.108-08 Section... ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy and Carbon-Related Exhaust Emission Test Procedures § 600.108-08 Analytical gases. The analytical gases for all fuel economy...

  9. 40 CFR 600.108-08 - Analytical gases.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Analytical gases. 600.108-08 Section... ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy and Carbon-Related Exhaust Emission Test Procedures § 600.108-08 Analytical gases. The analytical gases for all fuel economy...

  10. 49 CFR 173.307 - Exceptions for compressed gases.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Exceptions for compressed gases. 173.307 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.307 Exceptions for compressed gases. (a) The following materials are not subject to the requirements of this subchapter:...

  11. 40 CFR 600.108-78 - Analytical gases.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Analytical gases. 600.108-78 Section 600.108-78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL... gases. The analytical gases for all fuel economy testing must meet the criteria given in § 86.114...

  12. 40 CFR 600.108-08 - Analytical gases.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Analytical gases. 600.108-08 Section... ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy and Carbon-Related Exhaust Emission Test Procedures § 600.108-08 Analytical gases. The analytical gases for all fuel economy...

  13. 49 CFR 173.307 - Exceptions for compressed gases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Exceptions for compressed gases. 173.307 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.307 Exceptions for compressed gases. (a) The following materials are not subject to the requirements of this subchapter:...

  14. 49 CFR 173.307 - Exceptions for compressed gases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Exceptions for compressed gases. 173.307 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.307 Exceptions for compressed gases. (a) The following materials are not subject to the requirements of this subchapter:...

  15. 49 CFR 173.307 - Exceptions for compressed gases.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Exceptions for compressed gases. 173.307 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.307 Exceptions for compressed gases. (a) The following materials are not subject to the requirements of this subchapter:...

  16. 40 CFR 600.108-78 - Analytical gases.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Analytical gases. 600.108-78 Section 600.108-78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL... Model Year Automobiles-Test Procedures § 600.108-78 Analytical gases. The analytical gases for all...

  17. Learning the Critical Points for Addition in Matematika GASING

    ERIC Educational Resources Information Center

    Siregar, Johannes Hamonangan; Wiyanti, Wiwik; Wakhyuningsih, Nur Safitri; Godjali, Ali

    2014-01-01

    We propose learning Matematika GASING to help students better understand the addition material. Matematika GASING is a way of learning mathematics in an easy, fun and enjoyable fashion. GASING is short for GAmpang, aSyIk, and menyenaNGkan (Bahasa Indonesia for easy, fun and enjoyable). It was originally developed by Prof. Yohanes Surya at the…

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

    ERIC Educational Resources Information Center

    Biswas, Shyamal; Jana, Debnarayan

    2012-01-01

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

  19. Method for introduction of gases into microspheres

    DOEpatents

    Hendricks, C.D.; Koo, J.C.; Rosencwaig, A.

    A method is described for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500..mu.. with both thin walls (0.5 to 4/sub ..mu../) and thick walls (5 to 20/sub ..mu../) that contain various fill gases, such as Ar, Kr, Xe, Br, D, H/sub 2/, DT, He, N/sub 2/, Ne, CO/sub 2/, etc., in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-form-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace.

  20. Treatment of flue gas containing noxious gases

    SciTech Connect

    Dvirka, M.; Psihos, G.J.; Cosulich, J.J.

    1987-07-21

    A method is described of reducing the noxious gases such as chlorides including hydrogen chloride and chlorine from the flue gases derived from the incineration of solid waste materials in a furnace with a combustion chamber and a combustion zone to substantially reduce the formation of dioxins for a cleaner effluent gas to the atmosphere, comprising: introducing sodium bicarbonate into the flue gas of a furnace incinerating the waste materials, positioning introduction of sodium bicarbonate for at least one location along the path of the flue gas at a temperature below about 1564/sup 0/F but not below about 518/sup 0/F, heating the sodium bicarbonate in the flue gas for a time sufficient to drive off the water and carbon dioxide from the sodium bicarbonate, forming sodium carbonate particle during the heating of the sodium bicarbonate, the sodium carbonate having a higher porosity to produce a greater reaction area on the surface of the particles, contacting the porous sodium carbonate with chlorides in the flue gases for a sufficient time and temperature to react and produce sodium chloride and prevent their formation of dioxins; and separating the sodium chloride from the flue gas to produce a cleaner gas for exit to the atmosphere.