National Library of Energy BETA

Sample records for nitrogen ice cream

  1. Reprocessing of ices in turbulent protoplanetary disks: Carbon and nitrogen chemistry

    SciTech Connect (OSTI)

    Furuya, Kenji; Aikawa, Yuri

    2014-08-01

    We study the influence of the turbulent transport on ice chemistry in protoplanetary disks, focusing on carbon- and nitrogen-bearing molecules. Chemical rate equations are solved with the diffusion term, mimicking the turbulent mixing in the vertical direction. Turbulence can bring ice-coated dust grains from the midplane to the warm irradiated disk surface, and the ice mantles are reprocessed by photoreactions, thermal desorption, and surface reactions. The upward transport decreases the abundance of methanol and ammonia ices at r ? 30 AU because warm dust temperature prohibits their reformation on grain surfaces. This reprocessing could explain the smaller abundances of carbon and nitrogen bearing molecules in cometary coma than those in low-mass protostellar envelopes. We also show the effect of mixing on the synthesis of complex organic molecules (COMs) in two ways: (1) transport of ices from the midplane to the disk surface and (2) transport of atomic hydrogen from the surface to the midplane. The former enhances the COMs formation in the disk surface, while the latter suppresses it in the midplane. Then, when mixing is strong, COMs are predominantly formed in the disk surface, while their parent molecules are (re)formed in the midplane. This cycle expands the COMs distribution both vertically and radially outward compared with that in the non-turbulent model. We derive the timescale of the sink mechanism by which CO and N{sub 2} are converted to less volatile molecules to be depleted from the gas phase and find that the vertical mixing suppresses this mechanism in the inner disks.

  2. Nitrogen sorption

    DOE Patents [OSTI]

    Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Miller, Warren K.

    1996-01-01

    Nitrogen-sorbing and -desorbing compositions and methods of using the same are disclosed, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

  3. Nitrogen sorption

    DOE Patents [OSTI]

    Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Miller, Warren K.

    1993-01-01

    Nitrogen-sorbing and -desorbing compositions and methods of using the same are disclosed, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

  4. Nitrogen sorption

    DOE Patents [OSTI]

    Friesen, D.T.; Babcock, W.C.; Edlund, D.J.; Miller, W.K.

    1996-05-14

    Nitrogen-sorbing and -desorbing compositions and methods of using the same are disclosed, which are useful for the selective separation of nitrogen from other gases, especially natural gas. 5 figs.

  5. Nitrogen sorption

    DOE Patents [OSTI]

    Friesen, D.T.; Babcock, W.C.; Edlund, D.J.; Miller, W.K.

    1993-07-06

    Nitrogen-sorbing and -desorbing compositions and methods of using the same are disclosed, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

  6. THE EFFECTS OF INITIAL ABUNDANCES ON NITROGEN IN PROTOPLANETARY DISKS

    SciTech Connect (OSTI)

    Schwarz, Kamber R.; Bergin, Edwin A.

    2014-12-20

    The dominant form of nitrogen provided to most solar system bodies is currently unknown, though available measurements show that the detected nitrogen in solar system rocks and ices is depleted with respect to solar abundances and the interstellar medium. We use a detailed chemical/physical model of the chemical evolution of a protoplanetary disk to explore the evolution and abundance of nitrogen-bearing molecules. Based on this model, we analyze how initial chemical abundances provided as either gas or ice during the early stages of disk formation influence which species become the dominant nitrogen bearers at later stages. We find that a disk with the majority of its initial nitrogen in either atomic or molecular nitrogen is later dominated by atomic and molecular nitrogen as well as NH{sub 3} and HCN ices, where the dominant species varies with disk radius. When nitrogen is initially in gaseous ammonia, it later becomes trapped in ammonia ice except in the outer disk where atomic nitrogen dominates. For a disk with the initial nitrogen in the form of ammonia ice, the nitrogen remains trapped in the ice as NH{sub 3} at later stages. The model in which most of the initial nitrogen is placed in atomic N best matches the ammonia abundances observed in comets. Furthermore, the initial state of nitrogen influences the abundance of N{sub 2}H{sup +}, which has been detected in protoplanetary disks. Strong N{sub 2}H{sup +} emission is found to be indicative of an N{sub 2} abundance greater than n{sub N{sub 2}}/n{sub H{sub 2}}>10{sup ?6} in addition to tracing the CO snow line. Our models also indicate that NO is potentially detectable, with lower N gas abundances leading to higher NO abundances.

  7. ARM - Measurement - Ice nuclei

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

    : Ice nuclei Small particles around which ice particles form. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  8. PROTOSOLAR AMMONIA AS THE UNIQUE SOURCE OF TITAN's NITROGEN

    SciTech Connect (OSTI)

    Mandt, Kathleen E.; Mousis, Olivier; Gautier, Daniel

    2014-06-20

    The origin of Titan's nitrogen-rich atmosphere is thought to be ammonia ice, but this has not yet been confirmed. Furthermore, it is uncertain whether the building blocks of Titan formed within the Saturnian subnebula or in the colder protosolar nebula (PSN). Recent measurements of the nitrogen isotope ratio in cometary ammonia, combined with evolutionary constraints on the nitrogen isotopes in Titan's atmosphere provide firm evidence that the nitrogen in Titan's atmosphere must have originated as ammonia ice formed in the PSN under conditions similar to that of cometary formation. This result has important implications for the projected D/H ratio in cometary methane, nitrogen isotopic fractionation in the PSN and the source of nitrogen for Earth's atmosphere.

  9. Arctic ice islands

    SciTech Connect (OSTI)

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  10. METHANE AND NITROGEN ABUNDANCES ON PLUTO AND ERIS

    SciTech Connect (OSTI)

    Tegler, S. C.; Cornelison, D. M.; Abernathy, M. R.; Bovyn, M. J.; Burt, J. A.; Evans, D. E.; Maleszewski, C. K.; Thompson, Z.; Grundy, W. M.; Romanishin, W.; Vilas, F. E-mail: David.Cornelison@nau.ed E-mail: wjr@nhn.ou.ed

    2010-12-10

    We present spectra of Eris from the MMT 6.5 m Telescope and Red Channel Spectrograph (5700-9800 A, 5 A pixel{sup -1}) on Mt. Hopkins, AZ, and of Pluto from the Steward Observatory 2.3 m Telescope and Boller and Chivens Spectrograph (7100-9400 A, 2 A pixel{sup -1}) on Kitt Peak, AZ. In addition, we present laboratory transmission spectra of methane-nitrogen and methane-argon ice mixtures. By anchoring our analysis in methane and nitrogen solubilities in one another as expressed in the phase diagram of Prokhvatilov and Yantsevich, and comparing methane bands in our Eris and Pluto spectra and methane bands in our laboratory spectra of methane and nitrogen ice mixtures, we find Eris' bulk methane and nitrogen abundances are {approx}10% and {approx}90% and Pluto's bulk methane and nitrogen abundances are {approx}3% and {approx}97%. Such abundances for Pluto are consistent with values reported in the literature. It appears that the bulk volatile composition of Eris is similar to the bulk volatile composition of Pluto. Both objects appear to be dominated by nitrogen ice. Our analysis also suggests, unlike previous work reported in the literature, that the methane and nitrogen stoichiometry is constant with depth into the surface of Eris. Finally, we point out that our Eris spectrum is also consistent with a laboratory ice mixture consisting of 40% methane and 60% argon. Although we cannot rule out an argon-rich surface, it seems more likely that nitrogen is the dominant species on Eris because the nitrogen ice 2.15 {mu}m band is seen in spectra of Pluto and Triton.

  11. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, David F. (Idaho Falls, ID); Suciu, Dan F. (Idaho Falls, ID); Harris, Taryl L. (Idaho Falls, ID); Ingram, Jani C. (Idaho Falls, ID)

    1993-01-01

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  12. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, D.F.; Suciu, D.F.; Harris, T.L.; Ingram, J.C.

    1993-04-06

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  13. Fire In The Ice

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

    Fire in the Ice The methane hydrate newsletter, Fire in the Ice, is a quarterly publication highlighting the latest developments in international gas hydrates R&D. Fire in the Ice promotes the exchange of information amoung those involved in gas hydrates research and development, and also recognizes the efforts of a hydrate researcher in each issue. The newsletter now reaches nearly 1300 scientists and other interested individuals in sixteen countries. To subscribe electronically to Fire in

  14. Global Simulations of Ice nucleation and Ice Supersaturation with an

    Office of Scientific and Technical Information (OSTI)

    Improved Cloud Scheme in the Community Atmosphere Model (Journal Article) | SciTech Connect Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model Citation Details In-Document Search Title: Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model A process-based treatment of ice supersaturation and ice-nucleation is implemented in the National Center for

  15. Community Ice Sheet Model (CISM2) Development and Marine Ice...

    Office of Scientific and Technical Information (OSTI)

    Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet Simulations Citation ... Sponsoring Org: DOELANL Country of Publication: United States Language: English Subject: ...

  16. ARM - Measurement - Nitrogen

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

    Send Measurement : Nitrogen All gaseous compounds of nitrogen including N2, N2O, and NOx. Categories Atmospheric State Instruments The above measurement is considered...

  17. Arctic Sea ice model sensitivities.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  18. Nitrogen dioxide detection

    DOE Patents [OSTI]

    Sinha, Dipen N.; Agnew, Stephen F.; Christensen, William H.

    1993-01-01

    Method and apparatus for detecting the presence of gaseous nitrogen dioxide and determining the amount of gas which is present. Though polystyrene is normally an insulator, it becomes electrically conductive in the presence of nitrogen dioxide. Conductance or resistance of a polystyrene sensing element is related to the concentration of nitrogen dioxide at the sensing element.

  19. Icing rate meter estimation of in-cloud cable icing

    SciTech Connect (OSTI)

    McComber, P.; Druez, J.; Laflamme, J.

    1994-12-31

    In many northern countries, the design and reliability of power transmission lines are closely related to atmospheric icing overloads. It is becoming increasingly important to have reliable instrument systems to warn of icing conditions before icing loads become sufficient to damage the power transmission network. Various instruments are presently being developed to provide better monitoring of icing conditions. One such instrument is the icing rate meter (IRM) which counts icing and de-icing cycles per unit time on a standard probe and can be used to estimate the icing rate on nearby cables. The calibration presently used was originally based on experiments conducted in a cold room. Even though this calibration has shown that the IRM estimation already offers an improvement over model prediction based on standard meteorological parameters, it can certainly be improved further with appropriate field data. For this purpose, the instrument was tested on an icing test site at Mt. Valin (altitude 902 m) Quebec, Canada. In this paper measurements from twelve in-cloud icing events during the 1991--92 winter are divided into one hour periods of icing to provide the experimental icing rate data. The icing rates measured on a 12.5 mm and a 35 mm cables are then compared with the number of IRM signals, also for one hour periods, in relation to initial ice load, temperature, wind velocity and direction. From this analysis, a better calibration for the IRM instrument is suggested. The improvement of the IRM estimation is illustrated by making a comparison with measurements, of the icing load estimation with the old and new calibrations for two complete icing events.

  20. ARM - Measurement - Ice water content

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

    Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Ice water content The concentration (massvol) of ice water...

  1. ARM - Measurement - Ice water path

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

    Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Ice water path A measure of the weight of the ice particles in...

  2. ARM - Measurement - Cloud ice particle

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

    ice particle ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud ice particle...

  3. ARM - TWP-ICE Maps

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

    Fact Sheet (pdf, 211K) Press Releases TWP-ICE Images ARM flickr site <"" li"" height"14" width"16"> TWP-ICE Maps map1 map2 Download TWP-ICEDarwin annotated maps (pdf, 246K)....

  4. Nitrogen spark denoxer

    DOE Patents [OSTI]

    Ng, Henry K.; Novick, Vincent J.; Sekar, Ramanujam R.

    1997-01-01

    A NO.sub.X control system for an internal combustion engine includes an oxygen enrichment device that produces oxygen and nitrogen enriched air. The nitrogen enriched air contains molecular nitrogen that is provided to a spark plug that is mounted in an exhaust outlet of an internal combustion engine. As the nitrogen enriched air is expelled at the spark gap of the spark plug, the nitrogen enriched air is exposed to a pulsating spark that is generated across the spark gap of the spark plug. The spark gap is elongated so that a sufficient amount of atomic nitrogen is produced and is injected into the exhaust of the internal combustion engine. The injection of the atomic nitrogen into the exhaust of the internal combustion engine causes the oxides of nitrogen to be reduced into nitrogen and oxygen such that the emissions from the engine will have acceptable levels of NO.sub.X. The oxygen enrichment device that produces both the oxygen and nitrogen enriched air can include a selectively permeable membrane.

  5. Ice Storm Supercomputer

    ScienceCinema (OSTI)

    None

    2013-05-28

    "A new Idaho National Laboratory supercomputer is helping scientists create more realistic simulations of nuclear fuel. Dubbed 'Ice Storm,' this 2048-processor machine allows researchers to model and predict the complex physics behind nuclear reactor behavior. And with a new visualization lab, the team can see the results of its simulations on the big screen." For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

  6. Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report...

    Office of Scientific and Technical Information (OSTI)

    Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report Citation Details In-Document Search Title: Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report The ...

  7. The measured compositions of Uranus and Neptune from their formation on the CO ice line

    SciTech Connect (OSTI)

    Ali-Dib, Mohamad; Mousis, Olivier; Petit, Jean-Marc

    2014-09-20

    The formation mechanisms of the ice giants Uranus and Neptune, and the origin of their elemental and isotopic compositions, have long been debated. The density of solids in the outer protosolar nebula is too low to explain their formation, and spectroscopic observations show that both planets are highly enriched in carbon, very poor in nitrogen, and the ices from which they originally formed might have had deuterium-to-hydrogen ratios lower than the predicted cometary value, unexplained properties that were observed in no other planets. Here, we show that all these properties can be explained naturally if Uranus and Neptune both formed at the carbon monoxide ice line. Due to the diffusive redistribution of vapors, this outer region of the protosolar nebula intrinsically has enough surface density to form both planets from carbon-rich solids but nitrogen-depleted gas, in abundances consistent with their observed values. Water-rich interiors originating mostly from transformed CO ices reconcile the D/H value of Uranus's and Neptune's building blocks with the cometary value. Finally, our scenario generalizes a well known hypothesis that Jupiter formed on an ice line (water snow line) for the two ice giants, and might be a first step toward generalizing this mechanism for other giant planets.

  8. Winter Preparedness ? Slips on Ice

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

    can further increase traction; however, they must be removed when ice is no longer present, because their use on floors, smooth concrete, or gravel, presents a different...

  9. Climate Impacts of Ice Nucleation

    SciTech Connect (OSTI)

    Gettelman, A.; Liu, Xiaohong; Barahona, Donifan; Lohmann, U.; Chen, Chih-Chieh

    2012-10-27

    Several different ice nucleation parameterizations in two different General Circulation Models are used to understand the effects of ice nucleation on the mean climate state, and the climate effect of aerosol perturbations to ice clouds. The simulations have different ice microphysical states that are consistent with the spread of observations. These different states occur from different parameterizations of the ice cloud nucleation processes, and feature different balances of homogeneous and heterogeneous nucleation. At reasonable efficiencies, consistent with laboratory measurements and constrained by the global radiative balance, black carbon has a small (-0.06 Wm?2) and not statistically significant climate effect. Indirect effects of anthropogenic aerosols on cirrus clouds occur mostly due to increases in homogeneous nucleation fraction as a consequence of anthropogenic sulfur emissions. The resulting ice indirect effects do not seem strongly dependent on the ice micro-physical balance, but are slightly larger for those states with less homogeneous nucleation in the base state. The total ice AIE is estimated at 0.260.09 Wm?2 (1? uncertainty). This represents an offset of 20-30% of the simulated total Aerosol Indirect Effect for ice and liquid clouds.

  10. ARM - Lesson Plans: When Land Ice Melts

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

    The Arctic and Antarctica are covered with large, heavy sheets of ice. Other islands like New Zealand have ice masses in the form of glaciers on them. When land-based ice melts, ...

  11. Calibration and Characterization of the IceCube Photomultiplier Tube

    SciTech Connect (OSTI)

    IceCube Collaboration; Abbasi, R.; al., et

    2010-02-11

    Over 5,000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy neutrino interactions, and others are frozen into tanks on the surface to detect particles from atmospheric cosmic ray showers. IceCube is using the 10-inch diameter R7081-02 made by Hamamatsu Photonics. This paper describes the laboratory characterization and calibration of these PMTs before deployment. PMTs were illuminated with pulses ranging from single photons to saturation level. Parameterizations are given for the single photoelectron charge spectrum and the saturation behavior. Time resolution, late pulses and afterpulses are characterized. Because the PMTs are relatively large, the cathode sensitivity uniformity was measured. The absolute photon detection efficiency was calibrated using Rayleigh-scattered photons from a nitrogen laser. Measured characteristics are discussed in the context of their relevance to IceCube event reconstruction and simulation efforts.

  12. Biogeochemistry in Sea Ice: CICE model developments

    SciTech Connect (OSTI)

    Jeffery, Nicole; Hunke, Elizabeth; Elliott, Scott; Turner, Adrian

    2012-06-18

    Polar primary production unfolds in a dynamic sea ice environment, and the interactions of sea ice with ocean support and mediate this production. In spring, for example, fresh melt water contributes to the shoaling of the mixed layer enhancing ice edge blooms. In contrast, sea ice formation in the fall reduces light penetration to the upper ocean slowing primary production in marine waters. Polar biogeochemical modeling studies typically consider these types of ice-ocean interactions. However, sea ice itself is a biogeochemically active medium, contributing a significant and, possibly, essential source of primary production to polar regions in early spring and fall. Here we present numerical simulations using the Los Alamos Sea Ice Model (CICE) with prognostic salinity and sea ice biogeochemistry. This study investigates the relationship between sea ice multiphase physics and sea ice productivity. Of particular emphasis are the processes of gravity drainage, melt water flushing, and snow loading. During sea ice formation, desalination by gravity drainage facilitates nutrient exchange between ocean and ice maintaining ice algal blooms in early spring. Melt water flushing releases ice algae and nutrients to underlying waters limiting ice production. Finally, snow loading, particularly in the Southern Ocean, forces sea ice below the ocean surface driving an upward flow of nutrient rich water into the ice to the benefit of interior and freeboard communities. Incorporating ice microphysics in CICE has given us an important tool for assessing the importance of these processes for polar algal production at global scales.

  13. Therapeutic Hypothermia: Protective Cooling Using Medical Ice...

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

    Therapeutic Hypothermia: Protective Cooling Using Medical Ice Slurry Technology available for licensing: Proprietary method and equipment for making an ice slurry coolant to induce...

  14. Light propagation in the South Pole ice

    SciTech Connect (OSTI)

    Williams, Dawn; Collaboration: IceCube Collaboration

    2014-11-18

    The IceCube Neutrino Observatory is located in the ice near the geographic South Pole. Particle showers from neutrino interactions in the ice produce light which is detected by IceCube modules, and the amount and pattern of deposited light are used to reconstruct the properties of the incident neutrino. Since light is scattered and absorbed by ice between the neutrino interaction vertex and the sensor, IceCube event reconstruction depends on understanding the propagation of light through the ice. This paper presents the current status of modeling light propagation in South Pole ice, including the recent observation of an azimuthal anisotropy in the scattering.

  15. Community Ice Sheet Model (CISM2) Development and Marine Ice...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: CESM Land Ice Working Group ; 2015-06-17 - 2015-06-17 ; Breckenridge, Colorado, United ...

  16. Method of forming calthrate ice

    DOE Patents [OSTI]

    Hino, T.; Gorski, A.J.

    1985-09-30

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultransonically so that small crystals are formed in the liquid. Thes small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  17. Method of forming clathrate ice

    DOE Patents [OSTI]

    Hino, Toshiyuki (Tokyo, JP); Gorski, Anthony J. (Lemont, IL)

    1987-01-01

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultrasonically so that small crystals are formed in the liquid. These small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  18. CHEMICAL PROCESSING OF PURE AMMONIA AND AMMONIA-WATER ICES INDUCED BY HEAVY IONS

    SciTech Connect (OSTI)

    Bordalo, V.; Da Silveira, E. F.; Seperuelo Duarte, E.

    2013-09-10

    Cosmic rays are possibly the main agents to prevent the freeze-out of molecules onto grain surfaces in cold dense clouds. Ammonia (NH{sub 3}) is one of the most abundant molecules present in dust ice mantles, with a concentration of up to 15% relative to water (H{sub 2}O). FTIR spectroscopy is used to monitor pure NH{sub 3} and NH{sub 3}-H{sub 2}O ice samples as they are irradiated with Ni and Zn ion beams (500-600 MeV) at GANIL/France. New species, such as hydrazine (N{sub 2}H{sub 4}), diazene (N{sub 2}H{sub 2} isomers), molecular hydrogen (H{sub 2}), and nitrogen (N{sub 2}) were identified after irradiation of pure NH{sub 3} ices. Nitrous oxide (N{sub 2}O), nitrogen oxide (NO), nitrogen dioxide (NO{sub 2}), and hydroxylamine (NH{sub 2}OH) are some of the products of the NH{sub 3}-H{sub 2}O ice radiolysis. The spectral band at 6.85 {mu}m was observed after irradiation of both types of ice. Besides the likely contribution of ammonium (NH{sub 4}{sup +}) and amino (NH{sub 2}) radicals, data suggest a small contribution of NH{sub 2}OH to this band profile after high fluences of irradiation of NH{sub 3}-H{sub 2}O ices. The spectral shift of the NH{sub 3} ''umbrella'' mode (9.3 {mu}m) band is parameterized as a function of NH{sub 3}/H{sub 2}O ratio in amorphous ices. Ammonia and water destruction cross-sections are obtained, as well as the rate of NH{sub 3}-H{sub 2}O (1:10) ice compaction, measured by the OH dangling bond destruction cross-section. Ammonia destruction is enhanced in the presence of H{sub 2}O in the ice and a power law relationship between stopping power and NH{sub 3} destruction cross-section is verified. Such results may provide relevant information for the evolution of molecular species in dense molecular clouds.

  19. Highway De-icing Snowmelt Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    De-icing Snowmelt Low Temperature Geothermal Facility Jump to: navigation, search Name Highway De-icing Snowmelt Low Temperature Geothermal Facility Facility Highway De-icing...

  20. Aqueous phase removal of nitrogen from nitrogen compounds

    DOE Patents [OSTI]

    Fassbender, Alex G.

    1993-01-01

    A method is disclosed for denitrification of compounds containing nitrogen present in aqueous waste streams. The method comprises the steps of (1) identifying the types of nitrogen compounds present in a waste stream, (2) determining the concentrations of nitrogen compounds, (3) balancing oxidized and reduced form of nitrogen by adding a reactant, and (4) heating the mixture to a predetermined reaction temperature from about 300.degree. C. to about 600.degree. C., thereby resulting in less harmful nitrogen and oxygen gas, hydroxides, alcohols, and hydrocarbons.

  1. Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water

    SciTech Connect (OSTI)

    Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria

    2014-11-14

    Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

  2. Methane/nitrogen separation process

    DOE Patents [OSTI]

    Baker, R.W.; Lokhandwala, K.A.; Pinnau, I.; Segelke, S.

    1997-09-23

    A membrane separation process is described for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. The authors have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen. 11 figs.

  3. Methane/nitrogen separation process

    DOE Patents [OSTI]

    Baker, Richard W.; Lokhandwala, Kaaeid A.; Pinnau, Ingo; Segelke, Scott

    1997-01-01

    A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

  4. Water freezing and ice melting

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

    Malolepsza, Edyta; Keyes, Tom

    2015-10-12

    The generalized replica exchange method (gREM) is designed to sample states with coexisting phases and thereby to describe strong first order phase transitions. The isobaric MD version of the gREM is presented and applied to freezing of liquid water, and melting of hexagonal and cubic ice. It is confirmed that coexisting states are well sampled. The statistical temperature as a function of enthalpy, TS(H), is obtained. Hysteresis between freezing and melting is observed and discussed. The entropic analysis of phase transitions is applied and equilibrium transition temperatures, latent heats, and surface tensions are obtained for hexagonal ice↔liquid and cubic ice↔liquid,more » with excellent agreement with published values. A new method is given to assign water molecules among various symmetry types. As a result, pathways for water freezing, ultimately leading to hexagonal ice, are found to contain intermediate layered structures built from hexagonal and cubic ice.« less

  5. The New ICE Age | Department of Energy

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

    for the heavy truck market PDF icon deer12gruden.pdf More Documents & Publications The New ICE Age The New ICE Age Roadmapping Engine Technology for Post-2020 Heavy Duty ...

  6. Climate, Ocean and Sea Ice Modeling

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

    role of ocean and ice in high-latitude climate change and projecting the impacts of ... COSIM researchers develop, test and apply ocean and ice models in support of DOE Climate ...

  7. Ice in Arctic Mixed-phase Stratocumulus

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

    Ice Nuclei Recycling in the Maintenance of Cloud Ice in Arctic Mixed-phase Stratocumulus For original submission and image(s), see ARM Research Highlights http:www.arm.gov...

  8. Contractor SOW Template - ICE | Department of Energy

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

    ICE Contractor SOW Template - ICE The template presented below is a Statement of Work (SOW) for services of an ICE Support Contractor for assisting OECM in conducting an ICE. Project and review specific information should be incorporated. Explanatory text appears in italics, while information that should be selected appears in <<brackets>>. The format and contents of this SOW is not compulsory, and the use is at the discretion of the OECM Analysts, tailored as appropriate for the

  9. Climate, Ocean and Sea Ice Modeling (COSIM)

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

    Earth, Space Sciences » Climate, Ocean and Sea Ice Modeling (COSIM) Climate, Ocean and Sea Ice Modeling (COSIM) The COSIM project develops advanced ocean and ice models for evaluating the role of ocean and ice in high-latitude climate change and projecting the impacts of high-latitude change on regions throughout the globe. Contact Us Phil Jones Fluid Dynamics and Solid Mechanics Email Wilbert Weijer Computational Physics and Methods Email Elizabeth Hunke Fluid Dynamics and Solid Mechanics

  10. Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report Citation Details In-Document Search Title: Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report The Norwegian Young Sea Ice (N-ICE) experiment was conducted aboard the R/V Lance research vessel from January through June 2015. The primary purpose of the experiment was to better understand thin, first-year sea ice. This includes understanding of how different components of the Arctic system

  11. Medical ice slurry production device

    DOE Patents [OSTI]

    Kasza, Kenneth E.; Oras, John; Son, HyunJin

    2008-06-24

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  12. Nitrogen fixation apparatus

    DOE Patents [OSTI]

    Chen, Hao-Lin

    1984-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  13. Energy Cost Calculator for Commercial Ice Machines | Department of Energy

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

    Ice Machines Energy Cost Calculator for Commercial Ice Machines Vary capacity size, energy cost, hours of operation, and /or efficiency level. INPUT SECTION Input the following data (if any parameter is missing, calculator will set to default value). Defaults Type of Ice Cube Machine Ice Making Head Self-Contained Remote Condensing Unit Ice Making Head Type of Condenser Air Cooled Water Cooled Air Cooled Ice Harvest Rate (lbs. ice per 24 hrs.) lbs. per 24 hrs. 500 lbs. per 24 hrs. Energy

  14. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic

    Office of Scientific and Technical Information (OSTI)

    mixed-phase stratocumulus (Journal Article) | SciTech Connect The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus Citation Details In-Document Search Title: The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus This study investigates the maintenance of cloud ice production in Arctic mixed phase stratocumulus in large-eddy simulations that include a prognostic ice nuclei (IN) formulation and a

  15. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic

    Office of Scientific and Technical Information (OSTI)

    mixed-phase stratocumulus (Journal Article) | SciTech Connect The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus Citation Details In-Document Search Title: The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus This study investigates the maintenance of cloud ice production in Arctic mixed-phase stratocumulus in large eddy simulations that include a prognostic ice nuclei (IN) formulation and a

  16. Hydrogen ICE Vehicle Testing Activities

    SciTech Connect (OSTI)

    J. Francfort; D. Karner

    2006-04-01

    The Advanced Vehicle Testing Activity teamed with Electric Transportation Applications and Arizona Public Service to develop and monitor the operations of the APS Alternative Fuel (Hydrogen) Pilot Plant. The Pilot Plant provides 100% hydrogen, and hydrogen and compressed natural gas (H/CNG)-blended fuels for the evaluation of hydrogen and H/CNG internal combustion engine (ICE) vehicles in controlled and fleet testing environments. Since June 2002, twenty hydrogen and H/CNG vehicles have accumulated 300,000 test miles and 5,700 fueling events. The AVTA is part of the Department of Energy’s FreedomCAR and Vehicle Technologies Program. These testing activities are managed by the Idaho National Laboratory. This paper discusses the Pilot Plant design and monitoring, and hydrogen ICE vehicle testing methods and results.

  17. Eighth international congress on nitrogen fixation

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  18. Icing on wind-energy systems

    SciTech Connect (OSTI)

    Hoffer, T.; Reale, T.; Elfiqi, A.

    1981-01-01

    A source of icing data is the network of meteorological recording stations within the continental United States which collect meteorological measurements both at the surface and aloft. This report presents procedures for analyzing this data to determine the maximum possible icing to be expected at specified locations. Since the physical processes are different, the procedures for predicting maximum glaze ice and rime are presented in separate sections. Models developed to simulate the maximum possible ice buildup on an exposed surface using the rainfall and cloud water data as input are also presented. In addition to the maximal dynamic and static icing loads, comparative icing values based on an attempt to simulate actual field conditions are also shown. Included are assumptions of droplet splashing and water drainage for the glaze cases and atmospheric mixing during orographic lifting for rime cases.

  19. Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report

    Office of Scientific and Technical Information (OSTI)

    ... This includes understanding how different components of the Arctic system affect sea ice (e.g., atmosphere, ocean), but also how changing sea ice affects the system (e.g., ecology, ...

  20. Marginal Ice Zone Observations and Processes Experiment

    Office of Scientific and Technical Information (OSTI)

    46 Investigations of Spatial and Temporal Variability of Ocean and Ice Conditions in and Near the Marginal Ice Zone: The "Marginal Ice Zone Observations and Processes Experiment" (MIZOPEX) Final Campaign Summary JA Maslanik February 2016 CLIMATE RESEARCH FACILITY DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any

  1. Automatic Commercial Ice Makers | Department of Energy

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

    Automatic Commercial Ice Makers Automatic Commercial Ice Makers The Department of Energy (DOE) develops standardized data templates for reporting the results of tests conducted in accordance with current DOE test procedures. Templates may be used by third-party laboratories under contract with DOE that conduct testing in support of ENERGY STAR® verification, DOE rulemakings, and enforcement of the federal energy conservation standards. File Automatic Commercial Ice Makers -- v2.0 More Documents

  2. High-nitrogen explosives

    SciTech Connect (OSTI)

    Naud, D.; Hiskey, M. A.; Kramer, J. F.; Bishop, R. L.; Harry, H. H.; Son, S. F.; Sullivan, G. K.

    2002-01-01

    The syntheses and characterization of various tetrazine and furazan compounds offer a different approach to explosives development. Traditional explosives - such as TNT or RDX - rely on the oxidation of the carbon and hydrogen atoms by the oxygen carrying nitro group to produce the explosive energy. High-nitrogen compounds rely instead on large positive heats of formation for that energy. Some of these high-nitrogen compounds have been shown to be less sensitive to initiation (e.g. by impact) when compared to traditional nitro-containing explosives of similar performances. Using the precursor, 3,6-bis-(3,5-dimethylpyrazol-1-yl)-s-tetrazine (BDT), several useful energetic compounds based on the s-tetrazine system have been synthesized and studied. The compound, 3,3{prime}-azobis(6-amino-s-tetrazine) or DAAT, detonates as a half inch rate stick despite having no oxygen in the molecule. Using perfluoroacetic acid, DAAT can be oxidized to give mixtures of N-oxide isomers (DAAT03.5) with an average oxygen content of about 3.5. This energetic mixture burns at extremely high rates and with low dependency on pressure. Another tetrazine compound of interest is 3,6-diguanidino-s-tetrazine(DGT) and its dinitrate and diperchlorate salts. DGT is easily synthesized by reacting BDT with guanidine in methanol. Using Caro's acid, DGT can be further oxidized to give 3,6-diguanidino-s-tetrazine-1,4-di-N-oxide (DGT-DO). Like DGT, the di-N-oxide can react with nitric acid or perchloric acid to give the dinitrate and the diperchlorate salts. The compounds, 4,4{prime}-diamino-3,3{prime}-azoxyfurazan (DAAF) and 4,4{prime}-diamino-3,3{prime}-azofurazan (DAAzF), may have important future roles in insensitive explosive applications. Neither DAAF nor DAAzF can be initiated by laboratory impact drop tests, yet both have in some aspects better explosive performances than 1,3,5-triamino-2,4,6-trinitrobenzene TATB - the standard of insensitive high explosives. The thermal stability of DAAzF is equal to that of hexanitrostilbene (HNS), yet it has a greater CJ pressure and detonation velocity. In an effort to reduce the critical diameter of TATB without sacrificing its insensitivity, we have studied the explosive performances of TATB mixed with DAAzlF (X-0561) and TATB mixed with DAAF (X-0563).

  3. Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet

    Office of Scientific and Technical Information (OSTI)

    Simulations (Conference) | SciTech Connect Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet Simulations Citation Details In-Document Search Title: Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet Simulations Authors: Lipscomb, William [1] ; Leguy, Gunter [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2015-06-17 OSTI Identifier: 1186039 Report Number(s): LA-UR-15-24514 DOE Contract Number: AC52-06NA25396 Resource Type:

  4. Potassium chloride-bearing ice VII and ice planet dynamics (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect SciTech Connect Search Results Journal Article: Potassium chloride-bearing ice VII and ice planet dynamics Citation Details In-Document Search Title: Potassium chloride-bearing ice VII and ice planet dynamics Authors: Frank, Mark R. ; Scott, Henry P. ; Aarestad, Elizabeth ; Prakapenka, Vitali B. [1] ; UC) [2] ; NIU) [2] + Show Author Affiliations Indiana ( Publication Date: 2015-12-10 OSTI Identifier: 1229896 Resource Type: Journal Article Resource Relation:

  5. Sea ice - atmosphere interaction: Application of multispectral...

    Office of Scientific and Technical Information (OSTI)

    Application of multispectral satellite data in polar surface energy flux estimates. ... Title: Sea ice - atmosphere interaction: Application of multispectral satellite data in ...

  6. Southern Great Plains Ice Nuclei Characterization Experiment...

    Office of Scientific and Technical Information (OSTI)

    Characterization Experiment Final Campaign Summary Citation Details In-Document Search Title: Southern Great Plains Ice Nuclei Characterization Experiment Final Campaign ...

  7. Viscosity of interfacial water regulates ice nucleation

    SciTech Connect (OSTI)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan; University of Chinese Academy of Sciences, Beijing 100049 ; Xu, Shun; Zhou, Xin; Cui, Dapeng; Wang, Jianjun Song, Yanlin

    2014-03-10

    Ice formation on solid surfaces is an important phenomenon in many fields, such as cloud formation and atmospheric icing, and a key factor for applications in preventing freezing. Here, we report temperature-dependent nucleation rates of ice for hydrophilic and hydrophobic surfaces. The results show that hydrophilic surface presents a lower ice nucleation rate. We develop a strategy to extract the thermodynamic parameters, J{sub 0} and ?, in the context of classical nucleation theory. From the extracted J{sub 0} and ?, we reveal the dominant role played by interfacial water. The results provide an insight into freezing mechanism on solid surfaces.

  8. BISICLES Captures Details of Retreating Antarctic Ice

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

    ... Satellite and ground observations show that the ice in this region is thinning and retreating significantly as shifting wind patterns and ocean currents allow warmer water to flow ...

  9. Comparison of 17 Ice Nucleation Measurement Techniques

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

    17 Ice Nucleation Measurement Techniques for Immersion Freezing For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights Research...

  10. Turbine anti-icing system

    SciTech Connect (OSTI)

    Ball, B. D.

    1985-12-31

    Exhaust gas is recirculated from the exhaust stack of a gas fired turbine to the air inlet along a constantly-open path to prevent inlet freeze-up. When anti-icing is not needed the exhaust stack is fully opened, creating a partial vacuum in the exhaust stack. At the turbine inlet the recirculation line, is opened to atmosphere. The resultant pressure differential between the opposite ends of the recirculation line creates a driving force for positively purging the recirculation line of unwanted residual exhaust gases. This in turn eliminates a source of unwanted moisture which could otherwise condense, freeze and interfere with turbine operations.

  11. A direct evidence of vibrationally delocalized response at ice surface

    SciTech Connect (OSTI)

    Ishiyama, Tatsuya; Morita, Akihiro

    2014-11-14

    Surface-specific vibrational spectroscopic responses at isotope diluted ice and amorphous ice are investigated by molecular dynamics (MD) simulations combined with quantum mechanics/molecular mechanics calculations. The intense response specific to the ordinary crystal ice surface is predicted to be significantly suppressed in the isotopically diluted and amorphous ices, demonstrating the vibrational delocalization at the ordinary ice surface. The collective vibration at the ice surface is also analyzed with varying temperature by the MD simulation.

  12. Spongy icing in the marine environment

    SciTech Connect (OSTI)

    Lozowski, E.P.; Blackmore, R.Z.; Forest, T.W.; Shi, J.

    1996-12-01

    Newly formed marine ice accretions may include liquid brine amounts up to about 50% of the total accretion mass. Because they ignore this sponginess, traditional thermodynamic models of icing may significantly underestimate the total marine ice load. In an attempt to improve the capabilities of such models, the authors have undertaken experimental and theoretical research, directed at measuring and predicting the liquid fraction of ice accretions. The experimental work consisted of growing ice accretions on rotating cylinders in the Marine Icing Wind Tunnel at the University of Alberta, over a range of temperatures from {minus}2 C to {minus}25 C, and wind speeds from 19 to 30 m/s, at liquid water contents (3 to 9 g/m) typical of the marine spray environment. A calorimeter was used to measure the liquid fraction of the ice accretions. The experiments indicate that the liquid fraction is almost independent of the environmental conditions and ranges between about 32% and 47%. The authors have also developed a theoretical model of the morphology of the icing process which takes place under a falling supercooled liquid film. Comparisons between the model and experiments show that the model is able to predict accretion growth rate and sponginess with some degree of skill. However, there remain important aspects of the sponginess phenomenon which continue to elude them.

  13. Cable twisting due to atmospheric icing

    SciTech Connect (OSTI)

    McComber, P.; Druez, J.; Savadjiev, K.

    1995-12-31

    Samples of ice accretions collected on cables of overhead transmission lines have shown evidence of twisting of the cable during atmospheric icing. Previous work has attributed cable twisting to the torque created by the weight of an eccentric ice shape and by wind forces. However, testing of stranded cables and conductors has shown that such cables also twist when there is a change in tension in the cable span. This phenomenon is related to the interaction of the different strand layers under tension. When a cable is subjected to atmospheric icing, cable tension increases and this type of twisting should also be considered. In order to determine how the two types of twisting would compare on transmission lines, a numerical simulation was made using characteristics of a typical 35-mm stranded conductor. The twist angle was computed as a function of cable span, sag to span ratio and increasing ice loads. The simulation shows that for transmission lines, twisting due to varying tension will be significant. Since cable tension is influenced by wind speed and ambient temperature as well as ice load, this phenomenon, unless prevented, results in ice accretion more circular in shape and hence eventually in larger ice loads.

  14. Passive ice freezing-releasing heat pipe

    DOE Patents [OSTI]

    Gorski, Anthony J.; Schertz, William W.

    1982-01-01

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  15. Sandia Energy - Ice-Sheet Simulation Code Matures, Leveraging...

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

    and as the land ice component of coupled climate simulations in DOE's Earth System Model. The land ice component is responsible for simulating the evolution of the...

  16. Complex systems influence melting of Greenland ice sheet

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

    melting of Greenland ice sheet Complex systems influence melting of Greenland ice sheet International research team's field work shows that, well, things are more complicated...

  17. STATEMENT OF WORK (SOW) TEMPLATE FOR ICE SUPPORT CONTRACTOR

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

    ... ICE Scope: Perform a <ICE Contractor may mutually agree to add or delete particular sections, based ...

  18. ICR-ICE Standard Operating Procedures (Update Sept 2013) | Department...

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

    Documents & Publications INDEPENDENT COST REVIEW (ICR) and INDEPENDENT COST ESTIMATE (ICE) Standard Operating Procedures Contractor SOW Template - ICR Contractor SOW Template - ICE...

  19. Building a next-generation community ice sheet model: meeting...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Building a next-generation community ice sheet model: meeting summary Citation Details In-Document Search Title: Building a next-generation community ice sheet ...

  20. New climate model predicts likelihood of Greenland ice melt,...

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

    New climate model predicts likelihood of Greenland ice melt New climate model predicts likelihood of Greenland ice melt, sea level rise and dangerous temperatures A new computer ...

  1. Greenland Ice Sheet Modeling Update (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Greenland Ice Sheet Modeling Update Citation Details In-Document Search Title: Greenland Ice Sheet Modeling Update You are accessing a document from the Department of Energy's...

  2. Determination of Large-Scale Cloud Ice Water Concentration by...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Determination of Large-Scale Cloud Ice Water Concentration by Combining ... Title: Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface ...

  3. Optimal Initial Conditions for Coupling Ice Sheet Models to Earth...

    Office of Scientific and Technical Information (OSTI)

    for Coupling Ice Sheet Models to Earth System Models. Citation Details In-Document Search Title: Optimal Initial Conditions for Coupling Ice Sheet Models to Earth System Models. ...

  4. Department of Energy Land Ice Modeling Efforts (Conference) ...

    Office of Scientific and Technical Information (OSTI)

    Energy Land Ice Modeling Efforts Citation Details In-Document Search Title: Department of Energy Land Ice Modeling Efforts Authors: Price, Stephen F. Dr 1 + Show Author...

  5. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 m) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 m), known as the small mode. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 m wavelength relative to 11 m wavelength due to the process of wave resonance or photon tunneling more active at 12 m. This makes the 12/11 m absorption optical depth ratio (or equivalently the 12/11 m Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  6. Stanford Nitrogen Group | Department of Energy

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

    Stanford Nitrogen Group National Clean Energy Business Plan Competition Stanford Nitrogen Group Stanford University The Stanford Nitrogen Group developed a new wastewater treatment process for the removal and recovery of energy from waste nitrogen (i.e. ammonia). This process improves the efficiency and lowers the cost of nitrogen treatment. The process is termed the Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) and consists of 2 principal steps: biological conversion of ammonia

  7. Video monitoring of atmospheric icing

    SciTech Connect (OSTI)

    Wareing, J.B.; Chetwood, P.A.

    1995-12-31

    Over the past six years, EA Technology has been involved in the remote monitoring of test spans and samples of overhead transmission line conductors in the UK in areas chosen for their severe winter weather. The sites are unmanned and regularly suffer gales, blizzards and severe icing conditions. Test samples at the sites are monitored day and night using automate, computer and remotely controlled video and still cameras using both the visible and near infrared spectrum. Video and still picture data is stored on site for periodic collection. Meteorological and load force data is collected and also stored at these remote sites and is sent automatically by mobile phone link to a computer at the EA Technology center. All this data can also be monitored at any time at the center over 200 miles away.

  8. Wind turbine performance under icing conditions

    SciTech Connect (OSTI)

    Jasinski, W.J.; Noe, S.C.; Selig, M.S.; Bragg, M.B.

    1998-02-01

    The effects of rime ice on horizontal axis wind turbine performance were estimated. For typical supercooled fog conditions found in cold northern regions, four rime ice accretions on the S809 wind turbine airfoil were predicted using the NASA LEWICE code. The resulting airfoil/ice profile combinations were wind tunnel tested to obtain the lift, drag, and pitching moment characteristics over the Reynolds number range 1--2 {times} 10{sup 6}. These data were used in the PROPID wind turbine performance prediction code to predict the effects of rime ice on a 450-kW rated-power, 28.7-m diameter turbine operated under both stall-regulated and variable-speed/variable-pitch modes. Performance losses on the order of 20% were observed for the variable-speed/variable-pitch rotor. For the stall-regulated rotor, however, a relatively small rime ice profile yielded significantly larger performance losses. For a larger 0.08c-long rime ice protrusion, however, the rated peak power was exceeded by 16% because at high angles the rime ice shape acted like a leading edge flap, thereby increasing the airfoil C{sub l,max} and delaying stall.

  9. METHOD OF FIXING NITROGEN FOR PRODUCING OXIDES OF NITROGEN

    DOE Patents [OSTI]

    Harteck, P.; Dondes, S.

    1959-08-01

    A method is described for fixing nitrogen from air by compressing the air, irradiating the compressed air in a nuclear reactor, cooling to remove NO/ sub 2/, compressing the cooled gas, further cooling to remove N/sub 2/O and recirculating the cooled compressed air to the reactor.

  10. Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicity

    SciTech Connect (OSTI)

    Cox, Stephen J.; Kathmann, Shawn M.; Slater, B.; Michaelides, Angelos

    2015-05-14

    Ice formation is one of the most common and important processes on earth and almost always occurs at the surface of a material. A basic understanding of how the physicochemical properties of a material’s surface affect its ability to form ice has remained elusive. Here, we use molecular dynamics simulations to directly probe heterogeneous ice nucleation at a hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chemical catalyst, it is found that an optimal interaction between the surface and the water exists for promoting ice nucleation.We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability. C 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

  11. The influence of ice nucleation mode and ice vapor growth on simulation of

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

    arctic mixed-phase clouds The influence of ice nucleation mode and ice vapor growth on simulation of arctic mixed-phase clouds Avramov, Alexander The Pennsylvania State University Category: Modeling Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic . Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived

  12. A Smoothed Particle Hydrodynamics Model for Ice Sheet and Ice Shelf Dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2012-02-08

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) model for coupled ice sheet and ice shelf dynamics. SPH is a fully Lagrangian particle method. It is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface flows, large material deformation, and material fragmentation. In this paper SPH is used to study ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from the SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is further verified by simulating the plane shear flow of two immiscible fluids and the propagation of a highly viscous blob of fluid along a horizontal surface. In the experiment, the ice was represented with a viscous newtonian fluid. For consistency, in the described SPH model the ice is also modeled as a viscous newtonian fluid. Typically, ice sheets are modeled as a non-Newtonian fluid, accounting for the changes in the mechanical properties of ice. Implementation of a non-Newtonian rheology in the SPH model is the subject of our ongoing research.

  13. Smoothed particle hydrodynamics Non-Newtonian model for ice-sheet and ice-shelf dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2013-06-01

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) non-Newtonian model for coupled ice sheet and ice shelf dynamics. SPH, a fully Lagrangian particle method, is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface ?ows, large material deformation, and material fragmentation. In this paper, SPH is used to study 3D ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios, similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is veri?ed by simulating Poiseuille ?ow, plane shear ?ow with free surface and the propagation of a blob of ice along a horizontal surface. In the laboratory experiment, the ice was represented with a viscous Newtonian ?uid. In the present work, however, the ice is modeled as both viscous Newtonian ?uid and non-Newtonian ?uid, such that the e?ect of non-Newtonian rheology on the dynamics of grounding line was examined. The non-Newtonian constitutive relation is prescribed to be Glens law for the creep of polycrystalline ice. A V-shaped bedrock ramp is further introduced to model the real geometry of bedrock slope.

  14. De-icing: recovery of diffraction intensities in the presence of ice rings

    SciTech Connect (OSTI)

    Chapman, Michael S.; Somasundaram, Thayumanasamy

    2010-11-03

    Macromolecular structures are routinely determined at cryotemperatures using samples flash-cooled in the presence of cryoprotectants. However, sometimes the best diffraction is obtained under conditions where ice formation is not completely ablated, with the result that characteristic ice rings are superimposed on the macromolecular diffraction. In data processing, the reflections that are most affected by the ice rings are usually excluded. Here, an alternative approach of subtracting the ice diffraction is tested. High completeness can be retained with little adverse effect upon the quality of the integrated data. This offers an alternate strategy when high levels of cryoprotectant lead to loss of crystal quality.

  15. Communication: On the stability of ice 0, ice i, and I{sub h}

    SciTech Connect (OSTI)

    Quigley, D.; Alf, D.; Slater, B.

    2014-10-28

    Using ab initio methods, we examine the stability of ice 0, a recently proposed tetragonal form of ice implicated in the homogeneous freezing of water [J. Russo, F. Romano, and H. Tanaka, Nat. Mater. 13, 670 (2014)]. Vibrational frequencies are computed across the complete Brillouin Zone using Density Functional Theory (DFT), to confirm mechanical stability and quantify the free energy of ice 0 relative to ice I{sub h}. The robustness of this result is tested via dispersion corrected semi-local and hybrid DFT, and Quantum Monte-Carlo calculation of lattice energies. Results indicate that popular molecular models only slightly overestimate the stability of ice zero. In addition, we study all possible realisations of proton disorder within the ice zero unit cell, and identify the ground state as ferroelectric. Comparisons are made to other low density metastable forms of ice, suggesting that the ice i structure [C. J. Fennel and J. D. Gezelter, J. Chem. Theory Comput. 1, 662 (2005)] may be equally relevant to ice formation.

  16. SGP CART Site Affected by Ice Storm

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

    ... Dry nitrogen gas purges were installed to prevent condensation from forming on instrument ... compensation for damaged or destroyed property and cleanup costs not covered by insurance. ...

  17. Developing and Evaluating Ice Cloud Parameterizations by

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

    by remote sensing is that the transfer functions which relate the observables (e. g., radar Doppler spectrum) to cloud properties (e. g., ice water content, or IWC) are not...

  18. Spreading of oil spilled under ice

    SciTech Connect (OSTI)

    Yapa, P.D.; Chowdhury, T. )

    1990-12-01

    A new set of equations is presented to describe the process of oil spreading under ice in clam waters. These equations consider the gravity (buoyancy)-inertia phase, the gravity (buoyancy)-viscous phase, and the termination of spreading during the buoyancy-surface-tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to the termination of spreading is presented. Laboratory experiments were conducted using both real ice covers in a cold room and artificial ice covers. The experiments included different ice-cover roughnesses from smooth to rough, oils of different viscosities, and a variety of discharge conditions. The experimental data show close agreement with the theory. These equations can be used during cleanup or environmental impact assessment to estimate the area of an oil slick with respect to time.

  19. An analysis of selected atmospheric icing events on test cables

    SciTech Connect (OSTI)

    Druez, J.; McComber, P.; Laflamme, J.

    1996-12-01

    In cold countries, the design of transmission lines and communication networks requires the knowledge of ice loads on conductors. Atmospheric icing is a stochastic phenomenon and therefore probabilistic design is used more and more for structure icing analysis. For strength and reliability assessments, a data base on atmospheric icing is needed to characterize the distributions of ice load and corresponding meteorological parameters. A test site where icing is frequent is used to obtain field data on atmospheric icing. This test site is located on the Mt. Valin, near Chicoutimi, Quebec, Canada. The experimental installation is mainly composed of various instrumented but non-energized test cables, meteorological instruments, a data acquisition system, and a video recorder. Several types of icing events can produce large ice accretions dangerous for land-based structures. They are rime due to in-cloud icing, glaze caused by freezing rain, wet snow, and mixtures of these types of ice. These icing events have very different characteristics and must be distinguished, before statistical analysis, in a data base on atmospheric icing. This is done by comparison of data from a precipitation gauge, an icing rate meter and a temperature sensor. An analysis of selected icing periods recorded on the cables of two perpendicular test lines during the 1992--1993 winter season is presented. Only significant icing events have been considered. A comparative analysis of the ice load on the four test cables is drawn from the data, and typical accretion and shedding parameters are calculated separately for icing events related to in-cloud icing and precipitation icing.

  20. Icing modelling in NSMB with chimera overset grids

    SciTech Connect (OSTI)

    Pena, D.; Deloze, T.; Laurendeau, E.; Hoarau, Y.

    2015-03-10

    In aerospace Engineering, the accurate simulation of ice accretion is a key element to increase flight safety and avoid accidents related to icing effects. The icing code developed in the NSMB solver is based on an Eulerian formulation for droplets tracking, an iterative Messinger model using a modified water runback scheme for ice thickness calculation and mesh deformation to track the ice/air interface through time. The whole process is parallelized with MPI and applied with chimera grids.

  1. Investigations of Spatial and Temporal Variability of Ocean and Ice

    Office of Scientific and Technical Information (OSTI)

    Conditions in and Near the Marginal Ice Zone. The "Marginal Ice Zone Observations and Processes Experiment" (MIZOPEX) Final Campaign Summary (Technical Report) | SciTech Connect Investigations of Spatial and Temporal Variability of Ocean and Ice Conditions in and Near the Marginal Ice Zone. The "Marginal Ice Zone Observations and Processes Experiment" (MIZOPEX) Final Campaign Summary Citation Details In-Document Search Title: Investigations of Spatial and Temporal

  2. Melting of ice wedges adds to arctic warming

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

    Can we someday predict earthquakes? Melting of ice wedges adds to arctic warming New ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes-and when. March 14, 2016 Ice throughout the Arctic is vanishing due to a rapidly warming climate. Ice throughout the Arctic is vanishing due to a rapidly warming climate. Melting of ice wedges adds to arctic warming Ice wedges are a particularly cool surface feature in the

  3. Alternative Fuels Data Center: Electric Ice Resurfacers Improve Air Quality

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

    in Minnesota Electric Ice Resurfacers Improve Air Quality in Minnesota to someone by E-mail Share Alternative Fuels Data Center: Electric Ice Resurfacers Improve Air Quality in Minnesota on Facebook Tweet about Alternative Fuels Data Center: Electric Ice Resurfacers Improve Air Quality in Minnesota on Twitter Bookmark Alternative Fuels Data Center: Electric Ice Resurfacers Improve Air Quality in Minnesota on Google Bookmark Alternative Fuels Data Center: Electric Ice Resurfacers Improve Air

  4. Development of a Mobile Ice Nucleus Counter

    SciTech Connect (OSTI)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  5. Method of preparing nitrogen containing semiconductor material

    DOE Patents [OSTI]

    Barber, Greg D.; Kurtz, Sarah R.

    2004-09-07

    A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

  6. Seeking solutions for icing at dams and hydro plants

    SciTech Connect (OSTI)

    Haynes, F.D. )

    1993-12-01

    Hydroelectric plant operators in the northern US and Canada often encounter icing problems that interfere with normal operations. Icing can cause problems in machinery, valves, and gates, and frazil ice can block water intakes. (Frazil ice is a slightly super-cooled, slush-type ice commonly formed on northern rivers in a rapids area or any area without an ice cover.) Icing problems, especially blockage of water intakes, can shut down a hydropower plant and cause a considerable loss of power generation. The US Army Corps of Engineers' Cold Regions Research and Engineering Laboratory (CRREL) surveyed hydro plant operators about icing problems experienced at their facilities and solutions to these problems. By sharing the survey results, CRREL researchers hope to spread solutions among operators and to identify those problems for which no solutions are currently known that require more research. CRREL researchers also are developing promising technology that may help to alleviate icing problems.

  7. De-icing: recovery of diffraction intensities in the presence of ice rings

    SciTech Connect (OSTI)

    Chapman, Michael S.; Somasundaram, Thayumanasamy

    2010-06-01

    Correction for ice-rings in diffraction images is demonstrated as an alternative to exclusion of affected reflections. Completeness can be increased without significant loss of quality in the integrated data. Macromolecular structures are routinely determined at cryotemperatures using samples flash-cooled in the presence of cryoprotectants. However, sometimes the best diffraction is obtained under conditions where ice formation is not completely ablated, with the result that characteristic ice rings are superimposed on the macromolecular diffraction. In data processing, the reflections that are most affected by the ice rings are usually excluded. Here, an alternative approach of subtracting the ice diffraction is tested. High completeness can be retained with little adverse effect upon the quality of the integrated data. This offers an alternate strategy when high levels of cryoprotectant lead to loss of crystal quality.

  8. The Role of Snow and Ice in the Climate System

    SciTech Connect (OSTI)

    Barry, Roger

    2007-12-19

    Global snow and ice cover (the 'cryosphere') plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice - albedo feedback. Snow and ice cover undergo marked seasonal and long term changes in extent and thickness. The perennial elements - the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow and ice extent are discussed.

  9. The Role of Snow and Ice in the Climate System

    ScienceCinema (OSTI)

    Barry, Roger G.

    2009-09-01

    Global snow and ice cover (the 'cryosphere') plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice - albedo feedback. Snow and ice cover undergo marked seasonal and long term changes in extent and thickness. The perennial elements - the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow and ice extent are discussed.

  10. Better Buildings Residential Network Peer Exchange Call Series...

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

    ... who are repeat customers. 24 Program Experience: Eversource Broccoli or Ice Cream? ... Theodore Roosevelt Broccoli? 28 Ice Cream? 29 Credit cards Hotels A i r l i n e s G r o c ...

  11. SEP Success Story: Turkey Hill Dairy: Where Energy is Not Left...

    Office of Environmental Management (EM)

    Turkey Hill Dairy, the fourth largest producer of ice cream in the United States, uses wind power to produce its 26 million gallons of ice cream each year. Learn more. Addthis ...

  12. SEP Success Story: Turkey Hill Dairy: Where Energy is Not Left Flapping in the Wind

    Broader source: Energy.gov [DOE]

    Turkey Hill Dairy, the fourth largest producer of ice cream in the United States, uses wind power to produce its 26 million gallons of ice cream each year. Learn more.

  13. Aircraft de-icing best management plans

    SciTech Connect (OSTI)

    Simpson, A.

    1997-12-31

    The purpose of this paper is to summarize the environmental impact of glycol-based de-icing fluids and the best management practices utilized at Canadian airports. The operational, safety and environmental effects of glycol are discussed as well as the management instruments available to address these areas of concern. In today`s highly mobile society, increasing air travel necessitates an awareness of flight safety by the aviation industry. This is most evident during the inclement winter season when de-icing operations are mandatory. De-icing fluids are both a safety and an environmental concern. Although glycol-based de-icers are applied to ensure flight safety, the release of this chemical has a detrimental effect on the environment.

  14. Land Ice Verification and Validation Kit

    Energy Science and Technology Software Center (OSTI)

    2015-07-15

    To address a pressing need to better understand the behavior and complex interaction of ice sheets within the global Earth system, significant development of continental-scale, dynamical ice-sheet models is underway. The associated verification and validation process of these models is being coordinated through a new, robust, python-based extensible software package, the Land Ice Verification and Validation toolkit (LIVV). This release provides robust and automated verification and a performance evaluation on LCF platforms. The performance V&Vmore » involves a comprehensive comparison of model performance relative to expected behavior on a given computing platform. LIVV operates on a set of benchmark and test data, and provides comparisons for a suite of community prioritized tests, including configuration and parameter variations, bit-4-bit evaluation, and plots of tests where differences occur.« less

  15. Land Ice Verification and Validation Kit

    SciTech Connect (OSTI)

    2015-07-15

    To address a pressing need to better understand the behavior and complex interaction of ice sheets within the global Earth system, significant development of continental-scale, dynamical ice-sheet models is underway. The associated verification and validation process of these models is being coordinated through a new, robust, python-based extensible software package, the Land Ice Verification and Validation toolkit (LIVV). This release provides robust and automated verification and a performance evaluation on LCF platforms. The performance V&V involves a comprehensive comparison of model performance relative to expected behavior on a given computing platform. LIVV operates on a set of benchmark and test data, and provides comparisons for a suite of community prioritized tests, including configuration and parameter variations, bit-4-bit evaluation, and plots of tests where differences occur.

  16. Equations of state of ice VI and ice VII at high pressure and high temperature

    SciTech Connect (OSTI)

    Bezacier, Lucile; Hanfland, Michael; Journaux, Baptiste; Perrillat, Jean-Philippe; Cardon, Herv; Daniel, Isabelle

    2014-09-14

    High-pressure H{sub 2}O polymorphs among which ice VI and ice VII are abundant in the interiors of large icy satellites and exo-planets. Knowledge of the elastic properties of these pure H{sub 2}O ices at high-temperature and high-pressure is thus crucial to decipher the internal structure of icy bodies. In this study we assess for the first time the pressure-volume-temperature (PVT) relations of both polycrystalline pure ice VI and ice VII at high pressures and temperatures from 1 to 9 GPa and 300 to 450 K, respectively, by using in situ synchrotron X-ray diffraction. The PVT data are adjusted to a second-order Birch-Murnaghan equation of state and give V{sub 0} = 14.17(2) cm{sup 3}?mol{sup ?1}, K{sub 0} = 14.05(23) GPa, and ?{sub 0} = 14.6(14) 10{sup ?5} K{sup ?1} for ice VI and V{sub 0} = 12.49(1) cm{sup 3}?mol{sup ?1}, K{sub 0} = 20.15(16) GPa, and ?{sub 0} = 11.6(5) 10{sup ?5} K{sup ?1} for ice VII.

  17. Energy conservation in ice skating rinks

    SciTech Connect (OSTI)

    Dietrich, B.K.; McAvoy, T.J.

    1980-01-01

    An economic and energy analysis of ice rinks was made to examine the areas in which energy could be profitably conserved. The areas where new equipment could make a major reduction in energy use are: the use of waste heat for space heating, the installation of a low emissivity false ceiling to reduce radiant heat, the use of a load cycling controller to reduce refrigeration costs, and the installation of more efficient lighting systems. Changes in rink operating procedure that could cut energy use are: higher refrigerant temperatures, thinner ice, the use of colder resurfacing water, turning the compressors and pumps off at night, and reducing ventilation.

  18. Nanotextured Anti-Icing Surfaces | GE Global Research

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

    Demonstrate Promising Anti-icing Nano Surfaces Click to email this to a friend (Opens in ... GE Scientists Demonstrate Promising Anti-icing Nano Surfaces GE Global Research today ...

  19. A Nano Surface Icephobic Coating Delays Ice Formation | GE Global...

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

    ... at the water-substrate interface. icing-image-with-caption-300x193 I recently ... sensors, non-icing surfaces, nano-enabled media storage and optoelectronic devices. ...

  20. A TWP-ICE High-Level Cloud Case Study

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

    A TWP-ICE High-Level Cloud Case Study Mace, Gerald University of Utah Category: Field Campaigns The Tropical Warm Pool International Cloud Experiment (TWP ICE) was conducted near...

  1. Ice Sheet Model Reveals Most Comprehensive Projections for West...

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

    has been stage to dramatic thinning in recent years. The West Antarctic Ice Sheet (WAIS) is out of balance because it is losing significant amounts of ice to the ocean, with...

  2. Modeling the Effect of Ice Nuclei on ARM Clouds

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

    Upper-Tropospheric Ice Water Content in TWP-ICE Xiping Zeng, Wei-Kuo Tao, Minghua Zhang, and Shaochen Xie March 31, 2009 Papers Published Recently * Zeng, X., W.-K. Tao, M. Zhang,...

  3. Covered Product Category: Water-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance and federal efficiency requirements for water-cooled ice machines.

  4. Rapid Cooling Using Ice Slurries for Industrial and Medical Applications -

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

    Energy Innovation Portal Industrial Technologies Industrial Technologies Building Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Rapid Cooling Using Ice Slurries for Industrial and Medical Applications Argonne National Laboratory Contact ANL About This Technology Schematic of distributed-load ice slurry building cooling system Schematic of distributed-load ice slurry building cooling system Endoscopic view of a swine kidney covered with ice slurry delivered

  5. ARM - What About Melting Polar Ice Caps and Sea Levels?

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

    What About Melting Polar Ice Caps and Sea Levels? Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans What About Melting Polar Ice Caps and Sea Levels? As the northern polar zone warms up, sea ice could melt (very probable) and the sea/ice interface could retreat to the north. This is likely to

  6. Team advances understanding of the Greenland Ice Sheet's meltwater

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

    channels Greenland Ice Sheet's meltwater channels Team advances understanding of the Greenland Ice Sheet's meltwater channels An international research team's field work is showing that, well, things are more complicated than we thought. October 1, 2014 An international team of researchers deployed to western Greenland to study the melt rates of the Greenland Ice Sheet. An international team of researchers deployed to western Greenland to study the melt rates of the Greenland Ice Sheet.

  7. Nitrogen fixation method and apparatus

    DOE Patents [OSTI]

    Chen, Hao-Lin

    1983-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  8. Nitrogen fixation method and apparatus

    DOE Patents [OSTI]

    Chen, H.L.

    1983-08-16

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O[sub 2]/cm promotes the formation of vibrationally excited N[sub 2]. Atomic oxygen interacts with vibrationally excited N[sub 2] at a much quicker rate than unexcited N[sub 2], greatly improving the rate at which NO is formed. 1 fig.

  9. Nitrogen Removal from Natural Gas

    Office of Scientific and Technical Information (OSTI)

    Nitrogen Removal from Natural Gas Phase II Draft Final Report Contract Number DE-AC21-95MC32199--02 Contract Period: July 29, 1996 - December 31, 1999 prepared by Membrane Technology and Research, Inc. 1360 Willow Road Menlo Park, CA 94025 December 22, 1999 for the U.S. Department of Energy Morgantown Energy Technology Center Morgantown, WV Contributors to this Report: K.A. Lokhandwala M.B. Ringer T.T. Su Z. He I. Pinnau J.G. Wijmans A. Morisato K. Amo A. Da Costa R.W. Baker R. Olsen H. Hassani

  10. Therapeutic Hypothermia: Protective Cooling Using Medical Ice Slurry |

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

    Argonne National Laboratory Therapeutic Hypothermia: Protective Cooling Using Medical Ice Slurry Technology available for licensing: Proprietary method and equipment for making an ice slurry coolant to induce therapeutic hypothermia. Portable, automatic Advantageous for emergency care, cooling during surgeries, organ harvesting PDF icon ice_slurry

  11. Oil recovery by nitrogen flooding. Final report

    SciTech Connect (OSTI)

    Ronde, H.; Hagoort, J.

    1992-03-01

    The general objective of the project is the Establishment of technical and economic design criteria and evaluation tools for oil and condensate recovery by Nitrogen Injection. The main objective has been divided into the following specific objectives: Determination of the effect of oil composition on the oil recovery; Investigation of the pros and cons of slim-tube experiments as a tool for the design and evaluation of nitrogen flooding; Measurement and calculation of the minimum miscibility pressures (MMP) for nitrogen flooding.

  12. Electric heat tracing designed to prevent icing

    SciTech Connect (OSTI)

    Lonsdale, J.T.; Norrby, T.

    1985-11-01

    Mobile offshore rigs designed for warmer climates are not capable of operating year-round in the arctic or near-arctic regions. Icing is but one major operational problem in these waters. The danger of instability due to ice loading exists on an oil rig as well as on a ship. From a safety standpoint, ice must be prevented from forming on the helideck, escape passages, escape doors and hatches and handrails. Norsk Hydro A/S, as one of the major operators in the harsh environment outside northern Norway, recognized at an early stage the need for special considerations for the drilling rigs intended for year-round drilling in these regions. In 1982 Norsk Hydro awarded a contract for an engineering study leading to the design of a harsh environment semisubmersible drilling rig. The basic requirement was to develop a unit for safe and efficient year-round drilling operation in the waters of northern Norway. The study was completed in 1983 and resulted in a comprehensive report including a building specification. The electric heat tracing system designed to prevent icing on the unit is described.

  13. The Next ICE Age | Department of Energy

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

    developments in diesel engines for light- and heavy-duty applications PDF icon deer12_ruth.pdf More Documents & Publications The Next ICE Age Cummins SuperTruck Program - Technology and System Level Demonstration of Highly Efficient and Clean, Diesel Powered Class 8 Trucks SuperTruck Program: Engine Project Review

  14. Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report

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

    8 Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report VP Walden SR Hudson L Cohen , March 2016 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its

  15. Ingredients:

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

    Ingredients: Root beer Vanilla ice cream Tall glasses Straws and iced tea spoons Procedure: We are going to make an ice cream float. Experiment: What happens if you . . . 1. Put the ice cream in the glass before adding the root beer? 2. Put the root beer in the glass before adding the ice cream? 3. Compare the soda in the float with soda from the bottle? Try some experiments of your own! -Different kinds of soda or ice cream -Shapes of glasses -Warm or cold root beer What do you think? In what

  16. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim; Tuminaro, Ray

    2013-10-10

    The objective of this project was to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. This objective was achieved by developing novel physics based models for ice, novel numerical tools to enable the modeling of the physics and by collaboration with the ice community experts. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. To this end, our research findings through this project offers significant advancement to the field and closes a large gap of knowledge in understanding and modeling the fracture of ice sheets in the polar regions. Thus, we believe that our objective has been achieved and our research accomplishments are significant. This is corroborated through a set of published papers, posters and presentations at technical conferences in the field. In particular significant progress has been made in the mechanics of ice, fracture of ice sheets and ice shelves in polar regions and sophisticated numerical methods that enable the solution of the physics in an efficient way.

  17. How to measure the wind accurately in icing conditions

    SciTech Connect (OSTI)

    Kenyon, P.R.; Blittersdorf, D.C.

    1995-12-31

    Atmospheric icing occurs frequently in the northwestern, Midwestern and northeastern United States from early October through April at locations with high average wind speeds. It has caused wind data recovery problems at sites as far south as Texas. Icing slows anemometers used to assess the wind resource. Data recovered from sites prone to icing will show lower average wind speeds than actual, undervaluing them. The assessment of a wind site must present the actual wind potential. Anemometers used at these sites must remain free of ice. This report presents a description of icing types and the data distortion they cause based on NRG field experience. A brief history of anti-icing anemometers available today for remote site and turbine site monitoring follows. Comparative data of NRG`s IceFree anemometers and the industry standard unheated anemometer is included.

  18. The Nitrogen-Nitride Anode.

    SciTech Connect (OSTI)

    Delnick, Frank M.

    2014-10-01

    Nitrogen gas N 2 can be reduced to nitride N -3 in molten LiCl-KCl eutectic salt electrolyte. However, the direct oxidation of N -3 back to N 2 is kinetically slow and only occurs at high overvoltage. The overvoltage for N -3 oxidation can be eliminated by coordinating the N -3 with BN to form the dinitridoborate (BN 2 -3 ) anion which forms a 1-D conjugated linear inorganic polymer with -Li-N-B-N- repeating units. This polymer precipitates out of solution as Li 3 BN 2 which becomes a metallic conductor upon delithiation. Li 3 BN 2 is oxidized to Li + + N 2 + BN at about the N 2 /N -3 redox potential with very little overvoltage. In this report we evaluate the N 2 /N -3 redox couple as a battery anode for energy storage.

  19. Predicting Electrochemical Windows of Nitrogen Containing Aromatic

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

    Molecules - Joint Center for Energy Storage Research October 20, 2014, Research Highlights Predicting Electrochemical Windows of Nitrogen Containing Aromatic Molecules Various nitrogen containing aromatic base molecules and a descriptive relationship derived to predict their reduction potentials is shown. Scientific Achievement A descriptive relationship is derived for computing reduction potentials of quinoxaline derivatives from the orbital energies of the neutral molecules without

  20. FactSheet-TWP_ICE.indd

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

    Warm Pool International Cloud Experiment General Description The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) is a collaborative effort led by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program and the Australian Bureau of Meteo- rology. Beginning January 19 and ending February 28, 2006, the experiment will be conducted in the region near the ARM Climate Research Facility in Darwin, Northern Australia. This permanent facility is fully equipped with

  1. Flight Path 30L - ICE House

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

    Publications The shape of the neutron spectrum here is very similar to that of neutrons produced in the atmosphere by cosmic rays but with a neutron flux a million times higher, depending on altitude. This large flux allows testing of semiconductor devices at greatly accelerated rates. The Invisible Neutron Threat LANSCE - A Key Facility for National Science and Defense Neutron-Induced Failures in Semiconductor Devices THE ICE HOUSE - Neutron Testing Leads to More-Reliable Electronics

  2. Flight Path 30R - ICE II

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

    Links The shape of the neutron spectrum here is very similar to that of neutrons produced in the atmosphere by cosmic rays but with a neutron flux a million times higher, depending on altitude. This large flux allows testing of semiconductor devices at greatly accelerated rates. The Invisible Neutron Threat LANSCE - A Key Facility for National Science and Defense Neutron-Induced Failures in Semiconductor Devices THE ICE HOUSE - Neutron Testing Leads to More-Reliable Electronic

  3. Large Scale Ice Water Path and 3-D Ice Water Content

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

    Liu, Guosheng

    2008-01-15

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  4. Large Scale Ice Water Path and 3-D Ice Water Content

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

    Liu, Guosheng

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  5. Eighth international congress on nitrogen fixation. Final program

    SciTech Connect (OSTI)

    Not Available

    1990-12-31

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  6. Resonant vibrational energy transfer in ice Ih

    SciTech Connect (OSTI)

    Shi, L.; Li, F.; Skinner, J. L.

    2014-06-28

    Fascinating anisotropy decay experiments have recently been performed on H{sub 2}O ice Ih by Timmer and Bakker [R. L. A. Timmer, and H. J. Bakker, J. Phys. Chem. A 114, 4148 (2010)]. The very fast decay (on the order of 100 fs) is indicative of resonant energy transfer between OH stretches on different molecules. Isotope dilution experiments with deuterium show a dramatic dependence on the hydrogen mole fraction, which confirms the energy transfer picture. Timmer and Bakker have interpreted the experiments with a Frster incoherent hopping model, finding that energy transfer within the first solvation shell dominates the relaxation process. We have developed a microscopic theory of vibrational spectroscopy of water and ice, and herein we use this theory to calculate the anisotropy decay in ice as a function of hydrogen mole fraction. We obtain very good agreement with experiment. Interpretation of our results shows that four nearest-neighbor acceptors dominate the energy transfer, and that while the incoherent hopping picture is qualitatively correct, vibrational energy transport is partially coherent on the relevant timescale.

  7. Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption...

    Office of Scientific and Technical Information (OSTI)

    Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption of Sulfur and Fabrication of ... Title: Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption of Sulfur and ...

  8. Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...

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

    Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines ...

  9. ITP Steel: Hydrogen and Nitrogen Control in Ladle and Casting...

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

    Hydrogen and Nitrogen Control in Ladle and Casting Operations ITP Steel: Hydrogen and Nitrogen Control in Ladle and Casting Operations PDF icon castingops.pdf More Documents & ...

  10. IceVeto: Extended PeV neutrino astronomy in the Southern Hemisphere with IceCube

    SciTech Connect (OSTI)

    Auffenberg, Jan; Collaboration: IceCube Collaboration

    2014-11-18

    IceCube, the world's largest high-energy neutrino observatory, built at the South Pole, recently reported evidence of an astrophysical neutrino flux extending to PeV energies in the Southern Hemisphere. This observation raises the question of how the sensitivity in this energy range could be further increased. In the down-going sector, in IceCube's case the Southern Hemisphere, backgrounds from atmospheric muons and neutrinos pose a challenge to the identification of an astrophysical neutrino flux. The IceCube analysis, that led to the evidence for astrophysical neutrinos, is based on an in-ice veto strategy for background rejection. One possibility available to IceCube is the concept of an extended surface detector, IceVeto, which could allow the rejection of a large fraction of atmospheric backgrounds, primarily for muons from cosmic ray (CR) air showers as well as from neutrinos in the same air showers. Building on the experience of IceTop/IceCube, possibly the most cost-effective and sensitive way to build IceVeto is as an extension of the IceTop detector, with simple photomultiplier based detector modules for CR air shower detection. Initial simulations and estimates indicate that such a veto detector will significantly increase the sensitivity to an astrophysical flux of ?{sub ?} induced muon tracks in the Southern Hemisphere compared to current analyses. Here we present the motivation and capabilities based on initial simulations. Conceptual ideas for a simplified surface array will be discussed briefly.

  11. HYDROGEN-DEUTERIUM EXCHANGE IN PHOTOLYZED METHANE-WATER ICES

    SciTech Connect (OSTI)

    Weber, Amanda S.; Hodyss, Robert; Johnson, Paul V.; Willacy, Karen; Kanik, Isik

    2009-09-20

    Previous work has concluded that H-D exchange occurs readily in polycyclic aromatic hydrocarbons frozen in deuterated water (D{sub 2}O) irradiated with ultraviolet light. Here, we examine H-D exchange in methane-water ices following exposure to ultraviolet radiation and analyze the products formed as a result. We find that H-D exchange also occurs in methane-water ices by means of ultraviolet photolysis. Exchange proceeds through a radical mechanism that implies that almost all organic species will undergo significant H-D exchange with the matrix in water ices exposed to ultraviolet radiation. Given sufficient energetic processing of the ice, the H/D ratio of an ice matrix may be transferred to the organic species in the ice.

  12. Sandia's ice sheet modeling of Greenland, Antarctica helps predict

    National Nuclear Security Administration (NNSA)

    sea-level rise | National Nuclear Security Administration Sandia's ice sheet modeling of Greenland, Antarctica helps predict sea-level rise Wednesday, March 2, 2016 - 12:00am Sandia California researchers Irina Tezaur and Ray Tuminaro analyze a model of Antarctica. They are part of a Sandia team working to improve the reliability and efficiency of computational models that describe ice sheet behavior and dynamics. The Greenland and Antarctic ice sheets will make a dominant contribution to

  13. Ice Sheet Model Reveals Most Comprehensive Projections for West

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

    Antarctica's Future Most Comprehensive Projections for West Antarctica's Future Revealed Ice Sheet Model Reveals Most Comprehensive Projections for West Antarctica's Future BISICLES Simulations Run at NERSC Help Estimate Ice Loss, Sea Level Rise August 18, 2015 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov IceSheet Retreat in the Amundsen Sea Embayment in 2154 (Credit: Cornford et al., The Cryosphere, 2015) A new international study is the first to use a high-resolution, large-scale

  14. Sea ice-atmospheric interaction: Application of multispectral satellite

    Office of Scientific and Technical Information (OSTI)

    data in polar surface energy flux estimates. Annual progress report (Technical Report) | SciTech Connect ice-atmospheric interaction: Application of multispectral satellite data in polar surface energy flux estimates. Annual progress report Citation Details In-Document Search Title: Sea ice-atmospheric interaction: Application of multispectral satellite data in polar surface energy flux estimates. Annual progress report This is the third annual report on: Sea Ice-Atmosphere Interaction -

  15. ACAPEX - Ship-Based Ice Nuclei Collections Field Campaign Report

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect SciTech Connect Search Results Technical Report: ACAPEX - Ship-Based Ice Nuclei Collections Field Campaign Report Citation Details In-Document Search Title: ACAPEX - Ship-Based Ice Nuclei Collections Field Campaign Report Measurements were sought to evaluate a hypotheses that sea-spray-sourced ice-nucleating particles (INPs) are of biological origin and represent a distinctly different INP population in comparison to long-range-transported desert or urban

  16. Nanotextured Anti-Icing Surfaces | GE Global Research

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

    Demonstrate Promising Anti-icing Nano Surfaces Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) GE Scientists Demonstrate Promising Anti-icing Nano Surfaces GE Global Research today presented new research findings on its nanotextured anti-icing surfaces. In addition to dramatically reducing ice adhesion, these surfaces

  17. Ice Nuclei in Marine Air: Biogenic Particles or Dust? (Journal...

    Office of Scientific and Technical Information (OSTI)

    We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated ...

  18. Rapid development of an ice sheet climate application using the...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Rapid development of an ice sheet climate ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

  19. Covered Product Category: Water-Cooled Ice Machines | Department...

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

    Covered Product Category: Water-Cooled Ice Machines The Federal Energy Management Program (FEMP) provides acquisition guidance and federal efficiency requirements for water-cooled ...

  20. optimal initial conditions for coupling ice sheet models to earth...

    Office of Scientific and Technical Information (OSTI)

    optimal initial conditions for coupling ice sheet models to earth system models Perego, Mauro Sandia National Laboratories Sandia National Laboratories; Price, Stephen F. Dr...

  1. Single Particle Database of Natural Ice Crystals: Dimensions

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

    Particle Database of Natural Ice Crystals: Dimensions and Aspect Ratios For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights...

  2. A marine biogenic source of atmospheric ice-nucleating particles

    SciTech Connect (OSTI)

    Wilson, T. W.; Ladino, L. A.; Alpert, Peter A.; Breckels, M. N.; Brooks, I. M.; Browse, J.; Burrows, Susannah M.; Carslaw, K. S.; Huffman, J. A.; Judd, C.; Kilthau, W. P.; Mason, R. H.; McFiggans, Gordon; Miller, L. A.; Najera, J.; Polishchuk, E. A.; Rae, S.; Schiller, C. L.; Si, M.; Vergara Temprado, J.; Whale, Thomas; Wong, J P S; Wurl, O.; Yakobi-Hancock, J. D.; Abbatt, JPD; Aller, Josephine Y.; Bertram, Allan K.; Knopf, Daniel A.; Murray, Benjamin J.

    2015-09-09

    The formation of ice in clouds is facilitated by the presence of airborne ice nucleating particles1,2. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice3–11. Here we show that material in the sea surface microlayer, which is enriched in surface active organic material representative of that found in sub-micron sea- spray aerosol12–21, nucleates ice under conditions that occur in mixed-phase clouds and high-altitude ice clouds. The ice active material is likely biogenic and is less than ~0.2 ?m in size. We also show that organic material (exudate) released by a common marine diatom nucleates ice when separated from cells and propose that organic material associated with phytoplankton cell exudates are a candidate for the observed ice nucleating ability of the microlayer samples. By combining our measurements with global model simulations of marine organic aerosol, we show that ice nucleating particles of marine origin are dominant in remote marine environments, such as the Southern Ocean, the North Pacific and the North Atlantic.

  3. STORMVEX. Ice Nuclei and Cloud Condensation Nuclei Characterization...

    Office of Scientific and Technical Information (OSTI)

    Title: STORMVEX. Ice Nuclei and Cloud Condensation Nuclei Characterization Field Campaign ... warm clouds, require precise separation techniques and accurate identification of phase. ...

  4. IceCube: A Cubic Kilometer Radiation Detector

    SciTech Connect (OSTI)

    IceCube Collaboration; Klein, Spencer R; Klein, S.R.

    2008-06-01

    IceCube is a 1 km{sup 3} neutrino detector now being built at the Amudsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate {nu}{sub {mu}}, {nu}{sub t}, and {nu}{sub {tau}} interactions because of their different topologies. IceCube construction is currently 50% complete.

  5. Reducing uncertainty in high-resolution sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston

    2013-07-01

    Arctic sea ice is an important component of the global climate system, reflecting a significant amount of solar radiation, insulating the ocean from the atmosphere and influencing ocean circulation by modifying the salinity of the upper ocean. The thickness and extent of Arctic sea ice have shown a significant decline in recent decades with implications for global climate as well as regional geopolitics. Increasing interest in exploration as well as climate feedback effects make predictive mathematical modeling of sea ice a task of tremendous practical import. Satellite data obtained over the last few decades have provided a wealth of information on sea ice motion and deformation. The data clearly show that ice deformation is focused along narrow linear features and this type of deformation is not well-represented in existing models. To improve sea ice dynamics we have incorporated an anisotropic rheology into the Los Alamos National Laboratory global sea ice model, CICE. Sensitivity analyses were performed using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) to determine the impact of material parameters on sea ice response functions. Two material strength parameters that exhibited the most significant impact on responses were further analyzed to evaluate their influence on quantitative comparisons between model output and data. The sensitivity analysis along with ten year model runs indicate that while the anisotropic rheology provides some benefit in velocity predictions, additional improvements are required to make this material model a viable alternative for global sea ice simulations.

  6. Meltwater effects on flow of Greenland's ice sheet less severe...

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

    (University of Texas). Location: west coast of the Greenland Ice Sheet. Photo by Matt Hoffman, Los Alamos National Laboratory Contact Nancy Ambrosiano Communications Office (505)...

  7. An Ice Sheet Model Initialization Procedure for Smooth Coupling...

    Office of Scientific and Technical Information (OSTI)

    Procedure for Smooth Coupling with Climate Forcing. Citation Details In-Document Search Title: An Ice Sheet Model Initialization Procedure for Smooth Coupling with Climate Forcing. ...

  8. Purchasing Energy-Efficient Air-Cooled Ice Machines | Department...

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

    Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, a product category covered by ENERGY STAR efficiency requirements. Federal laws ...

  9. THE STICKINESS OF MICROMETER-SIZED WATER-ICE PARTICLES

    SciTech Connect (OSTI)

    Gundlach, B.; Blum, J.

    2015-01-01

    Water ice is one of the most abundant materials in dense molecular clouds and in the outer reaches of protoplanetary disks. In contrast to other materials (e.g., silicates), water ice is assumed to be stickier due to its higher specific surface energy, leading to faster or more efficient growth in mutual collisions. However, experiments investigating the stickiness of water ice have been scarce, particularly in the astrophysically relevant micrometer-sized region and at low temperatures. In this work, we present an experimental setup to grow aggregates composed of ?m-sized water-ice particles, which we used to measure the sticking and erosion thresholds of the ice particles at different temperatures between 114 K and 260 K. We show with our experiments that for low temperatures (below ?210 K), ?m-sized water-ice particles stick below a threshold velocity of 9.6 m s{sup 1}, which is approximately 10times higher than the sticking threshold of ?m-sized silica particles. Furthermore, erosion of the grown ice aggregates is observed for velocities above 15.3 m s{sup 1}. A comparison of the experimentally derived sticking threshold with model predictions is performed to determine important material properties of water ice, i.e., the specific surface energy and the viscous relaxation time. Our experimental results indicate that the presence of water ice in the outer reaches of protoplanetary disks can enhance the growth of planetesimals by direct sticking of particles.

  10. The Rush to Exploit an Increasingly Ice-Free Arctic

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

    Rush to Exploit an Increasingly Ice-Free Arctic - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy ...

  11. Sea ice-atmospheric interaction: Application of multispectral...

    Office of Scientific and Technical Information (OSTI)

    Cooperative Inst. for Research in Environmental Sciences Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL SCIENCES; CLOUDS; REMOTE SENSING; ICE; ...

  12. Determining Cloud Ice Water Path from High-Frequency Microwave...

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

    Determining Cloud Ice Water Path from High-Frequency Microwave Measurements G. Liu ... A better understanding of cloud water content and its large-scale distribution ...

  13. City of Eagan …Civic Ice Arena Renovation

    Broader source: Energy.gov [DOE]

    Project objectives: Provide a reliable central ice making and heating system that meets the performance requirements of the owner. Reduce operation and maintenance costs.

  14. Covered Product Category: Air-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, which are covered by the ENERGY STAR program.

  15. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus

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

    Solomon, A.; Feingold, G.; Shupe, M. D.

    2015-09-25

    This study investigates the maintenance of cloud ice production in Arctic mixed-phase stratocumulus in large eddy simulations that include a prognostic ice nuclei (IN) formulation and a diurnal cycle. Balances derived from a mixed-layer model and phase analyses are used to provide insight into buffering mechanisms that maintain ice in these cloud systems. We find that, for the case under investigation, IN recycling through subcloud sublimation considerably prolongs ice production over a multi-day integration. This effective source of IN to the cloud dominates over mixing sources from above or below the cloud-driven mixed layer. Competing feedbacks between dynamical mixing andmore » recycling are found to slow the rate of ice lost from the mixed layer when a diurnal cycle is simulated. The results of this study have important implications for maintaining phase partitioning of cloud ice and liquid that determine the radiative forcing of Arctic mixed-phase clouds.« less

  16. The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus

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

    Solomon, A.; Feingold, G.; Shupe, M. D.

    2015-04-21

    This study investigates the maintenance of cloud ice production in Arctic mixed phase stratocumulus in large-eddy simulations that include a prognostic ice nuclei (IN) formulation and a diurnal cycle. Balances derived from a mixed-layer model and phase analyses are used to provide insight into buffering mechanisms that maintain ice in these cloud systems. We find that for the case under investigation, IN recycling through subcloud sublimation considerably prolongs ice production over a multi-day integration. This effective source of IN to the cloud dominates over mixing sources from above or below the cloud-driven mixed layer. Competing feedbacks between dynamical mixing andmore » recycling are found to slow the rate of ice lost from the mixed layer when a diurnal cycle is simulated. The results of this study have important implications for maintaining phase partitioning of cloud ice and liquid that determine the radiative forcing of Arctic mixed-phase clouds.« less

  17. Transgenic plants that exhibit enhanced nitrogen assimilation

    DOE Patents [OSTI]

    Coruzzi, Gloria M.; Brears, Timothy

    2005-03-08

    The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

  18. Transgenic plants that exhibit enhanced nitrogen assimilation

    DOE Patents [OSTI]

    Coruzzi, Gloria M.; Brears, Timothy

    2000-01-01

    The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

  19. Transgenic plants that exhibit enhanced nitrogen assimilation

    DOE Patents [OSTI]

    Coruzzi, Gloria M.; Brears, Timothy

    1999-01-01

    The present invention relates to a method for producing plants with improved agronomic and nutritional traits. Such traits include enhanced nitrogen assimilatory and utilization capacities, faster and more vigorous growth, greater vegetative and reproductive yields, and enriched or altered nitrogen content in vegetative and reproductive parts. More particularly, the invention relates to the engineering of plants modified to have altered expression of key enzymes in the nitrogen assimilation and utilization pathways. In one embodiment of the present invention, the desired altered expression is accomplished by engineering the plant for ectopic overexpression of one of more the native or modified nitrogen assimilatory enzymes. The invention also has a number of other embodiments, all of which are disclosed herein.

  20. Microfabricated nitrogen-phosphorus detector : chemically mediated

    Office of Scientific and Technical Information (OSTI)

    thermionic emission. (Technical Report) | SciTech Connect Technical Report: Microfabricated nitrogen-phosphorus detector : chemically mediated thermionic emission. Citation Details In-Document Search Title: Microfabricated nitrogen-phosphorus detector : chemically mediated thermionic emission. Authors: Simonson, Robert Joseph ; Hess, Ryan Falcone ; Moorman, Matthew Wallace ; Boyle, Timothy J. Publication Date: 2012-09-01 OSTI Identifier: 1055647 Report Number(s): SAND2012-7778 DOE Contract

  1. Plant nitrogen regulatory P-PII genes

    DOE Patents [OSTI]

    Coruzzi, Gloria M.; Lam, Hon-Ming; Hsieh, Ming-Hsiun

    2001-01-01

    The present invention generally relates to plant nitrogen regulatory PII gene (hereinafter P-PII gene), a gene involved in regulating plant nitrogen metabolism. The invention provides P-PII nucleotide sequences, expression constructs comprising said nucleotide sequences, and host cells and plants having said constructs and, optionally expressing the P-PII gene from said constructs. The invention also provides substantially pure P-PII proteins. The P-PII nucleotide sequences and constructs of the

  2. Preparation of nitrogen-doped carbon tubes

    DOE Patents [OSTI]

    Chung, Hoon Taek; Zelenay, Piotr

    2015-12-22

    A method for synthesizing nitrogen-doped carbon tubes involves preparing a solution of cyanamide and a suitable transition metal-containing salt in a solvent, evaporating the solvent to form a solid, and pyrolyzing the solid under an inert atmosphere under conditions suitable for the production of nitrogen-doped carbon tubes from the solid. Pyrolyzing for a shorter period of time followed by rapid cooling resulted in a tubes with a narrower average diameter.

  3. Heat recovery anti-icing system

    SciTech Connect (OSTI)

    Cummins, J.R.

    1982-05-11

    A heat recovery anti-icing system is disclosed. The heat recovery system includes a blower which removes air from the air flow path of a combustion turbine power generating system and circulates the air through a heat exchanger located in the exhaust stack of the combustion turbine. The heated air circulating through the heat exchanger is returned to an inlet filter compartment in the air flow path so as to maintain the temperature of the air in the inlet filter compartment at an elevated level.

  4. The role of ice nuclei recycling in the maintenance of cloud...

    Office of Scientific and Technical Information (OSTI)

    The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus Citation Details In-Document Search Title: The role of ice nuclei recycling in ...

  5. ICE MINERALOGY ACROSS AND INTO THE SURFACES OF PLUTO, TRITON, AND ERIS

    SciTech Connect (OSTI)

    Tegler, S. C.; Grundy, W. M.; Olkin, C. B.; Young, L. A.; Romanishin, W.; Cornelison, D. M.; Khodadadkouchaki, R. E-mail: W.Grundy@lowell.edu E-mail: layoung@boulder.swri.edu E-mail: DavidCornelison@MissouriState.edu

    2012-05-20

    We present three near-infrared spectra of Pluto taken with the Infrared Telescope Facility and SpeX, an optical spectrum of Triton taken with the MMT and the Red Channel Spectrograph, and previously published spectra of Pluto, Triton, and Eris. We combine these observations with a two-phase Hapke model and gain insight into the ice mineralogy on Pluto, Triton, and Eris. Specifically, we measure the methane-nitrogen mixing ratio across and into the surfaces of these icy dwarf planets. In addition, we present a laboratory experiment that demonstrates it is essential to model methane bands in spectra of icy dwarf planets with two methane phases-one highly diluted by nitrogen and the other rich in methane. For Pluto, we find bulk, hemisphere-averaged, methane abundances of 9.1% {+-} 0.5%, 7.1% {+-} 0.4%, and 8.2% {+-} 0.3% for sub-Earth longitudes of 10 Degree-Sign , 125 Degree-Sign , and 257 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds these small differences are statistically significant. For Triton, we find bulk, hemisphere-averaged, methane abundances of 5.0% {+-} 0.1% and 5.3% {+-} 0.4% for sub-Earth longitudes of 138 Degree-Sign and 314 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds the differences are not statistically significant. For Eris, we find a bulk, hemisphere-averaged, methane abundance of 10% {+-} 2%. Pluto, Triton, and Eris do not exhibit a trend in methane-nitrogen mixing ratio with depth into their surfaces over the few centimeter range probed by these observations. This result is contrary to the expectation that since visible light penetrates deeper into a nitrogen-rich surface than the depths from which thermal emission emerges, net radiative heating at depth would drive preferential sublimation of nitrogen leading to an increase in the methane abundance with depth.

  6. Passive ice freezing-releasing heat pipe. [Patent application

    DOE Patents [OSTI]

    Gorski, A.J.; Schertz, W.W.

    1980-09-29

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  7. Third international workshop on ice storage for cooling applications

    SciTech Connect (OSTI)

    Gorski, A.J.

    1986-04-01

    The third international workshop on ice storage for cooling applications which was informal and interactive in nature, was open to persons interested in all ice-growing technologies and in ice storage, both seasonal and diurnal. Presentations were made on some 20 topics, ranging from freezers in Alaska to ice cooling of commercial jet aircraft. Workshop tours included visits to ice-storage systems at Commonwealth Edison's facilities in Bolingbrook and Des Plaines Valley, the A.C. Neilsen builing in Northbrook, and the new State of Illinois Center in Chicago. The first workshop in the present series considered the future of ice storage and predicted applications in the agricultural sector, desalinization, and commercial ice production. Progress has been rapid in the intervening two years, and an important topic at the third workshop was the possible use of ''warm ices'' (clathrate hydrates) for energy storage. This report consists primarily of abstracts of presentations made at the workshop. Persons wishing to obtain further information about particular papers should contact the speakers directly; speakers' addresses and telephone numbers are listed in this report.

  8. An update on land-ice modeling in the CESM (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    An update on land-ice modeling in the CESM Citation Details In-Document Search Title: An update on land-ice modeling in the CESM Mass loss from land ice, including the Greenland and Antarctic ice sheets as well as smaller glacier and ice caps, is making a large and growing contribution to global sea-level rise. Land ice is only beginning to be incorporated in climate models. The goal of the Land Ice Working Group (LIWG) is to develop improved land-ice models and incorporate them in CESM, in

  9. FELIX: The Albany Ice Sheet Modeling Code. (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    FELIX: The Albany Ice Sheet Modeling Code. Citation Details In-Document Search Title: FELIX: The Albany Ice Sheet Modeling Code. Abstract not provided. Authors: Kalashnikova, Irina ...

  10. Determination of Ice Water Path Over the ARM SGP Using Combined...

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

    Determination of Ice Water Path Over the ARM SGP Using Combined Surface and Satellite ... Global information of cloud ice water path (IWP) is urgently needed for testing ...

  11. Calculational method for determination of carburetor icing rate

    SciTech Connect (OSTI)

    Nazarov, V.I.; Emel'yanov, V.E.; Gonopol'ska, A.F.; Zaslavskii, A.A.

    1986-05-01

    This paper investigates the dependence of the carburetor icing rate on the density, distillation curve, and vapor pressure of gasoline. More than 100 gasoline samples, covering a range of volatility, were investigated. No clear-cut relationship can be observed between the carburetor icing rate and any specific property index of the gasoline. At the same time, there are certain variables that cannot be observed directly but can be interpreted readily through which the influence of gasoline quality on the carburetor icing rate can be explained. The conversion to these variables was accomplished with regard for the values of the variance and correlation of the carburetor icing rate. Equations are presented that may be used to predict the carburetor icing rate when using gasolines differing in quality. The equations can also determine the need for incorporating antiicing additives in the gasoline.

  12. Methods and apparatus for rotor blade ice detection

    DOE Patents [OSTI]

    LeMieux, David Lawrence

    2006-08-08

    A method for detecting ice on a wind turbine having a rotor and one or more rotor blades each having blade roots includes monitoring meteorological conditions relating to icing conditions and monitoring one or more physical characteristics of the wind turbine in operation that vary in accordance with at least one of the mass of the one or more rotor blades or a mass imbalance between the rotor blades. The method also includes using the one or more monitored physical characteristics to determine whether a blade mass anomaly exists, determining whether the monitored meteorological conditions are consistent with blade icing; and signaling an icing-related blade mass anomaly when a blade mass anomaly is determined to exist and the monitored meteorological conditions are determined to be consistent with icing.

  13. THE PHASES OF WATER ICE IN THE SOLAR NEBULA

    SciTech Connect (OSTI)

    Ciesla, Fred J.

    2014-03-20

    Understanding the phases of water ice that were present in the solar nebula has implications for understanding cometary and planetary compositions as well as the internal evolution of these bodies. Here we show that amorphous ice formed more readily than previously recognized, with formation at temperatures <70K being possible under protoplanetary disk conditions. We further argue that photodesorption and freeze-out of water molecules near the surface layers of the solar nebula would have provided the conditions needed for amorphous ice to form. This processing would be a natural consequence of ice dynamics and would allow for the trapping of noble gases and other volatiles in water ice in the outer solar nebula.

  14. Field demonstration of the ICE 250{trademark} Cleaning System

    SciTech Connect (OSTI)

    Johnston, J.L.; Jackson, L.M.

    1999-10-05

    The ICE 250{trademark} Cleaning System was engineered to convert water into small ice particles for use in cleaning and decontamination applications. Ice crystals are produced in a special icemaker and pressured through a hose-nozzle onto the surface to be cleaned. The Rocky Mountain Oilfield Testing Center and Ice Cleaning Systems, Inc., conducted a test of this system at Naval Petroleum Reserve No. 3 to evaluate the system's cleaning capabilities in an oil field environment. Equipment cleaned included an oil storage tank, a rod pumping unit, a road grader, and a wellhead. Contaminants were unrefined sour crude oil, hydraulic fluid, paraffin, and dirt, occurring separately and as mixtures. In all four demonstration cleaning tasks, the ICE 250 System effectively removed surface contaminant mixtures in a timely manner and left no oily residue. A minimal amount of waste moisture was generated, thereby reducing cleanup and disposal costs.

  15. ELECTRON IRRADIATION OF KUIPER BELT SURFACE ICES: TERNARY N{sub 2}-CH{sub 4}-CO MIXTURES AS A CASE STUDY

    SciTech Connect (OSTI)

    Kim, Y. S.; Kaiser, R. I.

    2012-10-10

    The space weathering of icy Kuiper Belt Objects was investigated in this case study by exposing methane (CH{sub 4}) and carbon monoxide (CO) doped nitrogen (N{sub 2}) ices at 10 K to ionizing radiation in the form of energetic electrons. Online and in situ Fourier transform infrared spectroscopy was utilized to monitor the radiation-induced chemical processing of these ices. Along with isocyanic acid (HNCO), the products could be mainly derived from those formed in irradiated binary ices of the N{sub 2}-CH{sub 4} and CO-CH{sub 4} systems: nitrogen-bearing products were found in the form of hydrogen cyanide (HCN), hydrogen isocyanide (HNC), diazomethane (CH{sub 2}N{sub 2}), and its radical fragment (HCN{sub 2}); oxygen-bearing products were of acetaldehyde (CH{sub 3}CHO), formyl radical (HCO), and formaldehyde (H{sub 2}CO). As in the pure ices, the methyl radical (CH{sub 3}) and ethane (C{sub 2}H{sub 6}) were also detected, as were carbon dioxide (CO{sub 2}) and the azide radical (N{sub 3}). Based on the temporal evolution of the newly formed products, kinetic reaction schemes were then developed to fit the temporal profiles of the newly formed species, resulting in numerical sets of rate constants. The current study highlights important constraints on the preferential formation of isocyanic acid (HNCO) over hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), thus guiding the astrobiological and chemical evolution of those distant bodies.

  16. Nitrogen doping study in ingot niobium cavities

    SciTech Connect (OSTI)

    Dhakal, Pashupati; Ciovati, Gianluigi; Kneisel, Peter; Myneni, Ganapati Rao; Makita, Junki

    2015-09-01

    Thermal diffusion of nitrogen in niobium superconducting radio frequency cavities at temperature ~800 C has resulted in the increase in quality factor with a low-field Q-rise extending to Bp > 90 mT. However, the maximum accelerating gradient of these doped cavities often deteriorates below the values achieved by standard treatments prior to doping. Here, we present the results of the measurements on ingot niobium cavities doped with nitrogen at 800 C. The rf measurements were carried out after the successive electropolishing to remove small amount of material from the inner surface layer. The result showed higher breakdown field with lower quality factor as material removal increases.

  17. Air conditioning system with supplemental ice storing and cooling capacity

    DOE Patents [OSTI]

    Weng, Kuo-Lianq; Weng, Kuo-Liang

    1998-01-01

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  18. Development and Applications of the Community Ice Sheet Model (Conference)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect and Applications of the Community Ice Sheet Model Citation Details In-Document Search Title: Development and Applications of the Community Ice Sheet Model The initial goals of the project are: (1) create a model for land ice that includes relevant and necessary dynamics, physical processes, and couplings; and (2) apply that model to say something more substantial about SLR in Lme for IPCC AR5 (AR6?). Authors: Hoffman, Matthew J. [1] ; Lipscomb, William H. [1] ; Price,

  19. Really Cool Models of Ice Nucleation | GE Global Research

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

    Really Cool Models of Ice Nucleation Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Really Cool Models of Ice Nucleation Rick Arthur 2013.08.20 I'm excited to highlight some progress GE Research has made in modeling the formation of ice from water droplets in contact with cold surfaces. For several years, a

  20. Searching for Cosmic Accelerators via IceCube

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

    Searching for Cosmic Accelerators via IceCube Searching for Cosmic Accelerators via IceCube Berkeley Lab Researchers Part of an International Hunt November 21, 2013 Lynn Yarris, lcyarris@lbl.gov, 510.486.5375 Bert.jpg This event display shows "Bert," one of two neutrino events discovered at IceCube whose energies exceeded one petaelectronvolt (PeV). The colors show when the light arrived, with reds being the earliest, succeeded by yellows, greens and blues. The size of the circle

  1. Development, sensitivity analysis, and uncertainty quantification of high-fidelity arctic sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana S.

    2010-09-01

    Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  2. THE STRUCTURE OF SURFACE H{sub 2}O LAYERS OF ICE-COVERED PLANETS WITH HIGH-PRESSURE ICE

    SciTech Connect (OSTI)

    Ueta, S.; Sasaki, T. E-mail: takanori@geo.titech.ac.jp

    2013-10-01

    Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. While the existence of bound and unbound terrestrial planets with liquid water is an important question, of particular importance is the question of these planets' habitability. Even for a globally ice-covered planet, geothermal heat from the planetary interior may melt the interior ice, creating an internal ocean covered by an ice shell. In this paper, we discuss the conditions that terrestrial planets must satisfy for such an internal ocean to exist on the timescale of planetary evolution. The question is addressed in terms of planetary mass, distance from a central star, water abundance, and abundance of radiogenic heat sources. In addition, we investigate the structure of the surface H{sub 2}O layers of ice-covered planets by considering the effects of ice under high pressure (high-pressure ice). As a fiducial case, a 1 M{sub ?} planet at 1 AU from its central star and with 0.6-25 times the H{sub 2}O mass of the Earth could have an internal ocean. We find that high-pressure ice layers may appear between the internal ocean and the rock portion on a planet with an H{sub 2}O mass over 25 times that of the Earth. The planetary mass and abundance of surface water strongly restrict the conditions under which an extrasolar terrestrial planet may have an internal ocean with no high-pressure ice under the ocean. Such high-pressure ice layers underlying the internal ocean are likely to affect the habitability of the planet.

  3. Microphysical Consequences of the Spatial Distribution of Ice Nucleation in Mixed-Phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, Fan; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2014-07-28

    Mixed-phase stratiform clouds can persist even with steady ice precipitation fluxes, and the origin and microphysical properties of the ice crystals are of interest. Vapor deposition growth and sedimentation of ice particles along with a uniform volume source of ice nucleation, leads to a power law relation between ice water content wi and ice number concentration ni with exponent 2.5. The result is independent of assumptions about the vertical velocity structure of the cloud and is therefore more general than the related expression of Yang et al. [2013]. The sensitivity of the wi-ni relationship to the spatial distribution of ice nucleation is confirmed by Lagrangian tracking and ice growth with cloud-volume, cloud-top, and cloud-base sources of ice particles through a time-dependent cloud field. Based on observed wi and ni from ISDAC, a lower bound of 0.006 m^3/s is obtained for the ice crystal formation rate.

  4. Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, F.; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2013-07-28

    The question of whether persistent ice crystal precipitation from super cooled layer clouds can be explained by time-dependent, stochastic ice nucleation is explored using an approximate, analytical model, and a large-eddy simulation (LES) cloud model. The updraft velocity in the cloud defines an accumulation zone, where small ice particles cannot fall out until they are large enough, which will increase the residence time of ice particles in the cloud. Ice particles reach a quasi-steady state between growth by vapor deposition and fall speed at cloud base. The analytical model predicts that ice water content (wi) has a 2.5 power law relationship with ice number concentration ni. wi and ni from a LES cloud model with stochastic ice nucleation also confirm the 2.5 power law relationship. The prefactor of the power law is proportional to the ice nucleation rate, and therefore provides a quantitative link to observations of ice microphysical properties.

  5. Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations

    SciTech Connect (OSTI)

    Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

    2014-10-01

    Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

  6. Liquid absorbent solutions for separating nitrogen from natural gas

    DOE Patents [OSTI]

    Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Lyon, David K.; Miller, Warren K.

    2000-01-01

    Nitrogen-absorbing and -desorbing compositions, novel ligands and transition metal complexes, and methods of using the same, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

  7. Electrochemical process for the preparation of nitrogen fertilizers

    DOE Patents [OSTI]

    Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

    2013-03-19

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be solid.

  8. Cutting NOx from Diesel Engines with Membrane-Generated Nitrogen...

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

    Cutting NOx from Diesel Engines with Membrane-Generated Nitrogen-Enriched Air Cutting NOx from Diesel Engines with Membrane-Generated Nitrogen-Enriched Air 2005 Diesel Engine ...

  9. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole...

  10. Operating Experience Level 3, Winter Preparedness: Slips on Ice

    Broader source: Energy.gov [DOE]

    OE-3 2015-06: This Operating Experience Level 3 (OE-3) document provides information about the hazards of slips, trips, and falls on ice across the Department of Energy (DOE) Complex.

  11. Radiokrypton Dating Identifies Ancient Antarctic Ice | U.S. DOE...

    Office of Science (SC) Website

    count the number of radioactive krypton-81 atoms remaining in ice using a laser trap. ... is demonstrated by counting the radioactive krypton-81 atoms with a laser-based atom trap. ...

  12. The TWP-ICE CRM Intercomparison Specification and First Results

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

    TWP-ICE CRM Intercomparison Specification and First Results Ann Fridlind (ann.fridlind@nasa.gov), Andrew Ackerman (andrew.ackerman@nasa.gov), Adrian Hill (adrian.hill@metoffice.gov...

  13. Ice Particle Projected Area- and Mass-dimension Expressions

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

    m-D and A-D expressions in BMPs is described in this paper. Figure 1. The m-D expression (black curve) for synoptic ice clouds between -20C and -40C based on SCPP m-D...

  14. Magnetic charge crystals imaged in artificial spin ice

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

    image of emergent domains of ordered magnetic charges in honeycomb artificial spin ice. The black and white dots in the image are the north and south magnetic poles of the...

  15. Arctic sea ice modeling with the material-point method.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston

    2010-04-01

    Arctic sea ice plays an important role in global climate by reflecting solar radiation and insulating the ocean from the atmosphere. Due to feedback effects, the Arctic sea ice cover is changing rapidly. To accurately model this change, high-resolution calculations must incorporate: (1) annual cycle of growth and melt due to radiative forcing; (2) mechanical deformation due to surface winds, ocean currents and Coriolis forces; and (3) localized effects of leads and ridges. We have demonstrated a new mathematical algorithm for solving the sea ice governing equations using the material-point method with an elastic-decohesive constitutive model. An initial comparison with the LANL CICE code indicates that the ice edge is sharper using Materials-Point Method (MPM), but that many of the overall features are similar.

  16. A New Approach for Representing Ice Particles in Weather

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

    mass mixing ratio, qi, c) cloud water mass mixing ratio, qc, d) rain mass mixing ratio, qr, e) rime mass fraction, Fr, f) mass-weighted mean ice particle density, p, g)...

  17. Magnetization plateaus of dipolar spin ice on kagome lattice

    SciTech Connect (OSTI)

    Xie, Y. L.; Wang, Y. L.; Yan, Z. B.; Liu, J.-M.

    2014-05-07

    Unlike spin ice on pyrochlore lattice, the spin ice structure on kagome lattice retains net magnetic charge, indicating non-negligible dipolar interaction in modulating the spin ice states. While it is predicted that the dipolar spin ice on kagome lattice exhibits a ground state with magnetic charge order and ?3???3 spin order, our work focuses on the magnetization plateau of this system. By employing the Wang-Landau algorithm, it is revealed that the lattice exhibits the fantastic three-step magnetization in response to magnetic field h along the [10] and [01] directions, respectively. For the h//[1 0] case, an additional ?3/6M{sub s} step, where M{sub s} is the saturated magnetization, is observed in a specific temperature range, corresponding to a new state with charge order and short-range spin order.

  18. Oil spreading in surface waters with an ice cover

    SciTech Connect (OSTI)

    Yapa, P.D.; Weerasuriya, S.A.; Belaskas, D.P.; Chowdhury, T.

    1993-02-01

    A study of oil spreading in surface waters in the presence of a floating ice cover is presented. The ice can be solid or fragmented. Both axi-symmetrical and uni-directional spreading are studied. The report describes the analytical and numerical model development, the experimental set-up, results from the laboratory experiments, and their comparison with the derived theory and the numerical simulation. To analyze the spreading of oil under solid ice, new equations are derived. These equations consider gravity (buoyancy) - inertia phase, gravity (buoyancy) - viscous phase, and the termination of spreading during the buoyancy - surface tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to termination of spreading is presented. The emphasis of the study is on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase.

  19. Process for separating nitrogen from methane using microchannel process

    Office of Scientific and Technical Information (OSTI)

    technology (Patent) | SciTech Connect Process for separating nitrogen from methane using microchannel process technology Citation Details In-Document Search Title: Process for separating nitrogen from methane using microchannel process technology The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator

  20. ARM: AOS: Oxides of Nitrogen Analyzer (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Hygroscopic growth; Inorganic chemical composition; Methane concentration; Nitrogen; Ozone; Ozone Concentration; Particle number concentration; Particle size distribution; Trace ...

  1. Greenland Ice Sheet Modeling Update (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Greenland Ice Sheet Modeling Update Citation Details In-Document Search Title: Greenland Ice Sheet Modeling Update Authors: Lipscomb, William H. [1] + Show Author Affiliations Los Alamos National Laboratory [Los Alamos National Laboratory Publication Date: 2014-06-05 OSTI Identifier: 1133752 Report Number(s): LA-UR-14-24034 DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: Regional Arctic System Model workshop ; 2014-06-04 - 2014-06-06 ; Monterey,

  2. Ice Nucleation of Fungal Spores from the Classes Agaricomycetes,

    Office of Scientific and Technical Information (OSTI)

    Ustilaginomycetes, and Eurotiomycetes, and the effect on the Atmospheric Transport of these Spores (Journal Article) | SciTech Connect Ice Nucleation of Fungal Spores from the Classes Agaricomycetes, Ustilaginomycetes, and Eurotiomycetes, and the effect on the Atmospheric Transport of these Spores Citation Details In-Document Search Title: Ice Nucleation of Fungal Spores from the Classes Agaricomycetes, Ustilaginomycetes, and Eurotiomycetes, and the effect on the Atmospheric Transport of

  3. Adjoint-based Deterministic Inversion for Ice Sheets. (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Adjoint-based Deterministic Inversion for Ice Sheets. Citation Details In-Document Search Title: Adjoint-based Deterministic Inversion for Ice Sheets. Abstract not provided. Authors: Perego, Mauro ; Salinger, Andrew G. ; Phipps, Eric Todd ; Ridzal, Denis ; Kouri, Drew Philip ; Kalashnikova, Irina ; S. Price ; G. Stadler Publication Date: 2014-11-01 OSTI Identifier: 1242148 Report Number(s): SAND2014-19449PE 540987 DOE Contract Number: AC04-94AL85000 Resource Type: Conference

  4. An Ice Sheet Model Initialization Procedure for Smooth Coupling with

    Office of Scientific and Technical Information (OSTI)

    Climate Forcing. (Conference) | SciTech Connect An Ice Sheet Model Initialization Procedure for Smooth Coupling with Climate Forcing. Citation Details In-Document Search Title: An Ice Sheet Model Initialization Procedure for Smooth Coupling with Climate Forcing. Abstract not provided. Authors: Perego, Mauro ; Price, Stephen [1] ; Stadler, Georg [2] ; Kalashnikova, Irina ; Salinger, Andrew G. + Show Author Affiliations (LANL) (Curant Institute) Publication Date: 2015-01-01 OSTI Identifier:

  5. Real and effective thermal equilibrium in artificial square spin ices

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Real and effective thermal equilibrium in artificial square spin ices Citation Details In-Document Search Title: Real and effective thermal equilibrium in artificial square spin ices Authors: Morgan, Jason P. ; Akerman, Johanna ; Stein, Aaron ; Phatak, Charudatta ; Evans, R. M. L. ; Langridge, Sean ; Marrows, Christopher H. Publication Date: 2013-01-09 OSTI Identifier: 1101866 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional

  6. STORMVEX. Ice Nuclei and Cloud Condensation Nuclei Characterization Field

    Office of Scientific and Technical Information (OSTI)

    Campaign Report (Technical Report) | SciTech Connect STORMVEX. Ice Nuclei and Cloud Condensation Nuclei Characterization Field Campaign Report Citation Details In-Document Search Title: STORMVEX. Ice Nuclei and Cloud Condensation Nuclei Characterization Field Campaign Report The relationship between aerosol particles and the formation of clouds is among the most uncertain aspects in our current understanding of climate change. Warm clouds have been the most extensively studied, in large part

  7. Sea ice - atmosphere interaction: Application of multispectral satellite

    Office of Scientific and Technical Information (OSTI)

    data in polar surface energy flux estimates. Semiannual Progress Report (Technical Report) | SciTech Connect ice - atmosphere interaction: Application of multispectral satellite data in polar surface energy flux estimates. Semiannual Progress Report Citation Details In-Document Search Title: Sea ice - atmosphere interaction: Application of multispectral satellite data in polar surface energy flux estimates. Semiannual Progress Report In the past six months, work has continued on energy flux

  8. Complex systems influence melting of Greenland ice sheet

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

    Complex systems influence melting of Greenland ice sheet Complex systems influence melting of Greenland ice sheet International research team's field work shows that, well, things are more complicated than we thought December 22, 2014 The newly discovered rolling movement shown in (A) three-dimensional cryo-electron microscopy image of ribosome, and (B) computer-generated atomic-resolution model of the human ribosome consistent with microscopy. An international team of researchers deployed to

  9. Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP): Evaluation of Historical and Projected Future Changes

    SciTech Connect (OSTI)

    Lamarque, Jean-Francois; Dentener, Frank; McConnell, J.R.; Ro, C-U; Shaw, Mark; Vet, Robert; Bergmann, D.; Cameron-Smith, Philip; Dalsoren, S.; Doherty, R.; Faluvegi, G.; Ghan, Steven J.; Josse, B.; Lee, Y. H.; MacKenzie, I. A.; Plummer, David; Shindell, Drew; Skeie, R. B.; Stevenson, D. S.; Strode, S.; Zeng, G.; Curran, M.; Dahl-Jensen, D.; Das, S.; Fritzsche, D.; Nolan, M.

    2013-08-20

    We present multi-model global datasets of nitrogen and sulfate deposition covering time periods from 1850 to 2100, calculated within the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The computed deposition fluxes are compared to surface wet deposition and ice-core measurements. We use a new dataset of wet deposition for 2000-2002 based on critical assessment of the quality of existing regional network data. We show that for present-day (year 2000 ACCMIP time-slice), the ACCMIP results perform similarly to previously published multi-model assessments. The analysis of changes between 1980 and 2000 indicates significant differences between model and measurements over the United States, but less so over Europe. This difference points towards misrepresentation of 1980 NH3 emissions over North America. Based on ice-core records, the 1850 deposition fluxes agree well with Greenland ice cores but the change between 1850 and 2000 seems to be overestimated in the Northern Hemisphere for both nitrogen and sulfur species. Using the Representative Concentration Pathways to define the projected climate and atmospheric chemistry related emissions and concentrations, we find large regional nitrogen deposition increases in 2100 in Latin America, Africa and parts of Asia under some of the scenarios considered. Increases in South Asia are especially large, and are seen in all scenarios, with 2100 values more than double 2000 in some scenarios and reaching >1300 mgN/m2/yr averaged over regional to continental scale regions in RCP 2.6 and 8.5, ~30-50% larger than the values in any region currently (2000). Despite known issues, the new ACCMIP deposition dataset provides novel, consistent and evaluated global gridded deposition fields for use in a wide range of climate and ecological studies.

  10. IceCube: An Instrument for Neutrino Astronomy

    SciTech Connect (OSTI)

    IceCube Collaboration; Halzen, F.; Klein, S.

    2010-06-04

    Neutrino astronomy beyond the Sun was first imagined in the late 1950s; by the 1970s, it was realized that kilometer-scale neutrino detectors were required. The first such instrument, IceCube, is near completion and taking data. The IceCube project transforms a cubic kilometer of deep and ultra-transparent Antarctic ice into a particle detector. A total of 5,160 optical sensors are embedded into a gigaton of Antarctic ice to detect the Cherenkov light emitted by secondary particles produced when neutrinos interact with nuclei in the ice. Each optical sensor is a complete data acquisition system, including a phototube, digitization electronics, control and trigger systems and LEDs for calibration. The light patterns reveal the type (flavor) of neutrino interaction and the energy and direction of the neutrino, making neutrino astronomy possible. The scientific missions of IceCube include such varied tasks as the search for sources of cosmic rays, the observation of Galactic supernova explosions, the search for dark matter, and the study of the neutrinos themselves. These reach energies well beyond those produced with accelerator beams.

  11. De-icing thermostat for air conditioners

    SciTech Connect (OSTI)

    Levine, M.R.

    1986-12-09

    This patent describes an electronic thermostat adapted to be connected to an air-cooling apparatus to control the operative state of the apparatus. The thermostat includes a means for generating a digital electrical signal representative of a desired temperature setpoint and means for generating a digital electrical signal representative of the ambient temperature at the thermostat. The improvement described here comprises: means for generating control signals for the aircooling apparatus in order to inhibit the accumulation of ice on the cooling element of the air-cooling apparatus when the ambient temperature is above the temperature setpoint; means, responsive to the control signals, for deenergizing the compressor in the air-cooling apparatus for a first preselected period of time whenever the compressor is determined to have run continuously for a second preselected period of time; and means for adaptively adjusting the length of at least one of the first or second preselected periods of time as a function of the change in the rate of change of the ambient temperature.

  12. Toward a mechanistic modeling of nitrogen limitation on vegetation dynamics

    SciTech Connect (OSTI)

    Xu, Chonggang [Los Alamos National Laboratory (LANL); Fisher, Rosie [National Center for Atmospheric Research (NCAR); Wullschleger, Stan D [ORNL; Wilson, Cathy [Los Alamos National Laboratory (LANL); Cai, Michael [Los Alamos National Laboratory (LANL); McDowell, Nathan [Los Alamos National Laboratory (LANL)

    2012-01-01

    Nitrogen is a dominant regulator of vegetation dynamics, net primary production, and terrestrial carbon cycles; however, most ecosystem models use a rather simplistic relationship between leaf nitrogen content and photosynthetic capacity. Such an approach does not consider how patterns of nitrogen allocation may change with differences in light intensity, growing-season temperature and CO{sub 2} concentration. To account for this known variability in nitrogen-photosynthesis relationships, we develop a mechanistic nitrogen allocation model based on a trade-off of nitrogen allocated between growth and storage, and an optimization of nitrogen allocated among light capture, electron transport, carboxylation, and respiration. The developed model is able to predict the acclimation of photosynthetic capacity to changes in CO{sub 2} concentration, temperature, and radiation when evaluated against published data of V{sub c,max} (maximum carboxylation rate) and J{sub max} (maximum electron transport rate). A sensitivity analysis of the model for herbaceous plants, deciduous and evergreen trees implies that elevated CO{sub 2} concentrations lead to lower allocation of nitrogen to carboxylation but higher allocation to storage. Higher growing-season temperatures cause lower allocation of nitrogen to carboxylation, due to higher nitrogen requirements for light capture pigments and for storage. Lower levels of radiation have a much stronger effect on allocation of nitrogen to carboxylation for herbaceous plants than for trees, resulting from higher nitrogen requirements for light capture for herbaceous plants. As far as we know, this is the first model of complete nitrogen allocation that simultaneously considers nitrogen allocation to light capture, electron transport, carboxylation, respiration and storage, and the responses of each to altered environmental conditions. We expect this model could potentially improve our confidence in simulations of carbon-nitrogen interactions and the vegetation feedbacks to climate in Earth system models.

  13. Understanding cirrus ice crystal number variability for different heterogeneous ice nucleation spectra

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

    Sullivan, Sylvia C.; Morales Betancourt, Ricardo; Barahona, Donifan; Nenes, Athanasios

    2016-03-03

    Along with minimizing parameter uncertainty, understanding the cause of temporal and spatial variability of the nucleated ice crystal number, Ni, is key to improving the representation of cirrus clouds in climate models. To this end, sensitivities of Ni to input variables like aerosol number and diameter provide valuable information about nucleation regime and efficiency for a given model formulation. Here we use the adjoint model of the adjoint of a cirrus formation parameterization (Barahona and Nenes, 2009b) to understand Ni variability for various ice-nucleating particle (INP) spectra. Inputs are generated with the Community Atmosphere Model version 5, and simulations are donemore » with a theoretically derived spectrum, an empirical lab-based spectrum and two field-based empirical spectra that differ in the nucleation threshold for black carbon particles and in the active site density for dust. The magnitude and sign of Ni sensitivity to insoluble aerosol number can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, which reveals a disparity in aerosol surface properties. In conclusion, Ni sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters; this low temperature sensitivity regime has been experimentally reported before but never deconstructed as done here.« less

  14. Understanding cirrus ice crystal number variability for different heterogeneous ice nucleation spectra

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

    Sullivan, S. C.; Morales Betancourt, R.; Barahona, D.; Nenes, A.

    2015-08-11

    Along with minimizing parameter uncertainty, understanding the cause of temporal and spatial variability of nucleated ice crystal number, Ni, is key to improving the representation of cirrus clouds in climate models. To this end, sensitivities of Ni to input variables like aerosol number and diameter provide valuable information about nucleation regime and efficiency for a given model formulation. Here we use the adjoint model of the Barahona and Nenes cirrus formation parameterization to understand Ni variability for various ice-nucleating particle (INP) spectra. Inputs are generated with the Community Atmosphere Model version 5, and simulations are done with a theoretically-derived spectrum,morea lab-based empirical spectrum, and two field-based empirical spectra that differ in the nucleation threshold for black carbon aerosol and in the active site density for dust. The magnitude and sign of Ni sensitivity to insoluble aerosol number can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, which reveals a disparity in aerosol surface properties. Ni sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters; this low temperature sensitivity regime has been experimentally reported before but never unraveled as done here.less

  15. Nitrogen control of chloroplast differentiation. Final report

    SciTech Connect (OSTI)

    Schmidt, G.W.

    1998-05-01

    This project was directed toward understanding at the physiological, biochemical and molecular levels of how photosynthetic organisms adapt to long-term nitrogen-deficiency conditions is quite incomplete even though limitation of this nutrient is the most commonly restricts plant growth and development. For our work on this problem, the unicellular green alga, Chlamydomonas reinhardtii, was grown in continuous cultures in which steady-state levels of nitrogen can be precisely controlled. N-limited cells exhibit the classical symptoms of deficiency of this nutrient, chlorosis and slow growth rates, and respond to nitrogen provision by rapid greening and chloroplast differentiation. We have addressed three aspects of this problem: (1) the regulation of pigment synthesis; (2) control of expression of nuclear genes encoding photosynthetic proteins; (3) changes in metabolic and electron transport pathways that enable sustained CO{sub 2} fixation even though they cannot be readily converted into amino and nucleic acids. For the last, principle components are: (a) enhanced mitochondrial respiratory activity intimately associated with photosynthates, and (b) the occurrence in thylakoids of a supplemental electron transport pathway that facilitates reduction of the plastoquinone pool. Together, these distinguishing features of N-limited cells are likely to enable cell survival, especially under conditions of high irradiance stress.

  16. Plant nitrogen regulatory P-PII polypeptides

    DOE Patents [OSTI]

    Coruzzi, Gloria M.; Lam, Hon-Ming; Hsieh, Ming-Hsiun

    2004-11-23

    The present invention generally relates to plant nitrogen regulatory PII gene (hereinafter P-PII gene), a gene involved in regulating plant nitrogen metabolism. The invention provides P-PII nucleotide sequences, expression constructs comprising said nucleotide sequences, and host cells and plants having said constructs and, optionally expressing the P-PII gene from said constructs. The invention also provides substantially pure P-PII proteins. The P-PII nucleotide sequences and constructs of the invention may be used to engineer organisms to overexpress wild-type or mutant P-PII regulatory protein. Engineered plants that overexpress or underexpress P-PII regulatory protein may have increased nitrogen assimilation capacity. Engineered organisms may be used to produce P-PII proteins which, in turn, can be used for a variety of purposes including in vitro screening of herbicides. P-PII nucleotide sequences have additional uses as probes for isolating additional genomic clones having the promoters of P-PII gene. P-PII promoters are light- and/or sucrose-inducible and may be advantageously used in genetic engineering of plants.

  17. Nitrogen Deposition: A Component of Global Change Analyses

    SciTech Connect (OSTI)

    Norby, Richard J.

    1997-12-31

    The global cycles of carbon and nitrogen are being perturbed by human activities that increase the transfer from large pools of nonreactive forms of the elements to reactive forms that are essential to the functioning of the terrestrial biosphere. The cycles are closely linked at all scales, and global change analyses must consider carbon and nitrogen cycles together. The increasing amount of nitrogen originating from fossil fuel combustion and deposited to terrestrial ecosystems as nitrogen oxides could increase the capacity of ecosystems to sequester carbon thereby removing some of the excess carbon dioxide from the atmosphere and slowing the development of greenhouse warming. Several global and ecosystem models have calculated the amount of carbon sequestration that can be attributed to nitrogen deposition based on assumptions about the allocation of nitrogen among ecosystem components with different carbon-nitrogen ratios. They support the premise that nitrogen deposition is responsible for a an increasing terrestrial carbon sink since industrialization began, but there are large uncertainties related to the continued capacity of ecosystems to retain exogenous nitrogen. Whether terrestrial ecosystems continue to sequester additional carbon will depend in part on their response to increasing atmospheric carbon dioxide concentrations, which is widely thought to be constrained by limited nitrogen availability. Ecosystem models generally support the conclusion that the responses of ecosystems to increasing concentrations of carbon dioxide will be larger, and the range of possible responses will be wider, in ecosystems with increased nitrogen inputs originating as atmospheric deposition.

  18. Electrochemical process for the preparation of nitrogen fertilizers

    DOE Patents [OSTI]

    Jiang, Junhua; Aulich, Ted R; Ignatchenko, Alexey V

    2015-04-14

    Methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia are disclosed. Embodiments include (1) ammonium nitrate produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source: (3) ammonia produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source.

  19. OBSERVATIONAL CONSTRAINTS ON METHANOL PRODUCTION IN INTERSTELLAR AND PREPLANETARY ICES

    SciTech Connect (OSTI)

    Whittet, D. C. B.; Cook, A. M.; Herbst, Eric; Chiar, J. E.; Shenoy, S. S.

    2011-11-20

    Methanol (CH{sub 3}OH) is thought to be an important link in the chain of chemical evolution that leads from simple diatomic interstellar molecules to complex organic species in protoplanetary disks that may be delivered to the surfaces of Earthlike planets. Previous research has shown that CH{sub 3}OH forms in the interstellar medium predominantly on the surfaces of dust grains. To enhance our understanding of the conditions that lead to its efficient production, we assemble a homogenized catalog of published detections and limiting values in interstellar and preplanetary ices for both CH{sub 3}OH and the other commonly observed C- and O-bearing species, H{sub 2}O, CO, and CO{sub 2}. We use this catalog to investigate the abundance of ice-phase CH{sub 3}OH in environments ranging from dense molecular clouds to circumstellar envelopes around newly born stars of low and high mass. Results show that CH{sub 3}OH production arises during the CO freezeout phase of ice-mantle growth in the clouds, after an ice layer rich in H{sub 2}O and CO{sub 2} is already in place on the dust, in agreement with current astrochemical models. The abundance of solid-phase CH{sub 3}OH in this environment is sufficient to account for observed gas-phase abundances when the ices are subsequently desorbed in the vicinity of embedded stars. CH{sub 3}OH concentrations in the ices toward embedded stars show order-of-magnitude object-to-object variations, even in a sample restricted to stars of low mass associated with ices lacking evidence of thermal processing. We hypothesize that the efficiency of CH{sub 3}OH production in dense cores and protostellar envelopes is mediated by the degree of prior CO depletion.

  20. Effects of Pre-Existing Ice Crystals on Cirrus Clouds and Comparison between Different Ice Nucleation Parameterizations with the Community Atmosphere Model (CAM5)

    SciTech Connect (OSTI)

    Shi, Xiangjun; Liu, Xiaohong; Zhang, Kai

    2015-01-01

    In order to improve the treatment of ice nucleation in a more realistic manner in the Community Atmospheric Model version 5.3 (CAM5.3), the effects of preexisting ice crystals on ice nucleation in cirrus clouds are considered. In addition, by considering the in-cloud variability in ice saturation ratio, homogeneous nucleation takes place spatially only in a portion of cirrus cloud rather than in the whole area of cirrus cloud. With these improvements, the two unphysical limiters used in the representation of ice nucleation are removed. Compared to observations, the ice number concentrations and the probability distributions of ice number concentration are both improved with the updated treatment. The preexisting ice crystals significantly reduce ice number concentrations in cirrus clouds, especially at mid- to high latitudes in the upper troposphere (by a factor of ~10). Furthermore, the contribution of heterogeneous ice nucleation to cirrus ice crystal number increases considerably.Besides the default ice nucleation parameterization of Liu and Penner (2005, hereafter LP) in CAM5.3, two other ice nucleation parameterizations of Barahona and Nenes (2009, hereafter BN) and Krcher et al. (2006, hereafter KL) are implemented in CAM5.3 for the comparison. In-cloud ice crystal number concentration, percentage contribution from heterogeneous ice nucleation to total ice crystal number, and preexisting ice effects simulated by the three ice nucleation parameterizations have similar patterns in the simulations with present-day aerosol emissions. However, the change (present-day minus pre-industrial times) in global annual mean column ice number concentration from the KL parameterization (3.24106 m-2) is obviously less than that from the LP (8.46106 m-2) and BN (5.62106 m-2) parameterizations. As a result, experiment using the KL parameterization predicts a much smaller anthropogenic aerosol longwave indirect forcing (0.24 W m-2) than that using the LP (0.46 W m-2) and BN (0.39 W m-2) parameterizations.

  1. The sticking of atomic hydrogen on amorphous water ice

    SciTech Connect (OSTI)

    Veeraghattam, Vijay K.; Manrodt, Katie; Lewis, Steven P.; Stancil, P. C. E-mail: lewis@physast.uga.edu

    2014-07-20

    Using classical molecular dynamics, we have simulated the sticking and scattering process of a hydrogen atom on an amorphous ice film to predict the sticking probability of hydrogen on ice surfaces. A wide range of initial kinetic energies of the incident hydrogen atom (10 K-600 K) and two different ice temperatures (10 K and 70 K) were used to investigate this fundamental process in interstellar chemistry. We report here the sticking probability of atomic hydrogen as a function of incident kinetic energy, gas temperature, and substrate temperature, which can be used in astrophysical models. The current results are compared to previous theoretical and experimental studies that have reported a wide range in the sticking coefficient.

  2. Nitrogen oxides storage catalysts containing cobalt

    DOE Patents [OSTI]

    Lauterbach, Jochen; Snively, Christopher M.; Vijay, Rohit; Hendershot, Reed; Feist, Ben

    2010-10-12

    Nitrogen oxides (NO.sub.x) storage catalysts comprising cobalt and barium with a lean NO.sub.x storage ratio of 1.3 or greater. The NO.sub.x storage catalysts can be used to reduce NO.sub.x emissions from diesel or gas combustion engines by contacting the catalysts with the exhaust gas from the engines. The NO.sub.x storage catalysts can be one of the active components of a catalytic converter, which is used to treat exhaust gas from such engines.

  3. Worldwide organic soil carbon and nitrogen data

    SciTech Connect (OSTI)

    Zinke, P.J.; Stangenberger, A.G.; Post, W.M.; Emanual, W.R.; Olson, J.S.

    1986-09-01

    The objective of the research presented in this package was to identify data that could be used to estimate the size of the soil organic carbon pool under relatively undisturbed soil conditions. A subset of the data can be used to estimate amounts of soil carbon storage at equilibrium with natural soil-forming factors. The magnitude of soil properties so defined is a resulting nonequilibrium values for carbon storage. Variation in these values is due to differences in local and geographic soil-forming factors. Therefore, information is included on location, soil nitrogen content, climate, and vegetation along with carbon density and variation.

  4. Ice plug employed on subsea pipeline bend during repair

    SciTech Connect (OSTI)

    1997-12-22

    The first controlled-temperature ice plug in the bend of an offshore gas trunkline has been carried out for Phillips Petroleum Co. Norway on its Norpipe A.S. platform in the German sector of the North Sea. The procedure was part of a subsea valve repair operation. The ice plug was successfully formed offshore and tested to a differential pressure of 1,450 psi. Repair of two valves required only 5 days during which time gas production was operating at close to 50--60% via the platform bypass, says the service company. The paper discusses the procedure.

  5. Progress on a TWP-ICE Monsoon Case Study

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

    Outline Introduction 25-mb large-scale forcing 10-mb large-scale forcing Tracers Future work Progress on a TWP-ICE Monsoon Case Study Ann Fridlind and Andrew Ackerman * NASA GISS thanks to Jon Petch * ECMWF Shaocheng Xie * LLNL TWP-ICE and ACTIVE Science Teams DOE ARM Program and Data Archive NASA Radiation Sciences Program NASA Advanced Supercomputing Division 18th Annual ARM Science Team Meeting 10 March 2008 Outline Introduction 25-mb large-scale forcing 10-mb large-scale forcing Tracers

  6. Statement of Work (SOW) Template (Combined EIR/ICE Support Contractor)

    Office of Energy Efficiency and Renewable Energy (EERE)

    The template presented below is a Statement of Work (SOW) for services of an EIR/ICE Support Contractor for assisting OECM in conducting a combined EIR/ICE at CD-2.

  7. Time-resolved x-ray diffraction across water-ices VI/VII transformatio...

    Office of Scientific and Technical Information (OSTI)

    diffraction across water-ices VIVII transformations using dynamic-DAC Citation Details In-Document Search Title: Time-resolved x-ray diffraction across water-ices VIVII ...

  8. An update on land-ice modeling in the CESM (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    approximation; and there is no ice-ocean coupling. During the next year we plan to implement two-way coupling (including ice-ocean coupling with a dynamic Antarcticmore ...

  9. Predicting Land-Ice Retreat and Sea-Level Rise with the Community...

    Office of Scientific and Technical Information (OSTI)

    linked to changes in Southern Ocean wind stress. To assess the likelihood of fast retreat of marine ice sheets, we need coupled ice-sheetocean models that do not yet exist (but ...

  10. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    Conference: Development of a land ice core for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model ...

  11. Predicting Land-Ice Retreat and Sea-Level Rise with the Community...

    Office of Scientific and Technical Information (OSTI)

    from the marine-based West Antarctic Ice Sheet, linked to changes in Southern Ocean wind stress. To assess the likelihood of fast retreat of marine ice sheets, we need coupled...

  12. Convergence of microbial assimilations of soil carbon, nitrogen,

    Office of Scientific and Technical Information (OSTI)

    phosphorus, and sulfur in terrestrial ecosystems (Journal Article) | SciTech Connect Convergence of microbial assimilations of soil carbon, nitrogen, phosphorus, and sulfur in terrestrial ecosystems Citation Details In-Document Search Title: Convergence of microbial assimilations of soil carbon, nitrogen, phosphorus, and sulfur in terrestrial ecosystems How soil microbes assimilate carbon-C, nitrogen-N, phosphorus-P, and sulfur-S is fundamental for understanding nutrient cycling in

  13. Nitrogen removal from natural gas using two types of membranes

    DOE Patents [OSTI]

    Baker, Richard W.; Lokhandwala, Kaaeid A.; Wijmans, Johannes G.; Da Costa, Andre R.

    2003-10-07

    A process for treating natural gas or other methane-rich gas to remove excess nitrogen. The invention relies on two-stage membrane separation, using methane-selective membranes for the first stage and nitrogen-selective membranes for the second stage. The process enables the nitrogen content of the gas to be substantially reduced, without requiring the membranes to be operated at very low temperatures.

  14. Fixation of nitrogen in the presence of water vapor

    DOE Patents [OSTI]

    Harteck, Paul

    1984-01-01

    A process for the fixation of nitrogen is disclosed which comprises combining a mixture of nitrogen, oxygen, metal oxide and water vapor, initially heating the combination to initiate a reaction which forms nitrate, but at a temperature and pressure range below the dissociation pressure of the nitrate. With or without the water component, the yield of fixed nitrogen is increased by the use of a Linde Molecular Sieve Catalyst.

  15. Ice at the Interface: Atmosphere-Ice-Ocean Boundary Layer Processes and Their Role in Polar Change---Workshop Report

    SciTech Connect (OSTI)

    Hunke, Elizabeth C.

    2012-07-23

    The atmosphere-ocean boundary layer in which sea ice resides includes many complex processes that require a more realistic treatment in GCMs, particularly as models move toward full earth system descriptions. The primary purpose of the workshop was to define and discuss such coupled processes from observational and modeling points of view, including insight from both the Arctic and Antarctic systems. The workshop met each of its overarching goals, including fostering collaboration among experimentalists, theorists and modelers, proposing modeling strategies, and ascertaining data availability and needs. Several scientific themes emerged from the workshop, such as the importance of episodic or extreme events, precipitation, stratification above and below the ice, and the marginal ice zone, whose seasonal Arctic migrations now traverse more territory than in the past.

  16. Ice formation on nitric acid coated dust particles: Laboratory and modeling studies

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Zhang, Kai; Zhao, Chun; Nandasiri, Manjula I.; Shutthanandan, V.; Liu, Xiaohong; Fast, Jerome D.; Berg, Larry K.

    2015-08-16

    Changes in the ice nucleation characteristics of atmospherically relevant mineral dust particles due to nitric acid coating are not well understood. Further, the atmospheric implications of dust coating on ice-cloud properties under different assumptions of primary ice nucleation mechanisms are unknown. We investigated ice nucleation ability of Arizona test dust, illite, K-feldspar and quartz as a function of temperature (-25 to -30C) and relative humidity with respect to water (75 to 110%). Particles were size selected at 250 nm and transported (bare or coated) to the ice nucleation chamber to determine the fraction of particles nucleating ice at various temperature and water saturation conditions. All dust nucleated ice at water-subsaturated conditions, but the coated particles showed a reduction in their ice nucleation ability compared to bare particles. However, at water-supersaturated conditions, we observed that bare and coated particles had nearly similar ice nucleation characteristics. X-ray diffraction patterns indicated that structural properties of bare dust particles modified after acid treatment. We found that lattice parameters were slightly different, but crystallite sizes of the coated particles were reduced compared to bare particles. Next, single-column model results show that simulated ice crystal number concentrations mostly depends upon fraction of particles that are coated, primary ice nucleation mechanisms, and the competition between ice nucleation mechanisms to nucleate ice. In general, we observed that coating modify the ice-cloud properties and the picture of ice and mixed-phase cloud evolution is complex when different primary ice nucleation mechanisms are competing for fixed water vapor mass.

  17. Continuous improvement in nitrogen rejection unit design

    SciTech Connect (OSTI)

    O`Brien, J.V.; Maloney, J.J.

    1997-12-31

    The design and fabrication of Nitrogen Rejection Units (NRU) has advanced considerably over the past 15 years. Improvements have been made in all aspects of producing an NRU plant and cold box. This paper presents the primary areas involved that have seen these improvements. (1) Process design: the two-column process has been superseded by an approach which utilizes multiple flash drums and one column. This leads to a smaller and lower cost cold box. With low nitrogen content feeds, the prefractionater recovers half the methane as a high pressure residue gas and reduces the cold box size. (2) Mechanical Design: improved software enables the design process to be more accurate, eliminate piping and equipment interferences, reduce the size of the box and save design time. (3) Manufacturing: the interfacing of the 3D software design tools and the manufacturing process enables the shop floor personnel to reduce the manufacturing time by 10%. All of these individual improvements have reduced the real cost of an NRU substantially over the past 15 years.

  18. Method and apparatus for nitrogen oxide determination

    DOE Patents [OSTI]

    Hohorst, Frederick A.

    1990-01-01

    Method and apparatus for determining nitrogen oxide content in a high temperature process gas, which involves withdrawing a sample portion of a high temperature gas containing nitrogen oxide from a source to be analyzed. The sample portion is passed through a restrictive flow conduit, which may be a capillary or a restriction orifice. The restrictive flow conduit is heated to a temperature sufficient to maintain the flowing sample portion at an elevated temperature at least as great as the temperature of the high temperature gas source, to thereby provide that deposition of ammonium nitrate within the restrictive flow conduit cannot occur. The sample portion is then drawn into an aspirator device. A heated motive gas is passed to the aspirator device at a temperature at least as great as the temperature of the high temperature gas source. The motive gas is passed through the nozzle of the aspirator device under conditions sufficient to aspirate the heated sample portion through the restrictive flow conduit and produce a mixture of the sample portion in the motive gas at a dilution of the sample portion sufficient to provide that deposition of ammonium nitrate from the mixture cannot occur at reduced temperature. A portion of the cooled dilute mixture is then passed to analytical means capable of detecting nitric oxide.

  19. Hydrogen and Nitrogen Control in Ladle and Casting Operations

    SciTech Connect (OSTI)

    2002-01-01

    Development of Models will Help Predict and Control Hydrogen and Nitrogen Levels in Electric Arc Furnace and Basic Oxygen Furnace Steelmaking

  20. Raman spectroscopy in hot compressed hydrogen and nitrogen -...

    Office of Scientific and Technical Information (OSTI)

    Raman spectroscopy in hot compressed hydrogen and nitrogen - implications for the intramolecular potential Citation Details In-Document Search Title: Raman spectroscopy in hot...

  1. Process for separating nitrogen from methane using microchannel...

    Office of Scientific and Technical Information (OSTI)

    microchannel process technology Citation Details In-Document Search Title: Process for separating nitrogen from methane using microchannel process technology The disclosed ...

  2. Characterization of Superhydrophobic Surfaces for Anti-icing in a Low-Temperature Wind Tunnel

    SciTech Connect (OSTI)

    Swarctz, Christopher; Alijallis, Elias; Hunter, Scott Robert; Simpson, John T; Choi, Chang-Hwan

    2010-01-01

    In this study, a closed loop low-temperature wind tunnel was custom-built and uniquely used to investigate the anti-icing mechanism of superhydrophobic surfaces in regulated flow velocities, temperatures, humidity, and water moisture particle sizes. Silica nanoparticle-based hydrophobic coatings were tested as superhydrophobic surface models. During tests, images of ice formation were captured by a camera and used for analysis of ice morphology. Prior to and after wind tunnel testing, apparent contact angles of water sessile droplets on samples were measured by a contact angle meter to check degradation of surface superhydrophobicity. A simple peel test was also performed to estimate adhesion of ice on the surfaces. When compared to an untreated sample, superhydrophobic surfaces inhibited initial ice formation. After a period of time, random droplet strikes attached to the superhydrophobic surfaces and started to coalesce with previously deposited ice droplets. These sites appear as mounds of accreted ice across the surface. The appearance of the ice formations on the superhydrophobic samples is white rather than transparent, and is due to trapped air. These ice formations resemble soft rime ice rather than the transparent glaze ice seen on the untreated sample. Compared to untreated surfaces, the icing film formed on superhydrophobic surfaces was easy to peel off by shear flows.

  3. Purchasing Energy-Efficient Air-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, a product category covered by ENERGY STAR efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified products or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

  4. Ice method for production of hydrogen clathrate hydrates

    DOE Patents [OSTI]

    Lokshin, Konstantin; Zhao, Yusheng

    2008-05-13

    The present invention includes a method for hydrogen clathrate hydrate synthesis. First, ice and hydrogen gas are supplied to a containment volume at a first temperature and a first pressure. Next, the containment volume is pressurized with hydrogen gas to a second higher pressure, where hydrogen clathrate hydrates are formed in the process.

  5. ARM-UAV TWP-ICE Payload Instrumentation Details

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

    Payload Instrumentation Details McCoy, Robert Sandia National Laboratories Tooman, Tim Sandia National Laboratories McFarquhar, Greg University of Illinois Category: Field Campaigns The Proteus aircraqft carried a wide variety of in-situ and remote sensing instrumention the TWP-ICE experiment. Instrument capabilites, characteristics and sample data will be covered

  6. Department of Energy Requests Fast Track Rulemaking for Implementing...

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

    ... This includes a variety of home appliances such as refrigerators, central air ... and furnaces, water heaters, commercial refrigerators and freezers and ice cream freezers. ...

  7. Strategies to Save 50% Site Energy in Grocery and General Merchandise...

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

    ... and ice cream refrigerated cases with efficient, vertical models that have doors, LED lighting with occupancy sensors, and hot gas defrost; and o replace baseline meat display ...

  8. Turkey Hill Dairy: Where Energy is Not Left Flapping in the Wind

    Broader source: Energy.gov [DOE]

    Nearly a quarter of the electricity Turkey Hill Dairy uses each year to produce its 26 million gallons of ice cream comes from wind power.

  9. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  10. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-12-01

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  11. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

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

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice numbermore » is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 μm for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.« less

  12. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect (OSTI)

    Wendt, J.O.L.; Mereb, J.B.

    1991-09-20

    Reburning is examined as a means of NO{sub x} destruction in a 17 kW down-fired pulverized coal combustor. In reburning, a secondary fuel is introduced downstream of the primary flame to produce a reducing zone, favorable to NO destruction, and air is introduced further downstream to complete the combustion. Emphasis is on natural gas reburning and a bituminous coal primary flame. A parametric examination of reburning employing a statistical experimental design, is conducted, complemented by detailed experiments. Mechanisms governing the inter-conversion of nitrogenous species in the fuel rich reburn zone is explored. The effect of reburning on N{sub 2}O emissions, the effect of primary flame mode (premixed and diffusion) and the effect of distributing the reburning fuel, are also investigated.

  13. Catalyst for reduction of nitrogen oxides

    DOE Patents [OSTI]

    Ott, Kevin C.

    2010-04-06

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  14. A marine biogenic source of atmospheric ice-nucleating particles (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect A marine biogenic source of atmospheric ice-nucleating particles Citation Details In-Document Search Title: A marine biogenic source of atmospheric ice-nucleating particles The formation of ice in clouds is facilitated by the presence of airborne ice nucleating particles1,2. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice3-11. Here we show that material in the sea

  15. On the scalability of the Albany/FELIX first-order Stokes approximation ice

    Office of Scientific and Technical Information (OSTI)

    sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets. (Conference) | SciTech Connect On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets. Citation Details In-Document Search Title: On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets. Abstract not

  16. Nitrogen-incorporated ultrananocrystalline diamond microneedle arrays for

    Office of Scientific and Technical Information (OSTI)

    electrochemical biosensing (Journal Article) | SciTech Connect Journal Article: Nitrogen-incorporated ultrananocrystalline diamond microneedle arrays for electrochemical biosensing Citation Details In-Document Search This content will become publicly available on March 4, 2017 Title: Nitrogen-incorporated ultrananocrystalline diamond microneedle arrays for electrochemical biosensing Authors: Skoog, Shelby A. ; Miller, Philip R. ; Boehm, Ryan D. ; Sumant, Anirudha V. ; Polsky, Ronen ;

  17. Electrochemical process for the preparation of nitrogen fertilizers

    DOE Patents [OSTI]

    Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

    2012-04-10

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia, at low temperature and pressure, preferably at ambient temperature and pressure, utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen or hydrogen equivalent. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be aqueous, non-aqueous, or solid.

  18. ELECTRON IRRADIATION OF CARBON DISULFIDE-OXYGEN ICES: TOWARD THE FORMATION OF SULFUR-BEARING MOLECULES IN INTERSTELLAR ICES

    SciTech Connect (OSTI)

    Maity, Surajit; Kaiser, Ralf I. [Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States)

    2013-08-20

    The formation of sulfur-bearing molecules in interstellar ices was investigated during the irradiation of carbon disulfide (CS{sub 2})-oxygen (O{sub 2}) ices with energetic electrons at 12 K. The irradiation-induced chemical processing of these ices was monitored online and in situ via Fourier transform infrared spectroscopy to probe the newly formed products quantitatively. The sulfur-bearing molecules produced during the irradiation were sulfur dioxide (SO{sub 2}), sulfur trioxide (SO{sub 3}), and carbonyl sulfide (OCS). Formations of carbon dioxide (CO{sub 2}), carbon monoxide (CO), and ozone (O{sub 3}) were observed as well. To fit the temporal evolution of the newly formed products and to elucidate the underlying reaction pathways, kinetic reaction schemes were developed and numerical sets of rate constants were derived. Our studies suggest that carbon disulfide (CS{sub 2}) can be easily transformed to carbonyl sulfide (OCS) via reactions with suprathermal atomic oxygen (O), which can be released from oxygen-containing precursors such as water (H{sub 2}O), carbon dioxide (CO{sub 2}), and/or methanol (CH{sub 3}OH) upon interaction with ionizing radiation. This investigation corroborates that carbonyl sulfide (OCS) and sulfur dioxide (SO{sub 2}) are the dominant sulfur-bearing molecules in interstellar ices.

  19. Removal of basic nitrogen compounds from hydrocarbon liquids

    DOE Patents [OSTI]

    Givens, Edwin N.; Hoover, David S.

    1985-01-01

    A method is provided for reducing the concentration of basic nitrogen compounds in hydrocarbonaceous feedstock fluids used in the refining industry by providing a solid particulate carbonaceous adsorbent/fuel material such as coal having active basic nitrogen complexing sites on the surface thereof and the coal with a hydrocarbonaceous feedstock containing basic nitrogen compounds to facilitate attraction of the basic nitrogen compounds to the complexing sites and the formation of complexes thereof on the surface of the coal. The adsorbent coal material and the complexes formed thereon are from the feedstock fluid to provide a hydrocarbonaceous fluid of reduced basic nitrogen compound concentration. The coal can then be used as fuel for boilers and the like.

  20. Molecular interactions with ice: Molecular embedding, adsorption, detection, and release

    SciTech Connect (OSTI)

    Gibson, K. D.; Langlois, Grant G.; Li, Wenxin; Sibener, S. J.; Killelea, Daniel R.

    2014-11-14

    The interaction of atomic and molecular species with water and ice is of fundamental importance for chemistry. In a previous series of publications, we demonstrated that translational energy activates the embedding of Xe and Kr atoms in the near surface region of ice surfaces. In this paper, we show that inert molecular species may be absorbed in a similar fashion. We also revisit Xe embedding, and further probe the nature of the absorption into the selvedge. CF{sub 4} molecules with high translational energies (?3 eV) were observed to embed in amorphous solid water. Just as with Xe, the initial adsorption rate is strongly activated by translational energy, but the CF{sub 4} embedding probability is much less than for Xe. In addition, a larger molecule, SF{sub 6}, did not embed at the same translational energies that both CF{sub 4} and Xe embedded. The embedding rate for a given energy thus goes in the order Xe > CF{sub 4} > SF{sub 6}. We do not have as much data for Kr, but it appears to have a rate that is between that of Xe and CF{sub 4}. Tentatively, this order suggests that for Xe and CF{sub 4}, which have similar van der Waals radii, the momentum is the key factor in determining whether the incident atom or molecule can penetrate deeply enough below the surface to embed. The more massive SF{sub 6} molecule also has a larger van der Waals radius, which appears to prevent it from stably embedding in the selvedge. We also determined that the maximum depth of embedding is less than the equivalent of four layers of hexagonal ice, while some of the atoms just below the ice surface can escape before ice desorption begins. These results show that energetic ballistic embedding in ice is a general phenomenon, and represents a significant new channel by which incident species can be trapped under conditions where they would otherwise not be bound stably as surface adsorbates. These findings have implications for many fields including environmental science, trace gas collection and release, and the chemical composition of astrophysical icy bodies in space.

  1. Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric...

    Office of Scientific and Technical Information (OSTI)

    Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric Chemistry and Climate ... Title: Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric Chemistry and ...

  2. Terra Nitrogen Company, L.P.: Ammonia Plant Greatly Reduces Natural...

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

    Terra Nitrogen Company, L.P.: Ammonia Plant Greatly Reduces Natural Gas Consumption After Energy Assessment Terra Nitrogen Company, L.P.: Ammonia Plant Greatly Reduces Natural Gas ...

  3. Present state-of-the-art of transmission line icing

    SciTech Connect (OSTI)

    Pohlman, J.C.; Landers, P.

    1982-08-01

    Icing of overhead power lines is a serious problem for electric utilities. The loads resulting from iced conductors take many forms. Existing Codes and Guides offer little help in establishing adequate design criteria. Each transmission line designer must, therefore, rely heavily on intuitive judgment to set performance levels for transmission lines to be built within his particular service area. A special study was undertaken by author Pohlman in behalf of the Electric Power Research Institute (EPRI) to accomplish the following objectives: Improve the general understanding of the total problem; Sample utility perceptions and experience with the problem; Accumulate and review professional opinion on the subject; Inventory past and on-going research activities; Consolidate the above into a definition of the present state-of-the-art to define the need for future research.

  4. Hydrogen Fuel Pilot Plant and Hydrogen ICE Vehicle Testing

    SciTech Connect (OSTI)

    J. Francfort

    2005-03-01

    The U.S. Department Energy's Advanced Vehicle Testing Activity (AVTA) teamed with Electric Transportation Applications (ETA) and Arizona Public Service (APS) to develop the APS Alternative Fuel (Hydrogen) Pilot Plant that produces and compresses hydrogen on site through an electrolysis process by operating a PEM fuel cell in reverse; natural gas is also compressed onsite. The Pilot Plant dispenses 100% hydrogen, 15 to 50% blends of hydrogen and compressed natural gas (H/CNG), and 100% CNG via a credit card billing system at pressures up to 5,000 psi. Thirty internal combustion engine (ICE) vehicles (including Daimler Chrysler, Ford and General Motors vehicles) are operating on 100% hydrogen and 15 to 50% H/CNG blends. Since the Pilot Plant started operating in June 2002, they hydrogen and H/CNG ICE vehicels have accumulated 250,000 test miles.

  5. Microsoft Word - 11_19_09 ice mkaer.doc

    Energy Savers [EERE]

    to: Department of Energy via email: expartecommunications@hq.doe.gov from: Debra Brunk date: November 20, 2009 subject: Exparte Communication This memo memorializes the meeting between AHAM and the Department of Energy on November 19, 2009 for inclusion in the public docket. The purpose of the meeting was to update the Department on the status of AHAM's development of an ice maker energy test procedure. The attendees are as follows: Ronald Lewis, Department of Energy Lucas Adin, Department of

  6. Microsoft Word - 11_4_09 ice maker.doc

    Energy Savers [EERE]

    gov from: Debra Brunk, Vice President Technical Services date: November 11, 2009 subject: Exparte Communication This memo memorializes the phone call between AHAM and the Department of Energy on November 4, 2009 for inclusion in the public docket. In summary, the issues discussed during the call were an update on including ice maker energy into the refrigerator-freezer test procedure and questions on the status regarding AHAM's clarification request on clothes washer drum volume determination.

  7. Indirect heating system for turbine anti-icing

    SciTech Connect (OSTI)

    Wagar, S.N.

    1980-03-01

    Gas-transmission service in northern Minnesota has verified the effectiveness of American Air Filter Co.'s indirect-heating method of preventing gas-turbine icing at compressor stations. By routing hot exhaust gases through a heat exchanger rather than directly into the inlet-air system, the indirect-heating method avoids turbine fouling, raises the air temperature at a constant specific humidity, and provides a uniform cross section of heated intake air for good turbine efficiency.

  8. doe sc arm 16 029 ACAPEX Shipbased Ice nuclei Collections

    Office of Scientific and Technical Information (OSTI)

    9 ACAPEX - Ship-Based Ice Nuclei Collections Field Campaign Report PJ DeMott TCJ Hill April 2016 CLIMATE RESEARCH FACILITY DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or

  9. American Indian Complex to Cool Off Using Ice Storage System

    Broader source: Energy.gov [DOE]

    In Oklahoma City, summer temperatures can get above 100 degrees, making cooling more of a necessity than a luxury. But the designers of the American Indian Cultural Center and Museum (AICCM) wanted to make cooling choices that reflect American Indian cultures' respect for the land. So, rather than using conventional air-conditioning, the museum's main complex will use an ice storage system estimated to save 644,000 kilowatt hours of electricity a year.

  10. COLLOQUIUM: Antarctic Ice Cores and Implications for the Earth's Climate

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

    | Princeton Plasma Physics Lab June 1, 2016, 4:15pm to 5:30pm Colloquia MBG Auditorium, PPPL (284 cap.) COLLOQUIUM: Antarctic Ice Cores and Implications for the Earth's Climate Professor John Higgins Princeton University Colloquium Committee: The Princeton Plasma Physics Laboratory 2015-2016 Colloquium Committee is comprised of the following people. Please feel free to contact them by e-mail regarding any possible speakers or topics for future colloquia. Carol Ann Austin, caustin@pppl.gov

  11. ARM-UAV TWP-ICE Activities and Data

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

    Activities and Data Tooman, Tim Sandia National Laboratories McCoy, Robert Sandia National Laboratories McFarquhar, Greg University of Illinois Category: Field Campaigns The instrument operational status, data availability and daily flight details for the ARM-UAV Proteus payload flown during the TWP-ICE experiment are presented. Data was also collected during the transit flight across the Pacific from Mojave California to Darwin Australia and on the return transit flight

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

    DOE Patents [OSTI]

    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.

  13. Nitrogen Trifluoride-Based Fluoride- Volatility Separations Process: Initial Studies

    SciTech Connect (OSTI)

    McNamara, Bruce K.; Scheele, Randall D.; Casella, Andrew M.; Kozelisky, Anne E.

    2011-09-28

    This document describes the results of our investigations on the potential use of nitrogen trifluoride as the fluorinating and oxidizing agent in fluoride volatility-based used nuclear fuel reprocessing. The conceptual process uses differences in reaction temperatures between nitrogen trifluoride and fuel constituents that produce volatile fluorides to achieve separations and recover valuable constituents. We provide results from our thermodynamic evaluations, thermo-analytical experiments, kinetic models, and provide a preliminary process flowsheet. The evaluations found that nitrogen trifluoride can effectively produce volatile fluorides at different temperatures dependent on the fuel constituent.

  14. Nitrogen-doped Graphene and Its Electrochemical Applications

    SciTech Connect (OSTI)

    Shao, Yuyan; Zhang, Sheng; Engelhard, Mark H.; Li, Guosheng; Shao, Guocheng; Wang, Yong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-06-04

    Nitrogen-doped graphene (N-graphene) is obtained by exposing graphene to nitrogen plasma. N-graphene exhibits much higher electrocatalytic activity toward oxygen reduction and H2O2 reduction than graphene, and much higher durability and selectivity than the widely-used expensive Pt. The excellent electrochemical performance of N-graphene is attributed to nitrogen functional groups and the specific properties of graphene. This indicates that N-graphene is promising for applications in electrochemical energy devices (fuel cells, metal-air batteries) and biosensors.

  15. Nitrogen dioxide and respiratory illnesses in infants

    SciTech Connect (OSTI)

    Samet, J.M.; Lambert, W.E.; Skipper, B.J.; Cushing, A.H.; Hunt, W.C.; Young, S.A.; McLaren, L.C.; Schwab, M.; Spengler, J.D. )

    1993-11-01

    Nitrogen dioxide is an oxidant gas that contaminates outdoor air and indoor air in homes with unvented gas appliances. A prospective cohort study was carried out to test the hypothesis that residential exposure to NO2 increases incidence and severity of respiratory illnesses during the first 18 months of life. A cohort of 1,205 healthy infants from homes without smokers was enrolled. The daily occurrence of respiratory symptoms and illnesses was reported by the mothers every 2 wk. Illnesses with wheezing or wet cough were classified as lower respiratory tract. Indoor NO2 concentrations were serially measured with passive samplers place in the subjects' bedrooms. In stratified analyses, illness incidence rates did not consistently increase with exposure to NO2 or stove type. In multivariate analyses that adjusted for potential confounding factors, odds ratios were not significantly elevated for current or lagged NO2 exposures, or stove type. Illness duration, a measure of illness severity, was not associated with NO2 exposure. The findings can be extended to homes with gas stoves in regions of the United States where the outdoor air is not heavily polluted by NO2.

  16. Decaying leptophilic dark matter at IceCube

    SciTech Connect (OSTI)

    Boucenna, Sofiane M.; Chianese, Marco; Mangano, Gianpiero; Miele, Gennaro; Morisi, Stefano; Pisanti, Ofelia; Vitagliano, Edoardo

    2015-12-29

    We present a novel interpretation of IceCube high energy neutrino events (with energy larger than 60 TeV) in terms of an extraterrestrial flux due to two different contributions: a flux originated by known astrophysical sources and dominating IceCube observations up to few hundreds TeV, and a new flux component where the most energetic neutrinos come from the leptophilic three-body decays of dark matter particles with a mass of few PeV. Differently from other approaches, we provide two examples of elementary particle models that do not require extremely tiny coupling constants. We find the compatibility of the theoretical predictions with the IceCube results when the astrophysical flux has a cutoff of the order of 100 TeV (broken power law). In this case the most energetic part of the spectrum (PeV neutrinos) is due to an extra component such as the decay of a very massive dark matter component. Due to the low statistics at our disposal we have considered for simplicity the equivalence between deposited and neutrino energy, however such approximation does not affect dramatically the qualitative results. Of course, a purely astrophysical origin of the neutrino flux (no cutoff in energy below the PeV scale — unbroken power law) is still allowed. If future data will confirm the presence of a sharp cutoff above few PeV this would be in favor of a dark matter interpretation.

  17. Isolation and characterization of Microtox{reg_sign}-active components from aircraft de-icing/anti-icing fluids

    SciTech Connect (OSTI)

    Cancilla, D.A.; Holtkamp, A.; Fang, X.; Matassa, L.

    1997-03-01

    The goal of this project was to isolate and identify individual components from aircraft de-icing/anti-icing fluids (ADAFs) through a toxicity-based bioassay analysis. A Microtox{reg_sign} bioassay fractionation scheme was used to isolate a number of active fractions from ADAFs. Active fractions were identified using multiple spectral techniques, including nuclear magnetic resonance, gas chromatograph-mass spectrometry, liquid chromatography-mass spectrometry, and ultraviolet characterization. The primary Microtox-active fraction was shown to be a mixture of benzotriazole and tolyltriazoles, which are used as corrosion inhibitors in ADAF formulations. The identity of the compounds was confirmed through spectral and Microtox-toxicity analysis and comparison of commercially available standards.

  18. Dimensions and aspect ratios of natural ice crystals

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

    Um, J.; McFarquhar, G. M.; Hong, Y. P.; Lee, S. -S.; Jung, C. H.; Lawson, R. P.; Mo, Q.

    2014-12-10

    During the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the Tropics, the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) in the Arctic, and the 2010 Small PARTicles In CirrUS (SPARTICUS) campaign in mid-latitudes, high-resolution images of ice crystals were recorded by a Cloud Particle Imager at temperatures (T) between -87 and 0 °C. The projected maximum dimension (D'), length (L'), and width (W') of pristine columns, plates, and component bullets of bullet rosettes were measured using newly developed software, the Ice Crystal Ruler. The number of bullets in each bullet rosette was also measured. Column crystals were furthermore » distinguished as either horizontally oriented columns or columns with other orientations to eliminate any orientation effect on the measured dimensions. Dimensions and aspect ratios (AR, dimension of major axis divided by dimension of minor axis) of crystals were determined as functions of temperature, geophysical location, and type of cirrus. Dimensions of crystals generally increased as temperature increased. Columns and bullets had larger dimensions (i.e., W') of the minor axis (i.e., a axis) for a given dimension (i.e., D' or L') of the major axis (i.e., c axis), and thus smaller AR, as T increased, whereas this trend did not occur for plate crystals. The average number of branches in bullet rosettes was 5.50±1.35 during three campaigns and 6.32±1.34 (5.46±1.34; 4.95±1.01) during TWP-ICE (SPARTICUS; ISDAC). The AR of bullets increased with the number of branches in bullet rosettes. Most dimensions of crystals and ARs of columnar crystals measured during SPARTICUS were larger than those measured during TWP-ICE and ISDAC at −67 < T < −35 °C and at −40 < T < −15 °C, respectively. The relative occurrence of varying pristine habits depended strongly on cirrus type (i.e., anvil or non-anvil clouds), with plates especially occurring more frequently in anvils. The L–W relationships of columns derived using current data exhibited a strong dependence on temperature; similar relationship determined in previous studies were within the range of the current data.« less

  19. Dimensions and aspect ratios of natural ice crystals

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

    Um, J.; McFarquhar, G. M.; Hong, Y. P.; Lee, S. -S.; Jung, C. H.; Lawson, R. P.; Mo, Q.

    2015-04-15

    During the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the tropics, the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) in the Arctic, and the 2010 Small PARTicles In CirrUS (SPARTICUS) campaign at mid-latitudes, high-resolution images of ice crystals were recorded by a Cloud Particle Imager at temperatures (T) between -87 and 0 °C. The projected maximum dimension (D'), length (L'), and width (W') of pristine columns, plates, and component bullets of bullet rosettes were measured using newly developed software, the Ice Crystal Ruler. The number of bullets in each bullet rosette was also measured. Column crystals were furthermore » distinguished as either horizontally oriented columns or columns with other orientations to eliminate any orientation effect on the measured dimensions. The dimensions and aspect ratios (AR, the dimension of the major axis divided by the dimension of the minor axis) of crystals were determined as functions of temperature, geophysical location, and type of cirrus. Dimensions of crystals generally increased with temperature. Columns and bullets had larger dimensions (i.e., W') of the minor axis (i.e., a axis) for a given dimension (i.e., D' orL') of the major axis (i.e., c axis), and thus smaller AR, as T increased, whereas this trend did not occur for plate crystals. The average number of branches in bullet rosettes was 5.50 ± 1.35 during three campaigns and 6.32 ± 1.34 (5.46 ± 1.34; 4.95 ± 1.01) during TWP-ICE (SPARTICUS; ISDAC). The AR of bullets increased with the number of branches in bullet rosettes. Most dimensions of crystals and ARs of columnar crystals measured during SPARTICUS were larger than those measured during TWP-ICE and ISDAC at −67 < T < -35 °C and at −40 < T < −15 °C, respectively. The relative occurrence of varying pristine habits depended strongly on cirrus type (i.e., anvil or non-anvil clouds), with plates especially occurring more frequently in anvils. The L–W relationships of columns derived using current data exhibited a strong dependence on temperature; similar relationships determined in previous studies were within the range of the current data.« less

  20. Substitutional Nitrogen in Nanodiamond and Bucky-Diamond Particles

    SciTech Connect (OSTI)

    Barnard, Amanda S.; Sternberg, Michael G.

    2005-09-15

    The inclusion of dopants (such as nitrogen) in diamond nanoparticles is expected to be important for use in future nanodevices, such as qubits for quantum computing. Although most commercial diamond nanoparticles contain a small fraction of nitrogen, it is still unclear whether it is located within the core or at the surface of the nanoparticle. Presented here are density functional tight binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional nitrogen in nanodiamond and bucky-diamond particles. The results predict that nitrogen is likely to be positioned at the surface of both hydrogenated nanodiamond and (dehydrogenated) bucky-diamond, and that the coordination of the dopants within the particles is dependent upon the surface structure.

  1. Hydrogen and nitrogen control in ladle and casting operations

    SciTech Connect (OSTI)

    Fruehan, R. J.; Misra, Siddhartha

    2005-01-15

    In recent years there has been an increasing demand to reduce and control the amount of dissolved gases in steel. Hydrogen and nitrogen are two of the most important gases which when dissolved in liquid steel affect its properties significantly.

  2. Nitrogen is a deep acceptor in ZnO

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

    Tarun, M. C.; Iqbal, M. Zafar; McCluskey, M. D.

    2011-04-14

    Zinc oxide is a promising material for blue and UV solid-state lighting devices, among other applications. Nitrogen has been regarded as a potential p-type dopant for ZnO. However, recent calculations indicate that nitrogen is a deep acceptor. This paper presents experimental evidence that nitrogen is, in fact, a deep acceptor and therefore cannot produce p-type ZnO. A broad photoluminescence (PL) emission band near 1.7 eV, with an excitation onset of ~2.2 eV, was observed, in agreement with the deep-acceptor model of the nitrogen defect. Thus the deep-acceptor behavior can be explained by the low energy of the ZnO valence bandmore » relative to the vacuum level.« less

  3. Nitrogen expander cycles for large capacity liquefaction of natural gas

    SciTech Connect (OSTI)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun; Choe, Kun Hyung

    2014-01-29

    Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity.

  4. Recovery of nitrogen and light hydrocarbons from polyalkene purge gas

    DOE Patents [OSTI]

    Zwilling, Daniel Patrick; Golden, Timothy Christoph; Weist, Jr., Edward Landis; Ludwig, Keith Alan

    2003-06-10

    A method for the separation of a gas mixture comprises (a) obtaining a feed gas mixture comprising nitrogen and at least one hydrocarbon having two to six carbon atoms; (b) introducing the feed gas mixture at a temperature of about 60.degree. F. to about 105.degree. F. into an adsorbent bed containing adsorbent material which selectively adsorbs the hydrocarbon, and withdrawing from the adsorbent bed an effluent gas enriched in nitrogen; (c) discontinuing the flow of the feed gas mixture into the adsorbent bed and depressurizing the adsorbent bed by withdrawing depressurization gas therefrom; (d) purging the adsorbent bed by introducing a purge gas into the bed and withdrawing therefrom an effluent gas comprising the hydrocarbon, wherein the purge gas contains nitrogen at a concentration higher than that of the nitrogen in the feed gas mixture; (e) pressurizing the adsorbent bed by introducing pressurization gas into the bed; and (f) repeating (b) through (e) in a cyclic manner.

  5. Amplification of subnanosecond nitrogen laser pulses in UV dyes

    SciTech Connect (OSTI)

    Au, M.; Rayner, D.M.; Malatesta, V.; Hackett, P.A.

    1982-12-01

    The performance of a short pulse netrogen laser system have been improved by replacing the subatmospheric TE nitrogen laser amplifier with a XV xenon chloride excimer pumped dye amplifier. (AIP)

  6. Realizing three-dimensional artificial spin ice by stacking planar nano-arrays

    SciTech Connect (OSTI)

    Chern, Gia-Wei; Reichhardt, Charles; Nisoli, Cristiano

    2014-01-06

    Artificial spin ice is a frustrated magnetic two-dimensional nano-material, recently employed to study variety of tailor-designed unusual collective behaviours. Recently proposed extensions to three dimensions are based on self-assembly techniques and allow little control over geometry and disorder. We present a viable design for the realization of a three-dimensional artificial spin ice with the same level of precision and control allowed by lithographic nano-fabrication of the popular two-dimensional case. Our geometry is based on layering already available two-dimensional artificial spin ice and leads to an arrangement of ice-rule-frustrated units, which is topologically equivalent to that of the tetrahedra in a pyrochlore lattice. Consequently, we show, it exhibits a genuine ice phase and its excitations are, as in natural spin ice materials, magnetic monopoles interacting via Coulomb law.

  7. Process for separating nitrogen from methane using microchannel process

    Office of Scientific and Technical Information (OSTI)

    technology (Patent) | SciTech Connect Process for separating nitrogen from methane using microchannel process technology Citation Details In-Document Search Title: Process for separating nitrogen from methane using microchannel process technology × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  8. Nitrogen concentration and isotope dataset for environmental samples from

    Office of Scientific and Technical Information (OSTI)

    2012 and 2013, Barrow, Alaska (Dataset) | Data Explorer Data Explorer Search Results Nitrogen concentration and isotope dataset for environmental samples from 2012 and 2013, Barrow, Alaska Title: Nitrogen concentration and isotope dataset for environmental samples from 2012 and 2013, Barrow, Alaska Dataset includes nitrate concentrations for polygonal active layer samples, snowmelt; ammonium concentrations for active layer samples; nitrate isotopes for active layer samples, snowmelt,

  9. Membrane-augmented cryogenic methane/nitrogen separation

    DOE Patents [OSTI]

    Lokhandwala, Kaaeid

    1997-01-01

    A membrane separation process combined with a cryogenic separation process for treating a gas stream containing methane, nitrogen and at least one other component. The membrane separation process works by preferentially permeating methane and the other component and rejecting nitrogen. The process is particularly useful in removing components such as water, carbon dioxide or C.sub.3+ hydrocarbons that might otherwise freeze and plug the cryogenic equipment.

  10. Membrane-augmented cryogenic methane/nitrogen separation

    DOE Patents [OSTI]

    Lokhandwala, K.

    1997-07-15

    A membrane separation process is described which is combined with a cryogenic separation process for treating a gas stream containing methane, nitrogen and at least one other component. The membrane separation process works by preferentially permeating methane and the other component and rejecting nitrogen. The process is particularly useful in removing components such as water, carbon dioxide or C{sub +2} hydrocarbons that might otherwise freeze and plug the cryogenic equipment. 10 figs.

  11. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic

  12. Using Doppler spectra to separate hydrometeor populations and analyze ice precipitation in multilayered mixed-phase clouds

    SciTech Connect (OSTI)

    Rambukkange, Mahlon P.; Verlinde, J.; Eloranta, E. W.; Flynn, Connor J.; Clothiaux, Eugene E.

    2011-01-31

    Multimodality of cloud radar Doppler spectra is used to partition cloud particle phases and to separate distinct ice populations in the radar sample volume, thereby facilitating analysis of individual ice showers in multilayered mixed-phase clouds. A 35-GHz cloud radar located at Barrow, Alaska, during the Mixed-Phase Arctic Cloud Experiment collected the Doppler spectra. Data from a pair of collocated depolarization lidars confirmed the presence of two liquid cloud layers reported in this study. Surprisingly, both of these cloud layers were embedded in ice precipitation yet maintained their liquid. Our spectral separation of the ice precipitation yielded two distinct ice populations: ice initiated within the two liquid cloud layers and ice precipitation formed in higher cloud layers. Comparisons of ice fall velocity versus radar reflectivity relationships derived for distinct showers reveal that a single relationship might not properly represent the ice showers during this period.

  13. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below 273 K

    SciTech Connect (OSTI)

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias R.; Gilles, Marry K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2012-09-25

    Atmospheric ice formation induced by particles with complex chemical and physical properties through heterogeneous nucleation is not well understood. Heterogeneous ice nucleation and water uptake by ambient particles collected from urban environments in Los Angeles and Mexico City are presented. Using a vapour controlled cooling system equipped with an optical microscopy, the range of onset conditions for ice nucleation and water uptake by the collected particles was determined as a function of temperature (200{273 K) and relative humidity with respect to ice (RHice) up to water saturation. Three distinctly different types of authentic atmospheric particles were investigated including soot particles associated with organics/inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn containing inorganic particles apportioned to anthropogenic emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption ne structure spectroscopy (STXM/NEXAFS). Above 230 K, signicant differences in water uptake and immersion freezing effciencies of the different particle types were observed. Below 230 K, the particles exhibited high deposition ice nucleation effciencies and formed ice at RHice values well below homogeneous ice nucleation limits. The data show that the chemical composition of these eld{collected particles plays an important role in determining water uptake and immersion freezing. Heterogeneous ice nucleation rate coeffcients, cumulative ice nuclei (IN) spectrum, and IN activated fraction for deposition ice nucleation are derived. The presented ice nucleation data demonstrate that anthropogenic and marine particles comprising of various chemical and physical properties exhibit distinctly different ice nucleation effciencies and can serve as effcient IN at atmospheric conditions typical for cirrus and mixed phase clouds. This indicates a potential link between human activities and cloud formation, and thus climate.

  14. A PHOTOMETRIC SYSTEM FOR DETECTION OF WATER AND METHANE ICES ON KUIPER BELT OBJECTS

    SciTech Connect (OSTI)

    Trujillo, Chadwick A.; Sheppard, Scott S.; Schaller, Emily L. E-mail: sheppard@dtm.ciw.edu

    2011-04-01

    We present a new near-infrared photometric system for detection of water ice and methane ice in the solar system. The system consists of two medium-band filters in the K-band region of the near-infrared, which are sensitive to water ice and methane ice, plus continuum observations in the J band and Y band. The primary purpose of this system is to distinguish between three basic types of Kuiper Belt Objects (KBOs)-those rich in water ice, those rich in methane ice, and those with little absorbance. In this work, we present proof-of-concept observations of 51 KBOs using our filter system, 21 of which have never been observed in the near-infrared spectroscopically. We show that our custom photometric system is consistent with previous spectroscopic observations while reducing telescope observing time by a factor of {approx}3. We use our filters to identify Haumea collisional family members, which are thought to be collisional remnants of a much larger body and are characterized by large fractions of water ice on their surfaces. We add 2009 YE{sub 7} to the Haumea collisional family based on our water ice band observations (J - H{sub 2}O = -1.03 {+-} 0.27) which indicate a high amount of water ice absorption, our calculated proper orbital elements, and the neutral optical colors we measured, V - R = 0.38 {+-} 0.04, which are all consistent with the rest of the Haumea family. We identify several objects dynamically similar to Haumea as being distinct from the Haumea family as they do not have water ice on their surfaces. In addition, we find that only the largest KBOs have methane ice, and Haumea itself has significantly less water ice absorption than the smaller Haumea family members. We find no evidence for other families in the Kuiper Belt.

  15. Measurement of nitrogen content in a gas mixture by transforming the nitrogen into a substance detectable with nondispersive infrared detection

    DOE Patents [OSTI]

    Owen, Thomas E.; Miller, Michael A.

    2007-03-13

    A method of determining the amount of nitrogen in a gas mixture. The constituent gases of the mixture are dissociated and transformed to create a substance that may measured using nondispersive infrared adsorption techniques.

  16. Measurement of nitrogen content in a gas mixture by transforming the nitrogen into a substance detectable with nondispersive infrared detection

    DOE Patents [OSTI]

    Owen, Thomas E.; Miller, Michael A.

    2010-08-24

    A method of determining the amount of nitrogen in a gas mixture. The constituent gases of the mixture are dissociated and transformed to create a substance that may measured using nondispersive infrared adsorption techniques.

  17. Microsoft PowerPoint - TWP-ICE_2006Nov_Rad.ppt

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

    TWP-ICE: Surface Radiation Chuck Long PNNL ARM Atmospheric Radiation Measurement Radiation Sites ARM Atmospheric Radiation Measurement Available Data ARM Atmospheric Radiation ...

  18. STATEMENT OF WORK (SOW) TEMPLATE COMBINED EIR/ICE SUPPORT CONTRACTOR

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

    ... ICE Scope: Perform a Type III (parametric estimate approach) andor Type IV (sampling ... OECM and the EIR Contractor may mutually agree to add or delete particular sections, based ...

  19. Determination of 3-D Cloud Ice Water Contents by Combining Multiple...

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

    Determination of 3-D Cloud Ice Water Contents by Combining Multiple Data Sources from Satellite, Ground Radar, and a Numerical Model Liu, Guosheng Florida State University Seo,...

  20. Progress on MPAS Land Ice Model Development (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Title: Progress on MPAS Land Ice Model Development Authors: Hoffman, Matthew J. 1 + Show Author Affiliations Los Alamos National Laboratory Los Alamos National Laboratory ...

  1. FELIX: advances in modeling forward and inverse ice-sheet problems...

    Office of Scientific and Technical Information (OSTI)

    Title: FELIX: advances in modeling forward and inverse ice-sheet problems. Abstract not provided. Authors: Salinger, Andrew G. ; Perego, Mauro ; Hoffman, Mattew ; Leng, Wei ; ...

  2. Radiation damage and associated phase change effect on photodesorption rates from icesLy? studies of the surface behavior of CO{sub 2}(ice)

    SciTech Connect (OSTI)

    Yuan, Chunqing; Yates, John T. Jr.

    2014-01-01

    Photodesorption from a crystalline film of CO{sub 2}(ice) at 75 K has been studied using Ly? (10.2 eV) radiation. We combine quantitative mass spectrometric studies of gases evolved and transmission IR studies of species trapped in the ice. Direct CO desorption is observed from the primary CO{sub 2} photodissociation process, which occurs promptly for CO{sub 2} molecules located on the outermost surface of the ice (Process I). As the fluence of Ly? radiation increases to ?5.5 10{sup 17} photons cm{sup 2}, extensive damage to the crystalline ice occurs and photo-produced CO molecules from deeper regions (Process II) are found to desorb at a rapidly increasing rate, which becomes two orders of magnitude greater than Process I. It is postulated that deep radiation damage to produce an extensive amorphous phase of CO{sub 2} occurs in the 50 nm ice film and that CO (and CO{sub 2}) diffusive transport is strongly enhanced in the amorphous phase. Photodesorption in Process II is a combination of electronic and thermally activated processes. Radiation damage in crystalline CO{sub 2} ice has been monitored by its effects on the vibrational line shapes of CO{sub 2}(ice). Here the crystalline-to-amorphous phase transition has been correlated with the occurrence of efficient molecular transport over long distances through the amorphous phase of CO{sub 2}(ice). Future studies of the composition of the interstellar region, generated by photodesorption from ice layers on grains, will have to consider the significant effects of radiation damage on photodesorption rates.

  3. SGP and TWP (Manus) Ice Cloud Vertical Velocities

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

    Kalesse, Heike

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  4. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    SciTech Connect (OSTI)

    Kalesse, Heike

    2013-06-27

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  5. Adjoint-based Deterministic Inversion for Ice Sheets

    Office of Scientific and Technical Information (OSTI)

    Adjoint-based deterministic Inversion for Ice Sheets SAND2014-19449PE ___ _---------------- M. Perego2- joint work with: A. Salinger2, E. Phipps2, D. Ridzal2, D. Kouri2, I. Kalashnikova2, S. Price2, G. Stadler3 2Sandia National Laboratories, Albuquerque, NM, USA 2Los Alamos National Laboratory, Los Alamos, NM, USA 3University of Texas at Austin, TX, USA (now at Courant institute, New York) October 29, TUG 2014, Albuquerque Sandia National Laboratories is a multi-program laboratory managed and

  6. Observed hemispheric asymmetry in global sea ice changes

    SciTech Connect (OSTI)

    Cavalieri, D.J.; Gloersen, P.; Parkinson, C.L.; Comiso, J.C.; Zwally, H.J.

    1997-11-07

    From November 1978 through December 1996, the areal extent of sea ice decreased by 2.9 {+-} 0.4 percent decade in the Arctic and increased by 1.3 {+-} 0.2 percent per decade in the Antarctic. The observed hemispheric asymmetry in these trends is consistent with a modeled response to a carbon dioxide-induced climate warming. The interannual variations, which are 2.3 percent of the annual mean in the Arctic, with a predominant period of about 5 years, and 3.4 percent of the annual mean in the Antarctic, with a predominant period of about 3 years, are uncorrelated. 29 refs., 2 figs., 1 tab.

  7. Hydrogen and Nitrogen Control in Ladle and Casting Operations

    SciTech Connect (OSTI)

    Richard J. Fruehan; Siddhartha Misra

    2005-01-15

    In recent years there has been an increasing demand to reduce and control the amount of dissolved gases in steel. Hydrogen and nitrogen are two of the most important gases which when dissolved in liquid steel affect its properties significantly. Several steelmaking additions have been investigated in this research for their effect on the hydrogen and nitrogen content of steels. It has been established that calcium hydroxide (hydrated lime) acts as a source of hydrogen. Carburizers, such as metallurgical coke, were found to result in no hydrogen pickup when added to liquid steel. Addition of petroleum coke, on the other hand, increased the hydrogen content of liquid steel. Ferroalloy such as medium carbon ferromanganese when added to the liquid iron was found to increase its nitrogen content, the increase being proportional to the amount of ferroalloy added. Similarly, addition of pitch coke, which had a significant nitrogen impurity, increased the nitrogen content of liquid iron. A mathematical model was developed to quantify the absorption of nitrogen and hydrogen from the air bubbles entrained during tapping of liquid steel. During the bottom stirring of liquid metal in a ladle, the inert gas escaping from the top displaces the slag layer and often forms an open eye. The absorption of atmospheric nitrogen through the spout eye was estimated for different slag thickness and gas flow rate. The ultimate goal of this research was to develop a comprehensive set of equations which could predict the nitrogen and hydrogen pickup from their various sources. Estimates of hydrogen and nitrogen pickup during the steel transfer operations such as tapping and ladle stirring and the predicted pickup from steelmaking additions were integrated into empirical equations. The comprehensive model is designed to predict the gas pickup under varying operating conditions such as the metal oxygen and sulfur content, the total tapping or stirring time, the stirring gas flow rate and the slag thickness. The model predictions are based on mathematical and empirical evidence which are derived from thermodynamic and kinetic fundamental principles.

  8. METHOD FOR THE PREPARATION OF BINARY NITROGEN-FLUORINE COMPOUNDS

    DOE Patents [OSTI]

    Frazer, J.W.

    1962-05-01

    A process is given for preparing binary nitrogenfluorine compounds, in particular, tetrafluorohydrazine (N/sub 2/F/sub 4/) and difluorodiazine (N/sub 2/ F/sub 2/), The process comprises subjecting gaseous nitrogen trifluoride to the action of an alternating current electrical glow discharge in the presence of mercury vapors. By the action of the electrical discharge, the nitrogen trifluoride is converted into a gaseous product comprising a mixture of tetrafluorohydrazine, the isomers of difluorodiazine, and other impurities including nitrogen, nitrogen oxides, silicon tetrafiuoride, and unreacted nitrogen trifluoride. The gaseous products and impurities are passed into a trap maintained at about - 196 deg C to freeze out the desired products and impurities with the exception of nitregen gas which passes off from the trap and is discarded. Subsequently, the desired products and remaining impurities are warmed to the gaseous state and passed through a silica gel trap maintained at about - 55DEC, wherein the desired tetrafluorohydrazine and difluorodiazine products are retained while the remaining gaseous impurities pass therethrough. The desired products are volatilized from the silica gel trap by heating and then separated by gas chrounatography means into the respective tetrafluorohydrazine and difluorodiazine products. (A.e.C)

  9. Nitrogen Monitoring of West Hackberry 117 Cavern Wells.

    SciTech Connect (OSTI)

    Bettin, Giorgia; Lord, David

    2015-02-01

    U.S. Strategic Petroleum Reserve (SPR) oil storage cavern West Hackberry 117 was tested under extended nitrogen monitoring following a successful mechanical integrity test in order to validate a newly developed hydrostatic column model to be used to differentiate between normal "tight" well behavior and small-leak behavior under nitrogen. High resolution wireline pressure and temperature data were collected during the test period and used in conjunction with the hydrostatic column model to predict the nitrogen/oil interface and the pressure along the entire fluid column from the bradenhead flange nominally at ground surface to bottom of brine pool. Results here and for other SPR caverns have shown that wells under long term nitrogen monitoring do not necessarily pressurize with a relative rate (P N2 /P brine) of 1. The theoretical relative pressure rate depends on the well configuration, pressure and the location of the nitrogen-oil interface and varies from well to well. For the case of WH117 the predicted rates were 0.73 for well A and 0.92 for well B. The measured relative pressurization rate for well B was consistent with the model prediction, while well A rate was found to be between 0.58-0.68. A number of possible reasons for the discrepancy between the model and measured rates of well A are possible. These include modeling inaccuracy, measurement inaccuracy or the possibility of the presence of a very small leak (below the latest calculated minimum detectable leak rate).

  10. Ice Nuclei in Marine Air: Biogenic Particles or Dust?

    SciTech Connect (OSTI)

    Burrows, Susannah M.; Hoose, C.; Poschl, U.; Lawrence, M.

    2013-01-11

    Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earths energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

  11. Hygroscopicity of fuels with anti-icing additives

    SciTech Connect (OSTI)

    Bedrik, B.G.; Golubushkin, V.N.; Uspenskii, S.I.

    1984-03-01

    This article investigates the accumulation of water by hydrocarbon fuels under static and dynamic conditions. Standard TS-1 fuel (aviation kerosine) is examined without an anti-icing additive (AIA) and blended with ethyl cellosolve or tetrahydrofurfuryl alcohol in the concentrations that are added to fuel before refueling flight vehicles under service conditions in order to prevent the formation of ice crystals in the fuel. The fuel hygroscopicity under static conditions is measured in desiccators over saturated salt solutions giving air relative humidities from 37% to 97% at 20/sup 0/C. It is determined that tetrahydrofurfuryl alcohol increases the fuel hygroscopicity to a greater degree than does the ethyl cellosolve. The fuel containing the AIA becomes a medium for the transfer of water from the ambient medium to the emulsion droplets, and these droplets in turn form a liquid phase. It is shown that the rate at which the fuel with the AIA becomes saturated with water under dynamic conditions is much greater than under static conditions. In the fuel without the AIA no water emulsion is formed, even with prolonged contact (more than 2 days) with 100% humidity air, whereas in the fuel with the AIA (even with 0.1% ethyl cellosolve), emulsion and liquid phase are formed. It is concluded that the physical stability of fuel containing AIA depends on the AIA concentration. Includes 3 tables.

  12. Experimental investigation of ice slurry flow pressure drop in horizontal tubes

    SciTech Connect (OSTI)

    Grozdek, Marino; Khodabandeh, Rahmatollah; Lundqvist, Per [Royal Institute of Technology, Department of Energy Technology, Division of Applied Thermodynamics and Refrigeration, Brinellvaegen 68, 10044 Stockholm (Sweden)

    2009-01-15

    Pressure drop behaviour of ice slurry based on ethanol-water mixture in circular horizontal tubes has been experimentally investigated. The secondary fluid was prepared by mixing ethyl alcohol and water to obtain initial alcohol concentration of 10.3% (initial freezing temperature -4.4 C). The pressure drop tests were conducted to cover laminar and slightly turbulent flow with ice mass fraction varying from 0% to 30% depending on test conditions. Results from flow tests reveal much higher pressure drop for higher ice concentrations and higher velocities in comparison to the single phase flow. However for ice concentrations of 15% and higher, certain velocity exists at which ice slurry pressure drop is same or even lower than for single phase flow. It seems that higher ice concentration delay flow pattern transition moment (from laminar to turbulent) toward higher velocities. In addition experimental results for pressure drop were compared to the analytical results, based on Poiseulle and Buckingham-Reiner models for laminar flow, Blasius, Darby and Melson, Dodge and Metzner, Steffe and Tomita for turbulent region and general correlation of Kitanovski which is valid for both flow regimes. For laminar flow and low buoyancy numbers Buckingham-Reiner method gives good agreement with experimental results while for turbulent flow best fit is provided with Dodge-Metzner and Tomita methods. Furthermore, for transport purposes it has been shown that ice mass fraction of 20% offers best ratio of ice slurry transport capability and required pumping power. (author)

  13. Performance of a stand-alone wind-electric ice maker for remote villages

    SciTech Connect (OSTI)

    Davis, H.C.; Brandemuehl, M.J.; Bergey, M.L.S.

    1995-01-01

    Two ice makers in the 1.1 metric tons per 24 hours (1.2 tons per day) size range were tested to determine their performance when directly coupled to a variable-frequency wind turbine generator. Initial tests were conducted using a dynamometer to simulate to wind to evaluate whether previously determined potential problems were significant and to define basic performance parameters. Field testing in Norman, Oklahoma, was completed to determine the performance of one of the ice makers under real wind conditions. As expected, the ice makers produced more ice at a higher speed than rated, and less ice at a lower speed. Due to the large start-up torque requirement of reciprocating compressors, the ice making system experienced a large start-up current and corresponding voltage drop which required a larger wind turbine that expected to provide the necessary current and voltage. Performance curves for ice production and power consumption are presented. A spreadsheet model was constructed to predict ice production at a user-defined site given the wind conditions for that location. Future work should include long-term performance tests and research on reducing the large start-up currents the system experiences when first coming on line.

  14. Ice storage rooftop retrofit for rooftop air conditioning

    SciTech Connect (OSTI)

    Tomlinson, J.J.; Jennings, L.W.

    1997-09-01

    A significant fraction of the floor space in commercial and federal buildings is cooled by single-package rooftop air conditioning units. These units are located on flat roofs and usually operate during the day under hot conditions. They are usually less energy efficient than a chiller system for building cooling. Several U.S. companies are developing systems that employ ice storage in conjunction with chillers to replace older, inefficient rooftop units for improved performance and minimal use of on-peak electricity. Although the low evaporator temperatures needed for ice making tend to reduce the efficiency of the chiller, the overall operating costs of the ice storage system may be lower than that of a packaged, conventional rooftop installation. One version of this concept, the Roofberg{reg_sign} System developed by the Calmac Corporation, was evaluated on a small building at Oak Ridge National Laboratory in Oak Ridge, Tennessee. The Roofberg system consists of a chiller, an ice storage tank, and one or more rooftop units whose evaporator coils have been adapted to use a glycol solution for cooling. The ice storage component decouples the cooling demand of the building from the operation of the chiller. Therefore, the chiller can operate at night (cooler, more efficient condensing temperatures) to meet a daytime cooling demand. This flexibility permits a smaller chiller to satisfy a larger peak cooling load. Further, the system can be operated to shift the cooling demand to off-peak hours when electricity from the utility is generated more efficiently and at lower cost. This Roofberg system was successfully installed last year on a small one-story office building in Oak Ridge and is currently being operated to cool the building. The building and system were sufficiently instrumented to allow a determination of the performance and efficiency of the Roofberg system. Although the energy efficiency of a simulated Roofberg storage/chiller concept operating in the full storage mode was about equal to what could be expected through a simple rooftop efficiency upgrade, the operating costs for the Roofberg system could be much more favorable depending on the utility rate structure. The ability of Roofberg to move much of the cooling load to off-peak periods enables it to take advantage of on-peak demand charges and time-of-use electricity rates. The Roofberg system, as installed, was able to reduce the on-peak energy use of the cooling system to 35% of the on-peak energy consumption of the baseline system. A comparative analysis of a rooftop replacement and Roofberg indicated that the Roofberg system on Building 2518 would be the better economic choice over a range of demand charges and on-off peak energy prices which are typical of utility rate tariffs for commercial buildings.

  15. No Confinement Needed: Observation of a Metastable Hydrophobic Wetting Two-Layer Ice on Graphene

    SciTech Connect (OSTI)

    Kimmel, Gregory A.; Matthiesen, Jesper; Baer, Marcel; Mundy, Christopher J.; Petrik, Nikolay G.; Smith, R. Scott; Dohnalek, Zdenek; Kay, Bruce D.

    2009-09-09

    The structure of water at interfaces is crucial for processes ranging from photocatalysis to protein folding. Here, we investigate the structure and lattice dynamics of two-layer crystalline ice films grown on a hydrophobic substrate - graphene on Pt(111) - with low energy electron diffraction, reflection-absorption infrared spectroscopy, rare-gas adsorption/desorption, and ab-initio molecular dynamics. Unlike hexagonal ice, which consists of stacks of puckered hexagonal "bilayers", this new ice polymorph consists of two flat hexagonal sheets of water molecules in which the hexagons in each sheet are stacked directly on top of each other. Such two-layer ices have been predicted for water confined between hydrophobic slits, but not previously observed. Our results show that the two-layer ice forms even at zero pressure at a single hydrophobic interface by maximizing the number of hydrogen bonds at the expense of adopting a non-tetrahedral geometry with weakened bonds.

  16. Direct visualization of atomically precise nitrogen-doped graphene nanoribbons

    SciTech Connect (OSTI)

    Zhang, Yi; Zhang, Yanfang; Li, Geng; Lu, Jianchen; Du, Shixuan, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Gao, Hong-Jun [Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China); Lin, Xiao [University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100049 (China); Berger, Reinhard; Feng, Xinliang, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Mllen, Klaus [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)

    2014-07-14

    We have fabricated atomically precise nitrogen-doped chevron-type graphene nanoribbons by using the on-surface synthesis technique combined with the nitrogen substitution of the precursors. Scanning tunneling microscopy and spectroscopy indicate that the well-defined nanoribbons tend to align with the neighbors side-by-side with a band gap of 1.02?eV, which is in good agreement with the density functional theory calculation result. The influence of the high precursor coverage on the quality of the nanoribbons is also studied. We find that graphene nanoribbons with sufficient aspect ratios can only be fabricated at sub-monolayer precursor coverage. This work provides a way to construct atomically precise nitrogen-doped graphene nanoribbons.

  17. On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets

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

    Tezaur, Irina K.; Tuminaro, Raymond S.; Perego, Mauro; Salinger, Andrew G.; Price, Stephen F.

    2015-01-01

    We examine the scalability of the recently developed Albany/FELIX finite-element based code for the first-order Stokes momentum balance equations for ice flow. We focus our analysis on the performance of two possible preconditioners for the iterative solution of the sparse linear systems that arise from the discretization of the governing equations: (1) a preconditioner based on the incomplete LU (ILU) factorization, and (2) a recently-developed algebraic multigrid (AMG) preconditioner, constructed using the idea of semi-coarsening. A strong scalability study on a realistic, high resolution Greenland ice sheet problem reveals that, for a given number of processor cores, the AMG preconditionermore » results in faster linear solve times but the ILU preconditioner exhibits better scalability. A weak scalability study is performed on a realistic, moderate resolution Antarctic ice sheet problem, a substantial fraction of which contains floating ice shelves, making it fundamentally different from the Greenland ice sheet problem. Here, we show that as the problem size increases, the performance of the ILU preconditioner deteriorates whereas the AMG preconditioner maintains scalability. This is because the linear systems are extremely ill-conditioned in the presence of floating ice shelves, and the ill-conditioning has a greater negative effect on the ILU preconditioner than on the AMG preconditioner.« less

  18. Engineering shallow spins in diamond with nitrogen delta-doping

    SciTech Connect (OSTI)

    Ohno, Kenichi; Joseph Heremans, F.; Bassett, Lee C.; Myers, Bryan A.; Toyli, David M.; Bleszynski Jayich, Ania C.; Palmstrom, Christopher J.; Awschalom, David D.

    2012-08-20

    We demonstrate nanometer-precision depth control of nitrogen-vacancy (NV) center creation near the surface of synthetic diamond using an in situ nitrogen delta-doping technique during plasma-enhanced chemical vapor deposition. Despite their proximity to the surface, doped NV centers with depths (d) ranging from 5 to 100 nm display long spin coherence times, T{sub 2} > 100 {mu}s at d = 5 nm and T{sub 2} > 600 {mu}s at d {>=} 50 nm. The consistently long spin coherence observed in such shallow NV centers enables applications such as atomic-scale external spin sensing and hybrid quantum architectures.

  19. Mechanism of Enhanced Carbon Cathode Performance by Nitrogen Doping in

    Office of Scientific and Technical Information (OSTI)

    Lithium¿Sulfur Battery: An X-ray Absorption Spectroscopic Study (Journal Article) | SciTech Connect Mechanism of Enhanced Carbon Cathode Performance by Nitrogen Doping in Lithium¿Sulfur Battery: An X-ray Absorption Spectroscopic Study Citation Details In-Document Search Title: Mechanism of Enhanced Carbon Cathode Performance by Nitrogen Doping in Lithium¿Sulfur Battery: An X-ray Absorption Spectroscopic Study Authors: Zhu, P. ; Song, J. ; Lv, D. ; Wang, D. ; Jaye, C. ; Fischer, D. ; Wu,

  20. Cesium Pentazolate: a New Nitrogen-rich Energetic Material (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Conference: Cesium Pentazolate: a New Nitrogen-rich Energetic Material Citation Details In-Document Search Title: Cesium Pentazolate: a New Nitrogen-rich Energetic Material Authors: Steele, B A ; Stavrou, E ; Prakapenka, V B ; Radousky, H B ; Zaug, J M ; Crowhurst, J C ; Oleynik, I I Publication Date: 2015-09-15 OSTI Identifier: 1223838 Report Number(s): LLNL-PROC-677378 DOE Contract Number: DE-AC52-07NA27344 Resource Type: Conference Resource Relation: Conference: Presented

  1. Method of manufacturing semiconductor having group II-group VI compounds doped with nitrogen

    DOE Patents [OSTI]

    Compaan, Alvin D.; Price, Kent J.; Ma, Xianda; Makhratchev, Konstantin

    2005-02-08

    A method of making a semiconductor comprises depositing a group II-group VI compound onto a substrate in the presence of nitrogen using sputtering to produce a nitrogen-doped semiconductor. This method can be used for making a photovoltaic cell using sputtering to apply a back contact layer of group II-group VI compound to a substrate in the presence of nitrogen, the back coating layer being doped with nitrogen. A semiconductor comprising a group II-group VI compound doped with nitrogen, and a photovoltaic cell comprising a substrate on which is deposited a layer of a group II-group VI compound doped with nitrogen, are also included.

  2. Novel two-step laser ablation and ionization mass spectrometry (2S-LAIMS) of actor-spectator ice layers: Probing chemical composition of D{sub 2}O ice beneath a H{sub 2}O ice layer

    SciTech Connect (OSTI)

    Yang, Rui Gudipati, Murthy S.

    2014-03-14

    In this work, we report for the first time successful analysis of organic aromatic analytes imbedded in D{sub 2}O ices by novel infrared (IR) laser ablation of a layered non-absorbing D{sub 2}O ice (spectator) containing the analytes and an ablation-active IR-absorbing H{sub 2}O ice layer (actor) without the analyte. With these studies we have opened up a new method for the in situ analysis of solids containing analytes when covered with an IR laser-absorbing layer that can be resonantly ablated. This soft ejection method takes advantage of the tenability of two-step infrared laser ablation and ultraviolet laser ionization mass spectrometry, previously demonstrated in this lab to study chemical reactions of polycyclic aromatic hydrocarbons (PAHs) in cryogenic ices. The IR laser pulse tuned to resonantly excite only the upper H{sub 2}O ice layer (actor) generates a shockwave upon impact. This shockwave penetrates the lower analyte-containing D{sub 2}O ice layer (spectator, a non-absorbing ice that cannot be ablated directly with the wavelength of the IR laser employed) and is reflected back, ejecting the contents of the D{sub 2}O layer into the vacuum where they are intersected by a UV laser for ionization and detection by a time-of-flight mass spectrometer. Thus, energy is transmitted from the laser-absorbing actor layer into the non-absorbing spectator layer resulting its ablation. We found that isotope cross-contamination between layers was negligible. We also did not see any evidence for thermal or collisional chemistry of PAH molecules with H{sub 2}O molecules in the shockwave. We call this shockwave mediated surface resonance enhanced subsurface ablation technique as two-step laser ablation and ionization mass spectrometry of actor-spectator ice layers. This method has its roots in the well-established MALDI (matrix assisted laser desorption and ionization) method. Our method offers more flexibility to optimize both the processesablation and ionization. This new technique can thus be potentially employed to undertake in situ analysis of materials imbedded in diverse media, such as cryogenic ices, biological samples, tissues, minerals, etc., by covered with an IR-absorbing laser ablation medium and study the chemical composition and reaction pathways of the analyte in its natural surroundings.

  3. Removal of nitrogen and sulfur from oil-shale

    SciTech Connect (OSTI)

    Olmstead, W.N.

    1986-01-28

    This patent describes a process for enhancing the removal of nitrogen and sulfur from oil-shale. The process consists of: (a) contacting the oil-shale with a sufficient amount of an aqueous base solution comprised of at least a stoichiometric amount of one or more alkali metal or alkaline-earth metal hydroxides based on the total amount of nitrogen and sulfur present in the oil-shale. Also necessary is an amount sufficient to form a two-phase liquid, solid system, a temperature from about 50/sup 0/C to about 350/sup 0/C., and pressures sufficient to maintain the solution in liquid form; (b) separating the effluents from the treated oil-shale, wherein the resulting liquid effluent contains nitrogen moieties and sulfur moieties from the oil-shale and any resulting gaseous effluent contains nitrogen moieties from the oil-shale, and (c) converting organic material of the treated oil-shale to shale-oil at a temperature from about 450/sup 0/C to about 550/sup 0/C.

  4. Preparation of high nitrogen compound and materials therefrom

    DOE Patents [OSTI]

    Huynh, My Hang V.; Hiskey, Michael A.

    2006-10-10

    The high-nitrogen compound of the formula ##STR00001## was prepared. Pyrolysis of the compound yields carbon nitrides C.sub.2N.sub.3 and C.sub.3N.sub.5. The carbon nitrides vary in their density, texture, and morphology.

  5. Analysis of 33 MeV Nitrogen irradiated UHMWPE

    SciTech Connect (OSTI)

    Grosso, Mariela del; Chappa, Veronica; Garcia Bermudez, Gerardo

    2007-10-26

    In this work, we irradiated UHMWPE with 33 MeV Nitrogen ions, at several fluences, to generate surface modifications without affecting the bulk properties. These modifications were quantified by means of wear resistance tests and Fourier transform infrared spectroscopy (FTIR) measurements. Experimental results show an optimum ion fluence value that maximizes UHMWPE wear resistance.

  6. Reducing Nitrogen Oxide Emissions: 1996 Compliance with Title IV Limits

    Reports and Publications (EIA)

    1998-01-01

    The purpose of this article is to summarize the existing federal nitrogen oxide (Nox) regulations and the 1996 performance of the 239 Title IV generating units. It also reviews the basics of low-Nox burner technology and presents cost and performance data for retrofits at Title IV units.

  7. Low NOx combustion using cogenerated oxygen and nitrogen streams

    DOE Patents [OSTI]

    Kobayashi, Hisashi; Bool, Lawrence E.; Snyder, William J.

    2009-02-03

    Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

  8. NOx reduction by electron beam-produced nitrogen atom injection

    DOE Patents [OSTI]

    Penetrante, Bernardino M.

    2002-01-01

    Deactivated atomic nitrogen generated by an electron beam from a gas stream containing more than 99% N.sub.2 is injected at low temperatures into an engine exhaust to reduce NOx emissions. High NOx reduction efficiency is achieved with compact electron beam devices without use of a catalyst.

  9. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    SciTech Connect (OSTI)

    Liu, Yang; Hu, Hui; Chen, Wen-Li; Bond, Leonard J.

    2014-02-18

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost $300, heavy wet snow removal can cost $3,000 and removal of accumulated frozen/freezing rain can cost close to $10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  10. Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

    SciTech Connect (OSTI)

    Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; Das, Sarah; King, Matt A.; Stevens, Laura; Lizarralde, Dan

    2015-06-25

    We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicity in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.

  11. Laboratory studies of oil spill behavior in broken ice fields. Final report Nov 80-Nov 81

    SciTech Connect (OSTI)

    Free, A.P.; Cox, J.C.; Schultz, L.A.

    1981-10-01

    This study examined the short-term behavior of oil spilled in or near a field of broken ice. The mechanics of oil seeping through the spaces between the ice blocks were examined, both on the level of a single straight gap and on the level of a random broken ice field, through experiments performed in ARCTEC, Incorporated's Ice Flume. The spreading of oil due to movement of the ice pack is discussed. The effects of the environment in the spill area, especially currents and winds, are taken into account throughout the study. The report gives information which permits the determination of the one-dimensional spread rate of oil spilled in a broken ice field, such as might be encountered in a natural lead or in a ship channel. The results are presented as a set of recommendations for use in oil spill response planning or for use by on-site response personnel in predicting the behavior of oil spilled in broken ice fields.

  12. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-07-15

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  13. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-12-08

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  14. Understanding Ice Supersaturation, Particle Growth, and Number Concentration in Cirrus Clouds

    SciTech Connect (OSTI)

    Comstock, Jennifer M.; Lin, Ruei-Fong; Starr, David O.; Yang, P.

    2008-12-10

    Many factors control the ice supersaturation and microphysical properties in cirrus clouds. We explore the effects of dynamic forcing, ice nucleation mechanisms, and ice crystal growth rate on the evolution and distribution of water vapor and cloud properties in cirrus clouds using a detailed microphysical model and remote sensing measurements obtained at the Department of Energys Atmospheric Radiation Measurement (ARM) Climate Research Facility located near Lamont, OK. To help understand dynamic scales important in cirrus formation, we force the model using both large-scale forcing derived using ARM variational analysis, and mean mesoscale velocity derived from radar Doppler velocity measurements. Both heterogeneous and homogeneous nucleation processes are explored, where we have implemented a rigorous classical theory heterogeneous nucleation scheme to compare with empirical representations. We evaluate model simulations by examining both bulk cloud properties and distributions of measured radar reflectivity, lidar extinction, and water vapor profiles, as well as retrieved cloud microphysical properties. This approach allows for independent verification of both the large and small particle modes of the particle size distribution. Our results suggest that mesoscale variability is the primary mechanism needed to reproduce observed quantities, while nucleation mechanism is secondary. Slow ice crystal growth tends to overestimate the number of small ice crystals, but does not seem to influence bulk properties such as ice water path and cloud thickness. The most realistic simulations as compared with observations are forced using mesoscale waves, include fast ice crystal growth, and initiate ice by either homogeneous or heterogeneous nucleation. Ice crystal number concentrations on the order of 10-100 L-1 produce results consistent with both lidar and radar observations during a cirrus event observed on 7 December 1999, which has an optical depth range typical of midlatitude cirrus.

  15. Evaluating and Constraining Ice Cloud Parameterizations in CAM5 using Aircraft Measurements from the SPARTICUS Campaign

    SciTech Connect (OSTI)

    Zhang, Kai; Liu, Xiaohong; Wang, Minghuai; Comstock, Jennifer M.; Mitchell, David; Mishra, Subhashree; Mace, Gerald G.

    2013-01-01

    This study uses aircraft measurements of relative humidity and ice crystal size distribution collected in synoptic cirrus during the SPARTICUS (Small PARTicles In CirrUS) field campaign to evaluate and constrain ice cloud parameterizations in the Community Atmosphere Model version 5. The probability density function (PDF) of ice crystal number concentration (Ni) derived from high frequency (1 Hz) measurements features a strong dependence on ambient temperature. As temperature decreases from -35C to -62C, the peak in the PDF shifts from 10-20 L-1 to 200-1000 L-1, while the ice crystal number concentration shows a factor of 6-7 increase. Model simulations are performed with two different insitu ice nucleation schemes. One of the schemes can reproduce a clear increase of Ni with decreasing temperature, by using either an observation based ice nuclei spectrum or a classical theory based spectrum with a relatively low (5%-10%) maximum freezing ratio for dust aerosols. The simulation with the other scheme, which assumes a high maximum freezing ratio (100%), shows much weaker temperature dependence of Ni. Simulations are also performed to test empirical parameters related to water vapor deposition and the auto-conversion of ice crystals to snow. Results show that a value between 0.05 and 0.1 for the water vapor deposition coefficient and 250 um for the critical ice crystal size can produce good agreements between model simulation and the SPARTICUS measurements in terms of ice crystal number concentration and effective radius. The climate impact of perturbing these parameters is also discussed.

  16. Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming

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

    de la Peña, S.; Howat, I. M.; Nienow, P. W.; van den Broeke, M. R.; Mosley-Thompson, E.; Price, S. F.; Mair, D.; Noël, B.; Sole, A. J.

    2015-06-11

    Atmospheric warming over the Greenland Ice Sheet during the last 2 decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of ice content from refrozen meltwater found in the firn above the superimposed ice zone. Here we present field and airborne radar observations of buried ice layers within the near-surface (0–20 m) firn in western Greenland, obtained from campaigns between 1998 and 2014. We find a sharp increase in firn-ice content in the form of thick widespread layers in the percolation zone,more » which decreases the capacity of the firn to store meltwater. The estimated total annual ice content retained in the near-surface firn in areas with positive surface mass balance west of the ice divide in Greenland reached a maximum of 74 ± 25 Gt in 2012, compared to the 1958–1999 average of 13 ± 2 Gt, while the percolation zone area more than doubled between 2003 and 2012. Increased melt and column densification resulted in surface lowering averaging –0.80 ± 0.39 m yr⁻¹ between 1800 and 2800 m in the accumulation zone of western Greenland. Since 2007, modeled annual melt and refreezing rates in the percolation zone at elevations below 2100 m surpass the annual snowfall from the previous year, implying that mass gain in the region is retained after melt in the form of refrozen meltwater. If current melt trends over high elevation regions continue, subsequent changes in firn structure will have implications for the hydrology of the ice sheet and related abrupt seasonal densification could become increasingly significant for altimetry-derived ice sheet mass balance estimates.« less

  17. Study of fuel-nitrogen reactions in rich, premixed flames

    SciTech Connect (OSTI)

    Roby, R.J.

    1988-01-01

    The formation and removal of nitrogen-containing species involved in fuel-nitrogen reactions have been studied in atmospheric-pressure fuel-rich hydrogen/oxygen/argon flames. The fuel-nitrogen reaction mechanism was investigated by addition of ammonia, nitric oxide, or hydrogen cyanide alone or with various hydrocarbons to a base flame. Profiles of stable nitrogen species and hydroxyl radical were measured in the post-flame gases. Results show that an initial rapid decay of nitric oxide added to a hydrogen/oxygen/argon flame to approximately 60% of its initial value occurs within 1.0 mm of the burner surface (0.5 msec). The primary reaction for removal of nitric oxide was found to be H + NO + M = HNO + M. The reaction of nitric oxide with various hydrocarbons to form hydrogen cyanide was found to be first order in both the initial hydrocarbon concentration and the initial nitric oxide concentration. A kinetic model was developed that only partially predicts the results obtained. Analysis showed that, by varying the heat of formation of imidogen within the limits of its uncertainty, agreement between the calculations and the data could be improved for nitric oxide and nitrogen. However, the amine, nitrous oxide and hydrogen cyanide profiles were found not to be significantly affected. The significant discrepancy between the measured and calculated ammonia profiles is discussed in terms of the model predictions of both the ammonia formation and decay rates. The reaction: NM + H = N + H/sub 2/ is identified as a key rate-controlling step for removal of amine species in these flames. Evidence from the data and theoretical calculations suggests that the rate of this reaction at the current flame conditions may be as much as a factor of ten slower than the previously reported value.

  18. Robust Nitrogen Oxide/Ammonia Sensors for Vehicle On-board Emissions...

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

    Robust Nitrogen OxideAmmonia Sensors for Vehicle On-board Emissions Control Robust Nitrogen OxideAmmonia Sensors for Vehicle On-board Emissions Control 2012 DOE Hydrogen and Fuel ...

  19. Fast proton hopping detection in ice I{sub h} by quasi-elastic neutron

    Office of Scientific and Technical Information (OSTI)

    scattering. (Journal Article) | SciTech Connect Fast proton hopping detection in ice I{sub h} by quasi-elastic neutron scattering. Citation Details In-Document Search Title: Fast proton hopping detection in ice I{sub h} by quasi-elastic neutron scattering. Quasi-elastic neutron scattering was employed on samples of HCl-doped polycrystalline ice I{sub h}. The analysis of the scattering signal provides the excess proton hopping time, {tau}{sub hop}, in the temperature range of 140-195 K. The

  20. Closing the window on strongly interacting dark matter with IceCube

    SciTech Connect (OSTI)

    Albuquerque, Ivone F. M.; Perez de los Heros, Carlos

    2010-03-15

    We use the recent results on dark matter searches of the 22-string IceCube detector to probe the remaining allowed window for strongly interacting dark matter in the mass range 10{sup 4}IceCube detector from the annihilation of such particles captured in the Sun and compare it to the detected background. As a result, the remaining allowed region in the mass versus cross section parameter space is ruled out. We also show the expected sensitivity of the complete IceCube detector with 86 strings.

  1. SGP and TWP (Manus) Ice Cloud Vertical Velocities (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Data Explorer Search Results SGP and TWP (Manus) Ice Cloud Vertical Velocities Title: SGP and TWP (Manus) Ice Cloud Vertical Velocities Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall

  2. Meltwater effects on flow of Greenland's ice sheet less severe for sea

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

    level rise than earlier feared, scientists say Side effects of increasing meltwater less severe than feared Meltwater effects on flow of Greenland's ice sheet less severe for sea level rise than earlier feared, scientists say The team found that accelerating ice sheet movement from increasing meltwater lubrication is likely to have only a minor role in future sea-level rise. August 19, 2013 A stream of meltwater on the surface of the Greenland Ice Sheet enters a moulin connecting to the

  3. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    SciTech Connect (OSTI)

    Shaw, Raymond A.

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to –40 °C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  4. On the Equivalence of Trapped Colloids, Pinned Vortices, and Spin Ice

    SciTech Connect (OSTI)

    Nisoli, Cristiano

    2014-04-23

    We investigate the recently reported analogies between pinned vortices in nano-structured superconductors or colloids in optical traps, and spin ice materials. The frustration of the two models, one describing colloids and vortices, the other describing spin ice, differs essentially. However, their effective energetics is made identical by the contribution of an emergent field associated to a topological charge. This equivalence extends to the local low-energy dynamics of the ice manifold, yet breaks down in lattices of mixed coordination, because of topological charge transfer between sub-latices.

  5. Update on Greenland Ice Sheet Simulations In CISM and CESM (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Update on Greenland Ice Sheet Simulations In CISM and CESM Citation Details In-Document Search Title: Update on Greenland Ice Sheet Simulations In CISM and CESM Authors: Lipscomb, William Henry [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2016-02-12 OSTI Identifier: 1238137 Report Number(s): LA-UR-16-20919 DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: Land Ice Working Group Meeting ; 2016-02-09

  6. Laboratory determination of the infrared band strengths of pyrene frozen in water ice: Implications for the composition of interstellar ices

    SciTech Connect (OSTI)

    Hardegree-Ullman, E. E.; Gudipati, M. S.; Werner, M.; Boogert, A. C. A.; Lignell, H.; Allamandola, L. J.; Stapelfeldt, K. R. E-mail: gudipati@jpl.nasa.gov

    2014-04-01

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 ?m) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H{sub 2}O and D{sub 2}O ices. The D{sub 2}O mixtures are used to measure pyrene bands that are masked by the strong bands of H{sub 2}O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 ?m. Our infrared band strengths were normalized to experimentally determined ultraviolet band strengths, and we find that they are generally ?50% larger than those reported by Bouwman et al. based on theoretical strengths. These improved band strengths were used to reexamine YSO spectra published by Boogert et al. to estimate the contribution of frozen PAHs to absorption in the 5-8 ?m spectral region, taking into account the strength of the 3.25 ?m CH stretching mode. It is found that frozen neutral PAHs contain 5%-9% of the cosmic carbon budget and account for 2%-9% of the unidentified absorption in the 5-8 ?m region.

  7. Engineering shallow spins in diamond with nitrogen delta-doping (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Engineering shallow spins in diamond with nitrogen delta-doping Citation Details In-Document Search Title: Engineering shallow spins in diamond with nitrogen delta-doping We demonstrate nanometer-precision depth control of nitrogen-vacancy (NV) center creation near the surface of synthetic diamond using an in situ nitrogen delta-doping technique during plasma-enhanced chemical vapor deposition. Despite their proximity to the surface, doped NV centers with depths

  8. Annealing Behavior of Ion-implanted Nitrogen in D9 Steel

    SciTech Connect (OSTI)

    Arunkumar, J.; David, C.; Nair, K. G. M.; Panigrahi, B. K.; Magudapathy, P.; Kennedy, John

    2011-07-15

    Nitrogen isotope N{sup 15} was implanted at the sub-surface of D9 steel. The resonance nuclear reaction analysis was used to probe the implanted nitrogen as a function of depth. The as-implanted D9 sample was isochronally annealed and by observing the broadening of nitrogen depth profile at various annealing junctures, activation energy for nitrogen diffusion in steel was deduced.

  9. Zirconium Catalyst Follows a Low Energy Pathway for Carbon-Nitrogen Bond

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

    Formation | The Ames Laboratory Zirconium Catalyst Follows a Low Energy Pathway for Carbon-Nitrogen Bond Formation Chemists have synthesized a highly selective and highly efficient zirconium catalyst that makes new carbon-nitrogen bonds by adding a nitrogen-hydrogen bond to a carbon-carbon double bond. Nitrogen-containing chemicals are important as agrichemicals, pharmaceuticals, and specialty chemicals. These zirconium catalysts are expected to show greater tolerance to other functionality

  10. Zirconium Catalyst Follows a Low Energy Pathway for Carbon-Nitrogen Bond

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

    Formation | The Ames Laboratory Zirconium Catalyst Follows a Low Energy Pathway for Carbon-Nitrogen Bond Formation Chemists have synthesized a highly selective and highly efficient zirconium catalyst that makes new carbon-nitrogen bonds by adding a nitrogen-hydrogen bond to a carbon-carbon double bond. Nitrogen-containing chemicals are important as agrichemicals, pharmaceuticals, and specialty chemicals. These zirconium catalysts are expected to show greater tolerance to other functionality

  11. Methods of detection and identificationoc carbon- and nitrogen-containing materials

    DOE Patents [OSTI]

    Karev, Alexander Ivanovich; Raevsky, Valery Georgievich; Dzhalivyan, Leonid Zavenovich; Brothers, Louis Joseph; Wilhide, Larry K

    2013-11-12

    Methods for detecting and identifying carbon- and/or nitrogen-containing materials are disclosed. The methods may comprise detection of photo-nuclear reaction products of nitrogen and carbon to detect and identify the carbon- and/or nitrogen-containing materials.

  12. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    DOE Patents [OSTI]

    Liu, D. Kwok-Keung; Chang, Shih-Ger

    1987-08-25

    The present invention relates to a method of removing of nitrogen monoxide from a nitrogen monoxide-containing gas which method comprises contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate complex. The NO absorption efficiency of ferrous urea-dithiocarbamate and ferrous diethanolamine-xanthate as a function of time, oxygen content and solution ph is presented. 3 figs., 1 tab.

  13. Time-resolved x-ray diffraction across water-ices VI/VII transformatio...

    Office of Scientific and Technical Information (OSTI)

    Conference: Time-resolved x-ray diffraction across water-ices VIVII transformations using dynamic-DAC Citation Details In-Document Search Title: Time-resolved x-ray diffraction ...

  14. VOLATILE TRANSPORT INSIDE SUPER-EARTHS BY ENTRAPMENT IN THE WATER-ICE MATRIX

    SciTech Connect (OSTI)

    Levi, A.; Podolak, M.; Sasselov, D.

    2013-05-20

    Whether volatiles can be entrapped in a background matrix composing planetary envelopes and be dragged via convection to the surface is a key question in understanding atmospheric fluxes, cycles, and composition. In this paper, we consider super-Earths with an extensive water mantle (i.e., water planets), and the possibility of entrapment of methane in their extensive water-ice envelopes. We adopt the theory developed by van der Waals and Platteeuw for modeling solid solutions, often used for modeling clathrate hydrates, and modify it in order to estimate the thermodynamic stability field of a new phase called methane filled ice Ih. We find that in comparison to water ice VII the filled ice Ih structure may be stable not only at the high pressures but also at the high temperatures expected at the core-water mantle transition boundary of water planets.

  15. Impact of heterogeneous ice nuclei on homogeneous freezing events in cirrus clouds

    SciTech Connect (OSTI)

    Spichtinger, Peter; Cziczo, Daniel J.

    2010-07-29

    The influence of initial heterogeneous nucleation on subsequent homogeneous nucleation events in cirrus clouds is investigated using a box model which includes the explicit impact of aerosols on the nucleation of ice crystals and sedimentation. Different effects are discussed, namely the impact of external mixtures of heterogeneous ice nuclei and the influence of size-dependent freezing thresholds. Several idealized experiments are carried out, which show that the treatment of external mixtures of ice nuclei can strongly change later homogeneous nucleation events (i.e., the ice crystal number densities) in different matters. The use of size-dependent freezing thresholds can also change the cloud prop erties when compared to more simple parameterizations. This size effect is most important for large IN concentrations. Based upon these findings, recommendations for future modeling and measurement efforts are presented.

  16. Progress on an ARM/GCSS/SPARC TWP-ICE Monsoon Case Study

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

    Progress on an ARMGCSSSPARC TWP-ICE Monsoon Case Study Ann Fridlind and Andrew Ackerman ann.fridlind@nasa.gov * www.giss.nasa.govfridlind Introduction Source: Lori Chappel, ...

  17. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) No ...

  18. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) ...

  19. Predicting Land-Ice Retreat and Sea-Level Rise with the Community...

    Office of Scientific and Technical Information (OSTI)

    Recent studies suggest a potential large contribution (approx0.5 mcentury) from the marine-based West Antarctic Ice Sheet, linked to changes in Southern Ocean wind stress. To ...

  20. Webinar: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Public Meeting

    Broader source: Energy.gov [DOE]

    DOE is conducting a public meeting and webinar for the notice of public meeting regarding energy conservation standards for automatic commercial ice makers. For more information, please visit the...

  1. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison...

    Office of Scientific and Technical Information (OSTI)

    Ice clouds play a major role in the radiative energy budget of the Earth-atmosphere system ... Sponsoring Org: Sponsor not identified (US) Country of Publication: United States Language...

  2. Biomimetic gradient scaffold from ice-templating for self-seeding...

    Office of Scientific and Technical Information (OSTI)

    Biomimetic gradient scaffold from ice-templating for self-seeding of cells with capillary effect Citation Details In-Document Search This content will become publicly available on ...

  3. Weakening of the Stratospheric Polar Vortex by Arctic Sea-Ice Loss

    SciTech Connect (OSTI)

    Kim, Baek-Min; Son, Seok-Woo; Min, Seung-Ki; Jeong, Jee-Hoon; Kim, Seong-Joong; Zhang, Xiangdong; Shim, Taehyoun; Yoon, Jin-Ho

    2014-09-02

    Successive cold winters of severely low temperatures in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although these cold winters are thought to be partly driven by dramatic losses of Arctic sea ice, the mechanism that links sea ice loss to cold winters remains a subject of debate. Here, by conducting observational analyses and model experiments, we show how Arctic sea ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea ice cover during early winter months (November-December), especially over the Barents-Kara seas, enhance the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January- February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.

  4. Predicting Land-Ice Retreat and Sea-Level Rise with the Community...

    Office of Scientific and Technical Information (OSTI)

    with the Community Earth System Model Citation Details In-Document Search Title: Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model You are ...

  5. Impacts of ocean albedo alteration on Arctic sea ice restoration and Northern Hemisphere climate

    SciTech Connect (OSTI)

    Cvijanovic, Ivana; Caldeira, Ken; MacMartin, Douglas G.

    2015-04-01

    The Arctic Ocean is expected to transition into a seasonally ice-free state by mid-century, enhancing Arctic warming and leading to substantial ecological and socio-economic challenges across the Arctic region. It has been proposed that artificially increasing high latitude ocean albedo could restore sea ice, but the climate impacts of such a strategy have not been previously explored. Motivated by this, we investigate the impacts of idealized high latitude ocean albedo changes on Arctic sea ice restoration and climate. In our simulated 4xCO₂ climate, imposing surface albedo alterations over the Arctic Ocean leads to partial sea ice recovery and a modest reduction in Arctic warming. With the most extreme ocean albedo changes, imposed over the area 70°–90°N, September sea ice cover stabilizes at ~40% of its preindustrial value (compared to ~3% without imposed albedo modifications). This is accompanied by an annual mean Arctic surface temperature decrease of ~2 °C but no substantial global mean temperature decrease. Imposed albedo changes and sea ice recovery alter climate outside the Arctic region too, affecting precipitation distribution over parts of the continental United States and Northeastern Pacific. For example, following sea ice recovery, wetter and milder winter conditions are present in the Southwest United States while the East Coast experiences cooling. We conclude that although ocean albedo alteration could lead to some sea ice recovery, it does not appear to be an effective way of offsetting the overall effects of CO₂ induced global warming.

  6. On the Development & Performance of a First Order Stokes Finite Element Ice

    Office of Scientific and Technical Information (OSTI)

    Sheet Dycore Built Using Trilinos Software Components. (Conference) | SciTech Connect On the Development & Performance of a First Order Stokes Finite Element Ice Sheet Dycore Built Using Trilinos Software Components. Citation Details In-Document Search Title: On the Development & Performance of a First Order Stokes Finite Element Ice Sheet Dycore Built Using Trilinos Software Components. Abstract not provided. Authors: Tezaur, Irina Kalashnikova ; Salinger, Andrew G. ; Perego, Mauro

  7. Marine Ice Nuclei Collections - MAGIC (MAGIC-IN) Final Campaign Summary

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Marine Ice Nuclei Collections - MAGIC (MAGIC-IN) Final Campaign Summary Citation Details In-Document Search Title: Marine Ice Nuclei Collections - MAGIC (MAGIC-IN) Final Campaign Summary This campaign augmented measurements obtained via deployment of the Atmospheric Radiation Measurement (ARM) Climate Research Facility's ARM Mobile Facility (AMF) in the Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign. The measurements, comprised of

  8. Building a next-generation community ice sheet model: meeting summary

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Building a next-generation community ice sheet model: meeting summary Citation Details In-Document Search Title: Building a next-generation community ice sheet model: meeting summary No abstract prepared. Authors: Lipscomb, William [1] ; Price, Stephen [1] ; Bueler, Ed [2] ; Holland, David [3] ; Johnson, Jesse [4] + Show Author Affiliations Los Alamos National Laboratory UNIV OF ALASKA NEW YORK UNIV UNIV OF MONTANA Publication Date:

  9. Impacts of ocean albedo alteration on Arctic sea ice restoration and Northern Hemisphere climate

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

    Cvijanovic, Ivana; Caldeira, Ken; MacMartin, Douglas G.

    2015-04-01

    The Arctic Ocean is expected to transition into a seasonally ice-free state by mid-century, enhancing Arctic warming and leading to substantial ecological and socio-economic challenges across the Arctic region. It has been proposed that artificially increasing high latitude ocean albedo could restore sea ice, but the climate impacts of such a strategy have not been previously explored. Motivated by this, we investigate the impacts of idealized high latitude ocean albedo changes on Arctic sea ice restoration and climate. In our simulated 4xCO₂ climate, imposing surface albedo alterations over the Arctic Ocean leads to partial sea ice recovery and a modestmore » reduction in Arctic warming. With the most extreme ocean albedo changes, imposed over the area 70°–90°N, September sea ice cover stabilizes at ~40% of its preindustrial value (compared to ~3% without imposed albedo modifications). This is accompanied by an annual mean Arctic surface temperature decrease of ~2 °C but no substantial global mean temperature decrease. Imposed albedo changes and sea ice recovery alter climate outside the Arctic region too, affecting precipitation distribution over parts of the continental United States and Northeastern Pacific. For example, following sea ice recovery, wetter and milder winter conditions are present in the Southwest United States while the East Coast experiences cooling. We conclude that although ocean albedo alteration could lead to some sea ice recovery, it does not appear to be an effective way of offsetting the overall effects of CO₂ induced global warming.« less

  10. Moving loads on sea ice: A juxtaposition of theory and experiment

    SciTech Connect (OSTI)

    Rayner, G.D.; Enlow, R.L.; Squire, V.A.; Robinson, W.H.

    1994-12-31

    New in situ experimental data relating to strains induced by the ground effect of overflying aircraft and vehicles operating on an ice sheet are examined alongside the sophisticated theoretical predictions of Strathdee et al. (1991). The dataset is very complete, allowing directional features as well as the magnitude of the induced strain field to be determined and compared with theory. Results have a direct application to safe operating criteria for dynamic loading of ice plates.

  11. Airborne Open Polar/Imaging Nephelometer for Ice Particles in Cirrus Clouds

    Office of Scientific and Technical Information (OSTI)

    and Aerosols Field Campaign Report (Technical Report) | SciTech Connect Airborne Open Polar/Imaging Nephelometer for Ice Particles in Cirrus Clouds and Aerosols Field Campaign Report Citation Details In-Document Search Title: Airborne Open Polar/Imaging Nephelometer for Ice Particles in Cirrus Clouds and Aerosols Field Campaign Report The Open Imaging Nephelometer (O-I-Neph) instrument is an adaptation of a proven laboratory instrument built and tested at the University of Maryland,

  12. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between

    Office of Scientific and Technical Information (OSTI)

    Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory (Conference) | SciTech Connect Conference: The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory Citation Details In-Document Search Title: The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory

  13. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between

    Office of Scientific and Technical Information (OSTI)

    Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory (Conference) | SciTech Connect Conference: The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory Citation Details In-Document Search Title: The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory

  14. On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets

    Office of Scientific and Technical Information (OSTI)

    013C This space is reserved for the Procedia header, do not use it On the scalability of the Albany/FELIX first-order Stokes approximation ice sheet solver for large-scale simulations of the Greenland and Antarctic ice sheets Irina Kalashnikova1, Raymond S. Tuminaro2, Mauro Perego2, Andrew G. Salinger2, and Stephen F. Price3 1 Quantitative Modeling & Analysis Dept., Sandia National Laboratories, Livermore, CA, USA Phone: (925)294-2474, E-mail: ikalash@sandia.gov 2 Computational Mathematics

  15. Method for reducing nitrogen oxides in combustion effluents

    DOE Patents [OSTI]

    Zauderer, Bert

    2000-01-01

    Method for reducing nitrogen oxides (NO.sub.x) in the gas stream from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone, NO.sub.x is converted to nitrogen by reaction with urea or ammonia with negligible remaining ammonia and other reaction pollutants. Specially designed injectors are used to introduce air atomized water droplets containing dissolved urea or ammonia into the gaseous combustion products in a manner that widely disperses the droplets exclusively in the optimum reaction temperature zone. The injector operates in a manner that forms droplet of a size that results in their vaporization exclusively in this optimum NO.sub.x -urea/ammonia reaction temperature zone. Also disclosed is a design of a system to effectively accomplish this injection.

  16. Method For Selective Catalytic Reduction Of Nitrogen Oxides

    DOE Patents [OSTI]

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  17. Method for selective catalytic reduction of nitrogen oxides

    DOE Patents [OSTI]

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  18. Temperature Mapping of Nitrogen-doped Niobium Superconducting Radiofrequency Cavities

    SciTech Connect (OSTI)

    Makita, Junki; Ciovati, Gianluigi; Dhakal, Pashupati

    2015-09-01

    It was recently shown that diffusing nitrogen on the inner surface of superconducting radiofrequency (SRF) cavities at high temperature can improve the quality factor of the niobium cavity. However, a reduction of the quench field is also typically found. To better understand the location of rf losses and quench, we used a thermometry system to map the temperature of the outer surface of ingot Nb cavities after nitrogen doping and electropolishing. Surface temperature of the cavities was recorded while increasing the rf power and also during the quenching. The results of thermal mapping showed no precursor heating on the cavities and quenching to be ignited near the equator where the surface magnetic field is maximum. Hot-spots at the equator area during multipacting were also detected by thermal mapping.

  19. Efficient boron-carbon-nitrogen nanotube formation via combined laser-gas flow levitation

    DOE Patents [OSTI]

    Whitney, R Roy; Jordan, Kevin; Smith, Michael W

    2015-03-24

    A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z. The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z.

  20. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOE Patents [OSTI]

    Apel, William A.

    1998-01-01

    A biofilter for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described.

  1. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOE Patents [OSTI]

    Apel, W.A.

    1998-08-18

    A biofilter is described for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method is described of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described. 6 figs.

  2. Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach

    SciTech Connect (OSTI)

    Baustian, Kelly J.; Cziczo, Daniel J.; Wise, M. A.; Pratt, Kerri; Kulkarni, Gourihar R.; Hallar, Anna G.; Tolbert, Margaret A.

    2012-03-30

    In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single-particle mass spectrometry. Aerosol sampling took place at Storm Peak Laboratory in Steamboat Springs, Colorado (elevation of 3210 m). A cascade impactor was used to collect coarse-mode aerosol particles for laboratory analysis by Raman spectroscopy; the composition, mixing state, and heterogeneous ice nucleation activity of individual particles were examined. For in situ analysis of fine-mode aerosol, ice nucleation on ambient particles was observed using a compact ice nucleation chamber. Ice crystals were separated from unactivated aerosol using a pumped counterflow virtual impactor, and ice nuclei were analyzed using particle analysis by laser mass spectrometry. For both fine and coarse modes, the ice nucleating particle fractions were enriched in minerals and depleted in sulfates and nitrates, compared to the background aerosol sampled. The vast majority of particles in both the ambient and ice active aerosol fractions contained a detectable amount of organic material. Raman spectroscopy showed that organic material is sometimes present in the form of a coating on the surface of inorganic particles. We find that some organic-containing particles serve as efficient ice nuclei while others do not. For coarse-mode aerosol, organic particles were only observed to initiate ice formation when oxygen signatures were also present in their spectra.

  3. Model Captures How Nitrogen Limitation Affects Hydrological Processes |

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

    U.S. DOE Office of Science (SC) Model Captures How Nitrogen Limitation Affects Hydrological Processes Biological and Environmental Research (BER) BER Home About Research Facilities Science Highlights Searchable Archive of BER Highlights External link Benefits of BER Funding Opportunities Biological & Environmental Research Advisory Committee (BERAC) Community Resources Contact Information Biological and Environmental Research U.S. Department of Energy SC-23/Germantown Building 1000

  4. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  5. Strategic Petroleum Reserve: Nitrogen Monitoring & Integrity Testing of SW

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

    Louisiana Caverns Petroleum Reserve: Nitrogen Monitoring & Integrity Testing of SW Louisiana Caverns - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid

  6. Nitrogen molecule activation by excited states of copper

    SciTech Connect (OSTI)

    Sanchez-Zamora, M.; Novaro, O.; Ruiz, M.E. )

    1990-04-05

    Ab initio molecular orbital studies that include variational (with a multiconfiguration reference state of 200 states) and perturbational (including over 3 million configurations) configuration interaction calculations were addressed to the interaction of nitrogen molecules with copper. The Cu ground state {sup 2}S and first two excited states {sup 2}P and {sup 2}D were studied as they interact in different geometrical approaches (including side-on and end-on geometries) with ground-state N{sub 2} molecules.

  7. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  8. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  9. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  10. FeN foils by nitrogen ion-implantation

    SciTech Connect (OSTI)

    Jiang, Yanfeng; Wang, Jian-Ping; Al Mehedi, Md; Fu, Engang; Wang, Yongqiang

    2014-05-07

    Iron nitride samples in foil shape (free standing, 500 nm in thickness) were prepared by a nitrogen ion-implantation method. To facilitate phase transformation, the samples were bonded on the substrate followed by a post-annealing step. By using two different substrates, single crystal Si and GaAs, structural and magnetic properties of iron nitride foil samples prepared with different nitrogen ion fluences were characterized. α″-Fe{sub 16}N{sub 2} phase in iron nitride foil samples was obtained and confirmed by the proposed approach. A hard magnetic property with coercivity up to 780 Oe was achieved for the FeN foil samples bonded on Si substrate. The feasibility of using nitrogen ion implantation techniques to prepare FeN foil samples up to 500 nm thickness with a stable martensitic phase under high ion fluences has been demonstrated. A possible mechanism was proposed to explain this result. This proposed method could potentially be an alternative route to prepare rare-earth-free FeN bulk magnets by stacking and pressing multiple free-standing thick α″-Fe{sub 16}N{sub 2} foils together.

  11. Multi-stage combustion using nitrogen-enriched air

    DOE Patents [OSTI]

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  12. Nitrogen-doped zirconia: A comparison with cation stabilized zirconia

    SciTech Connect (OSTI)

    Lee, Jong-Sook . E-mail: jong-sook.lee@fkf.mpg.de; Lerch, Martin; Maier, Joachim

    2006-01-15

    The conductivity behavior of nitrogen-doped zirconia is compared with that of zirconia doped with lower-valent cations and discussed in the framework of defect-defect interactions. While nominally introducing the same number of vacancies as yttrium, nitrogen dopants introduced in the anion sublattice of zirconia lead to substantially different defect kinetics and energetics. Compared to the equivalent yttrium doping nitrogen doping in the Y-Zr-O-N system substantially increases the activation energy and correspondingly decreases the conductivity at temperatures below 500{sup -}bar C in the vacancy range below 4mol%. The comparison of N-doped zirconia and zirconia systems doped with size-matched cation stabilizers, such as Sc, Yb and Y, shows that elastically driven vacancy-vacancy ordering interactions can phenomenologically account for the temperature- and composition-dependence. It is striking that materials with superior high-temperature conductivities due to weak dopant-vacancy interactions undergo severe deterioration at low temperature due to the strong vacancy-ordering. The analysis also explains qualitatively similar effects of Y co-doping in Yb-, Sc-, and N-doped zirconia. Small amount of Y in N-doped zirconia as well as in Sc-doped zirconia appears to hinder the formation of the long-range ordered phase and thus enhance the conductivity substantially.

  13. Control of work function of graphene by plasma assisted nitrogen doping

    SciTech Connect (OSTI)

    Akada, Keishi; Terasawa, Tomo-o; Imamura, Gaku; Obata, Seiji; Saiki, Koichiro, E-mail: saiki@k.u-tokyo.ac.jp [Department of Complexity Science and Engineering, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561 (Japan)

    2014-03-31

    Nitrogen doping is expected to provide several intriguing properties to graphene. Nitrogen plasma treatment to defect-free and defective highly oriented pyrolytic graphite (HOPG) samples causes doping of nitrogen atom into the graphene layer. Nitrogen atoms are initially doped at a graphitic site (inside the graphene) for the defect-free HOPG, while doping to a pyridinic or a pyrrolic site (edge of the graphene) is dominant for the defective HOPG. The work function of graphene correlates strongly with the site and amount of doped nitrogen. Nitrogen atoms doped at a graphitic site lower the work function, while nitrogen atoms at a pyridinic or a pyrrolic site increase the work function. Control of plasma treatment time and the amount of initial defect could change the work function of graphite from 4.3?eV to 5.4?eV, which would open a way to tailor the nature of graphene for various industrial applications.

  14. Black carbon aerosols and the third polar ice cap

    SciTech Connect (OSTI)

    Menon, Surabi; Koch, Dorothy; Beig, Gufran; Sahu, Saroj; Fasullo, John; Orlikowski, Daniel

    2010-04-15

    Recent thinning of glaciers over the Himalayas (sometimes referred to as the third polar region) have raised concern on future water supplies since these glaciers supply water to large river systems that support millions of people inhabiting the surrounding areas. Black carbon (BC) aerosols, released from incomplete combustion, have been increasingly implicated as causing large changes in the hydrology and radiative forcing over Asia and its deposition on snow is thought to increase snow melt. In India BC emissions from biofuel combustion is highly prevalent and compared to other regions, BC aerosol amounts are high. Here, we quantify the impact of BC aerosols on snow cover and precipitation from 1990 to 2010 over the Indian subcontinental region using two different BC emission inventories. New estimates indicate that Indian BC emissions from coal and biofuel are large and transport is expected to expand rapidly in coming years. We show that over the Himalayas, from 1990 to 2000, simulated snow/ice cover decreases by {approx}0.9% due to aerosols. The contribution of the enhanced Indian BC to this decline is {approx}36%, similar to that simulated for 2000 to 2010. Spatial patterns of modeled changes in snow cover and precipitation are similar to observations (from 1990 to 2000), and are mainly obtained with the newer BC estimates.

  15. Characterization of Nitrogen use efficiency in sweet sorghum

    SciTech Connect (OSTI)

    Dweikat, Ismail; Clemente, Thomas

    2014-09-09

    Sweet sorghum (Sorghum bicolor L. Moench) has the potential to augment the increasing demand for alternative fuels and for the production of input efficient, environmentally friendly bioenergy crops. Nitrogen (N) and water availability are considered two of the major limiting factors in crop growth. Nitrogen fertilization accounts for about 40% of the total production cost in sorghum. In cereals, including sorghum, the nitrogen use efficiency (NUE) from fertilizer is approximately 33% of the amount applied. There is therefore extensive concern in relation to the N that is not used by the plant, which is lost by leaching of nitrate, denitrification from the soil, and loss of ammonia to the atmosphere, all of which can have deleterious environmental effects. To improve the potential of sweet sorghum as a leading and cost effective bioenergy crop, the enhancement of NUE must be addressed. To this end, we have identified a sorghum line (SanChi San) that displays about 25% increase in NUE over other sorghum lines. As such, the overarching goal of this project is to employ three complementary strategies to enhance the ability of sweet sorghum to become an efficient nitrogen user. To achieve the project goal, we will pursue the following specific objectives: Objective 1: Phenotypic characterization of SanChi San/Ck60 RILs under low and moderate N-availability including biochemical profiles, vegetative growth and seed yield Objective 2: Conduct quantitative trait loci (QTL) analysis and marker identification for nitrogen use efficiency (NUE) in a grain sorghum RIL population. Objective 3: Identify novel candidate genes for NUE using proteomic and gene expression profiling comparisons of high- and low-NUE RILs. Candidate genes will be brought into the pipeline for transgenic manipulation of NUE This project will apply the latest genomics resources to discover genes controlling NUE, one of the most complex and economically important traits in cereal crops. As a result of the completion of the proposed work, we will have: 1) identified novel alleles in wild sorghum germplasm that is useful to improve both cultivated grain and sweet sorghum; 2) been able to select individuals plants that exhibit high NUE within a breeding population on the basis of these markers; 3) acquired essential information necessary to examine the roles of GS and GOGAT, AlaT, along with impact of transcription factor Dof1, on N assimilation in sweet sorghum; and 4) The information learned will provide new opportunities for improving NUE in sorghum and other cereals.

  16. Anaerobic treatment of aircraft de-icing agent using the SNC-LAVALIN Multiplate Reactor

    SciTech Connect (OSTI)

    Mulligan, C.; Chebib, J.; Safi, B.

    1997-12-31

    A system for the anaerobic treatment of aircraft de-icing agent has been developed by SNC Research Corp., a subsidiary of the SNC-LAVALIN Group (Montreal, Canada). The de-icing agent used in the evaluation contains 54% ethylene glycol, 46% water and trace additives such as surfactants and colorants. The process is comprised of a buffer tank and the SNC-LAVALIN Multiplate Reactor and is as follows. The effluent containing the aircraft de-icing agent with ethylene glycol as the major component enters the buffer tank where the temperature and pH adjustment and the addition of nutrients takes place. The water is then sent to the SNC-LAVALIN Multiplate Reactor. Here, the de-icing agent is converted to biogas which contains 80% methane and the liquid effluent which is essentially ethylene glycol free is discharged. The biogas can be either burned in a flare or used for heating purposes. The following results are typical for the aircraft de-icing agent: Greater than 90% total COD and 99% ethylene glycol removal at an organic load of 15 kg COD/m{sup 3}-day. The de-icing agent can be collected and subsequently treated on-site using the SNC-LAVALIN system. The advantages of the SNC-LAVALIN system are low capital and operating costs, possibility of treating a wide range of de-icing agent concentrations and other liquid effluents unlike evaporation processes, potential recuperation of the biogas and a gentle technology for the environment without generation of VOCs.

  17. Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

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

    Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; Das, Sarah; King, Matt A.; Stevens, Laura; Lizarralde, Dan

    2015-06-25

    We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicitymore » in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.« less

  18. Influence of surface morphology on the immersion mode ice nucleation efficiency of hematite particles

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Hoffmann, Nadine; Kiselev, Alexei; Dreyer, Axel; Zhang, Kai; Kulkarni, Gourihar R.; Koop, Thomas; Mohler, Ottmar

    2014-03-05

    In this paper, the effect of the morphological modification of aerosol particles with respect to heterogeneous ice nucleation is comprehensively investigated for laboratory-generated hematite particles as a model substrate for atmospheric dust particles. The surface area-scaled ice nucleation efficiencies of monodisperse cubic hematite particles and milled hematite particles were measured with a series of expansion cooling experiments using the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud simulation chamber. Complementary off-line characterization of physico-chemical properties of both hematite subsets were also carried out with scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, dynamic light scattering (DLS), and an electro-kinetical particle charge detector to further constrain droplet-freezing measurements of hematite particles. Additionally, an empirical parameterization derived from our laboratory measurements was implemented in the single-column version of the Community Atmospheric Model version 5 (CAM5) to investigate the model sensitivity in simulated ice crystal number concentration on different ice nucleation efficiencies. From an experimental perspective, our results show that the immersion mode ice nucleation efficiency of milled hematite particles is almost an order of magnitude higher at -35.2 ?C < T < -33.5 ?C than that of the cubic hematite particles, indicating a substantial effect of morphological irregularities on immersion mode freezing. Our modeling results similarly show that the increased droplet-freezing rates of milled hematite particles lead to about one order magnitude higher ice crystal number in the upper troposphere than cubic hematite particles. Overall, our results suggest that the surface irregularities and associated active sites lead to greater ice activation through droplet-freezing.

  19. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    DOE Patents [OSTI]

    Liu, David K.; Chang, Shih-Ger

    1989-01-01

    A method of removing nitrogen monoxide from a nitrogen monoxide-containing gas, which method comprises: (a) contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate of the formula: ##STR1## wherein the water-soluble organic compound is selected from compounds of the formula: ##STR2## wherein: R is selected from hydrogen or an organic moiety having at least one polar functional group; Z is selected from oxygen, sulfur, or --N--A wherein N is nitrogen and A is hydrogen or lower alkyl having from one to four carbon atoms; and M is selected from hydrogen, sodium or potassium; and n is 1 or 2, in a contacting zone for a time and at a temperature effective to reduce the nitrogen monoxide. These mixtures are useful to provide an unexpensive method of removing NO from gases, thus reducing atmospheric pollution from flue gases.

  20. Variable oxygen/nitrogen enriched intake air system for internal combustion engine applications

    DOE Patents [OSTI]

    Poola, Ramesh B.; Sekar, Ramanujam R.; Cole, Roger L.

    1997-01-01

    An air supply control system for selectively supplying ambient air, oxygen enriched air and nitrogen enriched air to an intake of an internal combustion engine includes an air mixing chamber that is in fluid communication with the air intake. At least a portion of the ambient air flowing to the mixing chamber is selectively diverted through a secondary path that includes a selectively permeable air separating membrane device due a differential pressure established across the air separating membrane. The permeable membrane device separates a portion of the nitrogen in the ambient air so that oxygen enriched air (permeate) and nitrogen enriched air (retentate) are produced. The oxygen enriched air and the nitrogen enriched air can be selectively supplied to the mixing chamber or expelled to atmosphere. Alternatively, a portion of the nitrogen enriched air can be supplied through another control valve to a monatomic-nitrogen plasma generator device so that atomic nitrogen produced from the nitrogen enriched air can be then injected into the exhaust of the engine. The oxygen enriched air or the nitrogen enriched air becomes mixed with the ambient air in the mixing chamber and then the mixed air is supplied to the intake of the engine. As a result, the air being supplied to the intake of the engine can be regulated with respect to the concentration of oxygen and/or nitrogen.

  1. The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

    SciTech Connect (OSTI)

    IceCube Collaboration; Ackermann, M.

    2007-11-02

    This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation software are running in production mode and the analyses, profiting from the improved data quality and increased overall sensitivity, are well under way.

  2. Development of photocatalyst by combined nitrogen and yttrium doping

    SciTech Connect (OSTI)

    Khan, Matiullah; Cao, Wenbin

    2014-01-01

    Graphical abstract: The simulated compensated YN{sub SUB} co-doped TiO{sub 2} model can reasonably explain the experimental observations. Calculation results show that substitutional Y at Ti sites and substitutional N at O sites with an oxygen vacancy give stable configuration, reduced band gap, better visible light absorption and enhance separations of photoexcited charge carriers. The experimental observations confirmed the theoretical findings. - Highlights: (Y, N) codoped TiO{sub 2} was synthesized by mild one pot hydrothermal method. The Y doping concentration was varied from 0.01 to 1.38 at%. 0.05% (Y, N) codoped TiO{sub 2} shows enhanced visible light photocatalytic activity. Compensated and noncompensated ab-initio calculations were performed. Calculation results reasonably explained the experimental findings. - Abstract: Titanium dioxide co-doped with yttrium and nitrogen with different yttrium doping concentration has been synthesized by mild one pot hydrothermal method without any post calcination for crystallization. Irrespective of the yttrium doping concentration, all the synthesized samples were composed of pure anatase phase with good crystallinity. And the synthesized co-doped samples have spherical morphology with uniform particle size distribution. The absorption edge of the co-doped TiO{sub 2} was shifted toward visible light region depicting that the intrinsic band gap of TiO{sub 2} was affected by the co-doping. Among the different samples, the co-doped sample with 0.05% yttrium doping concentration exhibits enhanced visible light photocatalytic activity by degradation of methylene blue in aqueous solution. Compensated and non-compensated yttriumnitrogen co-doped TiO{sub 2} models were simulated using density functional theory to explain the experimental findings. The calculation results show that the compensated yttriumnitrogen co-doped TiO{sub 2} model may reasonably explain the experimental observations due to its stable configuration, narrowed band gap and enhanced separation of photoexcited carriers.

  3. Method for the purification of noble gases, nitrogen and hydrogen

    DOE Patents [OSTI]

    Baker, John D.; Meikrantz, David H.; Tuggle, Dale G.

    1997-01-01

    A method and apparatus for the purification and collection of hydrogen isotopes in a flowing inert gaseous mixture containing impurities, wherein metal alloy getters having the capability of sorbing non-hydrogen impurities such as oxygen, carbon dioxide, carbon monoxide, methane, ammonia, nitrogen and water vapor are utilized to purify the gaseous mixture of impurities. After purification hydrogen isotopes may be more efficiently collected. A plurality of parallel process lines utilizing metal getter alloys can be used to provide for the continuous purification and collection of the hydrogen isotopes.

  4. Technological modifications in the nitrogen oxides tradable permit program

    SciTech Connect (OSTI)

    Linn, J.

    2008-07-01

    Tradable permit programs allow firms greater flexibility in reducing emissions than command-and-control regulations and encourage firms to use low cost abatement options, including small-scale modifications to capital equipment. This paper shows that firms have extensively modified capital equipment in the Nitrogen Oxides Budget Trading Program, which covers power plants in the eastern United States. The empirical strategy uses geographic and temporal features of the program to estimate counterfactual emissions, finding that modifications have reduced emission rates by approximately 10-15 percent. The modifications would not have occurred under command-and-control regulation and have reduced regulatory costs.

  5. Alignment of the diamond nitrogen vacancy center by strain engineering

    SciTech Connect (OSTI)

    Karin, Todd [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Dunham, Scott [Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States); Fu, Kai-Mei [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States)

    2014-08-04

    The nitrogen vacancy (NV) center in diamond is a sensitive probe of magnetic field and a promising qubit candidate for quantum information processing. The performance of many NV-based devices improves by aligning the NV(s) parallel to a single crystallographic direction. Using ab initio theoretical techniques, we show that NV orientation can be controlled by high-temperature annealing in the presence of strain under currently accessible experimental conditions. We find that (89??7)% of NVs align along the [111] crystallographic direction under 2% compressive biaxial strain (perpendicular to [111]) and an annealing temperature of 970?C.

  6. Method for the purification of noble gases, nitrogen and hydrogen

    DOE Patents [OSTI]

    Baker, J.D.; Meikrantz, D.H.; Tuggle, D.G.

    1997-09-23

    A method and apparatus are disclosed for the purification and collection of hydrogen isotopes in a flowing inert gaseous mixture containing impurities, wherein metal alloy getters having the capability of sorbing non-hydrogen impurities such as oxygen, carbon dioxide, carbon monoxide, methane, ammonia, nitrogen and water vapor are utilized to purify the gaseous mixture of impurities. After purification hydrogen isotopes may be more efficiently collected. A plurality of parallel process lines utilizing metal getter alloys can be used to provide for the continuous purification and collection of the hydrogen isotopes. 15 figs.

  7. Ice formation in PEM fuel cells operated isothermally at sub-freezing temperatures

    SciTech Connect (OSTI)

    Mukundan, Rangachary; Luhan, Roger W; Davey, John R; Spendelow, Jacob S; Borup, Rodney L; Hussey, Daniel S; Jacobson, David L; Arif, Muhammad

    2009-01-01

    The effect of MEA and GDL structure and composition on the performance of single-PEM fuel cells operated isothermally at subfreezing temperatures is presented. The cell performance and durability are not only dependent on the MEA/GDL materials used but also on their interfaces. When a cell is operated isothermally at sub-freezing temperatures in constant current mode, the water formation due to the current density initially hydrates the membrane/ionomer and then forms ice in the catalyst layer/GDL. An increase in high frequency resistance was also observed in certain MEAs where there is a possibility of ice formation between the catalyst layer and GDL leading to a loss in contact area. The total water/ice holding capacity for any MEA was lower at lower temperatures and higher current densities. The durability of MEAs subjected to multiple isothermal starts was better for LANL prepared MEAs as compared to commercial MEAs, and cloth GDLs when compared to paper GDLs. The ice formation was monitored using high-resolution neutron radiography and was found to be concentrated near the cathode catalyst layer. However, there was significant ice formation in the GDLs especially at the higher temperature ({approx} -10 C) and lower current density (0.02 A/cm{sup 2}) operations. These results are consistent with the longer-term durability observations that show more severe degradation at the lower temperatures.

  8. An update on modeling land-ice/ocean interactions in CESM

    SciTech Connect (OSTI)

    Asay-davis, Xylar

    2011-01-24

    This talk is an update on ongoing land-ice/ocean coupling work within the Community Earth System Model (CESM). The coupling method is designed to allow simulation of a fully dynamic ice/ocean interface, while requiring minimal modification to the existing ocean model (the Parallel Ocean Program, POP). The method makes use of an immersed boundary method (IBM) to represent the geometry of the ice-ocean interface without requiring that the computational grid be modified in time. We show many of the remaining development challenges that need to be addressed in order to perform global, century long climate runs with fully coupled ocean and ice sheet models. These challenges include moving to a new grid where the computational pole is no longer at the true south pole and several changes to the coupler (the software tool used to communicate between model components) to allow the boundary between land and ocean to vary in time. We discuss benefits for ice/ocean coupling that would be gained from longer-term ocean model development to allow for natural salt fluxes (which conserve both water and salt mass, rather than water volume).

  9. Benchmarking the x-ray phase contrast imaging for ICF DT ice characterization using roughened surrogates

    SciTech Connect (OSTI)

    Dewald, E; Kozioziemski, B; Moody, J; Koch, J; Mapoles, E; Montesanti, R; Youngblood, K; Letts, S; Nikroo, A; Sater, J; Atherton, J

    2008-06-26

    We use x-ray phase contrast imaging to characterize the inner surface roughness of DT ice layers in capsules planned for future ignition experiments. It is therefore important to quantify how well the x-ray data correlates with the actual ice roughness. We benchmarked the accuracy of our system using surrogates with fabricated roughness characterized with high precision standard techniques. Cylindrical artifacts with azimuthally uniform sinusoidal perturbations with 100 um period and 1 um amplitude demonstrated 0.02 um accuracy limited by the resolution of the imager and the source size of our phase contrast system. Spherical surrogates with random roughness close to that required for the DT ice for a successful ignition experiment were used to correlate the actual surface roughness to that obtained from the x-ray measurements. When comparing average power spectra of individual measurements, the accuracy mode number limits of the x-ray phase contrast system benchmarked against surface characterization performed by Atomic Force Microscopy are 60 and 90 for surrogates smoother and rougher than the required roughness for the ice. These agreement mode number limits are >100 when comparing matching individual measurements. We will discuss the implications for interpreting DT ice roughness data derived from phase-contrast x-ray imaging.

  10. Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization

    SciTech Connect (OSTI)

    Xie, Shaocheng; Liu, Xiaohong; Zhao, Chuanfeng; Zhang, Yuying

    2013-08-01

    Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model version 5 to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number concentration to aerosol properties. The default scheme parameterizes the IN concentration simply as a function of ice supersaturation. The new scheme leads to a significant reduction in simulated IN number concentrations at all latitudes while changes in cloud amount and cloud properties are mainly seen in high latitudes and middle latitude storm tracks. In the Arctic, there is a considerable increase in mid-level clouds and a decrease in low clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and the large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path due to the slow-down of the Bergeron-Findeisen process in mixed-phase clouds. Overall, there is an increase in the optical depth of Arctic clouds, which leads to a stronger cloud radiative forcing (net cooling) at the top of the atmosphere. The comparison with satellite data shows that the new scheme slightly improves low cloud simulations over most of the Arctic, but produces too many mid-level clouds. Considerable improvements are seen in the simulated low clouds and their properties when compared to Arctic ground-based measurements. Issues with the observations and the model-observation comparison in the Arctic region are discussed.

  11. Laser desorption time-of-flight mass spectrometry of ultraviolet photo-processed ices

    SciTech Connect (OSTI)

    Paardekooper, D. M. Bossa, J.-B.; Isokoski, K.; Linnartz, H.

    2014-10-01

    A new ultra-high vacuum experiment is described that allows studying photo-induced chemical processes in interstellar ice analogues. MATRICES - a Mass Analytical Tool to study Reactions in Interstellar ICES applies a new concept by combining laser desorption and time-of-flight mass spectrometry with the ultimate goal to characterize in situ and in real time the solid state evolution of organic compounds upon UV photolysis for astronomically relevant ice mixtures and temperatures. The performance of the experimental setup is demonstrated by the kinetic analysis of the different photoproducts of pure methane (CH?) ice at 20 K. A quantitative approach provides formation yields of several new species with up to four carbon atoms. Convincing evidence is found for the formation of even larger species. Typical mass resolutions obtained range from M/?M ~320 to ~400 for CH? and argon, respectively. Additional tests show that the typical detection limit (in monolayers) is ?0.02 ML, substantially more sensitive than the regular techniques used to investigate chemical processes in interstellar ices.

  12. The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling

    SciTech Connect (OSTI)

    Bernard, S.M.; Habash, D.Z.

    2009-07-02

    Glutamine synthetase assimilates ammonium into amino acids, thus it is a key enzyme for nitrogen metabolism. The cytosolic isoenzymes of glutamine synthetase assimilate ammonium derived from primary nitrogen uptake and from various internal nitrogen recycling pathways. In this way, cytosolic glutamine synthetase is crucial for the remobilization of protein-derived nitrogen. Cytosolic glutamine synthetase is encoded by a small family of genes that are well conserved across plant species. Members of the cytosolic glutamine synthetase gene family are regulated in response to plant nitrogen status, as well as to environmental cues, such as nitrogen availability and biotic/abiotic stresses. The complex regulation of cytosolic glutamine synthetase at the transcriptional to post-translational levels is key to the establishment of a specific physiological role for each isoenzyme. The diverse physiological roles of cytosolic glutamine synthetase isoenzymes are important in relation to current agricultural and ecological issues.

  13. Thermodynamic processes associated with frostbite in the handling of liquid nitrogen

    SciTech Connect (OSTI)

    Johnson, W. L.; Cook, C. R.

    2014-01-29

    It is often taught that exposure to liquid nitrogen will cause frostbite or more severe damage to exposed skin tissue. However, it is also demonstrated that a full hand can be briefly immersed in liquid nitrogen without damage. To better understand and possibly visualize the effects of human tissue exposure to liquid nitrogen, a series of tests were conducted using simulated hands and arms composed of molded gelatin forms. The simulated hands and arms were immersed, sprayed, or splashed with liquid nitrogen both with and without state of the art personal protective equipment. Thermocouples were located within the test articles to allow for thermal mapping during the freezing process. The study is aimed to help understand frostbite hazards and the time constants involved with the handling of liquid nitrogen to improve future safety protocols for the safe handling of cryogenic fluids. Results of the testing also show the limits to handling liquid nitrogen while using various means of protection.

  14. Sub-ambient carbon dioxide adsorption properties of nitrogen doped graphene

    SciTech Connect (OSTI)

    Tamilarasan, P.; Ramaprabhu, Sundara

    2015-04-14

    Carbon dioxide adsorption on carbon surface can be enhanced by doping the surface with heterogeneous atoms, which can increase local surface affinity. This study presents the carbon dioxide adsorption properties of nitrogen doped graphene at low pressures (<100 kPa). Graphene was exposed to nitrogen plasma, which dopes nitrogen atoms into carbon hexagonal lattice, mainly in pyridinic and pyrrolic forms. It is found that nitrogen doping significantly improves the CO{sub 2} adsorption capacity at all temperatures, due to the enrichment of local Lewis basic sites. In general, isotherm and thermodynamic parameters suggest that doped nitrogen sites have nearly same adsorption energy of surface defects and residual functional groups. The isosteric heat of adsorption remains in physisorption range, which falls with surface coverage, suggesting the distribution of magnitude of adsorption energy. The absolute values of isosteric heat and entropy of adsorption are slightly increased upon nitrogen doping.

  15. Multi-omics analysis reveals regulators of the response to nitrogen

    Office of Scientific and Technical Information (OSTI)

    limitation in Yarrowia lipolytica (Journal Article) | DOE PAGES Multi-omics analysis reveals regulators of the response to nitrogen limitation in Yarrowia lipolytica « Prev Next » Title: Multi-omics analysis reveals regulators of the response to nitrogen limitation in Yarrowia lipolytica Yarrowia lipolytica is an oleaginous ascomycete yeast that stores lipids in response to limitation of nitrogen. Furthermore, while the enzymatic pathways responsible for neutral lipid accumulation in Y.

  16. Deterministic coupling of delta-doped nitrogen vacancy centers to a

    Office of Scientific and Technical Information (OSTI)

    nanobeam photonic crystal cavity (Journal Article) | SciTech Connect Deterministic coupling of delta-doped nitrogen vacancy centers to a nanobeam photonic crystal cavity Citation Details In-Document Search Title: Deterministic coupling of delta-doped nitrogen vacancy centers to a nanobeam photonic crystal cavity The negatively charged nitrogen vacancy center (NV) in diamond has generated significant interest as a platform for quantum information processing and sensing in the solid state. For

  17. Reduction of nitrogen oxides with catalytic acid resistant aluminosilicate molecular sieves and ammonia

    DOE Patents [OSTI]

    Pence, Dallas T.; Thomas, Thomas R.

    1980-01-01

    Noxious nitrogen oxides in a waste gas stream such as the stack gas from a fossil-fuel-fired power generation plant or other industrial plant off-gas stream is catalytically reduced to elemental nitrogen and/or innocuous nitrogen oxides employing ammonia as reductant in the presence of a zeolite catalyst in the hydrogen or sodium form having pore openings of about 3 to 10 A.

  18. Impact of Solvent on Photocatalytic Mechanisms: Reactions of Photodesorption Products with Ice Overlayers on the TiO2(110) Surface

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-04-07

    The effects of water and methanol ice overlayers on the photodecomposition of acetone on rutile TiO2(110) were evaluated in ultrahigh vacuum (UHV) using photon stimulated desorption (PSD) and temperature programmed desorption (TPD). In the absence of ice overlayers, acetone photodecomposed on TiO2(110) at 95 K by ejection of a methyl radical into the gas phase and formation of acetate on the surface. With ice overlayers, the methyl radicals are trapped at the interface between TiO2(110) and the ice. When water ice was present, these trapped methyl radicals reacted either with each other to form ethane or with other molecules in the ice (e.g., water or displaced acetone) to form methane (CH4), ethane (CH3CH3) and other products (e.g., methanol), with all of these products trapped in the ice. The new products were free to revisit the surface or depart during desorption of the ice. When methanol ice was present, methane formation came about only from reaction of trapped methyl radicals with the methanol ice. Methane and ethane slowly leaked through methanol ice overlayers into vacuum at 95 K, but not through water ice overlayers. Different degrees of site competition between water and acetone, and between methanol and acetone led to different hydrogen abstraction pathways in the two ices. These results provide new insights into product formation routes and solution-phase radical formation mechanisms that are important in heterogeneous photocatalysis.

  19. Theory of nitrogen doping of carbon nanoribbons: Edge effects

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

    Jiang, Jie; Turnbull, Joseph; Lu, Wenchang; Oak Ridge National Lab.; Boguslawski, Piotr; Univ. of Warsaw; Bernholc, J.; Oak Ridge National Lab.

    2012-01-01

    Nitrogen doping of a carbon nanoribbon is profoundly affected by its one-dimensional character, symmetry, and interaction with edge states. Using state-of-the-art ab initio calculations, including hybrid exact-exchange density functional theory, we find that, for N-doped zigzag ribbons, the electronic properties are strongly dependent upon sublattice effects due to the non-equivalence of the two sublattices. For armchair ribbons, N-doping effects are different depending upon the ribbon family: for families 2 and 0, the N-induced levels are in the conduction band, while for family 1 the N levels are in the gap. In zigzag nanoribbons, nitrogen close to the edge is amore » deep center, while in armchair nanoribbons its behavior is close to an effective-mass-like donor with the ionization energy dependent on the value of the band gap. In chiral nanoribbons, we find strong dependence of the impurity level and formation energy upon the edge position of the dopant, while such site-specificity is not manifested in the magnitude of the magnetization.« less

  20. Absorption process for producing oxygen and nitrogen and solution therefor

    DOE Patents [OSTI]

    Roman, I.C.; Baker, R.W.

    1990-09-25

    Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible. 1 figure

  1. Absorption process for producing oxygen and nitrogen and solution therefor

    DOE Patents [OSTI]

    Roman, Ian C. [Wilmington, DE; Baker, Richard W. [Palo Alto, CA

    1990-09-25

    Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible.

  2. Absorption process for producing oxygen and nitrogen and solution therefor

    DOE Patents [OSTI]

    Roman, Ian C.

    1984-01-01

    Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible.

  3. Influence of the surface liquid film on cylinder icing under marine conditions

    SciTech Connect (OSTI)

    Lozowski, E.P.; Kobos, A.M.; Kachurin, L.G.

    1996-05-01

    A new steady-state icing model is presented which explicitly takes into account the dynamics and thermodynamics of a liquid film on the ice accretion surface under high liquid fluxes. The film is generated by excess unfrozen impinging liquid, is set in motion by the aerodynamic shear stress, and is eventually shed. In order to keep the model simple, it is formulated for a rotating cylinder subjected to a continuous supercooled freshwater spray. The model is used to explore the physics of the liquid film, and confirms that the film is thin and laminar except possibly under extreme liquid fluxes. It predicts supercooling of several degrees at the film surface, in agreement with recent observations. Further, the model is used to investigate the dependence of the icing rate on the following parameters: liquid water content, air temperature, wind speed, spray temperature, cylinder diameter, and heat transfer coefficient.

  4. Sterile neutrinos and indirect dark matter searches in IceCube

    SciTech Connect (OSTI)

    Argüelles, Carlos A.; Kopp, Joachim E-mail: jkopp@fnal.gov

    2012-07-01

    If light sterile neutrinos exist and mix with the active neutrino flavors, this mixing will affect the propagation of high-energy neutrinos from dark matter annihilation in the Sun. In particular, new Mikheyev-Smirnov-Wolfenstein resonances can occur, leading to almost complete conversion of some active neutrino flavors into sterile states. We demonstrate how this can weaken IceCube limits on neutrino capture and annihilation in the Sun and how potential future conflicts between IceCube constraints and direct detection or collider data might be resolved by invoking sterile neutrinos. We also point out that, if the dark matter-nucleon scattering cross section and the allowed annihilation channels are precisely measured in direct detection and collider experiments in the future, IceCube can be used to constrain sterile neutrino models using neutrinos from the dark matter annihilation.

  5. Final Report. Coupled simulations of Antarctic Ice-sheet/ocean interactions using POP and CISM

    SciTech Connect (OSTI)

    Asay-Davis, Xylar Storm

    2015-12-30

    The project performed under this award, referred to from here on as CLARION (CoupLed simulations of Antarctic Ice-sheet/Ocean iNteractions), included important advances in two models of ice sheet and ocean interactions. Despite its short duration (one year), the project made significant progress on its three major foci. First, together with collaborator Daniel Martin at Lawrence Berkeley National Laboratory (LBNL), I developed the POPSICLES coupled ice sheet-ocean model to the point where it could perform a number of pan-Antarctic simulations under various forcing conditions. The results were presented at a number of major conferences and workshops worldwide, and are currently being incorporated into two manuscripts in preparation.

  6. Sensitivity of IceCube-DeepCore to neutralino dark matter in the MSSM-25

    SciTech Connect (OSTI)

    Silverwood, Hamish; Adams, Jenni; Brown, Anthony M; Scott, Pat; Danninger, Matthias; Savage, Christopher; Edsj, Joakim; Hultqvist, Klas E-mail: patscott@physics.mcgill.ca E-mail: savage@physics.utah.edu E-mail: jenni.adams@canterbury.ac.nz E-mail: klas.hultqvist@fysik.su.se

    2013-03-01

    We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino dark matter in the solar core, generated within a 25 parameter version of the minimally supersymmetric standard model (MSSM-25). We explore the 25-dimensional parameter space using scanning methods based on importance sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced a database of 6.02 million parameter space points with neutralino dark matter consistent with the relic density implied by WMAP 7-year data, as well as with accelerator searches. We performed a model exclusion analysis upon these points using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We show that IceCube-DeepCore will be sensitive to a number of models that are not accessible to direct detection experiments such as SIMPLE, COUPP and XENON100, indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies, nor to current LHC searches.

  7. In Situ Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

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

    Baumgardner, Darrel; Kok, Greg; Avallone, L.; Bansemer, A.; Borrmann, S.; Brown, P.; Bundke, U.; Chuang, P. Y.; Cziczo, D.; Field, P.; et al

    2012-02-01

    A meeting of 31 international experts on in situ measurements from aircraft was held to identify unresolved questions concerning ice formation and evolution in ice clouds, assess the current state of instrumentation that can address these problems, introduce emerging technology that may overcome current measurement issues and recommend future courses of action that can improve our understanding of ice cloud microphysical processes and their impact on the environment. The meeting proceedings and outcome has been described in detail in a manuscript submitted to the Bulletin of the American Meteorological Society (BAMS) on March 24, 2011. This paper is currently undermore » review. The remainder of this summary, in the following pages, is the text of the BAMS article. A technical note that will be published by the National Center for Atmospheric Research is currently underway and is expected to be published before the end of the year.« less

  8. In Situ Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

    SciTech Connect (OSTI)

    Baumgardner, Darrel; Kok, Greg; Avallone, L.; Bansemer, A.; Borrmann, S.; Brown, P.; Bundke, U.; Chuang, P. Y.; Cziczo, D.; Field, P.; Gallagher, M.; Gayet, J. -F.; Korolev, A.; Kraemer, M.; McFarquhar, G.; Mertes, S.; Moehler, O.; Lance, S.; Lawson, P.; Petters, M. D.; Pratt, K.; Roberts, G.; Rogers, D.; Stetzer, O.; Stith, J.; Strapp, W.; Twohy, C.; Wendisch, M.

    2012-02-01

    A meeting of 31 international experts on in situ measurements from aircraft was held to identify unresolved questions concerning ice formation and evolution in ice clouds, assess the current state of instrumentation that can address these problems, introduce emerging technology that may overcome current measurement issues and recommend future courses of action that can improve our understanding of ice cloud microphysical processes and their impact on the environment. The meeting proceedings and outcome has been described in detail in a manuscript submitted to the Bulletin of the American Meteorological Society (BAMS) on March 24, 2011. This paper is currently under review. The remainder of this summary, in the following pages, is the text of the BAMS article. A technical note that will be published by the National Center for Atmospheric Research is currently underway and is expected to be published before the end of the year.

  9. Ab initio investigation of electronic and vibrational contributions to linear and nonlinear dielectric properties of ice

    SciTech Connect (OSTI)

    Casassa, S.; Baima, J.; Mahmoud, A.; Kirtman, B.

    2014-06-14

    Electronic and vibrational contributions to the static and dynamic (hyper)polarizability tensors of ice XI and model structures of ordinary hexagonal ice have been theoretically investigated. Calculations were carried out by the finite field nuclear relaxation method for periodic systems (FF-NR) recently implemented in the CRYSTAL code, using the coupled-perturbed Kohn-Sham approach (CPKS) for evaluating the required electronic properties. The effect of structure on the static electronic polarizabilities (dielectric constants) and second-hyperpolarizabilities is minimal. On the other hand, the vibrational contributions to the polarizabilities were found to be significant. A reliable evaluation of these (ionic) contributions allows one to discriminate amongst ice phases characterized by different degrees of proton-order, primarily through differences caused by librational motions. Transverse static and dynamic vibrational (hyper)polarizabilities were found by extrapolating calculations for slabs of increasing size, in order to eliminate substantial surface contributions.

  10. Zirconium Catalyst Follows a Low Energy Pathway for Carbon-Nitrogen...

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

    mechanism, carbon-nitrogen and carbon-hydrogen bond formation occurs in a concerted fashion. Article Title: A Highly Enantioselective Zirconium Catalyst for Intramolecular...

  11. Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001)

    SciTech Connect (OSTI)

    Urban, J. M.; Binder, J.; Wysmo?ek, A.; D?browski, P.; Strupi?ski, W.; Kopciuszy?ski, M.; Ja?ochowski, M.; Klusek, Z.

    2014-06-21

    We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N{sub 2} as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 510 10{sup 12}?cm{sup ?2} was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping.

  12. Patterns of Nitrogen Utilization in Deep-Sea Syntrophic Consortia (2010 JGI User Meeting)

    ScienceCinema (OSTI)

    Wiegel, Detlef

    2011-04-26

    Victoria Orphan from Caltech discusses "Patterns of nitrogen utilization in deep-sea syntrophic consortia" on March 25, 2010 at the 5th Annual DOE JGI User Meeting

  13. Separation of carbon and nitrogen isotopes by selective photodissociation azo or diazo compounds

    DOE Patents [OSTI]

    Chen, Hao-Lin [Walnut Creek, CA

    1977-12-20

    Separation of isotopes, particularly of carbon or nitrogen, is achieved by the selective photodissociation of an azo compound or a diazoalkane, particularly azomethane or diazomethane.

  14. LABORATORY STUDIES ON THE FORMATION OF FORMIC ACID (HCOOH) IN INTERSTELLAR AND COMETARY ICES

    SciTech Connect (OSTI)

    Bennett, Chris J.; Kim, Yong Seol; Kaiser, Ralf I.; Hama, Tetsuya; Kawasaki, Masahiro

    2011-01-20

    Mixtures of water (H{sub 2}O) and carbon monoxide (CO) ices were irradiated at 10 K with energetic electrons to simulate the energy transfer processes that occur in the track of galactic cosmic-ray particles penetrating interstellar ices. We identified formic acid (HCOOH) through new absorption bands in the infrared spectra at 1690 and 1224 cm{sup -1} (5.92 and 8.17 {mu}m, respectively). During the subsequent warm-up of the irradiated samples, formic acid is evident from the mass spectrometer signal at the mass-to-charge ratio, m/z = 46 (HCOOH{sup +}) as the ice sublimates. The detection of formic acid was confirmed using isotopically labeled water-d2 with carbon monoxide, leading to formic acid-d2 (DCOOD). The temporal fits of the reactants, reaction intermediates, and products elucidate two reaction pathways to formic acid in carbon monoxide-water ices. The reaction is induced by unimolecular decomposition of water forming atomic hydrogen (H) and the hydroxyl radical (OH). The dominating pathway to formic acid (HCOOH) was found to involve addition of suprathermal hydrogen atoms to carbon monoxide forming the formyl radical (HCO); the latter recombined with neighboring hydroxyl radicals to yield formic acid (HCOOH). To a lesser extent, hydroxyl radicals react with carbon monoxide to yield the hydroxyformyl radical (HOCO), which recombined with atomic hydrogen to produce formic acid. Similar processes are expected to produce formic acid within interstellar ices, cometary ices, and icy satellites, thus providing alternative processes for the generation of formic acid whose abundance in hot cores such as Sgr-B2 cannot be accounted for solely by gas-phase chemistry.

  15. Multilayer formation and evaporation of deuterated ices in prestellar and protostellar cores

    SciTech Connect (OSTI)

    Taquet, Vianney; Charnley, Steven B.; Sipil, Olli

    2014-08-10

    Extremely large deuteration of several molecules has been observed toward prestellar cores and low-mass protostars for a decade. New observations performed toward low-mass protostars suggest that water presents a lower deuteration in the warm inner gas than in the cold external envelope. We coupled a gas-grain astrochemical model with a one-dimensional model of a collapsing core to properly follow the formation and the deuteration of interstellar ices as well as their subsequent evaporation in the low-mass protostellar envelopes with the aim of interpreting the spatial and temporal evolutions of their deuteration. The astrochemical model follows the formation and the evaporation of ices with a multilayer approach and also includes a state-of-the-art deuterated chemical network by taking the spin states of H{sub 2} and light ions into account. Because of their slow formation, interstellar ices are chemically heterogeneous and show an increase of their deuterium fractionation toward the surface. The differentiation of the deuteration in ices induces an evolution of the deuteration within protostellar envelopes. The warm inner region is poorly deuterated because it includes the whole molecular content of ices, while the deuteration predicted in the cold external envelope scales with the highly deuterated surface of ices. We are able to reproduce the observed evolution of water deuteration within protostellar envelopes, but we are still unable to predict the super-high deuteration observed for formaldehyde and methanol. Finally, the extension of this study to the deuteration of complex organics, important for the prebiotic chemistry, shows good agreement with the observations, suggesting that we can use the deuteration to retrace their mechanisms and their moments of formation.

  16. Land-ice modeling for sea-level prediction (Technical Report) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Technical Report: Land-ice modeling for sea-level prediction Citation Details In-Document Search Title: Land-ice modeling for sea-level prediction Authors: Lipscomb, William H [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2010-06-11 OSTI Identifier: 1172858 Report Number(s): LA-UR-10-04049; LA-UR-10-4049 DOE Contract Number: AC52-06NA25396 Resource Type: Technical Report Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: DOE Country

  17. Entropic description of gas hydrate ice/liquid equilibrium via enhanced sampling of coexisting phases

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

    Malolepsza, Edyta; Kim, Jaegil; Keyes, Tom

    2015-04-28

    Metastable β ice holds small guest molecules in stable gas hydrates, so its solid/liquid equilibrium is of interest. However, aqueous crystal/liquid transitions are very difficult to simulate. A new MD algorithm generates trajectories in a generalized NPT ensemble and equilibrates states of coexisting phases with a selectable enthalpy. Furthermore, with replicas spanning the range between β ice and liquid water we find the statistical temperature from the enthalpy histograms and characterize the transition by the entropy, introducing a general computational procedure for first-order transitions.

  18. Bio-based Deicing/Anti-Icing Fluids - Energy Innovation Portal

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

    Find More Like This Return to Search Bio-based Deicing/Anti-Icing Fluids Battelle Memorial Institute Contact BMI About This Technology Technology Marketing SummaryThis technology is for preparing lower-toxicity, less corrosive, and typically bio-based deicing/anti-icing fluids for aerospace and non-aerospace applications.DescriptionThe use of bio-based ingredients allows the toxicity and corrosivity as well as the carbon footprint to be reduced. A major aspect of this technology is the

  19. Neutrino oscillations with IceCube DeepCore and PINGU

    SciTech Connect (OSTI)

    DeYoung, T.; Collaboration: IceCube-PINGU Collaboration

    2014-11-18

    The IceCube neutrino telescope was augmented with the DeepCore infill array, completed in the 2010/11 austral summer, to enhance its response to neutrinos below 100 GeV. At these energies, neutrino oscillation effects are visible in the flux of atmospheric neutrinos traversing path lengths comparable to the Earth's diameter. Initial measurements of muon neutrino disappearance parameters using data from DeepCore are presented, as well as an estimate of potential future precision. In addition, plans for a Precision IceCube Next Generation Upgrade (PINGU), which could permit determination of the neutrino mass hierarchy within the coming decade, are discussed.

  20. Optimal Initial Conditions for Coupling Ice Sheet Models to Earth System

    Office of Scientific and Technical Information (OSTI)

    Models. (Journal Article) | SciTech Connect Optimal Initial Conditions for Coupling Ice Sheet Models to Earth System Models. Citation Details In-Document Search Title: Optimal Initial Conditions for Coupling Ice Sheet Models to Earth System Models. Abstract not provided. Authors: Perego, Mauro ; Price, Stephen ; Stadler, Georg Publication Date: 2014-04-01 OSTI Identifier: 1142266 Report Number(s): SAND2014-2781J 507169 DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal Article

  1. Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth

    Office of Scientific and Technical Information (OSTI)

    System Model (Conference) | SciTech Connect Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model Citation Details In-Document Search Title: Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model Coastal stakeholders need defensible predictions of 21st century sea-level rise (SLR). IPCC assessments suggest 21st century SLR of {approx}0.5 m under aggressive emission scenarios. Semi-empirical models project SLR of {approx}1 m or more

  2. Progress in coupling Land Ice and Ocean Models in the MPAS Framework

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect in coupling Land Ice and Ocean Models in the MPAS Framework Citation Details In-Document Search Title: Progress in coupling Land Ice and Ocean Models in the MPAS Framework Authors: Hoffman, Matthew J. [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2013-02-14 OSTI Identifier: 1063255 Report Number(s): LA-UR-13-20973 DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: Community Earth System

  3. Progress on MPAS Land Ice Model Development (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    on MPAS Land Ice Model Development Citation Details In-Document Search Title: Progress on MPAS Land Ice Model Development × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this document is also available for sale to the public from the

  4. Development of a land ice core for the Model for Prediction Across Scales

    Office of Scientific and Technical Information (OSTI)

    (MPAS) (Conference) | SciTech Connect of a land ice core for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) No abstract prepared. Authors: Hoffman, Matthew J [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2012-06-25 OSTI Identifier: 1044843 Report Number(s): LA-UR-12-22469 TRN: US201214%%525 DOE Contract Number: AC52-06NA25396 Resource

  5. Progress in coupling Land Ice and Ocean Models in the MPAS Framework

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect in coupling Land Ice and Ocean Models in the MPAS Framework Citation Details In-Document Search Title: Progress in coupling Land Ice and Ocean Models in the MPAS Framework × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and

  6. Laboratory investigations of irradiated acetonitrile-containing ices on an interstellar dust analog

    SciTech Connect (OSTI)

    Abdulgalil, Ali G. M.; Marchione, Demian; Rosu-Finsen, Alexander; Collings, Mark P.; McCoustra, Martin R. S.

    2012-07-15

    Reflection-absorption infrared spectroscopy is used to study the impact of low-energy electron irradiation of acetonitrile-containing ices, under conditions close to those in the dense star-forming regions in the interstellar medium. Both the incident electron energy and the surface coverage were varied. The experiments reveal that solid acetonitrile is desorbed from its ultrathin solid films with a cross section of the order of 10{sup -17} cm{sup 2}. Evidence is presented for a significantly larger desorption cross section for acetonitrile molecules at the water-ice interface, similar to that previously observed for the benzene-water system.

  7. Effects of exchange bias on magnetotransport in permalloy kagome artificial spin ice

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

    Le, B. L.; Rench, D. W.; Misra, R.; O’Brien, L.; Leighton, C.; Samarth, N.; Schiffer, P.

    2015-02-01

    We investigate the magnetotransport properties of connected kagome artificial spin ice networks composed of permalloy nanowires. Our data show clear evidence of magnetic switching among the wires, both in the longitudinal and transverse magnetoresistance. An unusual asymmetry with field sweep direction appears at temperatures below about 20 K that appears to be associated with exchange bias resulting from surface oxidation of permalloy, and which disappears in alumina-capped samples. These results demonstrate that exchange bias is a phenomenon that must be considered in understanding the physics of such artificial spin ice systems, and that opens up new possibilities for their control.

  8. Time-resolved x-ray diffraction across water-ices VI/VII transformations

    Office of Scientific and Technical Information (OSTI)

    using dynamic-DAC (Conference) | SciTech Connect Conference: Time-resolved x-ray diffraction across water-ices VI/VII transformations using dynamic-DAC Citation Details In-Document Search Title: Time-resolved x-ray diffraction across water-ices VI/VII transformations using dynamic-DAC Authors: Chen, J Y ; Kim, M ; Yoo, C ; Evans, W J Publication Date: 2013-10-15 OSTI Identifier: 1104527 Report Number(s): LLNL-PROC-645202 DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource

  9. Heat sources within the Greenland Ice Sheet: dissipation, temperate paleo-firn and cryo-hydrologic warming

    SciTech Connect (OSTI)

    Lthi, M. P.; Ryser, C.; Andrews, L. C.; Catania, G. A.; Funk, M.; Hawley, R. L.; Hoffman, M. J.; Neumann, T. A.

    2015-01-01

    Ice temperature profiles from the Greenland Ice Sheet contain information on the deformation history, past climates and recent warming. We present full-depth temperature profiles from two drill sites on a flow line passing through Swiss Camp, West Greenland. Numerical modeling reveals that ice temperatures are considerably higher than would be expected from heat diffusion and dissipation alone. The possible causes for this extra heat are evaluated using a Lagrangian heat flow model. The model results reveal that the observations can be explained with a combination of different processes: enhanced dissipation (strain heating) in ice-age ice, temperate paleo-firn, and cryo-hydrologic warming in deep crevasses.

  10. Heat sources within the Greenland Ice Sheet: dissipation, temperate paleo-firn and cryo-hydrologic warming

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

    Lüthi, M. P.; Ryser, C.; Andrews, L. C.; Catania, G. A.; Funk, M.; Hawley, R. L.; Hoffman, M. J.; Neumann, T. A.

    2015-01-01

    Ice temperature profiles from the Greenland Ice Sheet contain information on the deformation history, past climates and recent warming. We present full-depth temperature profiles from two drill sites on a flow line passing through Swiss Camp, West Greenland. Numerical modeling reveals that ice temperatures are considerably higher than would be expected from heat diffusion and dissipation alone. The possible causes for this extra heat are evaluated using a Lagrangian heat flow model. The model results reveal that the observations can be explained with a combination of different processes: enhanced dissipation (strain heating) in ice-age ice, temperate paleo-firn, and cryo-hydrologic warmingmore » in deep crevasses.« less

  11. Adsorption configurations of two nitrogen atoms on graphene

    SciTech Connect (OSTI)

    Rani, Babita, E-mail: babitabaghla15@gmail.com [Department of Physics, Punjabi University, Patiala- 147 002 and Department of Physics, Panjab University, Chandigarh- 160 014 (India); Jindal, V. K.; Dharamvir, Keya [Department of Physics, Panjab University, Chandigarh- 160 014 (India)

    2014-04-24

    We present calculations for different possible configurations of two nitrogen adatoms on graphene using the code VASP, based on Density Functional Theory (DFT). Two N atoms adsorbed on the graphene sheet can share a bond in two ways. They take positions either just above two adjacent carbon atoms or they form a bridge across opposite bonds of a hexagon in the graphene sheet. Both these configurations result into structural distortion of the sheet. Another stable configuration involving two N atoms consists of an N{sub 2} molecule which is physisorbed at a distance 3.69 on the graphene sheet. Two N atoms can also be adsorbed on alternate bridge sites of neighbouring hexagons of graphene. This configuration again leads to distortion of the sheet in perpendicular direction.

  12. Nitrogen oxide abatement by distributed fuel addition. Final report

    SciTech Connect (OSTI)

    Wendt, J.O.L.; Mereb, J.B.

    1991-09-20

    Reburning is examined as a means of NO{sub x} destruction in a 17 kW down-fired pulverized coal combustor. In reburning, a secondary fuel is introduced downstream of the primary flame to produce a reducing zone, favorable to NO destruction, and air is introduced further downstream to complete the combustion. Emphasis is on natural gas reburning and a bituminous coal primary flame. A parametric examination of reburning employing a statistical experimental design, is conducted, complemented by detailed experiments. Mechanisms governing the inter-conversion of nitrogenous species in the fuel rich reburn zone is explored. The effect of reburning on N{sub 2}O emissions, the effect of primary flame mode (premixed and diffusion) and the effect of distributing the reburning fuel, are also investigated.

  13. Nitrogen-Doped Graphene and its Application in Electrochemical Biosensing

    SciTech Connect (OSTI)

    Wang, Ying; Shao, Yuyan; Matson, Dean W.; Li, Jinghong; Lin, Yuehe

    2010-05-05

    Chemical doping with foreign atoms is an effective method to intrinsically modify the properties of host materials. Among them, nitrogen (N) doping plays a critical role in regulating the electronic properties of carbon materials. Recently, graphene as a true 2-dimensional carbon material has shown fascinating applications in bioelectronics and biosensors. In this paper, we report a facile strategy to prepare N-doped graphene by using plasma treatment of pristine graphene synthesized via chemical method. Meanwhile, a possible schematic diagram has been proposed to detail the structure of N-doped graphene. By controlling the exposure time, N percentage in host grapheme can be regulated ranging from 0.11% to 1.35%. Moreover, the as prepared N-doped graphene has displayed high electrocatalytic activity to hydrogen peroxide and further been used for glucose biosensing with concentration as low as 0.01 mM in the presence of interferences.

  14. Catalyst and method for reduction of nitrogen oxides

    DOE Patents [OSTI]

    Ott, Kevin C.

    2008-08-19

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  15. Catalyst and method for reduction of nitrogen oxides

    DOE Patents [OSTI]

    Ott, Kevin C.

    2008-05-27

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  16. Preparation of carbon nanoparticles and carbon nitride from high nitrogen compound

    DOE Patents [OSTI]

    Huynh, My Hang V.; Hiskey, Michael A.

    2009-09-01

    The high-nitrogen compound 3,6-di(azido)-1,2,4,5-tetrazine (DiAT) was synthesized by a relatively simple method and used as a precursor for the preparation of carbon nanospheres and nanopolygons, and nitrogen-rich carbon nitrides.

  17. Properties of nitrogen implanted and electron beam annealed bulk ZnO

    SciTech Connect (OSTI)

    Kennedy, J.; Carder, D. A.; Markwitz, A.; Reeves, R. J.

    2010-05-15

    The optical properties of bulk ZnO ion implanted with nitrogen ions, at an energy of 23 keV have been studied as a function of implantation fluence and electron beam (EB) annealing conditions. Nuclear reaction analysis and Raman results have revealed the implanted N concentration and its structural changes with respect to various nitrogen ion fluences. The optical properties of nitrogen implanted bulk ZnO were investigated by low temperature photoluminescence measurements. An enhanced peak at 3.235 eV has been attributed to donor-accepter pair (DAP) emission involving the implanted N acceptor in ZnO. The emission near 3.3085 eV is attributed to a free electron to acceptor transition. We also report a broad band emission feature at {approx}3.09 eV in the nitrogen implanted with 1-2x10{sup 15} ions cm{sup -2} and EB annealed at 800-900 deg. C. This is assigned to a thermally activated nitrogen acceptor transition as it is unique only to nitrogen implanted samples. An ionization energy of 377 meV indicates that this line may correspond to a significantly less shallow acceptor level. In addition an increase in the intensity and dominance of this DAP line in nitrogen implanted samples over the other acceptor transitions was observed with increasing annealing time and temperatures. It is shown that EB annealing offers a method of enhanced nitrogen activation when compared to a more conventional furnace approach.

  18. Nitrogen concentration and isotope dataset for environmental samples from 2012 and 2013, Barrow, Alaska

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

    Jeff Heikoop; Heather Throckmorton

    2015-05-15

    Dataset includes nitrate concentrations for polygonal active layer samples, snowmelt; ammonium concentrations for active layer samples; nitrate isotopes for active layer samples, snowmelt, permafrost; ammonium isotopes for active layer samples; and nitrogen isotopes for soils and dissolved organic nitrogen extracted from soil pore waters.

  19. Method for combined removal of mercury and nitrogen oxides from off-gas streams

    DOE Patents [OSTI]

    Mendelsohn, Marshall H.; Livengood, C. David

    2006-10-10

    A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

  20. Device for detection and identification of carbon- and nitrogen-containing materials

    DOE Patents [OSTI]

    Karev, Alexander Ivanovich; Raevsky, Valery Georgievich; Dzhilavyan, Leonid Zavenovich; Laptev, Valery Dmitrievich; Pakhomov, Nikolay Ivanovich; Shvedunov, Vasily Ivanovich; Rykalin, Vladimir Ivanovich; Brothers, Louis Joseph; Wilhide, Larry K

    2014-03-25

    A device for detection and identification of carbon- and nitrogen-containing materials is described. In particular, the device performs the detection and identification of carbon- and nitrogen-containing materials by photo-nuclear detection. The device may comprise a race-track microtron, a breaking target, and a water-filled Cherenkov radiation counter.

  1. Cryogenic EBSD reveals structure of directionally solidified icepolymer composite

    SciTech Connect (OSTI)

    Donius, Amalie E.; Obbard, Rachel W.; Burger, Joan N.; Hunger, Philipp M.; Baker, Ian; Doherty, Roger D.; Wegst, Ulrike G.K.

    2014-07-01

    Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of icepolymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structurepropertyprocessing correlations. - Highlights: Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. The honeycomb-like polymer phase favors columnar ridges only on one side. Combining cryo-SEM with EBSD links solidification theory with experiment.

  2. Soil Physicochemical Characteristics from Ice Wedge Polygons, Barrow, Alaska, Ver. 1

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

    Chowdhury, Taniya; Graham, David

    2013-12-08

    This dataset provides details about soil cores (active layer and permafrost) collected from ice-wedge polygons during field expeditions to Barrow Environmental Observatory, Alaska in April, 2012 and 2013. Core information available are exact core locations; soil horizon descriptions and characteristics; and fundamental soil physico-chemical properties.

  3. Soil Physicochemical Characteristics from Ice Wedge Polygons, Barrow, Alaska, Ver. 1

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

    Chowdhury, Taniya

    2014-03-24

    This dataset provides details about soil cores (active layer and permafrost) collected from ice-wedge polygons during field expeditions to Barrow Environmental Observatory, Alaska in April, 2012 and 2013. Core information available are exact core locations; soil horizon descriptions and characteristics; and fundamental soil physico-chemical properties.

  4. Soil Physicochemical Characteristics from Ice Wedge Polygons, Barrow, Alaska, Ver. 1

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

    Chowdhury, Taniya

    This dataset provides details about soil cores (active layer and permafrost) collected from ice-wedge polygons during field expeditions to Barrow Environmental Observatory, Alaska in April, 2012 and 2013. Core information available are exact core locations; soil horizon descriptions and characteristics; and fundamental soil physico-chemical properties.

  5. Production and characterization of a nitrogen-implanted Fe standard to calibrate PIGE measurements

    SciTech Connect (OSTI)

    Rodrigues, C. L.; Silva, T. F.; Added, N.; Santos, H. C.; Tabacniks, M. H.

    2014-11-11

    Three calibration standard was produced by ion implantation of nitrogen in samples of Armco iron (99.7% iron). The samples was irradiated with nitrogen ion beams at several different energies (between 4 keV and 40 keV), and the ion doses were adjusted to obtain an uniform depth profile, using simulations with SRIM code. Two standards, one thick and other a foil (1.62mg/cm{sup 2}), was irradiated at same time with total nominal dose of 6.610{sup ?16} atoms/cm{sup 2} distributed in a region of 100 nm in depth, with an average concentration of 9.0% nitrogen in iron. The third sample uses the same profile, but with a small dose, 1.110{sup ?16} atoms/cm{sup 2} and average concentration of 1.5% nitrogen. The characterization of the implanted samples was done using RBS and NRA techniques to quantification of nitrogen.

  6. Molecular dynamics simulations of D{sub 2}O ice photodesorption

    SciTech Connect (OSTI)

    Arasa, C.; Andersson, S.; Cuppen, H. M.; Dishoeck, E. F. van; Kroes, G. J.

    2011-04-28

    Molecular dynamics (MD) calculations have been performed to study the ultraviolet (UV) photodissociation of D{sub 2}O in an amorphous D{sub 2}O ice surface at 10, 20, 60, and 90 K, in order to investigate the influence of isotope effects on the photodesorption processes. As for H{sub 2}O, the main processes after UV photodissociation are trapping and desorption of either fragments or D{sub 2}O molecules. Trapping mainly takes place in the deeper monolayers of the ice, whereas desorption occurs in the uppermost layers. There are three desorption processes: D atom, OD radical, and D{sub 2}O molecule photodesorption. D{sub 2}O desorption takes places either by direct desorption of a recombined D{sub 2}O molecule, or when an energetic D atom produced by photodissociation kicks a surrounding D{sub 2}O molecule out of the surface by transferring part of its momentum. Desorption probabilities are calculated for photoexcitation of D{sub 2}O in the top four monolayers and are compared quantitatively with those for H{sub 2}O obtained from previous MD simulations of UV photodissociation of amorphous water ice at different ice temperatures [Arasa et al., J. Chem. Phys. 132, 184510 (2010)]. The main conclusions are the same, but the average D atom photodesorption probability is smaller than that of the H atom (by about a factor of 0.9) because D has lower kinetic energy than H, whereas the average OD radical photodesorption probability is larger than that of OH (by about a factor of 2.5-2.9 depending on ice temperature) because OD has higher translational energy than OH for every ice temperature studied. The average D{sub 2}O photodesorption probability is larger than that of H{sub 2}O (by about a factor of 1.4-2.3 depending on ice temperature), and this is entirely due to a larger contribution of the D{sub 2}O kick-out mechanism. This is an isotope effect: the kick-out mechanism is more efficient for D{sub 2}O ice, because the D atom formed after D{sub 2}O photodissociation has a larger momentum than photogenerated H atoms from H{sub 2}O, and D transfers momentum more easily to D{sub 2}O than H to H{sub 2}O. The total (OD + D{sub 2}O) yield has been compared with experiments and the total (OH + H{sub 2}O) yield from previous simulations. We find better agreement when we compare experimental yields with calculated yields for D{sub 2}O ice than when we compare with calculated yields for H{sub 2}O ice.

  7. Synergistic Effect of Nitrogen in Cobalt Nitride and Nitrogen-Doped Hollow Carbon Spheres for Oxygen Reduction Reaction

    SciTech Connect (OSTI)

    Zhong, Xing; Liu, Lin; Jiang, Yu; Wang, Xinde; Wang, Lei; Zhuang, Guilin; Li, Xiaonian; Mei, Donghai; Wang, Jian-guo; Su, Dang S.

    2015-06-15

    The need for inexpensive and high-activity oxygen reduction reaction (ORR) electrocatalysts has attracted considerable research interest over the past years. Here we report a novel hybrid that contains cobalt nitride/nitrogen-rich hollow carbon spheres (CoxN/NHCS) as a high-performance catalyst for ORR. The CoxN nanoparticles were uniformly dispersed and confined in the hollow NHCS shell. The performance of the resulting CoxN/NHCS hybrid was comparable with that of a commercial Pt/C at the same catalyst loading toward ORR, but the mass activity of the former was 5.7 times better than that of the latter. The nitrogen in both CoxN and NHCS, especially CoxN, could weaken the adsorption of reaction intermediates (O and OOH), which follows the favourable reaction pathway on CoxN/NHCS according to the DFT-calculated Gibbs free energy diagrams. Our results demonstrated a new strategy for designing and developing inexpensive, non-precious metal electrocatalysts for next-generation fuels. The authors acknowledge the financial support from the National Basic Research Program (973 program, No. 2013CB733501) and the National Natural Science Foundation of China (No. 21306169, 21101137, 21136001, 21176221 and 91334013). Dr. D. Mei is supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational catalysis of the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). EMSL is a national scientific user facility located at Pacific Northwest National Laboratory (PNNL) and sponsored by DOE’s Office of Biological and Environmental Research.

  8. Ice Nucleation of Bare and Sulfuric Acid-coated Mineral Dust Particles and Implication for Cloud Properties

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Sanders, Cassandra N.; Zhang, Kai; Liu, Xiaohong; Zhao, Chun

    2014-08-27

    Ice nucleation properties of different dust species coated with soluble material are not well understood. We determined the ice nucleation ability of bare and sulfuric acid coated mineral dust particles as a function of temperature (-25 to -35 deg C) and relative humidity with respect to water (RHw). Five different mineral dust species: Arizona test dust (ATD), illite, montmorillonite, quartz and kaolinite were dry dispersed and size-selected at 150 nm and exposed to sulfuric acid vapors in the coating apparatus. The condensed sulfuric acid soluble mass fraction per particle was estimated from the cloud condensation nuclei activated fraction measurements. The fraction of dust particles nucleating ice at various temperatures and RHw was determined using a compact ice chamber. In water-subsaturated conditions, compared to bare dust particles, we found that only coated ATD particles showed suppression of ice nucleation ability while other four dust species did not showed the effect of coating on the fraction of particles nucleating ice. The results suggest that interactions between the dust surface and sulfuric acid vapor are important, such that interactions may or may not modify the surface via chemical reactions with sulfuric acid. At water-supersaturated conditions we did not observed the effect of coating, i.e. the bare and coated dust particles had similar ice nucleation behavior.

  9. Aerosol Effects on Cirrus through Ice Nucleation in the Community Atmosphere Model CAM5 with a Statistical Cirrus Scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Liu, Xiaohong; Zhang, Kai; Comstock, Jennifer M.

    2014-09-01

    A statistical cirrus cloud scheme that tracks ice saturation ratio in the clear-sky and cloudy portion of a grid box separately has been implemented into NCAR CAM5 to provide a consistent treatment of ice nucleation and cloud formation. Simulated ice supersaturation and ice crystal number concentrations strongly depend on the number concentrations of heterogeneous ice nuclei (IN), subgrid temperature formulas and the number concentration of sulfate particles participating in homogeneous freezing, while simulated ice water content is insensitive to these perturbations. 1% to 10% dust particles serving as heterogeneous IN is 20 found to produce ice supersaturaiton in better agreement with observations. Introducing a subgrid temperature perturbation based on long-term aircraft observations of meso-scale motion produces a better hemispheric contrast in ice supersaturation compared to observations. Heterogeneous IN from dust particles significantly alter the net radiative fluxes at the top of atmosphere (TOA) (-0.24 to -1.59 W m-2) with a significant clear-sky longwave component (0.01 to -0.55 W m-2). Different cirrus treatments significantly perturb the net TOA anthropogenic aerosol forcing from -1.21 W m-2 to -1.54 W m-2, with a standard deviation of 0.10 W m-2. Aerosol effects on cirrus clouds exert an even larger impact on the atmospheric component of the radiative fluxes (two or three times the changes in the TOA radiative fluxes) and therefore on the hydrology cycle through the fast atmosphere response. This points to the urgent need to quantify aerosol effects on cirrus clouds through ice nucleation and how these further affect the hydrological cycle.

  10. Optimizing the performance of Ice-storage Systems in Electricity Load Management through a credit mechanism. An analytical work for Jiangsu, China

    SciTech Connect (OSTI)

    Han, Yafeng; Shen, Bo; Hu, Huajin; Fan, Fei

    2015-01-12

    Ice-storage air-conditioning is a technique that uses ice for thermal energy storage. Replacing existing air conditioning systems with ice storage has the advantage of shifting the load from on-peak times to off-peak times that often have excess generation. However, increasing the use of ice-storage faces significant challenges in China. One major barrier is the inefficiency in the current electricity tariff structure. There is a lack of effective incentive mechanism that induces ice-storage systems from achieving optimal load-shifting results. This study presents an analysis that compares the potential impacts of ice-storage systems on load-shifting under a new credit-based incentive scheme and the existing incentive arrangement in Jiangsu, China. The study indicates that by changing how ice-storage systems are incentivized in Jiangsu, load-shifting results can be improved.

  11. Optimizing the performance of Ice-storage Systems in Electricity Load Management through a credit mechanism. An analytical work for Jiangsu, China

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

    Han, Yafeng; Shen, Bo; Hu, Huajin; Fan, Fei

    2015-01-12

    Ice-storage air-conditioning is a technique that uses ice for thermal energy storage. Replacing existing air conditioning systems with ice storage has the advantage of shifting the load from on-peak times to off-peak times that often have excess generation. However, increasing the use of ice-storage faces significant challenges in China. One major barrier is the inefficiency in the current electricity tariff structure. There is a lack of effective incentive mechanism that induces ice-storage systems from achieving optimal load-shifting results. This study presents an analysis that compares the potential impacts of ice-storage systems on load-shifting under a new credit-based incentive scheme andmore » the existing incentive arrangement in Jiangsu, China. The study indicates that by changing how ice-storage systems are incentivized in Jiangsu, load-shifting results can be improved.« less

  12. Critical Mechanisms for the Formation of Extreme Arctic Sea-Ice Extent in the Summers of 2007 and 1996

    SciTech Connect (OSTI)

    Dong, Xiquan; Zib, Benjamin J.; Xi, Baike; Stanfield, Ryan; Deng, Yi; Zhang, Xiangdong; Lin, B.; Long, Charles N.

    2014-07-29

    A warming Arctic climate is undergoing significant e 21 nvironmental change, most evidenced by the reduction of Arctic sea-ice extent during the summer. In this study, we examine two extreme anomalies of September sea-ice extent in 2007 and 1996, and investigate the impacts of cloud fraction (CF), atmospheric precipitable water vapor (PWV), downwelling longwave flux (DLF), surface air temperature (SAT), pressure and winds on the sea-ice variation in 2007 and 1996 using both satellite-derived sea-ice products and MERRA reanalysis. The area of the Laptev, East Siberian and West Chukchi seas (70-90oN, 90-180oE) has experienced the largest variation in sea-ice extent from year-to-year and defined here as the Area Of Focus (AOF). The record low September sea-ice extent in 2007 was associated with positive anomalies 30 of CF, PWV, DLF, and SAT over the AOF. Persistent anti-cyclone positioned over the Beaufort Sea coupled with low pressure over Eurasia induced easterly zonal and southerly meridional winds. In contrast, negative CF, PWV, DLF and SAT anomalies, as well as opposite wind patterns to those in 2007, characterized the 1996 high September sea-ice extent. Through this study, we hypothesize the following positive feedbacks of clouds, water vapor, radiation and atmospheric variables on the sea-ice retreat during the summer 2007. The record low sea-ice extent during the summer 2007 is initially triggered by the atmospheric circulation anomaly. The southerly winds across the Chukchi and East Siberian seas transport warm, moist air from the north Pacific, which is not only enhancing sea-ice melt across the AOF, but also increasing clouds. The positive cloud feedback results in higher SAT and more sea-ice melt. Therefore, 40 more water vapor could be evaporated from open seas and higher SAT to form more clouds, which will enhance positive cloud feedback. This enhanced positive cloud feedback will then further increase SAT and accelerate the sea-ice retreat during the summer 2007.

  13. Association of indoor nitrogen dioxide with respiratory symptoms and pulmonary function in children

    SciTech Connect (OSTI)

    Neas, L.M.; Dockery, D.W.; Ware, J.H.; Spengler, J.D.; Speizer, F.E.; Ferris, B.G. Jr. )

    1991-07-15

    The effect of indoor nitrogen dioxide on the cumulative incidence of respiratory symptoms and pulmonary function level was studied in a cohort of 1,567 white children aged 7-11 years examined in six US cities from 1983 through 1988. Week-long measurements of nitrogen dioxide were obtained at three indoor locations over 2 consecutive weeks in both the winter and the summer months. The household annual average nitrogen dioxide concentration was modeled as a continuous variable and as four ordered categories. Multiple logistic regression analysis of symptom reports from a questionnaire administered after indoor monitoring showed that a 15-ppb increase in the household annual nitrogen dioxide mean was associated with an increased cumulative incidence of lower respiratory symptoms (odds ratio (OR) = 1.4, 95% confidence interval (95% Cl) 1.1-1.7). The response variable indicated the report of one or more of the following symptoms: attacks of shortness of breath with wheeze, chronic wheeze, chronic cough, chronic phlegm, or bronchitis. Girls showed a stronger association (OR = 1.7, 95% Cl 1.3-2.2) than did boys (OR = 1.2, 95% Cl 0.9-1.5). An analysis of pulmonary function measurements showed no consistent effect of nitrogen dioxide. These results are consistent with earlier reports based on categorical indicators of household nitrogen dioxide sources and provide a more specific association with nitrogen dioxide as measured in children's homes.

  14. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes. Part II. Sensitivity to heterogeneous ice nucleation parameterizations and dust emissions

    SciTech Connect (OSTI)

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai -Yung

    2015-09-14

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of ice supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O₃, SO₄²⁻, and PM2.5, but increase surface concentrations of CO, NO₂, and SO₂ over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and precipitation depending on whether the dominant role of dust is CCN or IN. These results indicate the importance of the heterogeneous ice nucleation treatments and dust emissions in accurately simulating regional climate and air quality.

  15. Investigation of formation of nitrogen compounds in coal combustion. Final report

    SciTech Connect (OSTI)

    Blair, D.W.; Crane, I.D.; Wendt, J.O.L.

    1983-10-01

    This is the final report on DOE contract number DE-AC21-80MC14061. It concerns the formation of nitrogen oxide from fuel-bound nitrogen during coal combustion. The work reported was divided into three tasks. They addressed problems of time-resolving pyrolysis rates of coal under simulated combustion conditions, the combustion of the tar that results from such pyrolysis, and theoretical modeling of the pyrolysis process. In all of these tasks, special attention was devoted to the fate of coal nitrogen. The first two tasks were performed by Exxon Research and Engineering Company. 49 references.

  16. The nature of fluctuations in a double arc argon-nitrogen plasma jet

    SciTech Connect (OSTI)

    Tu Xin; Yan Jianhua; Yu Liang; Cen, Kefa; Cheron, Bruno

    2007-09-24

    The dynamic behavior of the double arc argon-nitrogen plasma jet is investigated by combined means of the fast Fourier transform, correlation function, and Wigner distribution. The restrike mode is identified as the fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which indicates that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the power supply undulation and both arc roots motion on the anode channels. It is further found that the double anode torch could inhibit and reduce the restrike phenomenon.

  17. Indriect Measurement Of Nitrogen In A Mult-Component Natural Gas By Heating The Gas

    DOE Patents [OSTI]

    Morrow, Thomas B.; Behring, II, Kendricks A.

    2004-06-22

    Methods of indirectly measuring the nitrogen concentration in a natural gas by heating the gas. In two embodiments, the heating energy is correlated to the speed of sound in the gas, the diluent concentrations in the gas, and constant values, resulting in a model equation. Regression analysis is used to calculate the constant values, which can then be substituted into the model equation. If the diluent concentrations other than nitrogen (typically carbon dioxide) are known, the model equation can be solved for the nitrogen concentration.

  18. Reduction of Nitrogen Oxide Emissions for lean Burn Engine Technology

    SciTech Connect (OSTI)

    McGill, R.N.

    1998-08-04

    Lean-burn engines offer the potential for significant fuel economy improvements in cars and trucks, perhaps the next great breakthrough in automotive technology that will enable greater savings in imported petroleum. The development of lean-burn engines, however, has been an elusive goal among automakers because of the emissions challenges associated with lead-burn engine technology. Presently, cars operate with sophisticated emissions control systems that require the engine's air-fuel ratio to be carefully controlled around the stoichiometric point (chemically correct mixture). Catalysts in these systems are called "three-way" catalysts because they can reduce hydrocarbon, carbon monoxide, and nitrogen oxide emissions simultaneously, but only because of the tight control of the air-fuel ratio. The purpose of this cooperative effort is to develop advanced catalyst systems, materials, and necessary engine control algorithms for reducing NOX emissions in oxygen-rich automotive exhaust (as with lean-burn engine technology) to meet current and near-future mandated Clean Air Act standards. These developments will represent a breakthrough in both emission control technology and automobile efficiency. The total project is a joint effort among five national laboratories, together with US CAR. The role of Lockheed-Martin Energy Systems in the total project is two fold: characterization of catalyst performance through laboratory evaluations from bench-scale flow reactor tests to engine laboratory tests of full-scale prototype catalysts, and microstructural characterization of catalyst material before and after test stand and/or engine testing.

  19. Nitrogen Deposition to and Cycling in a Deciduous Forest

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

    Pryor, Sara C.; Barthelmie, Rebecca J.; Carreiro, Margaret; Davis, Melissa L.; Hartley, Anne; Jensen, Bjame; Oliphant, Andrew; Randolph, Melissa J. C.; Schoof, Justin T.

    2001-01-01

    The project described here seeks to answer questions regarding the role increased nitrogen (N) deposition is playing in enhanced carbon (C) sequestration in temperate mid-latitude forests, using detailed measurements from an AmeriFlux tower in southern Indiana (Morgan-Monroe State Forest, or MMSF). The measurements indicate an average atmosphere-surface N flux of approximately 6 mg-N m -2 day -1 during the 2000 growing season, with approximately 40% coming from dry deposition of ammonia (NH 3 ), nitric acid (HNO 3 ), and particle-bound N. Wet deposition and throughfall measurements indicate significant canopy uptake of N (particularly NH 4 +) at themore » site, leading to a net canopy exchange (NCE) of –6 kg-N ha -1 for the growing season. These data are used in combination with data on the aboveground C:N ratio, litterfall flux, and soil net N mineralization rates to indicate the level of potential perturbation of C sequestration at this site.« less

  20. Indoor nitrogen dioxide in five Chattangooga, Tennessee public housing developments

    SciTech Connect (OSTI)

    Parkhurst, W.J.; Harper, J.P. ); Spengler, J.D.; Fraumeni, L.P.; Majahad, A.M. ); Cropp, J.W. )

    1988-01-01

    This report summarizes an indoor nitrogen dioxide (NO{sub 2}) sampling study conducted during January through March of 1987 in five Chattanooga public housing developments. The origins of this study date to the summer of 1983 when the Piney Woods Community Organization (a citizens action group) expressed concern about toxic industrial air pollution and the effects it might have on their community. In response to these concerns, the Chattanooga-Hamilton County Air Pollution Control Bureau (Bureau) requested assistance from the Tennessee Department of Health and Environment (TDHE) in conducting a community health survey and assistance from the Tennessee Valley Authority (TVA) in conducting a community air quality measurement program. The TDHE community health study did not find any significant differences between the mortality statistics for the Piney Woods community and a demographically similar control group. However, a health survey revealed that Piney Woods residents did not have a statistically significant higher self-reported prevalence of cough, wheezing, phlegm, breathlessness, colds, and respiratory illness.