National Library of Energy BETA

Sample records for air-cooled ice makers

  1. Covered Product Category: Air-Cooled Ice Machines

    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.

  2. Purchasing Energy-Efficient Air-Cooled Ice Machines

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  3. 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. Automatic Commercial Ice Makers -- v2.0 (111.62 KB) More

  4. Self-releasing submerged ice maker

    SciTech Connect (OSTI)

    Stewart, W.E. Jr.; Greer, M.E.; Stickler, L.A.

    1989-03-01

    This study reports the results of a series of experiments which investigated a thermal storage technology whereby slush ice is grown on a submerged cold surface and the resultant growth of slush ice released without auxiliary thermal or mechanical means. The process investigated consists of growing slush ice from an electrolyte solution of low molarity. The cold surface (substrate) upon which the slush ice forms is submerged in the bulk solution. As the buoyancy force on the ice crystals exceeds the adhesion to the cold surface, the slush ice is forced from the substrate and floats away, to the top of the solution. The results of this study reveal the relative insensitivity of the growth rate of ice crystals to solution initial bulk concentration over the range of values tested and to concentration of electrolyte during accumulation of ice crystals. The critical parameter appears to be substrate temperature, which generally cannot be less than approximately 2{degrees}C below the freezing point temperature of the solution, as apparent adhesion increases rapidly with decreasing substrate temperature.

  5. Microsoft Word - 11_4_09 ice maker.doc

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    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.

  6. ISSUANCE 2014-12-31: Energy Conservation Program: Energy Conservation Standards for Automatic Commercial Ice Makers, Final Rule

    Energy.gov [DOE]

    Energy Conservation Program: Energy Conservation Standards for Automatic Commercial Ice Makers, Final Rule

  7. Webinar: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Public Meeting

    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...

  8. AIR COOLED NEUTRONIC REACTOR

    DOE Patents [OSTI]

    Fermi, E.; Szilard, L.

    1958-05-27

    A nuclear reactor of the air-cooled, graphite moderated type is described. The active core consists of a cubicle mass of graphite, approximately 25 feet in each dimension, having horizontal channels of square cross section extending between two of the opposite faces, a plurality of cylindrical uranium slugs disposed in end to end abutting relationship within said channels providing a space in the channels through which air may be circulated, and a cadmium control rod extending within a channel provided in the moderator. Suitable shielding is provlded around the core, as are also provided a fuel element loading and discharge means, and a means to circulate air through the coolant channels through the fuel charels to cool the reactor.

  9. Air Cooling | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Air cooling is limited on ambient temperatures and typically require a larger footprint than Water Cooling, but when water restrictions are great enough to prevent the...

  10. 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.

  11. Hybrid and Advanced Air Cooling

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    and Advanced Air Cooling Desikan Bharathan National Renewable Energy Laboratory 15013 Denver West Parkway Golden, CO 80401 ARRA funded Project Officer: Tim Reinhardt Total Project Funding: $1079K April 22-25, 2013 This presentation does not contain any proprietary confidential, or otherwise restricted information. Do not include any proprietary or confidential information. Your presentation is public and will be posted to the DOE Geothermal Technologies Office website. You must include the

  12. Covered Product Category: Air-Cooled Electric Chillers | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Covered Product Category: Air-Cooled Electric Chillers Covered Product Category: Air-Cooled ... chillers (i.e., none with remote condensers) are covered. b Performance ...

  13. Hybrid and Advanced Air Cooling | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Hybrid and Advanced Air Cooling Hybrid and Advanced Air Cooling Hybrid and Advanced Air Cooling presentation at the April 2013 peer review meeting held in Denver, Colorado. hybrid_advanced_air_cooling_peer2013.pdf (575.73 KB) More Documents & Publications Hybrid and Advanced Air Cooling 300ºC DDS + 300ºC MWD Chena Hot Springs Resort - Electric Power Generation Using Geothermal Fluid Coproduced from Oil and/or Gas Wells

  14. Hybrid and Advanced Air Cooling | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    and Advanced Air Cooling Hybrid and Advanced Air Cooling DOE Geothermal Program Peer Review 2010 - Presentation. This project will identify and analyze advanced air cooling strategies thatallow air-cooled geothermal power plants to maintain a high electric power output during periods of high air dry bulb temperatures while minimizing water consumption. specialized_bharathan_advanced_cooling.pdf (507.83 KB) More Documents & Publications Hybird Geothemal-Solar Air-Cooled Condensers for Next

  15. 2014-06-09 Issuance: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Public Meeting

    Energy.gov [DOE]

    This document is a pre-publication Federal Register Notice of Public Meeting regarding Energy Conservation Standards for Automatic Commercial Ice Maker, as issued by the Deputy Assistant Secretary for Energy Efficiency on June 9, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

  16. Air-to-air turbocharged air cooling versus air-to-water turbocharged air cooling

    SciTech Connect (OSTI)

    Moranne, J.-P.; Lukas, J.J.

    1984-01-01

    In Europe, turbocharged air in diesel engines used in on-road vehicles is cooled only by air. It is expected that by 1990, ten to twelve percent of European heavy trucks with diesel engines will cool turbocharged air by water. Air-to-air turbocharges air cooling is reviewed and the evolution of air-to-water turbocharged air cooling presented before the two systems are compared.

  17. Liquid metal reactor air cooling baffle

    DOE Patents [OSTI]

    Hunsbedt, Anstein

    1994-01-01

    A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat.

  18. Liquid metal reactor air cooling baffle

    DOE Patents [OSTI]

    Hunsbedt, A.

    1994-08-16

    A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat. 3 figs.

  19. Air Cooling Technology for Advanced Power Electronics and Electric...

    Energy.gov (indexed) [DOE]

    More Documents & Publications Air Cooling Technology for Power Electronic Thermal Control Vehicle Technologies Office: 2008 Advanced Power Electronics and Electric Machinery R&D ...

  20. Hybrid Air-Cooled Condenser - Energy Innovation Portal

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Hybrid Air-Cooled Condenser National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary Geothermal energy has been a viable energy source...

  1. High-Temperature, Air-Cooled Traction Drive Inverter Packaging...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    More Documents & Publications Air-Cooled Traction Drive Inverter Benchmarking of Competitive Technologies High Temperature, High Voltage Fully Integrated Gate Driver Circuit

  2. Air-cooled Condensers in Next-generation Conversion Systems

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE Geothermal Program Peer Review 2010 - Presentation. Project objective: to reduce the costs associated with the generation of electrical power from air-cooled binary plants.

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

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... Annual Energy Use: Based on the federal standard for this product category. Annual Energy Cost: Calculated based on an assumed electricity price of 0.09kWh, which is the average ...

  4. Energy Cost Savings Calculator for Air-Cooled Electric Chillers |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Air-Cooled Electric Chillers Energy Cost Savings Calculator for Air-Cooled Electric Chillers This cost calculator is a screening tool that estimates a product's lifetime energy cost savings at various efficiency levels. Learn more about the calculator assumptions and definitions. Project Type Is this a new installation or a replacement? New Replacement How many chillers will you purchase? Performance Factors Existing What is the existing design condition? Full Load

  5. 2014-09-05 Issuance: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Data Availability and Request for Comment

    Energy.gov [DOE]

    This document is a pre-publication Federal Register notice of data availability and request for comment regarding energy conservation standards for automatic commercial ice makers, as issued by the Deputy Assistant Secretary for Energy Efficiency on September 5, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

  6. 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

  7. Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP Applications, April 2005 Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP...

  8. Closed-loop air cooling system for a turbine engine

    DOE Patents [OSTI]

    North, William Edward

    2000-01-01

    Method and apparatus are disclosed for providing a closed-loop air cooling system for a turbine engine. The method and apparatus provide for bleeding pressurized air from a gas turbine engine compressor for use in cooling the turbine components. The compressed air is cascaded through the various stages of the turbine. At each stage a portion of the compressed air is returned to the compressor where useful work is recovered.

  9. Air-Cooled Condensers for Next Generation Power Plants | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy Air-Cooled Condensers for Next Generation Power Plants Air-Cooled Condensers for Next Generation Power Plants Power plants presentation by Greg Mines at the 2013 Annual Peer Review in Colorado. aircooledcondensers_peerreview2013.pdf (1.56 MB) More Documents & Publications Hybrid and Advanced Air Cooling Advanced Heat/Mass Exchanger Technology for Geothermal and solar Renewable Energy Systems Air-cooled Condensers in Next-generation Conversion Systems

  10. High-Temperature Air-Cooled Power Electronics Thermal Design (Presentation)

    SciTech Connect (OSTI)

    Waye, S.

    2014-06-01

    This presentation discusses the status of research at NREL on high temperature air-cooled power electronics thermal design.

  11. Air Cooling for High Temperature Power Electronics (Presentation)

    SciTech Connect (OSTI)

    Waye, S.; Musselman, M.; King, C.

    2014-09-01

    Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

  12. Closed loop air cooling system for combustion turbines

    DOE Patents [OSTI]

    Huber, D.J.; Briesch, M.S.

    1998-07-21

    Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts. 1 fig.

  13. Closed loop air cooling system for combustion turbines

    DOE Patents [OSTI]

    Huber, David John; Briesch, Michael Scot

    1998-01-01

    Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts.

  14. Liquid Cooling v. Air Cooling Evaluation in the Maui High-Performance

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Computing Center | Department of Energy Liquid Cooling v. Air Cooling Evaluation in the Maui High-Performance Computing Center Liquid Cooling v. Air Cooling Evaluation in the Maui High-Performance Computing Center Study evaluates the energy efficiency of a new, liquid-cooled computing system applied in a retrofit project compared to the previously used air-cooled system. Download the study. (1.25 MB) More Documents & Publications Energy Efficiency Opportunities in Federal High

  15. Optimization of hybrid-water/air-cooled condenser in an enhanced turbine

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    geothermal ORC system | Department of Energy Optimization of hybrid-water/air-cooled condenser in an enhanced turbine geothermal ORC system Optimization of hybrid-water/air-cooled condenser in an enhanced turbine geothermal ORC system DOE Geothermal Program Peer Review 2010 - Presentation. Project objective: To improve the efficiency and output variability of geothermal-based ORC power production systems with minimal water consumption by deploying: 1) a hybrid-water/air cooled condenser with

  16. A fundamentally new approach to air-cooled heat exchangers.

    SciTech Connect (OSTI)

    Koplow, Jeffrey P.

    2010-01-01

    We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air-cooled heat exchangers. A longstanding but largely unrealized opportunity in energy efficiency concerns the performance of air-cooled heat exchangers used in air conditioners, heat pumps, and refrigeration equipment. In the case of residential air conditioners, for example, the typical performance of the air cooled heat exchangers used for condensers and evaporators is at best marginal from the standpoint the of achieving maximum the possible coefficient of performance (COP). If by some means it were possible to reduce the thermal resistance of these heat exchangers to a negligible level, a typical energy savings of order 30% could be immediately realized. It has long been known that a several-fold increase in heat exchanger size, in conjunction with the use of much higher volumetric flow rates, provides a straight-forward path to this goal but is not practical from the standpoint of real world applications. The tension in the market place between the need for energy efficiency and logistical considerations such as equipment size, cost and operating noise has resulted in a compromise that is far from ideal. This is the reason that a typical residential air conditioner exhibits significant sensitivity to reductions in fan speed and/or fouling of the heat exchanger surface. The prevailing wisdom is that little can be done to improve this situation; the 'fan-plus-finned-heat-sink' heat exchanger architecture used throughout the energy sector represents an extremely mature technology for which there is little opportunity for further optimization. But the fact remains that conventional fan-plus-finned-heat-sink technology simply doesn't work that well. Their primary physical limitation to performance (i.e. low thermal resistance) is the boundary layer of motionless air that adheres to and envelops all surfaces of the heat exchanger. Within this boundary layer

  17. Air Cooling Technology for Advanced Power Electronics and Electric Machines (Presentation)

    SciTech Connect (OSTI)

    Bharathan, D.

    2009-05-01

    This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Air Cooling for Power Electronics'.

  18. Investigation of vessel exterior air cooling for an HLMC reactor

    SciTech Connect (OSTI)

    Sienicki, J.J.; Spencer, B.W.

    2000-07-01

    The secure transportable autonomous reactor (STAR) concept under development at Argonne National Laboratory provides a small [300-MW(thermal)] reactor module for steam supply that incorporates design features to attain proliferation resistance, heightened passive safety, and improved cost competitiveness through extreme simplification. Examples are the achievement of 100% + natural-circulation heat removal from the low-power-density/low-pressure-drop ultralong lifetime core and utilization of lead-bismuth eutectic (LBE) coolant enabling elimination of main coolant pumps as well as the need for an intermediate heat transport circuit. It is required to provide a passive means of removing decay heat and effecting reactor cooldown in the event that the normal steam generator heat sink, including its normal shutdown heat removal mode, is postulated to be unavailable. In the present approach, denoted as the reactor exterior cooling system (RECS), passive decay heat removal is provided by cooling the outside of the containment/guard vessel with air. RECS is similar to the reactor vessel auxiliary cooling system (RVACS) incorporated into the PRISM design. However, to enhance the heat removal, RECS incorporates fins on the containment vessel exterior to enhance heat transfer to air as well as removable steel venetian conductors that provide a conduction heat transfer path across the reactor vessel-containment vessel gap to enhance heat transfer between the vessels. The objective of the present work is to investigate the effectiveness of air cooling in removing heat from the vessel and limiting the coolant temperature increase following a sudden complete loss of the steam generator heat sink.

  19. Investigation of vessel exterior air cooling for a HLMC reactor

    SciTech Connect (OSTI)

    Sienicki, J. J.; Spencer, B. W.

    2000-01-13

    The Secure Transportable Autonomous Reactor (STAR) concept under development at Argonne National Laboratory provides a small (300 MWt) reactor module for steam supply that incorporates design features to attain proliferation resistance, heightened passive safety, and improved cost competitiveness through extreme simplification. Examples are the achievement of 100%+ natural circulation heat removal from the low power density/low pressure drop ultra-long lifetime core and utilization of lead-bismuth eutectic (LBE) coolant enabling elimination of main coolant pumps as well as the need for an intermediate heat transport circuit. It is required to provide a passive means of removing decay heat and effecting reactor cooldown in the event that the normal steam generator heat sink, including its normal shutdown heat removal mode, is postulated to be unavailable. In the present approach, denoted as the Reactor Exterior Cooling System (RECS), passive decay heat removal is provided by cooling the outside of the containment/guard vessel with air. RECS is similar to the Reactor Vessel Auxiliary Cooling System (RVACS) incorporated into the PRISM design. However, to enhance the heat removal, RECS incorporates fins on the containment vessel exterior to enhance heat transfer to air as well as removable steel venetian conductors that provide a conduction heat transfer path across the reactor vessel-containment vessel gap to enhance heat transfer between the vessels. The objective of the present work is to investigate the effectiveness of air cooling in removing heat from the vessel and limiting the coolant temperature increase following a sudden complete loss of the steam generator heat sink.

  20. Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Applications, April 2005 | Department of Energy Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP Applications, April 2005 Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP Applications, April 2005 The objective of this paper is to summarize the development status of air-cooled lithium bromide (LiBr)-water absorption chillers to guide future efforts to develop chillers for combined heat and power (CHP) applications in light-commercial buildings. The key

  1. Effect of Ambient Design Temperature on Air-Cooled Binary Plant Output

    SciTech Connect (OSTI)

    Dan Wendt; Greg Mines

    2011-10-01

    Air-cooled binary plants are designed to provide a specified level of power production at a particular air temperature. Nominally this air temperature is the annual mean or average air temperature for the plant location. This study investigates the effect that changing the design air temperature has on power generation for an air-cooled binary plant producing power from a resource with a declining production fluid temperature and fluctuating ambient temperatures. This analysis was performed for plants operating both with and without a geothermal fluid outlet temperature limit. Aspen Plus process simulation software was used to develop optimal air-cooled binary plant designs for specific ambient temperatures as well as to rate the performance of the plant designs at off-design operating conditions. Results include calculation of annual and plant lifetime power generation as well as evaluation of plant operating characteristics, such as improved power generation capabilities during summer months when electric power prices are at peak levels.

  2. Dynamic performance testing of prototype 3 ton air-cooled carrier absorption chiller

    SciTech Connect (OSTI)

    Borst, R.R.; Wood, B.D.

    1985-05-01

    The performance of a prototype 3 ton cooling capacity air-cooled lithium bromide/water absorption chiller was tested using an absorption chiller test facility which was modified to expand its testing capabilities to include air-cooled chillers in addition to water-cooled chillers. Temperatures of the three externally supplied fluid loops: hot water, chilled water, and cooling air, were varied in order to determine the effects this would have on the two principal measures of chiller performance: cooling capacity and thermal coefficient of performance (COP). A number of interrelated factors were identified as contributing to less than expected performance. For comparison, experimental correlations of other investigators for this and other similar absorption chillers are presented. These have been plotted as both contour and three-dimensional performance maps in order to more clearly show the functional dependence of the chiller performance on the fluid loop temperatures.

  3. Evaluation of Hybrid Air-Cooled Flash/Binary Power Cycle

    SciTech Connect (OSTI)

    Greg Mines

    2005-10-01

    Geothermal binary power plants reject a significant portion of the heat removed from the geothermal fluid. Because of the relatively low temperature of the heat source (geothermal fluid), the performance of these plants is quite sensitive to the sink temperature to which heat is rejected. This is particularly true of air-cooled binary plants. Recent efforts by the geothermal industry have examined the potential to evaporatively cool the air entering the air-cooled condensers during the hotter portions of a summer day. While the work has shown the benefit of this concept, air-cooled binary plants are typically located in regions that lack an adequate supply of clean water for use in this evaporative cooling. In the work presented, this water issue is addressed by pre-flashing the geothermal fluid to produce a clean condensate that can be utilized during the hotter portions of the year to evaporatively cool the air. This study examines both the impact of this pre-flash on the performance of the binary plant, and the increase in power output due to the ability to incorporate an evaporative component to the heat rejection process.

  4. Assessment of Evaporative Cooling Enhancement Methods for Air-Cooled Geothermal Power Plants: Preprint

    SciTech Connect (OSTI)

    Kutscher, C.; Costenaro, D.

    2002-08-01

    Many binary-cycle geothermal power plants are air cooled because insufficient water is available to provide year-round water cooling. The performance of air-cooled geothermal plants is highly dependent on the dry bulb temperature of the air (much more so than fossil fuel plants that operate at higher boiler temperatures), and plant electric output can drop by 50% or more on hot summer days, compared to winter performance. This problem of reduced summer performance is exacerbated by the fact that electricity has a higher value in the summer. This paper describes a spreadsheet model that was developed to assess the cost and performance of four methods for using supplemental evaporative cooling to boost summer performance: (1) pre-cooling with spray nozzles, (2) pre-cooling with Munters media, (3) a hybrid combination of nozzles and Munters media, and (4) direct deluge cooling of the air-cooled condenser tubes. Although all four options show significant benefit, deluge cooling has the potential to be the most economic. However, issues of scaling and corrosion would need to be addressed.

  5. Passive air cooling of liquid metal-cooled reactor with double vessel leak accommodation capability

    DOE Patents [OSTI]

    Hunsbedt, A.; Boardman, C.E.

    1995-04-11

    A passive and inherent shutdown heat removal method with a backup air flow path which allows decay heat removal following a postulated double vessel leak event in a liquid metal-cooled nuclear reactor is disclosed. The improved reactor design incorporates the following features: (1) isolation capability of the reactor cavity environment in the event that simultaneous leaks develop in both the reactor and containment vessels; (2) a reactor silo liner tank which insulates the concrete silo from the leaked sodium, thereby preserving the silo`s structural integrity; and (3) a second, independent air cooling flow path via tubes submerged in the leaked sodium which will maintain shutdown heat removal after the normal flow path has been isolated. 5 figures.

  6. Passive air cooling of liquid metal-cooled reactor with double vessel leak accommodation capability

    DOE Patents [OSTI]

    Hunsbedt, Anstein; Boardman, Charles E.

    1995-01-01

    A passive and inherent shutdown heat removal method with a backup air flow path which allows decay heat removal following a postulated double vessel leak event in a liquid metal-cooled nuclear reactor. The improved reactor design incorporates the following features: (1) isolation capability of the reactor cavity environment in the event that simultaneous leaks develop in both the reactor and containment vessels; (2) a reactor silo liner tank which insulates the concrete silo from the leaked sodium, thereby preserving the silo's structural integrity; and (3) a second, independent air cooling flow path via tubes submerged in the leaked sodium which will maintain shutdown heat removal after the normal flow path has been isolated.

  7. Ambient air cooling arrangement having a pre-swirler for gas turbine engine blade cooling

    DOE Patents [OSTI]

    Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J

    2015-01-06

    A gas turbine engine including: an ambient-air cooling circuit (10) having a cooling channel (26) disposed in a turbine blade (22) and in fluid communication with a source (12) of ambient air: and an pre-swirler (18), the pre-swirler having: an inner shroud (38); an outer shroud (56); and a plurality of guide vanes (42), each spanning from the inner shroud to the outer shroud. Circumferentially adjacent guide vanes (46, 48) define respective nozzles (44) there between. Forces created by a rotation of the turbine blade motivate ambient air through the cooling circuit. The pre-swirler is configured to impart swirl to ambient air drawn through the nozzles and to direct the swirled ambient air toward a base of the turbine blade. The end walls (50, 54) of the pre-swirler may be contoured.

  8. Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

    SciTech Connect (OSTI)

    Waye, S. K.; Lustbader, J.; Musselman, M.; King, C.

    2015-05-06

    This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

  9. ISSUANCE 2015-12-11: Final Rule Regarding Test Procedures for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment

    Energy.gov [DOE]

    Final Rule Regarding Test Procedures for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment

  10. Interim Report: Air-Cooled Condensers for Next Generation Geothermal Power Plants Improved Binary Cycle Performance

    SciTech Connect (OSTI)

    Daniel S. Wendt; Greg L. Mines

    2010-09-01

    As geothermal resources that are more expensive to develop are utilized for power generation, there will be increased incentive to use more efficient power plants. This is expected to be the case with Enhanced Geothermal System (EGS) resources. These resources will likely require wells drilled to depths greater than encountered with hydrothermal resources, and will have the added costs for stimulation to create the subsurface reservoir. It is postulated that plants generating power from these resources will likely utilize the binary cycle technology where heat is rejected sensibly to the ambient. The consumptive use of a portion of the produced geothermal fluid for evaporative heat rejection in the conventional flash-steam conversion cycle is likely to preclude its use with EGS resources. This will be especially true in those areas where there is a high demand for finite supplies of water. Though they have no consumptive use of water, using air-cooling systems for heat rejection has disadvantages. These systems have higher capital costs, reduced power output (heat is rejected at the higher dry-bulb temperature), increased parasitics (fan power), and greater variability in power generation on both a diurnal and annual basis (larger variation in the dry-bulb temperature). This is an interim report for the task ‘Air-Cooled Condensers in Next- Generation Conversion Systems’. The work performed was specifically aimed at a plant that uses commercially available binary cycle technologies with an EGS resource. Concepts were evaluated that have the potential to increase performance, lower cost, or mitigate the adverse effects of off-design operation. The impact on both cost and performance were determined for the concepts considered, and the scenarios identified where a particular concept is best suited. Most, but not all, of the concepts evaluated are associated with the rejection of heat. This report specifically addresses three of the concepts evaluated: the use of

  11. Cooling circuit for steam and air-cooled turbine nozzle stage

    DOE Patents [OSTI]

    Itzel, Gary Michael (Clifton Park, NY); Yu, Yufeng (Guilderland, NY)

    2002-01-01

    The turbine vane segment includes inner and outer walls with a vane extending therebetween. The vane includes leading and trailing edge cavities and intermediate cavities. An impingement plate is spaced from the outer wall to impingement-cool the outer wall. Post-impingement cooling air flows through holes in the outer wall to form a thin air-cooling film along the outer wall. Cooling air is supplied an insert sleeve with openings in the leading edge cavity for impingement-cooling the leading edge. Holes through the leading edge afford thin-film cooling about the leading edge. Cooling air is provided the trailing edge cavity and passes through holes in the side walls of the vane for thin-film cooling of the trailing edge. Steam flows through a pair of intermediate cavities for impingement-cooling of the side walls. Post-impingement steam flows to the inner wall for impingement-cooling of the inner wall and returns the post-impingement cooling steam through inserts in other intermediate cavities for impingement-cooling the side walls of the vane.

  12. Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That in Conventional Data Centers

    SciTech Connect (OSTI)

    Coles, Henry C.; Han, Taewon; Price, Phillip N.; Gadgil, Ashok J.; Tschudi, William F.

    2011-07-17

    There is a concern that environmental-contamination caused corrosion may negatively affect Information Technology (IT) equipment reliability. Nineteen data centers in the United States and two in India were evaluated using Corrosion Classification Coupons (CCC) to assess environmental air quality as it may relate IT equipment reliability. The data centers were of two basic types: closed and outside-air cooled. A closed data center provides cool air to the IT equipment using air conditioning in which only a small percent age of the recirculation air is make-up air continuously supplied from outside to meet human health requirements. An outside-air cooled data center uses outside air directly as the primary source for IT equipment cooling. Corrosion measuring coupons containing copper and silver metal strips were placed in both closed and outside-air cooled data centers. The coupons were placed at each data center (closed and outside-air cooled types) with the location categorized into three groups: (1) Outside - coupons sheltered, located near or at the supply air inlet, but located before any filtering, (2) Supply - starting just after initial air filtering continuing inside the plenums and ducts feeding the data center rooms, and (3) Inside located inside the data center rooms near the IT equipment. Each coupon was exposed for thirty days and then sent to a laboratory for a corrosion rate measurement analysis. The goal of this research was to investigate whether gaseous contamination is a concern for U.S. data center operators as it relates to the reliability of IT equipment. More specifically, should there be an increased concern if outside air for IT equipment cooling is used To begin to answer this question limited exploratory measurements of corrosion rates in operating data centers in various locations were undertaken. This study sought to answer the following questions: (1) What is the precision of the measurements (2) What are the approximate statistical

  13. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    SciTech Connect (OSTI)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  14. Experimental evaluation of dry/wet air-cooled heat exchangers. Progress report

    SciTech Connect (OSTI)

    Hauser, S.G.; Gruel, R.L.; Huenefeld, J.C.; Eschbach, E.J.; Johnson, B.M.; Kreid, D.K.

    1982-08-01

    The ultimate goal of this project was to contribute to the development of improved cooling facilities for power plants. Specifically, the objective during FY-81 was to experimentally determine the thermal performance and operating characteristics of an air-cooled heat exchanger surface manufactured by the Unifin Company. The performance of the spiral-wound finned tube surface (Unifin) was compared with two inherently different platefin surfaces (one developed by the Trane Co. and the other developed by the HOETERV Institute) which were previously tested as a part of the same continuing program. Under dry operation the heat transfer per unit frontal area per unit inlet temperature difference (ITD) of the Unifin surface was 10% to 20% below that of the other two surfaces at low fan power levels. At high fan power levels, the performances of the Unifin and Trane surfaces were essentially the same, and 25% higher than the HOETERV surface. The design of the Unifin surface caused a significantly larger air-side pressure drop through the heat exchanger both in dry and deluge operation. Generally higher overall heat transfer coefficients were calculated for the Unifin surface under deluged operation. They ranged from 2.0 to 3.5 Btu/hr-ft/sup 2/-/sup 0/F as compared to less than 2.0 Btu hr-ft/sup 2/-/sup 0/F for the Trane and HOETERV surfaces under similar conditions. The heat transfer enhancement due to the evaporative cooling effect was also measureably higher with the Unifin surface as compared to the Trane surface. This can be primarily attributed to the better wetting characteristics of the Unifin surface. If the thermal performance of the surfaces are compared at equal face velocities, the Unifin surface is as much as 35% better. This method of comparison accounts for the wetting characteristics while neglecting the effect of pressure drop. Alternatively the surfaces when compared at equal pressure drop essentially the same thermal performance.

  15. Energy @ Bay Area Maker Faire

    Energy.gov [DOE]

    Representatives from the Department of Energy’s National Labs, the Office of Energy Efficiency and Renewable Energy (EERE), the Advanced Research Projects Agency (ARPA-E) and the Office of Technology Transitions (OTT) will be on hand at the first-ever Make | ENERGY Pavilion at the Bay Area Maker Faire May 20-22, 2016, at the San Mateo County Event Center.

  16. Report on Preliminary Engineering Study for Installation of an Air Cooled Steam Condenser at Brawley Geothermal Plant, Unit No. 1

    SciTech Connect (OSTI)

    1982-03-01

    The Brawley Geothermal Project comprises a single 10 MW nominal geothermal steam turbine-generator unit which has been constructed and operated by the Southern California Edison Company (SCE). Geothermal steam for the unit is supplied through contract by Union Oil Company which requires the return of all condensate. Irrigation District (IID) purchases the electric power generated and provides irrigation water for cooling tower make-up to the plant for the first-five years of operation, commencing mid-1980. Because of the unavailability of irrigation water from IID in the future, SCE is investigating the application and installation of air cooled heat exchangers in conjunction with the existing wet (evaporative) cooling tower with make-up based on use of 180 gpm (nominal) of the geothermal condensate which may be made available by the steam supplier.

  17. Evaluation of the Impact of Off-Design Operation on an Air-Cooled Binary Power Plant

    SciTech Connect (OSTI)

    Mines, Gregory Lee

    2002-09-01

    Geothermal power plants are designed and constructed to provide a rated power output at specific resource and ambient conditions. Due to both diurnal and seasonal changes in the ambient air temperature, as well as a decline in resource productivity over time, plants seldom operate at these "design" conditions. This paper examines the impact of "off- design" operation of an air-cooled binary geothermal power plant. An available energy analysis is used to evaluate operation at these conditions. This evaluation identifies those portions of the power cycle that are most sensitive to changing resource and ambient conditions, as well as where improvements in cycle component or system performance would have the largest impact in increasing power output.

  18. Evaluation of the Impact of Off-Design Operation on an Air-Cooled Binary Power Plant

    SciTech Connect (OSTI)

    Mines, G.L.

    2002-06-17

    Geothermal power plants are designed and constructed to provide a rated power output at specific resource and ambient conditions. Due to both diurnal and seasonal changes in the ambient air temperature, as well as a decline in resource productivity over time, plants seldom operate at these ''design'' conditions. This paper examines the impact of ''off- design'' operation of an air-cooled binary geothermal power plant. An available energy analysis is used to evaluate operation at these conditions. This evaluation identifies those portions of the power cycle that are most sensitive to changing resource and ambient conditions, as well as where improvements in cycle component or system performance would have the largest impact in increasing power output.

  19. ISSUANCE 2015-07-27: Energy Conservation Program: Test Procedures for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment, Notice of Proposed Rulemaking

    Office of Energy Efficiency and Renewable Energy (EERE)

    Energy Conservation Program: Test Procedures for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment, Notice of Proposed Rulemaking

  20. Design considerations and experimental observations for the TAMU air-cooled reactor cavity cooling system for the VHTR

    SciTech Connect (OSTI)

    Sulaiman, S. A. Dominguez-Ontiveros, E. E. Alhashimi, T. Budd, J. L. Matos, M. D. Hassan, Y. A.

    2015-04-29

    The Reactor Cavity Cooling System (RCCS) is a promising passive decay heat removal system for the Very High Temperature Reactor (VHTR) to ensure reliability of the transfer of the core residual and decay heat to the environment under all off-normal circumstances. A small scale experimental test facility was constructed at Texas A and M University (TAMU) to study pertinent multifaceted thermal hydraulic phenomena in the air-cooled reactor cavity cooling system (RCCS) design based on the General Atomics (GA) concept for the Modular High Temperature Gas-Cooled Reactor (MHTGR). The TAMU Air-Cooled Experimental Test Facility is ⅛ scale from the proposed GA-MHTGR design. Groundwork for experimental investigations focusing into the complex turbulence mixing flow behavior inside the upper plenum is currently underway. The following paper illustrates some of the chief design considerations used in construction of the experimental test facility, complete with an outline of the planned instrumentation and data acquisition methods. Computational Fluid Dynamics (CFD) simulations were carried out to furnish some insights on the overall behavior of the air flow in the system. CFD simulations assisted the placement of the flow measurement sensors location. Preliminary experimental observations of experiments at 120oC inlet temperature suggested the presence of flow reversal for cases involving single active riser at both 5 m/s and 2.25 m/s, respectively and four active risers at 2.25 m/s. Flow reversal may lead to thermal stratification inside the upper plenum by means of steady state temperature measurements. A Particle Image Velocimetry (PIV) experiment was carried out to furnish some insight on flow patterns and directions.

  1. Fiber optic diffraction grating maker

    DOE Patents [OSTI]

    Deason, V.A.; Ward, M.B.

    1991-05-21

    A compact and portable diffraction grating maker is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate. 4 figures.

  2. Fiber optic diffraction grating maker

    DOE Patents [OSTI]

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A compact and portable diffraction grating maker comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate.

  3. Category:Battery makers | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Battery makers Jump to: navigation, search Pages in category "Battery makers" The following 5 pages are in this category, out of 5 total. B Battery Ventures F Ford Electric Battery...

  4. Improved Performance of an Air Cooled Condenser (ACC) Using SPX Wind Guide Technology at Coal-Based Thermoelectric Power Plants

    SciTech Connect (OSTI)

    Ken Mortensen

    2010-12-31

    This project added a new airflow enhancement technology to an existing ACC cooling process at a selected coal power plant. Airflow parameters and efficiency improvement for the main plant cooling process using the applied technology were determined and compared with the capabilities of existing systems. The project required significant planning and pre-test execution in order to reach the required Air Cooled Condenser system configuration for evaluation. A host Power Plant ACC system had to be identified, agreement finalized, and addition of the SPX ACC Wind Guide Technology completed on that site. Design of the modification, along with procurement, fabrication, instrumentation, and installation of the new airflow enhancement technology were executed. Baseline and post-modification cooling system data was collected and evaluated. The improvement of ACC thermal performance after SPX wind guide installation was clear. Testing of the improvement indicates there is a 5% improvement in heat transfer coefficient in high wind conditions and 1% improvement at low wind speed. The benefit increased with increasing wind speed. This project was completed on schedule and within budget.

  5. 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.

  6. Improving Vortex Generators to Enhance the Performance of Air-Cooled Condensers in a Geothermal Power Plant

    SciTech Connect (OSTI)

    Manohar S. Sohal

    2005-09-01

    This report summarizes work at the Idaho National Laboratory to develop strategies to enhance air-side heat transfer in geothermal air-cooled condensers such that it should not significantly increase pressure drop and parasitic fan pumping power. The work was sponsored by the U.S. Department of Energy, NEDO (New Energy and Industrial Technology Development Organization) of Japan, Yokohama National University, and the Indian Institute of Technology, Kanpur, India. A combined experimental and numerical investigation was performed to investigate heat transfer enhancement techniques that may be applicable to largescale air-cooled condensers such as those used in geothermal power applications. A transient heat transfer visualization and measurement technique was employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements were obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that included four tube rows in a staggered array. Heat transfer and pressure drop measurements were also acquired in a separate multiple-tube row apparatus in the Single Blow Test Facility. In addition, a numerical modeling technique was developed to predict local and average heat transfer for these low-Reynolds number flows, with and without winglets. Representative experimental and numerical results were obtained that reveal quantitative details of local finsurface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. Heat transfer and pressure-drop results were obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500. The winglets were of triangular (delta) shape with a 1:2 or 1:3 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface heat transfer results indicate a significant level of heat transfer enhancement (in terms of

  7. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    SciTech Connect (OSTI)

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  8. Policy Makers' Guidebook for Geothermal Electricity Generation...

    Open Energy Information (Open El) [EERE & EIA]

    Electricity Generation Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Policy Makers' Guidebook for Geothermal Electricity Generation AgencyCompany Organization:...

  9. ISSUANCE 2015-12-17: Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment and Commercial Warm Air Furnaces

    Energy.gov [DOE]

    Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment and Commercial Warm Air Furnaces

  10. ISSUANCE 2015-12-17: Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment and Commercial Warm Air Furnaces

    Energy.gov [DOE]

    Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment and Commercial Warm Air Furnaces, Supplemental Notice of Proposed Rulemaking

  11. SCHEDULE: Bay Area Maker Faire 2016

    Energy.gov [DOE]

    Find out where and when to meet some of our top innovators and explore the technologies on display from the Department of Energy at the 11th annual Bay Area Maker Faire.

  12. Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

    SciTech Connect (OSTI)

    Praphairaksit, N.

    2000-09-12

    An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at {approximately}70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of {approximately}4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression

  13. Climate modeling with decision makers in mind

    DOE PAGES-Beta [OSTI]

    Jones, Andrew; Calvin, Katherine; Lamarque, Jean -Francois

    2016-04-27

    The need for regional- and local-scale climate information is increasing rapidly as decision makers seek to anticipate and manage a variety of context-specific climate risks over the next several decades. Furthermore, global climate models are not developed with these user needs in mind, and they typically operate at resolutions that are too coarse to provide information that could be used to support regional and local decisions.

  14. Marble Maker Slashes Energy Use | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Marble Maker Slashes Energy Use Marble Maker Slashes Energy Use April 9, 2010 - 3:04pm Addthis King is saving 11.8 percent a year on energy costs due to upgrades at its Paden City, ...

  15. Innovative Solar Panel Maker Scales Up, Lowering Costs while...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Solar Panel Maker Scales Up, Lowering Costs while Creating Jobs Innovative Solar Panel Maker Scales Up, Lowering Costs while Creating Jobs May 16, 2011 - 12:41pm Addthis The end of ...

  16. Air Cooling R&D

    Office of Energy Efficiency and Renewable Energy (EERE)

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  17. NNSA makers and hackers engage innovation and partnerships | National

    National Nuclear Security Administration (NNSA)

    Nuclear Security Administration | (NNSA) makers and hackers engage innovation and partnerships Monday, June 13, 2016 - 10:00am NNSA's laboratories took home multiple awards and recognitions from the 2016 Bay Area Maker Faire. NNSA's labs change the world everyday through cutting-edge developments in support of NNSA's critical national security missions. Some of those leading edge technologies went on display as scientists and representatives from DOE, including "makers" from NNSA's

  18. Maker Faire Tour Part 2 | GE Global Research

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    2 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) A Tour of the 2011 Maker Faire Part 2 Scientist Peter Tu shares more reflections from his trip to the 2011 Maker Faire in San Francisco. You Might Also Like 3-2-3-v-maker-faire-tour A Tour of the 2011 Maker Faire Part 1

  19. 9 Cool Technologies at the Bay Area Maker Faire

    Energy.gov [DOE]

    Get a glimpse of some of the technologies from our National Labs in the Make | ENERGY Pavilion at the Bay Area Maker Faire. You can look AND touch.

  20. NREL: Energy Analysis - Energy Data for Decision Makers

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Energy Data for Decision Makers The National Renewable Energy Laboratory (NREL) is home to a wealth of data and tools that can be linked together to derive knowledge and expand decision-making capabilities. Our platform links energy communities and decision makers such as policymakers, researchers, technology investors, venture capitalists, and market professionals - with valuable energy data, information, analyses, tools, images, maps, and other resources. Cover of the Renewable Energy Data

  1. ARM - Measurement - Ice nuclei

    U.S. Department of Energy (DOE) all 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...

  2. Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Solar Powered (Hot-Water-Fired) Absorption Unit

    SciTech Connect (OSTI)

    Zaltash, Abdolreza; Petrov, Andrei Y; Linkous, Randall Lee; Vineyard, Edward Allan

    2007-01-01

    During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This innovative absorption technology is based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the "next generation" absorption units. Rotartica Absorption Chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space, increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller (no cooling tower). The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35 C (95 F) design condition for ambient

  3. WeatherMaker: Weather file conversion and evaluation

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1999-07-01

    WeatherMaker is a weather-data utility for use with the ENERGY-10 design-tool computer program. The three main features are: Convert--Weather files can be converted from one format to another. For example, a TMY2 format file can be converted to an ENERGY-10 binary file that can be used in a simulation. This binary file can then be converted to a text format that allows it to be read and/or manipulated in WordPad or Excel. Evaluate--ENERGY-10 weather files can be studied in great detail. There are 8 graphical displays of the data that provide insight into the data, and a summary tables that presents results calculated from the hourly data. Adjust--Hourly temperature data can be adjusted starting with hourly data from a nearby TMY2 site. Dry-bulb and wet-bulb temperatures are adjusted up or down as required to match given monthly statistics. This feature can be used to generate weather files for any of 3,958 sites in the US where such monthly statistics are tabulated. The paper shows a variety of results, explains the methods used, and discusses the rationale for making the adjustments. It is anticipated that WeatherMaker will be released by the time of the ASES Solar 99 conference.

  4. 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 Details In-Document Search Title: Community Ice Sheet Model (CISM2) Development and Marine ...

  5. 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.

  6. Air-Cooled Traction Drive Inverter

    Energy.gov [DOE]

    2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  7. Microsoft Word - 11_19_09 ice mkaer.doc

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    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

  8. ARM - Ice Cores

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    PastIce Cores 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 Ice Cores Ice cores reveal information about the earth's climate history. The information from ice cores is both more precise and more compelling than from other sources. Accurate history of our earth's temperature and carbon

  9. 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.

  10. 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.

  11. Marketing_to_Win_How_to_Identify_the_Real_Decision_makers_and_Tailor_Your_Message

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Marketing to Win: How to Identify the Real Decision-makers and Tailor Your Message Gloria Larkin President, TargetGov 1 ©TargetGov 2016 2 Agenda * Disappearing act * First impressions * Mitigating risks * Identifying real decision makers * Layers of decision makers * How and why they choose * Marketing and positioning tools ©TargetGov 2016 Disappearing Act? * In 2000, $200 Billion in Contracts - Over 100,000 contracting and acquisition staff * In 2013, $500 Billion in contracts - Fewer than

  12. MeshMaker: Configurable Meshing Framework for Eco-Hydrology Models

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

    Nathan Collier; Jitendra Kumar

    2016-02-09

    MeshMaker is a Python-based framework for generation of high quality structured and unstructured grid computational meshes for Eco-Hydrological models.

  13. AMO Kicks Off Week of Making with Participation in 2nd Annual Maker Faire

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Gallery | Department of Energy AMO Kicks Off Week of Making with Participation in 2nd Annual Maker Faire Gallery AMO Kicks Off Week of Making with Participation in 2nd Annual Maker Faire Gallery Addthis 1 of 8 Makey the Robot welcoming over 15,000 people to the 2nd Annual National Maker Faire. Image: Kevin Jarrett 2 of 8 Secretary of Transportation, Anthony Foxx, visited the DOE booth to learn more about 3D printed wind turbine blade molds. 3 of 8 Maker's come in all shapes and sizes!

  14. AMO to Take Part in 2nd Annual National Maker Faire June 18 & 19 |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy to Take Part in 2nd Annual National Maker Faire June 18 & 19 AMO to Take Part in 2nd Annual National Maker Faire June 18 & 19 June 17, 2016 - 1:57pm Addthis AMO to Take Part in 2nd Annual National Maker Faire June 18 & 19 Tinkerers, builders, innovators and spectators of all ages will descend on the Washington DC area this weekend to participate in the Second Annual National Maker Faire held at the University of the District of Columbia, and The Advanced

  15. 3D Cobra, Renewable Energy, and Green Button at the National Maker Faire |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy D Cobra, Renewable Energy, and Green Button at the National Maker Faire 3D Cobra, Renewable Energy, and Green Button at the National Maker Faire June 12, 2015 - 9:15am Addthis The National Maker Faire aims to celebrate all things science, technology, engineering, art, and math through do-it-yourself and do-it-with-others projects and fun. The National Maker Faire aims to celebrate all things science, technology, engineering, art, and math through do-it-yourself and

  16. Webinar: Procuring Fuel Cells for Stationary Power: A Guide for Federal Decision Makers

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation slides from the May 8, 2012, Fuel Cell Technologies Program webinar, Procuring Fuel Cells for Stationary Power: A Guide for Federal Facility Decision Makers.

  17. AMO Kicks Off Week of Making with Participation in 2nd Annual Maker Faire |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Kicks Off Week of Making with Participation in 2nd Annual Maker Faire AMO Kicks Off Week of Making with Participation in 2nd Annual Maker Faire June 24, 2016 - 12:22pm Addthis 1 of 8 Makey the Robot welcoming over 15,000 people to the 2nd Annual National Maker Faire. Image: Kevin Jarrett 2 of 8 Secretary of Transportation, Anthony Foxx, visited the DOE booth to learn more about 3D printed wind turbine blade molds. 3 of 8 Maker's come in all shapes and sizes! Participants

  18. Procuring Fuel Cells for Stationary Power: A Guide for Federal Decision Makers

    Energy.gov [DOE]

    Presentation slides from the May 8, 2012, Fuel Cell Technologies Program webinar, Procuring Fuel Cells for Stationary Power: A Guide for Federal Facility Decision Makers.

  19. Webinar: Procuring Fuel Cells for Stationary Power: A Guide for Federal Facility Decision Makers

    Office of Energy Efficiency and Renewable Energy (EERE)

    Video recording and text version of the webinar titled, Procuring Fuel Cells for Stationary Power: A Guide for Federal Facility Decision Makers, originally presented on May 8, 2012.

  20. Mobile Ice Nucleus Spectrometer

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Kok, G. L.

    2012-05-07

    This first year report presents results from a computational fluid dynamics (CFD) study to assess the flow and temperature profiles within the mobile ice nucleus spectrometer.

  1. Global Simulations of Ice nucleation and Ice Supersaturation...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  2. 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: ...

  3. Marketing to Win: How to Identify the Real Decision-maker and Tailor Your

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Message | Department of Energy Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message Presented at the 15th Annual DOE Small Business Forum & Expo by: Gloria Larkin, President TargetGov Marketing to Win: How to Identify the Real Decision-maker and Tailor Your Message (4.06 MB) More Documents & Publications Presentations from the 12th Annual Small Business Conference, May 2011

  4. GE and Maker Faire Are a Match Made in Nerd Heaven | GE Global Research

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    and Maker Faire Are a Match Made in Nerd Heaven 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 and Maker Faire Are a Match Made in Nerd Heaven Peter Tu 2011.06.06 This year GE was a sponsor of the spring version of Maker Faire held out in San Francisco. Our main contributions to the festivities consisted of a

  5. Make Energy at The Bay Area Maker Faire | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Make Energy at The Bay Area Maker Faire Make Energy at The Bay Area Maker Faire Addthis Representatives from the Department of Energy's National Labs, the Office of Energy Efficiency and Renewable Energy (EERE), the Advanced Research Projects Agency (ARPA-E) and the Office of Technology Transitions (OTT) were on hand at the first-ever Make | ENERGY Pavilion at the Bay Area Maker Faire May 20-22, 2016, at the San Mateo County Event Center. Watch this video to learn more.

  6. Make Energy at the Bay Area Maker Faire | Department of Energy

    Energy.gov (indexed) [DOE]

    Make Energy at the Bay Area Maker Faire Video from the Department of Energy, published ... Here's a short video that captures some of their experiences at the Faire. For more ...

  7. Program for Converting C/C++ Texts to FrameMaker Representation

    Energy Science and Technology Software Center (OSTI)

    1995-06-23

    Used to insert pieces of C/C=+code into FrameMaker documents with fontified Language tokens. Different fonts can be used for different language constructions such as float, while, etc.

  8. Big solar-panel maker First Solar and Colorado's Clean Energy...

    Open Energy Information (Open El) [EERE & EIA]

    Big solar-panel maker First Solar and Colorado's Clean Energy Collective ink deal Home > Groups > Buildings Dc's picture Submitted by Dc(266) Contributor 11 December, 2014 - 15:40...

  9. 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.

  10. ICR ICE SOP

    Energy Savers

    have been removed. 2. Section 1 adds a reference to Public Law 2055 reflecting that we must now, as a matter of law, perform an ICE at CD-3 for projects with a TPC over 100 ...

  11. Global ice sheet modeling

    SciTech Connect (OSTI)

    Hughes, T.J.; Fastook, J.L.

    1994-05-01

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed.

  12. Independent Cost Estimate (ICE)

    Energy.gov [DOE]

    Independent Cost Estimate (ICE). On August 8-12, the Office of Project Management Oversight and Assessments (PM) will conduct an ICE on the NNSA Albuquerque Complex Project (NACP) at Albuquerque, NM. This estimate will support the Critical Decision (CD) for establishing the performance baseline and approval to start construction (CD-2/3). This project is at CD-1, with a total project cost range of $183M to $251M.

  13. 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.

  14. 9 Cool Technologies at the Bay Area Maker Faire | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    9 Cool Technologies at the Bay Area Maker Faire 9 Cool Technologies at the Bay Area Maker Faire May 12, 2016 - 10:14am Addthis PARTS FROM THE WORLD’S LARGEST LASER 1 of 9 PARTS FROM THE WORLD'S LARGEST LASER You're looking at the inside of the world's largest and most powerful laser. It focuses the intense energy of 192 giant laser beams on a BB-sized target in experiments to create nuclear fusion. Examples of the optics that focus the lasers and targets at which they're aimed will be on

  15. ARM - TWP-ICE Maps

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    TWP-ICE Maps Related Links TWP-ICE Home Tropical Western Pacific Home ARM Data Discovery Browse Data Post-Experiment Data Sets Weather Summary (pdf, 6M) New York Workshop Presentations Experiment Planning TWP-ICE Proposal Abstract Detailed Experiment Description Science Plan (pdf, 1M) Operations Plan (pdf, 321K) Maps Contact Info Related Links Daily Report Report Archives Press Media Coverage TWP-ICE Fact Sheet (pdf, 211K) Press Releases TWP-ICE Images ARM flickr site <=""

  16. 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.

  17. ARM - Measurement - Cloud ice particle

    U.S. Department of Energy (DOE) all 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 Particles made of ice found in clouds. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or

  18. 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.

  19. Winter Preparedness ? Slips on Ice

    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...

  20. Adva I iced' Technblo'

    Office of Legacy Management (LM)

    #_ ,: .,- ., . . . ..J.+ & ' 9 ,,:a.. :>a .LY,%. ai, VT &$,..,& $.a+ )' j,' ,l b ; ij _ ,. Ij , i 5.; &y.-: 2 ,.? ' 1 *I @q' r .3' &W. *, ,/ ' ? Adva I iced' Technblo' gy Di -yb$ . :>A ; -; ~~~~~~~~: 1;;; I' &;,. : . vwon ., > ' ." /. ,' ,f. .; 1 f DOE/OR/20722-15 (D E85000629) Distribution Category UC-70A FINAL REPORT ON REMEDIAL ACTION AT THE ACID/PUEBLO CANYON SITE LOS ALAMOS, NEW MEXICO OCTOBER 1984 Prepared for UNITED STATES DEPARTMENT OF ENERGY OAK

  1. 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.

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

    U.S. Department of Energy (DOE) all 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...

  3. 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.

  4. Learning environment simulator: a tool for local decision makers and first responders

    SciTech Connect (OSTI)

    Leclaire, Rene J; Hirsch, Gary B

    2009-01-01

    The National Infrastructure Simulation and Analysis Center (NISAC) has developed a prototype learning environment simulator (LES) based on the Critical Infrastructure Protection Decision Support System (CIPDSS) infrastructure and scenario models. The LES is designed to engage decision makers at the grass-roots level (local/city/state) to deepen their understanding of an evolving crisis, enhance their intuition and allow them to test their own strategies for events before they occur. An initial version is being developed, centered on a pandemic influenza outbreak and has been successfully tested with a group of hospital administrators and first responders. LES is not a predictive tool but rather a simulated environment allowing the user to experience the complexities of a crisis before it happens. Users can contrast various approaches to the crisis, competing with alternative strategies of their own or other participants. LES is designed to assist decision makers in making informed choices by functionally representing relevant scenarios before they occur, including impacts to critical infrastructures with their interdependencies, and estimating human health & safety and economic impacts. In this paper a brief overview of the underlying models are given followed by a description of the LES, its interface and usage and an overview of the experience testing LES with a group of hospital administrators and first responders. The paper concludes with a brief discussion of the work remaining to make LES operational.

  5. Clean Air-Cool Planet Community Toolkit | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    conservation, renewable energy (the resource focuses on wind power, solar power, and methane recovery), green power, transportation, waste, and land-use programs. Each topic is...

  6. Air-cooled condensers eliminate plant water use

    SciTech Connect (OSTI)

    Wurtz, W.; Peltier, R.

    2008-09-15

    River or ocean water has been the mainstay for condensing turbine exhaust steam since the first steam turbine began generating electricity. A primary challenge facing today's plant developers, especially in drought-prone regions, is incorporating processes that reduce plant water use and consumption. One solution is to shed the conventional mindset that once-through cooling is the only option and adopt dry cooling technologies that reduce plant water use from a flood to a few sips. A case study at the Astoria Energy plant, New York City is described. 14 figs.

  7. Air cooled turbine component having an internal filtration system

    DOE Patents [OSTI]

    Beeck, Alexander R.

    2012-05-15

    A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

  8. Air Cooling Technology for Advanced Power Electronics and Electric Machines

    Energy.gov [DOE]

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  9. Flow directing means for air-cooled transformers

    DOE Patents [OSTI]

    Jallouk, Philip A.

    1977-01-01

    This invention relates to improvements in systems for force-cooling transformers of the kind in which an outer helical winding and an insulation barrier nested therein form an axially extending annular passage for cooling-fluid flow. In one form of the invention a tubular shroud is positioned about the helical winding to define an axially extending annular chamber for cooling-fluid flow. The chamber has a width in the range of from about 4 to 25 times that of the axially extending passage. Two baffles extend inward from the shroud to define with the helical winding two annular flow channels having hydraulic diameters smaller than that of the chamber. The inlet to the chamber is designed with a hydraulic diameter approximating that of the coolant-entrance end of the above-mentioned annular passage. As so modified, transformers of the kind described can be operated at significantly higher load levels without exceeding safe operating temperatures. In some instances the invention permits continuous operation at 200% of the nameplate rating.

  10. Air Cooling Technology for Power Electronic Thermal Control

    Energy.gov [DOE]

    2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation

  11. Air-Cooled Condensers for Next Generation Power Plants

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... tube bundle for this project 'V' or 'A' frame condenser: * Higher heat transfer coefficient * Integral condensation more likely * Cross-flow design * Design typically limited to ...

  12. Hybrid and Advanced Air Cooling Geothermal Lab Call Project ...

    Open Energy Information (Open El) [EERE & EIA]

    various strategies for boosting the performance of air coolers in hot weather. Computer modeling and experimental measurements have been done on the use of evaporative media...

  13. Air Cooling Technology for Power Electronic Thermal Control

    Office of Energy Efficiency and Renewable Energy (EERE)

    2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  14. High-Temperature, Air-Cooled Traction Drive Inverter Packaging

    Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  15. Air Cooling Technology for Power Electronic Thermal Control

    Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  16. Covered Product Category: Air-Cooled Electric Chillers

    Office of Energy Efficiency and Renewable Energy (EERE)

    FEMP provides acquisition guidance and Federal efficiency requirements for electric chillers, which are a FEMP-designated product category. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

  17. Radiative properties of ice clouds

    SciTech Connect (OSTI)

    Mitchell, D.L.; Koracin, D.; Carter, E.

    1996-04-01

    A new treatment of cirrus cloud radiative properties has been developed, based on anomalous diffraction theory (ADT), which does not parameterize size distributions in terms of an effective radius. Rather, is uses the size distribution parameters directly, and explicitly considers the ice particle shapes. There are three fundamental features which characterize this treatment: (1) the ice path radiation experiences as it travels through an ice crystal is parameterized, (2) only determines the amount of radiation scattered and absorbed, and (3) as in other treatments, the projected area of the size distribution is conserved. The first two features are unique to this treatment, since it does not convert the ice particles into equivalent volume or area spheres in order to apply Mie theory.

  18. 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.

  19. 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.

  20. Climate, Ocean and Sea Ice Modeling

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Ocean and Sea Ice Modeling (COSIM) Summary 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. COSIM researchers develop, test and apply ocean and ice models in support of DOE Climate Change Research and the broader international climate science community. Additional research includes developing a set of next-generation ocean and ice

  1. ARM - Measurement - Ice water content

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    content 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 : Ice water content The concentration (mass/vol) of ice water particles in a cloud. Categories Cloud Properties, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including

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

    Open Energy Information (Open El) [EERE & EIA]

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

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

    Office of Scientific and Technical Information (OSTI)

    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 + ...

  4. 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.

  5. Water freezing and ice melting

    DOE PAGES-Beta [OSTI]

    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

  6. ARM - Measurement - Ice water path

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    path 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 : Ice water path A measure of the weight of the ice particles in the atmosphere above a unit surface area in kg m-2. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements,

  7. The New ICE Age | Department of Energy

    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 ...

  8. Ice in Arctic Mixed-phase Stratocumulus

    U.S. Department of Energy (DOE) all 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...

  9. Paleotopography of glacial-age ice sheets

    SciTech Connect (OSTI)

    Edwards, R.L.

    1995-01-27

    This is technical comment and response to the subject of paleotophography of glacial age ice sheets. The model presented by Peltier reconstructing the paleotopography of glacial age ice sheets has implications for atmospheric general circulation models of ice age climate. In addition, the model suggests that the glacial-age Antarctic Ice Sheet was significantly larger than today`s. The commentor, Edwards, suggests there is a discrepancy between data from Papua New Guinea and the model results.

  10. Microsoft Word - IceMountainFinal.docx

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Tumbled-down boulders, called talus, on Ice Mountain's north- western slope collect ice during the winter. In the summer, cold air flows out of vents in the base of the talus, lowering temperatures. Photo courtesy of Kent Mason West Virginia's Ice Mountain: Where Science Meets Magic On August 6, 1918, the thermometer hit 109 degrees in Hampshire County, West Virginia. It's easy to believe that the sweltering residents of North River Mills considered walking to nearby Ice Mountain, where the air

  11. 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

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

    U.S. Department of Energy (DOE) all 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

  13. 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

  14. Procuring Stationary Fuel Cells For CHP: A Guide for Federal Facility Decision Makers

    SciTech Connect (OSTI)

    Stinton, David P; McGervey, Joseph; Curran, Scott

    2011-11-01

    Federal agency leaders are expressing growing interest in using innovative fuel cell combined heat and power (CHP) technology at their sites, motivated by both executive branch sustainability targets and a desire to lead by example in the transition to a clean energy economy. Fuel cell CHP can deliver reliable electricity and heat with 70% to 85% efficiency. Implementing this technology can be a high efficiency, clean energy solution for agencies striving to meet ambitious sustainability requirements with limited budgets. Fuel cell CHP systems can use natural gas or renewable fuels, such as biogas. Procuring Stationary Fuel Cells for CHP: A Guide for Federal Facility Decision Makers presents an overview of the process for planning and implementing a fuel cell CHP project in a concise, step-by-step format. This guide is designed to help agency leaders turn their interest in fuel cell technology into successful installations. This guide concentrates on larger (100 kW and greater) fuel cell CHP systems and does not consider other fuel cell applications such as cars, forklifts, backup power supplies or small generators (<100 kW). Because fuel cell technologies are rapidly evolving and have high up front costs, their deployment poses unique challenges. The electrical and thermal output of the CHP system must be integrated with the building s energy systems. Innovative financing mechanisms allow agencies to make a make versus buy decision to maximize savings. This guide outlines methods that federal agencies may use to procure fuel cell CHP systems with little or no capital investment. Each agency and division, however, has its own set of procurement procedures. This guide was written as a starting point, and it defers to the reader s set of rules if differences exist. The fuel cell industry is maturing, and project developers are gaining experience in working with federal agencies. Technology improvements, cost reductions, and experienced project developers are making

  15. 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.

  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. Recent vs from IceCube

    SciTech Connect (OSTI)

    IceCube Collaboration; Klein, Spencer R.

    2008-10-03

    IceCube is a 1 km3 neutrino detector now being built at the South Pole. Its 4800 optical modules will detect Cherenkov radiation from charged particles produced in neutrino interactions. IceCube will search for neutrinos of astrophysical origin, with energies from 100 GeV up to 1019 eV. It will be able to separate nue, nu mu and nu tau. In addition to detecting astrophysical neutrinos, IceCube will also search for neutrinos from WIMP annihilation in the Sun and the Earth, look for low-energy (10 MeV) neutrinos from supernovae, and search for a host of exotic signatures. With the associated IceTop surface air shower array, it will study cosmic-ray air showers. IceCube construction is now 50percent complete. After presenting preliminary results from the partial detector, I will discuss IceCube's future plans.

  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. Antarctic sea ice mapping using the AVHRR

    SciTech Connect (OSTI)

    Zibordi, G. ); Van Woert, M.L. . SeaSpace, Inc.)

    1993-08-01

    A sea ice mapping scheme based on Advanced Very High Resolution Radiometer (AVHRR) data from the National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites has been developed and applied to daylight images taken between November 1989 to January 1990 and November 1990 to January 1991 over the Weddell and the Ross Seas. After masking the continent and ice shelves, sea ice is discriminated from clouds and open sea using thresholds applied to the multidimensional space formed by AVHRR Channel 2, 3, and 4 radiances. Sea ice concentrations in cloud-free regions are then computed using the tie-point method. Results based on the analysis of more than 70 images show that the proposed scheme is capable of properly discriminating between sea ice, open sea, and clouds, under most conditions, thus allowing high resolution sea ice maps to be produced during the austral summer season.

  20. ARM - Lesson Plans: When Land Ice Melts

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    When Land Ice Melts 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 Lesson Plans: When Land Ice Melts Objective The objective of this activity is to demonstrate what happens when land ice melts and how it is different from the effect of melting icebergs. Materials A big rectangular container

  1. IceT users' guide and reference.

    SciTech Connect (OSTI)

    Moreland, Kenneth D.

    2011-01-01

    The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

  2. BISICLES Captures Details of Retreating Antarctic Ice

    U.S. Department of Energy (DOE) all 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 ...

  3. 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.

  4. The Next ICE Age | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    More Documents & Publications The Next ICE Age Fuel Modification t Facilitate Future Combustion Regimes? Optimization of Advanced Diesel Engine Combustion Strategies...

  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. Comparison of 17 Ice Nucleation Measurement Techniques

    U.S. Department of Energy (DOE) all 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...

  7. 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.

  8. 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.

  9. U.S. DOE's Response to the Fukushima Daiichi Reactor Accident: Answers and Data Products for Decision Makers

    SciTech Connect (OSTI)

    Reed, A. L.

    2012-05-01

    The Fukushima Daiichi response posed a plethora of scientific questions to the U.S. Department of Energy’s (DOE) radiological emergency response community. As concerns arose for decision makers, the DOE leveraged a community of scientists well-versed in the tenants of emergency situations to provide answers to time-sensitive questions from different parts of the world. A chronology of the scientific Q and A that occurred is presented along with descriptions of the challenges that were faced and how new methods were employed throughout the course of the response.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. Complex systems influence melting of Greenland ice sheet

    U.S. Department of Energy (DOE) all 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...

  15. Polarimetric Scattering Database for Non-spherical Ice Particles...

    Office of Scientific and Technical Information (OSTI)

    Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths Title: Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave ...

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

    U.S. Department of Energy (DOE) all 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...

  17. 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 ...

  18. Purchasing Energy-Efficient Water-Cooled Ice Machines | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Purchasing Energy-Efficient Water-Cooled Ice Machines The Federal Energy Management Program (FEMP) provides efficiency requirements and acquisition guidance for water-cooled ice ...

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

    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...

  20. 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 ...

  1. 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...

  2. Anomalous Behavior of the Homogeneous Ice Nucleation Rate in...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Anomalous Behavior of the Homogeneous Ice Nucleation Rate in "No-Man's Land" Prev Next Title: Anomalous Behavior of the Homogeneous Ice Nucleation Rate in ...

  3. 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

  4. Communication with U.S. federal decision makers : a primer with notes on the use of computer models as a means of communication.

    SciTech Connect (OSTI)

    Webb, Erik Karl; Tidwell, Vincent Carroll

    2009-10-01

    This document outlines ways to more effectively communicate with U.S. Federal decision makers by outlining the structure, authority, and motivations of various Federal groups, how to find the trusted advisors, and how to structure communication. All three branches of Federal governments have decision makers engaged in resolving major policy issues. The Legislative Branch (Congress) negotiates the authority and the resources that can be used by the Executive Branch. The Executive Branch has some latitude in implementation and prioritizing resources. The Judicial Branch resolves disputes. The goal of all decision makers is to choose and implement the option that best fits the needs and wants of the community. However, understanding the risk of technical, political and/or financial infeasibility and possible unintended consequences is extremely difficult. Primarily, decision makers are supported in their deliberations by trusted advisors who engage in the analysis of options as well as the day-to-day tasks associated with multi-party negotiations. In the best case, the trusted advisors use many sources of information to inform the process including the opinion of experts and if possible predictive analysis from which they can evaluate the projected consequences of their decisions. The paper covers the following: (1) Understanding Executive and Legislative decision makers - What can these decision makers do? (2) Finding the target audience - Who are the internal and external trusted advisors? (3) Packaging the message - How do we parse and integrate information, and how do we use computer simulation or models in policy communication?

  5. 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.

  6. 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.

  7. SGP CART Site Affected by Ice Storm

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    2 SGP CART Site Affected by Ice Storm Beginning on January 29, 2002, a major winter storm passed through the Plains states, leaving snow and ice in its path. Northern locales received snow, but most of the SGP CART site received a coating of thick, damaging ice. The intense storm system moved out of the Rocky Mountains, pulling in moisture from the Gulf of Mexico. A cold, shallow air mass already over Oklahoma and Kansas set up a temperature inversion in the atmosphere, with warmer air

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Developing and Evaluating Ice Cloud Parameterizations by

    U.S. Department of Energy (DOE) all 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...

  14. 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.

  15. The Next ICE Age | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    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 ...

  16. Hydrogen Material Compatibility for Hydrogen ICE | Department...

    Energy.gov (indexed) [DOE]

    pm04smith.pdf (1.52 MB) More Documents & Publications Hydrogen Materials Compatibility for the H-ICE Engine Friction Reduction Through Surface Finish and Coatings Vehicle ...

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

    Alternative Fuels and Advanced Vehicles Data Center

    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

  18. Melting of ice wedges adds to arctic warming

    U.S. Department of Energy (DOE) all 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

  19. Picture of the Week: Better climate models? Just add ice.

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    1 Better climate models? Just add ice. With the help of supercomputers, Los Alamos scientists are modeling ice sheets to predict sea level rise and coupling ice sheet models to climate models to sharpen their predictive capabilities. September 22, 2016 3D simulation of electromagnetic radiation interacting with explosives With the help of supercomputers, Los Alamos scientists are modeling ice sheets to predict sea level rise and coupling ice sheet models to climate models to sharpen their

  20. 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.

  1. 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.

  2. 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.

  3. Ice Load Project Final Technical Report

    SciTech Connect (OSTI)

    McCoy, Timothy J.; Brown, Thomas; Byrne, Alex

    2014-10-30

    As interest and investment in offshore wind projects increase worldwide, some turbines will be installed in locations where ice of significant thickness forms on the water surface. This ice moves under the driving forces of wind, current, and thermal effects and may result in substantial forces on bottom-fixed support structures. The North and Baltic Seas in Europe have begun to see significant wind energy development and the Great Lakes of the United States and Canada may host wind energy development in the near future. Design of the support structures for these projects is best performed through the use of an integrated tool that can calculate the cumulative effects of forces due to turbine operations, wind, waves, and floating ice. The dynamic nature of ice forces requires that these forces be included in the design simulations, rather than added as static forces to simulation results. The International Electrotechnical Commission (IEC) standard[2] for offshore wind turbine design and the International Organization for Standardization (ISO) standard[3] for offshore structures provide requirements and algorithms for the calculation of forces induced by surface ice; however, currently none of the major wind turbine dynamic simulation codes provides the ability to model ice loads. The scope of work of the project described in this report includes the development of a suite of subroutines, collectively named IceFloe, that meet the requirements of the IEC and ISO standards and couples with four of the major wind turbine dynamic simulation codes. The mechanisms by which ice forces impinge on offshore structures generally include the forces required for crushing of the ice against vertical-sided structures and the forces required to fracture the ice as it rides up on conical-sided structures. Within these two broad categories, the dynamic character of the forces with respect to time is also dependent on other factors such as the velocity and thickness of the moving ice

  4. 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.

  5. 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.

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

    ScienceCinema (OSTI)

    Barry, Roger G.

    2016-07-12

    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.

  7. 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.

  8. 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.

  9. Hydrogen behavior in ice condenser containments

    SciTech Connect (OSTI)

    Lundstroem, P.; Hongisto, O.; Theofanous, T.G.

    1995-09-01

    A new hydrogen management strategy is being developed for the Loviisa ice condenser containment. The strategy relies on containment-wide natural circulations that develop, once the ice condenser doors are forced open, to effectively produce a well-mixed behavior, and a correspondingly slow rise in hydrogen concentration. Levels can then be kept low by a distributed catalytic recombiner system, and (perhaps) an igniter system as a backup, while the associated energy releases can be effectively dissipated in the ice bed. Verification and fine-tuning of the approach is carried out experimentally in the VICTORIA facility and by associated scaling/modelling studies. VICTORIA represents an 1/15th scale model of the Loviisa containment, hydrogen is simulated by helium, and local concentration measurements are obtained by a newly developed instrument specifically for this purpose, called SPARTA. This paper is focused on experimental results from several key experiments that provide a first delineation of key behaviors.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. CHEMISTRY IN EVAPORATING ICES-UNEXPLORED TERRITORY

    SciTech Connect (OSTI)

    Cecchi-Pestellini, Cesare; Rawlings, Jonathan M. C.; Viti, Serena; Williams, David A. E-mail: jcr@star.ucl.ac.u E-mail: daw@star.ucl.ac.u

    2010-12-20

    We suggest that three-body chemistry may occur in warm high-density gas evaporating in transient co-desorption events on interstellar ices. Using a highly idealized computational model we explore the chemical conversion from simple species of the ice to more complex species containing several heavy atoms, as a function of density and of adopted three-body rate coefficients. We predict that there is a wide range of densities and rate coefficients in which a significant chemical conversion may occur. We discuss the implications of this idea for the astrochemistry of hot cores.

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

    U.S. Department of Energy (DOE) all 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...

  16. Modeling the Effect of Ice Nuclei on ARM Clouds

    U.S. Department of Energy (DOE) all 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,...

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

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Nano Surface Icephobic Coating Delays Ice Formation Click to email this to a friend (Opens ... A Nano Surface Icephobic Coating Delays Ice Formation Azar Alizadeh 2012.03.08 Hi folks, ...

  18. Nanotextured Anti-Icing Surfaces | GE Global Research

    U.S. Department of Energy (DOE) all 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. ARM - What About Melting Polar Ice Caps and Sea Levels?

    U.S. Department of Energy (DOE) all 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

  20. Covered Product Category: Water-Cooled Ice Machines

    Energy.gov [DOE]

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

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

    U.S. Department of Energy (DOE) all 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

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

    U.S. Department of Energy (DOE) all 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.

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

    U.S. Department of Energy (DOE) all 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

  4. The influence of ice nucleation mode and ice vapor growth on...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    of ice crystals. Without depletion even the MPACE-derived IN lead to rapid glaciation and loss of all liquid water. These results suggest that in order to more accurately simulate...

  5. 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.

  6. ARM - Field Campaign - SGP Ice Nuclei Characterization Experiment

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    govCampaignsSGP Ice Nuclei Characterization Experiment Campaign Links Field Campaign Report 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 Campaign : SGP Ice Nuclei Characterization Experiment 2014.04.22 - 2014.06.14 Lead Scientist : Paul DeMott For data sets, see below. Abstract Ice nucleating particles are required to trigger the formation of ice crystals in the mixed-phase (liquid and ice) regions of clouds,

  7. 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.

  8. 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.

  9. Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica

    SciTech Connect (OSTI)

    Bougamont, M.; Christoffersen, P.; Price, S. F.; Fricker, H. A.; Tulaczyk, S.; Carter, S. P.

    2015-10-21

    Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leading to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.

  10. Market assessment for active solar heating and cooling products. Category B: a survey of decision-makers in the HVAC marketplace. Final report

    SciTech Connect (OSTI)

    1980-09-01

    A comprehensive evaluation of the market for solar heating and cooling products for new and retrofit markets is reported. The emphasis is on the analysis of solar knowledge among HVAC decision makers and a comprehensive evaluation of their solar attitudes and behavior. The data from each of the following sectors are described and analyzed: residential consumers, organizational and manufacturing buildings, HVAC engineers and architects, builders/developers, and commercial/institutional segments. (MHR)

  11. H2 ICE Combustion | Argonne National Laboratory

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    H2 ICE Combustion Share Description Hydrogen combustion inside a direct injection H2 engine Topic Energy Energy efficiency Vehicles Hydrogen & fuel cells Credit S. Ciatti This video captures the OH * radicals that are produced during the hydrogen combustion process inside a direct injection H2 engine. It provides a qualitative assessment of where (areas in white, red, and green) and how rapidly those combustion reactions occur. The video was recorded at 3,000 RPM and with 6 bar indicated

  12. Flight Path 30L - ICE House

    U.S. Department of Energy (DOE) all 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

  13. Flight Path 30R - ICE II

    U.S. Department of Energy (DOE) all 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

  14. The SPectrometer for Ice Nuclei (SPIN): An instrument to investigate ice nucleation

    DOE PAGES-Beta [OSTI]

    Garimella, Sarvesh; Kristensen, Thomas Bjerring; Ignatius, Karolina; Welti, Andre; Voigtlander, Jens; Kulkarni, Gourihar R.; Sagan, Frank; Kok, Gregory Lee; Dorsey, James; Nichman, Leonid; et al

    2016-07-06

    The SPectrometer for Ice Nuclei (SPIN) is a commercially available ice nucleating particle (INP) counter manufactured by Droplet Measurement Technologies in Boulder, CO. The SPIN is a continuous flow diffusion chamber with parallel plate geometry based on the Zurich Ice Nucleation Chamber and the Portable Ice Nucleation Chamber. This study presents a standard description for using the SPIN instrument and also highlights methods to analyze measurements in more advanced ways. It characterizes and describes the behavior of the SPIN chamber, reports data from laboratory measurements, and quantifies uncertainties associated with the measurements. Experiments with ammonium sulfate are used to investigatemore » homogeneous freezing of deliquesced haze droplets and droplet breakthrough. Experiments with kaolinite, NX illite, and silver iodide are used to investigate heterogeneous ice nucleation. SPIN nucleation results are compared to those from the literature. A machine learning approach for analyzing depolarization data from the SPIN optical particle counter is also presented (as an advanced use). Altogether, we report that the SPIN is able to reproduce previous INP counter measurements.« less

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Ice Sheet Model Reveals Most Comprehensive Projections for West

    U.S. Department of Energy (DOE) all 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

  1. ARM - Lesson Plans: When Floating Ice Melts in the Sea

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    When Floating Ice Melts in the Sea 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 Lesson Plans: When Floating Ice Melts in the Sea Objective The objective is to investigate the effect on sea level due to the melting of floating ice due to global warming. Materials Each student or group of

  2. Polarimetric Scattering Database for Non-spherical Ice Particles at

    Office of Scientific and Technical Information (OSTI)

    Microwave Wavelengths (Dataset) | Data Explorer Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths Title: Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths A database containing polarimetric single-scattering properties of various types of ice particles at millimeter to centimeter wavelengths is presented. This database is complementary to earlier ones in that it contains complete (polarimetric) scattering

  3. Independent Cost Review (ICR) and Independent Cost Estimate (ICE) Standard

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Operating Procedures, Revision 2 | Department of Energy Independent Cost Review (ICR) and Independent Cost Estimate (ICE) Standard Operating Procedures, Revision 2 Independent Cost Review (ICR) and Independent Cost Estimate (ICE) Standard Operating Procedures, Revision 2 This Standard Operating Procedures (SOP) provides guidance for Department of Energy (DOE) Project Management Oversight and Assessment (PM) staff and contractors performing either an Independent Cost Estimate (ICE) or an

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

    National Nuclear Security Administration (NNSA)

    sea-level rise | National Nuclear Security Administration | (NNSA) 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

  5. Rewritable Artificial Magnetic Charge Ice | Argonne National Laboratory

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Rewritable Artificial Magnetic Charge Ice June 17, 2016 Tweet EmailPrint Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. A team of researchers using the Center for Nanoscale Materials (CNM) designed an artificial spin structure that produces a magnetic charge ice with tunable

  6. Rapid ice-wedge melting accelerates permafrost decline

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Rapid ice-wedge melting accelerates permafrost decline Rapid ice-wedge melting accelerates permafrost decline A new study of permafrost has found that the ice wedges forming the prevalent honeycomb pattern across the tundra appear to be melting rapidly across the Arctic. March 15, 2016 Los Alamos National Laboratory scientist Cathy Wilson measuring how soil properties change with depth at the DOE Next Generation Ecosystem Experiment, NGEE-Arctic, field site near Barrow, Alaska. Los Alamos

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

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect 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 and regional land-sourced INP, and that the

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

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ICE SUPPORT CONTRACTOR 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 desired

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

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    A new computer model of accumulated carbon emissions predicts the likelihood of crossing several dangerous climate change thresholds. November 20, 2015 Greenland ice loss. ...

  10. Marine Ice Nuclei Collections - MAGIC (MAGIC-IN) Final Campaign...

    Office of Scientific and Technical Information (OSTI)

    for offline processing to measure ice nucleating particle (INP) number concentrations. ... time of this report, will include single particle analyses of marine boundary layer ...

  11. 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 ...

  12. Single Particle Database of Natural Ice Crystals: Dimensions

    U.S. Department of Energy (DOE) all 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...

  13. 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...

  14. Radiative transfer in atmosphere-sea ice-ocean system

    SciTech Connect (OSTI)

    Jin, Z.; Stamnes, K.; Weeks, W.F.; Tsay, S.C.

    1996-04-01

    Radiative energy is critical in controlling the heat and mass balance of sea ice, which significantly affects the polar climate. In the polar oceans, light transmission through the atmosphere and sea ice is essential to the growth of plankton and algae and, consequently, to the microbial community both in the ice and in the ocean. Therefore, the study of radiative transfer in the polar atmosphere, sea ice, and ocean system is of particular importance. Lacking a properly coupled radiative transfer model for the atmosphere-sea ice-ocean system, a consistent study of the radiative transfer in the polar atmosphere, snow, sea ice, and ocean system has not been undertaken before. The radiative transfer processes in the atmosphere and in the ice and ocean have been treated separately. Because the radiation processes in the atmosphere, sea ice, and ocean depend on each other, this separate treatment is inconsistent. To study the radiative interaction between the atmosphere, clouds, snow, sea ice, and ocean, a radiative transfer model with consistent treatment of radiation in the coupled system is needed and is under development.

  15. 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. ...

  16. 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.

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

    U.S. Department of Energy (DOE) all 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 ...

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

    U.S. Department of Energy (DOE) all 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 ...

  19. 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. Citation ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

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

    Office of Scientific and Technical Information (OSTI)

    Annual progress report This is the third annual report on: Sea Ice-Atmosphere Interaction ... Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL ...

  1. 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.

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

    U.S. Department of Energy (DOE) all 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)...

  4. 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.

  5. Nanotextured Anti-Icing Surfaces | GE Global Research

    U.S. Department of Energy (DOE) all 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

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

    DOE PAGES-Beta [OSTI]

    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

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

    DOE PAGES-Beta [OSTI]

    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

  8. Vehicle Technologies Office Merit Review 2014: High-Temperature Air-Cooled Power Electronics Thermal Design

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation given by National Renewable Energy Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high...

  9. Liquid Cooling v. Air Cooling Evaluation in the Maui High-Performance...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Study: Innovative Energy Efficiency Approaches in NOAA's Environmental Security Computing Center in Fairmont, West Virginia High-Performance Computing Data Center Metering Protocol

  10. Method and apparatus for enhancing reactor air-cooling system performance

    DOE Patents [OSTI]

    Hunsbedt, Anstein

    1996-01-01

    An enhanced decay heat removal system for removing heat from the inert gas-filled gap space between the reactor vessel and the containment vessel of a liquid metal-cooled nuclear reactor. Multiple cooling ducts in flow communication with the inert gas-filled gap space are incorporated to provide multiple flow paths for the inert gas to circulate to heat exchangers which remove heat from the inert gas, thereby introducing natural convection flows in the inert gas. The inert gas in turn absorbs heat directly from the reactor vessel by natural convection heat transfer.

  11. Method and apparatus for enhancing reactor air-cooling system performance

    DOE Patents [OSTI]

    Hunsbedt, A.

    1996-03-12

    An enhanced decay heat removal system is disclosed for removing heat from the inert gas-filled gap space between the reactor vessel and the containment vessel of a liquid metal-cooled nuclear reactor. Multiple cooling ducts in flow communication with the inert gas-filled gap space are incorporated to provide multiple flow paths for the inert gas to circulate to heat exchangers which remove heat from the inert gas, thereby introducing natural convection flows in the inert gas. The inert gas in turn absorbs heat directly from the reactor vessel by natural convection heat transfer. 6 figs.

  12. Optimization of hybrid-water/air-cooled condenser in an enhanced...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Optimization of hybrid-waterair-cooled condenser in an enhanced turbine geothermal ORC system Optimization of hybrid-waterair-cooled condenser in an enhanced turbine geothermal ORC ...

  13. Optimization of hybrid-water/air-cooled condenser in an enhanced...

    Open Energy Information (Open El) [EERE & EIA]

    Optimization of hybrid-waterair-cooled condenser in an enhanced turbine geothermal ORC system Geothermal Project Jump to: navigation, search Last modified on July 22, 2011....

  14. Clean Air-Cool Planet Small Town Carbon Calculator | Open Energy...

    Open Energy Information (Open El) [EERE & EIA]

    of New Hampshire, ICLEI, Environmental Protection Agency Sector: Climate Focus Area: Buildings, Transportation, Greenhouse Gas Phase: Determine Baseline, Evaluate Effectiveness...

  15. Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption...

    Energy.gov (indexed) [DOE]

    lithium bromide (LiBr)-water absorption chillers to guide future efforts to develop chillers for combined heat and power (CHP) applications in light-commercial buildings. ...

  16. Air-Cooled Condensers in Next-Generation Conversion Systems Geothermal...

    Open Energy Information (Open El) [EERE & EIA]

    expensive to develop, there will be increased incentive to use more efficient power plants. Because of increasing demand on finite supplies of water, this next generation of...

  17. CFD analyses of natural circulation in the air-cooled reactor cavity cooling system

    SciTech Connect (OSTI)

    Hu, R.; Pointer, W. D.

    2013-07-01

    The Natural Convection Shutdown Heat Removal Test Facility (NSTF) is currently being built at Argonne National Laboratory, to evaluate the feasibility of the passive Reactor Cavity Cooling System (RCCS) for Next Generation Nuclear Plant (NGNP). CFD simulations have been applied to evaluate the NSTF and NGNP RCCS designs. However, previous simulations found that convergence was very difficult to achieve in simulating the complex natural circulation. To resolve the convergence issue and increase the confidence of the CFD simulation results, additional CFD simulations were conducted using a more detailed mesh and a different solution scheme. It is found that, with the use of coupled flow and coupled energy models, the convergence can be greatly improved. Furthermore, the effects of convection in the cavity and the effects of the uncertainty in solid surface emissivity are also investigated. (authors)

  18. Hybrid Air-Cooled Condenser for Power Plants and other applications...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    The thermal efficiency of geothermal power plants is relatively low, e.g. in the range of 10 to 23 ... when extracting useful energy during the generation of electricity. ...

  19. Case Study: Evaluating Liquid v. Air Cooling in the Maui High...

    Energy Savers

    ... a holistic perspective, that energy distribution is far from optimal. ... output from the Uninterruptible Power Supply (UPS) input. While water flow was estimated using the pump ...

  20. Flight Path 30L - ICE House

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    L The shape of the neutron spectrum on the 30° flight paths 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. Target 4 Flight Path 30L (ICE House) Target 4 Flight Path 30L (4FP30L) utilizes the neutrons that scatter off the tungsten spallation source at approximately 30 degrees to beam left. The experiments

  1. Flight Path 30R | ICE II

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    R 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. Target 4 Flight Path 30R (ICE II) Target 4 Flight Path 30R (4FP30R) utilizes the neutrons that scatter off the tungsten spallation source at approximately 30 degrees to beam right. The experiments utilizing this flight path

  2. 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.

  3. 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 ...

  4. Controls on Arctic sea ice from first-year and multi-year survival rates

    SciTech Connect (OSTI)

    Hunke, Jes

    2009-01-01

    The recent decrease in Arctic sea ice cover has transpired with a significant loss of multi year ice. The transition to an Arctic that is populated by thinner first year sea ice has important implications for future trends in area and volume. Here we develop a reduced model for Arctic sea ice with which we investigate how the survivability of first year and multi year ice control the mean state, variability, and trends in ice area and volume.

  5. 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.

  6. 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.

  7. 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 ...

  8. Freezing a Droplet to Stop the Ice | U.S. DOE Office of Science...

    Office of Science (SC) [DOE]

    Freezing a Droplet to Stop the Ice Advances in simulating water molecules in droplets ... Million molecule simulation of ice formation in a single water droplet. The location of ...

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

    U.S. Department of Energy (DOE) all 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 ...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Ice slurry cooling development and field testing

    SciTech Connect (OSTI)

    Kasza, K.E. ); Hietala, J. ); Wendland, R.D. ); Collins, F. )

    1992-01-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  15. Ice slurry cooling development and field testing

    SciTech Connect (OSTI)

    Kasza, K.E.; Hietala, J.; Wendland, R.D.; Collins, F.

    1992-07-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  16. 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.

  17. Ice accretion modeling for wind turbine rotor blades

    SciTech Connect (OSTI)

    Chocron, D.; Brahimi, T.; Paraschivoiu, I.; Bombardier, J.A.

    1997-12-31

    The increasing application of wind energy in northern climates implies operation of wind turbines under severe atmospheric icing conditions. Such conditions are well known in the Scandinavian countries, Canada and most of Eastern European countries. An extensive study to develop a procedure for the prediction of ice accretion on wind turbines rotor blades appears to be essential for the safe and economic operation of wind turbines in these cold regions. The objective of the present paper is to develop a computer code capable of simulating the shape and amount of ice which may accumulate on horizontal axis wind turbine blades when operating in icing conditions. The resulting code is capable to predict and simulate the formation of ice in rime and glaze conditions, calculate the flow field and particle trajectories and to perform thermodynamic analysis. It also gives the possibility of studying the effect of different parameters that influence ice formation such as temperature, liquid water content, droplet diameter and accretion time. The analysis has been conducted on different typical airfoils as well as on NASA/DOE Mod-0 wind turbine. Results showed that ice accretion on wind turbines may reduce the power output by more than 20%.

  18. Metastable hydronium ions in UV-irradiated ice

    SciTech Connect (OSTI)

    Moon, Eui-Seong; Kang, Heon

    2012-11-28

    We show that the irradiation of UV light (10-11 eV) onto an ice film produces metastable hydronium (H{sub 3}O{sup +}) ions in the ice at low temperatures (53-140 K). Evidence of the presence of metastable hydronium ions was obtained by experiments involving adsorption of methylamine onto UV-irradiated ice films and hydrogen-deuterium (H/D) isotopic exchange reaction. The methylamine adsorption experiments showed that photogenerated H{sub 3}O{sup +} species transferred a proton to the methylamine arriving at the ice surface, thus producing the methyl ammonium ion, which was detected by low energy sputtering method. The H{sub 3}O{sup +} species induced the H/D exchange of water, which was monitored through the detection of water isotopomers on the surface by using the Cs{sup +} reactive ion scattering method. Thermal and temporal stabilities of H{sub 3}O{sup +} and its proton migration activity were examined. The lifetime of the hydronium ions in the amorphized ice was greater than 1 h at {approx}53 K and decreased to {approx}5 min at 140 K. Interestingly, a small portion of hydronium ions survived for an extraordinarily long time in the ice, even at 140 K. The average migration distance of protons released from H{sub 3}O{sup +} in the ice was estimated to be about two water molecules at {approx}54 K and about six molecules at 100 K. These results indicate that UV-generated hydronium ions can be efficiently stabilized in low-temperature ice. Such metastable hydronium ions may play a significant role in the acid-base chemistry of ice particles in interstellar clouds.

  19. Searching for Cosmic Accelerators via IceCube

    U.S. Department of Energy (DOE) all 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

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

    U.S. Department of Energy (DOE) all 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

  1. ARM - Publications: Science Team Meeting Documents: Investigation of Ice

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Crystal Shapes Using Multi-resolution Techniques Investigation of Ice Crystal Shapes Using Multi-resolution Techniques McFarquhar, Greg University of Illinois Better knowledge of small-scale features from ice crystals are needed to determine their effects on radiation and hence to improve the treatment of clouds in climate models. With the Cloud Particle Imager (CPI) it is now possible to capture ice crystal images with 2.3 μm resolution and 256 gray scales of illumination, providing an

  2. 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.

  3. Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica

    DOE PAGES-Beta [OSTI]

    Bougamont, M.; Christoffersen, P.; Price, S. F.; Fricker, H. A.; Tulaczyk, S.; Carter, S. P.

    2015-10-21

    Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leadingmore » to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.« less

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. ARM-UAV TWP-ICE Activities and Data

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    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 ...

  9. A New Approach for Representing Ice Particles in Weather

    U.S. Department of Energy (DOE) all 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)...

  10. 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 ...

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

    U.S. Department of Energy (DOE) all 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...

  12. Magnetic charge crystals imaged in artificial spin ice

    U.S. Department of Energy (DOE) all 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...

  13. Melting of ice wedges adds to arctic warming

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Ice wedges are a particularly cool surface feature in the Arctic tundra. And new research suggests they are melting fast, which is bad news for the ecosystem at the top of the ...

  14. 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.

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

    U.S. Department of Energy (DOE) all 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...

  16. 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.

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

    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.

  19. Ice Nucleation of Fungal Spores from the Classes Agaricomycetes...

    Office of Scientific and Technical Information (OSTI)

    Simulations show that inclusion of ice nucleation scavenging of fungal spores in mixed-phase clouds can decrease the surface annual mean mixing ratios of fungal spores over the ...

  20. 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

  1. Complex systems influence melting of Greenland ice sheet

    U.S. Department of Energy (DOE) all 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

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

    U.S. Department of Energy (DOE) all 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 Darwin, Australia during January and February, 2006. One of the primary goals of this experiment is to develop an integrated meteorological and high-level cloud data set that will increase our understanding of the processes that result in the formation and maintenance of tropical anvils and extended cirrus layers. In

  3. COLLOQUIUM: Extending the Ice Core Record of Atmospheric Composition and

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    the Global Carbon and Oxygen Cycles Beyond 1 Million Years | Princeton Plasma Physics Lab 1, 2016, 2:15pm to 3:30pm Colloquia MBG Auditorium, PPPL (284 cap.) COLLOQUIUM: Extending the Ice Core Record of Atmospheric Composition and the Global Carbon and Oxygen Cycles Beyond 1 Million Years Professor John Higgins Princeton University Ice cores serve as a critical archive of past environmental conditions, providing constraints on global atmospheric composition and the climate of polar regions.

  4. 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.

  5. TTW - PageMaker 2

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    5, 2004 By the Numbers State legislators tour WIPP Shipments scheduled to arrive at WIPP for the week 4/18 - 4/24/04: 25 Total shipments received at WIPP: 2,488 Total volume disposed at WIPP: 19,339 m 3 FY04 Performance Metrics D E P A R T M E N T O F E N E R G Y U N I T E D S T A T ES O F A M E R I C A TeamWorks TeamWorks TRU A weekly e-newsletter for the Waste Isolation Pilot Plant team Members of the National Conference of State Legislators (NCSL) Radioac- tive Waste Program toured WIPP on

  6. TTW - PageMaker 2

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    2, 2004 By the Numbers Second quarterly meeting held in Carlsbad Shipments scheduled to arrive at WIPP week of 4/25/04 - 5/1/04: 27 Total shipments received at WIPP as of 4/21/04: 2,509 Total volume disposed at WIPP as of 4/21/04: 19,550 m 3 FY04 Performance Metrics D E P A R T M E N T O F E N E R G Y U N I T E D S T A T ES O F A M E R I C A TeamWorks TeamWorks TRU A weekly e-newsletter for the Waste Isolation Pilot Plant team The second WIPP quarterly meeting for 2004 took place in Carlsbad

  7. TTW - PageMaker 2

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    9, 2004 By the Numbers WIPP employee reports from Iraq Shipments scheduled to arrive at WIPP week of 5/2/04 - 5/8/04: 34 Total shipments received at WIPP: 2,529 Total volume disposed at WIPP: 19,711 m 3 FY04 Performance Metrics D E P A R T M E N T O F E N E R G Y U N I T E D S T A T ES O F A M E R I C A TeamWorks TeamWorks TRU A weekly e-newsletter for the Waste Isolation Pilot Plant team Former WTS employee Ricardo Sanchez left WIPP in February to join the Washington Group International

  8. Bit makers fight to survive

    SciTech Connect (OSTI)

    Brezovec, D.

    1983-04-01

    Competition is fierce amongst the manufacturers of roof drill bits, and testing and machining techniques have improved to design bits that last longer. Information is given in tabulated form on various models and their USA manufacturers. Diamond bits for roof drilling are discussed.

  9. Bay Area Maker Faire 2016

    Energy.gov [DOE]

    Think. Make. Innovate. That’s what the U.S. Department of Energy (DOE) and its national laboratories do every day. By doing so, they help change the world!

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

    DOE PAGES-Beta [OSTI]

    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. 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

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

    DOE PAGES-Beta [OSTI]

    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

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

    DOE PAGES-Beta [OSTI]

    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

  13. 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.

  14. 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 Kärcher 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 (3.24×106 m-2) is obviously less than that from the LP (8.46×106 m-2) and BN (5.62×106 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

  15. 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.

  16. Progress on a TWP-ICE Monsoon Case Study

    U.S. Department of Energy (DOE) all 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

  17. 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.

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

    Energy.gov [DOE]

    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.

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

    Office of Scientific and Technical Information (OSTI)

    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 ...

  20. 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 ...

  1. New Method Relates Greenland Ice Sheet Changes to Sea-Level Rise...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... Research from Edwards et al. 2014a was funded by the ice2sea programme from the European Union (EU) 7th Framework Programme (grant number 226375; ice2sea contribution number 120). ...

  2. 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 ...

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

    Office of Scientific and Technical Information (OSTI)

    Fast proton hopping detection in ice Isub h by quasi-elastic neutron scattering. Citation Details In-Document Search Title: Fast proton hopping detection in ice Isub h by ...

  4. Neutrinos at IceCube from heavy decaying dark matter (Journal...

    Office of Scientific and Technical Information (OSTI)

    Neutrinos at IceCube from heavy decaying dark matter Citation Details In-Document Search Title: Neutrinos at IceCube from heavy decaying dark matter Authors: Feldstein, Brian ; ...

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

    Office of Scientific and Technical Information (OSTI)

    LJWG efforts to date have led to the inclusion of a dynamic ice-sheet model (the Glimmer Community Ice Sheet Model, or Glimmer-CISM) in the Community Earth System Model (CESM), ...

  6. 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...

  7. Land-ice modeling for sea-level prediction (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  8. 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.

  9. 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 -30°C) 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.

  10. City of Eagan …Civic Ice Arena Renovation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    City of Eagan …Civic Ice Arena Renovation City of Eagan …Civic Ice Arena Renovation Project objectives: Provide a reliable central ice making and heating system that meets the performance requirements of the owner. Reduce operation and maintenance costs. gshp_lutz_eagan_ice_arena.pdf (1.84 MB) More Documents & Publications GEOTHERMAL POWER GENERATION PLANT Wilders Grove Solid Waste Services Center Decision Analysis for EGS

  11. 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.

  12. Purchasing Energy-Efficient Water-Cooled Ice Machines

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    DOE PAGES-Beta [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 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

  18. A surface ice module for wind turbine dynamic response simulation using FAST

    DOE PAGES-Beta [OSTI]

    Yu, Bingbin; Karr, Dale G.; Song, Huimin; Sirnivas, Senu

    2016-06-03

    It is a fact that developing offshore wind energy has become more and more serious worldwide in recent years. Many of the promising offshore wind farm locations are in cold regions that may have ice cover during wintertime. The challenge of possible ice loads on offshore wind turbines raises the demand of modeling capacity of dynamic wind turbine response under the joint action of ice, wind, wave, and current. The simulation software FAST is an open source computer-aided engineering (CAE) package maintained by the National Renewable Energy Laboratory. In this paper, a new module of FAST for assessing the dynamicmore » response of offshore wind turbines subjected to ice forcing is presented. In the ice module, several models are presented which involve both prescribed forcing and coupled response. For conditions in which the ice forcing is essentially decoupled from the structural response, ice forces are established from existing models for brittle and ductile ice failure. For conditions in which the ice failure and the structural response are coupled, such as lock-in conditions, a rate-dependent ice model is described, which is developed in conjunction with a new modularization framework for FAST. In this paper, analytical ice mechanics models are presented that incorporate ice floe forcing, deformation, and failure. For lower speeds, forces slowly build until the ice strength is reached and ice fails resulting in a quasi-static condition. For intermediate speeds, the ice failure can be coupled with the structural response and resulting in coinciding periods of the ice failure and the structural response. A third regime occurs at high speeds of encounter in which brittle fracturing of the ice feature occurs in a random pattern, which results in a random vibration excitation of the structure. An example wind turbine response is simulated under ice loading of each of the presented models. This module adds to FAST the capabilities for analyzing the response of wind

  19. 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.

  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

  1. Probing Planck scale physics with IceCube

    SciTech Connect (OSTI)

    Anchordoqui, Luis A.; Goldberg, Haim; Gonzalez-Garcia, M.C.; Halzen, Francis; Hooper, Dan; Sarkar, Subir; Weiler, Thomas J.

    2005-09-15

    Neutrino oscillations can be affected by decoherence induced e.g. by Planck scale suppressed interactions with the space-time foam predicted in some approaches to quantum gravity. We study the prospects for observing such effects at IceCube, using the likely flux of TeV antineutrinos from the Cygnus spiral arm. We formulate the statistical analysis for evaluating the sensitivity to quantum decoherence in the presence of the background from atmospheric neutrinos, as well as from plausible cosmic neutrino sources. We demonstrate that IceCube will improve the sensitivity to decoherence effects of O(E{sup 2}/M{sub Pl}) by 17 orders of magnitude over present limits and, moreover, that it can probe decoherence effects of O(E{sup 3}/M{sub Pl}{sup 2}) which are well beyond the reach of other experiments.

  2. 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.

  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. American Indian Complex to Cool Off Using Ice Storage System

    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.

  5. 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.

  6. 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.

  7. 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.

  8. Dimensions and aspect ratios of natural ice crystals

    DOE PAGES-Beta [OSTI]

    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

  9. Dimensions and aspect ratios of natural ice crystals

    DOE PAGES-Beta [OSTI]

    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

  10. 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.

  11. 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.

  12. 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.

  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

  14. 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 ; ...

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

    U.S. Department of Energy (DOE) all 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,...

  16. Progress in coupling Land Ice and Ocean Models in the MPAS Framework...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Community Earth System Model Land Ice Working Group Meeting ... Sponsoring Org: DOELANL Country of Publication: United States Language: English Subject: ...

  17. Understanding Ice Loss in Earth's Coldest Regions | U.S. DOE...

    Office of Science (SC) [DOE]

    Thus, for accurate measurements in these environments, the processes of solar radiation ... The team investigated two processes: (1) penetration of solar radiation into the ice and ...

  18. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison...

    Office of Scientific and Technical Information (OSTI)

    is governed primarily by the equilibrium between their albedo and greenhouse effects. Both macrophysical and microphysical properties of ice clouds regulate this equilibrium. ...

  19. Update on Greenland Ice Sheet Simulations In CISM and CESM (Conference...

    Office of Scientific and Technical Information (OSTI)

    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: ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Ice Crystal Roughness on Satellite Retrieved Cloud Properties P. Minnis 1 , P. W. Heck 2 , R. F. Arduini 3 , R. Palikonda 3 , J. K. Ayers 3 , M. M. Khaiyer 3 , P. Yang 4 , Y. Xie 4 3 Science Systems & Applications, Inc. Hampton, VA 1 NASA Langley Research Center Hampton, VA Current Cirrus Models Inadequate Cirrus cloud optical depths τ (heights z e ) are often over (under) estimated when derived from solar reflectances. In situ data suggest smaller asymmetry factors, g, than used in most

  5. U

    Energy.gov (indexed) [DOE]

    ... i n t he M YPP 123456 7 00.00 00.00 00.00 00.00 SOLID FEEDER BUBBLING-BED PYROLYZER ESP DRY-ICE TRAP NITROGEN DRY-ICE FILTER GAS METER ONLINE GAS ANALYSIS AIR-COOLED CONDENSER ...

  6. Paleoclimatology: Second clock supports orbital pacing of the ice ages

    SciTech Connect (OSTI)

    Kerr, R.A.

    1997-05-02

    For a while, it looked as if a water-filled crack in the Nevada desert might doom the accepted explanation of the ice ages. Twenty years ago, the so-called astronomical theory had carried the day. Oceanographers had found evidence implying that the march of ice ages over the last million years was paced by the cyclical stretching and squeezing of Earth`s orbit around the sun, which would have altered the way sunlight fell on the planet`s surface. But in 1988, researchers scuba diving in Nevada`s Devils Hole came up with a climate record--captured in carbonate deposits in the crack-that seemed to contradict this chronology. This article discusses the findings and the puzzles that still remain. The records of sea-level change in Barbados coral appear to be right and the astronomical theory is on solid ground using a new clock based on the radioactive decay of uranium-235 to protactinium-231. However, the Devils Hole record also seems to be correct.

  7. 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.

  8. 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.

  9. 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)

  10. 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

  11. 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.

  12. 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 PAGES-Beta [OSTI]

    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

  13. 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

  14. 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.

  15. 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.

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

    DOE PAGES-Beta [OSTI]

    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

  17. 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.

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

    DOE PAGES-Beta [OSTI]

    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

  19. Microwave signatures of ice hydrometeors from ground-based observations above Summit, Greenland

    DOE PAGES-Beta [OSTI]

    Pettersen, Claire; Bennartz, Ralf; Kulie, Mark S.; Merrelli, Aronne J.; Shupe, Matthew D.; Turner, David D.

    2016-04-15

    Multi-instrument, ground-based measurements provide unique and comprehensive data sets of the atmosphere for a specific location over long periods of time and resulting data compliment past and existing global satellite observations. This paper explores the effect of ice hydrometeors on ground-based, high-frequency passive microwave measurements and attempts to isolate an ice signature for summer seasons at Summit, Greenland, from 2010 to 2013. Data from a combination of passive microwave, cloud radar, radiosonde, and ceilometer were examined to isolate the ice signature at microwave wavelengths. By limiting the study to a cloud liquid water path of 40 gm–2 or less, themore » cloud radar can identify cases where the precipitation was dominated by ice. These cases were examined using liquid water and gas microwave absorption models, and brightness temperatures were calculated for the high-frequency microwave channels: 90, 150, and 225 GHz. By comparing the measured brightness temperatures from the microwave radiometers and the calculated brightness temperature using only gas and liquid contributions, any residual brightness temperature difference is due to emission and scattering of microwave radiation from the ice hydrometeors in the column. The ice signature in the 90, 150, and 225 GHz channels for the Summit Station summer months was isolated. As a result, this measured ice signature was then compared to an equivalent brightness temperature difference calculated with a radiative transfer model including microwave single-scattering properties for several ice habits. Initial model results compare well against the 4 years of summer season isolated ice signature in the high-frequency microwave channels.« less

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

    DOE PAGES-Beta [OSTI]

    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

  1. 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.

  2. 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

  3. Century-scale simulations of the response of the West Antarctic Ice Sheet to a warming climate

    DOE PAGES-Beta [OSTI]

    Cornford, S. L.; Martin, D. F.; Payne, A. J.; Ng, E. G.; Le Brocq, A. M.; Gladstone, R. M.; Edwards, T. L.; Shannon, S. R.; Agosta, C.; van den Broeke, M. R.; et al

    2015-03-23

    We use the BISICLES adaptive mesh ice sheet model to carry out one, two, and three century simulations of the fast-flowing ice streams of the West Antarctic Ice Sheet. Each of the simulations begins with a geometry and velocity close to present day observations, and evolves according to variation in meteoric ice accumulation, ice shelf melting, and mesh resolution. Future changes in accumulation and melt rates range from no change, through anomalies computed by atmosphere and ocean models driven by the E1 and A1B emissions scenarios, to spatially uniform melt rates anomalies that remove most of the ice shelves overmore » a few centuries. We find that variation in the resulting ice dynamics is dominated by the choice of initial conditions, ice shelf melt rate and mesh resolution, although ice accumulation affects the net change in volume above flotation to a similar degree. Given sufficient melt rates, we compute grounding line retreat over hundreds of kilometers in every major ice stream, but the ocean models do not predict such melt rates outside of the Amundsen Sea Embayment until after 2100. Sensitivity to mesh resolution is spurious, and we find that sub-kilometer resolution is needed along most regions of the grounding line to avoid systematic under-estimates of the retreat rate, although resolution requirements are more stringent in some regions – for example the Amundsen Sea Embayment – than others – such as the Möller and Institute ice streams.« less

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

    Office of Scientific and Technical Information (OSTI)

    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 velocity (V_ter) are given at

  5. 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.

  6. Effects Of Crystallographic Properties On The Ice Nucleation Properties Of Volcanic Ash Particles

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Nandasiri, Manjula I.; Zelenyuk, Alla; Beranek, Josef; Madaan, Nitesh; Devaraj, Arun; Shutthanandan, V.; Thevuthasan, Suntharampillai; Varga, Tamas

    2015-04-28

    Specific chemical and physical properties of volcanic ash particles that could affect their ability to induce ice formation are poorly understood. In this study, the ice nucleating properties of size-selected volcanic ash and mineral dust particles in relation to their surface chemistry and crystalline structure at temperatures ranging from –30 to –38 °C were investigated in deposition mode. Ice nucleation efficiency of dust particles was higher compared to ash particles at all temperature and relative humidity conditions. Particle characterization analysis shows that surface elemental composition of ash and dust particles was similar; however, the structural properties of ash samples were different.

  7. 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.

  8. 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.

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

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    level rise than earlier feared, scientists say Stories » 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

  10. UV-induced protonation of molecules adsorbed on ice surfaces at low temperature

    SciTech Connect (OSTI)

    Moon, Eui-Seong; Lee, Chang-Woo; Kim, Joon-Ki; Park, Seong-Chan; Kang, Heon

    2008-05-21

    UV irradiation of ice films adsorbed with methylamine molecules induces protonation of the adsorbate molecules at low temperature (50-130 K). The observation indicates that long-lived protonic defects are created in the ice film by UV light, and they transfer protons to the adsorbate molecules via tunneling mechanism at low temperature. The methylammonium ion formed by proton transfer remains to be stable at the ice surface. It is suggested that this solid-phase protonation might play a significant role in the production of molecular ions in interstellar clouds.

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

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    COMBINED EIR/ICE SUPPORT CONTRACTOR 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. 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

  12. 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.

  13. 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.

  14. Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths

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

    Aydin, Kultegin; Verlinde, Johannes; Clothiaux, Eugene; Lu, Yinghui; Jiang, Zhiyuan; Botta, Giovanni

    2016-06-21

    A database containing polarimetric single-scattering properties of various types of ice particles at millimeter to centimeter wavelengths is presented. This database is complementary to earlier ones in that it contains complete (polarimetric) scattering property information for each ice particle - 44 plates, 30 columns, 405 branched planar crystals, 660 aggregates, and 640 conical graupel - and direction of incident radiation but is limited to four frequencies (W-, Ka-, Ku- and X-bands), does not include temperature dependencies of the single-scattering properties and does not include scattering properties averaged over randomly oriented ice particles. Rules for constructing the morphologies of ice particles from one database to the next often differ; consequently, analyses that incorporate all of the different databases will contain the most variability, while illuminating important differences between them.

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

    Office of Scientific and Technical Information (OSTI)

    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). ...

  16. 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 ...

  17. 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 ...

  18. 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.

  19. Proton disorder in cubic ice: Effect on the electronic and optical properties

    SciTech Connect (OSTI)

    Garbuio, Viviana; Pulci, Olivia; Cascella, Michele; Kupchak, Igor; Seitsonen, Ari Paavo

    2015-08-28

    The proton disorder in ice has a key role in several properties such as the growth mode, thermodynamical properties, and ferroelectricity. While structural phase transitions from proton disordered to proton ordered ices have been extensively studied, much less is known about their electronic and optical properties. Here, we present ab initio many body perturbation theory-based calculations of the electronic and optical properties of cubic ice at different levels of proton disorder. We compare our results with those from liquid water, that acts as an example of a fully (proton- and oxygen-)disordered system. We find that by increasing the proton disorder, a shrinking of the electronic gap occurs in ice, and it is smallest in the liquid water. Simultaneously, the excitonic binding energy decreases, so that the final optical gaps result to be almost independent on the degree of proton disorder. We explain these findings as an interplay between the local dipolar disorder and the electronic correlation.

  20. 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 ...

  1. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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 ...

  3. 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 ...

  4. ARM - PI Product - Polarimetric Scattering Database for Non-spherical Ice

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Particles at Microwave Wavelengths ProductsPolarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths Citation DOI: 10.5439/1258029 [ What is this? ] 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 PI Product : Polarimetric Scattering Database for Non-spherical Ice Particles at Microwave Wavelengths [ research data - External funding ] The atmospheric science community has entered

  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. Unusual dynamic properties of water near the ice-binding plane of hyperactive antifreeze protein

    SciTech Connect (OSTI)

    Kuffel, Anna; Czapiewski, Dariusz; Zielkiewicz, Jan

    2015-10-07

    The dynamical properties of solvation water of hyperactive antifreeze protein from Choristoneura fumiferana (CfAFP) are analyzed and discussed in context of its antifreeze activity. The protein comprises of three well-defined planes and one of them binds to the surface of ice. The dynamical properties of solvation water around each of these planes were analyzed separately; the results are compared with the dynamical properties of solvation water of ice around its two crystallographic planes: basal and prism. Three main conclusions are inferred from our investigations. The first one is that the solvation shell of CfAFP does not seem to be particularly far-ranged, at least not beyond what is usually observed for proteins that do not interact with ice. Therefore, it does not appear to us that the antifreeze activity is enhanced by a long-ranged retardation of water mobility. Also the correlation between the collective mobility of water and the collective mobility of protein atoms highly resembles the one measured for the protein that does not interact with ice. Our second conclusion is that the dynamical properties of solvation water of CfAFP are non-uniform. The dynamics of solvation water of ice-binding plane is, in some respects, different from the dynamics of solvation water of the two remaining planes. The feature that distinguishes the dynamics of solvation water of the three planes is the activation energy of diffusion process. The third conclusion is that—from the three analyzed solvation shells of CfAFP—the dynamical properties of solvation water of the ice-binding plane resemble the most the properties of solvation water of ice; note, however, that these properties still clearly differ from the dynamic properties of solvation water of ice.

  7. 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.

  8. optimal initial conditions for coupling ice sheet models to earth system

    Office of Scientific and Technical Information (OSTI)

    models (Conference) | SciTech Connect Conference: 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 Authors: Perego, Mauro [1] ; Price, Stephen F. Dr [2] ; Stadler, Georg [3] + Show Author Affiliations Sandia National Laboratories Los Alamos National Laboratory Institute for Computational Engineering and Sciences, Univ. of Texas at Austin

  9. 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,

  10. Inside Ice Under High Pressure | U.S. DOE Office of Science (SC)

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Inside Ice Under High Pressure Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) Community Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F: (301) 903-6594 E: Email Us More Information » 10.01.14 Inside Ice Under High Pressure New insights from neutron

  11. Impacts of ocean albedo alteration on Arctic sea ice restoration and Northern Hemisphere climate

    DOE PAGES-Beta [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 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

  12. American Flyers N-I Wine Makers

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... to connect to the phone and access the Internet via the phone provider's data network. ... them that radiation is commonly found in everyday things, such as the bananas they eat. ...

  13. DOE Subpoenas Maker of Super Power Showerhead

    Energy.gov [DOE]

    Yesterday, the Department of Energy’s Office of Enforcement issued a subpoena to Richard Graham of Long Beach, California seeking water efficiency information and sales records for the “Super Power...

  14. 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.

  15. 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.

  16. 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.

  17. ICEd-ALE Treatment of 3-D Fluid Flow.

    Energy Science and Technology Software Center (OSTI)

    1999-09-13

    Version: 00 SALE3D calculates three-dimensional fluid flow at all speeds, from the incompressible limit to highly supersonic. An implicit treatment of the pressure calculation similar to that in the Implicit Continuous-fluid Eulerian (ICE) technique provides this flow speed flexibility. In addition, the computing mesh may move with the fluid in a typical Lagrangian fashion, be held in an Eulerian manner, or move in some arbitrarily specified way to provide a continuous rezoning capability. This latitudemore » results from use of an Arbitrary Lagrangian-Eulerian (ALE) treatment of the mesh. The partial differential equations solved are the Navier-Stokes equations and the mass and internal energy equations. The fluid pressure is determined from an equation of state and supplemented with an artificial viscous pressure for the computation of shock waves. The computing mesh consists of a three-dimensional network of arbitrarily shaped, six-sided deformable cells, and a variety of user-selectable boundary conditions are provided in the program.« less

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

    DOE PAGES-Beta [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 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

  19. Uncertainty quantification and global sensitivity analysis of the Los Alamos sea ice model

    DOE PAGES-Beta [OSTI]

    Urrego-Blanco, Jorge Rolando; Urban, Nathan Mark; Hunke, Elizabeth Clare; Turner, Adrian Keith; Jeffery, Nicole

    2016-04-22

    Changes in the high-latitude climate system have the potential to affect global climate through feedbacks with the atmosphere and connections with midlatitudes. Sea ice and climate models used to understand these changes have uncertainties that need to be characterized and quantified. We present a quantitative way to assess uncertainty in complex computer models, which is a new approach in the analysis of sea ice models. We characterize parametric uncertainty in the Los Alamos sea ice model (CICE) in a standalone configuration and quantify the sensitivity of sea ice area, extent, and volume with respect to uncertainty in 39 individual modelmore » parameters. Unlike common sensitivity analyses conducted in previous studies where parameters are varied one at a time, this study uses a global variance-based approach in which Sobol' sequences are used to efficiently sample the full 39-dimensional parameter space. We implement a fast emulator of the sea ice model whose predictions of sea ice extent, area, and volume are used to compute the Sobol' sensitivity indices of the 39 parameters. Main effects and interactions among the most influential parameters are also estimated by a nonparametric regression technique based on generalized additive models. A ranking based on the sensitivity indices indicates that model predictions are most sensitive to snow parameters such as snow conductivity and grain size, and the drainage of melt ponds. Lastly, it is recommended that research be prioritized toward more accurately determining these most influential parameter values by observational studies or by improving parameterizations in the sea ice model.« less

  20. 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.

  1. 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.

  2. ICE CHEMISTRY ON OUTER SOLAR SYSTEM BODIES: ELECTRON RADIOLYSIS OF N{sub 2}-, CH{sub 4}-, AND CO-CONTAINING ICES

    SciTech Connect (OSTI)

    Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.; Imanaka, Hiroshi; Nuevo, Michel

    2015-10-20

    Radiation processing of the surface ices of outer Solar System bodies may be an important process for the production of complex chemical species. The refractory materials resulting from radiation processing of known ices are thought to impart to them a red or brown color, as perceived in the visible spectral region. In this work, we analyzed the refractory materials produced from the 1.2-keV electron bombardment of low-temperature N{sub 2}-, CH{sub 4}-, and CO-containing ices (100:1:1), which simulates the radiation from the secondary electrons produced by cosmic ray bombardment of the surface ices of Pluto. Despite starting with extremely simple ices dominated by N{sub 2}, electron irradiation processing results in the production of refractory material with complex oxygen- and nitrogen-bearing organic molecules. These refractory materials were studied at room temperature using multiple analytical techniques including Fourier-transform infrared spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy, and gas chromatography coupled with mass spectrometry (GC-MS). Infrared spectra of the refractory material suggest the presence of alcohols, carboxylic acids, ketones, aldehydes, amines, and nitriles. XANES spectra of the material indicate the presence of carboxyl groups, amides, urea, and nitriles, and are thus consistent with the IR data. Atomic abundance ratios for the bulk composition of these residues from XANES analysis show that the organic residues are extremely N-rich, having ratios of N/C ∼ 0.9 and O/C ∼ 0.2. Finally, GC-MS data reveal that the residues contain urea as well as numerous carboxylic acids, some of which are of interest for prebiotic and biological chemistries.

  3. Imaging of hydrogen halides photochemistry on argon and ice nanoparticles

    SciTech Connect (OSTI)

    Poterya, V. Lengyel, J.; Pysanenko, A.; Svrčková, P.; Fárník, M.

    2014-08-21

    The photodissociation dynamics of HX (X = Cl, Br) molecules deposited on large Ar{sub N} and (H{sub 2}O){sub N}, N{sup ¯}≈ 10{sup 2}–10{sup 3}, clusters is investigated at 193 nm using velocity map imaging of H and Cl photofragments. In addition, time-of-flight mass spectrometry after electron ionization complemented by pickup cross section measurements provide information about the composition and structure of the clusters. The hydrogen halides coagulate efficiently to generate smaller (HX){sub n} clusters on Ar{sub N} upon multiple pickup conditions. This implies a high mobility of HX molecules on argon. On the other hand, the molecules remain isolated on (H{sub 2}O){sub N}. The photodissociation on Ar{sub N} leads to strong H-fragment caging manifested by the fragment intensity peaking sharply at zero kinetic energy. Some of the Cl-fragments from HCl photodissociation on Ar{sub N} are also caged, while some of the fragments escape the cluster directly without losing their kinetic energy. The images of H-fragments from HX on (H{sub 2}O){sub N} also exhibit a strong central intensity, however, with a different kinetic energy distribution which originates from different processes: the HX acidic dissociation followed by H{sub 3}O neutral hydronium radical formation after the UV excitation, and the slow H-fragments stem from subsequent decay of the H{sub 3}O. The corresponding Cl-cofragment from the photoexcitation of the HCl·(H{sub 2}O){sub N} is trapped in the ice nanoparticle.

  4. 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.

  5. FORMATION AND ALIGNMENT OF ELONGATED, FRACTAL-LIKE WATER-ICE GRAINS IN EXTREMELY COLD, WEAKLY IONIZED PLASMA

    SciTech Connect (OSTI)

    Chai, Kil-Byoung; Bellan, Paul M. E-mail: pbellan@caltech.edu

    2015-04-01

    Elongated, fractal-like water-ice grains are observed to form spontaneously when water vapor is injected into a weakly ionized laboratory plasma formed in a background gas cooled to an astrophysically relevant temperature. The water-ice grains form in 1–2 minutes, levitate with regular spacing, and are aligned parallel to the sheath electric field. Water-ice grains formed in plasma where the neutrals and ions have low mass, such as hydrogen and helium, are larger, more elongated, and more fractal-like than water-ice grains formed in plasmas where the neutrals and ions have high mass such as argon and krypton. Typical aspect ratios (length to width ratio) are as great as 5 while typical fractal dimensions are ∼1.7. Water-ice grain lengths in plasmas with low neutral and ion masses can be several hundred microns long. Infrared absorption spectroscopy reveals that the water-ice grains are crystalline and so are similar in constitution to the water-ice grains in protoplanetary disks, Saturn’s rings, and mesospheric clouds. The properties and behavior of these laboratory water-ice grains may provide insights into morphology and alignment behavior of water-ice grains in astrophysical dusty plasmas.

  6. 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.

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 2014-03-07 Issuance: Energy Conservation Standards for Automatic Commercial

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Ice Makers; Notice of Proposed Rulemaking | Department of Energy 07 Issuance: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Proposed Rulemaking 2014-03-07 Issuance: Energy Conservation Standards for Automatic Commercial Ice Makers; Notice of Proposed Rulemaking This document is a pre-publication Federal Register notice of proposed rulemaking regarding energy conservation standards for automatic commercial ice makers, as issued by the Assistant Secretary on

  14. Southern Great Plains Ice Nuclei Characterization Experiment Final Campaign Summary

    SciTech Connect (OSTI)

    DeMott, PJ; Suski, KJ; Hill, TCJ; Levin, EJT

    2015-03-01

    The first ever ice nucleating particle (INP) measurements to be collected at the Southern Great Plains site were made during a period from late April to June 2014, as a trial for possible longer-term measurements at the site. These measurements will also be used to lay the foundation for understanding and parameterizing (for cloud resolving modeling) the sources of these climatically important aerosols as well as to augment the existing database containing this knowledge. Siting the measurements during the spring was intended to capture INP sources in or to this region from plant, soil, dust transported over long distances, biomass burning, and pollution aerosols at a time when they may influence warm-season convective clouds and precipitation. Data have been archived of real-time measurements of INP number concentrations as a function of processing conditions (temperature and relative humidity) during 18 days of sampling that spanned two distinctly different weather situations: a warm, dry and windy period with regional dust and biomass burning influences in early May, and a cooler period of frequent precipitation during early June. Precipitation delayed winter wheat harvesting, preventing intended sampling during that perturbation on atmospheric aerosols. INP concentrations were highest and most variable at all temperatures in the dry period, where we attribute the INP activity primarily to soil dust emissions. Additional offline INP analyses are underway to extend the characterization of INP to cover the entire mixed phase cloud regime from -5°C to -35°C during the full study. Initial comparisons between methods on four days show good agreement and excellent future promise. The additional offline immersion freezing data will be archived as soon as completed under separate funding. Analyses of additional specialized studies for specific attribution of INP to biological and smoke sources are continuing via the National Science Foundation and National Aeronautics

  15. 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.

  16. 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.

  17. 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.

  18. In Situ Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

    DOE PAGES-Beta [OSTI]

    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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Effects of exchange bias on magnetotransport in permalloy kagome artificial spin ice

    DOE PAGES-Beta [OSTI]

    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.

  5. Entropic description of gas hydrate ice/liquid equilibrium via enhanced sampling of coexisting phases

    DOE PAGES-Beta [OSTI]

    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.

  6. Progress in coupling Land Ice and Ocean Models in the MPAS Framework

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Progress 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:

  7. Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms

    SciTech Connect (OSTI)

    Sednev, Igor; Sednev, I.; Menon, S.; McFarquhar, G.

    2008-02-18

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9th-10th October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase

  8. Geoengineering by cloud seeding: influence on sea ice and climate system

    SciTech Connect (OSTI)

    Rasch, Philip J.; Latham, John; Chen, Chih-Chieh

    2009-12-18

    GCM computations using a fully coupled ocean atmosphere model indicate that increasing cloud reflectivity by seeding maritime boundary layer clouds with particles made from seawater may compensate for some of the effects on climate of increasing greenhouse gas concentrations. The chosen seeding strategy (one of many possible scenarios) can restore global averages of temperature, precipitation and sea ice to present day values, but not simultaneously. The response varies nonlinearly with extent of the seeding, and geoengineering generates local changes to important climatic features. The global tradeoffs of restoring ice cover and cooling the planet must be assessed alongside the local changes to climate features.

  9. Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiationmechanisms

    SciTech Connect (OSTI)

    Sednev, I.; Menon, S.; McFarquhar, G.

    2009-04-10

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during October 9th-10th, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-hour simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase

  10. Progress on an ARM/GCSS/SPARC TWP-ICE Monsoon Case Study

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Progress on an ARM/GCSS/SPARC TWP-ICE Monsoon Case Study Ann Fridlind and Andrew Ackerman ann.fridlind@nasa.gov * www.giss.nasa.gov/∼fridlind Introduction Source: Lori Chappel, Australian BOM The Tropical Warm Pool-International Cloud Experiment (TWP-ICE) assembled aircraft and ground instruments at the DOE-ARM long-term site in Darwin, Australia during the 2005/2006 monsoon, and the early part of the campaign encountered active monsoon conditions (left). The goal of this work is to help

  11. 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.

  12. 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.

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

    Office of Scientific and Technical Information (OSTI)

    (MPAS) (Conference) | SciTech Connect 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 Type:

  14. Bio-based Deicing/Anti-Icing Fluids - Energy Innovation Portal

    U.S. Department of Energy (DOE) all 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

  15. 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.

  16. Heat sources within the Greenland Ice Sheet: dissipation, temperate paleo-firn and cryo-hydrologic warming

    DOE PAGES-Beta [OSTI]

    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

  17. Soil Physicochemical Characteristics from Ice Wedge Polygons, Barrow, Alaska, Ver. 1

    SciTech Connect (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.

  18. 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.

  19. 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.

  20. 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.

  1. Ice and water droplets on graphite: A comparison of quantum and classical simulations

    SciTech Connect (OSTI)

    Ramírez, Rafael; Singh, Jayant K.; Müller-Plathe, Florian; Böhm, Michael C.

    2014-11-28

    Ice and water droplets on graphite have been studied by quantum path integral and classical molecular dynamics simulations. The point-charge q-TIP4P/F potential was used to model the interaction between flexible water molecules, while the water-graphite interaction was described by a Lennard-Jones potential previously used to reproduce the macroscopic contact angle of water droplets on graphite. Several energetic and structural properties of water droplets with sizes between 10{sup 2} and 10{sup 3} molecules were analyzed in a temperature interval of 50–350 K. The vibrational density of states of crystalline and amorphous ice drops was correlated to the one of ice Ih to assess the influence of the droplet interface and molecular disorder on the vibrational properties. The average distance of covalent OH bonds is found 0.01 Å larger in the quantum limit than in the classical one. The OO distances are elongated by 0.03 Å in the quantum simulations at 50 K. Bond distance fluctuations are large as a consequence of the zero-point vibrations. The analysis of the H-bond network shows that the liquid droplet is more structured in the classical limit than in the quantum case. The average kinetic and potential energy of the ice and water droplets on graphite has been compared with the values of ice Ih and liquid water as a function of temperature. The droplet kinetic energy shows a temperature dependence similar to the one of liquid water, without apparent discontinuity at temperatures where the droplet is solid. However, the droplet potential energy becomes significantly larger than the one of ice or water at the same temperature. In the quantum limit, the ice droplet is more expanded than in a classical description. Liquid droplets display identical density profiles and liquid-vapor interfaces in the quantum and classical limits. The value of the contact angle is not influenced by quantum effects. Contact angles of droplets decrease as the size of the water droplet

  2. 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

  3. Sensitivity of CAM5-simulated Arctic clouds and radiation to ice nucleation parameterization

    DOE PAGES-Beta [OSTI]

    Xie, Shaocheng; Liu, Xiaohong; Zhao, Chuanfeng; Zhang, Yuying

    2013-08-06

    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 concentration at all latitudes while changes in cloud amounts and properties are mainly seen at high- and midlatitude storm tracks. In the Arctic, there is a considerable increase in midlevel clouds and amore » decrease in low-level clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path caused by the slowdown 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-level cloud simulations over most of the Arctic but produces too many midlevel clouds. Considerable improvements are seen in the simulated low-level clouds and their properties when compared with Arctic ground-based measurements. As a result, issues with the observations and the model–observation comparison in the Arctic region are discussed.« less

  4. 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.

  5. SOFT X-RAY IRRADIATION OF PURE CARBON MONOXIDE INTERSTELLAR ICE ANALOGUES

    SciTech Connect (OSTI)

    Ciaravella, A.; Candia, R.; Collura, A.; Jimenez-Escobar, A.; Munoz Caro, G. M.; Cecchi-Pestellini, C.; Giarrusso, S.; Barbera, M.

    2012-02-10

    There is an increasing evidence for the existence of large organic molecules in the interstellar and circumstellar medium. Very few among such species are readily formed in conventional gas-phase chemistry under typical conditions of interstellar clouds. Attention has therefore focused on interstellar ices as a potential source of these relatively complex species. Laboratory experiments show that irradiation of interstellar ice analogues by fast particles or ultraviolet radiation can induce significant chemical complexity. However, stars are sources of intense X-rays at almost every stage of their formation and evolution. Such radiation may thus provide chemical changes in regions where ultraviolet radiation is severely inhibited. After H{sub 2}O, CO is often the most abundant component of icy grain mantles in dense interstellar clouds and circumstellar disks. In this work we present irradiation of a pure carbon monoxide ice using a soft X-ray spectrum peaked at 0.3 keV. Analysis of irradiated samples shows formation of CO{sub 2}, C{sub 2}O, C{sub 3}O{sub 2}, C{sub 3}, C{sub 4}O, and CO{sub 3}/C{sub 5}. Comparison of X-rays and ultraviolet irradiation experiments, of the same energy dose, shows that X-rays are more efficient than ultraviolet radiation in producing new species. With the exception of CO{sub 2}, X-ray photolysis induces formation of a larger number of products with higher abundances, e.g., C{sub 3}O{sub 2} column density is about one order of magnitude higher in the X-ray experiment. To our knowledge this is the first report on X-ray photolysis of CO ices. The present results show that X-ray irradiation represents an efficient photo-chemical way to convert simple ices to more complex species.

  6. 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.

  7. Developing and bounding ice particle mass- and area-dimension expressions for use in atmospheric models and remote sensing

    DOE PAGES-Beta [OSTI]

    Erfani, Ehsan; Mitchell, David L.

    2016-04-07

    Here, ice particle mass- and projected area-dimension (m-D and A-D) power laws are commonly used in the treatment of ice cloud microphysical and optical properties and the remote sensing of ice cloud properties. Although there has long been evidence that a single m-D or A-D power law is often not valid over all ice particle sizes, few studies have addressed this fact. This study develops self-consistent m-D and A-D expressions that are not power laws but can easily be reduced to power laws for the ice particle size (maximum dimension or D) range of interest, and they are valid overmore » a much larger D range than power laws. This was done by combining ground measurements of individual ice particle m and D formed at temperature T < –20 °C during a cloud seeding field campaign with 2-D stereo (2D-S) and cloud particle imager (CPI) probe measurements of D and A, and estimates of m, in synoptic and anvil ice clouds at similar temperatures. The resulting m-D and A-D expressions are functions of temperature and cloud type (synoptic vs. anvil), and are in good agreement with m-D power laws developed from recent field studies considering the same temperature range (–60 °C < T < –20 °C).« less

  8. 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.

  9. 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.

  10. Optimizing the performance of Ice-storage Systems in Electricity Load Management through a credit mechanism. An analytical work for Jiangsu, China

    DOE PAGES-Beta [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 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

  11. 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

  12. Design Report for the ½ Scale Air-Cooled RCCS Tests in the Natural convection Shutdown heat removal Test Facility (NSTF)

    SciTech Connect (OSTI)

    Lisowski, D. D.; Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Bremer, N.; Aeschlimann, R. W.

    2014-06-01

    The Natural convection Shutdown heat removal Test Facility (NSTF) is a large scale thermal hydraulics test facility that has been built at Argonne National Laboratory (ANL). The facility was constructed in order to carry out highly instrumented experiments that can be used to validate the performance of passive safety systems for advanced reactor designs. The facility has principally been designed for testing of Reactor Cavity Cooling System (RCCS) concepts that rely on natural convection cooling for either air or water-based systems. Standing 25-m in height, the facility is able to supply up to 220 kW at 21 kW/m2 to accurately simulate the heat fluxes at the walls of a reactor pressure vessel. A suite of nearly 400 data acquisition channels, including a sophisticated fiber optic system for high density temperature measurements, guides test operations and provides data to support scaling analysis and modeling efforts. Measurements of system mass flow rate, air and surface temperatures, heat flux, humidity, and pressure differentials, among others; are part of this total generated data set. The following report provides an introduction to the top level-objectives of the program related to passively safe decay heat removal, a detailed description of the engineering specifications, design features, and dimensions of the test facility at Argonne. Specifications of the sensors and their placement on the test facility will be provided, along with a complete channel listing of the data acquisition system.

  13. Effect of fins and repeated-rib roughness on the performance characteristics of a reactor vessel air cooling system for LMFBR shutdown heat removal

    SciTech Connect (OSTI)

    Cheung, F.B.; Chawla, T.C.; Pedersen, D.R.; Tessier, J.H.; Webb, R.L.

    1986-01-01

    The use of a totally passive cooling system for shutdown heat removal that rejects heat from the reactor vessel by radiation to the guard vessel and from the guard vessel to a circulating air stream driven by natural convection is a key feature of the US Department of Energy's liquid-metal reactor advanced design study concepts. General Electric refers to the system as the Reactor Vessel Auxiliary Cooling System (RVACS) and Rockwell International as the Reactor Auxiliary Cooling System (RACS). The circulating air stream is contained in the annular passage formed with guard vessel wall and the duct wall surrounding the guard vessel. Specifically, the RVACS/RACS is designed to assure adequate cooling of the reactor vessel under abnormal operational conditions associated with loss of heat removal through the normal heat transport path via the steam generator system or the DRACS, if available. To enhance the heat transfer, longitudinal radial fins or repeated ribs can be attached to the duct wall and/or the guard vessel. The purpose of the present paper is to summarize the status of the analytical work on the development of an optimum design configuration for the RVACS/RACS.

  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

  15. Development of the global sea ice 6.0 CICE configuration for the Met Office global coupled model

    SciTech Connect (OSTI)

    Rae, J. G. L.; Hewitt, H. T.; Keen, A. B.; Ridley, J. K.; West, A. E.; Harris, C. M.; Hunke, E. C.; Walters, D. N.

    2015-07-24

    The new sea ice configuration GSI6.0, used in the Met Office global coupled configuration GC2.0, is described and the sea ice extent, thickness and volume are compared with the previous configuration and with observationally based data sets. In the Arctic, the sea ice is thicker in all seasons than in the previous configuration, and there is now better agreement of the modelled concentration and extent with the HadISST data set. As a result, in the Antarctic, a warm bias in the ocean model has been exacerbated at the higher resolution of GC2.0, leading to a large reduction in ice extent and volume; further work is required to rectify this in future configurations.

  16. Development of the global sea ice 6.0 CICE configuration for the Met Office global coupled model

    DOE PAGES-Beta [OSTI]

    Rae, J. G. L.; Hewitt, H. T.; Keen, A. B.; Ridley, J. K.; West, A. E.; Harris, C. M.; Hunke, E. C.; Walters, D. N.

    2015-07-24

    The new sea ice configuration GSI6.0, used in the Met Office global coupled configuration GC2.0, is described and the sea ice extent, thickness and volume are compared with the previous configuration and with observationally based data sets. In the Arctic, the sea ice is thicker in all seasons than in the previous configuration, and there is now better agreement of the modelled concentration and extent with the HadISST data set. As a result, in the Antarctic, a warm bias in the ocean model has been exacerbated at the higher resolution of GC2.0, leading to a large reduction in ice extentmore » and volume; further work is required to rectify this in future configurations.« less

  17. Development of global sea ice 6.0 CICE configuration for the Met Office global coupled model

    SciTech Connect (OSTI)

    Rae, J. . G. L; Hewitt, H. T.; Keen, A. B.; Ridley, J. K.; West, A. E.; Harris, C. M.; Hunke, E. C.; Walters, D. N.

    2015-03-05

    The new sea ice configuration GSI6.0, used in the Met Office global coupled configuration GC2.0, is described and the sea ice extent, thickness and volume are compared with the previous configuration and with observationally-based datasets. In the Arctic, the sea ice is thicker in all seasons than in the previous configuration, and there is now better agreement of the modelled concentration and extent with the HadISST dataset. In the Antarctic, a warm bias in the ocean model has been exacerbated at the higher resolution of GC2.0, leading to a large reduction in ice extent and volume; further work is required to rectify this in future configurations.

  18. Development of global sea ice 6.0 CICE configuration for the Met Office global coupled model

    DOE PAGES-Beta [OSTI]

    Rae, J. . G. L; Hewitt, H. T.; Keen, A. B.; Ridley, J. K.; West, A. E.; Harris, C. M.; Hunke, E. C.; Walters, D. N.

    2015-03-05

    The new sea ice configuration GSI6.0, used in the Met Office global coupled configuration GC2.0, is described and the sea ice extent, thickness and volume are compared with the previous configuration and with observationally-based datasets. In the Arctic, the sea ice is thicker in all seasons than in the previous configuration, and there is now better agreement of the modelled concentration and extent with the HadISST dataset. In the Antarctic, a warm bias in the ocean model has been exacerbated at the higher resolution of GC2.0, leading to a large reduction in ice extent and volume; further work is requiredmore » to rectify this in future configurations.« less

  19. Little Ice Age glaciers in Britain: Glacier–climate modelling in the Cairngorm Mountains

    SciTech Connect (OSTI)

    Stephan Harrison; Ann V. Rowan; Neil F. Glasser; Jasper Knight; Mitchell A. Plummer; Stephanie C. Mills

    2014-02-01

    It is widely believed that the last glaciers in the British Isles disappeared at the end of the Younger Dryas stadial (12.9–11.7 cal. kyr BP). Here, we use a glacier–climate model driven by data from local weather stations to show for the first time that glaciers developed during the Little Ice Age (LIA) in the Cairngorm Mountains. Our model is forced from contemporary conditions by a realistic difference in mean annual air temperature of -1.5 degrees C and an increase in annual precipitation of 10%, and confirmed by sensitivity analyses. These results are supported by the presence of small boulder moraines well within Younger Dryas ice limits, and by a dating programme on a moraine in one cirque. As a result, we argue that the last glaciers in the Cairngorm Mountains (and perhaps elsewhere in upland Britain) existed in the LIA within the last few hundred years, rather than during the Younger Dryas.

  20. A Study of the Optical Properties of Ice Crystals with Black Carbon Inclusions

    SciTech Connect (OSTI)

    Arienti, Marco; Yang, Xiaoyuan; Kopacz, Adrian M; Geier, Manfred

    2015-09-01

    The report focu ses on the modification of the optical properties of ice crystals due to atmospheric black car bon (BC) contamination : the objective is to advance the predictive capabilities of climate models through an improved understanding of the radiative properties of compound particles . The shape of the ice crystal (as commonly found in cirrus clouds and cont rails) , the volume fraction of the BC inclusion , and its location inside the crystal are the three factors examined in this study. In the multiscale description of this problem, where a small absorbing inclusion modifies the optical properties of a much la rger non - absorbing particle, state - of - the - art discretization techniques are combined to provide the best compromise of flexibility and accuracy over a broad range of sizes .