Science.gov

Sample records for modelling interior salt

  1. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-05-26

    The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and shallow shelf sandstone facies; and carbonate shoal, shelf and reef facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary. Hydrocarbon

  2. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-02-05

    The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule. The principal objectives of the project are to develop through basin analysis and modeling the concept that petroleum systems acting in a basin can be identified through basin modeling and to demonstrate that the information and analysis resulting from characterizing and modeling of these petroleum systems in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin can be used in providing a more reliable and advanced approach for targeting stratigraphic traps and specific reservoir facies within a geologic system and in providing a refined assessment of undiscovered and underdeveloped reservoirs and associated oil and gas resources.

  3. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-02-28

    The principal research effort for Year 3 of the project is basin modeling and petroleum system identification, comparative basin evaluation and resource assessment. In the first six (6) months of Year 3, the research focus is on basin modeling and petroleum system identification and the remainder of the year the emphasis is on the comparative basin evaluation and resource assessment. No major problems have been encountered to date, and the project is on schedule. The principal objectives of the project are to develop through basin analysis and modeling the concept that petroleum systems acting in a basin can be identified through basin modeling and to demonstrate that the information and analysis resulting from characterizing and modeling of these petroleum systems in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin can be used in providing a more reliable and advanced approach for targeting stratigraphic traps and specific reservoir facies within a geologic system and in providing a refined assessment of undiscovered and underdeveloped reservoirs and associated oil and gas resources.

  4. Borehole locations on seven interior salt domes

    SciTech Connect

    Simcox, A.C.; Wampler, S.L.

    1982-08-01

    This report is designed as an inventory of all wells known to have been drilled within a five-mile radius of each of seven salt domes within the Interior Salt Basin in east Texas, northern Louisiana and Mississippi. There are 72 boreholes that entered salt above an elevation of -3000 feet mean sea level. For these, details of location, drilling dates, depth of casing and cement, elevation of top of caprock and salt, etc., are given on tables in the appendix. Of the seven domes, Oakwood has the largest number of boreholes, thirty-eight (including two sidetracked wells) that enter the salt stock above -3000 feet mean sea level; another dome in northeast Texas, Keechi, has eight; in northern Louisiana, Rayburn's has four and Vacherie has five; in southern Mississippi, Cypress Creek has seven, Lampton has one, and Richton has nine. In addition, all wells known outside the supra-domal area, but within a five-mile radius of the center of the 7 domes are separately catalogued.

  5. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect

    Mancini, Ernest A.

    2003-02-06

    The project objectives are improving access to information for the Mississippi Interior Salt Basin by inventorying data files and records of the major information repositories in the region, making these inventories easily accessible in electronic format, increasing the amount of information available on domestic sedimentary basins through a comprehensive analysis of the Mississippi Interior Salt Basin, and enhancing the understanding of the petroleum systems operating in the Mississippi Interior Salt Basin.

  6. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman

    2005-05-10

    The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary

  7. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2005-03-31

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  8. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-11-05

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  9. Dry Creek salt dome, Mississippi Interior Salt basin

    SciTech Connect

    Montgomery, S.L.; Ericksen, R.L.

    1997-03-01

    Recent drilling of salt dome flanks in the Mississippi Salt basin has resulted in important new discoveries and the opening of a frontier play. This play is focused on gas/condensate reserves in several Cretaceous formations, most notably the Upper Cretaceous Eutaw and lower Tuscaloosa intervals and Lower Cretaceous Paluxy and Hosston formations. As many as eight domes have been drilled thus far; sandstones in the upper Hosston Formation comprise the primary target. Production has been as high as 3-5 Mcf and 500-1200 bbl of condensate per day, with estimated ultimate reserves in the range of 0.2 to 1.5 MBOE (million barrels oil equivalent) per well. As typified by discovery at Dry Creek salt dome, traps are related to faulting, unconformities, and updip loss of permeability. Previous drilling at Dry Creek, and in the basin generally, avoided the flank areas of most domes, due to geologic models that predicted latestage (Tertiary) piercement and breached accumulations. Recent data from Dry Creek and other productive domes suggest that growth was episodic and that piercement of Tertiary strata did not affect deeper reservoirs charged with hydrocarbons in the Late Cretaceous.

  10. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2003-09-11

    The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule.

  11. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2003-11-11

    The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule.

  12. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard

    2005-08-01

    The principal research effort for Year 3 of the project is basin modeling and petroleum system identification, comparative basin evaluation and resource assessment. In the first six (6) months of Year 3, the research focus is on basin modeling and petroleum system identification and the remainder of the year the emphasis is on the comparative basin evaluation and resource assessment. No major problems have been encountered to date, and the project is on schedule.

  13. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2006-12-31

    The principal research effort for Year 1 of Phase 2 (Concept Demonstration) of the project is Smackover petroleum system characterization and modeling. The necessary software applications have been acquired to accomplish this work. No major problems have been encountered to date, and the project is on schedule.

  14. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2007-06-30

    The principal research effort for Year 2 of Phase 2 (Concept Demonstration) of the project is Mesozoic (Bossier) petroleum system characterization and modeling and refined resource assessment. The necessary software applications have been acquired to accomplish this work. No major problems have been encountered to date, and the project is on schedule.

  15. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2006-07-31

    The principal research effort for Year 1 of Phase 2 (Concept Demonstration) of the project is Smackover petroleum system characterization and modeling. The necessary software applications are in the process of being acquired to accomplish this work. No major problems have been encountered to date, and the project is on schedule.

  16. Basin Analysis and Petroleum System Characterization and Modelling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2006-09-30

    The principal research effort for Year 1 of Phase 2 (Concept Demonstration) of the project is Smackover petroleum system characterization and modeling. The necessary software applications have been acquired to accomplish this work. No major problems have been encountered to date, and the project is on schedule.

  17. Basin Analysis of Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect

    Ernest Mancini

    2001-03-01

    Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the topical report has been submitted to the U.S. DOE for review. Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. The information on the source rocks is being prepared for inclusion in the final report. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern and western parts of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis continues. Samples from the cores selected for the reservoir characterization are being used for this task. Task 5 - Underdeveloped Reservoirs - Two underdeveloped Smackover reservoirs have been identified. They are the microbial reef and shoal reservoirs. Work Planned (Year 5): Task 1 - Basin Flow - This task has been completed and the topical report has been submitted to the U.S. DOE. Task 2 - Petroleum Source Rocks - Petroleum source rock information will continue to be prepared for the final report. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis. Task 5 - Underdeveloped Reservoirs - Study of Smackover underdeveloped reservoirs will continue with focus on the microbial reef and shoal reservoirs.

  18. Modeling of interior explosions

    NASA Astrophysics Data System (ADS)

    Zakharova, Y. V.; Fedorova, N. N.; Fedorov, A. V.

    2016-10-01

    The results of numerical simulation of an interior explosion are presented. The main purpose of the work is an investigation of shock-wave structure caused by explosion and estimation of pressure level on building walls. The numerical simulation was carried out by means of ANSYS AUTODYN software at normal atmospheric conditions with different mass of charge and internal geometry of room. The effect of mass charge and presence of vent area were shown. The calculation results are compared with published experimental data.

  19. Maximum potential erosion and inundation of seven interior salt domes

    SciTech Connect

    Aronow, S.

    1982-08-01

    Seven interior salt domes have been evaluated in regard to erosion or inundation due to natural events. The most likely possibility of either event occurring would be associated with continental glaciation. The domes were evaluated based on maximum previous sea level changes due to glaciation and effects caused by melting of existing ice sheets. Results are listed for each of the seven domes. Past history indicates a likelihood of returning to a glacial period. The subsequent fall of sea level may cause regrading of streams in the area. A conservative evaluation of this phenomenon was performed and the results are reported.

  20. Propeller aircraft interior noise model

    NASA Technical Reports Server (NTRS)

    Pope, L. D.; Wilby, E. G.; Wilby, J. F.

    1984-01-01

    An analytical model was developed to predict the interior noise of propeller-driven aircraft. The fuselage model is that of a cylinder with a structurally-integral floor. The cabin sidewall is stiffened by stringers and ring frames, and the floor by longitudinal beams. The cabin interior is covered with a sidewall treatments consisting of layers of porous material and an impervious trim septum. Representation of the propeller pressure field is utilized as input data in the form of the propeller noise signature at a series of locations on a grid over the fuselage structure. Results obtained from the analytical model are compared with test data measured by NASA in a scale model cylindrical fuselage excited by a model propeller.

  1. Crushed Salt Constitutive Model

    SciTech Connect

    Callahan, G.D.

    1999-02-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well.

  2. Interior Design Research: A Human Ecosystem Model.

    ERIC Educational Resources Information Center

    Guerin, Denise A.

    1992-01-01

    The interior ecosystems model illustrates effects on the human organism of the interaction of the natural, behavioral, and built environment. Examples of interior lighting and household energy consumption show the model's flexibility for organizing study variables in interior design research. (SK)

  3. Bibliography, geophysical data locations, and well core listings for the Mississippi Interior Salt Basin

    SciTech Connect

    1998-05-01

    To date, comprehensive basin analysis and petroleum system modeling studies have not been performed on any of the basins in the northeastern Gulf of Mexico. Of these basins, the Mississippi Interior Salt Basin has been selected for study because it is the most petroliferous basin in the northeastern Gulf of Mexico, small- and medium-size companies are drilling the majority of the exploration wells. These companies do not have the resources to perform basin analysis or petroleum system modeling research studies nor do they have the resources to undertake elaborate information searches through the volumes of publicly available data at the universities, geological surveys, and regulatory agencies in the region. The Advanced Geologic Basin Analysis Program of the US Department of Energy provides an avenue for studying and evaluating sedimentary basins. This program is designed to improve the efficiency of the discovery of the nation`s remaining undiscovered oil resources by providing improved access to information available in the public domain and by increasing the amount of public information on domestic basins. This report provides the information obtained from Year 1 of this study of the Mississippi Interior Salt Basin. The work during Year 1 focused on inventorying the data files and records of the major information repositories in the northeastern Gulf of Mexico and making these inventories easily accessible in an electronic format.

  4. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain, Final Report and Topical Reports 5-8 on Smackover Petroleum system and Underdevelopment Reservoirs

    SciTech Connect

    Mancini, Ernest A.; Puckett, T. Markham; Parcell, William C.; Llinas, Juan Carlos; Kopaska-Merkel, David C.; Townsend, Roger N.

    2002-03-05

    The Smackover Formation, a major hydrocarbon-producing horizon in the Mississippi Interior Salt Basin (MISB), conformably overlies the Norphlet Formation and is conformably overlain by the Buckner Anhydrite Member of the Haynesville Formation. The Norphlet-Smackover contact can be either gradational or abrupt. The thickness and lithofacies distribution of the Smackover Formation were controlled by the configuration of incipient paleotopography. The Smackover Formation has been subdivided into three informal members, referred to as the lower, middle and upper members.

  5. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2005-10-28

    The principal research effort for Year 2 of the project has been petroleum system characterization and modeling. Understanding the burial, thermal maturation, and hydrocarbon expulsion histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in hydrocarbon resource assessment. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and initial thermal maturation and hydrocarbon expulsion modeling indicated that an effective regional petroleum source rock in the onshore interior salt basins and subbasins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was Upper Jurassic Smackover lime mudstone. The initial modeling also indicated that hydrocarbon generation and expulsion were initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin and that hydrocarbon generation and expulsion were initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Refined thermal maturation and hydrocarbon expulsion modeling and additional petroleum source rock analysis have confirmed that the major source rock in the onshore interior salt basins and subbasins is Upper Jurassic Smackover lime mudstone. Hydrocarbon generation and expulsion were initiated in the Early to Late Cretaceous and continued into the Tertiary.

  6. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    SciTech Connect

    Ernest Mancini

    2000-12-31

    Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the modeling results are being interpreted for report writing (Table 1). Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern part of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis has been initiated. Samples from the cores selected for the reservoir characterization are being used for this task. Work Planned (Year 5): Task 1 - Basin Flow - The report on basin flow will be completed. Task 2 - Petroleum Source Rocks - Petroleum source rock data will be reviewed in light of the basin flow model results. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis.

  7. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard

    2005-04-15

    The principal research effort for the first six months of Year 2 of the project has been petroleum system characterization. Understanding the burial and thermal maturation histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in petroleum system characterization. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and thermal maturation and hydrocarbon expulsion modeling indicate that an effective regional petroleum source rock in the onshore interior salt basins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was the Upper Jurassic Smackover lime mudstone. The Upper Cretaceous Tuscaloosa shale was an effective local petroleum source rock in the Mississippi Interior Salt Basin and a possible local source bed in the North Louisiana Salt Basin. Hydrocarbon generation and expulsion was initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin. Hydrocarbon generation and expulsion was initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Reservoir rocks include Jurassic, Cretaceous and Tertiary siliciclastic and carbonate strata. Seal rocks include Jurassic, Cretaceous and Tertiary anhydrite and shale beds. Petroleum traps include structural and combination traps.

  8. Enceladus' Interior: A Liquid Circulation Model

    NASA Astrophysics Data System (ADS)

    Matson, Dennis L.; Johnson, Torrence; Lunine, Jonathan; Castillo-Rogez, Julie

    We are studying a model for Enceladus' interior in which the water, gas, dust and heat are supplied to the plumes by a relatively deeply circulating brine solution. Data indicates such a source for the erupting material. On the basis of ammonia in the plume gas Waite et al. [1] suggested that the jets might originate from a liquid water region under Enceladus' icy surface. Postberg et al. [2] noted that the presence of ". . . grains that are rich in sodium salts (0.5-2 percent by mass). . . can arise only if the plumes originate from liquid water." Waite et al. [1] also regard the some of the plume chemicals as evidence for interactions with an ice layer presumably overlying the liquid water reservoir. They suggest that this could be in the form of dissociation of clathrate hydrates [3]. Additionally, there is a large heat flow of more than 15 GW [4, 5] coming out of Enceladus' south polar region. We consider a model that brings heat and chemical species up to the surface from a reservoir or "ocean" located below the ice crust that may be many tens of kilometers thick. Water transits to the surface via vertical conduits. The Cassini INMS data suggest that the water has a relatively large gas content of order a few percent. As the water travels upward and the pressure is released, exolving gases form bubbles. Since the bubbly liquid is less dense than the ice, it moves upward. (This part of the model is a variant of the "Perrier Ocean" Europa model of Crawford and Stevenson [6]. A similar model was studied for Ganymede by Murchie and Head [7].) Postberg et al. [2] model the plume eruptions that result from the water, gases, salts, and other chemicals that our circulation model provides. In the near-surface reservoir feeding the plumes, bubbles reaching the surface of the water pop and throw a very fine spray. Some of these very small droplets of brine exit with the plume gas and provide the observed salt-rich dust particles [2]. Much of the water-borne heat is

  9. Sensor-based interior modeling

    SciTech Connect

    Herbert, M.; Hoffman, R.; Johnson, A.; Osborn, J.

    1995-02-01

    Robots and remote systems will play crucial roles in future decontamination and decommissioning (D&D) of nuclear facilities. Many of these facilities, such as uranium enrichment plants, weapons assembly plants, research and production reactors, and fuel recycling facilities, are dormant; there is also an increasing number of commercial reactors whose useful lifetime is nearly over. To reduce worker exposure to radiation, occupational and other hazards associated with D&D tasks, robots will execute much of the work agenda. Traditional teleoperated systems rely on human understanding (based on information gathered by remote viewing cameras) of the work environment to safely control the remote equipment. However, removing the operator from the work site substantially reduces his efficiency and effectiveness. To approach the productivity of a human worker, tasks will be performed telerobotically, in which many aspects of task execution are delegated to robot controllers and other software. This paper describes a system that semi-automatically builds a virtual world for remote D&D operations by constructing 3-D models of a robot`s work environment. Planar and quadric surface representations of objects typically found in nuclear facilities are generated from laser rangefinder data with a minimum of human interaction. The surface representations are then incorporated into a task space model that can be viewed and analyzed by the operator, accessed by motion planning and robot safeguarding algorithms, and ultimately used by the operator to instruct the robot at a level much higher than teleoperation.

  10. Modeling the Interior of Haumea

    NASA Astrophysics Data System (ADS)

    Probst, Luke

    The Kuiper Belt Object Haumea is one of the most fascinating objects in the solar system. Spectral reflectance observations reveal a surface of almost pure water ice, yet it has a mass of 4.006 x 1021 kg, measured from orbits of its moons, along with an inferred mean radius of 715 km, and these imply a mean density of around 2600 kg m--3 . Thus the surface ice must be a veneer over a rocky core. This model is supported by observations of Haumea's light curve, which shows large photometric variations over an anomalously rapid 3.9154-hour rotational period. Haumea's surface composition is uniform, therefore the light curve must be due to a varying area presented to the observer, implying that Haumea has an oblong, ellipsoidal shape. If Haumea's rotation axis is normal to our line of sight, and Haumea reflects with a lunar-like scattering function, then its axis ratios are p = b/a = 0.80 (in the equatorial cross section) and q = c/a = 0.52 (in the polar cross section). In this work, I assume that Haumea is in hydrostatic equilibrium, and I model it as a two-phase ellipsoid with an ice mantle and a rocky core. I model the core assuming it has a given density in the range between 2700--3300 kg m--3 with axis ratios that are free to vary. The metric which my code uses calculates the angle between the gravity vector and the surface normal, then averages this over both the outer surface and the core-mantle boundary. When this fit angle is minimized, it allows an interpretation of the size and shape of the core, as well as the thickness of the ice mantle. Results of my calculations show that Haumea's most likely core density is 2700--2800 kg m--3, with ice thicknesses anywhere from 12--32 km over the poles and as thin as 4--18 km over the equator.

  11. Recent advances in modeling stellar interiors

    NASA Astrophysics Data System (ADS)

    Guzik, Joyce Ann

    2011-11-01

    Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid γ Dor/ δ Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as η Car and P Cyg, and the solar abundance problem.

  12. Recent advances in modeling stellar interiors (u)

    SciTech Connect

    Guzik, Joyce Ann

    2010-01-01

    Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid {gamma} Dor/{delta} Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as {eta} Car and P Cyg, and the solar abundance problem.

  13. INTERIOR MODELS OF URANUS AND NEPTUNE

    SciTech Connect

    Helled, Ravit; Schubert, Gerald; Anderson, John D.; Podolak, Morris E-mail: schubert@ucla.edu E-mail: morris@tau.ac.il

    2011-01-01

    'Empirical' models (pressure versus density) of Uranus and Neptune interiors constrained by the gravitational coefficients J{sub 2}, J{sub 4}, the planetary radii and masses, and Voyager solid-body rotation periods are presented. The empirical pressure-density profiles are then interpreted in terms of physical equations of state of hydrogen, helium, ice (H{sub 2}O), and rock (SiO{sub 2}) to test the physical plausibility of the models. The compositions of Uranus and Neptune are found to be similar with somewhat different distributions of the high-Z material. The big difference between the two planets is that Neptune requires a non-solar envelope, while Uranus is best matched with a solar composition envelope. Our analysis suggests that the heavier elements in both Uranus' and Neptune's interior might increase gradually toward the planetary centers. Indeed it is possible to fit the gravitational moments without sharp compositional transitions.

  14. Basin Analysis of the Mississippi Interior Salt Baisn and Petroleum System Modeling of the Jurassic smackover Formation, Eastern Gulf Costal Plain: Quarterly progress report, January 1, 1997-March 31, 1997

    SciTech Connect

    Mancini, E.A.

    1997-03-27

    Part I (Inventory of Existing Data and Information Sources) objectives are to provide improved access to information available in the public domain by inventorying data files and records of the major information repositories in the Eastern Gulf Coastal Plain and making these inventories easily accessible in electronic format. The producers in the region maintain that the accessibility of oil and gas information is the single-most important factor to assist them in finding new hydrocarbon discoveries and in improving production from established fields. The principal investigator continues to discuss the project with geologists for Alabama, Mississippi, and Florida. A subcontract has been executed between the University of Alabama and the Geological Survey of Alabama. A subcontract agreement is under review by the Mississippi Office of Geology. The principal investigator continues to discuss the project with a number of faculty members from departments of geology in the region. A listing of theses and dissertations from the University of Alabama, Auburn University, Mississippi State University, University of Mississippi, University of Southern Mississippi, University of Southwestern Louisiana, and Louisiana State University related to the petroleum geology of the Mississippi Interior Salt Basin has been compiled. This list is accessible electronically through the Home Page of the Eastern Gulf Region of the Pertroleum Technology Transfer Council (EGRPTTC) (http://egrpttc.geo.ua.edu).

  15. Jurassic sequence stratigraphy in the Mississippi interior salt basin of Alabama

    SciTech Connect

    Mancini, E.A. Univ. of Alabama, Tuscaloosa ); Tew, B.H.; Mink, R.M. )

    1990-09-01

    Three depositional sequences associated with cycles of eustatic sea-level change and coastal onlap can be identified in the Mississippi Interior Salt basin of Alabama. In the Mississippi Interior Salt basin, the lower depositional sequence is bounded by a basal unconformity and an upper Type 2 unconformity in the Callovian. This sequence includes Louann evaporites, Pine Hill anhydrites and shales, and Norphlet eolian sandstones. The middle depositional sequence reflects relative sea-level rise in the late Callovian. This sequence includes Norphlet marine sandstones and lower Smackover packstones and mudstones, middle Smackover mudstones and upper Smackover grainstones and anhydrites. The sequence has an upper Type 2 unconformity indicating relative sea-level fall in the Oxfordian. The upper depositional sequence reflects relative sea-level rise in the late Oxfordian. This sequence includes lower Haynesville evaporites and clastics (transgressive deposits), middle Haynesville carbonate mudstones and shales (condensed section), and upper Haynesville updip continental sandstones and downdip shales, limestones, and anhydrites (progradational highstand regressive deposits). The sequence has an upper Type 1 unconformity indicating abrupt sea-level fall in the late Kimmeridgian. In these depositional sequences, progradational highstand regressive deposits are the principal petroleum reservoirs. Condensed section deposits have the potential to be source rocks if subjected to proper burial conditions; however, only the lower and middle Smackover mudstones were deposited and buried under conditions favorable for hydrocarbon generation and preservation. An understanding of sequence stratigraphy can serve as an aid to identifying potential hydrocarbon exploration targets.

  16. Mobile Modelling for Crowdsourcing Building Interior Data

    NASA Astrophysics Data System (ADS)

    Rosser, J.; Morley, J.; Jackson, M.

    2012-06-01

    Indoor spatial data forms an important foundation to many ubiquitous computing applications. It gives context to users operating location-based applications, provides an important source of documentation of buildings and can be of value to computer systems where an understanding of environment is required. Unlike external geographic spaces, no centralised body or agency is charged with collecting or maintaining such information. Widespread deployment of mobile devices provides a potential tool that would allow rapid model capture and update by a building's users. Here we introduce some of the issues involved in volunteering building interior data and outline a simple mobile tool for capture of indoor models. The nature of indoor data is inherently private; however in-depth analysis of this issue and legal considerations are not discussed in detail here.

  17. Saturn - Implications of an 'Empirical' Interior Model

    NASA Astrophysics Data System (ADS)

    Helled Ita, Ravit; Schubert, Gerald; Anderson, John

    We present models of Saturn's interior constrained by the newly measured gravitational coeffi- cients J2, J4, and J6 for different rotation rates of the planet. We apply the internal pressuredensity profile to constrain the hydrogen to helium ratio in Saturn, using the hydrogen and helium equation of state of Saumon et al. (1995). For surface temperatures that range from 130 to 145 K at the 1 bar level, we find that the hydrogen mass fraction of the planet ranges from 0.82 to 0.65, respectively. The planet's internal structure and composition are found to be insensitive to the assumed rotation rate. We find that helium is depleted in the upper envelope while in the high pressure region ( logP [dyne/cm2 ] ≥ 12 ) the helium abundance is significantly larger and is typically above 70%. These findings support the suggestion of helium differentiation from molecular hydrogen in Saturn's deep interior (e.g, Stevenson, 1975; Fortney and Hubbard, 2003). Finally, the possibility of using the measured precession rate of Saturn's rotation axis to determine its rotation period is assessed. We find that the models yield a moment of inertia factor varying from 0.22271 to 0.22599 for rotation periods between 10h:32m:32s and 10h:41m:35s, respectively. It is concluded that uncertainties in the values of the precession rate and moment of inertia preclude an identification of the rotation period. In principle, a joint inversion of suf- ficiently accurate gravitational and precession rate data could determine Saturn's deep rotation rate.

  18. Stable aerobic granules for continuous-flow reactors: Precipitating calcium and iron salts in granular interiors.

    PubMed

    Juang, Yu-Chuan; Sunil S, Adav; Lee, Duu-Jong; Tay, Joo-Hwa

    2010-11-01

    Aerobic sludge granules are compact, strong microbial aggregates that have excellent settling ability and capability to efficiently treat high-strength and toxic wastewaters. The aerobic granules cultivated with low ammonium and phosphates lost structural stability within 3 days in continuous-flow reactors. Conversely, stable aerobic granules were cultivated in substrate with high levels of ammonium salts that could stably exist for 216 days in continuous-flow reactors with or without submerged membrane. The scanning electron microscopy, energy dispersive spectroscopy microanalysis and the confocal laser scanning microscopy imaging detected large amounts of calcium and iron precipitates in granule interiors. The Visual MINTEQ version 2.61 calculation showed that the phosphates and hydroxides were the main species in the precipitate.

  19. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Donald A. Goddard

    2004-10-28

    The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification.

  20. Effects of lowering interior canal stages on salt-water intrusion into the shallow aquifer in Southeast Palm Beach County, Florida

    USGS Publications Warehouse

    Land, Larry F.

    1975-01-01

    Land in southeast Palm Beach County is undergoing a large-scale change in use, from agricultural to residential. To accommodate residential use, a proposal has been made by developers to the Board of the Lake Worth Drainage District to lower the canal stages in the interior part of the area undergoing change. This report documents one of the possible effects of such lowering. Of particular interest to the Board was whether the lower canal stages would cause an increase in salt-water intrusion into the shallow aquifer along the coast. The two main tools used in the investigation were a digital model for aquifer evaluation and an analytical technique for predicting the movement of the salt-water front in response to a change of ground-water flow into the ocean. The method of investigation consisted of developing a digital ground-water flow model for three east-west test strips. They pass through the northern half of municipal well fields in Lake Worth, Delray Beach, and Boca Raton. The strips were first modeled with no change in interior canal stages. Then they were modeled with a change in canal stages of 2 to 4 feet (0.6 to 1.6 metres). Also, two land development schemes were tested. One was for a continuation of the present level of land development, simulated by continuing the present pumpage rates. The second scheme was for land development to continue until the maximum allowable densities were reached, simulated by increasing the pumping rates. The results of the test runs for an east-west strip through Lake Worth show that lowering part of the interior canal water levels 3 feet (1.0 metre), as done in 1961, does not affect the aquifer head or salt-water intrusion along the coastal area of Lake Worth. As a result, no effect in the coastal area would be expected as a result of canal stage lowering in other, interior parts of the study area. Results from the other test runs show that lowering interior canal water levels by as much as 4 feet (1.2 metres) would

  1. A universal salt model based on under-ground precipitation of solid salts due to supercritical water `out-salting'

    NASA Astrophysics Data System (ADS)

    Rueslåtten, H.; Hovland, M. T.

    2010-12-01

    shallow magma-chamber causes a sufficiently high heat-flow to drive a convection cell of seawater. The model shows that salt precipitates along the flow lines within the supercritical region (Hovland et al., 2006). During the various stages of planet Mars’ development, it must be inferred that zones with very high heat-flow also existed there. This meant that water (brine) confined in the crust of Mars was mobilized in a convective manner and would pass into the supercritical water zone during the down-going leg (the recharge leg) of the convective cell. The zones with supercritical out-salting would require accommodation space for large masses of solid salt, as modeled in the Red Sea analogy. However, as the accommodation space for the solid salt fills up, it will pile up and force its way upwards to form large, perhaps layered anticlines, as seen in the Hebes Mensa area of Mars and at numerous locations on Earth, including the Red Sea. Thus, we offer a universal ‘hydrothermal salt model’, which would be viable on all planets with free water in their interiors or on their surfaces, including Mars and Earth. Hovland, et al., 2006. Salt formation by supercritical seawater and submerged boiling. Marine and Petrol. Geol. 23, 855-69

  2. 21. INTERIOR, DOUBLE STAIRWAY LEADING TO MODEL HALL, DETAIL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. INTERIOR, DOUBLE STAIRWAY LEADING TO MODEL HALL, DETAIL OF ONE FLIGHT (5 x 7 negative; 8 x 10 print) - Patent Office Building, Bounded by Seventh, Ninth, F & G Streets, Northwest, Washington, District of Columbia, DC

  3. A numerical model for ETC gun interior ballistics applications

    NASA Astrophysics Data System (ADS)

    Hsiao, C.-C.; Phillips, G. T.; Su, F. Y.

    1993-01-01

    A multidimensional, transient, fluid dynamic model, BISON, has been developed to study the interior ballistic processes in an electrothermal chemical (ETC) gun. The model solves the full Navier-Stokes equations and uses a high-order numerical scheme to integrate the governing equations. Most of the important physical processes pertinent to ETC gun interior ballistics, including multiphase flow, chemical reactions, and plasma dynamics, are incorporated. Examples of applications to the study of ETC gun phenomena, such as plasma jet penetration and real gun design component analyses, are discussed. The modeling results not only compare well with experimental data, but also provide a better understanding of interior ballistics physics. The multidimensional BISON model is useful for ETC simulations.

  4. An improved source model for aircraft interior noise studies

    NASA Technical Reports Server (NTRS)

    Mahan, J. R.; Fuller, C. R.

    1985-01-01

    There is concern that advanced turboprop engines currently being developed may produce excessive aircraft cabin noise level. This concern has stimulated renewed interest in developing aircraft interior noise reduction methods that do not significnatly increase take off weight. An existing analytical model for noise transmission into aircraft cabins was utilized to investigate the behavior of an improved propeller source model for use in aircraft interior noise studies. The new source model, a virtually rotating dipole, is shown to adequately match measured fuselage sound pressure distributions, including the correct phase relationships, for published data. The virtually rotating dipole is used to study the sensitivity of synchrophasing effectiveness to the fuselage sound pressure trace velocity distribution. Results of calculations are presented which reveal the importance of correctly modeling the surface pressure phase relations in synchrophasing and other aircraft interior noise studies.

  5. An improved source model for aircraft interior noise studies

    NASA Technical Reports Server (NTRS)

    Mahan, J. R.; Fuller, C. R.

    1985-01-01

    There is concern that advanced turboprop engines currently being developed may produce excessive aircraft cabin noise levels. This concern has stimulated renewed interest in developing aircraft interior noise reduction methods that do not significantly increase take off weight. An existing analytical model for noise transmission into aircraft cabins was utilized to investigate the behavior of an improved propeller source model for use in aircraft interior noise studies. The new source model, a virtually rotating dipole, is shown to adequately match measured fuselage sound pressure distributions, including the correct phase relationships, for published data. The virtually rotating dipole is used to study the sensitivity of synchrophasing effectiveness to the fuselage sound pressure trace velocity distribution. Results of calculations are presented which reveal the importance of correctly modeling the surface pressure phase relations in synchrophasing and other aircraft interior noise studies.

  6. RESOURCE ASSESSMENT OF THE IN-PLACE AND POTENTIALLY RECOVERABLE DEEP NATURAL GAS RESOURCE OF THE ONSHORE INTERIOR SALT BASINS, NORTH CENTRAL AND NORTHEASTERN GULF OF MEXICO

    SciTech Connect

    Ernest A. Mancini

    2004-04-16

    The University of Alabama and Louisiana State University have undertaken a cooperative 3-year, advanced subsurface methodology resource assessment project, involving petroleum system identification, characterization and modeling, to facilitate exploration for a potential major source of natural gas that is deeply buried (below 15,000 feet) in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas. The project is designed to assist in the formulation of advanced exploration strategies for funding and maximizing the recovery from deep natural gas domestic resources at reduced costs and risks and with minimum impact. The results of the project should serve to enhance exploration efforts by domestic companies in their search for new petroleum resources, especially those deeply buried (below 15,000 feet) natural gas resources, and should support the domestic industry's endeavor to provide an increase in reliable and affordable supplies of fossil fuels. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification. The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The project objectives will be achieved through a 3-year effort. First, emphasis is on petroleum system identification and characterization in the North

  7. CIDGA - Coupling of Interior Dynamic models with Global Atmosphere models

    NASA Astrophysics Data System (ADS)

    Noack, Lena; Plesa, Ana-Catalina; Breuer, Doris

    2010-05-01

    Atmosphere temperatures and in particular the surface temperatures mostly depend on the solar heat flux and the atmospheric composition. The latter can be influenced by interior processes of the planet, i.e. volcanism that releases greenhouse gases such as H2O, CO2 and methane into the atmosphere and plate tectonics through which atmospheric CO2 is recycled via carbonates into the mantle. An increasing concentration of greenhouse gases in the atmosphere results in an increase of the surface temperature. Changes in the surface temperature on the other hand may influence the cooling behaviour of the planet and hence influence its volcanic activity [Phillips et al., 2001]. This feedback relation between mantle convection and atmosphere is not very well understood, since until now mostly either the interior dynamic of a planet or its atmosphere was investigated separately. 2D or 3D mantle convection models to the authors' knowledge haven't been coupled to the atmosphere so far. We have used the 3D spherical simulation code GAIA [Hüttig et al., 2008] including partial melt production and coupled it with the atmosphere module CIDGA using a gray greenhouse model for varying H2O concentrations. This way, not only the influence of mantle dynamics on the atmosphere can be investigated, but also the recoupling effect, that the surface temperature has on the mantle dynamics. So far, we consider one-plate planets without crustal and thus volatile recycling. Phillips et al. [2001] already investigated the coupling effect of the surface temperature on mantle dynamics by using simple parameterized convection models for Venus. In their model a positive feedback mechanism has been observed, i.e., an increase of the surface temperature leads to an increase of partial melt and hence an increase of atmosphere density and surface temperature. Applying our model to Venus, we show that an increase of surface temperature leads not only to an increase of partial melt in the mantle; it also

  8. Jurassic sequence stratigraphy in Mississippi interior salt basin: an aid to petroleum exploration in eastern Gulf of Mexico area

    SciTech Connect

    Mancini, E.A.; Mink, R.M.; Tew, B.H.

    1988-02-01

    An understanding of sequence stratigraphy of Jurassic units in onshore basins can serve as an aid to identify potential petroleum reservoir and source rocks in the eastern Gulf of Mexico area. Three depositional sequences associated with cycles of eustatic sea level change and coastal onlap have been identified in the Mississippi Interior Salt basin. Three depositional sequences probably correspond to the J2.4, J3.1, and J3.2 sequences of Vail et al for Callovian through Kimmeridgian strata. In the Mississippi Interior salt basin, the lower depositional sequence is bounded by a basal type 2 unconformity and an upper type 2 unconformity in the Callovian. This sequence includes Louann evaporites (transgressive), Pine Hill anhydrites and shales (condensed section), and Norphlet eolian sandstones (highstand regressive). The middle depositional sequence reflects relative sea level rise in the late Callovian. This sequence includes Norphlet marine sandstones and lower Smackover packstones and mudstones (transgressive), middle Smackover mudstones (condensed section), and upper Smackover grainstones and anhydrites (highstand regressive).

  9. Aptian ‘Shale Gas’ Prospectivity in the Downdip Mississippi Interior Salt Basin, Gulf Coast, USA

    USGS Publications Warehouse

    Hackley, Paul C.; Valentine, Brett J.; Enomoto, Catherine B.; Lohr, Celeste D.; Scott, Krystina R.; Dulong, Frank T.; Bove, Alana M.

    2016-01-01

    (41 aqueous measurements from calcite cements in one argillaceous James Limestone sample) indicates homogenization temperatures (Th) of 120-135°C, consistent with present-day bottom-hole conditions and measured bitumen Ro values towards the western end of the MSB. Downdip in the central MSB, microthermometry (26 aqueous measurements from quartz dust rims in one Paluxy sandstone sample) and measured bitumen Ro values indicate maximum temperatures may have been significantly higher (~25°C) than present-day conditions. High inclusion salinities (15-25 wt.% salt) at both locations suggest interaction of pore fluids with evaporites. Mercury injection capillary pressure (MICP) analyses (n=3) indicate porosity ranges 1.3-2.1% and permeability 0.006-0.02 µD for Pine Island and Rodessa shales. Overall, results from this work indicate generally poor ‘shale gas’ prospectivity compared to other shale reservoirs based primarily on depth, low organic content, low porosity, and high clay content. However, thickness and thermal maturity are appropriate, moderate reservoir pressures are present, and petroleum systems modelling by others has indicated high undiscovered gas potential for the basin as a whole.

  10. Model updating based on an affine scaling interior optimization algorithm

    NASA Astrophysics Data System (ADS)

    Zhang, Y. X.; Jia, C. X.; Li, Jian; Spencer, B. F.

    2013-11-01

    Finite element model updating is usually considered as an optimization process. Affine scaling interior algorithms are powerful optimization algorithms that have been developed over the past few years. A new finite element model updating method based on an affine scaling interior algorithm and a minimization of modal residuals is proposed in this article, and a general finite element model updating program is developed based on the proposed method. The performance of the proposed method is studied through numerical simulation and experimental investigation using the developed program. The results of the numerical simulation verified the validity of the method. Subsequently, the natural frequencies obtained experimentally from a three-dimensional truss model were used to update a finite element model using the developed program. After updating, the natural frequencies of the truss and finite element model matched well.

  11. Precipitates/Salts Model Sensitivity Calculation

    SciTech Connect

    P. Mariner

    2001-12-20

    The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation on potential seepage waters within a potential repository drift. This work is developed and documented using procedure AP-3.12Q, ''Calculations'', in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The specific objective of this calculation is to examine the sensitivity and uncertainties of the Precipitates/Salts model. The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b). The calculation in the current document examines the effects of starting water composition, mineral suppressions, and the fugacity of carbon dioxide (CO{sub 2}) on the chemical evolution of water in the drift.

  12. Mesoscale modeling of polyelectrolyte brushes with salt.

    PubMed

    Ibergay, Cyrille; Malfreyt, Patrice; Tildesley, Dominic J

    2010-06-03

    We report dissipative particle dynamics (DPD) simulations of a polyelectrolyte brush under athermal solvent conditions. The electrostatic interactions are calculated using the particle-particle particle-mesh (PPPM) method with charges distributed over the particles. The polymer beads, counterions, co-ions, and solvent particles are modeled explicitly. The DPD simulations show a dependence of the brush height on the grafting density and the charge fraction that is typical of the nonlinear osmotic brush regime. We report the effect of the addition of salt on the structural properties of the brush. In the case of a polyelectrolyte brush with a high surface coverage, the simulations reproduce the transition between the nonlinear osmotic brush regime where the thickness of the brush is independent of the salt concentration and the salted regime where the brush height decreases weakly with the salt concentration.

  13. Crushed-salt constitutive model update

    SciTech Connect

    Callahan, G.D.; Loken, M.C.; Mellegard, K.D.

    1998-01-01

    Modifications to the constitutive model used to describe the deformation of crushed salt are presented in this report. Two mechanisms--dislocation creep and grain boundary diffusional pressure solutioning--defined previously but used separately are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. New creep consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant and southeastern New Mexico salt to determine material parameters for the constitutive model. Nonlinear least-squares model fitting to data from the shear consolidation tests and a combination of the shear and hydrostatic consolidation tests produced two sets of material parameter values for the model. The change in material parameter values from test group to test group indicates the empirical nature of the model but demonstrates improvement over earlier work with the previous models. Key improvements are the ability to capture lateral strain reversal and better resolve parameter values. To demonstrate the predictive capability of the model, each parameter value set was used to predict each of the tests in the database. Based on the fitting statistics and the ability of the model to predict the test data, the model appears to capture the creep consolidation behavior of crushed salt quite well.

  14. Geological evaluation of Gulf Coast salt domes: overall assessment of the Gulf Interior Region

    SciTech Connect

    1981-10-01

    The three major phases in site characterization and selection are regional studies, area studies, and location studies. This report characterizes regional geologic aspects of the Gulf Coast salt dome basins. It includes general information from published sources on the regional geology; the tectonic, domal, and hydrologic stability; and a brief description the salt domes to be investigated. After a screening exercise, eight domes were chosen for further characterization: Keechi, Oakwood, and Palestine Domes in Texas; Vacherie and Rayburn's domes in North Louisiana; and Cypress Creek and Richton domes in Mississippi. A general description of each, maps of the location, property ownership, and surface geology, and a geologic cross section were presented for each dome.

  15. Chapter 5. Assessment of undiscovered conventional oil and gas resources-Lower Cretaceous Travis Peak and Hosston formations, Jurassic Smackover interior salt basins total petroleum system, in the East Texas basin and Louisiana-Mississippi salt basins provinces.

    USGS Publications Warehouse

    Dyman, T.S.; Condon, S.M.

    2006-01-01

    The petroleum assessment of the Travis Peak and Hosston Formations was conducted by using a total petroleum system model. A total petroleum system includes all of the important elements of a hydrocarbon fluid system needed to develop oil and gas accumulations, including source and reservoir rocks, hydrocarbon generation, migration, traps and seals, and undiscovered accumulations. A total petroleum system is mappable and may include one or more assessment units. For each assessment unit, reservoir rocks contain similar geology, exploration characteristics, and risk. The Jurassic Smackover Interior Salt Basins Total Petroleum System is defined for this assessment to include (1) Upper Jurassic Smackover carbonates and calcareous shales and organic-rich shales of the Upper Jurassic Bossier Shale of the Cotton Valley Group and (2) Lower Cretaceous Travis Peak and Hosston Formations. The Jurassic Smackover Interior Salt Basins Total Petroleum System includes three conventional Travis Peak-Hosston assessment units: Travis Peak-Hosston Gas and Oil (AU 50490205), Travis Peak-Hosston Updip Oil (AU 50490206), and Travis Peak-Hosston Hypothetical Updip Oil (AU 50490207). A fourth assessment unit, the Hosston Hypothetical Slope-Basin Gas Assessment Unit, was named and numbered (AU 50490208) but not geologically defined or quantitatively assessed owing to a lack of data. Together, assessment units 50490205 to 50490207 are estimated to contain a mean undiscovered conventional resource of 29 million barrels of oil, 1,136 billion cubic feet of gas, and 22 million barrels of natural gas liquids.

  16. Final report on decommissioning boreholes and wellsite restoration, Gulf Coast Interior Salt Domes of Mississippi

    SciTech Connect

    Not Available

    1989-04-01

    In 1978, eight salt domes in Texas, Louisiana, and Mississippi were identified for study as potential locations for a nuclear waste repository as part of the National Waste Terminal Storage (NWTS) program. Three domes were selected in Mississippi for ``area characterization`` phase study as follows: Lampton Dome near Columbia, Cypress Creek Dome near New Augusta, and Richton Dome near Richton. The purpose of the studies was to acquire geologic and geohydrologic information from shallow and deep drilling investigations to enable selection of sites suitable for more intensive study. Eleven deep well sites were selected for multiple-well installations to acquire information on the lithologic and hydraulic properties of regional aquifers. In 1986, the Gulf Coast salt domes were eliminated from further consideration for repository development by the selection of three candidate sites in other regions of the country. In 1987, well plugging and restoration of these deferred sites became a closeout activity. The primary objectives of this activity are to plug and abandon all wells and boreholes in accordance with state regulations, restore all drilling sites to as near original condition as feasible, and convey to landowners any wells on their property that they choose to maintain. This report describes the activities undertaken to accomplish these objectives, as outlines in Activity Plan 1--2, ``Activity Plan for Well Plugging and Site Restoration of Test Hole Sites in Mississippi.``

  17. Modelling of the inhomogeneous interior of polymer gels

    NASA Astrophysics Data System (ADS)

    Shew, Chwen-Yang; Iwaki, Takafumi

    2006-04-01

    A simple model has been investigated to elucidate the mean squared displacement (MSD) of probe molecules in cross-linked polymer gels. In the model, we assume that numerous cavities distribute in the inhomogeneous interior of a gel, and probe molecules are confined within these cavities. The individual probe molecules trapped in a gel are treated as Brownian particles confined to a spherical harmonic potential. The harmonic potential is chosen to model the effective potential experienced by the probe particle in the cavity of a gel. Each field strength is corresponding to the characteristic of one type of effective cavity. Since the statistical distribution of different effective cavity sizes is unknown, several distribution functions are examined. Meanwhile, the calculated averaged MSDs are compared to the experimental data by Nisato et al (2000 Phys. Rev. E 61 2879). We find that the theoretical results of the MSD are sensitive to the shape of the distribution function. For low cross-linked gels, the best fit is obtained when the interior cavities of a gel follow a bimodal distribution. Such a result may be attributed to the presence of at least two distinct classes of cavity in gels. For high cross-linked gels, the cavities in the gel can be depicted by a single-modal uniform distribution function, suggesting that the range of cavity sizes becomes smaller. These results manifest the voids inside a gel, and the shape of distribution functions may provide the insight into the inhomogeneous interior of a gel.

  18. A suitable model for emeraldine salt.

    PubMed

    Varela-Alvarez, Adrián; Sordo, José A

    2008-05-07

    A new mechanism for the formation of doped polyaniline is presented. Besides providing suitable structural and spectroscopic parameters, the new mechanism allows for the rationalization of the experimentally observed equilibrium between polaron and bipolaron defects in emeraldine salt. The magnetic behavior and the "metallic island" model for conduction in doped polyaniline are also theoretically supported by the new proposal.

  19. Propeller aircraft interior noise model: User's manual for computer program

    NASA Technical Reports Server (NTRS)

    Wilby, E. G.; Pope, L. D.

    1985-01-01

    A computer program entitled PAIN (Propeller Aircraft Interior Noise) has been developed to permit calculation of the sound levels in the cabin of a propeller-driven airplane. The fuselage is modeled as a cylinder with a structurally integral floor, the cabin sidewall and floor being stiffened by ring frames, stringers and floor beams of arbitrary configurations. The cabin interior is covered with acoustic treatment and trim. The propeller noise consists of a series of tones at harmonics of the blade passage frequency. Input data required by the program include the mechanical and acoustical properties of the fuselage structure and sidewall trim. Also, the precise propeller noise signature must be defined on a grid that lies in the fuselage skin. The propeller data are generated with a propeller noise prediction program such as the NASA Langley ANOPP program. The program PAIN permits the calculation of the space-average interior sound levels for the first ten harmonics of a propeller rotating alongside the fuselage. User instructions for PAIN are given in the report. Development of the analytical model is presented in NASA CR 3813.

  20. Propeller aircraft interior noise model utilization study and validation

    NASA Technical Reports Server (NTRS)

    Pope, L. D.

    1984-01-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  1. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini

    2006-09-30

    The objectives of the study were: (1) to perform resource assessment of the thermogenic gas resources in deeply buried (>15,000 ft) natural gas reservoirs of the onshore interior salt basins of the north central and northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling; and (2) to use the petroleum system based resource assessment to estimate the volume of the deep thermogenic gas resource that is available for potential recovery and to identify those areas in the interior salt basins with high potential for this thermogenic gas resource. Petroleum source rock analysis and petroleum system characterization and modeling, including thermal maturation and hydrocarbon expulsion modeling, have shown that the Upper Jurassic Smackover Formation served as the regional petroleum source rock in the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin. Thus, the estimates of the total hydrocarbons, oil, and gas generated and expelled are based on the assumption that the Smackover Formation is the main petroleum source rock in these basins and subbasins. The estimate of the total hydrocarbons generated for the North Louisiana Salt Basin in this study using a petroleum system approach compares favorably with the total volume of hydrocarbons generated published by Zimmermann (1999). In this study, the estimate is 2,870 billion barrels of total hydrocarbons generated using the method of Schmoker (1994), and the estimate is 2,640 billion barrels of total hydrocarbons generated using the Platte River software application. The estimate of Zimmermann (1999) is 2,000 to 2,500 billion barrels of total hydrocarbons generated. The estimate of gas generated for this basin is 6,400 TCF using the Platte River software application, and 12,800 TCF using the method of Schmoker (1994). Barnaby (2006) estimated that the total gas volume generated for this basin ranges from 4,000 to 8,000 TCF. Seventy

  2. Interior reconstruction method based on rotation-translation scanning model.

    PubMed

    Wang, Xianchao; Tang, Ziyue; Yan, Bin; Li, Lei; Bao, Shanglian

    2014-01-01

    In various applications of computed tomography (CT), it is common that the reconstructed object is over the field of view (FOV) or we may intend to sue a FOV which only covers the region of interest (ROI) for the sake of reducing radiation dose. These kinds of imaging situations often lead to interior reconstruction problems which are difficult cases in the reconstruction field of CT, due to the truncated projection data at every view angle. In this paper, an interior reconstruction method is developed based on a rotation-translation (RT) scanning model. The method is implemented by first scanning the reconstructed region, and then scanning a small region outside the support of the reconstructed object after translating the rotation centre. The differentiated backprojection (DBP) images of the reconstruction region and the small region outside the object can be respectively obtained from the two-time scanning data without data rebinning process. At last, the projection onto convex sets (POCS) algorithm is applied to reconstruct the interior region. Numerical simulations are conducted to validate the proposed reconstruction method.

  3. Core-Envelope Interior Models of the Outer Planets

    NASA Astrophysics Data System (ADS)

    Schubert, G.; Anderson, J. D.; Helled, R.

    2009-12-01

    The constraints on giant planet interior models with density discontinuities, for example, a core-envelope boundary, are more difficult to treat than a continuous density distribution that decreases monotonically and continuously from the center to the surface of the planet. We revise our previous interior calculations (Anderson, J. D., and G. Schubert, Saturn’s gravitational field, internal rotation, and interior structure, 2007, Science, 317, 1384-1387, doi: 101126/science.1144835, 2007), which solved a system of integro-differential equations to third order in the smallness parameter ω2a3/GM (ω is the angular velocity of the planet, a is the planet’s equatorial radius, G is the gravitational constant, and M is the planet’s mass), and introduce Clairaut’s differential equation for the flattening f, with appropriate boundary conditions at the planet’s surface and at its center. The calculations can be carried to second order in the smallness parameter by solving Darwin’s differential equation for k, a parameter that describes a second-order deviation from sphericity. In principle, the calculations can be extended to differential equations of arbitrary order in smallness. As with our earlier method, we apply this revised method to the outer planets with interiors comprising a compressible core, obeying a linear density distribution, and an envelope in which density vs. radius is described by a sixth degree polynomial. This method of gravity sounding, with cores and envelope polynomial density distributions, can yield insights into a class of possible cores that fit the boundary conditions, consisting of the measured even zonal gravitational harmonics, plus the measured size and total mass of the planet. We apply the method to the four outer planets.

  4. Combined Grammar for the Modeling of Building Interiors

    NASA Astrophysics Data System (ADS)

    Becker, S.; Peter, M.; Fritsch, D.; Philipp, D.; Baier, P.; Dibak, C.

    2013-11-01

    As spatial grammars have proven successful and efficient to deliver LOD3 models, the next challenge is their extension to indoor applications, leading to LOD4 models. Therefore, a combined indoor grammar for the automatic generation of indoor models from erroneous and incomplete observation data is presented. In building interiors where inaccurate observation data is available, the grammar can be used to make the reconstruction process robust, and verify the reconstructed geometries. In unobserved building interiors, the grammar can generate hypotheses about possible indoor geometries matching the style of the rest of the building. The grammar combines concepts from L-systems and split grammars. It is designed in such way that it can be derived from observation data fully automatically. Thus, manual predefinitions of the grammar rules usually required to tune the grammar to a specific building style, become obsolete. The potential benefit of using our grammar as support for indoor modeling is evaluated based on an example where the grammar has been applied to automatically generate an indoor model from erroneous and incomplete traces gathered by foot-mounted MEMS/IMU positioning systems.

  5. Modelling of cosmic-ray muon exposure in building's interior.

    PubMed

    Fujitaka, K; Abe, S

    1984-06-01

    Physical parameters on the exposure indoors from cosmic ray muons were determined in order to undertake computer simulations. The hitherto known information was compiled, and the unknowns were newly calculated. Assumptions and approximations required in making a practical model were also described. The stopping power and the range of muons in a normal concrete as well as the air were calculated for the energy up to hundreds GeV. The consistency of those results with ready-made tables was found satisfactory although the comparisons were available only in the low energy tail. The scattering effect of cosmic ray muons in building's interior was examined numerically through very simple model calculations. It was revealed that the overall scattering effect would be ignored unless very small variations are wanted. The iron fraction in a reinforced concrete as well as the density of the concrete was also shown to be an ineffective factor.

  6. A Simple Analytical Model for Rocky Planet Interiors

    NASA Astrophysics Data System (ADS)

    Zeng, Li; Jacobsen, Stein B.

    2017-03-01

    This work aims to explore the scaling relations among rocky exoplanets. The assumption that the internal gravity increases linearly in the core and stays constant in the mantle is tested against numerical simulations, and a simple model is constructed, applicable to rocky exoplanets of CMF (core mass fraction) = 0.2–0.35 and mass = 0.1–30 M ⊕. Various scaling relations are derived: (1) CMF ≈ CRF2 (core radius fraction squared), (2) {P}{typical}∼ {g}s2 (typical interior pressure scales as surface gravity squared), (3) energy released in core formation is ∼ \\tfrac{1}{10} the total gravitational energy, (4) effective heat capacity of the mantle ≈ ≤ft(\\tfrac{{M}p}{{M}\\oplus }\\right)× 7.5× {10}27 J K‑1, (5) moment of inertia ≈ \\tfrac{1}{3}{M}p{R}p2. These relations, though approximate, are handy for quick use owing to their simplicity and lucidity, and provide insights into the interior structures of those exoplanets.

  7. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    SciTech Connect

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-04-26

    The principal research effort for the first half of Year 3 of the project has been resource assessment. Emphasis has been on estimating the total volume of hydrocarbons generated and the potential amount of this resource that is classified as deep (>15,000 ft) gas in the North Louisiana Salt Basin, the Mississippi Interior Salt Basin, the Manila Subbasin and the Conecuh Subbasin. The amount of this resource that has been expelled, migrated and entrapped is also the focus of the first half of Year 3 of this study.

  8. Phytotoxicity of salt and plant salt uptake: Modeling ecohydrological feedback mechanisms

    NASA Astrophysics Data System (ADS)

    Bauer-Gottwein, Peter; Rasmussen, Nikolaj F.; Feificova, Dagmar; Trapp, Stefan

    2008-04-01

    A new model of phytotoxicity of salt and plant salt uptake is presented and is coupled to an existing three-dimensional groundwater simulation model. The implementation of phytotoxicity and salt uptake relationships is based on experimental findings from willow trees grown in hydroponic solution. The data confirm an s-shaped phytotoxicity relationship as found in previous studies. Uptake data were explained assuming steady state salt concentration in plant roots, passive salt transport into the roots, and active enzymatic removal of salt from plant roots. On the one hand, transpiration strongly depends on groundwater salinity (phytotoxicity); on the other hand, transpiration significantly changes the groundwater salinity (uptake). This feedback loop generates interesting dynamic phenomena in hydrological systems that are dominated by transpiration and are influenced by significant salinity gradients. Generic simulations are performed for the Okavango island system and are shown to reproduce essential phenomena observed in nature.

  9. INVESTIGATING SUPERCONDUCTIVITY IN NEUTRON STAR INTERIORS WITH GLITCH MODELS

    SciTech Connect

    Haskell, B.; Pizzochero, P. M.; Seveso, S.

    2013-02-20

    The high-density interior of a neutron star is expected to contain superconducting protons and superfluid neutrons. Theoretical estimates suggest that the protons will form a type II superconductor in which the stellar magnetic field is carried by flux tubes. The strong interaction between the flux tubes and the neutron rotational vortices could lead to strong ''pinning'', i.e., vortex motion could be impeded. This has important implications especially for pulsar glitch models as it would lead to a large part of the vorticity of the star being decoupled from the ''normal'' component to which the electromagnetic emission is locked. In this Letter, we explore the consequences of strong pinning in the core on the ''snowplow'' model for pulsar glitches, making use of realistic equations of state and relativistic background models for the neutron star. We find that, in general, a large fraction of the pinned vorticity in the core is not compatible with observations of giant glitches in the Vela pulsar. Thus, the conclusion is that either most of the core is in a type I superconducting state or the interaction between vortices and flux tubes is weaker than previously assumed.

  10. Interior Models and Gravity Field of Jupiter's Moon Amalthea

    NASA Astrophysics Data System (ADS)

    Weinwurm, G.; Weber, R.

    2003-12-01

    Before its final plunge into Jupiter in September 2003, GALILEO made a last visit to Jupiters moon Amalthea. This final flyby of the spacecrafts successful mission occurred on November 5, 2002. In order to analyse the spacecraft data with respect to Amaltheas gravity field, interior models of the moon had to be provided. The method used for this approach is based on the numerical integration of infinitesimal volume elements, which are calculated by the scale factors of a three-axial ellipsoid (elliptic coordinates). To derive the gravity field coefficients of the body, the second method of Neumann was applied. Based on the spacecraft trajectory data provided by the Jet Propulsion Laboratory, GALILEOs velocity perturbations at closest approach could be calculated. We have derived the harmonic coefficients of Amaltheas gravity field up to degree and order six, for both homogeneous and reasonable heterogeneous cases. Based on these numbers we calculated the impact on the trajectory of GALILEO and compared it to existing Doppler data. Although no two-way Doppler-data was available during the flyby and the harmonic coefficients of the gravity field are buried in the one-way Doppler-noise, the calculated gravity field models of Amalthea can be a basis for further exploration of the Jupiter system. Furthermore, the model approach can be used for any planetary body.

  11. Salt glacier and composite sediment-salt glacier models for the emplacement and early burial of allochthonous salt sheets

    SciTech Connect

    Fletcher, R.C.; Hudec, M.R.; Watson, I.A.

    1996-12-31

    Allochthonous salt sheets in the northern Gulf of Mexico were emplaced as extrusive {open_quotes}salt glaciers{close_quotes} at the sediment-water interface. Massive dissolution was suppressed by a thin carapace of pelagic sediments. During emplacement, several hundred meters of bathymetric relief restricted rapid sedimentation to outside the glacial margins. The glaciers acted as sediment dams, influencing the transport and deposition of sediment from an upslope source. Because of contemporaneous sedimentation, the base of the glaciers climbed upward in all directions away from their feeder stocks, and successive sedimentary horizons were truncated against it. The local slope at the base of the sheets is equal to the local rate of sedimentation divided by the local rate of salt advance. Alternating episodes of slow and rapid sedimentation gave rise to a basal salt surface of alternating flats and ramps, which are preserved. Many salt sheets have nearly circular map patterns but are strongly asymmetric. Feeder stocks occur near upslope edges, and base-of-salt slopes are greater updip of the feeder. The asymmetry is due to more rapid sedimentation at the upslope edge and to slower advance induced by the smaller hydraulic head between the salt fountain and the upslope edge compared to the downslope edge. Rapid emplacement of the Mickey salt sheet (Mitchell dome) from a preexisting salt stock took {approximately}4 m.y, as {approximately}1 km of sediment was deposited. A three-dimensional geomechanical model for the rapid salt emplacement yields the following relationship for the diapir`s downdip radius versus time: R(t) {approx} Mt{sup q} {approx} B[({rho} - {rho}{sub w})gK{sup 3} / {eta}]{sup 1/8}t{sup q}, where M, q, b, and K are constants related to salt supply into the sheet, {rho} and {rho}{sub w} are the densities of salt water, g is the acceleration of gravity, {eta} is salt viscosity, and t is a model time extrapolated back to zero sheet volume at t = 0.

  12. Models of a partially hydrated Titan interior with clathrate crust

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.; Castillo-Rogez, J.

    2012-04-01

    We present an updated model of the interior evolution of Titan over time, assuming the silicate core was hydrated early in Titan's history and is dehydrating over time. The original model presented in Castillo-Rogez and Lunine (2010) was motivated by a Cassini-derived moment of inertia (Iess et al., 2010) for Titan too large to be accommodated by classical fully differentiated models in which an anhydrous silicate core was overlain by a water ice (with possible perched ocean) mantle. Our model consisted of a silicate core still in the process of dehydrating today, a situation made possible by the leaching of radiogenic potassium from the silicates into the liquid water ocean. The crust of Titan was assumed to be pure water ice I. The model was consistent with the moment of inertia of Titan, but neglected the presence of large amounts of methane in the upper crust invoked to explain methane's persistence at present and through geologic time (Tobie et al. 2006). We have updated our model with such a feature. We have also improved our modeling with a better physical model for the dehydration of antigorite and other hydrated minerals. In particular our modeling now simulates heat advection resulting from water circulation (e.g., Seipold and Schilling 2003), rather than the purely conductive heat transfer regime assumed in the first version of our model. The modeling proceeds as in Castillo-Rogez and Lunine (2010), with the thermal conductivity of the methane clathrate crust rather than that of ice I. The former is several times lower than that of the latter, and the two have rather different temperature dependences (English and Tse, 2009). The crust turns out to have essentially no bearing on the temperature of the silicate core and hence the timing of dehydration, but it profoundly affects the thickness of the high-pressure ice layer beneath the ocean. Indeed, with the insulating methane clathrate crust, there must be a liquid water ocean beneath the methane clathrate

  13. Next step in Earth interior modeling for nutation

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Folgueira, M.; Puica, M.; Koot, L.; Van Hoolst, T.; Trinh, A.

    2014-12-01

    Accurate reference systems are important for many geophysical applications and satellite observations. It is therefore necessary to know the Earth rotation and orientation with high precision. Interactions between the solid Earth and its fluid layers (liquid core, atmosphere, ocean) induce variations in the Earth's speed of rotation. In addition, because the Earth is not a perfect sphere, but rather an ellipsoid flattened at its poles, the combined gravitational forces acting upon it produce changes in the orientation of its spin axis. Precession describes the long-term trend in the orientation of the Earth, while nutation refers to shorter-term periodic variations. The nutations of the Earth are the prime focus of the present paper. Models are used to predict the real-time Earth rotation and orientation, based on past observations and theoretical considerations of geophysical processes. In particular, the coupling mechanisms at the internal boundaries have been shown to be important for rotation. We here address the coupling mechanisms at the core boundaries such as the topographic, electromagnetic and viscous couplings, and discuss improvements in their computation and observation. The study uses and compares numerical and semi-analytical approaches, with the objective of both improving the nutation model and the rotation, and better understanding the interior of the Earth.

  14. Two planets: Earth and Mars - One salt model: The Hydrothermal SCRIW-Model

    NASA Astrophysics Data System (ADS)

    Hovland, M. T.; Rueslaatten, H.; Johnsen, H. K.; Indreiten, T.

    2011-12-01

    Red Sea indicates that a shallow magma-chamber causes a sufficiently high heat-flow to drive a convection cell of seawater. The model shows that salt precipitates along the flow lines within the SCRIW-region (Hovland et al., 2006). During the various stages of planet Mars' development, it must be inferred that zones with very high heat-flow also existed there. This meant that water (brine) confined in the crust of Mars was mobilized in a convective manner and would pass into the SCRIW-zone during the down-going leg (the recharge leg) of the convective cell. The zones with SCRIW out-salting would require accommodation space for large masses of solid salt, as modeled in the Red Sea analogy. However, as the accommodation space for the solid salt fills up, it will pile up and force its way upwards to form large, perhaps layered anticlines, as seen in the Hebes Mensa area of Mars and at numerous locations on Earth, including the Red Sea. Thus, we offer a universal 'hydrothermal salt model', which would be viable on all planets with free water in their interiors or on their surfaces, including Mars and Earth.

  15. Modeling Exoplanet Interiors From Host Star Elemental Abundances

    NASA Astrophysics Data System (ADS)

    Hamilton, B.; Green, D.

    2016-12-01

    Spectroscopy is used to determine elemental abundances of a star. These abundances represent the bulk composition of the system, and are the constituents from which all bodies within a system, including any terrestrial planets, are formed. Using these abundances, interior structures of terrestrial (exo)planets can be modeled, and more accurate estimations of their radii can be found than by using mass alone. The abundances are used to estimate mantle mineralogy based on the ratios of the most abundant heavy elements: Si, Mg, and Fe. The amount of volatiles incorporated is calculated according to these ratios, yielding estimated mineral percentages, and a core mass for the planet. To model a planet the mass must be input, along with the estimated mineralogy and a speculated starting radius. Physical changes are then calculated from the surface to the center of the planet at depth increments of 1 km. Known pressure related phase changes in the minerals are used to distinguish upper and lower mantle boundaries, with physical characteristics adjusted at these transitions to match the new mineralogy, and the amount of available Fe used to estimate the core mass. Physical properties, such as densities and bulk moduli, are determined based on the selected minerals, and changes to these attributes along with pressure, gravity, and thermal expansion are calculated with increasing depth. After compressional modeling has been completed and thermal corrections applied, behavior at the center is assessed, and the radius of the planet is adjusted. Subsequent iterations are ran until an equilibrium is found when gravity at the center approaches zero. The result of this method is a best fit radius for a planet, as well as the depth of the upper and lower mantle, which is unique to that specific star system and planet mass. Results of compressional and thermal modeling showed the core mass of a terrestrial planet has a large influence on planet radii. Experiments modeled planets

  16. In-Drift Precipitates/Salts Model

    SciTech Connect

    P. Mariner

    2003-10-21

    As directed by ''Technical Work Plan For: Engineered Barrier System Department Modeling and Testing FY03 Work Activities'' (BSC 2003 [165601]), the In-Drift Precipitates/Salts (IDPS) model is developed and refined to predict the aqueous geochemical effects of evaporation in the proposed repository. The purpose of this work is to provide a model for describing and predicting the postclosure effects of evaporation and deliquescence on the chemical composition of water within the proposed Engineered Barrier System (EBS). Application of this model is to be documented elsewhere for the Total System Performance Assessment License Application (TSPA-LA). The principal application of this model is to be documented in REV 02 of ''Engineered Barrier System: Physical and Chemical Environment Model'' (BSC 2003 [165601]). The scope of this document is to develop, describe, and validate the IDPS model. This model is a quasi-equilibrium model. All reactions proceed to equilibrium except for several suppressed minerals in the thermodynamic database not expected to form under the proposed repository conditions within the modeling timeframe. In this revision, upgrades to the EQ3/6 code (Version 8.0) and Pitzer thermodynamic database improve the applicable range of the model. These new additions allow equilibrium and reaction-path modeling of evaporation to highly concentrated brines for potential water compositions of the system Na-K-H-Mg-Ca-Al-Cl-F-NO{sub 3}-SO{sub 4}-Br-CO{sub 3}-SiO{sub 2}-CO{sub 2}-O{sub 2}-H{sub 2}O at temperatures in the range of 0 C to 125 C, pressures in the atmospheric range, and relative humidity in the range of 0 to 100 percent. This system applies to oxidizing conditions only, and therefore limits the model to applications involving oxidizing conditions. A number of thermodynamic parameters in the Pitzer database have values that have not been determined or verified for the entire temperature range. In these cases, the known values are used to approximate

  17. Mouse Model of Halogenated Platinum Salt Hypersensitivity ...

    EPA Pesticide Factsheets

    Occupational exposure to halogenated platinum salts can trigger the development of asthma. Concern for increased asthma risk exists for the general population due to the use of platinum (Pt) in catalytic converters and its emerging use as a diesel fuel additive. To investigate airway responses to Pt, we developed a mouse model of Pt hypersensitivity. Previously, we confirmed the dermal sensitizing potency of ammonium hexachloroplatinate (AHCP) using an ex vivo [3H]methyl thymidine labeling version of the local lymph node assay in BALB/c mice. Here, we investigated the ability of AHCP to induce airway responses in mice sensitized by the dermal route. Mice were sensitized through application of 100 µL 1% AHCP in DMSO to the shaved back on days 0, 5 and 19, and 25 µl to each ear on days 10, 11 and 12. Unsensitized mice received vehicle. On day 24, mice were challenged by oropharyngeal aspiration (OPA) with 0 or 100 µg AHCP in saline. Before and immediately after challenge, airway responses were assessed using whole body plethysmography (WBP). On day 26, changes in ventilatory responses to methacholine (Mch) aerosol were assessed by WBP; dose-dependent increases in Mch responsiveness occurred in sensitized mice. Bronchoalveolar lavage fluid harvested from sensitized mice contained an average of 7.5% eosinophils compared to less than 0.5% in control mice (p < 0.05). This model will be useful for assessing both relative sensitizing potency and cross-reacti

  18. Free energy landscape of a minimalist salt bridge model.

    PubMed

    Li, Xubin; Lv, Chao; Corbett, Karen M; Zheng, Lianqing; Wu, Dongsheng; Yang, Wei

    2016-01-01

    Salt bridges are essential to protein stability and dynamics. Despite the importance, there has been scarce of detailed discussion on how salt bridge partners interact with each other in distinct solvent exposed environments. In this study, employing a recent generalized orthogonal space tempering (gOST) method, we enabled efficient molecular dynamics simulation of repetitive breaking and reforming of salt bridge structures within a minimalist salt-bridge model, the Asp-Arg dipeptide and thereby were able to map its detailed free energy landscape in aqueous solution. Free energy surface analysis shows that although individually-solvated states are more favorable, salt-bridge states still occupy a noticeable portion of the overall population. Notably, the competing forces, e.g. intercharge attractions that drive the formation of salt bridges and solvation forces that pull the charged groups away from each other, are energetically comparable. As the result, the salt bridge stability is highly tunable by local environments; for instance when local water molecules are perturbed to interact more strongly with each other, the population of the salt-bridge states is likely to increase. Our results reveal the critical role of local solvent structures in modulating salt-bridge partner interactions and imply the importance of water fluctuations on conformational dynamics that involves solvent accessible salt bridge formations. © 2015 The Protein Society.

  19. Salt matters: How salt affects the rheological and physical properties of gelatine for analogue modelling

    NASA Astrophysics Data System (ADS)

    Brizzi, S.; Funiciello, F.; Corbi, F.; Di Giuseppe, E.; Mojoli, G.

    2016-06-01

    Gelatine is extensively used as analogue material for the easiness to tune its physical and rheological properties. The addition of salt to gelatine is generally adopted to increase the density of the material, improving the scaling of the models. However, the way the addition of salt changes the rheological properties of gelatine is generally underestimated. Here, we investigate both rheological and physical properties (i.e., density and transparency) of type A pig-skin 2.5 wt.% gelatine at T = 10 °C as a function of salt concentration, cNaCl, and ageing time. We established a standard preparation recipe and measuring protocol, yielding to uniform samples with reproducible behaviour. Rheometric measurements show that the presence of salt weakens the gelatine structure, with a decrease of both material rigidity and viscosity as cNaCl increases. Salted gelatine behaviour moves from viscoelastic to dominantly elastic as the ageing time increases. Density and cloudiness also increase with cNaCl. Finally, we present results from subduction interplate seismicity models performed with pure and salted gelatines, showing that the modified material may improve the modelling performance and open new perspectives in experimental tectonics.

  20. Study of materials performance model for aircraft interiors

    NASA Technical Reports Server (NTRS)

    Leary, K.; Skratt, J.

    1980-01-01

    A demonstration version of an aircraft interior materials computer data library was developed and contains information on selected materials applicable to aircraft seats and wall panels, including materials for the following: panel face sheets, bond plies, honeycomb, foam, decorative film systems, seat cushions, adhesives, cushion reinforcements, fire blocking layers, slipcovers, decorative fabrics and thermoplastic parts. The information obtained for each material pertains to the material's performance in a fire scenario, selected material properties and several measures of processability.

  1. Modeling Vehicle Interior Noise Exposure Dose on Freeways Considering Weaving Segment Designs and Engine Operation.

    PubMed

    Li, Qing; Qiao, Fengxiang; Yu, Lei; Shi, Junqing

    2017-07-05

    Vehicle interior noise functions at the dominant frequencies of 500 Hz below and around 800 Hz, which fall into the bands that may impair hearing. Recent studies demonstrated that freeway commuters are chronically exposed to vehicle interior noise, bearing the risk of hearing impairment. The interior noise evaluation process is mostly conducted in a lab environment. The test results and the developed noise models may underestimate or ignore the noise effects from dynamic traffic, road conditions and configuration. However, the interior noise is highly associated with vehicle maneuvering. The vehicle maneuvering on a freeway weaving segment is more complex for its nature of conflicting areas. This research is intended to explore the risk of the interior noise exposure on freeway weaving segments for freeway commuters, and improve the interior noise estimation by constructing a decision tree learning based noise exposure dose (NED) model, considering weaving segment designs and engine operation. On-road driving tests were conducted to twelve subjects on State Highway 288 in Houston, Texas. An On-board Diagnosis (OBD) II, a smartphone based roughness app, and a digital sound meter were used to collect vehicle maneuvering and engine information, International Roughness Index, and interior noise levels, respectively. Eleven variables were obtainable from the driving tests, including the length and type of a weaving segment, serving as predictors. The importance of the predictors was estimated by their Out-Of-Bag permuted predictor delta errors. The hazardous exposure level of the interior noise on weaving segments is quantified to Hazard Quotient, NED and daily noise exposure level, respectively. Results showed that the risk of hearing impairment on freeway is acceptable, the interior noise level is the most sensitive to the pavement roughness, and subject to freeway configuration and traffic conditions. The constructed NED model performs highly predictive power (R

  2. Sinking of anhydrite blocks within a Newtonian salt diapir: modelling the influence of block aspect ratio and salt stratification

    NASA Astrophysics Data System (ADS)

    Burchardt, Steffi; Koyi, Hemin; Schmeling, Harro; Fuchs, Lukas

    2012-03-01

    2-D Finite Differences models are used to analyse the strain produced by gravity-driven sinking of dense rectangular inclusions through homogeneous and vertically stratified Newtonian salt. We systematically modelled the descent of dense blocks of different sizes and initial orientations (aspect ratios) representing the Main Anhydrite fragments documented within, for example, the Gorleben salt diapir. Model results demonstrate that size of the blocks is a governing parameter which dictates the amount of strain produced within the block and in the surrounding host salt. Initial block orientation (aspect ratio), on the other hand, causes fundamental differences in block deformation, while the resulting structures produced in the salt are principally the same in all models with homogeneous salt, covering shear zones and folding of passive markers. In models with vertically stratified salt with different viscosities, block descent takes place along complex paths. This results from greater strain accommodation by the 'salt formation' with the lowest viscosity and an asymmetrical distribution of initial vertical shear stresses around the block. Consequently, in these models, block strain is lower compared with the models with homogeneous salt (for the same viscosity as the high-viscosity salt), and sinking is accompanied by block rotation. The latter causes diapir-scale disturbance of the pre-sinking salt stratigraphy and complex sinking paths of the blocks. In particular, vertically oriented blocks sink into high-viscosity salt and drag with them some low-viscosity salt, while horizontal blocks sink in the low-viscosity salt. The resultant sinking velocities vary strongly depending on the sinking path of the block. Based on model results and observed structural configuration within the Gorleben salt diapir, we conclude that the internal complexity of a salt diapir governs its post-ascent deformation. Salt structure and its interaction with dense blocks should hence be

  3. Final report on decommissioning of wells, boreholes, and tiltmeter sites, Gulf Coast Interior Salt Domes of Louisiana

    SciTech Connect

    Not Available

    1989-07-01

    In the late 1970s, test holes were drilled in northern Louisiana in the vicinity of Vacherie and Rayburn`s Salt Domes as part of the Department of Energy`s (DOE) National Waste Terminal Storage (NWTS) (rename the Civilian Radioactive Waste Management (CRWM)) program. The purpose of the program was to evaluate the suitability of salt domes for long term storage or disposal of high-level nuclear waste. The Institute for Environmental Studies at Louisiana State University (IES/LSU) and Law Engineering Testing Company (LETCo) of Marietta, Georgia performed the initial field studies. In 1982, DOE awarded a contract to the Earth Technology Corporation (TETC) of Long Beach, California to continue the Gulf Coast Salt Dome studies. In 1986, DOE deferred salt domes from further consideration as repository sites. This report describes test well plugging and site abandonment activities performed by SWEC in accordance with Activity Plan (AP) 1--3, Well Plugging and Site Restoration of Work Sites in Louisiana. The objective of the work outlined in this AP was to return test sites to as near original condition as possible by plugging boreholes, removing equipment, regrading, and seeding. Appendices to this report contain forms required by State of Louisiana, used by SWEC to document decommissioning activities, and pertinent documentation related to lease/access agreements.

  4. In-Drift Precipitates/Salts Model

    SciTech Connect

    P. Mariner

    2004-11-09

    This report documents the development and validation of the in-drift precipitates/salts (IDPS) model. The IDPS model is a geochemical model designed to predict the postclosure effects of evaporation and deliquescence on the chemical composition of water within the Engineered Barrier System (EBS) in support of the Total System Performance Assessment for the License Application (TSPA-LA). Application of the model in support of TSPA-LA is documented in ''Engineered Barrier System: Physical and Chemical Environment Model'' (BSC 2004 [DIRS 169860]). Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration (BSC 2004 [DIRS 171156]) is the technical work plan (TWP) for this report. It called for a revision of the previous version of the report (BSC 2004 [DIRS 167734]) to achieve greater transparency, readability, data traceability, and report integration. The intended use of the IDPS model is to estimate and tabulate, within an appropriate level of confidence, the effects of evaporation, deliquescence, and potential environmental conditions on the pH, ionic strength, and chemical compositions of water and minerals on the drip shield or other location within the drift during the postclosure period. Specifically, the intended use is as follows: (1) To estimate, within an appropriate level of confidence, the effects of evaporation and deliquescence on the presence and composition of water occurring within the repository during the postclosure period (i.e., effects on pH, ionic strength, deliquescence relative humidity, total concentrations of dissolved components in the system Na-K-H-Mg-Ca-Al-Cl-F-NO{sub 3}-SO{sub 4}-Br-CO{sub 3}-SiO{sub 2}-CO{sub 2}-O{sub 2}-H{sub 2}O, and concentrations of the following aqueous species that potentially affect acid neutralizing capacity: HCO{sub 3}{sup -}, CO{sub 3}{sup 2-}, OH{sup -}, H{sup +}, HSO{sub 4}{sup -}, Ca{sup 2+}, Mg{sup 2+}, CaHCO{sub 3}{sup +}, MgHCO{sub 3}{sup +}, HSiO{sub 3

  5. How to Observe (Rather Than Model) The Interiors of Stars

    NASA Astrophysics Data System (ADS)

    Elsworth, Yvonne

    2012-05-01

    Seismology - the study of the propagation of sound waves - allows us to make real observations of the interior of stars and provides a vital counterpoint to the inferences of theory. Helioseismology pioneered this activity and an autonomous small network (BiSON) run from the University of Birmingham (UK) has been making seismic observations of the Sun for more than three solar cycles. Its continuing observations have included the just past rather strange minimum. I will use some of the recent data to illustrate the curious behaviour of our home star. For other stars there have been several recent breakthrough missions. Foremost in these is the NASA Kepler mission which has opened up to view a very large number of stars. The prime aim of the Kepler mission is the hunt for earth-like planets and the role of the seismic analysis is to inform about the host stars. However, the observations of the stars are very important in their own right. My particular interest is in the solar-like main sequence stars and red giants. I will discuss some of the recent exciting results. Given that we can now observe the interior of stars like the Sun and also stars like the Sun will - in time - become, there is every hope that we will see major in our knowledge of stellar populations, structure and evolution.

  6. Mouse Model of Halogenated Platinum Salt Hypersensitivity

    EPA Science Inventory

    Occupational exposure to halogenated platinum salts can trigger the development of asthma. Concern for increased asthma risk exists for the general population due to the use of platinum (Pt) in catalytic converters and its emerging use as a diesel fuel additive. To investigate a...

  7. Mouse Model of Halogenated Platinum Salt Hypersensitivity

    EPA Science Inventory

    Occupational exposure to halogenated platinum salts can trigger the development of asthma. Concern for increased asthma risk exists for the general population due to the use of platinum (Pt) in catalytic converters and its emerging use as a diesel fuel additive. To investigate a...

  8. Health gain by salt reduction in europe: a modelling study.

    PubMed

    Hendriksen, Marieke A H; van Raaij, Joop M A; Geleijnse, Johanna M; Breda, Joao; Boshuizen, Hendriek C

    2015-01-01

    Excessive salt intake is associated with hypertension and cardiovascular diseases. Salt intake exceeds the World Health Organization population nutrition goal of 5 grams per day in the European region. We assessed the health impact of salt reduction in nine European countries (Finland, France, Ireland, Italy, Netherlands, Poland, Spain, Sweden and United Kingdom). Through literature research we obtained current salt intake and systolic blood pressure levels of the nine countries. The population health modeling tool DYNAMO-HIA including country-specific disease data was used to predict the changes in prevalence of ischemic heart disease and stroke for each country estimating the effect of salt reduction through its effect on blood pressure levels. A 30% salt reduction would reduce the prevalence of stroke by 6.4% in Finland to 13.5% in Poland. Ischemic heart disease would be decreased by 4.1% in Finland to 8.9% in Poland. When salt intake is reduced to the WHO population nutrient goal, it would reduce the prevalence of stroke from 10.1% in Finland to 23.1% in Poland. Ischemic heart disease would decrease by 6.6% in Finland to 15.5% in Poland. The number of postponed deaths would be 102,100 (0.9%) in France, and 191,300 (2.3%) in Poland. A reduction of salt intake to 5 grams per day is expected to substantially reduce the burden of cardiovascular disease and mortality in several European countries.

  9. Salt tectonics and shallow subseafloor fluid convection: models of coupled fluid-heat-salt transport

    USGS Publications Warehouse

    Wilson, A.; Ruppel, C.

    2007-01-01

    Thermohaline convection associated with salt domes has the potential to drive significant fluid flow and mass and heat transport in continental margins, but previous studies of fluid flow associated with salt structures have focused on continental settings or deep flow systems of importance to petroleum exploration. Motivated by recent geophysical and geochemical observations that suggest a convective pattern to near-seafloor pore fluid flow in the northern Gulf of Mexico (GoMex), we devise numerical models that fully couple thermal and chemical processes to quantify the effects of salt geometry and seafloor relief on fluid flow beneath the seafloor. Steady-state models that ignore halite dissolution demonstrate that seafloor relief plays an important role in the evolution of shallow geothermal convection cells and that salt at depth can contribute a thermal component to this convection. The inclusion of faults causes significant, but highly localized, increases in flow rates at seafloor discharge zones. Transient models that include halite dissolution show the evolution of flow during brine formation from early salt-driven convection to later geothermal convection, characteristics of which are controlled by the interplay of seafloor relief and salt geometry. Predicted flow rates are on the order of a few millimeters per year or less for homogeneous sediments with a permeability of 10−15 m2, comparable to compaction-driven flow rates. Sediment permeabilities likely fall below 10−15 m2 at depth in the GoMex basin, but such thermohaline convection can drive pervasive mass transport across the seafloor, affecting sediment diagenesis in shallow sediments. In more permeable settings, such flow could affect methane hydrate stability, seafloor chemosynthetic communities, and the longevity of fluid seeps.

  10. Mechanical stratification of autochthonous salt: Implications from basin-scale numerical models of rifted margin salt tectonics

    NASA Astrophysics Data System (ADS)

    Ings, Steven; Albertz, Markus

    2014-05-01

    Deformation of salt and sediments owing to the flow of weak evaporites is a common phenomenon in sedimentary basins worldwide, and the resulting structures and thermal regimes have a significant impact on hydrocarbon exploration. Evaporite sequences ('salt') of significant thickness (e.g., >1km) are typically deposited in many cycles of seawater inundation and evaporation in restricted basins resulting in layered autochthonous evaporite packages. However, analogue and numerical models of salt tectonics typically treat salt as a homogeneous viscous material, often with properties of halite, the weakest evaporite. In this study, we present results of two-dimensional plane-strain numerical experiments designed to illustrate the effects of variable evaporite viscosity and embedded frictional-plastic ('brittle') sediment layers on the style of salt flow and associated deformation of the sedimentary overburden. Evaporite viscosity is a first-order control on salt flow rate and the style of overburden deformation. Near-complete evacuation of low-viscosity salt occurs beneath expulsion basins, whereas significant salt is trapped when viscosity is high. Embedded frictional-plastic sediment layers (with finite yield strength) partition salt flow and develop transient contractional structures (folds, thrust faults, and folded faults) in a seaward salt-squeeze flow regime. Multiple internal sediment layers reduce the overall seaward salt flow during sediment aggradation, leaving more salt behind to be re-mobilized during subsequent progradation. This produces more seaward extensive allochthonous salt sheets. If there is a density difference between the embedded layers and the surrounding salt, then the embedded layers 'fractionate' during deformation and either float to the surface or sink to the bottom (depending on density), creating a thick zone of pure halite. Such a process of 'buoyancy fractionation' may partially explain the apparent paradox of layered salt in

  11. The Necessity of Salt Precipitation for the Dead Sea Modeling

    NASA Astrophysics Data System (ADS)

    Dvorkin, Y.; Lensky, N.; Lyahovsky, V.; Gertman, I.; Gavrieli, I.

    2006-12-01

    The Dead Sea is a hypersaline terminal lake with a composition that differs significantly from regular seawater. During the winter the DS is well mixed but in the spring a thermocline develops and the lake becomes stratified. Evaporation, mainly during summer leads to the development of a destabilizing halocline together with a stabilizing thermocline. Thus, the upper mixed layer is warmer due to heating and more saline due to evaporation than the lower layer. In the autumn, when the upper layer cools sufficiently, the lake overturns and becomes mixed again. To model this behavior one has to take into account the unique features of the Dead Sea. These features include the need for a special equation of state, determination of water activity and its impact on the evaporation rate, water inflow, including rejected brine (end brine) from the Dead Sea works and salt precipitation from the DS water body. The modeling of the water activity and salt precipitation requires a multicomponent (rather than usual salinity-based) model which enables determination of the degrees of saturation for specific salts and the calculation of the corresponding amount of precipitated salt required to maintain saturation. This precipitated salt accumulates on the bottom of the lake thus making the water deficit greater than surmised from observed water level drop. In the present study we modified the 1-D Princeton Oceanographic Model (POM) incorporating a new equation of state. The model correctly reproduces the measured temperature and salinity profiles, sea level drop and seasonal stratification and overturn of the DS. Our results show that the timing of the overturn is determined by the interplay between the temperature and the salinity of the mixed upper layer. The greater amount of salt in the water in the case of no salt precipitation results in premature overturn. Thus, salt precipitation and its impact on the mixed layer salinity were found to be of utmost importance.

  12. Examining Interior Grid Nudging Techniques Using Two-Way Nesting in the WRF Model for Regional Climate Modeling

    EPA Science Inventory

    This study evaluates interior nudging techniques using the Weather Research and Forecasting (WRF) model for regional climate modeling over the conterminous United States (CONUS) using a two-way nested configuration. NCEP–Department of Energy Atmospheric Model Intercomparison Pro...

  13. Examining Interior Grid Nudging Techniques Using Two-Way Nesting in the WRF Model for Regional Climate Modeling

    EPA Science Inventory

    This study evaluates interior nudging techniques using the Weather Research and Forecasting (WRF) model for regional climate modeling over the conterminous United States (CONUS) using a two-way nested configuration. NCEP–Department of Energy Atmospheric Model Intercomparison Pro...

  14. Improving Generalized Born Models by Exploiting Connections to Polarizable Continuum Models. II. Corrections for Salt Effects.

    PubMed

    Lange, Adrian W; Herbert, John M

    2012-11-13

    A previous analytical investigation of the generalized Born (GB) implicit solvation model is extended to solvents of nonzero ionic strength. The GB model with salt effects (GB-SE) is shown to resemble the Debye-Hückel-like screening model (DESMO), a polarizable continuum model (PCM) that we have recently developed for salty solutions. DESMO may be regarded either as a generalization of the conductor-like PCM (C-PCM) that extends C-PCM to electrolyte solutions or alternatively as a generalization of Debye-Hückel theory to arbitrary cavity shapes. The connection between GB-SE and DESMO suggests how the former can be modified to account for the exclusion of mobile ions from the cavity interior, an effect that is typically absent in GB-SE models. We propose two simple GB-SE models that are exact for a point charge in a spherical cavity and that introduce the ability to account, albeit approximately, for the finite size of the mobile ions. The accuracy of these new models is demonstrated by applications to both model systems and real proteins. These tests also demonstrate the accuracy of the DESMO approach, as compared to more sophisticated PCMs developed for electrolyte solutions.

  15. Environmental characterization report for the Gulf Interior Region, Texas study area. [Oakwood, Palestine and Keechi salt domes

    SciTech Connect

    Not Available

    1982-10-01

    This report is published as a product of the National Waste Terminal Storage (NWTS) Program. The objective of this program is the development of terminal waste storage facilities in deep, stable geologic formations for high-level nuclear waste, including spent fuel elements from commercial power reactors and transuranic nuclear waste for which the federal government is responsible. The report is part of the area study phase and contains environmental information for the Texas Study Area of the Gulf Interior Region acquired from federal, state, and regional agencies. The data in this report meet the requirements of predetermined survey plans and will be used in determining locations of approximately 80 square kilometers (30 square miles) that will be further characterized. Information on surface water, atmosphere, background radiation, natural ecosystems, agricultural systems, demography, socioeconomics, land use, and transportation is presented. The environmental characterization will ensure that data on environmental values required by the National Environmental Policy Act (NEPA) of 1969 are available.

  16. Modeling salt precipitation from brines on Mars: Evaporation versus freezing origin for soil salts

    NASA Astrophysics Data System (ADS)

    Toner, Jonathan D.; Catling, David C.; Light, Bonnie

    2015-04-01

    Perchlorates, in mixture with sulfates, chlorides, and carbonates, have been found in relatively high concentrations in martian soils. To determine probable soil salt assemblages from aqueous chemical data, equilibrium models have been developed to predict salt precipitation sequences during either freezing or evaporation of brines. However, these models have not been validated for multicomponent systems and some model predictions are clearly in error. In this study, we built a Pitzer model in the Na-K-Ca-Mg-Cl-SO4-ClO4-H2O system at 298.15 K using compilations of solubility data in ternary and quaternary perchlorate systems. The model is a significant improvement over FREZCHEM, particularly for Na-Mg-Cl-ClO4, Ca-Cl-ClO4, and Na-SO4-ClO4 mixtures. We applied our model to the evaporation of a nominal Phoenix Lander Wet Chemistry Laboratory (WCL) solution at 298.15 K and compare our results to FREZCHEM. Both models predict the early precipitation of KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), gypsum (CaSO4·2H2O), and epsomite (MgSO4·7H2O), followed by dehydration of epsomite and gypsum to kieserite (MgSO4·H2O) and anhydrite (CaSO4) respectively. At low residual water contents, our model predicts the precipitation of halite (NaCl), NaClO4·H2O, and Mg(ClO4)2·6H2O, whereas halite and NaClO4·H2O never precipitate in FREZCHEM. Our model predicts that calcite does not precipitate from evaporating WCL solutions at 298.15 K, which conflicts with other evidence for calcite in Phoenix soils. Previous studies that modeled freezing of WCL solutions found that calcite does form. Furthermore, our model predicts that ∼0.3 wt.% H2O is held in hydrated salts after the WCL solution has completely evaporated at 298.15 K, whereas previous studies have found that ∼1.3 wt.% H2O is held in hydrated salts if WCL solutions freeze. Given minimum water contents in Mars soils of 1.5-2 wt.% H2O measured from orbital spectra and in situ measurements, our modeling results suggest that

  17. Evaluating 1d Seismic Models of the Lunar Interior

    NASA Astrophysics Data System (ADS)

    Yao, Y.; Thorne, M. S.; Weber, R. C.; Schmerr, N. C.

    2012-12-01

    A four station seismic network was established on the Moon from 1969 to 1977 as part of the Apollo Lunar Surface Experiment Package (ALSEP). A total of nine 1D seismic velocity models were generated using a variety of different techniques. In spite of the fact that these models were generated from the same data set, significant differences exist between them. We evaluate these models by comparing predicted travel-times to published catalogs of lunar events. We generate synthetic waveform predictions for 1D lunar models using a modified version of the Green's Function of the Earth by Minor Integration (GEMINI) technique. Our results demonstrate that the mean square errors between predicted and measured P-wave travel times are smaller than those for S-wave travel times in all cases. Moreover, models fit travel times for artificial and meteoroid impacts better than for shallow and deep moonquakes. Overall, models presented by Nakamura [Nakamura, 1983] and Garcia et al. [Garcia et al., 2011] predicted the observed travel times better than all other models and were comparable in their explanation of travel-times. Nevertheless, significant waveform differences exist between these models. In particular, the seismic velocity structure of the lunar crust and regolith strongly affect the waveform characteristics predicted by these models. Further complexity is added by possible mantle discontinuity structure that exists in a subset of these models. We show synthetic waveform predictions for these models demonstrating the role that crustal structure has in generating long duration seismic coda inherent in the lunar waveforms.

  18. 3-D physical modeling of a complex salt canopy

    SciTech Connect

    Wiley, R.W.; Sekharan, K.K.

    1996-12-31

    Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather complex numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical model. The model is patterned after the SEG/EAEG Salt Model and is made from synthetic materials. It is a full three-dimensional model with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The model was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.

  19. Micro-Macro Analysis and Phenomenological Modelling of Salt Viscous Damage and Application to Salt Caverns

    NASA Astrophysics Data System (ADS)

    Zhu, Cheng; Pouya, Ahmad; Arson, Chloé

    2015-11-01

    This paper aims to gain fundamental understanding of the microscopic mechanisms that control the transition between secondary and tertiary creep around salt caverns in typical geological storage conditions. We use a self-consistent inclusion-matrix model to homogenize the viscoplastic deformation of halite polycrystals and predict the number of broken grains in a Representative Elementary Volume of salt. We use this micro-macro modeling framework to simulate creep tests under various axial stresses, which gives us the critical viscoplastic strain at which grain breakage (i.e., tertiary creep) is expected to occur. The comparison of simulation results for short-term and long-term creep indicates that the initiation of tertiary creep depends on the stress and the viscoplastic strain. We use the critical viscoplastic deformation as a yield criterion to control the transition between secondary and tertiary creep in a phenomenological viscoplastic model, which we implement into the Finite Element Method program POROFIS. We model a 850-m-deep salt cavern of irregular shape, in axis-symmetric conditions. Simulations of cavern depressurization indicate that a strain-dependent damage evolution law is more suitable than a stress-dependent damage evolution law, because it avoids high damage concentrations and allows capturing the formation of a damaged zone around the cavity. The modeling framework explained in this paper is expected to provide new insights to link grain breakage to phenomenological damage variables used in Continuum Damage Mechanics.

  20. CONVECTIVE OVERSHOOT MIXING IN MODELS OF THE STELLAR INTERIOR

    SciTech Connect

    Zhang, Q. S.

    2013-04-01

    Convective overshoot mixing plays an important role in stellar structure and evolution. However, overshoot mixing is also a long-standing problem; it is one of the most uncertain factors in stellar physics. As is well known, convective overshoot mixing is determined by the radial turbulent flux of the chemical component. In this paper, a local model of the radial turbulent flux of the chemical component is established based on hydrodynamic equations and some model assumptions and is tested in stellar models. The main conclusions are as follows. (1) The local model shows that convective overshoot mixing could be regarded as a diffusion process and the diffusion coefficient for different chemical elements is the same. However, if the non-local terms i.e., the gradient of the third-order moments, are taken into account, the diffusion coefficient for each chemical element should in general be different. (2) The diffusion coefficient of convective/overshoot mixing shows different behaviors in the convection zone and in the overshoot region because the characteristic length scale of the mixing is large in the convection zone and small in the overshoot region. Overshoot mixing should be regarded as a weak mixing process. (3) The diffusion coefficient of mixing is tested in stellar models, and it is found that a single choice of our central mixing parameter leads to consistent results for a solar convective envelope model as well as for core convection models of stars with masses from 2 M to 10 M.

  1. Solar Interior

    NASA Astrophysics Data System (ADS)

    Zahn, J.; Murdin, P.

    2000-11-01

    The interior of the Sun is hidden from our sight, because it is opaque to electromagnetic waves: the radiation we receive from it on Earth is emitted in the outermost layers. Our knowledge of the solar interior is based solely on theoretical models which are built with some assumptions about the physical conditions and processes that are likely to prevail there, and on helioseismology, a very pow...

  2. A hybrid SEA/modal technique for modeling structural-acoustic interior noise in rotorcraft

    NASA Astrophysics Data System (ADS)

    Jayachandran, V.; Bonilha, M. W.

    2003-03-01

    This paper describes a hybrid technique that combines Statistical Energy Analysis (SEA) predictions for structural vibration with acoustic modal summation techniques to predict interior noise levels in rotorcraft. The method was applied for predicting the sound field inside a mock-up of the interior panel system of the Sikorsky S-92 helicopter. The vibration amplitudes of the frame and panel systems were predicted using a detailed SEA model and these were used as inputs to the model of the interior acoustic space. The spatial distribution of the vibration field on individual panels, and their coupling to the acoustic space were modeled using stochastic techniques. Leakage and nonresonant transmission components were accounted for using space-averaged values obtained from a SEA model of the complete structural-acoustic system. Since the cabin geometry was quite simple, the modeling of the interior acoustic space was performed using a standard modal summation technique. Sound pressure levels predicted by this approach at specific microphone locations were compared with measured data. Agreement within 3 dB in one-third octave bands above 40 Hz was observed. A large discrepancy in the one-third octave band in which the first acoustic mode is resonant (31.5 Hz) was observed. Reasons for such a discrepancy are discussed in the paper. The developed technique provides a method for modeling helicopter cabin interior noise in the frequency mid-range where neither FEA nor SEA is individually effective or accurate.

  3. A hybrid SEA/modal technique for modeling structural-acoustic interior noise in rotorcraft.

    PubMed

    Jayachandran, V; Bonilha, M W

    2003-03-01

    This paper describes a hybrid technique that combines Statistical Energy Analysis (SEA) predictions for structural vibration with acoustic modal summation techniques to predict interior noise levels in rotorcraft. The method was applied for predicting the sound field inside a mock-up of the interior panel system of the Sikorsky S-92 helicopter. The vibration amplitudes of the frame and panel systems were predicted using a detailed SEA model and these were used as inputs to the model of the interior acoustic space. The spatial distribution of the vibration field on individual panels, and their coupling to the acoustic space were modeled using stochastic techniques. Leakage and nonresonant transmission components were accounted for using space-averaged values obtained from a SEA model of the complete structural-acoustic system. Since the cabin geometry was quite simple, the modeling of the interior acoustic space was performed using a standard modal summation technique. Sound pressure levels predicted by this approach at specific microphone locations were compared with measured data. Agreement within 3 dB in one-third octave bands above 40 Hz was observed. A large discrepancy in the one-third octave band in which the first acoustic mode is resonant (31.5 Hz) was observed. Reasons for such a discrepancy are discussed in the paper. The developed technique provides a method for modeling helicopter cabin interior noise in the frequency mid-range where neither FEA nor SEA is individually effective or accurate.

  4. Apply 3D model on the customized product color combination for the interior decoration

    NASA Astrophysics Data System (ADS)

    Chen, Cheih-Ying

    2013-03-01

    The customized product color interface for the interior decoration is designed to simulate the display of various color combination sofas in the interior of the room. There are 144 color combinations of the spatial image resulted from four the interior rooms and 36 popular color sofas. The image compositing technique is adopted to appear the 144 color combinations of the spatial image on computer screen. This study tests the experience of using the interface by the questionnaire for User Interface Satisfaction (QUIS). The results show that the high grade of evaluation items including wonderful, easy, satisfying, stimulating and flexible for the experience of users. Therefore, the entrepreneur who wants to display the color primarily commodity could using the customized color combination interface with 3D models for consumers to take opportunity to find the appropriate products to meet with the interior room, so as to shorten communication time between entrepreneurs and consumers.

  5. Mechanical modeling of the growth of salt structures

    SciTech Connect

    Alfaro, Ruben Alberto Mazariegos

    1993-05-01

    A 2D numerical model for studying the morphology and history of salt structures by way of computer simulations is presented. The model is based on conservation laws for physical systems, a fluid marker equation to keep track of the salt/sediments interface, and two constitutive laws for rocksalt. When buoyancy alone is considered, the fluid-assisted diffusion model predicts evolution of salt structures 2.5 times faster than the power-law creep model. Both rheological laws predict strain rates of the order of 4.0 x 10-15 s-1 for similar structural maturity level of salt structures. Equivalent stresses and viscosities predicted by the fluid-assisted diffusion law are 102 times smaller than those predicted by the power-law creep rheology. Use of East Texas Basin sedimentation rates and power-law creep rheology indicate that differential loading is an effective mechanism to induce perturbations that amplify and evolve to mature salt structures, similar to those observed under natural geological conditions.

  6. Chapter 2. Assessment of undiscovered conventional oil and gas resources--Upper Jurassic-Lower Cretaceous Cotton Valley group, Jurassic Smackover interior salt basins total petroleum system, in the East Texas basin and Louisiana-Mississippi salt basins provinces.

    USGS Publications Warehouse

    Dyman, T.S.; Condon, S.M.

    2006-01-01

    The Jurassic Smackover Interior Salt Basins Total Petroleum System is defined for this assessment to include (1) Upper Jurassic Smackover Formation carbonates and calcareous shales and (2) Upper Jurassic and Lower Cretaceous Cotton Valley Group organic-rich shales. The Jurassic Smackover Interior Salt Basins Total Petroleum System includes four conventional Cotton Valley assessment units: Cotton Valley Blanket Sandstone Gas (AU 50490201), Cotton Valley Massive Sandstone Gas (AU 50490202), Cotton Valley Updip Oil and Gas (AU 50490203), and Cotton Valley Hypothetical Updip Oil (AU 50490204). Together, these four assessment units are estimated to contain a mean undiscovered conventional resource of 29.81 million barrels of oil, 605.03 billion cubic feet of gas, and 19.00 million barrels of natural gas liquids. The Cotton Valley Group represents the first major influx of clastic sediment into the ancestral Gulf of Mexico. Major depocenters were located in south-central Mississippi, along the Louisiana-Mississippi border, and in northeast Texas. Reservoir properties and production characteristics were used to identify two Cotton Valley Group sandstone trends across northern Louisiana and east Texas: a high-permeability blanket-sandstone trend and a downdip, low-permeability massive-sandstone trend. Pressure gradients throughout most of both trends are normal, which is characteristic of conventional rather than continuous basin-center gas accumulations. Indications that accumulations in this trend are conventional rather than continuous include (1) gas-water contacts in at least seven fields across the blanket-sandstone trend, (2) relatively high reservoir permeabilities, and (3) high gas-production rates without fracture stimulation. Permeability is sufficiently low in the massive-sandstone trend that gas-water transition zones are vertically extensive and gas-water contacts are poorly defined. The interpreted presence of gas-water contacts within the Cotton Valley

  7. Fast, Automated, Photo realistic, 3D Modeling of Building Interiors

    DTIC Science & Technology

    2016-09-12

    important for applications in augmented and virtual reality , indoor navigation, and building simulation software. This paper presents a method to...navigation, augmented and virtual reality , as well as building energy simulation software. These applications require watertight models with limited...preservation, entertainment, and augmented reality , the demand for both fast and accurate scanning technologies has dramatically increased. In this

  8. Topographic controlled forcing of salt flow: Three-dimensional models of an active salt system, Canyonlands, Utah

    NASA Astrophysics Data System (ADS)

    Kravitz, Katherine; Upton, Phaedra; Mueller, Karl; Roy, Samuel G.

    2017-01-01

    The grabens within Canyonlands, Utah, is an active salt system primarily driven by differential unloading due to incision of the Colorado River. However, many other conditions exist in the region that potentially influence regional deformation, including the gentle dip of the evaporite deposits, unconfined salt within the river canyon, weaknesses in the overburden, and topographic gradients on various scales. Three-dimensional numerical models were built to test the scale at which salt responds to these parameters individually and as a whole. Topography has a large influence on salt flow on both a regional and local scales and predicts the formation of existing structures in the region on consistent spatial scales without the influence of overburden weakening or salt geometry. Topography also has a large influence on the direction of salt flow, which acts to divert salt away from the canyon at the edge of the grabens and enhance salt flow within the grabens. Unconfined salt within the canyon regionally alters displacement rates and patterns, indicating a clear shift in strain before and after incision of the river into the Paradox Formation. On a local scale, there is a strong coupling between overburden weakening and salt flow patterns, where salt responds to individual structures and less to regional drivers. All these driving forces create an ensemble of feedback that alters the strain field and structural development through time.

  9. Rhea gravity field and interior modeling from Cassini data analysis

    NASA Astrophysics Data System (ADS)

    Tortora, Paolo; Zannoni, Marco; Hemingway, Doug; Nimmo, Francis; Jacobson, Robert A.; Iess, Luciano; Parisi, Marzia

    2016-01-01

    During its tour of the Saturn system, Cassini performed two close flybys of Rhea dedicated to gravity investigations, the first in November 2005 and the second in March 2013. This paper presents an estimation of Rhea's fully unconstrained quadrupole gravity field obtained from a joint multi-arc analysis of the two Cassini flybys. Our best estimates of the main gravity quadrupole unnormalized coefficients are J2 × 106 = 946.0 ± 13.9, C22 × 106 = 242.1 ± 4.0 (uncertainties are 1-σ). Their resulting ratio is J2/C22 = 3.91 ± 0.10, statistically not compatible (at a 5-σ level) with the theoretical value of 10/3, predicted for a hydrostatic satellite in slow, synchronous rotation around a planet. Therefore, it is not possible to infer the moment of inertia factor directly using the Radau-Darwin approximation. The observed excess J2 (gravity oblateness) was investigated using a combined analysis of gravity and topography, under different plausible geophysical assumptions. The observed gravity is consistent with that generated by the observed shape for an undifferentiated (uniform density) body. However, because the surface is more likely to be water ice, a two-layer model may be a better approximation. In this case, and assuming a mantle density of 920 kg/m3, some 1-3 km of excess core oblateness is consistent with the observed gravity. A wide range of moments of inertia is allowed, but models with low moments of inertia (i.e., more differentiation) require greater magnitudes of excess core topography to satisfy the observations.

  10. Modeling Needs for Advancing Solar System Exploration: Magnetosphere-Ionosphere-Atmosphere-Surface-Interior Interactions

    NASA Astrophysics Data System (ADS)

    Daldorff, L. K. S.; Glocer, A.; Cohen, O.

    2017-02-01

    Models of planetary systems are key to understanding how these environments evolve and the implications for the origin and evolution of life. To do this, we need models that couple every aspect of the system from the Sun all the way to the interior.

  11. Harvesting cost model for small trees in natural stands in the interior northwest.

    Treesearch

    Bruce R. Hartsough; Xiaoshan Zhang; Roger D. Fight

    2001-01-01

    Realistic logging cost models are needed for long-term forest management planning. Data from numerous published studies were combined to estimate the costs of harvesting small trees in natural stands in the Interior Northwest of North America. Six harvesting systems were modeled. Four address gentle terrain: manual log-length, manual whole-tree, mechanized whole-tree,...

  12. Evaluation of potential crushed-salt constitutive models

    SciTech Connect

    Callahan, G.D.; Loken, M.C.; Sambeek, L.L. Van; Chen, R.; Pfeifle, T.W.; Nieland, J.D.

    1995-12-01

    Constitutive models describing the deformation of crushed salt are presented in this report. Ten constitutive models with potential to describe the phenomenological and micromechanical processes for crushed salt were selected from a literature search. Three of these ten constitutive models, termed Sjaardema-Krieg, Zeuch, and Spiers models, were adopted as candidate constitutive models. The candidate constitutive models were generalized in a consistent manner to three-dimensional states of stress and modified to include the effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant and southeastern New Mexico salt was used to determine material parameters for the candidate constitutive models. Nonlinear least-squares model fitting to data from the hydrostatic consolidation tests, the shear consolidation tests, and a combination of the shear and hydrostatic tests produces three sets of material parameter values for the candidate models. The change in material parameter values from test group to test group indicates the empirical nature of the models. To evaluate the predictive capability of the candidate models, each parameter value set was used to predict each of the tests in the database. Based on the fitting statistics and the ability of the models to predict the test data, the Spiers model appeared to perform slightly better than the other two candidate models. The work reported here is a first-of-its kind evaluation of constitutive models for reconsolidation of crushed salt. Questions remain to be answered. Deficiencies in models and databases are identified and recommendations for future work are made. 85 refs.

  13. Towards Coupled Giant Impact and Long Term Interior Evolution Models

    NASA Astrophysics Data System (ADS)

    Golabek, G.; Jutzi, M.; Gerya, T.; Asphaug, E. I.

    2014-12-01

    The crustal dichotomy is the dominant geological feature on planet Mars. The exogenic approach to the origin of the crustal dichotomy assumes that the northern lowlands correspond to a giant impact basin formed after primordial crust formation. However these simulations only consider the impact phase without studying the long-term repercussions of such a collision.The endogenic approach, suggesting a degree-1 mantle upwelling underneath the southern highlands, relies on a high Rayleigh number and a particular viscosity profile to form a low degree convective pattern within the geological constraints for the dichotomy formation. Such vigorous convection, however, results in continuous magmatic resurfacing, destroying the initially dichotomous crustal structure in the long-term.A further option is a hybrid exogenic-endogenic approach, which proposes an impact-induced magma ocean and subsequent superplume in the southern hemisphere. However these models rely on simple scaling laws to impose the thermal effects of the collision.Here we present the results of impact simulations performed with a SPH code serially coupled with geodynamical computations performed using the code I3VIS to improve the latter approach and test it against observations. We are exploring collisions varying the impactor velocities, impact angles and target body properties, and are gauging the sensitivity to the handoff from SPH to I3VIS.Our results indicate the formation of a transient hemispherical magma ocean in the impacted hemisphere, and the merging of the cores. We also find that impact angle and velocity have a strong effect on the post-impact temperature field and on the timescale and nature of core merger.

  14. Towards coupled giant impact and long term interior evolution models

    NASA Astrophysics Data System (ADS)

    Golabek, G. J.; Jutzi, M.; Gerya, T. V.; Asphaug, E. I.

    2014-04-01

    The crustal dichotomy [1] is the dominant geological feature on planet Mars. The exogenic approach to the origin of the crustal dichotomy [2-6] assumes that the northern lowlands correspond to a giant impact basin formed after primordial crust formation. However these simulations only consider the impact phase without studying the long-term repercussions of such a collision. The endogenic approach [7], suggesting a degree-1 mantle upwelling underneath the southern highlands [8-11], relies on a high Rayleigh number and a particular viscosity profile to form a low degree convective pattern within the geological constraints for the dichotomy formation. Such vigorous convection, however, results in continuous magmatic resurfacing, destroying the initially dichotomous crustal structure in the long-term. A further option is a hybrid exogenic-endogenic approach [12-15], which proposes an impact-induced magma ocean and subsequent superplume in the southern hemisphere. However these models rely on simple scaling laws to impose the thermal effects of the collision. Here we present the first results of impact simulations performed with a SPH code [16,17] serially coupled with geodynamical computations performed using the code I3VIS [18] to improve the latter approach and test it against observations. We are exploring collisions varying the impactor velocities, impact angles and target body properties, and are gauging the sensitivity to the handoff from SPH to I3VIS. As expected, our first results indicate the formation of a transient hemispherical magma ocean in the impacted hemisphere, and the merging of the cores. We also find that impact angle and velocity have a strong effect on the post-impact temperature field [5] and on the timescale and nature of core merger.

  15. Towards coupled giant impact and long term interior evolution models

    NASA Astrophysics Data System (ADS)

    Golabek, G.; Jutzi, M.; Gerya, T.; Asphaug, E. I.

    2013-12-01

    The crustal dichotomy [1] is the dominant geological feature on planet Mars. The exogenic approach to the origin of the crustal dichotomy [2-6] assumes that the northern lowlands correspond to a giant impact basin formed after primordial crust formation. However these simulations only consider the impact phase without studying the long-term repercussions of such a collision. The endogenic approach [7], suggesting a degree-1 mantle upwelling underneath the southern highlands [8-11], relies on a high Rayleigh number and a particular viscosity profile to form a low degree convective pattern within the geological constraints for the dichotomy formation. Such vigorous convection, however, results in continuous magmatic resurfacing, destroying the initially dichotomous crustal structure in the long-term. A further option is a hybrid exogenic-endogenic approach [12-15], which proposes an impact-induced magma ocean and subsequent superplume in the southern hemisphere. However these models rely on simple scaling laws to impose the thermal effects of the collision. Here we present the first results of impact simulations performed with a SPH code [16,17] serially coupled with geodynamical computations performed using the code I3VIS [18] to improve the latter approach and test it against observations. We are exploring collisions varying the impactor velocities, impact angles and target body properties, and are gauging the sensitivity to the handoff from SPH to I3VIS. As expected, our first results indicate the formation of a transient hemispherical magma ocean in the impacted hemisphere, and the merging of the cores. We also find that impact angle and velocity have a strong effect on the post-impact temperature field [5] and on the timescale and nature of core merger.

  16. Analytical model for investigation of interior noise characteristics in aircraft with multiple propellers including synchrophasing

    NASA Technical Reports Server (NTRS)

    Fuller, C. R.

    1986-01-01

    A simplified analytical model of transmission of noise into the interior of propeller-driven aircraft has been developed. The analysis includes directivity and relative phase effects of the propeller noise sources, and leads to a closed form solution for the coupled motion between the interior and exterior fields via the shell (fuselage) vibrational response. Various situations commonly encountered in considering sound transmission into aircraft fuselages are investigated analytically and the results obtained are compared to measurements in real aircraft. In general the model has proved successful in identifying basic mechanisms behind noise transmission phenomena.

  17. A dynamic nitrogen budget model of a Pacific Northwest salt ...

    EPA Pesticide Factsheets

    The role of salt marshes as either nitrogen sinks or sources in relation to their adjacent estuaries has been a focus of ecosystem service research for many decades. The complex hydrology of these systems is driven by tides, upland surface runoff, precipitation, evapotranspiration, and groundwater inputs, all of which can vary significantly on timescales ranging from sub-daily to seasonal. Additionally, many of these hydrologic drivers may vary with a changing climate. Due to this temporal variation in hydrology, it is difficult to represent salt marsh nitrogen budgets as steady-state models. A dynamic nitrogen budget model that varies based on hydrologic conditions may more accurately describe the role of salt marshes in nitrogen cycling. In this study we aim to develop a hydrologic model that is coupled with a process-based nitrogen model to simulate nitrogen dynamics at multiple temporal scales. To construct and validate our model we will use hydrologic and nitrogen species data collected from 2010 to present, from a 1.8 hectare salt marsh in the Yaquina Estuary, OR, USA. Hydrologic data include water table levels at two transects, upland tributary flow, tidal channel stage and flow, and vertical hydraulic head gradients. Nitrogen pool data include concentrations of nitrate and ammonium in porewater, tidal channel water, and extracted from soil cores. Nitrogen flux data include denitrification rates, nitrogen concentrations in upland runoff, and tida

  18. Progress in modeling solidification in molten salt coolants

    NASA Astrophysics Data System (ADS)

    Tano, Mauricio; Rubiolo, Pablo; Doche, Olivier

    2017-10-01

    Molten salts have been proposed as heat carrier media in the nuclear and concentrating solar power plants. Due to their high melting temperature, solidification of the salts is expected to occur during routine and accidental scenarios. Furthermore, passive safety systems based on the solidification of these salts are being studied. The following article presents new developments in the modeling of eutectic molten salts by means of a multiphase, multicomponent, phase-field model. Besides, an application of this methodology for the eutectic solidification process of the ternary system LiF-KF-NaF is presented. The model predictions are compared with a newly developed semi-analytical solution for directional eutectic solidification at stable growth rate. A good qualitative agreement is obtained between the two approaches. The results obtained with the phase-field model are then used for calculating the homogenized properties of the solid phase distribution. These properties can then be included in a mixture macroscale model, more suitable for industrial applications.

  19. A dynamic nitrogen budget model of a Pacific Northwest salt ...

    EPA Pesticide Factsheets

    The role of salt marshes as either nitrogen sinks or sources in relation to their adjacent estuaries has been a focus of ecosystem service research for many decades. The complex hydrology of these systems is driven by tides, upland surface runoff, precipitation, evapotranspiration, and groundwater inputs, all of which can vary significantly on timescales ranging from sub-daily to seasonal. Additionally, many of these hydrologic drivers may vary with a changing climate. Due to this temporal variation in hydrology, it is difficult to represent salt marsh nitrogen budgets as steady-state models. A dynamic nitrogen budget model that varies based on hydrologic conditions may more accurately describe the role of salt marshes in nitrogen cycling. In this study we aim to develop a hydrologic model that is coupled with a process-based nitrogen model to simulate nitrogen dynamics at multiple temporal scales. To construct and validate our model we will use hydrologic and nitrogen species data collected from 2010 to present, from a 1.8 hectare salt marsh in the Yaquina Estuary, OR, USA. Hydrologic data include water table levels at two transects, upland tributary flow, tidal channel stage and flow, and vertical hydraulic head gradients. Nitrogen pool data include concentrations of nitrate and ammonium in porewater, tidal channel water, and extracted from soil cores. Nitrogen flux data include denitrification rates, nitrogen concentrations in upland runoff, and tida

  20. Citronelle Dome: A giant opportunity for multizone carbon storage and enhanced oil recovery in the Mississippi Interior Salt Basin of Alabama

    USGS Publications Warehouse

    Esposito, R.A.; Pashin, J.C.; Walsh, P.M.

    2008-01-01

    The Citronelle Dome is a giant, salt-cored anticline in the eastern Mississippi Interior Salt Basin of southern Alabama that is located near several large-scale, stationary, carbon-emitting sources in the greater Mobile area. The dome forms an elliptical, four-way structural closure containing opportunities for CO2-enhanced oil recovery (CO2-EOR) and large-capacity saline reservoir CO2 sequestration. The Citronelle oil field, located on the crest of the dome, has produced more than 169 million bbl of 42-46?? API gravity oil from sandstone bodies in the Lower Cretaceous Rodessa Formation. The top seal for the oil accumulation is a thick succession of shale and anhydrite, and the reservoir is underfilled such that oil-water contacts are typically elevated 30-60 m (100-200 ft) above the structural spill point. Approximately 31-34% of the original oil in place has been recovered by primary and secondary methods, and CO2-EOR has the potential to increase reserves by up to 20%. Structural contour maps of the dome demonstrate that the area of structural closure increases upward in section. Sandstone units providing prospective carbon sinks include the Massive and Pilot sands of the lower Tuscaloosa Group, as well as several sandstone units in the upper Tuscaloosa Group and the Eutaw Formation. Many of these sandstone units are characterized by high porosity and permeability with low heterogeneity. The Tuscaloosa-Eutaw interval is capped by up to 610 m (2000 ft) of chalk and marine shale that are proven reservoir seals in nearby oil fields. Therefore, the Citronelle Dome can be considered a major geologic sink where CO2 can be safely stored while realizing the economic benefits associated with CO2-EOR. Copyright ?? 2008. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  1. New model describes toppling of salt marsh banks

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-05-01

    Salt marshes are coastal habitats that store important nutrients and serve as shelter for many estuarial species. These habitats are threatened by rising seas and human expansion, so it has become increasingly important to improve models of how these habitats degrade.

  2. Conceptual Model for Selenium Cycling in the Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Johnson, W. P.; Conover, M. R.; Wurtsbaugh, W. A.; Adams, J.

    2006-12-01

    The conceptual model for Selenium cycling in the Great Salt Lake was developed to guide investigations in support of determining an open water selenium standard for the Great Salt Lake. The motivation to determine this particular selenium standard derives from public concern for a plan to allow disposal of reverse osmosis (RO) concentrate in the GSL, which would contain elevated concentrations of major and trace elements, including selenium. The development of an open water standard for selenium requires a working knowledge of the biological significance of existing selenium concentrations in the Great Salt Lake, as well as a working understanding of the likely changes of these concentrations over time given existing and proposed loads to the system. This working knowledge" is being represented in a conceptual model that accounts for selenium in various stocks" in the system (e.g. water, sediment, biota) and the flow" of selenium between stocks (e.g., precipitation and settling, volatilization, bioconcentration). It illustrates the critical pathway of selenium in the Great Salt Lake from water, to microorganisms, to brine shrimp and brine flies, to birds, and to their eggs. It also addresses the complexity of the GSL system: a) Spatially diverse, being comprised by four distinct bays and two layers, with major differences in salinity among their waters. b) Temporally dynamic, due to seasonal and inter-annual variations in runoff. The conceptual model is presently descriptive, but will serve as the basis for a semi-quantitative model that will be fed by data accumulated during subsequent investigations.

  3. MIXING MODELING ANALYSIS FOR SRS SALT WASTE DISPOSITION

    SciTech Connect

    Lee, S.

    2011-01-18

    Nuclear waste at Savannah River Site (SRS) waste tanks consists of three different types of waste forms. They are the lighter salt solutions referred to as supernate, the precipitated salts as salt cake, and heavier fine solids as sludge. The sludge is settled on the tank floor. About half of the residual waste radioactivity is contained in the sludge, which is only about 8 percentage of the total waste volume. Mixing study to be evaluated here for the Salt Disposition Integration (SDI) project focuses on supernate preparations in waste tanks prior to transfer to the Salt Waste Processing Facility (SWPF) feed tank. The methods to mix and blend the contents of the SRS blend tanks were evalutaed to ensure that the contents are properly blended before they are transferred from the blend tank such as Tank 50H to the SWPF feed tank. The work consists of two principal objectives to investigate two different pumps. One objective is to identify a suitable pumping arrangement that will adequately blend/mix two miscible liquids to obtain a uniform composition in the tank with a minimum level of sludge solid particulate in suspension. The other is to estimate the elevation in the tank at which the transfer pump inlet should be located where the solid concentration of the entrained fluid remains below the acceptance criterion (0.09 wt% or 1200 mg/liter) during transfer operation to the SWPF. Tank 50H is a Waste Tank that will be used to prepare batches of salt feed for SWPF. The salt feed must be a homogeneous solution satisfying the acceptance criterion of the solids entrainment during transfer operation. The work described here consists of two modeling areas. They are the mixing modeling analysis during miscible liquid blending operation, and the flow pattern analysis during transfer operation of the blended liquid. The modeling results will provide quantitative design and operation information during the mixing/blending process and the transfer operation of the blended

  4. Interior-Point Methods for Estimating Seasonal Parameters in Discrete-Time Infectious Disease Models

    PubMed Central

    Word, Daniel P.; Young, James K.; Cummings, Derek A. T.; Iamsirithaworn, Sopon; Laird, Carl D.

    2013-01-01

    Infectious diseases remain a significant health concern around the world. Mathematical modeling of these diseases can help us understand their dynamics and develop more effective control strategies. In this work, we show the capabilities of interior-point methods and nonlinear programming (NLP) formulations to efficiently estimate parameters in multiple discrete-time disease models using measles case count data from three cities. These models include multiplicative measurement noise and incorporate seasonality into multiple model parameters. Our results show that nearly identical patterns are estimated even when assuming seasonality in different model parameters, and that these patterns show strong correlation to school term holidays across very different social settings and holiday schedules. We show that interior-point methods provide a fast and flexible approach to parameterizing models that can be an alternative to more computationally intensive methods. PMID:24167542

  5. Methods for integrated modeling of landscape change: Interior Northwest Landscape Analysis System.

    Treesearch

    Jane L. Hayes; Alan. A. Ager; R. James Barbour

    2004-01-01

    The Interior Northwest Landscape Analysis System (INLAS) links a number of resource, disturbance, and landscape simulations models to examine the interactions of vegetative succession, management, and disturbance with policy goals. The effects of natural disturbance like wildfire, herbivory, forest insects and diseases, as well as specific management actions are...

  6. Imaging Mars: Seeking Characteristic Signals in Models of the Martian Interior

    NASA Astrophysics Data System (ADS)

    Irving, J. C. E.; Wicks, J. K.

    2015-12-01

    We expect that the interiors of terrestrial planets look somewhat like our own - with a crust, a mantle hosting a range of mineralogical transformations and an iron alloy core. Data from existing geophysical observations of Mars, including its moment of inertia and mass, together with mineralogical, cosmochemical, geodynamical and meteorite information and modeling have lead to the creation of a variety of models of the density profile of the martian interior. A number of these density models are accompanied by seismic profiles in the planet. The presence of liquid layer in the outer core is supported by geodetic information; the presence of a solid inner core has not been conclusively ruled out by previous studies though it is unlikely. Some models predict jumps in seismic velocity in the mantle as steadily increasing pressure changes the stable phase assemblage, while other models instead show smooth increases in velocity. Attenuation in the martian mantle has been estimated by considering the tidal dissipation observed as Phobos orbits Mars. We investigate a range of models of Mars' density and velocity structure, using both simulations of Mars' normal mode oscillations and calculations of body wave travel times, ray paths and synthetic waveforms. For several features of the martian interior, from the presence of sharp boundaries in the mantle, to probable core sizes, we seek seismically observable signatures. Probing Mars' interior using seismic techniques is a key aim of the upcoming InSight mission to Mars; if seismic sources are sufficiently numerous and energetic then the presence of known seismic signatures for characteristics of the martian interior will help us to understand what lies beneath the surface of Mars.

  7. Subgrid Modeling Geomorphological and Ecological Processes in Salt Marsh Evolution

    NASA Astrophysics Data System (ADS)

    Shi, F.; Kirby, J. T., Jr.; Wu, G.; Abdolali, A.; Deb, M.

    2016-12-01

    Numerical modeling a long-term evolution of salt marshes is challenging because it requires an extensive use of computational resources. Due to the presence of narrow tidal creeks, variations of salt marsh topography can be significant over spatial length scales on the order of a meter. With growing availability of high-resolution bathymetry measurements, like LiDAR-derived DEM data, it is increasingly desirable to run a high-resolution model in a large domain and for a long period of time to get trends of sedimentation patterns, morphological change and marsh evolution. However, high spatial-resolution poses a big challenge in both computational time and memory storage, when simulating a salt marsh with dimensions of up to O(100 km^2) with a small time step. In this study, we have developed a so-called Pre-storage, Sub-grid Model (PSM, Wu et al., 2015) for simulating flooding and draining processes in salt marshes. The simulation of Brokenbridge salt marsh, Delaware, shows that, with the combination of the sub-grid model and the pre-storage method, over 2 orders of magnitude computational speed-up can be achieved with minimal loss of model accuracy. We recently extended PSM to include a sediment transport component and models for biomass growth and sedimentation in the sub-grid model framework. The sediment transport model is formulated based on a newly derived sub-grid sediment concentration equation following Defina's (2000) area-averaging procedure. Suspended sediment transport is modeled by the advection-diffusion equation in the coarse grid level, but the local erosion and sedimentation rates are integrated over the sub-grid level. The morphological model is based on the existing morphological model in NearCoM (Shi et al., 2013), extended to include organic production from the biomass model. The vegetation biomass is predicted by a simple logistic equation model proposed by Marani et al. (2010). The biomass component is loosely coupled with hydrodynamic and

  8. Precipitates/Salts Model Calculations for Various Drift Temperature Environments

    SciTech Connect

    P. Marnier

    2001-12-20

    The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b).

  9. Mediterranean salt giants beyond the evaporite model: The Sicily perspective

    NASA Astrophysics Data System (ADS)

    Carmelo Manuella, Fabio; Scribano, Vittorio; Carbone, Serafina; Hovland, Martin; Johnsen, Hans-Konrad; Rueslåtten, Håkon

    2017-04-01

    Mediterranean salt giants, occurring both in sub-seafloor and in onshore settings (the "Gessoso Solfifera Group"), are traditionally explained by repeated cycles of desiccation and replenishment of the entire basin. However, such hypotheses are strongly biased by mass balance calculations and geodynamic considerations. In addition, any hypothesis without full desiccation, still based on the evaporite model, should consider that seawater brines start to precipitate halite when 2/3 of the seawater has evaporated, and hence the level of the basin cannot be the same as the adjacent ocean. On the other hand, hydrothermal venting of hot saline brines onto the seafloor can precipitate salt in a deep marine basin if a layer of heavy brine exists along the seafloor. This process, likely related to sub-surface boiling or supercritical out-salting (Hovland et al., 2006), is consistent with geological evidence in the Red Sea "Deeps" (Hovland et al., 2015). Although supercritical out-salting and phase separation can sufficiently explain the formation of several marine salt deposits, even in deep marine settings, the Mediterranean salt giant formations can also be explained by the serpentinization model (Scribano et al., 2016). Serpentinization of abyssal peridotites does not involve seawater salts, and large quantities of saline brines accumulate in pores and fractures of the sub-seafloor serpentinites. If these rocks undergo thermal dehydration, for example, due to igneous intrusions, brines and salt slurries can migrate upwards as hydrothermal plumes, eventually venting at the seafloor, giving rise to giant salt deposits over time. These hydrothermal processes can take place in a temporal sequence, as it occurred in the "Caltanissetta Basin" (Sicily). There, salt accumulation associated with serpentinization started during Triassic times (and even earlier), and venting of heavy brines onto the seafloor eventually occurred in the Messinian via the hydrothermal plume mechanism

  10. Roughness modelling based on human auditory perception for sound quality evaluation of vehicle interior noise

    NASA Astrophysics Data System (ADS)

    Wang, Y. S.; Shen, G. Q.; Guo, H.; Tang, X. L.; Hamade, T.

    2013-08-01

    In this paper, a roughness model, which is based on human auditory perception (HAP) and known as HAP-RM, is developed for the sound quality evaluation (SQE) of vehicle noise. First, the interior noise signals are measured for a sample vehicle and prepared for roughness modelling. The HAP-RM model is based on the process of sound transfer and perception in the human auditory system by combining the structural filtering function and nonlinear perception characteristics of the ear. The HAP-RM model is applied to the measured vehicle interior noise signals by considering the factors that affect hearing, such as the modulation and carrier frequencies, the time and frequency maskings and the correlations of the critical bands. The HAP-RM model is validated by jury tests. An anchor-scaled scoring method (ASM) is used for subjective evaluations in the jury tests. The verification results show that the novel developed model can accurately calculate vehicle noise roughness below 0.6 asper. Further investigation shows that the total roughness of the vehicle interior noise can mainly be attributed to frequency components below 12 Bark. The time masking effects of the modelling procedure enable the application of the HAP-RM model to stationary and nonstationary vehicle noise signals and the SQE of other sound-related signals in engineering problems.

  11. Jupiter and Saturn Interior Models with an Equation of State Derived From First Principles Computer Simulations

    NASA Astrophysics Data System (ADS)

    Hubbard, William B.; Militzer, B.; Vorberger, J.

    2006-09-01

    We report results from recent investigations of the interior structures of Jupiter and Saturn using state-of-the-art computer simulations of dense fluid hydrogen and helium. Thermodynamic properties used in the models were obtained using density-functional molecular dynamics (DFT-MD) simulations on a grid of temperature and density points spanning the interiors of these planets. In addition to calculations for pure hydrogen, simulation results for the different concentrations of hydrogen-helium mixtures are presented. The corrections to the commonly used linear mixing approximation are characterized, and it is demonstrated how the addition of helium increases the stability of the molecular phase of hydrogen. Our interior models update the suite of models that were based on the widely used Saumon-Chabrier-Van Horn (SCVH) equation of state for hydrogen and helium. Unlike SCVH, the computed DFT-EOS does not predict any first-order thermodynamic discontinuities associated with pressure-dissociation and metallization of hydrogen. Instead, the DFT-EOS predicts that the molecular dissociation leads intermediate decrease in pressure, which has profound effects on the thermodynamic properties in a zone approximately 6000 km below the 1-bar level in Jupiter and 1100 km below that level in Saturn. Deviations of the DFT-EOS from SCVH are up to about +/- 5% depending on the pressure, and thus affect interior models at the same level as possible effects of a jovian core. We will discuss inferred core masses and interior metallicity for Jupiter and Saturn. Our results will eventually aid in interpretation of data expected from the Juno orbiter mission. Supported by NASA PGG Grants NAG5-13775 and PGG04-0000-0116 and NSF Grant 0507321.

  12. A Kronig-Penney Model of Salts of DNA

    PubMed Central

    Rosen, Philip

    1968-01-01

    A one dimensional Kronig-Penney model for a salt like Na DNA is given. The helical periodicity is treated in a manner suggested by Tinoco and Woody. Using data on the semiconductor band gap, we estimate the strength of the potential barrier. The energy limits of the ten bands filled by 20π electrons per unit cell are calculated and exhibited in Table I. PMID:5643271

  13. A coarse-grained model with implicit salt for RNAs: Predicting 3D structure, stability and salt effect

    SciTech Connect

    Shi, Ya-Zhou; Wang, Feng-Hua; Wu, Yuan-Yan; Tan, Zhi-Jie

    2014-09-14

    To bridge the gap between the sequences and 3-dimensional (3D) structures of RNAs, some computational models have been proposed for predicting RNA 3D structures. However, the existed models seldom consider the conditions departing from the room/body temperature and high salt (1M NaCl), and thus generally hardly predict the thermodynamics and salt effect. In this study, we propose a coarse-grained model with implicit salt for RNAs to predict 3D structures, stability, and salt effect. Combined with Monte Carlo simulated annealing algorithm and a coarse-grained force field, the model folds 46 tested RNAs (≤45 nt) including pseudoknots into their native-like structures from their sequences, with an overall mean RMSD of 3.5 Å and an overall minimum RMSD of 1.9 Å from the experimental structures. For 30 RNA hairpins, the present model also gives the reliable predictions for the stability and salt effect with the mean deviation ∼ 1.0 °C of melting temperatures, as compared with the extensive experimental data. In addition, the model could provide the ensemble of possible 3D structures for a short RNA at a given temperature/salt condition.

  14. Road salt emissions: A comparison of measurements and modelling using the NORTRIP road dust emission model

    NASA Astrophysics Data System (ADS)

    Denby, B. R.; Ketzel, M.; Ellermann, T.; Stojiljkovic, A.; Kupiainen, K.; Niemi, J. V.; Norman, M.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.; Sundvor, I.

    2016-09-01

    De-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes but a certain amount may be suspended, after drying of the road surface, into the air and will contribute to the concentration of particulate matter. Though some measurements of salt concentrations are available near roads, the link between road maintenance salting activities and observed concentrations of salt in ambient air is yet to be quantified. In this study the NORTRIP road dust emission model, which estimates the emissions of both dust and salt from the road surface, is applied at five sites in four Nordic countries for ten separate winter periods where daily mean ambient air measurements of salt concentrations are available. The model is capable of reproducing many of the salt emission episodes, both in time and intensity, but also fails on other occasions. The observed mean concentration of salt in PM10, over all ten datasets, is 4.2 μg/m3 and the modelled mean is 2.8 μg/m3, giving a fractional bias of -0.38. The RMSE of the mean concentrations, over all 10 datasets, is 2.9 μg/m3 with an average R2 of 0.28. The mean concentration of salt is similar to the mean exhaust contribution during the winter periods of 2.6 μg/m3. The contribution of salt to the kerbside winter mean PM10 concentration is estimated to increase by 4.1 ± 3.4 μg/m3 for every kg/m2 of salt applied on the road surface during the winter season. Additional sensitivity studies showed that the accurate logging of salt applications is a prerequisite for predicting salt emissions, as well as good quality data on precipitation. It also highlights the need for more simultaneous measurements of salt loading together with ambient air concentrations to help improve model parameterisations of salt and moisture removal processes.

  15. Dynamic modeling of Badaling molten salt tower CSP pilot plant

    NASA Astrophysics Data System (ADS)

    Yang, Zijiang; Lu, Jiahui; Zhang, Qiangqiang; Li, Zhi; Li, Xin; Wang, Zhifeng

    2017-06-01

    Under the collaboration framework between EDF China R&D Centre and CAS-IEE, a preliminary numerical model of 1MWth molten salt tower solar power demonstration plant in Badaling, Beijing is presented in this paper. All key components in the plant are presented throughout detailed modules in the model according to its design specifications. Control strategies are also implemented to maintain the design system performance at transient scenario. By this model some key design figures of plant has been validated and it will be used to guide experiment set-up and plant commissioning.

  16. Salt-Pond Box Model (SPOOM) and Its Application to the Napa-Sonoma Salt Ponds, San Francisco Bay, California

    USGS Publications Warehouse

    Lionberger, Megan L.; Schoellhamer, David H.; Buchanan, Paul A.; Meyer, Scott

    2004-01-01

    A box model to simulate water volume and salinity of a salt pond has been developed by the U.S. Geological Survey to obtain water and salinity budgets. The model, SPOOM, uses the principle of conservation of mass to calculate daily pond volume and salinity and includes a salt crystallization and dissolution algorithm. Model inputs include precipitation, evaporation, infiltration, and water transfers. Salinity and water-surface-elevation data were collected monthly in the Napa-Sonoma Salt-Pond Complex from February 1999 through September 2001 and were used to calibrate and validate the model. The months when water transfers occurred were known but the magnitudes were unknown, so the magnitudes of water transfers were adjusted in the model to calibrate simulated pond volumes to measured pond volumes for three ponds. Modeled salinity was then compared with measured salinity, which remained a free parameter, in order to validate the model. Comparison showed good correlation between modeled and measured salinity. Deviations can be attributed to lack of water-transfer information. Water and salinity budgets obtained through modeling will be used to help interpret ecological data from the ponds. This model has been formulated to be applicable to the Napa-Sonoma salt ponds, but can be applied to other salt ponds.

  17. An Accuracy Assessment of Automated Photogrammetric Techniques for 3d Modeling of Complex Interiors

    NASA Astrophysics Data System (ADS)

    Georgantas, A.; Brédif, M.; Pierrot-Desseilligny, M.

    2012-07-01

    This paper presents a comparison of automatic photogrammetric techniques to terrestrial laser scanning for 3D modelling of complex interior spaces. We try to evaluate the automated photogrammetric techniques not only in terms of their geometric quality compared to laser scanning but also in terms of cost in money, acquisition and computational time. To this purpose we chose as test site a modern building's stairway. APERO/MICMAC ( ©IGN )which is an Open Source photogrammetric software was used for the production of the 3D photogrammetric point cloud which was compared to the one acquired by a Leica Scanstation 2 laser scanner. After performing various qualitative and quantitative controls we present the advantages and disadvantages of each 3D modelling method applied in a complex interior of a modern building.

  18. Physics Model Based Scatter Correction in Multi-source Interior Computed Tomography.

    PubMed

    Gong, Hao; Li, Bin; Jia, Xun; Gao, Guohua

    2017-08-17

    Multi-source interior computed tomography (CT) has a great potential to provide ultra-fast and organ-oriented imaging at low radiation dose. However, X-ray cross scattering from multiple simultaneously activated X-ray imaging chains compromises imaging quality. Previously, we published two hardware based scatter correction methods for multi-source interior CT. Here, we propose a software based scatter correction method, with the benefit of no need for hardware modifications. The new method is based on a physics model and an iterative framework. The physics model was derived analytically, and was used to calculate X-ray scattering signals in both forward direction and cross directions in multi-source interior CT. The physics model was integrated to an iterative scatter correction framework to reduce scatter artifacts. The method was applied to phantom data from both Monte Carlo simulations and physical experimentation that were designed to emulate the image acquisition in a multi-source interior CT architecture recently proposed by our team. The proposed scatter correction method reduced scatter artifacts significantly, even with only one iteration. Within a few iterations, the reconstructed images fast converged toward the "scatter-free" reference images. After applying the scatter correction method, the maximum CT number error at the region-of-interests (ROIs) was reduced to 46 HU in numerical phantom dataset and 48 HU in physical phantom dataset respectively, and the contrast-noise-ratio (CNR) at those ROIs increased by up to 44.3% and up to 19.7% respectively. The proposed physics model based iterative scatter correction method could be useful for scatter correction in dual-source or multi-source CT.

  19. Interior Structure of Pinch Plasmoids in a GRT Gravitational-Electrodynamic Model

    NASA Astrophysics Data System (ADS)

    Bogdanovich, B. Yu.; Nestorovich, A. V.; Sukhanova, L. A.; Khlestkov, Yu. A.

    2016-11-01

    The need to take the gravitational field (the curvature of spacetime) into account in a description of pinch plasmoids formed in high-voltage discharges in which super-high energy densities are reached is demonstrated. A description of the interior structure of such a plasmoid with the help of a new exact solution of the Einstein-Maxwell equations is presented. With the help of the developed model we have estimated the main parameters of such pinch plasmoids.

  20. 3D Modeling of Interior Building Environments and Objects from Noisy Sensor Suites

    DTIC Science & Technology

    2015-05-14

    3D Modeling of Interior Building Environments and Objects from Noisy Sensor Suites Eric Turner Electrical Engineering and Computer Sciences ... Computer Sciences ,Berkeley,CA,94720 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S...Philosophy in Engineering – Electrical Engineering and Computer Sciences in the Graduate Division of the University of California, Berkeley Committee in

  1. Constitutive Modeling of the Thermomechanical Behavior of Rock Salt

    NASA Astrophysics Data System (ADS)

    Hampel, A.

    2016-12-01

    For the safe disposal of heat-generating high-level radioactive waste in rock salt formations, highly reliable numerical simulations of the thermomechanical and hydraulic behavior of the host rock have to be performed. Today, the huge progress in computer technology has enabled experts to calculate large and detailed computer models of underground repositories. However, the big ad­van­ces in computer technology are only beneficial when the applied material models and modeling procedures also meet very high demands. They result from the fact that the evaluation of the long-term integrity of the geological barrier requires an extra­polation of a highly nonlinear deforma­tion behavior to up to 1 million years, while the underlying experimental investigations in the laboratory or in situ have a duration of only days, weeks or at most some years. Several advanced constitutive models were developed and continuously improved to describe the dependences of various deformation phenomena in rock salt on in-situ relevant boundary conditions: transient and steady-state creep, evolution of damage and dilatancy in the DRZ, failure, post-failure behavior, residual strength, damage and dilatancy reduction, and healing. In a joint project series between 2004 and 2016, fundamental features of the advanced models were investigated and compared in detail with benchmark calculations. The study included procedures for the determination of characteristic salt-type-specific model parameter values and for the performance of numerical calculations of underground structures. Based on the results of this work and on specific laboratory investigations, the rock mechanical modeling is currently developed further in a common research project of experts from Germany and the United States. In this presentation, an overview about the work and results of the project series is given and the current joint research project WEIMOS is introduced.

  2. Effects of Interior Velocity Models and Scattering Structure on the Coda Decay Properties of Seismic Signals

    NASA Astrophysics Data System (ADS)

    Blanchette-guertin, J.; Johnson, C. L.; Lawrence, J. F.

    2013-12-01

    We investigate the effects of scattering on the coda rise and decay times of synthetic seismic signals using an adapted version of the seismic phonon method. We examine the amplitudes and dependence on epicentral distance of decay times for a range of interior models with 1D velocity structure as well as intrinsic attenuation that can be specified as a function of depth and frequency. Scattering is 3D, assuming longitudinal symmetry, and occurs globally within layer(s) of prescribed thickness. Scatterers within the layer(s) have random orientations, defined length-scales distributions (distance between scatterers), and random velocity and density perturbations within a prescribed range. We demonstrate that variations in the signal's coda decay attributes can be analyzed to assess the first-order structural properties of highly scattering bodies such as Earth's moon. The variation of decay time with epicentral distance is most affected by the event source depth (surface impact vs. deep event), the frequency content, the background velocity model and intrinsic attenuation. On the other hand, the magnitude of the decay times is controlled by the size-frequency distribution of scatterers, the thickness and location of the scattering layer(s) and the presence of a low velocity layer. We use this new understanding of the effects of interior scattering structure on coda decay times to examine suites of lunar interior models that produce rise and decay characteristics similar to those observed in the Apollo Passive Seismic Experiment data.

  3. A trade-off analysis design tool. Aircraft interior noise-motion/passenger satisfaction model

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.

    1977-01-01

    A design tool was developed to enhance aircraft passenger satisfaction. The effect of aircraft interior motion and noise on passenger comfort and satisfaction was modelled. Effects of individual aircraft noise sources were accounted for, and the impact of noise on passenger activities and noise levels to safeguard passenger hearing were investigated. The motion noise effect models provide a means for tradeoff analyses between noise and motion variables, and also provide a framework for optimizing noise reduction among noise sources. Data for the models were collected onboard commercial aircraft flights and specially scheduled tests.

  4. Present-day Mars' Seismicity Predicted from 3-D Thermal Evolution Models of Interior Dynamics

    NASA Astrophysics Data System (ADS)

    Knapmeyer, M.; Plesa, A. C.; Golombek, M.

    2016-12-01

    The InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission, to be launched in 2018, will carry the first in-situ seismic and heat flow instruments as well as a precision tracking on Mars. This Discovery-class mission will perform the most comprehensive geophysical investigation of the planet and provide an important baseline to constrain the present-day interior structure and heat budget of the planet, and, in turn, the thermal and chemical evolution of its interior. As the InSight lander will perform the measurements at a single location, numerical simulations of planetary interiors will greatly help to interpret the data in a global context. In this study we have used a series of numerical models of thermal evolution in a 3-D spherical geometry to assess the magnitude of present-day Mars seismicity. Our models assume a fixed crust with a variable thickness as inferred from gravity and topography data, that is enriched in radiogenic heat sources according to the surface abundances inferred from gamma-ray measurements. We test a diversity of parameters by varying the mantle reference viscosity as well as the depth-dependence of the viscosity, considering constant and variable thermal expansivity, varying the crustal thermal conductivity and the size of the core [1]. Our results predict an annual moment release between 1.60 x 1016 Nm and 5.46 x 1018 Nm similar to the values presented previously in [2] and [3]. However, while [2] used a mapping of tectonic surface faults to predict the spatial distribution of epicenters, we derive the distribution from the thermal evolution. Besides the Null-Hypothesis of a uniform distribution and the model of [2], this provides a new, self-consistent, competing hypothesis for both the amount and distribution of seismicity on Mars. [1] Plesa et al., LPSC, 2016 [2] Knapmeyer et al., JGR, 2006 [3] Golombek et al., Science 1992; LPSC 2002

  5. Influence of pre-salt topographic features on supra-salt deformation in Mediterranean basins: Geology vs. physical models

    NASA Astrophysics Data System (ADS)

    Ferrer, Oriol; Vidal-Royo, Oskar; Gratacós, Oscar; Roca, Eduard; Muñoz, Josep Anton; Esestime, Paolo; Rodriguez, Karyna; Yazmin Piragauta, Mary; Feliu, Nil

    2017-04-01

    The presence of a thick Messinian evaporite unit is a well known feature of the Mediterranean basins. This salt unit is composed of three sub-units (Lower, Mobile and Upper Units) in the Northwest Mediterranean. In contrast, in the Eastern Mediterranean it is characterized by a multilayered evaporite sequence. In both regions the salt acted as a detachment favoring the downslope gravitational failure of the overlying sediments in a thin-skinned deformation regime (e.g. Liguro-Provençal or Levant basins). As a result, these salt-bearing passive margins exhibit the classical three-domain structural zonation characterized by upslope extension, intermediate translation and downslope contraction. Nevertheless, the presence of pre-salt reliefs (e.g. irregularly eroded palaeotopography or volcanic edifices) is rather common in the translational domain of the Northwestern Mediterranean (e.g. Liguro-Provençal and West Corsica margins). In this scenario, pre-salt reliefs act as flow barriers and hinder salt drainage. When their summit lies close or above the top salt, these structures may partially or fully block salt flow. They also disrupt locally the structural zonation of the passive margin and constrain cover deformation. In contrast, in the Eastern Mediterranean the Eratosthenes seamount is characterized by a large scale submerged massif (ca. 120 km in size) that significantly influenced the structural evolution of the surrounding areas. This inherited relief acted as a buttress and deflected the Messinian salt flow constraining supra-salt deformation (e.g. Levant Basin and Nile margin). In addition, the geometry of the Eratosthenes seamount also restrained the structural style of the allochthonous salt that was expulsed during the development of the Cyprus subduction zone to the north. Using an experimental approach (sandbox models) and new analysis techniques, we investigate salt and supra-salt deformation in response to two different types of pre-salt relief: 1

  6. Validation of an interior noise prediction model for a composite cylinder

    NASA Technical Reports Server (NTRS)

    Beyer, Todd B.; Grosveld, Ferdinand W.

    1987-01-01

    An acoustic modal analysis has been performed in the cavity of a composite cylinder model of an aircraft fuselage. The filament wound, composite shell is 12 feet long and 5.5 feet in diameter. A one-half-in. thick plywood floor is attached to the shell 69 deg from the vertical centerline through the bottom of the shell. The acoustic modal frequencies were obtained from a sound pressure level and phase survey conducted throughout the interior volume bounded by the floor, endcaps and stiffened shell, while being excited by white noise from a loudspeaker source. The measured acoustic resonance frequencies and mode shapes compare well with analytical predictions from the Propeller Aircraft Interior Noise (PAIN) model. Details of the theory and derivation of the acoustic characteristics have been included. Reverberation time measurements, using the integrated impulse technique, have been performed to determine acoustic loss factors. These measured loss factors have been input to the PAIN program in order to more accurately predict the space-averaged interior noise of the composite cylinder.

  7. Validation of an interior noise prediction model for a composite cylinder

    NASA Technical Reports Server (NTRS)

    Beyer, Todd B.; Grosveld, Ferdinand W.

    1987-01-01

    An acoustic modal analysis has been performed in the cavity of a composite cylinder model of an aircraft fuselage. The filament wound, composite shell is 12 feet long and 5.5 feet in diameter. A one-half-in. thick plywood floor is attached to the shell 69 deg from the vertical centerline through the bottom of the shell. The acoustic modal frequencies were obtained from a sound pressure level and phase survey conducted throughout the interior volume bounded by the floor, endcaps and stiffened shell, while being excited by white noise from a loudspeaker source. The measured acoustic resonance frequencies and mode shapes compare well with analytical predictions from the Propeller Aircraft Interior Noise (PAIN) model. Details of the theory and derivation of the acoustic characteristics have been included. Reverberation time measurements, using the integrated impulse technique, have been performed to determine acoustic loss factors. These measured loss factors have been input to the PAIN program in order to more accurately predict the space-averaged interior noise of the composite cylinder.

  8. Some interior models of compact stars in f(R) gravity

    NASA Astrophysics Data System (ADS)

    Zubair, M.; Abbas, G.

    2016-10-01

    This paper deals with the interior models of compact stars in the framework of modified f(R) theory of gravity, which is the generalization of the Einstein's gravity. In order to complete the study, we have involved solution of Krori and Barua to the static spacetime with fluid source in modified f(R) theory of gravity. Further, we have matched the interior solution with the exterior solution to determine the constants of Krori and Barua solution. Finally, the constants have been formulated by using the observational data of various compact stars like 4U1820-30, Her X-1, SAX J1808-3658. Using the evaluated form of the solutions, we have discussed the regularity of matter components at the center as well as on the boundary, energy conditions, anisotropy, stability analysis and mass-radius relation of the compact stars 4U1820-30, Her X-1, SAX J1808-3658.

  9. Controls on interior West Antarctic Ice Sheet Elevations: inferences from geologic constraints and ice sheet modeling

    NASA Astrophysics Data System (ADS)

    Ackert, Robert P.; Putnam, Aaron E.; Mukhopadhyay, Sujoy; Pollard, David; DeConto, Robert M.; Kurz, Mark D.; Borns, Harold W.

    2013-04-01

    Knowledge of the West Antarctic Ice Sheet (WAIS) response to past sea level and climate forcing is necessary to predict its response to warmer temperatures in the future. The timing and extent of past interior WAIS elevation changes provides insight to WAIS behavior and constraints for ice sheet models. Constraints prior to the Last Glacial Maximum (LGM) however, are rare. Surface exposure ages of glacial erratics near the WAIS divide at Mt. Waesche in Marie Byrd Land, and at the Ohio Range in the Transantarctic Mountains, range from ∼10 ka to >500 ka without a dependence on elevation. The probability distribution functions (PDF) of the exposure ages at both locations, are remarkably similar. During the last glaciation, maximum interior ice elevations as recorded by moraines and erratics were reached between 10 ka and 12 ka. However, most exposure ages are older than the LGM and cluster around ∼40 ka and ∼80 ka. The peak in the exposure age distributions at ∼40 ka includes ages of alpine moraine boulders at Mercer Ridge in the Ohio Range. Comparison of the PDF of exposures ages from the Ohio Range and Mt. Waesche with the temperature record from the Fuji Dome ice core indicates that the youngest peak in the exposure age distributions corresponds to the abrupt warming during the Last Glacial termination. A prominent peak in the Ohio Range PDF corresponds to the penultimate termination (stage 5e). During the intervening glacial period, there is not a consistent relationship between the peaks in the PDF at each location and temperature. A combined ice sheet/ice shelf model with forcing scaled to marine δ18O predicts that interior WAIS elevations near the ice divide have varied ∼300 m over the Last Glacial cycle. Peaks in the PDF correspond to model highstands over the last 200 ka. In the simulated elevation history, maximum ice elevations at Ohio Range (+100 m) and Mt. Waesche (+60 m) occur at ∼10 ka, in agreement with observations from these sites

  10. Geomechanical modeling of salt-sediment interaction in evolving sedimentary basins

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.; Luo, G.; Nikolinakou, M. A.; Hudec, M.

    2011-12-01

    We use coupled geomechanical modeling to describe how stress and pore pressure evolve in sedimentary basins where salt is present. We treat salt as a visco-elastic material and sediment as a poro-elastic, poro-elastoplastic or Coloumb plastic material. At geological timescales (100 k.y. and longer) salt flow releases differential stresses, whereas sediment maintains significant differential stresses. Significant perturbations in stress and pore pressure occur near salt bodies to accommodate these material behaviors. In low permeability systems, where salt is encased by sediment, the least principal stress and pore pressure are reduced at the crest and base of salt whereas they are elevated at the flanks of salt. Salt loading induces pore pressures that extend kilometers away from the salt. These results are similar to drilling results that record reduced pore pressure and reduced least principal stress beneath salt. We also consider the case where a salt sheet advances across sediment. When salt advances over low permeability sediment, pore pressures rise and effective stresses are low beneath the salt, and the salt sheet advances rapidly. In contrast, when salt advances over a high permeability substrate, fluids drain, pore pressures are low and effective stresses are high beneath salt, and the salt sheet advances slowly. The magnitude of the overpressure beneath the salt can be estimated from its geometry. Our approach extends beyond large-scale uncoupled basin models that have assumed only uniaxial (vertical) strain. This coupled approach provides insight as to the interpretation of large scale geological structures and has the potential to predict in situ stresses and pore pressures.

  11. Development of a Mantle Convection Physical Model to Assist with Teaching about Earth's Interior Processes

    NASA Astrophysics Data System (ADS)

    Glesener, G. B.; Aurnou, J. M.

    2010-12-01

    The Modeling and Educational Demonstrations Laboratory (MEDL) at UCLA is developing a mantle convection physical model to assist educators with the pedagogy of Earth’s interior processes. Our design goal consists of two components to help the learner gain conceptual understanding by means of visual interactions without the burden of distracters, which may promote alternative conceptions. Distracters may be any feature of the conceptual model that causes the learner to use inadequate mental artifact to help him or her understand what the conceptual model is intended to convey. The first component, and most important, is a psychological component that links properties of “everyday things” (Norman, 1988) to the natural phenomenon, mantle convection. Some examples of everyday things may be heat rising out from a freshly popped bag of popcorn, or cold humid air falling from an open freezer. The second component is the scientific accuracy of the conceptual model. We would like to simplify the concepts for the learner without sacrificing key information that is linked to other natural phenomena the learner will come across in future science lessons. By taking into account the learner’s mental artifacts in combination with a simplified, but accurate, representation of what scientists know of the Earth’s interior, we expect the learner to have the ability to create an adequate qualitative mental simulation of mantle convection. We will be presenting some of our prototypes of this mantle convection physical model at this year’s poster session and invite constructive input from our colleagues.

  12. Numerical model of halite precipitation in porous sedimentary rocks adjacent to salt diapirs

    NASA Astrophysics Data System (ADS)

    Li, Shiyuan; Wang, Yan; Zhao, Pengyun

    2017-10-01

    Salt diapirs are commonly seen in the North Sea. Below the Zechstein Group exist possibly overpressured salt-anhydrite formations. One explanation as to the salt precipitation in areas with salt diapirs is that salt cementation is thermally driven and occurs strongly in places adjacent to salt diapirs. This paper assumes that the sealing effect of the cap rock above the salt formations is compromised and overpressured fluids, carrying dissolved minerals such as anhydrite (CaSO4) and salt mineral components (NaCl of halite), flow into the porous sedimentary layers above the salt formations. Additionally, a salt-diapir-like structure is assumed to be at one side of the model. The numerical flow and heat transport simulator SHEMAT-Suite was developed and applied to calculating the concentrations of species, and dissolution and precipitation amounts. Results show that the overpressured salt-anhydrite formations have higher pressure heads and the species elements sodium and chlorite are transported into porous sediment rocks through water influx (saturated brine). Halite can precipitate as brine with sodium and chlorite ions flows to the cooler environment. Salt cementation of reservoir rocks leads to decreasing porosity and permeability near salt domes, and cementation of reservoir formations decreases with growing distance to the salt diapir. The proposed approach in this paper can also be used to evaluate precipitation relevant to scaling problems in geothermal engineering.

  13. On purpose simulation model for molten salt CSP parabolic trough

    NASA Astrophysics Data System (ADS)

    Caranese, Carlo; Matino, Francesca; Maccari, Augusto

    2017-06-01

    The utilization of computer codes and simulation software is one of the fundamental aspects for the development of any kind of technology and, in particular, in CSP sector for researchers, energy institutions, EPC and others stakeholders. In that extent, several models for the simulation of CSP plant have been developed with different main objectives (dynamic simulation, productivity analysis, techno economic optimization, etc.), each of which has shown its own validity and suitability. Some of those models have been designed to study several plant configurations taking into account different CSP plant technologies (Parabolic trough, Linear Fresnel, Solar Tower or Dish) and different settings for the heat transfer fluid, the thermal storage systems and for the overall plant operating logic. Due to a lack of direct experience of Molten Salt Parabolic Trough (MSPT) commercial plant operation, most of the simulation tools do not foresee a suitable management of the thermal energy storage logic and of the solar field freeze protection system, but follow standard schemes. ASSALT, Ase Software for SALT csp plants, has been developed to improve MSPT plant's simulations, by exploiting the most correct operational strategies in order to provide more accurate technical and economical results. In particular, ASSALT applies MSPT specific control logics for the electric energy production and delivery strategy as well as the operation modes of the Solar Field in off-normal sunshine condition. With this approach, the estimated plant efficiency is increased and the electricity consumptions required for the plant operation and management is drastically reduced. Here we present a first comparative study on a real case 55 MWe Molten Salt Parabolic Trough CSP plant placed in the Tibetan highlands, using ASSALT and SAM (System Advisor Model), which is a commercially available simulation tool.

  14. Models for Callisto's Plasma Interaction: Implications for the satellite's Atmosphere and Interior

    NASA Astrophysics Data System (ADS)

    Seufert, M.; Saur, J.

    2012-04-01

    We present results from a MHD-model for the sub-Alfvénic interaction of Callisto with the surrounding magnetospheric plasma taking into account the influence of Callisto's neutral CO2 and O2 atmosphere on the plasma flow and magnetic fields induced in a possible subsurface liquid water ocean. The existence of a subsurface ocean was proposed e.g. by Neubauer [1998], Kivelson et al. [1999] and Zimmer et al. [2000] based on magnetometer data analysis. However, none of these previous studies included detailed modeling of Callisto's plasma interaction. We present the first 3D-MHD-models for the plasma interaction considering several flybys of Galileo at Callisto. We compare the magnetic signatures predicted by the plasma interaction model including an induced interior dipole with Galileo magnetometer data. We further use our models to investigate the structure of Callisto's atmosphere-ionosphere system for two cases: Static plasma conditions (v0 = 0) with an ionosphere in chemical and radiative equilibrium and for the corresponding dynamic plasma flow conditions. The ionospheric structure is then compared to radio occultation measurements by Kliore et al. [2002]. The final goal of this study is to deduce information about possible temporal variations and the overall structure of Callisto's atmosphere and ionosphere and eventually about the interior ocean layer from the magnetic field data.

  15. Important observations and parameters for a salt water intrusion model

    USGS Publications Warehouse

    Shoemaker, W.B.

    2004-01-01

    Sensitivity analysis with a density-dependent ground water flow simulator can provide insight and understanding of salt water intrusion calibration problems far beyond what is possible through intuitive analysis alone. Five simple experimental simulations presented here demonstrate this point. Results show that dispersivity is a very important parameter for reproducing a steady-state distribution of hydraulic head, salinity, and flow in the transition zone between fresh water and salt water in a coastal aquifer system. When estimating dispersivity, the following conclusions can be drawn about the data types and locations considered. (1) The "toe" of the transition zone is the most effective location for hydraulic head and salinity observations. (2) Areas near the coastline where submarine ground water discharge occurs are the most effective locations for flow observations. (3) Salinity observations are more effective than hydraulic head observations. (4) The importance of flow observations aligned perpendicular to the shoreline varies dramatically depending on distance seaward from the shoreline. Extreme parameter correlation can prohibit unique estimation of permeability parameters such as hydraulic conductivity and flow parameters such as recharge in a density-dependent ground water flow model when using hydraulic head and salinity observations. Adding flow observations perpendicular to the shoreline in areas where ground water is exchanged with the ocean body can reduce the correlation, potentially resulting in unique estimates of these parameter values. Results are expected to be directly applicable to many complex situations, and have implications for model development whether or not formal optimization methods are used in model calibration.

  16. 3D Modelling of Interior Spaces: Learning the Language of Indoor Architecture

    NASA Astrophysics Data System (ADS)

    Khoshelham, K.; Díaz-Vilariño, L.

    2014-06-01

    3D models of indoor environments are important in many applications, but they usually exist only for newly constructed buildings. Automated approaches to modelling indoor environments from imagery and/or point clouds can make the process easier, faster and cheaper. We present an approach to 3D indoor modelling based on a shape grammar. We demonstrate that interior spaces can be modelled by iteratively placing, connecting and merging cuboid shapes. We also show that the parameters and sequence of grammar rules can be learned automatically from a point cloud. Experiments with simulated and real point clouds show promising results, and indicate the potential of the method in 3D modelling of large indoor environments.

  17. Two-oscillator Kantowski-Sachs model of the Schwarzschild black hole interior

    NASA Astrophysics Data System (ADS)

    Djordjevic, Goran S.; Nesic, Ljubisa; Radovancevic, Darko

    2016-08-01

    In this paper the interior of the Schwarzschild black hole, which is presented as a vacuum, homogeneous and anisotropic Kantowski-Sachs minisuperspace cosmological model, is considered. Lagrangian of the model is reduced by a suitable coordinate transformation to Lagrangian of two decoupled oscillators with the same frequencies and with zero energy in total (an oscillator-ghost-oscillator system). The model is presented in a classical, a p-adic and a noncommutative case. Then, within the standard quantum approach Wheeler-DeWitt equation and its general solutions, i.e. a wave function of the model is written, and then an adelic wave function is constructed. Finally, thermodynamics of the model is studied by using the Feynman-Hibbs procedure.

  18. Modeling the VOC emissions from interior latex paint applied to gypsum board

    SciTech Connect

    Guo, Z.; Fortmann, R.; Marfiak, S.; Tichenor, B.; Sparks, L.

    1997-09-01

    The paper discusses modeling volatile organic compound (VOC) emissions from indoor latex paint applied to gypsum board. An empirical source model for a porous substrate was developed that takes both the wet- and dry-stage emission into consideration. Tests in the U.S. EPA`s Source Characterization Laboratory showed that common interior surfaces such as gypsum board and carpet could absorb significant amounts of latex paint VOCS from the air, and that they were re-emitted very slowly. An indoor air quality model incorporating the source model, an irreversible sink model, and the air movement data obtained from tracer gas tests made satisfactory predictions for the VOC levels in a test house.

  19. Recording and Modelling of MONUMENTS' Interior Space Using Range and Optical Sensors

    NASA Astrophysics Data System (ADS)

    Georgiadis, Charalampos; Patias, Petros; Tsioukas, Vasilios

    2016-06-01

    Three dimensional modelling of artefacts and building interiors is a highly active research field in our days. Several techniques are being utilized to perform such a task, spanning from traditional surveying techniques and photogrammetry to structured light scanners, laser scanners and so on. New technological advancements in both hardware and software create new recording techniques, tools and approaches. In this paper we present a new recording and modelling approach based on the SwissRanger SR4000 range camera coupled with a Canon 400D dSLR camera. The hardware component of our approach consists of a fixed base, which encloses the range and SLR cameras. The two sensors are fully calibrated and registered to each other thus we were able to produce colorized point clouds acquired from the range camera. In this paper we present the initial design and calibration of the system along with experimental data regarding the accuracy of the proposed approach. We are also providing results regarding the modelling of interior spaces and artefacts accompanied with accuracy tests from other modelling approaches based on photogrammetry and laser scanning.

  20. Modeling the Retreat Processes of Salt Marsh Edge

    NASA Astrophysics Data System (ADS)

    Bendoni, M.; Cappietti, L.; Francalanci, S.; Rinaldi, M.; Solari, L.

    2012-12-01

    Edge erosion of salt marshes due to surface waves and tide forcing is likely the chief mechanism that models marsh boundaries and by which salt marshes in worldwide coastal areas are being lost. In order to address this problem, experimental observations in a laboratory flume and field measurements in the lagoon of Venice were conducted to understand the main processes controlling marsh edge retreat, with a focus on the erosion mechanisms caused by the action of wind and tidal waves. A physical model reproducing a salt marsh bank was built inside a long wave current flume where random surface waves were generated according to a given wave spectrum. The physical model was constructed with the original soil and plants taken in a marsh of the lagoon of Venice, while the wave climate was reproduced according to field measurements. The experiments were conducted in the case of both unvegetated and vegetated bank: a first set of experiments was carried out considering only tidal wave; in the second, bank models experienced the effect of wind waves superimposed to the tide. The following data were collected during the experiments: wave climate interacting with the bank, flow velocity measurements in the eroded quasi-equilibrium configuration, pressure distribution along bank edge and internal pressure fluctuation and damping due to wave impact. Bank geometry profile and bottom topography at different times have also been collected to characterize the erosion rate with time and the evolution of bank retreat. Subsequent to laboratory activity wave climate was measured close to a marsh edge in the Lagoon of Venice with the aim at identifying wave forcing on the bank surface during a moderate wind event and comparing results with the wave stress experienced by bank models in laboratory tests. Several pressure transducers installed close to the bed were used to collect wave height and wave direction with respect to the edge of the marsh. Laboratory data and field measurement

  1. Modeling Coupled THM Processes and Brine Migration in Salt at High Temperatures

    SciTech Connect

    Rutqvist, Jonny; Blanco-Martin, Laura; Molins, Sergi; Trebotich, David; Birkholzer, Jens

    2015-09-01

    In this report, we present FY2015 progress by Lawrence Berkeley National Laboratory (LBNL) related to modeling of coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. This is a combined milestone report related to milestone Salt R&D Milestone “Modeling Coupled THM Processes and Brine Migration in Salt at High Temperatures” (M3FT-15LB0818012) and the Salt Field Testing Milestone (M3FT-15LB0819022) to support the overall objectives of the salt field test planning.

  2. Aircraft interior noise models - Sidewall trim, stiffened structures, and cabin acoustics with floor partition

    NASA Technical Reports Server (NTRS)

    Pope, L. D.; Wilby, E. G.; Willis, C. M.; Mayes, W. H.

    1983-01-01

    As part of the continuing development of an aircraft interior noise prediction model, in which a discrete modal representation and power flow analysis are used, theoretical results are considered for inclusion of sidewall trim, stiffened structures, and cabin acoustics with floor partition. For validation purposes, predictions of the noise reductions for three test articles (a bare ring-stringer stiffened cylinder, an unstiffened cylinder with floor and insulation, and a ring-stringer stiffened cylinder with floor and sidewall trim) are compared with measurements.

  3. The Modeling of Boattail Intrusion in a Lumped Parameter Interior Ballistic Code

    DTIC Science & Technology

    1993-08-01

    AD-A270 702 ARmy RESFARCH LABORATORY The Modeling of Boattail Intrusion in a Lumped Parameter Interior Ballistic Code Frederick W. Robbins Robert T...Puhalla Taquan S. Stewart ARL-TR-181 August 1993 xcf "APROVED MOR PUBC RUEASE; DISTRIBUTION IS UNLIMITED. 93-23103 93 10 1 2 34 A NOTICES Destroy this...to"ration Ooe~attorr% o;.z. Rnc-D" l"’ ’ etier~oin •)av• H*qt •. Ste 1204. Arhngton,. / A 22202-4302 and to the O ,ffie eof Marremerit ao Budget. Pa

  4. Evaluation of landscape models for wolverines in the interior northwest, USA

    USGS Publications Warehouse

    Rowland, M.M.; Wisdom, M.J.; Johnson, D.H.; Wales, B.C.; Copeland, J.P.; Edelmann, F.B.

    2003-01-01

    The wolverine (Gulo gulo) is an uncommon, wide-ranging carnivore of conservation concern. We evaluated performance of landscape models for wolverines within their historical range at 2 scales in the interior Northwest based on recent observations (n = 421) from Washington, Oregon, Idaho, and Montana. At the subbasin scale, simple overlays of habitat and road-density classes were effective in predicting observations of wolverines. At the watershed scale, we used a Bayesian belief network model to provide spatially explicit estimates of relative habitat capability. The model has 3 inputs: amount of habitat, human population density, and road density. At both scales, the best models revealed strong correspondence between means of predicted counts of wolverines and means of observed counts (P < 0.001). Our results can be used to guide regional conservation planning for this elusive animal.

  5. Evaluation of landscape models for wolverines in the interior Northwest, United States of America

    USGS Publications Warehouse

    Rowland, M.M.; Wisdom, M.J.; Johnson, D.H.; Wales, B.C.; Copeland, J.P.; Edelmann, F.B.

    2003-01-01

    The wolverine (Gulo gulo) is an uncommon, wide-ranging carnivore of conservation concern. We evaluated performance of landscape models for wolverines within their historical range at 2 scales in the interior Northwest based on recent observations (n = 421) from Washington, Oregon, Idaho, and Montana. At the subbasin scale, simple overlays of habitat and road-density classes were effective in predicting observations of wolverines. At the watershed scale, we used a Bayesian belief network model to provide spatially explicit estimates of relative habitat capability. The model has 3 inputs: amount of habitat, human population density, and road density. At both scales, the best models revealed strong correspondence between means of predicted counts of wolverines and means of observed counts (P < 0.001). Our results can be used to guide regional conservation planning for this elusive animal.

  6. Modeling salt movement and halophytic crop growth on marginal lands with the APEX model

    NASA Astrophysics Data System (ADS)

    Goehring, N.; Saito, L.; Verburg, P.; Jeong, J.; Garrett, A.

    2016-12-01

    Saline soils negatively impact crop productivity in nearly 20% of irrigated agricultural lands worldwide. At these saline sites, cultivation of highly salt-tolerant plants, known as halophytes, may increase productivity compared to conventional salt-sensitive crops (i.e., glycophytes), thereby increasing the economic potential of marginal lands. Through a variety of mechanisms, halophytes are more effective than glycophytes at excluding, accumulating, and secreting salts from their tissues. Each mechanism can have a different impact on the salt balance in the plant-soil-water system. To date, little information is available to understand the long-term impacts of halophyte cultivation on environmental quality. This project utilizes the Agricultural Policy/Environmental Extender (APEX) model, developed by the US Department of Agriculture, to model the growth and production of two halophytic crops. The crops being modeled include quinoa (Chenopodium quinoa), which has utilities for human consumption and forage, and AC Saltlander green wheatgrass (Elymus hoffmannii), which has forage utility. APEX simulates salt movement between soil layers and accounts for the salt balance in the plant-soil-water system, including salinity in irrigation water and crop-specific salt uptake. Key crop growth parameters in APEX are derived from experimental growth data obtained under non-stressed conditions. Data from greenhouse and field experiments in which quinoa and AC Saltlander were grown under various soil salinity and irrigation salinity treatments are being used to parameterize, calibrate, and test the model. This presentation will discuss progress on crop parameterization and completed model runs under different salt-affected soil and irrigation conditions.

  7. A hybrid plasma-induction model to study the electromagnetic response of an object's interior to a magnetic transient signal

    NASA Astrophysics Data System (ADS)

    Fatemi, S.; Delory, G. T.; Poppe, A. R.; Fuqua, H.

    2016-12-01

    Resolving the interior of the solar system objects is crucial to our understanding of the fundamental processes of their formation and evolution, and adds insight to the conditions in the early solar system and formation of the Earth. We have developed a three-dimensional (3D) self consistent hybrid model (kinetic ions, fluid electrons) that includes induction of the conducting interior of an object to simulate the electromagnetic response of the lunar interior to disturbances in the solar wind. Often the required time step to solve the diffusion equation for the interior, especially when a part of the interior contains highly resistive layers like the lunar crust, is much smaller than the minimum required time step to solve the general hybrid model equations. Therefore, we developed a new algorithm that explicitly solves the general hybrid model equations, while the diffusion equation for the interior is solved implicitly using Crank-Nicholson method. This new development enables us to overcome the diffusive restriction on the time step and run our hybrid model long enough to resolve the interior electromagnetic response. We used this model to analyze time-domain response of the Moon to a magnetic transient signal. We applied various conductivity profiles for the lunar interior, and examined the lunar electromagnetic response on the side day and night sides of the Moon. We also studied the effects of a magnetic transient on redistribution of the lunar plasma wake current systems, as well as their effects on the induced signals from lunar interior. A similar method can also be applied to study the plasma interaction with other solar system objects, like Europa.

  8. Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas

    SciTech Connect

    Bailey, J. E.; Rochau, G. A.; Mancini, R. C.; Iglesias, C. A.; MacFarlane, J. J.; Golovkin, I. E.; Blancard, C.; Cosse, Ph.; Faussurier, G.

    2009-05-15

    Theoretical opacities are required for calculating energy transport in plasmas. In particular, understanding stellar interiors, inertial fusion, and Z pinches depends on the opacities of mid-atomic-number elements over a wide range of temperatures. The 150-300 eV temperature range is particularly interesting. The opacity models are complex and experimental validation is crucial. For example, solar models presently disagree with helioseismology and one possible explanation is inadequate theoretical opacities. Testing these opacities requires well-characterized plasmas at temperatures high enough to produce the ion charge states that exist in the sun. Typical opacity experiments heat a sample using x rays and measure the spectrally resolved transmission with a backlight. The difficulty grows as the temperature increases because the heating x-ray source must supply more energy and the backlight must be bright enough to overwhelm the plasma self-emission. These problems can be overcome with the new generation of high energy density (HED) facilities. For example, recent experiments at Sandia's Z facility [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)] measured the transmission of a mixed Mg and Fe plasma heated to 156{+-}6 eV. This capability will also advance opacity science for other HED plasmas. This tutorial reviews experimental methods for testing opacity models, including experiment design, transmission measurement methods, accuracy evaluation, and plasma diagnostics. The solar interior serves as a focal problem and Z facility experiments illustrate the techniques.

  9. Heat flow and gravity responses over salt bodies: A comparative model analysis

    SciTech Connect

    Corrigan, J.; Sweat, M.

    1995-07-01

    Two-dimensional numerical modeling of sea-floor heat flow and water-bottom gravity responses to systematic variations in simple subsurface salt body geometries provides insight on the relative usefulness of these two data types for extracting salt geometry information. For a given salt body geometry, diffusion of heat through overlying sediments results in a dramatic decrease in the amplitude of heat flow anomalies as the depth to the top of the salt body increases. For top-of-salt depths greater than about 1 km, the heat flow response is insensitive to the length of salt feeder stocks and to the thickness of salt tongues/sheets. This shallow depth-to-top-of-salt sensitivity range, in addition to a number of environmental factors that can adversely affect interpretation of heat flow anomalies in terms of heat refraction towards and through salt bodies, severely limits the usefulness of sea-floor heat flow data for constraining aspects of salt body geometry. For gravity data, the critical factor for addressing salt body geometry is the distribution of salt relative to the sediment-salt density crossover depth (above and below which salt is more and less dense, respectively, than the surrounding sediment). Except when ht relevant geometry information being sought (presence and/or length of feeder stock, thickness of salt tongue or sheet) is near the density crossover depth, the geometry-related information content of the gravity field is greater than that of the heat flow field. Based on these model results, measurement uncertainty considerations, and data limitations, the authors conclude that gravity data generally offer an order of magnitude greater resolution capability than sea-floor heat flow data for addressing salt body geometry issues of exploration interest.

  10. Analytical prediction for electromagnetic performance of interior permanent magnet machines based on subdomain model

    NASA Astrophysics Data System (ADS)

    Shin, Kyung-Hun; Park, Hyung-II; Cho, Han-Wook; Choi, Jang-Young

    2017-05-01

    This paper presents an analytical model for the computation of the electromagnetic performance in interior permanent magnet (IPM) machines that accounts for the stator and the complex rotor structure. Using the subdomain method, we propose a simplified analytical model that considers the magnetic properties of the IPM machine. The analytical solutions are derived by solving the field-governing equations in each simple and regular subdomain, i.e., magnet, barrier, air gap, slot opening, and slot, and then applying the boundary conditions to the interfaces between these subdomains. The analytical model accurately accounts for the influence of the interaction between the slots, the relative recoil permeability of the magnets, and the boundary conditions. The magnetic field and electromagnetic performance obtained using the analytical method are compared with those obtained using finite element analysis. Finally, the analytical predictions are compared with the measured data in order to confirm the validity of the methods proposed in this paper.

  11. Modelling the long-term vertical dynamics of salt marshes

    NASA Astrophysics Data System (ADS)

    Zoccarato, Claudia; Teatini, Pietro

    2017-04-01

    Salt marshes are vulnerable environments hosting complex interactions between physical and biological processes with a strong influence on the dynamics of the marsh evolution. The estimation and prediction of the elevation of a salt-marsh platform is crucial to forecast the marsh growth or regression under different scenarios considering, for example, the potential climate changes. The long-term vertical dynamics of a salt marsh is predicted with the aid of an original finite-element (FE) numerical model accounting for the marsh accretion and compaction and for the variation rates of the relative sea level rise, i.e., land subsidence of the marsh basement and eustatic rise of the sea level. The accretion term considers the vertical sedimentation of organic and inorganic material over the marsh surface, whereas the compaction reflects the progressive consolidation of the porous medium under the increasing load of the overlying younger deposits. The modelling approach is based on a 2D groundwater flow simulator, which provides the pressure evolution within a compacting/accreting vertical cross-section of the marsh assuming that the groundwater flow obeys the relative Darcy's law, coupled to a 1D vertical geomechanical module following Terzaghi's principle of effective intergranular stress. Soil porosity, permeability, and compressibility may vary with the effective intergranular stress according to empirically based relationships. The model also takes into account the geometric non-linearity arising from the consideration of large solid grain movements by using a Lagrangian approach with an adaptive FE mesh. The element geometry changes in time to follow the deposit consolidation and the element number increases in time to follow the sedimentation of new material. The numerical model is tested on different realistic configurations considering the influence of (i) the spatial distribution of the sedimentation rate in relation to the distance from the marsh margin, (ii

  12. Volatile-rich Crater Interior Deposits on Mars: An Energy Balance Model of Modification

    NASA Technical Reports Server (NTRS)

    Russell, Patrick S.; Head, James W.; Hecht, Michael H.

    2003-01-01

    Several craters on Mars are partially filled by material emplaced by post-impact processes. Populations of such craters include those in the circumsouth polar cap region, in Arabia Terra, associated with the Medusae Fossae Formation, and in the northern lowlands proximal to the north polar cap. In this study, crater fill material refers to an interior mound, generally separated from the interior walls of the crater by a trough that may be continuous along the crater s circumference (i.e. a ring-shaped trough), or may only partially contact the crater walls (i.e. a crescent-shaped trough). The fill deposit is frequently off-center from the crater center and may be asymmetric, (i.e. not circular) in plan view shape. Here we test the hypothesis that asymmetries in volatile fill shape, profile, and center-location within a crater result from asymmetries in local energy balance within the crater due mainly to variation of solar insolation and radiative effects of the crater walls over the crater interior. We first focus on Korolev crater in the northern lowlands. We can then apply this model to other craters in different regions. If asymmetry in morphology and location of crater fill are consistent with radiative-dominated asymmetries in energy budget within the crater, then 1) the volatile-rich composition of the fill is supported (this process should not be effective at shaping volcanic or sedimentary deposits), and 2) the dominant factor determining the observed shape of volatile-rich crater fill is the local radiative energy budget within the crater (and erosive processes such as eolian deflation are not necessary).

  13. Volatile-rich Crater Interior Deposits on Mars: An Energy Balance Model of Modification

    NASA Technical Reports Server (NTRS)

    Russell, Patrick S.; Head, James W.; Hecht, Michael H.

    2003-01-01

    Several craters on Mars are partially filled by material emplaced by post-impact processes. Populations of such craters include those in the circumsouth polar cap region, in Arabia Terra, associated with the Medusae Fossae Formation, and in the northern lowlands proximal to the north polar cap. In this study, crater fill material refers to an interior mound, generally separated from the interior walls of the crater by a trough that may be continuous along the crater s circumference (i.e. a ring-shaped trough), or may only partially contact the crater walls (i.e. a crescent-shaped trough). The fill deposit is frequently off-center from the crater center and may be asymmetric, (i.e. not circular) in plan view shape. Here we test the hypothesis that asymmetries in volatile fill shape, profile, and center-location within a crater result from asymmetries in local energy balance within the crater due mainly to variation of solar insolation and radiative effects of the crater walls over the crater interior. We first focus on Korolev crater in the northern lowlands. We can then apply this model to other craters in different regions. If asymmetry in morphology and location of crater fill are consistent with radiative-dominated asymmetries in energy budget within the crater, then 1) the volatile-rich composition of the fill is supported (this process should not be effective at shaping volcanic or sedimentary deposits), and 2) the dominant factor determining the observed shape of volatile-rich crater fill is the local radiative energy budget within the crater (and erosive processes such as eolian deflation are not necessary).

  14. Hydrodynamic modeling for river delta salt marshes using lidar topography

    NASA Astrophysics Data System (ADS)

    Hodges, Ben R.

    2014-05-01

    Topographic data from lidar and multi-beam sonar create new challenges for hydrodynamic models of estuaries, tidelands, and river deltas. We now can readily obtain detailed elevation data on 1 m scales and finer, but solving hydrodynamics with model grid cells at these small scales remains computationally prohibitive (primarily because of the small time step required for small grid cells). Practical estuarine models for the next decade or so will likely have grid scales in the range of 5 to 15 m. So how should we handle known subgrid-scale features? Simply throwing out known data does not seem like a good idea, but there is no consensus on how best to incorporate knowledge of subgrid topography into either hydrodynamic or turbulence models. This presentation discusses both the theoretical foundations for modeling subgrid-scale features and the challenges in applying these ideas in the salt marshes of a river delta. The subgrid problem highlights some important areas for field and laboratory research to provide calibration parameters for new models that upscale the effects of known subgrid features.

  15. Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core

    NASA Astrophysics Data System (ADS)

    Wahl, S. M.; Hubbard, W. B.; Militzer, B.; Guillot, T.; Miguel, Y.; Movshovitz, N.; Kaspi, Y.; Helled, R.; Reese, D.; Galanti, E.; Levin, S.; Connerney, J. E.; Bolton, S. J.

    2017-05-01

    The Juno spacecraft has measured Jupiter's low-order, even gravitational moments, J2-J8, to an unprecedented precision, providing important constraints on the density profile and core mass of the planet. Here we report on a selection of interior models based on ab initio computer simulations of hydrogen-helium mixtures. We demonstrate that a dilute core, expanded to a significant fraction of the planet's radius, is helpful in reconciling the calculated Jn with Juno's observations. Although model predictions are strongly affected by the chosen equation of state, the prediction of an enrichment of Z in the deep, metallic envelope over that in the shallow, molecular envelope holds. We estimate Jupiter's core to contain a 7-25 Earth mass of heavy elements. We discuss the current difficulties in reconciling measured Jn with the equations of state and with theory for formation and evolution of the planet.

  16. Model for transient creep of southeastern New Mexico rock salt

    SciTech Connect

    Herrmann, W; Wawersik, W R; Lauson, H S

    1980-11-01

    In a previous analysis, existing experimental data pertaining to creep tests on rock salt from the Salado formation of S.E. New Mexico were fitted to an exponential transient creep law. While very early time portions of creep strain histories were not fitted very well for tests at low temperatures and stresses, initial creep rates in particular generally being underestimated, the exponential creep law has the property that the transient creep strain approaches a finite limit with time, and is therefore desirable from a creep modelling point of view. In this report, an analysis of transient creep is made. It is found that exponential transient creep can be related to steady-state creep through a universal creep curve. The resultant description is convenient for creep analyses where very early time behavior is not important.

  17. The role of interior watershed processes in improving parameter estimation and performance of watershed models.

    PubMed

    Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

    2014-09-01

    Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. A mathematical model of salt-sensitive hypertension: the neurogenic hypothesis.

    PubMed

    Averina, Viktoria A; Othmer, Hans G; Fink, Gregory D; Osborn, John W

    2015-07-15

    Salt sensitivity of arterial pressure (salt-sensitive hypertension) is a serious global health issue. The causes of salt-sensitive hypertension are extremely complex and mathematical models can elucidate potential mechanisms that are experimentally inaccessible. Until recently, the only mathematical model for long-term control of arterial pressure was the model of Guyton and Coleman; referred to as the G-C model. The core of this model is the assumption that sodium excretion is driven by renal perfusion pressure, the so-called 'renal function curve'. Thus, the G-C model dictates that all forms of hypertension are due to a primary shift of the renal function curve to a higher operating pressure. However, several recent experimental studies in a model of hypertension produced by the combination of a high salt intake and administration of angiotensin II, the AngII-salt model, are inconsistent with the G-C model. We developed a new mathematical model that does not limit the cause of salt-sensitive hypertension solely to primary renal dysfunction. The model is the first known mathematical counterexample to the assumption that all salt-sensitive forms of hypertension require a primary shift of renal function: we show that in at least one salt-sensitive form of hypertension the requirement is not necessary. We will refer to this computational model as the 'neurogenic model'. In this Symposium Review we discuss how, despite fundamental differences between the G-C model and the neurogenic model regarding mechanisms regulating sodium excretion and vascular resistance, they generate similar haemodynamic profiles of AngII-salt hypertension. In addition, the steady-state relationships between arterial pressure and sodium excretion, a correlation that is often erroneously presented as the 'renal function curve', are also similar in both models. Our findings suggest that salt-sensitive hypertension is not due solely to renal dysfunction, as predicted by the G-C model, but may

  19. Probability distributions for parameters of the Munson-Dawson salt creep model

    SciTech Connect

    Fossum, A.F.; Pfeifle, T.W.; Mellegard, K.D.

    1993-12-31

    Stress-related probability distribution functions are determined for the random variable material model parameters of the Munson-Dawson multi-mechanism deformation creep model for salt. These functions are obtained indirectly from experimental creep data for clean salt. The parameter distribution functions will form the basis for numerical calculations to generate an appropriate distribution function for room closure. Also included is a table that gives the values of the parameters for individual specimens of clean salt under different stresses.

  20. Sediment and vegetation spatial dynamics facing sea-level rise in microtidal salt marshes: Insights from an ecogeomorphic model

    NASA Astrophysics Data System (ADS)

    Belliard, J.-P.; Di Marco, N.; Carniello, L.; Toffolon, M.

    2016-07-01

    Modeling efforts have considerably improved our understanding on the chief processes that govern the evolution of salt marshes under climate change. Yet the spatial dynamic response of salt marshes to sea-level rise that results from the interactions between the tidal landforms of interest and the presence of bio-geomorphic features has not been addressed explicitly. Accordingly, we use a modeling framework that integrates the co-evolution of the marsh platform and the embedded tidal networks to study sea-level rise effects on spatial sediment and vegetation dynamics in microtidal salt marshes considering different ecological scenarios. The analysis unveils mechanisms that drive spatial variations in sedimentation rates in ways that increase marsh resilience to rising sea-levels. In particular, marsh survival is related to the effectiveness of transport of sediments toward the interior marshland. This study hints at additional dynamics related to the modulation of channel cross-sections affecting sediment advection in the channels and subsequent delivery in the inner marsh, which should be definitely considered in the study of marsh adaptability to sea-level rise and posterior management.

  1. Experimental investigation of opacity models for stellar interiors, inertial fusion, and high energy density plasmas

    NASA Astrophysics Data System (ADS)

    Bailey, James

    2008-11-01

    Theoretical opacities are required for calculating energy transport in plasmas. In particular, understanding stellar interiors, inertial fusion, and Z-pinches depends on the opacities of mid-atomic-number elements in the 150-300 eV temperature range. These models are complex and experimental validation is crucial. For example, solar models presently disagree with helioseismology and one possible explanation is inadequate opacities. Testing these opacities requires a uniform plasma at temperatures high enough to produce the ion charge states that exist in the sun. Typical opacity experiments heat a sample using x-rays and measure the spectrally resolved transmission with a backlight. The difficulty grows as the temperature increases because the heating x-ray source must supply more energy and the backlighter source must be bright enough to overwhelm the plasma self emission. These problems were overcome using the dynamic hohlraum x-ray source at Sandia's Z facility to measure the transmission of a mixed Mg-Fe plasma heated above 150 eV. This capability will also advance opacity science for other high energy density plasmas. This tutorial describes opacity experiment challenges including accurate transmission measurements, plasma diagnostics, and quantitative model comparisons. The solar interior serves as a focal problem and Z facility experiments are used to illustrate the techniques. **In collaboration with C. Iglesias (LLNL), R. Mancini (U. Nevada), J.MacFarlane, I. Golovkin and P. Wang (Prism), C. Blancard, Ph. Cosse, G. Faussurier, F. Gilleron, and J.C. Pain (CEA), J. Abdallah Jr. (LANL), and G.A. Rochau and P.W. Lake (Sandia). ++Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  2. INTERIOR MODELS OF SATURN: INCLUDING THE UNCERTAINTIES IN SHAPE AND ROTATION

    SciTech Connect

    Helled, Ravit; Guillot, Tristan

    2013-04-20

    The accurate determination of Saturn's gravitational coefficients by Cassini could provide tighter constraints on Saturn's internal structure. Also, occultation measurements provide important information on the planetary shape which is often not considered in structure models. In this paper we explore how wind velocities and internal rotation affect the planetary shape and the constraints on Saturn's interior. We show that within the geodetic approach the derived physical shape is insensitive to the assumed deep rotation. Saturn's re-derived equatorial and polar radii at 100 mbar are found to be 54,445 {+-} 10 km and 60,365 {+-} 10 km, respectively. To determine Saturn's interior, we use one-dimensional three-layer hydrostatic structure models and present two approaches to include the constraints on the shape. These approaches, however, result in only small differences in Saturn's derived composition. The uncertainty in Saturn's rotation period is more significant: with Voyager's 10{sup h}39{sup m} period, the derived mass of heavy elements in the envelope is 0-7 M{sub Circled-Plus }. With a rotation period of 10{sup h}32{sup m}, this value becomes <4 M{sub Circled-Plus }, below the minimum mass inferred from spectroscopic measurements. Saturn's core mass is found to depend strongly on the pressure at which helium phase separation occurs, and is estimated to be 5-20 M{sub Circled-Plus }. Lower core masses are possible if the separation occurs deeper than 4 Mbar. We suggest that the analysis of Cassini's radio occultation measurements is crucial to test shape models and could lead to constraints on Saturn's rotation profile and departures from hydrostatic equilibrium.

  3. Applications of Panoramic Images: from 720° Panorama to Interior 3d Models of Augmented Reality

    NASA Astrophysics Data System (ADS)

    Lee, I.-C.; Tsai, F.

    2015-05-01

    A series of panoramic images are usually used to generate a 720° panorama image. Although panoramic images are typically used for establishing tour guiding systems, in this research, we demonstrate the potential of using panoramic images acquired from multiple sites to create not only 720° panorama, but also three-dimensional (3D) point clouds and 3D indoor models. Since 3D modeling is one of the goals of this research, the location of the panoramic sites needed to be carefully planned in order to maintain a robust result for close-range photogrammetry. After the images are acquired, panoramic images are processed into 720° panoramas, and these panoramas which can be used directly as panorama guiding systems or other applications. In addition to these straightforward applications, interior orientation parameters can also be estimated while generating 720° panorama. These parameters are focal length, principle point, and lens radial distortion. The panoramic images can then be processed with closerange photogrammetry procedures to extract the exterior orientation parameters and generate 3D point clouds. In this research, VisaulSFM, a structure from motion software is used to estimate the exterior orientation, and CMVS toolkit is used to generate 3D point clouds. Next, the 3D point clouds are used as references to create building interior models. In this research, Trimble Sketchup was used to build the model, and the 3D point cloud was added to the determining of locations of building objects using plane finding procedure. In the texturing process, the panorama images are used as the data source for creating model textures. This 3D indoor model was used as an Augmented Reality model replacing a guide map or a floor plan commonly used in an on-line touring guide system. The 3D indoor model generating procedure has been utilized in two research projects: a cultural heritage site at Kinmen, and Taipei Main Station pedestrian zone guidance and navigation system. The

  4. Martian Craters with Interior Deposits: A Global Survey and Wind Models

    NASA Astrophysics Data System (ADS)

    Bennett, K. A.; Schmeeckle, M. W.

    2012-12-01

    Sediment mounds occur within impact craters across the surface of Mars, but their origin and evolution remain poorly understood. Interior deposits are found in craters of all sizes, are not always centered in their host crater, and can rise higher than the surrounding crater walls (Malin and Edgett 2000). Gale Crater, the landing site for the Mars Science Laboratory, is one prominent example of a crater containing a central mound. The prevalent hypothesis for their formation presents the mounds as eroded remnants of deposits that once filled the crater (Malin and Edgett 2000). Subaerial, subaqueous, volcanic, and impact processes have all been proposed as methods of deposition and/or erosion (e.g. Malin and Edgett 2000, Scott and Tanaka 1982, Cabrol et al. 1999). Previous surveys of these interior deposits have either been restricted to a limited area (Thompson et al. 2011) or generalized to all sedimentary deposits on Mars (Malin and Edgett 2000). This study examines the global population of craters with interior deposits independently from other sedimentary units. We catalog the location and radius for each mound and its parent crater. Preliminary results suggest certain areas on Mars that have concentrations of craters containing interior deposits show local biases as to where the deposit is located within the crater. For example, the deposits in western Arabia Terra are preferentially located on the western side of their host craters. We investigate the hypothesis that this bias developed from wind blowing in a preferred direction and causing sediment to either deposit or erode preferentially on one side. We have developed an aeolian morphodynamics model to test this hypothesis. In each time iteration the model first calculates the 3-dimensional steady-state wind field by solving the Reynolds-averaged Navier-Stokes (RANS) equations. Currently we employ the Spalart-Allmaras RANS closure equations with a rough wall approximation. Then the sediment flux field is

  5. A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna

    2017-08-01

    Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.

  6. Using Interior Point Method Optimization Techniques to Improve 2- and 3-Dimensional Models of Earth Structures

    NASA Astrophysics Data System (ADS)

    Zamora, A.; Gutierrez, A. E.; Velasco, A. A.

    2014-12-01

    2- and 3-Dimensional models obtained from the inversion of geophysical data are widely used to represent the structural composition of the Earth and to constrain independent models obtained from other geological data (e.g. core samples, seismic surveys, etc.). However, inverse modeling of gravity data presents a very unstable and ill-posed mathematical problem, given that solutions are non-unique and small changes in parameters (position and density contrast of an anomalous body) can highly impact the resulting model. Through the implementation of an interior-point method constrained optimization technique, we improve the 2-D and 3-D models of Earth structures representing known density contrasts mapping anomalous bodies in uniform regions and boundaries between layers in layered environments. The proposed techniques are applied to synthetic data and gravitational data obtained from the Rio Grande Rift and the Cooper Flat Mine region located in Sierra County, New Mexico. Specifically, we improve the 2- and 3-D Earth models by getting rid of unacceptable solutions (those that do not satisfy the required constraints or are geologically unfeasible) given the reduction of the solution space.

  7. The response of Dahl salt-sensitive and salt-resistant female rats to a space flight model

    NASA Technical Reports Server (NTRS)

    Thierry-Palmer, Myrtle; Cephas, Stacy; Cleek, Tammy; Sayavongsa, Phouyong; Arnaud, Sara B.

    2003-01-01

    Vitamin D metabolism in the Dahl salt-sensitive (S) rat, a model of salt-induced hypertension, differs from that in the Dahl salt-resistant (R) rat. We have tested the hypothesis that differences in vitamin D metabolism would render the Dahl S rat more susceptible than the Dahl R rat to the effects of a space flight model. Dahl female rats were tail suspended (hind limb unloaded) for 28 days, while fed a low salt (3 g/kg sodium chloride) diet. Plasma 25-OHD concentrations of S rats were significantly lower than that of R rats. Plasma 1,25-(OH)2D concentration was 50% lower in unloaded than in loaded S rats, but was unaffected in unloaded R rats. The left soleus muscle weight and breaking strength of the left femur (torsion test) were 50% and 25% lower in unloaded than in loaded S and R rats. The mineral content of the left femur, however, was significantly lower (by 11%) only in unloaded S rats. We conclude that female S rats are more vulnerable than female R rats to decreases in plasma 1,25-(OH)2D concentration and femur mineral content during hind limb unloading, but equally vulnerable to muscle atrophy and reduced breaking strength of the femur.

  8. The response of Dahl salt-sensitive and salt-resistant female rats to a space flight model

    NASA Technical Reports Server (NTRS)

    Thierry-Palmer, Myrtle; Cephas, Stacy; Cleek, Tammy; Sayavongsa, Phouyong; Arnaud, Sara B.

    2003-01-01

    Vitamin D metabolism in the Dahl salt-sensitive (S) rat, a model of salt-induced hypertension, differs from that in the Dahl salt-resistant (R) rat. We have tested the hypothesis that differences in vitamin D metabolism would render the Dahl S rat more susceptible than the Dahl R rat to the effects of a space flight model. Dahl female rats were tail suspended (hind limb unloaded) for 28 days, while fed a low salt (3 g/kg sodium chloride) diet. Plasma 25-OHD concentrations of S rats were significantly lower than that of R rats. Plasma 1,25-(OH)2D concentration was 50% lower in unloaded than in loaded S rats, but was unaffected in unloaded R rats. The left soleus muscle weight and breaking strength of the left femur (torsion test) were 50% and 25% lower in unloaded than in loaded S and R rats. The mineral content of the left femur, however, was significantly lower (by 11%) only in unloaded S rats. We conclude that female S rats are more vulnerable than female R rats to decreases in plasma 1,25-(OH)2D concentration and femur mineral content during hind limb unloading, but equally vulnerable to muscle atrophy and reduced breaking strength of the femur.

  9. Modeled Salt Density for Nuclear Material Estimation in the Treatment of Spent Nuclear Fuel

    SciTech Connect

    DeeEarl Vaden; Robert. D. Mariani

    2010-09-01

    Spent metallic nuclear fuel is being treated in a pyrometallurgical process that includes electrorefining the uranium metal in molten eutectic LiCl-KCl as the supporting electrolyte. We report a model for determining the density of the molten salt. Inventory operations account for the net mass of salt and for the mass of actinides present. It was necessary to know the molten salt density but difficult to measure, and it was decided to model the salt density for the initial treatment operations. The model assumes that volumes are additive for the ideal molten salt solution as a starting point; subsequently a correction factor for the lanthanides and actinides was developed. After applying the correction factor, the percent difference between the net salt mass in the electrorefiner and the resulting modeled salt mass decreased from more than 4.0% to approximately 0.1%. As a result, there is no need to measure the salt density at 500 C for inventory operations; the model for the salt density is found to be accurate.

  10. Modeled salt density for nuclear material estimation in the treatment of spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Mariani, Robert D.; Vaden, DeeEarl

    2010-09-01

    Spent metallic nuclear fuel is being treated in a pyrometallurgical process that includes electrorefining the uranium metal in molten eutectic LiCl-KCl as the supporting electrolyte. We report a model for determining the density of the molten salt. Material balances account for the net mass of salt and for the mass of actinides present. It was necessary to know the molten salt density, but difficult to measure. It was also decided to model the salt density for the initial treatment operations. The model assumes that volumes are additive for the ideal molten salt solution as a starting point; subsequently, a correction factor for the lanthanides and actinides was developed. After applying the correction factor, the percent difference between the net salt mass in the electrorefiner and the resulting modeled salt mass decreased from more than 4.0% to approximately 0.1%. As a result, there is no need to measure the salt density at 500 °C for inventory operations; the model for the salt density is found to be accurate.

  11. Interior radiances in optically deep absorbing media. 1: Exact solutions for one-dimensional model

    NASA Technical Reports Server (NTRS)

    Kattawar, G. W.; Plass, G. N.

    1973-01-01

    The exact solutions are obtained for a one dimensional model of a scattering and absorbing medium. The results are given for both the reflected and transmitted radiance for any arbitrary surface albedo as well as for the interior radiance. These same quantities are calculated by the matrix operator method. The relative error of the solutions is obtained by comparison with the exact solutions as well as by an error analysis of the equations. The importance of an accurate starting value for the reflection and transmission operators is shown. A fourth order Runge-Kutta method can be used to solve the differential equations satisfied by these operators in order to obtain such accurate starting values.

  12. Modeled Climate and Disturbance Impacts to Carbon Sequestration of Recent Interior Boreal Alaska Ecosystem Productivity Declines

    NASA Astrophysics Data System (ADS)

    Neigh, C. S.; Carvalhais, N.; Collatz, G. J.; Tucker, C. J.

    2010-12-01

    Terrestrial Higher Northern Latitude Boreal ecosystems over the past half century have and are expected to incur substantial future climate warming altering long-term biophysical processes that mediate carbon sink status. Boreal ecosystems are one of the primary terrestrial pools with high organic and mineral soil carbon concentrations due to reduced decomposition from extended periods below freezing. Direct impacts of changing local to regional climate have altered Interior Alaska disturbance regimes shifting patterns of net primary production (NPP), soil heterotrophic respiration (Rh), net ecosystem production (NEP = NPP - Rh) and net biome production (NBP = NEP - De) which includes disturbance events (De). We investigated ecosystem dynamics with a satellite remote sensing driven model accounting for fine-scale heterogeneous events observed from multi temporal-spectral index vectors derived from Landsat. Our intent was to elucidate local to regional processes which have resulted in negative trends observed from the NOAA series of Advanced Very High Resolution Radiometers (AVHRR) over the past decade. The Carnegie-Ames-Stanford approach (CASA) model was run with changing fractional burned area to simulate bi-monthly patterns of net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, combustion emissions, and microbial CO2 production. Carbon reallocation was based on fire disturbances identified with remote sensing data (Landsat, IKONOS, and aerial photography) and disturbance perimeter maps from land management agencies. Warming coupled with insect and fire disturbance emissions reduced interior Boreal forest recalcitrant carbon pools for which losses greatly exceed the North Slope Tundra sink. Our multi spatial-temporal approach confirms substantial forested NPP declines in Landsat and AVHRR while distinguishing abiotic and biophysical disturbance frequency impacts upon NBP.

  13. Making and Measuring a Model of a Salt Marsh

    ERIC Educational Resources Information Center

    Fogleman, Tara; Curran, Mary Carla

    2007-01-01

    Students are often confused by the difference between the terms "accuracy" and "precision." In the following activities, students explore the definitions of accuracy and precision while learning about salt march ecology and the methods used by scientists to assess salt marsh health. The activities also address the concept that the ocean supports a…

  14. Making and Measuring a Model of a Salt Marsh

    ERIC Educational Resources Information Center

    Fogleman, Tara; Curran, Mary Carla

    2007-01-01

    Students are often confused by the difference between the terms "accuracy" and "precision." In the following activities, students explore the definitions of accuracy and precision while learning about salt march ecology and the methods used by scientists to assess salt marsh health. The activities also address the concept that the ocean supports a…

  15. Modelling artificial sea salt emission in large eddy simulations

    PubMed Central

    Maalick, Z.; Korhonen, H.; Kokkola, H.; Kühn, T.; Romakkaniemi, S.

    2014-01-01

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s−1, the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10–20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks. PMID:25404679

  16. Modelling artificial sea salt emission in large eddy simulations.

    PubMed

    Maalick, Z; Korhonen, H; Kokkola, H; Kühn, T; Romakkaniemi, S

    2014-12-28

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s(-1), the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10-20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  17. Assessing Wildlife Habitat Value of New England Salt Marshes: II. Model Testing and Validation

    EPA Science Inventory

    We test a previously described model to assess the wildlife habitat value of New England salt marshes by comparing modeled habitat values and scores with bird abundance and species richness at sixteen salt marshes in Narragansett Bay, Rhode Island USA. Assessment scores ranged f...

  18. Assessing the Wildlife Habitat Value of New England Salt Marshes: I. Model and Application

    EPA Science Inventory

    We developed an assessment model to quantify the wildlife habitat value of New England salt marshes based on marsh characteristics and the presence of habitat types that influence habitat use by terrestrial wildlife. Applying the model to12 salt marshes located in Narragansett B...

  19. Assessing Wildlife Habitat Value of New England Salt Marshes: II. Model Testing and Validation

    EPA Science Inventory

    We test a previously described model to assess the wildlife habitat value of New England salt marshes by comparing modeled habitat values and scores with bird abundance and species richness at sixteen salt marshes in Narragansett Bay, Rhode Island USA. Assessment scores ranged f...

  20. Assessing the Wildlife Habitat Value of New England Salt Marshes: I. Model and Application

    EPA Science Inventory

    We developed an assessment model to quantify the wildlife habitat value of New England salt marshes based on marsh characteristics and the presence of habitat types that influence habitat use by terrestrial wildlife. Applying the model to12 salt marshes located in Narragansett B...

  1. Modeling and numerical simulation of interior ballistic processes in a 120mm mortar system

    NASA Astrophysics Data System (ADS)

    Acharya, Ragini

    Numerical Simulation of interior ballistic processes in gun and mortar systems is a very difficult and interesting problem. The mathematical model for the physical processes in the mortar systems consists of a system of non-linear coupled partial differential equations, which also contain non-homogeneity in form of the source terms. This work includes the development of a three-dimensional mortar interior ballistic (3D-MIB) code for a 120mm mortar system and its stage-wise validation with multiple sets of experimental data. The 120mm mortar system consists of a flash tube contained within an ignition cartridge, tail-boom, fin region, charge increments containing granular propellants, and a projectile payload. The ignition cartridge discharges hot gas-phase products and unburned granular propellants into the mortar tube through vent-holes on its surface. In view of the complexity of interior ballistic processes in the mortar propulsion system, the overall problem was solved in a modular fashion, i.e., simulating each physical component of the mortar propulsion system separately. These modules were coupled together with appropriate initial and boundary conditions. The ignition cartridge and mortar tube contain nitrocellulose-based ball propellants. Therefore, the gas dynamical processes in the 120mm mortar system are two-phase, which were simulated by considering both phases as an interpenetrating continuum. Mass and energy fluxes from the flash tube into the granular bed of ignition cartridge were determined from a semi-empirical technique. For the tail-boom section, a transient one-dimensional two-phase compressible flow solver based on method of characteristics was developed. The mathematical model for the interior ballistic processes in the mortar tube posed an initial value problem with discontinuous initial conditions with the characteristics of the Riemann problem due to the discontinuity of the initial conditions. Therefore, the mortar tube model was solved

  2. Models of a partially hydrated Titan interior with a clathrate crust

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.; Castillo-Rogez, J. C.; Choukroun, M.; Sotin, C.

    2012-04-01

    We present a model of the interior evolution of Titan over time, assuming the silicate core was hydrated early in Titan’s history and is dehydrating over time. The original model presented in Castillo-Rogez and Lunine (2010) was motivated by a Cassini-derived moment of inertia (Iess et al., 2010) for Titan too large to be accommodated by classical fully differentiated models in which an anhydrous silicate core was overlain by a water ice (with possible perched ocean) mantle. Our model consists of a silicate core still in the process of dehydrating today, a situation made possible by the leaching of radiogenic potassium from the silicates into the perched liquid water ocean. The most recent version of our model accounts for the likely presence of large amounts of methane in the upper crust invoked to explain methane’s persistence at present and through geologic time (Tobie et al. 2006). The methane-rich crust turns out to have essentially no bearing on the temperature of the silicate core and hence the timing of dehydration, but it profoundly affects the thickness of the high-pressure ice layer beneath the ocean. Indeed, the insulating effect of the methane clathrate crust could have delayed the formation of the high-pressure layer, resulting in the interaction of liquid water with the silicate core for extended periods of time. Although a high-pressure ice layer is likely in place today, it is thin enough that plumes of hot water from the dehydrating core probably breach that layer. The implications of such a deep hydrothermal system for the later stages of the evolution of Titan’s interior and surface will be discussed. Part of this work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged. References: Castillo-Rogez, J., Lunine, J.: “Evolution of Titan’s rocky core constrained by Cassini observations”. GRL, Vol. 37, L20205, 2010. Iess, L., et al.:

  3. Fire frequency in the Interior Columbia River Basin: Building regional models from fire history data

    USGS Publications Warehouse

    McKenzie, D.; Peterson, D.L.; Agee, James K.

    2000-01-01

    Fire frequency affects vegetation composition and successional pathways; thus it is essential to understand fire regimes in order to manage natural resources at broad spatial scales. Fire history data are lacking for many regions for which fire management decisions are being made, so models are needed to estimate past fire frequency where local data are not yet available. We developed multiple regression models and tree-based (classification and regression tree, or CART) models to predict fire return intervals across the interior Columbia River basin at 1-km resolution, using georeferenced fire history, potential vegetation, cover type, and precipitation databases. The models combined semiqualitative methods and rigorous statistics. The fire history data are of uneven quality; some estimates are based on only one tree, and many are not cross-dated. Therefore, we weighted the models based on data quality and performed a sensitivity analysis of the effects on the models of estimation errors that are due to lack of cross-dating. The regression models predict fire return intervals from 1 to 375 yr for forested areas, whereas the tree-based models predict a range of 8 to 150 yr. Both types of models predict latitudinal and elevational gradients of increasing fire return intervals. Examination of regional-scale output suggests that, although the tree-based models explain more of the variation in the original data, the regression models are less likely to produce extrapolation errors. Thus, the models serve complementary purposes in elucidating the relationships among fire frequency, the predictor variables, and spatial scale. The models can provide local managers with quantitative information and provide data to initialize coarse-scale fire-effects models, although predictions for individual sites should be treated with caution because of the varying quality and uneven spatial coverage of the fire history database. The models also demonstrate the integration of

  4. Interior Renovation.

    ERIC Educational Resources Information Center

    American School & University, 2002

    2002-01-01

    Describes notable interior renovations of educational facilities, including the educational context and design goals. Includes information on architects, suppliers, and cost, as well as photographs. (EV)

  5. Interior Renovation.

    ERIC Educational Resources Information Center

    American School & University, 2002

    2002-01-01

    Describes notable interior renovations of educational facilities, including the educational context and design goals. Includes information on architects, suppliers, and cost, as well as photographs. (EV)

  6. Coulombic free energy and salt ion association per phosphate of all-atom models of DNA oligomer: dependence on oligomer size.

    PubMed

    Shkel, Irina A; Record, M Thomas

    2012-08-23

    We investigate how the coulombic Gibbs free energy and salt ion association per phosphate charge of DNA oligomers vary with oligomer size (i.e. number of charged residues ∣ZD∣) at 0.15 M univalent salt by non-linear Poisson Boltzmann (NLPB) analysis of all-atom DNA models. Calculations of these quantities ([Formula: see text], [Formula: see text]) are performed for short and long double-stranded (ds) and single-stranded (ss) DNA oligomers, ranging from 4 to 118 phosphates (ds) and from 2 to 59 phosphates (ss). Behaviors of [Formula: see text] and [Formula: see text] as functions of ∣ZD∣ provide a measure of the range of the coulombic end effect and determine the size of an oligomer at which an interior region with the properties (per charge) of the infinite-length polyelectrolyte first appears. This size (10-11 phosphates at each end for ds DNA and 6-9 for ss DNA at 0.15 M salt) is in close agreement with values obtained previously by Monte Carlo and NLPB calculations for cylindrical models of polyions, and by analysis of binding of oligocations to DNA oligomers. Differences in [Formula: see text] and in [Formula: see text] between ss and ds DNA are used to predict effects of oligomeric size and salt concentration on duplex stability in the vicinity of 0.15 M salt. Results of all-atom calculations are compared with results of less structurally detailed models and with experimental data.

  7. Chemical Models of Salts in the Martian Regolith

    NASA Astrophysics Data System (ADS)

    Treiman, A. H.

    1999-01-01

    The martian regolith is rich in ionic salts, which affect its chemical and physical properties, and will affect its resource potential and toxicity. Sulphate, halide, and carbonate salts are expected from theory, chemical analyses, and martian meteorites. A new inference here is that chromate salts may be present and abundant in the regolith. The origin of these salts is not known; they have been ascribed to hydrothermal action, meteoritic contributions, and volcanic aerosols/gases. Low temperature alteration (diagenesis) is a potentially important contributor to regolith salts. Ionic salt minerals in the martian regolith are important tracers of global and local chemical processes on Mars, appear to be important in setting the physical properties (i.e. trafficability) of the martian surface, will likely be important resources for human exploitation, and could possibly present hazards to human health. MECA and other instruments on the MARS 2001 lander are designed to investigate the regolith, so it is appropriate to examine the current knowledge of likely salt mineral in the martian regolith.

  8. Understanding Measures of Magnetic Activity Using Physics-based Models of the Solar Interior and Atmosphere

    NASA Astrophysics Data System (ADS)

    Abbett, W. P.; Luhmann, J. G.

    2014-12-01

    Substantial progress has been made over the past decade in the effort to better understand how magnetic flux and energy is generated in the convective interior of the Sun, how it emerges into the solar atmosphere, and how manifestations of solar magnetic activity (such as sunspots, coronal mass ejections, and flares) are connected within a dynamic magnetic environment spanning the solar convection zone-to-corona system. Here, we present a brief overview of recent efforts to model the evolution of active region magnetic fields and sunspots over a range of physical conditions and spatial and temporal scales. We will focus on how dynamic, physics-based numerical models can be used to better understand observed relationships between different measures of solar activity as a function of time (e.g., sunspot activity and morphologies, unsigned magnetic flux measured at the photosphere, coronal X-ray emissivity). We will determine whether local physics-based models of active region evolution can be used to better constrain proxies of solar activity such as the sunspot number, which remains the only direct record available to trace the very long-term influence of the solar dynamo on the earth's environment.

  9. Interior Design.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for an eight-unit secondary education vocational home economics course on interior design. The units cover period styles of interiors, furniture and accessories, surface treatments and lighting, appliances and equipment, design and space planning in home and business settings, occupant needs, acquisition…

  10. Modeling Small Exoplanets Interiors: a Numerical Scheme to Explore Possible Compositions

    NASA Astrophysics Data System (ADS)

    Brugger, B.; Mousis, O.; Deleuil, M.

    2016-12-01

    Despite the huge number of discovered exoplanets, our knowledge of their compositions remains extremely limited. Modeling the interiors of such bodies is necessary to go further than the first approximation given by their mean density. Here we present a numerical model aiming at computing the internal structure of a given exoplanet from its measured mass and radius, and providing a range of compositions compatible with these data. Our model assumes the presence of a metal core surrounded by a silicate mantle and a water layer. Depending on their respective proportions, we can model various compositions, typically from terrestrial planets to ocean or Mercury-like planets. We apply this model to the case of CoRoT-7b, whose mass and radius values have recently been updated to 4.73 ± 0.95% mearth and 1.585 ± 0.064 rearth, respectively. We show that these values are fully compatible with a solid composition, and find that CoRoT-7b may present a core mass fraction of 80% at maximum, or on the opposite, a maximum water mass fraction of 51%. If this latter composition is compatible with that of several icy moons in the solar system, a 80% core in mass is less conceivable and a lower limit can be placed from solar system formation conditions. These results confirm the Super-Earth status of CoRoT-7b, and show that an Earth-like composition may be obtained more easily compared to previous conclusions.

  11. 3D modelling of salt tectonics with a brittle overburden in an extensional regime

    NASA Astrophysics Data System (ADS)

    Eichheimer, Philipp; Reuber, Georg; Kaus, Boris

    2016-04-01

    Most previous numerical models of salt tectonics only considered 2D cases or did not taken a brittle sedimentary overburden into account, both of which are likely to be important in nature. To get insights into the dynamics of diapiric rise of salt we here present time-dependent high resolution 3D models of salt tectonics in the presence of a brittle overburden and sedimentation. We focus on the internal deformation of an embedded anhydrite layer within a nonlinear viscous salt layer. As salt in nature tends to rise upwards to the surface along fault zones, the salt layer is overlain by a brittle overburden to simulate faulting. The resulting complex folding of the anhydrite layer obtained in our models is consistent with natural observations, e.g. Gorleben [1]. Regarding field examples we vary the shape of the anhydrite layer to understand different modes of deformation [2]. We test the effect of overburden rheology, extension and sedimentation rates on the 3D salt dome patterns and on its internal deformation. [1] O. Bornemann. Zur Geologie des Salzstocks Gorleben nach den Bohrergebnissen. Bundesamt für Strahlenschutz (1991). [2] Z. Chemia, H. Koyi, and H. Schmeling. Numerical modelling of rise and fall of a dense layer in salt diapirs. Geophysical Journal International 172.2 (2008): 798-816.

  12. Hydraulic modeling of an interior channel identified inside a Martian Valley

    NASA Astrophysics Data System (ADS)

    Baratti, Emanuele; Pajola, Maurizio; Coradini, Marcello; Montanari, Alberto; Pieri, David; McBride, Karen

    2014-05-01

    Constraining the amount of water flowing on the surface of Mars during the ancient hydrological activity of the planet is one of the fundamental and crucial aspects to understand its paleohydrology. Within this work, a detailed hydraulic study of an interior channel is presented. The river reach is located in the Memnonia quadrangle between 166°0'0"w and 168°0'0"w longitude and between 8°0'0"s and 9°0'0"s latitude. The Mars Express high-resolution stereo camera digital elevation model, HRSC DEM, H31850000DA4, presents a spatial resolution of 75 m and it was used to characterize the geometry of the interior channel. Geomorphic evidences (i.e. flood terraces) were used to identify the probable bank-full level. In particular, we found out that the channel appears to be characterized by two different terracing levels. The river reach segment is 10 km long and averagely 1 km wide. The paleoriver bed presents a complex topography, characterized by significant changes in slope. We used a hydraulic model capable to perform one-dimensional water surface profile calculations for steady gradually varied flow in natural channels. At each cross section we computed the water level by solving the energy equation or, where this was not considered applicable, by using the momentum equation. The identified terracing levels were used to constrain the water discharge flowing on the surface and the roughness coefficient of the surface (the latter, as well as the energy and momentum equations, being adapted to the Martian gravity). By applying a Monte Carlo procedure, the relative frequency of the most probable discharge and roughness coefficient for both bankfull levels was derived. Hints on the grain size distribution are also presented. Regarding the lower bankfull levels, we obtained a median value of stream discharge and Manning roughness coefficient equal to 17400 m3s-1 and 0.08 m-1/3s. When considering the upper terracing levels our methodology indicated a median value of

  13. Numerical Modelling of Multi-Phase Multi-Component Reactive Transport in the Earth's interior

    NASA Astrophysics Data System (ADS)

    Oliveira, Beñat; Afonso, Juan Carlos; Zlotnik, Sergio; Tilhac, Romain

    2017-04-01

    We present a conceptual and numerical approach to model processes in the Earth's interior that involve multiple phases that simultaneously interact thermally, mechanically and chemically. The approach is truly multiphase in the sense that each dynamic phase is explicitly modelled with an individual set of mass, momentum, energy and chemical mass balance equations coupled via interfacial interaction terms. It is also truly multi-component in the sense that the compositions of the system and its constituent thermodynamic phases are expressed by a full set of fundamental chemical components (e.g. SiO_2, Al_2O_3, MgO, etc) rather than proxies. In contrast to previous approaches these chemical components evolve, react with, and partition into, different phases with different physical properties according to an internally-consistent thermodynamic model. This enables a thermodynamically-consistent coupling of the governing set of balance equations. Interfacial processes such as surface tensions and/or surface energy contributions to the dynamics and energetics of the system are also taken into account. The model presented here describes the evolution of systems governed by Multi-Phase Multi-Component Reactive Transport (MPMCRT) based on Ensemble Averaging and Classical Irreversible Thermodynamics principles. This novel approach provides a flexible platform to study the dynamics and non-linear feedbacks occurring within various natural systems at different scales. This notably includes major- and trace-element transport, diffusion-controlled trace-element re-equilibration or rheological changes associated with melt generation and migration in the Earth's mantle.

  14. A sound quality model for objective synthesis evaluation of vehicle interior noise based on artificial neural network

    NASA Astrophysics Data System (ADS)

    Wang, Y. S.; Shen, G. Q.; Xing, Y. F.

    2014-03-01

    Based on the artificial neural network (ANN) technique, an objective sound quality evaluation (SQE) model for synthesis annoyance of vehicle interior noises is presented in this paper. According to the standard named GB/T18697, firstly, the interior noises under different working conditions of a sample vehicle are measured and saved in a noise database. Some mathematical models for loudness, sharpness and roughness of the measured vehicle noises are established and performed by Matlab programming. Sound qualities of the vehicle interior noises are also estimated by jury tests following the anchored semantic differential (ASD) procedure. Using the objective and subjective evaluation results, furthermore, an ANN-based model for synthetical annoyance evaluation of vehicle noises, so-called ANN-SAE, is developed. Finally, the ANN-SAE model is proved by some verification tests with the leave-one-out algorithm. The results suggest that the proposed ANN-SAE model is accurate and effective and can be directly used to estimate sound quality of the vehicle interior noises, which is very helpful for vehicle acoustical designs and improvements. The ANN-SAE approach may be extended to deal with other sound-related fields for product quality evaluations in SQE engineering.

  15. Numerical and measured data from the 3D salt canopy physical modeling project

    SciTech Connect

    Bradley, C.; House, L.; Fehler, M.; Pearson, J.; TenCate, J.; Wiley, R.

    1997-11-01

    The evolution of salt structures in the Gulf of Mexico have been shown to provide a mechanism for the trapping of significant hydrocarbon reserves. Most of these structures have complex geometries relative to the surrounding sedimentary layers. This aspect in addition to high velocities within the salt tend to scatter and defocus seismic energy and make imaging of subsalt lithology extremely difficult. An ongoing program the SEG/EAEG modeling project (Aminzadeh et al. 1994a: Aminzadeh et al. 1994b: Aminzadeh et al. 1995), and a follow-up project funded as part of the Advanced Computational Technology Initiative (ACTI) (House et al. 1996) have sought to investigate problems with imaging beneath complex salt structures using numerical modeling and more recently, construction of a physical model patterned after the numerical subsalt model (Wiley and McKnight. 1996). To date, no direct comparison of the numerical and physical aspects of these models has been attempted. We present the results of forward modeling a numerical realization of the 3D salt canopy physical model with the French Petroleum Institute (IFP) acoustic finite difference algorithm used in the numerical subsalt tests. We compare the results from the physical salt canopy model, the acoustic modeling of the physical/numerical model and the original numerical SEG/EAEG Salt Model. We will be testing the sensitivity of migration to the presence of converted shear waves and acquisition geometry.

  16. Salt transport in the Irminger Current: a regional and a global model

    NASA Astrophysics Data System (ADS)

    Born, A.; Stocker, T. F.; Sandø, A. B.

    2012-04-01

    Salt transport in the Irminger Current and thus the coupling between eastern and western subpolar North Atlantic play an important role for climate variability across a wide range of time scales. High resolution ocean modeling and observations indicate that salinities in the eastern subpolar North Atlantic correlate negatively with the circulation of the North Atlantic subpolar gyre (SPG). This has led to the perception that a weaker SPG also transports less salt. In contrast, global climate models simulate enhanced salt transport with a stronger gyre that acts as an important positive feedback mechanism for climate variability. Is this an artifact of insufficient model resolution or sub-grid parametrizations? We find that one of the current generation of global climate models shows good agreement with a regional ocean model in the simulated dynamics of the SPG. Enhanced salt transport in the Irminger Current is a robust feature of both models, because the increase in volume transport overcompensates the decrease in salinity.

  17. Potential constitutive models for salt: Survey of phenomenology, micromechanisms, and equations

    SciTech Connect

    Senseny, P.E.; Hansen, F.D.

    1987-12-01

    Results are given of a literature survey performed to document the thermomechanical phenomena and micromechanical processes observed for salt over the ranges of stress and temperature of interest for a high-level nuclear repository. The elastic and thermal expansion behavior of salt can be readily modeled by the generalized Duhamel Neumann form of Hooke's law with temperature-dependent elastic constants and coefficient of thermal expansion. Inelastic deformation is primarily viscoplastic, but also has a brittle component. The observed phenomenological behavior of salt occurs because of micromechanical processes. To the extent that these processes have been studied, a summary of deformation mechanisms in natural salt is included in this report. Eight constitutive models that appear to be capable of modeling the viscoplastic deformation have been selected from the literature. Two models have been selected to model brittle deformation. Insufficient data are available to develop a model for failure. 92 refs., 39 figs., 6 tabs.

  18. Numerical models of salt marsh evolution: Ecological, geomorphic, and climatic factors

    USGS Publications Warehouse

    Fagherazzi, S.; Kirwan, M.L.; Mudd, S.M.; Guntenspergen, G.R.; Temmerman, S.; D'Alpaos, A.; Van De Koppel, J.; Rybczyk, J.M.; Reyes, E.; Craft, C.; Clough, J.

    2012-01-01

    Salt marshes are delicate landforms at the boundary between the sea and land. These ecosystems support a diverse biota that modifies the erosive characteristics of the substrate and mediates sediment transport processes. Here we present a broad overview of recent numerical models that quantify the formation and evolution of salt marshes under different physical and ecological drivers. In particular, we focus on the coupling between geomorphological and ecological processes and on how these feedbacks are included in predictive models of landform evolution. We describe in detail models that simulate fluxes of water, organic matter, and sediments in salt marshes. The interplay between biological and morphological processes often produces a distinct scarp between salt marshes and tidal flats. Numerical models can capture the dynamics of this boundary and the progradation or regression of the marsh in time. Tidal channels are also key features of the marsh landscape, flooding and draining the marsh platform and providing a source of sediments and nutrients to the marsh ecosystem. In recent years, several numerical models have been developed to describe the morphogenesis and long-term dynamics of salt marsh channels. Finally, salt marshes are highly sensitive to the effects of long-term climatic change. We therefore discuss in detail how numerical models have been used to determine salt marsh survival under different scenarios of sea level rise. Copyright 2012 by the American Geophysical Union.

  19. Numerical models of salt marsh evolution: ecological, geomorphic, and climatic factors

    USGS Publications Warehouse

    Fagherazzi, Sergio; Kirwan, Matthew L.; Mudd, Simon M.; Guntenspergen, Glenn R.; Temmerman, Stijn; D'Alpaos, Andrea; van de Koppel, Johan; Rybczyk, John; Reyes, Enrique; Craft, Chris; Clough, Jonathan

    2012-01-01

    Salt marshes are delicate landforms at the boundary between the sea and land. These ecosystems support a diverse biota that modifies the erosive characteristics of the substrate and mediates sediment transport processes. Here we present a broad overview of recent numerical models that quantify the formation and evolution of salt marshes under different physical and ecological drivers. In particular, we focus on the coupling between geomorphological and ecological processes and on how these feedbacks are included in predictive models of landform evolution. We describe in detail models that simulate fluxes of water, organic matter, and sediments in salt marshes. The interplay between biological and morphological processes often produces a distinct scarp between salt marshes and tidal flats. Numerical models can capture the dynamics of this boundary and the progradation or regression of the marsh in time. Tidal channels are also key features of the marsh landscape, flooding and draining the marsh platform and providing a source of sediments and nutrients to the marsh ecosystem. In recent years, several numerical models have been developed to describe the morphogenesis and long-term dynamics of salt marsh channels. Finally, salt marshes are highly sensitive to the effects of long-term climatic change. We therefore discuss in detail how numerical models have been used to determine salt marsh survival under different scenarios of sea level rise.

  20. Numerical models of salt marsh evolution: Ecological, geomorphic, and climatic factors

    NASA Astrophysics Data System (ADS)

    Fagherazzi, Sergio; Kirwan, Matthew L.; Mudd, Simon M.; Guntenspergen, Glenn R.; Temmerman, Stijn; D'Alpaos, Andrea; van de Koppel, Johan; Rybczyk, John M.; Reyes, Enrique; Craft, Chris; Clough, Jonathan

    2012-01-01

    Salt marshes are delicate landforms at the boundary between the sea and land. These ecosystems support a diverse biota that modifies the erosive characteristics of the substrate and mediates sediment transport processes. Here we present a broad overview of recent numerical models that quantify the formation and evolution of salt marshes under different physical and ecological drivers. In particular, we focus on the coupling between geomorphological and ecological processes and on how these feedbacks are included in predictive models of landform evolution. We describe in detail models that simulate fluxes of water, organic matter, and sediments in salt marshes. The interplay between biological and morphological processes often produces a distinct scarp between salt marshes and tidal flats. Numerical models can capture the dynamics of this boundary and the progradation or regression of the marsh in time. Tidal channels are also key features of the marsh landscape, flooding and draining the marsh platform and providing a source of sediments and nutrients to the marsh ecosystem. In recent years, several numerical models have been developed to describe the morphogenesis and long-term dynamics of salt marsh channels. Finally, salt marshes are highly sensitive to the effects of long-term climatic change. We therefore discuss in detail how numerical models have been used to determine salt marsh survival under different scenarios of sea level rise.

  1. Modeling soil thermal and carbon dynamics of a fire chronosequence in interior Alaska

    USGS Publications Warehouse

    Zhuang, Q.; McGuire, A.D.; O'Neill, K. P.; Harden, J.W.; Romanovsky, V.E.; Yarie, J.

    2003-01-01

    In this study, the dynamics of soil thermal, hydrologic, and ecosystem processes were coupled to project how the carbon budgets of boreal forests will respond to changes in atmospheric CO2, climate, and fire disturbance. The ability of the model to simulate gross primary production and ecosystem respiration was verified for a mature black spruce ecosystem in Canada, the age-dependent pattern of the simulated vegetation carbon was verified with inventory data on aboveground growth of Alaskan black spruce forests, and the model was applied to a postfire chronosequence in interior Alaska. The comparison between the simulated soil temperature and field-based estimates during the growing season (May to September) of 1997 revealed that the model was able to accurately simulate monthly temperatures at 10 cm (R > 0.93) for control and burned stands of the fire chronosequence. Similarly, the simulated and field-based estimates of soil respiration for control and burned stands were correlated (R = 0.84 and 0.74 for control and burned stands, respectively). The simulated and observed decadal to century-scale dynamics of soil temperature and carbon dynamics, which are represented by mean monthly values of these variables during the growing season, were correlated among stands (R = 0.93 and 0.71 for soil temperature at 20- and 10-cm depths, R = 0.95 and 0.91 for soil respiration and soil carbon, respectively). Sensitivity analyses indicate that along with differences in fire and climate history a number of other factors influence the response of carbon dynamics to fire disturbance. These factors include nitrogen fixation, the growth of moss, changes in the depth of the organic layer, soil drainage, and fire severity.

  2. Using local knowledge, hydrological, and climate data to develop a driftwood harvest model in interior Alaska

    NASA Astrophysics Data System (ADS)

    Jones, C.; Hinzman, L. D.; Kielland, K.

    2011-12-01

    Residents of rural Alaska usually harvest driftwood from the Yukon River during two distinct periods in the summer. Typically, driftwood accompanies high flows on the Yukon River associated with spring break-up. A few weeks later, a second pulse of driftwood associated with the "2nd Rise" typically flows during early June. This study examines the nature of the differential timing of high flow events in the Yukon River to develop a model of the driftwood harvest. Many communities in interior Alaska have grown to rely upon driftwood as an important source of wood, which is used in construction and as a source of fuel. Increasingly, villages in rural Alaska are trying to lessen their dependence upon high-cost fossil fuels and other non-renewable energy sources. A number of Alaskan villages have recently installed wood chip-fired boilers to generate heat and/or electricity and additional boilers are slated to be installed in rural Alaska in the near future. These boilers are largely fed by driftwood which can be harvested cheaply and processed easily. But if the driftwood harvest is dependent upon high flows in the Yukon, how will fluctuations in river hydrology affect the efficacy and reliability of driftwood harvest? We examined this question using information from local knowledge in conjunction with U.S. census, hydrological, and climate reanalysis data sets to model the magnitude of Yukon River driftwood harvest during summer. It appears that since 1995, high flow events have decreased magnitude, but increased in frequency, compared to the period between 1977 and 1994. Based upon this observation, the annual potential driftwood harvest in Tanana since 1995 was modeled to be greater compared to the average prior to 1994. This pattern was largely driven by a change in the frequency and duration of high flow events. Thus, the availability of driftwood as an energy resource is expected to be commensurate to the recurrence of high flow events on the Yukon River.

  3. Developing and testing a landscape habitat suitability model for fisher (Martes pennanti) in forests of interior northern California

    Treesearch

    W.J. Zielinski; J. R. Dunk; J. S. Yaeger; D. W. LaPlante

    2010-01-01

    The fisher is warranted for protection under the Endangered Species Act in the western United States and, as such, it is especially important that conservation and management actions are based on sound scientific information. We developed a landscape-scale suitability model for interior northern California to predict the probability of detecting fishers and to identify...

  4. Modeling the hot-dense plasma of the solar interior in and out of thermal equilibrium

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Hsuan

    The developments in helioseismology ensure a wealth of studies in solar physics. In particular, with the high precision of the observations of helioseismology, a high-quality solar model is mandated, since even the tiny deviations between a model and the real Sun can be detected. One crucial ingredient of any solar model is the thermodynamics of hot-dense plasmas, in particular the equation of state. This has motivated efforts to develop sophisticated theoretical equations of state (EOS). It is important to realize that for the conditions of solar-interior plasmas, there are no terrestrial laboratory experiments; the only observational constraints come from helioseismology. Among the most successful EOS is so called OPAL EOS, which is part of the Opacity Project at Livermore. It is based on an activity expansion of the quantum plasma, and realized in the so-called "physical picture". One of its main competitor is the so called MHD EOS, which is part of the international Opacity Project (OP), a non-classified multi-country consortium. The approach of MHD is via the so-called "chemical picture". Since OPAL is the most accurate equation of state so far, there has been a call for a public-domain version of it. However, the OPAL code remains proprietary, and its "emulation" makes sense. An additional reason for such a project is that the results form OPAL can only be accessed via tables generated by the OPAL team. Their users do not have the flexibility to change the chemical composition from their end. The earlier MHD-based OPAL emulator worked well with its modifications of the MHD equation of state, which is the Planck-Larkin partition function and its corresponding scattering terms. With this modification, MHD can serve as a OPAL emulator with all the flexibility and accessibility. However, to build a really user-friendly OPAL emulator one should consider CEFF-based OPAL emulator. CEFF itself is already widely used practical EOS which can be easily implemented

  5. Interior Noise

    NASA Technical Reports Server (NTRS)

    Mixson, John S.; Wilby, John F.

    1991-01-01

    The generation and control of flight vehicle interior noise is discussed. Emphasis is placed on the mechanisms of transmission through airborne and structure-borne paths and the control of cabin noise by path modification. Techniques for identifying the relative contributions of the various source-path combinations are also discussed along with methods for the prediction of aircraft interior noise such as those based on the general modal theory and statistical energy analysis.

  6. Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

    SciTech Connect

    Turchi, C. S.; Heath, G. A.

    2013-02-01

    This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The reference plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.

  7. Modeling Ice Giant Interiors Using Constraints on the H2-H2O Critical Curve

    NASA Astrophysics Data System (ADS)

    Bailey, E.; Stevenson, D. J.

    2015-12-01

    We present a range of models of Uranus and Neptune, taking into account recent experimental data (Bali, 2013) implying the location of the critical curve of the H2-H2O system at pressures up to 2.6 GPa. The models presented satisfy the observed total mass of each planet and the radius at the observed 1-bar pressure level. We assume the existence of three regions at different depths: an outer adiabatic envelope composed predominately of H2 and He, with a helium mass fraction 0.26, a water-rich layer including varied amounts of rock and hydrogen, and a chemically homogeneous rock core. Using measured rotation rates of Uranus and Neptune, and a density profile obtained for each model using constituent equations of state and the assumption of hydrostatic equilibrium, we calculate the gravitational harmonics J2 and J4 for comparison with observed values as an additional constraint. The H2-H2O critical curve provides information about the nature of the boundary between the outer, hydrogen-rich envelope and underlying water-rich layer. The extrapolated critical curve for hydrogen-water mixtures crosses the adiabat of the outer atmospheric shell in these models at two depths, implying a shallow outer region of limited miscibility, an intermediate region between ~90 and 98 percent of the total planet radius within which hydrogen and water can mix in all proportions, and another, deeper region of limited miscibility at less than ~90 percent of the total planet radius. The pressure and temperature of the gaseous adiabatic shell at the depth of the shallowest extent of the water-rich layer determines whether a gradual compositional transition or an ocean surface boundary may exist at depth in these planets. To satisfy the observed J2, the outer extent of the water-rich layer in these models must be located between approximately 80 and 85 percent of the total planet radius, within the deep region of limited H2-H2O miscibility, implying an ocean surface is possible within the

  8. Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study.

    PubMed

    Wang, Miao; Moran, Andrew E; Liu, Jing; Coxson, Pamela G; Penko, Joanne; Goldman, Lee; Bibbins-Domingo, Kirsten; Zhao, Dong

    2016-01-01

    To estimate the effects of achieving China's national goals for dietary salt (NaCl) reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD) prevention. The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and mortality, quality-adjusted life-years (QALYs) gained, and CVD treatment costs saved. Reducing mean dietary salt intake to 9.0 g/day gradually over 10 years could prevent approximately 197 000 incident annual CVD events [95% uncertainty interval (UI): 173 000-219 000], reduce annual CVD mortality by approximately 2.5% (2.2-2.8%), gain 303 000 annual QALYs (278 000-329 000), and save approximately 1.4 billion international dollars (Int$) in annual CVD costs (Int$; 1.2-1.6 billion). Reducing mean salt intake to 6.0 g/day could approximately double these benefits. Implementing cooking salt-restriction spoons could prevent 183 000 fewer incident CVD cases (153 000-215 000) and avoid Int$1.4 billion in CVD treatment costs annually (1.2-1.7 billion). Implementing a cooking salt substitute strategy could lead to approximately three times the health benefits of the salt-restriction spoon program. More than three-quarters of benefits from any dietary salt reduction strategy would be realized in hypertensive adults. China could derive substantial health gains from implementation of population-wide dietary salt reduction policies. Most health benefits from any dietary salt reduction program would be realized in adults with hypertension.

  9. Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study

    PubMed Central

    Liu, Jing; Coxson, Pamela G.; Penko, Joanne; Goldman, Lee; Bibbins-Domingo, Kirsten; Zhao, Dong

    2016-01-01

    Objectives To estimate the effects of achieving China’s national goals for dietary salt (NaCl) reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD) prevention. Methods The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and mortality, quality-adjusted life-years (QALYs) gained, and CVD treatment costs saved. Results Reducing mean dietary salt intake to 9.0 g/day gradually over 10 years could prevent approximately 197 000 incident annual CVD events [95% uncertainty interval (UI): 173 000–219 000], reduce annual CVD mortality by approximately 2.5% (2.2–2.8%), gain 303 000 annual QALYs (278 000–329 000), and save approximately 1.4 billion international dollars (Int$) in annual CVD costs (Int$; 1.2–1.6 billion). Reducing mean salt intake to 6.0 g/day could approximately double these benefits. Implementing cooking salt-restriction spoons could prevent 183 000 fewer incident CVD cases (153 000–215 000) and avoid Int$1.4 billion in CVD treatment costs annually (1.2–1.7 billion). Implementing a cooking salt substitute strategy could lead to approximately three times the health benefits of the salt-restriction spoon program. More than three-quarters of benefits from any dietary salt reduction strategy would be realized in hypertensive adults. Conclusion China could derive substantial health gains from implementation of population-wide dietary salt reduction policies. Most health benefits from any dietary salt reduction program would be realized in adults with hypertension. PMID:26840409

  10. Optical property characterization of molten salt mixtures for thermal modeling of volumetrically absorbing solar receiver applications

    NASA Astrophysics Data System (ADS)

    Tetreault-Friend, Melanie; McKrell, Thomas; Baglietto, Emilio; Gil, Antoni; Slocum, Alexander H.; Calvet, Nicolas

    2017-06-01

    A method for experimentally determining the attenuation coefficient of high temperature semi-transparent liquids for volumetrically absorbing solar receiver applications was developed. The method was used to measure the attenuation coefficient over a broad spectral range in a 40 wt. % KNO3:60 wt. % NaNO3 binary nitrate molten salt mixture (solar salt). The measured absorption bands extend over 98% of the re-emission spectrum of the salt, indicating that thermal redistribution within the salt itself via radiative participating media effects is negligible. In addition, the effects of the salt's purity and thermal decomposition on the optical properties were also investigated and the light penetration depth is shown to vary significantly in the presence of impurities. The implications of these results for solar receiver design and modeling are discussed.

  11. Propeller aircraft interior noise model. II - Scale-model and flight-test comparisons

    NASA Technical Reports Server (NTRS)

    Willis, C. M.; Mayes, W. H.

    1987-01-01

    A program for predicting the sound levels inside propeller driven aircraft arising from sidewall transmission of airborne exterior noise is validated through comparisons of predictions with both scale-model test results and measurements obtained in flight tests on a turboprop aircraft. The program produced unbiased predictions for the case of the scale-model tests, with a standard deviation of errors of about 4 dB. For the case of the flight tests, the predictions revealed a bias of 2.62-4.28 dB (depending upon whether or not the data for the fourth harmonic were included) and the standard deviation of the errors ranged between 2.43 and 4.12 dB. The analytical model is shown to be capable of taking changes in the flight environment into account.

  12. Long Term Dynamics of Interior Least Tern Sandbar Habitat: Landsat's Contribution to a Metapopulation Ecological Model

    NASA Astrophysics Data System (ADS)

    Bulliner, E. A.; Jacobson, R. B.; Elliott, C. M.; Lott, C. A.

    2013-12-01

    Sandbars in sand-bedded rivers of the central U.S have ecological importance to many species. Many of these sandbars provide the primary historical breeding habitat for the endangered Interior Least Tern (Sterna antillarum), or ILT. Sandbars within these systems are highly variable both temporally and spatially due to morphodynamic and vegetative processes, as well as varying hydrology. Differences in available habitat type and quality occur not only among rivers but among individual reaches of a single river. Complete characterization of temporal and spatial shifts in sandbar habitat therefore requires long-term datasets spanning the entire range used by the species with sufficient temporal resolution to capture hydrologically-driven system dynamics. The Landsat series of satellites with their long-term, wide-scale, consistent data records provide a rich and unique source of information on this habitat. We developed methods to automate characterization of sandbar habitat within 13 rivers of the central U.S. plains using Thematic Mapper (TM) imagery. The rivers were divided into segments with relatively uniform flow regimes (between major tributaries). Approximately 25,000 combinations of river segments with daily streamflow records and unobscured TM images exist for the breeding range of the ILT. Within each of these combinations of flow segments and TM images, we have automated the identification of river, vegetation, and bare sand within the active river channel boundaries for image-specific streamflow using a combination of geoprocessing scripts and unsupervised ISODATA classification. The primary goal of this effort is to create physically-informed empirical models of sandbar habitat dynamics, including morphodynamic and vegetative influences on sandbar creation and degradation. The models will be used to parameterize sandbar habitat in an individual-based metapopulation model of the ILT. The geospatial data we have extracted from TM images allows

  13. Testing a 1-D Analytical Salt Intrusion Model and the Predictive Equation in Malaysian Estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, Jacqueline Isabella; Savenije, Hubert H. G.

    2013-04-01

    Little is known about the salt intrusion behaviour in Malaysian estuaries. Study on this topic sometimes requires large amounts of data especially if a 2-D or 3-D numerical models are used for analysis. In poor data environments, 1-D analytical models are more appropriate. For this reason, a fully analytical 1-D salt intrusion model, based on the theory of Savenije in 2005, was tested in three Malaysian estuaries (Bernam, Selangor and Muar) because it is simple and requires minimal data. In order to achieve that, site surveys were conducted in these estuaries during the dry season (June-August) at spring tide by moving boat technique. Data of cross-sections, water levels and salinity were collected, and then analysed with the salt intrusion model. This paper demonstrates a good fit between the simulated and observed salinity distribution for all three estuaries. Additionally, the calibrated Van der Burgh's coefficient K, Dispersion coefficient D0, and salt intrusion length L, for the estuaries also displayed a reasonable correlations with those calculated from the predictive equations. This indicates that not only is the salt intrusion model valid for the case studies in Malaysia but also the predictive model. Furthermore, the results from this study describe the current state of the estuaries with which the Malaysian water authority in Malaysia can make decisions on limiting water abstraction or dredging. Keywords: salt intrusion, Malaysian estuaries, discharge, predictive model, dispersion

  14. Salt as a 3D element in structural modelling - example from the Central European Basin System

    NASA Astrophysics Data System (ADS)

    Maystrenko, Y. P.; Scheck-Wenderoth, M.; Bayer, U.

    2010-12-01

    The Central European Basin System (CEBS) covers the northern part of Central and Western Europe and contains up to 12 km of Permian to Cenozoic deposits. Initiated in the Early Permian, the Central European Basin System accumulated Lower Permian clastics overlain by significant amount of Upper Permian (Zechstein) salt. Post-Permian differentiation of the basin system was controlled by several phases of tectonic activity. These tectonic phases not only provoked regional shifts in subsidence and erosion but also triggered movements of the Upper Permian (Zechstein) salt. Salt rise strongly influenced the Meso-Cenozoic structural evolution in terms of mechanical decoupling of the sedimentary cover from its basement. As a result of several phases of salt tectonics, the CEBS displays a wide variety of salt structures (walls, diapirs and pillows). In order to investigate the interaction of salt movements, deposition and tectonics, the 3D structural model of the CEBS has been constructed covering the entire salt basin (Northern and Southern Permian basins). Seismic interpretation and 3D backstripping have been used to investigate both the present-day structure and the evolution of the CEBS. 3D backstripping includes 3D salt redistribution in response to the changing load conditions in the salt cover. The results of 3D modelling of salt movements and seismic data indicate that the primary initiation of salt movements occurred during the Triassic. The Triassic regional extensional event initiated a phase of salt movements within the coeval depocenters of the CEBS, such as the Glueckstadt Graben, the Horn Graben, the Fjerritslev Trough and the adjacent Himmerland Graben in Denmark, as well as the Polish Basin. The Early Triassic (Buntsandstein) and the Late Triassic (Middle-Late Keuper) extensional events triggered strongest salt movements within the central part of the Glueckstadt Graben. During the Late Jurassic-Early Cretaceous, major erosion regionally truncated the study

  15. Testing the ability of the INSIGHT-SEIS experiment to model Mars deep interior

    NASA Astrophysics Data System (ADS)

    Panning, M. P.; Beucler, E.; Mocquet, A.; Drilleau, M.; Lognonne, P. H.; Banerdt, W. B.

    2013-12-01

    In 2016, the SEIS experiment, part of the INSIGHT mission of NASA's Discovery program to Mars, is expected to provide the very first seismic records on this planet. This experiment consists in a single station that will record both short-period and broad-band data. The challenge of obtaining information on the location of seismic sources and on the deep seismic structure of the planet using a single station is tested against Earth analogues recorded at the German Black Forest Observatory (BFO), where the signal to noise ratios of the records are close to the values expected for the SEIS experiment on Mars. Estimates of tectonic activity from mapped fault features and thermal modeling suggest that, in addition to smaller events, it is reasonable to anticipate recording a few events with equivalent Earth moment magnitudes in the range 4.5 - 5, or even larger, within one Martian year (i.e. two Earth years). Taking into account the smaller planetary radius of Mars relative to the Earth and lower anticipated seismic noise, due primarily to the absence of oceans, this may allow for recording of multiple orbit surface waves. Considering geometrical scaling between Mars and the Earth, we take a dataset of Earth events with moment magnitudes between 6 and 6.5, which are just above the threshold for detectability of 3rd orbit fundamental mode Rayleigh waves (R3) on quiet stations, and explore the use of several single station techniques for the estimation of source location (distance and back-azimuth from the station) and interior structure. By using the group arrival times of the first three orbits of the fundamental mode surface waves of these events, we are able to estimate the origin time and epicentral distance of the events within the accuracy of the shortest period used in the analysis (here 40 s). The precision on the estimate of the epicentral distance is about one degree, i.e. approximately 55 km on Mars, while the origin time is estimated with an accuracy of

  16. High Salt Intake Promotes Urinary Loss of Vitamin D Metabolites by Dahl Salt-Sensitive Rats in a Space Flight Model

    NASA Technical Reports Server (NTRS)

    Thierry-Palmer, M.; Cephas, S.; Sayavongsa, P.; Clark, T.; Arnaud, S. B.

    2004-01-01

    Vitamin D metabolism in the Dahl salt-sensitive (S) rat, a model of salt-induced hypertension, differs from that in the Dahl salt-resistant (R) rat. We have demonstrated that female S rats are more vulnerable than female R rats to decreases in plasma 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations during hind limb unloading (a space flight model). We report here on the response of the vitamin D endocrine system of S and R rats to hind limb unloading during high salt intake. Dahl female rats (9.7-week-old) were tail-suspended (hind limb unloaded) for 28 days, while fed a diet containing twice the salt in standard rat chow (2 % sodium chloride). Control rats were fed the same diet, but were not hind limb unloaded. Vitamin D metabolites were analyzed by HPLC and radioimmunoassay kits from Diasorin.

  17. High Salt Intake Promotes Urinary Loss of Vitamin D Metabolites by Dahl Salt-Sensitive Rats in a Space Flight Model

    NASA Technical Reports Server (NTRS)

    Thierry-Palmer, M.; Cephas, S.; Sayavongsa, P.; Clark, T.; Arnaud, S. B.

    2004-01-01

    Vitamin D metabolism in the Dahl salt-sensitive (S) rat, a model of salt-induced hypertension, differs from that in the Dahl salt-resistant (R) rat. We have demonstrated that female S rats are more vulnerable than female R rats to decreases in plasma 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations during hind limb unloading (a space flight model). We report here on the response of the vitamin D endocrine system of S and R rats to hind limb unloading during high salt intake. Dahl female rats (9.7-week-old) were tail-suspended (hind limb unloaded) for 28 days, while fed a diet containing twice the salt in standard rat chow (2 % sodium chloride). Control rats were fed the same diet, but were not hind limb unloaded. Vitamin D metabolites were analyzed by HPLC and radioimmunoassay kits from Diasorin.

  18. Modeling the influence of sinking anhydrite blocks on salt diapirs targeted for hazardous waste disposal

    NASA Astrophysics Data System (ADS)

    Koyi, Hemin A.

    2001-05-01

    Due to the low permeability and high ductility of rock salt, many salt diapirs, such as those in Germany and the Netherlands, are targeted as long-term repositories for disposal of high-level radioactive and chemical wastes. Geophysical and subsurface data show that the Gorleben salt diapir, which is one of the most extensively investigated diapirs in the world, and other salt diapirs of the Zechstein Formation in Germany contain large blocks (˜80 m thick) of high-density anhydrite inclusions. These blocks, which were carried upward by the rising salt, are considered to be detached segments of intercalated layers that initially were deposited with the salt. Results of physical and numerical models, presented here, show that such detached, high-density blocks, which were entrained and carried upward by the diapir at an earlier stage, tend to sink in the late stages of diapiric evolution when the rate of diapiric rise slows down. During their descent, these high- density competent blocks deform by folding and create shear zones at the immediate contact with the less competent salt. The descending blocks initiate a secondary internal flow within the salt diapirs they descend, and they may deform any repository built within such diapirs, which would otherwise be considered as tectonically inactive.

  19. The universal response of fluid interiors to end-member models of mechanical forcing

    NASA Astrophysics Data System (ADS)

    Grannan, A. M.; Favier, B.; Ribeiro, A.; Le Bars, M.; Aurnou, J. M.

    2015-12-01

    Turbulence generated in electrically conductive liquid interiors of planetary bodies may be due, in part, to mechanical forcing through geophysically relevant mechanisms of precession/nutation, librations, tidal forcing, and collisions. Using experimental particle image velocimetry techniques accompanied by selected high-resolution numerical simulations, we show, for the first time, the generation of bulk-filling turbulence driven by high frequency tidal forcing. The transition to sustained turbulence is characterized by a succession of resonances first between the tidally forced ellipsoidal base flow with two primary inertial modes and subsequently between secondary inertial modes and the primary inertial modes. Furthermore, deviations in the amplitude of the time-averaged retrograde zonal flow suggest an as yet unseen secondary flow transition that may promote additional turbulence. The turbulence generated by high frequency, low amplitude tidal forcing is similar to the libration-driven turbulent flows studied by Grannan et al. [2014] and Favier et al. [2015]. These works reveal the universal fluid response to elliptical instability driven by separate models that correspond, in geophysical terms, to two end member types of mechanical forcing. In the first, non-synchronous satellites possess elastically deformable boundaries such that shape of the distortion has a non-zero mean motion. In the second, the core-mantle boundary of a body possesses an inherently rigid or tidally frozen-in ellipsoidal shape in a synchronous orbit such that the mean motion of the elliptically deformed boundary is zero. Although the strength of the mechanical forcing is much weaker at planetary settings, the corresponding viscous dissipation is also weaker and thus may still permit the generation of the same turbulent flow found in both experiments and numerical simulations. The efficacy of such turbulent flows in magnetic field generation and dissipation is currently being pursued

  20. Internationalizing an Interior Design Course: A Model for Global FCS Curricula

    ERIC Educational Resources Information Center

    Charlson, Julie; Vouchilas, Gus

    2010-01-01

    Accreditation for Family and Consumer Sciences and for Interior Design programs includes standards to globalize education of undergraduate students. An integrative approach to planning curriculum relates the concept of global interdependence to the development of critical thinking skills for student decision-making. This was addressed in modifying…

  1. Internationalizing an Interior Design Course: A Model for Global FCS Curricula

    ERIC Educational Resources Information Center

    Charlson, Julie; Vouchilas, Gus

    2010-01-01

    Accreditation for Family and Consumer Sciences and for Interior Design programs includes standards to globalize education of undergraduate students. An integrative approach to planning curriculum relates the concept of global interdependence to the development of critical thinking skills for student decision-making. This was addressed in modifying…

  2. Piecewise-Constant-Model-Based Interior Tomography Applied to Dentin Tubules

    DOE PAGES

    He, Peng; Wei, Biao; Wang, Steve; ...

    2013-01-01

    Dentin is a hierarchically structured biomineralized composite material, and dentin’s tubules are difficult to study in situ. Nano-CT provides the requisite resolution, but the field of view typically contains only a few tubules. Using a plate-like specimen allows reconstruction of a volume containing specific tubules from a number of truncated projections typically collected over an angular range of about 140°, which is practically accessible. Classical computed tomography (CT) theory cannot exactly reconstruct an object only from truncated projections, needless to say a limited angular range. Recently, interior tomography was developed to reconstruct a region-of-interest (ROI) from truncated data in amore » theoretically exact fashion via the total variation (TV) minimization under the condition that the ROI is piecewise constant. In this paper, we employ a TV minimization interior tomography algorithm to reconstruct interior microstructures in dentin from truncated projections over a limited angular range. Compared to the filtered backprojection (FBP) reconstruction, our reconstruction method reduces noise and suppresses artifacts. Volume rendering confirms the merits of our method in terms of preserving the interior microstructure of the dentin specimen.« less

  3. Bone Density and High Salt Diets in a Space Flight Model

    NASA Technical Reports Server (NTRS)

    Arnaud, S. B.; Navidi, M.; Liang, M. T. C.; Wolinsky, I.

    1999-01-01

    High salt diets accelerate bone loss with aging in patients with postmenopausal osteoporosis except when calcium supplementation is provided. We have observed that the decrease in mineral content of growing femurs in juvenile rats, exposed to a space flight model which unloads the hind limbs , is substantially less in animals fed excess salt. To determine whether excess dietary salt has the same effect on the skeleton of the mature animal whose response to unloading is increased resorption and bone loss rather than impaired growth, we carried out a metabolic study in mature rats with hindlimbs unloaded by tailsuspension.

  4. Bone Density and High Salt Diets in a Space Flight Model

    NASA Technical Reports Server (NTRS)

    Arnaud, S. B.; Navidi, M.; Liang, M. T. C.; Wolinsky, I.

    1999-01-01

    High salt diets accelerate bone loss with aging in patients with postmenopausal osteoporosis except when calcium supplementation is provided. We have observed that the decrease in mineral content of growing femurs in juvenile rats, exposed to a space flight model which unloads the hind limbs , is substantially less in animals fed excess salt. To determine whether excess dietary salt has the same effect on the skeleton of the mature animal whose response to unloading is increased resorption and bone loss rather than impaired growth, we carried out a metabolic study in mature rats with hindlimbs unloaded by tailsuspension.

  5. A constitutive model for representing coupled creep, fracture, and healing in rock salt

    SciTech Connect

    Chan, K.S.; Bodner, S.R.; Munson, D.E.; Fossum, A.F.

    1996-03-01

    The development of a constitutive model for representing inelastic flow due to coupled creep, damage, and healing in rock salt is present in this paper. This model, referred to as Multimechanism Deformation Coupled Fracture model, has been formulated by considering individual mechanisms that include dislocation creep, shear damage, tensile damage, and damage healing. Applications of the model to representing the inelastic flow and fracture behavior of WIPP salt subjected to creep, quasi-static loading, and damage healing conditions are illustrated with comparisons of model calculations against experimental creep curves, stress-strain curves, strain recovery curves, time-to-rupture data, and fracture mechanism maps.

  6. Modeling Jupiter's Interior with a Hydrogen-Helium Equation of State Derived From First Principles Computer Simulations

    NASA Astrophysics Data System (ADS)

    Militzer, B.; Vorberger, J.; Hubbard, W.

    2006-12-01

    We report results from recent investigations of the interior structure of Jupiter using state-of-the-art computer simulations of dense fluid hydrogen and helium. Thermodynamic properties used in the models were obtained using density-functional molecular dynamics (DFT-MD) simulations on a grid of temperature and density points spanning the interiors of the planets. In addition to calculations for pure hydrogen, simulation results for the different concentrations of hydrogen- helium mixtures are presented. The corrections to the commonly used linear mixing approximation are characterized, and it is demonstrated how the presence of helium increases the stability of the molecular phase of hydrogen. Our interior models update the suite of models that were based on the widely used Saumon-Chabrier-Van Horn (SCVH) equation of state for hydrogen and helium. Deviations of the DFT-EOS from SCVH are up to about ±5% depending on the pressure, and thus affect interior models at the same level as possible effects of a jovian core. Unlike SCVH, the computed DFT-EOS does not predict any first-order thermodynamic discontinuities associated with pressure-dissociation and metallization of hydrogen. Instead, the DFT-EOS predicts that the molecular dissociation leads intermediate decrease in pressure, which has profound effects on the thermodynamic properties in a zone approximately 6000 km below the 1-bar level in Jupiter. Our results will eventually aid in interpretation of data expected from the Juno orbiter mission. Supported by NASA PGG Grants NAG5-13775 and PGG04-0000-0116 and NSF Grant 0507321.

  7. Modeling of salt and pH gradient elution in ion-exchange chromatography.

    PubMed

    Schmidt, Michael; Hafner, Mathias; Frech, Christian

    2014-01-01

    The separation of proteins by internally and externally generated pH gradients in chromatofocusing on ion-exchange columns is a well-established analytical method with a large number of applications. In this work, a stoichiometric displacement model was used to describe the retention behavior of lysozyme on SP Sepharose FF and a monoclonal antibody on Fractogel SO3 (S) in linear salt and pH gradient elution. The pH dependence of the binding charge B in the linear gradient elution model is introduced using a protein net charge model, while the pH dependence of the equilibrium constant is based on a thermodynamic approach. The model parameter and pH dependences are calculated from linear salt gradient elutions at different pH values as well as from linear pH gradient elutions at different fixed salt concentrations. The application of the model for the well-characterized protein lysozyme resulted in almost identical model parameters based on either linear salt or pH gradient elution data. For the antibody, only the approach based on linear pH gradients is feasible because of the limited pH range useful for salt gradient elution. The application of the model for the separation of an acid variant of the antibody from the major monomeric form is discussed.

  8. Equilibrium Model for Ion Exchange Between Multivalent Cations and Zeolite-A in a Molten Salt

    SciTech Connect

    Supathorn Phongikaroon; Michael Simpson

    2005-10-01

    A two-site equilibrium model that previously only accommodated monovalent cations has been extended to include divalent and trivalent cations for ion exchange between zeolite-A and molten chloride salts, a process being considered for concentrating nuclear fission products into high level waste forms. Equilibrium constants were determined by fitting the model to equilibrium data sets for ion exchange between zeolite-A and Cs ternary salt (CsCl-LiCl-KCl), Rb ternary salt (RbCl-LiCl-KCl), Na ternary salt (NaCl-LiCl-KCl), Sr ternary salt (SrCl2-LiCl-KCl), and U ternary salt (UCl3-LiCl-KCl). The results reveal a good fit between the experimental data sets and the model. The two ion exchange sites, framework sites and occluded sites, demonstrate different relative selectivities for the cations. It was found that Sr2_ is the preferred cation in the ion exchange site, and Cs_ is the preferred cation in the occlusion site. Meanwhile, Li_ has the highest combined selectivity when both ion exchange and occlusion sites are considered. Interestingly, divalent and trivalent species are more preferred in the ion exchange site than the monovalent species with the exception of Li_.

  9. 12. Historic American Buildings Survey, COPY, UTAH HERITAGE FOUNDATION (INTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Historic American Buildings Survey, COPY, UTAH HERITAGE FOUNDATION (INTERIOR PHOTO LATE 1880'S). - Zion's Cooperative Mercantile Institution, 15 South Main Street, Salt Lake City, Salt Lake County, UT

  10. Understanding the Interiors of Saturn and Mercury through Magnetic Field Observation and Dynamo Modeling

    NASA Astrophysics Data System (ADS)

    Cao, Hao

    Understanding the interior structure and dynamics of a planet is a key step towards understanding the formation and evolution of a planet. In this thesis, I combine field observation and dynamo modeling to understand planetary interiors. Focus has been put on planets Saturn and Mercury. The Cassini spacecraft has been taking continuous measurements in the Saturnian system since the Saturn orbital insertion in June 2004. Since the Mercury orbital insertion in March 2011, the MESSENGER spacecraft has been examining planet Mercury. After analyzing the close-in portion of the in-situ Cassini magnetometer measurements around Saturn, I find that Saturn's magnetic field features several surprising characteristics. First, Saturn's magnetic field is extremely axisymmetric. We cannot find any consistent departure from axisymmetry, and have put an extremely tight upper bound on the dipole tilt of Saturn: the dipole tilt of Saturn has to be smaller than 0.06 degrees. Second, we find that Saturn's magnetic field is extremely stable with time. Third, we estimated the magnetic moments of Saturn up to degree 5. This is the first magnetic field model for Saturn which goes beyond degree 3. We find that not only Saturn's intrinsic magnetic field is dominated by the axial moments; among these axial moments the odd degree ones dominate. In addition, the first three odd degree axial moments all take the same sign. This sign pattern of Saturn's magnetic moments is in contrast to that of the Earth's magnetic moments which takes alternative signs for the past century. The contrast between the geometries of Saturn's magnetic field and the Earth's magnetic field lead us to propose a dynamo hypothesis which speculates that such differences are caused by structural and dynamical differences inside these two planets. Our dynamo hypothesis for Saturn has two essential ingredients. The first concerns about the existence and size of a central core inside Saturn and its influence on Saturn's dynamo

  11. 3D modelling in salt tectonic context: the Crocodile minibasin in Sivas (Turkey)

    NASA Astrophysics Data System (ADS)

    Collon, Pauline; Pichat, Alexandre; Kergaravat, Charlie; Botella, Arnaud; Caumon, Guillaume; Favreau, Océane; Fuss, Gaétan; Godefroy, Gabriel; Lerat, Marine; Mazuyer, Antoine; Parquer, Marion; Charreau, Julien; Callot, Jean-Paul; Ringenbach, Jean-Claude

    2015-04-01

    Impermeable, with a low density and acting as a viscous fluid at the geological time scale, salt plays a unique tectonic role favouring hydrocarbon trap formations. Halokinetic structures are various and difficult to image with classic seismic techniques. Thus, outcrop analogues are precious and sought after. Since the re-interpretation in September 2011 of its evaporite deposits, the Oligo-Miocene basin of Sivas (Turkey) is a new choice analogue for the study of salt tectonic with outstanding outcrops reflecting the variety of salt related structures: minibasins, diapirs, welds... While studying these structures requires an important field work, building 3D models becomes an interesting way to better help understanding the three-dimensional organisation and to further perform numerical simulations (e.g., restoration, potential field measurement campaign simulation). The complex geometries observed in salt tectonic context make these 3D geological models particularly challenging to build, especially when only outcrops data are available. We focus on the Crocodile minibasin (Sivas) and present a modelling strategy using a subtle combination of recently developed techniques. Available data are: a Digital Elevation Model, satellite images and associated interpreted bedding traces on topography, orientation measurements of the strata and a conceptual interpretation. Located on an ancient salt extrusion, this minibasin is filled with lacustrine and sabkha sediments. It is interpreted with a closed synclinal structure on North. On its southern part, a central diapir has risen up, separating two tightened synclinals. The salt surface is modelled first as a triangulated surface using a classical explicit surface patch construction method and a manual post-process mesh improvement. Then, the minibasin sediments are modelled with an implicit approach that considers interfaces as equipotentials of a 3D scalar field. This requires to build a volumetric mesh conformable to the

  12. Finite Element Modeling of In-Situ Stresses near Salt Bodies

    NASA Astrophysics Data System (ADS)

    Sanz, P.; Gray, G.; Albertz, M.

    2011-12-01

    The in-situ stress field is modified around salt bodies because salt rock has no ability to sustain shear stresses. A reliable prediction of stresses near salt is important for planning safe and economic drilling programs. A better understanding of in-situ stresses before drilling can be achieved using finite element models that account for the creeping salt behavior and the elastoplastic response of the surrounding sediments. Two different geomechanical modeling techniques can be distinguished: "dynamic" modeling and "static" modeling. "Dynamic" models, also known as forward models, simulate the development of structural processes in geologic time. This technique provides the evolution of stresses and so it is used to simulate the initiation and development of structural features, such as, faults, folds, fractures, and salt diapers. The original or initial configuration and the unknown final configuration of forward models are usually significantly different therefore geometric non-linearities need to be considered. These models may be difficult to constrain when different tectonic, deposition, and erosion events, and the timing among them, needs to be accounted for. While dynamic models provide insight into the stress evolution, in many cases is very challenging, if not impossible, to forward model a configuration to its known present-day geometry; particularly in the case of salt layers that evolve into highly irregular and complex geometries. Alternatively, "static" models use the present-day geometry and present-day far-field stresses to estimate the present-day in-situ stress field inside a domain. In this case, it is appropriate to use a small deformation approach because initial and final configurations should be very similar, and more important, because the equilibrium of stresses should be stated in the present-day initial configuration. The initial stresses and the applied boundary conditions are constrained by the geologic setting and available data

  13. How do salt withdrawal minibasins form? Insights from forward modelling, and implications for hydrocarbon migration

    NASA Astrophysics Data System (ADS)

    Peel, Frank J.

    2014-09-01

    Existing models for the initiation of salt withdrawal minibasins focus on the role of triggers that exist within the minibasin, either stratigraphic (e.g. differential deposition) or tectonic (extension, translation or contraction). Existing studies tend to focus on complex settings, such as continental margins, which contain many different potential triggering mechanisms. It can be difficult in these settings to identify which process is responsible for minibasin initiation, or the influence of individual factors on their subsequent development. Salt withdrawal minibasins also exist in simpler settings, without any obvious intrinsic trigger; the region of the North German Basin used by Trusheim (1960) in the classic definition of salt withdrawal geometries was of this nature. There is no overall basal or surface slope, no major lateral movement, and there is no depositional heterogeneity. Previously recognized trigger processes for minibasin initiation do not apply in this benign setting, suggesting that other, potentially more fundamental, influences may be at work. A simple forward-modelling approach shows how, in the absence of any other mechanism, a new minibasin can develop as the consequence of salt movement driven by its neighbour, and families of withdrawal minibasins can propagate across a region from a single seed point. This new mechanism may explain how some minibasins appear to initiate before the sediment density has exceeded that of the underlying salt. The forward modelling also indicates that some minibasins begin to invert to form turtle anticlines before the underlying salt has been evacuated, so that the timing of turtle formation may not be diagnostic of weld formation. This mechanism may also give rise to salt-cored turtles that have a lens of salt trapped beneath their cores. These new findings have implications for hydrocarbon migration and trapping.

  14. Artificial neural network modeling using clinical and knowledge independent variables predicts salt intake reduction behavior

    PubMed Central

    Isma’eel, Hussain A.; Sakr, George E.; Almedawar, Mohamad M.; Fathallah, Jihan; Garabedian, Torkom; Eddine, Savo Bou Zein

    2015-01-01

    Background High dietary salt intake is directly linked to hypertension and cardiovascular diseases (CVDs). Predicting behaviors regarding salt intake habits is vital to guide interventions and increase their effectiveness. We aim to compare the accuracy of an artificial neural network (ANN) based tool that predicts behavior from key knowledge questions along with clinical data in a high cardiovascular risk cohort relative to the least square models (LSM) method. Methods We collected knowledge, attitude and behavior data on 115 patients. A behavior score was calculated to classify patients’ behavior towards reducing salt intake. Accuracy comparison between ANN and regression analysis was calculated using the bootstrap technique with 200 iterations. Results Starting from a 69-item questionnaire, a reduced model was developed and included eight knowledge items found to result in the highest accuracy of 62% CI (58-67%). The best prediction accuracy in the full and reduced models was attained by ANN at 66% and 62%, respectively, compared to full and reduced LSM at 40% and 34%, respectively. The average relative increase in accuracy over all in the full and reduced models is 82% and 102%, respectively. Conclusions Using ANN modeling, we can predict salt reduction behaviors with 66% accuracy. The statistical model has been implemented in an online calculator and can be used in clinics to estimate the patient’s behavior. This will help implementation in future research to further prove clinical utility of this tool to guide therapeutic salt reduction interventions in high cardiovascular risk individuals. PMID:26090333

  15. Artificial neural network modeling using clinical and knowledge independent variables predicts salt intake reduction behavior.

    PubMed

    Isma'eel, Hussain A; Sakr, George E; Almedawar, Mohamad M; Fathallah, Jihan; Garabedian, Torkom; Eddine, Savo Bou Zein; Nasreddine, Lara; Elhajj, Imad H

    2015-06-01

    High dietary salt intake is directly linked to hypertension and cardiovascular diseases (CVDs). Predicting behaviors regarding salt intake habits is vital to guide interventions and increase their effectiveness. We aim to compare the accuracy of an artificial neural network (ANN) based tool that predicts behavior from key knowledge questions along with clinical data in a high cardiovascular risk cohort relative to the least square models (LSM) method. We collected knowledge, attitude and behavior data on 115 patients. A behavior score was calculated to classify patients' behavior towards reducing salt intake. Accuracy comparison between ANN and regression analysis was calculated using the bootstrap technique with 200 iterations. Starting from a 69-item questionnaire, a reduced model was developed and included eight knowledge items found to result in the highest accuracy of 62% CI (58-67%). The best prediction accuracy in the full and reduced models was attained by ANN at 66% and 62%, respectively, compared to full and reduced LSM at 40% and 34%, respectively. The average relative increase in accuracy over all in the full and reduced models is 82% and 102%, respectively. Using ANN modeling, we can predict salt reduction behaviors with 66% accuracy. The statistical model has been implemented in an online calculator and can be used in clinics to estimate the patient's behavior. This will help implementation in future research to further prove clinical utility of this tool to guide therapeutic salt reduction interventions in high cardiovascular risk individuals.

  16. Pattern formation of down-built salt structures: insights from 3D numerical models

    NASA Astrophysics Data System (ADS)

    Fernandez, Naiara; Kaus, Boris

    2015-04-01

    Many salt diapirs are thought to have formed as a result of down-building, which implies that the top of the diapir remained close to the surface during sediment deposition. This process is largely three-dimensional and in order to better understand what controls the patterns that form as a result of this down-building process, we here perform three-dimensional numerical models and compare the results with analytical models. In our models, we vary several parameters such as initial salt thickness, sedimentation rate, salt viscosity, salt-sediment viscosity contrast as well as the density of sediments. Down-building of three-dimensional diapirs only occurs for a certain range of parameters and is favored by lower sediment/salt viscosity contrasts and sedimentation rates in agreement with analytical predictions and findings from previous 2D models. However, the models show that the sedimentation rate has an additional effect on the formation and evolution of three-dimensional diapir patterns. At low sedimentation rates, salt ridges that form during early model stages remain preserved at later stages as well. For higher sedimentation rates, the initial salt ridges break up and form finger-like diapirs at the junction of salt ridges, which results in different salt exposure patterns at the surface. Once the initial pattern of diapirs is formed, higher sedimentation rate can also result in covered diapirs if the diapir extrusion velocity is insufficiently large. We quantify the effect of sedimentation rate on the number of diapirs exposed at the surface as well as on their spacing. In some cases, this final pattern is distinctly different from the initial polygonal pattern. We also study the extrusion of salt through time in the simulations, and show that it can be related to the geometries of the sedimentary layers surrounding the diapirs. Acknowledgements. Funding was provided by the European Research Council under the European Community's Seventh Framework Program

  17. CHIC - Coupling Habitability, Interior and Crust: A new Code for Modeling the Thermal Evolution of Planets and Moons

    NASA Astrophysics Data System (ADS)

    Noack, Lena; Rivoldini, Attilio; Van Hoolst, Tim

    2015-04-01

    We present a new numerical code (CHIC) for the simulation of the thermal evolution of terrestrial planets. The code consists of both a 1d parameterised model to evaluate the temperature profile in the planet's interior and a 2d/3d convection model for the silicate mantle - the latter uses either a Cartesian box, a 2d cylindrical sphere or a 2d spherical annulus. The code is modular and can be easily extended (for example to include an atmosphere module). In the convection model next to the energy equation the conservation equations of mass and momentum are solved, as well. We apply either a Boussinesq approximation or an extended Boussinesq approximation for mantle convection; compressible treatment is planned for the future. The code provides information on the temperature field in the mantle, convective velocities and convective stresses. Simulations can be run under steady-state or thermal evolution conditions. The CHIC code handles surface volcanism, crustal development, and different regimes of surface mobilization like plate tectonics. It is therefore well suited for studying scenarios related to the habitability of terrestrial planets. The code provides a user updatable library of thermodynamic properties of iron and common mantle silicates as well as associated equations of state that allow to compute material properties at high pressure and temperature. Furthermore, the interior structure of a planet for given composition and mass can be determined, yielding the core and planet radius that can then be automatically used for the thermal evolution simulation. CHIC does also accommodate a module for computing a simple parameterised thermal evolution model of a planet's core that includes the formation of an inner core. This module can be combined with either the 1d parameterised thermal evolution model or the 2d/3d mantle convection model. The code has been benchmarked with different convection codes, and compared to published interior-structure models and 1d

  18. Heat Transfer Salts for Nuclear Reactor Systems - Chemistry Control, Corrosion Mitigation, and Modeling

    SciTech Connect

    Anderson, Mark; Sridharan, Kumar; Morgan, Dane; Peterson, Per; Calderoni, Pattrick; Scheele, Randall; Casekka, Andrew; McNamara, Bruce

    2015-01-22

    The concept of a molten salt reactor has existed for nearly sixty years. Previously all work was done during a large collaborative effort at Oak Ridge National Laboratory, culminating in a research reactor which operated for 15,000 hours without major error. This technical success has garnished interest in modern, high temperature, reactor schemes. Research using molten fluoride salts for nuclear applications requires a steady supply of high grade molten salts. There is no bulk supplier of research grade fluoride salts in the world, so a facility which could provide all the salt needed for testing at the University of Wisconsin had to be produced. Two salt purification devices were made for this purpose, a large scale purifier, and a small scale purifier, each designed to clean the salts from impurities and reduce their corrosion potential. As of now, the small scale has performed with flibe salt, hydrogen, and hydrogen fluoride, yielding clean salt. This salt is currently being used in corrosion testing facilities at the Massachusetts Institute of Technology and the University of Wisconsin. Working with the beryllium based salts requires extensive safety measures and health monitoring to prevent the development of acute or chronic beryllium disease, two pulmonary diseases created by an allergic reaction to beryllium in the lungs. Extensive health monitoring, engineering controls, and environment monitoring had to be set up with the University of Wisconsin department of Environment, Health and Safety. The hydrogen fluoride required for purification was also an extreme health hazard requiring thoughtful planning and execution. These dangers have made research a slow and tedious process. Simple processes, such as chemical handling and clean-up, can take large amounts of ingenuity and time. Other work has complemented the experimental research at Wisconsin to advance high temperature reactor goals. Modeling work has been performed in house to re

  19. Modeling of Dense Water Production and Salt Transport from Alaskan Coastal Polynyas

    NASA Technical Reports Server (NTRS)

    Signorini, Sergio R.; Cavalieri, Donald J.

    2000-01-01

    The main significance of this paper is that a realistic, three-dimensional, high-resolution primitive equation model has been developed to study the effects of dense water formation in Arctic coastal polynyas. The model includes realistic ambient stratification, realistic bottom topography, and is forced by time-variant surface heat flux, surface salt flux, and time-dependent coastal flow. The salt and heat fluxes, and the surface ice drift, are derived from satellite observations (SSM/I and NSCAT sensors). The model is used to study the stratification, salt transport, and circulation in the vicinity of Barrow Canyon during the 1996/97 winter season. The coastal flow (Alaska coastal current), which is an extension of the Bering Sea throughflow, is formulated in the model using the wind-transport regression. The results show that for the 1996/97 winter the northeastward coastal current exports 13% to 26% of the salt produced by coastal polynyas upstream of Barrow Canyon in 20 to 30 days. The salt export occurs more rapidly during less persistent polynyas. The inclusion of ice-water stress in the model makes the coastal current slightly weaker and much wider due to the combined effects of surface drag and offshore Ekman transport.

  20. DFT analysis of the structure and IR spectrum of potassium salt of diphenylsulfophthalide - A model compound for polydiphenylenesulfophthalide salts

    NASA Astrophysics Data System (ADS)

    Shishlov, N. M.; Akhmetzyanov, Sh S.; Khursan, S. L.

    2017-02-01

    Experimental IR spectra of crystalline dried and non-dried potassium diphenylsulfophthalide (TAC-K) as a model compound for polymeric salts are presented. DFT analysis (B3LYP/6-311G(d,p)) of the structure and IR spectra of a series of compounds similar in structure to TAC-K as well as their dimers indicates that the sulfonate group environment strongly affects the positions of absorption bands (ABs) of vibrations of Ssbnd O bonds and demonstrates that information on the exact structure of ion clusters is needed for reliable and unambiguous assignment of the ABs in experimental IR spectra of real sulfonate ion containing systems to particular vibrational modes. Various ways of metal ion coordination with sulfonate ion, as well as their reflection in IR spectra of model compounds, are considered and discussed. Using TAC-K as an example, the effect of an intramolecular hydrogen bond on the vibrational modes of sulfonate group and hydroxy group is considered. The effect of ion aggregation on the shape of the IR spectrum of TAC-K is analyzed for an energetically favorable dimer of this salt as an example. Based on a combination of calculated, literature and reference data, a number of ABs in the IR spectra of TAC-K have been tentatively assigned. In particular, the bands in the region of 3230-3180 cm-1 have been assigned to ν(Osbnd H); those at 1240-1160 cm-1, to νas(SO3-); the AB at 1080 cm-1, to νs(SO3-); that at 616 cm-1, to δ(oop)s(SO3-); and that at 570 cm-1, to δ(ip)as(SO3-).

  1. Modeling a Possible Volcanic Origin for Interior Layered Deposits on Mars

    NASA Astrophysics Data System (ADS)

    Chapman, M. G.; Kneissl, T.

    2011-12-01

    This study was undertaken to examine the valid range of temperatures required for sub-ice volcanic origin of interior layered deposits (ILDs) in Valles Marineris. To this end, using GIS the volume estimates of Ophir Chasma and its 4 ILDs were mapped and measured. The GIS volumes in this study are based on high-res HRSC topography overlain on MOLA. We determined the void space of Ophir Chasma sans ILDs to be 92,319 km3. Volumes for each ILD mound were determined to be 6,185 km3, 4,833 km3, 2,628 km3, and 0.2 km3 (negligible); totaling 13,642 km3. A sub-ice volcano requires eruption beneath an existing ice sheet or ponded ice. If during the formation of a sub-ice volcano the associated unstable englacial meltwater lake is drained by jökulhlaups or if the volcano rises above the meltwater, effused subaerial lava will cap the tuff cone forming resistant sheet lavas. Hence, the lava cap horizon can be used to estimate the minimum height of ice. Three resistant ILD caprock locales (found only on the 2 largest ILDs) were mapped and the hypothetical ice volumes measured beneath their elevations are 77,391 km3, 79,899 km3, and 51,695 km3. Following the equation from Chapman et al. (2003), if the known ILDs in Ophir are assumed to be basaltic subice volcanoes, calorimetry can be used to estimate the volumes of meltwater generated by their eruption [Allen, 1980; Björnsson, 1988; Gudmundsson and Björnsson, 1991; Gudmundsson et al., 1997; Höskuldsson and Sparks, 1997]. These estimates are based on (1) the volume and likely mound density, (2) the heat content of basaltic magmas, and (3) the specific heat capacity and the latent heat of fusion for ice. The ice that can be melted by a mass of magma as it solidifies and cools can be calculated by equating the heat content of the magma with the heat used for melting. Two possible end member cases were used. In the first case it is assumed that the chasma contained ice at its melting point of 273 K and in the other case the

  2. A Pore Scale Model for Migration of Brine Inclusions in Salt Crystals in Thermal Gradients

    NASA Astrophysics Data System (ADS)

    Molins, S.; Trebotich, D.

    2016-12-01

    Natural salt deposits have low permeability and are thus excellent candidates for hosting heat-emanating wastes (e.g., used nuclear fuels). However, salt may still contain a certain amount of water, either deposited with the salt or emplaced during some secondary process. A form this water may be present in salt formations is as intracrystalline inclusions. In the thermal gradients generated by the waste, because the solubility of salt increases with temperature, salt dissolves at the interface of the inclusion closest to the heat source, diffuse through the brine, and precipitate at the interface furthest from the heat source. Thus, the inclusions tend to migrate toward the heat source. Migration of brine inclusions in thermal gradients could negatively impact the safe disposal of heat-generating nuclear waste. In this contribution, we discuss the development of a pore scale model to simulation of the migration of brine inclusions in salt crystals in thermal gradients. In the pore scale approach, each point in space is assigned either to the solid or fluid phases; thus, there is no need to consider bulk properties for the porous medium as in the traditional Darcy-scale continuum approach. Rather, the size and shape of brine inclusions, and thus the solid-fluid interfaces are considered explicitly. Pore scale modeling is constrained by experimental observations. Specifically, we use the observed rate of migration to calibrate model reaction rates and to explore the effect of the magnitude of the temperature gradient as well as the effect of multiple minerals with different solubilities. We show that pore-scale modeling can provide a useful tool to inform constitutive relationships applicable at the continuum scale.

  3. Modeling Solute Thermokinetics in LiCI-KCI Molten Salt for Nuclear Waste Separation

    SciTech Connect

    Morgan, Dane; Eapen, Jacob

    2013-10-01

    Recovery of actinides is an integral part of a closed nuclear fuel cycle. Pyrometallurgical nuclear fuel recycling processes have been developed in the past for recovering actinides from spent metallic and nitride fuels. The process is essentially to dissolve the spent fuel in a molten salt and then extract just the actinides for reuse in a reactor. Extraction is typically done through electrorefining, which involves electrochemical reduction of the dissolved actinides and plating onto a cathode. Knowledge of a number of basic thermokinetic properties of salts and salt-fuel mixtures is necessary for optimizing present and developing new approaches for pyrometallurgical waste processing. The properties of salt-fuel mixtures are presently being studied, but there are so many solutes and varying concentrations that direct experimental investigation is prohibitively time consuming and expensive (particularly for radioactive elements like Pu). Therefore, there is a need to reduce the number of required experiments through modeling of salt and salt-fuel mixture properties. This project will develop first-principles-based molecular modeling and simulation approaches to predict fundamental thermokinetic properties of dissolved actinides and fission products in molten salts. The focus of the proposed work is on property changes with higher concentrations (up to 5 mol%) of dissolved fuel components, where there is still very limited experimental data. The properties predicted with the modeling will be density, which is used to assess the amount of dissolved material in the salt; diffusion coefficients, which can control rates of material transport during separation; and solute activity, which determines total solubility and reduction potentials used during electrorefining. The work will focus on La, Sr, and U, which are chosen to include the important distinct categories of lanthanides, alkali earths, and actinides, respectively. Studies will be performed using LiCl-KCl salt

  4. The Development of an Interior Ballistic Model for Automated Continuous Propellant Production Control

    DTIC Science & Technology

    1979-01-01

    t . Other requests for this document aust be referred to Director, USA Ballistic Research Laboratory, ATTN: DROAR-TSB...r PROPELLANT LINE HOLDING i t i 1 * ! CHEMICAL AND PHYSICAL TESTS 1 1 s \\ PROCESS CONTROLLER 4 1 ._J j \\. ! * INTERIOR...X UJ —i < U CO >• BO ■ — CO CO LU U o UJ — V) — o QC a 3 i—i OC z o (J — a - X 1 F !/) a. CO — A 0 T ^ — UJ >■ e 1—

  5. Reverse modeling of 2D and 3D diapiric salt structures

    NASA Astrophysics Data System (ADS)

    Fernandez, N.; Kaus, B.

    2013-12-01

    Mechanical forward modeling of salt diapirs formed by two different processes (differential loading and buoyancy driven) has been widely performed with numerical codes in many studies, whereas works focusing on the dynamic retro-deformation of such structures remain scarce. Buoyancy driven diapirs, in which the density difference between salt and overburden induces upward motion of salt, have been successfully retro-deformed in two and three dimensions using simple rheologies for the salt and overburden (e.g., Kaus & Podladchikov 2001). However, retro-deformation of down-building diapirs (syndepositional process in which salt structures grow while sediments are being deposited) using mechanical codes has only been done in two dimensions (e.g., Ismael-Zadeh et al. 2001), even though the importance of three-dimensionality in salt diapirism is accepted. We have used the two-dimensional visco-elasto-plastic finite element code MILAMIN_VEP to perform both forward and backward simulations and to check the validity of a reversed time step method (Kaus & Podladchikov 2001 and Ismael-Zadeh et al. 2001) for a wide range of parameters, variable sedimentation rates, and for non-linear rheologies. Forward simulations are run until the salt layer is exhausted and then a reverse time step is applied in order to retro-deform the model. Down-building process was mimicked using a fast-erosion condition at the surface, which keeps it flat and redistributes material at every time step. Initially, we have tested our method by retro-deforming salt structures that develop from an interface that is sinusoidally perturbed. More realistic simulations were performed by starting with randomly perturbed salt interface and using different rheological parameters for the salt and the overburden as well as variable sedimentation rates. Once the method has been proved successful for different parameters in two dimensions, the finite differences parallel code LaMEM has also been used to dynamically

  6. Heat and salt redistribution within the Mediterranean Sea in the Med-CORDEX model ensemble

    NASA Astrophysics Data System (ADS)

    Llasses, J.; Jordà, G.; Gomis, D.; Adloff, F.; Macías, D.; Harzallah, A.; Arsouze, T.; Akthar, N.; Li, L.; Elizalde, A.; Sannino, G.

    2016-06-01

    Characterizing and understanding the basic functioning of the Mediterranean Sea in terms of heat and salt redistribution within the basin is a crucial issue to predict its evolution. Here we quantify and analyze the heat and salt transfers using a simple box model consisting of four layers in the vertical for each of the two (western and eastern) basins. Namely, we box-average 14 regional simulations of the Med-CORDEX ensemble plus a regional and a global reanalysis, computing for each of them the heat and salt exchanges between layers. First, we analyze in detail the mechanisms behind heat and salt redistribution at different time scales from the outputs of a single simulation (NEMOMED8). We show that in the western basin the transfer between layer 1 (0-150 m) and layer 2 (150-600 m) is upwards for most models both for heat and salt, while in the eastern basin both transfers are downwards. A feature common to both basins is that the transports are smaller in summer than in winter due to the enhanced stratification, which dampen the mixing between layers. From the comparison of the 16 simulations we observe that the spread between models is much larger than the ensemble average for the salt transfer and for the heat transfer between layer 1 and layer 2. At lower layers (below 600 m) there is a set of models showing a good agreement between them, while others are not correlated with any other. The mechanisms behind the ensemble spread are not straightforward. First, to have a coarse resolution prevents the model to correctly represent the heat and salt redistribution in the basin. Second, those models with a very different initial stratification also show a very different redistribution, especially at intermediate and deep layers. Finally, the assimilation of data seems to perturb the heat and salt redistribution. Besides this, the differences among regional models that share similar spatial resolution and initial conditions are induced by more subtle mechanisms

  7. Thermo-mechanical modelling of cyclic gas storage applications in salt caverns

    NASA Astrophysics Data System (ADS)

    Böttcher, Norbert; Watanabe, Norihiro; Görke, Uwe-Jens; Kolditz, Olaf; Nagel, Thomas

    2016-04-01

    Due to the growing importance of renewable energy sources it becomes more and more necessary to investigate energy storage potentials. One major way to store energy is the power-to-gas concept. Excessive electrical energy can be used either to produce hydrogen or methane by electrolysis or methanation or to compress air, respectively. Those produced gases can then be stored in artificial salt caverns, which are constructed in large salt formations by solution mining. In combination with renewable energy sources, the power-to-gas concept is subjected to fluctuations. Compression and expansion of the storage gases lead to temperature differences within the salt rock. The variations can advance several metres into the host rock, influencing its material behaviour, inducing thermal stresses and altering the creep response. To investigate the temperature influence on the cavern capacity, we have developed a numerical model to simulate the thermo-mechanical behaviour of salt caverns during cyclic gas storage. The model considers the thermodynamic behaviour of the stored gases as well as the heat transport and the temperature dependent material properties of the host rock. Therefore, we utilized well-known constitutive thermo-visco-plastic material models, implemented into the open source-scientific software OpenGeoSys. Both thermal and mechanical processes are solved using a finite element approach, connected via a staggered coupling scheme. The model allows the assessment of the structural safety as well as the convergence of the salt caverns.

  8. Hydrologic modeling as a predictive basis for ecological restoration of salt marshes

    USGS Publications Warehouse

    Roman, C.T.; Garvine, R.W.; Portnoy, J.W.

    1995-01-01

    Roads, bridges, causeways, impoundments, and dikes in the coastal zone often restrict tidal flow to salt marsh ecosystems. A dike with tide control structures, located at the mouth of the Herring River salt marsh estuarine system (Wellfleet, Massachusetts) since 1908, has effectively restricted tidal exchange, causing changes in marsh vegetation composition, degraded water quality, and reduced abundance of fish and macroinvertebrate communities. Restoration of this estuary by reintroduction of tidal exchange is a feasible management alternative. However, restoration efforts must proceed with caution as residential dwellings and a golf course are located immediately adjacent to and in places within the tidal wetland. A numerical model was developed to predict tide height levels for numerous alternative openings through the Herring River dike. Given these model predictions and knowledge of elevations of flood-prone areas, it becomes possible to make responsible decisions regarding restoration. Moreover, tidal flooding elevations relative to the wetland surface must be known to predict optimum conditions for ecological recovery. The tide height model has a universal role, as demonstrated by successful application at a nearby salt marsh restoration site in Provincetown, Massachusetts. Salt marsh restoration is a valuable management tool toward maintaining and enhancing coastal zone habitat diversity. The tide height model presented in this paper will enable both scientists and resource professionals to assign a degree of predictability when designing salt marsh restoration programs.

  9. Heat and salt redistribution within the Mediterranean basin in the Med-CORDEX model ensemble

    NASA Astrophysics Data System (ADS)

    Llasses, Josep; Jordà, Gabriel; Gomis, Damià; Adloff, Fanny; Macías, Diego; Harzallah, Ali; Arsouze, Thomas; Akthar, Naveed; Li, Laurent; Elizalde, Alberto; Sannino, Gianmaria

    2016-04-01

    Characterizing and understanding the basic functioning of the Mediterranean Sea in terms of heat and salt redistribution within the basin is a crucial issue to predict its evolution. Here we quantify and analyze the heat and salt transfers using a simple box model consisting of 4 layers in the vertical for each of the two (western and eastern) sub-basins. Namely, we box-average 14 regional simulations of the MedCORDEX ensemble plus a regional and a global reanalysis, computing for each of them the heat and salt exchanges between layers. First, we analyze in detail the heat and salt redistribution at different time scales from the outputs of a single simulation (NEMOMED8). We show that in the western basin the transfer between the surface (0-150m) and intermediate (150-600 m) layers is upwards for both heat and salt, while in the eastern basin both transfers are downwards. A feature common to both sub-basins is that the transports are smaller in summer than in winter due to the enhanced stratification, which dampen the mixing between layers. From the comparison of the 16 simulations we observe that the spread between models is much larger than the ensemble average for the salt transfer and for the heat transfer between the surface and intermediate layers. At lower layers there is a set of models showing a good agreement between them, while others are not correlated with any other. The mechanisms behind the ensemble spread are not straightforward. First, to have a coarse resolution prevents the model to correctly represent the heat and salt redistribution in the basin. Second, those models with a very different initial stratification also show a very different redistribution, especially at intermediate and deep layers. Finally, the assimilation of data seems to perturb the heat and salt redistribution. Besides this, the differences among regional models that share similar spatial resolution and initial conditions are induced by more subtle mechanisms which depend on

  10. Dietary salt reduction and cardiovascular disease rates in India: a mathematical model.

    PubMed

    Basu, Sanjay; Stuckler, David; Vellakkal, Sukumar; Ebrahim, Shah

    2012-01-01

    Reducing salt intake has been proposed to prevent cardiovascular disease in India. We sought to determine whether salt reductions would be beneficial or feasible, given the worry that unrealistically large reductions would be required, worsening iodine deficiency and benefiting only urban subpopulations. Future myocardial infarctions (MI) and strokes in India were predicted with a Markov model simulating men and women aged 40 to 69 in both urban and rural locations, incorporating the risk reduction from lower salt intake. If salt intake does not change, we expect ~8.3 million MIs (95% CI: 6.9-9.6 million), 830,000 strokes (690,000-960,000) and 2.0 million associated deaths (1.5-2.4 million) per year among Indian adults aged 40 to 69 over the next three decades. Reducing intake by 3 g/day over 30 years (-0.1 g/year, 25% reduction) would reduce annual MIs by 350,000 (a 4.6% reduction; 95% CI: 320,000-380,000), strokes by 48,000 (-6.5%; 13,000-83,000) and deaths by 81,000 (-4.9%; 59,000-100,000) among this group. The largest decline in MIs would be among younger urban men, but the greatest number of averted strokes would be among rural men, and nearly one-third of averted strokes and one-fifth of averted MIs would be among rural women. Only under a highly pessimistic scenario would iodine deficiency increase (by <0.0001%, ~1600 persons), since inadequate iodized salt access--not low intake of iodized salt--is the major cause of deficiency and would be unaffected by dietary salt reduction. Modest reductions in salt intake could substantially reduce cardiovascular disease throughout India.

  11. Extension of the M-D model for treating stress drops in salt

    SciTech Connect

    Munson, D.E.; DeVries, K.L.; Fossum, A.F.; Callahan, G.D.

    1993-07-01

    Development of the multimechanism deformation (M-D) constitutive model for steady state creep, which incorporates irreversible workhardening and recovery transient strains, was motivated by the need to predict very long term closures in underground rooms for radioactive waste repositories in salt. The multimechanism deformation model for the creep deformation of salt is extended to treat the response of salt to imposed stress drops. Stress drop tests produce a very distinctive behavior where both reversible elastic strain and reversible time dependent strain occur. These transient strains are negative compared to the positive transient strains produced by the normal creep workhardening and recovery processes. A simple micromechanical evolutionary process is defined to account for the accumulation of these reversible strains, and their subsequent release with decreases in stress. A number of experimental stress drop tests for various stress drop magnitudes and temperatures are adequately simulated with the model.

  12. Beam hardening correction for interior tomography based on exponential formed model and radon inversion transform

    NASA Astrophysics Data System (ADS)

    Chen, Siyu; Zhang, Hanming; Li, Lei; Xi, Xiaoqi; Han, Yu; Yan, Bin

    2016-10-01

    X-ray computed tomography (CT) has been extensively applied in industrial non-destructive testing (NDT). However, in practical applications, the X-ray beam polychromaticity often results in beam hardening problems for image reconstruction. The beam hardening artifacts, which manifested as cupping, streaks and flares, not only debase the image quality, but also disturb the subsequent analyses. Unfortunately, conventional CT scanning requires that the scanned object is completely covered by the field of view (FOV), the state-of-art beam hardening correction methods only consider the ideal scanning configuration, and often suffer problems for interior tomography due to the projection truncation. Aiming at this problem, this paper proposed a beam hardening correction method based on radon inversion transform for interior tomography. Experimental results show that, compared to the conventional correction algorithms, the proposed approach has achieved excellent performance in both beam hardening artifacts reduction and truncation artifacts suppression. Therefore, the presented method has vitally theoretic and practicable meaning in artifacts correction of industrial CT.

  13. Modeling Coupled THMC Processes and Brine Migration in Salt at High Temperatures

    SciTech Connect

    Rutqvist, Jonny; Blanco Martin, Laura; Mukhopadhyay, Sumit; Houseworth, Jim; Birkholzer, Jens

    2014-08-14

    In this report, we present FY2014 progress by Lawrence Berkeley National Laboratory (LBNL) related to modeling of coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. LBNL’s work on the modeling of coupled THMC processes in salt was initiated in FY2012, focusing on exploring and demonstrating the capabilities of an existing LBNL modeling tool (TOUGH-FLAC) for simulating temperature-driven coupled flow and geomechanical processes in salt. This work includes development related to, and implementation of, essential capabilities, as well as testing the model against relevant information and published experimental data related to the fate and transport of water. we provide more details on the FY2014 work, first presenting updated tools and improvements made to the TOUGH-FLAC simulator, and the use of this updated tool in a new model simulation of long-term THM behavior within a generic repository in a salt formation. This is followed by the description of current benchmarking and validations efforts, including the TSDE experiment. We then present the current status in the development of constitutive relationships and the dual-continuum model for brine migration. We conclude with an outlook for FY2015, which will be much focused on model validation against field experiments and on the use of the model for the design studies related to a proposed heater experiment.

  14. Korean Solar Salt Ameliorates Colon Carcinogenesis in an AOM/DSS-Induced C57BL/6 Mouse Model.

    PubMed

    Ju, Jaehyun; Kim, Yeung-Ju; Park, Eui Seong; Park, Kun-Young

    2017-06-01

    The effects of Korean solar salt on an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon cancer C57BL/6 mouse model were studied. Korean solar salt samples (SS-S, solar salt from S salt field; SS-Yb, solar salt from Yb salt field), nine-time-baked bamboo salt (BS-9x, made from SS-Yb), purified salt (PS), and SS-G (solar salt from Guérande, France) were orally administered at a concentration of 1% during AOM/DSS colon cancer induction, and compared for their protective effects during colon carcinogenesis in C57BL/6 mice. SS-S and SS-Yb suppressed colon length shortening and tumor counts in mouse colons. Histological evaluation by hematoxylin and eosin staining also revealed suppression of tumorigenesis by SS-S. Conversely, PS and SS-G did not show a similar suppressive efficacy as Korean solar salt. SS-S and SS-Yb promoted colon mRNA expression of an apoptosis-related factor and cell-cycle-related gene and suppressed pro-inflammatory factor. SS-Yb baked into BS-9x further promoted these anti-carcinogenic efficacies. Taken together, the results indicate that Korean solar salt, especially SS-S and SS-Yb, exhibited anti-cancer activity by modulating apoptosis- and inflammation-related gene expression during colon carcinogenesis in mice, and bamboo salt baked from SS-Yb showed enhanced anti-cancer functionality.

  15. Non-Radiological Air Quality Modeling for the High-Level Waste Salt Disposition

    SciTech Connect

    Hunter, C.H.

    1999-11-29

    Dispersion modeling of non-radiological airborne emissions associated with the construction and operation of three alternatives for high-level waste salt disposition at the Savannah River Site has been completed. The results will be used by Department of Energy-Savannah River in the preparation of the salt disposition supplemental environmental impact statement. Estimated maximum ground-level concentrations of applicable regulated air pollutants of the site boundary and at the distance to a hypothetical, co-located onsite worker are summarized in tables. In all cases, model estimated ambient concentrations are less than regulatory standards.

  16. Computational modeling of latent-heat-storage in PCM modified interior plaster

    SciTech Connect

    Fořt, Jan; Maděra, Jiří; Trník, Anton; Pavlíková, Milena; Pavlík, Zbyšek

    2016-06-08

    The latent heat storage systems represent a promising way for decrease of buildings energy consumption with respect to the sustainable development principles of building industry. The presented paper is focused on the evaluation of the effect of PCM incorporation on thermal performance of cement-lime plasters. For basic characterization of the developed materials, matrix density, bulk density, and total open porosity are measured. Thermal conductivity is accessed by transient impulse method. DSC analysis is used for the identification of phase change temperature during the heating and cooling process. Using DSC data, the temperature dependent specific heat capacity is calculated. On the basis of the experiments performed, the supposed improvement of the energy efficiency of characteristic building envelope system where the designed plasters are likely to be used is evaluated by a computational analysis. Obtained experimental and computational results show a potential of PCM modified plasters for improvement of thermal stability of buildings and moderation of interior climate.

  17. Computational modeling of latent-heat-storage in PCM modified interior plaster

    NASA Astrophysics Data System (ADS)

    Fořt, Jan; Maděra, Jiří; Trník, Anton; Pavlíková, Milena; Pavlík, Zbyšek

    2016-06-01

    The latent heat storage systems represent a promising way for decrease of buildings energy consumption with respect to the sustainable development principles of building industry. The presented paper is focused on the evaluation of the effect of PCM incorporation on thermal performance of cement-lime plasters. For basic characterization of the developed materials, matrix density, bulk density, and total open porosity are measured. Thermal conductivity is accessed by transient impulse method. DSC analysis is used for the identification of phase change temperature during the heating and cooling process. Using DSC data, the temperature dependent specific heat capacity is calculated. On the basis of the experiments performed, the supposed improvement of the energy efficiency of characteristic building envelope system where the designed plasters are likely to be used is evaluated by a computational analysis. Obtained experimental and computational results show a potential of PCM modified plasters for improvement of thermal stability of buildings and moderation of interior climate.

  18. 2-D Modeling of the Variability of the Solar Interior for Climate Studies

    NASA Astrophysics Data System (ADS)

    Sofia, S.; Li, L. H.; Spada, F.; Ventura, P.

    2012-07-01

    To establish the possible influence of solar variability on climate, it is necessary to understand the luminosity changes induced by a variable dynamo magnetic field. To accomplish this, we have developed a 2D code of the structure and evolution of the solar interior (based on the 1D YREC code), that includes rotation, magnetic fields of arbitrary configuration, and turbulence, that can be run on very short time scales (down to 1 year), and that represents all global parameters (R, L, Teff) with a relative accuracy of 1 part per million, or better. This paper discusses the motivation for this work, the structure and the physical components of the code, and its application to interpret the results of the SODISM experiment on the PICARD satellite, and of the balloon-borne Solar Disk Sextant (SDS) experiment.

  19. Properties of alkali-halide salt solutions about polarizable nanoparticle solutes for different ion models.

    PubMed

    Wynveen, Aaron; Bresme, Fernando

    2010-10-14

    We investigate the distributions of various salts about large hydrophobic polarizable solutes in aqueous electrolyte solutions. The solutes are modeled as nanometer-sized cylindrical objects, a scale relevant to biomolecules and nanomaterials, and particularly high aspect ratio nanoparticles. Interactions, including image charge forces arising from the finite polarizability of the solute, between explicit solvent/ions and the solute are computed explicitly using a molecular dynamics simulation methodology we have recently introduced. Comparisons are made between several salt species and different models of the force fields for each ionic component of the salt. We find evidence that both small cations, Li(+), and large anions, I(-), adsorb at hydrophobic interfaces. Our results indicate that the ion structure about the solute is strongly dependent on the force field investigated, suggesting that ion selectivity is quite sensitive to the respective parameters defining the ion's size and binding energy as well as to the polarizability of the solute.

  20. Description of the Material Balance Model and Spreadsheet for Salt Dissolution

    SciTech Connect

    Wiersma, B.J.

    1994-10-12

    The model employed to estimate the amount of inhibitors necessary for bearing water and dissolution water during the salt dissolution process is described. This model was inputed on a spreadsheet which allowed many different case studies to be performed. This memo describes the assumptions and equations which are used in the model, and documents the input and output cells of the spreadsheet. Two case studies are shown as examples of how the model may be employed.

  1. Modeling of Unsaturated Salt-cake Dissolution for S-109 Simulant

    SciTech Connect

    Toghiani, R.K.; Lindner, J.S.; Toghiani, R.K.

    2008-07-01

    The Environmental Simulation Program (V7.0, OLI Systems, Inc.) with V7DBLSLT, the latest version of the double salt database developed by the Institute of Clean Energy Technology (ICET), was used to predict effluent stream compositions and densities, residual salt-cake composition, and salt-cake heights for an unsaturated salt-cake dissolution test with a simulant representative of waste contained in Hanford tank 241-S-109. Predictions for major cation and anion concentrations were in excellent agreement with the experimental data obtained at the Applied Research Center (ARC) at Florida International University (FIU). The utility of ESP as a means to predict effluent stream compositions and effluent stream properties, such as density and column salt-cake height, is demonstrated through the agreement between experimental and predicted values. These, and previous calculations, validate the use of thermodynamic models (with proper chemistry representations) for HLW pretreatment and retrievals. A powerful and useful tool is the result. Cost reductions are possible as the amount of sampling and subsequent laboratory analysis can be reduced. Additionally, overall processing risk is reduced through the ability to rapidly evaluate different processing and retrieval scenarios. The application of appropriate models can thus lead to more efficient operations and campaign cost savings while also evaluating parameters pertinent to safety. (authors)

  2. Developing a coupled analytical model for analyzing salt intrusion in alluvial estuaries

    NASA Astrophysics Data System (ADS)

    Savenije, H.; CAI, H.; Gisen, J.

    2013-12-01

    A predictive assessment technique to estimate the salt intrusion length and longitudinal salinity distribution in estuaries is important for policy makers and managers to maintain a healthy estuarine environment. In this study, the salt intrusion model of Savenije (2005, 2012) is applied and coupled to an explicit solution for tidal dynamics developed by Cai and Savenije (2013). The objective of the coupling is to reduce the number of calibration parameters, which subsequently strengthens the reliability of the salt intrusion model. Moreover, the fully analytical treatment allows assessing the effect of model forcing (i.e., tide and river discharge) and geometry adjustments (e.g., by dredging) on system performance. The coupled model has been applied to a wide range of estuaries, and the result shows that the correspondence between analytical estimations and observations is very good. As a result, the coupled model is a useful tool for decision makers to obtain first order estimates of salt intrusion in estuaries based on a minimum of information required. References Savenije, H.H.G. (2005), Salinity and Tides in Alluvial Estuaries, Elsevier. Savenije, H.H.G. (2012), Salinity and Tides in Alluvial Estuaries, completely revised 2nd edition, www.salinityandtides.com. Cai, H., and H. H. G. Savenije (2013), Asymptotic behavior of tidal damping in alluvial estuaries, Journal of Geophysical Research, submitted.

  3. Planetary Interiors

    NASA Technical Reports Server (NTRS)

    Banerdt, W. Bruce; Abercrombie, Rachel; Keddie, Susan; Mizutani, Hitoshi; Nagihara, Seiichi; Nakamura, Yosio; Pike, W. Thomas

    1996-01-01

    This report identifies two main themes to guide planetary science in the next two decades: understanding planetary origins, and understanding the constitution and fundamental processes of the planets themselves. Within the latter theme, four specific goals related to interior measurements addressing the theme. These are: (1) Understanding the internal structure and dynamics of at least one solid body, other than the Earth or Moon, that is actively convecting, (2) Determine the characteristics of the magnetic fields of Mercury and the outer planets to provide insight into the generation of planetary magnetic fields, (3) Specify the nature and sources of stress that are responsible for the global tectonics of Mars, Venus, and several icy satellites of the outer planets, and (4) Advance significantly our understanding of crust-mantle structure for all the solid planets. These goals can be addressed almost exclusively by measurements made on the surfaces of planetary bodies.

  4. A whole-moon thermal history model of Europa: Impact of hydrothermal circulation and salt transport

    NASA Astrophysics Data System (ADS)

    Travis, B. J.; Palguta, J.; Schubert, G.

    2012-04-01

    A whole-moon numerical model of Europa is developed to simulate its thermal history. The thermal evolution covers three phases: (i) an initial, roughly 0.5 Gyr-long period of radiogenic heating and differentiation, (ii) a long period from 0.5 Gyr to 4 Gyr with continuing radiogenic heating but no tidal dissipative heating (TDH), and (iii) a final period covering the last 0.5 Gyr until the present, during which TDH is active. Hydrothermal plumes develop after the initial period of heating and differentiation and transport heat and salt from Europa's silicate mantle to its ice shell. We find that, even without TDH, vigorous hydrothermal convection in the rocky mantle can sustain flow in an ocean layer throughout Europa's history. When TDH becomes active, the ice shell melts quickly to a thickness of about 20 km, leaving an ocean 80 km or more deep. Parameterized convection in the ice shell is non-uniform spatially, changes over time, and is tied to the deeper ocean-mantle dynamics. We also find that the dynamics are affected by salt concentrations. An initially non-uniform salt distribution retards plume penetration, but is homogenized over time by turbulent diffusion and time-dependent flow driven by initial thermal gradients. After homogenization, the uniformly distributed salt concentrations are no longer a major factor in controlling plume transport. Salt transport leads to the formation of a heterogeneous brine layer and salt inclusions at the bottom of the ice shell; the presence of salt in the ice shell could strongly influence convection in that layer.

  5. Thermodynamic modelling of hydrophobic interaction chromatography of biomolecules in the presence of salt.

    PubMed

    Mirani, Mohammad Reza; Rahimpour, Farshad

    2015-11-27

    Hydrophobic interaction chromatography (HIC) is a useful method for isolation and purification of macromolecules. HIC separates proteins on the basis of surface hydrophobicity while generally retaining the activity of proteins. Aqueous mobile phases with high salt concentrations are often used to adsorb the proteins on a mildly hydrophobic support. In this research, the thermodynamic model of Chen and Sun, which predicts the adsorption isotherms of protein in presence of different type of salts, was modified by substitution the protein and salt activities in the mobile phase instead of their concentrations. In addition, model was examined for studying the adsorption of BSA, HSA, α-lactalbumin and Trypsinogen on different sepharose gels. The model parameters of Chen and Sun are adsorption equilibrium constant (KP), protein dehydration equilibrium constant (Ks), salt coefficient (α) and number of ligand binding (n). By substitution activity instead of salt and protein concentration, two other parameters (c1 and As), which related to the activity coefficients, are added to the model. The parameters of this nonlinear model are calculated by genetic algorithm (GA). The maximum average absolute percentage deviation (AAD) for the data which are obtained from the adsorption isotherm of BSA on phenyl sepharose gel, in the presence of different concentration of NaCl was 4.8%, while for Chen and Sun model, was 22.0%. Also maximum ADD for HSA, α-lactalbumin, and Trypsinogen adsorption was 7.8, 6.9, and 8.4, respectively. The results indicate that the modified model has adequate accuracy to predict protein HIC behaviour.

  6. Salt transport properties of model reverse osmosis membranes using electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Feldman, Kathleen; Chan, Edwin; Stafford, Gery; Stafford, Christopher

    With the increasing shortage of clean water, efficient purification technologies including membrane separations are becoming critical. The main requirement of reverse osmosis in particular is to maximize water permeability while minimizing salt permeability. Such performance optimization has typically taken place through trial and error approaches. In this work, key salt transport metrics are instead measured in model reverse osmosis membranes using electrochemical impedance spectroscopy (EIS). As shown previously, EIS can provide both the membrane resistance Rm and membrane capacitance Cm, with Rm directly related to salt permeability. The membranes are fabricated in a molecular layer by layer approach, which allows for control over such parameters as thickness, surface and bulk chemistry, and network geometry/connectivity. Rm, and therefore salt permeability, follows the expected trends with thickness and membrane area but shows unusual behavior when the network geometry is systematically varied. By connecting intrinsic material properties such as the salt permeability with macroscopic performance measures we can begin to establish design rules for improving membrane efficiency and facilitate the creation of next-generation separation membranes.

  7. AQUIFEM-SALT; a finite-element model for aquifers containing a seawater interface

    USGS Publications Warehouse

    Voss, C.I.

    1984-01-01

    Described are modifications to AQUIFEM, a finite element areal ground-water flow model for aquifer evaluation. The modified model, AQUIFEM-SALT, simulates an aquifer containing a freshwater body that freely floats on seawater. Parts of the freshwater lens may be confined above and below by less permeable units. Theory, code modifications, and model verification are discussed. A modified input data list is included. This report is intended as a companion to the original AQUIFEM documentation. (USGS)

  8. Convection without eddy viscosity: An attempt to model the interiors of giant planets

    NASA Technical Reports Server (NTRS)

    Ingersoll, A. P.

    1986-01-01

    In the theory of hydrostatic quasi-geostrophic flow in the Earth's atmosphere the principal results do not depend on the eddy viscosity. This contrasts with published theories of convection in deep rotating fluid spheres, where the wavelength of the fastest growing disturbance varies as E sup 1/3, where E, the Ekman number, is proportional to the eddy viscosity. A new theory of quasi-columnar motions in stably stratified fluid spheres attempts to capture the luck of the meteorologists. The theory allows one to investigate the stability of barotropic and baroclinic zonal flows that extend into the planetary interior. It is hypothesized that the internal heat Jupiter and Saturn comes out not radially but on sloping surfaces defined by the internal entropy distribution. To test the hypothesis one searches for basic states in which the wavelength of the fastest-growing disturbance remains finite as E tends to zero, and is which the heat flux vector is radially outward and poleward.

  9. Automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners and RFID sensors.

    PubMed

    Valero, Enrique; Adan, Antonio; Cerrada, Carlos

    2012-01-01

    This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results.

  10. Automatic Construction of 3D Basic-Semantic Models of Inhabited Interiors Using Laser Scanners and RFID Sensors

    PubMed Central

    Valero, Enrique; Adan, Antonio; Cerrada, Carlos

    2012-01-01

    This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results. PMID:22778609

  11. A comparison of sea salt emission parameterizations in northwestern Europe using a chemistry transport model setup

    NASA Astrophysics Data System (ADS)

    Neumann, Daniel; Matthias, Volker; Bieser, Johannes; Aulinger, Armin; Quante, Markus

    2016-08-01

    Atmospheric sea salt particles affect chemical and physical processes in the atmosphere. These particles provide surface area for condensation and reaction of nitrogen, sulfur, and organic species and are a vehicle for the transport of these species. Additionally, HCl is released from sea salt. Hence, sea salt has a relevant impact on air quality, particularly in coastal regions with high anthropogenic emissions, such as the North Sea region. Therefore, the integration of sea salt emissions in modeling studies in these regions is necessary. However, it was found that sea salt concentrations are not represented with the necessary accuracy in some situations.In this study, three sea salt emission parameterizations depending on different combinations of wind speed, salinity, sea surface temperature, and wave data were implemented and compared: GO03 (Gong, 2003), SP13 (Spada et al., 2013), and OV14 (Ovadnevaite et al., 2014). The aim was to identify the parameterization that most accurately predicts the sea salt mass concentrations at different distances to the source regions. For this purpose, modeled particle sodium concentrations, sodium wet deposition, and aerosol optical depth were evaluated against measurements of these parameters. Each 2-month period in winter and summer 2008 were considered for this purpose. The shortness of these periods limits generalizability of the conclusions on other years.While the GO03 emissions yielded overestimations in the PM10 concentrations at coastal stations and underestimations of those at inland stations, OV14 emissions conversely led to underestimations at coastal stations and overestimations at inland stations. Because of the differently shaped particle size distributions of the GO03 and OV14 emission cases, the deposition velocity of the coarse particles differed between both cases which yielded this distinct behavior at inland and coastal stations. The PM10 concentrations produced by the SP13 emissions generally

  12. Analogue and geophysical modelling of the Garmsar Salt Nappe, Iran: constraints on the evolution of the Alborz Mountains

    NASA Astrophysics Data System (ADS)

    Baikpour, Shahram; Zulauf, Gernold; Sebti, Arash; Kheirolahi, Hassan; Dietl, Carlo

    2010-08-01

    The Alborz Mountains are forming a ~100-km-wide east-west trending orogenic belt that stretches 2000 m across northern Iran south of the Caspian Sea. The Alborz Mountains consist of salt-bearing Neogene sediments, which are folded and cut by faults. Global positioning system studies indicate N-S directed shortening across the Alborz range, which is accommodated by right and left-lateral strike-slip along ESE-WNW and ENE-WSW trending faults, respectively. A 20 km × 10 km × 03 km sheet of salt extruded over the central plateau of Iran arising at the front of the advancing Alborz Mountains. The extruded salt forms the Eyvanekey plateau between Eyvanekey and Garmsar, which is now known, as the Garmsar Salt Nappe. To get more insights in the evolution of the Garmsar Salt Nappe, analogue modelling has been carried out using PDMS as salt analogue and sand as analogue for the brittle overburden. The structures produced consist of folds and thrusts, which were formed while the salt analogue PDMS was rising up. The modelling results are compatible with our interpretation that the deformation front of the Alborz Mountains advanced SSW when overriding a salt sequence in the Garmsar area. Depth estimations using the gravity and magnetic fields suggest that the salt in the Garmsar Salt Nappe extruded from a depth less than 2000 m.

  13. Calibrating a salt water intrusion model with time-domain electromagnetic data.

    PubMed

    Herckenrath, Daan; Odlum, Nick; Nenna, Vanessa; Knight, Rosemary; Auken, Esben; Bauer-Gottwein, Peter

    2013-01-01

    Salt water intrusion models are commonly used to support groundwater resource management in coastal aquifers. Concentration data used for model calibration are often sparse and limited in spatial extent. With airborne and ground-based electromagnetic surveys, electrical resistivity models can be obtained to provide high-resolution three-dimensional models of subsurface resistivity variations that can be related to geology and salt concentrations on a regional scale. Several previous studies have calibrated salt water intrusion models with geophysical data, but are typically limited to the use of the inverted electrical resistivity models without considering the measured geophysical data directly. This induces a number of errors related to inconsistent scales between the geophysical and hydrologic models and the applied regularization constraints in the geophysical inversion. To overcome these errors, we perform a coupled hydrogeophysical inversion (CHI) in which we use a salt water intrusion model to interpret the geophysical data and guide the geophysical inversion. We refer to this methodology as a Coupled Hydrogeophysical Inversion-State (CHI-S), in which simulated salt concentrations are transformed to an electrical resistivity model, after which a geophysical forward response is calculated and compared with the measured geophysical data. This approach was applied for a field site in Santa Cruz County, California, where a time-domain electromagnetic (TDEM) dataset was collected. For this location, a simple two-dimensional cross-sectional salt water intrusion model was developed, for which we estimated five uniform aquifer properties, incorporating the porosity that was also part of the employed petrophysical relationship. In addition, one geophysical parameter was estimated. The six parameters could be resolved well by fitting more than 300 apparent resistivities that were comprised by the TDEM dataset. Except for three sounding locations, all the TDEM data

  14. Determining salt concentrations for equivalent water activity in reduced-sodium cheese by use of a model system.

    PubMed

    Grummer, J; Schoenfuss, T C

    2011-09-01

    The range of sodium chloride (salt)-to-moisture ratio is critical in producing high-quality cheese products. The salt-to-moisture ratio has numerous effects on cheese quality, including controlling water activity (a(w)). Therefore, when attempting to decrease the sodium content of natural cheese it is important to calculate the amount of replacement salts necessary to create the same a(w) as the full-sodium target (when using the same cheese making procedure). Most attempts to decrease sodium using replacement salts have used concentrations too low to create the equivalent a(w) due to the differences in the molecular weight of the replacers compared with salt. This could be because of the desire to minimize off-flavors inherent in the replacement salts, but it complicates the ability to conclude that the replacement salts are the cause of off-flavors such as bitter. The objective of this study was to develop a model system that could be used to measure a(w) directly, without manufacturing cheese, to allow cheese makers to determine the salt and salt replacer concentrations needed to achieve the equivalent a(w) for their existing full-sodium control formulas. All-purpose flour, salt, and salt replacers (potassium chloride, modified potassium chloride, magnesium chloride, and calcium chloride) were blended with butter and water at concentrations that approximated the solids, fat, and moisture contents of typical Cheddar cheese. Salt and salt replacers were applied to the model systems at concentrations predicted by Raoult's law. The a(w) of the model samples was measured on a water activity meter, and concentrations were adjusted using Raoult's law if they differed from those of the full-sodium model. Based on the results determined using the model system, stirred-curd pilot-scale batches of reduced- and full-sodium Cheddar cheese were manufactured in duplicate. Water activity, pH, and gross composition were measured and evaluated statistically by linear mixed model

  15. Modeling salt intrusion in the San Francisco Estuary prior to anthropogenic influence

    NASA Astrophysics Data System (ADS)

    Andrews, S. W.; Gross, E. S.; Hutton, P. H.

    2017-08-01

    Anthropogenic changes have dramatically transformed the upper San Francisco Estuary over the past two centuries. Key changes influencing the region's hydrology and hydrodynamics include land use changes, levee construction and channel modifications, upstream reservoir construction, and out-of-basin water exports. In order to examine how these changes have altered the physical characteristics of the estuary, 3-D hydrodynamic models were constructed to study the system in its ;pre-development; condition, prior to significant modern anthropogenic influence, and in its contemporary condition. The pre-development system model was calibrated by varying marsh plain elevations in order to match sparse observations of tidal characteristics; the contemporary system model was calibrated to observed flow, stage, and salinity data. A recent three-year period covering a wide range of flow conditions was used to compare and contrast the hydrodynamic behavior of the two systems. While the contemporary model simulation assumed historical observed boundary conditions, the pre-development model simulation assumed conditions thought to exist prior to the alterations of the past two centuries. The relationship between estuary outflow and the longitudinal distance from the estuary mouth to the 2 psu bottom salinity isohaline (X2) was analyzed. Salt intrusion in the pre-development system was found to be slightly more sensitive to outflow and responded faster to changes in outflow than in the contemporary system. Changes in estuary outflows were responsible for more of the salt intrusion differences between the two systems than were changes in estuary geometry and bathymetry. An analysis of the physical mechanisms contributing to salt intrusion found tidal trapping and other unsteady processes to be more important in the pre-development estuary than in the contemporary one. In both systems, steady processes such as estuarine circulation were strongest during neap tides and unsteady salt

  16. Dietary salt restriction improves cardiac and adipose tissue pathology independently of obesity in a rat model of metabolic syndrome.

    PubMed

    Hattori, Takuya; Murase, Tamayo; Takatsu, Miwa; Nagasawa, Kai; Matsuura, Natsumi; Watanabe, Shogo; Murohara, Toyoaki; Nagata, Kohzo

    2014-12-02

    Metabolic syndrome (MetS) enhances salt sensitivity of blood pressure and is an important risk factor for cardiovascular disease. The effects of dietary salt restriction on cardiac pathology associated with metabolic syndrome remain unclear. We investigated whether dietary salt restriction might ameliorate cardiac injury in DahlS.Z-Lepr(fa)/Lepr(fa) (DS/obese) rats, which are derived from a cross between Dahl salt-sensitive and Zucker rats and represent a model of metabolic syndrome. DS/obese rats were fed a normal-salt (0.36% NaCl in chow) or low-salt (0.0466% NaCl in chow) diet from 9 weeks of age and were compared with similarly treated homozygous lean littermates (DahlS.Z-Lepr(+)/Lepr(+), or DS/lean rats). DS/obese rats fed the normal-salt diet progressively developed hypertension and showed left ventricular hypertrophy, fibrosis, and diastolic dysfunction at 15 weeks. Dietary salt restriction attenuated all of these changes in DS/obese rats. The levels of cardiac oxidative stress and inflammation and the expression of cardiac renin-angiotensin-aldosterone system genes were increased in DS/obese rats fed the normal-salt diet, and dietary salt restriction downregulated these parameters in both DS/obese and DS/lean rats. In addition, dietary salt restriction attenuated the increase in visceral adipose tissue inflammation and the decrease in insulin signaling apparent in DS/obese rats without reducing body weight or visceral adipocyte size. Dietary salt restriction did not alter fasting serum glucose levels but it markedly decreased the fasting serum insulin concentration in DS/obese rats. Dietary salt restriction not only prevents hypertension and cardiac injury but also ameliorates insulin resistance, without reducing obesity, in this model of metabolic syndrome. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  17. Computational implementation of the multi-mechanism deformation coupled fracture model for salt

    SciTech Connect

    Koteras, J.R.; Munson, D.E.

    1996-05-01

    The Multi-Mechanism Deformation (M-D) model for creep in rock salt has been used in three-dimensional computations for the Waste Isolation Pilot Plant (WIPP), a potential waste, repository. These computational studies are relied upon to make key predictions about long-term behavior of the repository. Recently, the M-D model was extended to include creep-induced damage. The extended model, the Multi-Mechanism Deformation Coupled Fracture (MDCF) model, is considerably more complicated than the M-D model and required a different technology from that of the M-D model for a computational implementation.

  18. Radiative heat-transfer model in the interior of a pulverized coal furnace

    SciTech Connect

    Canadas, L.; Salvador, L.; Ollero, P. )

    1990-04-01

    A practical mathematical model simulating radiative heat transfer in the furnace of a pulverized coal boiler is presented. The inclusion of this model in a pulverized coal combustion model allows for testing its validity and its sensitivity to furnace walls and particle emissivity values, by comparison with measurements in a 550 MW power plant boiler.

  19. A non-ideal model for predicting the effect of dissolved salt on the flash point of solvent mixtures.

    PubMed

    Liaw, Horng-Jang; Wang, Tzu-Ai

    2007-03-06

    Flash point is one of the major quantities used to characterize the fire and explosion hazard of liquids. Herein, a liquid with dissolved salt is presented in a salt-distillation process for separating close-boiling or azeotropic systems. The addition of salts to a liquid may reduce fire and explosion hazard. In this study, we have modified a previously proposed model for predicting the flash point of miscible mixtures to extend its application to solvent/salt mixtures. This modified model was verified by comparison with the experimental data for organic solvent/salt and aqueous-organic solvent/salt mixtures to confirm its efficacy in terms of prediction of the flash points of these mixtures. The experimental results confirm marked increases in liquid flash point increment with addition of inorganic salts relative to supplementation with equivalent quantities of water. Based on this evidence, it appears reasonable to suggest potential application for the model in assessment of the fire and explosion hazard for solvent/salt mixtures and, further, that addition of inorganic salts may prove useful for hazard reduction in flammable liquids.

  20. MULTISCALE MODELING OF AIR FLOW IN SALT LAKE CITY AND THE SURROUNDING REGION

    SciTech Connect

    M. BROWN; ET AL

    2001-01-01

    A general overview is given of a modeling effort to simulate the fate and transport of a tracer within the downtown core of Salt Lake City and beyond into the Salt Lake Basin. The problem crosses three significant scales where different physics are predominant: atmospheric mesoscale, city scale, and building scale. Three different computational fluid dynamics models were used, each with strengths at particular spatial and temporal scales. We show preliminary results and discuss what we believe to be the relevant phenomenon one must model as one crosses from atmospheric scale to engineering scale flow problems. We also describe our model validation efforts, including wind-tunnel and tow-tank experiments and a recently completed urban field experiment.

  1. Application of Physiologically Based Absorption Modeling for Amphetamine Salts Drug Products in Generic Drug Evaluation.

    PubMed

    Babiskin, Andrew H; Zhang, Xinyuan

    2015-09-01

    Amphetamine (AMP) salts-based extended-release (ER) drug products are widely used for the treatment of attention deficit hyperactivity disorder. We developed physiologically based absorption models for mixed AMP salts ER capsules and dextroamphetamine sulfate ER capsules to address specific questions raised during generic drug postmarketing surveillance and bioequivalence (BE) guidance development. The models were verified against several data sets. Virtual BE simulations were conducted to assess BE in various populations other than normal healthy subjects where BE studies are generally conducted for approval. The models were also used to predict pharmacokinetics (PK) for hypothetical formulations having dissolution profiles falling within specification after the development of in vitro-in vivo relation. Finally, we demonstrated how to use the models to test sensitivity of PK metrics to the changes in formulation variables. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  2. Modeling of dielectric properties of aqueous salt solutions with an equation of state.

    PubMed

    Maribo-Mogensen, Bjørn; Kontogeorgis, Georgios M; Thomsen, Kaj

    2013-09-12

    The static permittivity is the most important physical property for thermodynamic models that account for the electrostatic interactions between ions. The measured static permittivity in mixtures containing electrolytes is reduced due to kinetic depolarization and reorientation of the dipoles in the electrical field surrounding ions. Kinetic depolarization may explain 25-75% of the observed decrease in the permittivity of solutions containing salts, but since this is a dynamic property, this effect should not be included in the thermodynamic modeling of electrolytes. Kinetic depolarization has, however, been ignored in relation to thermodynamic modeling, and authors have either neglected the effect of salts on permittivity or used empirical correlations fitted to the measured static permittivity, leading to an overestimation of the reduction in the thermodynamic static permittivity. We present a new methodology for obtaining the static permittivity over wide ranges of temperatures, pressures, and compositions for use within an equation of state for mixed solvents containing salts. The static permittivity is calculated from a new extension of the framework developed by Onsager, Kirkwood, and Fröhlich to associating mixtures. Wertheim's association model as formulated in the statistical associating fluid theory is used to account for hydrogen-bonding molecules and ion-solvent association. Finally, we compare the Debye-Hückel Helmholtz energy obtained using an empirical model with the new physical model and show that the empirical models may introduce unphysical behavior in the equation of state.

  3. Understanding Jupiter's interior

    NASA Astrophysics Data System (ADS)

    Militzer, Burkhard; Soubiran, François; Wahl, Sean M.; Hubbard, William

    2016-09-01

    This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provided constraints for the interior structure of Jupiter. We discuss typical three-layer interior models that consist of a dense central core and an inner metallic and an outer molecular hydrogen-helium layer. These models rely heavily on experiments, analytical theory, and first-principles computer simulations of hydrogen and helium to understand their behavior up to the extreme pressures ˜10 Mbar and temperatures ˜10,000 K. We review the various equations of state used in Jupiter models and compare them with shock wave experiments. We discuss the possibility that helium rain, core erosion, and double diffusive convection have affected the structure and evolution of giant planets. In July 2016 the Juno spacecraft entered orbit around Jupiter, promising high-precision measurements of the gravitational field that will allow us to test our understanding of gas giant interiors better than ever before.

  4. 3D gravity modeling of the Triassic salt diapirs of the Cubeta Alavesa (northern Spain)

    NASA Astrophysics Data System (ADS)

    Pinto, V.; Casas, A.; Rivero, L.; Torné, M.

    2005-08-01

    Up to now subsurface information permitted the delineation of the top of the Triassic salt, all throughout the Cantabro-Navarro domain, although little was known on the location and geometry of its base and thus on the estimation of the total salt thickness. A 3D-gravity inversion scheme combined with a 3D analytic method has been conducted to map out the geometry of the main salt structures of the basin. The gravity modeling results have been constrained by well log information and available geological and reflection seismic data. The combined 3D scheme integrated with available geological and geophysical data has allowed us to obtain the geometry of the main diapirs that characterize the central and marginal regions of the basin. From our interpretation, the Salinas de Añana diapir has almost vertical flanks and can be divided into two different parts, one of them forming a lateral overhang of the main body. The Salinas de Oro diapir has near vertical flanks and a main axis in the N-S direction. Also, the anomaly is rather more extensive than the outcrop of the diapir, which implies an important expansion of non-outcropping salt in this area. Like the Hoz-Sobrón diapir, the Salinas de Ollo diapir is long and narrow. stretching in the NW-SE direction, which includes three important highs, plus an intense zone of salt migration. The Estella and Alloz diapirs crop out individually in spite of being connected at depth. Also two non-outcropping salt domes have been detected to the south of Atauri that, like the Estella diapir, are related to the thrust front. We point out the gravity signature of the Murguia diapir, which shows an intense gravity high probably due to the presence of high-density rocks in the cap rock or more probably due to the existence of Triassic volcanites of ophitic texture pinched-off into the diapir.

  5. A multiprocessor coupled ice-ocean model for the Baltic Sea: Application to salt inflow

    NASA Astrophysics Data System (ADS)

    Meier, H. E. Markus; DöScher, Ralf; FaxéN, Torgny

    2003-08-01

    Within the Swedish Regional Climate Modeling Program, SWECLIM, a three-dimensional (3-D) coupled ice-ocean model for the Baltic Sea has been developed to simulate physical processes on timescales of hours to decades. The code has been developed based on the massively parallel version of the Ocean Circulation Climate Advanced Modeling (OCCAM) project of the Bryan-Cox-Semtner model. An elastic-viscous-plastic ice rheology is employed, resulting in a fully explicit numerical scheme that improves computational efficiency. An improved two-equation turbulence model has been embedded to simulate the seasonal cycle of surface mixed layer depths as well as deepwater mixing on decadal timescale. The model has open boundaries in the northern Kattegat and is forced with realistic atmospheric fields and river runoff. Optimized computational performance and advanced algorithms to calculate processor maps make the code fast and suitable for multi-year, high-resolution simulations. As test cases, the major salt water inflow event in January 1993 and the stagnation period 1980-1992, have been selected. The agreement between model results and observations is regarded as good. Especially, the time evolution of the halocline in the Baltic proper is realistically simulated also for the longer period without flux correction, data assimilation, or reinitialization. However, in particular, smaller salt water inflows into the Bornholm Basin are underestimated, independent of the horizontal model resolution used. It is suggested that the mixing parameterization still needs improvements. In addition, a series of process studies of the inflow period 1992/1993 have been performed to show the impact of river runoff, wind speed, and sea level in Kattegat. Natural interannual runoff variations control salt water inflows into the Bornholm Basin effectively. The effect of wind speed variation on the salt water flux from the Arkona Basin to the Bornholm Basin is minor.

  6. An electrochemical model for hot-salt stress-corrosion of titanium alloys

    NASA Technical Reports Server (NTRS)

    Garfinkle, M.

    1972-01-01

    An electrochemical model of hot-salt stress-corrosion cracking of titanium alloys is proposed based on an oxygen-concentration cell. Hydrogen embrittlement is proposed as the direct cause of cracking, the hydrogen being generated as the results of the hydrolysis of complex halides formed at the shielded anode of the electrochemical cell. The model found to be consistent with the diverse observations made both in this study and by many investigators in this field.

  7. Modeling Fecal Indicator Bacteria Like Salt in Newport Bay

    NASA Astrophysics Data System (ADS)

    Ciglar, A. M.; Rippy, M.; Grant, S. B.

    2015-12-01

    Newport Bay is a harbor and estuary located in Orange County, CA that provides many water sports and recreational activities for millions of southern California residents and tourists. The aim of this study is to quickly assess exceedances of FIB in the Newport Bay which pose a health risk to recreational users. The ability to quickly assess water quality is made possible with an advection-diffusion mass transport model that uses easily measurable parameters such as volumetric flow rate from tributaries. Current FIB assessment methods for Newport Bay take a minimum of 24 hours to evaluate health risk by either culturing for FIB or running a more complex fluid dynamics model. By this time the FIB may have already reached the ocean outlet thus no longer posing a risk in the bay or recreationists may have already come in close contact with contaminated waters. The advection-diffusion model can process and disseminate health risk information within a few hours of flow rate measurements, minimizing time between an FIB exceedance and public awareness about the event. Data used to calibrate and validate the model was collected from January 2006 through February 2007. Salinity data was used for calibration and FIB data was used for validation. Both steady-state and transient conditions were assessed to determine if dry weather patterns can be simplified to the steady-state condition.

  8. Cosmological Parameter Uncertainties from SALT-II Type Ia Supernova Light Curve Models

    SciTech Connect

    Mosher, J.; Guy, J.; Kessler, R.; Astier, P.; Marriner, J.; Betoule, M.; Sako, M.; El-Hage, P.; Biswas, R.; Pain, R.; Kuhlmann, S.; Regnault, N.; Frieman, J. A.; Schneider, D. P.

    2014-08-29

    We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ~120 low-redshift (z < 0.1) SNe Ia, ~255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ~290 SNLS SNe Ia (z ≤ 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w (input) – w (recovered)) ranging from –0.005 ± 0.012 to –0.024 ± 0.010. These biases are indistinguishable from each other within the uncertainty, the average bias on w is –0.014 ± 0.007.

  9. Cosmological parameter uncertainties from SALT-II type Ia supernova light curve models

    SciTech Connect

    Mosher, J.; Sako, M.; Guy, J.; Astier, P.; Betoule, M.; El-Hage, P.; Pain, R.; Regnault, N.; Marriner, J.; Biswas, R.; Kuhlmann, S.; Schneider, D. P.

    2014-09-20

    We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ∼120 low-redshift (z < 0.1) SNe Ia, ∼255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ∼290 SNLS SNe Ia (z ≤ 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w {sub input} – w {sub recovered}) ranging from –0.005 ± 0.012 to –0.024 ± 0.010. These biases are indistinguishable from each other within the uncertainty; the average bias on w is –0.014 ± 0.007.

  10. A new conceptual paradigm for the haemodynamics of salt-sensitive hypertension: a mathematical modelling approach

    PubMed Central

    Averina, Viktoria A; Othmer, Hans G; Fink, Gregory D; Osborn, John W

    2012-01-01

    A conceptually novel mathematical model of neurogenic angiotensin II-salt hypertension is developed and analysed. The model consists of a lumped parameter circulatory model with two parallel vascular beds; two distinct control mechanisms for both natriuresis and arterial resistances can be implemented, resulting in four versions of the model. In contrast with the classical Guyton–Coleman model (GC model) of hypertension, in the standard version of our new model natriuresis is assumed to be independent of arterial pressure and instead driven solely by sodium intake; arterial resistances are driven by increased sympathetic nervous system activity in response to the elevated plasma angiotensin II and increased salt intake (AngII-salt). We compare the standard version of our new model against a simplified Guyton–Coleman model in which natriuresis is a function of arterial pressure via the pressure–natriuresis mechanism, and arterial resistances are controlled via the whole-body autoregulation mechanism. We show that the simplified GC model and the new model correctly predict haemodynamic and renal excretory responses to induced changes in angiotensin II and sodium inputs. Importantly, the new model reproduces the pressure–natriuresis relationship – the correlation between arterial pressure and sodium excretion – despite the assumption of pressure-independent natriuresis. These results show that our model provides a conceptually new alternative to Guyton's theory without contradicting observed haemodynamic changes or pressure–natriuresis relationships. Furthermore, the new model supports the view that hypertension need not necessarily have a renal aetiology and that long-term arterial pressure could be determined by sympathetic nervous system activity without involving the renal sympathetic nerves. PMID:22890716

  11. Comparison of two propeller source models for aircraft interior noise studies

    NASA Technical Reports Server (NTRS)

    Mahan, J. R.; Fuller, C. R.

    1986-01-01

    The sensitivity of the predicted synchrophasing (SP) effectiveness trends to the propeller source model issued is investigated with reference to the development of advanced turboprop engines for transport aircraft. SP effectiveness is shown to be sensitive to the type of source model used. For the virtually rotating dipole source model, the SP effectiveness is sensitive to the direction of rotation at some frequencies but not at others. The SP effectiveness obtained from the virtually rotating dipole model is not very sensitive to the radial location of the source distribution within reasonable limits. Finally, the predicted SP effectiveness is shown to be more sensitive to the details of the source model used for the case of corotation than for the case of counterrotation.

  12. Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum

    SciTech Connect

    Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

    1980-05-30

    Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes.

  13. Box Model of a Series of Salt Ponds, as Applied to the Alviso Salt Pond Complex, South San Francisco Bay, California

    USGS Publications Warehouse

    Lionberger, Megan A.; Schoellhamer, David H.; Shellenbarger, Gregory; Orlando, James L.; Ganju, Neil K.

    2007-01-01

    This report documents the development and application of a box model to simulate water level, salinity, and temperature of the Alviso Salt Pond Complex in South San Francisco Bay. These ponds were purchased for restoration in 2003 and currently are managed by the U.S. Fish and Wildlife Service to maintain existing wildlife habitat and prevent a build up of salt during the development of a long-term restoration plan. The model was developed for the purpose of aiding pond managers during the current interim management period to achieve these goals. A previously developed box model of a salt pond, SPOOM, which calculates daily pond volume and salinity, was reconfigured to simulate multiple connected ponds and a temperature subroutine was added. The updated model simulates rainfall, evaporation, water flowing between the ponds and the adjacent tidal slough network, and water flowing from one pond to the next by gravity and pumps. Theoretical and measured relations between discharge and corresponding differences in water level are used to simulate most flows between ponds and between ponds and sloughs. The principle of conservation of mass is used to calculate daily pond volume and salinity. The model configuration includes management actions specified in the Interim Stewardship Plan for the ponds. The temperature subroutine calculates hourly net heat transfer to or from a pond resulting in a rise or drop in pond temperature and daily average, minimum, and maximum pond temperatures are recorded. Simulated temperature was compared with hourly measured data from pond 3 of the Napa?Sonoma Salt Pond Complex and monthly measured data from pond A14 of the Alviso Salt-Pond Complex. Comparison showed good agreement of measured and simulated pond temperature on the daily and monthly time scales.

  14. Introducing improved structural properties and salt dependence into a coarse-grained model of DNA

    SciTech Connect

    Snodin, Benedict E. K. Mosayebi, Majid; Schreck, John S.; Romano, Flavio; Doye, Jonathan P. K.; Randisi, Ferdinando; Šulc, Petr; Ouldridge, Thomas E.; Tsukanov, Roman; Nir, Eyal; Louis, Ard A.

    2015-06-21

    We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na{sup +}] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.

  15. Introducing improved structural properties and salt dependence into a coarse-grained model of DNA

    NASA Astrophysics Data System (ADS)

    Snodin, Benedict E. K.; Randisi, Ferdinando; Mosayebi, Majid; Šulc, Petr; Schreck, John S.; Romano, Flavio; Ouldridge, Thomas E.; Tsukanov, Roman; Nir, Eyal; Louis, Ard A.; Doye, Jonathan P. K.

    2015-06-01

    We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na+] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.

  16. Introducing improved structural properties and salt dependence into a coarse-grained model of DNA.

    PubMed

    Snodin, Benedict E K; Randisi, Ferdinando; Mosayebi, Majid; Šulc, Petr; Schreck, John S; Romano, Flavio; Ouldridge, Thomas E; Tsukanov, Roman; Nir, Eyal; Louis, Ard A; Doye, Jonathan P K

    2015-06-21

    We introduce an extended version of oxDNA, a coarse-grained model of deoxyribonucleic acid (DNA) designed to capture the thermodynamic, structural, and mechanical properties of single- and double-stranded DNA. By including explicit major and minor grooves and by slightly modifying the coaxial stacking and backbone-backbone interactions, we improve the ability of the model to treat large (kilobase-pair) structures, such as DNA origami, which are sensitive to these geometric features. Further, we extend the model, which was previously parameterised to just one salt concentration ([Na(+)] = 0.5M), so that it can be used for a range of salt concentrations including those corresponding to physiological conditions. Finally, we use new experimental data to parameterise the oxDNA potential so that consecutive adenine bases stack with a different strength to consecutive thymine bases, a feature which allows a more accurate treatment of systems where the flexibility of single-stranded regions is important. We illustrate the new possibilities opened up by the updated model, oxDNA2, by presenting results from simulations of the structure of large DNA objects and by using the model to investigate some salt-dependent properties of DNA.

  17. Sea salt aerosol from blowing snow on sea ice - modeling vs observation

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Frey, Markus; Norris, Sarah; Brooks, Ian; Anderson, Philip; Jones, Anna; wolff, Eric; Legrand, Michel

    2016-04-01

    Blowing snow over sea ice, through a subsequent sublimation process of salt-containing blown snow particles, has been hypothesized as a significant sea salt aerosol (SSA) source in high latitudes. This mechanism has been strongly supported by a winter cruise in the Weddell Sea (during June-August 2013). The newly collected data, including both physical and chemical components, provide a unique way to test and validate the parameterisation used for describing the SSA production from blowing snow events. With updates to some key parameters such as snow salinity in a global Chemistry-transport model pTOMCAT, simulated SSA concentrations can be well compared with measured SSA data. In this presentation, I will report modeled SSA number density against collected data on board of Polarstern ship during the Weddell Sea cruise, as well as modeled SSA massive concentrations against those measured at both coastal sites such as Alert in the North and Dumont d'Urville (DDU) in the South and central Antarctic sites such as Concordia and Kohnen stations. Model experiments indicated that open ocean-sourced SSA could not explain the observed winter SSA peaks seen in most polar sites, while with sea ice-sourced SSA in the model, the winter peaks can be well improved indicating the importance of sea ice-sourced SSA as a significant contributor to the salts (Na+, Cl-) recorded in the ice core.

  18. Thermo-mechanical modelling of salt caverns due to fluctuating loading conditions.

    NASA Astrophysics Data System (ADS)

    Böttcher, N.

    2015-12-01

    This work summarizes the development and application of a numerical model for the thermo-mechanical behaviour of salt caverns during cyclic gas storage. Artificial salt caverns are used for short term energy storage, such as power-to-gas or compressed air energy storage. Those applications are characterized by highly fluctuating operation pressures due to the unsteady power levels of power plants based on renewable energy. Compression and expansion of the storage gases during loading and unloading stages lead to rapidly changing temperatures in the host rock of the caverns. This affects the material behaviour of the host rock within a zone that extends several meters into the rock mass adjacent to the cavern wall, and induces thermo-mechanical stresses and alters the creep response.The proposed model features the thermodynamic behaviour of the storage medium, conductive heat transport in the host rock, as well as temperature dependent material properties of rock salt using different thermo-viscoplastic material models. The utilized constitutive models are well known and state-of-the-art in various salt mechanics applications. The model has been implemented into the open-source software platform OpenGeoSys. Thermal and mechanical processes are solved using a finite element approach, coupled via a staggered coupling scheme. The simulation results allow the conclusion, that the cavern convergence rate (and thus the efficiency of the cavern) is highly influenced by the loading cycle frequency and the resulting gas temperatures. The model therefore allows to analyse the influence of operation modes on the cavern host rock or on neighbouring facilities.

  19. Investigating the possible effects of salt in the fault zones on rates of seismicity - insights from analogue and numerical modeling

    NASA Astrophysics Data System (ADS)

    Urai, Janos; Kettermann, Michael; Abe, Steffen

    2017-04-01

    The presence of salt in dilatant normal faults may have a strong influence on fault mechanics and related seismicity. However, we lack a detailed understanding of these processes. This study is based on the geological setting of the Groningen area. During tectonic faulting in the Groningen area, rock salt may have flown downwards into dilatant faults, which thus may contain lenses of rock salt at present. Because of its viscous properties, the presence of salt lenses in a fault may introduce a strain-rate dependency to the faulting and affect the distribution of magnitudes of seismic events. We present a "proof of concept" showing that the above processes can be investigated using a combination of analogue and numerical modeling. Full scaling and discussion of the importance of these processes to induced seismicity in Groningen require further, more detailed study. The analogue experiments are based on a simplified stratigraphy of the Groningen area, where it is generally thought that most of the Rotliegend faulting has taken place in the Jurassic, after deposition of the Zechstein. This is interpreted to mean that at the time of faulting the sulphates were brittle anhydrite. If these layers were sufficiently brittle to fault in a dilatant fashion, rock salt could flow downwards into the dilatant fractures. To test this hypothesis, we use sandbox experiments where we combine cohesive powder as analog for brittle anhydrites and carbonates with viscous salt analogs to explore the developing fault geometry and the resulting distribution of salt in the faults. In the numerical models we investigate the stick-slip behavior of fault zones containing ductile material using the Discrete Element Method (DEM). Results show that the DEM approach is in principle suitable for the modeling of the seismicity of faults containing salt: the stick-slip motion of the fault becomes dependent on shear loading rate with a modification of the frequency magnitude distribution of the

  20. Bath Salts

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Bath Salts KidsHealth > For Teens > Bath Salts Print A A ... Someone Quit? Avoiding Bath Salts What Are Bath Salts? The name "bath salts" sounds innocent, but don' ...

  1. Interior structure of Uranus

    SciTech Connect

    Hubbard, W.B.

    1984-10-01

    Key measurements are discussed which are diagnostic of Uranus interior structure and evolutionary history, and reviews their present status. Typical interior models have chondritic cores, but have the bulk of their mass in an envelope consisting of ice component, principally H2O. The total amount of free H2 in the planet cannot exceed approximately 1 to 2 earth masses. Measurements of the gravitational moments of Uranus are beginning to be accurate enough to constrain models, but are limited in utility by uncertainty in the rotation period. Discussed is evidence that the outermost planetary layers have a gravitationally significant quantity of denser material (ice component) in addition to H2 and He. The He/H ratio and the deuterium abundance in the atmosphere may be diagnostic of the planet's previous evolutionary history. It is argued that the planet's interior is likely to now be at a temperature approximately 10(3) deg K. Uranus interior with Neptune's in a number of ways, considering heat flow, degree of internal differentiation, and possible magnetic field.

  2. A New Animal Model to Study Endogenous Cardiotonic Steroids and the Progression of Cardiovascular Events in Salt-Sensitive Hypertension

    PubMed Central

    Estape, Estela S; Torres-Negron, Ivette; Gonzalez, Lorena; Martinez-Maldonado, Manuel

    2015-01-01

    The Dahl salt-sensitive rat is a well-established model to study essential hypertension. We first described a subgroup of these rats based on the unique response pattern in systolic blood pressure during the first weeks of exposure to a high salt diet that included cataract formation. We classified this group as cataract-prone Dahl salt-sensitive rat. We also were able to predict and prevent cataract formation in these rats. Further studies showed an inhibition of lens Na, K-ATPase activity which may be in part responsible for the cataract formation. Other studies in Dahl salt-sensitive rats maintained on a high salt diet have also shown decreased Na, K-ATPase activity in several tissues and increased levels of endogenous circulating Na, K pump inhibitors. For over 20 years, endogenous cardiotonic steroids have been postulated to inhibit Na, K-ATPase in both humans as well as in experimental animal models of hypertension. Recent findings have shown results suggesting that there are several forms of cardiotonic steroids with minor differences in structural functionalities, site of production, and specific pump selectivity. We present original data that supports a role for cardiotonic steroids in disease progression related to increased salt-sensitivity. We found increased levels of free endogenous cardiotonic steroids in those rats that were classified as cataract-prone according to their initial systolic blood pressure response to a high salt intake when compared to non-cataract prone Dahl salt-sensitive rats and their control Dahl salt-resistant rats. The cataract-prone Dahl salt-sensitive rat is an animal model that can help and contribute to open a new door to possibly elucidate the role of endogenous cardiotonic steroids in the pathogenesis and progression of diseases related to salt-sensitive hypertension. PMID:26457335

  3. Modeling of tamped and decoupled explosions in salt (Simulation is easy. Prediction is difficult!)

    SciTech Connect

    Goldstein, P.; Glenn, L.A.

    1993-05-01

    We compare predictions of the strain hardening model of Glenn (1990), with and without damage, to free field and seismic observations of SALMON, STERLING, and 64 kt (tamped) and 8 kt (decoupled) explosions in an Azgir salt dome in the former Soviet Union (FSU). We find good agreement between the model (without damage) and observations of both SALMON and STERLING. In contrast, the average spectral ratio of the tamped to decoupled Azgir explosions is systematically smaller than predicted by the strain hardening model without damage. Much better agreement is obtained when damage is included in the model of the decoupled Azgir explosion.

  4. DFT models of molecular species in carbonate molten salts.

    PubMed

    Carper, W Robert; Wahlbeck, Phillip G; Griffiths, Trevor R

    2012-05-10

    Raman spectra of high temperature carbonate melts are correlated with carbonate species modeled at 923 K using B3LYP/(6-311+G(2d,p)) density functional calculations. Species that are theoretically stable at 923 K include O(2-), O(2)(-), O(2)(2-), CO(3)(2-), C(2)O(6)(2-), CO(4)(-), CO(4)(2-), CO(4)(4-), CO(5)(2-), KCO(4)(-), LiCO(4)(-), KO(2)(-), LiO(2)(-), NaO(2)(-), KO(2), LiO(2), NaO(2), KCO(3)(-), LiCO(3)(-), and NaCO(3)(-). Triangular, linear, and bent forms are theoretically possible for KO(2)(-) and NaO(2)(-). Triangular and linear forms may exist for LiO(2)(-). Linear and triangular versions are theoretically possible for LiO(2)(-) and KO(2). A triangular version of NaO(2) may exist. The correlation between measured and theoretical Raman spectra indicate that monovalent cations are to be included in several of the species that produce Raman spectra.

  5. D Textured Modelling of both Exterior and Interior of Korean Styled Architectures

    NASA Astrophysics Data System (ADS)

    Lee, J.-D.; Bhang, K.-J.; Schuhr, W.

    2017-08-01

    This paper describes 3D modelling procedure of two Korean styled architectures which were performed through a series of processing from data acquired with the terrestrial laser scanner. These two case projects illustate the use of terrestrial laser scanner as a digital documentation tool for management, conservation and restoration of the cultural assets. We showed an approach to automate reconstruction of both the outside and inside models of a building from laser scanning data. Laser scanning technology is much more efficient than existing photogrammetry in measuring shape and constructing spatial database for preservation and restoration of cultural assets as well as for deformation monitoring and safety diagnosis of structures.

  6. Modelling the Interior Structure of Enceladus Based on the 2014's Cassini Gravity Data

    NASA Astrophysics Data System (ADS)

    Taubner, R.-S.; Leitner, J. J.; Firneis, M. G.; Hitzenberger, R.

    2016-06-01

    We present a model for the internal structure of Saturn's moon Enceladus. This model allows us to estimate the physical conditions at the bottom of the satellite's potential subsurface water reservoir and to determine the radial distribution of pressure and gravity. This leads to a better understanding of the physical and chemical conditions at the water/rock boundary. This boundary is the most promising area on icy moons for astrobiological studies as it could serve as a potential habitat for extraterrestrial life similar to terrestrial microbes that inhabit rocky mounds on Earth's sea floors.

  7. Modelling the Interior Structure of Enceladus Based on the 2014's Cassini Gravity Data.

    PubMed

    Taubner, R-S; Leitner, J J; Firneis, M G; Hitzenberger, R

    2016-06-01

    We present a model for the internal structure of Saturn's moon Enceladus. This model allows us to estimate the physical conditions at the bottom of the satellite's potential subsurface water reservoir and to determine the radial distribution of pressure and gravity. This leads to a better understanding of the physical and chemical conditions at the water/rock boundary. This boundary is the most promising area on icy moons for astrobiological studies as it could serve as a potential habitat for extraterrestrial life similar to terrestrial microbes that inhabit rocky mounds on Earth's sea floors.

  8. Analytical and numerical modeling of an axisymmetrical electrostatic transducer with interior geometrical discontinuity.

    PubMed

    Honzík, Petr; Podkovskiy, Alexey; Durand, Stéphane; Joly, Nicolas; Bruneau, Michel

    2013-11-01

    The main purpose of the paper is to contribute at presenting an analytical and a numerical modeling which would be relevant for interpreting the couplings between a circular membrane, a peripheral cavity having the same external radius as the membrane, and a thin air gap (with a geometrical discontinuity between them), and then to characterize small scale electrostatic receivers and to propose procedures that could be suitable for fitting adjustable parameters to achieve optimal behavior in terms of sensitivity and bandwidth expected. Therefore, comparison between these theoretical methods and characterization of several shapes is dealt with, which show that the models would be appropriate to address the design of such transducers.

  9. Interior design for passive solar homes

    NASA Astrophysics Data System (ADS)

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building from incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitably of various interior elements.

  10. Interior design for passive solar homes

    SciTech Connect

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems has brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building form incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitability of various interior elements.

  11. Modeling soil thermal and carbon dynamics of a fire chronosequence in interior Alaska

    Treesearch

    Q. Zhuang; A. D. McGuire; K. P. O' Neill; J. W. Harden; V. E. Romanovsky; J. Yarie

    2003-01-01

    In this study, the dynamics of soil thermal, hydrologic, and ecosystem processes were coupled to project how the carbon budgets of boreal forests will respond to changes in atmospheric CO2, climate, and fire disturbance. The ability of the model to simulate gross primary production and ecosystem respiration was verified for a mature black spruce...

  12. Development of field-based models of suitable thermal regimes for interior Columbia Basin salmonids

    Treesearch

    Jason B. Dunham; Bruce Rieman; Gwynne Chandler

    2001-01-01

    This report describes results of research sponsored through an interagency agreement between the U.S. Forest Service Rocky Mountain Research Station and U.S. Environmental Protection Agency (Interagency Agreement #00-IA-11222014-521). The primary objectives of this research included 1) develop models relating occurrence of two threatened inland salmonid fishes to...

  13. 3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

    NASA Astrophysics Data System (ADS)

    Hong, Ik-Seon; Yi, Yu; Yu, Jaehyung; Haruyama, Junichi

    2015-06-01

    When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP) competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

  14. Assessing the wildlife habitat value of New England salt marshes: I. Model and application.

    PubMed

    McKinney, Richard A; Charpentier, Michael A; Wigand, Cathleen

    2009-07-01

    We developed an assessment model to quantify the wildlife habitat value of New England salt marshes based on marsh characteristics and the presence of habitat types that influence habitat use by terrestrial wildlife. Applying the model to 12 salt marshes located in Narragansett Bay, RI resulted in assessment scores that ranged over a factor of 1.5 from lowest to highest. Pre-classifying the results based on marsh size and morphology helped to compare assessment scores between marshes, and demonstrated that even the lower ranking marshes had substantial habitat value. Stepwise multiple regression analysis of assessment scores and model components demonstrated that salt marsh morphology, the degree of anthropogenic modification, and salt marsh vegetative heterogeneity were significant variables and accounted for 91.3% of the variability in component scores. Our results suggest that targeting these components for restoration may lead to improved assessment scores for our study marshes. We also examined the use of lower resolution remote sensing data in the assessment in order to minimize the time and effort required to complete the model. Scores obtained using smaller-scale, lower resolution data were significantly lower than those obtained using larger-scale, higher resolution data (df = 11; t = 2.2; p < 0.001). The difference was significantly positively correlated with the portion of the assessment score that could be attributed to trees, pools, and pannes and marsh size (r (2) =0.50, F = 4.6, p = 0.04), and could indicate a bias against smaller, more heterogeneous marshes. We conclude that potential differences need to be weighed against the time benefit of using this type of data, bearing in mind the marsh size and the goals of the assessment. Overall, our assessment can provide information to aid in prioritizing marshes for protection and restoration, identify marshes that may harbor significant biodiversity, or help monitor changes in habitat value over time.

  15. Modeling the surface and interior structure of comet nuclei using a multidisciplinary approach

    NASA Technical Reports Server (NTRS)

    Odell, C. R.; Dakoulas, Panos C.; Pharr, George M.

    1991-01-01

    The goal was to investigate the structural properties of the surface of comet nucleus and how the surface should change with time under effect of solar radiation. The basic model that was adopted was that the nucleus is an aggregate of frosty particles loosely bound together, so that it is essentially a soil. The nucleus must mostly be composed of dust particles. The observed mass ratios of dust to gas in the coma is never much greater than unity, but this ratio is probably a much lower limit than that of the nucleus because it is vastly easier to remove the gaseous component by sublimation than by carrying off the dust. Therefore the described models assumed that the particles in the soil were frost covered grains of submicron basic size, closely resembling the interstellar grains. The surface properties of such a nucleus under the effects of heating and cooling as the nucleus approaches and recedes from the Sun generally characterized.

  16. Infrared near-Earth-object survey modeling for observatories interior to the Earth's orbit

    NASA Astrophysics Data System (ADS)

    Buie, M.

    2014-07-01

    The search for and dynamical characterization of the near-Earth population of objects (NEOs) has been a busy topic for surveys for many years. Most of the work thus far has been from ground-based optical surveys such as the Catalina Sky Survey and LINEAR. These surveys have essentially reached a complete inventory of objects down to 1 km diameter and have shown that the known objects do not pose any significant impact threat. Smaller objects are correspondingly smaller threats but there are more of them and fewer of them have so far been discovered. The next generation of surveys is looking to extend their reach down to much smaller sizes. From an impact risk perspective, those objects as small as 30--40 m are still of interest (similar in size to the Tunguska bolide). Smaller objects than this are largely of interest from a space resource or in-situ analysis efforts. A recent mission concept promoted by the B612 Foundation and Ball Aerospace calls for an infrared survey telescope in a Venus-like orbit, known as the Sentinel Mission. This wide-field facility has been designed to complete the inventory down to a 140 m diameter while also providing substantial constraints on the NEO population down to a Tunguska-sized object. I have been working to develop a suite of tools to provide survey modeling for this class of survey telescope. The purpose of the tool is to uncover hidden complexities that govern mission design and operation while also working to quantitatively understand the orbit quality provided on its catalog of objects without additional followup assets. The baseline mission design calls for a 6.5 year survey lifetime. This survey model is a statistically based tool for establishing completeness as a function of object size and survey duration. Effects modeled include the ability to adjust the field-of-regard (includes all pointing restrictions), field-of-view, focal plane array fill factor, and the observatory orbit. Consequences tracked include time

  17. Models of the thermal effects of melt migration at continental interiors, with applications to the Colorado Plateau

    NASA Astrophysics Data System (ADS)

    Johnson, A.; Roy, M.

    2016-12-01

    The relative plate motion of continental regions with respect to underlying asthenosphere produces shear forces which change the physical characteristics of the lithospheric plate. Dynamic pressure gradients created by relative motion between variable thickness lithosphere and the mantle beneath determine the path with which melt migrates by percolative flow towards the surface. This melt migration introduces a warming effect which weakens the lithospheric structure, especially in areas where melt is focused. The temperature profile of the lithosphere is modified by melt migration which leads to further changes in the shape and structure of the lithosphere through deformation and weakening. We build upon previous models in which a solid matrix with constant porosity and permeability with pore space filled with low-viscosity melt comprises a two-phase medium. We focus on deformation in regions with thicker than average lithosphere, where a protruding ``keel'' interacts with the underlying asthenosphere. In this model, advective heat transport in porous flow is introduced in the limit that inter-phase heat transfer dominates over the intra-phase thermal conduction of both solid and melt. The heat transfer coefficient for inter-phase heat exchange, dependent on the pore distribution and grain geometry, parameterizes the model. Our model quantatively assesses the spatially variable thermal weakening and its effect on melt transport. By understanding the way in which melt transport produces the surface spatial and temporal distribution of magmatic activity, continental interior regions with a variable thickness lithosphere, such as the colorado plateau, can be better understood.

  18. Long term cavity closure in salt using a Carreau viscosity model.

    NASA Astrophysics Data System (ADS)

    Cornet, Jan; Dabrowski, Marcin; Schmid, Daniel

    2017-04-01

    The problem of a pressurized hole in an infinite homogenous body is one of the most classical problems in geoscience. The solution is well-known when the rheology is linear but becomes much more complicated when applied to formations such as salt that can behave nonlinearly. Defining a constitutive law for the steady state deformation of salt is already a challenge and we rely on two deformation mechanisms - dislocation creep and pressure solution - to do that. More precisely, we use a Carreau model for viscosity to take into account in a single and smooth manner a linear and a nonlinear process. We use this rheology to revisit the classical two-dimensional problem of a pressurized cylindrical hole in an infinite and homogeneous body under general far field loads. We are interested in characterizing the maximum closure velocity at the rim. We provide analytical solutions for pressure and far field pure shear loads and we give a proxy for the general case based on the two end members. Using this general approach, we show that adding pressure solution to the constitutive law is especially important when studying long term hole closure under low pressure loads or when the grain size is in the order of 0.1 mm. Only considering dislocation creep can lead to underestimating the closure velocity by several orders of magnitude. Adding far field shear stress also dramatically enhances hole closure. The stress situation in salt bodies is often considered as isotropic but some shear exists at the interface between moving salt bodies and cap rock so pressurized holes in these regions experience increased closure. The analytical approach adopted in this study enables us to better understand the influence of all the input parameters on hole closure in salt.

  19. Salt effects on functional traits in model and in economically important Lotus species.

    PubMed

    Uchiya, P; Escaray, F J; Bilenca, D; Pieckenstain, F; Ruiz, O A; Menéndez, A B

    2016-07-01

    A common stress on plants is NaCl-derived soil salinity. Genus Lotus comprises model and economically important species, which have been studied regarding physiological responses to salinity. Leaf area ratio (LAR), root length ratio (RLR) and their components, specific leaf area (SLA) and leaf mass fraction (LMF) and specific root length (SRL) and root mass fraction (RMF) might be affected by high soil salinity. We characterised L. tenuis, L. corniculatus, L. filicaulis, L. creticus, L. burtii and L. japonicus grown under different salt concentrations (0, 50, 100 and 150 mm NaCl) on the basis of SLA, LMF, SRL and RMF using PCA. We also assessed effects of different salt concentrations on LAR and RLR in each species, and explored whether changes in these traits provide fitness benefit. Salinity (150 mm NaCl) increased LAR in L. burtii and L. corniculatus, but not in the remaining species. The highest salt concentration caused a decrease of RLR in L. japonicus Gifu, but not in the remaining species. Changes in LAR and RLR would not be adaptive, according to adaptiveness analysis, with the exception of SLA changes in L. corniculatus. PCA revealed that under favourable conditions plants optimise surfaces for light and nutrient acquisition (SLA and SRL), whereas at higher salt concentrations they favour carbon allocation to leaves and roots (LMF and RMF) in detriment to their surfaces. PCA also showed that L. creticus subjected to saline treatment was distinguished from the remaining Lotus species. We suggest that augmented carbon partitioning to leaves and roots could constitute a salt-alleviating mechanism through toxic ion dilution.

  20. Intravital Imaging of the Kidney in a Rat Model of Salt-Sensitive Hypertension.

    PubMed

    Endres, Bradley T; Sandoval, Ruben M; Rhodes, George J; Campos-Bilderback, Silvia B; Kamocka, Malgorzata M; McDermott-Roe, Christopher; Staruschenko, Alexander; Molitoris, Bruce A; Geurts, Aron M; Palygin, Oleg

    2017-04-12

    Hypertension is one of the most prevalent diseases worldwide, and a major risk factor for renal failure and cardiovascular disease. The role of albuminuria, a common feature of hypertension and robust predictor of cardiorenal disorders, remains incompletely understood. The goal of this study was to investigate the mechanisms leading to albuminuria in the kidney of a rat model of hypertension, the Dahl salt-sensitive (SS) rat. To determine the relative contributions of the glomerulus and proximal tubule (PT) to albuminuria, we applied intravital two-photon-based imaging to investigate the complex renal physiological changes that occur during salt-induced hypertension. Following a high salt diet, SS rats exhibited elevated blood pressure, increased glomerular sieving of albumin (GSCalb=0.0686), relative permeability to albumin (+∆16%) and impaired volume hemodynamics (-∆14%). Serum albumin, but not serum globulins or creatinine, concentration was decreased (-0.54g/dL), which was concomitant with increased filtration of albumin (3.7 vs 0.8 g per day normal diet). Pathologically, hypertensive animals had significant tubular damage as indicated by increased prevalence of granular casts, expansion and necrosis of PT epithelial cells (+∆2.20score/image), progressive augmentation of red blood cell velocity (+∆269µm/s) and micro vessel diameter (+∆4.3µm), and increased vascular injury (+∆0.61leakage/image). Therefore, development of salt-induced hypertension can be triggered by fast and progressive pathogenic remodeling of PT epithelia, which can be associated with changes in albumin handling. Collectively, these results indicate that both the glomerulus and the PT contribute to albuminuria and dual treatment of glomerular filtration and albumin reabsorption may represent an effective treatment of salt-sensitive hypertension.

  1. High-fidelity gravity modeling applied to spacecraft trajectories and lunar interior analysis

    NASA Astrophysics Data System (ADS)

    Chappaz, Loic P. R.

    As the complexity and boldness of emerging mission proposals increase, and with the rapid evolution of the available computational capabilities, high-accuracy and high-resolution gravity models and the tools to exploit such models are increasingly attractive within the context of spaceflight mechanics, mission design and analysis, and planetary science in general. First, in trajectory design applications, a gravity representation for the bodies of interest is, in general, assumed and exploited to determine the motion of a spacecraft in any given system. The focus is the exploration of trajectories in the vicinity of a system comprised of two small irregular bodies. Within this context, the primary bodies are initially modeled as massive ellipsoids and tools to construct third-body trajectories are developed. However, these dynamical models are idealized representations of the actual dynamical regime and do not account for any perturbing effects. Thus, a robust strategy to maintain a spacecraft near reference third-body trajectories is constructed. Further, it is important to assess the perturbing effect that dominates the dynamics of the spacecraft in such a region as a function of the baseline orbit. Alternatively, the motion of the spacecraft around a given body may be known to extreme precision enabling the derivation of a very high-accuracy gravity field for that body. Such knowledge can subsequently be exploited to gain insight into specific properties of the body. The success of the NASA's GRAIL mission ensures that the highest resolution and most accurate gravity data for the Moon is now available. In the GRAIL investigation, the focus is on the specific task of detecting the presence and extent of subsurface features, such as empty lava tubes beneath the mare surface. In addition to their importance for understanding the emplacement of the mare flood basalts, open lava tubes are of interest as possible habitation sites safe from cosmic radiation and

  2. Constraints on the Moment of Inertia of Jupiter via Interior Models

    NASA Astrophysics Data System (ADS)

    Cody, Ann Marie; Stevenson, D. J.

    2006-09-01

    It has long been known that there is no one-to-one correspondence between the measured J2/q (gravitational response to a prescribed uniform rotation) and C/MR2 (non-dimensionalized moment of inertia) of a planet, despite the Radau-Darwin formula. Here, q is the ratio of centrifugal acceleration to direct gravity at the equator and other symbols have their usual meanings. J2/q is quite precisely known for Jupiter but C/MR2 has not been measured. Standard Jupiter models typically give a moment of inertia factor C/MR2 0.25 or more, suggesting little or no core, but a recently proposed value (Ward & Canup 2006), based on dynamical considerations, is 5 to 10% smaller. Is it possible to reconcile the claimed value of C with the observed value of J2? This is difficult to assess through the traditional computationally intensive approaches. In order to evaluate a very large number of possible models, we make use of the well known analytical solutions for the n=1 polytrope (with and without a simple modification to include a zero pressure density) to construct piecewise continuous models of density containing multiple adjustable parameters that can mimic more realistic equations of state. Our results at constant J2 indicate that the C/MR2 may vary up to as much as 13% less than the value typically predicted for Jupiter from the Radau-Darwin formula. Nevertheless, we show that incorporating the criteria of Jupiter's observed J4 value along with a set of physical constraints (density and compressibility of possible materials) further restricts the allowed range of C/MR2. Many and perhaps all of the most extreme models can be eliminated, suggesting a difficulty in fitting the value suggested by Ward & Canup (2006) and supporting the usual inferences about Jupiter's putative core. This approach can also be used for the other giant planets.

  3. Ranking contributing areas of salt and selenium in the Lower Gunnison River Basin, Colorado, using multiple linear regression models

    USGS Publications Warehouse

    Linard, Joshua I.

    2013-01-01

    Mitigating the effects of salt and selenium on water quality in the Grand Valley and lower Gunnison River Basin in western Colorado is a major concern for land managers. Previous modeling indicated means to improve the models by including more detailed geospatial data and a more rigorous method for developing the models. After evaluating all possible combinations of geospatial variables, four multiple linear regression models resulted that could estimate irrigation-season salt yield, nonirrigation-season salt yield, irrigation-season selenium yield, and nonirrigation-season selenium yield. The adjusted r-squared and the residual standard error (in units of log-transformed yield) of the models were, respectively, 0.87 and 2.03 for the irrigation-season salt model, 0.90 and 1.25 for the nonirrigation-season salt model, 0.85 and 2.94 for the irrigation-season selenium model, and 0.93 and 1.75 for the nonirrigation-season selenium model. The four models were used to estimate yields and loads from contributing areas corresponding to 12-digit hydrologic unit codes in the lower Gunnison River Basin study area. Each of the 175 contributing areas was ranked according to its estimated mean seasonal yield of salt and selenium.

  4. Groundwater Flow and Salt Transport at a Sand Tailings Dam: Field Observations and Modelling Results.

    NASA Astrophysics Data System (ADS)

    Price, A. C.; Mendoza, C. A.

    2004-05-01

    Large volumes of sand tailings are produced during the extraction of bitumen from the oil sands of Northeastern Alberta. The long-term groundwater response and subsequent movement of water and solutes within the large permeable sand tailings storage areas is uncertain. At the Southwest Sand Storage (SWSS) Facility, located at Syncrude's Mildred Lake operations near Ft. McMurray, there is concern that salts from the tailings water may discharge to newly placed reclamation material that covers the sand tailings. This saline discharge water could destroy the reclamation soil structure and negatively impact vegetation. The steady-state groundwater flow and transient movement of salts at the local (bench and slope) and intermediate (pile) scales in the SWSS are investigated. Water levels, seepage and groundwater quality (including TDS) have been measured for over a year along two transects of piezometers installed in the SWSS. The field data have been used to complete traditional hydrogeological interpretations of the site, and to develop a conceptual model of flow and transport. The local and intermediate flow systems and salt transport in the dam are being evaluated with numerical models. The models will allow possible future hydrogeological behaviour of the structure to be tested. Preliminary results show differences in flow systems and salinity distribution that depend on the deposition of the SWSS. This research will facilitate better long-term environmental management of this and similar sites.

  5. Buchdahl-Vaidya-Tikekar model for stellar interior in pure Lovelock gravity

    NASA Astrophysics Data System (ADS)

    Molina, Alfred; Dadhich, Naresh; Khugaev, Avas

    2017-07-01

    In the paper (Khugaev et al. in Phys Rev D94:064065. arXiv: 1603.07118, 2016), we have shown that for perfect fluid spheres the pressure isotropy equation for Buchdahl-Vaidya-Tikekar metric ansatz continues to have the same Gauss form in higher dimensions, and hence higher dimensional solutions could be obtained by redefining the space geometry characterizing Vaidya-Tikekar parameter K. In this paper we extend this analysis to pure Lovelock gravity; i.e. a (2N+2)-dimensional solution with a given K_{2N+2} can be taken over to higher n-dimensional pure Lovelock solution with K_n=(K_{2N+2}-n+2N+2)/(n-2N-1) where N is degree of Lovelock action. This ansatz includes the uniform density Schwarzshild and the Finch-Skea models, and it is interesting that the two define the two ends of compactness, the former being the densest and while the latter rarest. All other models with this ansatz lie in between these two limiting distributions.

  6. [Effect of cold preservation and reperfusion injury on early-stage bile salt secretion after liver transplantation in rat model].

    PubMed

    Chen, Geng; Ding, Min; Wang, Meng; Zhang, Yu-Jun; Li, Xiao-Wu; Wang, Shu-Guang; Dong, Jia-Hong

    2007-08-01

    To explore the effect of cold preservation and reperfusion injury (CPRI) on the bile salt spectrum in rat orthotopic liver transplantation (OLT) model. A special analysis method was established to investigate the bile salts in rat by reverse phase high performance liquid chromatography (RP-HPLC). Rats were randomly divided into 3 groups: group A (control group, n = 6), group B (group with 1 h graft preservation pre-OLT, n = 6) and group C (group with 12 h graft preservation pre-OLT, n = 6). The bile samples of 0 - 14 post-transplantation days were analyzed by RP-HPLC. Eleven kinds of bile salts were detected in rat bile. It showed that CPRI could influence the concentration of bile salts significantly in rat model after OLT, the concentration of hydrophobic bile salts (TCA and TCDCA) increased significantly in group B and C. However, the concentration of hydrophilic bile salts (TUDCA and THDCA) just increased in a short-time. The hydrophobicity index (HI) wasn't significantly changed during the first 4 post-transplant days. Thus the HI of bile salts elevated gradually from the 5th day and reached the peak at the 10th day after OLT. The increase of the proportion of hydrophobic bile salts may be one of the major factors leading to the increase of bile toxicity after OLT.

  7. Complete Budding and Asymmetric Division of Primitive Model Cells To Produce Daughter Vesicles with Different Interior and Membrane Compositions

    PubMed Central

    2011-01-01

    Asymmetric cell division is common in biology and plays critical roles in differentiation and development. Unicellular organisms are often used as model systems for understanding the origins and consequences of asymmetry during cell division. Although basic as compared to mammalian cells, these are already quite complex. We report complete budding and asymmetric fission of very simple nonliving model cells to produce daughter vesicles that are chemically distinct in both interior and membrane compositions. Our model cells are based on giant lipid vesicles (GVs, 10–30 μm) encapsulating a polyethylene glycol (PEG)/dextran aqueous two-phase system (ATPS) as a crowded and compartmentalized cytoplasm mimic. Ternary lipid compositions were used to provide coexisting micrometer-scale liquid disordered (Ld) and liquid ordered (Lo) domains in the membranes. ATPS-containing vesicles formed buds when sucrose was added externally to provide increased osmotic pressure, such that they became not only morphologically asymmetric but also asymmetric in both their interior and their membrane compositions. Further increases in osmolality drove formation of two chemically distinct daughter vesicles, which were in some cases connected by a lipid nanotube (complete budding), and in others were not (fission). In all cases, separation occurred at the aqueous–aqueous phase boundary, such that one daughter vesicle contained the PEG-rich aqueous phase and the other contained the dextran-rich aqueous phase. PEGylated lipids localized in the Lo domain resulted in this membrane domain preferentially coating the PEG-rich bud prior to division, and subsequently the PEG-rich daughter vesicle. Varying the mole ratio of lipids resulted in excess surface area of Lo or Ld membrane domains such that, upon division, this excess portion was inherited by one of the daughter vesicles. In some cases, a second “generation” of aqueous phase separation and budding could be induced in these daughter

  8. Experimental study of planetary gases with applications to planetary interior models

    NASA Technical Reports Server (NTRS)

    Bell, Peter M.; Mao, Ho-Kwang

    1988-01-01

    High-pressure experimental data on planetary materials are critical in developing planetary models and in addressing otherwise insoluble problems of the internal structure of the major planets. Progress in the last five years has been particularly marked. Maximum static pressure of 550 GPa was achieved. For the first time, X-ray diffraction of solidified gases (Ne, Xe) and ices (H2O) were obtained at pressures above one megabar, single-crystal diffraction of ultralight elements (H2, He) were detected up to 25 GPa, pressures over 200 GPa at 77 K were reached in solid hydrogen, including the discovery of a phase transformation in the molecular solid. Advances in instrumentation and new measurements performed during 1983 to 1988 are summarized.

  9. Modelling the thermo-chemical evolution of the interiors of Venus, Mars and Mercury

    NASA Astrophysics Data System (ADS)

    Tackley, P. J.; Keller, T.; Armann, M.; Aurnou, J. M.

    2009-04-01

    The latest generation of the global 3-D spherical convection model StagYY [Tackley, PEPI 2008] allows the direct computation of a planet's thermo-chemical evolution, including self-consistent lithospheric behavior (e.g., rigid lid, plate tectonics, or episodic plate tectonics [van Heck and Tackley, GRL 2008]), chemical differentiation induced by melting, large viscosity variations, a parameterized core heat balance, and a realistic treatment of phase diagrams and material properties. The latter has recently been added using free energy minimization to compute stable phases as a function of temperature, pressure, and composition as expressed by ratios of the five main oxides, and thus avoids the need for increasingly complicated and ad hoc parameterizations of phase transitions. Global models allow the computation of planetary secular cooling including prediction of how the core heat flux varies with time hence the evolution of the geodynamo, and possible transitions in plate tectonic mode. Modern supercomputers and clusters allow increasingly higher resolution, with up to 1.2 billion unknowns possible on only 32 dual-processor nodes of an opteron cluster. In ongoing research, this tool is being applied to understand the evolution of Earth, Mars, Venus, and Mercury. Our Mars models [T. Keller and P.J. Tackley, submitted] show that with an appropriate viscosity profile, convection rapidly develops a 'one ridge' planform consisting of a single ridge-like upwelling and small-scale downwellings below a stagnant lid, and that this produces a dichotomous crustal distribution that bears a striking first-order resemblance to the crustal distribution on Mars. The actual boundary of the crustal dichotomy on Mars is not hemispherical but rather like the seam on a tennis ball, and this is reproduced by our models, with the highland region being located above the upwelling. Furthermore, the elevation difference between the highland and lowland regions is very similar to that on

  10. Interannual to decadal climate variability of sea salt aerosols in the coupled climate model CESM1.0: Climate variability of sea salt aerosols

    SciTech Connect

    Xu, Li; Pierce, David W.; Russell, Lynn M.; Miller, Arthur J.; Somerville, Richard C. J.; Twohy, Cynthia H.; Ghan, Steven J.; Singh, Balwinder; Yoon, Jin-Ho; Rasch, Philip J.

    2015-02-21

    This study examines multi-year climate variability associated with sea salt aerosols and their contribution to the variability of shortwave cloud forcing (SWCF) using a 150-year simulation for pre-industrial conditions of the Community Earth System Model version 1.0 (CESM1). The results suggest that changes in sea salt and related cloud and radiative properties on interannual timescales are dominated by the ENSO cycle. Sea salt variability on longer (interdecadal) timescales is associated with low-frequency Pacific ocean variability similar to the interdecadal Pacific Oscillation (IPO), but does not show a statistically significant spectral peak. A multivariate regression suggests that sea salt aerosol variability may contribute to SWCF variability in the tropical Pacific, explaining up to 25-35% of the variance in that region. Elsewhere, there is only a small aerosol influence on SWCF through modifying cloud droplet number and liquid water path that contributes to the change of cloud effective radius and cloud optical depth (and hence cloud albedo), producing a multi-year aerosol-cloud-wind interaction.

  11. Sea ice as a source of sea salt aerosol to Greenland ice cores: a model-based study

    NASA Astrophysics Data System (ADS)

    Rhodes, Rachael H.; Yang, Xin; Wolff, Eric W.; McConnell, Joseph R.; Frey, Markus M.

    2017-08-01

    Growing evidence suggests that the sea ice surface is an important source of sea salt aerosol and this has significant implications for polar climate and atmospheric chemistry. It also suggests the potential to use ice core sea salt records as proxies for past sea ice extent. To explore this possibility in the Arctic region, we use a chemical transport model to track the emission, transport, and deposition of sea salt from both the open ocean and the sea ice, allowing us to assess the relative importance of each. Our results confirm the importance of sea ice sea salt (SISS) to the winter Arctic aerosol burden. For the first time, we explicitly simulate the sea salt concentrations of Greenland snow, achieving values within a factor of two of Greenland ice core records. Our simulations suggest that SISS contributes to the winter maxima in sea salt characteristic of ice cores across Greenland. However, a north-south gradient in the contribution of SISS relative to open-ocean sea salt (OOSS) exists across Greenland, with 50 % of winter sea salt being SISS at northern sites such as NEEM (77° N), while only 10 % of winter sea salt is SISS at southern locations such as ACT10C (66° N). Our model shows some skill at reproducing the inter-annual variability in sea salt concentrations for 1991-1999, particularly at Summit where up to 62 % of the variability is explained. Future work will involve constraining what is driving this inter-annual variability and operating the model under different palaeoclimatic conditions.

  12. Modeling the structure of magnetic fields in Neutron Stars: from the interior to the magnetosphere

    NASA Astrophysics Data System (ADS)

    Bucciantini, Niccolò; Pili, Antonio G.; Del Zanna, Luca

    2016-05-01

    The phenomenology of the emission of pulsars and magnetars depends dramatically on the structure and properties of their magnetic field. In particular it is believed that the outbursting and flaring activity observed in AXPs and SRGs is strongly related to their internal magnetic field. Recent observations have moreover shown that charges are present in their magnetospheres supporting the idea that their magnetic field is tightly twisted in the vicinity of the star. In principle these objects offer a unique opportunity to investigate physics in a regime beyond what can be obtained in the laboratory. We will discuss the properties of equilibrium models of magnetized neutron stars, and we will show how internal and external currents can be related. These magnetic field configurations will be discussed considering also their stability, relevant for their origin and possibly connected to events like SNe and GRBs. We will also show what kind of deformations they induce in the star, that could lead to emission of gravitational waves. In the case of a twisted magnetosphere we will show how the amount of twist regulates their general topology. A general formalism based on the simultaneous numerical solution of the general relativistic Grad-Shafranov equation and Einstein equations will be presented.

  13. Integrative functional genomics of salt acclimatization in the model legume Lotus japonicus.

    PubMed

    Sanchez, Diego H; Lippold, Felix; Redestig, Henning; Hannah, Matthew A; Erban, Alexander; Krämer, Ute; Kopka, Joachim; Udvardi, Michael K

    2008-03-01

    The model legume Lotus japonicus was subjected to non-lethal long-term salinity and profiled at the ionomic, transcriptomic and metabolomic levels. Two experimental designs with various stress doses were tested: a gradual step acclimatization and an initial acclimatization approach. Ionomic profiling by inductively coupled plasma/atomic emission spectrometry (ICP-AES) revealed salt stress-induced reductions in potassium, phosphorus, sulphur, zinc and molybdenum. Microarray profiling using the Lotus Genechip allowed the identification of 912 probesets that were differentially expressed under the acclimatization regimes. Gas chromatography/mass spectrometry-based metabolite profiling identified 147 differentially accumulated soluble metabolites, indicating a change in metabolic phenotype upon salt acclimatization. Metabolic changes were characterized by a general increase in the steady-state levels of many amino acids, sugars and polyols, with a concurrent decrease in most organic acids. Transcript and metabolite changes exhibited a stress dose-dependent response within the range of NaCl concentrations used, although threshold and plateau behaviours were also observed. The combined observations suggest a successive and increasingly global requirement for the reprogramming of gene expression and metabolic pathways to maintain ionic and osmotic homeostasis. A simple qualitative model is proposed to explain the systems behaviour of plants during salt acclimatization.

  14. Magnesium degradation influenced by buffering salts in concentrations typical of in vitro and in vivo models.

    PubMed

    Agha, Nezha Ahmad; Feyerabend, Frank; Mihailova, Boriana; Heidrich, Stefanie; Bismayer, Ulrich; Willumeit-Römer, Regine

    2016-01-01

    Magnesium and its alloys have considerable potential for orthopedic applications. During the degradation process the interface between material and tissue is continuously changing. Moreover, too fast or uncontrolled degradation is detrimental for the outcome in vivo. Therefore in vitro setups utilizing physiological conditions are promising for the material/degradation analysis prior to animal experiments. The aim of this study is to elucidate the influence of inorganic salts contributing to the blood buffering capacity on degradation. Extruded pure magnesium samples were immersed under cell culture conditions for 3 and 10 days. Hank's balanced salt solution without calcium and magnesium (HBSS) plus 10% of fetal bovine serum (FBS) was used as the basic immersion medium. Additionally, different inorganic salts were added with respect to concentration in Dulbecco's modified Eagle's medium (DMEM, in vitro model) and human plasma (in vivo model) to form 12 different immersion media. Influences on the surrounding environment were observed by measuring pH and osmolality. The degradation interface was analyzed by electron-induced X-ray emission (EIXE) spectroscopy, including chemical-element mappings and electron microprobe analysis, as well as Fourier transform infrared reflection micro-spectroscopy (FTIR).

  15. Modeling soluble salt assemblages on Mars: past aqueous history and present-day habitability

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Catling, D. C.; Light, B.

    2014-12-01

    Soluble salt assemblages formed through aqueous processes are widespread on Mars. These minerals are important for understanding the past aqueous history of Mars and indicate critical habitability parameters such as pH, temperature, water activity, and salinity. Equilibrium models have been used to determine solution chemistry and salt precipitation sequences from aqueous chemical data; however, current models are limited by a lack of experimental data for low-temperature perchlorates, and some model predictions are clearly anomalous. To address the need for accurate equilibrium models, we have developed a comprehensive model for low-temperature perchlorate-rich brines using (1) previously neglected literature data, (2) experimental solubilities determined in low-temperature perchlorate solutions, and (3) solubility and heat capacity results determined using Differential Scanning Calorimetry (DSC). Our resulting model is a significant improvement over existing models, such as FREZCHEM, particularly for perchlorate mixtures. We have applied our model to evaporation and freezing of a nominal Wet Chemistry Laboratory (WCL) solution measured at the Phoenix site. For a freezing WCL solution, our model indicates that ice, KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), calcite (CaCO3), meridianiite (MgSO4·11H2O), MgCl2·12H2O, NaClO4·2H2O, and Mg(ClO4)2·6H2O form at the eutectic (209 K); whereas, KClO4, hydromagnesite, kieserite (MgSO4·H2O), anhydrite (CaSO4), halite (NaCl), NaClO4·H2O, and Mg(ClO4)2·6H2O form upon complete evaporation at 298 K. In general, evaporation yields more dehydrated mineral assemblages than salts produced by freezing. Hydrated phases that form during evaporation contain 0.3 wt. % water, which compares with 1.2 wt. % during freezing. Given independent evidence for the presence of calcite and minimum water contents in Martian soils of ~1.5 wt. %, salts at the Phoenix site, and possibly elsewhere, appear more likely to have formed during

  16. Effect of excess dietary salt on calcium metabolism and bone mineral in a spaceflight rat model

    NASA Technical Reports Server (NTRS)

    Navidi, Meena; Wolinsky, Ira; Fung, Paul; Arnaud, Sara B.

    1995-01-01

    High levels of salt promote urinary calcium (UCa) loss and have the potential to cause bone mineral deficits if intestinal Ca absorption does not compensate for these losses. To determine the effect of excess dietary salt on the osteopenia that follows skeletal unloading, we used a spaceflight model that unloads the hindlimbs of 200-g rats by tail suspension (S). Rats were studied for 2 wk on diets containing high salt (4 and 8%) and normal calcium (0.45%) and for 4 wk on diets containing 8% salt (HiNa) and 0.2% Ca (LoCa). Final body weights were 9-11% lower in S than in control rats (C) in both experiments, reflecting lower growth rates in S than in C during pair feeding. UCa represented 12% of dietary Ca on HiNA diets and was twofold higher in S than in C transiently during unloading. Net intestinal Ca absorption was consistently 11-18% lower in S than in C. Serum 1,25-dihydroxyvitamin D was unaffected by either LoCa or HiNa diets in S but was increased by LoCa and HiNa diets in C. Despite depressed intestinal Ca absoption in S and a sluggish response of the Ca endocrine system to HiNa diets, UCa loss did not appear to affect the osteopenia induced by unloading. Although any deficit in bone mineral content from HiNa diets may have been too small to detect or the duration of the study too short to manifest, there were clear differences in Ca metabolism from control levels in the response of the spaceflight model to HiNa diets, indicated by depression of intestinal Ca absorption and its regulatory hormone.

  17. Effect of excess dietary salt on calcium metabolism and bone mineral in a spaceflight rat model

    NASA Technical Reports Server (NTRS)

    Navidi, Meena; Wolinsky, Ira; Fung, Paul; Arnaud, Sara B.

    1995-01-01

    High levels of salt promote urinary calcium (UCa) loss and have the potential to cause bone mineral deficits if intestinal Ca absorption does not compensate for these losses. To determine the effect of excess dietary salt on the osteopenia that follows skeletal unloading, we used a spaceflight model that unloads the hindlimbs of 200-g rats by tail suspension (S). Rats were studied for 2 wk on diets containing high salt (4 and 8%) and normal calcium (0.45%) and for 4 wk on diets containing 8% salt (HiNa) and 0.2% Ca (LoCa). Final body weights were 9-11% lower in S than in control rats (C) in both experiments, reflecting lower growth rates in S than in C during pair feeding. UCa represented 12% of dietary Ca on HiNA diets and was twofold higher in S than in C transiently during unloading. Net intestinal Ca absorption was consistently 11-18% lower in S than in C. Serum 1,25-dihydroxyvitamin D was unaffected by either LoCa or HiNa diets in S but was increased by LoCa and HiNa diets in C. Despite depressed intestinal Ca absoption in S and a sluggish response of the Ca endocrine system to HiNa diets, UCa loss did not appear to affect the osteopenia induced by unloading. Although any deficit in bone mineral content from HiNa diets may have been too small to detect or the duration of the study too short to manifest, there were clear differences in Ca metabolism from control levels in the response of the spaceflight model to HiNa diets, indicated by depression of intestinal Ca absorption and its regulatory hormone.

  18. Melting point trends and solid phase behaviors of model salts with ion size asymmetry and distributed cation charge.

    PubMed

    Lindenberg, E K; Patey, G N

    2015-07-14

    The melting point trends of model salts composed of coarse grain ions are examined using NPT molecular dynamics simulations. The model salts incorporate ion size asymmetry and distributed cation charge, which are two common features in ionic liquids. A series of single-phase and two-phase simulations are done at set temperatures with 50 K intervals for each salt, and the normal melting point is estimated within 50 K. The melting point trends are then established relative to a charge-centered, size symmetric salt with a normal melting point between 1250 K and 1300 K. We consider two sets of size asymmetric salts with size ratios up to 3:1; the melting point trends are different in each set. The lowest melting point we find is between 450 K and 500 K, which is a reduction of over 60% from the charge-centered, size symmetric case. In both sets, we find diversity in the solid phase structures. For all size ratios with small cation charge displacements, the salts crystallize with orientationally disordered cations. When the partial cation charge is far enough off-center in salts with ion size ratios near 1:1, the salts can become trapped in glassy states and have underlying crystal structures that are orientationally ordered. At ion size ratios near 3:1, the salts with large cation charge displacements show premelting transitions at temperatures as low as 300 K. After the premelting transition, these salts exist either as fast ion conductors, where the smaller anions move through a face centered cubic (fcc) cation lattice, or as plastic crystals, where ion pairs rotate on a fcc lattice.

  19. Modelling the impacts of strategic tree plantings on salt loads and flows in the Macquarie river catchment, NSW, Australia.

    PubMed

    Herron, Natasha; Davis, Richard; Dawes, Warrick; Evans, Ray

    2003-05-01

    In Australia, problems of dryland and stream salinity have recently become the focus of a National Action Plan. In many river catchments, preliminary stream salt load and salinity targets have been set to define maximum permissible export levels in 2015. Afforestation has been proposed as a strategy for meeting these targets, although several studies suggest that widespread commercial tree plantations are likely to deliver net dis-benefits. However, the impacts on stream salt loads of more localised tree plantings in high salt yielding areas have not been quantified. In this paper we use a simple empirical model to predict the effects of various strategic and non-strategic tree planting scenarios on flows and salt loads in the mid-Macquarie catchment, New South Wales. A simple salt routing model is then used to estimate the effect of these changes on salt loads at the end-of-valley monitoring site for the Macquarie catchment. Results suggest that widespread land management interventions will be required to meet the preliminary salt load targets for this catchment. On their own, small-scale, strategic tree planting in high salt export areas of the mid-Macquarie area will not have a significant impact on salt loads at the end-of-valley monitoring site. While widespread tree plantings may reduce salt loads in the longer term, they are likely to cause streamflow losses in the shorter term. Thus, stream salinities are expected to rise initially, due to the different response times of groundwater and surface water systems to land use change.

  20. SDSS-II: Determination of shape and color parameter coefficients for SALT-II fit model

    SciTech Connect

    Dojcsak, L.; Marriner, J.; /Fermilab

    2010-08-01

    In this study we look at the SALT-II model of Type IA supernova analysis, which determines the distance moduli based on the known absolute standard candle magnitude of the Type IA supernovae. We take a look at the determination of the shape and color parameter coefficients, {alpha} and {beta} respectively, in the SALT-II model with the intrinsic error that is determined from the data. Using the SNANA software package provided for the analysis of Type IA supernovae, we use a standard Monte Carlo simulation to generate data with known parameters to use as a tool for analyzing the trends in the model based on certain assumptions about the intrinsic error. In order to find the best standard candle model, we try to minimize the residuals on the Hubble diagram by calculating the correct shape and color parameter coefficients. We can estimate the magnitude of the intrinsic errors required to obtain results with {chi}{sup 2}/degree of freedom = 1. We can use the simulation to estimate the amount of color smearing as indicated by the data for our model. We find that the color smearing model works as a general estimate of the color smearing, and that we are able to use the RMS distribution in the variables as one method of estimating the correct intrinsic errors needed by the data to obtain the correct results for {alpha} and {beta}. We then apply the resultant intrinsic error matrix to the real data and show our results.

  1. Discrete element modeling of the faulting in the sedimentary cover above an active salt diapir

    NASA Astrophysics Data System (ADS)

    Yin, Hongwei; Zhang, Jie; Meng, Lingsen; Liu, Yuping; Xu, Shijing

    2009-09-01

    Geological mapping, seismic analyses, and analogue experiments show that active salt diapirism results in significant faulting in the overburden strata. Faults associated with active diapirism generally develop over the crest of the dome and form a radial pattern. In this study, we have created a 3-D discrete element model and used this model to investigate the fault system over active diapirs. The model reproduces some common features observed in physical experiments and natural examples. The discrete element results show that most faults initiate near the model surface and have displacement decreasing downward. In addition, model results indicate that the earliest fault, working as the master fault, has a strong influence on the subsequent fault pattern. The footwall of the master fault is mainly deformed by arc-parallel stretching and develops a subradial fault pattern, whereas the hanging wall is deformed by both arc-parallel stretching and gliding along the master fault and top of salt, and hence develops both parallel and oblique faults. Model results replicate the fault pattern and deformation mechanism of the Reitbrook dome, Germany.

  2. Simulation of arrested salt wedges with a multi-layer Shallow Water Lattice Boltzmann model

    NASA Astrophysics Data System (ADS)

    Prestininzi, P.; Montessori, A.; La Rocca, M.; Sciortino, G.

    2016-10-01

    The ability to accurately and efficiently model the intrusion of salt wedges into river beds is crucial to assay its interaction with human activities and the natural environment. We present a 2D multi-layer Shallow Water Lattice Boltzmann (SWLB) model able to predict the salt wedge intrusion in river estuaries. The formulation usually employed for the simulation of gravity currents is here equipped with proper boundary conditions to handle both the downstream seaside outlet and the upstream river inlet. Firstly, the model is validated against highly accurate semi-analytical solutions of the steady state 1D two-layer Shallow Water model. Secondly, the model is applied to a more complex, fully 3D geometry, to assess its capability to handle realistic cases. The simple formulation proposed for the shear interlayer stress is proven to be consistent with the general 3D viscous solution. In addition to the accuracy, the model inherits the efficiency of the Lattice Boltzmann approach to fluid dynamics problems.

  3. A decision support model to assess vulnerability to salt water intrusion in the great bend prairie aquifer of Kansas

    USGS Publications Warehouse

    Sophocleous, M.; Ma, T.

    1998-01-01

    A relatively simple ground water decision support system (DSS) was developed to assist in identifying salt water vulnerable areas and in developing management policies to prevent salt water intrusion in central Kansas. The DSS is based on a combination of numerical modeling sensitivity analyses, multiple regression analyses, and classification procedures derived from our knowledge of the area. Six ground water salinity models are proposed to evaluate irrigation well permit applications. The choice of model depends on the availability of site-specific data. The DSS takes advantage of GIS database management procedures, and is applied to an actual salt water intrusion problem site in south-central Kansas. This approach can help local ground water management districts make better decisions on protecting ground water use in salt water vulnerable areas.

  4. Modelling sustainable salt water management under deficit irrigation conditions for melon in Spain and Brazil.

    PubMed

    Leite, Kelly N; Cabello, María J; Valnir Júnior, Manuel; Tarjuelo, José M; Domínguez, Alfonso

    2015-08-30

    In water scarcity areas the use of saline water for irrigation is a common practice. In this study, experimental data from two two-year melon tests were collected for the calibration (2004 'Yellow Melon' (YeMe) type) and validation (2002 YeMe, 2005 and 2006 'Piel de Sapo' (PiSa) type) processes in melon crop simulation under deficit irrigation conditions using salt water. The simulations were carried out for Castilla-La Mancha (Spain) and Ceará (Brazil) using the MOPECO model, which includes optimized regulated deficit irrigation (ORDI) methodology. The objective was to determine the most suitable irrigation strategy for both areas. Under fresh water conditions, ORDI may increase yield by up to 20% (PiSa) and 7% (YeMe) compared with constant deficit irrigation. Higher water deficit should be induced during the vegetative development and ripening stages. The rainfall between irrigation periods is able to leach the salts supplied by the irrigation water. The combination of ORDI with different strategies for managing saline water may increase water use efficiency. In these areas it may be of interest not to apply the leaching fraction (saving up to 67% of irrigation water). However, leaching of the soluble salts accumulated before starting the most sensitive periods may be suitable. © 2014 Society of Chemical Industry.

  5. Iron(III)-induced activation of chloride and bromide from modeled salt pans.

    PubMed

    Wittmer, Julian; Bleicher, Sergej; Zetzsch, Cornelius

    2015-05-14

    The photochemistry of halides in sea spray aerosol, on salt pans, and on other salty surfaces leads to a formation of reactive halogen species. We investigated the photochemical formation of atomic chlorine (Cl) and bromine (Br) in the gas phase in the presence of laboratory-modeled salt pans consisting of sodium chloride doped with iron(III) chloride hexahydrate (0.5 and 2 wt %). The samples were spread on a Teflon sheet and exposed to simulated sunlight in a Teflon smog chamber in purified, humidified air in the presence of a test mixture of hydrocarbons at the ppb level to determine Cl, Br, and OH formation by the radical clock method. Driven by the photolytic reduction of Fe(III) to Fe(II), the production rates of the Fe(III)-doped NaCl salt samples (up to10(7) atoms cm(-3) s(-1)) exceeded the release of Cl above a pure NaCl sample by more than an order of magnitude in an initially O3-free environment at low NOX. In bromide-doped samples (0.5 wt % NaBr), a part of the Cl release was replaced by Br when Fe(III) was present. Additions of sodium sulfate, sodium oxalate, oxalic acid, and catechol to NaCl/FeCl3 samples were found to restrain the activation of chloride.

  6. Transports and budgets of volume, heat, and salt from a global eddy-resolving ocean model

    SciTech Connect

    McCann, M.P.; Semtner, A.J. Jr.; Chervin, R.M.

    1994-07-01

    The results from an integration of a global ocean circulation model have been condensed into an analysis of the volume, heat, and salt transports among the major ocean basins. Transports are also broken down between the model`s Ekman, thermocline, and deep layers. Overall, the model does well. Horizontal exchanges of mass, heat, and salt between ocean basins have reasonable values: and the volume of North Atlantic Deep Water (NADW) transport is in general agreement with what limited observations exist. On a global basis the zonally integrated meridional heat transport is poleward at all latitudes except for the latitude band 30{degrees}S to 45{degrees}S. This anomalous transport is most likely a signature of the model`s inability to form Antarctic Intermediate (AAIW) and Antarctic bottom water (AABW) properly. Eddy heat transport is strong at the equator where its convergence heats the equatorial Pacific about twice as much as it heats the equatorial Atlantic. The greater heating in the Pacific suggests that mesoscale eddies may be a vital mechanism for warming and maintaining an upwelling portion of the global conveyor-belt circulation. The model`s fresh water transport compares well with observations. However, in the Atlantic there is an excessive southward transport of fresh water due to the absence of the Mediterranean outflow and weak northward flow of AAIW. Perhaps the model`s greatest weakness is the lack of strong AAIW and AABW circulation cells. Accurate thermohaline forcing in the North Atlantic (based on numerous hydrographic observations) helps the model adequately produce NADW. In contrast, the southern ocean is an area of sparse observation. Better thermohaline observations in this area may be needed if models such as this are to produce the deep convection that will achieve more accurate simulations of the global 3-dimensional circulation. 41 refs., 18 figs., 1 tab.

  7. Encasement and subsidence of salt minibasins: observations from the SE Precaspian Basin and numerical modeling.

    NASA Astrophysics Data System (ADS)

    Fernandez, Naiara; Duffy, Oliver B.; Hudec, Michael R.; Jackson, Christopher A.-L.; Dooley, Tim P.; Jackson, Martin P. A.; Burg, George

    2017-04-01

    The SE Precaspian Basin is characterized by an assemblage of Upper Permian to Triassic minibasins. A recently acquired borehole-constrained 3D reflection dataset reveals the existence of abundant intrasalt reflection packages lying in between the Permo-Triassic minibasins. We propose that most of the mapped intrasalt reflection packages in the study area are minibasins originally deposited on top of salt that were later incorporated into salt by encasement processes. This makes the SE Precaspian Basin a new example of a salt province populated by encased minibasins, which until now had been mainly described from the Gulf of Mexico. Identifying salt-encased sediment packages in the study area has been crucial, not only because they provide a new exploration target, but also because they can play a key role on improving seismic imaging of adjacent or deeper stratigraphic sections. Another remarkable feature observed in the seismic dataset is the widespread occurrence of distinct seismic sequences in the Permo-Triassic minibasins. Bowl- and wedge-shaped seismic sequences define discrete periods of vertical and asymmetric minibasin subsidence. In the absence of shortening, the bowl-to-wedge transition is typically associated with the timing of basal welding and subsequent rotation of the minibasins. Timing of minibasin welding has important implications when addressing the likelihood of suprasalt reservoir charging. We performed a set of 2D numerical simulations aimed at investigating what drives the tilting of minibasins and how it relates to welding. A key observation from the numerical models is that the bowl-to-wedge transition can predate the time of basal welding.

  8. Regional-Scale Salt Tectonics Modelling: Bench-Scale Validation and Extension to Field-Scale

    NASA Astrophysics Data System (ADS)

    Crook, A. J. L.; Yu, J. G.; Thornton, D. A.

    2010-05-01

    The role of salt in the evolution of the West African continental margin, and in particular its impact on hydrocarbon migration and trap formation, is an important research topic. It has attracted many researchers who have based their research on bench-scale experiments, numerical models and seismic observations. This research has shown that the evolution is very complex. For example, regional analogue bench-scale models of the Angolan margin (Fort et al., 2004) indicate a complex system with an upslope extensional domain with sealed tilted blocks, growth fault and rollover systems and extensional diapers, and a downslope contractional domain with squeezed diapirs, polyharmonic folds and thrust faults, and late-stage folding and thrusting. Numerical models have the potential to provide additional insight into the evolution of these salt driven passive margins. The longer-term aim is to calibrate regional-scale evolution models, and then to evaluate the effect of the depositional history on the current day geomechanical and hydrogeologic state in potential target hydrocarbon reservoir formations adjacent to individual salt bodies. To achieve this goal the burial and deformational history of the sediment must be modelled from initial deposition to the current-day state, while also accounting for the reaction and transport processes occurring in the margin. Accurate forward modeling is, however complex, and necessitates advanced procedures for the prediction of fault formation and evolution, representation of the extreme deformations in the salt, and for coupling the geomechanical, fluid flow and temperature fields. The evolution of the sediment due to a combination of mechanical compaction, chemical compaction and creep relaxation must also be represented. In this paper ongoing research on a computational approach for forward modelling complex structural evolution, with particular reference to passive margins driven by salt tectonics is presented. The approach is an

  9. Statistical Interior Tomography

    PubMed Central

    Xu, Qiong; Wang, Ge; Sieren, Jered; Hoffman, Eric A.

    2011-01-01

    This paper presents a statistical interior tomography (SIT) approach making use of compressed sensing (CS) theory. With the projection data modeled by the Poisson distribution, an objective function with a total variation (TV) regularization term is formulated in the maximization of a posteriori (MAP) framework to solve the interior problem. An alternating minimization method is used to optimize the objective function with an initial image from the direct inversion of the truncated Hilbert transform. The proposed SIT approach is extensively evaluated with both numerical and real datasets. The results demonstrate that SIT is robust with respect to data noise and down-sampling, and has better resolution and less bias than its deterministic counterpart in the case of low count data. PMID:21233044

  10. Modelling the coupling between salt kinematics and subsidence evolution: Inferences for the Miocene evolution of the Transylvanian Basin

    NASA Astrophysics Data System (ADS)

    Tilita, Marius; Scheck-Wenderoth, Magdalena; Matenco, Liviu; Cloetingh, Sierd

    2015-09-01

    Large-scale diapiric salt movements affect the architecture of sedimentary basins and often prevent the understanding of their mechanics by hiding or distorting subsidence patterns. One good example is the evolution of the Transylvanian Basin, which formed during Miocene times in an area located in between the rapid slab rollback and continental collision recorded at the exterior of the Carpathians and the extension of the neighbouring Pannonian Basin. In the absence of major genetic fault systems, quantifying these external tectonic forcing factors requires an accurate reconstruction of subsidence evolution. Having the advent of a detailed 3D geometrical model of the Transylvanian Basin, we apply a 3D numerical modelling technique that couples salt re-distribution and subsidence evolution to quantify and understand the basin kinematics and vertical motions. Two techniques, backward and forward modelling are coupled in order to discriminate between salt migration driven by overburden and the influence of external tectonic forcing factors. The results show that salt kinematics was more complex than simple unidirectional migration, suggesting the existence of areas with significant subsidence hidden by the inward salt migration and areas with apparent large subsidence that are in reality artefacts of outwards salt migration. Additionally, the results suggest that parts of the basin have been successively affected by in- and out-ward salt migration events, an effect of localising subsidence and overburden. Furthermore, accelerated moments of salt migration took place during the main Miocene contraction events recorded at the exterior of the Carpathians, demonstrating that salt migration is enhanced by intraplate stresses. Our study also infers that the subsidence of the Transylvanian Basin is the result of the superposition of the contraction at the exterior of the orogenic chain and the back-arc extension.

  11. Comparison and Tensorial Formulation of Inelastic Constitutive Models of Salt Rock Behaviour and Efficient Numerical Implementatio

    NASA Astrophysics Data System (ADS)

    Nagel, T.; Böttcher, N.; Görke, U. J.; Kolditz, O.

    2014-12-01

    The design process of geotechnical installations includes the application of numerical simulation tools for safety assessment, dimensioning and long term effectiveness estimations. Underground salt caverns can be used for the storage of natural gas, hydrogen, oil, waste or compressed air. For their design one has to take into account fluctuating internal pressures due to different levels of filling, the stresses imposed by the surrounding rock mass, irregular geometries and possibly heterogeneous material properties [3] in order to estimate long term cavern convergence as well as locally critical wall stresses. Constitutive models applied to rock salt are usually viscoplastic in nature and most often based on a Burgers-type rheological model extended by non-linear viscosity functions and/or plastic friction elements. Besides plastic dilatation, healing and damage are sometimes accounted for as well [2]. The scales of the geotechnical system to be simulated and the laboratory tests from which material parameters are determined are vastly different. The most common material testing modalities to determine material parameters in geoengineering are the uniaxial and the triaxial compression tests. Some constitutive formulations in widespread use are formulated based on equivalent rather than tensorial quantities valid under these specific test conditions and are subsequently applied to heterogeneous underground systems and complex 3D load cases. We show here that this procedure is inappropriate and can lead to erroneous results. We further propose alternative formulations of the constitutive models in question that restore their validity under arbitrary loading conditions. For an efficient numerical simulation, the discussed constitutive models are integrated locally with a Newton-Raphson algorithm that directly provides the algorithmically consistent tangent matrix for the global Newton iteration of the displacement based finite element formulation. Finally, the finite

  12. A comparison of genomic selection models across time in interior spruce (Picea engelmannii × glauca) using unordered SNP imputation methods.

    PubMed

    Ratcliffe, B; El-Dien, O G; Klápště, J; Porth, I; Chen, C; Jaquish, B; El-Kassaby, Y A

    2015-12-01

    Genomic selection (GS) potentially offers an unparalleled advantage over traditional pedigree-based selection (TS) methods by reducing the time commitment required to carry out a single cycle of tree improvement. This quality is particularly appealing to tree breeders, where lengthy improvement cycles are the norm. We explored the prospect of implementing GS for interior spruce (Picea engelmannii × glauca) utilizing a genotyped population of 769 trees belonging to 25 open-pollinated families. A series of repeated tree height measurements through ages 3-40 years permitted the testing of GS methods temporally. The genotyping-by-sequencing (GBS) platform was used for single nucleotide polymorphism (SNP) discovery in conjunction with three unordered imputation methods applied to a data set with 60% missing information. Further, three diverse GS models were evaluated based on predictive accuracy (PA), and their marker effects. Moderate levels of PA (0.31-0.55) were observed and were of sufficient capacity to deliver improved selection response over TS. Additionally, PA varied substantially through time accordingly with spatial competition among trees. As expected, temporal PA was well correlated with age-age genetic correlation (r=0.99), and decreased substantially with increasing difference in age between the training and validation populations (0.04-0.47). Moreover, our imputation comparisons indicate that k-nearest neighbor and singular value decomposition yielded a greater number of SNPs and gave higher predictive accuracies than imputing with the mean. Furthermore, the ridge regression (rrBLUP) and BayesCπ (BCπ) models both yielded equal, and better PA than the generalized ridge regression heteroscedastic effect model for the traits evaluated.

  13. A Model for the Thermal and Chemical Evolution of the Moon's Interior: Implications for the Onset of Mare Volcanism

    NASA Technical Reports Server (NTRS)

    Hess, Paul C.; Parmentier, E. M.

    1995-01-01

    Crystallization of the lunar magma ocean creates a chemically stratified Moon consisting of an anorthositic crust and magma ocean cumulates overlying the primitive lunar interior. Within the magma ocean cumulates the last liquids to crystallize form dense, ilmenite-rich cumulates that contain high concentrations of incompatible radioactive elements. The underlying olivine-orthopyroxene cumulates are also stratified with later crystallized, denser, more Fe-rich compositions at the top. This paper explores the chemical and thermal consequences of an internal evolution model accounting for the possible role of these sources of chemical buoyancy. Rayleigh-Taylor instability causes the dense ilmenite-rich cumulate layer and underlying Fe-rich cumulates to sink toward the center of the Moon, forming a dense lunar core. After this overturn, radioactive heating within the ilmenite-rich cumulate core heats the overlying mantle, causing it to melt. In this model, the source region for high-TiO2 mare basalts is a convectively mixed layer above the core-mantle boundary which would contain small and variable amounts of admixed ilmenite and KREEP. This deep high-pressure melting, as required for mare basalts, occurs after a reasonable time interval to explain the onset of mare basalt volcanism if the content of radioactive elements in the core and the chemical density gradients above the core are sufficiently high but within a range of values that might have been present in the Moon. Regardless of details implied by particular model parameters, gravitational overturn driven by the high density of magma ocean Fe-rich cumulates should concentrate high-TiO2 mare basalt sources, and probably a significant fraction of radioactive heating, toward the center of the Moon. This will have important implications for both the thermal evolution of the Moon and for mare basalt genesis.

  14. A comparison of genomic selection models across time in interior spruce (Picea engelmannii × glauca) using unordered SNP imputation methods

    PubMed Central

    Ratcliffe, B; El-Dien, O G; Klápště, J; Porth, I; Chen, C; Jaquish, B; El-Kassaby, Y A

    2015-01-01

    Genomic selection (GS) potentially offers an unparalleled advantage over traditional pedigree-based selection (TS) methods by reducing the time commitment required to carry out a single cycle of tree improvement. This quality is particularly appealing to tree breeders, where lengthy improvement cycles are the norm. We explored the prospect of implementing GS for interior spruce (Picea engelmannii × glauca) utilizing a genotyped population of 769 trees belonging to 25 open-pollinated families. A series of repeated tree height measurements through ages 3–40 years permitted the testing of GS methods temporally. The genotyping-by-sequencing (GBS) platform was used for single nucleotide polymorphism (SNP) discovery in conjunction with three unordered imputation methods applied to a data set with 60% missing information. Further, three diverse GS models were evaluated based on predictive accuracy (PA), and their marker effects. Moderate levels of PA (0.31–0.55) were observed and were of sufficient capacity to deliver improved selection response over TS. Additionally, PA varied substantially through time accordingly with spatial competition among trees. As expected, temporal PA was well correlated with age-age genetic correlation (r=0.99), and decreased substantially with increasing difference in age between the training and validation populations (0.04–0.47). Moreover, our imputation comparisons indicate that k-nearest neighbor and singular value decomposition yielded a greater number of SNPs and gave higher predictive accuracies than imputing with the mean. Furthermore, the ridge regression (rrBLUP) and BayesCπ (BCπ) models both yielded equal, and better PA than the generalized ridge regression heteroscedastic effect model for the traits evaluated. PMID:26126540

  15. Basin Model of Total Dissolved Salts Transformation in Water of a Small River (the Kirgizka River, Tomsk, Russia)

    NASA Astrophysics Data System (ADS)

    Savichev, O. G.; Matveenko, I. A.; Titov, I. V.

    2016-09-01

    The basin model of total dissolved salt transformation in river water has been developed. It was tested in the Kirgizka River, the right tributary of the Tom River (Russia, Western Siberia, Tomsk). It was shown that the river system has the capacity of selfpurification and is characterized by rather stable salt composition. It is explained by the fact that the growth in dissolved salt concentration in river water is limited to some extent by, firstly, dilution of more mineralized groundwaters drained by rivers, and, secondly, relatively low solubility of some compounds.

  16. A diameter growth model for single-stem growth forms for the interior west forest inventory and analysis’s region

    Treesearch

    Michael T. Thompson

    2015-01-01

    The Interior West Forest Inventory and Analysis Unit (IWFIA) will soon transition from a regional system to a national FIA system for compiling estimates of forest growth, removals, and mortality. The national system requires regional diameter-growth models to estimate diameters on trees in situations where the initial or terminal diameter is not known at the beginning...

  17. 25 CFR Appendix A to Part 1000 - Model Compact of Self-Governance Between the Tribe and the Department of the Interior

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Model Compact of Self-Governance Between the Tribe and... Compact of Self-Governance Between the Tribe and the Department of the Interior Article I—Authority and Purpose Section 1—Authority This agreement, denoted a compact of Self-Governance (hereinafter referred...

  18. 25 CFR Appendix A to Part 1000 - Model Compact of Self-Governance Between the Tribe and the Department of the Interior

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Model Compact of Self-Governance Between the Tribe and... Compact of Self-Governance Between the Tribe and the Department of the Interior Article I—Authority and Purpose Section 1—Authority This agreement, denoted a compact of Self-Governance (hereinafter referred...

  19. 25 CFR Appendix A to Part 1000 - Model Compact of Self-Governance Between the Tribe and the Department of the Interior

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Model Compact of Self-Governance Between the Tribe and... Compact of Self-Governance Between the Tribe and the Department of the Interior Article I—Authority and Purpose Section 1—Authority This agreement, denoted a compact of Self-Governance (hereinafter referred...

  20. 25 CFR Appendix A to Part 1000 - Model Compact of Self-Governance Between the Tribe and the Department of the Interior

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Model Compact of Self-Governance Between the Tribe and... Compact of Self-Governance Between the Tribe and the Department of the Interior Article I—Authority and Purpose Section 1—Authority This agreement, denoted a compact of Self-Governance (hereinafter referred...

  1. 25 CFR Appendix A to Part 1000 - Model Compact of Self-Governance Between the Tribe and the Department of the Interior

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Model Compact of Self-Governance Between the Tribe and... Compact of Self-Governance Between the Tribe and the Department of the Interior Article I—Authority and Purpose Section 1—Authority This agreement, denoted a compact of Self-Governance (hereinafter referred...

  2. Assessing the wildlife habitat value of New England salt marshes: II. Model testing and validation.

    PubMed

    McKinney, Richard A; Charpentier, Michael A; Wigand, Cathleen

    2009-07-01

    We tested a previously described model to assess the wildlife habitat value of New England salt marshes by comparing modeled habitat values and scores with bird abundance and species richness at sixteen salt marshes in Narragansett Bay, Rhode Island USA. As a group, wildlife habitat value assessment scores for the marshes ranged from 307-509, or 31-67% of the maximum attainable score. We recorded 6 species of wading birds (Ardeidae; herons, egrets, and bitterns) at the sites during biweekly survey. Species richness (r (2)=0.24, F=4.53, p=0.05) and abundance (r (2)=0.26, F=5.00, p=0.04) of wading birds significantly increased with increasing assessment score. We optimized our assessment model for wading birds by using Akaike information criteria (AIC) to compare a series of models comprised of specific components and categories of our model that best reflect their habitat use. The model incorporating pre-classification, wading bird habitat categories, and natural land surrounding the sites was substantially supported by AIC analysis as the best model. The abundance of wading birds significantly increased with increasing assessment scores generated with the optimized model (r (2)=0.48, F=12.5, p=0.003), demonstrating that optimizing models can be helpful in improving the accuracy of the assessment for a given species or species assemblage. In addition to validating the assessment model, our results show that in spite of their urban setting our study marshes provide substantial wildlife habitat value. This suggests that even small wetlands in highly urbanized coastal settings can provide important wildlife habitat value if key habitat attributes (e.g., natural buffers, habitat heterogeneity) are present.

  3. Physical analog (centrifuge) model investigation of contrasting structural styles in the Salt Range and Potwar Plateau, northern Pakistan

    NASA Astrophysics Data System (ADS)

    Faisal, Shah; Dixon, John M.

    2015-08-01

    We use scaled physical analog (centrifuge) modeling to investigate along- and across-strike structural variations in the Salt Range and Potwar Plateau of the Himalayan foreland fold-thrust belt of Pakistan. The models, composed of interlayered plasticine and silicone putty laminae, comprise four mechanical units representing the Neoproterozoic Salt Range Formation (basal detachment), Cambrian-Eocene carapace sequence, and Rawalpindi and Siwalik Groups (Neogene molasse), on a rigid base representing the Indian craton. Pre-cut ramps simulate basement faults with various structural geometries. A pre-existing north-dipping basement normal fault under the model foreland induces a frontal ramp and a prominent fault-bend-fold culmination, simulating the Salt Range. The ramp localizes displacement on a frontal thrust that occurs out-of-sequence with respect to other foreland folds and thrusts. With a frontal basement fault terminating to the east against a right-stepping, east-dipping lateral ramp, deformation propagates further south in the east; strata to the east of the lateral ramp are telescoped in ENE-trending detachment folds, fault-propagation folds and pop-up structures above a thick basal detachment (Salt Range Formation), in contrast to translated but less-deformed strata with E-W-trending Salt-Range structures to the west. The models are consistent with Salt Range-Potwar Plateau structural style contrasts being due to basement fault geometry and variation in detachment thickness.

  4. Interior of Titan

    NASA Technical Reports Server (NTRS)

    Stevenson, David J.

    1992-01-01

    General principles of Titan formation and evolution are addressed. Attention is focused on the volatile reservoir (defined as all constituents more volatile than water) of Titan's interior. Volatile poor models, in which Titan is like Granymede or Callisto with a thin (observed) volatile veneer are discussed and discarded. Volatile rich models in which the present Titan consists of a methane clathrate shell overlying a deep water ammonia ocean and solid ammonia hydrate are discussed. Titan has a central core of rock which is about one half of the total mass, and a superficial hydrocarbon 'ocean' stored in subsurface caverns and pore space.

  5. Modeling the Influence of River Flow and Salt Water Intrusion in the Terengganu Estuary, Malaysia

    NASA Astrophysics Data System (ADS)

    Lee, H. L.; Tangang, F.; Hamid, M. R.; Benson, Y.; Razali, M. R.

    2016-07-01

    Salinity intrusion is a major concern when the freshwater extraction station is located in the estuary. This paper attempt to predict the salt intrusion length in the upper stretch of estuary, by applying different magnitudes of freshwater discharge at the river regime. The integrated two dimensional hydrodynamics model associated with advection dispersion model was performed to investigate the salinity intrusion. The model was well calibrated and verified by the measured data undertaken during dry season. The maximum salt intrusion length to the threshold of salinity density is 1.00 ppt on the existing condition was predicted at 9.97 km from the river mouth. Moreover, with the magnitude of 100.00 m3s-1 and 30.00 m3s-1 freshwater discharges at the upstream boundary (Kpg Tanggol), it was predicted the maximum salt intrusion length was 11.84 km and 21.41 km, respectively, from the river mouth. Therefore, it was determined the minimum freshwater discharge of approximately 100.00 m3s-1 is required at the Kpg Tanggol river gauging station, in order to maintain the acceptable salinity levels at the Pulau Musang freshwater pump house. However, the actual water discharge at the Kpg Tanggol boundary station should be higher, since the minimum discharge does not take into consideration the amount of water extraction by the Pulau Musang and SATU pump stations. Further analysis is required to execute the consequences of water extraction toward the salinity intrusion in the Terengganu estuary that coupled with projected sea level rise.

  6. Modeling deformation processes of salt caverns for gas storage due to fluctuating operation pressures

    NASA Astrophysics Data System (ADS)

    Böttcher, N.; Nagel, T.; Goerke, U.; Khaledi, K.; Lins, Y.; König, D.; Schanz, T.; Köhn, D.; Attia, S.; Rabbel, W.; Bauer, S.; Kolditz, O.

    2013-12-01

    In the course of the Energy Transition in Germany, the focus of the country's energy sources is shifting from fossil to renewable and sustainable energy carriers. Since renewable energy sources, such as wind and solar power, are subjected to annual, seasonal, and diurnal fluctuations, the development and extension of energy storage capacities is a priority in German R&D programs. Common methods of energy storage are the utilization of subsurface caverns as a reservoir for natural or artificial fuel gases, such as hydrogen, methane, or the storage of compressed air. The construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to the possibility of solution mining. Another advantage of evaporite as a host material is the self-healing capacity of salt rock. Gas caverns are capable of short-term energy storage (hours to days), so the operating pressures inside the caverns are fluctuating periodically with a high number of cycles. This work investigates the influence of fluctuating operation pressures on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. Our simulations include the thermodynamic behaviour of the gas during the loading/ unloading of the cavern. This provides information on the transient pressure and temperature distribution on the cavern boundary to calculate the deformation of its geometry. Non-linear material models are used for the mechanical analysis, which describe the creep and self-healing behavior of the salt rock under fluctuating loading pressures. In order to identify the necessary material parameters, we perform experimental studies on the mechanical behaviour of salt rock under varying pressure and temperature conditions. Based on the numerical results, we further derive concepts for monitoring THM quantities in the

  7. A Salt Marsh Erosion Model: Interplay Between Biotic and Physical Factors at the Seaward Edge

    NASA Astrophysics Data System (ADS)

    Weiner, M. E.; Gilbert, L. A.; Alves, C. L.; Poole, P. A.; Schleicher, S.

    2014-12-01

    We present a new model to monitor the cycle of erosion occurring on the seaward edge of salt marshes as sea level rises. In our model, a southern New England salt marsh edge is stable when the bank edge exhibits a normal slope, is fringed by the low-marsh grass Spartina alterniflora, and the ribbed mussel Guekensia demissa is abundant. As erosion proceeds, the seaward bank becomes vertical (Stage 1), then undercut (Stage 2), then slumped (Stage 3), and finally a detached island (Stage 4) to expose a new vertical bank. If erosion progresses relatively slowly, S. alterniflora will dominate and G. demissa will be abundant. We applied this model to four sites at the Barn Island Salt Marsh in southeastern Connecticut. The central headland of the heavily mosquito-ditched Headquarters Marsh appears to be the most rapidly retreating: from 2006 to 2014, the seaward bank advanced two erosional stages and lost 3 m horizontally. This headland is dominated by low-marsh S. alterniflora, with mid-marsh grasses Distichlis spicata and Spartina patens also present on the seaward edge. By comparison, the nearby seaward edge of Wequetequock Point has only S. alterniflora and bare patches with no mid-marsh species. Wequetequock Point also appears more stable, with about one quarter of the seaward bank on a normal slope and abundant mussels (mean 4,500 m-2; max 20,000 m-2). Repeat surveys since 2006 show mussel vacancy rate is related to the rate of erosion. Open holes appear in normal slope banks due to wave erosion of rocks and other material embedded in the exposed peat. Banks that remain in the same erosion stage for multiple years show increased mussel occupation of these holes. In contrast, rapidly eroding banks at Barn Island Marsh have very few mussels (<100 m-2) and are typically fringed by grasses other than S. alterniflora. Much of the Barn Island Marsh bank is eroding too rapidly for mussel settlement and growth and normal marsh grass succession. In addition to documenting

  8. Salted matters: modifying gelatine rheology for subduction thrust fault seismicity models

    NASA Astrophysics Data System (ADS)

    Brizzi, Silvia; Funiciello, Francesca; Corbi, Fabio; Di Giuseppe, Erika; Mojoli, Giorgio

    2016-04-01

    Most of the world's greatest earthquakes (Mw > 8.5, usually known as mega-earthquakes) occur at shallow depths along the subduction thrust fault (STF), i.e., the frictional interface between the subducting and overriding plates. The contribution of each subduction zone to the globally released seismic moment is not homogeneous, as well as the maximum Mw recorded in the instrumental and historical catalogues. To contribute to the unravelling of the seismic cycle along the STF, we used analogue models. Viscoelastic laboratory experiments realised with type A gelatine 2.5 wt% at 10 °C (Corbi et al., 2013) successfully simulate the seismic cycle along the STF, providing dynamic similarities with earthquakes in nature. However, analogue earthquakes are still not perfectly comparable to the natural prototype. In this work, we try to improve STF seismicity models by modifying the rheological behaviour of gelatine with the addition of NaCl. After testing salted gelatine rheology as a function of increasing concentration of NaCl, we selected 20 wt% NaCl gelatine, as this NaCl concentration provides a quasi-viscoelastic lithospheric analogue. Subduction interplate seismicity models were performed using both pure and salted gelatine to highlight the strengths and advantages this new material can provide for simulating the seismic cycle along the STF. We analysed analogue earthquakes Mw, recurrence time and rupture duration, which at first-order characterise the seismogenic behaviour of the STF. Results show that the experimental source parameters cover a wider range of values than obtained with pure gelatine, which is more compatible to the high variability globally observed. In particular, salted gelatine allows to simulate also smaller seismic events, giving the opportunity to apply the G-R law to the experimental seismicity of STF. Recurrence time and rupture duration are also characterised by an increased range of values when salted gelatine is used as analogue material

  9. Progress in Studying Salt Secretion from the Salt Glands in Recretohalophytes: How Do Plants Secrete Salt?

    PubMed Central

    Yuan, Fang; Leng, Bingying; Wang, Baoshan

    2016-01-01

    To survive in a saline environment, halophytes have evolved many strategies to resist salt stress. The salt glands of recretohalophytes are exceptional features for directly secreting salt out of a plant. Knowledge of the pathway(s) of salt secretion in relation to the function of salt glands may help us to change the salt-tolerance of crops and to cultivate the extensive saline lands that are available. Recently, ultrastructural studies of salt glands and the mechanism of salt secretion, particularly the candidate genes involved in salt secretion, have been illustrated in detail. In this review, we summarize current researches on salt gland structure, salt secretion mechanism and candidate genes involved, and provide an overview of the salt secretion pathway and the asymmetric ion transport of the salt gland. A new model recretohalophyte is also proposed. PMID:27446195

  10. Sensitivity of modeled atmospheric nitrogen species to variations in sea salt emissions in the North and Baltic Sea regions

    NASA Astrophysics Data System (ADS)

    Neumann, D.; Matthias, V.; Bieser, J.; Aulinger, A.; Quante, M.

    2015-10-01

    Coarse sea salt particles are emitted ubiquitously from the oceans' surfaces by wave breaking and bubble bursting processes. These particles impact atmospheric chemistry by affecting condensation of gas-phase species and nucleation of new fine particles, particularly in regions with high air pollution. In this study, atmospheric particle concentrations are modeled for the North and Baltic Sea regions, Northwestern Europe, using the Community Multiscale Air Quality (CMAQ) modeling system and evaluated against European Monitoring and Evaluation Programme (EMEP) measurement data. As model extension, sea salt emissions are scaled by water salinity because of low salinity in large parts of the Baltic Sea and in certain river estuaries. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is separately considered. Additionally, the impact of sea salt particles on atmospheric nitrate, ammonium and sulfate concentrations is evaluated. The comparisons show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated when going inland. The introduced salinity scaling improves predicted Baltic Sea sea salt concentrations considerably. Dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to a minor increase of NH4+ and NO3- and a minor decrease of SO42- concentrations. However, the overall effect is very low and lower than the deviation from measurements. Size resolved measurements of Na+, NH4+, NO3-, and SO42- are needed for a more detailed analysis on the impact of sea salt particles.

  11. Proteomic and phosphoproteomic analysis of renal cortex in a salt-load rat model of advanced kidney damage

    PubMed Central

    Jiang, Shaoling; He, Hanchang; Tan, Lishan; Wang, Liangliang; Su, Zhengxiu; Liu, Yufeng; Zhu, Hongguo; Zhang, Menghuan; Hou, Fan Fan; Li, Aiqing

    2016-01-01

    Salt plays an essential role in the progression of chronic kidney disease and hypertension. However, the mechanisms underlying pathogenesis of salt-induced kidney damage remain largely unknown. Here, Sprague-Dawley rats, that underwent 5/6 nephrectomy (5/6Nx, a model of advanced kidney damage) or sham operation, were treated for 2 weeks with a normal or high-salt diet. We employed aTiO2 enrichment, iTRAQ labeling and liquid-chromatography tandem mass spectrometry strategy for proteomic and phosphoproteomic profiling of the renal cortex. We found 318 proteins differentially expressed in 5/6Nx group relative to sham group, and 310 proteins significantly changed in response to salt load in 5/6Nx animals. Totally, 1810 unique phosphopeptides corresponding to 550 phosphoproteins were identified. We identified 113 upregulated and 84 downregulated phosphopeptides in 5/6Nx animals relative to sham animals. Salt load induced 78 upregulated and 91 downregulated phosphopeptides in 5/6Nx rats. The differentially expressed phospholproteins are important transporters, structural molecules, and receptors. Protein-protein interaction analysis revealed that the differentially phosphorylated proteins in 5/6Nx group, Polr2a, Srrm1, Gsta2 and Pxn were the most linked. Salt-induced differential phosphoproteins, Myh6, Lmna and Des were the most linked. Altered phosphorylation levels of lamin A and phospholamban were validated. This study will provide new insight into pathogenetic mechanisms of chronic kidney disease and salt sensitivity. PMID:27775022

  12. A revised Pitzer model for low-temperature soluble salt assemblages at the Phoenix site, Mars

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Catling, D. C.; Light, B.

    2015-10-01

    The Wet Chemistry Laboratory (WCL) on the Mars Phoenix Lander measured ions in a soil-water extraction and found Na+, K+, H+ (pH), Ca2+, Mg2+, SO42-, ClO4-, and Cl-. Equilibrium models offer insights into salt phases that were originally present in the Phoenix soil, which dissolved to form the measured WCL solution; however, there are few experimental datasets for single cation perchlorates (ClO4-), and none for mixed perchlorates, at low temperatures, which are needed to build models. In this study, we measure ice and salt solubilities in binary and ternary solutions in the Na-Ca-Mg-ClO4 system, and then use this data, along with existing data, to construct a low-temperature Pitzer model for perchlorate brines. We then apply our model to a nominal WCL solution. Previous studies have modeled either freezing of a WCL solution or evaporation at a single temperature. For the first time, we model evaporation at subzero temperatures, which is relevant for dehydration conditions that might occur at the Phoenix site. Our model indicates that a freezing WCL solution will form ice, KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), calcite (CaCO3), meridianiite (MgSO4·11H2O), MgCl2·12H2O, NaClO4·2H2O, and Mg(ClO4)2·6H2O at the eutectic (209 K). The total water held in hydrated salt phases at the eutectic is ∼1.2 wt.%, which is much greater than hydrated water contents when evaporation is modeled at 298.15 K (∼0.3 wt.%). Evaporation of WCL solutions at lower temperatures (down to 210 K) results in lower water activities and the formation of more dehydrated minerals, e.g. kieserite (MgSO4·H2O) instead of meridianiite. Potentially habitable brines, with water activity aw > 0.6, can occur when soil temperatures are above 220 K and when the soil liquid water content is greater than 0.4 wt.% (100 ×gH2O gsoil-1). In general, modeling indicates that mineral assemblages derived from WCL-type solutions are characteristic of the soil temperature, water content, and water

  13. Quantifying Wave Attenuation due to Salt Marshes with a Phase-Averaged Wave Model

    NASA Astrophysics Data System (ADS)

    Marsooli, R.; Orton, P. M.; Blumberg, A. F.; Georgas, N.

    2016-12-01

    This study uses a mixture of laboratory validation, real-world site/scenario modeling, and data on seasonal variation in salt marsh characteristics to quantify their capacity to mitigate storm waves. We assess the accuracy of four existing empirical formulas to determine the vegetation drag coefficient and, in turn, vegetation-induced wave attenuation. We adopt these formulas in the phase-averaged wave model of Mellor et al. (2008), MDO hereafter, which is improved in the present study to simulate wave energy dissipation due to vegetation drag force. One attribute of MDO is speed, due to parameterized energy in frequency space, and as a result the model may be preferable for hazard assessments and ensemble forecasting. We evaluate the performance of the improved MDO wave model and the empirical drag formulas using existing laboratory data. Comparisons between the model results and measurements show that the model based on the drag formula of Kobayashi et al. (1993) performs better than other models. We further apply MDO based on this formula to Jamaica Bay, the largest natural open space left in New York City, to quantify the influence of estuarine-scale salt marshes on storm waves. The model results show that the vegetation in summer season, when Spartina alterniflora is at its maximum height, is more effective to reduce wave height than in fall season. Moreover, the influence of the Spartina on wave height is more pronounced during a severe storm than a moderate storm. This is because the smaller water depth during a moderate storm causes intense depth-induced wave breaking over shallow marsh islands and thus the contribution of vegetation drag to wave attenuation becomes negligible. On the other hand, during a severe storm with high water elevation, the depth-induced breaking is small and vegetation-induced drag becomes the primary source of wave attenuation.

  14. Steady-State Creep of Rock Salt: Improved Approaches for Lab Determination and Modelling

    NASA Astrophysics Data System (ADS)

    Günther, R.-M.; Salzer, K.; Popp, T.; Lüdeling, C.

    2015-11-01

    Actual problems in geotechnical design, e.g., of underground openings for radioactive waste repositories or high-pressure gas storages, require sophisticated constitutive models and consistent parameters for rock salt that facilitate reliable prognosis of stress-dependent deformation and associated damage. Predictions have to comprise the active mining phase with open excavations as well as the long-term development of the backfilled mine or repository. While convergence-induced damage occurs mostly in the vicinity of openings, the long-term behaviour of the backfilled system is dominated by the damage-free steady-state creep. However, because in experiments the time necessary to reach truly stationary creep rates can range from few days to years, depending mainly on temperature and stress, an innovative but simple creep testing approach is suggested to obtain more reliable results: A series of multi-step tests with loading and unloading cycles allows a more reliable estimate of stationary creep rate in a reasonable time. For modelling, we use the advanced strain-hardening approach of Günther-Salzer, which comprehensively describes all relevant deformation properties of rock salt such as creep and damage-induced rock failure within the scope of an unified creep ansatz. The capability of the combination of improved creep testing procedures and accompanied modelling is demonstrated by recalculating multi-step creep tests at different loading and temperature conditions. Thus reliable extrapolations relevant to in-situ creep rates (10^{-9} to 10^{-13} s^{-1}) become possible.

  15. Coarse-grained model of glycosaminoglycans in aqueous salt solutions. A field-theoretical approach.

    PubMed

    Kolesnikov, Andrei L; Budkov, Yurij A; Nogovitsyn, Evgenij A

    2014-11-20

    We present results of self-consistent field calculations of thermodynamic and structural properties of glycosaminoglycans (chondroitin sulfate, hyaluronic acid, and heparin) in aqueous solutions with added monovalent and divalent salts. A semiphenomenological coarse-grained model for semiflexible polyelectrolyte chains in solution is proposed. The coarse-grained model permits one to focus on the essential features of these systems and provides significant computational advantages with respect to more detailed models. Our approach relies on the method of Gaussian equivalent representation for the calculation of the partition functions in the form of functional integrals. This method provides reliable thermodynamic information for polyelectrolyte solutions over wide ranges of monomer concentrations. In the present work, we use the comparison and fitting of the experimental osmotic pressure with a theoretical equation of state within the Gaussian equivalent representation. The degrees of ionization, radii of gyration, persistence lengths, and structure factors of chondroitin sulfate, hyaluronic acid, and heparin in aqueous solutions with added monovalent and divalent salts are calculated and discussed.

  16. Validity of a moving boundary finite element model for salt intrusion in a branching estuary

    NASA Astrophysics Data System (ADS)

    Das, D. B.; Nassehi, V.

    A previously developed scheme for modelling of salt intrusion in estuaries with significant flow channel boundary variations during tidal cycles has been applied to a narrow branching estuary. It is shown that realistic simulations for complex tidal water systems can be obtained with this scheme provided that a suitable modification to the solution algorithm is implemented. The required modification is explained in detail and the model is applied to simulate salt intrusion in the Upper Milford Haven estuary in Wales, UK. Essentially, this moving boundary scheme introduces a distinct procedure for transient mass balance to ensure logical division of flow at an estuary junction and tracking of fluid particle trajectories along various branches of the estuary. Computational results and available field survey data for depth-averaged salinities are compared to determine the accuracy of the developed model. It is shown that the numerical results converge closer to field values than those previously reported. The method promises to provide new insights for environmental assessment, such as the determination of more accurate effluent discharge policies for estuaries.

  17. 12. INTERIOR VIEW OF TRANSFORMER BUILDING, HIGHLINE PUMP PLANT, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. INTERIOR VIEW OF TRANSFORMER BUILDING, HIGHLINE PUMP PLANT, SHOWING NEW SWITCHES AND METERS, December 3, 1952 - Highline Canal & Pumping Station, South side of Salt River between Tempe, Phoenix & Mesa, Tempe, Maricopa County, AZ

  18. INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED SALT BRINE TO MAKE BICARBONATE OF SODA. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

  19. 32. INTERIOR LAYOUT PLAN OF CROSSCUT STEAM AND DIESEL PLANT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. INTERIOR LAYOUT PLAN OF CROSSCUT STEAM AND DIESEL PLANT, TRACED FROM DRAWING BY C.C. MOORE AND CO., ENGINEERS. July 1947 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  20. Modeling the chemistry of the marine boundary layer: Sulphate formation and the role of sea-salt aerosol particles

    NASA Astrophysics Data System (ADS)

    van den Berg, Ad; Dentener, Frank; Lelieveld, Jos

    2000-05-01

    A one-dimensional model is presented that interactively simulates the dynamics and the gas-aqueous phase chemistry of the cloud-topped marine boundary layer. The model is described and tested using observations from the Atlantic Stratocumulus Transition Experiment/Marine Aerosol and Gas Exchange (ASTEX/MAGE) measurement campaign. The comparison generally indicates satisfactory agreement for dynamical properties and chemical species, except for SO2. We present several explanations for this discrepancy. However, a conclusive account is dependent on quantitative information about free tropospheric SO2 and H2O2 that is not available. Furthermore, a series of sensitivity runs is presented to explain the large quantities of non-sea-salt sulphate associated with sea-salt particles, as observed during ASTEX/MAGE. The main conclusions are that most sulphate associated with sea-salt particles is formed in cloud droplets that subsequently evaporate and that only a small amount is formed in deliquesced aerosol particles. The model results are sensitive to changes in the assumed sea-salt emission rate and the overall aerosol size distribution. The latter indicates that a shift in the sea-salt aerosol distribution toward the smaller particle sizes might explain the observed amount of sulphate associated with sea-salt particles.

  1. Deformations of the Protection Shelf in the "Wapno" Salt Mine, Based on Model Studies

    NASA Astrophysics Data System (ADS)

    Kortas, Grzegorz; Maj, Agnieszka

    2014-12-01

    The catastrophic mine failure resulting from the inrush of water into the Wapno Salt Mine was probably caused by a fracture in the roof protection shelf. The purpose of the present study was to apply the method of the homogenization of the multi-level room-and-pillar structure in the Wapno Salt Mine for 3D+t modelling of the elastic-viscous medium to determine the distribution of stress and strain, and, on that basis, to estimate the geomechanical conditions existing in the roof shelf. This paper presents briefly the spatial development of the salt mine's structure and the results of the surveying measurements carried out during the salt mine's operation and after the mine was flooded. Those results constituted a basis for the verification of the introduced homogenization parameters, i.e. the time-dependent changes of the elasticity modulus and the susceptibility to creep at particular salt mine's levels. A simulated process demonstrated the development of positive values of principle stresses, increasing with time, and of omnidirectional tensile strains. In such conditions, the cracking of the protection shelf body could proceed, also with opening of water flow paths from the dome cap into the salt mine's workings. This paper presents a new research method, the results of its application, and the obtained distribution of stresses and strains that can be useful for the assessment of water hazard in other salt mines. Katastrofa górnicza wywołana wdarciem wody do kopalni soli w Wapnie spowodowana była prawdopodobnie pęknięciem ochronnej półki stropowej. Celem tej pracy było zastosowanie metody homogenizacji struktury komorowo-filarowej wielopoziomowej kopalni Wapno do modelowania ośrodka sprężysto-lepkiego 3D+t dla określenia rozkładu naprężeń i odkształceń oraz na tej podstawie oszacowania warunków geomechanicznych w półce stropowej. W pracy przedstawiono krótko rozwój przestrzenny struktury kopalni oraz wyniki przeprowadzonych pomiar

  2. Incorporation of physiologically based pharmacokinetic modeling in the evaluation of solubility requirements for the salt selection process: a case study using phenytoin.

    PubMed

    Chiang, Po-Chang; Wong, Harvey

    2013-10-01

    In the pharmaceutical industry, salt is commonly used to improve the oral bioavailability of poorly soluble compounds. Currently, there is a limited understanding on the solubility requirement for salts that will translate to improvement in oral exposure. Despite the obvious need, there is very little research reported in this area mainly due to the complexity of such a system. To our knowledge, no report has been published to guide this important process and salt solubility requirement still remains unanswered. Physiologically based pharmacokinetic (PBPK) modeling offers a means to dynamically integrate the complex interplay of the processes determining oral absorption. A sensitivity analysis was performed using a PBPK model describing phenytoin to determine a solubility requirement for phenytoin salts needed to achieve optimal oral bioavailability for a given dose. Based on the analysis, it is predicted that phenytoin salts with solubility greater than 0.3 mg/mL would show no further increases in oral bioavailability. A salt screen was performed using a variety of phenytoin salts. The piperazine and sodium salts showed the lowest and highest aqueous solubility and were tested in vivo. Consistent with our analysis, we observed no significant differences in oral bioavailability for these two salts despite an approximate 60 fold difference in solubility. Our study illustrates that higher solubility salts sometimes provide no additional improvements in oral bioavailability and PBPK modeling can be utilized as an important tool to provide guidance to the salt selection and define a salt solubility requirement.

  3. Modeling of the T S D E Heater Test to Investigate Crushed Salt Reconsolidation and Rock Salt Creep for the Underground Disposal of High-Level Nuclear Waste

    NASA Astrophysics Data System (ADS)

    Blanco Martin, L.; Rutqvist, J.; Birkholzer, J. T.; Wolters, R.; Lux, K. H.

    2014-12-01

    Rock salt is a potential medium for the underground disposal of nuclear waste because it has several assets, in particular its water and gas tightness in the undisturbed state, its ability to heal induced fractures and its high thermal conductivity as compared to other shallow-crustal rocks. In addition, the run-of-mine, granular salt, may be used to backfill the mined open spaces. We present simulation results associated with coupled thermal, hydraulic and mechanical processes in the TSDE (Thermal Simulation for Drift Emplacement) experiment, conducted in the Asse salt mine in Germany [1]. During this unique test, conceived to simulate reference repository conditions for spent nuclear fuel, a significant amount of data (temperature, stress changes and displacements, among others) was measured at 20 cross-sections, distributed in two drifts in which a total of six electrical heaters were emplaced. The drifts were subsequently backfilled with crushed salt. This test has been modeled in three-dimensions, using two sequential simulators for flow (mass and heat) and geomechanics, TOUGH-FLAC and FLAC-TOUGH [2]. These simulators have recently been updated to accommodate large strains and time-dependent rheology. The numerical predictions obtained by the two simulators are compared within the framework of an international benchmark exercise, and also with experimental data. Subsequently, a re-calibration of some parameters has been performed. Modeling coupled processes in saliniferous media for nuclear waste disposal is a novel approach, and in this study it has led to the determination of some creep parameters that are very difficult to assess at the laboratory-scale because they require extremely low strain rates. Moreover, the results from the benchmark are very satisfactory and validate the capabilities of the two simulators used to study coupled thermal, mechanical and hydraulic (multi-component, multi-phase) processes relative to the underground disposal of high

  4. Analysis of hypoxia in the western interior parts of the Ariake Sea, Japan, using a box model.

    PubMed

    Koriyama, Masumi; Seguchi, Masahiro; Ishitani, Tetuhiro; Isnansetyo, Alim

    2011-08-01

    To clarify the mechanism of hypoxia in the western interior parts of the Ariake Sea (WIAS), field observation data collected in the period of 1972-2004 were analyzed using a two-layer box model. Monthly averages of advection velocity, vertical diffusion coefficient (K(z)), and biochemical oxygen consumption rate (R) in WIAS were evaluated quantitatively during the above period. The estimated advection velocity comparatively corresponded to the observed residual flow pattern of bay head in summer and winter. The estimated K(z) was relatively high (0.6-5.3 cm(2) s( -1)) from September to March but lower (0.2-0.4 cm(2) s( -1)) from April to August. The estimated R ranged from 0.30 to 0.46 mg L( -1) day( -1) during May to August. In summer, the temporal variation of dissolved oxygen (DO) concentration in the lower layer was controlled largely by K ( z ) and R. Monthly variations of K(z), R, and degree of density stratification (P) in the 1970s, the 1980s, and the 1990s-early 2000s were analyzed. P, K ( z ), and R were not significantly different among the calculated periods (p = 0.93, 0.23, and 0.49). However, the variations of R in summer between the 1970s and the other calculated periods changed. DO consumption period was longer in the 1980s and the 1990s-early 2000s than in the 1970s. R in the 1980s was highest among the calculated periods. The increase in R in the 1980s was caused by the increase in organic matter load originating from red tide phytoplankton due to a decrease in the suspension feeders.

  5. Mathematical modelling of the uptake and transport of salt in plant roots.

    PubMed

    Foster, Kylie J; Miklavcic, Stanley J

    2013-11-07

    In this paper, we present and discuss a mathematical model of ion uptake and transport in roots of plants. The underlying physical model of transport is based on the mechanisms of forced diffusion and convection. The model can take account of local variations in effective ion and water permeabilities across the major tissue regions of plant roots, represented through a discretized coupled system of governing equations including mass balance, forced diffusion, convection and electric potential. We present simulation results of an exploration of the consequent enormous parameter space. Among our findings we identify the electric potential as a major factor affecting ion transport across, and accumulation in, root tissues. We also find that under conditions of a constant but realistic level of bulk soil salt concentration and plant-soil hydraulic pressure, diffusion plays a significant role even when convection by the water transpiration stream is operating. Crown Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

  6. High-Albedo Salt Crusts on the Tropical Ocean of Snowball Earth: Measurements and Modeling

    NASA Astrophysics Data System (ADS)

    Carns, R.; Light, B.; Warren, S. G.

    2014-12-01

    During a Snowball Earth event, almost all of the ocean surface first freezes as sea ice. As in modern sea ice, trapped inclusions of liquid brine permeate the ice cover. As the ice grows and cools, salt crystals precipitate within the inclusions. At -23C, the most abundant salt in seawater, sodium chloride, begins to precipitate as the dihydrate mineral hydrohalite (NaCl·2H2O). Crystals of hydrohalite within the sea ice scatter light. Measurements of cold, natural sea ice show a broadband albedo increase of 10-20% when salt precipitates. Such snow-free natural sea ice with a surface temperature below -23C is rare on modern Earth, but would have been common in tropical regions of a Snowball Earth where evaporation exceeded precipitation. The persistent cold and lack of summer melt on the Snowball ocean surface, combined with net evaporation, is hypothesized to yield lag deposits of hydrohalite crystals on the ice surface. To investigate this process, we prepared laboratory-grown sea ice in a 1000 liter tank in a walk-in freezer laboratory. The ice was cooled below -23 C and the surface sprayed with a 23% NaCl solution to create a layer of hydrohalite-enriched ice, a proxy for lag deposits that would have formed over long periods of surface sublimation. We have developed a novel technique for measuring the spectral albedo of ice surfaces in the laboratory; this technique was used to monitor the evolution of the surface albedo of our salt crust as the ice matrix sublimated away leaving a layer of fine-grained hydrohalite crystals. Measurements of this hydrohalite surface crust show a very high albedo, comparable to fresh snow at visible wavelengths and significantly larger than fresh snow at near infrared wavelengths. Broadband albedos are 0.55 for bare artificial sea ice at -30C, 0.75 for ice containing 25% hydrohalite by volume, 0.84 after five days of desiccation and 0.93 after 47 days of desiccation. Using our laboratory measurements, along with estimates of

  7. Measuring and modeling the salting-out effect in ammonium sulfate solutions.

    PubMed

    Wang, Chen; Lei, Ying Duan; Endo, Satoshi; Wania, Frank

    2014-11-18

    The presence of inorganic salts significantly influences the partitioning behavior of organic compounds between environmentally relevant aqueous phases, such as seawater or aqueous aerosol, and other, nonaqueous phases (gas phase, organic phase, etc.). In this study, salting-out coefficients (or Setschenow constants) (KS [M(-1)]) for 38 diverse neutral compounds in ammonium sulfate ((NH4)2SO4) solutions were measured using a shared headspace passive dosing method and a negligible depletion solid phase microextraction technique. The measured KS were all positive, varied from 0.216 to 0.729, and had standard errors in the range of 0.006-0.060. Compared to KS for sodium chloride (NaCl) in the literature, KS values for (NH4)2SO4 are always higher for the same compound, suggesting a higher salting-out effect of (NH4)2SO4. A polyparameter linear free energy relationship (pp-LFER) for predicting KS in (NH4)2SO4 solutions was generated using the experimental data for calibration. pp-LFER predicted KS agreed well with measured KS reported in the literature. KS for (NH4)2SO4 was also predicted using the quantum-chemical COSMOtherm software and the thermodynamic model AIOMFAC. While COSMOtherm generally overpredicted the experimental KS, predicted and experimental values were correlated. Therefore, a fitting factor needs to be applied when using the current version of COSMOtherm to predict KS. AIOMFAC tends to underpredict the measured KS((NH4)2SO4) but always overpredicts KS(NaCl). The prediction error is generally larger for KS(NaCl) than for KS((NH4)2SO4). AIOMFAC also predicted a dependence of KS on the salt concentrations, which is not observed in the experimental data. In order to demonstrate that the models developed and calibrated in this study can be applied to estimate Setschenow coefficients for atmospherically relevant compounds involved in secondary organic aerosol formation based on chemical structure alone, we predicted and compared KS for selected

  8. Schematic of Mars Interior

    NASA Image and Video Library

    1997-10-14

    The interior of Mars is simply modeled as a core and mantle with a thin crust, similar to Earth. Mars' size and total mass have been determined by previous missions. Given four parameters, the core size and mass, and mantle size and mass can be determined. The combination of Pathfinder Doppler data with earlier data from the Viking landers has determined a third parameter, the moment of inertia, through measurement of Mars' precession rate. A fourth measurement is needed to complete the interior model. This may be achieved through future Doppler tracking of Pathfinder, since the presence of a fluid core may be detectable through its effect on Mars' nutation. The determination of the moment of inertia is a significant constraint on possible models for Mars' interior. If the core is as dense as possible (i.e. completely iron) and the mantle is similar to Earth's (or similar to the SNC meteorites thought to originate on Mars) then the minimum core radius is about 1300 km. If the core is made of less-dense material (i.e. a mixture of iron and sulfur) then the core radius is probably no more than 2000 km. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00974

  9. Hanford Supplemental Treatment: Literature and Modeling Review of SRS HLW Salt Dissolution and Fractional Crystallization

    SciTech Connect

    Choi, A. S.; Flach, G. P.; Martino, C. J.; Zamecnik, J. R.; Harris, M. K.; Wilmarth, W. R.; Calloway, T. B.

    2005-03-23

    In order to accelerate waste treatment and disposal of Hanford tank waste by 2028, the Department of Energy (DOE) and CH2M Hill Hanford Group (CHG), Inc. are evaluating alternative technologies which will be used in conjunction with the Waste Treatment Plant (WTP) to safely pretreat and immobilize the tank waste. Several technologies (Bulk Vitrification and Steam Reforming) are currently being evaluated for immobilizing the pretreated waste. Since the WTP does not have sufficient capacity to pretreat all the waste going to supplemental treatment by the 2028 milestone, two technologies (Selective Dissolution and Fractional Crystallization) are being considered for pretreatment of salt waste. The scope of this task was to: (1) evaluate the recent Savannah River Site (SRS) Tank 41 dissolution campaign and other literature to provide a more complete understanding of selective dissolution, (2) provide an update on the progress of salt dissolution and modeling activities at SRS, (3) investigate SRS experience and outside literature sources on industrial equipment and experimental results of previous fractional crystallization processes, and (4) evaluate recent Hanford AP104 boildown experiments and modeling results and recommend enhancements to the Environmental Simulation Program (ESP) to improve its predictive capabilities. This report provides a summary of this work and suggested recommendations.

  10. Modeling spatially explicit fire impact on gross primary production in interior Alaska using satellite images coupled with eddy covariance

    USGS Publications Warehouse

    Huang, Shengli; Liu, Heping; Dahal, Devendra; Jin, Suming; Welp, Lisa R.; Liu, Jinxun; Liu, Shuguang

    2013-01-01

    In interior Alaska, wildfires change gross primary production (GPP) after the initial disturbance. The impact of fires on GPP is spatially heterogeneous, which is difficult to evaluate by limited point-based comparisons or is insufficient to assess by satellite vegetation index. The direct prefire and postfire comparison is widely used, but the recovery identification may become biased due to interannual climate variability. The objective of this study is to propose a method to quantify the spatially explicit GPP change caused by fires and succession. We collected three Landsat images acquired on 13 July 2004, 5 August 2004, and 6 September 2004 to examine the GPP recovery of burned area from 1987 to 2004. A prefire Landsat image acquired in 1986 was used to reconstruct satellite images assuming that the fires of 1987–2004 had not occurred. We used a light-use efficiency model to estimate the GPP. This model was driven by maximum light-use efficiency (Emax) and fraction of photosynthetically active radiation absorbed by vegetation (FPAR). We applied this model to two scenarios (i.e., an actual postfire scenario and an assuming-no-fire scenario), where the changes in Emax and FPAR were taken into account. The changes in Emax were represented by the change in land cover of evergreen needleleaf forest, deciduous broadleaf forest, and shrub/grass mixed, whose Emax was determined from three fire chronosequence flux towers as 1.1556, 1.3336, and 0.5098 gC/MJ PAR. The changes in FPAR were inferred from NDVI change between the actual postfire NDVI and the reconstructed NDVI. After GPP quantification for July, August, and September 2004, we calculated the difference between the two scenarios in absolute and percent GPP changes. Our results showed rapid recovery of GPP post-fire with a 24% recovery immediately after burning and 43% one year later. For the fire scars with an age range of 2–17 years, the recovery rate ranged from 54% to 95%. In addition to the averaging

  11. Interaction between crustal tectonics and salt deformation in the Eastern Sardinian margin, Western Tyrrhenian Sea: seismic data and analogue modelling

    NASA Astrophysics Data System (ADS)

    Vendeville, Bruno; Lymer, Gael; Gaullier, Virginie; Chanier, Frank; Maillard, Agnes; Sage, Françoise; Lofi, Johanna; Thinon, Isabelle

    2014-05-01

    by analogue modelling) show that basement fault slip and tilting (Eastward or Westward) was accommodated by lateral flow of salt, which thinned upslope and inflated downslope, while the overlying sediments remained sub-horizontal.

  12. Salt tectonics on Venus

    SciTech Connect

    Wood, C.A.; Amsbury, D.

    1986-05-01

    The discovery of a surprisingly high deuterium/hydrogen ratio on Venus immediately led to the speculation that Venus may have once had a volume of surface water comparable to that of the terrestrial oceans. The authors propose that the evaporation of this putative ocean may have yielded residual salt deposits that formed various terrain features depicted in Venera 15 and 16 radar images. By analogy with models for the total evaporation of the terrestrial oceans, evaporite deposits on Venus should be at least tens to hundreds of meters thick. From photogeologic evidence and in-situ chemical analyses, it appears that the salt plains were later buried by lava flows. On Earth, salt diapirism leads to the formation of salt domes, anticlines, and elongated salt intrusions - features having dimensions of roughly 1 to 100 km. Due to the rapid erosion of salt by water, surface evaporite landforms are only common in dry regions such as the Zagros Mountains of Iran, where salt plugs and glaciers exist. Venus is far drier than Iran; extruded salt should be preserved, although the high surface temperature (470/sup 0/C) would probably stimulate rapid salt flow. Venus possesses a variety of circular landforms, tens to hundreds of kilometers wide, which could be either megasalt domes or salt intrusions colonizing impact craters. Additionally, arcurate bands seen in the Maxwell area of Venus could be salt intrusions formed in a region of tectonic stress. These large structures may not be salt features; nonetheless, salt features should exist on Venus.

  13. An economic evaluation of salt reduction policies to reduce coronary heart disease in England: a policy modeling study.

    PubMed

    Collins, Marissa; Mason, Helen; O'Flaherty, Martin; Guzman-Castillo, Maria; Critchley, Julia; Capewell, Simon

    2014-07-01

    Dietary salt intake has been causally linked to high blood pressure and increased risk of cardiovascular events. Cardiovascular disease causes approximately 35% of total UK deaths, at an estimated annual cost of £30 billion. The World Health Organization and the National Institute for Health and Care Excellence have recommended a reduction in the intake of salt in people's diets. This study evaluated the cost-effectiveness of four population health policies to reduce dietary salt intake on an English population to prevent coronary heart disease (CHD). The validated IMPACT CHD model was used to quantify and compare four policies: 1) Change4Life health promotion campaign, 2) front-of-pack traffic light labeling to display salt content, 3) Food Standards Agency working with the food industry to reduce salt (voluntary), and 4) mandatory reformulation to reduce salt in processed foods. The effectiveness of these policies in reducing salt intake, and hence blood pressure, was determined by systematic literature review. The model calculated the reduction in mortality associated with each policy, quantified as life-years gained over 10 years. Policy costs were calculated using evidence from published sources. Health care costs for specific CHD patient groups were estimated. Costs were compared against a "do nothing" baseline. All policies resulted in a life-year gain over the baseline. Change4life and labeling each gained approximately 1960 life-years, voluntary reformulation 14,560 life-years, and mandatory reformulation 19,320 life-years. Each policy appeared cost saving, with mandatory reformulation offering the largest cost saving, more than £660 million. All policies to reduce dietary salt intake could gain life-years and reduce health care expenditure on coronary heart disease. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  14. Modeling and Investigation of the Wear Resistance of Salt Bath Nitrided Aisi 4140 via ANN

    NASA Astrophysics Data System (ADS)

    Ekinci, Şerafettin; Akdemir, Ahmet; Kahramanli, Humar

    2013-05-01

    Nitriding is usually used to improve the surface properties of steel materials. In this way, the wear resistance of steels is improved. We conducted a series of studies in order to investigate the microstructural, mechanical and tribological properties of salt bath nitrided AISI 4140 steel. The present study has two parts. For the first phase, the tribological behavior of the AISI 4140 steel which was nitrided in sulfinuz salt bath (SBN) was compared to the behavior of the same steel which was untreated. After surface characterization using metallography, microhardness and sliding wear tests were performed on a block-on-cylinder machine in which carbonized AISI 52100 steel discs were used as the counter face. For the examined AISI 4140 steel samples with and without surface treatment, the evolution of both the friction coefficient and of the wear behavior were determined under various loads, at different sliding velocities and a total sliding distance of 1000 m. The test results showed that wear resistance increased with the nitriding process, friction coefficient decreased due to the sulfur in salt bath and friction coefficient depended systematically on surface hardness. For the second part of this study, four artificial neural network (ANN) models were designed to predict the weight loss and friction coefficient of the nitrided and unnitrided AISI 4140 steel. Load, velocity and sliding distance were used as input. Back-propagation algorithm was chosen for training the ANN. Statistical measurements of R2, MAE and RMSE were employed to evaluate the success of the systems. The results showed that all the systems produced successful results.

  15. Influence of counterions on the interaction of pyridinium salts with model membranes.

    PubMed

    Sarapuk, J; Kleszczyńska, H; Pernak, J; Kalewska, J; Rózycka-Roszak, B

    1999-11-01

    The interaction of pyridinium salts (PS) with red blood cells and planar lipid membranes was studied. The aim of the work was to find whether certain cationic surfactant counterion influence its possible biological activity. The counterions studied were Cl-, Br-, I-, ClO4-, BF4- and NO3-. The model membranes used were erythrocyte and planar lipid membranes (BLM). At high concentration the salts caused 100% erythrocyte hemolysis (C100) or broke BLMs (CC). Both parameters describe mechanical properties of model membranes. It was found that the efficiency of the surfactant to destabilize model membranes depended to some degree on its counterion. In both, erythrocyte and BLM experiments, the highest efficiency was observed for Br-, the lowest for NO3-. The influence of all other anions on surfactant efficiency changed between these two extremities; that of chloride and perchlorate ions was similar. Some differences were found in the case of BF4- ion. Its influence on hemolytic possibilities of PS was significant while BLM destruction required relatively high concentration of this anion. Apparently, the influence of various anions on the destructive action of PS on the model membrane used may be attributed to different mobilities and radii of hydrated ions and hence, to different possibilities of particular anions to modify the surface potential of model membranes. This can lead to a differentiated interaction of PS with modified bilayers. Moreover, the effect of anions on the water structure must be taken into account. It is important whether the anions can be classified as water ordering kosmotropes that hold the first hydration shell tightly or water disordering chaotropes that hold water molecules in that shell loosely.

  16. Desolvation Costs of Salt Bridges across Protein Binding Interfaces: Similarities and Differences between Implicit and Explicit Solvent Models

    PubMed Central

    2010-01-01

    The prevalence of salt bridges across protein binding interfaces is surprising given the significant costs of desolvating the two charged groups upon binding. These desolvation costs, which are difficult to examine using laboratory experiments, have been computed in previous studies using the Poisson−Boltzmann (PB) implicit solvent model. Here, for the first time, we directly compare the PB implicit solvent model with several explicit water models in computing the desolvation penalties of salt bridges across protein−protein interfaces. We report both overall agreement as well as significant differences between the implicit and explicit solvent results. These differences highlight challenges to be faced in the application of implicit solvent methods. PMID:24920993

  17. Speciation of the major inorganic salts in atmospheric aerosols of Beijing, China: Measurements and comparison with model

    NASA Astrophysics Data System (ADS)

    Tang, Xiong; Zhang, Xiaoshan; Ci, Zhijia; Guo, Jia; Wang, Jiaqi

    2016-05-01

    In the winter and summer of 2013-2014, we used a sampling system, which consists of annular denuder, back-up filter and thermal desorption set-up, to measure the speciation of major inorganic salts in aerosols and the associated trace gases in Beijing. This sampling system can separate volatile ammonium salts (NH4NO3 and NH4Cl) from non-volatile ammonium salts ((NH4)2SO4), as well as the non-volatile nitrate and chloride. The measurement data was used as input of a thermodynamic equilibrium model (ISORROPIA II) to investigate the gas-aerosol equilibrium characteristics. Results show that (NH4)2SO4, NH4NO3 and NH4Cl were the major inorganic salts in aerosols and mainly existed in the fine particles. The sulfate, nitrate and chloride associated with crustal ions were also important in Beijing where mineral dust concentrations were high. About 19% of sulfate in winter and 11% of sulfate in summer were associated with crustal ions and originated from heterogeneous reactions or direct emissions. The non-volatile nitrate contributed about 33% and 15% of nitrate in winter and summer, respectively. Theoretical thermodynamic equilibrium calculations for NH4NO3 and NH4Cl suggest that the gaseous precursors were sufficient to form stable volatile ammonium salts in winter, whereas the internal mixing with sulfate and crustal species were important for the formation of volatile ammonium salts in summer. The results of the thermodynamic equilibrium model reasonably agreed with the measurements of aerosols and gases, but large discrepancy existed in predicting the speciation of inorganic ammonium salts. This indicates that the assumption on crustal species in the model was important for obtaining better understanding on gas-aerosol partitioning and improving the model prediction.

  18. Ion diffusion coefficients model and molar conductivities of ionic salts in aprotic solvents.

    PubMed

    Garrido, Leoncio; Mejía, Alberto; García, Nuria; Tiemblo, Pilar; Guzmán, Julio

    2015-02-19

    In the study of the electric properties of electrolytes, the determination of the diffusion coefficients of the species that intervene in the charge transport process is of great importance, particularly that of the free ions (D(+) and D(-)), the only species that contribute to the conductivity. In this work we propose a model that allows, with reasonable assumptions, determination of D(+) and D(-), and the degree of dissociation of the salt, α, at different concentrations, using the diffusion coefficients experimentally obtained with NMR. Also, it is shown that the NMR data suffice to estimate the conductivity of the electrolytes. The model was checked by means of experimental results of conductivity and NMR diffusion coefficients obtained with solutions of lithium triflate in ethylene and propylene carbonates, as well as with other results taken from the literature.

  19. A reduced model for salt-fingering convection in the small Lewis number limit

    NASA Astrophysics Data System (ADS)

    Xie, Jin-Han; Knobloch, Edgar

    2016-11-01

    We derive a reduced model that captures key features of salt-fingering convection, including secondary instabilities, in the asymptotic limit of small Lewis number and large flux ratio. In the infinite Prandtl number limit, this model combines a prognostic equation for the evolution of the salinity field with a novel diagnostic relation between the streamfunction and salinity. When the salinity and temperature Rayleigh numbers RaS and RaT are large, simulations reveal the existence of statistically steady saturated states, characterized by fluxes and kinetic energy that scale as powers of (RaS / RaT) - 1 . Three distinguished regimes are identified: a weakly nonlinear regime and two strongly nonlinear regimes characterized by distinct exponents. The processes responsible for saturation are described in detail and the probability density function of the saturated fields is determined. This work was supported by the National Science Foundation under Grant No. DMS-1317666.

  20. The impact of ice I rheology on interior models of Ganymede: The elastic vs. the visco-elastic case

    NASA Astrophysics Data System (ADS)

    Steinbrügge, Gregor; Hussmann, Hauke; Sohl, Frank; Oberst, Jürgen

    2015-04-01

    Many investigations on key processes of icy satellites are driven by the rheological behavior of planetary ices. Future missions to Jupiter's icy moons (e.g. JUICE / Europa clipper) aimed at constraining the thickness of the outer ice shell using radio science and/or laser altimetry will have to address this problem. We investigate for the case of Ganymede under which conditions the ice I viscosity could be constrained by measuring the phase-lag of the tidal response using laser altimetry. In the absence of seismic data, interior structure models are constrained by the satellite's mean density and mean moment-of-inertia factor. One key observable to reduce the ambiguity of the corresponding structural models is the measurement of the dynamic response of the satellite's outer ice shells to tidal forces exerted by Jupiter and characterized by the body tide surface Love numbers h2 and k2. The Love number k2 measures the variation of the gravitational potential due to tidally induced internal redistribution of mass and can be inferred from radio science experiments. The Love number h2 is a measure for the tide-induced radial displacement of the satellite's surface. It is an advantage that Ganymede's surface displacement Love number h2 can be expected to be measured with a high accuracy using laser altimetry (Steinbrügge et al., 2014). However, the determination of the resulting ice thickness further depends on the possible existence of a liquid subsurface water ocean and on the tidally effective rheology of the outer ice shell (Moore and Schubert, 2003). Here, we distinguish between an elastic, visco-elastic or even fluid behavior in the sense of the Maxwell model and alternative rheological models. In the case of Ganymede the fluid case would imply high ice temperatures which are at odds with thermal equilibrium models calculated by Spohn and Schubert (2003). However the visco-elastic case is still possible. Laboratory measurements of ice I (e.g. Sotin et al., 1998

  1. SALMO and S3M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies

    PubMed Central

    De Stefano, Concetta

    2015-01-01

    A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium in in vitro equilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, and temperature changes. To simplify equilibrium calculations, a plain approach is also proposed, in order to take into account all the interactions among the major components of saliva, by considering the inorganic components of saliva as a single 1 : 1 salt (MX), whose concentration is c MX = (1/2)∑c i (c i = analytical concentration of all the ions) and z ion charge calculated as z=±(I/c MX)1/2 = ±1.163. The use of the Single Saliva Salt Model (S3M) considerably reduces the complexity of the systems to be investigated. In fact, only four species deriving from internal ionic medium interactions must be considered. PMID:25733975

  2. SALMO and S3M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies.

    PubMed

    Crea, Francesco; De Stefano, Concetta; Milea, Demetrio; Pettignano, Alberto; Sammartano, Silvio

    2015-01-01

    A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium in in vitro equilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, and temperature changes. To simplify equilibrium calculations, a plain approach is also proposed, in order to take into account all the interactions among the major components of saliva, by considering the inorganic components of saliva as a single 1 : 1 salt (MX), whose concentration is c MX = (1/2)∑c i (c i = analytical concentration of all the ions) and z ion charge calculated as z=±(I/c MX)(1/2) = ±1.163. The use of the Single Saliva Salt Model (S3M) considerably reduces the complexity of the systems to be investigated. In fact, only four species deriving from internal ionic medium interactions must be considered.

  3. ABA flow modelling in Ricinus communis exposed to salt stress and variable nutrition

    PubMed Central

    Peuke, Andreas D.

    2016-01-01

    In a series of experiments with Ricinus communis, abscisic acid (ABA) concentrations in tissues and transport saps, its de novo biosynthesis, long-distance transport, and metabolism (degradation) were affected by nutritional conditions, nitrogen (N) source, and nutrient limitation, or salt stress. In the present study these data were statistically re-evaluated, and new correlations presented that underpin the importance of this universal phytohormone. The biggest differences in ABA concentration were observed in xylem sap. N source had the strongest effect; however, nutrient limitation (particularly phosphorus limitation) and salt also had significant effects. ABA was found in greater concentration in phloem sap compared with xylem sap; however, the effect of treatment on ABA concentration in phloem was lower. In the leaves, ABA concentration was most variable compared with the other tissues. This variation was only affected by the N source. In roots, ABA was significantly decreased by nutrient limitation. Of the compartments in which ABA was quantified, xylem sap ABA concentration was most significantly correlated with leaf stomatal conductance and leaf growth. Additionally, ABA concentration in xylem was significantly correlated to that in phloem, indicating a 6-fold concentration increase from xylem to phloem. The ABA flow model showed that biosynthesis of ABA in roots affected the xylem flow of ABA. Moreover, ABA concentration in xylem affected the degradation of the phytohormone in shoots and also its export from shoots via phloem. The role of phloem transport is discussed since it stimulates ABA metabolism in roots. PMID:27440939

  4. Building the 3D Geological Model of Wall Rock of Salt Caverns Based on Integration Method of Multi-source data

    NASA Astrophysics Data System (ADS)

    Yongzhi, WANG; hui, WANG; Lixia, LIAO; Dongsen, LI

    2017-02-01

    In order to analyse the geological characteristics of salt rock and stability of salt caverns, rough three-dimensional (3D) models of salt rock stratum and the 3D models of salt caverns on study areas are built by 3D GIS spatial modeling technique. During implementing, multi-source data, such as basic geographic data, DEM, geological plane map, geological section map, engineering geological data, and sonar data are used. In this study, the 3D spatial analyzing and calculation methods, such as 3D GIS intersection detection method in three-dimensional space, Boolean operations between three-dimensional space entities, three-dimensional space grid discretization, are used to build 3D models on wall rock of salt caverns. Our methods can provide effective calculation models for numerical simulation and analysis of the creep characteristics of wall rock in salt caverns.

  5. Application of the Kwei equation to model the Tg behavior of binary blends of sugars and salts.

    PubMed

    Weng, Lindong; Vijayaraghavan, Ranganathan; Macfarlane, Douglas R; Elliott, Gloria D

    2014-02-01

    Vitrification of sugar-based solutions plays an important role in cryopreservation, lyophilization, and the emerging field of anhydrous preservation. An understanding of the glass transition characteristics of such formulations is essential for determining an appropriate storage temperature to ensure an extended shelf life of vitrified products. To better understand the effect of salts on the glass transition temperature (T(g)) of glass-forming sugars, we investigated several data-fitting models (Fox, Gordon-Taylor and Kwei) for sugar-salt formulations using data from the literature, as well as new data generated on blends of trehalose and choline dihydrogen phosphate (CDHP). CDHP has recently been shown to have promise as a stabilizing agent for proteins and DNA. The Kwei equation, which has a specific parameter characterizing intermolecular interactions, provides good fits to the T(g) data for sugar-salt blends, and complements other commonly used models that are frequently used to model T(g) data.

  6. Hepatic cytochrome P450 deficiency in mouse models for intrahepatic cholestasis predispose to bile salt-induced cholestasis.

    PubMed

    Kunne, Cindy; de Graaff, Marijke; Duijst, Suzanne; de Waart, Dirk R; Oude Elferink, Ronald P J; Paulusma, Coen C

    2014-10-01

    Progressive familial intrahepatic cholestasis (PFIC) types 1 and 3 are severe cholestatic liver diseases caused by deficiency of ATB8B1 and ABCB4, respectively. Mouse models for PFIC display mild phenotypes compared with human patients, and this can be explained by the difference in bile salt pool composition. Mice, unlike humans, have the ability to detoxify hydrophobic bile salts by cytochrome P450-mediated (re)hydroxylation and thus have a less toxic bile salt pool. We have crossed mouse models for PFIC1 and PFIC3 with Hrn mice that have a reduced capacity to (re)hydroxylate bile salts. Double transgenes were obtained by backcrossing Atp8b1(G308V/G308V) and Abcb4(-/-) mice with Hrn mice that have a liver-specific disruption of the cytochrome P450 reductase gene and therefore have markedly reduced P450 activity. In these mice, a more hydrophobic bile salt pool was instilled by cholic acid supplementation of the diet, and bile formation and liver pathology was studied. As opposed to single transgenes, Atp8b1(G308V/G308V)/Hrn and Abcb4(-/-)/Hrn mice rapidly developed strong cholestasis that was evidenced by increased plasma bilirubin and bile salt levels. The bile salt pool was more toxic in both models; Atp8b1(G308V/G308V)/Hrn mice had a more hydrophobic plasma pool compared with the single transgene, whereas Abcb4(-/-)/Hrn mice had a more hydrophobic biliary pool compared with the single transgene. In line with these findings, liver damage was not aggravated in Atp8b1(G308V/G308V)/Hrn but was more severe in Abcb4(-/-)/Hrn mice. These data indicate that bile salt pool composition is a critical determinant in the initiation and progression of cholestasis and liver pathology in PFIC1 and PFIC3. Most importantly, our data suggest that the hydrophobicity of the plasma bile salt pool is an important determinant of the severity of cholestasis, whereas the hydrophobicity of the biliary bile salt pool is an important determinant of the severity of liver pathology.

  7. 5. Photographic copy of photograph (Source: Salt River Project Archives, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photographic copy of photograph (Source: Salt River Project Archives, Lubken collection, R#-511) Interior of power plant prior to installation of 10' penstock generators. CA. 1911. - Theodore Roosevelt Dam, Power Plant, Salt River, Tortilla Flat, Maricopa County, AZ

  8. Three dimensional mechanical analysis of a gravity driven salt system using InSAR and numerical modeling

    NASA Astrophysics Data System (ADS)

    Kravitz, Katherine; Mueller, Karl; Upton, Phaedra

    2017-04-01

    The Grabens of Canyonlands National Park is a well-exposed gravity driven system of salt structures driven by the incision of the Colorado River canyon toward a 300 m thick evaporite layer. The region contains an array of normal faults with displacement accommodated by a combination of salt flow and overburden gliding toward the canyon and provides the opportunity to explore salt deformation mechanics in three dimensions. Maybe describe other structures besides faults? Meander anticline, diapirs. Using a combination of interferometric synthetic aperture radar (InSAR) and three-dimensional numerical modeling, we: 1) quantify displacement rates and kinematics of the region, 2) explore how various parameters driving deformation interact and control deformation, and 3) use these results to understand the mechanics of a gravity driven salt system. Initial InSAR results show average line-of-sight (LOS) displacement of 1-3 mm/yr throughout the deforming region. The data set can additionally provide a time series from 1992-2011 and multiple components of deformation using both ascending and descending scenes. Three-dimensional numerical models were created to explore the roles of overburden rheology, salt geometry, and topography on salt deformation. We converted the model displacement into LOS displacement rates for direct comparison to InSAR rates. Within the Grabens, overburden rheology plays an important role on deformation patterns. Not only do preexisting weaknesses allow propagation of deformation away from the river canyon and an increase in overburden displacement rates, the mechanics in the region are spatially complex. The models indicate a transition from gravity spreading to gliding dependent on topography, where spreading is dominant below horsts and transitions to gliding toward the grabens. Additionally, salt flow is more sensitive to smaller scale topographic features and is diverted toward individual side tributaries and grabens on spatial scales of

  9. Numerical modelling of salt diapirism and the surrounding temperature field during thin-skinned extension

    NASA Astrophysics Data System (ADS)

    Thieulot, Cedric; Harms, Guido

    2016-04-01

    The occurrence of salt diapirs is strongly associated with potential geothermal and hydrocarbon energy sources. Many numerical modelling studies of diapirism have been done in the past, though very few of these in fact use geologically realistic settings and materials. Besides, only analogue and structural studies have been done on full scale diapirism during thin-skinned extension. Two-dimensional numerical modelling of this problem using a Finite Element code aims at addressing the following questions: which geometrical or material parameters affect the growth rate and shape of the diapir and how? what is the effect of this diapirism on the temperature field and surface heat flux? How does the inclusion of simple surface processes influence these observations to first order ? Our results show that, in compliance with both analogue modelling and structural geological studies, a diapir formed during thin-skinned extension undergoes three phases: reactional piercement, active piercement and passive piercement. Extension rates directly influence the total time required for the diapir to reach the surface, as well as how long the system remains in a state of reactional diapirism, which both affect the shape of the resulting diapir. Erosion efficiency is found to affect the growth rate of the diapir during its active stage and the total rising time, which affects in turn its the shape. The density contrast between the salt and the sediments also influences the growth rate during active and passive piercement. Finally, the temperature surrounding a rising diapir (especially in the region above it) is found to be heightened by a few dozens of degrees.

  10. Salt marsh retreat induced by wind waves: experiments, field and modeling

    NASA Astrophysics Data System (ADS)

    Solari, L.; Francalanci, S.; Bendoni, M.; Cappietti, L.

    2013-12-01

    Edge erosion of salt marshes due to surface waves and tide forcing is likely the chief mechanism that models marsh boundaries and by which salt marshes in worldwide areas are being lost. To address this problem, an experimental investigation in a laboratory flume and field measurements collected in the lagoon of Venice were conducted to understand the main processes controlling marsh edge retreat with a focus on the erosion mechanisms caused by the impact of wind waves in the case of various tidal levels. A physical model reproducing a salt marsh bank was built inside a long wave current flume where random surface waves have been generated according to a given wave spectrum. The physical model was constructed with the original soil of salt marshes from the Venice Lagoon, while the wave climate was reproduced according to field measurements. In order to reveal the effect of vegetation on bank stability, two identical banks were built but for the inclusion of halophytic plants. A first set of experiments was conducted reproducing only tidal waves, a second set with wind waves superimposed to the tide. A third set o f experiments were aimed to investigate the dynamic impact and transmission of the waves on and within the bank. The following quantities were collected during the experiments: water content and pore water pressure inside the bank, water levels and velocities at various distances from the bank, dynamic pressures on the bank edge surface and internal pressure fluctuations due to wave impact. Bank geometry profile and bottom topography at different times have also been collected to characterize the erosion rate with time and the evolution of bank retreat. Two types of mass failures were observed during the experiments: slides and toppling failures. The latter were most frequently observed failures, consisting in the toppling of blocks and were often the consequence of the presence of deep tension cracks. In most cases the impact of wind waves caused the

  11. Two-site equilibrium model for ion exchange between monovalent cations and zeolite-a in a molten salt.

    SciTech Connect

    Simpson, M. F.; Gougar, M. L. D.; Engineering Technology

    2003-09-03

    A two-site model has been derived and tested against experimental data for monovalent species ion exchange in molten chloride salt/zeolite A. This system is of interest for the application of spent nuclear fuel treatment. Fission products and transuranics that accumulate in a molten salt electrorefining process can be preferentially removed and eventually stabilized in a waste form, using zeolite A. An excellent fit of Cs-Rb-Na-Li-K data to the model was found with different selectivity sequences for the two sites. Cesium was found to be the preferred cation in the ?-cage sites, while lithium was preferred in the framework sites.

  12. 77 FR 23506 - Notice of Inventory Completion: U.S. Department of Interior, Bureau of Reclamation, Upper...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ..., Upper Colorado Regional Office, Salt Lake City, UT, and Arizona State University, School of Human... U.S. Department of the Interior, Bureau of Reclamation, Upper Colorado Region, Salt Lake City, UT... Interior, Bureau of Reclamation, Upper Colorado Region, 125 South State Street, Salt Lake City, UT...

  13. Salt Composition Derived from Veazey Composition by Thermodynamic Modeling and Predicted Composition of Drum Contents

    SciTech Connect

    Weisbrod, Kirk Ryan; Veirs, Douglas Kirk; Funk, David John; Clark, David Lewis

    2016-03-11

    This report describes the derivation of the salt composition from the Veazey salt stream analysis. It also provides an estimate of the proportions of the kitty litter, nitrate salt and neutralizer that was contained in drum 68660. While the actinide content of waste streams was judiciously followed in the 1980s in TA-55, no record of the salt composition could be found. Consequently, a salt waste stream produced from 1992 to 1994 and reported by Gerry Veazey provided the basis for this study. While chemical analysis of the waste stream was highly variable, an average analysis provided input to the Stream Analyzer software to calculate a composition for a concentrated solid nitrate salt and liquid waste stream. The calculation predicted the gas / condensed phase compositions as well as solid salt / saturated liquid compositions. The derived composition provides an estimate of the nitrate feedstream to WIPP for which kinetic measurements can be made. The ratio of salt to Swheat in drum 68660 contents was estimated through an overall mass balance on the parent and sibling drums. The RTR video provided independent confirmation concerning the volume of the mixture. The solid salt layer contains the majority of the salt at a ratio with Swheat that potentially could become exothermic.

  14. Molten salt reactor neutronics and fuel cycle modeling and simulation with SCALE

    DOE PAGES

    Betzler, Benjamin R.; Powers, Jeffrey J.; Worrall, Andrew

    2017-03-01

    Current interest in advanced nuclear energy and molten salt reactor (MSR) concepts has enhanced interest in building the tools necessary to analyze these systems. A Python script known as ChemTriton has been developed to simulate equilibrium MSR fuel cycle performance by modeling the changing isotopic composition of an irradiated fuel salt using SCALE for neutron transport and depletion calculations. Some capabilities in ChemTriton that have improved, include a generic geometry capable of modeling multi-zone and multi-fluid systems, enhanced time-dependent feed and separations, and a critical concentration search. Although more generally applicable, the capabilities developed to date are illustrated in thismore » paper in three applied problems: (1) simulating the startup of a thorium-based MSR fuel cycle (a likely scenario requires the first of these MSRs to be started without available 233U); (2) determining the effect of the removal of different fission products on MSR operations; and (3) obtaining the equilibrium concentration of a mixed-oxide light-water reactor fuel in a two-stage fuel cycle with a sodium fast reactor. Moreover, the third problem is chosen to demonstrate versatility in an application to analyze the fuel cycle of a non-MSR system. During the first application, the initial fuel salt compositions fueled with different sources of fissile material are made feasible after (1) removing the associated nonfissile actinides after much of the initial fissile isotopes have burned and (2) optimizing the thorium concentration to maintain a critical configuration without significantly reducing breeding capability. In the second application, noble metal, volatile gas, and rare earth element fission products are shown to have a strong negative effect on criticality in a uranium-fueled thermal-spectrum MSR; their removal significantly increases core lifetime (by 30%) and fuel utilization. In the third application, the fuel of a mixed-oxide light

  15. Dynamic modelling and simulation of linear Fresnel solar field model based on molten salt heat transfer fluid

    NASA Astrophysics Data System (ADS)

    Hakkarainen, Elina; Tähtinen, Matti

    2016-05-01

    Demonstrations of direct steam generation (DSG) in linear Fresnel collectors (LFC) have given promising results related to higher steam parameters compared to the current state-of-the-art parabolic trough collector (PTC) technology using oil as heat transfer fluid (HTF). However, DSG technology lacks feasible solution for long-term thermal energy storage (TES) system. This option is important for CSP technology in order to offer dispatchable power. Recently, molten salts have been proposed to be used as HTF and directly as storage medium in both line-focusing solar fields, offering storage capacity of several hours. This direct molten salt (DMS) storage concept has already gained operational experience in solar tower power plant, and it is under demonstration phase both in the case of LFC and PTC systems. Dynamic simulation programs offer a valuable effort for design and optimization of solar power plants. In this work, APROS dynamic simulation program is used to model a DMS linear Fresnel solar field with two-tank TES system, and example simulation results are presented in order to verify the functionality of the model and capability of APROS for CSP modelling and simulation.

  16. Interior Cornice Profile, Interior Pilaster Profile, Lions Head Roof Scupper, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior Cornice Profile, Interior Pilaster Profile, Lions Head Roof Scupper, and Interior Panel Moulding - Flanders Field American Cemetery & Memorial, Chapel, Wortegemseweg 117, Waregem, West Flanders (Belgium)

  17. Model of the biotic cycle "plants germs - microorganisms" by affect heavy metal salts

    NASA Astrophysics Data System (ADS)

    Pisman, Tamara

    The growth of wheat germ roots exposed to heavy metal salts (ZnSO4) was studied experimentally and theoretically. During the experiment the plant seeds were preliminarily treated with an experimental microbial association. As a result, data were obtained about the decrease of the inhibiting effect of zinc on the growth of wheat germ roots where the seeds had been treated with the microbial association. To understand such effect, calculations were made to reveal the specific growth rate of a germ root depending on the inhibitor concentration with and without microorganism association treatment. It was shown that in case with the wheat germ roots the seeds of which had been treated with the microorganisms the inhibition constant (kI = 45 MPC (Maximum Permissible Concentration) was higher than in the case with the roots growing out of the seeds that hadn't been treated with the microorganisms (kI = 32 MPC). One of possible reasons for the decrease of growth inhibition of wheat germ roots by zinc salt is the protective function of microorganism's treatment of the seeds. To verify and confirm the experimental results, a mathematical model was created imitating the interaction between wheat germ roots and microbial association exposed to an inhibitor. Investigation of the model proved that the microbial association has a positive effect on the growth of wheat germ roots exposed to an inhibitor. The experimental and theoretical results agreed quantitatively. It was found out that the increase of the inhibitor concentration led to the effect of maximum relief of zinc inhibiting impact. The work is supported by grants Yenissei 07-04-96806.

  18. Pre-operative simulation of periacetabular osteotomy via a three-dimensional model constructed from salt

    PubMed Central

    Fukushima, Kensuke; Takahira, Naonobu; Uchiyama, Katsufumi; Moriya, Mitsutoshi; Takaso, Masashi

    2017-01-01

    Introduction: Periacetabular osteotomy (PAO) is an effective joint-preserving procedure for young adults with developmental dysplasia of the hip. Although PAO provides excellent radiographic and clinical results, it is a technically demanding procedure with a distinct learning curve that requires careful 3D planning and, above all, has a number of potential complications. We therefore developed a pre-operative simulation method for PAO via creation of a new full-scale model. Methods: The model was prepared from the patient’s Digital Imaging and Communications in Medicine (DICOM) formatted data from computed tomography (CT), for construction and assembly using 3D printing technology. A major feature of our model is that it is constructed from salt. In contrast to conventional models, our model provides a more accurate representation, at a lower manufacturing cost, and requires a shorter production time. Furthermore, our model realized simulated operation normally with using a chisel and drill without easy breakage or fissure. We were able to easily simulate the line of osteotomy and confirm acetabular version and coverage after moving to the osteotomized fragment. Additionally, this model allowed a dynamic assessment that avoided anterior impingement following the osteotomy. Results: Our models clearly reflected the anatomical shape of the patient’s hip. Our models allowed for surgical simulation, making realistic use of the chisel and drill. Our method of pre-operative simulation for PAO allowed for the assessment of accurate osteotomy line, determination of the position of the osteotomized fragment, and prevented anterior impingement after the operation. Conclusion: Our method of pre-operative simulation might improve the safety, accuracy, and results of PAO. PMID:28186873

  19. Nutritional modelling: distributions of salt intake from processed foods in New Zealand.

    PubMed

    Thomson, Barbara M

    2009-09-01

    The salt content of processed foods is important because of the high intake of Na by most New Zealanders. A database of Na concentrations in fifty-eight processed foods was compiled from existing and new data and combined with 24 h diet recall data from two national nutrition surveys (5771 respondents) to derive salt intakes for seven population groups. Mean salt intakes from processed foods ranged from 6.9 g/d for young males aged 19-24 years to 3.5 g/d for children aged 5-6 years. A total of > or = 50 % of children aged 5-6 years, boys aged 11-14 years and young males aged 19-24 years had salt intakes that exceeded the upper limit for Na, calculated as salt (3.2-5.3 g/d), from processed foods only. Bread accounted for the greatest contribution to salt intake for each population group (35-43 % of total salt intake). Other foods that contributed 2 % or more and common across most age groups were sausage, meat pies, pizza, instant noodles and cheese. The Na concentrations of key foods have changed little over the 16-year period from 1987 to 2003 except for corned beef and whole milk that have decreased by 34 and 50 % respectively. Bread is an obvious target for salt reduction but the implication on iodine intake needs consideration as salt is used as a vehicle for iodine fortification of bread.

  20. Analog modeling and kinematic restoration of inverted hangingwall synclinal basins developed above syn-kinematic salt: Application to the Lusitanian and Parentis basins

    NASA Astrophysics Data System (ADS)

    Roma, Maria; Vidal-Royo, Oskar; McClay, Ken; Ferrer, Oriol; Muñoz, Josep Anton

    2017-04-01

    The formation of hagingwall syncline basins is basically constrained by the geometry of the basement-involved fault, but also by salt distribution . The formation of such basins is common around the Iberian Peninsula (e.g. Lusitanian, Parentis, Basque-Cantabian, Cameros and Organyà basins) where Upper Triassic (Keuper) salt governed their polyphasic Mesozoic extension and their subsequent Alpine inversion. In this scenario, a precise interpretation of the sub-salt faults geometry and a reconstruction of the initial salt thickness are key to understand the kinematic evolution of such basins. Using an experimental approach (sandbox models) and these Mesozoic basins as natural analogues, the aim of this work is to: 1) investigate the main parameters that controlled the formation and evolution of hagingwall syncline basins analyzing the role of syn-kinematic salt during extension and subsequent inversion; and 2) quantify the deformation and salt mobilization based on restoration of analog model cross sections. The experimental results demonstrate that premature welds are developed by salt deflation with consequent upward propagation of the basal fault in salt-bearing rift systems with a large amount of extension,. In contrast, thicker salt inhibits the upward fault propagation, which results into a further salt migration and development of a hagingwall syncline basins flanked by salt walls. The inherited extensional architecture as well as salt continuity dramatically controlled subsequent inversion. Shortening initially produced the folding and the uplift of the synclinal basins. Minor reverse faults form as a consequence of overtightening of welded diapir stems. However, no trace of reverse faulting is found around diapirs stems, as ductile unit is still available for extrusion, squeezing and accommodation of shortening. Restoration of the sandbox models has demonstrated that this is a powerful tool to unravel the complex structures in the models and this may

  1. micro-RNA screening and prediction model construction for diagnosis of salt-sensitive essential hypertension.

    PubMed

    Qi, Han; Liu, Zheng; Liu, Bin; Cao, Han; Sun, Weiping; Yan, Yuxiang; Zhang, Ling

    2017-04-01

    Commonly used tests for diagnosis of salt-sensitive hypertension (SSH) are complex and time-consuming, so new methods are required. Many studies have demonstrated roles for miRNAs in hypertension; however, the diagnostic value of miRNAs has yet to be determined for human SSH. In this study, we examined miRNA expression profiles by initial high-throughput miRNA sequencing of samples from patients with salt-sensitive and salt-resistant hypertension (SSH and SRH, respectively; n = 6, both groups), followed by validation by quantitative real-time polymerase chain reaction (qRT-PCR) in a larger cohort (n = 91). We also evaluated differences in baseline characteristics (e.g., age, sex, body mass index, consumption of specific foods) between the SSH and SRH groups. Of 36 miRNAs identified as differentially expressed between SSH and SRH groups by RNA-Seq, 8 were analyzed by qRT-PCR. There were significant differences in the expression levels of hsa-miR-361-5p and hsa-miR-362-5p between the 2 groups (P = .023 and.049, respectively). In addition, there were significant differences in sauce and poultry consumption between the 2 groups (P = .004 and.001, respectively). The areas under the curve (AUC) determined by receptor operating characteristic (ROC) analysis for hsa-miR-361-5p and all 8 miRNAs were 0.793 (95% CI, 0.698-0.888; sensitivity = 73.9%, specificity = 74.4%; P < .001) and 0.836 (95% CI, 0.749-0.922; sensitivity = 80.4%, specificity = 81.4%; P < .001), respectively, when sauce and poultry consumption were included in the models. Assay feasibility and economic considerations make hsa-miR-361-5p combined with the dietary factors the preferred markers for diagnosis of SSH.

  2. Cerebral salt wasting in subarachnoid hemorrhage rats: model, mechanism, and tool.

    PubMed

    Kojima, Jun; Katayama, Yoichi; Moro, Nobuhiro; Kawai, Hiroyuki; Yoneko, Maki; Mori, Tatsuro

    2005-04-01

    Cerebral salt wasting (CSW) frequently occurs concomitantly with aneurysmal subarachnoid hemorrhage (SAH). CSW induces excessive natriuresis and osmotic diuresis, and reduces total blood volume. As a result, the risk of symptomatic cerebral vasospasm may be elevated. Therefore, it is important to determine the mechanism of CSW. The purpose of this study was to evaluate whether the rat SAH model exhibits CSW and to investigate the relationship between CSW and natriuretic peptides. A SAH model was produced in 24 rats by perforating a cerebral artery with a nylon thread up through the common carotid artery. To evaluate CSW, urine was cumulatively collected from SAH onset to 12 hours and sodium (Na) excretion was analyzed. Body weight and hematocrit were analyzed before and after SAH onset. Concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in plasma were also analyzed. Urine volume and total Na excretion of SAH rats were significantly higher than those of sham rats (p<0.05). Body weight of SAH rats significantly decreased and hematocrit significantly increased (p < 0.05). ANP concentration was significantly decreased in SAH rats (p<0.05). However, BNP concentrations did not change. This study demonstrated for the first time that a rat SAH model exhibited CSW. It was suggested that the cause of CSW was neither ANP nor BNP. In addition, this rat SAH model will be useful for study of CSW after SAH.

  3. Binding Enthalpy Calculations for a Neutral Host-Guest Pair Yield Widely Divergent Salt Effects across Water Models

    PubMed Central

    Gao, Kaifu; Yin, Jian; Henriksen, Niel M.; Fenley, Andrew T.; Gilson, Michael K.

    2015-01-01

    Dissolved salts are a part of the physiological milieu and can significantly influence the kinetics and thermodynamics of varied biomolecular processes, such as binding and catalysis, so it is important for molecular simulations to reliably describe their effects. The present study uses a simple, non-ionized host-guest model system to study the sensitivity of computed binding enthalpies to the choice of water and salt models. Molecular dynamics simulations of a cucurbit[7]uril host with a neutral guest molecule show striking differences in the salt dependency of the binding enthalpy across four water models, TIP3P, SPC/E, TIP4P-Ew and OPC, with additional sensitivity to the choice of parameters for sodium and chloride. In particular, although all of the models predict that binding will be less exothermic with increasing NaCl concentration, the strength of this effect varies by 7 kcal/mol across models. The differences appear to result primarily from differences in the number of sodium ions displaced from the host on binding the guest, rather than from differences in the enthalpy associated with this displacement; and it is the electrostatic energy that contributes most to the changes in enthalpy with increasing salt concentration. That a high sensitivity of salt effects to the choice of water model is observed for the present host-guest system, despite its being non-ionized, raises issues regarding the selection and adjustment of water models for use with biological macromolecules, especially as these typically possess multiple ionized groups which can interact relatively strongly with ions in solution. PMID:26574247

  4. Binding enthalpy calculations for a neutral host-guest pair yield widely divergent salt effects across water models.

    PubMed

    Gao, Kaifu; Yin, Jian; Henriksen, Niel M; Fenley, Andrew T; Gilson, Michael K

    2015-10-13

    Dissolved salts are a part of the physiological milieu and can significantly influence the kinetics and thermodynamics of various biomolecular processes, such as binding and catalysis; thus, it is important for molecular simulations to reliably describe their effects. The present study uses a simple, nonionized host-guest model system to study the sensitivity of computed binding enthalpies to the choice of water and salt models. Molecular dynamics simulations of a cucurbit[7]uril host with a neutral guest molecule show striking differences in the salt dependency of the binding enthalpy across four water models, TIP3P, SPC/E, TIP4P-Ew, and OPC, with additional sensitivity to the choice of parameters for sodium and chloride. In particular, although all of the models predict that binding will be less exothermic with increasing NaCl concentration, the strength of this effect varies by 7 kcal/mol across models. The differences appear to result primarily from differences in the number of sodium ions displaced from the host upon binding the guest rather than from differences in the enthalpy associated with this displacement, and it is the electrostatic energy that contributes most to the changes in enthalpy with increasing salt concentration. That a high sensitivity of salt affecting the choice of water model, as observed for the present host-guest system despite it being nonionized, raises issues regarding the selection and adjustment of water models for use with biological macromolecules, especially as these typically possess multiple ionized groups that can interact relatively strongly with ions in solution.

  5. Additional disinfection with a modified salt solution in a root canal model.

    PubMed

    van der Waal, Suzette V; Oonk, Charlotte A M; Nieman, Selma H; Wesselink, Paul R; de Soet, Johannes J; Crielaard, Wim

    2015-10-01

    The aim of this study is to investigate the disinfecting properties of a modified salt solution (MSS) and calcium hydroxide (Ca(OH)2) in a non-direct-contact ex-vivo model. Seventy-four single-canal roots infected with Enterococcus faecalis were treated with 1% sodium hypochlorite (NaOCl) irrigation or with NaOCl irrigation with subsequent dressing with MSS or Ca(OH)2. After removal of the dressings, the roots were filled with bacterial growth medium and incubated for seven days to enable the surviving bacteria to repopulate the root canal lumen. Growth was determined by sampling the root canals with paper points before treatment (S1), after treatment (S2) and incubation after treatment (S3). The colony forming units were counted at S1 and S2. At S3, growth was determined as no/yes regrowth. The Kruskal-Wallis, McNemar and χ(2) test were used for statistical analyses. At S2, in the NaOCl group, growth was found in 5 of 19 root canals. After the removal of MSS or Ca(OH)2 bacteria were retrieved from one root canal in both groups. At S3, repopulation of the root canals had occurred in 14 of 19 roots after sole NaOCl irrigation, 6 of 20 roots after MSS-dressing and in 14 of 20 roots after Ca(OH)2-dressing. MSS was more effective in preventing regrowth than Ca(OH)2 (P=0.009). The modified salt solution prevented regrowth in roots which indicates that it can eliminate persistent bacteria. Dressing the root canals with Ca(OH)2 did not provide additional disinfection after NaOCl irrigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Miocene to recent ice elevation variations from the interior of the West Antarctic ice sheet: Constraints from geologic observations, cosmogenic nuclides and ice sheet modeling

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sujoy; Ackert, Robert P.; Pope, Allen E.; Pollard, David; DeConto, Robert M.

    2012-07-01

    Observations of long-term West Antarctic Ice Sheet (WAIS) behavior can be used to test and constrain dynamic ice sheet models. Long-term observational constraints are however, rare. Here we present the first constraints on long-term (Miocene-Holocene) WAIS elevation from the interior of the ice sheet near the WAIS divide. We use geologic observations and measurements of cosmogenic 21Ne and 10Be in bedrock surfaces to constrain WAIS elevation variations to <160 m above the present-day ice levels since 7 Ma, and <110 m above present-day ice levels since 5.4 Ma. The cosmogenic nuclide data indicate that bedrock surfaces 35 m above the present-day ice levels had near continuous exposure over the past 3.5 Ma, requiring average interior WAIS elevations to have been similar to, or lower than present, since the beginning of the Pliocene warm period. We use a continental ice sheet model to simulate the history of ice cover at our sampling sites and thereby compute the expected concentration of the cosmogenic nuclides. The ice sheet model indicates that during the past 5 Ma interior WAIS elevations of >65 m above present-day ice levels at the Ohio Range occur only rarely during brief ice sheet highstands, consistent with the observed cosmogenic nuclide data. Furthermore, the model's prediction that highstand elevations have increased on average since the Pliocene is in good agreement with the cosmogenic nuclide data that indicate the highest ice elevation over the past 5 Ma was reached during the highstand at 11 ka. Since the simulated cosmogenic nuclide concentrations derived from the model's ice elevation history are in good agreement with our measurements, we suggest that the model's prediction of more frequent collapsed-WAIS states and smaller WAIS volumes during the Pliocene are also correct.

  7. Non-monotonic course of protein solubility in aqueous polymer-salt solutions can be modeled using the sol-mxDLVO model.

    PubMed

    Herhut, Marcel; Brandenbusch, Christoph; Sadowski, Gabriele

    2016-02-01

    Protein purification is often performed using cost-intensive chromatographic steps. To discover economic alternatives (e.g., crystallization), knowledge on protein solubility as a function of temperature, pH, and additives in solution as well as their concentration is required. State-of-the-art models for predicting protein solubility almost exclusively consider aqueous salt systems, whereas "salting-in" and "salting-out" effects induced by the presence of an additional polymer are not considered. Thus, we developed the sol-mxDLVO model. Using this newly developed model, protein solubility in the presence of one salt and one polymer, especially the non-monotonic course of protein solubility, could be predicted. Systems considered included salts (NaCl, Na-p-Ts, (NH(4))(2) SO(4)) and the polymer polyethylene glycol (MW: 2000 g/mol, 12000 g/mol) and proteins lysozyme from chicken egg white (pH 4 to 5.5) and D-xylose ketol-isomerase (pH 7) at 298.15 K. The results show that by using the sol-mxDLVO model, protein solubility in polymer-salt solutions can be modeled in good agreement with the experimental data for both proteins considered. The sol-mxDLVO model can describe the non-monotonic course of protein solubility as a function of polymer concentration and salt concentration, previously not covered by state-of-the-art models. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. [Simulation of effect of irrigation with reclaimed water on soil water-salt movement by ENVIRO-GRO model].

    PubMed

    Lü, Si-Dan; Chen, Wei-Ping; Wang, Mei-E

    2012-12-01

    As the conflict between water supply and demand, wastewater reuse has become an important measure, which can relieve the water shortage in Beijing. In order to promote safe irrigation with reclaimed water and prevent soil salinisation, the dynamic transport of salts in urban soils of Beijing, a city of water shortage, under irrigation of reclaimed water was simulated by ENVIRO-GRO model in this research. The accumulation trends of soil salinity were predicted. Simultaneously, it investigated the effects of different irrigation practices on soil water-salt movement and salt accumulation. Results indicated that annual averages of soil salinity (EC(e)) increased 29.5%, 97.2%, 197.8% respectively, with the higher irrigation, normal irrigation, and low irrigation under equilibrium conditions. Irrigation frequency had little effect on soil salt-water movement, and soil salt accumulation was in a downward trend with low frequency of irrigation. Under equilibrium conditions, annual averages of EC(e) increased 23.7%, 97.2%, 208.5% respectively, with irrigation water salinity (EC(w)) 0.6, 1.2, 2.4 dS x m(-1). Soil salinity increased slightly with EC(w) = 0.6 dS x m(-1), while soil salinization did not appear. Totally, the growth of Blue grass was not influenced by soil salinity under equilibrium conditions with the regular irrigation in Beijing, but mild soil salinization appeared.

  9. Using Kinetic Network Models To Probe Non-Native Salt-Bridge Effects on α-Helix Folding.

    PubMed

    Zhou, Guangfeng; Voelz, Vincent A

    2016-02-11

    Salt-bridge interactions play an important role in stabilizing many protein structures, and have been shown to be designable features for protein design. In this work, we study the effects of non-native salt bridges on the folding of a soluble alanine-based peptide (Fs peptide) using extensive all-atom molecular dynamics simulations performed on the Folding@home distributed computing platform. Using Markov State Models, we show how non-native salt-bridges affect the folding kinetics of Fs peptide by perturbing specific conformational states. Furthermore, we present methods for the automatic detection and analysis of such states. These results provide insight into helix folding mechanisms and useful information to guide simulation-based computational protein design.

  10. Simple theoretical model for ion cooperativity in aqueous solutions of simple inorganic salts and its effect on water surface tension.

    PubMed

    Gao, Yi Qin

    2011-11-03

    Careful analysis of experimental data showed that the salt aqueous solution/air surface tension depends on a rather complicated manner of salt composition and points to the importance of ion cooperativity. In this short article, we include the selective binding of anions over cations at interfaces (as revealed from molecular dynamics simulations, spectroscopic measurements, and Record's analysis of the surface tension data) and the anion-cation association (based on the observation of matching water affinity) in a simple theoretical model to understand salt effects on surface tension. The introduction of the surface effect and ion association provides a qualitative explanation of the experimental data, in particular, the strong anion dependence of the cations' rank according to their ability of increasing water surface tension. We hope that the physical insight provided by this study can be used to point to new directions for more detailed studies.

  11. Adaptation of Staphylococcus xylosus to Nutrients and Osmotic Stress in a Salted Meat Model.

    PubMed

    Vermassen, Aurore; Dordet-Frisoni, Emilie; de La Foye, Anne; Micheau, Pierre; Laroute, Valérie; Leroy, Sabine; Talon, Régine

    2016-01-01

    Staphylococcus xylosus is commonly used as starter culture for meat fermentation. Its technological properties are mainly characterized in vitro, but the molecular mechanisms for its adaptation to meat remain unknown. A global transcriptomic approach was used to determine these mechanisms. S. xylosus modulated the expression of about 40-50% of the total genes during its growth and survival in the meat model. The expression of many genes involved in DNA machinery and cell division, but also in cell lysis, was up-regulated. Considering that the S. xylosus population remained almost stable between 24 and 72 h of incubation, our results suggest a balance between cell division and cell lysis in the meat model. The expression of many genes encoding enzymes involved in glucose and lactate catabolism was up-regulated and revealed that glucose and lactate were used simultaneously. S. xylosus seemed to adapt to anaerobic conditions as revealed by the overexpression of two regulatory systems and several genes encoding cofactors required for respiration. In parallel, genes encoding transport of peptides and peptidases that could furnish amino acids were up-regulated and thus concomitantly a lot of genes involved in amino acid synthesis were down-regulated. Several genes involved in glutamate homeostasis were up-regulated. Finally, S. xylosus responded to the osmotic stress generated by salt added to the meat model by overexpressing genes involved in transport and synthesis of osmoprotectants, and Na(+) and H(+) extrusion.

  12. Adaptation of Staphylococcus xylosus to Nutrients and Osmotic Stress in a Salted Meat Model

    PubMed Central

    Vermassen, Aurore; Dordet-Frisoni, Emilie; de La Foye, Anne; Micheau, Pierre; Laroute, Valérie; Leroy, Sabine; Talon, Régine

    2016-01-01

    Staphylococcus xylosus is commonly used as starter culture for meat fermentation. Its technological properties are mainly characterized in vitro, but the molecular mechanisms for its adaptation to meat remain unknown. A global transcriptomic approach was used to determine these mechanisms. S. xylosus modulated the expression of about 40–50% of the total genes during its growth and survival in the meat model. The expression of many genes involved in DNA machinery and cell division, but also in cell lysis, was up-regulated. Considering that the S. xylosus population remained almost stable between 24 and 72 h of incubation, our results suggest a balance between cell division and cell lysis in the meat model. The expression of many genes encoding enzymes involved in glucose and lactate catabolism was up-regulated and revealed that glucose and lactate were used simultaneously. S. xylosus seemed to adapt to anaerobic conditions as revealed by the overexpression of two regulatory systems and several genes encoding cofactors required for respiration. In parallel, genes encoding transport of peptides and peptidases that could furnish amino acids were up-regulated and thus concomitantly a lot of genes involved in amino acid synthesis were down-regulated. Several genes involved in glutamate homeostasis were up-regulated. Finally, S. xylosus responded to the osmotic stress generated by salt added to the meat model by overexpressing genes involved in transport and synthesis of osmoprotectants, and Na+ and H+ extrusion. PMID:26903967

  13. Interior intrusion detection systems

    SciTech Connect

    Rodriguez, J.R.; Matter, J.C. ); Dry, B. )

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

  14. Parenteral nutrition dysregulates bile salt homeostasis in a rat model of parenteral nutrition-associated liver disease.

    PubMed

    Koelfat, Kiran V K; Schaap, Frank G; Hodin, Caroline M J M; Visschers, Ruben G J; Svavarsson, Björn I; Lenicek, Martin; Shiri-Sverdlov, Ronit; Lenaerts, Kaatje; Olde Damink, Steven W M

    2017-10-01

    Parenteral nutrition (PN), a lifesaving therapy in patients with intestinal failure, has been associated with hepatobiliary complications including steatosis, cholestasis and fibrosis, collectively known as parenteral nutrition-associated liver disease (PNALD). To date, the pathogenesis of PNALD is poorly understood and therapeutic options are limited. Impaired bile salt homeostasis has been proposed to contribute PNALD. The objective of this study was to establish a PNALD model in rats and to evaluate the effects of continuous parenteral nutrition (PN) on bile salt homeostasis. Rats received either PN via the jugular vein or received normal diet for 3, 7 or 14 days. Serum biochemistry, hepatic triglycerides, circulating bile salts and C4, IL-6 and TNF-alpha, and lipogenic and bile salt homeostatic gene expression in liver and ileum were assessed. PN increased hepatic triglycerides already after 3 days of administration, and resulted in conjugated bilirubin elevation after 7 or more days. This indicates PN-induced steatosis and impaired canalicular secretion of bilirubin, the latter which is in line with reduced hepatic expression of Mrp2 mRNA. There was no histological evidence for liver inflammation after PN administration, and circulating levels of pro-inflammatory cytokines IL-6 and TNF-α, were comparable in all groups. Hepatic expression of Fxr mRNA was decreased after 7 days of PN, without apparent effect on expression of Fxr targets Bsep and Shp. Nonetheless, Cyp7a1 expression was reduced after 7 days of PN, indicative for lowered bile salt synthesis. Circulating levels of C4 (marker of bile salt synthesis) were also decreased after 3, 7 and 14 days of PN. Levels of circulating bile salts were not affected by PN. This study showed that PN in rats caused early mild steatosis and cholestasis, while hepatic and systemic inflammation were not present. The onset of these abnormalities was associated with alterations in bile salt synthesis and transport. This

  15. Simulating Salt Movement and Transformation using a Coupled Reactive Transport Model in Variably-Saturated Groundwater Systems

    NASA Astrophysics Data System (ADS)

    Tavakoli Kivi, S.; Bailey, R. T.; Gates, T.

    2016-12-01

    Salinization is one of the major concerns in irrigated agricultural landscapes. Increasing salinity concentrations are due principally to evaporative concentration; dissolution of salts from weathered minerals and bedrock; and a high water table that results from excessive irrigation, canal seepage, and a lack of efficient drainage systems; leading to decreasing crop yield. High groundwater salinity loading to nearby river systems also impacts downstream areas, with saline river water diverted for application on irrigated fields. In this study, a solute transport model coupled with equilibrium chemistry reactions has been developed to simulate transport of individual salt ions in regional-scale aquifer systems and thereby investigate strategies for salinity remediation. The physically-based numerical model is based on the UZF-RT3D variably-saturated, multi-species groundwater reactive transport modeling code, and accounts for advection, dispersion, carbon and nitrogen cycling, oxidation-reduction reactions, and salt ion equilibrium chemistry reactions such as complexation, ion exchange, and precipitation/dissolution. Each major salt ion (sulfate, chloride, bicarbonate, calcium, sodium, magnesium, potassium) is included. The model has been tested against measured soil salinity at a small scale (soil profile) and against soil salinity, groundwater salinity, and groundwater salinity loading to surface water at the regional scale (500 km2) in the Lower Arkansas River Valley (LARV) in southeastern Colorado, an area acutely affected by salinization for many decades and greatly influenced by gypsum deposits. Preliminary results of using the model in scenario analysis suggest that increasing irrigation efficiency, sealing earthen canals, and rotational fallowing of land can decrease the groundwater salt load to the Arkansas River by 50 to 70% and substantially lower soil salinity in the root zone.

  16. Introductory lecture: interpreting and predicting Hofmeister salt ion and solute effects on biopolymer and model processes using the solute partitioning model.

    PubMed

    Record, M Thomas; Guinn, Emily; Pegram, Laurel; Capp, Michael

    2013-01-01

    Understanding how Hofmeister salt ions and other solutes interact with proteins, nucleic acids, other biopolymers and water and thereby affect protein and nucleic acid processes as well as model processes (e.g. solubility of model compounds) in aqueous solution is a longstanding goal of biophysical research. Empirical Hofmeister salt and solute "m-values" (derivatives of the observed standard free energy change for a model or biopolymer process with respect to solute or salt concentration m3) are equal to differences in chemical potential derivatives: m-value = delta(dmu2/dm3) = delta mu23, which quantify the preferential interactions of the solute or salt with the surface of the biopolymer or model system (component 2) exposed or buried in the process. Using the solute partitioning model (SPM), we dissect mu23 values for interactions of a solute or Hofmeister salt with a set of model compounds displaying the key functional groups of biopolymers to obtain interaction potentials (called alpha-values) that quantify the interaction of the solute or salt per unit area of each functional group or type of surface. Interpreted using the SPM, these alpha-values provide quantitative information about both the hydration of functional groups and the competitive interaction of water and the solute or salt with functional groups. The analysis corroborates and quantifies previous proposals that the Hofmeister anion and cation series for biopolymer processes are determined by ion-specific, mostly unfavorable interactions with hydrocarbon surfaces; the balance between these unfavorable nonpolar interactions and often-favorable interactions of ions with polar functional groups determine the series null points. The placement of urea and glycine betaine (GB) at opposite ends of the corresponding series of nonelectrolytes results from the favorable interactions of urea, and unfavorable interactions of GB, with many (but not all) biopolymer functional groups. Interaction potentials and

  17. Optically measuring interior cavities

    SciTech Connect

    Stone, Gary Franklin

    2008-12-21

    A method of measuring the three-dimensional volume or perimeter shape of an interior cavity includes the steps of collecting a first optical slice of data that represents a partial volume or perimeter shape of the interior cavity, collecting additional optical slices of data that represents a partial volume or perimeter shape of the interior cavity, and combining the first optical slice of data and the additional optical slices of data to calculate of the three-dimensional volume or perimeter shape of the interior cavity.

  18. 3-D density modelling of underground structures and spatial distribution of salt diapirism in the Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Götze, H.-J.; Meyer, U.; Group, Desire

    2011-03-01

    A new compilation of Bouguer gravity data stemming from airborne, shipborne and terrestrial data set in the entire Dead Sea Basin (DSB) was reinterpreted by applying 3-D density modelling that incorporated independent information on other geophysical researches allowing for regional and residual filtering in the gravity field, carrying out curvature analysis and Euler deconvolution of the combined gravity field. 3-D density modelling enables us to detailed resolution of upper crustal structures from the southern to the northern subbasin below the saline Dead Sea. 3-D gravity modelling led to the identification of three salt structures, which are found beneath the Sedom area, the Lisan Peninsula and the Dead Sea. In the vicinity of the western margin of the Dead Sea, a salt diapir segment with a thickness of about 4 km has been identified at a top depth of about 2 km, which has not been recognised by any other geophysical interpretations. The thickness of the sedimentary infill overlying the basement in the DSB decreases from 14 km in the vicinity of the Lisan Peninsula to 8 km in the northern and the southern subbasins. Large negative gravity anomalies (lower than -100 × 10-5 m s-2) observed in the DSB correspond with the spatial distribution of salt diapirism with an average density of 2 100 kg m-3. The shallower microearthquakes registered in the DSB are related to the movement of salt diapir in the DSB.

  19. Comparing field-based and numerically modelled reconstructions of the last Cordilleran Ice Sheet deglaciation over the Thompson Plateau, southern interior British Columbia, Canada.

    NASA Astrophysics Data System (ADS)

    Cripps, Jonathan; Brennand, Tracy; Seguinot, Julien; Perkins, Andrew

    2016-04-01

    Palaeoglaciological and palaeoclimate reconstructions of the deglaciation of the last Cordilleran Ice Sheet (CIS) over British Columbia (BC), Canada, are limited by the relative lack of understanding of the late-glacial ice sheet margins and dynamics. Deglaciation of the last CIS over the southern Interior Plateau of BC has been characterised as proceeding via stagnation and downwasting into dead ice lobes in valleys where ice was thickest. This conceptual model explains the apparent lack of moraines, which may otherwise imply active recession, and known palaeo-glacial lakes are explained as being dammed by these dead ice lobes. However, downwasting alone is at odds with coeval ice sheets which receded systematically towards their interiors. Presented here is a comparison between a new field-based reconstruction of the deglaciation of the northern Thompson Plateau, and ice sheet model results of the same area. Glacioisostatic tilts, reconstructed using mapped shoreline elevations, rise to the north-northwest at around 1.8 m/km, implying an ice surface slope, and likely active recession, towards the Coast Mountains. New reconstructions of the stages of glacial Lake Nicola (gLN), utilising field and aerial photographic mapping of shorelines, and sedimentology and geophysical surveys on ice-marginal and glaciolacustrine landforms, largely support this interpretation; the lake expanded and lowered to the north-northwest as progressively lower outlets were opened during ice retreat in this direction. Fields of newly discovered glaciotectonised moraines, grounding-line deposits and overridden glacial lake sediments record ice margin oscillations and minor readvances within gLN; the general alignment of these features further supports recession to the north-northwest. Numerical simulations of deglaciation of the area results in ice retreat to the north-northeast, which is inconsistent with the north-north-westward evolution of gLN. Excess precipitation over the eastern

  20. Faraday Discussion 160 Introductory Lecture: Interpreting and Predicting Hofmeister Salt Ion and Solute Effects on Biopolymer and Model Processes Using the Solute Partitioning Model

    PubMed Central

    Record, M. Thomas; Guinn, Emily; Pegram, Laurel; Capp, Michael

    2013-01-01

    Understanding how Hofmeister salt ions and other solutes interact with proteins, nucleic acids, other biopolymers and water and thereby affect protein and nucleic acid processes as well as model processes (e.g solubility of model compounds) in aqueous solution is a longstanding goal of biophysical research. Empirical Hofmeister salt and solute “m-values” (derivatives of the observed standard free energy change for a model or biopolymer process with respect to solute or salt concentration m3) are equal to differences in chemical potential derivatives: m-value = Δ(dμ2/dm3) = Δμ23 which quantify the preferential interactions of the solute or salt with the surface of the biopolymer or model system (component 2) exposed or buried in the process. Using the SPM, we dissect μ23 values for interactions of a solute or Hofmeister salt with a set of model compounds displaying the key functional groups of biopolymers to obtain interaction potentials (called α-values) that quantify the interaction of the solute or salt per unit area of each functional group or type of surface. Interpreted using the SPM, these α-values provide quantitative information about both the hydration of functional groups and the competitive interaction of water and the solute or salt with functional groups. The analysis corroborates and quantifies previous proposals that the Hofmeister anion and cation series for biopolymer processes are determined by ion-specific, mostly unfavorable interactions with hydrocarbon surfaces; the balance between these unfavorable nonpolar interactions and often-favorable interactions of ions with polar functional groups determine the series null points. The placement of urea and glycine betaine (GB) at opposite ends of the corresponding series of nonelectrolytes results from the favorable interactions of urea, and unfavorable interactions of GB, with many (but not all) biopolymer functional groups. Interaction potentials and local-bulk partition coefficients

  1. Surface-induced liquid-gas transition in salt-free solutions of model charged colloids.

    PubMed

    Budkov, Yu A; Frolov, A I; Kiselev, M G; Brilliantov, N V

    2013-11-21

    We report a novel phenomenon of a surface-induced phase transition in salt-free solutions of charged colloids. We develop a theory of this effect and confirm it by Molecular Dynamics s