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Sample records for white sands complex

  1. Integration of the White Sands Complex into a Wide Area Network

    NASA Technical Reports Server (NTRS)

    Boucher, Phillip Larry; Horan, Sheila, B.

    1996-01-01

    The NASA White Sands Complex (WSC) satellite communications facility consists of two main ground stations, an auxiliary ground station, a technical support facility, and a power plant building located on White Sands Missile Range. When constructed, terrestrial communication access to these facilities was limited to copper telephone circuits. There was no local or wide area communications network capability. This project incorporated a baseband local area network (LAN) topology at WSC and connected it to NASA's wide area network using the Program Support Communications Network-Internet (PSCN-I). A campus-style LAN is configured in conformance with the International Standards Organization (ISO) Open Systems Interconnect (ISO) model. Ethernet provides the physical and data link layers. Transmission Control Protocol and Internet Protocol (TCP/IP) are used for the network and transport layers. The session, presentation, and application layers employ commercial software packages. Copper-based Ethernet collision domains are constructed in each of the primary facilities and these are interconnected by routers over optical fiber links. The network and each of its collision domains are shown to meet IEEE technical configuration guidelines. The optical fiber links are analyzed for the optical power budget and bandwidth allocation and are found to provide sufficient margin for this application. Personal computers and work stations attached to the LAN communicate with and apply a wide variety of local and remote administrative software tools. The Internet connection provides wide area network (WAN) electronic access to other NASA centers and the world wide web (WWW). The WSC network reduces and simplifies the administrative workload while providing enhanced and advanced inter-communications capabilities among White Sands Complex departments and with other NASA centers.

  2. Numerical study of turbulent flow over complex aeolian dune fields: The White Sands National Monument

    NASA Astrophysics Data System (ADS)

    Anderson, William; Chamecki, Marcelo

    2014-01-01

    The structure and dynamics of fully developed turbulent flows responding to aeolian dune fields are studied using large-eddy simulation with an immersed boundary method. An aspect of particular importance in these flows is the downwind migration of coherent motions associated with Kelvin-Helmholtz instabilities that originate at the dune crests. These instabilities are responsible for enhanced downward transport of high-momentum fluid via the so-called turbulent sweep mechanism. However, the presence of such structures and their role in determining the bulk characteristics of fully developed dune field sublayer aerodynamics have received relatively limited attention. Moreover, many existing studies address mostly symmetric or mildly asymmetric dune forms. The White Sands National Monument is a field of aeolian gypsum sand dunes located in the Tularosa Basin in southern New Mexico. Aeolian processes at the site result in a complex, anisotropic dune field. In the dune field sublayer, the flow statistics resemble a mixing layer: At approximately the dune crest height, vertical profiles of streamwise velocity exhibit an inflection and turbulent Reynolds stresses are maximum; below this, the streamwise and vertical velocity fluctuations are positively and negatively skewed, respectively. We evaluate the spatial structure of Kelvin-Helmholtz instabilities present in the dune field sublayer (shear length Ls and vortex spacing ?x) and show that ?x=mduneLs, where mdune?7.2 in the different sections considered (for turbulent mixing layers, 7

  3. Numerical study of turbulent flow over complex aeolian dune fields: the White Sands National Monument.

    PubMed

    Anderson, William; Chamecki, Marcelo

    2014-01-01

    The structure and dynamics of fully developed turbulent flows responding to aeolian dune fields are studied using large-eddy simulation with an immersed boundary method. An aspect of particular importance in these flows is the downwind migration of coherent motions associated with Kelvin-Helmholtz instabilities that originate at the dune crests. These instabilities are responsible for enhanced downward transport of high-momentum fluid via the so-called turbulent sweep mechanism. However, the presence of such structures and their role in determining the bulk characteristics of fully developed dune field sublayer aerodynamics have received relatively limited attention. Moreover, many existing studies address mostly symmetric or mildly asymmetric dune forms. The White Sands National Monument is a field of aeolian gypsum sand dunes located in the Tularosa Basin in southern New Mexico. Aeolian processes at the site result in a complex, anisotropic dune field. In the dune field sublayer, the flow statistics resemble a mixing layer: At approximately the dune crest height, vertical profiles of streamwise velocity exhibit an inflection and turbulent Reynolds stresses are maximum; below this, the streamwise and vertical velocity fluctuations are positively and negatively skewed, respectively. We evaluate the spatial structure of Kelvin-Helmholtz instabilities present in the dune field sublayer (shear length L(s) and vortex spacing ?(x)) and show that ?(x)=m(dune)L(s), where m(dune)?7.2 in the different sections considered (for turbulent mixing layers, 7

  4. White Sands, Carrizozo Lava Beds, NM

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A truly remarkable view of White Sands and the nearby Carrizozo Lava Beds in southeast NM (33.5N, 106.5W). White Sands, site of the WW II atomic bomb development and testing facility and later post war nuclear weapons testing that can still be seen in the cleared circular patterns on the ground.

  5. Ecological release in White Sands lizards

    PubMed Central

    Roches, S Des; Robertson, J M; Harmon, L J; Rosenblum, E B

    2011-01-01

    Ecological opportunity is any change that allows populations to escape selection from competition and predation. After encountering ecological opportunity, populations may experience ecological release: enlarged population size, broadened resource use, and/or increased morphological variation. We identified ecological opportunity and tested for ecological release in three lizard colonists of White Sands, New Mexico (Sceloporus undulatus, Holbrookia maculata, and Aspidoscelis inornata). First, we provide evidence for ecological opportunity by demonstrating reduced species richness and abundance of potential competitors and predators at White Sands relative to nearby dark soils habitats. Second, we characterize ecological release at White Sands by demonstrating density compensation in the three White Sands lizard species and expanded resource use in White Sands S. undulatus. Contrary to predictions from ecological release models, we observed directional trait change but not increased trait variation in S. undulatus. Our results suggest that ecological opportunity and ecological release can be identified in natural populations, especially those that have recently colonized isolated ecosystems. PMID:22393523

  6. V-2 Rocket at White Sands

    NASA Technical Reports Server (NTRS)

    1946-01-01

    A V-2 rocket takes flight at White Sands, New Mexico, in 1946. The German engineers and scientists who developed the V-2 came to the United States at the end of World War II and continued rocket testing under the direction of the U. S. Army, launching more than sixty V-2s.

  7. Early diagenesis of eolian dune and interdune sands at White Sands, New Mexico

    USGS Publications Warehouse

    Schenk, C.J.; Fryberger, S.G.

    1988-01-01

    The degree of early diagenesis in eolian dune and interdune sands at White Sands, New Mexico, is largely a function of the relationship between sand location and the water table. Most active and vegetation-stabilized dune sands are in the vadose zone, whereas interdune sands are in the capillary fringe and phreatic zones. Crystallographically controlled dissolution of the framework gypsum grains results in elongate, prismatic etch pits on sand grains from the capillary fringe and phreatic zones, whereas dissolution of sand grains in the vadose zone is slight, causing minute irregularities on grain surfaces. Vadose water percolating through the sand is manifest as meniscus layers. Consequently, dune sands in the vadose zone are cemented mainly by meniscus-shaped gypsum at grain contacts. Pendant cements formed on the lower margins of some sand grains. Cementation in the capillary fringe and the phreatic zone is more extensive than the vadose regardless of strata type. Typically, well-developed gypsum overgrowths form along the entire edge of a grain, or may encompass the entire grain. Complex diagenetic histories are suggested by multiple overgrowths and several episodes of dissolution on single grains, attesting to changing saturation levels with respect to gypsum in the shallow ground water. These changes in saturation are possibly due to periods of dilution by meteoric recharge, alternating with periods of concentration of ions and the formation of cement due to evaporation through the capillary fringe. ?? 1988.

  8. Optics At White Sands Missile Range

    NASA Astrophysics Data System (ADS)

    Fronczek, Ron C.; Hayslett, Charles R.

    1985-11-01

    We present an overview of the optics and optical data gathering programs conducted at White Sands Missile Range. Activities at White Sands Missile Range have always been diverse - the first test conducted there was the world's first nuclear explosion. In the forty years since that event the range has hosted a large assortment of vehicles including V2, Nike, Aerobee, Space Shuttle, Cruise, and the Copperhead. The last three of these devices illustrate the difficulty of the White Sands optical data gathering task. One is acquired in orbit, one as it crosses through a mountain pass, and one as it issues from the muzzle of a cannon. A combination of optical, radar, video, computer, and communications technology has produced a versatile system that can satisfy the data gathering requirements of most range users. Another example of the diverse optics programs at the range is the development of the High Energy Laser Systems Test Facility (HELSTF). Because of the nature of the systems being tested, the HELSTF is full of optics and optical systems including the TRW MIRACL laser and the Hughes SEA LITE Beam Director.

  9. Annual water-resources review, White Sands Missile Range: 1971

    USGS Publications Warehouse

    Cruz, R.R.

    1972-01-01

    This report presents water-resource information that was collected at White Sands Missile Range during 1971 and early 1972 by personnel of the U.S. Geological Survey, Water Resources Division. Data on ground-water pumpage and resulting water-level fluctuation, chemical quality, percipitation, and surface-water runoff are summarized in the report. The data were obtained as a result of the continuing water-resources basic-data collection program sponsored by the Facilities Engineering Directorate, White Sands Missile Range.

  10. Trends in Gypsiferous Aerosol Downwind of White Sands, New Mexico

    NASA Astrophysics Data System (ADS)

    White, W. H.; Trzepla, K.; Yatkin, S.; Gill, T. E.; Jin, L.

    2013-12-01

    White Sands is a known 'hotspot' of dust emissions in southwestern North America where an active gypsum dunefield abuts erodible playa sediments. Aerosols entrained from White Sands are sometimes visible on satellite images as distinct, light-colored plumes crossing the Sacramento Mountains to the northeast. The U.S. Forest Service operates an aerosol sampler at White Mountain in the lee of the Sacramento range as part of the IMPROVE network (Interagency Monitoring of PROtected Visual Environments). In recent years a spring pulse of sulfate aerosol has appeared at White Mountain, eclipsing the regional summer peak attributed to atmospheric reactions of sulfur dioxide emissions. A significant fraction of this spring sulfate is contributed by gypsum and other salts from White Sands, with clearly increased concentrations of calcium, strontium, and chloride. The increase in these species coincides with a drought following a period of above-average precipitation. White Sands and White Mountain thus provide an unusually well-defined natural laboratory: a climatically sensitive dust source that is both well characterized and chemically distinct from its surroundings, with a signature that remains identifiably distinct at a long-term observatory ~100 km downwind. This paper examines the routine PM2.5 (fine-particle, Dp < 2.5 um) composition data available from White Mountain and other regional IMPROVE sites (e.g. Bosque del Apache), supplemented by some elemental analysis of collocated PM10 samples. The ambient data are compared with chemical analyses of surface samples from White Sands, bulk dry dustfall and soil surface composition at White Mountain, satellite observations of dust plumes, and available meteorological records. Together, the observations document significant, episodic aeolian transport of gypsum and other salts across the Sacramento Mountains. Figure 1. Left: Monthly average concentrations of every-third-day 24h samples. Top right: MODIS image, 2/28/2012, http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=77294). Bottom right: Correlation (r) matrix for 2011 daily elemental data from White Mountain (n = 105).

  11. NASA White Sands Test Facility Remote Hypervelocity Test Laboratory - Duration: 7 minutes, 52 seconds.

    NASA Video Gallery

    Tour the NASA White Sands Test Facility's Remote Hypervelocity Test Laboratory in Las Cruces, New Mexico. To learn more about White Sands Test Facility, go to http://www.nasa.gov/centers/wstf/home/...

  12. NASA Johnson Space Center: White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Aggarwal, Pravin; Kowalski, Robert R.

    2011-01-01

    This slide presentation reviews the testing facilities and laboratories available at the White Sands Test Facility (WSTF). The mission of WSTF is to provide the expertise and infrastructure to test and evaluate spacecraft materials, components and propulsion systems that enable the safe exploration and use of space. There are nine rocket test stands in two major test areas, six altitude test stands, three ambient test stands,

  13. Regional transport of a chemically distinctive dust: Gypsum from White Sands, New Mexico (USA)

    NASA Astrophysics Data System (ADS)

    White, Warren H.; Hyslop, Nicole P.; Trzepla, Krystyna; Yatkin, Sinan; Rarig, Randy S.; Gill, Thomas E.; Jin, Lixin

    2015-03-01

    The White Sands complex, a National Monument and adjoining Missile Range in southern New Mexico, occupies the dry bed of an ice-age lake where an active gypsum dunefield abuts erodible playa sediments. Aerosols entrained from White Sands are sometimes visible on satellite images as distinct, light-colored plumes crossing the Sacramento Mountains to the east and northeast. The IMPROVE network (Interagency Monitoring of PROtected Visual Environments) operates long-term aerosol samplers at two sites east of the Sacramento range. In recent years a spring pulse of sulfate aerosol has appeared at these sites, eclipsing the regional summer peak resulting from atmospheric reactions of sulfur dioxide emissions. A significant fraction of this spring sulfate is contributed by gypsum and other salts from White Sands, with much of the sulfur in coarse particles and concentrations of calcium and strontium above regional levels. The increase in these gypsiferous species coincides with a drought following a period of above-average precipitation. White Sands and the IMPROVE samplers together provide a natural laboratory: a climatically sensitive dust source that is both well characterized and chemically distinct from its surroundings, with a signature that remains identifiable at long-term observatories 100-200 km downwind.

  14. 3. GENERAL VIEW OF COMPLEX LOOKING SOUTH, SAND DRAINING & ...

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

    3. GENERAL VIEW OF COMPLEX LOOKING SOUTH, SAND DRAINING & DRYING BUILDING (right) AND SAND-SORTING BUILDING (left) - Mill "C" Complex, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  15. 1. GENERAL VIEW OF COMPLEX FROM SANDPIT LOOKING NORTHEAST, SAND ...

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

    1. GENERAL VIEW OF COMPLEX FROM SANDPIT LOOKING NORTHEAST, SAND DRAINING & DRYING BUILDING (left) AND SAND-SORTING BUILDING (right) - Mill "C" Complex, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  16. 2. GENERAL VIEW OF COMPLEX FROM SANDPIT LOOKING NORTHEAST, SAND ...

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

    2. GENERAL VIEW OF COMPLEX FROM SANDPIT LOOKING NORTHEAST, SAND DRAINING & DRYING BUILDING (left) AND SAND-SORTING BUILDING (right) - Mill "C" Complex, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  17. Renewable Energy Opportunities at White Sands Missile Range, New Mexico

    SciTech Connect

    Chvala, William D.; Solana, Amy E.; States, Jennifer C.; Warwick, William M.; Weimar, Mark R.; Dixon, Douglas R.

    2008-09-01

    The document provides an overview of renewable resource potential at White Sands Missile Range (WSMR) based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 DoD Renewable Energy Assessment. This effort focuses on grid-connected generation of electricity from renewable energy sources and also ground source heat pumps (GSHPs) for heating and cooling buildings, as directed by IMCOM.

  18. Two-Phase Abrasion in Eolian Transport of Gypsum Sand, White Sands NM

    NASA Astrophysics Data System (ADS)

    Shaw, S.; Jerolmack, D. J.; Miller, K. L.

    2014-12-01

    Downstream rounding of grains is consistently observed in natural sediment transport settings. A recent theory put forth by Domokos et al. (2014) attributes particle rounding and size reduction to a geometric curvature-driven abrasion process. This process occurs in two phases, in which irregularly shaped or angular particles round to convex shapes with negligible change in axis dimension, then slowly reduce in particle diameter. Miller et al (in review) establish the existence of two-phase abrasion in the natural setting of a fluvial gravel stream. This study examines field samples from White Sands, NM to investigate the presence of two-phase abrasion in a different, non-idealized natural environment - a high-energy, eolian gypsum dunefield. Analysis of grain shapes from White Sands confirms the two-phase abrasion process, dependent upon mode of sediment transport. We find that large sand grains carried in saltation bed load transport exhibit shape change indicative of two-phase abrasion, while smaller particles carried in suspension do not. We observe rapid shape change in bed load particles approaching a convex shape, followed by slower reduction in grain axis dimensions. Confirmation of this process in a natural, non-idealized setting establishes two-phase abrasion as a general application for bed load transport.

  19. Sublethal effects of aged oil sands-affected water on white sucker (Catostomus commersonii).

    PubMed

    Arens, Collin J; Hogan, Natacha S; Kavanagh, Richard J; Mercer, Angella G; Kraak, Glen J Van Der; van den Heuvel, Michael R

    2015-03-01

    To investigate impacts of proposed oil sands aquatic reclamation techniques on benthic fish, white sucker (Catostomus commersonii Lacépède, 1803) were stocked in 2 experimental ponds-Demonstration Pond, containing aged fine tailings capped with fresh water, consistent with proposed end-pit lake designs, and South Bison Pond, containing aged unextracted oil sands material-to examine the effects of unmodified hydrocarbons. White sucker were stocked from a nearby reservoir at both sites in May 2010 and sampled 4 mo later to measure indicators of energy storage and utilization. Comparisons were then made with the source population and 2 reference lakes in the region. After exposure to aged tailings, white sucker had smaller testes and ovaries and reduced growth compared with the source population. Fish introduced to aged unextracted oil sands material showed an increase in growth over the same period. Limited available energy, endocrine disruption, and chronic stress likely contributed to the effects observed, corresponding to elevated concentrations of naphthenic acids, aromatic compounds in bile, and increased CYP1A activity. Because of the chemical and biological complexity of these systems, direct cause-effect relationships could not be identified; however, effects were associated with naphthenic acids, polycyclic aromatic hydrocarbons, ammonia, and high pH. Impacts on growth have not been previously observed in pelagic fishes examined in these systems, and may be related to differences in sediment interaction. PMID:25545538

  20. When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

    PubMed Central

    Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  1. When field experiments yield unexpected results: lessons learned from measuring selection in White Sands lizards.

    PubMed

    Hardwick, Kayla M; Harmon, Luke J; Hardwick, Scott D; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  2. Groundwater Remediation and Alternate Energy at White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Fischer, Holger

    2008-01-01

    White Sands Test Facility Core Capabilities: a) Remote Hazardous Testing of Reactive, Explosive, and Toxic Materials and Fluids; b) Hypergolic Fluids Materials and Systems Testing; c) Oxygen Materials and System Testing; d) Hypervelocity Impact Testing; e)Flight Hardware Processing; and e) Propulsion Testing. There is no impact to any drinking water well. Includes public wells and the NASA supply well. There is no public exposure. Groundwater is several hundred feet below ground. No air or surface water exposure. Plume is moving very slowly to the west. Plume Front Treatment system will stop this westward movement. NASA performs on-going monitoring. More than 200 wells and zones are routinely sampled. Approx. 850 samples are obtained monthly and analyzed for over 300 different hazardous chemicals.

  3. Standards Development Activities at White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Baker, D. L.; Beeson, H. D.; Saulsberry, R. L.; Julien, H. L.; Woods, S. S.

    2003-01-01

    The development of standards and standard activities at the JSC White Sands Test Facility (WSTF) has been expanded to include the transfer of technology and standards to voluntary consensus organizations in five technical areas of importance to NASA. This effort is in direct response to the National Technology Transfer Act designed to accelerate transfer of technology to industry and promote government-industry partnerships. Technology transfer is especially important for WSTF, whose longterm mission has been to develop and provide vital propellant safety and hazards information to aerospace designers, operations personnel, and safety personnel. Meeting this mission is being accomplished through the preparation of consensus guidelines and standards, propellant hazards analysis protocols, and safety courses for the propellant use of hydrogen, oxygen, and hypergols, as well as the design and inspection of spacecraft pressure vessels and the use of pyrovalves in spacecraft propulsion systems. The overall WSTF technology transfer program is described and the current status of technology transfer activities are summarized.

  4. Simultaneous Ka-Band Site Characterization: Goldstone, CA, White Sands, NM, and Guam, USA

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto; Morse, Jacquelynne; Zemba, Michael; Nessel, James; Morabito, David; Caroglanian, Armen

    2011-01-01

    To statistically characterize atmospheric effects on Ka-band links at NASA operational sites, NASA has constructed site test interferometers (STI s) which directly measure the tropospheric phase stability and rain attenuation. These instruments observe an unmodulated beacon signal broadcast from a geostationary satellite (e.g., Anik F2) and measure the phase difference between the signals received by the two antennas and its signal attenuation. Three STI s have been deployed so far: the first one at the NASA Deep Space Network Tracking Complex in Goldstone, California (May 2007); the second at the NASA White Sands Complex, in Las Cruses, New Mexico (February 2009); and the third at the NASA Tracking and Data Relay Satellite (TDRS) Remote Ground Terminal (GRGT) complex in Guam (May 2010). Two station-years of simultaneous atmospheric phase fluctuation data have been collected at Goldstone and White Sands, while one year of data has been collected in Guam. With identical instruments operating simultaneously, we can directly compare the phase stability and rain attenuation at the three sites. Phase stability is analyzed statistically in terms of the root-mean-square (rms) of the tropospheric induced time delay fluctuations over 10 minute blocks. For two years, the time delay fluctuations at the DSN site in Goldstone, CA, have been better than 2.5 picoseconds (ps) for 90% of the time (with reference to zenith), meanwhile at the White Sands, New Mexico site, the time delay fluctuations have been better than 2.2 ps with reference to zenith) for 90% of time. For Guam, the time delay fluctuations have been better than 12 ps (reference to zenith) at 90% of the time, the higher fluctuations are as expected from a high humidity tropical rain zone. This type of data analysis, as well as many other site quality characteristics (e.g., rain attenuation, infrastructure, etc.) will be used to determine the suitability of all the sites for NASA s future communication services at Ka-band.

  5. Annual water resources review, White Sands Missile Range, New Mexico, 1980

    USGS Publications Warehouse

    Cruz, R.R.

    1981-01-01

    Ground-water data were collected in 1980 at White Sands Missile Range in south-central New Mexico. The total water pumped at White Sands Missile Range in 1980 was 725,053,000 gallons, which was 32.5 million gallons more than in 1979. The Post Headquarters well field, which produces more than 98 percent of the water used at White Sands Missile Range, pumped 712,909,000 gallons, which was 31.1 million gallons more in 1980 than in 1979. Data were collected for specific Range areas north of the Post Headquarters area that might have potential for future water-supply development. (USGS)

  6. NASA 947 and NASA 904 during training flight over White Sands, New Mexico

    NASA Technical Reports Server (NTRS)

    1982-01-01

    NASA 947 and NASA 904 during a training and familiarization flight over White Sands, New Mexico. The Gulfstream aircraft on the left is NASA's Space Shuttle Training aircraft (STA) and the T-38 jet serves as a chase plane.

  7. Rescue Simulation - NASA White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp - Duration: 70 seconds.

    NASA Video Gallery

    The White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp prepares students to deal with normal propellant operations, emergency events, and pre-operation planning by engaging studen...

  8. Gypsum Dunes from White Sands National Monument - Potential Analog to North Polar Dunes on Mars

    NASA Astrophysics Data System (ADS)

    Szynkiewicz, A.; Pratt, L. M.; Glamoclija, M.; Bustos, D.

    2008-03-01

    Three aspects of White Sands gypsum dunes evolution relating to climate variation are discussed in comparison to Olimpia Undae gypsum-rich dunes on Mars: gypsum source, groundwater discharge into interdunes areas, and desiccation of dunes.

  9. NASA White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp - Duration: 71 seconds.

    NASA Video Gallery

    The NASA White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp prepares students to deal with normal propellant operations, emergency events, and pre-operation planning by engaging s...

  10. NASA White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp - Duration: 65 seconds.

    NASA Video Gallery

    The White Sands Test Facility Totally Encapsulating Suit (TES) Boot Camp prepares students to deal with normal propellant operations, emergency events, and pre-operation planning by engaging studen...

  11. Formational Mechanisms and Morphology of Windblown Coarse-Grained Sand Ripples at White Sands, New Mexico

    NASA Astrophysics Data System (ADS)

    Glade, R.; Jerolmack, D. J.; Pelletier, J. D.

    2014-12-01

    Coarse-grained ripples, also known as "megaripples," are large sand ripples found in both aeolian and aquatic environments on Earth, and are common on Mars. The formation and morphology of coarse-grained ripples are not as well understood as more common splash ripples. Current understanding suggests that formative wind speeds are above the saltation threshold for the fine grains, but below this threshold for coarse grains found on the crests, such that they creep. Based on this idea, we hypothesize that wind speeds above this coarse-grain saltation threshold will destroy the ripples. We further hypothesize that these ripples do not have an equilibrium size; rather, their size is related to the persistence of formative winds in a given direction. To test this model, we studied windblown coarse-grained ripples in White Sands, New Mexico. Terrestrial LiDAR was used to obtain high resolution ripple morphology and migration over a three month period. Wind velocity profiles and concurrent saltating grain size data were collected during a wind storm to directly relate modes of transport to particle size and wind stress. These local data were used to calibrate wind records from a nearby meteorological station to estimate local fluid stress using a long-term record. LiDAR data indicate that these ripples were destroyed and reoriented between March and June 2013, while the wind record shows that the coarse-grain saltation threshold was indeed exceeded during this time. Morphological analysis indicates that the lee slope of these ripples is set by saltation impact - similar to splash ripples - but that height, wavelength and stoss slope are not related to instantaneous transport conditions. The historical wind record also shows that the range of wind directions decreases rapidly with increasing speed, restricting strong winds to a narrow range of direction. From these results we explore the idea that coarse-grained ripples are typically larger and less frequently destroyed than splash ripples because the stronger winds required to create them are drawn from a more consistent direction. The ability to constrain wind conditions required to form and destroy coarse-grained ripples gives insight into formational conditions both in preserved paleo-ripples on Earth, and also on Mars where these bedforms are ubiquitous.

  12. Morphology and stratigraphic evolution of aeolian protodunes at White Sands Dune Field

    NASA Astrophysics Data System (ADS)

    Ewing, R. C.; Weymer, B. A.; Barrineaux, P.

    2014-12-01

    Protodunes are low-relief, slipfaceless migrating bed forms thought to represent fundamental emergent bed forms that develop from a flat bed of sand and evolve into dunes. Protodunes at White Sands Dune Field in New Mexico are found at the upwind margin of the field, on dune stoss slopes and in interdune areas. Here we used time-series aerial photos from 1996, 2003, 2005 and 2012 and digital elevation models from 2007, 2008, 2009 and 2010 in conjunction with ground penetrating radar (GPR) to characterize the morphodynamics of protodunes and the stratigraphy generated by protodune migration. Protodunes at the upwind margin of the dune field are larger in wavelength and amplitude and coarser grained than those in the interior of the field. Wind ripples cover protodunes in all areas of the field, but the protodunes at the upwind margin are covered by coarse grained ripples. A consistent progression of ripple patterns occurs over protodunes in which ripples coarsen in wavelength and grain size toward the protodune crest and then decrease in wavelength and grain size toward the troughs. Ripple migration across the protodunes appears to the primary mode by which the protodunes migrate. Trenching and GPR data show low-angle cross-stratification generated by wind ripples migrating down the protodune lee slope of the protodunes. Internal bounding surfaces within the protodunes likely arise from laterally migration and lee slope reactivation in response to the complex wind regime and dune-modified secondary flow within the dune field at White Sands. Understanding the morphology, distribution and genesis of protodunes in dune fields provides a basis to evaluate the significance of protodune strata in the rock record.

  13. Testing Planetary Radiative Transfer Models via Remote Sensing of Gypsum Sands in White Sands National Monument

    NASA Astrophysics Data System (ADS)

    Siebach, K. L.; Arvidson, R. E.; Boettger, J.; Bova, S.; Murrey, P.; Rudd, M.; Spera, S.; Stein, T.; Witchger, M.

    2010-12-01

    Directional reflectance and emission spectra for particulate materials are governed by the mineralogy, grain size, packing, and topography of the sample observed. White Sands National Monument, as the largest homogeneous gypsum dune field in the world, provides a unique in-situ environment in which to isolate the textural components of spectra and determine the ability of remote sensing models to retrieve material properties. In this study, a traverse between two interdune regions across a transverse-barchan dune was conducted in August 2010 and detailed spectral field measurements ranging from 0.4 to 20 m were taken at 17 sites along the traverse. These field measurements were used to calibrate the test the ability of three radiative transfer models to retrieve material properties. Specifically, the Shkuratov (1999) model assumes that incidence, emergence, and phase angles can be integrated over their elevation and azimuthal ranges and that the surface can be modeled as layered mineral slabs. The Hapke model uses directional information, but makes simplifying assumptions about the nature of scattering in particulate material (Hapke, 1993 and follow-on papers). Mishchenko (2008) models Maxwells equations rigorously for particulate surfaces as distributed dipoles, but is computationally intensive. A subset of the field sites textural characteristics were carefully measured and used to calibrate the models to match laboratory gypsum spectra. The remaining field sites were used as blind samples to test the ability of the models to retrieve gypsum material properties without detailed textural measurements. These data improve understanding of the benefits and limitations of available radiative transfer models to better understand similar data retrieved from planetary surface observations, including observations covering a similar gypsum dune field near the north pole of Mars and ripples currently being crossed by the Opportunity rover.

  14. Annual water-resources review, White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Cruz, R.R.

    1983-01-01

    Ground-water data were collected in 1982 at White Sands Missile Range in south-central New Mexico. Depth-to-water measurements in the Post Headquarters supply wells continued to show seasonal declines. Test wells east of the Headquarters well field continue to show long-term declines as well as seasonal fluctuations. The total amount of water pumped from White Sands Missile Range supply wells was 66,226,600 gallons more in 1982 than in 1981. The difference in the specific-conductance values of the water samples collected from the Post Headquarters supply wells in the winter and summer increased in 1982. (USGS)

  15. Annual water-resources review White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Cruz, R.R.

    1980-01-01

    Ground-water data were collected in 1979 at White Sands Missile Range in south-central New Mexico. Total ground-water pumpage from the Post Headquarters well field, which produces more than 98% of the water used at White Sands Missile Range, was 1.4 million gallons more in 1979 than in 1978. The most significant seasonal water-level declines observed in 1979 were in supply well 22 (36.35 feet) and test well T-7 (15.98 feet). The chemical quality of water samples collected in 1979 was similar to that collected at comparable depths and periods in 1978. (USGS)

  16. Annual water-resources review, White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Cruz, R.R.

    1982-01-01

    Ground-water data were collected in 1981 at White Sands Missile Range in south-central New Mexico. The total amount of water pumped at White Sands Missile Range was approximately 59 million gallons less than in 1980; however the five supply wells in the Range areas adjacent to the Post Headquarters area produced approximately 16.2 million gallons more in 1981 than in 1980. Depth-to-water measurements in the Post Headquarters supply wells continued to show seasonal declines. (USGS)

  17. El Paso and White Sands area as seen from the Apollo 6 unmanned spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    The El Paso and White Sands area are photographed from the Apollo 6 (Spacecraft 020/Saturn 502) unmanned space mission three hours and eight minutes after liftoff. North is toward top of picture. Near bottom center of picture is the El Paso-Ciudad Juarez, Mexico metropolitan area. At the top is the White Sands National Monument area. Note Rio Grande River on left side of picture. The snow-covered Sacremento Mountains are seen in the upper right corner. The altitude of the spacecraft when this photograph was taken was 115 nautical miles.

  18. Annual water-resources review, White Sands Missile Range, New Mexico, 1984

    USGS Publications Warehouse

    Cruz, R.R.

    1985-01-01

    Hydrologic data were collected at White Sands Missile Range in 1984. The total groundwater withdrawal in 1984 was 685,275,000 gallons. The Post Headquarters well field produced 650,821,000 gallons in 1984. Six new wells were drilled at White Sands Missile Range in 1984. Nineteen water samples were collected for major chemical-constituent, trace-element, or radiochemical analysis in 1984. Depth-to-water measurements in the Post Headquarters supply wells showed seasonal fluctuations as well as continued long-term declines. (USGS)

  19. Overview of NASA White Sands Test Facility Composite Overwrapped Pressure Vessel Testing

    NASA Technical Reports Server (NTRS)

    Greene, Nathanael; Saulsberry, Regor; Thesken, John; Phoenix, Leigh

    2006-01-01

    This viewgraph presentation examines the White Sands Test Facility testing of Composite overwrapped pressure vessel (COPV). A COPV is typically a metallic liner overwrapped with a fiber epoxy matrix. There is a weight advantage over the traditional all metal design. The presentation shows pictures of the facilities at White Sands, and then examines some of the testing performed. The tests include fluids compatibility, and Kevlar COPV. Data for the Kevlar tests are given, and an analysis is reviewed. There is also a comparison between Carbon COPVs and the Kevlar COPVs.

  20. Space radiation studies at the White Sands Missile Range Fast Burst Reactor

    NASA Technical Reports Server (NTRS)

    Delapaz, A.

    1972-01-01

    The operation of the White Sands Missile Range Fast Burst Reactor is discussed. Space radiation studies in radiobiology, dosimetry, and transient radiation effects on electronic systems and components are described. Proposed modifications to increase the capability of the facility are discussed.

  1. Meso-scale cooling effects of high albedo surfaces: Analysis of meteorological data from White Sands National Monument and White Sands Missile Range

    SciTech Connect

    Fishman, B.; Taha, H.; Akbari, H.

    1994-05-20

    Urban summer daytime temperatures often exceed those of the surrounding rural areas. Summer ``urban heat islands`` are caused by dark roofs and paved surfaces as well as the lack of vegetation. Researchers at Lawrence Berkeley Laboratory are interested in studying the effects of increasing the albedo of roof tops and paved surfaces in order to reduce the impacts of summer urban heat islands. Increasing the albedo of urban surfaces may reduce this heat island effect in two ways, directly and indirectly. The direct effect involves reducing surface temperature and, therefore, heat conduction through the building envelope. This effect of surface albedo on surface temperatures is better understood and has been quantified in several studies. The indirect effect is the impact of high albedo surfaces on the near surface air temperatures. Although the indirect effect has been modeled for the Los Angeles basin by Sailor, direct field observations are required. The objective of this report is to investigate the meso-scale climate of a large high albedo area and identify the effects of albedo on the near surface air temperature. To accomplish this task, data from several surface weather stations at White Sands, New Mexico were analyzed. This report is organized into six sections in addition to this introduction. The first gives the general geological, topographic, and meteorological background of White Sands. The second is a discussion of the basic surface meteorology of the White Sands region. This section is followed by a general discussion of the instrumentation and available data. The fourth section is a description of the method used for data analyis. The fifth section which presents the results of this analysis. Finally, the last section is the summary and conclusion, where a discussion of the results is presented.

  2. Two Years of Simultaneous K(sub a)-Band Measurements: Goldstone, CA; White Sands, NM; and Guam, USA

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.; Zemba, M.; Morse, J.; Nessel, J.

    2012-01-01

    In order to statistically characterize the effect of the Earth's atmosphere on Ka-Band links, site test interferometers (STIs) have been deployed at three of NASA s operational sites to directly measure each site's tropospheric phase stability and rain attenuation. These STIs are composed of two antennas on a short baseline (less than 1km) that observe the same unmodulated beacon signal broadcast from a geostationary satellite (e.g., Anik F2). The STIs are used to measure the differential phase between the two received signals as well as the individual signal attenuation at each terminal. There are currently three NASA sites utilizing STIs; the Goldstone Deep Space Communications Complex near Barstow, California; the White Sands Complex in Las Cruces, New Mexico; and the Guam Remote Ground Terminal on the island of Guam. The first two sites are both located in desert regions that have highly similar climates in terms of their seasonal temperatures, average humidity, and annual rain fall (the primary factors in determining phase stability). In contrast, Guam is in a tropical region with drastically higher annual rainfall and humidity. Five station years of data have been collected in Goldstone, three in White Sands, and two in Guam, yielding two years of simultaneous data collection across all three sites. During this period of simultaneous data collection, the root-mean-square (RMS) of the time delay fluctuations stayed under 2.40 picoseconds for 90% of the time in Goldstone, under 2.07 picoseconds for 90% of the time in White Sands, and under 10.13 picoseconds for 90% of the time in Guam. For the 99th percentile, the statistics were 6.32 ps, 6.03 ps, and 24.85 ps, respectively. These values, as well as various other site quality characteristics, will be used to determine the suitability of these sites for NASA s future communication services at Ka-Band.

  3. Ka-Band Atmospheric Phase Stability Measurements in Goldstone, CA; White Sands, NM; and Guam

    NASA Technical Reports Server (NTRS)

    Zemba, Michael J.; Morse, Jacquelynne Rose; Nessel, James A.

    2014-01-01

    As spacecraft communication links are driven to higher frequencies (e.g. Ka-band) both by spectrum congestion and the appeal of higher data rates, the propagation phenomena at these frequencies must be well characterized for effective system design. In particular, the phase stability of a site at a given frequency will govern whether or not the site is a practical location for an antenna array, particularly if uplink capabilities are desired. Propagation studies to characterize such phenomena must be done on a site-by-site basis due to the wide variety of climates and weather conditions at each ground terminal. Accordingly, in order to statistically characterize the atmospheric effects on Ka-Band links, site test interferometers (STIs) have been deployed at three of NASA's operational sites to directly measure each site's tropospheric phase stability. Using three years of results from these experiments, this paper will statistically characterize the simultaneous atmospheric phase noise measurements recorded by the STIs deployed at the following ground station sites: the Goldstone Deep Space Communications Complex near Barstow, CA; the White Sands Ground Terminal near Las Cruces, NM; and the Guam Remote Ground Terminal on the island of Guam.

  4. Annual water-resources review, White Sands Missile Range, New Mexico, 1983

    USGS Publications Warehouse

    Cruz, R.R.

    1984-01-01

    Ground-water data were collected at White Sands Missile Range in 1983. The total amount of water pumped from White Sands Missile Range supply wells in 1983 was 713,557,500 gallons. The Post Headquarters well field accounted for 686,499,200 gallons of the total. Seasonal water-level fluctuations in the supply wells ranged from a 3.00-foot rise in Stallion Range Well-2 (SRC-2) to a 51.00 foot decline in Post headquarters supply well 11 (SW-11). All of the test wells and observation wells up to 2 miles east of the Post Headquarters well field showed a decline for the period 1973-1983. Only one test well and one borehole west of the Post Headquarters well field showed a decline in water level; the other five showed a rise in water level for the period 1973-1983. (USGS)

  5. Evaluating the Emergency Notification Systems of the NASA White Sands Test

    NASA Technical Reports Server (NTRS)

    Chavez, Alfred Paul

    2004-01-01

    The problem was that the NASA Fire and Emergency Services did not know if the current emergency notification systems on the NASA White Sands Test Facility were appropriate for alerting the employees of an emergency. The purpose of this Applied Research Project was to determine if the current emergency notification systems of the White Sands Test Facility are appropriate for alerting the employees of an emergency. This was a descriptive research project. The research questions were: 1) What are similar facilities using to alert the employees of an emergency?; 2) Are the current emergency notification systems suitable for the community hazards on the NASA White Sands Test Facility?; 3) What is the NASA Fire and Emergency Services currently using to measure the effectiveness of the emergency notification systems?; and 4) What are the current training methods used to train personnel to the emergency notification systems at the NASA White Sands Test Facility? The procedures involved were to research other established facilities, research published material from credible sources, survey the facility to determine the facility perception of the emergency notification systems, and evaluate the operating elements of the established emergency notification systems for the facility. The results were that the current systems are suitable for the type of hazards the facility may endure. The emergency notification systems are tested frequently to ensure effectiveness in the event of an emergency. Personnel are trained and participate in a yearly drill to make certain personnel are educated on the established systems. The recommendations based on the results were to operationally improve the existing systems by developing and implementing one system that can overall notify the facility of a hazard. Existing procedures and training should also be improved to ensure that all personnel are educated on what to do when the emergency notification systems are activated.

  6. Test wells T27 and T28, White Sands Missile Range, Dona Ana County, New Mexico

    USGS Publications Warehouse

    Myers, R.G.; Pinckley, K.M.

    1985-01-01

    Two test wells, T27 and T28, were drilled at White Sands Missile Range in south-central New Mexico as part of a joint military training program sponsored by the U.S. Army in February and March 1983. Test wells T27 and T28 were drilled as observation wells in the vicinity of the Liquid Propellant Storage Area. Information obtained from these wells includes lithologic logs, driller 's logs, and borehole-geophysical logs from the cased wells. (USGS)

  7. A seismic search for the paleoshorelines of Lake Otero beneath White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Wagner, P. F.; Reece, R.; Ewing, R. C.

    2014-12-01

    The Tularosa Basin, which now houses White Sands Dune Field, was once occupied by Pleistocene Lake Otero. Several paleoshorelines of Lake Otero have been identified throughout the basin by field surveys and remote sensing using digital elevation models. Up to four shorelines may be buried beneath White Sands Dune Field and it has been posited that the current upwind margin of White Sands coincides with a one of these shorelines. Here we employ a novel geophysical instrument and method to image the subsurface: the seismic land streamer. The land streamer utilizes weighted base plates and one-component vertical geophones in a towed array. With a seisgun acoustic source, we imaged in the Alkali Flats area near the upwind margin, one potential location of paleoshorelines, as well as the Film Lot closer to the center of the dune field. Surfaces in both locations are indurated gypsum playa, which made seismic imaging possible and successful. We collected one SW-NE trending seismic line at each location, which matches the dominant wind and dune migration directions. Based on initial data analysis we find some subsurface structure that may coincide with the paleo lake bed of Lake Otero. The successful demonstration of this new method provides the foundation for an expanded regional subsurface study to image the strata and structure of the Tularosa Basin.

  8. Male territoriality and 'sex confusion' in recently adapted lizards at White Sands.

    PubMed

    Robertson, J M; Rosenblum, E B

    2010-09-01

    The evolution of intersexual interactions, like mate choice, during ecological speciation has received widespread attention. However, changes in intrasexual interactions, like male territoriality, during ecological divergence are largely unexamined. We conducted field experiments with adaptively diverged populations of the eastern fence lizard (Sceloporus undulatus) to determine whether territorial males behaved differently towards ecologically similar vs. dissimilar intruders. We performed trials with light-coloured males from White Sands, New Mexico and dark-coloured males from the surrounding desert. We found that intruders from White Sands elicited more aggression than intruders from dark-soil habitat. We also documented a case of 'sex confusion' where white-sand males courted dark-soil intruders. We found population differences in signalling patch size that can explain both aggression bias and sex misidentification. We argue that direct selection (for population recognition or optimal signal transmission) and indirect selection (by-products of ecological adaptation) should influence both intersexual and intrasexual interactions during ecological speciation. PMID:20695966

  9. The population genomics of rapid adaptation: disentangling signatures of selection and demography in white sands lizards.

    PubMed

    Laurent, Stefan; Pfeifer, Susanne P; Settles, Matthew L; Hunter, Samuel S; Hardwick, Kayla M; Ormond, Louise; Sousa, Vitor C; Jensen, Jeffrey D; Rosenblum, Erica Bree

    2016-01-01

    Understanding the process of adaptation during rapid environmental change remains one of the central focal points of evolutionary biology. The recently formed White Sands system of southern New Mexico offers an outstanding example of rapid adaptation, with a variety of species having rapidly evolved blanched forms on the dunes that contrast with their close relatives in the surrounding dark soil habitat. In this study, we focus on two of the White Sands lizard species, Sceloporus cowlesi and Aspidoscelis inornata, for which previous research has linked mutations in the melanocortin-1 receptor gene (Mc1r) to blanched coloration. We sampled populations both on and off the dunes and used a custom sequence capture assay based on probed fosmid libraries to obtain >50 kb of sequence around Mc1r and hundreds of other random genomic locations. We then used model-based statistical inference methods to describe the demographic and adaptive history characterizing the colonization of White Sands. We identified a number of similarities between the two focal species, including strong evidence of selection in the blanched populations in the Mc1r region. We also found important differences between the species, suggesting different colonization times, different genetic architecture underlying the blanched phenotype and different ages of the beneficial alleles. Finally, the beneficial allele is dominant in S. cowlesi and recessive in A. inornata, allowing for a rare empirical test of theoretically expected patterns of selective sweeps under these differing models. PMID:26363411

  10. Analysis of the Dryden Wet Bulb GLobe Temperature Algorithm for White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    LaQuay, Ryan Matthew

    2011-01-01

    In locations where workforce is exposed to high relative humidity and light winds, heat stress is a significant concern. Such is the case at the White Sands Missile Range in New Mexico. Heat stress is depicted by the wet bulb globe temperature, which is the official measurement used by the American Conference of Governmental Industrial Hygienists. The wet bulb globe temperature is measured by an instrument which was designed to be portable and needing routine maintenance. As an alternative form for measuring the wet bulb globe temperature, algorithms have been created to calculate the wet bulb globe temperature from basic meteorological observations. The algorithms are location dependent; therefore a specific algorithm is usually not suitable for multiple locations. Due to climatology similarities, the algorithm developed for use at the Dryden Flight Research Center was applied to data from the White Sands Missile Range. A study was performed that compared a wet bulb globe instrument to data from two Surface Atmospheric Measurement Systems that was applied to the Dryden wet bulb globe temperature algorithm. The period of study was from June to September of2009, with focus being applied from 0900 to 1800, local time. Analysis showed that the algorithm worked well, with a few exceptions. The algorithm becomes less accurate to the measurement when the dew point temperature is over 10 Celsius. Cloud cover also has a significant effect on the measured wet bulb globe temperature. The algorithm does not show red and black heat stress flags well due to shorter time scales of such events. The results of this study show that it is plausible that the Dryden Flight Research wet bulb globe temperature algorithm is compatible with the White Sands Missile Range, except for when there are increased dew point temperatures and cloud cover or precipitation. During such occasions, the wet bulb globe temperature instrument would be the preferred method of measurement. Out of the 30 dates examined, 23 fell under the category of having good accuracy.

  11. Definition and origin of the dune-field pattern at White Sands, New Mexico

    NASA Astrophysics Data System (ADS)

    Baitis, Elke; Kocurek, Gary; Smith, Virginia; Mohrig, David; Ewing, Ryan C.; Peyret, A.-P. B.

    2014-12-01

    A LiDAR-derived digital elevation model (DEM) of a representative portion of the White Sands Dune Field, New Mexico, allows for characterization of an unprecedented range of dune-field parameters and serves as a basis for pattern analysis. Dune-field parameters were measured and statistically analyzed for populations of dunes selected at random and occurring along transects. Populations sampled by these two different methods are comparable, but highlight the sensitivity of transect placement in a dune field that has pattern heterogeneity. Based upon coefficients of variation, pattern emerges at White Sands primarily because of a strong fabric of crestline orientation, and secondarily because of the regularity of spacing between dunes of similar shape as defined by sinuosity, height and length. Linear regression of dune parameters shows that dune geometric relationships vary primarily with crestline length, but there is little correlation between other parameters, including dune spacing and height. This result highlights the sensitivity of identifying topographic heterogeneity in a LiDAR-derived DEM, given that mean ratios conform to global averages. Stripping off the dunes in Matlab shows a terraced surface, which is interpreted to represent paleo-shorelines formed during relative still stands in the overall retreat of Lake Otero. Elevated bands of higher, more closely spaced dunes occur just leeward of the paleo-shorelines. A revised model for the White Sands Dune Field consists of the basinward progradation of successive dune-field segments. Each segment is associated with a paleo-shoreline, and consists of an upwind dune ridge, represented by the elevated bands, and a leeward dune field.

  12. Spacecraft propulsion systems test capability at the NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Baker, Pleddie; Gorham, Richard

    1993-01-01

    The NASA White Sands Facility (WSTF), a component insallation of the Johnson Space Center, is located on a 94-square-mile site in southwestern New Mexico. WSTF maintains many unique capabilities to support its mission to test and evaluate spacecraft materials, components, and propulsion systems to enable the safe human exploration and utilization of space. WSTF has tested over 340 rocket engines with more than 2.5 million firings to date. Included are propulsion system testing for Apollo, Shuttle, and now Space Station as well as unmanned spacecraft such as Viking, Pioneer, and Mars Observer. This paper describes the current WSTF propulsion test facilities and capabilities.

  13. Application of boost guidance to NASA sounding rocket launch operations at the White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    Montag, W. H.; Detwiler, D. F., Jr.; Hall, L.

    1986-01-01

    This paper addresses the unique problems associated with launching the Black Brant V, VIII, and IX sounding rocket vehicles at White Sands Missile Range (WSMR) and the significance of the introduction of the S19 to the NASA Goddard Space Flight Center Wallops Flight Facility sounding rocket program in terms of launch flexibility, improved impact dispersion, higher flight reliability, and reduced program costs. This paper also discusses salient flight results from NASA 36.011UL (the first S19 guided Black Brant launched at WSMR) and the NASA Comet Halley missions (36.010DL and 36.017DL).

  14. AVTA Federal Fleet PEV Readiness Data Logging and Characterization Study for NASA White Sands Test Facility

    SciTech Connect

    Stephen Schey; Jim Francfort

    2014-10-01

    This report focuses on the NASA White Sands Test Facility (WSTF) fleet to identify daily operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of plug-in electric vehicles (PEVs) into the agencies’ fleets. Individual observations of these selected vehicles provide the basis for recommendations related to electric vehicle adoption and whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively plug-in electric vehicles, or PEVs) can fulfill the mission requirements.

  15. Annual water-resources review, White Sands Missile Range, 1976: a basic-data report

    USGS Publications Warehouse

    Cruz, R.R.

    1977-01-01

    Information is presented on the water resources of the White Sands Missile Range, N. Mex., that was collected during the period December 1975 to December 1976 by personnel of the U.S. Geological Survey, Water Resources Division. Data on ground-water pumpage and resulting water-level fluctuation, chemical quality and precipitation, and miscellaneous items of interest are summarized. Water-level observations were made in 63 borehole, supply, test, and observation wells on the Range. Water samples were collected and analyzed for chemical quality from 8 test wells. (Woodard-USGS)

  16. Annual water-resources review, White Sands Missile Range, New Mexico, 1978

    USGS Publications Warehouse

    Cruz, R.R.

    1979-01-01

    Ground-water data were collected in 1978 at White Sands Missile Range in south-central New Mexico. Total ground-water pumpage in 1978 was 692,045,700 gallons or 7,248,300 less than in 1977. Wells at the Post Headquarters produced 98 percent of the total volume. Water levels in test wells around the Post Headquarters well field show seasonal declines ranging from 14.78 feet to 0.71 feet. The water samples collected from the supply wells show that the chemical quality of the water is slightly better during the period of greatest declines. (Woodard-USGS)

  17. Summary of ground-water data, Post Headquarters and adjacent areas, White Sands Missile Range

    USGS Publications Warehouse

    Kelly, T.E.

    1973-01-01

    Geohydrologic data have been obtained from more than 100 wells and test holes that have been drilled in the Post Headquarters and adjacent areas of White Sands Missile Range. Observation-well data show that, in general, a continuous decline of the water table has occurred in the vicinity of the well field since production began in 1949. Approximately 40,000 acre-feet of water has been produced from the aquifer to date (1972). A series of maps are presented which show the changes that have occurred in the well field as the result of development.

  18. Investigation of earth's albedo using Skylab data. [White Sands, New Mexico and Lake Michigan

    NASA Technical Reports Server (NTRS)

    Turner, R. E. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. Specific test sites in the White Sands, New Mexico and Lake Michigan areas were chosen because of their stability and known reflectances. Skylab S192 multispectral data and ERIM aircraft multispectral data were collected for these sites and were compared with results of atmospheric radiative transfer calculations in order to determine the aerosol content of the atmosphere. The spectral shape of the Skylab data compared quite favorably with the nearly simultaneous spectral character of the aircraft data. Although there were difficulties in the calibration of the S192 instrument which remain unresolved, interesting mathematical and physical relationships were discovered.

  19. Transport and mixing of eolian sand from local sources resulting in variations in grain size in a gypsum dune field, White Sands, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Langford, Richard P.; Gill, Thomas E.; Jones, Slade B.

    2016-03-01

    The White Sands Dune Field, New Mexico (USA), provides a unique opportunity to study sources and eolian transport of sand. End member mixing analysis provides unbiased correlation of the grain size distributions of populations that mix sands from four different local source surface types. Textural differences between sources allow local transport paths to be deduced. In total, 1214 surface samples from 10 dunes and 2 downwind-oriented transects were collected. Neither elevation on the dune, lee or stoss location nor distance downwind correlated with mean grain size, coarsest 10% (D90), or sorting. Instead, grain size distributions are controlled by mixing of locally sourced sand populations. Adjacent dunes can have different mean grain sizes, resulting from different local source populations. Local within-dune and between-dune variability resulting from different sand sources dominates any larger-scale trends across and within dunes. Four sand populations are identified, based on microscopically observable differences in grain size, shape and angularity. Each correlates with high loading of a different statistical factor, derived from End Member Mixing Analysis. End Member 1 (EM1) correlates with well-sorted populations of finer-grained, equant, rounded sands. EM2 correlates with samples that contain moderately sorted populations containing angular blades and crystal aggregates associated with erosional interdunes. EM3 is associated with samples of moderately to poorly sorted fine-grained sand containing fine sand-sized gypsum needles collected from areas of vegetated interdunes, and EM4 is associated with moderately well sorted coarse- and very coarse-grained sands collected from granule ripples. These results suggest that downwind mixing of different populations and segregation by different depositional processes influence grain size distributions in the dune field, rather than by dune-scale or erg-scale transport and sorting.

  20. Emplacement and dewatering of the world's largest exposed sand injectite complex

    NASA Astrophysics Data System (ADS)

    Sherry, Timothy J.; Rowe, Christie D.; Kirkpatrick, James D.; Brodsky, Emily E.

    2012-08-01

    Sandstone injectites form by up or down-section flow of a mobilized sand slurry through fractures in overlying rock. They act as reservoirs and high-permeability conduits through lower permeability rock in hydrocarbon systems. The Yellow Bank Creek Complex, Santa Cruz County, California is the largest known exposure of a sandstone injectite in the world. The complex contains granular textures that record processes of sand slurry flow, multiple pore fluids, and dewatering after emplacement. The injection was initially mobilized from a source containing both water and hydrocarbons. The water-sand slurry reached emplacement depth first, due to lower fluid viscosity. As the sand slurry emplaced, the transition from slurry flow to pore water percolation occurred. This transition resulted in preferred flow channels 6 mm wide in which sand grains were weakly aligned (laminae). The hydrocarbon-sand slurry intruded the dewatering sands and locally deformed the laminae. Compaction of the injectite deposit and pore fluid escape caused spaced compaction bands and dewatering pipes which created convolutions of the laminae. The hydrocarbon-rich sand slurry is preserved today as dolomite-cemented sand with oil inclusions. The laminae in this injectite are easily detected due to preferential iron oxide-cementation of the well-aligned sand laminae, and lack of cement in the alternating laminae. Subtle textures like these may develop during sand flow and be present but difficult to detect in other settings. They may explain permeability anisotropy in other sand deposits.

  1. Annual water-resources review, White Sands Missile Range, New Mexico, 1977; a hydrologic-data report

    USGS Publications Warehouse

    Cruz, R.R.

    1978-01-01

    Ground-water data were collected in 1977 at White Sands Missile Range in south-central New Mexico. Near the Post Headquarters water-level declines for the period 1968-77 declined about 20 feet. Total ground-water pumpage at White Sands Missile Range for 1977 was 2,146 acre-feet, 93 acre-feet more than in 1976. Wells at the Post Headquarters produced 2,112 acre-feet of the total volume. Specific conductance of ground water ranged from 277 to 2,410 micromhos per centimeter at 25 degrees Celsius for wells T-4 and T-14 respectively at Post Headquarters. (Woodard-USGS)

  2. Test wells TW1 and TW2, and TW3, White Sands Missile Range, Otero County, New Mexico

    USGS Publications Warehouse

    Myers, R.G.; Pinckley, K.M.

    1987-01-01

    Three test wells, TW1, TW2, and TW3, were drilled at White Sands Missile Range in south-central New Mexico in July, August, and October 1983 as part of a joint military training program sponsored by the U.S. Navy and U.S. Army in July, August, and October 1983. The test wells were drilled as exploratory and monitoring wells for the toxic waste storage facility at White Sands Missile Range. Information obtained from these wells includes lithologic logs for all wells and borehole-geophysical logs for the cased wells. (Author 's abstract)

  3. In-flight Absolute Radiometric Calibration of the Thematic Mapper. [White Sands, New Mexico

    NASA Technical Reports Server (NTRS)

    Palmer, J.; Slater, P. N. (principal investigators); Castle, K. R.; Holm, R. G.; Kastner, C. J.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1984-01-01

    Ground spectral reflectance and atmospheric spectral optical depth measurements made at White Sands, New Mexico were used with an atmospheric radiative transfer program to determine the spectral radiance at the entrance pupil of the LANDSAT-4 TM. Comparison with the output digital counts of the TM, when imaging the measured ground area, provided an absolute calibration for five detectors in TM bands 2, 3, and 4. By reference to an adjacent, larger uniform area, the calibration was extended to all 16 detectors in each of three bands. Preflight calibration results agreed with these inflight measurements to 6.6%, 2.4%, and 12.9% in bands 2,3, and 4, respectively.

  4. Biannual water-resources review, White Sands Missile Range, New Mexico, 1986 and 1987

    USGS Publications Warehouse

    Myers, Robert G.; Sharp, Steven C.

    1989-01-01

    Hydrologic data were collected at White Sands Missile Range, New Mexico in 1986 and 1987. The total groundwater withdrawal in 1986 was 565,462,500 gal and in 1987 it was 620,492,000 gal. The total groundwater withdrawal was 110,971,300 gal less in 1986 than in 1985, but 55,029,500 gal more in 1987 than in 1986. Water samples from five Post Headquarters water supply wells were collected for chemical analysis in 1986. In 1987, water samples were collected from four test wells in the Post Headquarters area for analysis of selected volatile organic compounds. Twenty-eight water samples from wells were collected for analysis of specific conductance in 1986 and 1987. (USGS)

  5. Depleted uranium investigation at missile impact sites in White Sands Missile Range

    SciTech Connect

    Van Etten, D.M.; Purtymun, W.D.

    1994-01-01

    An investigation for residual depleted uranium was conducted at Pershing missile impact sites on the White Sands Missile Range. Subsurface core soil samples were taken at Chess, Salt Target, and Mine Impact Sites. A sampling pump was installed in a monitoring well at Site 65 where a Pershing earth penetrator was not recovered. Pumping tests and water samples were taken at this site. Chess Site, located in a gypsum flat, was the only location showing elevated levels of depleted uranium in the subsurface soil or perched groundwater. Small fragments can still be found on the surface of the impact sites. The seasonal flooding and near surface water has aided in the movement of surface fragments.

  6. ICESat Calibration and Validation Experiments at White Sands, New Mexico, 2003-2010

    NASA Astrophysics Data System (ADS)

    Schutz, B. E.; Urban, T. J.

    2010-12-01

    The Center for Space Research (CSR) at the University of Texas at Austin has operated a primary site for ICESat cal/val activities near the White Sands Space Harbor (WSSH) area of the White Sands Missile Range, NM. This site was chosen for both geophysical (flat, reflective) and logistical (domestic, secure site) reasons. Before launch in 2003, a several-hundred-meter-scale grid comprised of hundreds of numbered PVC base-plates was installed at the chosen site to permanently mark the locations of various pieces of experiment hardware. In summary, CSR has supported four primary types of experiments at the cal/val site: (1) a permanent grid of laser retro-reflectors (corner cube reflectors) placed on top of poles of various known heights and collocated with 25 of the base plates, in use for the duration of the mission, (2) a set of computer-monitored position and timing detectors utilized for cal/val during the first three years of the project, (3) several camera-equipped aircraft flyovers of the area designed to capture images of the green and infrared footprints on the surface at the precise time of ICESat overflights, (4) elevation comparisons between the ICESat data and a high-resolution (1 m) DEM derived via small-footprint airborne lidar collections in 2003 and 2007. The experiments at WSSH were targeted by the ICESat spacecraft approximately four times per campaign, making this cal/val site one of the most sampled locations in the world. This presentation will chronicle the extensive collection of ICESat and experimental data collected at WSSH from 2003 to 2010.

  7. Deciphering complex soil/site formation in sands

    NASA Astrophysics Data System (ADS)

    Johnson, D. L.; Johnson, D. N.; Benn, D. W.; Bettis, E. A., III

    2008-10-01

    This paper summarizes aspects of the geoarchaeological research at two adjacent multi-component archaeological sites, 13JP86 and 13JP87, along Indian Creek in central Iowa, USA. The sites, both recently salvaged but now destroyed, formed in late Pleistocene sands reworked from glacial sediments that emanated from the wasting Des Moines Lobe glacier some 13,000-14,000 years ago. The soils contained shallowly dispersed and mixed artifacts that span the Paleoindian-to-historic cultural spectrum. In open areas, as at Indian Creek, site formation processes equate to natural soil genetic processes, plus human imprints. Cultural materials, once deposited, become part of the soil and subject to dynamic soil processes. These soils had reasonably well expressed Ap, A, and E horizons that collectively formed thick one-layered biomantles, underlain by well expressed argillic Bt horizons. The biomantles had been well bioturbated, deeply in some pedons, but still exhibited organized A and E horizons. The Bt horizons were also bioturbated, though less so, and consisted of multiple thin to thick sandy clay bands, termed illuvial clay lamellae (icl's). The icl's contained modest to appreciable amounts of illuvial clay as bridges between grains, and as diffuse splotches and blebs separated by less clayey, E horizon-like interlamellar sandy zones. Deeper and less bioturbated E-like sandy zones had accumulated so much clay that they had coalesced with icl's into thick, complexly banded argillic Bt horizons. The process histories of the sandy pedons were obviously extremely complex. The geoarchaeological aspects of the project, which were mainly complex pedologic ones, were largely interpreted by drawing on the genetic principles of dynamic denudation to explain soil/site evolution. Many questions were raised, and most were answered under these principles. New concepts and perspectives were gained in this study, and the resulting interpretive scenarios carry explanatory implications for sandy soils everywhere, whether charged with cultural materials or not.

  8. Sand remobilization enhanced complexity to mounded geometry, Early Tertiary deep water sand reservoirs, Balder Oil Field North Sea

    SciTech Connect

    Bergslien, D.; Rye-Larsen, M.; Jenssen, A.I. )

    1996-01-01

    Sand remobilization played a major role in generating the high relief mounded geometries that trap oil in the early Tertiary reservoirs at Balder Field in Norwegian North Sea blocks 25/10 and 25/11. The thick massive submarine-fan sandstones were shed from the East Shetland Platform and deposited from high density turbidity currents. These thick massive sandstones lie in the distal portions of the fan system on the northwestern margin of the Utsira High. An intricate interaction between deposition and soft sediment deformation processes generated the complex cluster of thick mounded sand geometries comprising the Balder oil field. Slumping, sliding and sand remobilization with associated sand injections into overlying shales were the dominant deformation processes that mainly occurred during the early Eocene. The field is comprised of three reservoirs, the Paleocene Heimdal and Hermod Formations and the Early Eocene Balder Formation. The sandstones, which have excellent reservoir properties, share a common pressure system and oil-water contact. This is probably related to the soft-sediment deformation and associated sand injections establishing cross-stratal communication.

  9. Sand remobilization enhanced complexity to mounded geometry, Early Tertiary deep water sand reservoirs, Balder Oil Field North Sea

    SciTech Connect

    Bergslien, D.; Rye-Larsen, M.; Jenssen, A.I.

    1996-12-31

    Sand remobilization played a major role in generating the high relief mounded geometries that trap oil in the early Tertiary reservoirs at Balder Field in Norwegian North Sea blocks 25/10 and 25/11. The thick massive submarine-fan sandstones were shed from the East Shetland Platform and deposited from high density turbidity currents. These thick massive sandstones lie in the distal portions of the fan system on the northwestern margin of the Utsira High. An intricate interaction between deposition and soft sediment deformation processes generated the complex cluster of thick mounded sand geometries comprising the Balder oil field. Slumping, sliding and sand remobilization with associated sand injections into overlying shales were the dominant deformation processes that mainly occurred during the early Eocene. The field is comprised of three reservoirs, the Paleocene Heimdal and Hermod Formations and the Early Eocene Balder Formation. The sandstones, which have excellent reservoir properties, share a common pressure system and oil-water contact. This is probably related to the soft-sediment deformation and associated sand injections establishing cross-stratal communication.

  10. Response of vegetation stability and groundwater depth to spatial variability in sediment transport; White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

    Masteller, C.; Jerolmack, D. J.; Bhattachan, A.

    2012-12-01

    Spatial variability in sediment transport can drive changes in dune morphology and vegetation cover across desert dunefields. Due to the complex interaction of vegetation with both water table dynamics and the soil-salt balance a discontinuous ecosystem response may exist. A theoretical model predicts that salt-vegetation feedback can lead to two stable states; one with sparse or no vegetation cover and a shallow brackish water table, and another with dense vegetation and a deep, fresh water table (Runyan and D'Odorico, 2010). Results presented here suggest that both stable states are present at White Sands National Monument, New Mexico - a gypsum dune field with a shallow, saline groundwater table - as actively-migrating barchan dunes abruptly transition to stable, vegetated parabolic forms. Vertical profiles of soil salinity, soil moisture, and depth to groundwater table were measured across the barchan-parabolic transition. Groundwater depth drops from ~0.5 m to ~1 m across this transition, likely a response to increasing transpiration. Salinity is uniform with depth in the unvegetated dunes; parabolics with dense vegetation exhibit a strong partitioning of salts.. Groundwater salinity drops by more than an order of magnitude, while there is a spike in soil salinity at the surface; consistent with model predictions. The spatial transition in dune-plant stability may therefore be applied to understand temporal shifts in dune field stability that may result from environmental change.

  11. Narrowband Angular Reflectance Properties of the Alkali Flats at White Sands, New Mexico

    NASA Technical Reports Server (NTRS)

    Whitlock, Charles H.; LeCroy, Stuart R.; Wheeler, Robert J.

    1994-01-01

    Results from helicopter measurements of the angular properties of surface reflectance for the alkali flats regions of the White Sands Missile Range are presented for the wavelength interval of 0.4 to 0.85 microns. This work was performed to allow accurate radiative transfer calculations over the region. Detailed tables and interpolation equations are given that permit other investigators to perform satellite calibrations over the alkali flats site. The effects of wavelength and soil moisture on narrowband angular reflectance are also investigated. Although there is a spectral variation in surface albedo, there is little spectral effect in Anisotropic Factor except in the forward scattering peak at solar zenith angles greater than 60 deg. The magnitude of the forward-scattering peak is also sensitive to soil moisture, with wet conditions causing a larger peak. The significance of this result is that angular reflectance properties at the center of the alkali flats usually will be different than those at the flats edge because moisture differences typically exist.

  12. Development of CFC-Free Cleaning Processes at the NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

    1995-01-01

    The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-113- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. The presentation will include the findings of investigations of aqueous cleaning and verification processes that are based on a draft of a proposed NASA Kennedy Space Center (KSC) cleaning procedure. Verification testing with known contaminants, such as hydraulic fluid and commonly used oils, established correlations between nonvolatile residue and CFC-113. Recoveries ranged from 35 to 60 percent of theoretical. WSTF is also investigating enhancements to aqueous sampling for organics and particulates. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon-225 (HCFC-225), tert-butylmethylether, and n-Hexane was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC-113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autoignition and liquid oxygen mechanical impact testing.

  13. A laboratory study of subjective response to sonic booms measured at White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    Sullivan, Brenda M.; Leatherwood, Jack D.

    1993-01-01

    The Sonic Boom Simulator of the Langley Research Center was used to quantify subjective loudness response to boom signatures consisting of: (1) simulator reproductions of booms recently recorded at White Sands Missile Range; (2) idealized N-waves; and (3) idealized booms having intermediate shocks. The booms with intermediate shocks represented signatures derived from CFD predictions. The recorded booms represented those generated by F15 and T38 aircraft flyovers and represented a variety of waveforms reflecting the effects of propagation through a turbulent atmosphere. These waveforms included the following shape categories: N-waves, peaked, rounded, and U-shaped. Results showed that Perceived Level and Zwicker Loudness Level were good estimators of the loudness of turbulence modified sonic booms. No significant differences were observed between loudness responses for the several shape categories when expressed in terms of Perceived Level. Thus, Perceived Level effectively accounted for waveform differences due to turbulence. Idealized booms with intermediate shocks, however, were rated as being approximately 2.7 dB(PL) less loud than the recorded signatures. This difference was not accounted for by PL.

  14. A laboratory study of subjective response to sonic booms measured at White Sands Missile Range

    NASA Astrophysics Data System (ADS)

    Sullivan, Brenda M.; Leatherwood, Jack D.

    1993-05-01

    The Sonic Boom Simulator of the Langley Research Center was used to quantify subjective loudness response to boom signatures consisting of: (1) simulator reproductions of booms recently recorded at White Sands Missile Range; (2) idealized N-waves; and (3) idealized booms having intermediate shocks. The booms with intermediate shocks represented signatures derived from CFD predictions. The recorded booms represented those generated by F15 and T38 aircraft flyovers and represented a variety of waveforms reflecting the effects of propagation through a turbulent atmosphere. These waveforms included the following shape categories: N-waves, peaked, rounded, and U-shaped. Results showed that Perceived Level and Zwicker Loudness Level were good estimators of the loudness of turbulence modified sonic booms. No significant differences were observed between loudness responses for the several shape categories when expressed in terms of Perceived Level. Thus, Perceived Level effectively accounted for waveform differences due to turbulence. Idealized booms with intermediate shocks, however, were rated as being approximately 2.7 dB(PL) less loud than the recorded signatures. This difference was not accounted for by PL.

  15. Potential for substitution of geothermal energy at domestic defense installations and White Sands Missile Range

    SciTech Connect

    Bakewell, C.A.; Renner, J.L.

    1982-01-01

    Geothermal resources that might provide substitute energy at any of 76 defense installations are identified and evaluated. The geologic characteristics and related economics of potential geothermal resources located at or near the 76 installations were estimated. The geologic assessment identified 18 installations with possible geothermal resources and 4 Atlantic Coastal Plain resource configurations that represented the alternatives available to East Coast bases. These 18 locations and 4 resource configurations, together with 2 possible resources at the White Sands Missile Range and a potential resource at Kings Bay, Georgia, were examined to determine the relative economics of substituting potential geothermal energy for part or all of the existing oil, gas, and electrical energy usage. Four of the military installations - Mountain Home, Norton, Hawthorne, and Sierra - appear to be co-located with possible geothermal resources which, if present, might provide substitute energy at or below current market prices for oil. Six additional locations - Ellsworth, Luke, Williams, Bliss, Fallon, and Twentynine Palms - could become economically attractive under certain conditions. No geothermal resource was found to be economically competitive with natural gas at current controlled prices. Generation of electric power at the locations studied is estimated to be uneconomic at present.

  16. Aqueous Cleaning and Validation for Space Shuttle Propulsion Hardware at the White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Hornung, Steven D.; Biesinger, Paul; Kirsch, Mike; Beeson, Harold; Leuders, Kathy

    1999-01-01

    The NASA White Sands Test Facility (WSTF) has developed an entirely aqueous final cleaning and verification process to replace the current chlorofluorocarbon (CFC) 113 based process. This process has been accepted for final cleaning and cleanliness verification of WSTF ground support equipment. The aqueous process relies on ultrapure water at 50 C (323 K) and ultrasonic agitation for removal of organic compounds and particulate. The cleanliness is verified bv determining the total organic carbon (TOC) content and filtration with particulate counting. The effectiveness of the aqueous methods for detecting hydrocarbon contamination and particulate was compared to the accepted CFC 113 sampling procedures. Testing with known contaminants, such as hydraulic fluid and cutting and lubricating oils, to establish a correlation between aqueous TOC and CFC 113 nonvolatile residue (NVR) was performed. Particulate sampling on cleaned batches of hardware that were randomly separated and sampled by the two methods was performed. This paper presents the approach and results, and discusses the issues in establishing the equivalence of aqueous sampling to CFC 113 sampling, while describing the approach for implementing aqueous techniques on Space Shuttle Propulsion hardware.

  17. Long term geological record of a global deep subsurface microbial habitat in sand injection complexes

    PubMed Central

    Parnell, John; Boyce, Adrian J.; Hurst, Andrew; Davidheiser-Kroll, Brett; Ponicka, Joanna

    2013-01-01

    There is extensive evidence from drilling into continental margins for microbial colonization of a deep biosphere. However it is difficult to prove deep biosphere activity in the geological record, where evidence for life is dominated by the remains of organic matter buried after deposition at the surface. Nevertheless we propose that natural injections of sand into muddy strata at continental margins represent an excellent habitat opportunity for deep microbial activity down to several kilometres' present day depth. Sulphur isotope data for iron sulphides precipitated soon after injection indicate consistent microbial sulphate reduction through the geological record. The complexes are favourable sites for colonization, because high permeability and extensive sand/mud interface allow ready availability of electron donors and nutrients. The measured examples of iron sulphide in injected sands extend back to the Proterozoic, and show that injected sand complexes have been a long-term environment for deep subsurface microbial colonization. PMID:23681146

  18. Long term geological record of a global deep subsurface microbial habitat in sand injection complexes.

    PubMed

    Parnell, John; Boyce, Adrian J; Hurst, Andrew; Davidheiser-Kroll, Brett; Ponicka, Joanna

    2013-01-01

    There is extensive evidence from drilling into continental margins for microbial colonization of a deep biosphere. However it is difficult to prove deep biosphere activity in the geological record, where evidence for life is dominated by the remains of organic matter buried after deposition at the surface. Nevertheless we propose that natural injections of sand into muddy strata at continental margins represent an excellent habitat opportunity for deep microbial activity down to several kilometres' present day depth. Sulphur isotope data for iron sulphides precipitated soon after injection indicate consistent microbial sulphate reduction through the geological record. The complexes are favourable sites for colonization, because high permeability and extensive sand/mud interface allow ready availability of electron donors and nutrients. The measured examples of iron sulphide in injected sands extend back to the Proterozoic, and show that injected sand complexes have been a long-term environment for deep subsurface microbial colonization. PMID:23681146

  19. The Holocene History of the White Sands Dune Field and the influences of Climate on Eolian Deflation and Playa Lakes

    NASA Astrophysics Data System (ADS)

    Langford, R. P.

    2001-12-01

    White Sands National Monument is the largest gypsum dune field in the world. The dunes have formed downwind of a 20-m-deep, 19-km-wide deflation basin containing large playa lakes. Today, the gypsum sand is derived from the edge of the deflation basin, next to the dune field, rather than the alkali flat and playa lakes where gypsum crystals are forming. Three erosional shorelines mark wetter episodes when playa lakes formed in the deflation basin. The youngest shoreline is forming today around Lake Lucero playa. The oldest shoreline, termed L1 is degraded and probably formed at the Pleistocene-Holocene transition. Deflation from the L1 to the L2 shoreline cut through Pleistocene bedded evaporites and probably marks initiation of the dune field. This event was before 5,840 years BP, based on radiocarbon in a lake dammed by the dunes. This reinforces an evolving consensus that episodes of deflation have characterized desert basins in the southwestern United States. Regional deflation events have been dated at 7,000 years and 4,000 years BP. The shorelines in the deflation basin imply that the White Sands dune field was created in short episodes and the modern dune field may not represent conditions active during expansion of the dune sea. >http://www.geo.utep.edu/Faculty_Staff/langford.html

  20. Fine root dynamics in lodgepole pine and white spruce stands along productivity gradients in reclaimed oil sands sites.

    PubMed

    Jamro, Ghulam Murtaza; Chang, Scott X; Naeth, M Anne; Duan, Min; House, Jason

    2015-10-01

    Open-pit mining activities in the oil sands region of Alberta, Canada, create disturbed lands that, by law, must be reclaimed to a land capability equivalent to that existed before the disturbance. Re-establishment of forest cover will be affected by the production and turnover rate of fine roots. However, the relationship between fine root dynamics and tree growth has not been studied in reclaimed oil sands sites. Fine root properties (root length density, mean surface area, total root biomass, and rates of root production, turnover, and decomposition) were assessed from May to October 2011 and 2012 using sequential coring and ingrowth core methods in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench.) Voss) stands. The pine and spruce stands were planted on peat mineral soil mix placed over tailings sand and overburden substrates, respectively, in reclaimed oil sands sites in Alberta. We selected stands that form a productivity gradient (low, medium, and high productivities) of each tree species based on differences in tree height and diameter at breast height (DBH) increments. In lodgepole pine stands, fine root length density and fine root production, and turnover rates were in the order of high > medium > low productivity sites and were positively correlated with tree height and DBH and negatively correlated with soil salinity (P < 0.05). In white spruce stands, fine root surface area was the only parameter that increased along the productivity gradient and was negatively correlated with soil compaction. In conclusion, fine root dynamics along the stand productivity gradients were closely linked to stand productivity and were affected by limiting soil properties related to the specific substrate used for reconstructing the reclaimed soil. Understanding the impact of soil properties on fine root dynamics and overall stand productivity will help improve land reclamation outcomes. PMID:26668730

  1. Test wells T21, T22, and T25, White Sands Missile Range, Dona Ana County, New Mexico

    USGS Publications Warehouse

    Myers, R.G.

    1983-01-01

    Three test wells, T21, T22, and T25, were drilled at White Sands Missile Range in south-central New Mexico as part of a joint military program sponsored by the U.S. Army in September 1982. T21 and T22 were drilled as observation wells for two old landfills. T25 was drilled as an exploratory hole to obtain lithologic and borehole-geophysical data in the vicinity of the proposed replacement well for Supply Well 15. Information obtained from these wells includes borehole-geophysical and driller's logs.

  2. Dust Plume Modeling from Ranges and Maneuver Areas on Fort Bliss and the White Sands Missile Range: Final Report

    SciTech Connect

    Chapman, Elaine G.; Barnard, James C.; Rutz, Frederick C.; Pekour, Mikhail S.; Rishel, Jeremy P.; Shaw, William J.

    2009-05-04

    The potential for air quality impacts from heavy mechanized vehicles operating on and between the unpaved main supply routes at Fort Bliss and White Sands Missile Range was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical move-out activities occurring on the installations were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing the modeling scenarios are summarized and results of simulations conducted under these assumptions are presented for four representative meteorological periods.

  3. 6. General view of complex. Sand tower at left (MN99E) ...

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

    6. General view of complex. Sand tower at left (MN-99-E) and oil house (MN-99-C) at right. Machine shop section of roundhouse (Mn-99-A) in background at center. View to west. - Duluth & Iron Range Rail Road Company Shops, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  4. Complex resistivity signatures of ethanol in sand-clay mixtures

    USGS Publications Warehouse

    Personna, Yves Robert; Slater, Lee; Ntarlagiannis, Dimitrios; Werkema, Dale; Szabo, Zoltan

    2013-01-01

    We performed complex resistivity (CR) measurements on laboratory columns to investigate changes in electrical properties as a result of varying ethanol (EtOH) concentration (0% to 30% v/v) in a sand–clay (bentonite) matrix. We applied Debye decomposition, a phenomenological model commonly used to fit CR data, to determine model parameters (time constant: τ, chargeability: m, and normalized chargeability: mn). The CR data showed a significant (P ≤ 0.001) time-dependent variation in the clay driven polarization response (~ 12 mrad) for 0% EtOH concentration. This temporal variation probably results from the clay–water reaction kinetics trending towards equilibrium in the sand–clay–water system. The clay polarization is significantly suppressed (P ≤ 0.001) for both measured phase (ϕ) and imaginary conductivity (σ″) with increasing EtOH concentration. Normalized chargeability consistently decreases (by up to a factor of ~ 2) as EtOH concentration increases from 0% to 10% and 10 to 20%, respectively. We propose that such suppression effects are associated with alterations in the electrical double layer (EDL) at the clay–fluid interface due to (a) strong EtOH adsorption on clay, and (b) complex intermolecular EtOH–water interactions and subsequent changes in ionic mobility on the surface in the EDL. Changes in the CR data following a change of the saturating fluid from EtOH 20% to plain water indicate strong hysteresis effects in the electrical response, which we attribute to persistent EtOH adsorption on clay. Our results demonstrate high sensitivity of CR measurements to clay–EtOH interactions in porous media, indicating the potential application of this technique for characterization and monitoring of ethanol contamination in sediments containing clays.

  5. Characterization of oil sands mineral components and clay-organic complexes

    SciTech Connect

    Axelson, D.E.; Mikula, R.J.; Potoczny, Z.M. )

    1989-01-01

    Differences in oil sands processability and extraction yields can be dependent upon many factors including the composition of the mineral components and the organic complexes that are associated with certain minerals. These mineral-organic associations help provide the bridge which leads to carry over of bitumen with the tailing as well as carry over of water and mineral matter with the product. The nature of the organic component of clay-organic complexes extracted from various streams in an oil sands recovery process is discussed in relation to the stability of both water-in-oil and oil-in-water emulsions formed. These samples have been studied with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) as well as with other techniques such as interfacial tension measurements.

  6. GroundwaterGeochemistry,SeasonalChangesandControlsonEolianMorphology.WhiteSandsNationalMonument,NewMexi co,TX

    NASA Astrophysics Data System (ADS)

    Rose, J. M.; Langford, R. P.; Cueto, M. J.

    2005-12-01

    The White Sands of New Mexico is composed of transverse, barchan and parabolic dunes formed of gypsum sand. Transverse dunes pass downwind into barchans and then vegetated parabolic dunes. This study focuses on the transition from barchan dunes that migrate rapidly (12 m/year) through an unvegetated landscape, to isolated parabolic dunes migrating at 1 to 2 m/year through vegetated, stabilized dunes and sand sheets. One theory is the vegetated parabolic dunes form where enough sand has been deposited above the permanent saline water table to allow the formation of a fresh water lens. Conversely, where there is enough vegetation, due to the permanent and highly saline groundwater table, the sand blows away as barchan dunes, deflating the dune field. In a 5 km long swath through the dunes, six sampling sites were established: two barchan, two parabolic and two in the transition zone between the two dune types. Groundwater as well as soil samples were collected to measure the seasonal variations on water salinity and of sand movement in the dune field. The water table is less than 1.5 m at all sites. During successive sampling during the first half of 2005, at the barchan sites, the water is three times more saline than the parabolic sites at (20,000 g/ml vs. 3,000-8000 g/ml). Sampling each two months from early December through June suggests the influx of fresh water into the basin has caused a salinity decrease in the soil water in both the transition and parabolic sites during the spring and summer from about 2,000-3,000 mg/L to about 1,000 mg/L). March results show an overall decrease in salinity readings although in May the results are more varied, showing some sites high and some showing low salinity readings but mostly ranging about 1,000 mg/L. The parabolic dunes specifically show an increase, in salinity from 1,000 mg/L in December to 8,000 mg/L in May. During the winter, thin zones of high salinity, or spikes, are found between 40 and 80 cm deep in the soil column in the parabolic dune area. These may correlate with very fine grained layers (mean 5 microns) in the soil. In the Transition sites, salinity decreases from December to May but hovers around 10,000 mg/L. The Barchan sites have relatively low salinity readings above the groundwater, whereas the groundwater is very saline. The values at the barchans sites remained relatively the same throughout the six months at around 20,000 mg/L. TDS (total dissolved solids) decreases from 7 g/L in the barchan to 2g/L in the parabolic dunes. In the barchan area, the amount of DO (dissolved oxygen) is also greater. It is presumed the vegetation and the associated ecology withdraw soil water, creating higher salinities in the soil column. These layers may have formed through precipitation from groundwater or through soil alteration of the eolian sand. The dramatic changes in groundwater salinity suggest dune fields can be shaped by dynamic feedback between eolian dynamics, vegetation and groundwater chemistry.

  7. Additive surface complexation modeling of uranium(VI) adsorption onto quartz-sand dominated sediments.

    PubMed

    Dong, Wenming; Wan, Jiamin

    2014-06-17

    Many aquifers contaminated by U(VI)-containing acidic plumes are composed predominantly of quartz-sand sediments. The F-Area of the Savannah River Site (SRS) in South Carolina (USA) is an example. To predict U(VI) mobility and natural attenuation, we conducted U(VI) adsorption experiments using the F-Area plume sediments and reference quartz, goethite, and kaolinite. The sediments are composed of ?96% quartz-sand and 3-4% fine fractions of kaolinite and goethite. We developed a new humic acid adsorption method for determining the relative surface area abundances of goethite and kaolinite in the fine fractions. This method is expected to be applicable to many other binary mineral pairs, and allows successful application of the component additivity (CA) approach based surface complexation modeling (SCM) at the SRS F-Area and other similar aquifers. Our experimental results indicate that quartz has stronger U(VI) adsorption ability per unit surface area than goethite and kaolinite at pH ? 4.0. Our modeling results indicate that the binary (goethite/kaolinite) CA-SCM under-predicts U(VI) adsorption to the quartz-sand dominated sediments at pH ? 4.0. The new ternary (quartz/goethite/kaolinite) CA-SCM provides excellent predictions. The contributions of quartz-sand, kaolinite, and goethite to U(VI) adsorption and the potential influences of dissolved Al, Si, and Fe are also discussed. PMID:24865372

  8. Variation of bee communities on a sand dune complex in the Great Basin: Implications for sand dune conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sand dunes across the Mojave and Great Basin Deserts house rich bee communities. The pollination services these bees provide can be vital in maintaining the diverse, and often endemic, dune flora. These dune environments, however, are threatened by intense off-highway vehicle (OHV) use. Conservati...

  9. Compilation of hydrologic data for White Sands pupfish habitat and nonhabitat areas, northern Tularosa Basin, White Sands Missile Range and Holloman Air Force Base, New Mexico, 1911-2008

    USGS Publications Warehouse

    Naus, C.A.; Myers, R.G.; Saleh, D.K.; Myers, N.C.

    2014-01-01

    The White Sands pupfish (Cyprinodon tularosa), listed as threatened by the State of New Mexico and as a Federal species of concern, is endemic to the Tularosa Basin, New Mexico. Because water quality can affect pupfish and the environmental conditions of their habitat, a comprehensive compilation of hydrologic data for pupfish habitat and nonhabitat areas in the northern Tularosa Basin was undertaken by the U.S. Geological Survey in cooperation with White Sands Missile Range. The four locations within the Tularosa Basin that are known pupfish habitat areas are the Salt Creek, Malpais Spring and Malpais Salt Marsh, Main Mound Spring, and Lost River habitat areas. Streamflow data from the Salt Creek near Tularosa streamflow-gaging station indicated that the average annual mean streamflow and average annual total streamflow for water years 19952008 were 1.35 cubic feet per second (ft3/s) and 983 acre-feet, respectively. Periods of no flow were observed in water years 2002 through 2006. Dissolved-solids concentrations in Salt Creek samples collected from 1911 through 2007 ranged from 2,290 to 66,700 milligrams per liter (mg/L). The average annual mean streamflow and average annual total streamflow at the Malpais Spring near Oscura streamflow-gaging station for water years 20038 were 6.81 ft3/s and 584 acre-feet, respectively. Dissolved-solids concentrations for 16 Malpais Spring samples ranged from 3,882 to 5,500 mg/L. Isotopic data for a Malpais Spring near Oscura water sample collected in 1982 indicated that the water was more than 27,900 years old. Streamflow from Main Mound Spring was estimated at 0.007 ft3/s in 1955 and 1957 and ranged from 0.02 to 0.07 ft3/s from 1996 to 2001. Dissolved-solids concentrations in samples collected between 1955 and 2007 ranged from an estimated 3,760 to 4,240 mg/L in the upper pond and 4,840 to 5,120 mg/L in the lower pond. Isotopic data for a Main Mound Spring water sample collected in 1982 indicated that the water was about 19,600 years old. Dissolved-solids concentrations of Lost River samples collected from 1984 to 1999 ranged from 8,930 to 118,000 (estimated) mg/L. Dissolved-solids concentrations in samples from nonhabitat area sites ranged from 1,740 to 54,200 (estimated) mg/L. In general, water collected from pupfish nonhabitat area sites tends to have larger proportions of calcium, magnesium, and sulfate than water from pupfish habitat area sites. Water from springs associated with mounds in pupfish nonhabitat areas was of a similar type (calcium-sulfate) to water associated with mounds in pupfish habitat areas. Alkali Spring had a sodium-chloride water type, but the proportions of sodium-chloride and magnesium-sulfate are unique as compared to samples from other sites.

  10. Microbial Nitrogen and Sulfur Cycles at the Playa and Playa-lake Deposits of White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

    Glamoclija, M.; Fogel, M. L.; Steele, A.

    2011-12-01

    A deflationary basin, Alkali Flat, of White Sands National Monument holds active playas and a playa lake, which allows for an excellent comparison of these different (hyper)saline habitats. Playa lakes are commonly studied as extreme hypersaline environments, however from our data, less studied playa sediments and coarse selenite crystals showed to be more biologically challenging environments. The Flat contains dome structures composed of coarse selenites, an alternative newly discovered microbial habitat. A comparison of environmental physicochemical conditions and molecular biology was used to determine the characteristics of microbial habitats and communities and to decipher nodes of nitrogen and sulfur cycles. On Mars, the presence of sulfate rich playa deposits has been suggested for the deposits discovered by the Opportunity rover at Meridiani Planum. Recently, it has been suggested that the playa settings extended to a larger, Arabia Terra, zone of groundwater upwelling. The study of terrestrial analogue site with playa settings, such as Alkali Flat from New Mexico, provides an analogue system to explore and characterize the proposed habitable zones and their potential biosignatures. At White Sands, playa lake deposits held up to 55wt.% of water within the surface mirabilite crust, bottom layers composed of sulfates, clay, halite, and carbonates had less water. The lake deposits hold the only setting with reducing chemistry that was detected in the layers beneath the crust (with 3.42:1 ammonium (NH4) over nitric oxides (NO)). Playa sediments were 10 times drier than the playa lake deposits and had patchy surface crust of halite and gypsum. Selenite crystals were the driest among studied habitats (0.16wt.% H2O). Playa sediments and selenites contained 9.49 and 3.9 times more NO than NH4, suggesting importance of nitrification processes in these settings. Nitrogen fixation genes were detected only in playa lake deposits. A variety of ammonium oxidation genes (β-, γ-proteobacteria, archaea) were detected in all of the samples, which supports the nitrification hypothesis suggested by nitrogen analyses. Denitrification genes, including anammox bacteria, were detected in all of the settings, showing that microbial organisms from the analyzed habitats do have abilities to complete the nitrogen metabolic circuit. A variety of sulfur bearing minerals provides nutrient compounds necessary for microbial life. Genetic assaying identified the presence of sulfate reducing microbes in all of the samples, as well as anoxyphototrophs and organisms with the APS reductase. The detected organisms have the ability to reduce sulfate and utilize reduced sulfur compounds and to oxidize them back to sulfate. Detected variety of carbonate precipitates associated with biofilms confirms the presence of sulfate reducing microbes in playa lake deposits and selenites. However, absence of carbonates and the presence of Fe and K chlorites at the playa sediments suggest likely stunted microbial sulfate reduction. Indicating microbial response to multiple environmental stress (drought and high salinity) and possible limiting conditions for, at least, microbial sulfate reduction reached in playa surface habitats.

  11. Gold Nanocluster and Quantum Dot Complex in Protein for Biofriendly White-Light-Emitting Material.

    PubMed

    Bhandari, Satyapriya; Pramanik, Sabyasachi; Khandelia, Rumi; Chattopadhyay, Arun

    2016-01-27

    We report the synthesis of a biofriendly highly luminescent white-light-emitting nanocomposite. The composite consisted of Au nanoclusters and ZnQ2 complex (on the surface of ZnS quantum dots) embedded in protein. The combination of red, green, and blue luminescence from clusters, complex, and protein, respectively, led to white light generation. PMID:26741861

  12. Impacts of bridging complexation on the transport of surface-modified nanoparticles in saturated sand

    NASA Astrophysics Data System (ADS)

    Torkzaban, Saeed; Wan, Jiamin; Tokunaga, Tetsu K.; Bradford, Scott A.

    2012-08-01

    The transport of polyacrylic acid capped cadmium telluride (CdTe) quantum dots (QDs), carboxylate-modified latex (CML), and bare silica nanoparticles (NPs) was studied in packed columns at various electrolyte concentrations and cation types. The breakthrough curves (BTCs) of QDs and CML particles in acid-treated Accusand showed significant amounts of increasing deposition with 0.5, 1, and 2 mM Ca2+, but only minute deposition at 50 and 100 mM Na+. Negligible QD and CML deposition occurred at 2 mM Ca2+ in columns packed with ultrapure quartz sand that was similar in size to the Accusand. These observations are not consistent with interpretations based on Derjaguin-Landau-Verwey-Overbeek (DLVO) calculations of interaction energies. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis demonstrated that there were regions on the acid-treated Accusand covered with small amounts of clay that were absent on the ultrapure quartz sand. A salt cleaning method was therefore used to remove the clay from the acid-treated Accusand. The BTCs of QDs and CML in this acid + salt treated Accusand exhibited much less deposition at any given Ca2+ concentration compared to those obtained from the acid-treated sand. SEM images showed that most of the QD deposited in acid-treated Accusand occurred on clay surfaces. Unlike our results with QDs and CML, negligible deposition of bare silica NPs occurred at 5 and 10 mM Ca2+ in acid-treated Accusand. The high deposition of QDs and CML particles was therefore attributed to bridging complexation in which Ca2+ serves as a bridge between the cation exchange locations on the clay and carboxyl functional groups on the QD and CML particles, which were absent on the bare silica NPs. Our results suggest that the transport of carboxylic ligand-modified NPs may be limited in subsurface environments because of the ubiquitous presence of clay and divalent cations.

  13. Analysis of the NASA White Sands Test Facility (WSTF) Test System for Friction-Ignition of Metallic Materials

    NASA Technical Reports Server (NTRS)

    Shoffstall, Michael S.; Wilson, D. Bruce; Stoltzfus, Joel M.

    2000-01-01

    Friction is a known ignition source for metals in oxygen-enriched atmospheres. The test system developed by the NASA White Sands Test Facility in response to ASTM G-94 has been used successfully to determine the relative ignition from friction of numerous metallic materials and metallic materials pairs. These results have been ranked in terms of a pressure-velocity product (PV) as measured under the prescribed test conditions. A high value of 4.1(exp 8) watts per square meter for Inconel MA 754 is used to imply resistance to friction ignition, whereas a low value of 1.04(exp 8) watts per square meter for stainless steel 304 is taken as indicating material susceptible to friction ignition. No attempt has been made to relate PV values to other material properties. This work reports the analysis of the WSTF friction-ignition test system for producing fundamental properties of metallic materials relating to ignition through friction. Three materials, aluminum, titanium, and nickel were tested in the WSTF frictional ignition instrument system under atmospheres of oxygen or nitrogen. Test conditions were modified to reach a steady state of operation, that is applied, the force was reduced and the rotational speed was reduced. Additional temperature measurements were made on the stator sample. The aluminum immediately galled on contact (reproducible) and the test was stopped. Titanium immediately ignited as a result of non-uniform contact of the stator and rotor. This was reproducible. A portion of the stator sampled burned, but the test continued. Temperature measurements on the stator were used to validate the mathematical model used for estimating the interface (stator/rotor) temperature. These interface temperature measurements and the associate thermal flux into the stator were used to distinguish material-phase transitions, chemical reaction, and mechanical work. The mechanical work was used to analyze surface asperities in the materials and to estimate a coefficient of fiction. The coefficient of fiction was analyzed in terms of material properties that is, hardness, Young's modulus and elasticity/plasticity of the material.

  14. An investigation of several aspects of LANDSAT-5 data quality. [Palmer County, Shelby, mt; White sands, NM; Great Salt Lake, UT; San Matted Bridge and Sacramento, California

    NASA Technical Reports Server (NTRS)

    Wrigley, R. C. (Principal Investigator)

    1984-01-01

    Band-to-band registration, geodetic registration, interdector noise, and the modulation transfer function (MTE) are discussed for the Palmer County; TX scene. Band combinations for several LANDSAT 4 and LANDSAT 5 scenes; the geodetic registration test for the Sacramento, CA area; periodic noise components in TM band 5; and grey level measurements by detector for Great Salt Lake (UT) dark water forescans and backscans are considered. Results of MTF analyses of the San Mateo Bridge and of TM high resolution and aerial Daedalus scanner imagery are consistent and appear to be repeatable. An oil-on-sand target was constructed on the White Sands Missile Range in New Mexico. The two-image analysis procedure used is summarized.

  15. LIDAR first results from the Oil Sands Region: A complex vertical atmosphere

    NASA Astrophysics Data System (ADS)

    Strawbridge, K. B.

    2012-12-01

    Environment Canada is using LIDAR technology to probe the complex vertical structure of the atmosphere over the oil sands region. This provided the critical vertical context for the interpretation of ground-based chemistry measurements and model verification and validation. In recent years, Environment Canada has designed an autonomous aerosol LIDAR system that can be deployed to remote areas such as the oil sands. The trailer that contains the LIDAR system includes a roof hatch assembly, basic meteorological tower, radar interlock system, climate control system and leveling stabilizers. A precipitation sensor is used to operate the roof hatch and three pan/tilt webcams capture sky conditions and monitor the Lidar system's health. A remote control interface is used to monitor all vital components of the system, including the ability to provide hard resets to the various electronic devices onboard. Every 10 seconds the system provides vertical aerosol profiles from near ground to 20 km. The LIDAR transmitter emits two wavelengths (1064nm and 532nm) and the detector assembly collects three channels (1064nm backscatter, 532nm backscatter and 532nm depolarization). The depolarization channel provided key information in identifying and discriminating the various aerosol layers aloft such as dust, forest fire plumes, industrial plume sources or ice crystals. It operates 24 hours a day, seven days a week except during precipitation events and when aircraft fly over the site. The system is operated remotely and the data are updated every hour to a website to allow near real-time capability. First results from an intensive field campaign will be presented. LIDAR false color plot showing the bottom 7 km of the atmosphere during a forest fire event. Note the forest fire plume is between 1.5 and 5 km.

  16. Airborne Measurements of Aerosol Emissions From the Alberta Oil Sands Complex

    NASA Astrophysics Data System (ADS)

    Howell, S. G.; Clarke, A. D.; McNaughton, C. S.; Freitag, S.

    2012-12-01

    The Alberta oil sands contain a vast reservoir of fossil hydrocarbons. The extremely viscous bitumen requires significant energy to extract and upgrade to make a fluid product suitable for pipelines and further refinement. The mining and upgrading process constitute a large industrial complex in an otherwise sparsely populated area of Canada. During the ARCTAS project in June/July 2008, while studying forest fire plumes, the NASA DC-8 and P-3B flew through the plume a total of 5 times. Once was a coordinated visit by both aircraft; the other 3 were fortuitous passes downwind. One study has been published about gas emissions from the complex. Here we concentrate on aerosol emissions and aging. As previously reported, there appear to be at least 2 types of plumes produced. One is an industrial-type plume with vast numbers of ultrafine particles, SO2, sulfate, black carbon (BC), CO, and NO2. The other, probably from the mining, has more organic aerosol and BC together with dust-like aerosols at 3 μm and a 1 μm mode of unknown origin. The DC-8 crossed the plume about 10 km downwind of the industrial site, giving time for the boundary layer to mix and enabling a very crude flux calculation suggesting that sulfate and organic aerosols were each produced at about 500 g/s (estimated errors are a factor of 2, chiefly due to concerns about vertical mixing). Since this was a single flight during a project dedicated to other purposes and operating conditions and weather may change fluxes considerably, this may not be a typical flux. As the plume progresses downwind, the ultrafine particles grow to sizes effective as cloud condensation nucei (CCN), SO2 is converted to sulfate, and organic aerosol is produced. During fair weather in the summer, as was the case during these flights, cloud convection pumps aerosol above the mixed layer. While the aerosol plume is difficult to detect from space, NO2 is measured by the OMI instrument an the Aura satellite and the oil sands plume often exceeds the detection limit. There is a rough correlation between NO2 and aerosol, so it may be possible to indirectly monitor aerosol production.

  17. Adsorption and dissociation of Co-EDTA complexes in iron oxide-containing subsurface sands

    SciTech Connect

    Zachara, J.M.; Smith, S.C.; Kuzel, L.S.

    1995-12-31

    The sorption of Co(II)EDTA{sup 2-} (where EDTA is ethylenediaminetetracetic acid) was investigated on goethite and on eight sand-textured Quaternary and Pliocene fluvial sediments. Dual-label tracer techniques were used to follow the distribution of {sup 60}Co(II)- {sup 14}C/EDTA added as the performed 1:1, Co(II) EDTA{sup 2-} complex. Sorption experiments were performed with fixed concentrations of Co(II)EDTA{sup 2-} (10{sup -5} mol/L) and variable pH (all materials), and fixed pH (4.4) with variable Co(II)EDTA{sup 2-} concentrations (two materials), using solids concentrations of 0.5 g/L for goethite and 500 g/L for the sediments and electrolyte concentrations of 0.003 and 0.03 (geothite only) mol/L Ca(ClO{sub 4}){sub 2}. Aqueous Fe{sub aq}{sup 3+} and Al{sub aq}{sup 3+} were measured at the time of the sorption determination. On goethite, Co(II)EDTA{sup 2-} exhibited anion-like sorption, increasing with decreasing pH. Increasing electrolyte concentration decreased sorption, indicating a weak, ion-pair type surface complex. Below pH 6, however, the sorption chemistry of Co{sup 2+} and EDTA{sup 4-} became complex and disparate as a result of Co(II)EDTA{sup 2-} dissociation. Dissociation was driven by exchange with Fe{sub aq}{sup 3+}. A nonelectrostatic surface complexation model that explicitly considered the Fe{sup 3+} -Co(II)EDTA{sup 2-} exchange reaction was able to adequately describe the sorption data using surface complexes with Co(II)EDTA{sup 2-}, FeEDTA{sup -}, and Co{sup 2+}. Iron oxides were a dominant grain-coating phase on over half the sorbents, and X-ray diffraction (XRD), chemical extraction, and microscopic techniques documented the presence of poorly crystalline forms as well as geothite, hematite, and feroxyhite. The coupled adsorption, dissolution, and dissociation process will cause complex distance-variant speciation and retardation behavior for Co(II)EDTA{sup 2-} in subsurface environments. 58 refs., 14 figs., 6 tabs.

  18. Whiteness.

    PubMed

    Altman, Neil

    2006-01-01

    This paper seeks to make meaning of the experience of being white in the United States at this point in history. The self-awareness of white people is limited by a blind spot around the meaning and impact of being white in a multiracial society. Using psychoanalytic and literary methodology, the author seeks to cast light with which to explore this blind spot. Everyday experiences are used to illustrate the widely pervasive impact of race in the lives of white people, and a clinical vignette illustrates how race might show up in a white-on-white psychotherapy. Enactments within this paper are noted when they are evident to the author PMID:16482960

  19. Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

    SciTech Connect

    Hansen, W.R.; Rodgers, J.C.

    1985-06-01

    Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs.

  20. XRD and mineralogical analysis of gypsum dunes at White Sands National Monument, New Mexico and applications to gypsum detection on Mars

    NASA Astrophysics Data System (ADS)

    Lafuente, B.; Bishop, J. L.; Fenton, L. K.; King, S. J.; Blake, D.; Sarrazin, P.; Downs, R.; Horgan, B. H.

    2013-12-01

    A field portable X-ray Diffraction (XRD) instrument was used at White Sands National Monument to perform in-situ measurements followed by laboratory analyses of the gypsum-rich dunes and to determine its modal mineralogy. The field instrument is a Terra XRD (Olympus NDT) based on the technology of the CheMin (Chemistry and Mineralogy) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity which is providing the mineralogical and chemical composition of scooped soil samples and drilled rock powders collected at Gale Crater [1]. Using Terra at White Sands will contribute to 'ground truth' for gypsum-bearing environments on Mars. Together with data provided by VNIR spectra [2], this study clarifies our understanding of the origin and history of gypsum-rich sand dunes discovered near the northern polar region of Mars [3]. The results obtained from the field analyses performed by XRD and VNIR spectroscopy in four dunes at White Sands revealed the presence of quartz and dolomite. Their relative abundance has been estimated using the Reference Intensity Ratio (RIR) method. For this study, particulate samples of pure natural gypsum, quartz and dolomite were used to prepare calibration mixtures of gypsum-quartz and gypsum-dolomite with the 90-150?m size fractions. All single phases and mixtures were analyzed by XRD and RIR factors were calculated. Using this method, the relative abundance of quartz and dolomite has been estimated from the data collected in the field. Quartz appears to be present in low amounts (2-5 wt.%) while dolomite is present at percentages up to 80 wt.%. Samples from four dunes were collected and prepared for subsequent XRD analysis in the lab to estimate their composition and illustrate the changes in mineralogy with respect to location and grain size. Gypsum-dolomite mixtures: The dolomite XRD pattern is dominated by an intense diffraction peak at 2??36 deg. which overlaps a peak of gypsum, This makes low concentrations of dolomite difficult to quantify in mixtures with high concentration of gypsum. Dolomite has been detected in some locations at dune 3 as high as 80 wt.%. Gypsum-quartz mixtures: The intensity of the main diffraction peak of quartz at 2??31 deg. decreases progressively with the decrease of the amount of quartz in the mixtures. Samples from dune 1 and 2 show quartz abundance at 5.6 and 2.6 wt.% respectively . [1] Blake et al. Space Sci. Rev. (2012). doi:10.1007/s11214-012-9905-1. [2] King et al. (2013) AGU, submitted. [3] Langevin et al. (2005). Science 307, 1584-1586.

  1. Controls on the large-scale spatial variations of dune field properties in the barchanoid portion of White Sands dune field, New Mexico

    NASA Astrophysics Data System (ADS)

    Pelletier, Jon D.

    2015-03-01

    Previous studies have shown that sediment fluxes and dune sizes are a maximum near the upwind margin of the White Sands dune field and decrease, to first order, with increasing distance downwind. These patterns have alternatively been attributed to a shear-stress overshoot associated with a roughness transition localized at the upwind margin and to the influence of long-wavelength topography on the hydrology and hence erodibility of dune field sediments. I point out an issue that compromises the shear-stress overshoot model and further test the hypothesis that long-wavelength topographic variations, acting in concert with feedbacks among aerodynamic, granulometric, and geomorphic variables, control dune field properties at White Sands. Building upon the existing literature, I document that the mean and variability of grain sizes, sand dryness, aerodynamic roughness lengths, bed shear stresses, sediment fluxes, and ripple and dune heights all achieve local maxima at the crests of the two most prominent scarps in the dune field, one coincident with the upwind margin and the other located 6-7 km downwind. Computational fluid dynamics (CFD) modeling predicts that bed shear stresses, erosion rates, and the supply of relatively coarse, poorly sorted sediments are localized at the two scarps due to flow line convergence, hydrology, and the spatially distributed adjustment of the boundary layer to variations in dune size. As a result, the crests of the scarps have larger ripples due to the granulometric control of ripple size. Larger grain sizes and/or larger ripples lead to larger dunes and hence larger values of bed shear stress in a positive feedback.

  2. Results of calibrations of the NOAA-11 AVHRR made by reference to calibrated SPOT imagery at White Sands, N.M

    NASA Technical Reports Server (NTRS)

    Nianzeng, Che; Grant, Barbara G.; Flittner, David E.; Slater, Philip N.; Biggar, Stuart F.; Jackson, Ray D.; Moran, M. S.

    1991-01-01

    The calibration method reported here makes use of the reflectances of several large, uniform areas determined from calibrated and atmospherically corrected SPOT Haute Resolution Visible (HRV) scenes of White Sands, New Mexico. These reflectances were used to predict the radiances in the first two channels of the NOAA-11 Advanced Very High Resolution Radiometer (AVHRR). The digital counts in the AVHRR image corresponding to these known reflectance areas were determined by the use of two image registration techniques. The plots of digital counts versus pixel radiance provided the calibration gains and offsets for the AVHRR. A reduction in the gains of 4 and 13 percent in channels 1 and 2 respectively was found during the period 1988-11-19 to 1990-6-21. An error budget is presented for the method and is extended to the case of cross-calibrating sensors on the same orbital platform in the Earth Observing System (EOS) era.

  3. Test wells T23, T29, and T30, White Sands Missile Range and Fort Bliss Military Reservation, Dona Ana County, New Mexico

    USGS Publications Warehouse

    Myers, R.G.; Pinckley, K.M.

    1984-01-01

    Three test wells, T23, T29, and T30, were drilled in south-central New Mexico as part of a joint military training program sponsored by the U.S. Army in November 1982. Test well T23 was drilled as an exploratory and monitoring well in the proposed Soledad well field at the Fort Bliss Military Reservation. Test wells T29 and T30 were drilled at White Sands Missile Range. Test well T29 was drilled as an observation well in the vicinity of the outfall channel from the sewage treatment plant. Test well T30 was drilled as an observation well for a landfill south of the well site. Information obtained from these wells includes lithologic logs for all wells and borehole-geophysical logs from the cased wells for test wells T29 and T30. (USGS)

  4. Friction evaluation of unpaved, gypsum-surface runways at Northrup Strip, White Sands Missile Range, in support of Space Shuttle Orbiter landing and retrieval operations

    NASA Technical Reports Server (NTRS)

    Yager, T. J.; Horne, W. B.

    1980-01-01

    Friction measurement results obtained on the gypsum surface runways at Northrup Strip, White Sands Missile Range, N. M., using an instrumented tire test vehicle and a diagonal braked vehicle, are presented. These runways were prepared to serve as backup landing and retrieval sites to the primary sites located at Dryden Flight Research Center for shuttle orbiter during initial test flights. Similar friction data obtained on paved and other unpaved surfaces was shown for comparison and to indicate that the friction capability measured on the dry gypsum surface runways is sufficient for operations with the shuttle orbiter and the Boeing 747 aircraft. Based on these ground vehicle friction measurements, estimates of shuttle orbiter and aircraft tire friction performance are presented and discussed. General observations concerning the gypsum surface characteristics are also included and several recommendations are made for improving and maintaining adequate surface friction capabilities prior to the first shuttle orbiter landing.

  5. Apollo 14 crew arrive at White Room atop Pad A, Launch Complex 39

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The three Apollo 14 astronauts arrive at the White Room atop Pad A, Launch Complex 39, during the Apollo 14 prelaunch countdown. Note identifying red bands on the sleeve and leg of Shepard. Standing in the center background is Astronaut Thomas P. Stafford, Chief of the Manned Spacecraft Center Astronaut Office.

  6. Occult White Matter Damage Contributes to Intellectual Disability in Tuberous Sclerosis Complex

    ERIC Educational Resources Information Center

    Yu, Chunshui; Lin, Fuchun; Zhao, Li; Ye, Jing; Qin, Wen

    2009-01-01

    Whether patients with tuberous sclerosis complex (TSC) have brain normal-appearing white matter (NAWM) damage and whether such damage contributes to their intellectual disability were examined in 15 TSC patients and 15 gender- and age-matched healthy controls using diffusion tensor imaging (DTI). Histogram and region of interest (ROI) analyses of

  7. Issues of Indigenous Representation: White Advocacy and the Complexities of Ethical Leadership

    ERIC Educational Resources Information Center

    Niesche, Richard; Keddie, Amanda

    2014-01-01

    This paper explores the tensions and complexities for two principals as they work towards equity and improved social and educational outcomes for their Indigenous students. Drawing on Foucault's fourfold ethical frame and poststructuralist notions of the subject, this paper presents the different ways the white female principals of Indigenous

  8. Orange phosphorescent iridium complexes chelated with phenylbenzothiazolate derivatives for white organic light-emitting diodes.

    PubMed

    Lee, Hye Joo; Lee, Ho Won; Kim, Young Kwan; Ha, Yunkyoung

    2014-08-01

    For the application to white organic light-emitting diodes (OLEDs), the iridium complexes containing phenylbenzothiazolate derivatives as main ligands were prepared and their photophysical properties were investigated. We introduced a series of substituted 2-phenylbenzothiazolate (pbt) ligands to the iridium complexes. Variation of the substituent (R) in the ligand backbones could lead to the emission color tuning of the complexes. As ancillary ligands, the anions of 2,3-diphenyl-4-methyl-quinoline-C2,N (4-Me-2,3-dpq) and phenylpyridine (ppy) were chelated to the iridium center to complete 6-coodinate complexes. The iridium complexes prepared herein are Ir(pbt-R)2(4-Me-2,3-dpq) (pbt-R = 2-(4-R-phenylbenzothiazolate (R = H, OCH3, F); 4-Me-2,3-dpq = 2,3-diphenyl-4-methyl-quinolinate-C2,N) and Ir(pbt-R)2(ppy) (ppy = 2-phenylpyridinate). The PL spectra of the iridium complexes showed yellow to orange emission at 540-595 nm with some variation in luminescence maxima depending on the ancillary ligand rather than on the substituents of the main ligands. The electrochemical characteristics of the complexes were also investigated with cyclic voltammetry and the resulting energy gaps between HOMOs and LUMOs were consistent with the PL maxima. The electroluminescence (EL) properties of the new iridium complexes were studied as possible phosphors for the application to orange and white OLEDs. PMID:25936079

  9. Drilling, construction, and testing of water-supply wells 21 and 22, White Sands Missle Range, Dona Ana County, New Mexico

    USGS Publications Warehouse

    Wilson, Clyde A.; White, R.R.; Roybal, R.G.; Gonzales, J.L.

    1978-01-01

    During the spring and summer of 1976, two municipal-supply wells (designated as well 21 and well 22 - 2,000 feet apart) were drilled at the Post Headquarters area of White Sands Missile Range, New Mexico. The design specifications for both wells called for 24-inch diameter surface casing cemented in place to a depth of about 430 feet, with 16-inch liner and slotted casing from the surface to a depth of about 700 feet. Each well was pumped continuously for 32 hours in a step-drawdown test. This test consisted of four steps, with discharge rates varying from about 500 to 1,150 gallons per minute. The drawdown test for well 21 gave an estimated transmissivity of 17,300 gallons per day per foot, and a final specific capacity of slightly less than 11 gallons per minute per foot of drawdown. The step-drawdown test and later drawdown and recovery test on well 22 gave an average transmissivity of 32,600 gallons per day per foot, and a final specific capacity of about 15 gallons per minute per foot of drawdown. The data collected indicated that the aquifer in the vicinity of well 22 is more permeable than the aquifer around well 21. Both wells furnish a satisfactory quantity of excellent-quality water. The dissolved-solids content of water from wells 21 and 22 is 232 and 301 mg/liter respectively. (Woodard-USGS)

  10. The effects of ground-water development on the water supply in the Post Headquarters area, White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Kelly, T.E.; Hearne, Glenn A.

    1976-01-01

    Water-level declines in the Post Headquarters area, White Sands Missile Range, N. Mex., have been accompanied by slight but progressive increases in the concentration of dissolved solids in water withdrawn from the aquifer. Projected water-level declines through 1996 are estimated from a digital simulation model to not exceed 200 feet (61 metres). A conceptual model of water quality provides three potential sources for water that is relatively high in dissolved solids: brine from the Tularosa Basin to the east, slightly saline water beneath the subjacent aquatard, and very slightly saline water from the less permeable units within the aquifer itself. Management of the well field to minimize drawdown and spread the cone of depression would minimize the rate of water-quality deterioration. A well designed monitoring network may provide advance warning of severe or rapid water-quality deterioration.. The Soledad Canyon area 10 miles (16.1 kilometres) south of the Post Headquarters offers the greatest potential for development of additional water supplies.

  11. Simulated water-level and water-quality changes in the bolson-fill aquifer, Post Headquarters area, White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Risser, D.W.

    1988-01-01

    The quantity of freshwater available in the Post Headquarters well field, White Sand Missile Range, New Mexico, is limited and its quality is threatened by saltwater enroachment. A three-dimensional, finite-difference, groundwater flow model and a cross-sectional, density-dependent solute-transport model were constructed to simulate possible future water level declines and water quality changes in the Post Headquarters well field. A six-layer flow model was constructed using hydraulic-conductivity values in the upper 600 ft of saturated aquifer ranging from 0.1 to 10 ft/day, specific yield of 0.15, and average recharge of about 1,590 acre-ft/yr. Water levels simulated by the model closely matched measured water levels for 1948-82. Possible future water level changes for 1983-2017 were simulated using rates of groundwater withdrawal of 1,033 and 2 ,066 acre-ft/year and wastewater return flow of 0 or 30% of the groundwater withdrawal rate. The cross-sectional solute-transport model indicated that the freshwater zone is about 1,500 to 2,000 ft thick beneath the well field. Transient simulations show that solutes probably will move laterally toward the well field rather than from beneath the well field. (USGS)

  12. GBFEL-TIE (Ground-Based Free Electron Laser Technology Experiment) sample survey on White Sands Missile Range, New Mexico: The NASA, Stallion, and Orogrande Alternatives. Final report

    SciTech Connect

    Seaman, T.J.; Doleman, W.H.

    1988-09-30

    Three locations on White Sands Missile Range, New Mexico, are under consideration as alternatives for the proposed Ground-Based Free-Electron Laser Technology Integration Experiment (GBFEL-TIE). The study conducted jointly by Prewitt and Associates, Inc., and the Office of Contract Archeology, was designed to provide input into the GBFEL-TIE Draft Environmental Impact Statement concerning the potential impact of the proposed project on cultural resources in each of the alternatives. The input consists of a series of predictions based on data gathered from two sources: (1) a cultural resource sample survey (15%) of two alternatives conducted as part of this study, and (2) from a previous survey of the third alternative. A predictive model was devleoped and applied using these data that estimated the potential impact of the GBFEL-TIE facility on the cultural resources within each alternative. The predictions indicate that the NASA alternatives, by far, the least favorable location for the facility followed by the Orogrande and Stallion Alternatives.

  13. 22. V2 GANTRY, LAUNCH COMPLEX 33: GENERAL VIEW, LOOKING WEST ...

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

    22. V-2 GANTRY, LAUNCH COMPLEX 33: GENERAL VIEW, LOOKING WEST AND UPWARD FROM APRON OF BLAST PIT, 20,000 POUND MOTOR TEST AND LAUNCH FACILITY - White Sands Missile Range, V-2 Rocket Facilities, Near Headquarters Area, White Sands, Dona Ana County, NM

  14. 21. V2 GANTRY, LAUNCH COMPLEX 33: VIEW OF CRANE WITH ...

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

    21. V-2 GANTRY, LAUNCH COMPLEX 33: VIEW OF CRANE WITH BLAST PIT OF 20,000 POUND MOTOR TEST AND LAUNCH FACILITY, IN FOREGROUND, LOOKING WEST - White Sands Missile Range, V-2 Rocket Facilities, Near Headquarters Area, White Sands, Dona Ana County, NM

  15. Synchronous Tricolor Emission-Based White Light from Quantum Dot Complex.

    PubMed

    Pramanik, Sabyasachi; Bhandari, Satyapriya; Roy, Shilaj; Chattopadhyay, Arun

    2015-04-01

    Herein we report the generation of synchronous tricolor emission for a single wavelength excitation from a quantum dot complex (QDC). The single-component QDC was formed out of a complexation reaction, at room temperature, between ligand-free Mn(2+)-doped ZnS quantum dots (Qdots) and a mixture of two organic ligands (acetylsalicylic acid and 8-hydroxyquinoline). Furthermore, the tunability in chromaticity color coordinates, which is important for solid-state lighting, was achieved following the synthesis of QDC. Moreover, the photostable QDC emitted white light (?ex 320 nm) with (0.30, 0.33) and (0.32, 0.32) chromaticity color coordinates in the liquid and the solid phases, respectively. Hence, the white light-emitting QDC may be a superior material for light-emitting applications. PMID:26262986

  16. 2005 annual progress report: elk and bison grazing ecology in the Great Sand Dunes complex of lands

    USGS Publications Warehouse

    Schoenecker, Kate A.; Lubow, Bruce C.; Zeigenfuss, Linda C.; Mao, Julie

    2006-01-01

    Introduction: In 2000 the U.S. Congress authorized the expansion of the former Great Sand Dunes National Monument by establishing a new Great Sand Dunes National Park and Preserve in its place, and establishing the Baca National Wildlife Refuge. The establishment of Great Sand Dunes National Park and Preserve and the new Baca National Wildlife Refuge in the San Luis Valley (SLV), Colorado was one of the most significant land conservation actions in the western U.S. in recent years. The action was a result of cooperation between the National Park Service (NPS), U.S. Fish and Wildlife Service (USFWS), Bureau of Land Management (BLM), U.S. Forest Service (USDA-FS), and The Nature Conservancy (TNC). The new national park, when fully implemented, will consist of 107,265 acres, the new national preserve 41,872 acres, and the new national wildlife refuge (USFWS lands) 92,180 acres (fig. 1). The area encompassed by this designation protects a number of natural wonders and features including a unique ecosystem of natural sand dunes, the entire watershed of surface and groundwaters that are necessary to preserve and recharge the dunes and adjacent wetlands, a unique stunted forest, and other valuable riparian vegetation communities that support a host of associated wildlife and bird species. When the National Park was initially established, there were concerns about over-concentrations and impacts on native plant communities of the unhunted segments of a large and possibly growing elk (Cervus elaphus) population. This led to the designation of the Preserve as a compromise solution, where the elk could be harvested. The Preserve Unit, however, will not address all the ungulate management challenges. In order to reduce the current elk population, harvests of elk may need to be aggressive. But aggressive special hunts of elk to achieve population reductions can result in elk avoidance of certain areas or elk seeking refuge in areas where they cannot be hunted, while removals of whole herd segments and abandonment or alterations of migration routes can occur (Smith and Robbins, 1994; Boyce and others, 1991). Elk may seek refuge from hunting in the newly expanded Park Unit and TNC lands where they might over-concentrate and impact unique vegetation communities. In these sites of refugia, or preferred loafing sites, elk and bison could accelerate a decline in woody riparian shrubs and trees. This decline may also be due to changes in hydrology, climatic, or dunal processes, but ungulate herbivory might exacerbate the effects of those processes. To address the questions and needs of local resource managers, a multi-agency research project was initiated in 2005 to study the ecology, forage relations, and habitat relations of elk and bison in the Great Sand Dunes-Sangre de Cristo-Baca complex of lands. Meetings and discussions of what this research should include were started in 2001 with representatives from NPS, USFWS, TNC, the Colorado Division of Wildlife (CDOW), and USDA-FS/BLM. The final study plan was successfully funded in 2004 with research scheduled to start in 2005. The research was designed to encompass three major study elements: (1) animal movements and population dynamics, (2) vegetation and nutrient effects from ungulate herbivory, and (3) development of ecological models, using empirical data collected from the first two components, that will include estimates of elk carrying capacity and management scenarios for resource managers.

  17. Subduction Complex Provenance redefined: modern sands from the Indo-Burman-Andaman-Nicobar Ridge and Barbados Island

    NASA Astrophysics Data System (ADS)

    Limonta, Mara; Resentini, Alberto; And, Sergio; Vezzoli, Giovanni; Bandopadhyay, Pinaki C.; Najman, Yani; Boni, Maria; Bechstdt, Thilo; Garzanti, Eduardo

    2013-04-01

    Subduction complexes large enough to be exposed subaerially and to become significant sources of terrigenous detritus are formed by tectonic accretion above trenches choked with thick sections of remnant-ocean turbidites. They thus need to be connected along strike to a large Alpine-type or Andean-type orogen, where huge volumes of orogenic detritus are produced and conveyed via a major fluvio-deltaic system to the deep sea (Ingersoll et al., 2003). We investigated sediment generation and recycling in the Indo-Burman-Andaman-Nicobar subduction complex, representing the archetype of such settings in the eastern prolongation of the Himalayan collisional system. "Subduction Complex Provenance" is composite, and chiefly consists of detritus recycled from largely turbiditic parent rocks (Recycled Clastic Provenance), with local supply from ultramafic and mafic rocks of forearc lithosphere (Ophiolite Provenance) or recycled paleovolcanic to neovolcanic sources (Volcanic Arc Provenance; Garzanti et al., 2007). In order to specifically investigate the effect of recycling, we characterized the diverse detrital signatures of Cenozoic sandstones deposited during subsequent stages of "soft" and "hard" Himalayan collision and exposed from Bangladesh to the Andaman Islands, and discuss the reasons for compositional discrepancies between parent sandstones and their recycled daughter sands. A companion study was carried out with the same methodologies, rationale and goals on Barbados Island, one of the few other places where a large accretionary prism is subaerially exposed. Also modern Barbados sands are largely multicyclic, reflecting mixing in various proportions of detritus from the basal Scotland Formation (sandstones and mudrocks), their stratigraphic and tectonic cover, the Oceanic Formation (quartzose turbidites and deep-water biogenic oozes including radiolarite), and from the Pleistocene calcarenite and reefal cap, as well as from volcanic layers ultimately derived from the Lesser Antilles. Mixing of detritus recycled from orogen-derived turbidites transported long distance with detritus from oceanic mlange, pelagic sediments and younger calcareous cap rocks and in addition volcaniclastic products thus redefines the diagnostic mark of Subduction Complex Provenance as quite distinct from the original definition by Dickinson and Suczek (1979). REFERENCES Dickinson, W.R., and Suczek, C.A., 1979, Plate tectonics and sandstone composition: American Association Petroleum Geologists Bulletin, 63, 2164-2172. Garzanti, E., Doglioni, C., Vezzoli, G., and And, S., 2007, Orogenic belts and orogenic sediment provenances: Journal of Geology, 115, 315-334. Ingersoll, R.V., Dickinson, W.R., and Graham, S.A., 2003, Remnant-ocean submarine fans: largest sedimentary systems on Earth, [in] Chan, M.A., and Archer, A.W., eds., Extreme Depositional Environments: Mega End Members in Geologic Time: Geological Society of America, Special Paper 370, 191-208.

  18. Liquid Oxygen/Liquid Methane Test Summary of the RS-18 Lunar Ascent Engine at Simulated Altitude Conditions at NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Melcher, John C., IV; Allred, Jennifer K.

    2009-01-01

    Tests were conducted with the RS18 rocket engine using liquid oxygen (LO2) and liquid methane (LCH4) propellants under simulated altitude conditions at NASA Johnson Space Center White Sands Test Facility (WSTF). This project is part of NASA s Propulsion and Cryogenics Advanced Development (PCAD) project. "Green" propellants, such as LO2/LCH4, offer savings in both performance and safety over equivalently sized hypergolic propellant systems in spacecraft applications such as ascent engines or service module engines. Altitude simulation was achieved using the WSTF Large Altitude Simulation System, which provided altitude conditions equivalent up to approx.120,000 ft (approx.37 km). For specific impulse calculations, engine thrust and propellant mass flow rates were measured. Propellant flow rate was measured using a coriolis-style mass-flow meter and compared with a serial turbine-style flow meter. Results showed a significant performance measurement difference during ignition startup. LO2 flow ranged from 5.9-9.5 lbm/sec (2.7-4.3 kg/sec), and LCH4 flow varied from 3.0-4.4 lbm/sec (1.4-2.0 kg/sec) during the RS-18 hot-fire test series. Thrust was measured using three load cells in parallel. Ignition was demonstrated using a gaseous oxygen/methane spark torch igniter. Data was obtained at multiple chamber pressures, and calculations were performed for specific impulse, C* combustion efficiency, and thrust vector alignment. Test objectives for the RS-18 project are 1) conduct a shakedown of the test stand for LO2/methane lunar ascent engines, 2) obtain vacuum ignition data for the torch and pyrotechnic igniters, and 3) obtain nozzle kinetics data to anchor two-dimensional kinetics codes.

  19. Infrared Camera Characterization of Bi-Propellant Reaction Control Engines during Auxiliary Propulsion Systems Tests at NASA's White Sands Test Facility in Las Cruces, New Mexico

    NASA Technical Reports Server (NTRS)

    Holleman, Elizabeth; Sharp, David; Sheller, Richard; Styron, Jason

    2007-01-01

    This paper describes the application of a FUR Systems A40M infrared (IR) digital camera for thermal monitoring of a Liquid Oxygen (LOX) and Ethanol bi-propellant Reaction Control Engine (RCE) during Auxiliary Propulsion System (APS) testing at the National Aeronautics & Space Administration's (NASA) White Sands Test Facility (WSTF) near Las Cruces, New Mexico. Typically, NASA has relied mostly on the use of ThermoCouples (TC) for this type of thermal monitoring due to the variability of constraints required to accurately map rapidly changing temperatures from ambient to glowing hot chamber material. Obtaining accurate real-time temperatures in the JR spectrum is made even more elusive by the changing emissivity of the chamber material as it begins to glow. The parameters evaluated prior to APS testing included: (1) remote operation of the A40M camera using fiber optic Firewire signal sender and receiver units; (2) operation of the camera inside a Pelco explosion proof enclosure with a germanium window; (3) remote analog signal display for real-time monitoring; (4) remote digital data acquisition of the A40M's sensor information using FUR's ThermaCAM Researcher Pro 2.8 software; and (5) overall reliability of the system. An initial characterization report was prepared after the A40M characterization tests at Marshall Space Flight Center (MSFC) to document controlled heat source comparisons to calibrated TCs. Summary IR digital data recorded from WSTF's APS testing is included within this document along with findings, lessons learned, and recommendations for further usage as a monitoring tool for the development of rocket engines.

  20. High performance hybrid white OLEDs based on new platinum complexes and new blue fluorescence host

    NASA Astrophysics Data System (ADS)

    Poloek, Anurach; Wang, Chieh; Lin, Chiao-Wen; Chen, Chin-Ti; Chen, Chao-Tsen

    2014-10-01

    A new series of platinum complexes containing 4-hydroxy-1,5-naphtyridine derivative with different substitutens such as methyl, dimethyl, phenyl, phenoxy, dimethyl amine, piperidine, morpholine, phenoxazine or carbazole unit as the primary ligand and 2-(2,4-difluorophenyl)pyridine as the secondary ligand were synthesized and characterized. Single crystal X-ray diffraction studies of FPtOPhND, FPtCzND and FPtdmaND showed trans-coordinated in distorted square-planar geometry. Their photophysical properties and electrochemical properties were examined. All platinum complexes in these series exhibited dual emissions not only in solution but also in solid state thin film. Employing CBP or 4P-NPD as host material, high efficiency monochromatic and high quality hybrid white organic light emitting diodes (WOLEDs) were achieved with the single platinum complex dopant device, a relatively simple device configuration.

  1. Pulsed-neutron monitoring in the Bunter sands of the Esmond complex

    SciTech Connect

    Johnson, A.; Scanlon, M.E. )

    1991-09-01

    This paper reports that the fields in the Esmond complex (Esmond, Forbes and Gordon) produce gas from the Triassic Bunter sandstone formation. Production started from all three fields in 1985, and an annual cased-hole, pulsed-neutron-monitoring program was initiated in 1986. The main objective of this program was to detect changes in formation water saturation resulting from invasion by influx from the aquifer. Initial interpretation of the pulsed-neutron logs was hampered by two factors that make the Esmond complex a borderline environment for this type of logging: a large, gas-filled borehole that attenuates the tool response and a halite cement in the formation with a very high capture cross section. Increased understanding of these factors has improved the reliability of interpretations. Recent results indicate water advance in all three fields. Currently, water production has been observed only on Forbes, the smallest of the three fields. Observed pressure behavior, however, does show the effects of water influx in all three fields, confirming the log indications. Detailed analysis of the log results led to the identification of different modes of water influx, either as an overall rise in the gas/water contact or as fingering along permeable layers. This information is valuable in production planning.

  2. Measurements of the complex dielectric constant of sand and dust particles at 11 GHz

    NASA Astrophysics Data System (ADS)

    Al-Rizzo, Hussain M.; Al-Hafid, Hafid T.

    1988-03-01

    Measurements are reported of the refractive index (Delta-n) and loss tangent (tan delta) of dust particles in a laboratory-simulated model of dust storms, carried out at 11 GHz utilizing a confocal microwave open-cavity resonator. Four samples were used namely, sandy, silty, clayey silt, and clayey, for concentrations varying from 10-4 to 4 x 10-3 g/cu cm. The particle-size distribution (PSD) of each sample was measured by seiving along with the hydrometer technique. Dielectric-constant measurements were also conducted at bulk concentrations using the standing-wave technique for the dry samples and as a function of volumetric moisture content for up to 0.5 cu cm/cu cm. The complex dielectric constant of the dust particle material was evaluated by two approaches. In one the data for permittivities obtained over the whole range of measured concentrations were extrapolated to the particle densities of the samples. In the other a mixing formula was utilized for the determination of epsilon(s) from permittivities measured at bulk concentrations.

  3. Liquid Oxygen/Liquid Methane Test Results of the RS-18 Lunar Ascent Engine at Simulated Altitude Conditions at NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Melcher, John C., IV; Allred, Jennifer K.

    2009-01-01

    Tests were conducted with the RS-18 rocket engine using liquid oxygen (LO2) and liquid methane (LCH4) propellants under simulated altitude conditions at NASA Johnson Space Center White Sands Test Facility (WSTF). This project is part of NASA's Propulsion and Cryogenics Advanced Development (PCAD) project. "Green" propellants, such as LO2/LCH4, offer savings in both performance and safety over equivalently sized hypergolic propulsion systems in spacecraft applications such as ascent engines or service module engines. Altitude simulation was achieved using the WSTF Large Altitude Simulation System, which provided altitude conditions equivalent up to 122,000 ft (37 km). For specific impulse calculations, engine thrust and propellant mass flow rates were measured. LO2 flow ranged from 5.9 - 9.5 lbm/sec (2.7 - 4.3 kg/sec), and LCH4 flow varied from 3.0 - 4.4 lbm/sec (1.4 - 2.0 kg/sec) during the RS-18 hot-fire test series. Propellant flow rate was measured using a coriolis mass-flow meter and compared with a serial turbine-style flow meter. Results showed a significant performance measurement difference during ignition startup due to two-phase flow effects. Subsequent cold-flow testing demonstrated that the propellant manifolds must be adequately flushed in order for the coriolis flow meters to give accurate data. The coriolis flow meters were later shown to provide accurate steady-state data, but the turbine flow meter data should be used in transient phases of operation. Thrust was measured using three load cells in parallel, which also provides the capability to calculate thrust vector alignment. Ignition was demonstrated using a gaseous oxygen/methane spark torch igniter. Test objectives for the RS-18 project are 1) conduct a shakedown of the test stand for LO2/methane lunar ascent engines, 2) obtain vacuum ignition data for the torch and pyrotechnic igniters, and 3) obtain nozzle kinetics data to anchor two-dimensional kinetics codes. All of these objectives were met with the RS-18 data and additional testing data from subsequent LO2/methane test programs in 2009 which included the first simulated-altitude pyrotechnic ignition demonstration of LO2/methane.

  4. Bedform-field pattern formation through bedform interactions within a set of boundary conditions: Example from White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Ewing, R. C.; Kocurek, G.; Mohrig, D.

    2009-12-01

    The emergence of bedform patterns is explored within the context of self-organizing systems and the imposition of boundary conditions that affect the types and frequency of bedform interactions. One explanation for bedform patterns is self-organization in which the pattern emerges because of interactions among the bedforms themselves. Models, remote images, field studies and lab experiments have identified bedform interactions that involve whole bedforms, only bedform defects, or that are remote interactions between bedforms. It is proposed that bedform interactions form a spectrum from constructive to regenerative in pattern development. Constructive interactions, including merging, lateral linking, cannibalization, and remote transfer of sediment, push the system toward fewer, larger, more widely spaced bedforms. Regenerative interactions, including bedform splitting, defect creation and calving, push the system back toward a more initial state. Other interactions, including off-center collision, defect migration, and bedform and defect repulsion, cause pattern change, but may not be strongly constructive or regenerative. We argue that the rich diversity of bedform-field patterns arises because of boundary conditions, which are the unique set of environmental variables within which each field evolves. Boundary conditions are broadly similar within system types, but are unique for each bedform field so that no two are ever exactly alike. Boundary conditions guide the uniqueness of each pattern by altering the type and frequency of interactions. These hypotheses are tested using time-series aerial photographs and airborne LiDAR at White Sands Dune Field, New Mexico. Time-series imagery shows that fully developed, crescentic aeolian dunes, interact and the dune pattern organizes in systematically similar ways as wind ripples and subaqueous dunes and ripples. Documented interactions include: (1) merging, (2) lateral linking, (3) defect repulsion, (4) bedform repulsion, (5) off-center collision, (6) defect creation, and (7) dune splitting. Measurements of pattern parameters (number of dunes, crest length, defect density, crest spacing, dune height), dune migration rates, and the type and frequency of dune interactions within a 3,500 m box transect from the upwind margin to the core of the dune field show that most pattern organization occurs within the upwind field. Upwind dominance by constructive interactions yields to neutral and regenerative interactions in the field center. This spatial change reflects upwind line-source and sediment-availability boundary conditions arising from antecedent paleo-lake topography. Pattern evolution is most strongly coupled to the pattern parameters of dune spacing and defect density, such that spatially or temporally the frequency of bedform interactions decreases as the dunes become farther apart and have fewer defects.

  5. Effect of organic complexing agents on the interactions of Cs(+), Sr(2+) and UO(2)(2+) with silica and natural sand.

    PubMed

    Reinoso-Maset, Estela; Worsfold, Paul J; Keith-Roach, Miranda J

    2013-05-01

    Sorption processes play a key role in controlling radionuclide migration through subsurface environments and can be affected by the presence of anthropogenic organic complexing agents found at contaminated sites. The effect of these complexing agents on radionuclide-solid phase interactions is not well known. Therefore the aim of this study was to examine the processes by which EDTA, NTA and picolinate affect the sorption kinetics and equilibria of Cs(+), Sr(2+) and UO2(2+) onto natural sand. The caesium sorption rate and equilibrium were unaffected by the complexing agents. Strontium however showed greater interaction with EDTA and NTA in the presence of desorbed matrix cations than geochemical modelling predicted, with SrNTA(-) enhancing sorption and SrEDTA(2-) showing lower sorption than Sr(2+). Complexing agents reduced UO2(2+) sorption to silica and enhanced the sorption rate in the natural sand system. Elevated concentrations of picolinate reduced the sorption of Sr(2+) and increased the sorption rate of UO2(2+), demonstrating the potential importance of this complexing agent. These experiments provide a direct comparison of the sorption behaviour of Cs(+), Sr(2+) and UO2(2+)onto natural sand and an assessment of the relative effects of EDTA, NTA and picolinate on the selected elements. PMID:23473428

  6. Probing the Structure, Dynamics, and Bonding of Coinage Metal Complexes of White Phosphorus.

    PubMed

    Forfar, Laura C; Zeng, Dihao; Green, Michael; McGrady, John E; Russell, Christopher A

    2016-04-01

    A series of cationic white phosphorus complexes of the coinage metals Au and Cu have been synthesised and characterised both in the solid state and in solution. All complexes feature a P4 unit coordinated through an edge P-P vector (η(2) -like), although the degree of activation (as measured by the coordinated P-P bond length) is greater in the gold species. All of the cations are fluxional on the NMR timescale at room temperature, but in the case of the gold systems fluxionality is frozen out at -90 °C. Electronic structure calculations suggest that this fluxionality proceeds via an η(1) -coordinated M-P4 intermediate. PMID:26918670

  7. Intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte Eremurus anisopterus (Xanthorrhoeaceae; Liliaceae s.l.)

    PubMed Central

    Mamut, Jannathan; Tan, Dun Yan; Baskin, Carol C.; Baskin, Jerry M.

    2014-01-01

    Background and Aims Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level. Methods Embryo growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for embryo growth and dormancy break were investigated. Key Results At the time of seed dispersal in summer, the embryo length:seed length (E:S) ratio was 073, but it increased to 087 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 C, both embryo growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD. Conclusions Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of embryo growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment. PMID:25180288

  8. Crest line minimal model for sand dune

    NASA Astrophysics Data System (ADS)

    Guignier, Lucie; Valance, Alexandre; Lague, Dimitri

    2013-04-01

    In desert, complex patterns of dunes form. Under unidirectional wind, transverse rectilinear dunes or crescent shaped dunes called barchan dunes can appear, depending on the amount of sediment available. Most rectilinear transverse sand dunes are observed to fragment, for example at White Sands (New Mexico, United States of America) or Walvis Bay (Namibia). We develop a reduced complexity model to investigate the morphodynamics of sand dunes migrating over a non-erodible bed under unidirectional wind. The model is simply based on two physical ingredients, namely, the sand capture process at the slip face and the cross-wind sand transport. The efficiency of the sand capture process is taken to be dependent of the dune height and lateral diffusion is considered on both the windward and lee sides of the dune. In addition, the dune cross section is assumed to be scale invariant and is approximated by a triangular shape. In this framework, the dune dynamics is reduced to the motion of a string representing the dune crest line and is expressed as a set of two coupled nonlinear differential equations. This simple model reveals its ability to reproduce basic features of barchan and transverse dunes. Analytical predictions are drawn concerning dune equilibrium shape, stability and long-term dynamics. We derive, in particular, analytical solutions for barchan dunes, yielding explicit relationships between their shape and the lateral sand diffusion; and analytical predictions for the migration speed and equilibrium sand flux. A stability analysis of a rectilinear transverse dune allows us to predict analytically the wavelength emerging from fluctuations of the dune crest. We also determine the characteristic time needed for the rectilinear dune to fragment into a multitude of barchan dunes. These outcomes show that extremely simple ingredients can generate complex patterns for migrating dunes. From several dune field data, we are able to determine values of the model parameters and in particular the intensity of the lateral sand diffusion on upwind and downwind sides of the dune, bringing a new light on sediment transport processes.

  9. Sand Storage

    USGS Multimedia Gallery

    A sand storage silo at Steamtown National Historic Site. Sand was stored in a dome on top of the engine and, as the train traveled the tracks, the sand would be sprinkled down pipes to land on the tracks in front of the wheels. This would aid the wheels in gripping the tracks, especially when the ra...

  10. Modeling fluid diffusion in cerebral white matter with random walks in complex environments

    NASA Astrophysics Data System (ADS)

    Levy, Amichai; Cwilich, Gabriel; Buldyrev, Sergey V.; Weeden, Van J.

    2012-02-01

    Recent studies with diffusion MRI have shown new aspects of geometric order in the brain, including complex path coherence within the cerebral cortex, and organization of cerebral white matter and connectivity across multiple scales. The main assumption of these studies is that water molecules diffuse along myelin sheaths of neuron axons in the white matter and thus the anisotropy of their diffusion tensor observed by MRI can provide information about the direction of the axons connecting different parts of the brain. We model the diffusion of particles confined in the space of between the bundles of cylindrical obstacles representing fibrous structures of various orientations. We have investigated the directional properties of the diffusion, by studying the angular distribution of the end point of the random walks as a function of their length, to understand the scale over which the distribution randomizes. We will show evidence of qualitative change in the behavior of the diffusion for different volume fractions of obstacles. Comparisons with three-dimensional MRI images will be illustrated.

  11. Geochemical Trends and Natural Attenuation of RDX, Nitrate, and Perchlorate in the Hazardous Test Area Fractured-Granite Aquifer, White Sands Missile Range, New Mexico, 1996-2006

    USGS Publications Warehouse

    Langman, Jeff B.; Robertson, Andrew J.; Bynum, Jamar; Gebhardt, Fredrick E.

    2008-01-01

    A fractured-granite aquifer at White Sands Missile Range is contaminated with the explosive compound RDX, nitrate, and perchlorate (oxidizer associated with rocket propellant) from the previous use of the Open Burn/Open Detonation site at the Hazardous Test Area. RDX, nitrate, and perchlorate ground-water concentrations were analyzed to examine source characteristics, spatial and temporal variability, and the influence of the natural attenuation processes of dilution and degradation in the Hazardous Test Area fractured-granite aquifer. Two transects of ground-water wells from the existing monitoring-site network - one perpendicular to ground-water flow (transect A-A') and another parallel to ground-water flow (transect B-B') - were selected to examine source characteristics and the spatial and temporal variability of the contaminant concentrations. Ground-water samples collected in 2005 from a larger sampling of monitoring sites than the two transects were analyzed for various tracers including major ions, trace elements, RDX degradates, dissolved gases, water isotopes, nitrate isotopes, and sulfate isotopes to examine the natural attenuation processes of dilution and degradation. Recharge entrains contaminants at the site and transports them downgradient towards the Tularosa Basin floor through a poorly connected fracture system(s). From 1996 to 2006, RDX, nitrate, and perchlorate concentrations in ground water downgradient from the Open Burn/Open Detonation site have been relatively stable. RDX, nitrate, and perchlorate in ground water from wells near the site indicate dispersed contaminant sources in and near the Open Burn/Open Detonation pits. The sources of RDX and nitrate in the pit area have shifted with time, and the shift correlates with the regrading of the south and east berms of each pit in 2002 and 2003 following closure of the site. The largest RDX concentrations were in ground water about 0.1 mile downgradient from the pits, the largest perchlorate concentrations were in ground water about 0.15 mile downgradient from the pits, and the largest nitrate concentrations were in ground water about 0.25 mile down-gradient from the pits. Strong and moderate correlation of water level and the contaminant concentrations near the source areas and low correlation outside and downgradient from the source areas indicates a diminishing of the water level/contaminant relation with downgradient flow. Ground water was not progressively older at all locations downgradient from the Open Burn/Open Detonation site indicating multiple recharge areas. Major ion and strontium concentrations and d2H and d18O values identified similar sources of recharge waters comprising the aquifer except along the basin periphery where recharge water may be influenced by dissolution of mineral assemblages associated with ore deposits that are present along the basin margins. Ground-water ages, dissolved-solids concentrations, and calcium-strontium concentrations indicate limited or partial connectivity between fractures and contributions of uncontaminated recharge water downgradient from the site that dilutes contaminant concentrations. Changes in RDX and nitrate concentration patterns, the presence of methane, changes in carbon dioxide concentrations and d15N and d34S values, and variable reduction-oxidation conditions suggest degradation of contaminants in the downgradient direction. Estimated values of electron potential were assigned to ground water collected in October 2005 from all monitoring sites at the Hazardous Test Area. Moderate to strong reducing conditions were present upgradient from the Open Burn/Open Detonation site, at the site, and at various locations downgradient from the site, but the aquifer contained well-oxygenated water between many of the reducing areas. The spatial variability of reduction-oxidation conditions in the aquifer exemplifies the partial connectivity of the fracture system(s). Dilution of the contaminants i

  12. WIND VELOCITIES AND SAND FLUXES IN MESQUITE DUNE-LANDS IN THE NORTHERN CHIHUAHUAN DESERT: A COMPARISON BETWEEN FIELD MEASUREMENTS AND THE QUIC (QUICK URBAN AND INDUSTRIAL COMPLEX) MODEL

    EPA Science Inventory

    The poster shows comparisons of wind velocities and sand fluxes between field measurements and a computer model, called QUIC (Quick Urban & Industrial Complex). The comparisons were made for a small desert region in New Mexico.

  13. Evolutionary and demographic history of the Californian scrub white oak species complex: an integrative approach.

    PubMed

    Ortego, Joaqun; Noguerales, Vctor; Gugger, Paul F; Sork, Victoria L

    2015-12-01

    Understanding the factors promoting species formation is a major task in evolutionary research. Here, we employ an integrative approach to study the evolutionary history of the Californian scrub white oak species complex (genus Quercus). To infer the relative importance of geographical isolation and ecological divergence in driving the speciation process, we (i) analysed inter- and intraspecific patterns of genetic differentiation and employed an approximate Bayesian computation (ABC) framework to evaluate different plausible scenarios of species divergence. In a second step, we (ii) linked the inferred divergence pathways with current and past species distribution models (SDMs) and (iii) tested for niche differentiation and phylogenetic niche conservatism across taxa. ABC analyses showed that the most plausible scenario is the one considering the divergence of two main lineages followed by a more recent pulse of speciation. Genotypic data in conjunction with SDMs and niche differentiation analyses support that different factors (geography vs. environment) and modes of speciation (parapatry, allopatry and maybe sympatry) have played a role in the divergence process within this complex. We found no significant relationship between genetic differentiation and niche overlap, which probably reflects niche lability and/or that multiple factors, have contributed to speciation. Our study shows that different mechanisms can drive divergence even among closely related taxa representing early stages of species formation and exemplifies the importance of adopting integrative approaches to get a better understanding of the speciation process. PMID:26547661

  14. 13. SANDSORTING BUILDING, THIRD FLOOR, VIBRATING SCREENS FOR SAND SORTING, ...

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

    13. SAND-SORTING BUILDING, THIRD FLOOR, VIBRATING SCREENS FOR SAND SORTING, LOOKING SOUTHWEST - Mill "C" Complex, Sand-Sorting Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  15. Yellow/orange emissive heavy-metal complexes as phosphors in monochromatic and white organic light-emitting devices.

    PubMed

    Fan, Cong; Yang, Chuluo

    2014-09-01

    Owing to the electron spin-orbit coupling (SOC) and fast intersystem crossing (ISC), heavy-metal complexes (such as iridium(III), platinum(II) and osmium(II) complexes, etc.) are phosphorescent emitters at room temperature. Since 1998, heavy-metal complexes as phosphors have received considerable academic and industrial attention in the field of organic light-emitting diodes (OLEDs), because they can harvest both the singlet (25%) and triplet (75%) excitons for emission during the electro-generated processes. Among all the visible colors (blue, green, yellow, orange and red), the yellow/orange heavy-metal complexes play an important role for realizing full-color OLEDs as well as high-efficiency white OLEDs, and thus the development of highly efficient yellow/orange heavy-metal complexes is a pressing concern. In this article, we will review the progress on yellow/orange heavy-metal complexes as phosphors in OLEDs. The general principles and useful tactics for designing the yellow/orange heavy-metal complexes will be systematically summarized. The structure-property relationship and electrophosphorescence performance of the yellow/orange heavy-metal complexes in monochromatic phosphorescent OLEDs (PhOLEDs) and white OLEDs (WOLEDs) will be comprehensively surveyed and discussed. PMID:24927103

  16. Sands-on Learning.

    ERIC Educational Resources Information Center

    Vandervoort, Frances S.

    1989-01-01

    Provides information for the development of a lesson which teaches students about sand, discusses facts about sands, sand studies, life in the sands, and sand activities. Includes diagrams showing the range in sand grain shape, formation of sand ripples, and sand samples from around the world. (RT)

  17. Sand Volcano Following Earthquake

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Sand boil or sand volcano measuring 2 m (6.6 ft.) in length erupted in median of Interstate Highway 80 west of the Bay Bridge toll plaza when ground shaking transformed loose water-saturated deposit of subsurface sand into a sand-water slurry (liquefaction) in the October 17, 1989, Loma Prieta earthquake. Vented sand contains marine-shell fragments. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditions that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. (Credit: J.C. Tinsley, U.S. Geological Survey)

  18. Investigation of REE adsorption to aquifer sand under different CO2 partial pressures and in the presence or absence of humic substances: Experimental results and surface complexation modeling

    NASA Astrophysics Data System (ADS)

    Tang, J.; Johannesson, K. H.

    2010-12-01

    To better understand the mobility and transport of rare earth elements (REE) in groundwater flow systems, the influence of carbonate ions as well as humic substances on REE adsorption onto Carrizo Aquifer sand was investigated as a function of CO2 partial pressures, pH, ionic strength, and initial REE concentrations. Batch adsorption experiments were carried out at room temperature in a glove box under different CO2 partial pressures (i.e., 0 to 0.05 atm). Our experiments show that carbonate ions can either increase or decrease REE adsorption depending on the carbonate ion concentrations or the initial REE concentrations. More specifically, the degree that REEs are adsorbed onto the aquifer sand is inversely related to the amount of solution complexation of REEs with carbonate ions. In addition, our experiments show that in the presence of carbonate ions, increasing pH from neutral pH to more alkaline pH leads to decreases in REE adsorption. The presence of humic substances can also either increase or decrease REE adsorption, depending on the pH range of the solution. Humic substances enhance REE adsorption at pH < 4 and suppress REE adsorption when pH is above 4. Ionic strength has a negligible effect on REE adsorption in dilute solutions, and only when ionic strength was increased to 0.1 M was a decrease in REE adsorption noticeable. Geochemical modeling indicates that at low REE loading condition (i.e., low initial REE concentration at high solid/solution ratio), REE adsorption onto Carrizo sand mainly occurs via surface complexation reactions. However, at high REE loading condition (i.e., high initial REE concentration at low solid/solution ratio), both surface complexation and cation exchange occur in REE adsorption onto Carrizo sand. With the increase of REE loading, cation exchange apparently plays a more important role. According to the model calculations, at high REE loading and relatively low pH, besides cation exchange and surface complexation of free cations, surface complexation of LnCO3+ species is also required to describe REE adsorption under CO2 partial pressures ranging from 0.000316 atm to 0.05 atm. Whereas, at low REE loading (e.g., 10 ?g/kg) or at high pH (> 8), additional surface complexation of Ln(CO3)2- species is necessary to correctly describe REE adsorption. Our modeling calculations also indicate that the ionic strength effect observed in our experiments is mainly due to competition for exchange sites between REEs and Na ions at high ionic strength (i.e., 0.1 M). Surface compelxation only slightly increase REE adsorption at high ionic strength. This is consistent with previous studies that indicate that the ionic strength effect is absent on cation surface complexation onto hydrous ferric oxides. Thus, in natural groundwater-aquifer systems, the mobility and transport of REEs are mainly influenced by the amount and type of solution complexing ligands presented and the groundwater pH.

  19. Sand ridges off Sarasota, Florida: A complex facies boundary on a low-energy inner shelf environment

    USGS Publications Warehouse

    Twichell, D.; Brooks, Gillian L.; Gelfenbaum, G.; Paskevich, V.; Donahue, B.

    2003-01-01

    The innermost shelf off Sarasota, Florida was mapped using sidescan-sonar imagery, seismic-reflection profiles, surface sediment samples, and short cores to define the transition between an onshore siliciclastic sand province and an offshore carbonate province and to identify the processes controlling the distribution of these distinctive facies. The transition between these facies is abrupt and closely tied to the morphology of the inner shelf. A series of low-relief nearly shore-normal ridges characterize the inner shelf. Stratigraphically, the ridges are separated from the underlying Pleistocene and Tertiary carbonate strata by the Holocene ravinement surface. While surficial sediment is fine to very-fine siliciclastic sand on the southeastern sides of the ridges and shell hash covers their northwestern sides, the cores of these Holocene deposits are a mixture of both of these facies. Along the southeastern edges of the ridges the facies boundary coincides with the discontinuity that separates the ridge deposits from the underlying strata. The transition from siliciclastic to carbonate sediment on the northwestern sides of the ridges is equally abrupt, but it falls along the crests of the ridges rather than at their edges. Here the facies transition lies within the Holocene deposit, and appears to be the result of sediment reworking by modern processes. This facies distribution primarily appears to result from south-flowing currents generated during winter storms that winnow the fine siliciclastic sediment from the troughs and steeper northwestern sides of the ridges. A coarse shell lag is left armoring the steeper northwestern sides of the ridges, and the fine sediment is deposited on the gentler southeastern sides of the ridges. This pronounced partitioning of the surficial sediment appears to be the result of the siliciclastic sand being winnowed and transported by these currents while the carbonate shell hash falls below the threshold of sediment movement and is left as a lag. The resulting facies boundaries on this low-energy, sediment-starved inner continental shelf are of two origins which both are tied to the remarkably subtle ridge morphology. Along the southeastern sides of the ridges the facies boundary coincides with a stratigraphic discontinuity that separates Holocene from the older deposits while the transition along the northwestern sides of the ridges is within the Holocene deposit and is the result of sediment redistribution by modern processes. ?? 2003 Elsevier B.V. All rights reserved.

  20. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves an interaction between solar heating, thermal instability, atmospheric turbulence, wind strength, and surface threshold conditions. During the day, solar heating produces thermal instability, which enhances the convect...

  1. Efficient and tunable white-light emission of metal–organic frameworks by iridium-complex encapsulation

    PubMed Central

    Sun, Chun-Yi; Wang, Xin-Long; Zhang, Xiao; Qin, Chao; Li, Peng; Su, Zhong-Min; Zhu, Dong-Xia; Shan, Guo-Gang; Shao, Kui-Zhan; Wu, Han; Li, Jing

    2013-01-01

    Metal–organic frameworks (MOFs) are well known for their tunable structure and porosity. Many studies have shown they are promising for various important applications, for which their performance can be further enhanced by encapsulating functional species, such as luminescent guest molecules, within the frameworks. Although numerous MOFs are luminescent, very few emit white light and their quantum yield is usually low. Here we report a strategy to achieve efficient white-light emission by encapsulating an iridium complex in the MOF cavity. A mesoporous blue-emitting MOF is prepared as host to encapsulate a yellow-emitting iridium complex, [Ir(ppy)2(bpy)]+. The resultant composites emit bright white light with good colour quality (for example, Commission International de I’Eclairage coordinates, colour-rendering index and correlated colour temperature of (0.31, 0.33), 84.5 and 5409 K, respectively), and high quantum yield up to 115 °C. This strategy may open new perspectives for developing high-performance energy-saving solid-state lighting materials. PMID:24212250

  2. Novel core-shell structure microspheres based on lanthanide complexes for white-light emission and fluorescence sensing.

    PubMed

    Lian, Xiao; Yan, Bing

    2016-02-14

    A series of new core-shell structure materials based on lanthanide complexes [H2NMe2]3[Ln(dpa)3] (Ln = Eu, Tb, Sm, Dy, Nd, and Yb; [H2NMe2](+) = dimethylamino cation; dpa = 2-dipicolinate) and silica microspheres has been prepared under solvothermal conditions. Electron microscopy reveals that the nanosized materials SiO2@Ln-dpa are spherical with a narrow size distribution and a [H2NMe2]3[Ln(L)3] coating was generated on the surface of silica microspheres successfully. The core-shell structure materials exhibit excellent optical performance. The white-light-emitting material SiO2@(Dy:Eu)-dpa has a potential application in the development of a white-light device, as a result of the fact that its CIE chromaticity coordinate is very close to that of pure white. Then, we selected SiO2@Eu-dpa as a representative sample for sensing experiments. Eventually, we found that the core-shell structure sensors are highly selective and sensitive for acetone and Cu(2+) cations. The detection of Cu(2+) in the human body is an important issue. Interestingly, the core-shell structure materials display better selectivity and higher sensitivity than the pure lanthanide complexes in sensing Cu(2+) and the value of the quenching effect coefficient has increased by more than 20%. PMID:26743163

  3. Magnetic field evolution in white dwarfs: The hall effect and complexity of the field

    NASA Technical Reports Server (NTRS)

    Muslimov, A. G.; Van Horn, H. M.; Wood, M. A.

    1995-01-01

    We calculate the evolution of the magnetic fields in white dwarfs, taking into account the Hall effect. Because this effect depends nonlinearly upon the magnetic field strength B, the time dependences of the various multipole field components are coupled. The evolution of the field is thus significantly more complicated than has been indicated by previous investigations. Our calculations employ recent white dwarf evolutionary sequences computed for stars with masses 0.4, 0.6, 0.8, and 1.0 solar mass. We show that in the presence of a strong (up to approximately 10(exp 9) G) internal toroidal magnetic field; the evolution of even the lowest order poloidal modes can be substantially changed by the Hall effect. As an example, we compute the evolution of an initially weak quadrupole component, which we take arbitrarily to be approximately 0.1%-1% of the strength of a dominant dipole field. We find that coupling provided by the Hall effect can produce growth of the ratio of the quadrupole to the dipole component of the surface value of the magnetic field strength by more than a factor of 10 over the 10(exp 9) to 10(exp 10) year cooling lifetime of the white dwarf. Some consequences of these results for the process of magnetic-field evolution in white dwarfs are briefly discussed.

  4. Production Mechanisms for the Sand on Titan and the Prospects for a Global Sand Sea

    NASA Astrophysics Data System (ADS)

    Barnes, Jason W.; Lorenz, Ralph D.; Radebaugh, Jani; Hayes, Alexander G.; MacKenzie, Shannon

    2014-11-01

    With ~15% of its surface covered by sand seas, Titan turns out to be the Arrakis of the solar system. How the sand particles that make up the dunes are created, however, remains an outstanding question. Titan's haze particles are organic in composition as required by spectral analysis of dunes, however they have diameters of ~1um, and are 10,000,000 times too small by mass to directly represent the ~200-um sand particles. In addition to previous suggestions that sand could come from sintering of sand particles or by burial, lithification, and subsequent erosion (more like typical sands on Earth), we suggest two new mechanisms for production of sand in association with Titan's liquid reservoirs. Dissolution and reprecipitation as evaporite forms the gypsum dunes of White Sands, NM, USA on Earth, and could play a role on Titan as well. Alternatively, haze particles in the lakes and seas could aggregate into larger particles via flocculation, a mechanism seen to occur on Earth in Morocco. Each of these sand particle production ideas has associated predictions that can be tested by future observations. The lack of evident sand sources in VIMS data implies that Titan's sand seas may be old and their continuous interconnectedness across the Dark Equatorial Belt implies that all of the equatorial dunefields may represent a single compositionally uniform sand sea. We will present possibilities for sands from this sea to bridge the large gap across Xanadu, including barchan chains and fluvial transport.

  5. Ganges Chasma Sand Sheet

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    Today's sand sheet is located in the Ganges Chasma portion of Valles Marineris. As with yesterday's image, note that the dune forms are seen only at the margin and that the interior of the sand sheet at this resolution appears to completely lack dune forms.

    Image information: VIS instrument. Latitude -6.4, Longitude 310.7 East (49.3 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. Utility of unipolar recordings for complex WolffParkinsonWhite ablation

    PubMed Central

    Sundaram, Ponnusamy Shunmuga; Sra, Jasbir

    2015-01-01

    Radiofrequency ablation has been shown to be a safe and effective treatment strategy for the management of symptomatic patients with WolffParkinsonWhite syndrome. It is supported by a success rate of 95% and a recurrence rate of less than 5%. However, ablation of accessory pathways can be challenging at times. The causes for failure can be grouped into three categories unusual location of the pathway, technical difficulties in delivering the ablation and localization error [1]. In this case report we are reporting a case of a young male who presented to us with symptomatic WolffParkinsonWhite syndrome with two failed prior ablations at another institution. This case illustrates the importance of knowing accurate localization and course of the accessory pathway by utilizing the unipolar and bipolar electrograms simultaneously during radiofrequency ablation.

  7. Theoretical and functional complexity of white variegation of unripe fleshy fruits

    PubMed Central

    Lev-Yadun, Simcha

    2013-01-01

    In many plant species, the bright colors of ripe fruit serve to attract frugivores to enable efficient seed dispersal. Here I show that the fleshy fruit of several dozens of species originating from Asia (southeastern, eastern and central), the Middle East, Africa, America (South, Central and North), Australia, Polynesia and Micronesia, with fruit usually larger than 1 cm, have white or light green spots while they are still unripe. In many of these species, while the spots are conspicuous, the unripe fruit is known to be poisonous, bitter or sour. I propose that this fruit syndrome may signal frugivores that the fruit is still unripe. Similarly to the succulent leaves of window-plants, these spots form windows that enable light to penetrate deeper into the photosynthetic layers in the developing fruit. This seems to be a solution to overcome the limitations of light harvest because of the high volume to surface ratio of developing fleshy fruits. The white or whitish variegation in these unripe fleshy fruits may serve at least five functions: 1) Windows for photosynthesis, 2) camouflage, 3) signaling to frugivores that they are not ripe (possibly sometimes a type of mutualism with frugivores), 4) signaling to frugivores that they are poisonous - aposematism, and 5) mimicking insect eggs to reduce egg laying. All these functions may be partly or fully simultaneous. Because these white spots appear in plants of diverse geographical and taxonomic origin, it is probably an old adaptation, and such a syndrome has appeared and been selected for many times. PMID:23921545

  8. Complex bacterial diversity in the white biofilms of the Catacombs of St. Callixtus in Rome evidenced by different investigation strategies.

    PubMed

    Krakova, Lucia; De Leo, Filomena; Bruno, Laura; Pangallo, Domenico; Urz, Clara

    2015-05-01

    Roman Catacombs are affected by different kinds of biofilms that were extensively investigated in the last 14 years. In particular, the areas far from the lamps are often covered by white biofilms of different extension, consistency and nature. The aim of this paper is to describe the profile of the microbial community present in two areas of the Ocean's Cubiculum (CSC13), characterized by similar alterations described as white biofilms, by using a multistep approach that included direct microscopy observations, culture-dependent and culture-independent methodologies through the extraction of DNA and RNA directly from the sampled areas. In addition to this, we extracted the DNA directly from the Petri dishes containing R2A and B4 media after incubation and growth of bacteria. Our results evidenced that a complex bacterial community (mainly constituted by filamentous Actinobacteria, as well as Firmicutes and Proteobacteria) colonizes the two different white biofilms, and its detection, quantitative and qualitative, could be revealed only by different approaches, each method giving different information that only partially overlap. PMID:25244154

  9. Sonic sands.

    PubMed

    Andreotti, Bruno

    2012-02-01

    Many desert sand dunes emit a loud sound with a characteristic tremolo around a well-defined frequency whenever sand is avalanching on their slip face. This phenomenon, called the 'song of dunes', has been successfully reproduced in the lab, on a smaller scale. In all cases, the spontaneous acoustic emission in air is due to a vibration of the sand, itself excited by a granular shear flow. This review presents a complete characterization of the phenomenon-frequency, amplitude, source shape, vibration modes, instability threshold-based on recent studies. The most prominent characteristics of acoustic propagation in weakly compressed granular media are then presented. Finally, this review describes the different mechanisms proposed to explain booming avalanches. Measurements performed to test these theories against data allow one to contrast explanations that must be rejected-sound resonating in a surface layer of the dune, for instance-with those that still need to be confirmed to reach a scientific consensus-amplification of guided elastic waves by friction, in particular. PMID:22790349

  10. 1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR ...

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

    1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR (LOWER RIGHT) THAT EXTENDS TO THE SAND-SORTING BUILDING, AND REMAINS OF ORIGINAL (1917) WASHING, DRAINING & DRYING BUILDING (LEFT), VIEW LOOKING WEST FROM TOP OF SAND-SORTING BUILDING - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  11. Ganges Chasma Sands

    NASA Technical Reports Server (NTRS)

    2005-01-01

    8 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark, windblown sand in the form of dunes and a broad, relatively flat, sand sheet in Ganges Chasma, part of the eastern Valles Marineris trough complex. The winds responsible for these dunes blew largely from the north. Sand dunes on Mars, unlike their Earthly counterparts, are usually dark in tone. This is a reflection of their composition, which includes minerals that are more rich in iron and magnesium than the common silica-rich dunes of Earth. Similar dark sands on Earth are found in volcanic regions such as Iceland and Hawaii. A large dune field of iron/magnesium-rich grains, in the form fragments of the volcanic rock, basalt, occurs south of Moses Lake, Washington, in the U.S.

    Location near: 7.7oS, 45.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  12. Large-eddy Simulation of Boundary Layer Flow over Desert Sand Dune Structures

    NASA Astrophysics Data System (ADS)

    Uhlrich, S.; Anderson, W.; Passalacqua, P.; Mohrig, D. C.; Kocurek, G.

    2012-12-01

    Complex spatiotemporal coupling exists between desert sand dune topography and surface layer physics of the atmospheric boundary layer (ABL). Although the interactions of individual desert sand dunes have been extensively studied, with categorical interaction mechanisms identified, the aero-mechanical coupling associated with these dune interactions remains an open problem. Large-eddy simulation (LES) is used to simulate turbulent boundary layer flow over dune structures from White Sands, NM. The dunes are resolved with an immersed boundary method (IBM). The flow-forcing (imposed pressure gradient) is varied to simulate the three common prevailing wind conditions at White Sands (southwest, southeast, and northwest, with southwest being the most common). In the present research, comparison between flow statistics (dune wall pressure distribution retrieved from the IBM) and time-difference dune elevation data are used to characterize the mechanisms responsible for erosion (stoss side) and deposition (lee side) of sand. Additionally, statistical details of time series of aerodynamic forcing at different locations on the dune face are evaluated, which may be used to deepen understanding of erosion and deposition events observed in the time-difference lidar data.

  13. Effect of adsorbed metals ions on the transport of Zn- and Ni-EDTA complexes in a sand and gravel aquifer

    USGS Publications Warehouse

    Kent, D.B.; Davis, J.A.; Anderson, L.C.D.; Rea, B.A.; Coston, J.A.

    2002-01-01

    Adsorption, complexation, and dissolution reactions strongly influenced the transport of metal ions complexed with ethylenediaminetetraacetic acid (EDTA) in a predominantly quartz-sand aquifer during two tracer tests conducted under mildly reducing conditions at pH 5.8 to 6.1. In tracer test M89, EDTA complexes of zinc (Zn) and nickel (Ni), along with excess free EDTA, were injected such that the lower portion of the tracer cloud traveled through a region with adsorbed manganese (Mn) and the upper portion of the tracer cloud traveled through a region with adsorbed Zn. In tracer test S89, Ni- and Zn-EDTA complexes, along with excess EDTA complexed with calcium (Ca), were injected into a region with adsorbed Mn. The only discernable chemical reaction between Ni-EDTA and the sediments was a small degree of reversible adsorption leading to minor retardation. In the absence of adsorbed Zn, the injected Zn was displaced from EDTA complexes by iron(III) [Fe(III)] dissolved from the sediments. Displacement of Zn by Fe(III) on EDTA became increasingly thermodynamically favorable with decreasing total EDTA concentration. The reaction was slow compared to the time-scale of transport. Free EDTA rapidly dissolved aluminum (Al) from the sediments, which was subsequently displaced slowly by Fe. In the portion of tracer cloud M89 that traveled through the region contaminated with adsorbed Zn, little displacement of Zn complexed with EDTA was observed, and Al was rapidly displaced from EDTA by Zn desorbed from the sediments, in agreement with equilibrium calculations. In tracer test S89, desorption of Mn dominated over the more thermodynamically favorable dissolution of Al oxyhydroxides. Comparison with results from M89 suggests that dissolution of Al oxyhydroxides in coatings on these sediment grains by Ca-EDTA was rate-limited whereas that by free EDTA reached equilibrium on the time-scale of transport. Rates of desorption are much faster than rates of dissolution of Fe oxyhydroxides from sediment-grain surfaces and, therefore, adsorbed metal ions can strongly influence the speciation of ligands like EDTA in soils and sediments, especially over small temporal and spatial scales. Copyright ?? 2002 Elsevier Science Ltd.

  14. White Rock

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can't see . . . things like information about what kinds of minerals make up the landforms. Mars scientists once thought, for instance, that these unusual features might be vast hills of salt, the dried up remains of a long-ago, evaporated lake. Not so, said an instrument on the Mars Global Surveyor spacecraft, which revealed that the bright material is probably made up of volcanic ash or windblown dust instead. And talk about a cyclical 'ashes to ashes, dust to dust' story! Particles of this material fell and fell until they built up quite a sedimentary deposit, which was then only eroded away again by the wind over time, leaving the spiky terrain seen today. It looks white, but its apparent brightness arises from the fact that the surrounding material is so dark. Of course, good eyesight always helps in understanding. A camera on Mars Global Surveyor with close-up capabilities revealed that sand dunes are responsible for the smudgy dark material in the bright sediment and around it. But that's not all. The THEMIS camera on the Mars Odyssey spacecraft that took this image reveals that this ashy or dusty deposit once covered a much larger area than it does today. Look yourself for two small dots of white material on the floor of a small crater nearby (center right in this image). They preserve a record that this bright deposit once reached much farther. Since so little of it remains, you can figure that the material probably isn't very hard, and simply blows away. One thing's for sure. No one looking at this image could ever think that Mars is a boring place. With all of its bright and dark contrasts, this picture would be perfect for anyone who loves Ansel Adams and his black-and-white photography.

  15. Northern Sand Sea

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes.

    Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2011-01-01

    Domestic production of industrial sand and gravel in 2010 was about 26.5 Mt (29.2 million st), a 6-percent increased from 2009. Certain end uses of industrial sand and gravel, such as sand for container glass, golf course sand, recreational sand, specialty glass and water filtration, showed increased demand in 2010.

  17. Enhancement Performances in White Organic Light-Emitting Diode (WOLED) by Formation of Charge-Transfer (CT) Complex.

    PubMed

    Sze, Po-Wen; Huang, Chien-Jung; Lin, Fong-Yi; Lan, Wen-How

    2015-11-01

    This study elucidates the optoelectronic properties of high efficiency white organic light-emitting diodes (WOLED) with molybdenum oxide (MoO3) doping into N, N0-di (naphthalene-1-yl)-N, N0-diphenyl-benzidine (NPB) as a p-doping hole-transport layer (p-HTL). The device with a MoO3-doping NPB layer shows a turn-on voltage of 2.01 V and the maximum power efficiency of 4.6 lm/W. The X-ray photoelectron spectroscopy (XPS) and UV-vis-NIR absorption spectra of MoO3-doping NPB layer revealed that the MoO3-doping NPB p-HTL had an improvement on holes injection. The improvement is caused by the formation of the charge transfer (CT) complex (NPB(+)-MoO3-) that is generated by doping MoO3 into NPB, markedly increasing the number of holes carrier, improving the balance of the electrons and holes in recombination zone. The pure white light emission with Commissions Internationale De L'Eclairage (CIE) coordinates of (0.335, 0.321) was achieved at the operating voltage of 6 V. This device shows the maximum luminance of 12230 cd/cm2 and the maximum luminous efficiency of 7.01 cd/A at an operating voltage of 7 V. PMID:26726664

  18. Sand Dunes in Noachis Terra

    NASA Technical Reports Server (NTRS)

    2004-01-01

    11 February 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-toned sand dunes in a crater in eastern Noachis Terra. Most big martian dunes tend to be dark, as opposed to the more familiar light-toned dunes of Earth. This difference is a product of the composition of the dunes; on Earth, most dunes contain abundant quartz. Quartz is usually clear (transparent), though quartz sand grains that have been kicked around by wind usually develop a white, frosty surface. On Mars, the sand is mostly made up of the darker minerals that comprise iron- and magnesium-rich volcanic rocks--i.e., like the black sand beaches found on volcanic islands like Hawaii. Examples of dark sand dunes on Earth are found in central Washington state and Iceland, among other places. This picture is located near 49.0oS, 326.3oW. Sunlight illuminates this scene from the upper left; the image covers an area 3 km (1.9 mi) wide.

  19. Tar sand

    SciTech Connect

    McLendon, T.R.; Bartke, T.C.

    1990-01-01

    Research on tar sand is briefly discussed. The research program supported by the US Department of Energy (DOE) includes a variety of surface extraction schemes. The University of Utah has process development units (PDU) employing fluidized bed, hot, water-assisted, and fluidized-bed/heat-pipe, coupled combustor technology. Considerable process variable test data have been gathered on these systems: (1) a rotary kiln unit has been built recently; (2) solvent extraction processing is being examined; and (3) an advanced hydrogenation upgrading scheme (hydropyrolysis) has been developed. The University of Arkansas, in collaboration with Diversified Petroleum, Inc., has been working on a fatty acid, solvent extraction process. Oleic acid is the solvent/surfactant. Solvent is recovered by adjusting processing fluid concentrations to separate without expensive operations. Western Research Institute has a PDU-scale scheme called the Recycle Oil Pyrolysis and Extraction (ROPE) process, which combines solvent (hot recycle bitumen) and pyrolytic extraction. 14 refs., 19 figs.

  20. Sand Diver

    NASA Astrophysics Data System (ADS)

    Scott, Alan J.

    2005-01-01

    A few years ago, I was preparing to teach a summer enrichment program for middle school students at the University of Wisconsin-Stout. With swimming on the minds of most kids during the summer, I thought buoyancy would be a fun topic to discuss. An interesting way to introduce this concept is by discussing the beer-drinking balloonist who, in a lawn chair, floated to 11,000 feet above Los Angeles in 1997. However, I needed a hands-on project and was not about to go purchase some lawn chairs to duplicate this experiment. A simple submersible called the "Sand Diver" was designed and is now used as a hands-on activity for my introductory physics course.

  1. Complex Response of White Pines to Past Environmental Variability Increases Understanding of Future Vulnerability

    PubMed Central

    Iglesias, Virginia; Krause, Teresa R.; Whitlock, Cathy

    2015-01-01

    Ecological niche models predict plant responses to climate change by circumscribing species distributions within a multivariate environmental framework. Most projections based on modern bioclimatic correlations imply that high-elevation species are likely to be extirpated from their current ranges as a result of rising growing-season temperatures in the coming decades. Paleoecological data spanning the last 15,000 years from the Greater Yellowstone region describe the response of vegetation to past climate variability and suggest that white pines, a taxon of special concern in the region, have been surprisingly resilient to high summer temperature and fire activity in the past. Moreover, the fossil record suggests that winter conditions and biotic interactions have been critical limiting variables for high-elevation conifers in the past and will likely be so in the future. This long-term perspective offers insights on species responses to a broader range of climate and associated ecosystem changes than can be observed at present and should be part of resource management and conservation planning for the future. PMID:25885810

  2. Complex response of white pines to past environmental variability increases understanding of future vulnerability.

    PubMed

    Iglesias, Virginia; Krause, Teresa R; Whitlock, Cathy

    2015-01-01

    Ecological niche models predict plant responses to climate change by circumscribing species distributions within a multivariate environmental framework. Most projections based on modern bioclimatic correlations imply that high-elevation species are likely to be extirpated from their current ranges as a result of rising growing-season temperatures in the coming decades. Paleoecological data spanning the last 15,000 years from the Greater Yellowstone region describe the response of vegetation to past climate variability and suggest that white pines, a taxon of special concern in the region, have been surprisingly resilient to high summer temperature and fire activity in the past. Moreover, the fossil record suggests that winter conditions and biotic interactions have been critical limiting variables for high-elevation conifers in the past and will likely be so in the future. This long-term perspective offers insights on species responses to a broader range of climate and associated ecosystem changes than can be observed at present and should be part of resource management and conservation planning for the future. PMID:25885810

  3. 2. INTERIOR OF SAND DRAINING & DRYING BUILDING WITH DRYING ...

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

    2. INTERIOR OF SAND DRAINING & DRYING BUILDING WITH DRYING BINS TO THE RIGHT, LOOKING SOUTHWEST - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  4. The White Collar Complex Is Involved in Sexual Development of Fusarium graminearum

    PubMed Central

    Lee, Seunghoon; Yun, Sung-Hwan

    2015-01-01

    Sexual spores (ascospores) of Fusarium graminearum, a homothallic ascomycetous fungus, are believed to be the primary inocula for epidemics of the diseases caused by this species in cereal crops. Based on the light requirement for the formation of fruiting bodies (perithecia) of F. graminearum under laboratory conditions, we explored whether photoreceptors play an important role in sexual development. Here, we evaluated the roles of three genes encoding putative photoreceptors [a phytochrome gene (FgFph) and two white collar genes (FgWc-1 and FgWc-2)] during sexual development in F. graminearum. For functional analyses, we generated transgenic strains lacking one or two genes from the self-fertile Z3643 strain. Unlike the wild-type (WT) and add-back strains, the single deletion strains (ΔFgWc-1 and ΔFgWc-2) produced fertile perithecia under constant light on complete medium (CM, an unfavorable medium for sexual development) as well as on carrot agar (a perithecial induction condition). The expression of mating-type (MAT) genes increased significantly in the gene deletion strains compared to the WT under both conditions. Deletion of FgFph had no significant effect on sexual development or MAT gene expression. In contrast, all of the deletion strains examined did not show significant changes in other traits such as hyphal growth, mycotoxin production, and virulence. A split luciferase assay confirmed the in vivo protein-protein interactions among three photoreceptors along with FgLaeA, a global regulator of secondary metabolism and fungal development. Introduction of an intact copy of the A. nidulans LreA and LreB genes, which are homologs of FgWc-1 and FgWc-2, into the ΔFgWc-1 and ΔFgWc-2 strains, respectively, failed to repress perithecia formation on CM in the gene deletion strains. Taken together, these results demonstrate that FgWc-1 and FgWc-2, two central components of the blue-light sensing system, negatively regulate sexual development in F. graminearum, which differs from the regulation pattern in A. nidulans. PMID:25785736

  5. Measurements of thermal updraft intensity over complex terrain using American white pelicans and a simple boundary-layer forecast model

    USGS Publications Warehouse

    Shannon, H.D.; Young, G.S.; Yates, M.; Fuller, Mark R.; Seegar, W.

    2003-01-01

    An examination of boundary-layer meteorological and avian aerodynamic theories suggests that soaring birds can be used to measure the magnitude of vertical air motions within the boundary layer. These theories are applied to obtain mixed-layer normalized thermal updraft intensity over both flat and complex terrain from the climb rates of soaring American white pelicans and from diagnostic boundary-layer model-produced estimates of the boundary-layer depth zi and the convective velocity scale w*. Comparison of the flatland data with the profiles of normalized updraft velocity obtained from previous studies reveals that the pelican-derived measurements of thermal updraft intensity are in close agreement with those obtained using traditional research aircraft and large eddy simulation (LES) in the height range of 0.2 to 0.8 zi. Given the success of this method, the profiles of thermal vertical velocity over the flatland and the nearby mountains are compared. This comparison shows that these profiles are statistically indistinguishable over this height range, indicating that the profile for thermal updraft intensity varies little over this sample of complex terrain. These observations support the findings of a recent LES study that explored the turbulent structure of the boundary layer using a range of terrain specifications. For terrain similar in scale to that encountered in this study, results of the LES suggest that the terrain caused less than an 11% variation in the standard deviation of vertical velocity.

  6. Luminescence properties of Sm, Tb(Sal)3Phen complex in polyvinyl alcohol: an approach for white-light emission

    NASA Astrophysics Data System (ADS)

    Kaur, Gagandeep; Rai, S. B.

    2011-10-01

    Polyvinyl alcohol polymer films doped with Sm,Tb(Sal)3Phen complexes have been synthesized using solution casting technique. An enhancement in absorption intensity is observed revealing the encapsulation of rare earth ions by salicylic acid (Sal)/1,10 phenanthroline (Phen) complex. Photoluminescence spectra of the co-doped samples were examined by varying the concentration of Tb3+ keeping concentration of Sm3+ ions fixed and vice-versa. It is found that the polymer samples emit a combination of blue, green and orange-red wavelengths tunable to white light when excited with 355 nm radiation. The emission spectra also show a self-quenching effect at higher concentration of Sm3+ ions. An efficient energy transfer was observed from Tb3+ : 5D4 ? Sm3+ : 4G9/2. The reason for the enhancement in fluorescence intensities of Sm3+ in the co-doped polymer sample is the intermolecular as well as the intramolecular energy transfer.

  7. Alternative Use of DNA Binding Domains by the Neurospora White Collar Complex Dictates Circadian Regulation and Light Responses.

    PubMed

    Wang, Bin; Zhou, Xiaoying; Loros, Jennifer J; Dunlap, Jay C

    2015-01-01

    In the Neurospora circadian system, the White Collar complex (WCC) of WC-1 and WC-2 drives transcription of the circadian pacemaker gene frequency (frq), whose gene product, FRQ, as a part of the FRQ-FRH complex (FFC), inhibits its own expression. The WCC is also the principal Neurospora photoreceptor; WCC-mediated light induction of frq resets the clock, and all acute light induction is triggered by WCC binding to promoters of light-induced genes. However, not all acutely light-induced genes are also clock regulated, and conversely, not all clock-regulated direct targets of WCC are light induced; the structural determinants governing the shift from WCC's dark circadian role to its light activation role are poorly described. We report that the DBD region (named for being defective in binding DNA), a basic region in WC-1 proximal to the DNA-binding zinc finger (ZnF) whose function was previously ascribed to nuclear localization, instead plays multiple essential roles assisting in DNA binding and mediating interactions with the FFC. DNA binding for light induction by the WCC requires only WC-2, whereas DNA binding for circadian functions requires WC-2 as well as the ZnF and DBD motif of WC-1. The data suggest a means by which alterations in the tertiary and quaternary structures of the WCC can lead to its distinct functions in the dark and in the light. PMID:26711258

  8. The effect of serologically defined major histocompatibility complex haplotypes on Marek's disease resistance in commercially bred White Leghorn chickens.

    PubMed

    Blankert, J J; Albers, G A; Briles, W E; Vrielink-van Ginkel, M; Groot, A J; te Winkel, G P; Tilanus, M G; van der Zijpp, A J

    1990-01-01

    In commercial pure white leghorn lines, A, B, and C, the effects on resistance against a virulent strain of Marek's disease virus were assessed for B19 and B21 haplotypes of the chicken major histocompatibility complex. B haplotypes were identified by direct hemagglutination using alloantisera raised against erythrocyte antigens. In homozygous B21 female chicks from lines A and B, mortality upon challenge with virus was 16% and 9%, respectively; in B19 chicks, mortality was 42% and 60%, respectively. Intermediate mortality was observed in heterozygous B19/B21 birds. When line A and B hens were crossed with B15/B15 or B5/B19 cocks from line C, differences between B19 and B21 were significant only in the progeny from B5/B19 sires. Therefore, it was concluded that selection for major histocompatibility complex-associated disease resistance markers may be useful only when B haplotypes complement each other in commercial line crosses and when interactions with genetic background do not severely obscure the differential haplotype effects, as are observed within pure lines. PMID:2282011

  9. Identification and Characterization of Complex Bioactive Oligosaccharides in White and Red Wine by a Combination of Mass Spectrometry and Gas Chromatography

    PubMed Central

    Bordiga, Matteo; Travaglia, Fabiano; Meyrand, Mickael; German, J. Bruce; Lebrilla, Carlito B.; Coïsson, Jean Daniel; Arlorio, Marco; Barile, Daniela

    2012-01-01

    Over forty-five complex free oligosaccharides (of which several are novel) have been isolated and chemically characterized by gas chromatography and high resolution and high mass accuracy matrix-assisted laser desorption/ionization mass spectrometry (MALDI-FTICR MS) in red and white wines, Grignolino and Chardonnay, respectively. Oligosaccharides with a degree of polymerization between 3 and 14 were separated from simple monosaccharides and disaccharides by solid-phase extraction. The concentrations free oligosaccharides were over 100 mg/L in both red and white wines. The free oligosaccharides—characterized for the first time in the present study include hexose-oligosaccharides, xyloglucans and arabinogalactans, and may be the natural by-products of the degradation of cell wall polysaccharides. The coupled gas chromatography and accurate mass spectrometry approach revealed an effective method to characterize and quantify complex functional oligosaccharides in both red and white wine. PMID:22429017

  10. Complex Geometric Models of Diffusion and Relaxation in Healthy and Damaged White Matter

    PubMed Central

    Farrell, Jonathan A.D.; Smith, Seth A.; Reich, Daniel S.; Calabresi, Peter A.; van Zijl, Peter C.M.

    2010-01-01

    Which aspects of tissue microstructure affect diffusion weighted MRI signals? Prior models, many of which use Monte-Carlo simulations, have focused on relatively simple models of the cellular microenvironment and have not considered important anatomic details. With the advent of higher-order analysis models for diffusion imaging, such as high-angular-resolution diffusion imaging (HARDI), more realistic models are necessary. This paper presents and evaluates the reproducibility of simulations of diffusion in complex geometries. Our framework is quantitative, does not require specialized hardware, is easily implemented with little programming experience, and is freely available as open-source software. Models may include compartments with different diffusivities, permeabilities, and T2 time constants using both parametric (e.g., spheres and cylinders) and arbitrary (e.g., mesh-based) geometries. Three-dimensional diffusion displacement-probability functions are mapped with high reproducibility, and thus can be readily used to assess reproducibility of diffusion-derived contrasts. PMID:19739233

  11. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2012-01-01

    Domestic production of industrial sand and gravel in 2011 was about 30 Mt (33 million st), increasing slightly compared with 2010. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  12. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2013-01-01

    Domestic production of industrial sand and gravel in 2012 was about 49.5 Mt (55 million st), increasing 13 percent compared with that of 2011. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  13. Dinural patterns of blowing sand and dust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex interaction between the sun, the atmosphere, and the sand surface. During the day, solar heating produces thermal instability, which enhances convective mixing of high momentum winds from the upper levels of the atmosphere to the surface la...

  14. Wet sand flows better than dry sand

    NASA Astrophysics Data System (ADS)

    Wagner, Christian

    2015-03-01

    Wet sand that does not contain too much water is known to be stiff enough to build sand castles or in physical words has a significant yield stress. However, we could recently show that there are quite a few conditions under which such wet sand opposes less resistant to flow than its dry counterpart. This effect might have been already known to the old Egyptians: The Ancient painting of El Bersheh at the tomb of Tehutihetep shows that there was liquid poured in front of the sledge that was used to transport heavy weight stones and statues. While archeologist have attributed this to a sacral ceremony, our data clearly show that wetting the sand ground drastically decreases the effective sliding friction coefficient. We first study the stress-strain behavior of sand with and without small amounts of liquid under steady and oscillatory shear. Using a technique to quasistatically push the sand through a tube with an enforced parabolic (Poiseuille-like) profile, we minimize the effect of avalanches and shear localization. We observe that the resistance against deformation of the wet (partially saturated) sand is much smaller than that of the dry sand, and that the latter dissipates more energy under flow. Second we show experimentally that the sliding friction on sand is greatly reduced by the addition of some--but not too much--water. The formation of capillary water bridges increases the shear modulus of the sand, which facilitates the sliding.

  15. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves the interaction between the sun, wind, and earth. During the day, solar heating produces thermal instability, which enhances the convective mixing of high momentum winds from the upper levels of the atmosphere to the s...

  16. Bioremediation of the heavy metal complex dye Isolan Dark Blue 2SGL-01 by white rot fungus Irpex lacteus.

    PubMed

    Kalpana, Duraisamy; Shim, Jae Hong; Oh, Byung-Taek; Senthil, Kalaiselvi; Lee, Yang Soo

    2011-12-30

    The present study was conducted to evaluate the decolorization and degradation of the chromium metal complex dye Isolan Dark Blue 2SGL-01 by Irpex lacteus, a white rot lignolytic fungus. I. lacteus effectively decolorized the sulphonated reactive dye at a high concentration of 250 mg/l over a wide range of pH values of 5-9 and temperatures between 20 and 35C. Complete (100%) decolorization occurred within 96h, and I. lacteus demonstrated resistance to the metallic dye. UV-vis spectroscopy, HPLC, GC-MS, and FT-IR analyses of the extracted metabolites confirmed that the decolorization process occurred due to degradation of the dye and not merely by adsorption. GC-MS analysis indicated the formation of 1(2H)-naphthalenone, 3,4-dihydro- and 2-naphthalenol as the main metabolite. ICP analysis demonstrated the removal of 13.49% chromium, and phytotoxicity studies using germinated seeds of Vigna radiata and Brassica juncea demonstrated the nontoxic nature of the metabolites formed during the degradation of Isolan Dark Blue 2SGL-01 dye. PMID:22071260

  17. A High Resolution Look at Black Sand Particles from Sand Dunes of Saudi Arabia Using Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Hussain, M. M.; Aburizaiza, O. S.; Siddique, A.; Hershey, D. L.; Guerrieri, D. A.; Qurashi, J.; Abbass, M.; Blake, D. R.; Khwaja, H. A.

    2013-12-01

    Particulate air pollution is a problem of health concern. The microscopic make-up of different varieties of sand particles found and collected at a sand dune site in Badr, Saudi Arabia has been determined. Primary emphasis is given to the use of multiple high resolution electron microscopy (viz., Scanning Electron Microscopy with Energy Dispersive X-ray spectrometry (SEM/EDS) and Laser Scanning Microscopy (LSM)) to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of ';coatings or contaminants' adsorbed or carried on by the black sand particles. White sand contains natural coarse particles associated with wind-blown releases from crustal surfaces, weathering of an igneous/metamorphic rock source, and volcanic activities. Silicates (alumino-silicates) and quartz (clear, milky, rose) dominate white sand and rest appears to contain calcite, olivine, feldspar, and magnetite. Black sand particles exhibit very different morphologies and microstructures (surface roughness) compared with white sand and volcanic ash. Morphological analyses have shown that the black sand contain ultrafine particles. Black sand is strongly magnetic, which indicates the mineral magnetite (strongly magnetic) or elemental iron. Iron, C, O, Ti, Si, V, and S particles dominate the black sand. Natural and anthropogenic sources have been implicated for the observed particles. Analysis revealed that the surface of white sand particles is mainly covered with the fine particles. It is known that emissions from combustion contain carbon soot and other contaminants that are easily absorbed by soil particles during a long-range transport.

  18. Luminescence color-tuning through polymorph doping: preparation of a white-emitting solid from a single gold(I)-isocyanide complex by simple precipitation.

    PubMed

    Seki, Tomohiro; Kurenuma, Sayaka; Ito, Hajime

    2013-11-25

    We report the luminescent color tuning of a new complex, 2-benzothiophenyl(4-methoxyphenyl isocyanide)gold(I) (1), by using a new "polymorph doping" approach. The slow crystallization of the complex 1 afforded three different pure polymorphic crystals with blue, green, and orange emission under UV-light irradiation. The crystal structures of pure polymorphs of 1 were investigated in detail by means of single-crystal X-ray analyses. Theoretical calculations based on the single-crystal structures provided qualitative explanation of the difference in the excited energy-levels of the three polymorphs of 1. In sharp contrast, the rapid precipitation of 1, with the optimized conditions reproducibly afforded homogeneous powder materials showing solid-state white-emission with Commission Internationale de l'clairage (CIE) 1931 chromaticity coordinates of (0.33, 0.35), which is similar to pure white. New "polymorphic doping" has been revealed to be critical to this white emission through spectroscopic and X-ray diffraction analyses. The coexistence of the multiple polymorphs of 1 within the homogeneous powder materials and the ideal mixing of multiple luminescent colors gave its white emission accompanied with energy transfer from the predominant green-emitting polymorph to the minor orange-emitting polymorph. PMID:24249690

  19. Exposed Tsunami Sand Layers

    USGS Multimedia Gallery

    An outcrop composed of six tsunami deposits on the inland side of the lowland backing Stardust Bay over 0.5 miles from the sea. Brown soils developed into the top of each sand sheet and black tephra (air fall volcanic ash) layers between two of the sand deposits aided correlation of the six sand she...

  20. Sand for Traction

    USGS Multimedia Gallery

    Steam engines used high-grade silica sand for traction on the rails. Sand was stored in a dome on top of the engine and, as the train traveled the tracks, the sand would be sprinkled down pipes to land on the tracks in front of the wheels. This would aid the wheels in gripping the tracks, especially...

  1. Investigating the Capability to Resolve Complex White Matter Structures with High b-Value Diffusion Magnetic Resonance Imaging on the MGH-USC Connectom Scanner

    PubMed Central

    Nummenmaa, Aapo; Witzel, Thomas; Zanzonico, Roberta; Keil, Boris; Cauley, Stephen; Polimeni, Jonathan R.; Tisdall, Dylan; Van Dijk, Koene R.A.; Buckner, Randy L.; Wedeen, Van J.; Rosen, Bruce R.; Wald, Lawrence L.

    2014-01-01

    Abstract One of the major goals of the NIH Blueprint Human Connectome Project was to map and quantify the white matter connections in the brain using diffusion tractography. Given the prevalence of complex white matter structures, the capability of resolving local white matter geometries with multiple crossings in the diffusion magnetic resonance imaging (dMRI) data is critical. Increasing b-value has been suggested for delineation of the finer details of the orientation distribution function (ODF). Although increased gradient strength and duration increase sensitivity to highly restricted intra-axonal water, gradient strength limitations require longer echo times (TE) to accommodate the increased diffusion encoding times needed to achieve a higher b-value, exponentially lowering the signal-to-noise ratio of the acquisition. To mitigate this effect, the MGH-USC Connectom scanner was built with 300 mT/m gradients, which can significantly reduce the TE of high b-value diffusion imaging. Here we report comparisons performed across b-values based on q-ball ODF metrics to investigate whether high b-value diffusion imaging on the Connectom scanner can improve resolving complex white matter structures. The q-ball ODF features became sharper as the b-value increased, with increased power fraction in higher order spherical harmonic series of the ODF and increased peak heights relative to the overall size of the ODF. Crossing structures were detected in an increasingly larger fraction of white matter voxels and the spatial distribution of two-way and three-way crossing structures was largely consistent with known anatomy. Results indicate that dMRI with high diffusion encoding on the Connectom system is a promising tool to better characterize, and ultimately understand, the underlying structural organization and motifs in the human brain. PMID:25287963

  2. High temperature thermal energy storage in moving sand

    NASA Technical Reports Server (NTRS)

    Turner, R. H.; Awaya, H. I.

    1978-01-01

    Several high-temperature (to 500 C) heat-storage systems using sand as the storage medium are described. The advantages of sand as a storage medium include low cost for sand, widespread availability, non-toxicity, non-degradation characteristics, easy containment, and safety. The systems considered include: stationary sand with closely spaced tubes throughout the volume, the use of a fluidized bed, use of conveyor belt transporter, and the use of a blower rapid transport system. For a stationary sand bed, very close spacing of heat transfer tubes throughout the volume is required, manifesting as high power related system cost. The suggestion of moving sand past or around pipes is intended to reduce the power related costs at the penalty of added system complexity. Preliminary system cost estimates are offered. These rough calculations indicate that mobile sand heat storage systems cost less than the stationary sand approach.

  3. The Eastern Pelagonian metamorphic core complex: insight from the 40Ar/39Ar dating of white micas

    NASA Astrophysics Data System (ADS)

    Schenker, F. L.; Forster, M.; Burg, J.-P.

    2012-04-01

    The Pelagonian Zone in continental Greece is the westernmost unit of the Internal Hellenides that constitutes a pre-alpine crystalline block in-between two oceanic domains, the Pindos in the west and the Vardar zone in the east. We present petrographic, structural and geochronological evidence for a metamorphic core complex in eastern Pelagonian. The denuded metamorphic dome extends about 20 x 15 km with the long axis striking NNW-SSE. A shallow-dipping foliation defines the structural dome. The mineralogy of the lithologies (gneiss, impure marbles and amphibolites) show metamorphic conditions that decrease from upper-amphibolite in the core to greenschist metamorphic conditions in the flanks of the dome, reflecting structural depth and thus erosion of the dome. Aligned micas and amphiboles and elongated quartz and feldspar define a prominent lineation trending SW-NE. Asymmetric structures in the XZ finite strain plane of rocks show two regional senses of shear: (i) everywhere, top-to-the-SW sense of shear (direction: 252°±30; plunge: 8°±25) associated with strain gradients from protomylonite to ultramylonite and recumbent, isoclinal and occasional sheath folds; (ii) top-to-the-E sense of shear (direction: 88°±24; plunge: 11°±12) in narrow (0.1 to 100 m) low-angle shear zones on the eastern flanks of subdomes. The 40Ar/39Ar step-heating dating technique has been applied to micas from orthogneisses from the core to the flanks of the dome to constrain its thermal and structural evolution. The micas have been separated with acoustical shockwave produced in the SELFRAG apparatus, with the advantage to liberate morphologically intact grains. The liberated grains were sieved at different grain-sizes (between 100 and 300 μm) depending on the micro-textures observed in thin-sections. Results show "plateau"-ages at ca. 100-120 Ma and at ca. 80 Ma. Interestingly, the 100-160 μm fraction of white micas in a mylonitic orthogneiss yielded slightly younger ages than the 160-300 μm fraction, arguing for neo-crystallization age during deformation of the smaller grain fraction and a more retentive apparent age with multiple diffusion domains for the larger. Micro-textures confirm an early generation of mica fish (>160 μm) arranged between c-type shear bands representing a later generation of micas. These new ages are consistent with ages published on the southern Pelagonian, demonstrating major tectonic and metamorphic activity during early Cretaceous times.

  4. Complex phenological changes and their consequences in the breeding success of a migratory bird, the white stork Ciconia ciconia.

    PubMed

    Gordo, Oscar; Tryjanowski, Piotr; Kosicki, Jakub Z; Fuln, Miroslav

    2013-09-01

    1. The timing of bird migration has shifted in response to climate change. However, few studies have linked the potential consequences of any phenological shift on individual fitness and even fewer have disentangled the role of plasticity and microevolution in the observed shifts. 2. The arrival date and breeding success of white storks (Ciconia ciconia) have been recorded since the 1880 s in Slovakia. We used data for two periods (1895-1913 and 1977-2007), which were considered, respectively, as populations before and after the start of climate warming. About 4000 male and 2500 female arrival dates along with 3000 breeding attempts were studied. 3. Mean arrival dates did not differ between the two periods. During 1977-2007, males tended towards a slight delay for most fractions of arrival distribution. Protandry was reduced by 30% (1.44 days). 4. In both sexes, the early percentiles of the arrival distribution arrived later those years with warmer temperatures at the African wintering grounds, while late percentiles advanced their arrival when temperatures were higher in the European areas flown over during migration. 5. Mean breeding success of the Slovakian population has not changed since 1977. However, fecundity selection for arrival date reduced over the years: at the end of 1970s and 1980s, early breeders had more success than late breeders, but this seasonal trend disappeared towards the end of the study period. An early arrival and territory acquisition may have become less of an advantage due to the enhancement of feeding opportunities during the breeding season in recent decades. 6. A century ago, stork arrival varied spatially, with earlier arrivals at low altitudes, southern slopes and warmer and drier regions. This spatial variation mostly vanished, and at present, we found little correlations with topographical and climatic gradients. 7. We showed that long-term temporal changes in the timing of biological events may be complex because each fraction of a population and sex may show different temporal trends in their arrival dates. In addition, the effect of biotic and abiotic factors may change consistently in space and time, and thereby phenotypes' value depends on the circumstances that are expressed due to its variable fitness consequences. PMID:23855800

  5. Wind profiles on the stoss slope of sand dunes: Implications for eolian sand transport

    SciTech Connect

    Frank, A.; Kocurek, G. . Dept. of Geological Sciences)

    1993-04-01

    Starting with the work of R.A. Bagnold it has been recognized that the shear stress exerted by the wind on sand grains is the driving force for eolian sand transport. Calculation of accurate rates of sand transport is essential for prediction of migration rates of sand dunes in modern environments as well as reconstructing paleoclimates (wind speed and direction) from eolian deposits. Because a sand dune is a streamlined obstacle in the path of the wind, continuity necessitates that the flow field is compressed over the windward side of a dune and shear stress should progressively increase up the slope as the flow accelerates. However, airflow measurements over 14 dunes (at White Sands, New Mexico; Algodones, CA; and Padre Island, TX) show that compression of the flow field occurs very close to the surface and as a consequence, the overlying flow actually shows an overall decrease in shear stress up the slope. Measurements commonly collected in the overlying zone are not representative of the near-surface, sand-driving wind. Furthermore, near-surface compression of the flow field implies that a pressure gradient exists that would render the current transport models inappropriate for sloping surfaces that dominate natural sandy desert terrains.

  6. White Lupin (Lupinus albus) Response to Phosphorus Stress: Evidence for Complex Regulation of LaSAP1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin (Lupinus albus) has a unique adaptation to phosphorus deficiency stress, such that a set of tightly coordinated physiological and morphological responses gives rise to the formation of cluster, or proteoid roots, structures that allow the plant to live in extremely infertile soils. The c...

  7. Contextual Complexity and Violent Delinquency among Black and White Males. Institute for Research on Poverty Discussion Paper.

    ERIC Educational Resources Information Center

    Bruce, Marino A.

    Most social scientists assert that Whites and African Americans exist in different economic, political, and social environments and that these contextual differences contribute substantially to group differences in violence and other antisocial outcomes. This paper uses data from the National Longitudinal Study of Adolescent Health and structural

  8. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2006-01-01

    In 2005, domestic production of industrial sand and gravel was about 31 Mt, a 5% increase from 2004. This increase was bouyed by robust construction and petroleum sectors of the US economy. Based on estimated world production figures, the United States was the world's leading producer and consumer of industrial sand and gravel. In the short term, local shortages of industrial sand and gravel will continue to increase.

  9. Processing of tar sands

    SciTech Connect

    Mitchell, T.O.

    1984-01-03

    The present invention relates to an improved process for the recovery of bitumen from tar sands comprising first heating the raw tar sands with steam at a temperature sufficient to visbreak a portion of the bitumen without significant thermal cracking thereby producing a vaporous distillate product mixed with steam and lowering the viscosity and specific gravity of the residual bitumen on the heat treated tar sands. The distillate product and steam are cooled and condensed and mixed the heat treated tar sands containing residual beneficiated bitumen to form a slurry. Bitumen is then recovered from the slurry by a hot-water separation process.

  10. Effects of complex radiative and convective environments on the thermal biology of the white-crowned sparrow (Zonotrichia leucophrys gambelii).

    PubMed

    Wolf, B O; Wooden, K M; Walsberg, G E

    2000-02-01

    The energy budgets of small endotherms are profoundly affected by characteristics of the physical environment such as wind speed, air temperature and solar radiation. Among these, solar radiation represents a potentially very large heat load to small animals and may have an important influence on their thermoregulatory metabolism and heat balance. In this investigation, we examined the interactive effects of wind speed and irradiance on body temperature, thermoregulatory metabolism and heat balance in the white-crowned sparrow (Zonotrichia leucophrys gambelii). We measured changes in metabolic heat production by exposing birds to different wind speeds (0.25, 0.5, 1.0 and 2.0 m s(-1)) and irradiance combinations (<3 W m(-2) and 936+/-11 W m(-2); mean +/- s.d.) at an air temperature of 10 degrees C. Body temperature was not affected by wind speed, but was significantly higher in animals not exposed to simulated solar radiation compared with those exposed at most wind speeds. In the absence of solar radiation, metabolic heat production was strongly affected by wind speed and increased by 30 % from 122 to 159 W m(-2) as wind speed increased from 0.25 to 2.0 m s(-1). Metabolic heat production was even more strongly influenced by wind speed in the presence of simulated solar radiation and increased by 51% from 94 to 142 W m(-2) as wind speed increased from 0.25 to 2. 0 m s(-1). Solar heat gain was negatively correlated with wind speed and declined from 28 to 12 W m(-2) as wind speed increased from 0.25 to 2.0 m s(-1) and, at its maximum, equaled 11% of the radiation intercepted by the animal. The overall thermal impact of the various wind speed and irradiance combinations on the animal's heat balance was examined for each treatment. Under cold conditions, with no solar radiation present, an increase in wind speed from 0.25 to 2.0 m s(-1) was equivalent to a decrease in chamber air temperature of 12.7 degrees C. With simulated solar radiation present, a similar increase in wind speed was equivalent to a decrease in chamber air temperature of 16 degrees C. Overall, shifting environmental conditions from a wind speed of 0.25 m s(-1) and irradiance of 936 W m(-2) to a wind speed of 2.0 m s(-1) with no short-wave radiation present was equivalent to decreasing chamber air temperature by approximately 20 degrees C. The sensitivity to changes in the convective environment, combined with the complex effects of changes in irradiance levels revealed by re-analyzing data published previously, significantly complicates the task of estimating the heat balance of animals in nature. PMID:10648222

  11. WHITE LUPIN NITROGEN FIXATION UNDER PHOSPHORUS DEFICIENCY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin is highly adapted to growth in a low P environment. The objective of the present study was to evaluate whether white lupin grown under P-stress has adaptations in nodulation and N2 fixation that facilitate continued functioning. Nodulated plants were grown in silica sand supplied with N-...

  12. Steam sand dryer in northeast part of sand tower. View ...

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

    Steam sand dryer in northeast part of sand tower. View to northeast - Duluth & Iron Range Rail Road Company Shops, Sand Tower, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  13. Geologic implications of new zircon U-Pb ages from the White Mountain Peak Metavolcanic Complex, eastern California

    NASA Astrophysics Data System (ADS)

    Scherer, Hannah H.; Ernst, W. G.; Brooks Hanson, R.

    2008-04-01

    The NNW-trending White-Inyo Range includes intrusive and volcanic rocks on the eastern flank of the Sierran volcano-plutonic arc. The NE-striking, steeply SE-dipping Barcroft reverse fault separates folded, metamorphosed Mesozoic White Mountain Peak mafic and felsic volcanic flows, volcanogenic sedimentary rocks, and minor hypabyssal plugs on the north from folded, well-bedded Neoproterozoic-Cambrian marble and siliciclastic strata on the south. The 163 ± 2 Ma Barcroft Granodiorite rose along this fault, and thermally recrystallized its wall rocks. However, new SHRIMP-RG ages of magmatic zircons from three White Mountain Peak volcanogenic metasedimentary rocks and a metafelsite document stages of effusion at ˜115-120 Ma as well as at ˜155-170 Ma. The U-Pb data confirm the interpretation by Hanson et al. (1987) that part of the metasedimentary-metavolcanic pile was laid down after Late Jurassic intrusion of the Barcroft pluton. The Lower Cretaceous, largely volcanogenic metasedimentary section lies beneath a low-angle thrust fault, the upper plate of which includes interlayered Late Jurassic mafic and felsic metavolcanic rocks and the roughly coeval Barcroft pluton. Late Jurassic and Early Cretaceous volcanism in this sector of the Californian continental margin, combined with earlier petrologic, structural, and geochronologic studies, indicates that there was no gap in igneous activity at this latitude of the North American continental margin.

  14. Sand dunes as migrating strings

    NASA Astrophysics Data System (ADS)

    Guignier, L.; Niiya, H.; Nishimori, H.; Lague, D.; Valance, A.

    2013-05-01

    We develop a reduced complexity model for three-dimensional sand dunes, based on a simplified description of the longitudinal and lateral sand transport. The spatiotemporal evolution of a dune migrating over a nonerodible bed under unidirectional wind is reduced to the dynamics of its crest line, providing a simple framework for the investigation of three-dimensional dunes, such as barchan and transverse dunes. Within this model, we derive analytical solutions for barchan dunes and investigate the stability of a rectilinear transverse dune against lateral fluctuations. We show, in particular, that the latter is unstable only if the lateral transport on the dune slip face prevails over that on the upwind face. We also predict the wavelength and the characteristic time that control the subsequent evolution of an unstable transverse dune into a wavy ridge and the ultimate fragmentation into barchan dunes.

  15. Sand dunes as migrating strings.

    PubMed

    Guignier, L; Niiya, H; Nishimori, H; Lague, D; Valance, A

    2013-05-01

    We develop a reduced complexity model for three-dimensional sand dunes, based on a simplified description of the longitudinal and lateral sand transport. The spatiotemporal evolution of a dune migrating over a nonerodible bed under unidirectional wind is reduced to the dynamics of its crest line, providing a simple framework for the investigation of three-dimensional dunes, such as barchan and transverse dunes. Within this model, we derive analytical solutions for barchan dunes and investigate the stability of a rectilinear transverse dune against lateral fluctuations. We show, in particular, that the latter is unstable only if the lateral transport on the dune slip face prevails over that on the upwind face. We also predict the wavelength and the characteristic time that control the subsequent evolution of an unstable transverse dune into a wavy ridge and the ultimate fragmentation into barchan dunes. PMID:23767529

  16. Fuels from tar sands

    SciTech Connect

    Woods, L.M.

    1986-03-01

    A general discussion of the tar sand resource in the US in presented. The difficulties and uncertainties associated with the development of synfuels are discussed. Predictions are made concerning the development of the tar sands resource in the US and Canada during the next 15 years.

  17. Strength and sintering effects at ejection of explosively driven sand

    NASA Astrophysics Data System (ADS)

    Resnyansky, A. D.; Weckert, S. A.

    2014-05-01

    A description of the response of sand to extreme loads is very important for the evaluation of the sand ejecta impact effects on various targets. Sand is a complex material to simulate because of its porosity where the inter-phase equilibrium is hard to achieve under transient shock wave loading. A previously developed two-phase model with strength has been implemented in CTH and applied to sand. The shock response of the sand, including the Hugoniot abnormality known from the literature for highly porous silica, is adequately described with the material model. The sand unloading effects appearing as the ejecta are observed in the present work using dynamic flash X-ray of an aluminium target plate loaded by limestone sand ejecta from the detonation of a buried high explosive charge. The CTH modelling results compared with the flash X-ray images have demonstrated good agreement, particularly, in the description of momentum transfer to the target.

  18. Enhancing genetic mapping of complex genomes through the design of highly-multiplexed SNP arrays: application to the large and unsequenced genomes of white spruce and black spruce

    PubMed Central

    Pavy, Nathalie; Pelgas, Betty; Beauseigle, Stphanie; Blais, Sylvie; Gagnon, France; Gosselin, Isabelle; Lamothe, Manuel; Isabel, Nathalie; Bousquet, Jean

    2008-01-01

    Background To explore the potential value of high-throughput genotyping assays in the analysis of large and complex genomes, we designed two highly multiplexed Illumina bead arrays using the GoldenGate SNP assay for gene mapping in white spruce (Picea glauca [Moench] Voss) and black spruce (Picea mariana [Mill.] B.S.P.). Results Each array included 768 SNPs, identified by resequencing genomic DNA from parents of each mapping population. For white spruce and black spruce, respectively, 69.2% and 77.1% of genotyped SNPs had valid GoldenGate assay scores and segregated in the mapping populations. For each of these successful SNPs, on average, valid genotyping scores were obtained for over 99% of progeny. SNP data were integrated to pre-existing ALFP, ESTP, and SSR markers to construct two individual linkage maps and a composite map for white spruce and black spruce genomes. The white spruce composite map contained 821 markers including 348 gene loci. Also, 835 markers including 328 gene loci were positioned on the black spruce composite map. In total, 215 anchor markers (mostly gene markers) were shared between the two species. Considering lineage divergence at least 10 Myr ago between the two spruces, interspecific comparison of homoeologous linkage groups revealed remarkable synteny and marker colinearity. Conclusion The design of customized highly multiplexed Illumina SNP arrays appears as an efficient procedure to enhance the mapping of expressed genes and make linkage maps more informative and powerful in such species with poorly known genomes. This genotyping approach will open new avenues for co-localizing candidate genes and QTLs, partial genome sequencing, and comparative mapping across conifers. PMID:18205909

  19. Tar sands` asphaltic mixes

    SciTech Connect

    Akinrogunde, E.A.

    1995-12-31

    This paper presents the results obtained from the laboratory investigation aimed at determining the possibility of making asphaltic mixes of acceptable quality for road surfacing, from raw tar sands (as they occur in nature). The tar sand samples consist mainly of fine sand, water, and bitumen. Five different types of asphaltic mixes were produced from tar sands and superheated aggregates. On the basis of Marshall and indirect tensile (Brazilian) tests carried out on the produced asphaltic mixes, the investigation revealed that raw tar sands are good material for the production of asphaltic mixes. The results of the investigation also suggest that for a given mix set, there may be correlation between maximum value of Marshall stability and maximum indirect tensile strength.

  20. Retrieval of sand density from hyperspectral BRDF

    NASA Astrophysics Data System (ADS)

    Bachmann, Charles M.; Abelev, Andrei; Philpot, William; Doctor, Katarina Z.; Montes, Marcos J.; Fusina, Robert; Li, Rong-Rong; van Roggen, Elena

    2014-06-01

    In past work, we have shown that density effects in hyperspectral bi-directional reflectance function (BRDF) data are consistent in laboratory goniometer data, field goniometer measurements with the NRL Goniometer for Portable Hyperspectral Earth Reflectance (GOPHER), and airborne CASI-1500 hyperspectral imagery. Density effects in granular materials have been described in radiative transfer models and are known, for example, to influence both the overall level of reflectance as well as the size of specific characteristics such as the width of the opposition effect in the BRDF. However, in mineralogically complex sands, such as coastal sands, the relative change in reflectance with density depends on the composite nature of the sand. This paper examines the use of laboratory and field hyperspectral goniometer data and their utility for retrieving sand density from airborne hyperspectral imagery. We focus on limitations of current models to describe density effects in BRDF data acquired in the field, laboratory setting, and from airborne systems.

  1. Pollack Crater's White Rock

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image of White Rock in Pollack crater was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on February 3, 2007 at 1750 UTC (12:50 p.m. EST), near 8 degrees south latitude, 25 degrees east longitude. The CRISM image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 40 meters (132 feet) across. The region covered is roughly 20 kilometers (12 miles) long and 10 kilometers (6 miles) wide at its narrowest point.

    First imaged by the Mariner 9 spacecraft in 1972, the enigmatic group of wind-eroded ridges known as White Rock has been the subject of many subsequent investigations. White Rock is located on the floor of Pollack Crater in the Sinus Sabaeus region of Mars. It measures some 15 by 18 kilometers (9 by 11 miles) and was named for its light-colored appearance. In contrast-enhanced images, the feature's higher albedo or reflectivity compared with the darker material on the floor of the crater makes it appear white. In reality, White Rock has a dull, reddish color more akin to Martian dust. This higher albedo as well as its location in a topographic low suggested to some researchers that White Rock may be an eroded remnant of an ancient lake deposit. As water in a desert lake on Earth evaporates, it leaves behind white-colored salts that it leached or dissolved out of the surrounding terrain. These salt deposits may include carbonates, sulfates, and chlorides.

    In 2001, the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor measured White Rock and found no obvious signature of carbonates or sulfates, or any other indication that White Rock holds evaporite minerals. Instead, it found Martian dust.

    CRISM's challenge was to obtain greater detail of White Rock's mineralogical composition and how it formed. The instrument operates at a different wavelength range than TES, giving it greater sensitivity to carbonate, sulfate and phyllosilicate (clay-like) minerals. It also has a higher spatial resolution that enables CRISM to see smaller exposures of these minerals, if they occur. If White Rock is an evaporative lacustrine or lake deposit, CRISM has the best chance of detecting telltale mineralogical signatures. The images above reveal what CRISM found.

    The top panel in the montage above shows the location of the CRISM image on a mosaic of Pollack Crater taken by the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS). White Rock actually appears dark in the THEMIS mosaic due to a low daytime temperature, because its light color leads to less heating by the Sun. The middle-left image is an infrared, false color image that reveals White Rock's reddish hue. The middle-right image shows the signatures of different minerals that are present. CRISM found that White Rock is composed of accumulated dust perhaps with some fine-grained olivine (an igneous mineral), surrounded by basaltic sand containing olivine and dark-colored pyroxene. The lower two images were constructed by draping CRISM images over topography and exaggerating the vertical scale to better illustrate White Rock's topography. White Rock still appears not to contain evaporite, but instead to be composed of accumulated dust and sand.

    CRISM is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter and the Mars Science Laboratory for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter.

  2. Analysis of Wind-blown Sand Movement over Transverse Dunes

    NASA Astrophysics Data System (ADS)

    Jiang, Hong; Huang, Ning; Zhu, Yuanjian

    2014-12-01

    Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

  3. Analysis of Wind-blown Sand Movement over Transverse Dunes

    PubMed Central

    Jiang, Hong; Huang, Ning; Zhu, Yuanjian

    2014-01-01

    Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification. PMID:25434372

  4. Analysis of wind-blown sand movement over transverse dunes.

    PubMed

    Jiang, Hong; Huang, Ning; Zhu, Yuanjian

    2014-01-01

    Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification. PMID:25434372

  5. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  6. VNIR reflectance spectra of gypsum mixtures for comparison with White Sands National Monument, New Mexico (WSNM) dune samples as an analog study of the Olympia Undae region of Mars

    NASA Astrophysics Data System (ADS)

    King, S. J.; Bishop, J. L.; Fenton, L. K.; Lafuente, B.; Garcia, G. C.; Horgan, B. H.

    2013-12-01

    Dunes at WSNM are being used as an analog study area for gypsum-rich dunes near the northern polar region of Mars. Samples were collected from 4 dunes at WSNM for this study. In order to determine abundances of the gypsum, quartz and dolomite present in the dune sand, size separates (<45, 45-90, 90-150, 150-250, >250 ?m) were prepared for gypsum, quartz and dolomite, mixtures were prepared using the 90-150 ?m size fraction, and all samples were characterized in the lab. Analyses of the VNIR spectral data are presented here (Figs. 1-2) and analyses of the XRD data are presented in a companion abstract [1]. The majority of the dune sand is dominated by gypsum, while the coarse grains at some ripples are largely dolomite. Mid-IR spectra will be evaluated as well. Gypsum/Dolomite Mixtures (Fig. 1) There is a clear progression of albedo and band strength in these mixture spectra as one mineral is increased and the other decreased. The mixture spectra are dominated by the gypsum bands for mixtures that are gypsum rich (?50wt.% gypsum) including a triplet at 1.446-1.535 ?m, plus bands at 1.749, 1.945, 2.217 and 2.267 ?m. When mixtures become predominantly dolomite (10/90 & 20/80 mixtures), the gypsum bands are significantly weaker, while the dolomite band at 2.322 becomes much more visible. Gypsum/Quartz Mixtures (Fig. 2) The gypsum/quartz mixture spectra are dominated to an even greater extent by gypsum, resulting in readily observable gypsum features for spectra of samples with only 10 wt.% gypsum. [1] Lafuente et al. (2013) AGU, submitted.

  7. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2010-01-01

    Domestic production of industrial sand and gravel in 2009 was about 27 Mt (30 million st), declining by 10 percent compared with 2008. Certain end uses of industrial sand and gravel, such as foundry and glassmaking sand, may have declined by a factor greater than 10 percent in 2009. U.S. apparent consumption was 24.7 Mt (27.2 million st) in 2009, down by 10 percent from the previous year, and imports declined to 83 kt (91,000 st).

  8. Sand consolidation methods

    SciTech Connect

    Friedman, R.H.

    1984-01-24

    Methods are provided for selectively consolidating sand grains within a subterranean formation. First an acidic salt catalyst such as ZnCl/sub 2/ is injected into the subterranean formation, wherein the acidic salt catalyst is adsorbed to the surface of the sand grains. Next a polymerizable resin composition such as furfuryl alcohol oligomer is introduced into the well formation. Polymerization of the resin occurs upon exposure to the elevated well temperatures and contact with the acid salt catalyst adsorbed to the sand grains. The polymerized resin serves to consolidate the surfaces of the sand grains while retaining permeability through the pore spaces. An ester of a weak organic acid is included with the resin compositions to control the extent of a polymerization by consuming the water by-product formed druing the polymerization reaction.

  9. Avalanches of dry sand

    NASA Astrophysics Data System (ADS)

    Boutreux, T.; Raphal, E.; de Gennes, P. G.

    We present here some general features of sand heaps and of dunes. We mainly discuss avalanche flows, using a modified version of the equations of Bouchaud et al., which might be valid for thick avalanches.

  10. The Flow of Sand.

    ERIC Educational Resources Information Center

    Yersel, Metin

    2000-01-01

    Describes a simple demonstration of the flow of sand through an orifice at the bottom of a sandbox. Advocates the experiment's use with dimensional analysis for students in an introductory physics course. (WRM)

  11. Sand boils without earthquakes

    USGS Publications Warehouse

    Holzer, T.L.; Clark, M.M.

    1993-01-01

    Sedimentary deformation caused by liquefaction has become a popular means for inferring prehistoric strong earthquakes. This report describes a new mechanism for generating such features in the absence of earthquakes. Sand boils and a 180-m-long sand dike formed in Fremont Valley, California, when sediment-laden surface runoff was intercepted along the upslope part of a 500-m-long preexisting ground crack, flowed subhorizonally in the crack, and then flowed upward in the downslope part of the crack where it discharged as sand boils on the land surface. If the sand boils and their feeder dike were stratigraphically preserved, they could be misinterpreted as evidence for earthquake-induced liquefaction. -Authors

  12. Vent of Sand Volcano

    USGS Multimedia Gallery

    Vent of sand volcano produced by liquefaction is about 4 ft across in strawberry field near Watsonville. Strip spanning vent is conduit for drip irrigation system. Furrow spacing is about 1.2 m (4 ft) on center....

  13. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

    Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

  14. Assessing the Effects of Light on Differentiation and Virulence of the Plant Pathogen Botrytis cinerea: Characterization of the White Collar Complex

    PubMed Central

    Hevia, Montserrat A.; Tudzynski, Paul; Larrondo, Luis F.

    2013-01-01

    Organisms are exposed to a tough environment, where acute daily challenges, like light, can strongly affect several aspects of an individual's physiology, including pathogenesis. While several fungal models have been widely employed to understand the physiological and molecular events associated with light perception, various other agricultural-relevant fungi still remain, in terms of their responsiveness to light, in the dark. The fungus Botrytis cinerea is an aggressive pathogen able to cause disease on a wide range of plant species. Natural B. cinerea isolates exhibit a high degree of diversity in their predominant mode of reproduction. Thus, the majority of naturally occurring strains are known to reproduce asexually via conidia and sclerotia, and sexually via apothecia. Studies from the 1970′s reported on specific developmental responses to treatments with near-UV, blue, red and far-red light. To unravel the signaling machinery triggering development – and possibly also connected with virulence – we initiated the functional characterization of the transcription factor/photoreceptor BcWCL1 and its partner BcWCL2, that form the White Collar Complex (WCC) in B. cinerea. Using mutants either abolished in or exhibiting enhanced WCC signaling (overexpression of both bcwcl1 and bcwcl2), we demonstrate that the WCC is an integral part of the mentioned machinery by mediating transcriptional responses to white light and the inhibition of conidiation in response to this stimulus. Furthermore, the WCC is required for coping with excessive light, oxidative stress and also to achieve full virulence. Although several transcriptional responses are abolished in the absence of bcwcl1, the expression of some genes is still light induced and a distinct conidiation pattern in response to daily light oscillations is enhanced, revealing a complex underlying photobiology. Though overlaps with well-studied fungal systems exist, the light-associated machinery of B. cinerea appears more complex than those of Neurospora crassa and Aspergillus nidulans. PMID:24391918

  15. Steady-State Phosphorylation of Light-Harvesting Complex II Proteins Preserves Photosystem I under Fluctuating White Light1[W][OA

    PubMed Central

    Grieco, Michele; Tikkanen, Mikko; Paakkarinen, Virpi; Kangasjrvi, Saijaliisa; Aro, Eva-Mari

    2012-01-01

    According to the state transitions theory, the light-harvesting complex II (LHCII) phosphorylation in plant chloroplasts is essential to adjust the relative absorption cross section of photosystem II (PSII) and PSI upon changes in light quality. The role of LHCII phosphorylation upon changes in light intensity is less thoroughly investigated, particularly when changes in light intensity are too fast to allow the phosphorylation/dephosphorylation processes to occur. Here, we demonstrate that the Arabidopsis (Arabidopsis thaliana) stn7 (for state transition7) mutant, devoid of the STN7 kinase and LHCII phosphorylation, shows a growth penalty only under fluctuating white light due to a low amount of PSI. Under constant growth light conditions, stn7 acquires chloroplast redox homeostasis by increasing the relative amount of PSI centers. Thus, in plant chloroplasts, the steady-state LHCII phosphorylation plays a major role in preserving PSI upon rapid fluctuations in white light intensity. Such protection of PSI results from LHCII phosphorylation-dependent equal distribution of excitation energy to both PSII and PSI from the shared LHCII antenna and occurs in cooperation with nonphotochemical quenching and the proton gradient regulation5-dependent control of electron flow, which are likewise strictly regulated by white light intensity. LHCII phosphorylation is concluded to function both as a stabilizer (in time scales of seconds to minutes) and a dynamic regulator (in time scales from tens of minutes to hours and days) of redox homeostasis in chloroplasts, subject to modifications by both environmental and metabolic cues. Exceeding the capacity of LHCII phosphorylation/dephosphorylation to balance the distribution of excitation energy between PSII and PSI results in readjustment of photosystem stoichiometry. PMID:23033142

  16. A study of morphology, provenance, and movement of desert sand seas in Africa, Asia, and Australia

    NASA Technical Reports Server (NTRS)

    Mckee, E. D.; Breed, C. S.; Harris, L. F. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Examination of sand samples from both dune and interdune areas at White Sands, New Mexico, indicates marked differences in composition and texture between these two types of facies. If these differences are characteristics of dune fields in general, information concerning them may help to explain the contrast in appearance of the two kinds of sand areas on ERTS imagery and to permit interpretation of similar features in remote areas, such as Saudi Arabia.

  17. 7. SAND FILTERS, CANAL TO LEFT. CONCRETE OVERFLOW AREA TO ...

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

    7. SAND FILTERS, CANAL TO LEFT. CONCRETE OVERFLOW AREA TO LEFT OF CANAL ORIGINALLY PLANNED AS A STORAGE LAKE. VIEW LOOKING DUE WEST OF HINDS COMPLEX IN BACKGROUND OF SAND FILTERS. - Hinds Pump Plant, East of Joshua Tree National Monument, 5 miles north of Route 10, Hayfield, Riverside County, CA

  18. Sand Sheet on Crater Floor

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    As with yesterday's image, this dune field is located inside a crater, in this case an unnamed crater at 26 degrees North latitude. In this VIS image the dunes are coalescing into a sand sheet, note the lack of dune forms to the north of the small hills. The presence of ridges and hills in the area is affecting the dune shapes.

    Image information: VIS instrument. Latitude 26.4, Longitude 62.7 East (297.3 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Kinetic Parameters of Secondary Carbide Precipitation in High-Cr White Iron Alloyed by Mn-Ni-Mo-V Complex

    NASA Astrophysics Data System (ADS)

    Efremenko, V. G.; Chabak, Yu. G.; Brykov, M. N.

    2013-05-01

    This study presents kinetics of precipitation of secondary carbides in 14.55%Cr-Mn-Ni-Mo-V white cast iron during the destabilization heat treatment. The as-cast iron was heat treated at temperatures in the range of 800-1100 C with soaking up to 6 h. Investigation was carried out by optical and electron microscopy, dilatometric analysis, Ms temperature measurement, and bulk hardness evaluation. TTT-curve of precipitation process of secondary carbides (M7C3, M23C6, M3C2) has been constructed in this study. It was determined that the precipitation occurs at the maximum rate at 950 C where the process is started after 10 s and completed within 160 min further. The precipitation leads to significant increase of Ms temperature and bulk hardness; large soaking times at destabilization temperatures cause coarsening of secondary carbides and decrease in particles number, followed by decrease in hardness. The results obtained are discussed in terms of solubility of carbon in the austenite and diffusion activation of Cr atoms. The precipitation was found to consist of two stages with activation energies of 196.5 kJ/g-mole at the first stage and 47.1 kJ/g-mole at the second stage.

  20. The mitochondrial 13513G > A mutation is most frequent in Leigh syndrome combined with reduced complex I activity, optic atrophy and/or Wolff-Parkinson-White.

    PubMed

    Ruiter, E Mariken; Siers, Marloes H; van den Elzen, Christa; van Engelen, Baziel G; Smeitink, Jan A M; Rodenburg, Richard J; Hol, Frans A

    2007-02-01

    The m.13513G > A transition in the mitochondrial gene encoding the ND5 subunit of respiratory chain complex I, can cause mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and has been reported to be a frequent cause of Leigh syndrome (LS). We determined the frequency of the mutation in a cohort of 123 patients with reduced complex I activity in muscle (n = 113) or fibroblast (n = 10) tissue. We describe a Pyrosequencing assay for rapid detection and quantification of the m.13513G > A mutation. Two patients with the mutation were identified; both had LS, optical atrophy and a Wolff-Parkinson-White Syndrome (WPWS)-like cardiac conduction defect. The clinical presentation of the m.13513G > A mutation is discussed. We conclude that the m.13513G > A mutation seems not as frequent as previously suggested and is most likely to be present in patients with Leigh (-like) syndrome combined with a complex I deficiency, optic atrophy and/ or WPWS. In addition, we confirmed that the adjacent m.13514A > G mutation is a rare cause of LS or MELAS since no cases with this transition were found. PMID:17106447

  1. The Uve1 endonuclease is regulated by the white collar complex to protect cryptococcus neoformans from UV damage.

    PubMed

    Verma, Surbhi; Idnurm, Alexander

    2013-01-01

    The pathogenic fungus Cryptococcus neoformans uses the Bwc1-Bwc2 photoreceptor complex to regulate mating in response to light, virulence and ultraviolet radiation tolerance. How the complex controls these functions is unclear. Here, we identify and characterize a gene in Cryptococcus, UVE1, whose mutation leads to a UV hypersensitive phenotype. The homologous gene in fission yeast Schizosaccharomyces pombe encodes an apurinic/apyrimidinic endonuclease acting in the UVDE-dependent excision repair (UVER) pathway. C. neoformans UVE1 complements a S. pombe uvde knockout strain. UVE1 is photoregulated in a Bwc1-dependent manner in Cryptococcus, and in Neurospora crassa and Phycomyces blakesleeanus that are species that represent two other major lineages in the fungi. Overexpression of UVE1 in bwc1 mutants rescues their UV sensitivity phenotype and gel mobility shift experiments show binding of Bwc2 to the UVE1 promoter, indicating that UVE1 is a direct downstream target for the Bwc1-Bwc2 complex. Uve1-GFP fusions localize to the mitochondria. Repair of UV-induced damage to the mitochondria is delayed in the uve1 mutant strain. Thus, in C. neoformans UVE1 is a key gene regulated in response to light that is responsible for tolerance to UV stress for protection of the mitochondrial genome. PMID:24039606

  2. Frosted Sand Dunes

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] (Released 22 July 2002) This image, located near 79.6 N and 142.7 E, displays sand dunes covered in CO2 frost. This is a region of Mars that contains circumpolar sand seas. The large sand deposits and the high winds that circulate around the pole allow for the formation of a huge dune field that surrounds the north polar cap. As the northern hemisphere progresses towards winter, CO2 frost condenses out of the atmosphere and covers the dunes. During northern spring, the CO2 sublimates and the dunes are once again uncovered and active. This image was taken as northern spring progresses and the crests of the dunes are just starting to be exposed. The dark dune material absorbs sunlight more efficiently than the brighter frost, aiding in the sublimation of the remaining frost.

  3. Sidewinding snakes on sand

    NASA Astrophysics Data System (ADS)

    Marvi, Hamidreza; Dimenichi, Dante; Chrystal, Robert; Mendelson, Joseph; Goldman, Daniel; Hu, David; Georgia Tech and Zoo Atlanta Collaboration

    2012-11-01

    Desert snakes such as the rattlesnake Crotalus cerastes propel themselves over sand using sidewinding, a mode of locomotion relying upon helical traveling waves. While sidewinding on hard ground has been described, the mechanics of movement on more natural substrates such as granular media remain poorly understood. In this experimental study, we use 3-D high speed video to characterize the motion of a sidewinder rattlesnake as it moves on a granular bed. We study the movement both on natural desert sand and in an air-fluidized bed trackway which we use to challenge the animal on different compactions of granular media. Particular attention is paid to rationalizing the snake's thrust on this media using friction and normal forces on the piles of sand created by the snake's body. The authors thank the NSF (PHY-0848894), Georgia Tech, and the Elizabeth Smithgall Watts endowment for support. We would also like to thank Zoo Atlanta staff for their generous help with this project.

  4. Asbestos in play sand

    SciTech Connect

    Langer, A.M.; Nolan, R.P.

    1987-04-02

    A letter in the New England Journal of Medicine (Oct. 2 issue) stated that a carbonate sand marketed in New Jersey was contaminated with 2 to 4 percent tremolite asbestos. The authors were called on by one of the federal agencies to repeat the analysis of this sand, specifically for its asbestos content. The sand was pulverized and immersed in oils with known refractive indexes, and the predominant amphibole was characterized by polarized light microscopy. The optical characteristics were noted, and the indexes of refraction were measured and found to be consistent with tremolite. On the basis of optical characterization, the authors concluded that all the tremolite visualized with light microscopy consisted of large, single cleavage fragments and was not asbestiform. They used the technique of x-ray diffraction, as did the author of the original report, which showed the presence of an amphibole mineral (probably tremolite) in the carbonate sand. The technique was not used, and cannot be used, to distinguish between the tremolite habits (asbestiform or nonasbestiform). An acid-insoluble residue, recovered from the carbonate sand, was examined by analytic electron microscopy. The tremolite grains were observed to consist of single untwinned, crystalline fragments. Few defects were noted. Selected area electron diffraction nets were indicative of fragments lying near or at the common amphibole cleavage plane. These characteristics are consistent with cleavage fragments and not asbestos. Aspect ratios reflected short particles (less than 5.1). On the basis of their examination of the carbonate play sand, they conclude that it did not contain tremolite asbestos.

  5. Sand Dunes with Frost

    NASA Technical Reports Server (NTRS)

    2004-01-01

    9 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of frost-covered sand dunes in the north polar region of Mars in early spring, 2004. The dunes indicate wind transport of sand from left to right (west to east). These landforms are located near 78.1oN, 220.8oW. This picture is illuminated by sunlight from the lower left and covers an area about 3 km (1.9 mi) across.

  6. Activation of White Phosphorus by Low-Valent Group 5 Complexes: Formation and Reactivity of cyclo-P4 Inverted Sandwich Compounds

    PubMed Central

    2015-01-01

    We report the synthesis and comprehensive study of the electronic structure of a unique series of dinuclear group 5 cyclo-tetraphosphide inverted sandwich complexes. White phosphorus (P4) reacts with niobium(III) and tantalum(III) ?-diketiminate (BDI) tert-butylimido complexes to produce the bridging cyclo-P4 phosphide species {[(BDI)(NtBu)M]2(?-?3:?3P4)} (1, M = Nb; 2, M = Ta) in fair yields. 1 is alternatively synthesized upon hydrogenolysis of (BDI)Nb(NtBu)Me2 in the presence of P4. The trinuclear side product {[(BDI)NbNtBu]3(?-P12)} (3) is also identified. Protonation of 1 with [HOEt2][B(C6F5)4] does not occur at the phosphide ring but rather involves the BDI ligand to yield {[(BDI#)Nb(NtBu)]2(?-?3:?3P4)}[B(C6F5)4]2 (4). The monocation and dication analogues {[(BDI)(NtBu)Nb]2(?-?3:?3P4)}{B(ArF)4}n (5, n = 1; 6, n = 2) are both synthesized by oxidation of 1 with AgBArF. DFT calculations were used in combination with EPR and UVvisible spectroscopies to probe the nature of the metalphosphorus bonding. PMID:25469924

  7. Does complex terrain matter for global terrestrial ecosystem models? Forest ecosystem dynamics in the White Mountains, NH. (Invited)

    NASA Astrophysics Data System (ADS)

    Dietze, M. C.; Richardson, A. D.; Moorcroft, P. R.

    2010-12-01

    Environmental scientists have long recognized that vegetation varies consistently at a landscape-scale due to variation in soils, hydrology, and topography. We expect that this variation to interact with climate change in complex ways, potentially allowing some species to persist in refugia while shifting other species to locations that may be edaphically unfavorable. Despite the recognized importance of this variation, it has not been incorporated into global and regional scale models because this heterogeneity occurs at a finer spatial scale than can be captured explicitly by refining model resolution. Rather than represent landscape-scale variability explicitly, we develop a spatially implicit approach to capture variation in soils, lateral hydrologic flow, and the effects of topography on microclimate and radiation interception. This scheme is incorporated in the Ecosystem Demography model. We tested this approach by first calibrating the model to forest inventory data and eddy-covariance fluxes of carbon, water, and energy from the Bartlett Experimental Forest in central NH and then validating it against 40+ years of vegetation and hydrology data from the Hubbard Brook Ecosystem Study, located 40km in forests of similar composition. When applied to Hubbard Brook the model is able to capture watershed streamflow at monthly to interannual scales and the variation in growth rates with topography, soils, and hydrology, and reproduces observed NPP during the forest growth phase. Growth rates were overestimated during the latter portion of the record, likely due to the cumulative impacts of acid rain which are not yet accounted for in the model. By sequentially switching off each source of edaphic variation, we find that the effect of elevation on microclimate has the greatest impact on the within-watershed distribution of NEE and NPP. The effects of slope and aspect on radiation are strongest at mid-elevation while lateral hydrology is most important on ridges and in valley-bottoms. A failure to include the effects of complex terrain is shown to result in a non-trivial overestimation of the net carbon sink. The model is then applied at a regional scale to forecast forest change under climate change scenarios. The addition of complex terrain is shown to buffer the effects of climate change on regional carbon fluxes. This effect occurs because climate change effects differ not only in magnitude but also in direction at a landscape-scale.

  8. Sand and sandstone

    SciTech Connect

    Pettijohn, F.J.; Potter, P.E.; Siever, R.

    1987-01-01

    Here is a new, second edition of a classical textbook in sedimentology, petrology, and petrography of sand and sandstones. It has been extensively revised and updated, including: new techniques and their utility; new literature; new illustrations; new, explicitly stated problems for the student; and a wider scope.

  9. Building with Sand

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of

  10. Building with Sand

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  11. Fracture behavior of cemented sand

    NASA Astrophysics Data System (ADS)

    Alqasabi, Ahmad Othman

    While fracture mechanics for cementitious materials and composites in the past three decades have developed mainly in concrete applications, it has not yet gained its rightful place in the geotechnical field. There are many examples in the geotechnical literature, especially those related to brittle and stiff soils, where traditional approaches of analysis have proven to be inadequate. While geotechnical problems are inherently complex in nature, using the finite element method (FEM) with fracture mechanics (FM) have been shown to provide powerful analytical tool that could be used to investigate and solve many problems in geomechanics and geotechnical engineering. This thesis addresses the application of FM concepts and theories in analysis of cemented soils. In addition to theoretical aspects, experiments were conducted to evaluate the application of FM to cemented soils. Three point bending beam tests with crack mouth opening displacements (CMOD) conducted on cemented sand samples showed that fracture parameters, such as CMOD, indeed could play an important role in investigation of such soils. Using this unambiguous material parameter, field engineers might have a reliable measure that could prove to be useful in stability assessment of earth structures and soil structure system. By studying size effect on cemented sand, strong relationship was established between critical CMOD and failure, which might be a very useful index and analysis tool in geotechnical engineering practice.

  12. Extracting Oil From Tar Sands

    NASA Technical Reports Server (NTRS)

    Ford, L. B.; Daly, D.

    1984-01-01

    Recovery of oil from tar sands possible by batch process, using steam produced by solar heater. In extraction process, solar heater provides steam for heating solvent boiler. Boiling solvent removes oil from tar sands in Soxhlet extractor.

  13. Bitumen recovery from tar sands

    SciTech Connect

    Miller, J.D.; Hupka, J.

    1984-09-11

    A process for recovering bitumen from tar sands wherein the tar sands are pretreated with a diluent, such as kerosene in the preferred embodiment, to lower the viscosity of the bitumen such that it is in the range of about 5 to about 20 poise at the digestion temperature. The tar sands are then digested at a temperature in the range of about 45/sup 0/ C. to about 60/sup 0/ C. and at a pH of about 7.8 to about 8.6. The tar sands are then transferred to a flotation cell where the bitumen-rich concentrate is separated from the sand.

  14. Sand hazards on tourist beaches.

    PubMed

    Heggie, Travis W

    2013-01-01

    Visiting the beach is a popular tourist activity worldwide. Unfortunately, the beach environment is abundant with hazards and potential danger to the unsuspecting tourist. While the traditional focus of beach safety has been water safety oriented, there is growing concern about the risks posed by the sand environment on beaches. This study reports on the death and near death experience of eight tourists in the collapse of sand holes, sand dunes, and sand tunnels. Each incident occurred suddenly and the complete burial in sand directly contributed to the victims injury or death in each case report. PMID:23290717

  15. The Chromosomal Polymorphism Linked to Variation in Social Behavior in the White-Throated Sparrow (Zonotrichia albicollis) Is a Complex Rearrangement and Suppressor of Recombination

    PubMed Central

    Thomas, James W.; Cceres, Mario; Lowman, Joshua J.; Morehouse, Caroline B.; Short, Meghan E.; Baldwin, Erin L.; Maney, Donna L.; Martin, Christa L.

    2008-01-01

    Variation in social behavior and plumage in the white-throated sparrow (Zonotrichia albicollis) is linked to an inversion polymorphism on chromosome 2. Here we report the results of our comparative cytogenetic mapping efforts and population genetics studies focused on the genomic characterization of this balanced chromosomal polymorphism. Comparative chromosome painting and cytogenetic mapping of 15 zebra finch BAC clones to the standard (ZAL2) and alternative (ZAL2m) arrangements revealed that this chromosome is orthologous to chicken chromosome 3, and that at a minimum, ZAL2 and ZAL2m differ by a pair of included pericentric inversions that we estimate span at least 98 Mb. Population-based sequencing and genotyping of multiple loci demonstrated that ZAL2m suppresses recombination in the heterokaryotype and is evolving as a rare nonrecombining autosomal segment of the genome. In addition, we estimate that the first inversion within the ZAL2m arrangement originated 2.2 0.3 million years ago. Finally, while previously recognized as a genetic model for the evolution of social behavior, we found that the ZAL2/ZAL2m polymorphism also shares genetic and phenotypic features with the mouse t complex and we further suggest that the ZAL2/ZAL2m polymorphism is a heretofore unrecognized model for the early stages of sex chromosome evolution. PMID:18562641

  16. A 550 Mbit/s real-time visible light communication system based on phosphorescent white light LED for practical high-speed low-complexity application.

    PubMed

    Li, Honglei; Chen, Xiongbin; Guo, Junqing; Chen, Hongda

    2014-11-01

    In this paper, we first experimentally demonstrate a 550 Mbit/s real-time visible light communication (VLC) system based on nonreturn-to-zero on-off keying (NRZ-OOK) modulation of a commercial phosphorescent white light LED. The 3-dB modulation bandwidth of such devices is only a few megahertz. We proposed an analog pre-emphasis circuit based on NPN transistors and an active post-equalization circuit based on an amplifier to enhance the 3-dB bandwidth of VLC link. Utilizing our proposed pre-emphasis and post-equalization circuits, the 3-dB bandwidth of VLC link could be extended from 3 to 233 MHz with blue-filter, to the best of our knowledge, which is the highest ever achieved in VLC systems reported. The achieved data rate was 550 Mbit/s at the distance of 60 cm and the resultant bit-error-ratio (BER) was 2.6 10(-9). When the VLC link operated at 160 cm, the data rate was 480 Mbit/s with 2.3 10(-7) of BER. Our proposed VLC system is a good solution for high-speed low-complexity application. PMID:25401871

  17. Intricately Rippled Sand Deposits

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for Intricately Rippled Sand Deposits (QTVR)

    NASA's Mars Exploration Rover Spirit welcomed the beginning of 2006 on Earth by taking this striking panorama of intricately rippled sand deposits in Gusev Crater on Mars. This is an approximate true-color rendering of the 'El Dorado' ripple field provided by Spirit over the New Year's holiday weekend. The view spans about 160 degrees in azimuth from left to right and consists of images acquired by Spirit's panoramic camera on Spirit's 708th and 710th Martian days, or sols, (Dec. 30, 2005 and Jan. 1, 2006). Spirit used the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters to capture the colors on Mars. Scientists have eliminated seams between individual frames in the sky portion of the mosaic to better simulate the vista a person standing on Mars would see. Spirit spent several days acquiring images, spectral data, and compositional and mineralogical information about these large sand deposits before continuing downhill toward 'Home Plate.'

  18. White Toenails

    MedlinePLUS

    ... body, causing protein to be deposited within the nail bed. A fungal infection that affects the outermost layer of the toenail may cause a bright white discoloration of the toenail. A white area close to the nail fold (the lunula) varies in size from one ...

  19. Biological Significance of Photoreceptor Photocycle Length: VIVID Photocycle Governs the Dynamic VIVID-White Collar Complex Pool Mediating Photo-adaptation and Response to Changes in Light Intensity

    PubMed Central

    Dasgupta, Arko; Chen, Chen-Hui; Lee, ChangHwan; Gladfelter, Amy S.; Dunlap, Jay C.; Loros, Jennifer J.

    2015-01-01

    Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD) is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability of the adduct state (light state), that is, altering the photocycle length. We have examined the biological significance of VVD photocycle length to photoadaptation and report that a double substitution mutant (vvdI74VI85V), previously shown to have a very fast light to dark state reversion in vitro, shows significantly reduced interaction with the White Collar Complex (WCC) resulting in a substantial photoadaptation defect. This reduced interaction impacts photoreceptor transcription factor WHITE COLLAR-1 (WC-1) protein stability when N. crassa is exposed to light: The fast-reverting mutant VVD is unable to form a dynamic VVD-WCC pool of the size required for photoadaptation as assayed both by attenuation of gene expression and the ability to respond to increasing light intensity. Additionally, transcription of the clock gene frequency (frq) is sensitive to changing light intensity in a wild-type strain but not in the fast photo-reversion mutant indicating that the establishment of this dynamic VVD-WCC pool is essential in general photobiology and circadian biology. Thus, VVD photocycle length appears sculpted to establish a VVD-WCC reservoir of sufficient size to sustain photoadaptation while maintaining sensitivity to changing light intensity. The great diversity in photocycle kinetics among photoreceptors may be viewed as reflecting adaptive responses to specific and salient tasks required by organisms to respond to different photic environments. PMID:25978382

  20. Booming Sand Dunes

    NASA Astrophysics Data System (ADS)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local cementation of sand grains within the discrete layers that explains the increase in velocity and decrease in porosity. The subsurface layering may influence the speed of dune migration and therefore have important consequences on desertification. The positive qualitative and quantitative correlation between the subsurface layering in the dune and the manifestation of the booming sound implies a close relation between environmental factors and the booming emission. In this thesis, the frequency of booming is correlated with the depth of the waveguide and the seismic velocities. The variability on location and season suggests that the waveguide theory successfully unravels the phenomenon of booming sand dunes.

  1. Solvent extraction of southern US tar sands

    SciTech Connect

    Not Available

    1989-05-01

    The socioeconomic aspects of the tar sands recovery were investigated by Diversified Petroleum Recovery, Inc. Mineral Resources Institute at the University of Alabama conducted characterization and beneficiation studies on Alabama tar sands. Two sources in the state were identified, namely, Black Wax Hill and Spring Creek. Samples were obtained, beneficiated, then shared with the University of Arkansas. The University of Arkansas conducted research in three areas, namely, solvation and characterization of the tar sands phase equilibria as well as the design and operation of a bench-scale batch model. In the solvation studies, the results indicate that grinding the tar sands too fine results in downstream processing problems. Also, preliminary indications are that the beneficiation step may not be necessary in the solvation of the bitumen. The phase equilibria of the heptane/brine/isopropyl alcohol/XTOL{trademark} system is very complex. The salt concentration of the brine is significant in the partitioning of the isopropanol and heptane. Equilibrium data for some of the various combinations of chemical constituents have been obtained. Also included are appendices: statistical data on highways; petrography; Dean-Starke technique; FTIR and NMR spectra; FORTRAN computer program for GC; simulation of flash behavior for IPA/brine/fatty acid/N-C{sub 7} mixture; and previous progress reports. 32 figs., 28 tabs.

  2. Committed White Male Teachers and Identifications: Toward Creative Identifications and a "Second Wave" of White Identity Studies

    ERIC Educational Resources Information Center

    Jupp, James C.; Slattery, G. Patrick, Jr.

    2010-01-01

    Committed White male teachers of inner-city students seeks to supersede previous research on White teacher and other White identities by narrating respondents' "creative identifications" and initiating a "second wave" of White identity studies. This research reflection articulates complex, viable, and creative White identities, reconceptualized

  3. Laboratory singing sand avalanches.

    PubMed

    Dagois-Bohy, Simon; Ngo, Sandrine; du Pont, Sylvain Courrech; Douady, Stphane

    2010-02-01

    Some desert sand dunes have the peculiar ability to emit a loud sound up to 110 dB, with a well-defined frequency: this phenomenon, known since early travelers (Darwin, Marco Polo, etc.), has been called the song of dunes. But only in late 19th century scientific observations were made, showing three important characteristics of singing dunes: first, not all dunes sing, but all the singing dunes are composed of dry and well-sorted sand; second, this sound occurs spontaneously during avalanches on a slip face; third this is not the only way to produce sound with this sand. More recent field observations have shown that during avalanches, the sound frequency does not depend on the dune size or shape, but on the grain diameter only, and scales as the square root of g/d--with g the gravity and d the diameter of the grains--explaining why all the singing dunes in the same vicinity sing at the same frequency. We have been able to reproduce these singing avalanches in laboratory on a hard plate, which made possible to study them more accurately than on the field. Signals of accelerometers at the flowing surface of the avalanche are compared to signals of microphones placed above, and it evidences a very strong vibration of the flowing layer at the same frequency as on the field, responsible for the emission of sound. Moreover, other characteristics of the booming dunes are reproduced and analyzed, such as a threshold under which no sound is produced, or beats in the sound that appears when the flow is too large. Finally, the size of the coherence zones emitting sound has been measured and discussed. PMID:19880153

  4. Ganges Rocks and Sand

    NASA Technical Reports Server (NTRS)

    2005-01-01

    17 January 2004 The top half of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows wind-eroded remnants of sedimentary rock outcrops in Ganges Chasma, one of the troughs of the Valles Marineris system. The lower half shows a thick accumulation of dark, windblown sand. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the upper left. These features are located near 7.6oS, 49.4oW.

  5. Sand dollar sites orogenesis

    NASA Astrophysics Data System (ADS)

    Amos, Dee

    2013-04-01

    The determinology of the humble sand dollars habitat changing from inception to the drastic evolution of the zone to that of present day. Into the cauldron along the southern Californian 'ring of fire' lithosphere are evidence of geosynclinals areas, metasedimentary rock formations and hydrothermal activity. The explanation begins with 'Theia' and the Moon's formation, battles with cometary impacts, glacial ages, epochs with evolutionary bottlenecks and plate tectonics. Fully illustrated the lecture includes localised diagrams and figures with actual subject photographic examples of plutonic, granitic, jade and peridodite. Finally, the origins of the materials used in the lecture are revealed for prosecution by future students and the enjoyment of interested parties in general.

  6. Fortune Cookie Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-432, 25 July 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small barchan sand dunes in the north polar region near 71.7oN, 51.3oW. Some of them are shaped like fortune cookies. The message these dunes provide: winds blow through this region from the lower right toward the upper left. The steep slip face slopes of these dunes, which point toward the upper left, indicate the wind direction. The scene is illuminated by sunlight from the upper right. The image is 3 km (1.9 mi) wide.

  7. Gullies and Sand

    NASA Technical Reports Server (NTRS)

    2004-01-01

    15 December 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies running down a slope on the side of a mesa in a pit in the south polar region of Mars. The dark material in this scene is windblown sand. These landforms are located near 70.9oS, 357.3oW. The image covers an area approximately 3 km (1.9 mi) wide and is illuminated by sunlight from the upper left.

  8. Sand Dunes in Hellas

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-537, 7 November 2003

    The smooth, rounded mounds in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture are sand dunes. The scene is located in southern Hellas Planitia and was acquired in mid-southern autumn, the ideal time of year for Hellas imaging. Sunlight illuminates the scene from the upper left. These dunes are located near 49.1oS, 292.6oW. The picture covers an area 3 km (1.9 mi) wide.

  9. Compressive behavior of fine sand.

    SciTech Connect

    Martin, Bradley E.; Kabir, Md. E.; Song, Bo; Chen, Wayne

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  10. Geology and resources of the Tar Sand Triangle, southeastern Utah

    NASA Astrophysics Data System (ADS)

    Dana, G. F.; Oliver, R. L.; Elliott, J. R.

    1984-05-01

    The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyolands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well sorted sandstone which was deposited in a shallow marine environment. The total in place resources, are 6.3 billion barrels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses is necessary before a more accurate determination of resources is attempted.

  11. White House

    MedlinePLUS

    ... White House events and statements as they happen Music & Arts Performances See the lineup of artists and ... News Share-Worthy Photos Video Gallery Live Events Music & Arts Performances From the Press Office Your Weekly ...

  12. Legged locomotion on sand

    NASA Astrophysics Data System (ADS)

    Li, Chen; Umbanhowar, Paul; Komsuoglu, Haldun; Koditschek, Daniel; Goldman, Daniel

    2009-11-01

    To understand how and why animals modulate foot kinematics to achieve effective locomotion on granular media, we study the speed of a six-legged robot with c-shaped legs, SandBot, moving on granular media for varying volume fraction, ?, limb frequency, f, and gait timing parameters.footnotetextLi et. al, PNAS, 106, 3029, 2009 Speed is determined by step length which in turn depends on limb penetration. At low f and high ? penetration is small, step length is large, and SandBot advances with a rotary walking gait in which c-legs rotate about their centers by slipping relative to stationary grains. In the opposite extreme, grains cannot support the robot; its underside always contacts the ground and it advances slowly via thrust generated as the c-legs translate through the grains. For varied gait parameters, high speeds are only observed in a small area of parameter space. A yield stress based model predicts the speed and reveals that performance is maximized when gait parameters minimize limb acceleration and interference, and limbs utilize the solidification properties of the media.

  13. Legged locomotion on sand

    NASA Astrophysics Data System (ADS)

    Li, Chen; Umbanhowar, Paul; Komsuoglu, Haldun; Koditschek, Daniel; Goldman, Daniel

    2009-11-01

    To understand how and why animals modulate foot kinematics to achieve effective locomotion on granular media, we study the speed of a six-legged robot with c-shaped legs, SandBot, moving on granular media for varying volume fraction, ?, limb frequency, f, and gait timing parametersfootnotetextLi et. al, PNAS, 106, 3029, 2009. Speed is determined by step length which in turn depends on limb penetration. At low f and high ? penetration is small, step length is large, and SandBot advances with a rotary walking gait in which c-legs rotate about their centers by slipping relative to stationary grains. In the opposite extreme, grains cannot support the robot; its underside always contacts the ground and it advances slowly via thrust generated as the c-legs translate through the grains. For varied gait parameters, high speeds are only observed in a small area of parameter space. A yield stress based model predicts the speed and reveals that performance is maximized when gait parameters minimize limb acceleration and interference, and limbs utilize the solidification properties of the media.

  14. Vanishing White Matter Disease

    MedlinePLUS

    ... Vanishing White Matter Disease What is Vanishing White Matter Disease? Vanishing White Matter Disease (VWM) is inherited ... about this). Other Clinical Names for Vanishing White Matter Disease Other clinical names of Vanishing White Matter ...

  15. A new class of gadolinium complexes employed to obtain high-phasing-power heavy-atom derivatives: results from SAD experiments with hen egg-white lysozyme and urate oxidase from Aspergillus flavus.

    PubMed

    Girard, E; Stelter, M; Anelli, P L; Vicat, J; Kahn, R

    2003-01-01

    Seven gadolinium complexes are shown to be excellent compounds for the preparation of heavy-atom derivatives for macromolecular crystallography projects. De novo phasing has been carried out using single-wavelength anomalous diffraction (SAD) on a series of gadolinium-derivative crystals of two proteins: hen egg-white lysozyme and urate oxidase from Aspergillus flavus. Lysozyme derivative crystals were obtained by co-crystallizing the protein with the corresponding gadolinium complex at a concentration of 100 mM. Diffraction data were collected to a resolution of 1.7 A using Cu K(alpha) radiation from a rotating-anode generator, making use of the high anomalous signal of gadolinium at this wavelength. Urate oxidase derivative crystals were obtained by soaking native crystals in 100 mM gadolinium complex solutions. Diffraction data were collected to a resolution close to 3 A using X-rays at the Gd L(III) absorption edge, taking advantage of the sharp white line on that edge. For all urate oxidase derivative crystals and three of the lysozyme crystals, SAD phasing led to electron-density maps of very high quality, allowing unambiguous chain tracing. From this study, the binding effectiveness of the gadolinium complexes seems to be related to the nature of the precipitant used for crystallization. These gadolinium complexes represent a new class of high-phasing-power heavy-atom derivatives that may be used for high-throughput structure-determination projects. PMID:12499547

  16. Science Learning in the Sand.

    ERIC Educational Resources Information Center

    Sexton, Ursula

    1997-01-01

    Presents activities that allow students to think about the Earth in a contextual manner and become familiar with constructive and destructive processes as they relate to sand - its origins, cyclical processes, and yielding of new products. Explores the bigger idea with a developmentally appropriate study of water, rocks, sand, physical phenomena,

  17. Sand and Dust on Mars

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Haberle, Robert M.

    1991-01-01

    Mars is a planet of high scientific interest. Various studies are currently being made that involve vehicles that have landed on Mars. Because Mars is known to experience frequent wind storms, mission planners and engineers require knowledge of the physical and chemical properties of Martian windblown sand and dust, and the processes involved in the origin and evolution of sand and dust storms.

  18. Science Learning in the Sand.

    ERIC Educational Resources Information Center

    Sexton, Ursula

    1997-01-01

    Presents activities that allow students to think about the Earth in a contextual manner and become familiar with constructive and destructive processes as they relate to sand - its origins, cyclical processes, and yielding of new products. Explores the bigger idea with a developmentally appropriate study of water, rocks, sand, physical phenomena,…

  19. Dark Sand Dunes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    18 March 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of low-albedo (i.e., dark) sand dunes in a crater in Noachis Terra. Dunes on Earth are usually light while those on Mars are usually dark. This contrast results from a difference in the mineral composition. Earth dunes often contain abundant quartz, which appears light, while martian dunes typically contain minerals and rock fragments abundant in iron- and magnesium-rich minerals, which are usually dark. This dune field is located near 41.7oS, 319.8oW. The steeper slopes on these dunes, known as slip faces, point toward the lower left (southwest), indicating the dominant winds come from the northeast (upper right). This picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  20. Sand and Water

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 7 November 2003

    This image shows a relatively small crater (35 km across) in the heavily cratered terrain of the southern highlands. At the midlatitudes, this area is known both for its water-formed gullies and its sand dunes. This crater shows spectacular examples of both. In fact, the gullies running down the northern edge of the crater made it to the cover of Science magazine on June 30, 2000. The large dark spot in the floor of the crater is sand that has accumulated into one large dune with a single curvilinear crest.

    Image information: VIS instrument. Latitude -54.9, Longitude 17.5 East (342.5 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Paleoenvironment and depositional environment of Miocene Olcese Sand, Bakersfield, California

    SciTech Connect

    Olson, H.C.

    1986-04-01

    The Olcese Sand near Bakersfield, California, contains evidence of a range of paleoenvironments including nonmarine, estuarine, and outer shelf depositional settings. Foraminifera from surface and subsurface samples place the Olcese in the Saucesian and Relizian of the California benthic stages. A pumice bed in the Olcese has been dated by fission track methods at 15.5 Ma. The Olcese Sand interfingers with the underlying Freeman Silt and the overlying Round Mountain Silt. In the type area, in Round Mountain oil field, the Olcese is 300-360 m thick. The Olcese is subdivided into three environmental facies. In the Knob Hill Quadrangle, the lower Olcese consists of (1) thinly bedded to blocky white tuffaceous silt and sand, or (2) planar cross-bedded fine to coarse-grained sand with pumice pebbles lining the bedding surfaces. Fossil mollusks and skate teeth indicate a shallow marine environment for the lower Olcese. Although the Olcese is predominantly a marine unit, the middle Olcese is nonmarine, with lenses of marine deposition. The middle Olcese is well exposed in the Knob Hill, Oil Center, and Rio Bravo Ranch Quadrangles, and is characterized by fine to coarse sand with occasional gravel lenses, strong cross-bedding, and a blue-gray color. The upper Olcese is a very fine to medium-grained, marine sand that fines upward into a sandy siltstone southward toward the Kern River. Foraminifera and mollusks from outcrops in the Rio Bravo Ranch Quadrangle indicate outer shelf to estuarine environments for the upper Olcese. The varying environments in the Olcese Sand reflect slight but frequent fluctuations in water depth and can be used to interpret the basin-margin history.

  2. White phosphorus

    Integrated Risk Information System (IRIS)

    White phosphorus ; CASRN 7723 - 14 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  3. White Tern

    USGS Multimedia Gallery

    The White Tern is one of eight seabird species whose population density and susceptibility to sea-level rise was studied on the French Frigate Shoals' Tern Island by biologists with the USGS Pacific Island Ecosystems Research Center's Northwestern Hawaiian Islands Climate Change Project.  ...

  4. White Nights.

    PubMed

    Shani, Michal

    2016-01-01

    "How can you sleep at night after you ruined my life?" Arthur, a veteran patient of mine, implored after receiving his test results. This essay recounts my experience as a physician in coping with an extremely anxious patient, its influence on me, and some of my reflections on the ensuing white nights. PMID:26755788

  5. Sand, Syrup and Supervolcanoes

    NASA Astrophysics Data System (ADS)

    Kennedy, B.; Jellinek, M.; Stix, J.

    2006-12-01

    Supervolcanic eruptions are amongst the most awesome events in the history of the Earth. A supervolcano can erupt thousands of cubic kilometers of ash devastating entire countries and changing the climate for decades. During the eruption, the magma chamber partially empties and collapses. As the chamber collapses at depth, a massive subsidence pit develops at the surface, called a caldera, some calderas can be the size of the entire San Francisco Bay Area. Fortunately, a supervolcano of this size has not erupted since the development of modern man. Due to the infrequency and massive scale of these eruptions, volcanologists do not yet fully understand how calderas form and how the eruption is affected by the roof collapse and vice versa. Therefore, simple analogue experiments are amongst the best ways to understand these eruptions. We present two of these experiments that can be fun, cheap, and helpful to high school and university instructors to demonstrate caldera formation. The first experiment illustrates how magma chamber roofs collapse to produce different style calderas, the second experiment demonstrates how the magma in the chamber affects the collapse style and magma mixing during a supervolcanic eruption. The collapse of a magma chamber can be demonstrated in a simple sandbox containing a buried balloon filled with air connected to a tube that leads out of the sandbox. At this small scale the buried balloon is a good analogue for a magma chamber and sand has an appropriate strength to represent the earths crust. Faults propagate through the sand in a similar way to faults propagating through the crust on a larger scale. To form a caldera just let the air erupt out of the balloon. This experiment can be used to investigate what controls the shape and structure of calderas. Different shaped balloons, and different burial depths all produce sand calderas with different sizes and structures. Additionally, experiments can be done that erupt only part of the volume of the balloon. These sandbox experiments can be compared to natural calderas and help us understand their internal structure. The second experiment helps us understand how magma behaves during collapse. For this experiment we allowed dense cylindrical blocks to sink into syrup solutions filled with poppy seeds. We mix the syrup with warm water to reduce its viscosity. A series of sinking experiments can be done at different viscosities to investigate different regimes of fluid flow. A key parameter used to the character of the flow of magma is the Reynolds number, the ratio between inertial and viscous forces. The experiments show how the Reynolds number of the magma affects the speed and the style that the block sinks, and also how the magma behaves in the chamber. Fast subsidence in low viscosity fluid (high Reynolds numbers) produces seed vortices in the syrup, indicating mixing. This experiment helps us understand the interplay between eruption and collapse and why mixed magma frequently erupts from calderas. These two simple experiments not only demonstrate caldera formation, but also can be used to get quantative information about the processes governing caldera formation.

  6. Nearshore oblique sand bars

    NASA Astrophysics Data System (ADS)

    Ribas, F.; FalquS, A.; Montoto, A.

    2003-04-01

    The coupling between hydrodynamics and the evolving topography in the surf zone has been theoretically examined for oblique wave incidence. It is shown that positive feedback can lead to the initial growth of several types of rhythmic systems of sand bars. The bars can be down-current oriented or up-current oriented, which means that the offshore end of the bar is shifted down-current or up-current with respect to the shore attachment. In the limit of strong current compared to wave orbital motion, very oblique down-current oriented b ars are obtained with a spacing of several times the surf zone width. When wave orbital motions are dominant, systems of up-current oriented bars and crescentic/down-current oriented bars appear with spacings of the order of the surf zone width. The latter feature consists of alternating shoals and troughs at both sides of the break line with the inner shoals being bar-shaped and oblique to the coast. The growth (e-folding) time of the bars ranges from a few hours to a few days and it is favored by constant wave conditions. The range of model parameters leading to growth corresponds to intermediate beach states in between the fully dissipative and the fully reflective situations. Preliminary comparison with field observations shows qualitative agreement.

  7. Sand transport, erosion and granular electrification

    NASA Astrophysics Data System (ADS)

    Merrison, J. P.

    2012-06-01

    The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate and impacting directly upon human health. Research in aeolian transport involves the inter-related fields of fluid dynamics, granular materials and electrification/electrostatics which are in themselves diverse and complex. This review only touches upon this intricacy, but aims to overview the latest work which is expanding our current understanding and outline the areas of advancement needed in the future. Presentation is made of current models for wind driven detachment/entrainment and the transport rates of sand and dust, including the effects of contact induced grain electrification. This ubiquitous phenomenon can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work has implications for the evolution of all terrestrial-like planetary surfaces. Studies in non-terrestrial environments force researchers to be less empirical, ultimately leading to a deeper understanding of these processes.

  8. Geology of the Athabasca oil sands

    SciTech Connect

    Mossop, G.D.

    1980-01-11

    In-place bitumen resources in the Alberta oil sands are estimated at 1350 billion barrels. Open-pit mining and hot water extraction methods, which involve the handling of huge tonnages of earth materials, are being employed in the two commercial plants now operating. In situ recovery methods will be required to tap the 90% of reserves that are too deeply buried to be surface mined. Development of in situ technologies will be painstaking and expensive, and success will hinge on their compatibility with extremely complex geological conditions in the subsurface. 10 figures.

  9. Ambivalent White Racial Identities: Fear and an Elusive Innocence

    ERIC Educational Resources Information Center

    Lensmire, Timothy J.

    2010-01-01

    This article examines the complex social production of white racial identity. Specifically, the author theorizes white people's fear of people of color and make a case for conceiving of white racial identities as profoundly ambivalent. Drawing from a larger ethnographic interview study conducted in a small, rural, white community in the Midwest of

  10. METHOD OF PROCESSING MONAZITE SAND

    DOEpatents

    Calkins, G.D.

    1957-10-29

    A method is given for the pretreatment of monazite sand with sodium hydroxide. When momazite sand is reacted with sodium hydroxide, the thorium, uranium, and rare earths are converted to water-insoluble hydrous oxides; but in the case of uranium, the precipitate compound may at least partly consist of a slightly soluble uranate. According to the patent, monazite sand is treated with an excess of aqueous sodium hydroxide solution, and the insoluble compounds of thorium, uranium, and the rare earths are separated from the aqueous solution. This solution is then concentrated causing sodium phosphate to crystallize out. The crystals are removed from the remaining solution, and the solution is recycled for reaction with a mew supply of momazite sand.

  11. Deceleration of Projectiles in Sand

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Cooper, William; Stone, Zach; Watanabe, Keiko; Peden, Robert; Air Force Research Labratory, Eglin AFB Collaboration; InstituteAdvanced Technology-UT Austin Collaboration; Department of Physics-UT Austin Collaboration; Osaka University Collaboration

    2011-06-01

    Deceleration of projectiles has been measured for hemispherical and conical nose shapes penetrating granular media. Targets were beds of Ottawa sand and Eglin sand. The velocity range extended up to 600 m/s. Projectiles were rigid metals. Deceleration was measured by conventional time-of-arrival screens plus several innovative techniques: embedded EM coils, embedded optical fibers, and a photonic Doppler velocimeter (PDV), which observed the rear surface of the penetrator. Experimental parameters that were varied included velocity (from 300 to 600 m/s), sand density, and scale (from 5 mm to 25 mm). In this paper we will compare these various measurement techniques and we will show how the cavity geometry (cavitation and crushed veins of sand) and retarding stress (MdV / dt) / A vary with velocity, scale, and density.

  12. Sand release apparatus and method

    SciTech Connect

    Hall, L.D.

    1991-05-28

    This patent describes a sand release apparatus for enabling the release of a pump. It comprises first and second telescoped tubular sleeves; a first restricting means; sleeve located drain opening means and means for enabling controlled separation of the pump from the apparatus at a specified joint. This patent also describes a method for releasing a pump determined to be sand locked. It comprises applying an upward force on the sucker rod string to break a shear pin restricting relative axial extension of telescoped sleeve members connected in the well below the pump; extending the telescoped sleeve members to expose drain openings to permit sand to flow away from the annular space; and disconnecting from the tubing string below the pump to pull the pump free of the sand locked condition.

  13. Advanced Techniques for Simulating the Behavior of Sand

    NASA Astrophysics Data System (ADS)

    Clothier, M.; Bailey, M.

    2009-12-01

    Computer graphics and visualization techniques continue to provide untapped research opportunities, particularly when working with earth science disciplines. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs we are developing new techniques for simulating sand. In addition, through collaboration with the Oregon Space Grant, we’ve been communicating with the Jet Propulsion Laboratory (JPL) to exchange ideas and gain feedback on our work. More specifically, JPL’s DARTS Laboratory specializes in planetary vehicle simulation, such as the Mars rovers. This simulation utilizes a virtual "sand box" to test how planetary rovers respond to different terrains while traversing them. Unfortunately, this simulation is unable to fully mimic the harsh, sandy environments of those found on Mars. Ideally, these simulations should allow a rover to interact with the sand beneath it, particularly for different sand granularities and densities. In particular, there may be situations where a rover may become stuck in sand due to lack of friction between the sand and wheels. In fact, in May 2009, the Spirit rover became stuck in the Martian sand and has provided additional motivation for this research. In order to develop a new sand simulation model, high performance computing will play a very important role in this work. More specifically, graphics processing units (GPUs) are useful due to their ability to run general purpose algorithms and ability to perform massively parallel computations. In prior research, simulating vast quantities of sand has been difficult to compute in real-time due to the computational complexity of many colliding particles. With the use of GPUs however, each particle collision will be parallelized, allowing for a dramatic performance increase. In addition, spatial partitioning will also provide a speed boost as this will help limit the number of particle collision calculations. However, since the goal of this research is to simulate the look and behavior of sand, this work will go beyond simple particle collision. In particular, we can continue to use our parallel algorithms not only on single particles but on particle “clumps” that consist of multiple combined particles. Since sand is typically not spherical in nature, these particle “clumps” help to simulate the coarse nature of sand. In a simulation environment, multiple combined particles could be used to simulate the polygonal and granular nature of sand grains. Thus, a diversity of sand particles can be generated. The interaction between these particles can then be parallelized using GPU hardware. As such, this research will investigate different graphics and physics techniques and determine the tradeoffs in performance and visual quality for sand simulation. An enhanced sand model through the use of high performance computing and GPUs has great potential to impact research for both earth and space scientists. Interaction with JPL has provided an opportunity for us to refine our simulation techniques that can ultimately be used for their vehicle simulator. As an added benefit of this work, advancements in simulating sand can also benefit scientists here on earth, especially in regard to understanding landslides and debris flows.

  14. Lipid, fatty acid and energy density profiles of white sharks: insights into the feeding ecology and ecophysiology of a complex top predator.

    PubMed

    Pethybridge, Heidi R; Parrish, Christopher C; Bruce, Barry D; Young, Jock W; Nichols, Peter D

    2014-01-01

    Lipids are major sources of metabolic energy in sharks and are closely linked to environmental conditions and biological cycles, such as those related to diet, reproduction and migration. In this study, we report for the first time, the total lipid content, lipid class composition and fatty acid profiles of muscle and liver tissue of white sharks, Carcharodon carcharias, of various lengths (1.5-3.9 m), sampled at two geographically separate areas off southern and eastern Australia. Muscle tissue was low in total lipid content (<0.9% wet mass, wm) and was dominated by phospholipids (>90% of total lipid) and polyunsaturated fatty acids (3412% of total fatty acids). In contrast, liver was high in total lipid which varied between 51-81% wm and was dominated by triacylglycerols (>93%) and monounsaturated fatty acids (3612%). With knowledge of total lipid and dry tissue mass, we estimated the energy density of muscle (18.40.1 kJ g-1 dm) and liver (34.13.2 kJ g-1 dm), demonstrating that white sharks have very high energetic requirements. High among-individual variation in these biochemical parameters and related trophic markers were observed, but were not related to any one biological or environmental factor. Signature fatty acid profiles suggest that white sharks over the size range examined are generalist predators with fish, elasmobranchs and mammalian blubber all contributing to the diet. The ecological applications and physiological influences of lipids in white sharks are discussed along with recommendations for future research, including the use of non-lethal sampling to examine the nutritional condition, energetics and dietary relationships among and between individuals. Such knowledge is fundamental to better understand the implications of environmental perturbations on this iconic and threatened species. PMID:24871223

  15. Lipid, Fatty Acid and Energy Density Profiles of White Sharks: Insights into the Feeding Ecology and Ecophysiology of a Complex Top Predator

    PubMed Central

    Pethybridge, Heidi R.; Parrish, Christopher C.; Bruce, Barry D.; Young, Jock W.; Nichols, Peter D.

    2014-01-01

    Lipids are major sources of metabolic energy in sharks and are closely linked to environmental conditions and biological cycles, such as those related to diet, reproduction and migration. In this study, we report for the first time, the total lipid content, lipid class composition and fatty acid profiles of muscle and liver tissue of white sharks, Carcharodon carcharias, of various lengths (1.5–3.9 m), sampled at two geographically separate areas off southern and eastern Australia. Muscle tissue was low in total lipid content (<0.9% wet mass, wm) and was dominated by phospholipids (>90% of total lipid) and polyunsaturated fatty acids (34±12% of total fatty acids). In contrast, liver was high in total lipid which varied between 51–81% wm and was dominated by triacylglycerols (>93%) and monounsaturated fatty acids (36±12%). With knowledge of total lipid and dry tissue mass, we estimated the energy density of muscle (18.4±0.1 kJ g−1 dm) and liver (34.1±3.2 kJ g−1 dm), demonstrating that white sharks have very high energetic requirements. High among-individual variation in these biochemical parameters and related trophic markers were observed, but were not related to any one biological or environmental factor. Signature fatty acid profiles suggest that white sharks over the size range examined are generalist predators with fish, elasmobranchs and mammalian blubber all contributing to the diet. The ecological applications and physiological influences of lipids in white sharks are discussed along with recommendations for future research, including the use of non-lethal sampling to examine the nutritional condition, energetics and dietary relationships among and between individuals. Such knowledge is fundamental to better understand the implications of environmental perturbations on this iconic and threatened species. PMID:24871223

  16. Sand transport over an immobile gravel substrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted in a laboratory flume channel to evaluate the effects of increasing amounts of sand with an immobile gravel fraction on the sand transport rate and configuration of the sand bed. Knowledge of the movement of sand in gravel beds is important for the management of streams a...

  17. Photodegradation of chlorinated pesticides dispersed on sand.

    PubMed

    Zertal, Abdennour; Jacquet, Michel; Lavdrine, Bernadette; Sehili, Tahar

    2005-03-01

    The photochemical behaviour of several chlorinated pesticides, namely 4-chloro-2-methylphenoxyacetic acid (MCPA), dichlorophen (DCPH), flamprop-methyl (FPM) and vinclozolin (VCZ) is studied on various kinds of sand: Fontainebleau sand (almost pure silica), Touggourt sand (coloured sand from Sahara) and Jijel sand (dark marine sand). The photodegradation of MCPA is more rapid on Fontainebleau sand than on the two others, because the former is almost colourless pure silica and the others adsorb on the internal surface of the reactor. The degradation rate decreases in the order MCPA, DCPH, FPM, VCZ. The main products identified are 4-chloro-2-methylphenol with MCPA and reduction product with DCPH. PMID:15686762

  18. Nematodes Infect, But Do Not Manipulate Digging By, Sand Crabs, Lepidopa benedicti

    PubMed Central

    Joseph, Meera; Faulkes, Zen

    2014-01-01

    We examined sand crabs (Lepidopa benedicti) for endoparasites, and found the only parasite consistently infecting the studied population were small nematodes. Because many nematodes have complex life cycles involving multiple hosts, often strongly manipulating their hosts, we hypothesized that nematodes alter the behavior of their sand crab hosts. We predicted that more heavily infected crabs would spend more time above sand than less heavily infected crabs. Our data indicate infection by nematodes was not correlated with duration of time crabs spent above sand. We also suggest that organisms living in sandy beaches may benefit from relatively low parasite loads due to the low diversity of species in the habitat. PMID:24916475

  19. Pt(II) metal complexes tailored with a newly designed spiro-arranged tetradentate ligand; harnessing of charge-transfer phosphorescence and fabrication of sky blue and white OLEDs.

    PubMed

    Liao, Kuan-Yu; Hsu, Che-Wei; Chi, Yun; Hsu, Ming-Kuan; Wu, Szu-Wei; Chang, Chih-Hao; Liu, Shih-Hung; Lee, Gene-Hsiang; Chou, Pi-Tai; Hu, Yue; Robertson, Neil

    2015-04-20

    Tetradentate bis(pyridyl azolate) chelates are assembled by connecting two bidentate 3-trifluoromethyl-5-(2-pyridyl)azoles at the six position of pyridyl fragment with the tailored spiro-arranged fluorene and/or acridine functionalities. These new chelates were then utilized in synthesizing a series of Pt(II) metal complexes [Pt(Ln)], n = 1-5, from respective chelates L1-L5 and [PtCl2(DMSO)2] in 1,2-dimethoxyethane. The single-crystal X-ray structural analyses were executed on 1, 3, and 5 to reveal the generalized structures and packing arrangement in crystal lattices. Their photophysical properties were measured in both solution and solid state and are discussed in the context of computational analysis. These L1-L5 coordinated Pt(II) species exhibit intense emission, among which complex 5 shows remarkable solvatochromic phosphorescence due to the dominant intraligand charge transfer transition induced by the new bis(pyridyl azolate) chelates. Moreover, because of the higher-lying highest occupied molecular orbital of acridine, complex 5 can be considered as a novel bipolar phosphor. Successful fabrication of blue and white organic light-emitting diodes (OLEDs) using Pt(II) complexes 3 and 5 as the phosphorescent dopants are reported. In particular, blue OLEDs with 5 demonstrated peak efficiencies of 15.3% (36.3 cd/A, 38.0 lm/W), and CIE values of (0.190, 0.342) in a double-emitting layer structure. Furthermore, a red-emitting Os(II) complex and 5 were used to fabricate warm-white OLEDs to achieve peak external quantum efficiency, luminance efficiency, and power efficiency values as high as 12.7%, 22.5 cd/A, and 22.1 lm/W, respectively. PMID:25848710

  20. Rapid formation of large coastal sand bodies after emplacement of Magdalena river jetties, northern Colombia

    NASA Astrophysics Data System (ADS)

    Martinez, J. O.; Pilkey, O. H.; Neal, W. J.

    1990-11-01

    The Magdalena River is noted for its high discharge of river sediment and its importance as the sediment source for a large delta complex and downdrift coastal sand bodies. The emplacement of jetties, completed in 1935 to stabilize the river mouth, contributed to major changes in the downstream coastal sand bodies. The western delta front retreated an average 65 m/yr. Puerto Colombia spit detached and migrated toward Puerto Colombia at rates of 230 430 m/yr, ultimately running into the town's quay and port facility. Galerazamba spit alternately elongated and shortened over the short term, leading to the destruction or damage of coastal town sites. Isla Cascajo acted as a significant sand trap with nearly 12 km2 of accretion over a 47-year period. Sand is now bypassing the tombolo, and the accretion zone continues migrating southwest. The small Punta Canaos spit also has shown significant accretion since 1974. The changes imply high rates of sediment transport; furthermore their growth is probably dependent on jetty-caused alterations of wave patterns, causing remobilization of shelf sands as well as delta-derived sand. Understanding sand body evolution and behavior is important to future development of the northern Colombia coast. Placement of port facilities, recreational beaches, tourist villages, and related support facilities on these sand bodies, as well as utilizing the sand bodies for aggregate, beach nourishment sands for other areas, or heavy mineral resources will require significant planning.

  1. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    NASA Astrophysics Data System (ADS)

    Hovad, E.; Larsen, P.; Walther, J. H.; Thorborg, J.; Hattel, J. H.

    2015-06-01

    The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry to emulate some of these important conditions found in the real moulding process. The sand flow is simulated with the DEM and compared with corresponding video footages from the interior of the chamber during the moulding process. The effect of the rolling resistance and the static friction coefficient is analysed and discussed in relation to the experimental findings.

  2. Physical modelling of sand injectites

    NASA Astrophysics Data System (ADS)

    Rodrigues, N.; Cobbold, P. R.; Løseth, H.

    2009-09-01

    Sand injectites are structures that result from intrusion of fluidized sand into fractures. We have studied them in the Tampen Spur area of the North Sea, and have reproduced them experimentally, by driving compressed air through layers of sand, glass microspheres, and silica powder. The silica powder was cohesive and capable of hydraulic fracturing, whereas the sand and glass microspheres were almost non-cohesive and therefore able to fluidize. The models were dynamically similar to their natural counterparts, for as long as equilibrium was static. When the processes became dynamic, so that inertial forces were significant, the scaling was approximate and the corresponding Reynolds numbers differed. The experimental apparatus was a square box, 1 m × 1 m wide, resting on a grid of fluid diffusers. During the experiments, the fluid pressure increased, until it attained and surpassed the weight of overburden. Flat-lying hydraulic fractures, containing air, formed within cohesive and least permeable layers. Heterogeneities in material properties and layer thicknesses were responsible for localizing fracture networks. When any one network broke through to the surface, rapid flow of air through the fractures fluidized the underlying mobile materials and even depleted some of the layers. Some of the fluidized material extruded at the surface through vents, forming volcanoes and sheets. The remainder lodged at depth, forming sand injectites or laccoliths. Conical sand injectites formed preferentially, where layers had high resistance to bending. Laccoliths formed nearer the surface, where overlying layers had low resistance to bending. The experimental sand injectites were broadly similar to those in the Tampen Spur area of the North Sea, as well as other areas.

  3. Windblown Sand in West Candor

    NASA Technical Reports Server (NTRS)

    2004-01-01

    23 December 2003

    West Candor Chasma, a part of the vast Valles Marineris trough system, is known for its layered sedimentary rock outcrops. It is less known for dark fields of windblown sand, but that is what occurs in the north-central part of the chasm. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, obtained in December 2003, shows the interplay of dark, wind-blown sand with buttes and mesas of layered rock in west Candor Chasma. Dark streamers of sand point toward the east/southeast (right/lower right), indicating that dominant winds blow from the west. This picture is located near 5.2oS, 75.7oW, and covers an area 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  4. Sands at Gusev Crater, Mars

    NASA Astrophysics Data System (ADS)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth; Knoll, Andrew H.; Farmer, Jack; Arvidson, Raymond; Grin, Edmond; Li, Ronxing; Fenton, Lori; Cohen, Barbara; Bell, James F.; Aileen Yingst, R.

    2014-05-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  5. Computed tomography investigation of microgravity-tested sand samples

    NASA Astrophysics Data System (ADS)

    Batiste, Susan N.; Alshibli, Khalid A.; Lankton, Mark R.; Sture, Stein; Swanson, Roy A.; Costes, Nicholas C.

    2001-07-01

    Computed Tomography (CT) is being used to investigate the complex internal structure of axisymmetric (triaxial) sand specimens. A series of triaxial experiments was conducted on dry Ottawa sand specimens at very low effective confining stresses in a microgravity environment aboard the Space Shuttle during two missions. Post-flight analysis includes studying the internal fabric and failure patterns using CT. In addition ground-tested specimens subjected to different compression levels are scanned to investigate the evolution of instability patterns, quantify void ratio variation, and provide a direct comparison with microgravity specimens. For an upcoming Shuttle mission, trial specimens are scanned to investigate an experimental reforming method for flight and evaluate techniques for reconstituting specimens. The CT technique demonstrates good ability to detect specimen inhomogeneities and localization patterns, and quantify void ratio variation within sand specimens.

  6. The binding of platinum hexahalides (Cl, Br and I) to hen egg-white lysozyme and the chemical transformation of the PtI{sub 6} octahedral complex to a PtI{sub 3} moiety bound to His15

    SciTech Connect

    Tanley, Simon W. M.; Starkey, Laurina-Victoria; Lamplough, Lucinda; Kaenket, Surasek; Helliwell, John R.

    2014-08-29

    The platinum hexahalides have an octahedral arrangement of six halogen atoms bound to a Pt centre, thus having an octahedral shape that could prove to be useful in interpreting poor electron-density maps. In a detailed characterization, PtI{sub 6} chemically transformed to a square-planar PtI{sub 3} complex bound to the N{sup ?} atom of His15 of HEWL was also observed, which was not observed for PtBr{sub 6} or PtCl{sub 6}. This study examines the binding and chemical stability of the platinum hexahalides K{sub 2}PtCl{sub 6}, K{sub 2}PtBr{sub 6} and K{sub 2}PtI{sub 6} when soaked into pre-grown hen egg-white lysozyme (HEWL) crystals as the protein host. Direct comparison of the iodo complex with the chloro and bromo complexes shows that the iodo complex is partly chemically transformed to a square-planar PtI{sub 3} complex bound to the N{sup ?} atom of His15, a chemical behaviour that is not exhibited by the chloro or bromo complexes. Each complex does, however, bind to HEWL in its octahedral form either at one site (PtI{sub 6}) or at two sites (PtBr{sub 6} and PtCl{sub 6}). As heavy-atom derivatives of a protein, the octahedral shape of the hexahalides could be helpful in cases of difficult-to-interpret electron-density maps as they would be recognisable objects.

  7. Happy Birthday White House!

    ERIC Educational Resources Information Center

    Dillon, Doris; And Others

    1992-01-01

    An integrated elementary teaching package offers interesting facts about presidents and the White House. Cross-curricular activities focus on architecture, presidential birthplaces, portraits, communications, science, technology, touring the White House, children in the White House, a day in the life of the White House, and a White House birthday

  8. Internal geometry of sand waves: a comparison between modern and fossil examples

    SciTech Connect

    Berne, S.; Homewood, P.

    1988-08-01

    Recent developments in acquiring and processing very high-resolution geophysical data help us better understand large subtidal sand waves of the French continental shelf. They are compared with ancient analogs, especially from the Miocene Swiss Molasse. Internal structure, interpreted from seismic sections, vibracorings, and large outcrops, shows a hierarchy comparable to aeolian dunes. (1) Steep (25/degree/-30/degree/) reflectors, dipping leeward, are interpreted as foreset beds. Vibracoring shows that in modern cases they consist of alternating layers of medium- and coarse-grained sand, similar to those produced by sand avalanching. These deposits give the highest porosity values in the central body of the sand wave. They are comparable to the Miocene sand waves of the Swiss Molasse. (2) Erosional reflectors, dipping at lower angles cut across the foresets, are interpreted as reactivation surfaces created by high-energy events (equinox tides, added tidal and wave effects) rather than by the semidiurnal currents occasionally preserved in fossil sand waves. (3) Subhorizontal reflectors were probably created by truncation of sand waves during major storms. Fossil analogs more like larger present-day sand waves might be difficult to recognize due to the complex internal architecture of the sand body.

  9. Registration of 'Centennial' Sand Bluestem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Centennial’ sand bluestem (PI 670042, Andropogon hallii Hack.) is a synthetic variety selected for greater percentage seed germination and percentage seedling establishment under field conditions. Centennial was tested under the experimental designation of ‘AB-Medium Syn-2’. Two cycles of recurren...

  10. Geology on a Sand Budget

    ERIC Educational Resources Information Center

    Kane, Jacqueline

    2004-01-01

    Earth science teachers know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, to use the models for only a few class periods. To avoid emptying an already limited science budget, the author states that teachers can use a simple alternative to the expensive 3-D models--sand. She

  11. Sand and Water Table Play

    ERIC Educational Resources Information Center

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical

  12. Modern analog for deep-water deposition of shallow-water Pliocene Sands, Gulf of Mexico

    SciTech Connect

    Kohl, B.

    1985-02-01

    Paleoenvironmental studies using benthic foraminifers and total fauna can be used to identify displaced shallow-water sands. A productive sand in Eugene Island field, which has a high resistivity but suppressed spontaneous-potential, was conventionally cored to determine reservoir characteristics and environment of deposition. Grain-size analysis shows a composition of very fine sand with a large silt and clay component. Studies of sand-size distribution throughout the 13-ft core did not reveal graded bedding, thus excluding turbidity currents as a depositional mechanism. Analysis of the benthic fauna within the sand unit indicates that the sands and thin-bedded shales were originally deposited on the inner to middle shelf. The occurrence of bathyal shale above and below the productive unit suggests that the shallow-water sands were transported basinward into a slope environment. Regional paleobathymetric maps indicate that there was a progradation of the shelf edge during deposition of the sand unit. This evidence, along with the fine-grained character of the sands, suggests that a deltaic complex was developing updip of the field. The depositional environment is very similar to that described by J.M. Coleman and others near the modern Mississippi River Delta. The processes that are moving shallow-water sands across the shelf, stimulating mass movement and shelf-ridge slumping, were also active around ancient deltas. Based on the modern analog, it is interpreted that the field sand is part of a debris flow initiated by shelf-edge failure. The geometry of the sand unit also supports this hypothesis.

  13. Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development

    SciTech Connect

    Ruple, John; Keiter, Robert

    2010-12-31

    Oil shale and oil sands resources located within the intermountain west represent a vast, and as of yet, commercially untapped source of energy. Development will require water, and demand for scarce water resources stands at the front of a long list of barriers to commercialization. Water requirements and the consequences of commercial development will depend on the number, size, and location of facilities, as well as the technologies employed to develop these unconventional fuels. While the details remain unclear, the implication is not – unconventional fuel development will increase demand for water in an arid region where demand for water often exceeds supply. Water demands in excess of supplies have long been the norm in the west, and for more than a century water has been apportioned on a first-come, first-served basis. Unconventional fuel developers who have not already secured water rights stand at the back of a long line and will need to obtain water from willing water purveyors. However, uncertainty regarding the nature and extent of some senior water claims combine with indeterminate interstate river management to cast a cloud over water resource allocation and management. Quantitative and qualitative water requirements associated with Endangered Species protection also stand as barriers to significant water development, and complex water quality regulations will apply to unconventional fuel development. Legal and political decisions can give shape to an indeterminate landscape. Settlement of Northern Ute reserved rights claims would help clarify the worth of existing water rights and viability of alternative sources of supply. Interstate apportionment of the White River would go a long way towards resolving water availability in downstream Utah. And energy policy clarification will help determine the role oil shale and oil sands will play in our nation’s future.

  14. Treating tar sands formations with karsted zones

    SciTech Connect

    Vinegar, Harold J.; Karanikas, John Michael

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  15. Sand Dome on a Steam Engine

    USGS Multimedia Gallery

    Steam engines used high-grade silica sand for traction on the rails. Sand was stored in a dome on top of the engine and, as the train traveled the tracks, the sand would be sprinkled down pipes to land on the tracks in front of the wheels. This would aid the wheels in gripping the tracks, especially...

  16. Dravo tar sand extraction process and its applicability to Kentucky tar sand

    SciTech Connect

    Benson, L.B.; Tis, D.J.

    1985-02-01

    A process for solvent extraction of oil from tar sands has been developed. The process concept has been successfully tested on Kentucky tar sand in a pilot plant capable of processing 200 tons per day of tar sand. The Dravo process is described. Some of the elements which distinguish it from other solvent extraction processes for tar sand are detailed.

  17. The Permian Weissliegend of NW Europe: The partial deformation of aeolian dune sands caused by the Zechstein transgression

    NASA Astrophysics Data System (ADS)

    Glennie, K. W.; Buller, A. T.

    1983-05-01

    The Weissliegend is a European sandstone unit of largely late Early Permian age. It is underlain by the Early Permian Rotliegend red desert sandstones and is overlain by the conventionally accepted basal bed of the Zechstein-the bituminous marine shales of the Kupferschiefer. The Weissliegend sandstones are characteristically white or grey in colour and have been recognised beneath the North Sea, in Germany and in Poland. Equivalents, which are red or yellow in colour, occur in NE England and at the southern edge of the Moray Firth Basin in Scotland. From an examination of cliff and quarry exposures in Britain, and of drill cores from southern North Sea gas wells, it is now believed that the bulk of the Weissliegend sandstones (and their equivalents) were originally deposited as aeolian dunes. These dune sands, however, were later modified by a widespread event, the Zechstein transgression, which caused their partial homogenisation, the creation of large-scale soft-sediment deformation structures, and the local and minor reworking of some of the dune flanks. The preferred mechanism of deformation is interpreted as: (1) entrapment of large pockets of air within the bodies of the dunes by flanking and overlying wetted dune sands; (2) venting of the air pockets when the rising internal air pressures overcame the weight of the hydrostatic head of water and the capillary (cohesive) strength of the overlying wetted sands; (3) the rapid replacement of air by water, which caused liquidisation of the original dune laminae; and (4) the associated collapse and final consolidation of the sands into a tigher packing configuration. Deformations seem to be more developed in former transverse dunes than in seif dunes. The reason may be that the relatively tightly packed low-angle accretion bedding common on the flanks of seif dunes is more resistant to deformation than the looser avalanche sands that form a major part of transverse dunes. Limited reworking of former dune sands was probably best developed on the steep lee slopes of transverse dunes and the steeper upper slopes of seif dunes. The lack of reddening of the Weissliegend sandstones-proper is attributed to a combination of their accumulation above the Rotliegend water table, to the rapidity of the Zechstein transgression, and to the anoxic state of the early Zechstein sea floor. The Weissliegend sands, unlike the underlying Rotliegend into which they grade, were thus never in a diagenetic environment that was conducive to reddening. Finally, it is recommended that the term Weissliegend be dropped in any formational sense. It should only be retained for the Weissliegend proper, and their equivalents, to denote a complex facies association dominated by (1) the uppermost Early Permian Rotliegend dune sands (now partly deformed) that lay above the water table just prior to the Zechstein transgression, together with (2) the minor erosional marine products caused by that transgression. The latter, sensu stricto, are Zechstein sandstones of earliest Late Permian age.

  18. SLOW SAND FILTRATION: INFLUENCES OF SELECTED PROCESS VARIABLES

    EPA Science Inventory

    Biological activity within the sand bed had the strongest influence on removal efficiency of total coliform bacteria by slow sand filtration, as determined by six pilot filters. Temperature, sand bed depth, and sand size also had a strong influecee.

  19. Australian Red Dune Sand: A Potential Martian Regolith Analog

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Marshall, J.; Evans, N. D.; Luttge, A.

    2001-01-01

    To demonstrate the potential scientific and technical merits of in situ microscopy on Mars, we analyzed a possible Martian regolith analog - an acolian red dune sand from the central Australian desert (near Mt. Olga). This sand was chosen for its ubiquitous red coating and the desert environment in which is it found. Grains of this sand were analyzed using a variety of microanalytical techniques. A database of detailed studies of such terrestrial analogs would assist the study of geological and astrobiological specimens in future missions to Mars. Potential instrument concepts for in situ deployment on Mars include local electrode atom probe nanoanalysis (LEAP), vertical scanning white light interferometry (VSWLI), scanning electron microscopies, energy dispersive x-ray microanalysis (EDX), atomic force microscopy (AFM) and X-ray diffraction (XRD). While in situ deployment of these techniques is many years away, ground-based studies using these analytical techniques extend our understanding of the data obtained from instruments to be flown in the near future.

  20. Geology and resources of the Tar Sand Triangle, southeastern Utah

    SciTech Connect

    Dana, G.F.; Oliver, R.L.; Elliott, J.R.

    1984-05-01

    The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyonlands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well-sorted sandstone which was deposited in a shallow marine environment. Resources were calculated from analytical data from the three coreholes drilled by the Laramie Energy Technology Center and other available data. The total in-place resources, determined from this study, are 6.3 billion barels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses will be necessary before a more accurate determination of resources can be attempted. 8 references, 11 figures, 7 tables.

  1. Proppant selection for fracturing and sand control

    SciTech Connect

    Sparlin, D.D.; Hagen, R.W. Jr. )

    1995-01-01

    Starting with definitions of gravel, sand and proppants, this article proceeds to discuss the basic design dilemma of selecting proppant size to achieve the optimum permeability of larger particles vs. higher strength and sand screening ability of smaller sizes. Equations for preventing sand invasion by velocity control are introduced and tables of data give engineers actual design information; tips on table use are included. Hydraulic frac/gravel pack treatments are accepted means of obtaining high well productivity and sand control. A one-step, tip-screenout efficiently creates a short fracture through near-wellbore formation damage and packs the screen/casing annulus to prevent sand production.

  2. Induced polarization of clay-sand mixtures. Experiments and modelling.

    NASA Astrophysics Data System (ADS)

    Okay, G.; Leroy, P.

    2012-04-01

    The complex conductivity of saturated unconsolidated sand-clay mixtures was experimentally investigated using two types of clay minerals, kaolinite and smectite (mainly Na-Montmorillonite) in the frequency range 1.4 mHz - 12 kHz. The experiments were performed with various clay contents (1, 5, 20, and 100 % in volume of the sand-clay mixture) and salinities (distilled water, 0.1 g/L, 1 g/L, and 10 g/L NaCl solution). Induced polarization measurements were performed with a cylindrical four-electrode sample-holder associated with a SIP-Fuchs II impedance meter and non-polarizing Cu/CuSO4 electrodes. The results illustrate the strong impact of the CEC of the clay minerals upon the complex conductivity. The quadrature conductivity increases steadily with the clay content. We observe that the dependence on frequency of the quadrature conductivity of sand-kaolinite mixtures is more important than for sand-bentonite mixtures. For both types of clay, the quadrature conductivity seems to be fairly independent on the pore fluid salinity except at very low clay contents. The experimental data show good agreement with predicted values given by our SIP model. This complex conductivity model considers the electrochemical polarization of the Stern layer coating the clay particles and the Maxwell-Wagner polarization. We use the differential effective medium theory to calculate the complex conductivity of the porous medium constituted of the grains and the electrolyte. The SIP model includes also the effect of the grain size distribution upon the complex conductivity spectra.

  3. Thermal Properties of oil sand

    NASA Astrophysics Data System (ADS)

    LEE, Y.; Lee, H.; Kwon, Y.; Kim, J.

    2013-12-01

    Thermal recovery methods such as Cyclic Steam Injection or Steam Assisted Gravity Drainage (SAGD) are the effective methods for producing heavy oil or bitumen. In any thermal recovery methods, thermal properties (e.g., thermal conductivity, thermal diffusivity, and volumetric heat capacity) are closely related to the formation and expansion of steam chamber within a reservoir, which is key factors to control efficiency of thermal recovery. However, thermal properties of heavy oil or bitumen have not been well-studied despite their importance in thermal recovery methods. We measured thermal conductivity, thermal diffusivity, and volumetric heat capacity of 43 oil sand samples from Athabasca, Canada, using a transient thermal property measurement instrument. Thermal conductivity of 43 oil sand samples varies from 0.74 W/mK to 1.57 W/mK with the mean thermal conductivity of 1.09 W/mK. The mean thermal diffusivity is 5.710-7 m2/s with the minimum value of 4.210-7 m2/s and the maximum value of 8.010-7 m2/s. Volumetric heat capacity varies from 1.5106 J/m3K to 2.11106 J/m3K with the mean volumetric heat capacity of 1.91106 J/m3K. In addition, physical and chemical properties (e.g., bitumen content, electric resistivity, porosity, gamma ray and so on) of oil sand samples have been measured by geophysical logging and in the laboratory. We are now proceeding to investigate the relationship between thermal properties and physical/chemical properties of oil sand.

  4. Offshore sand and gravel mining

    SciTech Connect

    Pandan, J.W.

    1983-05-01

    This paper reviews the status of mining offshore for sand and gravel on a world-wide basis. It discusses the technology for exploration and evaluation of sea floor mineral targets, as well as mining, transportation, and processing. Large operations in Japan and Europe are described, based upon personal observations of the author. The U.S. situation is outlined and opinions offered as to the outlook for the future.

  5. Drag Reduction using Superhydrophobic Sanded Teflon

    NASA Astrophysics Data System (ADS)

    Song, Dong; Daniello, Robert; Rothstein, Jonathan

    2013-11-01

    In this talk, we present a series of microfluidic experiments designed to investigate drag reduction using series of roughened Teflon surfaces. The Teflon surfaces where made superhydrophobic by imparting surface texture through sanding with sand papers with a range of grit sizes. Our previous work showed that there exists an optimal sand paper grit (240 grit) for eliminating contact angle hysteresis. We will show that a Teflon surface roughened with the same sand paper grit also maximizes the drag reduction and the slip length observed in laminar flows. Increasing or decreasing the grit size was found to reduce the drag reduction and slip length. A number of different sanding protocols were investigated including sanding preferentially in the flow direction, normal to the flow direction and with a randomized circular pattern. Of these three techniques, sanding in the flow direction was found to maximize the slip length.

  6. High-temperature sand consolidation

    SciTech Connect

    Friedman, R.H.; Suries, B.W.; Kleke, D.E.

    1987-05-01

    A sand consolidation system has been developed that is stable to wellbore temperatures of 700/sup 0/F (371/sup 0/C). Two improvements in technique have contributed to this development. First, a controlled quantity of catalyst is absorbed on the sand. Consequently, consolidation occurs only on or very near the sand grains, resulting in a high-permeability consolidation. Second, the reaction is driven to completion by avoiding, insofar as possible, the adverse effect of water. The resin used for the consolidation is a very viscous derivative of furfuryl alcohol that requires a diluent to make it injectable. The diulent used to reduce viscosity is a hydrolyzable ester. The diluted fluid, which is sill more viscous than water, displaces much of the water present in the pore space. During the catalyzed consolidation, water produced by the polymerization is removed by reaction with the diluent (hydrolysis of the ester). The high-molecular-weight polymeric consolidation is better able to resist the high temperatures encountered in steam-displacement producing wells. Adaptation of the technology has been made so that the process can also be used in low-temperature wells. Because of the catalysis method, long shelf life is guaranteed for the consolidating formation.

  7. Pyrophosphate complexation of tin(II) in aqueous solutions as applied in electrolytes for the deposition of tin and tin alloys such as white bronze.

    PubMed

    Buchner, Magnus R; Kraus, Florian; Schmidbaur, Hubert

    2012-08-20

    Electrodeposition of tin and tin alloys from electrolytes containing tin(II) and pyrophosphates is an important process in metal finishing, but the nature of the tin pyrophosphate complexes present in these solutions in various pH regions has remained unknown. Through solubility and pH studies, IR and (31)P and (119)Sn NMR spectroscopic investigations of solutions obtained by dissolving Sn(2)P(2)O(7) in equimolar quantities of either Na(4)P(2)O(7)10H(2)O or K(4)P(2)O(7) the formation of anionic 1:1 complexes {[Sn(P(2)O(7))]}(n)(2n-) has now been verified and the molecular structures of the monomer (n = 1) and the dimer (n = 2) have been calculated by density functional theory (DFT) methods. Whereas the alkali pyrophosphates Na/K(4)P(2)O(7) give strongly alkaline aqueous solutions (pH ?13), because of partial protonation of the [P(2)O(7)](4-) anion, the [Sn(P(2)O(7))](2-) anion is not protonated and the solutions of Na/K(2)[Sn(P(2)O(7))] are almost neutral (pH ?8). The monomeric dianion appears to have a ground state with C(2v) symmetry with the Sn atom in a square pyramidal coordination and the lone pair of electrons in the apical position, while the dimer approaches C(2) symmetry with the Sn atoms in a rhombic pyramidal coordination, also with a sterically active lone pair. A comparison of experimental and calculated IR details favors the monomer as the most abundant species in solution. With an excess of pyrophosphate, 3:2 and 2:1 complexes (P(2)O(7)):(Sn) are first formed, which, in the presence of more pyrophosphate, undergo rapid ligand exchange on the NMR time scale. The structure of the 2:1 complex [Sn(P(2)O(7))(2)](6-) was calculated to have a pyramidal complexation by two 1,5-chelating pyrophosphate ligands. Neutralization of these alkaline solutions by sulfuric or sulfonic acids (H(2)SO(4), MeSO(3)H), as also practiced in electroplating, appears to afford the tin(II) hydrogen pyrophosphates [Sn(P(2)O(7)H)](-) and [Sn(H(2)P(2)O(7))](0). The molecular structures of the mononuclear model units have also been calculated and were shown to have an unsymmetrical complexation and to feature trigonal pyramidal (pseudotetrahedral) coordination. NMR observations have shown that, contrary to the results obtained for Sn(II) compounds, Sn(IV) as present in K(2)SnO(3) or its hydrated form (K(2)Sn(OH)(6)) does not form a pyrophosphate complex in aqueous solution near pH 7. There is also no interference of sulfite. PMID:22857614

  8. A Rebuttal to Jack Niemonen's "Whither the White Working Class?"

    ERIC Educational Resources Information Center

    Khanna, Nikki; Harris, Cherise A.

    2015-01-01

    Prof. Niemonen claims that the concept of white privilege is "anti-sociological" and "mask[s] complex race-class interactions." He highlights the importance of including social class in discussions of white privilege but focuses exclusively on the white working class, neglecting how race and social class also intersect for

  9. Documentation of Recent Surface Winds on Martian Sand Dunes

    NASA Astrophysics Data System (ADS)

    Zimbelman, J. R.; Johnson, M. B.

    2013-12-01

    Images from the High Resolution Imaging Science Experiment (HiRISE) are of sufficient resolution to record wind ripple patterns on the surfaces of sand dunes present across the surface of Mars. We are in the early stages of an investigation to map the ripple orientations preserved on Martian sand dunes, in order to evaluate the recent wind flow over the dunes, and compare that wind flow pattern to the winds documented over terrestrial sand dunes. HiRISE image ESP_025645_1455 covers a sand dune field on the floor of a 20-km-diameter unnamed impact crater in the Terra Cimmeria region of the southern highlands, east of the Hellas impact basin. This image is centered at 34.23 S latitude, 138.437 E longitude with 25 cm/pixel resolution, and was taken on Jan 25 of 2012 during northern spring (Ls = 57.4). Using ArcGIS, lines were drawn across three ripples perpendicular to the ripple crests, avoiding places where complex ripple patterns suggest more than one recent wind direction. The length of the lines provides a measure of ripple wavelength, and the line orientation gives azimuth (with a 180 degree absolute ambiguity). The barchan-like shape of some dunes, including occasional slip faces, suggest sand driving winds were from the southwest, although dune asymmetries indicate the wind regime likely was much more complex than a unimodal wind. Measurements of ripple orientations are being collected from dune locations across the planet, which should provide new constraints for the modeling of recent Martian winds. This work was supported by NASA MDAP grant NNX12AJ38G.

  10. Cadmium selenide nanocrystals as white-light phosphors

    NASA Astrophysics Data System (ADS)

    Gosnell, Jonathan D.; Schreuder, Michael A.; Bowers, Michael J., II; Rosenthal, Sandra J.; Weiss, Sharon M.

    2006-08-01

    Recently, there has been great interest in developing direct white-light phosphors for solid state lighting. Current commercial white light emitting diodes (LEDs) rely on complicated fabrication methods to produce white light. Utilizing magic-sized, white-light emitting cadmium selenide (CdSe) nanocrystals as a direct white-light phosphor eliminates the need for complex doping schemes and deposition techniques. Herein we report preliminary data representing the first elementary steps in designing and optimizing device architectures for building high-quality, highly efficient white-light emitting LEDs for solid state lighting.

  11. Rethinking White Resistance: Exploring the Discursive Practices and Psychical Negotiations of "Whiteness" in Feminist, Anti-Racist Education

    ERIC Educational Resources Information Center

    Ringrose, Jessica

    2007-01-01

    This article explores how under-theorized representations of whiteness in pedagogical literatures have informed simplistic ideas about white resistance among students. It is argued that the performance and practice of discourses of whiteness in pedagogical contexts, and the subjective, psychical and emotional complexities of engaging with

  12. Rethinking White Resistance: Exploring the Discursive Practices and Psychical Negotiations of "Whiteness" in Feminist, Anti-Racist Education

    ERIC Educational Resources Information Center

    Ringrose, Jessica

    2007-01-01

    This article explores how under-theorized representations of whiteness in pedagogical literatures have informed simplistic ideas about white resistance among students. It is argued that the performance and practice of discourses of whiteness in pedagogical contexts, and the subjective, psychical and emotional complexities of engaging with…

  13. The White Nile sedimentary system

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Andò, Sergio; Padoan, Marta; Resentini, Alberto; Vezzoli, Giovanni; Villa, Igor

    2014-05-01

    The Nile River flows for ~6700 km from south of the Equator to finally reach the Mediterranean Sea at northern subtropical latitudes (Woodward et al. 2007). This is the longest sedimentological laboratory on Earth, a unique setting in which we are investigating changes in sediment composition associated with diverse chemical and physical processes, including weathering and hydraulic sorting. The present study focuses on the southern branch of the Nile across 20° of latitude, from hyperhumid Burundi and Rwanda highlands in central Africa to Khartoum, the capital city of Sudan at the southern edge of the Sahara. Our study of the Kagera basin emphasizes the importance of weathering in soils at the source rather than during stepwise transport, and shows that the transformation of parent rocks into quartzose sand may be completed in one sedimentary cycle (Garzanti et al. 2013a). Micas and heavy minerals, less effectively diluted by recycling than main framework components, offer the best key to identify the original source-rock imprint. The different behaviour of chemical indices such as the CIA (a truer indicator of weathering) and the WIP (markedly affected by quartz dilution) helps us to distinguish strongly weathered first-cycle versus polycyclic quartz sands (Garzanti et al. 2013b). Because sediment is efficiently trapped in East African Rift lakes, the composition of Nile sediments changes repeatedly northwards across Uganda. Downstream of both Lake Kyoga and Lake Albert, quartzose sands are progressively enriched in metamorphiclastic detritus supplied from tributaries draining amphibolite-facies basements. The evolution of White Nile sediments across South Sudan, a scarcely accessible region that suffered decades of civil war, was inferred from the available information (Shukri 1950), integrated by original petrographic, heavy-mineral and geochemical data (Padoan et al. 2011). Mineralogical and isotopic signatures of Bahr-el-Jebel and Sobat sediments, derived respectively from Archean gneisses of Uganda and Neoproterozoic basements of Ethiopia, become gradually homogenized and enriched in quartz, and remain finally unchanged down to Khartoum. This suggests massive sediment dumping in the Sudd and Machar Marshes, and explains why White Nile sediment contribution to the main Nile is negligible (Garzanti et al. 2006). REFERENCES Garzanti E., Andò S., Vezzoli G., Megid A.A.A., El Kammar A., 2006. Petrology of Nile River sands (Ethiopian and Sudan): sediment budgets and erosion patterns. EPSL 252:327-341. Garzanti E., Padoan M., Setti M., Peruta L., Najman Y., Villa I.M., 2013. Weathering geochemistry and Sr-Nd fingerprints of equatorial upper Nile and Congo muds. Geochem. Geophys. Geosyst. 14:292-316. Garzanti E., Padoan M., Andò S., Resentini A., Vezzoli G., Lustrino M., 2013. Weathering and relative durability of detrital minerals in equatorial climate: sand petrology and geochemistry in the East African Rift. J.Geol. 121:547-580. Padoan M., Garzanti E., Harlavan Y., Villa I.M., 2011. Tracing Nile sediment sources by Sr and Nd isotope signatures (Uganda, Ethiopia, Sudan). Geochim. Cosmochim. Acta 75:3627-3644. Shukri N.M., 1950. The mineralogy of some Nile sediments. Quart. J. Geol. Soc. London 105:511-534. Woodward J.C., Macklin M.G., Krom M.D., Williams M.A.J. 2007. The Nile: Evolution, quaternary river environments and material fluxes. In: Large Rivers, Avijit Gupta (Ed.), Wiley, 261-292.

  14. Geomorphology of desert sand dunes: A review of recent progress

    NASA Astrophysics Data System (ADS)

    Livingstone, Ian; Wiggs, Giles F. S.; Weaver, Corinne M.

    2007-02-01

    Through the 1980s and 1990s studies of the geomorphology of desert sand dunes were dominated by field studies of wind flow and sand flow over individual dunes. Alongside these there were some attempts numerically to model dune development as well as some wind tunnel studies that investigated wind flow over dunes. As developments with equipment allowed, field measurements became more sophisticated. However, by the mid-1990s it was clear that even these more complex measurements were still unable to explain the mechanisms by which sand is entrained and transported. Most importantly, the attempt to measure the stresses imposed by the wind on the sand surface proved impossible, and the use of shear (or friction) velocity as a surrogate for shear stress also failed to deliver. At the same time it has become apparent that turbulent structures in the flow may be as or more important in explaining sand flux. In a development paralleled in fluvial geomorphology, aeolian geomorphologists have attempted to measure and model turbulent structures over dunes. Progress has recently been made through the use of more complex numerical models based on computational fluid dynamics (CFD). Some of the modelling work has also suggested that notions of dune 'equilibrium' form may not be particularly helpful. This range of recent developments has not meant that field studies are now redundant. For linear dunes careful observations of individual dunes have provided important data about how the dunes develop but in this particular field some progress has been made through ground-penetrating radar images of the internal structure of the dunes. The paradigm for studies of desert dune geomorphology for several decades has been that good quality empirical data about wind flow and sand flux will enable us to understand how dunes are created and maintain their form. At least some of the difficulty in the past arose from the plethora of undirected data generated by largely inductive field studies. More recently, attention has shifted-although not completely-to modelling approaches, and very considerable progress has been made in developing models of dune development. It is clear, however, that the models will continue to require accurate field observations in order for us to be able to develop a clear understanding of desert sand dune geomorphology.

  15. [Environmental toxicity of waste foundry sand].

    PubMed

    Zhang, Hai-Feng; Wang, Yu-Jue; Wang, Jin-Lin; Huang, Tian-You; Xiong, Ying

    2013-03-01

    The metal leaching characteristics and volatile organic compounds (VOCs) of five different types of waste foundry sands were analyzed with the toxicity characteristic leaching procedure (TCLP) and head space-gas chromatography (HS-GC). Microtox and soil dehydrogenase activity (DHA) tests were then used to evaluate the bio-effects of these waste sands. The results showed that due to the different metals poured and casting materials used to make the sand molds, there was significant difference among the five waste foundry sands in the compositions and concentrations of metal and organic pollutants. The concentrations of Fe in the leachates of iron and steel casting waste foundry sand exceeded the maximal allowable concentrations specified in the National Standard of Drinking Water Quality, whereas the As concentration in the leachate of aluminum casting waste foundry sand exceeded the standard. The five waste foundry sands had quite different compositions and levels of VOCs, which resulted in different levels of inhibition effects on the luminescent bacteria (30% and 95%). Additionally, the soil DHA tests suggested that metal pollutants in waste foundry sands may inhibit the soil microbial activity, whereas organics in the sands may slightly promote the microbial activity. The results of this study indicated that the waste foundry sands may pose considerable threat to the environment when improperly disposed. PMID:23745431

  16. A comparison of culture-dependent and culture-independent techniques used to characterize bacterial communities on healthy and white plague-diseased corals of the Montastraea annularis species complex

    NASA Astrophysics Data System (ADS)

    Cook, G. M.; Rothenberger, J. P.; Sikaroodi, M.; Gillevet, P. M.; Peters, E. C.; Jonas, R. B.

    2013-06-01

    Diseases of hermatypic corals pose a global threat to coral reefs, and investigations of bacterial communities associated with healthy corals and those exhibiting signs of disease are necessary for proper diagnosis. One disease, commonly called white plague (WP), is characterized by acute tissue loss. This investigation compared the bacterial communities associated with healthy coral tissue ( N = 15), apparently healthy tissue on WP-diseased colonies ( N = 15), and WP-diseased tissues ( N = 15) from Montastraea annularis (species complex) colonies inhabiting a Bahamian reef. Aliquots of sediment ( N = 15) and water ( N = 15) were also obtained from the proximity of each coral colony sampled. Samples for culture-dependent analyses were inoculated onto one-half strength Marine Agar ( MA) and Thiosulfate Citrate Bile Salts Sucrose Agar to quantify the culturable communities. Length heterogeneity PCR (LH-PCR) of the 16S rRNA gene characterized the bacterial operational taxonomic units (OTU) associated with lesions on corals exhibiting signs of a white plague-like disease as well as apparently healthy tissue from diseased and non-diseased conspecifics. Analysis of Similarity was conducted on the LH-PCR fingerprints, which indicated no significant difference in the composition of bacterial communities associated with apparently healthy and diseased corals. Comparisons of the 16S rRNA gene amplicons from cultured bacterial colonies ( MA; N = 21) with all amplicons obtained from the whole coral-associated bacterial community indicated ?39 % of coral-associated bacterial taxa could be cultured. Amplicons from these bacterial cultures matched amplicons from the whole coral-associated bacterial community that, when combined, accounted for >70 % total bacterial abundance. An OTU with the same amplicon length as Aurantimonas coralicida (313.1 bp), the reported etiological agent of WPII, was detected in relatively low abundance (<0.1 %) on all tissue types. These findings suggest a coral disease resembling WP may result from multiple etiologies.

  17. Bootstrapping white matter segmentation, Eve++

    NASA Astrophysics Data System (ADS)

    Plassard, Andrew; Hinton, Kendra E.; Venkatraman, Vijay; Gonzalez, Christopher; Resnick, Susan M.; Landman, Bennett A.

    2015-03-01

    Multi-atlas labeling has come in wide spread use for whole brain labeling on magnetic resonance imaging. Recent challenges have shown that leading techniques are near (or at) human expert reproducibility for cortical gray matter labels. However, these approaches tend to treat white matter as essentially homogeneous (as white matter exhibits isointense signal on structural MRI). The state-of-the-art for white matter atlas is the single-subject Johns Hopkins Eve atlas. Numerous approaches have attempted to use tractography and/or orientation information to identify homologous white matter structures across subjects. Despite success with large tracts, these approaches have been plagued by difficulties in with subtle differences in course, low signal to noise, and complex structural relationships for smaller tracts. Here, we investigate use of atlas-based labeling to propagate the Eve atlas to unlabeled datasets. We evaluate single atlas labeling and multi-atlas labeling using synthetic atlases derived from the single manually labeled atlas. On 5 representative tracts for 10 subjects, we demonstrate that (1) single atlas labeling generally provides segmentations within 2mm mean surface distance, (2) morphologically constraining DTI labels within structural MRI white matter reduces variability, and (3) multi-atlas labeling did not improve accuracy. These efforts present a preliminary indication that single atlas labels with correction is reasonable, but caution should be applied. To purse multi-atlas labeling and more fully characterize overall performance, more labeled datasets would be necessary.

  18. Boston Public School White Enrollment Decline: White Flight or Demographic Factors?

    ERIC Educational Resources Information Center

    McDonald, Lauren E.

    1997-01-01

    Investigates the myth of white flight in response to school desegregation. Using data from urban and suburban enrollment and overall demographic shifts, reveals a trend in population changes more complex than can be explained by "white flight." Concluding comments discuss the implications and relevance of these findings to education policy. (GR)

  19. Sand banks of finite amplitude

    NASA Astrophysics Data System (ADS)

    Tambroni, N.; Blondeaux, P.

    2008-10-01

    The process which leads to the appearance of sand banks in shallow seas is investigated by studying the growth of small-amplitude perturbations of the sea bottom, forced by oscillatory tidal currents. Since the analysis of field data carried out by Dyer and Huntley (1999) suggests that sand banks are likely to occur where the tidal ellipse is circular or characterized by a low ellipticity, attention is focused on small values of ?, where e is the ratio between minor and major axes of the tidal ellipse. The linear analysis, which considers perturbations of small (strictly infinitesimal) amplitude, shows the existence of a critical value rC of the Keulegan-Carpenter number r of the tide (r = U0*/(h0*?*), U0* and ?* being the amplitude and angular frequency of the velocity oscillations induced by the tide propagation and h0* being the averaged water depth) such that for r smaller than rC the flat bottom configuration is stable, while for r larger than rC the sand banks start to appear. Close to the critical condition, the wavelength of the most unstable mode turns out to be finite. Then a weakly nonlinear analysis is developed which allows the evaluation of the equilibrium amplitude of the bottom forms when the parameter r is close to its critical value. The configuration of the sea bottom, when the bottom forms attain their equilibrium, is characterized by the presence of long ridges, almost parallel to the main axis of the tidal ellipse, with crest-to-crest distances similar to those observed during field surveys. The crests of the bottom forms turn out to be flat, and the extensive shallow waters at the crests are compensated by deep troughs between the ridges.

  20. SAMPLING FOR SAND FLIES (DIPTERA: PSYCHODIDAE) ON RANCHES WITH HISTORIES OF VESICULAR STOMATITIS DISEASE IN NEW MEXICO AND COLORADO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possible presence of sand flies (Diptera: Psychodidae) among colonies of white-tailed prairie dogs, Cynomys gunnisoni Baird, was investigated on or near ranches with histories of vesicular stomatitis (VS) in domestic livestock in the mid-Rio Grande River Valley, New Mexico and West-slope region...

  1. The search for a source rock for the giant Tar Sand triangle accumulation, southeastern Utah

    USGS Publications Warehouse

    Huntoon, J.E.; Hansley, P.L.; Naeser, N.D.

    1999-01-01

    A large proportion (about 36%) of the world's oil resource is contained in accumulations of heavy oil or tar. In these large deposits of degraded oil, the oil in place represents only a fraction of what was present at the time of accumulation. In many of these deposits, the source of the oil is unknown, and the oil is thought to have migrated over long distances to the reservoirs. The Tar Sand triangle in southeastern Utah contains the largest tar sand accumulation in the United States, with 6.3 billion bbl of heavy oil estimated to be in place. The deposit is thought to have originally contained 13-16 billion bbl prior to the biodegradation, water washing, and erosion that have taken place since the middle - late Tertiary. The source of the oil is unknown. The tar is primarily contained within the Lower Permian White Rim Sandstone, but extends into permeable parts of overlying and underlying beds. Oil is interpreted to have migrated into the White Rim sometime during the Tertiary when the formation was at a depth of approximately 3500 m. This conclusion is based on integration of fluid inclusion analysis, time-temperature reconstruction, and apatite fission-track modeling for the White Rim Sandstone. Homogenization temperatures cluster around 85-90??C for primary fluid inclusions in authigenic, nonferroan dolomite in the White Rim. The fluid inclusions are associated with fluorescent oil-bearing inclusions, indicating that dolomite precipitation was coeval with oil migration. Burial reconstruction suggests that the White Rim Sandstone reached its maximum burial depth from 60 to 24 Ma, and that maximum burial was followed by unroofing from 24 to 0 Ma. Time-temperature modeling indicates that the formation experienced temperatures of 85-90??C from about 35 to 40 Ma during maximum burial. Maximum formation temperatures of about 105-110??C were reached at about 24 Ma, just prior to unroofing. Thermal modeling is used to examine the history of potential source rocks for the White Rim oil. The most attractive potential sources for White Rim oil include beds within one or more of the following formations: the Proterozoic Chuar Group, which is present in the subsurface southwest of the Tar Sand triangle; the Mississippian Delle Phosphatic Member of the Deseret Limestone and equivalent formations, the Permian Kaibab Limestone, the Sinbad Limestone Member of the Triassic Moenkopi Formation, and the Jurassic Arapien Shale, Twin Creek Limestone, and Carmel Formation, which are present west of the Tar Sand triangle; the Pennsylvanian Paradox Formation in the Paradox basin east of the Tar Sand triangle; and the Permian Park City Formation northwest of the Tar Sand triangle. Each formation has a high total organic carbon content and is distributed over a wide enough geographic area to have provided a huge volume of oil. Source beds in all of the formations reached thermal maturity at times prior to or during the time that migration into the White Rim is interpreted to have occurred. Based on all available data, the most likely source for the Tar Sand triangle appears to be the Mississippian Delle Phosphatic Member of the Deseret Limestone. Secondary migration out of the Delle is interpreted to have occurred during the Cretaceous, during Sevier thrusting. Subsequent tertiary migration into the Tar Sand triangle reservoir is interpreted to have occurred later, during middle Tertiary Laramide deformation.

  2. Minerals yearbook, 1988: Industrial sand and gravel

    SciTech Connect

    Bolen, W.P.

    1988-01-01

    Production of industrial sand and gravel in 1988 increased to 28.5 million short tons, about a 2% increase over that of 1987, but remained 15% below the record-high production level of 1979. The production increase was due in part to the addition of new operations in California and Tennessee. Imports of industrial sand and gravel decreased about 59% in quantity, but the associated value increased 79%. Exports of industrial sand and gravel increased about 40% in quantity with a slight increase in average value per ton. Domestic apparent consumption of industrial sand and gravel in 1988 was 27.5 million tons.

  3. A branching process model for sand avalanches

    SciTech Connect

    Garcia-Pelayo, R.; Salazar, I.; Schieve, W.C. )

    1993-07-01

    An analytically solvable model for sand avalanches of noninteracting grains of sand, based on the Chapman-Kolmogorov equations, is presented. For a single avalanche, distributions of lifetimes, sizes of overflows and avalanches, and correlation functions are calculated. Some of these are exponentials, some are power laws. Spatially homogeneous distributions of avalanches are also studied. Computer simulations of avalanches of interacting grains of sand are compared to the solutions to the Chapman-Kolmogorov equations. It is found that within the range of parameters explored in the simulation, the approximation of noninteracting grains of sand is a good one. 20 refs., 4 figs.

  4. Thermal chemistry of a Utah tar sand

    SciTech Connect

    Rudnick, L.R.; Audeh, C.A.

    1988-08-01

    A study of the thermal chemistry of a Utah tar sand is described. The coking behavior of the intact Utah tar sand is compared with that of the bitumen after extraction from the sand. The yield structure and oil properties are compared. Study of the free radicals present in the samples was made by using electron spin resonance (ESR) spectroscopy. Radical generation and termination reactions during coking at two heating rates (12 and 120/sup 0/C/min) of the intact tar sand and the extracted bitumen were studied directly in the ESR spectrometer.

  5. Coupled changes in sand grain size and sand transport driven by changes in the upstream supply of sand in the Colorado River: relative importance of changes in bed-sand grain size and bed-sand area

    USGS Publications Warehouse

    Topping, D.J.; Rubin, D.M.; Melis, T.S.

    2007-01-01

    Sand transport in the Colorado River in Marble and Grand canyons was naturally limited by the upstream supply of sand. Prior to the 1963 closure of Glen Canyon Dam, the river exhibited the following four effects of sand supply limitation: (1) hysteresis in sediment concentration, (2) hysteresis in sediment grain size coupled to the hysteresis in sediment concentration, (3) production of inversely graded flood deposits, and (4) development or modification of a lag between the time of a flood peak and the time of either maximum or minimum (depending on reach geometry) bed elevation. Construction and operation of the dam has enhanced the degree to which the first two of these four effects are evident, and has not affected the degree to which the last two effects of sand supply limitation are evident in the Colorado River in Marble and Grand canyons. The first three of the effects involve coupled changes in suspended-sand concentration and grain size that are controlled by changes in the upstream supply of sand. During tributary floods, sand on the bed of the Colorado River fines; this causes the suspended sand to fine and the suspended-sand concentration to increase, even when the discharge of water remains constant. Subsequently, the bed is winnowed of finer sand, the suspended sand coarsens, and the suspended-sand concentration decreases independently of discharge. Also associated with these changes in sand supply are changes in the fraction of the bed that is covered by sand. Thus, suspended-sand concentration in the Colorado River is likely regulated by both changes in the bed-sand grain size and changes in the bed-sand area. A physically based flow and suspended-sediment transport model is developed, tested, and applied to data from the Colorado River to evaluate the relative importance of changes in the bed-sand grain size and changes in the bed-sand area in regulating suspended-sand concentration. Although the model was developed using approximations for steady, uniform flow, and other simplifications that are not met in the Colorado River, the results nevertheless support the idea that changes in bed-sand grain size are much more important than changes in bed-sand area in regulating the concentration of suspended sand.

  6. Fecal indicators in sand, sand contact, and risk of enteric illness among beach-goers

    EPA Science Inventory

    BACKGROUND: Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. METHODS: In 2007, visitors at 2 recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days...

  7. Investigating Sand on the Coast of Oregon and Washington.

    ERIC Educational Resources Information Center

    Komar, Paul D.

    2002-01-01

    Describes factors affecting sand composition and distribution along coastlines. Uses variations in sand types along the Oregon coast to illustrate the influences of sand grain density, wave action, and headlands on sand movements. Describes the seasonal movement of sand across beaches. (DLH)

  8. Confronting White Privilege

    ERIC Educational Resources Information Center

    Swalwell, Katy

    2012-01-01

    Even as the United States becomes more diverse, a new era of "white flight" is unfolding. Whether they live in urban, suburban or rural communities, white students are likely to attend schools that reinforce their perceptions of cultural dominance. The average white student attends a school where 77 percent of the student body is of their race.…

  9. Confronting White Privilege

    ERIC Educational Resources Information Center

    Swalwell, Katy

    2012-01-01

    Even as the United States becomes more diverse, a new era of "white flight" is unfolding. Whether they live in urban, suburban or rural communities, white students are likely to attend schools that reinforce their perceptions of cultural dominance. The average white student attends a school where 77 percent of the student body is of their race.

  10. Mapping the Stratigraphy of Booming Sand Dunes

    NASA Astrophysics Data System (ADS)

    Vriend, N. M.; Hunt, M. L.; Clayton, R. W.

    2008-12-01

    Booming dunes emit a loud rumbling sound after a man-made or natural sand avalanche is generated on the slip face of a large desert dune. The sound consist of one dominant frequency (70 - 105 Hz) with several higher harmonics. A recent publication (Vriend et al., 2007) presented a model of an internal, natural waveguide that propagates the booming emission, amplifies the sound, and sets the booming frequency. The mapping of the subsurface layering, which is necessary for the existence of a waveguide, prompted additional work on the dune structure and stratigraphy. The current work highlights geophysical measurements at Eureka Dunes in Death Valley National Park, CA and Dumont Dunes in the Mojave Desert, CA. Seismic refraction studies indicate strong layering with large velocity jumps across the interfaces. Ground Penetrating Radar (GPR) profiles, at frequencies of 100 MHz and 200 MHz, map out the stratigraphic structure of the dunes. Variations in the near surface layering are able to predict the seasonal variability in booming frequency both quantitatively and qualitatively. The Kirchhoff migrated GPR profiles are superimposed on the local topography obtained with a laser rangefinder. The complex dune structure is resolved to a depth of over 30 meters for the 100 MHz antenna. The GPR profiles of the longitudinal Eureka dune display complex internal structures from old dune crests. Both slopes have slip faces at 30 degrees with parallel layering (< 2m) at the near surface. At the transverse Dumont dune the GPR profile exhibits strong parallel layering on the booming leeward slipface only. The shallower windward face features a remarkable tilted repetitive layering that cuts through the surface. At Dumont Dunes the layering on the leeward face explains the change in booming frequency between 70 - 95 Hertz in the period 2005 - 2008. The tilted layering structure of the shallow windward face prevents the formation of a waveguide and is never able to sustain the booming sound. The Dumont dune progresses slowly, estimated at ~ 1 m/year from correlating satellite images, by forming new slip faces on the leeward face over time. Large precipitation events may cause a new layer to form. Sand sampling provides a quantitative measure on the chemical composition and water content of the layering.

  11. The effect of EDTA, NTA and picolinic acid on Th(IV) mobility in a ternary system with natural sand.

    PubMed

    Reinoso-Maset, Estela; Worsfold, Paul J; Keith-Roach, Miranda J

    2012-03-01

    Organic complexing agents, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA) and picolinic acid, have been widely used at nuclear sites and are therefore found as common co-contaminants in radioactive contaminated land. This study has explored the mechanisms by which these three complexing agents affect the sorption of Th(IV) to pure silica and a natural sand. EDTA, NTA and, to a lesser extent, picolinic acid decreased the sorption of Th to silica, demonstrating the formation and solubility of Th complexes. However, Th sorption to sand was kinetically controlled and complexation enhanced the rate of Th sorption. EDTA and NTA did not sorb significantly to the sand, and metal desorption indicated that the mechanism involved exchange with sand-associated metals. At equilibrium, however, Th sorption was not affected by the presence of the ligands, and modelling suggested that the interaction between Th and the surface binding sites controlled Th sorption thermodynamically. PMID:22243891

  12. Intergroup Stereotypes of Working Class Blacks and Whites: Implications for Stereotype Threat.

    ERIC Educational Resources Information Center

    Niemann, Yolanda Flores; O'Connor, Elizabeth; McClorie, Randall

    1998-01-01

    Examined stereotypes of urban blacks and whites at a flea market with 68 black respondents, and at another flea market with 20 white respondents. Cluster-analysis results show that blacks have a relatively complex, multidimensional representation of themselves and of whites, while whites seem to have a more simplistic and negative view of blacks.

  13. Liquefaction in Subsurface Layer of Sand

    USGS Multimedia Gallery

    Ground shaking triggered liquefaction in a subsurface layer of sand, producing differential lateral and vertical movement in a overlying carapace of unliquified sand and silt, which moved from right to left toward the Pajaro River. This mode of ground failure, termed "lateral spreading,

  14. RADIUM REMOVAL USING SORPTION TO FILTER SAND

    EPA Science Inventory

    The study evaluated the use of a novel sand filtration process that exploits the natural capacity of filter sand to sorb radium through the use of a periodic dilute acid rinse to maintain its sorptive capacity. Batch studies were conducted to determine distribution coefficients s...

  15. NEW DEVELOPMENTS IN SLOW SAND FILTRATION

    EPA Science Inventory

    Recent regulations promulgated by the U.S. Environmental Protection Agency (EPA), including the Surface Water Treatment Rule, have helped to renew the interest in the use of slow sand filtration (SSF) for treating surface waters for small communities. low sand filtration is not a...

  16. Sand reinforced with shredded waste tires

    SciTech Connect

    Foose, G.J.; Benson, C.H.; Bosscher, P.J.

    1996-09-01

    The objective of this study was to investigate the feasibility of using shredded waste tires to reinforce sand. Direct shear tests were conducted on mixtures of dry sand and shredded waste tires. The following factors were studied to evaluate their influence on shear strength: normal stress, sand matrix unit weight, shred content, shred length, and shred orientation. From results of the tests, three significant factors affecting shear strength were identified: normal stress, shred content, and sand matrix unit weight. A model for estimating the strength of reinforced soils was also evaluated to determine its applicability to mixtures of sand and tire shreds. When the model is calibrated using results from one shred content, it may be useful for estimating the friction angle for other shred contents. In all cases, adding shredded tires increased the shear strength of sand, with an apparent friction angle ({phi}{prime}) as large as 67{degree} being obtained. Shred content and sand matrix unit weight were the most significant characteristics of the mixes influencing shear strength. Increasing either of these variables resulted in an increase in {phi}{prime}. Tests were also conducted on specimens consisting of only shredded tires (no sand), and the friction angle obtained was 30{degree}.

  17. Sand Tray Group Counseling with Adolescents

    ERIC Educational Resources Information Center

    Draper, Kay; Ritter, Kelli B.; Willingham, Elizabeth U.

    2003-01-01

    Sand tray group counseling with adolescents is an activity-based intervention designed to help participants address specific intrapersonal concerns, learn important skills of socialization, and develop a caring community. The main focus of the group is building small worlds with miniature figures in individual trays of sand and having an

  18. Introduction to Exploring Sand and Water

    ERIC Educational Resources Information Center

    Early Childhood Today, 2006

    2006-01-01

    What happens when children pour water through a funnel? They begin to understand science and math concepts such as flow, force, gravity, and volume. What happens when children mold sand to create a tunnel? They develop skills in areas such as problem solving and predicting. They also gain knowledge about absorption and the properties of sand and

  19. Explorations with the Sand and Water Table.

    ERIC Educational Resources Information Center

    Texas Child Care, 2001

    2001-01-01

    Presents sand and water activities for young children as examples of sensory explorations, science activities, and comforting play. Includes information on health and safety precautions, adaptations for children with physical disabilities, the use of other materials, and sand and water toys made from one-liter plastic bottles. (KB)

  20. DRINKING WATER TREATMENT USING SLOW SAND FILTRATION

    EPA Science Inventory

    Recent re-interest in slow sand filtration was brought about by the needs for small communities to install treatment technologies that are effective, less costly, and easier to operate and maintain than the more sophisticated rapid sand filters. These simpler technologies for sma...

  1. Introduction to Exploring Sand and Water

    ERIC Educational Resources Information Center

    Early Childhood Today, 2006

    2006-01-01

    What happens when children pour water through a funnel? They begin to understand science and math concepts such as flow, force, gravity, and volume. What happens when children mold sand to create a tunnel? They develop skills in areas such as problem solving and predicting. They also gain knowledge about absorption and the properties of sand and…

  2. 8? x 10? black and white photographic print made from ...

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

    8? x 10? black and white photographic print made from original 1933, 8? x 10? black and white photographic negative. New 4? x 5? archival negative made from print. Original photographer unknown. Original 8? x 10? negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. DECEMBER 18, 1933 PHOTOGRAPH NO. 87 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE SAND ISLAND FILL PIER I. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. 8? x 10? black and white photographic print made from ...

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

    8? x 10? black and white photographic print made from original 1933, 8? x 10? black and white photographic negative. New 4? x 5? archival negative made from print. Original photographer unknown. Original 8? x 10? negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. SEPTEMBER 25, 1933 PHOTOGRAPH NO. 41 OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING SAND ISLAND FILL AT PIER NO. III. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  4. 8? x 10? black and white photographic print made from ...

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

    8? x 10? black and white photographic print made from original 1933, 8? x 10? black and white photographic negative. New 4? x 5? archival negative made from print. Original photographer unknown. Original 8? x 10? negative located in the files of the New Orleans Public Belt Railroad administrative offices at 5100 Jefferson Highway, Jefferson, LA 70123. OCTOBER 17, 1933 PHOTOGRAPH NO. 57A OF CONTRACT NO. 3 SHOWING MAIN BRIDGE PLACING OF SAND FILL AT PIER NO. II. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  5. Shock response of dry sand.

    SciTech Connect

    Reinhart, William Dodd; Thornhill, Tom Finley, III; Chhabildas, Lalit C..; Vogler, Tracy John; Brown, Justin L.

    2007-08-01

    The dynamic compaction of sand was investigated experimentally and computationally to stresses of 1.8 GPa. Experiments have been performed in the powder's partial compaction regime at impact velocities of approximately 0.25, 0.5, and 0.75 km/s. The experiments utilized multiple velocity interferometry probes on the rear surface of a stepped target for an accurate measurement of shock velocity, and an impedance matching technique was used to deduce the shock Hugoniot state. Wave profiles were further examined for estimates of reshock states. Experimental results were used to fit parameters to the P-Lambda model for porous materials. For simple 1-D simulations, the P-Lambda model seems to capture some of the physics behind the compaction process very well, typically predicting the Hugoniot state to within 3%.

  6. Hematite Outlier and Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 4 December 2003

    This image shows a crater just south of the edge of the famous hematite-bearing surface, which is visible in the context image as a smooth area to the north. The crater has two features of immediate note. The first is a layered mound in the north part of the crater floor. This mound contains hematite, and it is an outlying remnant of the greater deposits to the north that have otherwise completely disappeared in this crater. The second feature is a dune field in the center of the crater floor, with dark dunes indicating winds from the northwest. The dunes grade into a dark sand sheet with no coherent structure, indicating that the sand layer thins out to the south and east.

    Image information: VIS instrument. Latitude -4.4, Longitude 357.3 East (2.7 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. Mutations in MITF and PAX3 Cause Splashed White and Other White Spotting Phenotypes in Horses

    PubMed Central

    Blatter, Marlis; Brooks, Samantha A.; Burger, Dominik; Drgemller, Cord; Gerber, Vincent; Henke, Diana; Janda, Jozef; Jude, Rony; Magdesian, K. Gary; Matthews, Jacqueline M.; Poncet, Pierre-Andr; Svansson, Vilhjlmur; Tozaki, Teruaki; Wilkinson-White, Lorna; Penedo, M. Cecilia T.; Rieder, Stefan; Leeb, Tosso

    2012-01-01

    During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The splashed white pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes. PMID:22511888

  8. Earth-like sand fluxes on Mars.

    PubMed

    Bridges, N T; Ayoub, F; Avouac, J-P; Leprince, S; Lucas, A; Mattson, S

    2012-05-17

    Strong and sustained winds on Mars have been considered rare, on the basis of surface meteorology measurements and global circulation models, raising the question of whether the abundant dunes and evidence for wind erosion seen on the planet are a current process. Recent studies showed sand activity, but could not determine whether entire dunes were moving--implying large sand fluxes--or whether more localized and surficial changes had occurred. Here we present measurements of the migration rate of sand ripples and dune lee fronts at the Nili Patera dune field. We show that the dunes are near steady state, with their entire volumes composed of mobile sand. The dunes have unexpectedly high sand fluxes, similar, for example, to those in Victoria Valley, Antarctica, implying that rates of landscape modification on Mars and Earth are similar. PMID:22596156

  9. Altitude of the top of the Sparta Sand and Memphis Sand in three areas of Arkansas

    USGS Publications Warehouse

    Pugh, Aaron L.; Westerfield, Paul W.; Gonthier, Gerard J.; Poynter, David T.

    1998-01-01

    The Sparta Sand and Memphis Sand form the second most productive aquifer in Arkansas. The Sparta Sand and Memphis Sand range in thick- ness from 0 to 900 feet, consisting of fine- to medium-grained sands interbedded with layers of silt, clay, shale, and minor amounts of lignite. Within the three areas of interest, the top surface of the Sparta Sand and Memphis Sand dips regionally east and southeast towards the axis of the Mississippi Embayment syncline and Desha Basin. Local variations in the top surface may be attributed to a combination of continued development of structural features, differential compaction, localized faulting, and erosion of the surface prior to subsequent inundation and deposition of younger sediments.

  10. Imaging of sand production in a horizontal sand pack by X-ray computed tomography

    SciTech Connect

    Tremblay, B.; Sedgwick, G.; Forshner, K.

    1996-06-01

    A laboratory experiment was performed to better understand how sand production can increase heavy oil recovery. A horizontal sand pack with an orifice at one end modeled the production of oil and sand into a perforation in a vertical well. The sand pack was scanned using X-ray computed tomography (CT). The CT images revealed that a high-porosity channel (wormhole) formed in the pack while sand was produced. The wormhole followed regions within the pack where the porosity was higher, and, consequently, the unconfined compressive strength of the sand was lower. This experiment suggests that wormholes will form within the weaker sands of a formation. The development of these high-permeability channels increases the drainage of the reservoir, which leads to higher oil recovery.

  11. Internal geometry and reservoir potential of some modern crevasse splay sands

    SciTech Connect

    Bowles, K.W.; Moslow, T.F.

    1984-09-01

    Cores taken along strike and dip transects through the Baptiste Collette crevasse splay, modern Mississippi River Delta, have been analyzed to determine the sedimentologic nature and potential reservoir quality of modern crevasse splay sands. The stratigraphic framework is more complex than previously recognized. This is demonstrated by the presence of several fine-grained (61-125..mu..) sand bodies (1-2 m or 3-6 ft thick) reflecting deposition in three distinct environments. Subaerial levee sands, which thicken toward the proximal end of the splay, contain 50-80% fine-grained (88..mu..) sand, 10% interlaminated muds, and 5-25% rooting. Distributary-mouth bar and point bar deposits (2 m or 6 ft below mean sea level) are 50-60% finegrained sand (88..mu..) and 40-50% interlaminated mud, with 5% cross-bedding and a gradational base. The deeper (below 6 m or 18 ft) channel sands are 80-95% fine-grained (99-125..mu..) sand, with 20-75% cross-bedding, 10% interlaminated muds, and an erosional base. These correlatable sands are encased in thick, organic-rich, bioturbated, bay and abandoned channel muds forming an impermeable seal. Channel sands have the greatest reservoir potential, being more laterally continuous along dip, clean (<5% silt and clay), well sorted, fine grained, and more homogeneous with few permeability barriers (i.e., mud layers and laminae). This study should complement the limited knowledge of modern crevasse splay systems as well as provide insight into the exploration or enhanced recovery of hydrocarbons in ancient equivalents, such as the Admire 650-ft sandstone of Kansas.

  12. BMM SHAKEOUT AND VIBRATING CONVEYOR TRANSPORT SAND AND CASTINGS TO ...

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

    BMM SHAKEOUT AND VIBRATING CONVEYOR TRANSPORT SAND AND CASTINGS TO SEPARATIONS SCREENS. - Southern Ductile Casting Company, Shaking, Degating & Sand Systems, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  13. Process for extracting oil from tar sands

    SciTech Connect

    Hall, J.B.; Russo, A.

    1990-10-30

    This patent describes a process for the extraction of oil and bitumen fractions from tar sands. It comprises: heating the tar sands within the range of about seventy degrees Fahrenheit (70{degrees} F.) to about one hundred fifty five degrees Fahrenheit (155{degrees} F.); mixing the mined tar sands with an aqueous solution of water soluble separation chemicals that induce separation of the oil and bitumen from the sand under such temperature conditions, the chemicals being such that they also induce separation of the oil and bitumen from the water and separation chemicals. The separation chemicals comprise an aqueous solution of an effective amount of water conditioner, wetting agents and a coupling agent selected from the group consisting of sulfonated fatty acid salts; holding the mined tar sands and the separation chemicals for a sufficient period of time under sufficient quiescent conditions that the oil and bitumen become substantially separated from the sands, the separated oil and bitumen floating on the water and the sand sinking in the water; segregation of the oil or bitumen fractions from the water and separation chemicals and retention of the fractions for use as a chemical resource.

  14. Critical State of Sand Matrix Soils

    PubMed Central

    Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

    2014-01-01

    The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, ?, and ?. The range of the value of M, ?, and ? is 0.8030.998, 0.1440.248, and 1.7272.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

  15. Critical state of sand matrix soils.

    PubMed

    Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

    2014-01-01

    The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, ?, and ?. The range of the value of M, ?, and ? is 0.803-0.998, 0.144-0.248, and 1.727-2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

  16. Adsorption of dyes on Sahara desert sand.

    PubMed

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures. PMID:19515485

  17. Invasive plants on disturbed Korean sand dunes

    NASA Astrophysics Data System (ADS)

    Kim, Kee Dae

    2005-01-01

    The sand dunes in coastal regions of South Korea are important ecosystems because of their small size, the rare species found in this habitat, and the beautiful landscapes they create. This study investigated the current vegetative status of sand dunes on three representative coasts of the Korean peninsula, and on the coasts of Cheju Island, and assessed the conditions caused by invasive plants. The relationships between the degree of invasion and 14 environmental variables were studied. Plots of sand dunes along line transects perpendicular to the coastal lines were established to estimate vegetative species coverage. TWINSPAN (Two-Way Indicator Species Analysis), CCA (Canonical Correspondence Analysis), and DCCA (Detrended Canonical Correspondence Analysis) were performed to classify communities on sand dunes and assess species composition variation. Carex kobomugi, Elymus mollis, and Vitex rotundifolia were found to be the dominant species plotted on the east, the west, and the peripheral coasts of Cheju Island, respectively. Vegetation on the south coast was totally extinct. The 19 communities, including representative C. kobomugi, C. kobomugi- Ixeris repens, C. kobomugi- Oenothera biennis, E. mollis, Lolium multiflorum- Calystegia soldanella, and V. rotundifolia- C. kobomugi, were all classified according to TWINSPAN. Oenothera biennis and L. multiflorum were exotics observed within these native communities. CCA showed that invasive native and exotic species distribution was segregated significantly, according to disturbance level, exotic species number, gravel, sand and silt contents, as well as vegetation size. It further revealed that human disturbance can strongly favor the settlement of invasive and exotic species. Restoration options to reduce exotic plants in the South Korean sand dune areas were found to be the introduction of native plant species from one sand dune into other sand dune areas, prohibition of building and the introduction of exotic soils, and conservation of surrounding sand dune areas.

  18. A comparison of general circulation model predictions to sand drift and dune orientations

    SciTech Connect

    Blumberg, D.G.; Greeley, R.

    1996-12-01

    The growing concern over climate change and decertification stresses the importance of aeolian process prediction. In this paper the use of a general circulation model to predict current aeolian features is examined. A GCM developed at NASA/Goddard Space Flight Center was used in conjunction with White`s aeolian sand flux model to produce a global potential aeolian transport map. Surface wind shear stress predictions were used from the output of a GCM simulation that was performed as part of the Atmospheric Model Intercomparison Project on 1979 climate conditions. The spatial resolution of this study (as driven by the GCM) is 4{degrees} X 5{degrees}; instantaneous 6-hourly wind stress data were saved by the GCM and used in this report. A global map showing potential sand transport was compared to drift potential directions as inferred from Landsat images from the 1980s for several sand seas and a coastal dune field. Generally, results show a good correlation between the simulated sand drift direction and the drift direction inferred for dune forms. Discrepancies between the drift potential and the drift inferred from images were found in the North American deserts and the Arabian peninsula. An attempt to predict the type of dune that would be formed in specific regions was not successful. The model could probably be further improved by incorporating soil moisture, surface roughness, and vegetation information for a better assessment of sand threshold conditions. The correlation may permit use of a GCM to analyze {open_quotes}fossil{close_quotes} dunes or to forecast aeolian processes. 48 refs., 8 figs.

  19. Insecticide resistance in the sand fly, Phlebotomus papatasi from Khartoum State, Sudan

    PubMed Central

    2012-01-01

    Background Phlebotomus papatasi the vector of cutaneous leishmaniasis (CL) is the most widely spread sand fly in Sudan. No data has previously been collected on insecticide susceptibility and/or resistance of this vector, and a first study to establish a baseline data is reported here. Methods Sand flies were collected from Surogia village, (Khartoum State), Rahad Game Reserve (eastern Sudan) and White Nile area (Central Sudan) using light traps. Sand flies were reared in the Tropical Medicine Research Institute laboratory. The insecticide susceptibility status of first progeny (F1) of P. papatasi of each population was tested using WHO insecticide kits. Also, P. papatasi specimens from Surogia village and Rahad Game Reserve were assayed for activities of enzyme systems involved in insecticide resistance (acetylcholinesterase (AChE), non-specific carboxylesterases (EST), glutathione-S-transferases (GSTs) and cytochrome p450 monooxygenases (Cyt p450). Results Populations of P. papatasi from White Nile and Rahad Game Reserve were sensitive to dichlorodiphenyltrichloroethane (DDT), permethrin, malathion, and propoxur. However, the P. papatasi population from Surogia village was sensitive to DDT and permethrin but highly resistant to malathion and propoxur. Furthermore, P. papatasi of Surogia village had significantly higher insecticide detoxification enzyme activity than of those of Rahad Game Reserve. The sand fly population in Surogia displayed high AChE activity and only three specimens had elevated levels for EST and GST. Conclusions The study provided evidence for malathion and propoxur resistance in the sand fly population of Surogia village, which probably resulted from anti-malarial control activities carried out in the area during the past 50 years. PMID:22397726

  20. Fecal indicators in sand, sand contact, and risk of enteric illness among beachgoers

    PubMed Central

    Heaney, Christopher D.; Sams, Elizabeth; Dufour, Alfred P.; Brenner, Kristen P.; Haugland, Richard A.; Chern, Eunice; Wing, Steve; Marshall, Stephen; Love, David C.; Serre, Marc; Noble, Rachel; Wade, Timothy J.

    2011-01-01

    Background Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. Methods In 2007, visitors at two recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days later, participants answered questions about health symptoms since the visit. F+ coliphage, Enterococcus, Bacteroidales, fecal Bacteroides, and Clostridium spp. in wet sand were measured using culture and molecular methods. Results We analyzed 144 wet sand samples and completed 4,999 interviews. Adjusted odds ratios (aORs) were computed, comparing those in the highest tertile of fecal indicator exposure with those who reported no sand contact. Among those digging in sand compared with those not digging in sand, a molecular measure of Enterococcus spp. (calibrator cell equivalents/g) in sand was positively associated with gastrointestinal (GI) illness (aOR = 2.0 [95% confidence interval (CI) = 1.2–3.2]) and diarrhea (2.4 [1.4–4.2]). Among those buried in sand, point estimates were greater for GI illness (3.3 [1.3–7.9]) and diarrhea (4.9 [1.8–13]). Positive associations were also observed for culture-based Enterococcus (colony-forming units/g) with GI illness (aOR digging = 1.7 [1.1–2.7]) and diarrhea (2.1 [1.3–3.4]). Associations were not found among non-swimmers with sand exposure. Conclusions We observed a positive relationship between sand contact activities and enteric illness as a function of concentrations of fecal microbial pollution in beach sand. PMID:22157306

  1. Geochemistry of beach sands from Sithonia Peninsula (Chalkidiki, Northern Greece)

    NASA Astrophysics Data System (ADS)

    Papadopoulos, A.; Christofides, G.; Pe-Piper, G.; Koroneos, A.; Papadopoulou, L.

    2015-02-01

    Thirty beach sand samples from the granitic shoreline of the Sithonia Plutonic Complex (SPC) were analyzed for their REE and major element contents. The obtained results are compared with the adjacent SPC rock-types, in order to determine any enrichments or depletions. Among the samples enriched in REE, three are seasonal deposits of heavy minerals and their concentrations are controlled by the action of sea-waves. The available geochemical characteristics were also used to confirm the parental rocks of the beach sands, which are the SPC rock-types. The heavy fractions (total, total magnetic and total non-magnetic) of the beach sands were correlated with the REE concentrations, revealing a strong correlation between the heavy non-magnetic fraction and REE content. Among the minerals of the heavy non-magnetic fraction, monazite seems to control the REE content in the heavy mineral-enriched samples, whereas in the rest of the samples allanite, belonging to the heavy magnetic fraction may be the most important REE mineral.

  2. Wind Induced Raindrop Splash Sand Transport

    NASA Astrophysics Data System (ADS)

    Li, B.; Sherman, D.

    2009-12-01

    AGU abstract Title: Wind Induced Raindrop Splash Sand Transport Raindrop splash is widely accepted as an important mechanism of soil erosion (e.g. Van Dijk, Bruijnzeel, and Eisma 2003) as it can cause both particle detachment and transport. Since 1950, a number of papers have been published to identify and quantify the factors that influence splash transport (e.g. Ekern 1944; Rose 1960; Hudson 1963; Morgan 1981). More recently there has been attention focused on the combined processes of splash detachment and grain transport enhanced by the presence of wind using numerical models to simulate raindrop trajectories and terminal velocities as well as some empirical experiments to estimate the distribution of ejected particles. s (e.g. Erpul et al., 2009, 2008; Foulds and Warbuton 2007a, b; Cornelis et al. 2004a, 2004b; Erpul, Norton, and Gabriels 2002). These efforts have ignored the role of wind in altering particle trajectories after the initiation drop-induced ejection. The purpose of this paper is to use numerical simulation to describe the wind-enhanced splash transport process for a flat, sandy surface before and after a splash event. In this study, we first consider a single falling raindrop and use a physics model to analyze its behavior in the air, at impact and then the behaviors of droplets and grains ejected by the splash. The simulation shows that the speed of the raindrop relative to the wind speed is zero, but the relative speed increases rapidly very near the surface. The angle of drop incidence and terminal velocity are functions of drop size and the wind velocity profile. Once the raindrop hits the surface, a number of droplets are ejected; most of them include a number of sand particles. We apply several empirical measurements to represent the distributions of ejected drop sizes, number of grains entrained, and the angles and speeds of ejecta, and then use a coordinate transformation to convert them into conditions related to the angle of incidence of the impinging raindrop. The transport distance is the function of near-surface wind speed, droplet size, and ejection angle and speed. As the ejecting droplets are very small, resaltation after their impact is not considered. After we get the result from a single raindrop, we enlarge our picture to all the raindrops in a certain rainfall event, and then estimate the transport rate to all the directions from the estimate of raindrop distribution. The simulated results are compared with some empirical studies for verification purposes. In summary, the process of wind induced raindrop splash sand transport is very complex. Wind plays a role in the changing the raindrop terminal velocity and incidence angle and the droplets flying distance and direction. Numerical simulation can help us to understand on the internal mechanism of the whole wind induced splash process.

  3. Indications and potential sources of change in sand transport in the Brazos River, Texas

    USGS Publications Warehouse

    Dunn, David D.; Raines, Timothy H.

    2001-01-01

    Changes in the capacity of the Brazos River to transport sand can be identified within the context of Lane?s relation through changes in channel geometry, changes in the characteristics of suspended loads, and changes in discharge. The Brazos River channel has been undergoing continual adjustment since the 1940s. For a discharge of 5,000 cubic feet per second, the water-surface altitude has decreased 2 to 4 feet at the Hempstead and Richmond streamflow-gaging stations between 1940 and 1995. The characteristics of suspended-sediment samples at the Richmond streamflow-gaging station have changed between the periods 1969?81 and 1982?95. The amount of sand-size sediment transported in suspension has decreased. The distribution of both daily and annual-peak discharges has changed. However, the computed annual loads of suspended sand indicate no statistically significant change in the median annual load. The transport of sand in the Brazos River depends on a complex set of factors, most of which are continually changing. Potential sources of change in sand transport in the Brazos River include the effects of reservoir construction, changes in land use, and instream sand and gravel mining. Extensive reservoir construction in the Brazos River Basin has reduced sand transport by trapping sediment and by reducing the magnitude of peak discharges. However, reductions in sand transport associated with reservoir construction apparently are compensated for by increases associated with tributary sediment inflow and localized bank erosion. The total area of harvested acres of non-hay crops in the lower Brazos River Basin during 1924?92 decreased more than 75 percent from about 32 percent to about 8 percent of the total area. Correspondingly, erosion potential has decreased substantially. Several sand and gravel mining sites are located on the Brazos River between Hempstead and Rosharon. The quantity of sediment extracted by instream sand and gravel mining operations could represent from 11 to 25 percent of the total sand transported by the Brazos River. The effects of mining on sand transport could not be quantified.

  4. Syncrude-oil from Alberta's tar sands

    SciTech Connect

    Lund, C.N.

    1980-12-01

    Synthetic crude oil can be produced from bitumen contained in oil sands such as those located in Alberta, Canada. The most recent plant to come on stream, that of Syncrude Canada Ltd., mines the oil sand by open pit methods, recovers the bitumen using the hot water flotation process, and produces synthetic crude from bitumen by coking and hydrotreating. The product is competitive in price with imported conventional crude at today's world prices. The lead time and investment required to put a plant on stream are substantial. Nevertheless, synthetic crude from oil sands has the potential to fill a significant portion of Canada's liquid fuel requirements.

  5. White matter dementia

    PubMed Central

    2012-01-01

    White matter dementia (WMD) is a syndrome introduced in 1988 to highlight the potential of cerebral white matter disorders to produce cognitive loss of sufficient severity to qualify as dementia. Neurologists have long understood that such a syndrome can occur, but the dominance of gray matter as the locus of higher function has strongly directed neurobehavioral inquiry to the cerebral cortex while white matter has received less attention. Contemporary neuroimaging has been crucial in enabling the recognition of white matter abnormalities in a host of disorders, and the correlation of these changes with cognitive performance. Comprising about half the brain, white matter is prominently or exclusively involved in well over 100 disorders, in each of which white matter dysfunction can potentially cause or contribute to dementia. Neuropsychological findings from ten categories of white matter disorder lead to a convergence of findings that document remarkable neurobehavioral commonality among the dementias produced. More recently, the syndrome of mild cognitive dysfunction (MCD) has been introduced to expand the concept of WMD by proposing a precursor syndrome related to early white matter neuropathology. WMD and MCD inform the understanding of how white matter contributes to normal and abnormal cognition, and the specific neuroanatomic focus of these syndromes may enhance the diagnosis and treatment of many disabling disorders that do not primarily implicate the cerebral cortex. Forming essential connections within widely distributed neural networks, white matter is critical for rapid and efficient information transfer that complements the information processing of gray matter. As neuroimaging continues to advance, further information on white matter structure can be expected, and behavioral neurology will play a central role in elucidating the functional significance of these emerging data. By emphasizing the contribution of myelinated systems to higher function, the study of white matter and cognition represents investigation of the basic neuroscience of human behavior. PMID:22973423

  6. White Space Regions

    NASA Astrophysics Data System (ADS)

    Ehsani, Shayan; Fazli, Mohammadamin; Ghodsi, Mohammad; Safari, Mohammadali; Saghafian, Morteza; Tavakkoli, Mohammad

    We study a classical problem in communication and wireless networks called Finding White Space Regions. In this problem, we are given a set of antennas (points) some of which are noisy (black) and the rest are working fine (white). The goal is to find a set of convex hulls with maximum total area that cover all white points and exclude all black points. In other words, these convex hulls make it safe for white antennas to communicate with each other without any interference with black antennas. We study the problem on three different settings (based on overlapping between different convex hulls) and find hardness results and good approximation algorithms.

  7. Whiteness in Social Work Education Authentic White Allies

    ERIC Educational Resources Information Center

    Hornung, Rebecca

    2012-01-01

    This dissertation is guided by the following questions: How do People of Color define and experience White people as "authentic" allies? What does a White ally look like to People of Color? How do White allies view themselves as "authentic" White allies? What experiences lead White people to anti-racism and anti-racist praxis?

  8. Whiteness in Social Work Education Authentic White Allies

    ERIC Educational Resources Information Center

    Hornung, Rebecca

    2012-01-01

    This dissertation is guided by the following questions: How do People of Color define and experience White people as "authentic" allies? What does a White ally look like to People of Color? How do White allies view themselves as "authentic" White allies? What experiences lead White people to anti-racism and anti-racist praxis?…

  9. Improved Measurement of Ejection Velocities From Craters Formed in Sand

    NASA Technical Reports Server (NTRS)

    Cintala, Mark J.; Byers, Terry; Cardenas, Francisco; Montes, Roland; Potter, Elliot E.

    2014-01-01

    A typical impact crater is formed by two major processes: compression of the target (essentially equivalent to a footprint in soil) and ejection of material. The Ejection-Velocity Measurement System (EVMS) in the Experimental Impact Laboratory has been used to study ejection velocities from impact craters formed in sand since the late 1990s. The original system used an early-generation Charge-Coupled Device (CCD) camera; custom-written software; and a complex, multicomponent optical system to direct laser light for illumination. Unfortunately, the electronic equipment was overtaken by age, and the software became obsolete in light of improved computer hardware.

  10. Holocene stratigraphy of the Alabama inner continental shelf: Influence of shelf sand ridges on determining lithofacies architecture

    SciTech Connect

    Davies, D.J.; Parker, S.J. . Energy and Coastal Geology Div.)

    1993-03-01

    Surface and subsurface distribution of lithofacies from Holocene sediments of the AL inner continental shelf was determined from a series of 59 vibracores and associated surface sediment grab sediments. Five Holocene lithofacies composed of 12 discrete microfacies were delineated based on grain size, color, sedimentary structures, shell content, and fabric of samples. These lithofacies include: (1) Graded Shelly Sand Lithofacies; (2) Clean Sand Lithofacies; (3) Dirty Sand Lithofacies; (4) Biogenic Sediment Lithofacies; and (5) Muddy Sediment Lithofacies. These represent four major depositional environments: The Shelf Sand Sheet Environment (lithofacies 1 and 2); the Sand Ridge Environment (lithofacies 1, 2, and 3); the Bay/Lagoon Environment (lithofacies 3, 4 and 5); and the Muddy Shelf Environment (lithofacies 5). East of the Main Pass of Mobile Bay, the seafloor is composed of a clean Shelf Sand Sheet with oblique shelf sand ridges; Clean Sand and Graded Shelly Sand are the dominant surface sediment types. Coarse shell beds that grade up to quartz sand units (total thickness 0.1 to 3+m) interpreted as tempestites comprise most of the upper portion of the ridges. West of the Pass, the muddier lithofacies (3 and 5) dominate surface samples. Microfacies at depth represent the early Holocene transgressive systems tract; these include the Muddy Shelf Depositional Environment and the filled estuaries and bays of the flooded Pleistocene fluvial valleys represented by the Bay/Lagoon Depositional Environment. The AL inner shelf provides an excellent model of the variability of sedimentation mode in time and space during deposition of a transgressive systems tract. Development of the palimpsest sand sheet/ridge complex progressed on the eastern shelf due to shut off of sediment influx, westward longshore currents, and episodic incidence of major hurricanes. On the western shelf a patchy distribution of muddier sediments developed from input of floodwaters from Mobile Bay.

  11. Batch and column studies of adsorption of Li, Ni and Br by a reference sand for contaminant transport experiments

    SciTech Connect

    Seigel, M.D.; Ward, D.B.; Bryan, C.R.

    1995-09-01

    A processed quartz sand (Wedron 510), mined from the St. Peter sandstone, has been characterized by a variety of chemical and physical methods for use as a reference porous media in transport model validation experiments. Wedron 510 sand was used in an intermediate-scale experiment involving migration of Ni, Li and Br through a 6-m high x 3-m diameter caisson. Ni and Li adsorption/desorption, and Li/Ni site-competition experiments yielded information on the importance of the trace mineral phases to adsorption of Li and Ni by the sand. The presence of an iron hydroxide coating similar to goethite on the sand grains is suggested by visual observation and leaching experiments. Kaolinite was identified by SEM and XRD as a significant trace mineral phase in the sand and occurs as small particles coating the sand grains. Quartz, the predominant constituent of the sand by weight, does not appear to contribute significantly to the adsorption properties of the sand. Qualitatively, the adsorption properties of the sand can be adequately modeled as a two-mineral system (goethite and kaolinite). The studies described in this report should provide a basis for understanding transport of Ni, Li and Br through porous media similar to the reference sand. Techniques were developed for obtaining parameter values for surface complexation and kinetic adsorption models for the sand and its mineral components. These constants can be used directly in coupled hydrogeochemical transport codes. The techniques should be useful for characterization of other natural materials and elements in high-level nuclear waste in support of coupled hydrogeochemical transport calculations for Yucca Mountain.

  12. Sand consolidation methods using adsorbable catalysts

    SciTech Connect

    Friedman, R. H.

    1985-04-23

    Methods are provided for selectively consolidating sand grains within a subterranean formation. First an acidic zirconium salt catalyst, such as ZrOCl/sub 2/, Zr(SO/sub 4/)/sub 2/, or ZrCl/sub 4/, is injected into the subterranean formation, wherein the acidic salt catalyst is adsorbed to the surface of the sand grains. Next a polymerizable resin composition such as furfuryl alcohol oligomer is introduced into the well formation. Polymerization of the resin occurs upon exposure to the elevated well temperatures and contact with the acid salt catalyst adsorbed to the sand grains. The polymerized resin serves to consolidate the surfaces of the sand grains while retaining permeability through the pore spaces. An ester of a weak organic acid is included with the resin compositions to control the extent of a polymerization by consuming the water by-product formed during the polymerization reaction.

  13. Petrophysical Analysis of Oil Sand in Athabasca

    NASA Astrophysics Data System (ADS)

    cheong, S.; Lee, H.

    2013-12-01

    Oil sands are the major unconventional energy sources which have great reserves in Alberta, Canada. Recovery techniques such as CSS (Cyclic Steam Stimulation) and SAGD (Steam Assisted Gravity Drainage) enabled to develop deeper bitumen about several hundred meter depth. Before applying CSS and SAGD, reservoir heterogeneity of mud barriers or shale breccias should be clarified to establish injection and production wells successfully. We conducted the integrated petro-physical analysis for oil sands deposits in Athabasca by correlating well logs with seismic data. From 33 well logs and 3D seismic, we have made P-wave impedance by recursive inversion. Target formations of our analysis were the top of Wabiskaw member. Using inverted impedance and multi-attributes, porosity volume was derived at a target depth. Porosity of time slice 375 ms ranged 20 ~ 40 % stretching porous sand body from NE to SW direction. Characteristics of porosity distribution may be useful to design optimum oil sands recovery in Athabasca.

  14. The day the sands caught fire.

    NASA Astrophysics Data System (ADS)

    Wynn, J. C.; Shoemaker, E. M.

    1998-11-01

    Not so long ago a garage-size meteorite slammed into the uninhabited heart of Arabia and flash-cooked the sand into glass. Exploration of the site is a sober reminder of the destructive power of rocks from space.

  15. Nigeria to step up tar sands activity

    SciTech Connect

    Not Available

    1987-03-01

    The Nigerian government has directed its Ministry of Mines, Power and Steel to assume responsibility for the exploration and exploitation of tar sands deposits in Bendel, Ondo and Oyo States. The directive resulted from a survey report by the University of Ife's geological consultancy unit on bituminous sand deposits in the area. The statement said the government was satisfied that there were large commercial quantities of the sands in the three states. The survey had reported that Nigeria could recover between 31 and 40 billion barrels of heavy crude from the tar sand deposits. Exploration for hydrocarbons is currently going on in Anambra and Lake Chad basins as well as the Benue Trough. Apart from the Nigerian National Petroleum Corporation, Shell Petroleum and Gulf Oil have begun exploration activities in the Ondo area. Meanwhile, Nigeria has had to import heavy crude from Venezuela, for processing at the Kaduna refinery.

  16. New developments in slow sand filtration

    SciTech Connect

    Fox, K.R.

    1993-01-01

    Recent regulations promulgated by the U.S. Environmental Protection Agency (EPA), including the Surface Water Treatment Rule, have helped to renew the interest in the use of slow sand filtration (SSF) for treating surface waters for small communities. Slow sand filtration is not a new process, but is one that has been used to treat water effectively since the early 1800's. Interest in slow sand filtration in the United States has increased dramatically in the past thirteen years. New analytical techniques, such as particle counting, improved turbidity, improved growth media for microbiological analysis, and advanced techniques for measuring organic constituents allowed for more detailed studies than were possible in the early 1900's. The new work led to the publication of design manuals and task committee reports describing slow sand filtration in detail.

  17. The analysis of electrification in windblown sand

    NASA Astrophysics Data System (ADS)

    Bo, Tian-Li; Zhang, Huan; Hu, Wen-Wen; Zheng, Xiao-Jing

    2013-12-01

    Based on asymmetric contact, we present a contact electrification model of high-energy trapped holes which considered the plastic deformation of the contact process in a single normal collision to predict the contact electrification and the charge-to-mass ratio of sand particles. Furthermore, the contact electrification was measured using a charge collection method. Our results show that the charged species trapped in high-energy states of sand particles are positive holes, the predicted results agree well with our experiments qualitatively and quantitatively, the impacting velocity and the particle size are two important factors affecting the magnitude of the charge-to-mass ratio of sand particles, and the number of collisions also affects the charge-to-mass ratio of sand particles.

  18. Developing Alberta's oil sands, 1920--2002

    NASA Astrophysics Data System (ADS)

    Chastko, Paul Anthony

    This dissertation examines the origins and development of the Alberta oil sands industry over the last century from a scientific project to a commercial endeavor. Based on extensive use of primary sources, the manuscript integrates the developments in a number of fields (politics, international relations, business and economics, and changing oil-recovery technology) that have made it possible to "manufacture" oil from the Alberta tar sands at less than $10 U.S. per barrel.

  19. Sand Beach Bacteria: Enumeration and Characterization

    PubMed Central

    Khiyama, H. M.; Makemson, J. C.

    1973-01-01

    Bacteria in the water-saturated sand of a relatively unpolluted sand beach were enumerated by direct microscope and viable counting. The number of interstitial bacteria was estimated to be a significant fraction of the total number of bacteria present. Three hundred sixty-two strains were isolated and submitted to cultural and biochemical tests. Fermentational abilities and the production of indole suggested that a significant number of these bacteria were symbiotically associated with resident metazoans. PMID:4356458

  20. Treating tar sands formations with dolomite

    SciTech Connect

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  1. A Physical Taxonomy of Martian Sand and Dust Grainsat the Phoenix Landing Site

    NASA Astrophysics Data System (ADS)

    Marshall, John; Stoker, Carol

    2014-11-01

    A quantitative taxonomy of martian sand and dust grains for soil samples at the Phoenix lander site has been developed from the mission’s optical microscope data with a resolution of 4 μm per pixel. Approx. 3-4000 grains were analyzed for color, hue, size, shape, surface texture, aspect ratio, and optical properties. At least 26 types of sand and dust grains have been identified. Grain colors include black, brown, orange, red, white, and clear. Most grains are opaque, but many are translucent or transparent. Grain shapes range from botryoidal, blackberry-like, bead-like and rounded, to subrounded, elongate, angular, and highly irregular forms. Surface textures range from knobbly, rough, and multifaceted to smooth and polished. Surface reflectivity varied from dull to shiny to specularly reflective. Materials may include augite, pyroxenes, olivine, volcanic glass, hematite, other iron oxides, and salts. Grain size of the sand has a modal value of ~90 μm, but there is no gradation into dust sizes, indicating a bimodal distribution of the samples. The dust was probably imported into the region from aeolian dust storms. This accords with a mineralogical dissimilarity between the sand and dust grain populations. The sand is dominated by black and brown grains; the dust is dominated by orange grains. The Phoenix site also has centimeter and larger stones in abundance that again have no apparent gradation into the sand size material. Thus, the Phoenix landing site soil appears multimodal. The soil appears to be magnetically susceptible, but it is unclear what the source of magnetism might be. Specific magnetic minerals were not identified in the samples with the possible exception of paramagnetic microbotryoidal hematite. The soil was nevertheless adhesive to the substrates and internally cohesive (forming spherical aggregates) owing to van der Waals forces and possibly salt/moisture bonding.

  2. Textural characteristics of the Nigerian tar sands

    NASA Astrophysics Data System (ADS)

    Enu, E. I.

    1985-05-01

    Extensive tar sands with reserves of about 41 billion barrels of oil are known to occur in Cretaceous terrigenous sediments in Ondo and Ogun States of Nigeria. The hydrocarbon occurs in two predominantly sandy zones separated by an 8 m thick oil shale. The lower (Horizon Y) is mostly quartz sand, 3-26 m thick. It shows an upward fining of grains and increased consolidation updip. The upper Horizon X is 10-22 m of sandstone with interbedded shales and siltstones. The sands are loosely consolidated. Cementing material is lacking, the grains being held together largely by the tarry oil. Porosity is about 30% and mean oil saturation in both zones is 12%. The recorded clay content (2-7%) is considerably lower than the average for Athabasca, Canada (10-25%) and may enhance the settling properties of the tailing ponds. The sands are water-wet, fine- to medium-grained, moderately well sorted, mesokurtic and positively skewed to near symmetrical. The Nigerian tar sands compare closely with the Athabasca sands in all the above textural parameters. They would thus be expected to show identical response to mining processing, except for the influence of higher ground-water table and the high humidity and ambient temperatures in Nigeria.

  3. Recent Sand Avalanching on Rabe Crater Dunes

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Dark streaks on the steep, down-wind slopes of sand dunes in Rabe Crater are seen at several locations in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. These streaks indicate relatively recent (i.e., in the past few years or less) movement of sand down these slopes.

    Sand dunes move forward by the combined action of wind that drives sand up the shallow slope on the windward side of the dune (in this case, the slopes that face toward the lower right) and the avalanching of this sand down the steeper, lee-side slope. The steep slope is also known as the slip face. The dark streaks indicated by arrows are evidence for sand avalanches that occurred within a few months or years of the time when the picture was taken in March 1999. Other streaks which are seen criss-crossing the dunes may be the result of passing dust devils. This image is illuminated from the upper left and located in Rabe Crater of the Hellespontus-Noachis region near 44.2oS, 325.6oW.

  4. COMPLEX CONDUCTIVITY RESPONSE TO NANOMATERIALS IN A SAND MATRIX

    EPA Science Inventory

    Nano-scale metallic particles are being used with increasing frequency in a variety of industrial, medical, and environmental remediation applcations. The fate and transport of such materials in the subsurface is not fully understood, neither is the impact of these materials on ...

  5. Layers, Landslides, and Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 27 October 2003

    This image shows the northern rim of one of the Valles Marineris canyons. Careful inspection shows many interesting features here. Note that the spurs and gullies in the canyon wall disappear some distance below the top of the canyon wall, indicating the presence of some smooth material here that weathers differently from the underlying rocks. On the floor of the canyon, there are remains from a landslide that came hurtling down the canyon wall between two spurs. Riding over the topography of the canyon floor are many large sand dunes, migrating generally from the lower right to upper left.

    Image information: VIS instrument. Latitude -14.1, Longitude 306.7 East (53.3 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. Tidal sands as biogeochemical reactors

    NASA Astrophysics Data System (ADS)

    Anschutz, Pierre; Smith, Thomas; Mouret, Aurlia; Deborde, Jonathan; Bujan, Stphane; Poirier, Dominique; Lecroart, Pascal

    2009-08-01

    Sandy sediments of continental shelves and most beaches are often thought of as geochemical deserts because they are usually poor in organic matter and other reactive substances. The present study focuses on analyses of dissolved biogenic compounds of surface seawater and pore waters of Aquitanian coastal beach sediments. To quantitatively assess the biogeochemical reactions, we collected pore waters at low tide on tidal cross-shore transects unaffected by freshwater inputs. We recorded temperature, salinity, oxygen saturation state, and nutrient concentrations. These parameters were compared to the values recorded in the seawater entering the interstitial environment during floods. Cross-shore topography and position of piezometric level at low tide were obtained from kinematics GPS records. Residence time of pore waters was estimated by a tracer approach, using dissolved silica concentration and kinetics estimate of quartz dissolution with seawater. Kinetics parameters were based on dissolved silica concentration monitoring during 20-day incubations of sediment with seawater. We found that seawater that entered the sediment during flood tides remained up to seven tidal cycles within the interstitial environment. Oxygen saturation of seawater was close to 100%, whereas it was as low as 80% in pore waters. Concentrations of dissolved nutrients were higher in pore waters than in seawater. These results suggest that aerobic respiration occurred in the sands. We propose that mineralised organic matter originated from planktonic material that infiltrated the sediment with water during flood tides. Therefore, the sandy tidal sediment of the Aquitanian coast is a biogeochemical reactor that promotes or accelerates remineralisation of coastal pelagic primary production. Mass balance calculations suggest that this single process supplies about 37 kmol of nitrate and 1.9 kmol of dissolved inorganic phosphorus (DIP) to the 250-km long Aquitanian coast during each semi-diurnal tidal cycle. It represents about 1.5% of nitrate and 5% of DIP supplied by the nearest estuary.

  7. Advanced inline measurement and control tools for sand filling and compaction in lost foam casting

    NASA Astrophysics Data System (ADS)

    Whelan, Matthew J.; Janoyan, Kerop D.

    2004-07-01

    Lost Foam Casting (LFC) enables metal casters to produce complex parts by making foam patterns having the same geometry as the desired finished parts. Among the greatest strengths of LFC process is that it allows designers to consolidate parts, reduce machining and minimize assembly operations. One of the key steps in the LFC process takes place in the compaction box, where the foam pattern is suspended in a steel container that is vibrated while sand is added to surround the pattern. The sand provides the mechanical support to the pattern as molten metal is poured into the mold. Discussed in this paper will be the development of an advanced sensor array for the measurement and control of the sand compaction stage. Compaction of the sand is key in controlling casting distortion and is instrumental in the efficiency rating of the LFC process. Too much compaction can cause the foam part to distort or even get crushed. Too little compaction can lead to a defective final product due to inadequate support of the foam part or lack of sand flow into small cavities in the foam part. To understand and control the behavior of the sand compaction stage, the key parameters that must first be measured are: (1) Energy imparted on the compaction box, sand and foam part, (2) compaction of the sand in the casting box, and (3) distortion of the foam part. The sensor array is to be placed inline in order to give direct feedback that can then be used in both passive and active process control.

  8. Bonding energies of bitumen to tar sand mineral

    SciTech Connect

    Ensley, E.K.; Scott, M.A.

    1986-03-01

    The bonding energy of bitumen in a tar sand was found by algebraically adding the heat of dissolution of bitumen on tar sand, heat of dissolution of recovered bitumen and the heat of wetting of extracted tar sand mineral. The value for an Asphalt Ridge tar sand was found to be 270 cal/mole. 6 refs., 3 figs.

  9. Sailing to White Boat

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is a composite red-green-blue image of the rock called White Boat. It is the first rock target that Spirit drove to after finishing a series of investigations on the rock Adirondack. White Boat stood out to scientists due to its light color and more tabular shape compared to the dark, rounded rocks that surround it.

  10. Western White Pine

    USGS Multimedia Gallery

    A western white pine (Pinus monticola) in Kings Canyon National Park, Calif., towers over USGS ecologist Nathan Stephenson. Scientists analyzed data from 403 species of trees from around the world -- including western white pine (Pinus monticola), pictured here -- and learned that in general, a tre...

  11. Black Dean, White College

    ERIC Educational Resources Information Center

    Motley, Frank

    1977-01-01

    There is a natural dilemma and irony in being a Black administrator at a white institution. Black students and white administrators are both suspicious of his intentions and his competence. Race clouds all issues. Success is more dependent upon style than effort or productivity. (Author)

  12. 1. Elevation from E. White Holly in foreground, with White ...

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

    1. Elevation from E. White Holly in foreground, with White Sage behind. - U.S. Coast Guard Cutter WHITE HOLLY, U.S. Coast Guard 8th District Base, 4640 Urquhart Street, New Orleans, Orleans Parish, LA

  13. Deposition of carbonate mud beds within high-energy subtidal sand Dunes, Bahamas

    SciTech Connect

    Dill, R.F.; Steinen, R.P.

    1988-01-01

    Laminated, carbonate mud beds are being deposited in the interisland channels of the Exuma Cays in the Bahamas. They are associated with stromatolites and interbedded with ooid sands that form large migrating subtidal dunes on flood tidal deltas and bars. Currents up to 3 knots sweep in and out of the 4-8 m deep channels 3 hours out of every 6 hours, creating a high-energy bank margin environment not usually considered to be the site of mud-sized particle deposition. Mud deposits reach thicknesses of 1 m and have individual beds 2-5 cm thick. When exposed to flowing seawater, bed surfaces become encrusted with carbonate cement and algal mats. The white interior of mud beds between the crusts appears homogeneous, is soft, and has the consistency of ''tooth paste.'' Loose uncemented ooid sand is found above and below the mud beds, showing that both are occupying the same depositional environment. Rip-up clasts of the crusted mud beds, formed by scour of underlying sands, are carried throughout the channels and accumulate as a lag deposit within the troughs of migrating dunes. Some clasts are colonized by algal mats that trap ooid and skeletal sands forming stromatolite structures that can grow up to 2 m high.

  14. Composition of the sand fly fauna in Khash County, Southeast Iran.

    PubMed

    Kassiri, Hamid; Javadian, Ezatoeddin

    2012-01-01

    Sand flies (Diptera: Psychodidae: Phlebotominae) are the biological vectors of leishmaniasis all around the world. In 1997, sand flies were collected in 14 cities and villages of Khash County in southeastern Iran, using 848 sticky traps (castor oil-coated white papers 20 × 30 cm). In this study, a total of 4673 sand flies, with 25.23% females and 74.77% males, were collected and identified to species mainly from mountainous areas. The 21 species of sand flies belonged to the genus Phlebotomus (nine species) and the genus Sergentomyia (12 species). The following 14 species were reported for the first time in Khash County: P. papatasi, P. bergeroti, P. eleanorae, P. halepensis, P. major, P. mesghali, S. hodgsoni, S. mervynae, S. dreyfussi, S. iranica, S. theodori, S. africana, S. clydei, and S. christophersi. The composition of species in Khash County is similar to other parts of Iran. However, the dominance of P. kazeruni in Khash County may suggest that this species should be considered as a potential vector in the region of Khash. PMID:23448262

  15. Composition of the Sand Fly Fauna in Khash County, Southeast Iran

    PubMed Central

    Kassiri, Hamid; Javadian, Ezatoeddin

    2012-01-01

    Sand flies (Diptera: Psychodidae: Phlebotominae) are the biological vectors of leishmaniasis all around the world. In 1997, sand flies were collected in 14 cities and villages of Khash County in southeastern Iran, using 848 sticky traps (castor oil-coated white papers 20 × 30 cm). In this study, a total of 4673 sand flies, with 25.23% females and 74.77% males, were collected and identified to species mainly from mountainous areas. The 21 species of sand flies belonged to the genus Phlebotomus (nine species) and the genus Sergentomyia (12 species). The following 14 species were reported for the first time in Khash County: P. papatasi, P. bergeroti, P. eleanorae, P. halepensis, P. major, P. mesghali, S. hodgsoni, S. mervynae, S. dreyfussi, S. iranica, S. theodori, S. africana, S. clydei, and S. christophersi. The composition of species in Khash County is similar to other parts of Iran. However, the dominance of P. kazeruni in Khash County may suggest that this species should be considered as a potential vector in the region of Khash. PMID:23448262

  16. Histophysiology of the obesity-diabetes syndrome in sand rats.

    PubMed

    Hahn von Dorsche, H; Schfer, H; Titlbach, M

    1994-01-01

    Insulin, glucagon, somatostatin, and PP cells were found by immunotopochemical and electron-optical techniques in the islets of Langerhans of the sand rat, proving that the islets in this species also contain the four basic cell types known to be found in the islets in mammals in general. The ratio of A cells to B cells was 1:4 (19.1% A cells to 80.9% B cells). The pancreas of the sand rat contained assemblages of various numbers of neurons in the intralobal and interlobular connective tissue. They did not seem related in any regular fashion to specific blood vessels or branches of the pancreatic ducts. No bundles of nerve fibers were found by either light or electron microscopy. Nonmyelinated nerve fibers were detected by electron microscopy in the stroma of the islets. In the sand rat the neuroinsular complexes are formed by the penetration of single nerve cells into the pancreatic islets. In the NH or long-term group the islets exhibited signs of stimulation. The number of islets was higher than normal (polynesia), with the islets themselves enlarged (macronesia). Double islets in the secretory ducts of the exocrine pancreas were frequent. The increase in islet size was due to hyperplasia of the B cells. The numbers of beta-granules in the B cells varied considerably. Glycogen was demonstrated in some islets. The fusion of beta-granules was shown in electron microscopic pictures. The electron-opaque centers of these granules were brighter than the others and appeared to have partly dissolved. The organelles of the B cells (ER, Golgi apparatus, and mitochondria) were well developed, this also being a sign of cell stimulation. No changes were observed in the B and PP cells. Stimulation of the islet cells was even more pronounced in the diabetic group. Due to hyperplasia, the islets in this group were significantly larger not only than those in the control group, but also than those in the NH group. The pancreata of this group of sand rats contained numerous small islets. Although necrotic B cells were found in the large islets of the pancreas, none were discovered in the small islets. The small islets were considered to be "regenerated" islets. Granulation was slight in the remaining functioning B cells. The hypophyses of the control group contained the GH, LTH, FSH, LH, and TSH cell types typical of this organ in other species. In the sand rat the granules of these cell types are of about the same size as has been stated for other rodents.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8085478

  17. Standardization and Whiteness: One and the Same?

    ERIC Educational Resources Information Center

    Weilbacher, Gary

    2012-01-01

    The article "There Is No Culturally Responsive Teaching Spoken Here: A Critical Race Perspective" by Cleveland Hayes and Brenda C. Juarez suggests that the current focus on meeting standards incorporates limited thoughtful discussions related to complex notions of diversity. Our response suggests a strong link between standardization and White

  18. Influence of Oil Saturation Upon Spectral Induced Polarization of Oil Bearing Sands

    EPA Science Inventory

    The presence of oil in an unconsolidated granular porous material such as sand changes both the resistivity of the material and the value of the phase shift between the low-frequency current and the voltage. The resistivity and the phase angle can be written as a complex-valued r...

  19. South America and a Few Grains of Sand. Part 1: Beach Sands.

    ERIC Educational Resources Information Center

    Potter, Paul Edwin

    1986-01-01

    Continental geology and tectonics are explored through this study of modern beach sands of South America. This report assesses how well petrographic studies of sandstones can recreate continental geography. Data on the petrography of 218 modern South American beach sands are presented and analyzed. The five major mineral associations of light

  20. Short-term impact of deep sand extraction and ecosystem-based landscaping on macrozoobenthos and sediment characteristics.

    PubMed

    de Jong, Maarten F; Baptist, Martin J; Lindeboom, Han J; Hoekstra, Piet

    2015-08-15

    We studied short-term changes in macrozoobenthos in a 20m deep borrow pit. A boxcorer was used to sample macrobenthic infauna and a bottom sledge was used to sample macrobenthic epifauna. Sediment characteristics were determined from the boxcore samples, bed shear stress and near-bed salinity were estimated with a hydrodynamic model. Two years after the cessation of sand extraction, macrozoobenthic biomass increased fivefold in the deepest areas. Species composition changed significantly and white furrow shell (Abra alba) became abundant. Several sediment characteristics also changed significantly in the deepest parts. Macrozoobenthic species composition and biomass significantly correlated with time after cessation of sand extraction, sediment and hydrographical characteristics. Ecosystem-based landscaped sand bars were found to be effective in influencing sediment characteristics and macrozoobenthic assemblage. Significant changes in epifauna occurred in deepest parts in 2012 which coincided with the highest sedimentation rate. We recommend continuing monitoring to investigate medium and long-term impacts. PMID:26119627

  1. Recycling of iron foundry sand and glass waste as raw material for production of whiteware.

    PubMed

    Bragança, Saulo R; Vicenzi, Juliane; Guerino, Kareline; Bergmann, Carlos P

    2006-02-01

    The purpose of this study was to evaluate the production feasibility of triaxial whiteware using sand from cast iron moulds as a raw material instead of silica, and recycled glass in place of feldspar. Formulations were prepared using sand, glass waste, and white-firing clay such that only 50% of the composition was virgin material (clay). The ceramic bodies were formed by pressing and fired at different temperatures (between 1100 and 1300 degrees C). Specimens were characterized in terms of green density prior to firing; and their flexural strength, linear shrinkage, and water absorption were measured after firing. The microstructure was determined by scanning electron microscopy. Possible environmental impacts of this recycling process were also evaluated, through solubility and leaching tests, according to Brazilian standards. Gaseous emissions during the firing process were also analysed. The results showed that it is possible to produce triaxial ceramics by using such alternative raw materials. PMID:16496871

  2. White is green

    NASA Astrophysics Data System (ADS)

    Glicksman, Hal

    1998-12-01

    Green is the center of the visible spectrum and the hue to which we are most sensitive. In RGB color, green is 60 percent of white. When we look through a prism at a white square, as Goethe did, we see white between yellow and cyan, just where green appears in the spectrum of Newton. Additional arguments were published previously and appear at www.csulb.edu/-percept, along with the Percept color chart of the hue/value relationships. A new argument, derived from the perception of leaves, is presented here. The Percept color chart transformed into a color wheel is also presented.

  3. Seismites in continental sand sea deposits of the Late Cretaceous Caiu Desert, Bauru Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Fernandes, Luiz Alberto; de Castro, Alice Bonatto; Basilici, Giorgio

    2007-07-01

    Two large-scale sediment deformation structures, minor fold occurrences in cross-bedded sand dune deposits and complex convolute folds, are observed in red sandstones, in a zone about 1.5 km long in floodway cuts at the Srgio Motta/Porto Primavera dam, So Paulo state, Brazil. The most important structures are confined to planar zones, up to 10 m thick, in undeformed dune foreset strata were they can be traced laterally for about 50-60 m. The sandstones are part of the Rio Paran Formation, Caiu Group, which accumulated in a great sand sea of about 100,000 km 2. The Caiu Desert developed during the Late Cretaceous in the southern part of the Bauru Basin, an intracontinental subsiding area in the central-southern part of the South-American Platform. The basin was filled by a sandy sequence about 300 m thick. The sand sea deposits correspond to the Caiu Group and comprise: a) deposits of dry sand sheets (Santo Anastcio Formation), b) deposits of medium-sized dunes and humid interdunes of the sand sea peripheral zones (Goio Er Formation), and c) deposits of large-sized complex aeolian dunes and draas, that correspond to the central part of the inland sand sea (Rio Paran Formation). The deformations in the sediments are attributed to the effects of fluidization, liquefaction and shear stress, which are interpreted as being earthquake-induced structures, mainly because: (1) the deformed horizons are confined between undeformed cross-bedded strata, (2) the complex convolute folds sometimes include nappe-like structures that overlie foreset facies, (3) during the Bauru Basin infilling there was tectonic activity associated with alkaline volcanism on the borders of the basin and related silicification in the central-southern part. The main silicification zones are aligned to regional lineaments that cross the area near the large-scale sedimentary deformation structures.

  4. Object technology: A white paper

    SciTech Connect

    Jordan, S.R.; Arrowood, L.F.; Cain, W.D.; Stephens, W.M.; Vickers, B.D.

    1992-05-11

    Object-Oriented Technology (OOT), although not a new paradigm, has recently been prominently featured in the trade press and even general business publications. Indeed, the promises of object technology are alluring: the ability to handle complex design and engineering information through the full manufacturing production life cycle or to manipulate multimedia information, and the ability to improve programmer productivity in creating and maintaining high quality software. Groups at a number of the DOE facilities have been exploring the use of object technology for engineering, business, and other applications. In this white paper, the technology is explored thoroughly and compared with previous means of developing software and storing databases of information. Several specific projects within the DOE Complex are described, and the state of the commercial marketplace is indicated.

  5. Activity of Wind-Blown Sand and the Formation of Feathered Sand Ridges in the Kumtagh Desert, China

    NASA Astrophysics Data System (ADS)

    Liao, Kongtai; Qu, Jianjun; Tang, Jinnian; Ding, Feng; Liu, Hujun; Zhu, Shujuan

    2010-05-01

    We study the activity of wind-blown sand and its effects on the evolution of feathered sand ridges in the Kumtagh Desert, China, and attempt to reveal the formation process of feathered sand ridges using wind-tunnel experiments, remote sensing data, and detailed field observations from 2005 to 2008. The prevailing wind direction in the Kumtagh Desert is easterly in winter and north-easterly in other seasons. The average annual wind speed is 5.9 ms-1, and winds sufficiently strong to entrain sand occur on 143 days per annum. The sand transport rate within 0.4 m of the ground is strongly influenced by local landforms, and is related to wind speed by a power function. Wind erosion occurs on the crest, the windward slope of crescent sand ridges and inter-ridge sand strips, where the blowing sand cloud is in an unsaturated state; in contrast, sand accumulation occurs on the leeward slope of the crescent sand ridges, where the blowing sand cloud is in an over-saturated state. These results indicate that the development of feathered sand ridges in the Kumtagh Desert is mainly controlled by the local wind regime. The dominant winds (from the north, north-north-east and north-east) and additional winds (from the east-north-east, east and east-south-east) determine the development of crescent sand ridges, but winds that are approximately parallel to sand ridges form the secondary inter-ridge sand strips.

  6. Interior of Left Powerhouse showing the Whiting (Company's) "Tiger" crane ...

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

    Interior of Left Powerhouse showing the Whiting (Company's) "Tiger" crane with a capacity of 350 tons, looking west. Note the terrazzo floor below depicting a Francis turbine. - Columbia Basin Project, Grand Coulee Dam Powerplant Complex, Grand Coulee, Grant County, WA

  7. A study of morphology, provenance, and movement of desert sand seas in Africa, Asia, and Australia

    NASA Technical Reports Server (NTRS)

    Mckee, E. D.; Breed, C. S.

    1973-01-01

    A description and classification of major types of sand seas on the basis of morphological pattern and lineation are discussed. The steps involved in analyzing the patterns of deposits on ERTS-1 imagery, where the visible forms are mostly dune complexes rather than individual dunes are outlined. After completion of thematic maps portraying the pattern and lineation of the sand bodies, data on directions and intensity of prevailing and other winds are plotted on corresponding bases, as a preliminary to determination of internal structures through ground truth.

  8. White Dwarfs in UKIDSS

    NASA Astrophysics Data System (ADS)

    Steele, P. R.; Burleigh, M. R.; Farihi, J.; Gänsicke, B.; Jameson, R. F.; Dobbie, P. D.; Barstow, M. A.

    We present a near-infrared photometric search for low mass stellar and substellar companions, and for debris disks around white dwarfs in the UKIDSS Large Area Survey DR5. A cross correlation of the SDSS DR4 and McCook and Sion catalogues of white dwarfs gave near-infrared photometry for 1,161 stars. Atmospheric models are fitted to the optical and near-infrared photometry of the matched stars to identify those with a photometric excess consistent with an unresolved companion or debris disk. In total 7 new potential white dwarf + brown dwarf binary candidates have been identified. We present follow-up spectroscopy of a previously identified candidate; PHL5038. We confirm that this system is a resolved white dwarf + L8 brown dwarf binary.

  9. Mine Drainage and Oil Sand Water.

    PubMed

    Wei, Xinchao; Wolfe, F Andrew; Li, Yanjun

    2015-10-01

    Mine drainage from the mining of mineral resources (coal, metals, oil sand, or industrial minerals) remains as a persistent environmental problem. This review summarizes the scientific literature published in 2014 on the technical issues related to mine drainage or mine water in active and abandoned coal/hard rock mining sites or waste spoil piles. Also included in this review is the water from oil sand operations. This review is divided into the four sections: 1) mine drainage characterization, 2) prediction and environmental impact, 3) treatment technologies, 4) oil sand water. Many papers presented in this review address more than one aspect and different sections should not be regarded as being mutuallyexclusive or all-inclusive. PMID:26420092

  10. The yield stress of foamy sands

    SciTech Connect

    Kam, S. I.; Gauglitz, Phillip A.; Rossen, W R.

    2002-03-26

    The yield stress of a mixture of foam and solids, or foamy sand, was investigated theoretically using 2D periodic model. The range of solid fractions considered was from about 40 to 68%. The yield stress of a foamy sand increases with gas fraction at a given solid fraction and increases with solid fraction at a given gas fraction. At a fixed fraction of solid plus gas, yield stress is relatively insensitive to gas or solid fraction alone. There exists a maximum liquid fraction above which the yield stress disappears. These trends agree with those reported for foamy sands encountered in tunneling through soft sediments and proppant-laden fracturing fluids used in the petroleum industry.

  11. Sliding friction on wet and dry sand.

    PubMed

    Fall, A; Weber, B; Pakpour, M; Lenoir, N; Shahidzadeh, N; Fiscina, J; Wagner, C; Bonn, D

    2014-05-01

    We show experimentally that the sliding friction on sand is greatly reduced by the addition of some-but not too much-water. The formation of capillary water bridges increases the shear modulus of the sand, which facilitates the sliding. Too much water, on the other hand, makes the capillary bridges coalesce, resulting in a decrease of the modulus; in this case, we observe that the friction coefficient increases again. Our results, therefore, show that the friction coefficient is directly related to the shear modulus; this has important repercussions for the transport of granular materials. In addition, the polydispersity of the sand is shown to also have a large effect on the friction coefficient. PMID:24836256

  12. UV disinfection for onsite sand filter effluent

    SciTech Connect

    Lowery, J.D.; Romatzick, S.

    1982-05-01

    The technical and economic feasibility of using ultraviolet (uv) light as a viable alternative to chlorine as the required disinfectant for onsite sand filter effluents discharged to surface waters in Maine was determined. To obtain a reliable cross section of performance for sand filters in Maine, 74 filters were selected for an effluent characterization program. The effluent characterization study allowed general conclusions to be made with regard to the potential of uv disinfection. A simple suspended lamp uv disinfection unit was designed, constructed, and tested in the laboratory and in the field. The efficiency of the uv disinfection unit was determined through field testing at 10 of the 74 sand filter sites used in the effluent characterization program.

  13. The sand-glass gas detector (SGG)

    NASA Astrophysics Data System (ADS)

    Majewski, P.; Brom, J.-M.; ?wiok, M.; Dominik, W.; Krlikowski, J.; Labb, J.-C.; Lounis, A.; Veenhof, R.

    2002-02-01

    A novel position-sensitive micro-pattern gas detector called Sand-Glass is introduced. It has been manufactured using printed circuit board technique and its structure is based on two thin kapton foils joined together. The foils are copper-clad on both sides with the strip electrodes structure engraved on either side, and with a very dense perforation in the form of a conically shaped hole pattern etched through both foils, which forms the Sand-Glass shape. The two foils are in electrical contact; the outer faces form cathodes, and the inner layer becomes an anode. Due to the electric field symmetry, electrons from avalanches are collected on the central electrode of the Sand-Glass holes. This geometry may allow 2D readout in the single gas amplification structure. Preliminary results of the SGG detector prototype tests are reported.

  14. White Racial Identity Statuses as Predictors of White Privilege Awareness

    ERIC Educational Resources Information Center

    Hays, Danica G.; Chang, Catherine Y.; Havice, Pamela

    2008-01-01

    This study explored the relationship between White privilege awareness and White racial identity development for 197 counseling trainees. Results indicated that 3 of J. E. Helms's (1984, 1990, 1995) White racial identity statuses (i.e., Contact, Reintegration, and Immersion/Emersian) significantly predicted White privilege awareness. Implications

  15. White Racial Identity Statuses as Predictors of White Privilege Awareness

    ERIC Educational Resources Information Center

    Hays, Danica G.; Chang, Catherine Y.; Havice, Pamela

    2008-01-01

    This study explored the relationship between White privilege awareness and White racial identity development for 197 counseling trainees. Results indicated that 3 of J. E. Helms's (1984, 1990, 1995) White racial identity statuses (i.e., Contact, Reintegration, and Immersion/Emersian) significantly predicted White privilege awareness. Implications…

  16. Beyond Black and White.

    ERIC Educational Resources Information Center

    Comer, James P.

    Black and white conflict is a by-product of a more basic problem: the failure of this society to develop a social system that enables all people to meet their basic human needs at a reasonable level. Until this is done, we will not be able to move beyond black and white. The underlying problem is related to a sudden acceleration of human history

  17. Creating fluid injectivity in tar sands formations

    SciTech Connect

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2010-06-08

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

  18. Creating fluid injectivity in tar sands formations

    SciTech Connect

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2012-06-05

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons including mobilized hydrocarbons are produced from the portion.

  19. Electrical properties of eolian sand and silt

    NASA Astrophysics Data System (ADS)

    Kanagy, S. P.; Mann, C. John

    1994-08-01

    A review of observed and theoretically expected electrical properties of eolian sand, silt and dust reveals that little attention has been directed by geologists and geophysicists toward sand and silt even though much research on dust has demonstrated the importance of electrical charging. Potential mechanisms for non-uniform charging and/or polarization of sand and silt particles include (1) polarization by Earth's atmospheric electric field, (2) triboelectrification, (3) contact electrification, (4) cleavage/fractoelectrification, (5) radiation (X-rays, gamma rays, UV and visible) and charged particle bombardment electrification, (6) pyroelectrification and (7) piezoelectrification. Electrical charges may have significant effects upon sand and silt behavior during transport, deposition and, subsequently, at rest. These effects include greater mobility during particle repulsion, aggregation and greater stability after particle deposition. Charged particles in Earth's electromagnetic field also may add or subtract from the effect of Earth's gravitational field, depending on net sign of charge. Electric charge retention among grains at rest may be much greater than intuitive inference suggests and may be a major factor in explaining larger angles of repose in ancient sediments compared to present sediments. Although light and acoustical emissions during sand and silt transport have long been recognized and at times inferred to be due to electric discharging of grains, no scientific models or explanations have been proposed which adequately explain these phenomena. Charges on individual grains are expected to range from 10 -1 to 10 2 pC, but never have been measured under field conditions. During a sand storm, field strength arising from the cumulative effect of grain charges can be expected to range from 10-30 kV/m. Many additional data need to be accumulated and more detailed research performed before an adequate electrical model for sand behavior during transport and deposition, as well as at rest, can be formulated. All major empirical observations, including relative contributions by various charging mechanisms and associated light and acoustical emissions, should be predicted accurately by an acceptable model for electrical charging of eolian sand and silt.

  20. Threshold for sand mobility on Mars calibrated from seasonal variations of sand flux.

    PubMed

    Ayoub, F; Avouac, J-P; Newman, C E; Richardson, M I; Lucas, A; Leprince, S; Bridges, N T

    2014-01-01

    Coupling between surface winds and saltation is a fundamental factor governing geological activity and climate on Mars. Saltation of sand is crucial for both erosion of the surface and dust lifting into the atmosphere. Wind tunnel experiments along with measurements from surface meteorology stations and modelling of wind speeds suggest that winds should only rarely move sand on Mars. However, evidence for currently active dune migration has recently accumulated. Crucially, the frequency of sand-moving events and the implied threshold wind stresses for saltation have remained unknown. Here we present detailed measurements of Nili Patera dune field based on High Resolution Imaging Science Experiment images, demonstrating that sand motion occurs daily throughout much of the year and that the resulting sand flux is strongly seasonal. Analysis of the seasonal sand flux variation suggests an effective threshold for sand motion for application to large-scale model wind fields (1-100?km scale) of ?(s)=0.010.0015?N?m(-2). PMID:25268931

  1. Discrimination and psychological distress: does Whiteness matter for Arab Americans?

    PubMed

    Abdulrahim, Sawsan; James, Sherman A; Yamout, Rouham; Baker, Wayne

    2012-12-01

    The white racial category in the U.S. encompasses persons who have Arab ancestry. Arab Americans, however, have always occupied a precarious position in relationship to Whiteness. This study examined differences in reporting racial/ethnic discrimination among Arab Americans. It also investigated whether and how the association between discrimination and psychological distress varies by characteristics that capture an Arab American's proximity to/distance from Whiteness. We used data from the Detroit Arab American Study (2003; n = 1016), which includes measures of discrimination and the Kessler-10 scale of psychological distress. A series of logistic regression models were specified to test the discrimination-psychological distress association, stratified by five measures that capture Whiteness--subjective racial identification, religion, skin color, ethnic centrality, and residence in the ethnic enclave. Discrimination was more frequently reported by Muslim Arab Americans, those who racially identify as non-white, and who live in the ethnic enclave. Conversely, the association between discrimination and psychological distress was stronger for Christian Arab Americans, those who racially identify as white, who have dark skin color, and who live outside the ethnic enclave. Even though Arab Americans who occupy an identity location close to Whiteness are less subjected to discrimination, they are more negatively affected by it. The findings illuminate the complex pathways through which discrimination associates with psychological distress among 'white' immigrants. Further research on discrimination and health among Arab Americans can help unpack the white racial category and deconstruct Whiteness. PMID:22901668

  2. Sand fly fauna (Diptera, pcychodidae, phlebotominae) in different leishmaniasis-endemic areas of ecuador, surveyed using a newly named mini-shannon trap.

    PubMed

    Hashiguchi, Kazue; Velez N, Lenin; Kato, Hirotomo; Criollo F, Hipatia; Romero A, Daniel; Gomez L, Eduardo; Martini R, Luiggi; Zambrano C, Flavio; Calvopina H, Manuel; Caceres G, Abraham; Hashiguchi, Yoshihisa

    2014-12-01

    To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named "mini-Shannon trap" and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps. PMID:25589880

  3. Sand Fly Fauna (Diptera, Pcychodidae, Phlebotominae) in Different Leishmaniasis-Endemic Areas of Ecuador, Surveyed Using a Newly Named Mini-Shannon Trap

    PubMed Central

    Hashiguchi, Kazue; Velez N., Lenin; Kato, Hirotomo; Criollo F., Hipatia; Romero A., Daniel; Gomez L., Eduardo; Martini R., Luiggi; Zambrano C., Flavio; Calvopina H., Manuel; Caceres G., Abraham; Hashiguchi, Yoshihisa

    2014-01-01

    To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named “mini-Shannon trap” and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps. PMID:25589880

  4. Role of a large marine protected area for conserving landscape attributes of sand habitats on Georges Bank (NW Atlantic)

    USGS Publications Warehouse

    Lindholm, J.; Auster, P.; Valentine, P.

    2004-01-01

    Mobile fishing gear reduces seafloor habitat complexity through the removal of structure-building fauna, e.g. emergent organisms that create pits and burrows, as well as by smoothing of sedimentary bedforms (e.g. sand ripples). In this study, we compared the relative abundance of microhabitat features (the scale at which individual fish associate with seafloor habitat) inside and outside of a large fishery closed area (6917 km2) on Georges Bank. Starting in late 1994, the closed area excluded all bottom tending fishing gear capable of capturing demersal fishes. A total of 32 stations were selected inside and outside of the closed area in sand habitats. Video and still photographic transects were conducted at each station using the Seabed Observation and Sampling System (SEABOSS). Seven common (i.e. featureless sand, rippled sand, sand with emergent fauna, bare gravelly sand, gravelly sand with attached-erect fauna, whole shell, shell fragment) and 2 rare (sponges, biogenic depressions) microhabitat types were compared separately. Results showed significant differences in the relative abundance of the shell fragment and sponge microhabitat types between fished and unfished areas. The lack of differences for the other microhabitats may indicate that the level of fishing activity in the area is matched by the system's ability to recover.

  5. White Students' Understanding of Race: An Exploration of How White University Students, Raised in a Predominately White State, Experience Whiteness

    ERIC Educational Resources Information Center

    Smith, Barbara A.

    2014-01-01

    This study examines White university students' understanding of race. Based in the scholarship on higher education and diversity, and framed in Critical Race Theory (CRT), this study explores the racial awareness of White students. This study contributes to the literature on the racial experience of Whites and an understanding of how White

  6. White Skin, Black Friend: A Fanonian Application to Theorize Racial Fetish in Teacher Education

    ERIC Educational Resources Information Center

    Matias, Cheryl E.

    2016-01-01

    In "Black Skin, white masks" (1967, Grove Press), Franz Fanon uses a psychoanalytic framework to theorize the inferiority-dependency complex of Black men in response to the colonial racism of white men. Applying his framework in reverse, this theoretical article psychoanalyzes the white psyche and emotionality with respect to the

  7. White Skin, Black Friend: A Fanonian Application to Theorize Racial Fetish in Teacher Education

    ERIC Educational Resources Information Center

    Matias, Cheryl E.

    2016-01-01

    In "Black Skin, white masks" (1967, Grove Press), Franz Fanon uses a psychoanalytic framework to theorize the inferiority-dependency complex of Black men in response to the colonial racism of white men. Applying his framework in reverse, this theoretical article psychoanalyzes the white psyche and emotionality with respect to the…

  8. Exploring how sand ramps respond to Quaternary environmental change in Southern Africa

    NASA Astrophysics Data System (ADS)

    Rowell, Alex; Thomas, David; Bailey, Richard

    2014-05-01

    The current climate of southern Africa is particularly complex and interesting due to the interaction of several climatic systems. However, reconstructions of how these systems behaved in the past, and how the environment responded, have been hampered by a general paucity of records and poor chronological control. Sand ramps may provide the potential to improve palaeoenvironmental reconstructions of southern Africa (and beyond). Formed against a topographic barrier, sand ramps include a combination of aeolian, fluvial and colluvial deposits in varying proportions. Therefore, they have the potential to record changes in moisture availability, circulation patterns and sediment supply which can be independently dated using luminescence dating. Nevertheless relatively little attention has been paid to these features and thus the environmental controls on their formation are not yet fully understood. In particular, there is debate as to whether they reflect deposition during a 'window of opportunity' in which high-magnitude, low-frequency events are recorded (Bateman et al. 2012) or whether they record more gradual, cyclic climate change (Bertram, 2003) or even if there is a uniform control on their formation. This research aims to investigate how sand ramps respond to environmental change and what they can tell us about the paleoenvironment of southern Africa. This poster displays preliminary results based on initial field investigation. This confirmed sand ramps to be ubiquitous in southern Africa and that they record a complex interaction of aeolian, fluvial and colluvial deposits which appears to differ between sand ramps. Preliminary luminescence dating results and sedimentology are displayed for two sand ramps, one from south west Namibia the other from the Karoo region of South Africa.

  9. Simulation of aeolian sand saltation with rotational motion

    NASA Astrophysics Data System (ADS)

    Huang, Ning; Wang, Cong; Pan, Xiying

    2010-11-01

    In this work, we propose a theoretical model based on the distribution functions of initial liftoff velocity and angular velocity of sand grains to describe a sand saltation process in which both wind field-sand grain coupling and the Magnus force experienced by saltating sand grains have been incorporated. The computation results showed that the Magnus force had significant effects on sand grain saltation. In particular, when the Magnus force was incorporated, the calculated sand transport fluxes and sand transport rate per unit width were closer to the experimental value than when this force was excluded. The sand transport flux is enhanced because the Magnus force owing to particle rotation causes the particles to have higher and longer trajectories, so the particles can get more speed and energy from the wind, which leads to a larger sand transport flux. In addition, it was found that when taking the Magnus force into account, the probability density of the impact velocity and angular velocity of saltating sand grains followed an exponential distribution and a unimodal asymmetric distribution, respectively. Moreover, the sand energy flux increased with the height above the sand surface until the energy flux reached its maximum and then decreased. Furthermore, the energy flux near the ground surface decreased as the grain diameter increased, but beyond a specific height the energy flux increased with the grain diameter. Finally, for the same sand grain diameter, the energy flux increased with the friction velocity.

  10. Sarcoglycan Complex

    PubMed Central

    Groh, Sverine; Zong, Haihong; Goddeeris, Matthew M.; Lebakken, Connie S.; Venzke, David; Pessin, Jeffrey E.; Campbell, Kevin P.

    2009-01-01

    The sarcoglycans are known as an integral subcomplex of the dystrophin glycoprotein complex, the function of which is best characterized in skeletal muscle in relation to muscular dystrophies. Here we demonstrate that the white adipocytes, which share a common precursor with the myocytes, express a cell-specific sarcoglycan complex containing ?-, ?-, and ?-sarcoglycan. In addition, the adipose sarcoglycan complex associates with sarcospan and laminin binding dystroglycan. Using multiple sarcoglycan null mouse models, we show that loss of ?-sarcoglycan has no consequence on the expression of the adipocyte sarcoglycan complex. However, loss of ?- or ?-sarcoglycan leads to a concomitant loss of the sarcoglycan complex as well as sarcospan and a dramatic reduction in dystroglycan in adipocytes. We further demonstrate that ?-sarcoglycan null mice, which lack the sarcoglycan complex in adipose tissue and skeletal muscle, are glucose-intolerant and exhibit whole body insulin resistance specifically due to impaired insulin-stimulated glucose uptake in skeletal muscles. Thus, our data demonstrate a novel function of the sarcoglycan complex in whole body glucose homeostasis and skeletal muscle metabolism, suggesting that the impairment of the skeletal muscle metabolism influences the pathogenesis of muscular dystrophy. PMID:19494113

  11. Sand injectites network as a marker of the palaeo-stress field, the structural framework and the distance to the sand source: Example in the Vocontian Basin, SE France

    NASA Astrophysics Data System (ADS)

    Monnier, Damien; Gay, Aurélien; Imbert, Patrice; Cavailhes, Thibault; Soliva, Roger; Lopez, Michel

    2015-10-01

    A large sand injectite network is very well exposed in the area of Bevons, Southeast France. The associated sandstone turbiditic channel-fill and the host marls are the Aptian-Albian rocks of the Vocontian Basin. The sand injection network is composed of dykes, sills and sedimentary laccoliths ranging in thickness from mm to pluri-m. The dykes and sills have vertical and horizontal lengths of up to and over 100 m and 1 km, respectively. Outcrop observations show that the architecture and morphology of the sand injectites in the marls is governed by the local stress field during injection, pre-existing faults, the host-rock lithology, compaction, and distance to the potential sand source(s). The main set of dykes is oriented N50-60° perpendicular to the minimum compressive stress σ3 during sand injection. Two other sets of dykes are intruded along pre-existing syn-sedimentary faults oriented N140-150° (set 2) and N90° (set 3) during the Apto-Cenomanian interval. Sills and dykes thin laterally away from their potential sand sources and thin laterally away from them. The vertical thickness variations of the dykes and wings are more complex, as thinning away from the sand sources is often compensated by thickening toward the palaeo-surface. Based on field observations and measurements, we characterized the 3D architecture of the sand injectites and showed that the injectites probably formed due to a forceful injection from an overpressured sand body sealed by low-permeability lithologies.

  12. White Rabbit in space related application

    NASA Astrophysics Data System (ADS)

    Jamro?y, M.; Gumi?ski, M.; Kasprowicz, G.; Romaniuk, R.; Po?niak, K.

    2015-09-01

    This paper describes study results regarding potential use of White Rabbit technology in Space Related Applications. During the study Technology Readiness Level and Compliance with Space Related Applications was evaluated. After considering possible deployment and development scenarios, main focus has been put on European Space Agency's tracking station system. This outcome derived from specific requirements of tracking system which are coherent with White Rabbit technology scope of application and further development plans. Current state of Time and Frequency Distribution technology implemented into tracking stations is based on multiple different technologies coexisting in parallel creating a complex system. It requires specific, custom made hardware to combine all the technologies which makes it expensive and difficult to maintain. White Rabbit could be use to reduce Time and Frequency Distribution to a single Ethernet based network with link redundancy, payload data transfer and sub-nanosecond accuracy.

  13. Connecting onshore and offshore near-surface geology: Delaware's sand inventory project

    USGS Publications Warehouse

    Ramsey, K.W.; Jordan, R.R.; Talley, J.H.

    1999-01-01

    Beginning in 1988, the Delaware Geological Survey began a program to inventory on-land sand resources suitable for beach nourishment. The inventory included an assessment of the native beach textures using existing data and developing parameters of what would be considered suitable sand textures for Delaware's Atlantic beaches. An assessment of the economics of on-land sand resources was also conducted, and it was determined that the cost of the sand was competitive with offshore dredging costs. In addition, the sand resources were put into a geologic context for purposes of predicting which depositional environments and lithostratigraphic units were most likely to produce suitable sand resources. The results of the work identified several suitable on-land sand resource areas in the Omar and Beaverdam formations that were deposited in barrier-tidal delta and fluvial-estuarine environments, respectively. The identified on-land resources areas have not been utilized due to difficulties of truck transport and development pressures in the resource areas. The Delaware Geological Survey's participation in years 8, 9, and 10 of the Continental Margins Program was developed to extend the known resource areas onshore to offshore Delaware in order to determine potential offshore sand resources for beach nourishment. Years 8 and 9 involved primarily the collection of all available data on the offshore geology. These data included all seismic lines, surface grab samples, and cores. The data were filtered for those that had reliable locations and geologic information that could be used for geologic investigations. Year 10 completed the investigations onshore by construction of a geologic cross-section from data along the coast of Delaware from Cape Henlopen to Fenwick. This cross section identified the geologic units and potential sand resource bodies as found immediately along the coast. These units and resources are currently being extended offshore and tied to known and potential sand resources as part of the continuing cooperative effort between the Delaware Geological Survey and the Minerals Management Service's INTERMAR office as sand resources are identified in federal waters off Delaware. Offshore sand resources are found in the Pliocene Beaverdam Formation offshore where overlying Quaternary units have been stripped, in the tidal delta complexes of several Quaternary units likely equivalent to the onshore Omar Formation, and in late Pleistocene- and Holocene-age shoal complexes. Onshore lithostratigraphic units can be traced offshore and show another reason for continued geologic mapping both onshore and offshore.The Delaware Geological Survey's participation in years 8, 9, and 10 of the Continental Margins Program was developed to extend the known resource areas onshore to offshore Delaware in order to determine potential offshore sand resources for beach nourishment. Years 8 and 9 involved primarily the collection of all available data on the offshore geology. These data included all seismic lines, surface grab samples, and cores. The data were filtered for those that had reliable locations and geologic information that could be used for geologic investigations. Year 10 completed the investigations onshore by construction of a geologic cross-section from data along the coast of Delaware from cape Henlopen to Fenwick.

  14. Building Whales in Sand and Mind.

    ERIC Educational Resources Information Center

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales…

  15. WASTEWATER STABILIZATION LAGOON, INTERMITTENT SAND FILTER SYSTEMS

    EPA Science Inventory

    The performance of three prototype lagoon-intermittent sand filtration systems were evaluated for three 30 consecutive day periods during different seasons throughout a sixteen month period. Twenty-four different parameters were monitored on 24-hour composite samples. Design crit...

  16. TOXOPLASMOSIS IN SAND FOX (VULPUS RUEPPELLII)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatal toxoplasmosis was diagnosed in a sand fox (Vulpes rueppelli) from United Arab Emirates. Toxoplasma gondii-like tachyzoites were found associated with necrosis in intestine, spleen, liver, pancreas, lungs, mesenteric lymph nodes, and the heart. Ttachyzoites reacted positively with T. gondii-spe...

  17. Building Whales in Sand and Mind.

    ERIC Educational Resources Information Center

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales

  18. Sand sagebrush rangeland utilization by cattle producers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1939, when the USDA purchased the Southern Plains Experimental Range (SPER), scientists of the USDA-Agricultural Research Service have been researching the appropriate uses of native mixed-grass prairie with an over story of sand sagebrush (Artemisia filifolia Torr.). This range type inhabits...

  19. SOURCE ASSESSMENT: TRANSPORT OF SAND AND GRAVEL

    EPA Science Inventory

    This report describes a study of atmospheric emissions from the transport of sand and gravel on unpaved roads. The potential environmental effect of this emission source was evaluated using source severity, defined as the ratio of the time-averaged maximum ground level concentrat...

  20. EXPRESSING SUPPLY LIMITATION IN SAND SALTATION

    EPA Science Inventory

    Saltation-driven sandblasting is the most effective producer of windblown dust. Modeling of wind-blown dust emissions requires an efficient parameterization of sand flux in the saltating mode. According to the theory of P. R. Owen the horizontal mass flux of saltating uniform p...

  1. Thermal diffusivity of peat, sand and their mixtures at different water contents

    NASA Astrophysics Data System (ADS)

    Gvozdkova, Anna; Arkhangelskaya, Tatiana

    2014-05-01

    Thermal diffusivity of peat, sand and their mixtures at different water contents was studied using the unsteady-state method described in (Parikh et al., 1979). Volume sand content in studied samples was 0 % (pure peat), 5, 10, 15, 20, 30, 40, 50, 55 and 62 % (pure sand). Thermal diffusivity of air-dry samples varied from 0.610-7m2s-1 for pure peat to 7.010-7m2s-1 for pure sand. Adding 5 and 10 vol. % of sand didn't change the thermal diffusivity of studied mixture as compared with that of the pure air-dry peat. Adding 15 % of sand resulted in significant increase of thermal diffusivity by approximately 1.5 times: from 0.610-7m2s-1 to 0.910-7m2s-1. It means that small amounts of sand with separate sand particles distributed within the peat don't contribute much to the heat transfer through the studied media. And there is a kind of threshold between the 10 and 15 vol. % of sand, after which the continuous sandy chains are formed within the peat, which can serve as preferential paths of heat transport. Adding 20 and 30 % of sand resulted in further increase of thermal diffusivity to 1.310-7m2s-1 and 1.710-7m2s-1, which is more than two and three times greater than the initial value for pure peat. Thermal diffusivity vs. moisture content dependencies had different shapes. For sand contents of 0 to 40 vol. % the thermal diffusivity increased with water content in the whole studied range from air-dry samples to the capillary moistened ones. For pure peat the experimental curves were almost linear; the more sand was added the more pronounced became the S-shape of the curves. For sand contents of 50 % and more the curves had a pronounced maximum within the range of water contents between 0.10 and 0.25 m3m-3 and then decreased. The experimental k(?) curves, where k is soil thermal diffusivity, ? is water content, were parameterized with a 4-parameter approximating function (Arkhangelskaya, 2009, 2014). The suggested approximation has an advantage of clear physical interpretation: the parameters are (1) the thermal diffusivity of the dry sample; (2) the difference between the highest thermal diffusivity at some optional water content and that of the dry sample; (3) the optional water content at which the thermal diffusivity reaches its maximum; (4) half-width of the peak of the k(?) curve. The increase of sand contents in studied mixtures was accompanied by the increase of the parameters (1), (2) and (4) and the decrease of the parameter (3). References Parikh R.J., Havens J.A., Scott H.D., 1979. Thermal diffusivity and conductivity of moist porous media. Soil Science Society of America Journal 43, 1050-1052. Arkhangel'skaya T.A., 2009. Parameterization and mathematical modeling of the dependence of soil thermal diffusivity on the water content. Eurasian Soil Science 42 (2), 162-172. doi: 10.1134/S1064229309020070 Arkhangelskaya T.A., 2014. Diversity of thermal conditions within the paleocryogenic soil complexes of the East European Plain: The discussion of key factors and mathematical modeling // Geoderma. Vol. 213. P. 608-616. doi 10.1016/j.geoderma.2013.04.001

  2. The provenance of Taklamakan desert sand

    NASA Astrophysics Data System (ADS)

    Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

    2016-03-01

    Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run-off and wind intensity are strongly seasonal, their respective transport strength and opposing directions maintain the Taklamakan in its position and topography.

  3. Deformation and shock consolidation of various sands under explosive loading

    NASA Astrophysics Data System (ADS)

    Weckert, S. A.; Resnyansky, A. D.

    2015-06-01

    Transmission of a shock wave through various geological materials is important in military applications, for assessing the effects from a buried explosive device to an above-ground target. The composition of a real soil is complex and involves multiple constituents that undergo a number of physical and mechanical transformations during the shock loading. The present study analyzes several model soils represented by limestone sand, silica sand, and a small aggregate soil. The soils are compressed using two different steel encapsulation assemblies subject to explosive compression. These set-ups attempt to vary the level of applied load to the encapsulated soil and the length of the high-temperature effects. The assemblies are instrumented with embedded manganin gauges within the encapsulation casing for comparative analysis of the waves propagating through the soil and steel encapsulation. A comparative analysis of the recovered soil samples, including a microstructural analysis focusing on the grain breakage, soil compaction and consolidation, is correlated with a CTH numerical analysis employing a multi-phase rate sensitive material model.

  4. Ottawa Sand for Mechanics of Granular Materials (MGM) Experiment

    NASA Technical Reports Server (NTRS)

    2000-01-01

    What appear to be boulders fresh from a tumble down a mountain are really grains of Ottawa sand, a standard material used in civil engineering tests and also used in the Mechanics of Granular Materials (MGM) experiment. The craggy surface shows how sand grans have faces that can cause friction as they roll and slide against each other, or even causing sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. MGM uses the microgravity of space to simulate this behavior under conditions that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. These images are from an Electron Spectroscopy for Chemical Analysis (ESCA) study conducted by Dr. Binayak Panda of IITRI for Marshall Space Flight Center (MSFC). (Credit: NASA/MSFC)

  5. Mineral resource of the month: industrial sand and gravel

    USGS Publications Warehouse

    Dolley, Thomas P.

    2007-01-01

    With many diverse uses, industrial sand and gravel, also known as silica sand, is one of the most important nonmetallic minerals in the world. Industrial sand and gravel is a mining industry term used for sands that have a very high percentage of silicon dioxide, or greater than 95 percent quartz. Deposits of industrial sand and gravel can be found virtually everywhere on Earth, but are less widespread than deposits of common construction sand and gravel. Industrial sand and gravel is distinctive in grain size, hardness, inertness and resistance to high temperature and chemical action. Beverage containers, fiberglass insulation, fiber-optic cables and light bulbs are just some of todays many products produced from industrial sand and gravel.

  6. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. ...

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

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  7. New Method for Estimation of Aeolian Sand Transport Rate Using Ceramic Sand Flux Sensor (UD-101)

    PubMed Central

    Udo, Keiko

    2009-01-01

    In this study, a new method for the estimation of aeolian sand transport rate was developed; the method employs a ceramic sand flux sensor (UD-101). UD-101 detects wind-blown sand impacting on its surface. The method was devised by considering the results of wind tunnel experiments that were performed using a vertical sediment trap and the UD-101. Field measurements to evaluate the estimation accuracy during the prevalence of unsteady winds were performed on a flat backshore. The results showed that aeolian sand transport rates estimated using the developed method were of the same order as those estimated using the existing method for high transport rates, i.e., for transport rates greater than 0.01 kg m?1 s?1. PMID:22291553

  8. New Method for Estimation of Aeolian Sand Transport Rate Using Ceramic Sand Flux Sensor (UD-101).

    PubMed

    Udo, Keiko

    2009-01-01

    In this study, a new method for the estimation of aeolian sand transport rate was developed; the method employs a ceramic sand flux sensor (UD-101). UD-101 detects wind-blown sand impacting on its surface. The method was devised by considering the results of wind tunnel experiments that were performed using a vertical sediment trap and the UD-101. Field measurements to evaluate the estimation accuracy during the prevalence of unsteady winds were performed on a flat backshore. The results showed that aeolian sand transport rates estimated using the developed method were of the same order as those estimated using the existing method for high transport rates, i.e., for transport rates greater than 0.01 kg m(-1) s(-1). PMID:22291553

  9. Drag reduction using superhydrophobic sanded Teflon surfaces

    NASA Astrophysics Data System (ADS)

    Song, Dong; Daniello, Robert J.; Rothstein, Jonathan P.

    2014-08-01

    In this paper, a series of experiments are presented which demonstrate drag reduction for the laminar flow of water through microchannels using superhydrophobic surfaces with random surface microstructure. These superhydrophobic surfaces were fabricated with a simple, inexpensive technique of sanding polytetrafluoroethylene (PTFE) with sandpaper having grit sizes between 120- and 600-grit. A microfluidic device was used to measure the pressure drop as a function of the flow rate to determine the drag reduction and slip length of each surface. A maximum pressure drop reduction of 27 % and a maximum apparent slip length of b = 20 ?m were obtained for the superhydrophobic surfaces created by sanding PTFE with a 240-grit sandpaper. The pressure drop reduction and slip length were found to increase with increasing mean particle size of the sandpaper up to 240-grit. Beyond that grit size, increasing the pitch of the surface roughness was found to cause the interface to transition from the Cassie-Baxter state to the Wenzel state. This transition was observed both as an increase in the contact angle hysteresis and simultaneously as a reduction in the pressure drop reduction. For these randomly rough surfaces, a correlation between the slip length and the contact angle hysteresis was found. The surfaces with the smallest contact angle hysteresis were found to also have the largest slip length. Finally, a number of sanding protocols were tested by sanding preferentially along the flow direction, across the flow direction and with a random circular pattern. In all cases, sanding in the flow direction was found to produce the largest pressure drop reduction.

  10. Inorganic nitrogen transformations within permeable carbonate sands

    NASA Astrophysics Data System (ADS)

    Erler, Dirk V.; Santos, Isaac R.; Eyre, Bradley D.

    2014-04-01

    A combination of in-situ push pull tests and a flow through reactor trial were used to quantify the inorganic nitrogen sinks in the permeable carbonate sands of a tropical coral cay (Heron Island - Great Barrier Reef). Addition of dissolved inorganic nitrogen (DIN in the form of nitrate - NO3-, and ammonium - NH4+) directly into sediment porewater resulted in uptake of up to 97% and 60% of added DIN respectively. The initial push pull experiment qualitatively showed that dissimilatory nitrate reduction to ammonia (DNRA), denitrification and nitrification were all active in the sediments. A flow through reactor experiment provided a more detailed approach to quantify these processes and showed that both denitrification and DNRA occurred within the sands at rates of 7.3 and 5.5 μmol N cm-3 d-1, respectively. Unexpectedly the addition of labile organic material (fresh coral spawn) to the permeable sands did not result in the release of DIN from the reactors, on the contrary it resulted in the increased uptake of both NO3- and NH4+. This was most likely because of the stimulated N uptake associated with the addition of high C:N coral spawn material. The bulk of NH4+ produced via DNRA was found to be adsorbed to sediments within the reactor and was not released with the outlet water. A mass balance over the entire experimental period showed that more inorganic N was retained within the sediments than lost as gaseous products. Our results point to permeable carbonate sands acting as reservoirs of N under the influence of advective flow, even during sudden enrichment periods such as those following coral mass spawning. This implies that permeable carbonate sands may help to buffer coral reefs during periods of extreme oligotrophy.

  11. Imaging of Acoustic Waves in Sand

    SciTech Connect

    Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

    2003-08-01

    There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

  12. Geochemical evidence for a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria

    NASA Astrophysics Data System (ADS)

    Bata, Timothy; Parnell, John; Samaila, Nuhu K.; Abubakar, M. B.; Maigari, A. S.

    2015-11-01

    Paleogeographic studies have shown that Earth was covered with more water during the Cretaceous than it is today, as the global sea level was significantly higher. The Cretaceous witnessed one of the greatest marine transgressions in Earth's history, represented by widespread deposition of sands directly on underlying basement. These sand bodies hold much of the world's heavy oil. Here, we present for the first time, geochemical evidence of a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria. Bima oil sand is similar to other Cretaceous oil sands, predominantly occurring at shallow depths on basin flanks and generally lacking a seal cover, making the oil susceptible to biodegradation. The bulk properties and distribution of molecular features in oils from the Bima oil sand suggest that they are biodegraded. Sterane maturity parameters and the trisnorhopane thermal indicator for the oils suggest thermal maturities consistent with oils generated as conventional light oils, which later degraded into heavy oils. These oils also show no evidence of 25-norhopane, strongly suggesting that biodegradation occurred at shallow depths, consistent with the shallow depth of occurrence of the Bima Formation at the study locality. Low diasterane/sterane ratios and C29H/C30H ratios greater than 1 suggest a carbonate source rock for the studied oil. The Sterane distribution further suggests that the oils were sourced from marine carbonate rocks. The C32 homohopane isomerization ratios for the Bima oil sand are 0.59-0.60, implying that the source rock has surpassed the main oil generation phase, consistent with burial depths of the Fika and Gongila Formations, which are both possible petroleum source rocks in the basin.

  13. Sand sheet dynamics and Quaternary landscape evolution of the Selima Sand Sheet, southern Egypt

    NASA Astrophysics Data System (ADS)

    Maxwell, Ted A.; Haynes, C. Vance

    2001-09-01

    The Selima Sand Sheet occupies more than 120,000 km 2 of the hyperarid, uninhabited Darb el-Arba'in Desert centered at the border of Egypt and Sudan at latitude 22° N, and is characterized by a featureless surface of lag granules and fine sand broken only by widely separated dune fields and giant ripples of varying height and wavelength. Monitoring of the largest of these chevron-shaped ripples using repeat orbital images and field surveys indicates migration rates of 500-1000 m/yr, accompanied by 0-2.0 cm erosion or deposition of the youngest sand sheet stratigraphic units. Beneath this active surface, several developmental stages of sand sheet sediments have undulatory upper contacts and varying degrees of pedogenic alteration. The younger stages retain their horizontal lamination and have cracking patterns indicative of past wetter conditions, while older stages have lost their laminar structure through pedogenesis. Historical remains in the desert as well as 14C and Uranium-series dating indicate that the younger strata of the sand sheet have a very low accumulation rate, despite the active movement of the surface. The lower strata were extensively modified during mid and late Pleistocene pluvials, resulting in an initial undulatory surface that set the stage for later accumulation of sand sheet. Below these Quaternary sediments lies irregular topography dissected by channels of mid-Tertiary drainage. The Selima Sand Sheet is neither the result of net aggradation nor degradation, but results from inheritance of an initial fluvial landscape increasingly modified during climatic cycles. Wet periods led to local drainage and deposition, while the increasingly severe arid periods of the late Pleistocene and Holocene resulted in deposition of the blanketing bimodal sediments of the sand sheet.

  14. 22. INTERIOR VIEW WITH INTERIOR VIEW OF MOLDING SANDS CONTROL ...

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

    22. INTERIOR VIEW WITH INTERIOR VIEW OF MOLDING SANDS CONTROL AND TEST LAB FOR UNIT NO. 2 GREY IRON DISAMATIC. SAND CASTING TECHNICIAN, ROY BATES, TESTS THE WEIGHT OF THE SAND, DRYS IT, AND WEIGHT IT AGAINST STANDARDS TO CALCULATE THE CORRECT MOISTURE NEEDED FOR DIFFERENT MOLDS. THE SAND MIX VARY WITH THE SIZE AND COMPOSITION OF THE CASTING. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  15. White light emitting diodes

    NASA Astrophysics Data System (ADS)

    Baur, J.; Schlotter, P.; Schneider, J.

    Using blue-emitting GaN LEDs on SiC substrate chips as primary light sources, we have fabricated green, yellow, red and white light emitting diodes (LUCOLEDs). The generation of mixed colors, as turquoise and magenta, is also demonstrated. The underlying physical principle is that of luminescence downconversion (Stokes shift), as typical for organic dye molecules and many inorganic phosphors. For white light generation via the LUCOLED principle, the phosphor Y3Al5O12:Ce3+(4f1) is ideally suited. The optical characteristics of Ce3+(4f1) in Y3Al5O12(YAG) are discussed in detail. Possibilities to "tune" the white color by various substitutions in the garnet lattice are shortly outlined.

  16. White LED performance

    NASA Astrophysics Data System (ADS)

    Gu, Yimin; Narendran, Nadarajah; Freyssinier, Jean Paul

    2004-10-01

    Two life tests were conducted to compare the effects of drive current and ambient temperature on the degradation rate of 5 mm and high-flux white LEDs. Tests of 5 mm white LED arrays showed that junction temperature increases produced by drive current had a greater effect on the rate of light output degradation than junction temperature increases from ambient heat. A preliminary test of high-flux white LEDs showed the opposite effect, with junction temperature increases from ambient heat leading to a faster depreciation. However, a second life test is necessary to verify this finding. The dissimilarity in temperature effect among 5 mm and high-flux LEDs is likely caused by packaging differences between the two device types.

  17. Temporal and spatial variability of ooid sand shoals: Comparison of Mississippian of Kentucky and Quaternary of Bahamas

    SciTech Connect

    Boardman, M.R. )

    1989-08-01

    An examination of the lithology and topography of Andros Island, Bahamas, reveals it is a Pleistocene ooid sand shoal. A comparison with Joulters Cays (a modern ooid sand shoal directly to the north) shows that much of the original depositional topography is preserved through at least one cycle of sea level highstand and lowstand. Both the Pleistocene and the Holocene ooid sand bodies are a few kilometers to tens of kilometers wide. The total vertical relief of a single episode of Quaternary ooid sand deposition is more than 10 m and includes accumulation in tidal channels, shallow flat areas, and eolian dunes. Today, much of Andros Island is within 2 m of present sea level and is the site of a belt several kilometers wide consisting of muddy tidal flat sediments overlying an exposure surface. The site of ooid sand deposition and shoal complex formation is not continuous along shorelines, especially windward margins, but shifts abruptly along the margins of platforms as a result of minor fluctuations of sea level. Thus, it should be expected that ooid sand shoals (ancient and modern) should be in direct lateral and vertical contact with lagoons, tidal flats, and reefs. The Mississippian Slade Formation contains many of the features of Quaternary ooid sand accumulation: abrupt vertical and lateral gradations between oolitic grainstones, packstones, and lime mudstones, vertical relief of individual oolitic sedimentary packages up to 30 m (perhaps with eolian dunes) and numerous exposure surfaces of varying intensities. These characteristics suggest that this formation represents a time of rapid fluctuations of relative sea level and abrupt shifts in the sites of ooid sand shoal complexes.

  18. Smectite grain coating and low-resistivity pay sands, Santa Margarita Sand, southern San Joaquin Valley

    SciTech Connect

    Orlando, R.C.; Hickey, J.J.; Wydrinski, R.

    1989-04-01

    Log evaluations of the Santa Margarita Sand (upper Miocene Delmontian) from the ARCO Tejon A 579-35 well, Kern County, California, calculate S/sub W/ of up to 100%. Fluid resistivity (R/sub W/) measured 5.5-6.0 ohm-m; yet, when tested, the initial production was 33 BOPD with 8 BWPD. Deep resistivity (R/sub ILD/) ranged between 5.7-9.5 ohm-m with corresponding LDT-CNL porosities of less than 30%. Initial analyses suggested that high clay content was influencing resistivity. Grain-coating authigenic clay is extensively developed in the sands throughout the interval of interest. Average clay content of the sands is about 26 wt.%. The clay fraction is dominated by highly swelling smectitic clay (90% expandable illite/smectite) that occurs as a thin honeycomblike grain-surface coating. The smectite grain coatings, with a high specific surface area and high cation exchange capacity, form a physically continuous network through the sands. This network contributes both surface (matrix) and bound-water conductivity, generating a low-resistivity pathway for induced currents. Well logs from the field are being reevaluated to determine if Santa Margarita Sands are productive in areas where the sands calculate wet. Additional petrophysical data, including electrical properties (Archie equation parameters, i.e., a, m, and n), are needed to assess quantitatively the influence of the smectite-clay network on log response and to determine appropriate formation evaluation parameters.

  19. Groundwater Flow and Sand Body Interconnectedness in a Thick, Multiple-Aquifer System

    NASA Astrophysics Data System (ADS)

    Fogg, Graham E.

    1986-05-01

    Many so-called sandstone aquifers are actually multiple-aquifer systems consisting of discontinuous sand bodies distributed complexly in a matrix of lower-permeability silts and clays. The arrangement and Interconnectedness of these various lithofacies strongly influence spatial patterns of hydraulic conductivity (K) and, in turn, groundwater flow and mass transport. A promising technique of estimating such patterns of K involves careful analysis of both subsurface geologic and subsurface hydrologic data. In this study the three-dimensional distribution of K was estimated for a numerical flow model of part of the Wilcox aquifer system in Texas, using K data from core samples and pumping tests and more than 100 geophysical logs. The aquifer system, which is up to 320 m thick, consists of multiple, elongate sand bodies and silts and clays deposited in a fluvial environment and is similar to many other systems found in the Gulf Coast and other sedimentary basins. The resulting deterministic-conceptual flow model demonstrates the importance and methods of incorporating geologic information in groundwater models. Flow in the aquifer is shown to be controlled not so much by K of the sands as by their continuity and Interconnectedness. Much of the aquifer system consists of large zones in which the fluvial channel-fill sands are sparse and apparently disconnected, resulting in groundwater flow rates lower by a factor of 101 to 103 than in adjacent, well-interconnected belts of fluvial channel-fill sand belts. Modeling results also raise serious doubts regarding our ability to predict regional scale flow and mass transport in complex aquifers such as the Wilcox, using current technology. Though sand body Interconnectedness is critically important, it is also very difficult to estimate. One or two well-connected sands among a system of otherwise disconnected sands can completely alter a velocity field. This is particularly true if the sands are connected vertically and nonzero vertical hydraulic gradients exist. Because the model is three-dimensional, sensitivity of hydraulic head to heterogeneity or Interconnectedness is much less than normally observed in two-dimensional models, and therefore heads computed by the model give little to no indication of the location of well-interconnected zones. Thus such zones can easily go undetected, even in carefully calibrated models which yield reasonably accurate hydraulic heads. This is a significant point for modeling of solute transport.

  20. WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS): Research Implementation Status

    NASA Astrophysics Data System (ADS)

    Nickovic, Slobodan; Barrie, Leonard

    2010-05-01

    Strong winds cause lifting of large amounts of sand and dust from bare, dry soils into the atmosphere. For countries in and downwind of arid regions, airborne sand and dust presents serious risks to the environment, property and human health. Impacts on health include respiratory and cardio-vascular problems, eye infections and in some regions, diseases such as meningitis and valley fever. Dust can efficiently carry irritating spores, bacteria, viruses and persistent organic pollutants. It can also efficiently transport nutrients to parts of the world oceans and affect marine biomass production. Other impacts include negative effects on the ground transport, aviation, agriculture and visibility. The Inter-governmental Panel on Climate Change (IPCC) recognizes dust as a major component of the atmospheric aerosol that is an essential climate variable. Dust aerosol has important effects on weather through feedback on atmospheric dynamics, clouds and precipitation formation. Approximately 15 centres around the world provide sand and dust research operational forecasts. Many are operated by national meteorological services of the World Meteorological Organization (WMO). Sand and dust storm models can substantially reduce risk by providing dust concentration predictions for several days in advance. Numerical weather prediction systems that drive these models use complex parameterizations and assimilation of satellite, and surface-based observations to predict winds, clouds, precipitation and dust mobilization, transport, and removal from the atmosphere. Sand and dust forecast products contribute to the mitigation and reduction of risk through research based advances in understanding and forecasting products. Observations of sand and dust are made by many agencies and some of them are being coordinated globally through the WMO Global Atmosphere Watch (GAW) programme. In 2006, WMO and partners initiated the implementation of the Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS) in order to improve the capabilities of countries affected by dust to reduce risks associated with airborne sand and dust. This project is in response to the desire of more than 40 WMO member countries to improve capabilities for more reliable sand and dust storm forecasts. The project has strong crosscutting features: it relies on real-time delivery of products; it integrates research communities (modelling, observation groups, and effects) and communities of practice (e.g. medical, aeronautical, agricultural users). There are two already established SDS-WAS nodes (Asian and North-Africa-Europe-Middle East) that coordinate implementation of the project objectives at regional levels. This presentation will review current status and future steps in the project implementation.

  1. Numerical simulation of wind sand movement in straw checkerboard barriers.

    PubMed

    Huang, Ning; Xia, Xianpan; Tong, Ding

    2013-09-01

    Straw checkerboard barrier (SCB) is the most representative antidesertification measure and plays a significant role in antidesertification projects. Large-eddy simulation and discrete-particle tracing were used to numerically simulate the wind sand movement inside the straw checkerboard barrier (SCB), study the movement characteristics of sand particles, find the transverse velocities of sand particles and flow field, and obtain the contour of the transverse velocity of coupled wind field within the SCB. The results showed that 1) compared with that at the inlet of the SCB, the sand transport rate inside the SCB greatly decreases and the speed of sand grain movement also evidently drops, indicating that the SCB has very good sand movement preventing and fixing function; 2) within the SCB there exists a series of unevenly distributed eddies of wind sand flow, their strength decreases gradually with increasing the transverse distance; 3) affected by eddies or reflux, sand particles carried by the wind sand flow have to drop forward and backward the two interior walls inside the SCB, respectively, forming a v-shaped sand trough; 4) the sand transport rate gradually decreases with increasing number of SCBs, which reveals that the capacity of the wind field to transport sand particles decreases. This research is of significance in sandstorm and land desertification control. PMID:24026396

  2. Tar sands. (Latest citations from the COMPENDEX database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning mining of tar sands and the recovery of bitumen and other materials from tar sands. The physical and chemical properties of tar sands are discussed, and the economics of their use are considered. Processes include alkaline extraction, water cracking, catalytic cracking, and in situ combustion. (Contains 250 citations and includes a subject term index and title list.)

  3. Supercritical-Fluid Extraction of Oil From Tar Sands

    NASA Technical Reports Server (NTRS)

    Compton, L. E.

    1982-01-01

    New supercritical solvent mixtures have been laboratory-tested for extraction of oil from tar sands. Mixture is circulated through sand at high pressure and at a temperature above critical point, dissolving organic matter into the compressed gas. Extract is recovered from sand residues. Low-temperature super-critical solvents reduce energy consumption and waste-disposal problems.

  4. Design and management of conventional fluidized-sand biofilters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fluidized sand biofilters (FSBs) are relatively compact, efficient, and cost-competitive biofilters, especially in recirculating systems that require maintaining consistently low levels of ammonia and nitrite. Filter sand is low cost (often $70-200/m3 of sand delivered) and has a high specific surf...

  5. Well completion process for formations with unconsolidated sands

    SciTech Connect

    Davies, David K.; Mondragon, III, Julius J.; Hara, Philip Scott

    2003-04-29

    A method for consolidating sand around a well, involving injecting hot water or steam through well casing perforations in to create a cement-like area around the perforation of sufficient rigidity to prevent sand from flowing into and obstructing the well. The cement area has several wormholes that provide fluid passageways between the well and the formation, while still inhibiting sand inflow.

  6. Erosion Potential of Various Golf Course Bunker Sands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sand bunkers are principal golf course features adding aesthetic beauty and challenge for golfers. Bunkers often require substantial resources for proper maintenance particularly where sand is installed on severe slopes in humid climates subject to occasional heavy rainfall. Numerous sands are comme...

  7. Plant Availability of Metals in Waste Foundry Sands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foundries in the United States generate several million tons of waste sand each year. These sands are no longer suitable for metalcasting processes, and about 90% are discarded in landfills. However, the majority of these waste foundry sands (WFSs) qualify as non-hazardous industrial waste and the...

  8. BMM SEPARATION SCREEN PERMITS SAND TO PASS TO BELT CONVEYORS ...

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

    BMM SEPARATION SCREEN PERMITS SAND TO PASS TO BELT CONVEYORS BELOW THAT TRANSPORT THE SAND BACK TO STORAGE AND RECONDITIONING BINS WHILE CASTINGS ARE TRANSPORTED ON ADDITIONAL VIBRATING CONVEYORS TO DEGATING AREAS. - Southern Ductile Casting Company, Shaking, Degating & Sand Systems, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  9. Acetylcholinesterase mutations and organophosphate resistance in sand flies and mosquitoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leishmaniasis is an insect-borne disease caused by several protozoan species in the genus Leishmania, which are vectored by sand fly species in the genera Phlebotomus or Lutzomyia, depending on the sand fly species geographic range. Sand fly bites and leishmaniasis significantly impacted U.S. milita...

  10. Early Selection on Sand: Preliminary Studies on Repeatability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greater improvement has been achieved for sugar cane genotypes cultivated on organic soils than on sand soils. The expansion of the sugar cane crop will necessarily involve the planting on sand and /or poorer soils. Previously selection on sand soils has been done at later stages: one location in ...

  11. White hemithorax in children.

    PubMed

    Lucaya, Javier; Garcs-Iigo, Enrique F; Garca-Pea, Pilar; Piqueras, Joaquim; Enriquez, Goya

    2011-07-01

    The aim of this pictorial review is to introduce the radiologist to the differential diagnosis of a white hemithorax in children, to provide significant information on the diagnostic work-up, and to promote radiation-free techniques whenever possible. There are many causes of white hemithorax in children and it can be due to a variety of chest disorders. In most cases, plain chest radiographs and ultrasound will suffice. However, additional information provided by, e.g., CT or MRI is sometimes required. PMID:21553041

  12. White light velocity interferometer

    DOEpatents

    Erskine, D.J.

    1999-06-08

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

  13. White light velocity interferometer

    DOEpatents

    Erskine, David J. (Oakland, CA)

    1997-01-01

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

  14. White light velocity interferometer

    DOEpatents

    Erskine, David J. (Oakland, CA)

    1999-01-01

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

  15. White light velocity interferometer

    DOEpatents

    Erskine, D.J.

    1997-06-24

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

  16. Sand, die and investment cast parts via the SLS selective laser sintering process

    NASA Astrophysics Data System (ADS)

    van de Crommert, Simon; Seitz, Sandra; Esser, Klaus K.; McAlea, Kevin

    1997-09-01

    Complex three-dimensional parts can be manufactured directly from CAD data using rapid prototyping processes. SLS selective laser sintering is a rapid prototyping process developed at the University of Texas at Austin and commercialized by DTM Corporation. SLS parts are constructed layer by layer from powdered materials using laser energy to melt CAD specified cross sections. Polymer, metal, and ceramic powders are all potential candidate materials for this process. In this paper the fabrication of complex metal parts rapidly using the investment, die and sand casting technologies in conjunction with the selective laser sintering process are being explained and discussed. TrueForm and polycarbonate were used for investment casting, while RapidSteel metal mould inserts were used for the die casting trials. Two different SandForm materials, zircon and silica sand, are currently available for the direct production of sand moulds and cores. The flexible and versatile selective laser sintering process all these materials on one single sinterstation. Material can be changed fast and easily between two different builds.

  17. An added dimension: GC atmospheric pressure chemical ionization FTICR MS and the Athabasca oil sands.

    PubMed

    Barrow, Mark P; Peru, Kerry M; Headley, John V

    2014-08-19

    The Athabasca oil sands industry, an alternative source of petroleum, uses large quantities of water during processing of the oil sands. In keeping with Canadian environmental policy, the processed water cannot be released to natural waters and is thus retained on-site in large tailings ponds. There is an increasing need for further development of analytical methods for environmental monitoring. The following details the first example of the application of gas chromatography atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry (GC-APCI-FTICR MS) for the study of environmental samples from the Athabasca region of Canada. APCI offers the advantages of reduced fragmentation compared to other ionization methods and is also more amenable to compounds that are inaccessible by electrospray ionization. The combination of GC with ultrahigh resolution mass spectrometry can improve the characterization of complex mixtures where components cannot be resolved by GC alone. This, in turn, affords the ability to monitor extracted ion chromatograms for components of the same nominal mass and isomers in the complex mixtures. The proof of concept work described here is based upon the characterization of one oil sands process water sample and two groundwater samples in the area of oil sands activity. Using the new method, the Ox and OxS compound classes predominated, with OxS classes being particularly relevant to the oil sands industry. The potential to resolve retention times for individual components within the complex mixture, highlighting contributions from isomers, and to characterize retention time profiles for homologous series is shown, in addition to the ability to follow profiles of double bond equivalents and carbon number for a compound class as a function of retention time. The method is shown to be well-suited for environmental forensics. PMID:25036898

  18. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas 3141.2 Prelease exploration within Special Tar Sand Areas....

  19. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas 3141.2 Prelease exploration within Special Tar Sand Areas....

  20. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas 3141.2 Prelease exploration within Special Tar Sand Areas....

  1. 43 CFR 3141.2 - Prelease exploration within Special Tar Sand Areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Sand Areas. 3141.2 Section 3141.2 Public Lands: Interior Regulations Relating to Public Lands... SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas 3141.2 Prelease exploration within Special Tar Sand Areas....

  2. The Rheology of Acoustically Fluidized Sand

    NASA Astrophysics Data System (ADS)

    Conrad, J. W.; Melosh, J.

    2013-12-01

    The collapse of large craters and the formation of central peaks and peak rings is well modeled by numerical computer codes that incorporate the acoustic fluidization mechanism to temporarily allow the fluid-like flow of rock debris immediately after crater excavation. Furthermore, long runout landslides require a similar mechanism to explain their almost frictionless movement, which is probably also a consequence of their granular composition coupled with internal vibrations. Many different investigators have now confirmed the ability of vibrations to fluidize granular materials. Yet it still remains to fully describe the rheology of vibrated sand as a function of stress, frequency and amplitude of the vibrations in the sand itself. We constructed a rotational viscometer to quantitatively investigate the relation between the stress and strain rate in a horizontal bed of strongly vibrated sand. In addition to the macroscopic stain rate, the amplitude and frequency of the vibrations produced by a pair of pneumatic vibrators were also measured with the aid of miniaturized piezoelectric accelerometers (B&K 4393) whose output was recorded on a digital storage oscilloscope. The initial gathering of the experimental data was difficult due to granular memory, but by having the sand compacted vibrationally for 8 minutes before each run the scatter of data was reduced and we were able to obtain consistent results. Nevertheless, our major source of uncertainty was variations in strain rate from run to run. We find that vibrated sand flows like a highly non-Newtonian fluid, in which the shear strain rate is proportional to stress to a power much greater than one, where the precise power depends on the amplitude and frequency of the applied vibrations. Rapid flow occurs at stresses less than half of the static yield stress (that is, the yield stress when no vibration is applied) when strong vibrations are present. For a Newtonian fluid, such as water, the relation between strain rate and stress is linear. In our experiments we found that the shear strain rate is proportional to shear stress raised to the powers 5.9 and 8.4 at frequencies of 8.5 kHz and 7.4 kHz and increasing amplitude of vibration, respectively. This demonstrates that vibrated sand behaves as a strongly nonlinear pseudo-plastic material that, like glacier ice, can also be approximated as a Bingham material with a rate-dependent yield stress. The flow of acoustically fluidized granular materials provides a reasonable explanation of crater collapse, long runout landslides, and other events involving large masses of granular material.

  3. Sand Bank Weakly Nonlinear Stability Analysis

    NASA Astrophysics Data System (ADS)

    Tambroni, N.; Blondeaux, P.

    2006-12-01

    In the continental shelf, tidal currents often give rise to large scale periodic bed forms named sand banks. Sand banks are long ridges (length of the order of several tens of kilometers) with a spacing (crest to crest distance) up to 10 km and a height up to several tens of meters. Their crests are almost aligned with the tidal currents, forming small positive or negative angles. Although reliable models based on linear stability analyses exist to predict the main geometrical characteristics of the sand banks as they start to appear, little is known on the morphodynamic processes that shape and maintain these bed forms in equilibrium conditions. A weakly nonlinear analysis is a powerful tool to investigate the equilibrium configuration attained by unstable bottom perturbations when the parameters of the problem are close to the critical values. However difficulties arise to apply a weakly nonlinear analysis of sand bank dynamics because the linear approaches predict infinite wavelengths of the most unstable mode close to the critical conditions. Here we first revisit the linear approach of Hulscher et al. (1993, Cont. Shelf Res. 13). In particular the time development of small amplitude bottom perturbations forced by tidal currents is studied using a different parameterization of both the bed shear stress and the sediment transport predictor which provides vanishing values of the sediment transport rate when the bottom shear stress is smaller than a critical value and accounts for the deviation of the sediment transport rate from the depth averaged velocity. With these improvements, both clockwise and counterclockwise sand banks are predicted. Moreover the wavelength of the most unstable mode close to the critical conditions turns out to be finite. This result opens the possibility to carry out a weakly nonlinear stability analysis. Then the time development of the most unstable mode is studied for values of the parameters close to the marginal conditions. The analysis provides estimates of the sand bank equilibrium amplitude and predicts equilibrium profiles characterized by crests sharper than the troughs, a feature often observed in field surveys.

  4. Origin of Titan's dunes: noncohesive sand in bidirectional winds or sticky sand in unidirectional winds?

    NASA Astrophysics Data System (ADS)

    Rubin, D. M.

    2009-12-01

    Eolian dunes occur on Earth, Venus, Mars, and Titan, distinguishing them as one of the more widespread landforms in the solar system. On Earth, unidirectional winds blowing over loose, noncohesive sand produce crescentic-shaped dunes with crests oriented normal to the sand-transport direction (transverse dunes), but roughly half of Earth's large deserts are covered with longer-crested dunes (linear dunes) that are commonly oriented parallel or oblique to the resultant sand-transport vector (longitudinal dunes and oblique dunes, respectively). Such linear dunes form in at least two situations: (1) directionally bimodal winds blowing over loose sand, and (2) unimodal winds blowing over sediment that is vegetated, cohesive, sheltered by upwind topography, or otherwise locally stabilized. This study documents an example (Qaidam Basin, China) where a downwind increase in sediment cohesiveness (due to salt and mud incorporated from the local land surface) causes dunes to change orientation from transverse to longitudinal, and the work presents a compilation of related situations where stabilization of dune sediment has been reported to produce linear dunes. This family of stabilized dunes functions dynamically as self-extending "sand-shadow" or lee dunes. Loose sediment accumulates locally on these dunes, where it becomes stabilized, thereby allowing the dune itself to function as an obstacle that induces subsequent deposition farther downwind. Linear dunes on Titan previously have been interpreted as forming in the first situation listed above: bimodal winds blowing over loose sand. Because Titan's sand is believed to be composed of hydrocarbons or nitriles, however, the hypothesized loose, non-sticky nature of the sand has surprised researchers. In addition, the previous hypothesis of bimodal winds requires that north-south tidal flow be stronger than west-east zonal flow, which also was unexpected. The new hypothesis presented herethat Titan's dunes formed by unidirectional winds blowing over cohesive or sticky sandresolves these two puzzles, cannot be ruled out with existing observations, and has grossly different implications regarding Titan's sediment properties, surface moisture, and wind regime. Satellite image of dunes in the Qaidam Basin, China. Change in sediment properties causes a change from transverse to longitudinal orientation of the dunes. Transverse dunes are higher in elevation than the longitudinal dunes and composed of noncohesive sand. Longitudinal dunes are cemented with silt, clay, and salt acquired locally.

  5. Ryan White Program

    MedlinePLUS

    ... the payer of last resort by filling the gaps for those who have no other source of coverage or face coverage limits. Federal Ryan White funding, which must be appropriated by Congress each year, is provided to cities, states and territories, 3 ...

  6. White Mountain Reader.

    ERIC Educational Resources Information Center

    Pulu, Tupou L.; And Others

    This illustrated reader is part of a series designed for use in the Alaska State-Operated Schools' bilingual education program. The reader describes in story form some aspects of life, primarily hunting, fishing and related activities, among natives of the White Mountain region of Alaska. The text is provided in both English and Inupiat and is…

  7. Snow White 5 Trench

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image was acquired by NASA's Phoenix Mars Lander's Robotic Arm Camera on the 35th Martian day of the mission, or Sol 34 (June 29, 2008), after the May 25, 2008, landing. This image shows the trench informally called 'Snow White 5.' The trench is 4-to-5 centimeters (about 1.5-to-1.9 inches) deep, 24 centimeters (about 9 inches) wide and 33 centimeters (13 inches) long.

    Snow White 5 is Phoenix's current active digging area after additional trenching, grooming, and scraping by Phoenix's Robotic Arm in the last few sols to trenches informally called Snow White 1, 2, 3, and 4. Near the top center of the image is the Robotic Arm's Thermal and Electrical Conductivity Probe.

    Snow White 5 is located in a patch of Martian soil near the center of a polygonal surface feature, nicknamed 'Cheshire Cat.' The digging site has been named 'Wonderland.'

    This image has been enhanced to brighten shaded areas.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. White Sea - Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    At bottom center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 13, 2001, the White Sea in western Russia is becoming free of ice in its southern extent. Meanwhile, the blue-green waters along the coast of the peninsula jutting out into the Barents Sea to the northeast could be due to a phytoplankton bloom.

  9. Big White Wall app.

    PubMed

    2015-11-11

    For anyone struggling with anxiety or stress, the Big White Wall app offers an anonymous space to voice concerns or speak to others. Before trying the app, users need to go to www.bigwhitewall . com and answer a brief questionnaire to set up login details and a password to protect anonymity. PMID:26554985

  10. Black and White Slides.

    ERIC Educational Resources Information Center

    Tanner, Jackie

    1979-01-01

    Outlines procedures for using some photographic techniques to start a black and white slide collection. Instructions are given for: (1) necessary equipment and materials; (2) photographing images such as photos, charts or drawings; (3) developing the film; and (4) setting up the filing system. Photographs and drawings illustrate the process. (AMH)

  11. The White Sea, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Editor's Note: The caption below, published on May 10, 2001, is incorrect. According to Masha Vorontsova, director of the International Fund for Animal Welfare in Moscow, the situation with the seal pups in the White Sea is normal. There is no disaster and there never was. For more details, refer to the article entitled 'No Danger' on the New Scientist home page. The Earth Observatory regrets the earlier errant report. Original Caption According to the Russian Polar Research Institute for Fisheries and Oceanography, between 250,000 and 300,000 Greenland seal pups face death by starvation over the next two months due to a cruel trick by mother nature. The seals, most of them less than two months old, are trapped on ice sheets that remain locked in the White Sea, located near Archangel in Northern Russia. Typically, during the spring thaw the ice sheets break up and flow with the currents northward into the Barents Sea, the seals' spring feeding grounds. The seal pups hitch a ride on the ice floes, living on their own individual stores of fat until they arrive in the Barents Sea. Their mothers departed for the Barents Sea weeks ago. In a normal year, the seal pups' trip from the White Sea out to the Barents takes about six weeks and the seals have adapted to rely upon this mechanism of mother nature. During their yearly migration, the mother seals usually stay with their pups and feed them until their pelts turn from white to grey--a sign that the pups are mature enough to swim and feed themselves. Unfortunately, this year unusually strong northerly winds created a bottleneck of ice near the mouth of the white sea, thus blocking the flow of ice and trapping the pups. These true-color images of the White Sea were acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. This image, taken May 2, 2000 that there is usually much less ice in the White Sea this time of year as most of it is typically en route to the Barents Sea.

  12. The physics of wind-blown sand and dust.

    PubMed

    Kok, Jasper F; Parteli, Eric J R; Michaels, Timothy I; Karam, Diana Bou

    2012-10-01

    The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This paper presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan. PMID:22982806

  13. Injection with ultra-fine cement into fine sand layer

    SciTech Connect

    Tamura, Masahito; Goto, Toshiyoshi; Ogino, Takuya; Shimizu, Kazunari

    1994-12-31

    In-situ injection test was carried out in fine sand layer with ordinary portland, colloid and ultra-fine cement. Permeability of the sand layer was 10{sup {minus}3} cm/sec. Suspension grout with ordinary portland and colloid cement was impossible to permeate into the sand. However with ultra fine cement small solidified sand was obtained and with ultra-fine cement-waterglass grout, water cement ratio of 0.8 and waterglass concentration of 75%, solidified sand with expected volume can be obtained.

  14. Laboratory and field evaluation of an underwater sand height gage

    NASA Technical Reports Server (NTRS)

    Swift, D. J. P.; Mcgrath, D. G.

    1972-01-01

    An underwater sand height gage was investigated. This instrument consisted of two transducers, one screened and one unscreened. Laboratory experimentation included static and dynamic tests with three test sands--fine, medium, and coarse. Field tests were conducted at Rudee Inlet, Virginia Beach, Virginia. Test results showed a linear response to up to 10 inches of sand loading. Deviation observed in identical tests appeared to be due to variation in the density of sand. Density differences reflected varying packing styles which, in turn, were a consequence of grain size and flow regime. Further evaluations of the sand height gage reflect this instrument's potential.

  15. White Dwarf Stars

    NASA Astrophysics Data System (ADS)

    Kepler, S. O.

    2014-10-01

    White dwarfs are the evolutionary endpoint for nearly 95% of all stars born in our Galaxy, the final stages of evolution of all low- and intermediate mass stars, i.e., main sequence stars with masses below (8.5± 1.5) M_{odot}, depending on metallicity of the progenitor, mass loss and core overshoot. Massive white dwarfs are intrinsically rare objects, tand produce a gap in the determination of the initial vs. final mass relation at the high mass end (e.g. Weidemann 2000 A&A, 363, 647; Kalirai et al. 2008, ApJ, 676, 594; Williams, Bolte & Koester 2009, ApJ, 693, 355). Main sequences stars with higher masses will explode as SNII (Smartt S. 2009 ARA&A, 47, 63), but the limit does depend on the metallicity of the progenitor. Massive white dwarfs are probably SNIa progenitors through accretion or merger. They are rare, being the final product of massive stars (less common) and have smaller radius (less luminous). Kepler et al. 2007 (MNRAS, 375, 1315), Kleinman et al. 2013 (ApJS, 204, 5) estimate only 1-2% white dwarfs have masses above 1 M_{odot}. The final stages of evolution after helium burning are a race between core growth and loss of the H-rich envelope in a stellar wind. When the burning shell is exposed, the star rapidly cools and burning ceases, leaving a white dwarf. As they cool down, the magnetic field freezes in, ranging from a few kilogauss to a gigagauss. Peculiar type Ia SN 2006gz, SN 2007if, SN 2009dc, SN 2003fg suggest progenitors in the range 2.4-2.8 M_{odot}, and Das U. & Mukhopadhyay B. (2012, Phys. Rev. D, 86, 042001) estimate that the Chandrasekhar limit increases to 2.3-2.6 M_{odot} for extremely high magnetic field stars, but differential rotation induced by accretion could also increase it, according to Hachisu I. et al. 2012 (ApJ, 744, 69). García-Berro et al. 2012, ApJ, 749, 25, for example, proposes double degenerate mergers are the progenitors of high-field magnetic white dwarfs. We propose magnetic fields enhance the line broadening in WDs, causing an overestimated surface gravity, and ultimately determine if these magnetic fields are likely developed through the star's own surface convection zone, or inherited from massive Ap/Bp progenitors. We discovered around 20 000 spectroscopic white dwarfs with the Sloan Digital Sky Survey (SDSS), with a corresponding increase in relatively rare varieties of white dwarfs, including the massive ones (Kleinman et al. 2013, ApJS, 204, 5, Kepler et al. 2013, MNRAS, 439, 2934). The mass distributions of the hydrogen-rich (DA) measured from fitting the spectra with model atmospheres calculated using unidimensinal mixing lenght-theory (MLT) shows the average mass (as measured by the surface gravity) increases apparently below 13 000K for DAs (e.g. Bergeron et al. 1991, ApJ, 367, 253; Tremblay et al. 2011, ApJ, 730, 128; Kleinman et al. 2013). Only with the tridimensional (3D) convection calculations of Tremblay et al. 2011 (A&A, 531, L19) and 2013 (A&A, 552, 13; A&A, 557, 7; arXiv 1309.0886) the problem has finally been solved, but the effects of magnetic fields are not included yet in the mass determinations. Pulsating white dwarf stars are used to measure their interior and envelope properties through seismology, and together with the luminosity function of white dwarf stars in clusters and around the Sun are valuable tools for the study of high density physics, and the history of stellar formation.

  16. Microscopic characterization of oil sands processing emulsions

    SciTech Connect

    Mikula, R.J.; Munoz, V.A.; Lam, W.W. )

    1989-01-01

    Microscopic characterization of oil sands emulsions can be important in the prediction of processing characteristics and process yields in the extraction of oil from oil sands. The size distribution of the emulsion can determine how efficiently the oil can be separated from the water and by what means: mechanically or chemically. In addition, it is possible to characterize the nature of the dispersed phase by using fluorescence behaviour under an optical microscope or via x-ray analysis with a scanning electron microscope. In certain cases it is also possible to characterize the interface between the dispersed and the continuous phases. This paper presents results from our laboratory using microscopic techniques and illustrates their utility, not only for determining the morphology of these economically important emulsions, but also to characterize the composition of the interface itself.

  17. Microscopic characterization of oil sands processing emulsions

    SciTech Connect

    Mikula, R.J.; Munoz, V.A.; Axelson, D.E.

    1988-06-01

    Microscopic characterization of oil sands emulsions can be important in the prediction of processing characteristics and process yields in the extraction of oil from oil sands. The size distribution of the process emulsion can determine how efficiently the oil can be separated from the water and by what means: mechanically or chemically. Optical and scanning electron microscopy coupled with automated image analysis can be applied to characterization of the size distribution of the dispersed phase in emulsion systems. In addition, it is possible to characterize the nature of the dispersed phase by using fluorescence behavior in the optical system or via X-ray analysis with the scanning electron microscope. In certain cases it is possible to characterize the interface between the dispersed and continuous phases. This paper presents results from our laboratory using microscopic techniques, not only for characterizing the morphology of these economically important emulsions, but also for compositional determinations of the interface itself.

  18. Exposure to mineral sands dust particles

    NASA Astrophysics Data System (ADS)

    Dias da Cunha, K.; Barros Leite, C. V.; Zays, Z.

    2004-06-01

    The aim of this study is to characterize the airborne particles in a Brazilian region with high concentration of mineral sands (Buena village). In this study proton induced X-ray emission (PIXE), plasma desorption mass spectrometry and alpha spectrometry were used for analyses of airborne particles. The analyses of aerosol samples and lichen samples show that the inhabitants of the Buena village are exposed to airborne particles in the fine fraction of aerosols. The main anthropogenic sources of particles are the mineral sands processing plant and truck traffic, and natural sources as the sea, soil and the swamp. The results from the lichen samples show that at least during the last 15 years the inhabitants of the village have been exposed to monazite particles. The results from aerosols and lichens samples also suggested that the swamp is a source of 226Ra and 210Pb bearing particles besides the monazite dust.

  19. a Branching Process Model for Sand Avalanches

    NASA Astrophysics Data System (ADS)

    Garcia-Pelayo Novo, Ricardo Angel

    In the introduction scale invariance is discussed at length and the concept of self organized criticality (S.O.C.) is introduced. A new example of it, the Gutenberg -Richter law for starquakes, is provided. We present an analytically solvable model for avalanches of non-interacting grains of sand, based on the Chapman-Kolmogorov equations. For this model, distributions of life-times, sizes of overflows, correlations functions as well as other quantities are calculated. Special attention is given to the spatial probability density of the homogeneous, isotropic implementation of this model. To study the range of validity of the approximation of independence of the grains of sand computer simulations have been performed and the critical dimension has been calculated. Finally we discuss the relevance of the oscillations of the slope around its critical value and state some conclusions and directions of future research.

  20. Three dimensional fabric evolution of sheared sand

    SciTech Connect

    Hasan, Alsidqi; Alshibli, Khalid

    2012-10-24

    Granular particles undergo translation and rolling when they are sheared. This paper presents a three-dimensional (3D) experimental assessment of fabric evolution of sheared sand at the particle level. F-75 Ottawa sand specimen was tested under an axisymmetric triaxial loading condition. It measured 9.5 mm in diameter and 20 mm in height. The quantitative evaluation was conducted by analyzing 3D high-resolution x-ray synchrotron micro-tomography images of the specimen at eight axial strain levels. The analyses included visualization of particle translation and rotation, and quantification of fabric orientation as shearing continued. Representative individual particles were successfully tracked and visualized to assess the mode of interaction between them. This paper discusses fabric evolution and compares the evolution of particles within and outside the shear band as shearing continues. Changes in particle orientation distributions are presented using fabric histograms and fabric tensor.