Science.gov

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 Λx) and show that Λx=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 Λ(x)) and show that Λ(x)=m(dune)L(s), where m(dune)≈7.2 in the different sections considered (for turbulent mixing layers, 7

  4. A numerical study of turbulent flow over complex aeolian dune fields: the White Sands National Monument

    NASA Astrophysics Data System (ADS)

    Anderson, W. W.; Chamecki, M.; Kocurek, G.; Mohrig, D. C.

    2013-12-01

    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 which 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 has 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, Lambda_x -- and show that Ls = m Lambda_x, where m is approximately 8 in the different sections considered (for turbulent mixing layers, 7 < m < 10, Rogers and Moser, 1994: Phys. Fluids A, 6, 903-922). These results guide discussion on the statistics of aerodynamic drag across the dunes; probability density functions of time-series of aerodynamic drag for the dunes are shown to exhibit skewness and variance much greater than values reported for turbulent boundary layer flow over an homogeneous roughness distribution. Thus, we propose that aeolian processes and dune pattern evolution is strongly influenced by the mixing layer physics in the dune field sublayer, and these physics are different to what would otherwise be predicted when using the equilibrium logarithmic law.

  5. A numerical study of turbulent flow over complex aeolian dune fields: the White Sands National Monument

    NASA Astrophysics Data System (ADS)

    Anderson, William; Chamecki, Marcelo; Kocurek, Gary; Mohrig, David

    2013-11-01

    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 which 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 has 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 in southern New Mexico. 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, Lambda_x - and show that Ls = m Lambda_x, where m is approximately 8 in the different sections considered.

  6. About White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Information on the White Sands Missile Range is given in viewgraph form. Navy programs, test sites, rocket programs, research rockets' booster capacity, current boost capabilities, ordnance and payload assembly areas, commercial space launch history and agreements, and lead times are among the topics covered.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. White Sands, New Mexico as seen from STS-60

    NASA Technical Reports Server (NTRS)

    1994-01-01

    White Sands National Monument (Park) is easily recognized in the center of this near-vertical color photograph. White Sands is the world's largest gypsum dune field. It represents an alabaster sea that covers nearly 300 square miles. At the southwest corner of the White Sands is dry lake, Lucero. In terms of cultural features the city of Alamogordo and Holloman Air Force Base can be seen with great clarity on this photograph.

  13. White Sands Space Harbor Area 1, Microwave Scanning Beam Landing ...

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

    White Sands Space Harbor Area 1, Microwave Scanning Beam Landing Ground Stations, 1,500' to the south of the north end of Runway 17/35; 1,500' to the west of the east end of Runway 23/05; and 1,500' southwest of the northeast end of Runway 20/02., White Sands, Dona Ana County, NM

  14. 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.

  15. 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).

  16. White Sands Space Harbor Area 1, Crash/Rescue Standby Support GPS ...

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

    White Sands Space Harbor Area 1, Crash/Rescue Standby Support GPS Buildings, East side of Runway 17/35, approximately 2,650 feet north of intersection with Runway 23/05, White Sands, Dona Ana County, NM

  17. White Sands Space Harbor Area 1, Runway 17/35, Extending 35,000 ...

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

    White Sands Space Harbor Area 1, Runway 17/35, Extending 35,000 feet north from Range Road 10, beginning approximately 4.2 miles northeast of intersection with Range Road 7, White Sands, Dona Ana County, NM

  18. 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/...

  19. 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,

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. Molecular and functional basis of phenotypic convergence in white lizards at White Sands

    PubMed Central

    Rosenblum, Erica Bree; Römpler, Holger; Schöneberg, Torsten; Hoekstra, Hopi E.

    2009-01-01

    There are many striking examples of phenotypic convergence in nature, in some cases associated with changes in the same genes. But even mutations in the same gene may have different biochemical properties and thus different evolutionary consequences. Here we dissect the molecular mechanism of convergent evolution in three lizard species with blanched coloration on the gypsum dunes of White Sands, New Mexico. These White Sands forms have rapidly evolved cryptic coloration in the last few thousand years, presumably to avoid predation. We use cell-based assays to demonstrate that independent mutations in the same gene underlie the convergent blanched phenotypes in two of the three species. Although the same gene contributes to light phenotypes in these White Sands populations, the specific molecular mechanisms leading to reduced melanin production are different. In one case, mutations affect receptor signaling and in the other, the ability of the receptor to integrate into the melanocyte membrane. These functional differences have important ramifications at the organismal level. Derived alleles in the two species show opposite dominance patterns, which in turn affect their visibility to selection and the spatial distribution of alleles across habitats. Our results demonstrate that even when the same gene is responsible for phenotypic convergence, differences in molecular mechanism can have dramatic consequences on trait expression and ultimately the adaptive trajectory. PMID:20080544

  8. 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.

  9. 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.

  10. 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.

  11. Hydrologic Modeling of the White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Bourret, S. M.; Newton, B. T.; Person, M. A.

    2013-12-01

    The shallow groundwater flow system of White Sands dune field, located within the Tularosa Basin of Southern New Mexico, likely stabilizes the base of the largest gypsum dunefield in the world. Water table geometry and elevation play a critical role in controlling dune thickness, spatial extent, and migration rates. The White Sands National Monument (WHSA) is concerned that lowering the water table may lead to increased scour and migration of the dune field, which could be unfavorable to the preservation of the flora and fauna that have adapted to survive there. In response to projected increases in groundwater pumping in the regional Tularosa Basin groundwater system, changes in surface water use, and the threat of climate change, the WHSA is interested in understanding how these changes on a regional scale may impact the shallow dune aquifer. We have collected hydrological, geochemical, and geophysical data in order to identify the sources of recharge that contribute to the shallow dune aquifer and to assess interactions between this water table aquifer and the basin-scale, regional system. Vertical head gradients, temperature, and water quality data strongly suggest that local precipitation is the primary source of recharge to the dune aquifer today. This suggests that the modern dune system is relatively isolated from the deeper regional system. However, geochemical and electrical resistivity data indicates that the deeper basin groundwater system does contribute to the shallow system and suggests that hydrologic conditions have changed on geologic time scales. We have constructed a preliminary cross-sectional hydrologic model to attempt to characterize the interaction of the shallow dune aquifer with the deeper basin groundwater. The model cross-section extends about 80 km across the Tularosa Basin in a NW-SE direction parallel to the primary flow path. We represented 6 km of Precambrian crystalline basement, Paleozoic sedimentary rocks as well as Pleistocene and Quaternary units. Preliminary results indicate a component of deep groundwater flows to a depth of 5 km and is discharged near Lake Lucero located west of the WHSA. Computed and observed salinity and groundwater residence times are the primary means of model calibration. The results will allow for an improved understanding of the interaction between the basin- and dune-scale groundwater flow systems.

  12. 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)

  13. Historical Dune Pattern Dynamics: White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Rachal, David M.; Dugas, Daniel P.

    2009-01-01

    Research efforts studying dune fields as spatial units are limited and the historical dynamics associated with dune field-scale pattern attributes are currently not well documented. Historical repeat aerial photography was used to quantify temporal changes in the crescentic dune pattern at the White Sands Dune Field, New Mexico. A Geographic Information System (GIS) was used to digitize ~ 14,000 dune crests from the combined photoset. Crest length, sinuosity, spacing, orientation, transport vector, and defect density were calculated from these measurements and statistically analyzed. The pattern analysis revealed that crest length, sinuosity, and defect density were highly variable pattern elements over a 60-year period. These dune pattern elements also exhibited temporal relationships, such as the inverse relationship between crest length and sinuosity over time. Defect density calculations revealed that the dune field is trending to a possible state of disorganization. This trend was temporarily interrupted in 1985 by a massive period of organization in which crest length was inversely related to defect density and defect density was proportionally related to sinuosity. The temporal variations in these pattern elements and the episodic organizational event in 1985 were likely climatically induced.

  14. 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...

  15. 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...

  16. 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.

  17. Microbial Signatures from the Dune Field at White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

    White Sands National Monument (New Mexico) is studied as a terrestrial analog to gypsum rich dunes from Mars. Microbial signatures from the dune field are investigated to assess a variety and distribution of available habitats.

  18. Microbial Signatures from the Arid Environments of White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    Since the White Sands National Monument has been proposed as a terrestrial analog to sulfates on Mars, we investigated the arid evaporitic systems in the WSNM in order to find different microbial habitats and assess their ecological characteristics.

  19. 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...

  20. Good Laboratory Practices of Materials Testing at NASA White Sands Test Facility

    NASA Technical Reports Server (NTRS)

    Hirsch, David; Williams, James H.

    2005-01-01

    An approach to good laboratory practices of materials testing at NASA White Sands Test Facility is presented. The contents include: 1) Current approach; 2) Data analysis; and 3) Improvements sought by WSTF to enhance the diagnostic capability of existing methods.

  1. 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.

  2. 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.

  3. 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 µm 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 Maxwell’s 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.

  4. 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.

  5. 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.

  6. 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)

  7. 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)

  8. 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)

  9. 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)

  10. Goddard Space Flight Center sounding rocket facilities at White Sands Missile Range

    NASA Technical Reports Server (NTRS)

    Windsor, R. M.

    1976-01-01

    This report describes the facilities being made available for sounding-rocket experimenters at the White Sands Missile Range. As a result of the transfer of the SPARCS Program from Ames to Goddard, facilities had to be made available to accommodate the integration and preparation effort previously performed at Ames. This facility will provide total support at White Sands Missile Range for the solar rocket experimenter. In addition to the solar physics that can be done, there is no restriction that would prevent other scientific disciplines from taking advantage of the facilities.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. Mapping Playa Evaporite Minerals, White Sands, New Mexico Using Landsat ETM+

    NASA Astrophysics Data System (ADS)

    Ghrefat, H. A.; Goodell, P. C.

    2002-12-01

    Evaporite minerals are the main source of several industrial and agricultural minerals important to the U.S. and world economy. Landsat ETM+ data covering the White Sands, New Mexico have been used in this study. The White Sands Dune Field, Lake Lucero, and Alkali Flat have been chosen as target sites. The study aims to determine the number of evaporite mineral endmembers that can be detected and mapped using Landsat ETM+. Furthermore, the study also aims to determine the spatial distribution of fractional abundances of evaporite mineral endmembers assuming a linear mixing model. The Minimum Noise Fraction (MNF) transform and Principal Component Analysis (PCA) were employed to determine a reduced set of noise-free spectral bands. The Pixel Purity Index (PPI) and n-D Visualization (nDV) were conducted on the reduced set of spectral bands to identify spectrally pure evaporite mineral endmembers in the image. Mineral maps of the spatial distribution and relative abundance of evaporite minerals were performed using two different algorithms: Spectral Angle Mapper (SAM) and Linear Spectral Unmixing (LSU). Four evaporite mineral endmembers have been identified using Spectral Angle Mapper. These minerals are gypsum, halite, calcite, and thenardite. The results of Linear Spectral Unmixing showed that the most common and abundant evaporite mineral in the White Sands is gypsum. The results of Spectral Angle Mapper (SAM) and Linear Spectral Unmixing (LSU) are validated by collecting field samples from different locations within the White Sands. A good match has been determined between results of Landsat ETM+ data and field and laboratory work. Mapping of playa evaporite minerals is of potential importance for the goal of saline soil characterization, regional groundwater hydrology and quality, and mineral resource development.

  17. 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.

  18. 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.

  19. Convergent evolution and divergent selection: lizards at the White Sands ecotone.

    PubMed

    Rosenblum, Erica Bree

    2006-01-01

    Ecological transition zones, where organismal phenotypes result from a delicate balance between selection and migration, highlight the interplay of local adaptation and gene flow. Here, I study the response of an entire species assemblage to natural selection across a common ecotone. Three lizard species, distributed along a dramatic environmental gradient in substrate color, display convergent adaptation of blanched coloration on the gypsum dunes of White Sands National Monument. I investigate the role of gene flow in modulating phenotypic response to selection by quantifying color variation and genetic variation across the ecotone. I find species differences in degree of background matching and in genetic connectivity of populations across the ecotone. Differences among species in phenotypic response to selection scale precisely to levels of genetic isolation. Species with higher levels of gene flow across the ecotone exhibit less dramatic responses to selection. Results also reveal a strong signal of ecologically mediated divergence for White Sands lizards. For all species, phenotypic variation is better explained by habitat similarity than genetic similarity. Convergent evolution of blanched coloration at White Sands clearly reflects the action of strong divergent selection; however, adaptive response appears to be modulated by gene flow and demographic history and can be predicted by divergence-with-gene-flow models. PMID:16475095

  20. 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

  1. 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

  2. Microbial Influences on Aeolian Sulfates; A Case Study of a Dune Field at White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    Similarly to martian sulfate-rich dunes, the White Sands National Monument exhibits partially different mineral signatures of dune crests and interdune areas. At the WSNM these differences are caused by diagenetic processes and by biological activity.

  3. Whiteness Enacted, Whiteness Disrupted: The Complexity of Personal Congruence

    ERIC Educational Resources Information Center

    Chubbuck, Sharon M.

    2005-01-01

    This study of the enactment and disruption of Whiteness in two White secondary literacy teachers focuses on their life histories and their practice and policy in relation to students of color. Both teachers demonstrated some disruption of Whiteness as well as some continued enactment of Whiteness, despite their stated intentions. The findings…

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. 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)

  11. 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)

  12. 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.

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

    PubMed

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

    2013-06-01

    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. PMID:23603518

  14. 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)

  15. Multi-scale Hydrologic Modeling of the White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Bourret, S. M.; Newton, B. T.

    2014-12-01

    The shallow groundwater flow system of White Sands dune field, located within the arid to semi-arid Tularosa Basin of Southern New Mexico, likely stabilizes the base of the largest gypsum dune field in the world. The dune is saturated throughout nearly its entire accumulation thickness, resulting in a shallow water table (< 3 ft bgs) in the inter-dunal areas. Water table elevation influences the spatial extent of the dune field and accumulation thickness. The White Sands National Monument (WHSA) is concerned that lowering the water table may lead to increased scour and migration of the dune field, which could be unfavorable to the preservation of the flora and fauna that have adapted to survive there. In response to projected increases in groundwater pumping in the regional Tularosa Basin groundwater system, changes in surface water use, and the threat of climate change, the WHSA is interested in understanding how these changes on a regional scale may impact the shallow dune field aquifer. Mathematical modeling techniques on varying spatial and temporal scales are used to characterize the relative importance of the sources of water (local vs. regional) to the dune aquifer, and to quantify the timescales on which changes may affect the water table in the dune field. A 2-dimensional, dune-scale heat and fluid flow model uses the seasonal temperature fluctuations to estimate the vertical and horizontal flow of water from the regional system to the dune field aquifer. We have also constructed a 2-dimensional, hydrologic model to characterize the regional groundwater flow regime near to the dune aquifer system, as well as across the Tularosa Basin to a depth of 6 km. Additionally, a 3-dimensional, hydrologic model of the Tularosa Basin and the White Sands dune field quantifies hydrologic characteristics, sources and sinks of groundwater in the basin and at the dune field. Computed and observed salinity, groundwater residence times, and water level data are the primary means of model calibration. Preliminary results from the three models indicate the regional groundwater system does contribute flow to the dune aquifer, and that increased pumping may increase drawdown of the regional groundwater system near the dune field. These results indicate the dune is sensitive to regional hydrologic changes.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. Genetic features of soils on marine sands and their windblown derivatives on the White Sea coast (the Kola Peninsula)

    NASA Astrophysics Data System (ADS)

    Pereverzev, V. N.; Kazakov, L. A.; Chamin, V. A.

    2011-01-01

    The Quaternary deposits on the Tersk coast of the White Sea are represented by marine deposits (the Tersk sands) enriched in the sea-sorted eluvium of the red Tersk sandstone. These deposits and the soils developed from them are characterized by the predominance of the fine sand fraction and the absence of gravel and the coarser fractions. The sediments derived from the red Tersk sandstone have an impoverished chemical composition (the silica content reaches 75-80%). The iron-illuvial podzols developed from them are characterized by the slightly pronounced differentiation of the main oxides and by the eluvial-illuvial redistribution of the amorphous Al and Fe compounds. Sandy soils—psammozems—with undifferentiated soil profiles are developed from windblown sands subjected to afforestation and from coastal marine sands under a relatively thin natural plant cover. Iron-illuvial podzols buried under a thin sand layer preserve the Al-Fe-humus type of the profile differentiation. In the recently deposited sand layer, the eluvial-illuvial redistribution of the chemical elements is absent.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Groundwater salinity as a control on development of eolian landscape: An example from the White Sands of New Mexico

    NASA Astrophysics Data System (ADS)

    Langford, Richard P.; Rose, Jessica M.; White, Diane E.

    2009-04-01

    The White Sands of southern New Mexico form the largest field of gypsum dunes in the world. The juxtaposition of several different types of dunes within the field has long been recognized and has generally been attributed to changes in the rate of sand transport across the dune field. However, Steven Fryberger [Fryberger, S.G., 2003. Geology of White Sands National Monument, web page www2.nature.nps.gov/geology/parks/whsa/] recently hypothesized, however, that a primary control is groundwater salinity. The White Sands dune field is underlain by saline waters. Fryberger proposed that parabolic dunes could form in topographic highs that accumulated a lens of fresher water derived from precipitation. Water with lower salinity allowed vegetation to grow, and stabilized the sand except for the active noses of the parabolic dunes. This study is a test of that hypothesis. A study transect was established across the boundary between parabolic and barchan dunes. Groundwater and soil at six sites were sampled during December, 2004 and March, May, and June of 2005. Two sites were established in the parabolic field, two in the barchans, and two in the transition zone between them. Groundwater was found to be three times more saline in the barchan area. Conductivity and chloride decreased across the transition zone. A GPS topographic survey revealed two abrupt topographic steps, one at the boundary between the barchans and the transition zone and a second at the edge of the parabolic field. A second, larger topographic step was found outside the study area defining a higher parabolic dune field. These data indicate that Fryberger's (2003) hypothesis is correct and groundwater is controlling the dune field morphology. The dune field did not begin to form until the Mid-Holocene (6500 years ago). A compilation of dates shows that the parabolic dune field has probably been stable for the last 3500 years. In contrast, the barchan area has been recently deflated and exposed 2000 year old sediment near the surface.

  9. 6. MCDONALD RANCH: AERIAL VIEW OF RANCH COMPLEX, LOOKING SOUTH ...

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

    6. MCDONALD RANCH: AERIAL VIEW OF RANCH COMPLEX, LOOKING SOUTH TOWARD NORTHERN TIP OF SAN ANDREAS RANGE - White Sands Missile Range, Trinity Site, Vicinity of Routes 13 & 20, White Sands, Dona Ana County, NM

  10. 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

  11. Adsorption of rare earth elements onto Carrizo sand: Experimental investigations and modeling with surface complexation

    NASA Astrophysics Data System (ADS)

    Tang, Jianwu; Johannesson, Karen H.

    2005-11-01

    Rare earth element (REE) adsorption onto sand from a well characterized aquifer, the Carrizo Sand aquifer of Texas, has been investigated in the laboratory using a batch method. The aim was to improve our understanding of REE adsorption behavior across the REE series and to develop a surface complexation model for the REEs, which can be applied to real aquifer-groundwater systems. Our batch experiments show that REE adsorption onto Carrizo sand increases with increasing atomic number across the REE series. For each REE, adsorption increases with increasing pH, such that when pH >6.0, >98% of each REE is adsorbed onto Carrizo sand for all experimental solutions, including when actual groundwaters from the Carrizo Sand aquifer are used in the experiments. Rare earth element adsorption was not sensitive to ionic strength and total initial REE concentrations in our batch experiments. It is possible that the differences in experimental ionic strength conditions (i.e., 0.002-0.01 M NaCl) chosen were insufficient to affect REE adsorption behavior. However, cation competition (e.g., Ca, Mg, and Zn) did affect REE adsorption onto Carrizo sand, especially for light rare earth elements (LREEs) at low pH. Rare earth element adsorption onto Carrizo sand can be successfully modeled using a generalized two-layer surface complexation model. Our model calculations suggest that REE complexation with strong surface sites of Carrizo sand exceeds the stability of the aqueous complexes LnOH 2+, LnSO 4+, and LnCO 3+, but not that of Ln(CO 3) 2- or LnPO 4o in Carrizo groundwaters. Thus, at low pH (<7.3), where major inorganic ligands did not effectively compete with surface sites for dissolved REEs, free metal ion (Ln 3+) adsorption was sufficient to describe REE adsorption behavior. However, at higher pH (>7.3) where solution complexation of the dissolved REEs was strong, REEs were adsorbed not only as free metal ion (Ln 3+) but also as aqueous complexes (e.g., as Ln(CO 3) 2- in Carrizo groundwaters). Because heavy rare earth elements (HREEs) were preferentially adsorbed onto Carrizo sand compared to LREEs, original HREE-enriched fractionation patterns in Carrizo groundwaters from the recharge area flattened along the groundwater flow path in the Carrizo Sand aquifer due to adsorption of free- and solution-complexed REEs.

  12. 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

  13. 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

  14. Determining soil moisture and sediment availability at White Sands Dune Field, New Mexico, from apparent thermal inertia data

    NASA Astrophysics Data System (ADS)

    Scheidt, Stephen; Ramsey, Michael; Lancaster, Nicholas

    2010-06-01

    Determinations of soil moisture and sediment availability in arid regions are important indicators of local climate variability and the potential for future dust storm events. Data from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer were used to derive the relationships among potential soil erosion, soil moisture, and thermal inertia (TI) at the spatial scale of aeolian landforms for the White Sands Dune Field between May 2000 and March 2008. Land surface apparent thermal inertia (ATI) data were used to derive an approximation of actual TI in order to estimate the wind threshold velocity ratio (WTR). The WTR is a ratio of the wind velocity thresholds at which soil erosion occurs for wet soil versus dry soil. The ASTER-derived soil moisture retrievals and the changes through time at White Sands were interpreted to be driven primarily by precipitation, but the presence of a perched groundwater table may also influence certain areas. The sediment availability of dunes, active playa surfaces and the margin of the alluvial fans to the west were determined to be consistently higher than the surrounding area. The sediment availability can be primarily explained by precipitation events and the number of dry days prior to the data acquisition. Other factors such as vegetation and the amount of surface crusting may also influence soil mobility, but these were not measured in the field. This approach showed the highest modeled sediment availability values just days prior to the largest dust emission event at White Sands in decades. Such an approach could be extended to a global monitoring technique for arid land systems that are prone to dust storms and for other regional land surface studies in the Sahara.

  15. 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.

  16. Multiscale bed form interactions and their implications for the abruptness and stability of the downwind dune field margin at White Sands, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Pelletier, Jon D.; Jerolmack, Douglas J.

    2014-11-01

    The downwind margin of White Sands dune field is an abrupt transition from mobile aeolian dunes to a dune-free vegetated surface. This margin is also relatively stable; over the past 60 years it has migrated several times more slowly than the slowest dunes within the dune field, resulting in a zone of dune coalescence, aggradation, and, along most of the margin, development of a dune complex (i.e., dunes superimposed on draas). Repeat terrestrial laser scanning surveys conducted over a 3 month period demonstrate that sediment fluxes within the dune complex decrease on approach to the margin. Computational fluid dynamics modeling indicates that this decrease is due, in part, to a decrease in mean turbulent bed shear stress on the lee side of the dune complex as a result of flow line divergence or sheltering of the lee-side dunes by the stoss side of the dune complex. Conservation of mass demands that this decrease in bed shear stress causes aggradation. We speculate that aggradation on the lee side of the dune complex further enhances the sheltering effect in a positive feedback, contributing to the growth and/or maintenance of the dune complex and a relatively abrupt and stable dune field margin. Our model and data add to a growing body of evidence that aeolian dune field patterns are influenced by feedbacks that occur at scales larger than individual dunes.

  17. Growth of mycorrhizal jack pine (Pinus banksiana) and white spruce (Picea glauca) seedlings planted in oil sands reclaimed areas.

    PubMed

    Onwuchekwa, Nnenna E; Zwiazek, Janusz J; Quoreshi, Ali; Khasa, Damase P

    2014-08-01

    The effectiveness of ectomycorrhizal inoculation at the tree nursery seedling production stage on growth and survival was examined in jack pine (Pinus banksiana) and white spruce (Picea glauca) planted in oil sands reclamation sites. The seedlings were inoculated with Hebeloma crustuliniforme strain # UAMH 5247, Suillus tomentosus strain # UAMH 6252, and Laccaria bicolor strain # UAMH 8232, as individual pure cultures and in combinations. These treatments were demonstrated to improve salinity resistance and water uptake in conifer seedlings. The field responses of seedlings to ectomycorrhizal inoculation varied between plant species, inoculation treatments, and measured parameters. Seedling inoculation resulted in higher ectomycorrhizal colonization rates compared with non-inoculated control, which had also a relatively small proportion of roots colonized by the nursery contaminant fungi identified as Amphinema byssoides and Thelephora americana. Seedling inoculation had overall a greater effect on relative height growth rates, dry biomass, and stem volumes in jack pine compared with white spruce. However, when examined after two growing seasons, inoculated white spruce seedlings showed up to 75% higher survival rates than non-inoculated controls. The persistence of inoculated fungi in roots of planted seedlings was examined at the end of the second growing season. Although the inoculation with H. crustuliniforme triggered growth responses, the fungus was not found in the roots of seedlings at the end of the second growing season suggesting a possibility that the observed growth-promoting effect of H. crustuliniforme may be transient. The results suggest that the inoculation of conifer seedlings with ectomycorrhizal fungi could potentially be carried out on a large scale in tree nurseries to benefit postplanting performance in oil sands reclamation sites. However, these practices should take into consideration the differences in responses between the different plant species and fungal strains. PMID:24424508

  18. 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.

  19. Aeolian sand transport over complex intertidal bar-trough beach topography

    NASA Astrophysics Data System (ADS)

    Anthony, Edward J.; Ruz, Marie-Hélène; Vanhée, Stéphane

    2009-04-01

    Aeolian sand transport on macrotidal beaches with complex intertidal bar-trough topography (ridge-and-runnel beaches) was assessed from experiments in northern France that involved measurements of wind speed, saltation, surface moisture contents, and rates of sand trapping across surveyed portions of the upper beach profile. Beaches exhibiting intertidal bars and troughs are much more complex, topographically, than simple reflective or dissipative beaches. Furthermore, the intertidal bar-trough morphology commonly exhibits strong cross-shore variations in the moisture contents of the beach surface and in patterns of bedform development. The results of four 30-minute experiments, conducted along topographically surveyed portions of the upper beach-dune toe profile, show that troughs act as extremely efficient sand interceptors, because of their permanently saturated state, which also inhibits sand mobilisation. Troughs, thus, limit or segment the dry fetch during conditions of intermittent saltation. Flow lines, inferred from the wind profiles, suggest that complex interactions at the boundary layer are generated by the bar-trough topography. Troughs systematically appear to be characterised by air expansion, while bar faces generate ramp wind acceleration for onshore winds, and sometimes immediate downwind deceleration for offshore winds. These effects may also contribute to cross-shore variations in the rates of sand trapping. Finally, a simple conceptual model of effective fetch development, integrating the effects of the spring-neap tidal range and of gross bar-trough morphological variability over time, is proposed for bar-trough beaches. The model highlights the key theme of fetch segmentation induced by cross-shore differentiation in the moisture contents of the beach surface hinged on the complex topography of multiple bars and troughs.

  20. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 3. A new species of Aleptina Dyar, 1902 (Lepidoptera, Noctuidae, Amphipyrinae, Psaphidini).

    PubMed

    Metzler, Eric H; Forbes, Gregory S

    2011-01-01

    In 2006 the US National Park Service initiated a long-term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Aleptina arenariasp. n., described here, was discovered in 2008, the second year of the study. The adult moths and male and female genitalia are illustrated. PMID:22207800

  1. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 4. A new species of Schinia Hübner, 1818 (Lepidoptera, Noctuidae, Heliothinae).

    PubMed

    Metzler, Eric H; Forbes, Gregory S

    2011-01-01

    In 2006 the U.S. National Park Service initiated a long term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Schinia pogueisp. n., described here, was discovered in 2007, the second year of the study. The male and female adult moths and genitalia are illustrated. PMID:22207801

  2. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 3. A new species of Aleptina Dyar, 1902 (Lepidoptera, Noctuidae, Amphipyrinae, Psaphidini)

    PubMed Central

    Metzler, Eric H.; Forbes, Gregory S.

    2011-01-01

    Abstract In 2006 the US National Park Service initiated a long-term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Aleptina arenaria sp. n., described here, was discovered in 2008, the second year of the study. The adult moths and male and female genitalia are illustrated. PMID:22207800

  3. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 4. A new species of Schinia Hübner, 1818 (Lepidoptera, Noctuidae, Heliothinae)

    PubMed Central

    Metzler, Eric H.; Forbes, Gregory S.

    2011-01-01

    Abstract In 2006 the U.S. National Park Service initiated a long term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Schinia poguei sp. n., described here, was discovered in 2007, the second year of the study. The male and female adult moths and genitalia are illustrated. PMID:22207801

  4. Quantifying wind blown landscapes using time-series airborne LiDAR at White Sands Dune Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Ewing, R. C.

    2011-12-01

    Wind blown landscapes are a default geomorphic and sedimentary environment in our solar system. Wind sand dunes are ubiquitous features on the surfaces of Earth, Mars and Titan and prevalent within the aeolian rock records of Earth and Mars. Dunes are sensitive to environmental and climatic changes and a complete understanding of this system promises a unique, robust and quantitative record of paleoclimate extending to the early histories of these worlds. However, our understanding of how aeolian dune landscapes evolve and how the details of the wind are recorded in cross-strata is limited by our lack of understanding of three-dimensional dune morphodynamics related to changing boundary conditions such as wind direction and magnitude and sediment source area. We use airborne LiDAR datasets over 40 km2 of White Sands Dune Field collected from June 2007, June 2008, January 2009, September 2009 and June 2010 to quantify 1) three-dimensional dune geometries, 2) annual and seasonal patterns of erosion and deposition across dune topography, 3) spatial changes in sediment flux related to position within the field, 4) spatial changes in sediment flux across sinuous crestlines and 5) morphologic changes through dune-dune interactions. In addition to measurements, we use the LiDAR data along with wind data from two near-by weather stations to develop a simple model that predicts depositional and stratigraphic patterns on dune lee slopes. Several challenges emerged using time series LiDAR data sets at White Sands Dune Field. The topography upon which the dunes sit is variable and rises by 16 meters over the length of the dune field. In order to compare individual dune geometries across the field and between data sets a base surface was interpolated from local minima and subtracted from the dune topography. Co-registration and error calculation between datasets was done manually using permanent vegetated features within the active dune field and structures built by the national monument as control points. Rapid dune migration rates, particularly at the upwind margin of the field ~6m/yr, result in significant decorrelation between data sets over longer time ranges, which limits the effectiveness of comparing these data sets.

  5. 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...

  6. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 2. Rediscovery and description of Sparkia immacula (Grote, 1883) (Noctuidae, Noctuinae, Hadenini).

    PubMed

    Metzler, Eric H; Forbes, Gregory S

    2011-01-01

    In 2006 the U.S. National Park Service initiated a long term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Sparkia immacula (Grote, 1883), previously known only from historical specimens collected in Arizona and New Mexico, was discovered in the Monument in 2007 during the second year of the study. The adult moths and male and female genitalia are illustrated for the first time. PMID:22207799

  7. The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 2. Rediscovery and description of Sparkia immacula (Grote, 1883) (Noctuidae, Noctuinae, Hadenini)

    PubMed Central

    Metzler, Eric H.; Forbes, Gregory S.

    2011-01-01

    Abstract In 2006 the U.S. National Park Service initiated a long term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Sparkia immacula (Grote, 1883), previously known only from historical specimens collected in Arizona and New Mexico, was discovered in the Monument in 2007 during the second year of the study. The adult moths and male and female genitalia are illustrated for the first time. PMID:22207799

  8. 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 1995–2008 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 2003–8 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.

  9. CYP1A induction and blue sac disease in early life stages of white suckers (Catostomus commersoni) exposed to oil sands.

    PubMed

    Colavecchia, Maria V; Hodson, Peter V; Parrott, Joanne L

    2006-05-01

    The objectives of this study were to evaluate the influence of natural oil sands on the early developmental stages of white sucker (Catostomus commersoni) and to determine whether biochemical responses in this species were similar to native fish caught in the Athabasca Oil Sands area. Early life stage (ELS) sediment toxicity tests were conducted using controls, reference sediments, natural oil sands, and industrially contaminated (wastewater pond) sediments collected from sites along the Athabasca River, Alberta (Canada). Eggs and larvae were observed for mortality, hatching, deformities, growth, and cytochrome P-4501A (CYP1A) activity using immunohistochemistry. E-Nat-, S-Nat-, and wastewater pond sediment-exposed groups showed significant premature hatching, reduced growth, and exposure-dependent increases in ELS mortality and larval malformations relative to controls. The most common larval deformities included edemas (pericardial, yolk sac, and subepidermal), hemorrhages, and spinal defects. Juveniles exposed to oil sands and wastewater pond sediments (96 h) demonstrated significantly increased 7-ethoxyresorufin-O-deethylase (EROD) activity (30- to 50-fold) as compared to controls. Reference sediment-exposed groups and water controls demonstrated reliable embryo and larval survival, minimal malformations, and negligible CYP1A staining. These observed signs of blue sac disease (ELS mortality, malformations, growth reductions, CYP1A activity induction) may produce deleterious reproductive effects in natural fish populations exposed to oil sands mixtures. PMID:16728374

  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. Origin of coarsely crystalline gypsum domes in a saline playa environment at the White Sands National Monument, New Mexico

    NASA Astrophysics Data System (ADS)

    Szynkiewicz, Anna; Moore, Craig H.; Glamoclija, Mihaela; Bustos, David; Pratt, Lisa M.

    2010-06-01

    Dome-like structures up to 3 m in height, composed predominantly of coarse crystals of selenite gypsum, occur on the surface of Alkali Flat, a saline playa lake in White Sands National Monument, New Mexico. The structures were investigated using field observations, aerial images, and geochemical methods. The domes are inferred to be remnants of lake sediments that have been preserved from Holocene eolian erosion due to higher cementation resulting from crystallization of large gypsum (selenite) crystals in the playa's clay-rich sediments. Low δ2H values of the selenite, from -90 to -69 ‰, suggest precipitation from saturated solutions associated with groundwater seepage in the playa related to the upward flows of groundwater, primarily fed by meteoric water rather than the evaporation of the playa water. Values of δ34S for selenite range from 12.1 to 13.8 ‰ (median 13.0 ‰) and are notably higher than the dissolved sulfate in the modern groundwater system that has δ34S values from 10.2 to 11.8 ‰ (median 11.4 ‰). The two main regional sources of sulfate are Middle Permian evaporites with median δ34S values of 12.0 ‰ and Lower Permian evaporites with median δ34S values of 13.0 ‰. The δ34S values measured in domes suggest their formation during a period of time when groundwater seepage might have been dominated by deeply circulating water that interacted with Lower Permian evaporites buried in the basin center. The apparent alignments of domes suggest that past groundwater seepage was controlled by fractures beneath Alkali Flat which are associated with a regional fault system in the area.

  12. 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.

  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. 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.

  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. Water management challenges at the world`s largest integrated oil sands mining and refining complex

    SciTech Connect

    Rogers, M.E.; Ferguson, D.; MacKinnon, M.

    1996-08-01

    The world`s largest oil sands mining and bitumen upgrading complex (150 million tons of ore to produce 75 million barrels of sweet crude per year) is operated in Northern Alberta, Canada. The company`s license to operate prohibits the discharge of any process affected water from the site. With an annual raw water import of approximately 34 million cubic meters, the company`s water management program has been limited to the impounding of the waste water. The impounded volume has grown to over 350 million cubic meters and will continue to grow in future years. The storage of this waste water (contaminated with sand, fines, hydrocarbons and salts) is governed by the storage space that is made available by the mine plan, and the need to maintain sufficiently low suspended solids water for recycling in the process. In addition, the final reclamation of the site, on abandonment of operations, requires restoration of the land to an environmentally acceptable condition, and it is important that the quality of the water associated with the various areas is not limiting to this goal. This paper discusses the operation as well as research and development efforts that are in place to optimize the water management plans. Some of the areas that must be addressed include aspects of corrosion and scaling control, water balances and maintenance of water quality. To aid in this, a model using High-Performance Numeric Computation and Visualization Software has been developed. Also some impacts from alternative tailings management approaches will be discussed.

  17. Tuberous sclerosis complex and Wolff-Parkinson-White syndrome.

    PubMed

    O'Callaghan, F J; Clarke, A C; Joffe, H; Keeton, B; Martin, R; Salmon, A; Thomas, R D; Osborne, J P

    1998-02-01

    This report highlights the association between tuberous sclerosis and Wolff-Parkinson-White syndrome. Ten patients with concurrent diagnoses of Wolff-Parkinson-White syndrome and tuberous sclerosis were identified. Wolff-Parkinson-White syndrome presented early in life, nine cases being diagnosed in the first year. Eight of the 10 cases were male. In eight cases, the syndrome was associated with supraventricular tachycardias, and in nine with cardiac rhabdomyomata. One child died from cardiac failure secondary to obstruction of the left ventricular outflow tract by a rhabdomyoma. Five of nine survivors showed resolution of Wolff-Parkinson-White syndrome on follow up. The accessory pathway was localised in nine patients from surface electrocardiograms: six children had left sided pathways and three had right sided pathways. PMID:9579160

  18. 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.

  19. 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

  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 90-150μm 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 2θ≈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 2θ≈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. 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.

  2. 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.

  3. Efficient white light generation from 2,3-diphenyl-1,2-dihydro-quinoxaline complex

    NASA Astrophysics Data System (ADS)

    Dwivedi, Y.; Kant, S.; Rai, R. N.; Rai, S. B.

    2010-11-01

    In this article, we report two organic materials dispersed in transparent poly (methyl methacrylate) matrix for efficient white light simulation under different optical excitations. A newly synthesized complex of benzoin and o-phenyldiamine is observed to be white on illumination with a blue LED. A new concept of white light emitting tube is also demonstrated. A mixture of 2,2″-([1,1'-biphenyl]-4,4'-diyldi-2,1-ethenediyl)-bis-benzenesulfonic acid disodium salt and complex is optimized to emit white light extended in the violet region on 355 nm laser excitation. The optical quality of the emitted white light is adjudged by the CIE coordinate, correlated color temperature and color rendition index in both the cases.

  4. Airflow and sand transport variations within a backshore parabolic dune plain complex: NE Graham Island, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Anderson, Jeffrey L.; Walker, Ian J.

    2006-07-01

    Onshore aeolian sand transport beyond the beach and foredune is often overlooked in the morphodynamics and sediment budgets of sandy coastal systems. This study provides detailed measurements of airflow, sand transport (via saltation and modified suspension), vegetation density, and surface elevation changes over an extensive (325 × 30 m) "swath" of a backshore foredune-parabolic dune plain complex. Near-surface (30 cm) wind speeds on the backshore ranged from 4.3 to 7.3 m s - 1 , gusting to 14.0 m s - 1 . Oblique onshore flow is steered alongshore near the incipient foredune then landward into a trough blowout where streamline compression, flow acceleration to 1.8 times the incident speed, and increasing steadiness occur. Highest saltation rates occur in steady, topographically accelerated flow within the blowout. As such, the blowout acts as a conduit to channel flow and sand through the foredune into the foredune plain. Beyond the blowout, flow expands, vegetation roughness increases, and flow decelerates. Over the foredune plain, localized flow steering and acceleration to 1.6 times the incident speed occurs followed by a drop to 40% of incident flow speed in a densely vegetated zone upwind of an active parabolic dune at 250 m from the foredune. Sediment properties reflect variations in near-surface flow and transport processes. Well-sorted, fine skewed backshore sands become more poorly sorted and coarse skewed in the blowout due to winnowing of fines. Sorting improves and sands become fine skewed over the foredune plain toward the parabolic dune due to grainfall of finer sands winnowed from the beach and foredune. During the fall-winter season, significant amounts of sand (up to 110 kg m - 2 ) are transported via modified suspension and deposited as grainfall up to 300 m landward of the foredune. No distinct trend in grainfall was found, although most fell on the depositional lobe of the blowout and at 200 m near an isolated, active parabolic dune. Grainfall amounts may reflect several transporting events over the measurement period and the transport process is likely via localized, modified suspension from the crest of the foredune and other compound dune features in the foredune plain. This evidence suggests that the process of grainfall delivery, though often overlooked in coastal research, may be a key process in maintaining active dunes hundreds of metres from the shoreline in a densely vegetated foredune plain. The effectiveness of this process is controlled by seasonal changes in vegetation cover and wind strength as well as shorter term (e.g., tidally controlled) variations in sand availability from the beach.

  5. 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)

  6. 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.

  7. 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.

  8. 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…

  9. 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

  10. 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…

  11. 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

  12. Probabilistic characterization of nonlinear systems under α-stable white noise via complex fractional moments

    NASA Astrophysics Data System (ADS)

    Alotta, G.; Di Paola, M.

    2015-02-01

    The probability density function of the response of a nonlinear system under external α-stable Lévy white noise is ruled by the so called Fractional Fokker-Planck equation. In such equation the diffusive term is the Riesz fractional derivative of the probability density function of the response. The paper deals with the solution of such equation by using the complex fractional moments. The analysis is performed in terms of probability density for a linear and a non-linear half oscillator forced by Lévy white noise with different stability indexes α. Numerical results are reported for a wide range of non-linearity of the mechanical system and stability index of the Lévy white noise.

  13. 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)

  14. 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)

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Mancos B interval of Upper Cretaceous Mancos Shale, Douglas Creek Arch, northwest Colorado: a shelf-sand complex

    SciTech Connect

    Cole, R.D.; Young, R.G.

    1986-08-01

    The Mancos B interval of the Mancos Shale, a major gas producer on the Douglas Creek arch is a shelf-sand complex represented by up to 1345 ft (404 m) of thinly interstratified claystone, siltstone, and very fine to fine-grained sandstone deposited approximately 100 mi (161 km) offshore in the Western Interior seaway. In the subsurface, the Mancos B is subdivided into four major units, ranging in thickness from 175 to 480 ft 953 to 146 m). Each unit thins over the arch's crest and, in the process, becomes more sand rich. In outcrops along the southern flank of the arch, the lower Mancos B forms a series of coarsening-upward sequences, 25 to 90 ft (8 to 27 m) thick. A typical sequence begins with silty claystone or bioturbated mudstone at the base, followed upward by bioturbated muddy sandstone, and topped with sandy dolomite (as concretions or thin beds). Sedimentary structures include horizontal lamination, wavy lamination, lenticular bedding, flaser bedding, and ripple lamination. Paleocurrent measurements from ripple foresets have a mean azimuth of 111/sup 0/. Burrows characteristic of the Cruziana ichnofacies are common to abundant in all lithofacies.

  20. 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 (λex 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

  1. 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

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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; Andò, Sergio; Vezzoli, Giovanni; Bandopadhyay, Pinaki C.; Najman, Yani; Boni, Maria; Bechstädt, 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 mèlange, 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 Andò, 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.

  6. 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.

  7. Effects of salinity and anatomical hook location on the mortality and physiological response of angled-and-released sand whiting Sillago ciliata.

    PubMed

    McGrath, S P; Butcher, P A; Broadhurst, M K

    2009-01-01

    Three experiments were done with sand whiting Sillago ciliata: the first two assessed the short-term mortality and physiological response of individuals after being mouth hooked and then subjected to rapid changes in salinity, while the third experiment investigated their longer-term fate after ingesting hooks (independent of salinity changes). In experiment one, 48 tanks containing a single S. ciliata were randomly assigned as either one of three treatments or a control. The fish in treatments one and two were exposed to salinity changes during their angling and subsequent release while those in treatment three were only subjected to angling and air exposure. Control fish remained untouched. Fish were then monitored for up to 6 days for mortalities before blood samples were taken to determine concentrations of plasma cortisol and glucose. Blood samples were also taken from five wild-caught fish to provide baseline estimates of the above variables. None of the treatment or control fish died over the 6 days, and there were no significant differences in blood cortisol or glucose between treatment, control and wild fish. In experiment two, 102 S. ciliata and 52 experimental tanks were used. The treatments were repeated as above, however, six individuals from each treatment and control group were removed and sampled for blood (and then glucose and cortisol) at 0, 24, 48 and 72 h post release. Some changes in behaviour due to the salinity changes occurred as well as a significant main effect of time for cortisol, with all fish having significantly elevated acute stress at the first sample time. In experiment three, 52 S. ciliata were placed into individual tanks. Twenty-six of these fish were allowed to ingest baited J-hooks, played for 60 s, removed from their tanks, and then released after their lines were cut (50 mm from their mouths). Control fish were not touched. All fish were then monitored over 21 days. Six of the treatment fish died (between 3 h and 14 days), while the remaining hooked fish resumed feeding within 5 days and 25% ejected their hooks (between 1 and 19 days). It was concluded that (1) salinity and mouth hooking had few independent or interactive effects on the mortality or physiological response of angled-and-released S. ciliata and (2) while hook ingestion caused some mortalities, the protracted physiological effects were limited, with all surviving fish resuming feeding and some eventually ejecting their hooks. PMID:20735535

  8. Land cover mapping at Alkali Flat and Lake Lucero, White Sands, New Mexico, USA using multi-temporal and multi-spectral remote sensing data

    NASA Astrophysics Data System (ADS)

    Ghrefat, Habes A.; Goodell, Philip C.

    2011-08-01

    The goal of this research is to map land cover patterns and to detect changes that occurred at Alkali Flat and Lake Lucero, White Sands using multispectral Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced Land Imager (ALI), and hyperspectral Hyperion and Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data. The other objectives of this study were: (1) to evaluate the information dimensionality limits of Landsat 7 ETM+, ASTER, ALI, Hyperion, and AVIRIS data with respect to signal-to-noise and spectral resolution, (2) to determine the spatial distribution and fractional abundances of land cover endmembers, and (3) to check ground correspondence with satellite data. A better understanding of the spatial and spectral resolution of these sensors, optimum spectral bands and their information contents, appropriate image processing methods, spectral signatures of land cover classes, and atmospheric effects are needed to our ability to detect and map minerals from space. Image spectra were validated using samples collected from various localities across Alkali Flat and Lake Lucero. These samples were measured in the laboratory using VNIR-SWIR (0.4-2.5 μm) spectra and X-ray Diffraction (XRD) method. Dry gypsum deposits, wet gypsum deposits, standing water, green vegetation, and clastic alluvial sediments dominated by mixtures of ferric iron (ferricrete) and calcite were identified in the study area using Minimum Noise Fraction (MNF), Pixel Purity Index (PPI), and n-D Visualization. The results of MNF confirm that AVIRIS and Hyperion data have higher information dimensionality thresholds exceeding the number of available bands of Landsat 7 ETM+, ASTER, and ALI data. ASTER and ALI data can be a reasonable alternative to AVIRIS and Hyperion data for the purpose of monitoring land cover, hydrology and sedimentation in the basin. The spectral unmixing analysis and dimensionality eigen analysis between the various datasets helped to uncover the most optimum spatial-spectral-temporal and radiometric-resolution sensor characteristics for remote sensing based on monitoring of seasonal land cover, surface water, groundwater, and alluvial sediment input changes within the basin. The results demonstrated good agreement between ground truth data and XRD analysis of samples, and the results of Matched Filtering (MF) mapping method.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Sand Storage

    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...

  15. Morphology, evolution and fill: Implications for sand and mud distribution in filling deep-water canyons and slope channel complexes

    NASA Astrophysics Data System (ADS)

    Cronin, Bryan T.; Akhmetzhanov, Andrey M.; Mazzini, Adriano; Akhmanov, Grigorii; Ivanov, Michael; Kenyon, Neil H.; TTR-10 Shipboard Scientists

    2005-08-01

    A survey of the northeastern margin of the Rockall Trough on the Irish margin examined the transition from shelf edge to basin floor, in morphology and sedimentary activity, of a deeply incised submarine canyon system, the Donegal Bay submarine canyon. The survey produced superb 3D profiling of the canyon along its entire length, marking a transition from 'cauliflower' shaped head region with numerous tributary gullies feeding into one main canyon, to a single trunk canyon. This canyon, with an initial combined width and depth of > 17 km and > 800 m in the 'cauliflower' head area, decreases rapidly to > 4.5 km wide and > 450 m deep after the zone of tributary confluence. Eighteen kilometers further down dip, the canyon loses topographic expression as it approaches the lower rise and floor of the Rockall Trough. Degrees of recent sedimentary activity are evaluated by comparing side scan sonar systems of different frequency, and thus of different penetration sub sea, and by ground-truthing using drop (gravity) cores. The canyon was a very active system, dominated by sand transportation towards the floor of the Rockall Trough, along the slope as coarse-grained contourite, or as sand spillover from the shelf. Sand was also deposited as overbank deposits outside the main head region of the canyon, presumably by large volume turbidity currents and more active lateral gullies. The head area of the canyon system has been progressively cut off from sand source by progressive sea level rise since the last glaciation. Sand was locally deposited on terraces but not in the overbank area. Less frequent, lower volume and finer grained turbidity currents have become more common in the system. The initial sand and bypass-dominated system with small sediment waves, which may be gravels, has become dominated by muddy debrites in the lower reaches and by slumps in the upper reaches. Slumping in those upper reaches leads to ponding of sand in the head and upper reach areas, with only very occasional turbidity currents transporting sand further down the system in small channels. A model is produced to explain the mechanism and expression of backfilling in a large deep-water canyon system whose hinterland has been flooded back since glacial drawdown of sea level in the eastern Rockall Trough area. This model explains how sand may be trapped in large volumes in the upper reaches of a canyon system, due to slumping from the canyon margins and nearby upper slope regions. The focusing of sand deposition in areas where this is not usually expected will have important implications for hydrocarbon explorationists who wish to map the distribution of potential reservoir sand bodies within large, confined deep-water canyon systems.

  16. 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.

  17. 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

  18. Depositional model for a muddy shelf-sand complex and their relationship to reservoir development: Mancos B interval of Late Cretaceous Mancos Shale, northwest Colorado and northeast Utah

    SciTech Connect

    Cole, R.D.; Young, R.G.

    1987-05-01

    The Mancos B interval of the Mancos Shale is an unusually thick (up to 1345 ft or 410 m) assemblage of sandy mudstone and muddy sandstone deposited in the Western Interior seaway approximately 100 mi (161 km) offshore. The basic sedimentation unit for the Mancos B is a thin couplet consisting of a basal fine-grained sandstone component and an upper mud rock component. Individual couplets are lenticular and generally less than 0.3 ft (0.09 m) thick and 2.5 ft (0.8 m) across. The sand component has sharp upper and lower contacts and is characterized by ripple lamination, wavy lamination, flaser lamination, and graded lamination (rare), whereas the mud rock component has discontinuous horizontal lamination accentuated by thin sandy streaks. Paleocurrents taken from ripples are to the southeast. Sequential deposition of sand/mud couplets resulted in formation of muddy sandstone sequences that range in thickness from 25 to 90 ft (8 to 27 m). The gross sand content in a sequence increases from approximately 30% at the base to 50 to 80% at the top. Bioturbation, which is characterized by members of the Cruziana ichnofacies, increases proportionally with sand content. Sequences are usually capped by thin intervals of sandy Fe-dolomite (beds and concretions). Sequences are typically stacked into packages, ranging in thickness from 175 to 480 ft (53 to 146 m). Four main packages are present in the Mancos B. A depositional model involving uplift, sea-bottom shoaling, and sediment winnowing by episodic shelf currents is proposed for the generation of the Mancos B shelf-sand complex.

  19. Crack Geometry and Morphology in Hydrous Sulfate Sands

    NASA Astrophysics Data System (ADS)

    Chavdarian, G. V.; Sumner, D. Y.

    2008-03-01

    We use observations of crack morphology in gypsum sand from an analog site at White Sands National Monument, New Mexico, to understand the processes affecting crack morphology over time in order to develop working hypotheses of cracks on Meridiani.

  20. 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.

  1. 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

  2. 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

  3. 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)

  4. 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)

  5. 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 μg/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.

  6. 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...

  7. Tunable and Efficient White Light Phosphorescent Emission Based on Single Component N-Heterocyclic Carbene Platinum(II) Complexes.

    PubMed

    Bachmann, Michael; Suter, Dominik; Blacque, Olivier; Venkatesan, Koushik

    2016-05-16

    A new class of cyclometalated pyridine N-heterocyclic carbene (NHC) Pt(II) complexes with electronically different alkyne derivatives (C≡CR; R = C6H4C(CH3)3 (1), C6H5 (2), C6H4F (3), C6H3(CF3)2 (4)) as ancillary ligands were synthesized, and the consequences of the electronic properties of the different substituted phenylacetylene ligands on the phosphorescent emission efficiencies were studied, where C≡CC6H4C(CH3)3 = 4-tert-butylphenylacetylene, C≡CC6H5 = phenylacetylene, C≡CC6H4F = 4-fluorophenylacetylene, and C≡CC6H3(CF3)2 = 3,5-bis(trifluoromethyl)phenylacetylene. Structural characterization, electrochemistry, and photophysical investigations were performed for all four compounds. Moreover, the emission quantum efficiencies and wavelength emission intensities of the complexes were also recorded in different weight percents in poly(methyl methacrylate) films (PMMA) and evaluated in the CIE-1931 chromaticity diagram. The square planar coordination geometry with the alkynyl ligands was corroborated for complexes 1, 2, and 3 by single crystal X-ray diffraction studies. These complexes show tunable monomeric high energy triplet emission and an additional concentration-dependent low-energy excimer-based phosphorescence. While adopting weight percent concentrations between 15 and 25%, the two emission bands covering the entire visible spectrum were obtained with these particular complexes displaying the properties of an efficient white light triplet emitter with excellent CIE-1931 coordinates (0.31, 0.33). On the basis of the high luminescent quantum efficiency of over 50% for white light emission, these compounds could be potentially useful for white organic light-emitting diodes (WOLEDs) based applications. PMID:27135529

  8. 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

  9. 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

  10. Gastrointestinal responses of rats fed on white and wholemeal breads: complex carbohydrate digestibility and the influence of dietary fat content.

    PubMed

    Key, F B; Mathers, J C

    1993-03-01

    To obtain quantitative information on the digestibility of the non-starch polysaccharides (NSP) fraction of white and wholemeal breads, rats were fed on diets in which freeze-dried bread (white, wholemeal or mixtures of the two) provided all the complex carbohydrates. In a second experiment the possibility that dietary fat concentration might influence NSP digestibility was tested by feeding diets containing 30 or 170 g maize oil/kg and either white or wholemeal bread. Multiple linear regression analysis provided little evidence of associative effects of dietary components on NSP digestibility and in the two experiments digestibilities of NSP for white and wholemeal breads were 0.77-0.82 and 0.47-0.52 respectively. Xylose- and arabinose-containing polymers were better digested than was cellulose for both breads. Replacing white by wholemeal bread markedly increased the molar proportion of butyrate in caecal volatile fatty acids at the expense of acetate. This was associated with greater flows of organic matter to the large bowel (LB) and a reduction in caecal transit time (Expt 2). There was little detectable effect of dietary maize oil concentration on NSP digestibility or on LB fermentation. All breads contained some starch resistant to pancreatic alpha-amylase (EC 3.2.1.1) without previous treatment with dimethyl sulphoxide. The digestibility of this starch fraction was not significantly different from 1.0 for all diets except that containing wholemeal bread and the higher maize oil concentration where the apparent digestibility was 0.89. PMID:8490002

  11. 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.

  12. 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.

  13. 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.

  14. Utility of unipolar recordings for complex Wolff–Parkinson–White 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 Wolff–Parkinson–White 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 Wolff–Parkinson–White 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. PMID:26937099

  15. 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

  16. 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

  17. White Rock

    NASA Technical Reports Server (NTRS)

    2005-01-01

    14 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the famous 'White Rock' feature in Pollack Crater in the Sinus Sabaeus region of Mars. The light-toned rock is not really white, but its light tone caught the eye of Mars geologists as far back as 1972, when it was first spotted in images acquired by Mariner 9. The light-toned materials are probably the remains of a suite of layered sediments that once spread completely across the interior of Pollack Crater. Dark materials in this image include sand dunes and large ripples.

    Location near: 8.1oS, 335.1oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  18. 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

  19. 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

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

    PubMed

    Lev-Yadun, Simcha

    2013-10-01

    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

  1. 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.

  2. Design and Synthesis of Pyrimidine-Based Iridium(III) Complexes with Horizontal Orientation for Orange and White Phosphorescent OLEDs.

    PubMed

    Cui, Lin-Song; Liu, Yuan; Liu, Xiang-Yang; Jiang, Zuo-Quan; Liao, Liang-Sheng

    2015-05-27

    Two phosphorescent Ir(III) complexes Ir(ppm)2(acac) and Ir(dmppm)2(acac) were synthesized and characterized with emission ranged at 584/600 nm and high photoluminescence quantum yields (PLQYs) of 0.90/0.92, respectively. The angle-dependent PL spectra analysis reveals that the two orange iridium(III) complexes embodied horizontal orientation property. The high photoluminescence quantum yield and high horizontal dipoles ratio determine their excellent device performance. The devices based on Ir(ppm)2(acac) and Ir(dmppm)2(acac) achieved efficiencies of 26.8% and 28.2%, respectively, which can be comparable to the best orange phosphorescent devices reported in the literature. Furthermore, with the introduction of FIrpic as sky-blue emitter, phosphorescent two-element white organic light-emitting devices (OLEDs) have been realized with external quantum efficiencies (EQEs) as high as 25%, which are the highest values among the reported two-element white OLEDs. PMID:25943159

  3. 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.

  4. 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.

  5. Water Cycling in Hydrous Sulfate Sands as a Possible Analog for Dehydration of Meridiani Planum Outcrops

    NASA Astrophysics Data System (ADS)

    Chavdarian, G. V.; Sumner, D. Y.

    2007-07-01

    Cracks and fins in hydrous sulfate sands at White Sands National Monument, New Mexico, demonstrate vapor transport between the atmosphere and subsurface. A similar process may be forming cracks and fins in Meridiani outcrops in the recent past.

  6. Cracks as Evidence for Water Evaporation and Condensation Associated with Temperature Changes in Hydrous Sulfate Sands

    NASA Astrophysics Data System (ADS)

    Chavdarian, G. V.; Sumner, D. Y.

    2007-03-01

    Mineral-atmospheric water cycling promotes crack formation in the hydrous sulfate (gypsum) sands at White Sands National Monument, New Mexico. A similar water cycling process may promote crack formation in sulfate outcrops on Meridiani Planum, Mars.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Effects of methylmercury and spatial complexity on foraging behavior and foraging efficiency in juvenile white ibises (Eudocimus albus).

    PubMed

    Adams, Evan M; Frederick, Peter C

    2008-08-01

    Methylmercury is a globally distributed neurotoxin, endocrine disruptor, and teratogen, the effects of which on wildlife at environmentally relevant levels are largely unknown. In birds, foraging efficiency and learning may be sensitive endpoints for sublethal methylmercury toxicity, and these endpoints also may be biologically relevant at the population level. In the present study, groups of wild-caught, prefledgling white ibises (Eudocimus albus) were raised in a free-flight, open-air aviary on diets that approximated the measured range of methylmercury exposure in the Everglades ecosystem (0, 0.05, 0.1, and 0.3 mg/kg/d). The effect of methylmercury exposure on group foraging efficiency was examined by allowing birds to forage on 200 fathead minnows (Pimephales promelas) in artificial ponds for 15 min by straining the arenas' contents through a seine net and counting all remaining prey. Additionally, we varied the difficulty of foraging by these tactile feeding birds by adding multiple levels of structural complexity (e.g., increased vegetation and prey refugia) to the pond. Structural complexity affected both foraging efficiency and the rate of increase in efficiency over time (improvement). Methylmercury exposure affected foraging efficiency (p = 0.03). It did not affect foraging improvement in the face of increasingly challenging environments, however, and the dose-response relationship was nonlinear (e.g., the control and high-exposure groups were the least efficient foragers). Evidence for an effect of methylmercury on foraging efficiency therefore was inconclusive because of unpredicted results and no interaction with time or habitat complexity. These data suggest a nonlinear dose-response relationship at low levels of methylmercury exposure; future research is needed to verify this hypothesis. This appears to be the first experimental demonstration of the effects of habitat complexity on foraging efficiency in long-legged wading birds. PMID:18315390

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. Exposed Tsunami Sand Layers

    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...

  10. Sand for Traction

    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...

  11. China Dust and Sand

    Atmospheric Science Data Center

    2013-04-16

    article title:  Dust and Sand Sweep Over Northeast China     ... (MISR) captured these views of the dust and sand that swept over northeast China on March 10, 2004. Information on the ... available at JPL March 10, 2004 - Dust and sand sweep the northeast region. project:  MISR ...

  12. 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

  13. 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.

  14. 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.

  15. Murzuk Sand Sea, Sahara Desert, Libya, Africa

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This near vertical view of the Murzuk Sand Sea, Sahara Desert, Libya (22.5N, 13.0E) shows the very diverse landscape that is part of the great Sahara Desert of North Africa. The vast expanse of sand dunes known as the Murzuk sand Sea of Libya and the adjacent rock outcrops support little human habitation. In fact, the tiny village of Murzuk with its center pivot, swing arm irrigated agriculture complex is the only sign of life in the region.

  16. 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...

  17. 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.

  18. 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-...

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. Submarine sand sampler

    SciTech Connect

    Casciano, F.M.

    1980-08-19

    A subsurface sampler which obtains samples of sand from offshore deposits is described. A 27-foot tube within a tube is lowered to the ocean floor while suspended from flotation tanks. The sampler is free of suspension cables and thus is detached from boat motions. Surface sand is sucked up through the suction tube and pumped to a container on deck by a jet pump. A jet pump is actuated by high pressure drive water sent down a three inch hose to the top of the sampler, through the void between the two pipes, and to an annular jet nozzle. The nozzle directs the flow upward in the two-inch center pipe through a venturi-shaped throat piece. The throat piece causes sand to be sucked up the suction tube and transported in a slurry through the inner pipe and a two-inch slurry hose to the surface. A manifold valve in the inner pipe shuts off upward flow, jetting water from the lower intake and flowing away sand to let the sampler drop deeper into a deposit. Upward pointing nozzles on the outer pipe provide an upward flow of water around the periphery of the sampler, preventing sand from collapsing around the sampler embedding it in the sand. A sharpened cutting tip helps break up compacted sand. A mercury switch senses deviation from vertical, and a sonar device measures distance of the tip of the sampler pipe from the sand surface.

  4. An Affair with Sand.

    ERIC Educational Resources Information Center

    Stroud, Sharon

    1980-01-01

    Described is a resource idea developed for the teaching of oceanography to junior high students. Sand is studied to help make the study of beaches more relevant to students who may have never seen an ocean. Sand samples are brought into the classroom from various coastal cities, then analyzed and compared. (Author/DS)

  5. Processing of tar sands

    SciTech Connect

    Audeh, C.A.

    1980-04-08

    Petroliferous material of tar sands is processed to recover both low and higher boiling distillate material in a sequential combination operation involving thermal distillation and solvent extraction. Residue of solvent extraction is gasified with hot sand product of gasification step used in the thermal distillation operation.

  6. 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, Stéphanie; 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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 μm) were prepared for gypsum, quartz and dolomite, mixtures were prepared using the 90-150 μm 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 μm, plus bands at 1.749, 1.945, 2.217 and 2.267 μm. 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.

  13. Sand sheets show chevrons

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    In Saharan Africa, sand sheets stretch in virtually flat expanses for hundreds of kilometers. The sheets have been considered devoid not only of life but of regional landforms that might provide insight into the wind-driven processes of erosion and transport by which deserts sustain themselves and grow. Now a fresh, computer-enhanced look at satellite images of sand sheets in Egypt and Sudan by Ted Maxwell of the Smithsonian Institution's Center for Earth and Planetary Studies (Washington, D.C,) and C. Vance Haynes of the University of Arizona (Tucson) has led to the discovery of huge, flat sand dunes.

  14. 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).

  15. Hydraulic Fracturing Sand

    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....

  16. Vent of Sand Volcano

    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....

  17. 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.

  18. Foundry sand reclamation

    SciTech Connect

    Filipovitch, A.J.; Bleuenstein, J.M.

    1984-05-22

    A dry method of conditioning spent foundry sand is disclosed. After having sized the sand and removal of tramp metallic elements, the sand is subjected to a sequence of squeezing under a high-stress low kinetic energy system for a period of 5-30 minutes, and then propelled against a target with high-kinetic energy in the presence of a suction for several minutes. This sequence can be preferably repeated to increase the quality of the resulting product which should have 0.1% or less of fine particles, a pH of 6-9, a clay content and organic combustible content of substantially zero. The reclaimed sand will exhibit a density of at least 100 grams/biscuit when compacted for core making or molding.

  19. Assessing the effects of light on differentiation and virulence of the plant pathogen Botrytis cinerea: characterization of the White Collar Complex.

    PubMed

    Canessa, Paulo; Schumacher, Julia; 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

  20. 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

  1. 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; Kangasjärvi, 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

  2. 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.

  3. Heat-treatment of metal parts facilitated by sand embedment

    NASA Technical Reports Server (NTRS)

    Briscoe, C. C.; Kelley, R. C.

    1966-01-01

    Embedding metal parts of complex shape in sand contained in a steel box prevents strains and warping during heat treatment. The sand not only provides a simple, inexpensive support for the parts but also ensures more uniform distribution of heat to the parts.

  4. 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

  5. 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.

  6. Intranasal Inoculation of White-Tailed Deer (Odocoileus virginianus) with Lyophilized Chronic Wasting Disease Prion Particulate Complexed to Montmorillonite Clay

    PubMed Central

    Nichols, Tracy A.; Spraker, Terry R.; Rigg, Tara D.; Meyerett-Reid, Crystal; Hoover, Clare; Michel, Brady; Bian, Jifeng; Hoover, Edward; Gidlewski, Thomas; Balachandran, Aru; O'Rourke, Katherine; Telling, Glenn C.; Bowen, Richard

    2013-01-01

    Chronic wasting disease (CWD), the only known prion disease endemic in wildlife, is a persistent problem in both wild and captive North American cervid populations. This disease continues to spread and cases are found in new areas each year. Indirect transmission can occur via the environment and is thought to occur by the oral and/or intranasal route. Oral transmission has been experimentally demonstrated and although intranasal transmission has been postulated, it has not been tested in a natural host until recently. Prions have been shown to adsorb strongly to clay particles and upon oral inoculation the prion/clay combination exhibits increased infectivity in rodent models. Deer and elk undoubtedly and chronically inhale dust particles routinely while living in the landscape while foraging and rutting. We therefore hypothesized that dust represents a viable vehicle for intranasal CWD prion exposure. To test this hypothesis, CWD-positive brain homogenate was mixed with montmorillonite clay (Mte), lyophilized, pulverized and inoculated intranasally into white-tailed deer once a week for 6 weeks. Deer were euthanized at 95, 105, 120 and 175 days post final inoculation and tissues examined for CWD-associated prion proteins by immunohistochemistry. Our results demonstrate that CWD can be efficiently transmitted utilizing Mte particles as a prion carrier and intranasal exposure. PMID:23671598

  7. Kentucky tar sand project

    SciTech Connect

    Kelley, M.N.; Jones, H.D. II; Lewis, F.W.

    1985-03-01

    Engineering details and pilot-plant results from a pioneering investigation based on a Kentucky tar-sand reserve are presented. The tar sand deposits of Kentucky are generally situated in the southeastern rim of the Illinois Basin along the southern boundary of the Western Coal Field region. In a recent study of US tar sand reserves, it was reported that over 3.4 billion barrels of oil are in Kentucky tar sand deposits alone. In the 22,000 acres, estimated reserves are over 100 million barrels of recoverable heavy oil. The oil-impregnated section of the deposit ranges in heavy oil content from five gallons per ton to over fifteen gallons per ton. The ore body is up to thirty-five feet thick and the overall stripping ratio for a commercial plant is estimated to be one cubic yard of undisturbed overburden material per ton of tar sand ore. A shovel and truck-type strip mining operation would be used to provide feedstock to the plant.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. The Engineering of Sand.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.

    1989-01-01

    Discussed are beach replenishment, and hard structures in relation to the sand transportation system. Failures of current engineering practices and the resulting costs to the taxpayer are stressed. Equations and parameters used to make predictions of beach durability are criticized. (CW)

  15. Sand Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Berry, Don; Lawhorn, William

    2009-06-01

    In an experimental program, steel bullets and short cylinders, and tungsten alloy rods were shot into dry silica sand at 600 to 1100 m/s. The rods included finsets that were designed for aerodynamic stabilization. The fins also apparently provided trajectory stabilization within the sand as well. Time-of-arrival screens allowed measurement of velocity. Analysis of those data indicated that drag coefficients increased as projectiles slowed down. Comparison with previous data indicates there was a slight increase in drag coefficient of rods over expected values for unfinned rods; however, the net result was penetration normalized by length was as high as 40, depending on nose shape. It was found that when the velocity exceeded about 80 m/s (which is close to the speed of sound in sand) sand particles were broken down into their constituent grains, resulting in a decrease in size by about 1000. Normalized penetration is expected to scale as kinetic energy per unit area, and it was significantly higher for the rods than for the other projectiles. This is attributed to stabilization from interaction of the fins with the cavity wall.

  16. 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…

  17. 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.

  18. 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.

  19. Revisiting a type locality for Late Glacial aeolian sand deposition in NW Europe: Optical dating of the dune complex at Opgrimbie (NE Belgium)

    NASA Astrophysics Data System (ADS)

    Derese, Cilia; Vandenberghe, Dimitri; Paulissen, Etienne; Van den haute, Peter

    2009-08-01

    The Late Glacial dune complex at Opgrimbie (NE Belgium) is thought to represent a complete record of the Late Pleniglacial to Holocene change at the southernmost part of the coversand area. In this work, the chronology of the site was reinvestigated using quartz-based single-aliquot optical dating. Nine samples in total were collected from sediments above and below a bleached horizon, the Opgrimbie layer, which laterally passes into a sandy peat layer; earlier radiometric radiocarbon dating and pollen analyses showed the latter to be of Bølling age (14.8-14.1 ka cal. BP). The sampled sequence is overlain by a second horizon, the Usselo horizon, for which an Allerød age (14.0-13.0 ka cal. BP) was deduced from one radiometric 14C age and palynological evidence. This was confirmed by AMS data obtained as part of this study. All nine quartz samples showed satisfactory luminescence characteristics, and yielded an internally consistent set of optical ages. The dataset contains no clear outliers and the observed variation is not much larger than that expected from uncertainties. The sediments over- and underlying the lowermost bleached horizon are dated at 12.9 ± 0.9 ka ( n = 6) and 13.0 ± 0.8 ka ( n = 3), respectively. These ages do not confirm the Bølling age that was previously established for this horizon; the optical ages are, however, consistent with the chronostratigraphical position of the sediments below the Usselo soil of Allerød age. As such, the OSL ages question if the Lateglacial aeolian succession is fully developed at Opgrimbie, and they challenge its significance as a type locality.

  20. 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

  1. Windblown Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-557, 27 November 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows sand dunes and large ripples in a crater in the Hellespontus region of Mars. The winds that formed these dunes generally blew from the left/lower-left (west/southwest). Unlike the majority of dunes on Earth, sand dunes on Mars are mostly made up of dark, rather than light, grains. This scene is located near 50.3oS, 327.5oW. The image covers an area 3 km (1.9 mi) wide, and is illuminated by sunlight from the upper left.

  2. PROCESSING OF MONAZITE SAND

    DOEpatents

    Calkins, G.D.; Bohlmann, E.G.

    1957-12-01

    A process for the recovery of thorium, uranium, and rare earths from monazite sands is presented. The sands are first digested and dissolved in concentrated NaOH, and the solution is then diluted causing precipitation of uranium, thorium and rare earth hydroxides. The precipitate is collected and dissolved in HCl, and the pH of this solution is adjusted to about 6, precipitating the hydroxides of thorium and uranium but leaving the rare earths in solution. The rare earths are then separated from the solution by precipitation at a still higher pH. The thorium and uranium containing precipitate is redissolved in HNO/sub 3/ and the two elements are separated by extraction into tributyl phosphate and back extraction with a weakly acidic solution to remove the thorium.

  3. Mutations Linked to Leukoencephalopathy with Vanishing White Matter Impair the Function of the Eukaryotic Initiation Factor 2B Complex in Diverse Ways

    PubMed Central

    Li, Wei; Wang, Xuemin; van der Knaap, Marjo S.; Proud, Christopher G.

    2004-01-01

    Leukoencephalopathy with vanishing white matter (VWM) is a severe inherited human neurodegenerative disorder that is caused by mutations in the genes for the subunits of eukaryotic initiation factor 2B (eIF2B), a heteropentameric guanine nucleotide exchange factor that regulates both global and mRNA-specific translation. Marked variability is evident in the clinical severity and time course of VWM in patients. Here we have studied the effects of VWM mutations on the function of human eIF2B. All the mutations tested cause partial loss of activity. Frameshift mutations in genes for eIF2Bɛ or eIF2Bβ lead to truncated polypeptides that fail to form complexes with the other subunits and are effectively null mutations. Certain point mutations also impair the ability of eIF2Bβ or -ɛ to form eIF2B holocomplexes and also diminish the intrinsic nucleotide exchange activity of eIF2B. A point mutation in the catalytic domain of eIF2Bɛ impairs its ability to bind the substrate, while two mutations in eIF2Bβ actually enhance eIF2 binding. We provide evidence that expression of VWM mutant eIF2B may enhance the translation of specific mRNAs. The variability of the clinical phenotype in VWM may reflect the multiple ways in which VWM mutations affect eIF2B function. PMID:15060152

  4. 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 ...

  5. 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.'

  6. Cracks and Fins in Sulfate Sand: Evidence for Recent Mineral-Atmospheric Water Cycling in Meridiani Planum Outcrops?

    NASA Astrophysics Data System (ADS)

    Chavdarian, G. V.; Sumner, D. Y.

    2006-03-01

    The MER rover Opportunity catalogued polygonal cracks and fins on Meridiani. Similar cracks and fins are documented at White Sands National Monument, NM, providing evidence for recent water cycling between sulfate outcrops and the martian atmosphere.

  7. 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.

  8. 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

  9. 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

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

    2015-05-01

    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

  10. Metamorphic evolution of the Rechnitz metamorphic core complex in relation to the Neogene Pannonian basin, Eastern Alps: Constraints from Ar-Ar white mica ages

    NASA Astrophysics Data System (ADS)

    Cao, Shuyun; Neubauer, Franz; Genser, Johann; Bernroider, Manfred; Friedl, Gertrude

    2015-04-01

    The exhumation of Cordilleran-type metamorphic core complexes (MCC) is generally related to largely contemporaneous collapse-type sedimentary basins (mainly halfgrabens). Here, we investigate the example of the Rechnitz MCC, which formed by Miocene orogen-parallel extension within the Neogene Pannonian basin. The Rechnitz MCC is located on the South Burgenland basement High within the western part of the Neogene Pannonian basin, with the Styrian basin in the west and the Danube basin in the east. The Rechnitz MCC is metamorphosed within greenschist facies conditions (maximum temperature of 430 °C) ideal for Ar-Ar white mica dating. For the first time, we undertook an extensive survey of 40Ar/39Ar white mica dating combined with microfabrics and electron microprobe compositional data and we compare the new data with major evolutionary stages of adjacent sedimentary basins, mainly based on re-evaluation of existing reflection seismic lines. The internal structure of the Rechnitz window is characterized by two tectonic cover nappes, a lower nappe with distal continental affinity, and an upper nappe representing the infilling of an oceanic basin. Both within greenschist facies metamorphic conditions and few blueschists were found in the northwestern part of the upper nappe. We found a number of distinct white mica age spectra: (1) A sample from the northwesternmost upper nappe yield a staircase pattern ranging from 14.8 ± 0.9 Ma to 41.5 ± 1.0 Ma. We interpret the older age is minimum age of high-pressure metamorphism and the younger age as age of overprint during extensional exhumation. (2) A number of samples from the western part, independent from positions within the nappes yield plateau ages between 20 and maximum 23 Ma and are variably affected by a younger thermal overprint between 13 and 15 Ma. (3) The eastern and lower units show plateau-like patterns with plateau ages of 17 - 19 Ma with a majority at ca. 18 Ma and a single younger outlier at ca. 16 Ma. Some samples are thermally overprinted at ca. 13 Ma. We interpret the plateau ages between 23 Ma and 17 Ma as represent peak conditions of greenschist facies metamorphism. The younger ages (ca. 18 Ma) of the 17 - 23 Ma age group coincide with the onset of subsidence and terrestrial sedimentation in the Styrian basin during Ottnagian and Karpathian and is well constrained by east down normal faults. The ages also indicate an earlier stage cooling of the western part than in the east of overprint representing evidence for an eastward migrating rolling hinge type exhumation of the Rechnitz MCC. The age of overprint centering at ca. 13 Ma correlates with last extensional motions, which are also constrained by youngest normal faults in reflection seismic lines of the Styrian basin. Together the data indicate the main stage of crustal thinning in the early Miocene between 19 and 13 Ma in response of eastward retreating subduction of the land-locked Carpathian basin.

  11. 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.

  12. 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…

  13. 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.

  14. Defrosting Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-434, 27 July 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows retreating patches of frost on a field of large, dark sand dunes in the Noachis region of Mars. Large, windblown ripples of coarse sediment are also seen on some of the dunes. This dune field is located in a crater at 47.5oS, 326.3oW. The scene is illuminated by sunlight from the upper left.

  15. 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.

  16. 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.

  17. Sand Dunes, Afghanistan

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER image covers an area of 10.5 x 15 km in southern Afghanistan and was acquired on August 20, 2000. The band 3-2-1 composite shows part of an extensive field of barchan sand dunes south of Kandahar. The shape of the dunes indicates that the prevailing wind direction is from the west. The image is located at 30.7 degrees north latitude and 65.7 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  18. 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.

  19. Enhancing Simulation of Sand Behavior through 3D Subdivision Techniques

    NASA Astrophysics Data System (ADS)

    Clothier, M.; Bailey, M.

    2011-12-01

    Through the use of modern computer graphics, visualization and parallel computation continue to provide academic disciplines with new techniques to work with raw data. This is particularly true in the earth and planetary sciences as many researchers are using graphics hardware to process large amounts of data for analysis. Thus, there is an increasing demand for collaboration between computer graphics and the earth sciences. Recognizing this opportunity, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate new techniques for simulating the behavior of sand. In addition, we are also collaborating with the Jet Propulsion Laboratory's (JPL) DARTS Lab to exchange ideas and gain feedback on our work. The DARTS Lab 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, providing further insight into its performance. In particular, there may be situations where a rover may become stuck in sand due to lack of friction between the sand and wheels. Thus, we have been developing a sand simulation framework to mimic the behavior of sand. Treated naively, this is a computationally complex problem, especially if trying to represent millions or even billions of sand particles interacting with each other. However, we can use graphics processing units (GPUs) on modern graphics hardware to subdivide and parallelize the problem. Basically, our idea is to subdivide regions of sand similar to a Level of Detail (LoD) method. Put another way, the more active the sand is in interacting with outside objects, the smaller the region the sand will be represented in the simulation. For example, let's say there is a planetary rover interacting with our sand simulation. Sand that is actively interacting with a rover wheel will be represented as an individual particle whereas sand that is further under the surface will be represented by a 3D region that represents several particles. As a particle region moves closer to the surface, it subdivides into smaller regions until individual sand particles are left. Our technique uses a variation of a 3D Voronoi decomposition in order to generate regions of sand. However, in our iteration, sand on the surface will be subdivided as particles whereas sand deeper into the earth will be subdivided into subsequently larger regions. By doing this, we can represent many more particles of sand than through traditional means. In addition, we have the added benefit of being able to parallelize the interaction between active particles through the use of the GPU. As such, not only are we able to represent vast amounts of sand, but we can also utilize more individual particles at the interaction source. An enhanced sand model through the use of subdivision techniques and GPUs has great potential for earth science research. Our collaborations with JPL have helped to further refine our simulation framework. As a result, we feel this work could also benefit other earth science fields, such as understanding sinkholes and debris flows.

  20. Vanishing White Matter Disease

    MedlinePlus

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

  1. 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,…

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Unchanging Desert Sand Dunes

    NASA Astrophysics Data System (ADS)

    Gadhiraju, S.; Banerjee, B.; Buddhiraju, K.; Shah, V.

    2013-12-01

    Deserts are one of the major landforms on earth. They occupy nearly 20% of the total land area but are relatively less studied. With the rise in human population, desert regions are being gradually occupied for settlement posing a management challenge to the concerned authorities. Unrestrained erosion is generally a feature of bare dunes. Stabilized dunes, on the other hand, do not undergo major changes in textures, and can thus facilitate the growth of vegetation. Keeping in view of the above factors, better mapping and monitoring of deserts and particularly of sand dunes is needed. Mapping dunes using field instruments is very arduous and they generate relatively sparse data. In this communication, we present a method of clustering and monitoring sand dunes through imagery captured by remote sensing sensors. Initially Radon spectrum of an area is obtained by decomposition of the image into various projections sampled at finer angular directions. Statistical features such as mode, entropy and standard deviation of Radon spectrum are used in delineation and clustering of regions with different dune orientations. These clustered boundaries are used to detect if there are any changes occurring in the dune regions. In the experiment's, remote sensing data covering various dune regions of the world are observed for possible changes in dune orientations. In all the cases, it is seen that there are no major changes in desert dune orientations. While these findings have implications for understanding of dune geomorphology and changes occurring in dune directions, they also highlight the importance of a wider study of dunes and their evolution both at regional and global scales. Results for Dataset 1 & Dataset 2 Results for Dataset 3

  7. 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.

  8. Experimental measurement of wind-sand flux and sand transport for naturally mixed sands.

    PubMed

    Zhou, You-He; Guo, Xiang; Zheng, Xiao Jing

    2002-08-01

    This article presents an experimental test and a program to empirically fit experimental data for the horizontal flux of wind-blown sand passing through a unit area along a vertical direction per unit time. The experimental data for the sand flow flux as a function of the height for naturally mixed sands, which were chosen from a sand dune at the southeastern edge of the Tengger desert, were measured with a sand collector in a field wind tunnel. On the basis of the experimental data and a least squares method, a fitting program is proposed here and, further, an explicit form of an empirical formula varying with height and axial wind velocity or friction velocity for the flux structure of the sands is gained. After that, we obtain an explicit form of the empirical equation for the measurement of streamwise sand transport per unit width and unit time by integrating the empirical formula for sand flux along the height direction and considering the contribution of sand creep. Finally, we evaluate the effectiveness of the predictions of some equations, especially the well-known Bagnold equation and Kawamura equation, for predicting streamwise wind-sand transport using the empirical equation obtained for mixed sands. The results show that the predictions from Bagnold's equation in the region of friction velocity u(*)>0.47 m/s and Kawamura's equation in the region u(*t)

  9. White Tern

    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.  ...

  10. 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

  11. 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.

  12. Saltation of non-spherical sand particles.

    PubMed

    Wang, Zhengshi; Ren, Shan; Huang, Ning

    2014-01-01

    Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement. PMID:25170614

  13. Geology of the athabasca oil sands.

    PubMed

    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 percent 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. PMID:17809090

  14. Geology of the Athabasca oil sands

    NASA Astrophysics Data System (ADS)

    Mossop, G. D.

    1980-01-01

    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 percent 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.

  15. Augmenting Sand Simulation Environments through Subdivision and Particle Refinement

    NASA Astrophysics Data System (ADS)

    Clothier, M.; Bailey, M.

    2012-12-01

    Recent advances in computer graphics and parallel processing hardware have provided disciplines with new methods to evaluate and visualize data. These advances have proven useful for earth and planetary scientists as many researchers are using this hardware to process large amounts of data for analysis. As such, this has provided opportunities for collaboration between computer graphics and the earth sciences. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs, we are investigating techniques for simulating the behavior of sand. We are also collaborating with the Jet Propulsion Laboratory's (JPL) DARTS Lab to exchange ideas and gain feedback on our research. The DARTS Lab specializes in simulation of planetary vehicles, such as the Mars rovers. Their simulations utilize a virtual "sand box" to test how a planetary vehicle responds to different environments. Our research builds upon this idea to create a sand simulation framework so that planetary environments, such as the harsh, sandy regions on Mars, are more fully realized. More specifically, we are focusing our research on the interaction between a planetary vehicle, such as a rover, and the sand beneath it, providing further insight into its performance. Unfortunately, this can be a computationally complex problem, especially if trying to represent the enormous quantities of sand particles interacting with each other. However, through the use of high-performance computing, we have developed a technique to subdivide areas of actively participating sand regions across a large landscape. Similar to a Level of Detail (LOD) technique, we only subdivide regions of a landscape where sand particles are actively participating with another object. While the sand is within this subdivision window and moves closer to the surface of the interacting object, the sand region subdivides into smaller regions until individual sand particles are left at the surface. As an example, let's say there is a planetary rover interacting with our sand simulation environment. Sand that is actively interacting with a rover wheel will be represented as individual particles whereas sand that is further under the surface will be represented by larger regions of sand. The result of this technique allows for many particles to be represented without the computational complexity. In developing this method, we have further generalized these subdivision regions into any volumetric area suitable for use in the simulation. This is a further improvement of our method as it allows for more compact subdivision sand regions. This helps to fine tune the simulation so that more emphasis can be placed on regions of actively participating sand. We feel that through the generalization of our technique, our research can provide other opportunities within the earth and planetary sciences. Through collaboration with our academic colleagues, we continue to refine our technique and look for other opportunities to utilize our research.

  16. Aeolian sand ripples around plants.

    PubMed

    Zhang, Qian-Hua; Miao, Tian-De

    2003-05-01

    Plants in the desert may locally change the aeolian process, and hence the pattern of sand ripples traveling nearby. The effect of plants on ripples is investigated using a coupled map lattice model with nonuniform coupling coefficients. PMID:12786143

  17. 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.

  18. 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.

  19. 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.

  20. 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…

  1. Modern Graywacke-Type Sands.

    PubMed

    Hollister, C D; Heezen, B C

    1964-12-18

    A preliminary study of more than 100 deep-sea cores from abyssal plains has revealed two examples of recent muddy sands of the graywacke type which, together with the microcrystalline matrix, form a bimodal-size distribution sands have a well-sorted framework of quartz, feldspar, and rock fragments which, together with the microcrystalline matrix, form a bimodal-size distribution that is also typical of ancient graywackes. The matrix is considered to be primary. PMID:17775982

  2. 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.

  3. Dust and Sand Mixing

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 10 November 2003

    The bright and dark tones observed in this THEMIS image of part of an unnamed impact crater (85 km in diameter) near the larger impact crater Schiaparelli are due to variable amounts of bright dust and dark sand covering the surface. Wind Shadows observed around small impact craters at the top of the image and small grooves and ripple-like marks observed throughout the scene illustrate dynamic and continued aeolian processes on Mars.

    Image information: VIS instrument. Latitude -1.4, Longitude 10.9 East (349.1 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.

  4. 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...

  5. 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 (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

  6. 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

  7. Cracks and fins in sulfate sand: Evidence for recent mineral-atmospheric water cycling in Meridiani Planum outcrops?

    NASA Astrophysics Data System (ADS)

    Chavdarian, Gregory V.; Sumner, Dawn Y.

    2006-04-01

    Gypsum dunes at White Sands National Monument, New Mexico, provide an excellent analog to sulfate-rich eolian outcrops on Meridiani Planum, Mars, as characterized by the Rover Opportunity. Numerous outcrops imaged by Opportunity contain polygonal cracks that crosscut bedding and extend across most surfaces of boulders. Some of these cracks are associated with millimeter-thick platy fins that protrude as much as a few centimeters above outcrops. Similar cracks crosscut bedding at White Sands on erosional stoss slopes and in pedestals of cemented dune sand. The cracks at White Sands form in response to cementation of damp gypsum sand followed by contraction due to dehydration. During warm seasons, cracked sand is dry and cracks rarely grow, although some may form after rainstorms. Two types of fins form along cracks and differentially eroded laminae. White fins represent subsurface differential cementation along cracks followed by differential erosion. Tan fins form due to cementation of crack edges and laminae on exposed dune surfaces. Wind-blown sediment adheres to damp tan fins. Similar processes may be important for crack and fin formation in Meridiani Planum outcrops, implying recent water cycling between sulfate outcrops and the Martian atmosphere.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

    NASA Astrophysics Data System (ADS)

    Clothier, M.

    2013-12-01

    Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by their proximity to the interacting object or force with the sand. To illustrate an example, as a rover wheel moves forward and approaches a particular sand region, that region will continue to subdivide until individual sand particles are represented. Conversely, if the rover wheel moves away, previously subdivided sand regions will recombine. Thus, individual sand particles are available when an interacting force is present but stored away if there is not. As such, this technique allows for many particles to be represented without the computational complexity. We have also further generalized these subdivision regions in our sand framework into any volumetric area suitable for use in the simulation. This allows for more compact subdivision regions and has fine-tuned our framework so that more emphasis can be placed on regions of actively participating sand. We feel that this increases the framework's usefulness across scientific applications and can provide for other research opportunities within the earth and planetary sciences. Through continued collaboration with our academic partners, we continue to build upon our sand simulation framework and look for other opportunities to utilize this research.

  13. 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.

  14. A sand wave simulation model

    NASA Astrophysics Data System (ADS)

    Németh, A.; Hulscher, S.; van Damme, R.

    2003-04-01

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water surface and a general bed load formula. The water movement is coupled to the sediment transport equation with a seabed evolution equation. The domain is non-periodic in both directions. The spatial discretisation is performed by a spectral method based on Chebyshev polynomials. A fully implicit method is chosen for the discretisation in time. Firstly, we validate the model mathematically by reproducing the results obtained using a linear stability analysis for infinitely small sand waves. Hereby, we investigate a steady current situation induced by a wind stress applied at the sea surface. The bed forms we find have wavelengths in the order of hundreds of metres when the resistance at the seabed is relatively large. The results show that it is possible to model the initial evolution of sand waves with a numerical simulation model. Next, we investigate the influence of the chosen turbulent viscosity parameterisation by comparing the constant viscosity model with a depth dependent viscosity. This paper forms a part of a study to investigate the intermediate term behaviour of sand waves.

  15. 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).

  16. 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.

  17. 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 δ} 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 δ} 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’.

  18. Sand effects on thermal barrier coatings for gas turbine engines

    NASA Astrophysics Data System (ADS)

    Walock, Michael; Barnett, Blake; Ghoshal, Anindya; Murugan, Muthuvel; Swab, Jeffrey; Pepi, Marc; Hopkins, David; Gazonas, George; Kerner, Kevin

    Accumulation and infiltration of molten/ semi-molten sand and subsequent formation of calcia-magnesia-alumina-silicate (CMAS) deposits in gas turbine engines continues to be a significant problem for aviation assets. This complex problem is compounded by the large variations in the composition, size, and topology of natural sands, gas generator turbine temperatures, thermal barrier coating properties, and the incoming particulate's momentum. In order to simplify the materials testing process, significant time and resources have been spent in the development of synthetic sand mixtures. However, there is debate whether these mixtures accurately mimic the damage observed in field-returned engines. With this study, we provide a direct comparison of CMAS deposits from both natural and synthetic sands. Using spray deposition techniques, 7% yttria-stabilized zirconia coatings are deposited onto bond-coated, Ni-superalloy discs. Each sample is coated with a sand slurry, either natural or synthetic, and exposed to a high temperature flame for 1 hour. Test samples are characterized before and after flame exposure. In addition, the test samples will be compared to field-returned equipment. This research was sponsored by the US Army Research Laboratory, and was accomplished under Cooperative Agreement # W911NF-12-2-0019.

  19. 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…

  20. 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…

  1. 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...

  2. Retention capacity of natural sands for the treatment of waters containing arsenic trace levels

    NASA Astrophysics Data System (ADS)

    Le Hécho, I.; Chappaz, A.; Potin-Gautier, M.; Behra, P.

    2003-05-01

    The aim of this work is to study the As retention capacity of two natural sand, a quartz sand and a volcanic red sand. Sorption experiments were performed in batch reactors at a constant ionic strength (0.010 M Na03). pH was controlled by acid or base microadditions. As, Fe, Al and Si were analysed in the aqueous phase to control their fate. Kinetic experiments of arsenic sorption showed that a fast step followed by a slow one could be observed depending on the sand. In the most rapid step, the formation of monodentate complexes could be the main phenomenon while in the slowest one bidendate and binuclear complexes could predominate. During As (V) sorption, the analyses of Al, Fe and Si showed that the dissolution of the different minerals present in the sands as Al, Si and Fe (hydr) oxides was not affected by As (V) sorption. From the point of view of the surface reactivity, the quartz sand bas more available sites for arsenic sorption than the volcanic sand However, the red soil shows a better retelltion capacity as expressed in amount of As per solid mass unit : 666 nmol g^{-1} and 9.4 nmol g^{-1} for the red soil and the quartz sand, respectively, for a contact time of 288 h.

  3. Formation of aeolian ripples and sand sorting.

    PubMed

    Manukyan, Edgar; Prigozhin, Leonid

    2009-03-01

    We present a continuous model capable of demonstrating some salient features of aeolian sand ripples: the realistic asymmetric ripple shape, coarsening of the ripple field at the nonlinear stage of ripple growth, saturation of ripple growth for homogeneous sand, typical size segregation of sand, and formation of armoring layers of coarse particles on ripple crests and windward slopes if the sand is inhomogeneous. PMID:19391931

  4. 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.

  5. Sand Dome on a Steam Engine

    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...

  6. 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.

  7. 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.

  8. An Evi1-C/EBPβ Complex Controls Peroxisome Proliferator-Activated Receptor γ2 Gene Expression To Initiate White Fat Cell Differentiation

    PubMed Central

    Ishibashi, Jeff; Firtina, Zeynep; Rajakumari, Sona; Wood, Kathleen H.; Conroe, Heather M.; Steger, David J.

    2012-01-01

    Fibroblastic preadipocyte cells are recruited to differentiate into new adipocytes during the formation and hyperplastic growth of white adipose tissue. Peroxisome proliferator-activated receptor γ (PPARγ), the master regulator of adipogenesis, is expressed at low levels in preadipocytes, and its levels increase dramatically and rapidly during the differentiation process. However, the mechanisms controlling the dynamic and selective expression of PPARγ in the adipocyte lineage remain largely unknown. We show here that the zinc finger protein Evi1 increases in preadipocytes at the onset of differentiation prior to increases in PPARγ levels. Evi1 expression converts nonadipogenic cells into adipocytes via an increase in the predifferentiation levels of PPARγ2, the adipose-selective isoform of PPARγ. Conversely, loss of Evi1 in preadipocytes blocks the induction of PPARγ2 and suppresses adipocyte differentiation. Evi1 binds with C/EBPβ to regulatory sites in the Pparγ locus at early stages of adipocyte differentiation, coincident with the induction of Pparγ2 expression. These results indicate that Evi1 is a key regulator of adipogenic competency. PMID:22473998

  9. Ruthenium metalation of proteins: the X-ray structure of the complex formed between NAMI-A and hen egg white lysozyme.

    PubMed

    Messori, Luigi; Merlino, Antonello

    2014-04-28

    A crystallographic study of the adduct formed between hen egg white lysozyme (HEWL) and NAMI-A, an established ruthenium(III) anticancer agent in clinical trials, is presented here. The X-ray structure reveals that NAMI-A coordinates the protein, as a naked ruthenium ion, at two distinct sites (namely Asp101 or Asp119) after releasing all its original ligands (DMSO, imidazole and Cl(-)). Structural data of the HEWL/NAMI-A adduct are compared with those previously obtained for the HEWL adduct of AziRu, a NAMI-A analogue bearing a pyridine in place of imidazole. The present results further support the view that NAMI-A exerts its biological effects acting as a classical "prodrug" first undergoing activation and then causing extensive metalation of relevant protein targets. It is also proposed that the original Ru-ligands, although absent in the final adduct, play a major role in directing the ruthenium center to its ultimate anchoring site on the protein surface. PMID:24553967

  10. 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.

  11. 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.

  12. METHOD OF PROCESSING MONAZITE SAND

    DOEpatents

    Welt, M.A.; Smutz, M.

    1958-08-26

    A process is described for recovering thorium, uranium, and rare earth values from monazite sand. The monazite sand is first digested with sulfuric acid and the resulting "monazite sulfate" solution is adjusted to a pH of between 0.4 and 3.0, and oxalate anions are added causing precipitation of the thorium and the rare earths as the oxalates. The oxalate precipitate is separated from the uranium containing supernatant solution, and is dried and calcined to the oxides. The thorium and rare earth oxides are then dissolved in nitric acid and the solution is contacted with tribntyl phosphate whereby an organic extract phase containing the cerium and thorium values is obtained, together with an aqueous raffinate containing the other rare earth values. The organic phase is then separated from the aqueous raffinate and the cerium and thorium are back extracted with an aqueous medium.

  13. 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.

  14. 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 5.7×10-7 m2/s with the minimum value of 4.2×10-7 m2/s and the maximum value of 8.0×10-7 m2/s. Volumetric heat capacity varies from 1.5×106 J/m3K to 2.11×106 J/m3K with the mean volumetric heat capacity of 1.91×106 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.

  15. 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.

  16. Crystal structures of hen egg-white lysozyme complexes with gadolinium(III) and gadolinium(III)-N-acetyl-D-glucosamine.

    PubMed Central

    Perkins, S J; Johnson, L N; Machin, P A; Phillips, D C

    1979-01-01

    Analysis at 0.25 nm resolution of the crystal structures of lysozyme-Gd(III) and lysozyme-Gd(III)-N-acetyl-D-glucosamine (GlcNac), prepared by diffusion methods, show that there are two main binding positions for Gd(III), one of which is close to glutamic acid-35 and the other close to aspartic acid-52. The two sites are 0.36 nm part. There is no evidence for the weak binding of Gd(III) to any of the eight other carboxy groups of lysozyme. In the presence of Gd(III), the binding of GlcNac is similar to that observed for the binding of the beta-anomer in subsite C. There are numerous small conformational changes in the protein on binding (Gd(III) and the sugar, and these have been quantified to a first approximation by real-space refinement. These changes are similar in both structures, and involve, among other small movements, shifts of one of the disulphide bridges by up to 0.05 nm. The movement of residues 70--74 observed in the binary complex of lysozyme-GlcNac [Perkins, Johnson, Machin & Phillips (1978) Biochem. J. 173-617] is not observed in the ternary complex of lysozyme-Gd(III)-GlcNac. The nature of the lysozyme-Gd(III) complex is discussed in the light of evidence from other crystallographic studies and n.m.r. solution studies. Preliminary findings for a lysozyme-Gd(III) complex prepared by co-crystallization methods are reported. PMID:486153

  17. 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.

  18. 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

  19. 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…

  20. 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

  1. Upper Miocene Stevens sands in the Maricopa depocenter southern San Joaquin Valley, California

    SciTech Connect

    Quinn, M.J. )

    1991-02-01

    During the late Miocene, the Maricopa depocenter was a northwest-southeast-trending trough located in the southeastern corner of the San Joaquin Valley. Uplifting granitic source terranes in the Salinian block to the southwest, the Sierra Nevada to the northeast, and the Tehachapi Mountains to the southeast shed coarse-grained quartz-rich sands into the subsiding basin in the form of deep marine turbidites. These upper Miocene turbidites are collectively referred to as the Stevens sands. Based upon studies from several oil fields within the depocenter, a generalized model has been developed for the ramp, channel, and fan deposits seen within the Stevens system. This model, and the field studies are used to examine the size, morphology, sand distribution patterns, and seismic response of these sand-rich turbidite deposits. Within the Stevens system, the majority of the hydrocarbons are found within the middle to outer parts of the turbidites fans, with post depositional compaction, uplift, and folding providing three primary types of trapping mechanism: closure due to shale compaction over sand thicks, emplacement of sands across an anticlinal axis, and updip porosity pinch-outs. Finally, the chronostratigraphy of the basin developed from the field studies is used to examine upper Miocene strike-slip movement along the San Andreas fault, uplift of the Sierra Nevada, strike-slip and normal movement along the White Wolf fault, and how these various tectonic events relate to the Stevens deposition.

  2. 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.

  3. 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.

  4. 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…

  5. 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

  6. 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.

  7. Giant sand waves at the mouth of San Francisco Bay

    USGS Publications Warehouse

    Barnard, P.L.; Hanes, D.M.; Rubin, D.M.; Kvitek, R.G.

    2006-01-01

    A field of giant sand waves, among the largest in the world, recently was mapped in high resolution for the first time during a multibeam survey in 2004 and 2005 through the strait of the Golden Gate at the mouth of San Francisco Bay in California (Figure la). This massive bed form field covers an area of approximately four square kilometers in water depths ranging from 30 to 106 meters, featuring more than 40 distinct sand waves with crests aligned approximately perpendicular to the dominant tidally generated cross-shore currents, with wavelengths and heights that measure up to 220 meters and 10 meters, respectively. Sand wave crests can be traced continuously for up to two kilometers across the mouth of this energetic tidal inlet, where depth-averaged tidal currents through the strait below the Golden Gate Bridge exceed 2.5 meters per second during peak ebb flows. Repeated surveys demonstrated that the sand waves are active and dynamic features that move in response to tidally generated currents. The complex temporal and spatial variations in wave and tidal current interactions in this region result in an astoundingly diverse array of bed form morphologies, scales, and orientations. Bed forms of approximately half the scale of those reported in this article previously were mapped inside San Francisco Bay during a multibeam survey in 1997 [Chin et al., 1997].

  8. Effects of autochthonous microbial community on the die-off of fecal indicators in tropical beach sand.

    PubMed

    Feng, Fan; Goto, Dustin; Yan, Tao

    2010-10-01

    The recently observed high levels of fecal indicators in beach sand confound beach water monitoring efforts. The high levels of fecal indicators may be caused by the loss or the reduced activities of common environmental stresses controlling die-off in the sand. Microcosm experiments were conducted to compare the effects of biotic stresses from autochthonous sand bacteria, protozoa, and viruses on Escherichia coli and Enterococcus faecalis in two tropical beach sands. The inhibition of protozoan activities by cycloheximide did not significantly affect the die-off of E. coli, indicating that protozoan predation played a limited role in beach sand. The contribution from phage infection to E. coli die-off was also negligible. Consequently, autochthonous bacteria were identified as the predominant biotic stress to the die-off of E. coli in beach sand. Subsequent experiments demonstrated that the beach sand had a very low protozoan concentration and low protozoan growth potential when compared with various environmental samples. Co-culturing of E. coli with autochthonous sand bacterial isolates significantly enhanced E. coli die-off. PCR-denaturing gradient gel electrophoresis analysis revealed a complex sand bacterial community, suggesting that bacterial antagonistic effects may be widespread. The study also found that E. faecalis exhibited a much longer survival in beach sand compared with E. coli. PMID:20629750

  9. 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)

  10. 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...

  11. Surface instability in windblown sand.

    PubMed

    Kurtze, D A; Both, J A; Hong, D C

    2000-06-01

    We investigate the formation of ripples on the surface of windblown sand based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71, 197 (1993)], which contains the processes of saltation and grain relaxation. We carry out a nonlinear analysis to determine the propagation speed of the restabilized ripple patterns, and the amplitudes and phases of their first, second, and third harmonics. The agreement between the theory and our numerical simulations is excellent near the onset of the instability. We also determine the Eckhaus boundary, outside which the steady ripple patterns are unstable. PMID:11088369

  12. Dynamical evolution of sand ripples under water.

    PubMed

    Stegner, A; Wesfreid, J E

    1999-10-01

    We have performed an experimental study on the evolution of sand ripples formed under the action of an oscillatory flow. An annular sand-water cell was used in order to investigate a wide range of parameters. The sand ripples follow an irreversible condensation mechanism from small to large wavelength until a final state is reached. The wavelength and the shape of these stable sand patterns are mainly governed by the fluid displacement and the static angle of the granular media. A strong hysteresis affects the evolution of steep ripples. When the acceleration of the sand bed reaches a critical value, the final pattern is modified by the superficial fluidization of the sand layer. PMID:11970264

  13. Decreased fecal corticosterone levels due to domestication: a comparison between the white-backed Munia (Lonchura striata) and its domesticated strain, the Bengalese finch (Lonchura striata var. domestica) with a suggestion for complex song evolution.

    PubMed

    Suzuki, Kenta; Yamada, Hiroko; Kobayashi, Tetsuya; Okanoya, Kazuo

    2012-11-01

    The Bengalese finch (BF; Lonchura striata var. domestica) is a domesticated strain of the white-backed munia (WBM; Lonchura striata). Environmental stresses activate the hypothalamic-pituitary-adrenal (HPA) axis and release corticosterone (CORT). We hypothesized that domesticated songbirds have reduced CORT levels because of reduced levels of environmental stresses (compared to wild conditions) and reductions in the role of CORT, which is necessary for survival in the wild. However, no study has examined the effects of domestication on songbird CORT levels. To explore the domestication effects, we compared CORT levels between domesticated BFs and their wild ancestors WBMs. We also compared CORT levels between bought and aviary-raised BFs, and between wild-caught and captive-raised WBMs to examine the influence of being raised. However, blood collection causes stress, which affects endocrine dynamics and makes continuous sampling difficult in small birds. Therefore, we used a non-invasive method to measure fecal CORT. Parallelism between diluted fecal extracts and a CORT standard, extraction efficiency, and ACTH challenge demonstrated the effectiveness of this method. This study demonstrates that BFs have lower fecal CORT than do WBMs, regardless of whether the WBMs were wild-caught or captive-raised. In addition, BFs sing more complex songs than WBMs. Considerable evidence suggests that song complexity is related to CORT levels. Previously, we found that the corticosteroid receptors were expressed in song-control areas of the BF brain. Based on these results, we hypothesize that reduced CORT levels through domestication might be one factor allowing for the development of more complex songs in BFs. PMID:22927235

  14. 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.

  15. The Sahara Desert as an Analogue to Sand Seas on Titan

    NASA Astrophysics Data System (ADS)

    Radebaugh, J.; Lorenz, R. D.; Savage, C. J.; Farr, T. G.; Wall, S. D.; Lancaster, N.; Cassini RADAR Team

    2010-12-01

    The prevalence of tens of thousands of sand dunes on Titan, nearly all of which are linear in form and of similar size and spacing to those in Earth’s large deserts, leads to useful comparisons across sand seas on both bodies. Outcomes of these analyses include the importance of process over materials. Earth’s quartz or gypsum and Titan’s organic sands all produce the same resultant form, highlighting the process of saltation in similar atmospheric conditions, likely even in similar boundary layer conditions (Lorenz et al. 2010). Another result of combined analyses is the recognition that linear dune forms are affected by topographic obstacles, which disrupt sand-carrying winds and provide indicators of wind directions. Over time, sands may collect upwind of an obstacle, where winds decrease in strength and saltation is diminished. Evidence of this can be seen in the eastern Sahara Desert of Earth and on Titan, providing indication of the long-term, time-averaged wind direction. Recent winds, which may deviate from time-averaged winds, produce sand streaks behind the obstacles and crests and ripples. Large sand streaks can be seen on Titan at Cassini instrument resolutions, but not crests or ripples. Many Saharan dunes have sand-free interdunes, indicating sand is sparse because sediment bypassing is occurring in the region. This is true for the Fensal sand sea of Titan’s equatorial leading hemisphere. Analysis of sand transport patterns in the eastern Sahara will provide information about sand transport, as well as sand sources and sinks, in Fensal. The age of Titan’s dunes, though among the youngest features on Titan from superposition relationships, is not decisively known. Though limited by resolution, the apparent absence of compound or complex dune forms across Titan indicates the dune systems may be mature, and that the current atmospheric/climatic conditions have persisted for long time periods. Titan, with its lack of oceans, vegetation, and extensive, circulation-blocking mountain ranges may have allowed its sand deposits to evolve to equilibrium forms consistent in morphology and orientation over large expanses. Careful consideration of the conditions on Titan responsible for producing broadly consistent, perhaps evolved dune forms will lead to new conclusions about the formation of linear dunes, landforms not well understood on Earth.

  16. 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.

  17. Sand Dunes in Kaiser Crater

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Full size (780 KBytes) This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows a field of dark sand dunes on the floor of Kaiser Crater in southeastern Noachis Terra. The steepest slopes on each dune, the slip faces, point toward the east, indicating that the strongest winds that blow across the floor of Kaiser move sand in this direction. Wind features of three different scales are visible in this image: the largest (the dunes) are moving across a hard surface (light tone) that is itself partially covered by large ripples. These large ripples appear not to be moving--the dunes are burying some and revealing others. Another type of ripple pattern is seen on the margins of the dunes and where dunes coalesce. They are smaller (both in their height and in their separation) than the large ripples. These are probably coarse sediments that are moving with the dunes. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated from the upper left.

  18. 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.

  19. 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...

  20. 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)

  1. New light on the age of the White Nile

    NASA Astrophysics Data System (ADS)

    Williams, Martin A. J.; Adamson, Donald; Prescott, John R.; Williams, Frances M.

    2003-11-01

    Landsat 5 Thematic Mapper and 7 Enhanced Thematic Mapper imagery reveal lake shorelines in the White Nile valley as far south as lat 10°N. The highest shoreline is at 386 m elevation and was eroded when the White Nile formed a lake as wide as 70 km and >500 km long. Finely laminated green clays laid down on the floor of this lake are overlain by alluvial sands and clays, dated by optically stimulated luminescence as 15 ka to older than 250 ka. The alluvium was deposited during interglacial episodes of stronger summer monsoons and very high White Nile floods. The White Nile paleolake is much older than marine oxygen isotope stage 7 and may have formed ca. 400 ka, during the exceptionally long stage 11 interglacial.

  2. 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.…

  3. 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.

  4. 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.

  5. 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.

  6. 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.…

  7. 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…

  8. Nonlinear dynamics of Aeolian sand ripples.

    PubMed

    Prigozhin, L

    1999-07-01

    We study the initial instability of flat sand surface and further nonlinear dynamics of wind ripples. The proposed continuous model of ripple formation allowed us to simulate the development of a typical asymmetric ripple shape and the evolution of a sand ripple pattern. We suggest that this evolution occurs via ripple merger preceded by several soliton-like interaction of ripples. PMID:11969814

  9. 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...

  10. Liquefaction in Subsurface Layer of Sand

    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,

  11. 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}.

  12. 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)

  13. 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…

  14. Internal structures and developing mechanisms of tidal sand ridges in the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Z.

    2004-12-01

    *Abstract:* The internal structures of the tidal sand ridges in the East China Sea are characterized by the southwest-dipping beddings and several erosion surfaces, which resulted in young sand ridges overlying old ones and forming a unique multi-layer complex structure. These characteristics reveal the multi-phase development of the tidal sand ridges, and their multi-repetitive forming history of accumulation, erosion and accumulation. There are two mechanisms interpreting the migration and evolution of these sand ridges. One mechanism concerns the evolution tidal sand ridge itself. The tidal current difference along two flanks of a ridge makes the sediments migrate toward the side with lower current speed. This is so-called auto-cyclic process of sand ridge developing. For the tidal sand ridges in the East China Sea, one side is dominated by flood currents in a NW direction, the other side is dominated by ebb current in a SE direction. Due to the influences of topography gradient of the continental shelf and the runoff from Chinese main land, the velocity of the ebb currents is larger than that of the flood currents, so the sediment is transported to southwest continuously, and it is a certainty for the sand ridges migrate toward SW and form the beddings inclining toward SW. The other mechanism is allo-cyclic process, which relates to global or regional hydrodynamic changes, such as sea-level fluctuations or storm waves. The post-glacial sea level rose rapidly in a stepwise pattern caused by the four postglacial melting water pulses (MWP-1A, 1B, 1C, 1D) (Liu et al., 2004) and it should play an important role in this mechanism. Both mechanisms exist in the development of the tidal sand ridges in the East China Sea, so there is some difficulties to distinguish them clearly. It is obvious that the tidal sand ridges of the East China Sea have evolved continuously since the postglacial period; four stages of sand ridges have formed in sequence: younger ridges overlaid the old ones and finally formed the multi-layer complex structure. *Key words:* East China Sea, tidal sand ridge, internal structure, auto-cyclic processes, allo-cyclic process

  15. 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%.

  16. Mutations in MITF and PAX3 cause "splashed white" and other white spotting phenotypes in horses.

    PubMed

    Hauswirth, Regula; Haase, Bianca; Blatter, Marlis; Brooks, Samantha A; Burger, Dominik; Drögemüller, Cord; Gerber, Vincent; Henke, Diana; Janda, Jozef; Jude, Rony; Magdesian, K Gary; Matthews, Jacqueline M; Poncet, Pierre-André; Svansson, Vilhjálmur; 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Coating of silica sand with aluminosilicate clay.

    PubMed

    Jerez, Jorge; Flury, Markus; Shang, Jianying; Deng, Youjun

    2006-02-01

    The objective of this work was to coat aluminosilicate clays on an inert silica support, and to characterize the properties and stability of the clay-silica coating. Two polymers, polyacrylamide (PAM) and polyvinyl alcohol (PVA), were used to bind kaolinite, illite, and smectite onto silica grains. The clay-polymer composites were studied by X-ray diffraction, FTIR, and electrophoretic mobility. Clay coatings on silica grains were characterized by mass coverage, scanning electron microscopy, specific surface area, and pH stability. Silica sand was successfully coated with clays by using the two polymers, but with PVA, the clay coating had a greater mass coverage and was more stable against pH variations. Less polymer was needed for the clay coating using PVA as compared to using PAM. Clay-polymer complexes and pure clay minerals had similar cation exchange capacities and electrophoretic mobilities, indicating that overall surface charge of the clays was little affected by the polymers. Some decrease in hydrophilicity was observed for illite and smectite when clays where coated with the polymers. The methodology reported here allows the generation of a clay-based porous matrix, with hydraulic properties that can be varied by adjusting the grain size of the inert silica support. PMID:16085082

  2. Acoustic detection of Immiscible Liquids in Sand

    SciTech Connect

    Geller, Jil T.; Kowalsky, Michael B.; Seifert, Patricia K.; Nihei, Kurt T.

    1999-03-01

    Laboratory cross-well P-wave transmission at 90 kHz was measured in a 61 cm diameter by 76 cm tall water-saturated sand pack, before and after introducing a non-aqueous phase organic liquid (NAPL) (n-dodecane). In one experiment NAPL was introduced to form a lens trapped by a low permeability layer; a second experiment considered NAPL residual trapped behind the front of flowing NAPL. The NAPL caused significant changes in the travel time and amplitude of first arrivals, as well as the generation of diffracted waves arriving after the direct wave. The spatial variations in NAPL saturation obtained from excavation at the end of the experiment correlated well with the observed variations in the P-wave amplitudes and travel times. NAPL residual saturation changes from NAPL flow channels of 3 to 4% were detectable and the 40 to 80% NAPL saturation in the NAPL lens was clearly visible at acoustic frequencies. The results of these experiments demonstrate that small NAPL saturations may be more easily detected with amplitude rather than travel time data, but that the relationships between the amplitude changes and NAPL saturation maybe more complex than those for velocity.

  3. 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

  4. 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

  5. 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, λ, and Γ. The range of the value of M, λ, and Γ 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

  6. 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.

  7. 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

  8. Influence of sand grain diameter and wind velocity on lift-off velocities of sand particles.

    PubMed

    Bo, Tian-Li; Zheng, Xiao-Jing; Duan, Shao-Zhen; Liang, Yi-Rui

    2013-05-01

    In this paper, the velocities of sand particles near the sand bed in the saltation cloud were measured in a wind tunnel through an improved experimental scheme of the Particle Image Velocimetry (PIV) system. The influences of the diameter of sand particles in the saltation cloud and wind velocity on the probability distribution function (PDF) of lift-off velocities of sand particles were investigated. Results demonstrate that for the sand particles saltating above the sand bed with the mean grain diameter (d m = 0.3 mm), smaller and larger ones have the same velocity distribution, and wind velocity has no obvious influence on the distribution shape of the lift-off velocities, i.e., the PDFs of the horizontal and vertical lift-off velocities both follow a lognormal distribution, but the diameter of sand particles in the saltation cloud and wind velocity have an influence on the parameters of the PDF of horizontal and vertical lift-off velocities. Eventually, we present formulas to describe the PDF of lift-off velocities of sand particles with regard to the influence of wind velocity and the diameter of sand particles in the saltation cloud above the sand bed with d m = 0.3 mm. PMID:23695368

  9. 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.

  10. Sensilla on the terminalia of Lutzomyia spp. (Diptera: Psychodidae) sand flies.

    PubMed

    Spiegel, C N; Brazil, R P; Soares, M J

    2000-11-01

    Sensilla on the male terminalia of four different species of sand flies (Diptera: Psychodidae) are described. Two species belonged to the same species complex: Lutzomyia longipalpis (Lutz & Neiva) and L. cruzi (Mangabeira). Other Brazilian species complex was represented by L. lenti (Mangabeira) and L. carmelinoi (Ryan, Fraiha, Lainson & Shaw). Approximately 5-15 sensilla were found on the initial part of the styles of all species. Structurally, the sensory organs were similar to small coeloconica sensilla. Their number varied both individually and interspecifically. These sensilla may play an important role in the copulation behavior of these species of sand flies. PMID:11126541

  11. 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

  12. Large-eddy simulation of sand dune morphodynamics

    NASA Astrophysics Data System (ADS)

    Khosronejad, Ali; Sotiropoulos, Fotis; St. Anthony Falls Laboratory, University of Minnesota Team

    2015-11-01

    Sand dunes are natural features that form under complex interaction between turbulent flow and bed morphodynamics. We employ a fully-coupled 3D numerical model (Khosronejad and Sotiropoulos, 2014, Journal of Fluid Mechanics, 753:150-216) to perform high-resolution large-eddy simulations of turbulence and bed morphodynamics in a laboratory scale mobile-bed channel to investigate initiation, evolution and quasi-equilibrium of sand dunes (Venditti and Church, 2005, J. Geophysical Research, 110:F01009). We employ a curvilinear immersed boundary method along with convection-diffusion and bed-morphodynamics modules to simulate the suspended sediment and the bed-load transports respectively. The coupled simulation were carried out on a grid with more than 100 million grid nodes and simulated about 3 hours of physical time of dune evolution. The simulations provide the first complete description of sand dune formation and long-term evolution. The geometric characteristics of the simulated dunes are shown to be in excellent agreement with observed data obtained across a broad range of scales. This work was supported by NSF Grants EAR-0120914 (as part of the National Center for Earth-Surface Dynamics). Computational resources were provided by the University of Minnesota Supercomputing Institute.

  13. 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.

  14. Sudan challenges the sand dragon.

    PubMed

    Tinker, J

    1978-01-01

    Formerly productive areas have become wasteland as the desert advances in the Sudan. To understand how desertification is undermining the very survival of the Sahel, one ecosystem is reviewed in detail here: the gum arabic zone of Kordofan. After cotton, gum arabic is Sudan's largest export, worth from $14-26 million in recent years. In this zone the ecologically balanced cycle of gum gardens, fire, grain crops, and fallow is now breaking down; the 1968-1973 drought having in many areas delivered the final blow. Because of a growing population, the cultivation period is extended, and the soil becomes impoverished. Overgrazing in the fallow period, and the lopping of gum trees for firewood is producing a low return on the gum trees. Without this gum to harvest for cash, farmers must repeatedly replant their subsistence crops until the land becomes useless sand. The Sudanese have recognized the problem earlier than most, and a number of imaginative and practicable pilot projects are already in use: 1) waterpoint management; 2) construction of firebreaks; 3) land threatened by shifting dunes has been enclosed by stockproof fence and afforested with local trees; and 4) shelter belts have been planted around town perimeters where old gum tree stumps have started to sprout and the grass is reseeding itself. Out of these pilot projects, and with the advice of the U.N. Environment Program, the U.N. Development Program, and FAO, the Sudanese have developed a modest $26 million desert encroachment control and rehabilitation program (DECARP). PMID:12278008

  15. White ink, measurement methods

    NASA Astrophysics Data System (ADS)

    Kleinmann, Johanna; Green, Phil; Eve, Will; MacDonald, Lindsay

    2008-01-01

    Printing with white ink plays an important role in many printing processes, but white is difficult to integrate into colour management processes since conventional measurements are uncorrelated with the ink amount. A control method for white ink is proposed in which white is printed and measured over black. The resulting colorimetric densities can be modelled by polynomial regression, allowing accurate prediction of tonal value. The model can readily be inverted to predict the colorant amount required to match a given colorimetric density, and hence is a suitable method of measurement that can support process control and colour management.

  16. 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?

  17. 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?…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Sahara Desert Sand Storm, Mali, Africa

    NASA Technical Reports Server (NTRS)

    1990-01-01

    In this view of the southern Sahara Desert in Mali, Africa (16.5N, 3.0W), unusually strong surface winds accompanied by an unstable atmosphere produced a large area of blowing sand over western Africa. Between 26 and 29 April, observers in the area noted a dense cloud of sand appeared from out of central Mali and migrated offshore of the African coast near Guinea. Satellite measurements of the extent of the storm was 270, 000 square miles.

  6. Bioprocess for treating coproduced oily sands

    SciTech Connect

    Munnecke, D.M.; Ireland, J.

    1996-12-31

    The production of oil from certain oil fields creates significant amounts of oily sand which in many regulatory jurisdictions is regulated as a hazardous material, thus disposal costs can be significant. Environmental BioTechnologies, Inc. (San Carlos, CA) has developed a physical/biological treatment process that is able to economically treat these coproduced sands and produce a product that contains less than 2,000 ppm total petroleum hydrocarbons.

  7. Great Sand Dune National Monument, CO, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Great Sand Dune National Monument, CO (38.0N, 126.0W) appears near the center of the image. The sands of these dunes, blown from the valley floor by westerly winds in the course of the past few tens of thousands of years, are now banked up against the foot of the 14,000 ft. Sangre de Christo Mountains. In the fields nearby, center pivot irrigation agriculture has almost entirely replaced the earlier rectangular grid pattern.

  8. 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.

  9. Laboratory evaluation of selected tar sand asphalts

    SciTech Connect

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  10. 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.

  11. Acoustic properties of coral sands, Waikiki, Hawaii

    NASA Astrophysics Data System (ADS)

    Fu, S. S.; Tao, C.; Prasad, M.; Wilkens, R. H.; Frazer, L. N.

    2004-05-01

    An in situ experimental study of variations of compressional wave speed and attenuation with depth in natural coral sands has been made offshore of Oahu, Hawaii. In situ data were collected at a center frequency of 7.5 kHz. Compressional wave speed averages around 1620 m/s and attenuation (expressed as Qp-1, the reciprocal of the quality factor) decreases from 0.04 at the seafloor to 0.01 at 2 m depth. Very little change in compressional wave speed is seen to 9 m below the seafloor. Coral sand sound speeds are lower than those reported elsewhere for quartz sand. Waveforms recorded over the upper 9 m below the seafloor exhibit virtually no peak broadening, suggesting that scattering contributes little to the in situ attenuation. The relationship of attenuation to frequency in the coral sands agrees with Hamilton's observations of attenuation in other sediments, although the coral sand attenuation is slightly higher than in other sediments. The coral sand relationship between attenuation and porosity also agrees with Hamilton's when the volume of intraparticle voids is deducted from the total porosity.

  12. 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.

  13. 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.

  14. Western White Pine

    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...

  15. White Teachers Talking Race

    ERIC Educational Resources Information Center

    Segall, Avner; Garrett, James

    2013-01-01

    In light of the increasing racial diversity in American schools and the consistently homogenous teacher workforce in the United States, understanding the ways white teachers consider and attend to racial issues is of crucial importance to the educational landscape. This paper, based on a qualitative study, explores five white American…

  16. Elevation from east. White Holly in foreground, with White Sage ...

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

    Elevation from east. 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

  17. Working decks for buoy maintenance. White Sage on left, White ...

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

    Working decks for buoy maintenance. White Sage on left, White Holly on right. - U.S. Coast Guard Cutter WHITE HOLLY, U.S. Coast Guard 8th District Base, 4640 Urquhart Street, New Orleans, Orleans Parish, LA

  18. Sand ripples under water with complex wave motion.

    PubMed

    Scheibye-Knudsen, K; Ellegaard, C; Bundgaard, F; Sams, Thomas

    2005-07-01

    Experiments studying ripple formation under water have usually used sinusoidal driving force. Here an experiment is presented where the driving force can be an arbitrary wave form, thus trying to mimic the realistic wave motion in shallow water coastal zones. We study a simple modulated sine wave and more complicated wave forms with several superposed harmonics. In particular we demonstrate how a small higher order harmonic can have a dramatic effect on the wavelength of the ripple pattern. PMID:16090068

  19. 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 ...

  20. 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.

  1. 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

  2. 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

  3. Sand dynamics at the mouth of a rock-bound, tide-dominated estuary

    NASA Astrophysics Data System (ADS)

    FitzGerald, D. M.; Buynevich, I. V.; Fenster, M. S.; McKinlay, P. A.

    2000-03-01

    The lowermost Kennebec River is a relatively narrow, deep, bedrock-cut estuary situated along the highly indented, central coast of Maine. A large tidal prism and strong tidal currents control bedload sediment transport at the estuary mouth. Riverine sediment is introduced to the estuary during spring freshets when freshwater discharge may increase by an order of magnitude. During the same time, some of the existing estuarine sediment is exported to the nearshore. A barrier adjacent to the estuary is the product of an abundant riverine sand supply and numerous bedrock ridges, which anchor this sand deposit. A variety of sedimentologic, geomorphic, and hydraulic data collected over a 14-year period document a clockwise, sand-circulation cell that involves the exchange of bedload among the entrance channel to the estuary, adjacent beaches, nearshore, and offshore region. Tidal currents transport sand from the estuary through a subsidiary channel, bordered on both sides by bedrock islands, to an offshore subtidal bar. Northeast storm waves breaking along this outer bar move sand westward and landward toward the beach, leading to the development of large bar complexes. The welding of a bar complex to the western end of Hunnewell Beach occurs every 6-9 years and adds 2-300,000 m 3 of sand to the shoreline. Sediment transport calculations along the outer bar are consistent with this volume of sand. The sediment gyre is completed as beach sands are moved eastward along the beach and dumped into the estuarine channel. This movement of sand is produced by wave action and tidal currents that enter the estuary peripherally during the flooding tide. During the ebb cycle, strong tidal currents flowing seaward through the subsidiary channel advect water from along the beach, which enhances sand transport into the estuary. Thirteen years of beach profile surveys demonstrate a good correspondence between bar welding events and short-term (1-4 years) accretionary shoreline changes. However, the volumetric changes of Hunnewell Beach cannot be accounted for by bar welding alone. The apparent movement of sand between Hunnewell Beach and other sand is further evidenced by the 135 year record of historical shoreline changes that reveal up to 200 m of shoreline excursions over a 26 year period. These data suggest that erosional-depositional trends along Hunnewell Beach are complex and the result of the exchange of sand among the adjacent beaches, nearshore zone, Fox and Wood Island tombolos, Kennebec River channel, and offshore region. The effects of major spring floods and strong bedrock influences produce patterns of sedimentation and a distribution of sand bodies at the mouth of Kennebec River that differ markedly from accepted estuarine models that are based on the relative importance of wave and tidal energy. This study demonstrates the need to consider structural controls when using these models.

  4. 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...

  5. Bright sand/dark dust: The identification of active sand surfaces on the Earth and Mars

    NASA Technical Reports Server (NTRS)

    Blount, H. G., II; Greeley, R.; Christensen, P. R.; Arvidson, R.

    1987-01-01

    Field studies and analysis of LANDSAT Thematic Mapper data in the Gran Desierto, Mexico may shed light on a technique to distinguish active from inactive (relict) sand surfaces. Active sand bodies in the study area are consistently brighter (by an average of 20%) at visual and near infrared wavelengths and darker at thermal infrared wavelengths than compositionally similar inactive sands. The reasons for the albedo difference between active and inactive sands are reviewed and the mixing model of Johnson et al. is examined for tracing the provenance of sands based on albedo and spectral variations. Portions of the wavelengths covered by the Mars Orbiter correspond to the Thematic Mapper data. The identification of active sands on Earth, with a priori knowledge of bulk composition and grain size distribution, may allow the remote mapping of active sand surfaces on Mars. In conjuction with thermal infrared remote sensing for composition, it may also provide a method for the remote determination of grain size distributions within sand/silt mixtures.

  6. Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves

    USGS Publications Warehouse

    Sterlini, F.; Hulscher, S.J.M.H.; Hanes, D.M.

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity to study sand wave variation between locations, within one well-measured, large area. The nonlinear model used in this paper is presently the only tool that provides information on the nonlinear evolution of large-amplitude sand waves. The model is used to increase our understanding of the coupling between the variability in environmental conditions and the sand wave characteristics. Results show that the model is able to describe the variation in the Golden Gate sand waves well when both the local oscillating tidal current and the residual current are taken into account. Current and water depth seem to be the most important factors influencing sand wave characteristics. The simulation results give further confidence in the underlying model hypothesis and assumptions. Copyright 2009 by the American Geophysical Union.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. When White Dwarfs Collide

    NASA Astrophysics Data System (ADS)

    Hawley, Wendy Phyllis

    3D models of white dwarf collisions are used to assess the likelihood of double-degenerate mergers as progenitors for Type Ia supernovae (henceforth SNIa) and to identify observational signatures of double-degenerate collisions. Observations of individual SNIa, SNIa rates in different galaxy types, and double white dwarf binary systems suggest that mergers or collisions between two white dwarfs play a role in the overall SNIa population. Given the possibility of two progenitor systems (single-degenerate and double-degenerate), the sample of SNIa used in cosmological calcula- tions needs to be carefully examined. To improve calculations of cosmological parameters, the development of calibrated diagnostics for double-degenerate progenitor SNIa is essential. Head-on white dwarf collision simulations are used to provide an upper limit on the 56Ni production in white dwarf collisions. In chapter II, I explore zero impact parameter collisions of white dwarfs using the Eulerian grid code FLASH. The initial 1D white dwarf profiles are created assuming hydrostatic equilibrium and a uniform composition of 50% 12C and 50% 16O. The masses range from 0.64 to 0.81 solar masses and have an isothermal temperature of 107 K. I map these 1D models onto a 3D grid, where the dimensions of the grid are each eight times the white dwarf radius, and the dwarfs are initially placed four white dwarf radii apart (center to center). To provide insight into a larger range of physical possibilities, I also model non-zero impact parameter white dwarf collisions (Chapter III). Although head-on white dwarf collisions provide an upper limit on 56Ni production, non-zero impact parameter collisions provide insight into a wider range of physical scenarios. The initial conditions (box size, initial separation, composition, and initial temperature) are identical to those used for the head-on collisions (Chapter II) for the same range of masses. For each mass pair- ing, collision simulations are carried out at impact parameters b=1 and b=2 (grazing). Finally, I will address future work to be performed (Chapter IV).

  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. 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.

  18. 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

  19. Planet-wide sand motion on mars

    USGS Publications Warehouse

    Bridges, N.T.; Bourke, M.C.; Geissler, P.E.; Banks, M.E.; Colon, C.; Diniega, S.; Golombek, M.P.; Hansen, C.J.; Mattson, S.; McEwen, A.S.; Mellon, M.T.; Stantzos, N.; Thomson, B.J.

    2012-01-01

    Prior to Mars Reconnaissance Orbiter data, images of Mars showed no direct evidence for dune and ripple motion. This was consistent with climate models and lander measurements indicating that winds of sufficient intensity to mobilize sand were rare in the low-density atmosphere. We show that many sand ripples and dunes across Mars exhibit movement of as much as a few meters per year, demonstrating that Martian sand migrates under current conditions in diverse areas of the planet. Most motion is probably driven by wind gusts that are not resolved in global circulation models. A past climate with a thicker atmosphere is only required to move large ripples that contain coarse grains. ?? 2012 Geological Society of America.

  20. 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.

  1. 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

  2. Shifting-sand control in central Tibet.

    PubMed

    Liu, Z; Zhao, W

    2001-09-01

    The middle reaches of the Yarlung Zangbo, the Lhasa, and the Nianchu rivers form the center of politics, economy, and culture in the Tibetan Autonomous Region. Due to the fragility of the natural environment and overexploitation of land by the local people, desertification is becoming a serious problem in the valleys. Shifting sands cover an area of 578 km2 and have caused problems such as damage to farmland and grassland, traffic blockage and burying of water projects. This paper discusses strategies and techniques for combating shifting sands, including reformation of the agricultural structure, exploitation of new sources of energy, and combinations of mechanical and biotic measures. Using mechanical measures, straw barriers, and gravel layer covers, artificial vegetation can be established on the mobile sand dune by sowing and planting introduced species. PMID:11757287

  3. Granular size segregation in underwater sand ripples.

    PubMed

    Rousseaux, G; Caps, H; Wesfreid, J-E

    2004-02-01

    We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The initial wavelength of the mixture is measured. In the final steady state, a segregation in volume is observed instead of a segregation at the surface as reported before. The correlation between this phenomenon and the fluid flow is emphasised. Finally, different "exotic" patterns and their geophysical implications are presented. PMID:15052430

  4. 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.

  5. 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.

  6. Flocculation settling characteristics of mud: sand mixtures

    NASA Astrophysics Data System (ADS)

    Manning, Andrew J.; Baugh, John V.; Spearman, Jeremy R.; Whitehouse, Richard J. S.

    2010-04-01

    When natural muds become mixed with sandy sediments in estuaries, it has a direct effect on the flocculation process and resultant sediment transport regime. Much research has been completed on the erosion and consolidation of mud/sand mixtures, but very little is known quantitatively about how mixed sediments interact whilst in suspension, particularly in terms of flocculation. This paper presents the settling velocity findings from a recent laboratory study which examined the flocculation dynamics for three different mud/sand mixtures at different concentrations (0.2-5 g.l-1) and turbulent shear stresses (0.06-0.9 Pa) in a mini-annular flume. The low intrusive video-based Laboratory Spectral Flocculation Characteristics instrument was used to determine floc/aggregate properties (e.g., size, settling velocity, density and mass) for each population. Settling data was assessed in terms of macrofloc (>160 μm) and microfloc (<160 μm) settling parameters: Wsmacro and Wsmicro, respectively. For pure muds, the macroflocs are regarded as the most dominant contributors to the total depositional flux. The parameterised settling data indicates that by adding more sand to a mud/sand mixture, the fall velocity of the macrofloc fraction slows and the settling velocity of microflocs quickens. Generally, a mainly sandy suspension comprising 25% mud and 75% sand (25M:75S), will produce resultant Wsmacro which are slower than Wsmicro. The quickest Wsmicro appears to consistently occur at a higher level of turbulent shear stress (τ ˜ 0.6 Pa) than both the macrofloc and microfloc fractions from suspensions of pure natural muds. Flocculation within a more cohesively dominant muddy-sand suspension (i.e., 75M:25S) produced macroflocs which fell at similar speeds (±10%) to pure mud suspensions at both low (200 mg l-1) and intermediate (1 g l-1) concentrations at all shear stress increments. Also, low sand content suspensions produced Wsmacro values that were faster than the Wsmicro rates. In summary, the experimental results of the macrofloc and microfloc settling velocities have demonstrated that flocculation is an extremely important factor with regards to the depositional behaviour of mud/sand mixtures, and these factors must be considered when modelling mixed sediment transport in the estuarine or marine environment.

  7. 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

  8. 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

  9. 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

  10. Nugget-Navaho-Aztec sandstone: interaction of eolian sand sea with Andean-type volcanic arc

    SciTech Connect

    Marzolf, J.E.

    1986-05-01

    The Nugget-Navaho-Aztec sand sea was deposited east of an Andean-type volcanic arc. During the early stage of eolian deposition, fluvially transported sand was concentrated in the marine littoral zone and returned inland by onshore winds from the northwest. With progressive development of the arc, the sea withdrew. Wind direction changed from northwest to northeast. Previously deposited eolian sand was transported southwestward into the volcanic arc. Proximity of the arc can be detected with great difficulty by examining eolian and underlying red-bed facies. In southern Nevada, the volcanic arc is undetectable in eolian facies, but thin sandstone beds containing volcanic clasts or weathered feldspar in the finer grained red-bed facies indicate arc volcanism; volcanic clasts are distinct in a basal conglomerate. Westward into California, the sub-Aztec Sandstone contains volcanic pebbles. The upper part of the Aztec Sandstone contains a 1 to 2-m thick volcaniclastic siltstone. Farther west, the Aztec Sandstone is interbedded with volcanic flows, ash flows, and flow breccias. These rocks might easily be mistaken for red beds in well cores or cuttings. Sand in sets of large-scale cross-beds remain virtually identical in composition and texture to sand in eolian facies of the Colorado Plateau. Where sets of eolian cross-beds lie on volcanics, the quartzose sandstone contains pebble to cobble-size volcanic clasts. Locally, cross-bed sets of yellowish-white, quartzose sandstone alternate with purplish-gray cross-bed sets containing numerous pebble to cobble-size volcanic clasts. The ability to recognize volcanic indicators within Nugget-Navaho-Aztec eolian facies is important in delineating the western margin of the back-arc eolian basin.

  11. 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…

  12. 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

  13. Genome-Wide Analysis of Sorbitol Dehydrogenase (SDH) Genes and Their Differential Expression in Two Sand Pear (Pyrus pyrifolia) Fruits

    PubMed Central

    Dai, Meisong; Shi, Zebin; Xu, Changjie

    2015-01-01

    Through RNA-seq of a mixed fruit sample, fourteen expressed sorbitol dehydrogenase (SDH) genes have been identified from sand pear (Pyrus pyrifolia Nakai). Comparative phylogenetic analysis of these PpySDHs with those from other plants supported the closest relationship of sand pear with Chinese white pear (P. bretschneideri). The expression levels varied greatly among members, and the strongest six (PpySDH2, PpySDH4, PpySDH8, PpySDH12, PpySDH13 and PpySDH14) accounted for 96% of total transcript abundance of PpySDHs. Tissue-specific expression of these six members was observed in nine tissues or organs of sand pear, with the greatest abundance found in functional leaf petioles, followed by the flesh of young fruit. Expression patterns of these six PpySDH genes during fruit development were analyzed in two sand pear cultivars, “Cuiguan” and “Cuiyu”. Overall, expression of PpySDHs peaked twice, first at the fruitlet stage and again at or near harvest. The transcript abundance of PpySDHs was higher in “Cuiguan” than in “Cuiyu”, accompanied by a higher content of sugars and higher ratio of fructose to sorbitol maintained in the former cultivar at harvest. In conclusion, it was suggested that multiple members of the SDH gene family are possibly involved in sand pear fruit development and sugar accumulation and may affect both the sugar amount and sugar composition. PMID:26068235

  14. Genome-Wide Analysis of Sorbitol Dehydrogenase (SDH) Genes and Their Differential Expression in Two Sand Pear (Pyrus pyrifolia) Fruits.

    PubMed

    Dai, Meisong; Shi, Zebin; Xu, Changjie

    2015-01-01

    Through RNA-seq of a mixed fruit sample, fourteen expressed sorbitol dehydrogenase (SDH) genes have been identified from sand pear (Pyrus pyrifolia Nakai). Comparative phylogenetic analysis of these PpySDHs with those from other plants supported the closest relationship of sand pear with Chinese white pear (P. bretschneideri). The expression levels varied greatly among members, and the strongest six (PpySDH2, PpySDH4, PpySDH8, PpySDH12, PpySDH13 and PpySDH14) accounted for 96% of total transcript abundance of PpySDHs. Tissue-specific expression of these six members was observed in nine tissues or organs of sand pear, with the greatest abundance found in functional leaf petioles, followed by the flesh of young fruit. Expression patterns of these six PpySDH genes during fruit development were analyzed in two sand pear cultivars, "Cuiguan" and "Cuiyu". Overall, expression of PpySDHs peaked twice, first at the fruitlet stage and again at or near harvest. The transcript abundance of PpySDHs was higher in "Cuiguan" than in "Cuiyu", accompanied by a higher content of sugars and higher ratio of fructose to sorbitol maintained in the former cultivar at harvest. In conclusion, it was suggested that multiple members of the SDH gene family are possibly involved in sand pear fruit development and sugar accumulation and may affect both the sugar amount and sugar composition. PMID:26068235

  15. 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.

  16. 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.

  17. White Rabbit in space related application

    NASA Astrophysics Data System (ADS)

    JamroŻy, M.; Gumiński, M.; Kasprowicz, G.; Romaniuk, R.; Poźniak, 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.

  18. 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…

  19. 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...

  20. 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...

  1. 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...

  2. 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

  3. Microbial diversity in Calamita ferromagnetic sand.

    PubMed

    Perfumo, Amedea; Cockell, Charles; Elsaesser, Andreas; Marchant, Roger; Kminek, Gerhard

    2011-08-01

    Calamita is a black ferromagnetic sand from a marine iron ore on Elba Island (Italy). Its total iron content is approximately 80% and a major fraction (63% w/w) has magnetic properties. Desiccation, ultraviolet irradiation and the high temperature induced by the thermal conductivity of iron make Calamita sand an extreme biotope. We report, for the first time, the geomicrobiological characterization of Calamita sand, which showed a low bacterial biodiversity as determined by denaturing gradient gel electrophoresis and 16S rRNA gene clone library analysis. We retrieved sequences closely affiliated with uncultured bacteria inhabiting the harshest deserts on Earth. Radiation- and desiccation-tolerant bacteria from the phyla Proteobacteria, Actinobacteria and Deinococcus-Thermus dominated the community. Heavy metal-resistant organisms, for example Variovorax sp. were also abundant. Sequences of organisms with an inferred metabolism based on lithotrophic iron oxidation were detected. The sands also contained thermophilic bacilli, which were cultivated at 60°C. These data provided important insights also into the biogeographical distribution of these organisms in the Mediterranean region. In summary, this study on Calamita helps to expand our knowledge of the biodiversity in extreme, iron-rich, environments. PMID:23761311

  4. 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...

  5. 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 0.6×10-7m2s-1 for pure peat to 7.0×10-7m2s-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 0.6×10-7m2s-1 to 0.9×10-7m2s-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 1.3×10-7m2s-1 and 1.7×10-7m2s-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(θ) curves, where k is soil thermal diffusivity, θ 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(θ) 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

  6. 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.

  7. 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)

  8. Pattern formation of underwater sand ripples with a skewed drive.

    PubMed

    Bundgaard, F; Ellegaard, C; Scheibye-Knudsen, K; Bohr, T; Sams, T

    2004-12-01

    In this paper we present an experimental study of the dynamics of underwater sand ripples when a regular pattern of ripples is subjected to a skewed oscillatory flow, i.e., one not perpendicular to the direction of the ripple crests. Striking patterns with new, superposed ripples on top of the original ones occur very quickly with a characteristic angle, which is, in general, not perpendicular to the flow. A slower, more complex transition then follows, leading to the final state where the ripples are again perpendicular to the flow. We investigate the variation of the superposed pattern as a function of the direction, amplitude, and frequency of the drive, and as a function of the viscosity (by changing the temperature). We quantify the dynamics of the entire transition process and finally study the grain motion around idealized (solid) skewed ripples. This leads to a characteristic mean path of a single particle. The path has a shape close to a parallelogram, with no apparent connection to the pattern of real, superposed ripples. On the other hand, a thin layer of sand sprinkled on the solid ripples leads to qualitatively similar patterns. PMID:15697484

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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 μm 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.

  15. 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.

  16. 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.

  17. Great sand sea and selima sand sheet, eastern sahara: geochronology of desertification.

    PubMed

    Haynes, C V

    1982-08-13

    The relation of playa sediments and associated archeological sites with longitudinal dunes allows estimation of ages for the two uppermost strata of the Great Sand Sea. Active dune formation corresponds with interpluvial periods of hyperaridity; dune stability corresponds with semiarid pluvial periods. Archeological sites associated with truncated paleosols in the Selima Sand Sheet suggest a similar climatic relation and indicate that the isohyets of central Sudan shifted at least 400 kilometers northward during the peak of pluvials. PMID:17817531

  18. 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.

  19. 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.

  20. 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

  1. Investigation of the sand sea with the tallest dunes on Earth: China's Badain Jaran Sand Sea

    NASA Astrophysics Data System (ADS)

    Dong, Zhibao; Qian, Guangqiang; Lv, Ping; Hu, Guangyin

    2013-05-01

    China's Badain Jaran Sand Sea features the tallest dunes on Earth and a unique mega-dune-lake landscape. It had been explored little until the 1990s, though early scientific explorations surrounding the sand sea had begun by the early 20th century. Heated debates now focus on the desert environment, and particularly how the mega-dunes and desert lakes develop and evolve. This paper reviews the status of these debates and summarizes the supporting evidences. The environmental research mainly concerns formation and evolution of the sand sea, and its relationship with climate change. The proposed formation time ranges from the Early Pleistocene to the Holocene. Opinions vary about climate change on different time scales. The reconstructed climate change history is shorter than the sand sea's history, with the longest record extending to the Late Pleistocene. The mega-dune research focuses on sediments, dune morphology, and formation processes. It remains unclear whether the mega-dunes result primarily from wind action, control by the underlying topography, or groundwater maintenance. The sources of lake water are also debated, but there are four main hypotheses: atmospheric precipitation, groundwater from nearby areas, precipitation and snowmelt in remote areas such as the Qilian Mountains and the Qinghai-Tibetan Plateau, or paleowater that formed during past periods of wet climate. We believe that the sand sea deserves further study in terms of its dune geomorphology, evolution, and hydrology, and their responses to climate change. Meteorological and hydrological observations and monitoring in the sand sea are particularly necessary.

  2. Impact on demersal fish of a large-scale and deep sand extraction site with ecosystem-based landscaped sandbars

    NASA Astrophysics Data System (ADS)

    de Jong, Maarten F.; Baptist, Martin J.; van Hal, Ralf; de Boois, Ingeborg J.; Lindeboom, Han J.; Hoekstra, Piet

    2014-06-01

    For the seaward harbour extension of the Port of Rotterdam in the Netherlands, approximately 220 million m3 sand was extracted between 2009 and 2013. In order to decrease the surface area of direct impact, the authorities permitted deep sand extraction, down to 20 m below the seabed. Biological and physical impacts of large-scale and deep sand extraction are still being investigated and largely unknown. For this reason, we investigated the colonization of demersal fish in a deep sand extraction site. Two sandbars were artificially created by selective dredging, copying naturally occurring meso-scale bedforms to increase habitat heterogeneity and increasing post-dredging benthic and demersal fish species richness and biomass. Significant differences in demersal fish species assemblages in the sand extraction site were associated with variables such as water depth, median grain size, fraction of very fine sand, biomass of white furrow shell (Abra alba) and time after the cessation of sand extraction. Large quantities of undigested crushed white furrow shell fragments were found in all stomachs and intestines of plaice (Pleuronectes platessa), indicating that it is an important prey item. One and two years after cessation, a significant 20-fold increase in demersal fish biomass was observed in deep parts of the extraction site. In the troughs of a landscaped sandbar however, a significant drop in biomass down to reference levels and a significant change in species assemblage was observed two years after cessation. The fish assemblage at the crests of the sandbars differed significantly from the troughs with tub gurnard (Chelidonichthys lucerna) being a Dufrêne-Legendre indicator species of the crests. This is a first indication of the applicability of landscaping techniques to induce heterogeneity of the seabed although it remains difficult to draw a strong conclusion due the lack of replication in the experiment. A new ecological equilibrium is not reached after 2 years since biotic and abiotic variables are still adapting. To understand the final impact of deep and large-scale sand extraction on demersal fish, we recommend monitoring for a longer period, at least for a period of six years or even longer.

  3. 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.

  4. 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.

  5. White light velocity interferometer

    SciTech Connect

    Erskine, David J.

    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.

  6. White light velocity interferometer

    SciTech Connect

    Erskine, David J.

    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.

  7. 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.

  8. 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...

  9. 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...

  10. 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

  11. 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

  12. 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 ...

  13. Well completion process for formations with unconsolidated sands

    DOEpatents

    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.

  14. Process for production of oil from oil sand

    SciTech Connect

    Horikoshi, K.; Nakamura, N.; Shibanai, I.

    1981-03-10

    A process for the production of oil from oil sand includes adding cyclodextrin or a starch decomposition product containing cyclodextrin to oil sand to convert petroleum in the oil sand to an inclusion compound and separating and collecting petroleum alone from the inclusion compound.

  15. 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.

  16. 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...

  17. 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...

  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, 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....

  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....