Sample records for silty fine sand

  1. Influence of initial conditions on liquefaction resistance of silty sands

    Microsoft Academic Search

    K. Rangaswamy; A. Boominathan; K. Rajagopal

    2010-01-01

    The influence of initial conditions, i.e. stress state and void ratio, on the liquefaction resistance of silty sands under two-way cyclic loading is investigated in this paper. Using a cyclic triaxial test device, a series of undrained stress-controlled cyclic triaxial tests was performed on reconstituted specimens of sand and sand mixed with 15, 30 and 50% non-plastic fines content (finer

  2. Liquefaction Resistance of Silty Sands and Dynamic Properties of Cohesive Soils from Düzce, Turkey

    Microsoft Academic Search

    A. Papadopoulou; P. Kallioglou; Th. Tika; S. Papadopoulos; E. Batum

    2010-01-01

    This article presents results from a laboratory investigation into the cyclic and dynamic properties of soils from Düzce, Turkey, conducted after the destructive November 12, 1999 earthquake. The investigation was mainly conducted by means of monotonic and cyclic triaxial, as well as resonant-column tests. The triaxial tests allowed the determination of the liquefaction resistance of silty sands, as well as

  3. Chlorofluorocarbons as tracers of groundwater transport processes in a shallow, silty sand aquifer

    Microsoft Academic Search

    P. G. Cook; D. K. Solomon; L. N. Plummer; E. Busenberg; S. L. Schiff

    1995-01-01

    Detailed depth profiles of chlorofluorocarbons CFC-11 (CFCl3), CFC-12 (CF2Cl2), and CFC-113 (C2F3Cl3) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined 3H peak has been tracked through time. Detailed vertical

  4. Chlorofluorocarbons as Tracers of Groundwater Transport Processes in a Shallow, Silty Sand Aquifer

    Microsoft Academic Search

    P. G. Cook; D. K. Solomon; L. N. Plummer; E. Busenberg; S. L. Schiff

    1995-01-01

    Detailed depth profiles of Chlorofluorocarbons CFC-11(CFCl3(, CFC-12 (CF2Cl2) and CFC-113 (C2F3Cl3) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined 3H peak has been tracked through time. Detailed vertical sampling

  5. Static and Cyclic Behavior of a Silty Sand According to Tests on Undisturbed Samples

    Microsoft Academic Search

    A. B. Huang; Y. T. Huang

    The effects of plastic or nonplastic fines on the static and cyclic strength of sand have been a subject of laboratory studies for many decades. These studies have not lead to a consensus as to how fines can affect the behavior of sand. Earlier studies have mostly been limited to tests on reconstituted specimens. Some of the controversies stem from

  6. Cyclic Behavior of Nonplastic Silty Sand under Direct Simple Shear Loading

    NASA Astrophysics Data System (ADS)

    El-Mamlouk, H. H.; Hussein, A. K.; Hassan, A. M.

    The cyclic behavior of clean sands pertaining to earthquake loading have been studied extensively. However, natural sands may contain significant amounts of silt or clay, which have long been thought to affect the cyclic resistance of such soils. In fact, the literature contains what appears to be conflicting results. There was a need to clarify the effect of fines content on the cyclic resistance of sand which was addressed in this paper. A series of constant volume stress-controlled cyclic tests using the DSS apparatus was performed on reconstituted specimens of sand with fines content of 0%, 20%, and 40%. The samples were prepared at relative densities of 40% and 80%; consolidated at vertical stresses of 50, 100, 200, and 400kPa; and sheared at cyclic stress ratios of 0.05, 0.10, and 0.15. Test results indicate that failure criterion should be identified based on whether the sand behavior is contractive or dilative. The cyclic resistance is found to be controlled by the relative density of the soil.

  7. Food-chain relationships in subtidal silty sand marine sediments and the role of meiofauna in stimulating bacterial productivity

    Microsoft Academic Search

    Sebastian A. Gerlach

    1978-01-01

    From bibliographic data the biomass correlations (organic dry weight) are constructed for the subsurface layer of a hypothetical 30 m deep silty sand station: 200 µg\\/ml macrofauna (including 120 µg\\/ml subsurface deposit feeders), 50 µg\\/ml meiofauna, 20 µg\\/ml Foraminifera, 1 µg\\/ml Ciliata and Flagellata, and 100 µg\\/ml bacteria. ATP-biomass is discussed.

  8. Chlorofluorocarbons as tracers of groundwater transport processes in a shallow, silty sand aquifer

    SciTech Connect

    Cook, P.G.; Schiff, S.L. [Univ. of Waterloo, Ontario (Canada)] [Univ. of Waterloo, Ontario (Canada); Solomon, D.K. [Univ. of Utah, Salt Lake City, UT (United States)] [Univ. of Utah, Salt Lake City, UT (United States); Plummer, L.N.; Busenberg, E. [Geological Survey, Reston, VA (United States)] [Geological Survey, Reston, VA (United States)

    1995-03-01

    Detailed depth profiles of chlorofluorocarbons CFC-11 (CFCl{sub 3}), CFC-12 (CF{sub 2}Cl{sub 2}) and CFC-113 (C{sub 2}F{sub 3}Cl{sub 3}) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined {sup 3}H peak has been tracked through time. Detailed vertical sampling has allowed CFC tracer velocities to be estimated to within 10%. Comparison with {sup 3}H profiles enables estimation of chlorofluorocarbon transport parameters. CFC-12 appears to be the most conservative of the CFCs measured. Sorption at this site is low (K{sub d} < 0.03), and degradation does not appear to be important. CFC-113 is retarded both with respect to CFC-12 and with respect to {sup 3}H (K{sub d} = 0.09-0.14). CFC-11 appears to be degraded both in the highly organic unsaturated zone and below 3.5 m depth in the aquifer, where dissolved oxygen concentrations decrease to below 0.5 mg L{sup {minus}1}. The half-life for CFC-11 degradation below 3.5 m depth is less than 2 years. While apparent CFC-12 ages match hydraulic ages to within 20% (up to 30 years), apparent CFC-11 and CFC-113 ages significantly overestimate hydraulic ages at our field site. 37 refs., 9 figs., 3 tabs.

  9. Transport and transformation of sulfadiazine in soil columns packed with a silty loam and a loamy sand.

    PubMed

    Unold, M; Kasteel, R; Groeneweg, J; Vereecken, H

    2009-01-01

    Concerning the transport of the veterinary antibiotic sulfadiazine (SDZ) little is known about its possible degradation during transport. Also its sorption behaviour is not yet completely understood. We investigated the transport of SDZ in soil columns with a special emphasis on the detection of transformation products in the outflow of the soil columns and on modelling of the concentration distribution in the soil columns afterwards. We used disturbed soil columns near saturation, packed with a loamy sand and a silty loam. SDZ was applied as a 0.57 mg L(-1) solution at a constant flow rate of 0.25 cm h(-1) for 68 h. Breakthrough curves (BTC) of SDZ and its transformation products 4-(2-iminopyrimidin-1(2H)-yl)aniline and 4-hydroxy-SDZ were measured for both soils. For the silty loam we additionally measured a BTC for an unknown transformation product which we only detected in the outflow samples of this soil. After the leaching experiments the (14)C-concentration was quantified in different layers of the soil columns. The transformation rates were low with mean SDZ mass fractions in the outflow samples of 95% for the loamy sand compared to 97% for the silty loam. The formation of 4-(2-iminopyrimidin-1(2H)-yl)aniline appears to be light dependent and did probably not occur in the soils, but afterwards. In the soil columns most of the (14)C was found near the soil surface. The BTCs in both soils were described well by a model with one reversible (kinetic) and one irreversible sorption site. Sorption kinetics played a more prominent role than sorption capacity. The prediction of the (14)C -concentration profiles was improved by applying two empirical models other than first order to predict irreversible sorption, but also these models were not able to describe the (14)C concentration profiles correctly. Irreversible sorption of sulfadiazine still is not well understood. PMID:18951658

  10. Transport and transformation of sulfadiazine in soil columns packed with a silty loam and a loamy sand

    NASA Astrophysics Data System (ADS)

    Unold, M.; Kasteel, R.; Groeneweg, J.; Vereecken, H.

    2009-01-01

    Concerning the transport of the veterinary antibiotic sulfadiazine (SDZ) little is known about its possible degradation during transport. Also its sorption behaviour is not yet completely understood. We investigated the transport of SDZ in soil columns with a special emphasis on the detection of transformation products in the outflow of the soil columns and on modelling of the concentration distribution in the soil columns afterwards. We used disturbed soil columns near saturation, packed with a loamy sand and a silty loam. SDZ was applied as a 0.57 mg L - 1 solution at a constant flow rate of 0.25 cm h - 1 for 68 h. Breakthrough curves (BTC) of SDZ and its transformation products 4-(2-iminopyrimidin-1(2 H)-yl)aniline and 4-hydroxy-SDZ were measured for both soils. For the silty loam we additionally measured a BTC for an unknown transformation product which we only detected in the outflow samples of this soil. After the leaching experiments the 14C-concentration was quantified in different layers of the soil columns. The transformation rates were low with mean SDZ mass fractions in the outflow samples of 95% for the loamy sand compared to 97% for the silty loam. The formation of 4-(2-iminopyrimidin-1(2 H)-yl)aniline appears to be light dependent and did probably not occur in the soils, but afterwards. In the soil columns most of the 14C was found near the soil surface. The BTCs in both soils were described well by a model with one reversible (kinetic) and one irreversible sorption site. Sorption kinetics played a more prominent role than sorption capacity. The prediction of the 14C -concentration profiles was improved by applying two empirical models other than first order to predict irreversible sorption, but also these models were not able to describe the 14C concentration profiles correctly. Irreversible sorption of sulfadiazine still is not well understood.

  11. Numerical evaluation of seismic response of shallow foundation on loose silt and silty sand

    NASA Astrophysics Data System (ADS)

    Asgari, Ali; Golshani, Aliakbar; Bagheri, Mohsen

    2014-03-01

    This study includes the results of a set of numerical simulations carried out for sands containing plastic/non-plastic fines, and silts with relative densities of approximately 30-40% under different surcharges on the shallow foundation using FLAC 2D. Each model was subjected to three ground motion events, obtained by scaling the amplitude of the El Centro (1940), Kobe (1995) and Kocaeli (1999) Q12earthquakes. Dynamic behaviour of loose deposits underlying shallow foundations is evaluated through fully coupled nonlinear effective stress dynamic analyses. Effects of nonlinear soil structure interaction (SSI) were also considered by using interface elements. This parametric study evaluates the effects of soil type, structure weight, liquefiable soil layer thickness, event parameters (e.g., moment magnitude of earthquake ( M w ), peak ground acceleration PGA, PGV/PGA ratio and the duration of strong motion ( D 5-95) and their interactions on the seismic responses. Investigation on the effects of these parameters and their complex interactions can be a valuable tool to gain new insights for improved seismic design and construction.

  12. Behavior of Nonplastic Silty Soils under Cyclic Loading

    PubMed Central

    Ural, Nazile; Gunduz, Zeki

    2014-01-01

    The engineering behavior of nonplastic silts is more difficult to characterize than is the behavior of clay or sand. Especially, behavior of silty soils is important in view of the seismicity of several regions of alluvial deposits in the world, such as the United States, China, and Turkey. In several hazards substantial ground deformation, reduced bearing capacity, and liquefaction of silty soils have been attributed to excess pore pressure generation during dynamic loading. In this paper, an experimental study of the pore water pressure generation of silty soils was conducted by cyclic triaxial tests on samples of reconstituted soils by the slurry deposition method. In all tests silty samples which have different clay percentages were studied under different cyclic stress ratios. The results have showed that in soils having clay content equal to and less than 10%, the excess pore pressure ratio buildup was quicker with an increase in different cyclic stress ratios. When fine and clay content increases, excess pore water pressure decreases constant cyclic stress ratio in nonplastic silty soils. In addition, the applicability of the used criteria for the assessment of liquefaction susceptibility of fine grained soils is examined using laboratory test results. PMID:24672343

  13. Downstream fining in large sand-bed rivers

    Microsoft Academic Search

    Roy M. Frings

    2008-01-01

    Downstream fining of bed sediments is a well-known phenomenon in gravel-bed rivers, but also occurs in (large) sand-bed rivers. The underlying processes, however, are not necessarily the same, due to the difference in sediment mobility, grain-size distribution width and geographical setting. Downstream fining studies focusing on large sand-bed rivers are scarce, nevertheless. In this paper, the processes that affect downstream

  14. Variation in grain shape and surface textures of fine guartz sands in the South Texas Eolian Sand Sheet

    E-print Network

    Sims, Donald Ralph

    1984-01-01

    VARIATION IN GRAIN SHAPE AND SURFACE TEXTURES OF FINE QUARTZ SANDS IN THE SOUTH TEXAS EOLIAN SAND SHEET A Thesis by DONALD RALPH SIMS JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 198'4 Major Subject: Geology VARIATION IN GRAIN SHAPE AND SURFACE TEXTURES OF FINE QUARTZ SANDS IN THE SOUTH TEXAS EOLIAN SAND SHEET A Thesis by DONALD RALPH SINS JR. Approved as to style and content by: Jame...

  15. Experimental Study of the Possibility to Make a Mortar with Ternary Sand (Natural and Artificial Fine Aggregates)

    NASA Astrophysics Data System (ADS)

    Baali, L.; Naceri, A.; Rahmouni, Z.; Mehidi, M. W. Noui

    This experimental study investigates the possibility to make a mortar with a ternary sand (natural and artificial fine aggregates). This method is utilized to correct the particle size distribution of various sands used in mortar. For this investigation, three sands have been used: a dune sand (DS), a slag sand (SS), and brick sand (BS) at different proportions in mortar. After crushing, the artificial fine aggregate (blast furnace slag and waste brick fine aggregate) was sifted in order to use it as fine aggregate. The effect of the quality and grain size distribution of natural fine aggregate (i.e., DS) and artificial fine aggregates (i.e., SS and BS) on the physical properties of ternary sand confected (density, porosity, fineness modulus, equivalent sand, particle size distribution, water absorption) and properties of fresh and hardened mortar were analysed. In the same way for this study, the physical properties and chemical compositions of DS, SS, BS and cement were investigated. The results obtained show that the mechanical strength on mortar depends of the nature and particle size distribution of sand studied. The reuse of this recycled material (slag blast furnace and waste brick) in the industry would contribute to the protection of the environment. This study shows the potential of this method to make mortar with ternary sand (natural and artificial fine aggreagates) in order to improve the physical properties of sand. Utilising natural and artificial fine aggregates to produce quality mortar should yield significant environmental benefits.

  16. ISET Journal of Earthquake Technology, Paper No. 450, Vol. 41, No. 2-4, June-December 2004, pp. 249-260 CYCLIC AND MONOTONIC UNDRAINED SHEAR RESPONSE OF SILTY

    E-print Network

    Gupta, Vinay Kumar

    -260 CYCLIC AND MONOTONIC UNDRAINED SHEAR RESPONSE OF SILTY SAND FROM BHUJ REGION IN INDIA T.G. Sitharam, L in villages and cities. In many places of the affected area, large masses of silty sands were ejected;250 Cyclic and Monotonic Undrained Shear Response of Silty Sand from Bhuj Region in India Fig. 1 Location

  17. The Microstructure and Formation of Artificial Biological Crusts of Cyanobacteria Nostoc flagelliforme on Fine Sands

    Microsoft Academic Search

    Hai-feng Yu; Yun-Ya He

    2011-01-01

    The arid desert area is expanding by 6 million ha per year. Nostoc flagelliforme, a terrestrial cyanobacterium, is known as a pioneer organism which can photosynthesize, fix atmospheric nitrogen, and secrete polysaccharides. In order to explore the potential of it as a countermeasure to soil desertification, N. flagelliforme cells in liquid culture was cultivated on fine sands and developed an

  18. Organic compound tracers of fine soil and sand particles during summer in the metropolitan area of Riyadh, Saudi Arabia

    Microsoft Academic Search

    Khalid Al-Mutlaq; Ahmed I. Rushdi; Bernd R. T. Simoneit

    2007-01-01

    Soil and sand fine particles, which may be resuspended as fine dust in the atmosphere, contain a variety of anthropogenic\\u000a and natural organic components. Samples of fine soil and sand particles (sieved to <125 ?M) were collected from the Riyadh\\u000a area in the summer of 2003 and extracted with a mixture of dichloromethane and methanol (3:1, v:v). The derivatized total\\u000a extracts were

  19. Bauxite residue fines as an amendment to residue sands to enhance plant growth potential—a glasshouse study

    Microsoft Academic Search

    Jonathan D. Anderson; Richard W. Bell; Ian R. Phillips

    Purpose  This glasshouse study was conducted to determine if amending bauxite residue sand with residue fines would improve its suitability\\u000a as a growth medium. Alcoa’s West Australian operations mechanically separate residue into two size fractions: residue fines\\u000a (which are dominated by particles 150 ?m). Residue sand represents the primary material used\\u000a as a growth medium for rehabilitation, and prior to amendments, it

  20. Dry mature fine tailings as oil sands reclamation substrates for three native grasses.

    PubMed

    Luna Wolter, Gabriela L; Naeth, M Anne

    2014-07-01

    Mature fine tailings (MFT) are a by-product of oil sands mining that must be reclaimed through capping or use as a reclamation substrate. Some chemical and physical properties of MFT make it inhospitable for plant growth, such as high concentrations of sodium, sulfate, chloride, and hydrocarbons. A greenhouse study assessed whether substrates of various mixes of dry MFT, overburden sand, and peat mineral soil mix (PMM) and caps of forest floor organic material (LFH) and PMM would support the emergence and growth of three native grass species commonly used in land reclamation. Select vegetation properties were monitored for 16 wk in the greenhouse; select chemical and physical substrate properties were determined in the laboratory. was more tolerant of dry MFT than and . Mean aboveground and belowground biomass were more than twice as high on substrates with <60% MFT than on 100% MFT. Aboveground biomass was two to four times greater with capping than without and 30% greater on LFH than PMM caps. Cover and density followed similar trends. Belowground biomass on capped substrates was at least double that on uncapped substrates. Aboveground biomass was almost doubled with the use of fertilizer. High concentrations of hydrocarbons and exchangeable ions were associated with reduced plant growth and health. Results from this study show that capping, amendments, and fertilizer may improve the reclamation potential of dry MFT. PMID:25603099

  1. The fine sand Abra alba community of the bay of morlaix twenty years after the Amoco Cadiz oil spill

    Microsoft Academic Search

    J-C Dauvin

    1998-01-01

    The fine sand Abra alba community from the Bay of Morlaix (western English Channel) was strongly affected by the Amoco Cadiz oil spill of April 1978. The long term changes in the community (1977–1996) show that reconstitution of this community is slow (over 10 yr). A progressive recolonization by amphipod Ampelisca populations constituting the dominant species is observed. The results

  2. Compression and Creep of Venice Lagoon Sands

    E-print Network

    Sanzeni, Alex

    A laboratory test program was conducted to evaluate the one-dimensional (1D) compression and creep properties of intact sand (and silty-sand) samples from a deep borehole at the Malamocco Inlet to the Venice Lagoon. The ...

  3. Measuring solid percentage of oil sands mature fine tailings using the dual probe heat pulse method.

    PubMed

    Li, Min; Barbour, S Lee; Si, Bing Cheng

    2015-01-01

    The reclamation of mature fine tailings (MFT) is a critical challenge for the oil sands industry in western Canada, and a nonradioactive, automated, and inexpensive method to monitor the MFT solidification is needed. The objective of this paper is to evaluate the feasibility of a dual-probe heat pulse (DPHP) method to measure MFT solid percentage. Dual-probe heat pulse measurements were performed on three MFT samples, each at various solid percentages. A linear relationship ( = 0.9495 + 0.0558) was established between the DPHP-measured solid percentage () and that of oven-dry method (). Six additional MFT samples were collected and measured to validate the DPHP method. The specific heats of the six MFT solids were measured independently using a modulated differential scanning calorimetry method, and the sensitivity of DPHP-measured MFT solid percentage to the specific heat of MFT solids was evaluated. The result shows that the DPHP method can be used to accurately measure MFT solid percentages, and the accuracy can be further improved if the specific heat of the MFT solids is measured independently. PMID:25602345

  4. Petrographic, stratigraphic, and structural study of the Smackover gray sand (Jurassic) in north Louisiana

    SciTech Connect

    Miciotto, S.A.

    1980-01-01

    The gas-producing gray sand, a dark gray to black, very fine-grained sand, occurs as 3 sand tongues in the lower member of the Smackover Formation in the subsurface of Bossier, Webster, Claiborne, and Lincoln parishes, Louisiana. A Flaser-bedded silty shale facies indicates deposition on a mid-tidal flat environment. Smackover deposition during the Jurassic in the study area was located on the gently dipping slope between a broad coastal shelf to the north and a basin to the south. The gray sand was deposited over the Norphlet formation and Louann salt before flowage and swelling of the Louann salt began. Uplift and swelling of the Louann salt later in the Jurassic created growing anticlines; sediment slumped off the structural highs of the growing salt anticlines into basinal muds and silts. The Smackover gray sand continues to challenge exploration geologists because of the lateral pinch out of its sand tongues. 11 references.

  5. Modeling fine-scale geological heterogeneity--examples of sand lenses in tills.

    PubMed

    Kessler, Timo Christian; Comunian, Alessandro; Oriani, Fabio; Renard, Philippe; Nilsson, Bertel; Klint, Knud Erik; Bjerg, Poul Løgstrup

    2013-01-01

    Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated on till outcrops producing binary images of geological cross-sections capturing the size, shape and distribution of individual features. Sand lenses occur as elongated, anisotropic geobodies that vary in size and extent. Besides, sand lenses show strong non-stationary patterns on section images that hamper subsequent simulation. Transition probability (TP) and multiple-point statistics (MPS) were employed to simulate sand lens heterogeneity. We used one cross-section to parameterize the spatial correlation and a second, parallel section as a reference: it allowed testing the quality of the simulations as a function of the amount of conditioning data under realistic conditions. The performance of the simulations was evaluated on the faithful reproduction of the specific geological structure caused by sand lenses. Multiple-point statistics offer a better reproduction of sand lens geometry. However, two-dimensional training images acquired by outcrop mapping are of limited use to generate three-dimensional realizations with MPS. One can use a technique that consists in splitting the 3D domain into a set of slices in various directions that are sequentially simulated and reassembled into a 3D block. The identification of flow paths through a network of elongated sand lenses and the impact on the equivalent permeability in tills are essential to perform solute transport modeling in the low-permeability sediments. PMID:23252428

  6. Anomalous sand deposit associated with evidence of late Holocene uplift near Bremerton, Washington

    NASA Astrophysics Data System (ADS)

    Martin, M. E.; Maxcia, C.; Gerardi, F.; Bourgeois, J.

    2007-12-01

    The origins of a puzzling sand unit at the head of Sinclair Inlet likely include a Puget Sound tsunami and its return flow but may also include sand volcanoes, debris flows, or both.. The inlet, a branch of Puget Sound 22 km west of Seattle, contains at its head an intertidal mudflat that is fringed by partly urbanized tidal marshes and alder swamps. Cores and pits in these remnant wetlands reveal an abrupt upward change from tidal flats to freshwater forest that probably resulted from uplift during the Seattle fault earthquake of A.D. 900-930 or during slip of similar age on the Tacoma fault. The puzzling sand unit formed at or about the time of this uplift. The unit consists of silty fine sand commonly 1 m in thickess. It has a sharp contact with shelly mudflat deposits below and a sharp to gradational contact with overlying peat. The lower part of this peat contains the growth-position roots of western red cedar (Thuja placata), and the upper part forms the soil of modern salt marshes. We found the sand unit, 1.1 m thick in areas, along 0.5 km of the upper inlet's shoreline, beneath modern tidal marshes and alder swamps. The unit contains at least three parts: a basal subunit that fines upward from medium and coarse sand to fine sand and silt; a thin (less than 1 cm thick) clay bed, commonly with flame structures; and a capping subunit up to 50 cm thick that is dominated by silty fine to medium sand but which also contains pebbles derived from rock and glacial outwash. Preliminary diatom analysis shows the unit contains diatoms from a brackish environment. A possibly related sand unit lies 0.8 km inland, up the valley of Gorst Creek. Its thickness is in the range 0.2-1.0 m as observed thus far in creek banks and in pits at a nearby park. Unlike the sand that borders the inlet, it contains trough cross-bedding. We are investigating the relationship between this deposit and the silty sand deposit in the tide flats. Preliminary diatom analysis did not find any diatoms in this deposit.

  7. Provenance and glacial history of very fine quartz sand from the Weddell Sea, Antarctica

    E-print Network

    Smith, Caryn Hallett

    1988-01-01

    and me, hanical surface textures and is considered multicyclic sediments derived rom the Northern Antarctic Peninsula or Beacon type rocks on East Autarch~ca. Downhole variatior. in these sand types at ODP site 694 suggests that the central basin wa... Mountains (modified from Sclsnidt and Ford, 1969) 16 Generalized geologic map of the Ellsworth Mountains (modified from Craddock, 1969). 18 Jurassic to Pleistocene stratigraphy of the West Antarctic formations adjacent to the Weddell Sea. 19 10...

  8. Fine dust emissions in sandy and silty agricultural soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dust emissions from strong winds are common in arid and semi-arid regions and occur under both natural and managed land systems. A portable field wind tunnel has been developed to allow measurements of dust emissions from soil surfaces to test the premise that dust concentrations are highly correlat...

  9. The effect of fines upon the compaction characteristics of a well graded sand

    E-print Network

    Long, Robert Eugene

    1954-01-01

    ' or meohanioal analysis. 1 The mechanical analysis and Atterberg Limits were determined by following the procedures outlined by Lambe. Liquid and plastic limit 2 determinations were made for all of the fine-grained soils used in this investigation. Table I..., 1960. 2. Lambe, T. N. , "Atterberg Limits and Indioes, " Soil Testing John Miley ds Sons, Inc. I. Y. , H. Y. , 1951, p. p. -22. TABLE 1 SOIL CONSTANTS 23 Type of Fines Send Liquid Limit 20. 4 Plastic Limit 16. 6 Plasticity Index Opt...

  10. Growth and reproduction assessment of fathead minnows inhabiting an oil-sands fine tailings pond

    SciTech Connect

    Siwik, P.; Paszkowski, C. [Univ. of Alberta, Edmonton, Alberta (Canada); Heuvel, M.R. van den; Dixon, D.G. [Univ. of Waterloo, Ontario (Canada); Boerger, H.; Meer, T. van; McKinnon, M. [Syncrude Canada Ltd., Fort McMurray, Alberta (Canada)

    1995-12-31

    The objective of this study was to assess the relative success of fathead minnows (Pimephales promelas) in Syncrude`s Large Scale Wet Option Fine Tailings Demonstration Pond (DP). The DP is a 4-ha pond, constructed in 1993, containing 69,000 m{sup 3} of fine tailings capped with 73,790 m{sup 3} of natural water. Endpoints associated with growth and reproduction, including total length, weight, body condition factor, number of eggs laid, and % hatch were monitored in DP and other ponds, in 1995 and 1996. Relative exposure to PAHs were estimated using the biochemical indicators 7-ethoxyresorufin-O-deethylase (EROD) and bile PAH metabolites. Data were collected through regular sampling, and the introduction and monitoring of breeding boards. The length frequency distribution of the minnows in DP was significantly different from other sites and age suggested that larval recruitment during the 1994 breeding season was low or absent. Spawning was delayed in DP. Liver EROD activity in the DP fish was slightly induced during the spring but not during the fall, indicating negligible exposure to EROD inducing compounds. Reproductive endpoints and bile PAH metabolite results will be discussed.

  11. ORIGINAL PAPER Historical sand injections on the Mediterranean shore

    E-print Network

    Marco, Shmuel "Shmulik"

    ORIGINAL PAPER Historical sand injections on the Mediterranean shore of Israel: evidence Springer Science+Business Media Dordrecht 2014 Abstract The abundant silt and sand along the coastal plain field evidence for it. We report the first finding of typical liquefaction features and silty sand

  12. Cyclic stress-strain and liquefaction characteristics of sands

    Microsoft Academic Search

    Alarcon-Guzman

    1986-01-01

    Liquefaction of saturated sand and silty sand deposits has been recognized as a major cause of damage during earthquakes. However, in spite of many research studies during the past two decades, there are still conflicting opinions on critical aspects of the phenomenon of soil liquefaction, including the definition of the term liquefaction. For these reasons, a research program on the

  13. Kemik sandstone: inner shelf sand from northeast Alaska

    SciTech Connect

    Melvin, J.

    1986-05-01

    The upper Neocomian Kemik Sandstone crops out in and around Ignek Valley in northeast Alaska. It lies unconformably on the Jurassic to Lower Cretaceous Kingak Shale, and is overlain by the Hauterivian to Barremian Pebble shale. It is a fine-grained, glauconitic quartzose sandstone, up to 120 ft thick. Four lithofacies are recognized: (1) a basal, moderately well-sorted pebble conglomerate; (2) fine to very fine-grained, laminated and bioturbated sandstones; (3) a poorly sorted conglomerate; and (4) low-angle to hummocky cross-stratified fine-grained sandstones. Facies relationships suggest that the basal conglomerate represents a transgressive lag deposit. It is overlain by a sequence comprising laminated and bioturbated sandstones with interbedded, poorly sorted conglomerates. The sandstones exhibit a mixed assemblage of ichnofossils, including Gyrochorte, Muensteria, Ophiomorpha, Planolites, and Skolithos, and (.)Conichnus. In places, they grade upward from low-angle laminations to symmetrical ripple forms to silty laminated deposits. Their upper parts are bioturbated, but to varying extent. these sandstones and the conglomerates were deposited abruptly but sporadically below storm wave base by storm-generated currents. The sandstones were subsequently modified by strong but waning oscillating storm waves. The hummocky cross-stratified sediment comprises an upper sequence that was probably deposited under the influence of storm-induced conditions between fair-weather and storm wave base. The Kemik Sandstone represents a storm-deposited inner shelf sand with regressive characteristics, deposited within an overall transgressive setting.

  14. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

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

  15. Relict sand wedges in southern Patagonia and their stratigraphic and paleo-environmental significance

    NASA Astrophysics Data System (ADS)

    Bockheim, J.; Coronato, A.; Rabassa, J.; Ercolano, B.; Ponce, J.

    2009-06-01

    Relict sand wedges are ubiquitous in southern Patagonia. At six sites we conducted detailed investigations of stratigraphy, soils, and wedge frequency and characteristics. Some sections contain four or more buried horizons with casts. The cryogenic features are dominantly relict sand wedges with an average depth, maximum apparent width, minimum apparent width, and H/W of 78, 39, 3.8, and 2.9 cm, respectively. The host materials are fine-textured (silt loam, silty clay loam, clay loam) till and the infillings are aeolian sand. The soils are primarily Calciargidic Argixerolls that bear a legacy of climate change. Whereas the sand wedges formed during very cold (-4 to -8 °C or colder) and dry (ca. ?100 mm precipitation/yr) glacial periods, petrocalcic horizons from calcium carbonate contributed by dustfall formed during warmer (7 °C or warmer) and moister (?250 mm/yr) interglacial periods. The paleo-argillic (Bt) horizons reflect unusually moist interglacial events where the mean annual precipitation may have been 400 mm/yr. Permafrost was nearly continuous in southern Patagonia during the Illinoian glacial stage (ca. 200 ka), the early to mid-Pleistocene (ca. 800-500 ka), and on two occasions during the early Pleistocene (ca. 1.0-1.1 Ma).

  16. sand mold

    NASA Astrophysics Data System (ADS)

    Kova?evi?, Lazar; Terek, Pal; Mileti?, Aleksandar; Kakaš, Damir

    2014-08-01

    Interfacial heat transfer coefficient at the metal-mold interface (IHTC) was estimated by an iterative algorithm based on the function specification method. An Al-9 wt% Si alloy plate casting was made in a sand mold prepared by CO2 process. Thermal history obtained from the experiment was used to solve an inverse heat conduction problem. Acquired transient IHTC values are then given in function of the casting surface temperature at the interface. By comparing the obtained results with previous findings, the influence of grain fineness number and consequently of mold roughness on maximum IHTC values is revealed.

  17. Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

    PubMed Central

    Wu, Yankai; Li, Yanbin; Niu, Bin

    2014-01-01

    Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10?mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment. PMID:24982951

  18. Assessment of the mechanical properties of sisal fiber-reinforced silty clay using triaxial shear tests.

    PubMed

    Wu, Yankai; Li, Yanbin; Niu, Bin

    2014-01-01

    Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10?mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment. PMID:24982951

  19. CYCLIC STRESS-STRAIN AND LIQUEFACTION CHARACTERISTICS OF SANDS. (VOLUMES I AND II)

    Microsoft Academic Search

    ADOLFO ALARCON-GUZMAN

    1986-01-01

    Liquefaction of saturated sand and silty sand deposits has been recognized as a major cause of damage during earthquakes. However, in spite of many research studies during the past two decades, there are still conflicting opinions on critical aspects of the phenomenon of soil liquefaction, including the definition of the term \\

  20. A TOXICITY IDENTIFICATION EVALUATION OF SILTY MARINE HARBOR SEDIMENTS TO CHARACTERIZE PERSISTENT AND NON-PERSISTENT CONSTITUENTS

    EPA Science Inventory

    Sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. To investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity i...

  1. Chlorofluorocarbons as tracers of groundwater transport processes in a shallow, silty and aquifer

    SciTech Connect

    Cook, P.G. [Univ. of Waterloo, Ontario (Canada)] [Univ. of Waterloo, Ontario (Canada); [CSIRO Division of Water Resources, Glen Osmond (Australia); Schiff, S.L. [Univ. of Waterloo Ontario (Canada)] [Univ. of Waterloo Ontario (Canada); Solomon, D.K. [Univ. of Utah, Salt Lake City, UT (United States)] [Univ. of Utah, Salt Lake City, UT (United States); Plummer, L.N.; Busenberg, E. [Geological Survey, Reston, VA (United States)] [Geological Survey, Reston, VA (United States)

    1995-03-01

    Detailed depth profiles of chlorofluorocarbons CFC-11 (CFCl{sub 3}), CFC-12 (CF{sub 2}Cl{sub 2}) and CFC-113 (C{sub 2}F{sub 3}Cl{sub 3}) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined {sup 3}H peak has been tracked through time. Detailed vertical sampling has allowed CFC tracer velocities to be estimated to within 10%. Comparison with {sup 3}H profiles enables estimation of chlorofluorocarbon transport parameters. CFC-12 appears to be the most conservative of the CFCs measured. Sorption at this site is low (K{sub d} < 0.03), and degradation does not appear to be important. CFC-113 is retarded both with respect to CFC-12 and the respect to {sup 3}H (K{sub d} = 0.09-0.14). CFC-11 appears to be degraded both in the highly organic unsaturated zone and below 3.5 m depth in the aquifer, where dissolved oxygen concentrations decrease to below 0.5 mg L{sup -1}. The half-life for CFC-11 degradation below 3.5 m depth is less than 2 years. While apparent CFC-12 ages match hydraulic ages to within 20% (up to 30 years), apparent CFC-11 and CFC-113 ages significantly overestimate hydraulic ages at our field site. 37 refs., 9 figs., 3 tabs.

  2. Tar sands` asphaltic mixes

    SciTech Connect

    Akinrogunde, E.A. [Univ. of Stuttgart (Germany)

    1995-12-31

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

  3. SAND REPORT SAND2002xxxx

    E-print Network

    Newman, Alantha

    SAND REPORT SAND2002­xxxx Unlimited Release August 2002 Discrete Optimization Models for Protein://www.ntis.gov/ordering.htm DEPARTMENTOF ENERGY . . UNITED STATES OF AMERICA #12; SAND2002-xxxx Unlimited Release Printed August 2002

  4. Mystery Sand

    NSDL National Science Digital Library

    2012-06-08

    In this activity, learners play with surprising sand that doesn’t get wet! Learners explore how water behaves differently when it comes in contact with "magic sand" and regular sand. Learners learn about the hydrophobic properties of "magic sand." Use this activity to talk about how many materials behave differently at the nanoscale.

  5. Texture development in naturally compacted and experimentally deformed silty clay sediments from the Nankai Trench and Forearc, Japan

    NASA Astrophysics Data System (ADS)

    Schumann, Kai; Stipp, Michael; Leiss, Bernd; Behrmann, Jan H.

    2014-12-01

    The petrophysical properties of fine-grained marine sediments to a large extent depend on the microstructure and crystallographic preferred orientations (CPOs). In this contribution we show that Rietveld-based synchrotron texture analysis is a new and valuable tool to quantify textures of water-saturated fine-grained phyllosilicate-rich sediments, and assess the effects of compaction and tectonic deformation. We studied the CPO of compositionally almost homogeneous silty clay drillcore samples from the Nankai Accretionary Prism slope and the incoming Philippine Sea plate, offshore SW Japan. Basal planes of phyllosilicates show bedding-parallel alignment increasing with drillhole depth, thus reflecting progressive burial and compaction. In some samples calcite and albite display a CPO due to crystallographically controlled non-isometric grain shapes, or nannofossil tests. Consolidated-undrained experimental deformation of a suite of thirteen samples from the prism slope shows that the CPOs of phyllosilicate and calcite basal planes develop normal to the experimental shortening axis. There is at least a qualitative relation between CPO intensity and strain magnitude. Scanning electron micrographs show concurrent evolution of preferred orientations of micropores and detrital illite flakes normal to axial shortening. This indicates that the microfabrics are sensitive strain gauges, and contribute to anisotropic physical properties along with the CPO.

  6. Sources and distribution of fine quartz sand in the northeastern Gulf of Mexico: a paleogeographic reconstruction using fourier grain shape analysis

    E-print Network

    Bates, Charles Arthur

    1985-01-01

    30 40 0 20 40 60 80 Kilometers rd Q P ~, Chandala r ' a4 6 ' Cll and . Ie n isla ds la a a O a Bistnn Oc m)IQ Ca yd No Samples Missile Test Area ) Grain Shape Type 1 0-25'/o 26-5046 Q 51-765th sr) 40 band dominated... to the shoreline. One type conta'. ns high proportions (51-76K) of grain roundness type one sand derived from the Appalachian Mountains and the other type contains a relative lower amount of this grain roundness type (Z6-5 0%) and therefo re represents sedi...

  7. Quantifying the role of sandy-silty sediments in generating slope failures during earthquakes: example from the Algerian margin

    NASA Astrophysics Data System (ADS)

    Dan, Gabriela; Sultan, Nabil; Savoye, Bruno; Deverchere, Jacques; Yelles, Karim

    2009-06-01

    The Algerian margin is a seismically active region, where during the last century, several large magnitude earthquakes took place. This study combines geotechnical and sedimentological data with numerical modelling to quantitatively assess the present-day slope stability of the Algerian margin. Geotechnical laboratory tests, such as cyclic triaxial tests, oedometric tests and vane shear tests were carried out on sediment cores collected on the study area. The liquefaction potential of a sediment column located about 30 km from the Boumerdès earthquake epicentre of 21st May 2003 was evaluated theoretically for an earthquake of M w = 6.8. We show that thin sand and silt beds such as those described on recovered sediment cores are the main cause of sediment deformation and liquefaction during earthquakes. Numerical calculations showed that the slope failure may occur during an earthquake characterised by a PGA in excess of 0.1 g, and also that, under a PGA of 0.2 g liquefaction could be triggered in shallow silty-sandy deposits. Moreover, comparison of the predicted slope failure with failure geometries inferred from seafloor morphology showed that earthquakes and subsequent mass movements could explain the present-day morphology of the study area.

  8. Sand Stories

    NSDL National Science Digital Library

    Hilary Christensen

    The objective of this project is to use a sample of sand from a give are to tell its geologic history. Each student is given a 50 mL tube of sand labeled with the latitude and longitude of where it was found. They must then use this information along with analysis of the sand itself to tell the story of its formation.

  9. Accumulation and movement of residual phosphorus in sludge?treated Decatur silty clay loam soil

    Microsoft Academic Search

    Pauline V. Lindo; Robert W. Taylor; James W. Shuford; Domy C. Adriano

    1993-01-01

    Phosphorus (P) is generally known to be immobile in soils due to several factors that include fixation processes. Nevertheless, this study has attempted to evaluate the accumulation and\\/or movement of residual P in previously sewage sludge?amended plots of a Decatur silty clay loam, six years after the final of five consecutive annual applications of Huntsville and Chicago sludges at 20

  10. Original article Mechanical behaviour of silty clay loam/peat mixtures

    E-print Network

    Paris-Sud XI, Université de

    Original article Mechanical behaviour of silty clay loam/peat mixtures: cyclic compression or amended with 20 or 40 % by volume of spagh- num peat, were studied at different values of water contentPa is increased to about 55 and 115 % for 20 and 40 % peat contents, respectively. A comparison of the cyclic test

  11. 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)

  12. Discovering Sand and Sand Paintings

    NSDL National Science Digital Library

    John Eichinger

    2009-05-30

    This activity blends social studies and art with math and science. First, students will explore the visible characteristics of sand, and then they will make Navajo-style sand paintings with paper, glue, and colored sand. In the process, they will hone the

  13. Study on Dynamic Properties of Saturated Clay and Undisturbed Silty Clay

    Microsoft Academic Search

    Ying Nie; Maotian Luan; Qi Shao; Shujie Liu; Meng Wang

    The testing is employed to perform cyclic torsional shear test under isotropic consolidated condition. The authors conducted\\u000a three dynamic torsional with single sample achieving dynamic properties under three confining pressures with saturated clay\\u000a and undisturbed silty clay in Dalian. Special attention was paid to the maximum dynamic shear modulus G\\u000a maxand ? obtained from single sample of cyclic simple shear

  14. Moist Olive Husks Addition to a Silty Clay Soil: Influence on Microbial and Biochemical Parameters

    Microsoft Academic Search

    PIERO PERUCCI; STEFANO DUMONTET; CRISTIANO CASUCCI; MORRIS SCHNITZER; HENRI DINEL; ELGA MONACI; COSTANTINO VISCHETTI

    2006-01-01

    To investigate the effects of moist olive husks (MOH-residues) on soil respiration, microbial biomass, and enzymatic (o-diphenoloxidase, ?-glucosidase, dehydrogenase and alkaline phosphatase) activities, a silty clay soil was incubated with 0 (control), 8 × 10 (D), 16 × 10 (2D) and 80 × 10 (10D) kg ha of MOH-residues on a dry weight basis. Soil respiration and microbial biomass data indicated that the addition of MOH-residues

  15. High resolution sequence stratigraphic and reservoir characterization studies of D-07, D-08 and E-01 sands, Block 2 Meren field, offshore Niger Delta

    E-print Network

    Esan, Adegbenga Oluwafemi

    2004-09-30

    - to fine-grained poorly-sorted sandstone (delta front facies); (5) muddy silt-to fine- grained wavy-bedded sandstone (lower shoreface facies); (6) very-fine- to fine-grained iv sandy mudstone (lower shoreface facies); and (7) massive, silty shales.... The progradational parasequence set consists of upward-coarsening delta front to upper shoreface facies, whereas the upward- fining retrogradational parasequence sets are composed of middle to lower shoreface deposits overlain by offshore marine shales...

  16. Sand Dunes

    NSDL National Science Digital Library

    Enright, Rachel

    Most will agree that nothing is more relaxing that lying or walking on a beach. While unwinding, have you ever wondered what caused those big mounds of sand that you crossed to get there? This topic in depth addresses this issue, featuring Web sites that discuss sand dune processes and formations. Some of the Web sites also discuss research, mining, and protection activities taking place in areas with sand dune.The Environment Bay of Plenty in New Zealand has an online brochure (1) dealing with the coastal processes that form sand dunes and beaches. From this site, users can obtain a general understanding of how dunes change with time. Ted Brambleby developed the second site (2) for the Marine Education Society of Australasia, Inc. This site gives a great overview of the functions and formations of dunes as well as describing their unique beauty and strategies on how to care for the dunes. Produced by Nova Scotia Museum of Natural History, the third site (3) is an online pamphlet discussing the physical features and locations of sand dunes in Nova Scotia. Visitors can also read about the ecosystem supported by these dynamic features. The forth site (4), created by John Mangimeli for the National Park Service, is a review of the scientific research completed throughout the years dealing with the geology of sand dunes. Visitors will find a more in-depth discussion about sand movement, sand accumulation, and sand dune features. The fifth site is a scientific paper (5 ) written by R.L. Van Dam, et al. Studying the long term evolution of the Parengarenga Sandspit, these researchers used ground penetrating radar (GPR) "to (1) explore the possibilities for mapping lateral continuity of the coffee rock, (2) study the sedimentary architecture and stratigraphy of the solitary dunes, and (3) reconstruct the wind regime on the sandspit." The next two sites discuss the threats to sand dunes and activities taking place to protect them. The Lake Michigan Federation addresses the issues of mining (6). Visitors can learn about alternatives to mining dune sand and the ecological values of dunes. The Department of Environmental Quality in Michigan created a site (7) that provides users with statistical information dealing with the amount of sand harvested, the regulations of mining, and maps of critical dune areas. After learning about the formation, processes, threats, and protections efforts; the last site (8), created by Eva Hornecker with the University of Bremen, will allow users to get a real sense of the beauty of the sand dunes. The site features a collage of spectacular images of the Great Sand Dunes in the San Luis Valley.

  17. Sand Dunes

    NSDL National Science Digital Library

    2012-06-26

    This outdoor activity (on page 2 of the PDF) is a full inquiry investigation into how the amount of moisture in a sand dune relates to the number of plants growing there. Groups of learners will scout at least two locations in a sandy area, count the number and types of plants in contact with a 10 meter line, and then sample the moisture in the top 30 cm of sand in each location, graphing their results to analyze their data. Relates to linked video, DragonflyTV: Sand Dunes.

  18. 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)

  19. Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Xiujuan; Hutchinson, Deborah R.; Wu, Shiguo; Yang, Shengxiong; Guo, Yiqun

    2011-05-01

    Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190-221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (Rt) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone.

  20. Long-term leaching of trace elements in a heavily sludge-amended silty clay loam soil

    SciTech Connect

    McBride, M.B.; Richards, B.K.; Steenhuis, T.; Spiers, G.

    1999-09-01

    Analysis by ICP-MS of shallow groundwater collected at a field site in New York that had been heavily loaded with sewage sludge more than 15 years earlier revealed elevated concentrations of Cu, Zn, Sr, Rb, Mo, Cd, As, Cr, Ni, Sb, W, Ag, Hg, and Sn compared with a nearby control site. Enhanced leaching of some elements from this near-neutral, fine-textured (silty clay loam) soil could be explained by exchange of soil-bound elements by components of the added sludge. For most of the heavy metals, however, increased leaching was a response to the high metal loadings in the soil, probably facilitated by higher dissolved organic matter in the leachate. Laboratory-determined distribution coefficients, K{sub D}, for the metals in newly prepared sludge/soil mixtures were lower than K{sub D} values of the field-aged sludge-treated soil, suggesting that metal mobility may have been substantially higher shortly after sludge application than many years later. Cumulative losses of certain trace elements from the topsoil have been estimated relative to Cr, a comparatively immobile element. These suggest that relative long-term losses range from 20 to 80%, with the order being: Sr, Mo, Sb {gt} Ni, Cd, Cu {gt} Zn, Ag. Generally, those elements with the smallest K{sub D} values (most soluble) measured recently in the soil had the largest loss estimates. However, present leaching loss rates are too slow to explain the estimated relative losses of several of these elements from the topsoil over the 15 or more years since sludge application.

  1. Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea

    USGS Publications Warehouse

    Wang, X.; Hutchinson, D.R.; Wu, S.; Yang, S.; Guo, Y.

    2011-01-01

    Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190-221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (Rt) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone. Copyright 2011 by the American Geophysical Union.

  2. Hydraulic filling of dams constructed of silty soils, using a flattened profile

    Microsoft Academic Search

    D. L. Melamut; L. G. Borodulina

    1973-01-01

    Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Construction experience and experimental investigations established that it is advantageous to use silty soils for the construction\\u000a of dams with a flattened profile, consisting of a downstream impervious shoulder (hydraulic fill) and upstream wave-resistant\\u000a ramp (dumped material). This design eliminates the construction of massive shoulders of gravel-pebble material which are needed\\u000a in hydraulic filling of compressed dams of

  3. Liquefaction characteristics of a fine sand

    E-print Network

    Brandon, Donald Timothy

    1974-01-01

    percent minus 0. 002 mm 3. Atterberg limits - Nonplastic This material has many advantages for use on partly saturated soils because it is nonplastic, thus its material properties should remain relatively constant, and it is capable of achieving very...

  4. Sand Babies

    NSDL National Science Digital Library

    2013-07-30

    In this math lesson, learners explore and investigate measurement using standard and non-standard units. First, learners round their birth weight to the nearest pound and construct a bar graph displaying the weights of the entire group. Next, learners measure and place enough sand into a plastic bag to equal their birth weight. With construction paper, crayons and markers, they draw a head, arms, and legs and turn the bags into sand babies. At centers, learners also investigate other types of measurements using non-standard plastic links to measure parts of their body and square tiles to measure the area of a footprint.

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

    USGS Publications Warehouse

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

    2007-01-01

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

  6. 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).

  7. SAND REPORT SAND2003-3410

    E-print Network

    Ho, Cliff

    SAND REPORT SAND2003-3410 Unlimited Release Printed September 2003 Chemiresistor Microsensors://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online 2 #12;SAND2003-3410 Unlimited Release Printed September 2003 Chemiresistor Microsensors

  8. SAND REPORT SAND2003-0799

    E-print Network

    Ho, Cliff

    SAND REPORT SAND2003-0799 Unlimited Release Printed March 2003 Field Demonstrations://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2003-0799 Unlimited Release Printed March 2003 Field Demonstrations

  9. Beach Sand

    NSDL National Science Digital Library

    Francis Eberle

    2005-01-01

    The purpose of this assessment probe is to elicit students' ideas about weathering, erosion, deposition, and landforms. It is designed to determine if students recognize that sand on a beach may have come from distant mountains and landforms as a result of the weathering of rock, subsequent erosion, and deposition.

  10. Directional response of a reconstituted fine-grained soil - Part I: experimental investigation

    Microsoft Academic Search

    Daniele Costanzo; Gioacchino Viggiani; Claudio Tamagnini

    2006-01-01

    This paper discusses the results of a large experimental program designed to investigate in a systematic manner the main features of the incremental response of fine-grained soils. The results are obtained from triaxial stress probing experiments carried out on a French silty clay (Beaucaire Marl). All the tests have been performed on reconstituted specimens, normally consolidated to an initial state

  11. 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.

  12. Electroosmotic flow and the validity of the classical Darcy equation in silty shales

    NASA Astrophysics Data System (ADS)

    Revil, A.; Pessel, M.

    2002-05-01

    Electroosmotic flow represents the flow of pore water through a porous medium submitted to an electrical field or an electrical current density. A model is developed to describe the coupled electric/hydraulic flow problem in silty shales. The strength of electroosmotic flow is modeled here as a function of porosity, grain shape, pH, and ionic strength of the pore water. In the case of forced flow under a pore fluid pressure gradient, electroosmosis reduces the filtration velocity. This effect can be modeled by introducing an effective or apparent permeability into the classical form of the Darcy equation. This apparent permeability can be much smaller than the intrinsic permeability and becomes very sensitive to the salinity of the pore water.

  13. Bromide transport in a sandy and a silty soil - a comparative lysimeter study

    NASA Astrophysics Data System (ADS)

    Schober, L.; Iden, S. C.; Durner, W.

    2009-04-01

    The aim of this study was a comparison of bromide leaching through a silty and a sandy soil and the characterization of systematic differences in solute transport in these undisturbed soils of differing texture. The amount of seepage water and bromide concentrations in the water were measured in 5 lysimeters for each soil type for a period of 460 days. Additionally, meteorological data were measured next to the lysimeter station for this period. The water transport regime of the lysimeters was simulated by means of a numerical solution of the Richards equation using the software package HYDRUS 1D. The observed bromide transport was simulated by steady-state approximation, applying the simulation tool CXTFIT, which is implemented in the software package STANMOD, version 2.0. Analysis of the measured data showed that a correct reproduction of the water balance was possible, but required the adaptation of soil-dependent crop coefficients for the potential transpiration of Phacelia and Winter Rape. The mean bromide transport through the sandy soil could be approximately reproduced assuming a bromide uptake by plants. Observed double peaks of some of the individual breakthrough curves, however, indicated that the actual transport regime in the lysimeters was subject to local heterogeneity which cannot be covered by the effective one-dimensional transport model. Bromide transport through the silty soil showed an unexplained mass deficit of nearly 90 % of the applied bromide and the detection of a mean distinct bromide peak in seepage water after percolation of only 0.5 pore volumes. It was not possible to simulate this behaviour with an effective 1D equilibrium or nonequilibrium convection-dispersion model.

  14. 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

  15. Contrasting hydrological and mechanical properties of clayey and silty muds cored from the shallow Nankai Trough accretionary prism

    E-print Network

    Kanagawa, Kyuichi

    Nankai Trough accretionary prism Miki Takahashi a , Shuhei Azuma b,1 , Shin-ichi Uehara c , Kyuichi January 2013 Keywords: Clayey mud Silty mud Nankai Trough accretionary prism Permeability Failure strength Friction Two mud samples cored from the shallow (1000 mbsf) Nankai Trough accretionary prism at Site C0002

  16. Infiltration capacity and macroporosity of a silty-loamy soil under different tillage systems

    NASA Astrophysics Data System (ADS)

    Wahl, N. A.; Buczko, U.; Bens, O.; Hüttl, R. F.

    2003-04-01

    For soils under both agricultural and forest use, management and tillage practice have significant influence on different hydraulic properties. Under agricultural land use, the properties of the macropore system are, amongst others, a function of the applied management and tillage system (i.e. conventional vs. conservation tillage). Macropores are crucial to rapid infiltration of surface water and aeration of the soil. Low macroporosity will give rise to higher surface flow rates especially on sloping areas, thus enhancing the risk for higher erosion. Investigations were carried out near the town of Adenstedt (52^o00', 9^o56'), app. 50 km S of Hannover in Lower Saxony. The predominant soil in the study area is an eroded orthic Luvisol from glacial deposits with a predominant silty-loamy texture. The experimental site with two crop rotations has been run with two different tillage systems (e.g. conventional and conservative tillage) since 1990. In this study, the minimum radius of a macropore is set to r = 0.5 cm. Dye tracer experiments were performed with methylene blue that was sprayed on a confined irrigation plot. Staining patterns were recorded two hours later at defined depth increments and results of stained and unstained areas were manually digitized and processed with an appropriate GIS-software. Tension infiltrometer experiments were performed simultaneously with the dye tracer experiments using a tension infiltrometer (hood infiltrometer) at different hydraulic supply potentials and soils depths. Dye tracer experiments with methylene blue indicate a penetration depth of 120 cm on the reduced tilled plot as compared to the conventionally tilled plot (60 cm). Both tillage systems exhibit the highest density of macropores in the topsoil, ranging between 100 and 1.000 macropores per square meter. The conventionally tilled plot exhibits a higher number of macropores in the upper 20 cm than the reduced tilled plot while at greater soil depth, this holds true for the reduced tiled plot. Macroporosity derived from tension infiltrometer experiments yield results about one order of magnitude lower than those obtained by visual inventarization. The results indicate a greater continuity of vertically oriented macropores for soils with reduced tillage systems. Thus, in the context of a more effective prevention of flooding events in watersheds, tillage practices with reduced soil disturbance offer a means to decrease surface runoff by enhancing vertical drainage in agricultural areas with silty soils. However, the effect of this local-scale soil hydraulic property on the hydrological behavior on the scale of whole watersheds on the mesoscale (100--500 km^2) needs yet to be tested by simulations with physically based hydrological models.

  17. 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.

  18. Laboratory and field evaluation of an underwater sand height gage

    NASA Technical Reports Server (NTRS)

    Swift, D. J. P.; Mcgrath, D. G.

    1972-01-01

    An underwater sand height gage was investigated. This instrument consisted of two transducers, one screened and one unscreened. Laboratory experimentation included static and dynamic tests with three test sands--fine, medium, and coarse. Field tests were conducted at Rudee Inlet, Virginia Beach, Virginia. Test results showed a linear response to up to 10 inches of sand loading. Deviation observed in identical tests appeared to be due to variation in the density of sand. Density differences reflected varying packing styles which, in turn, were a consequence of grain size and flow regime. Further evaluations of the sand height gage reflect this instrument's potential.

  19. Thermal behavior of fine-grained soils. Building science series

    NASA Astrophysics Data System (ADS)

    Salomone, L. A.; Kovacs, W. D.; Wechsler, H.

    1982-11-01

    Laboratory thermal probe tests performed on an AASHTO standard reference material (a silty clay) showed that thermal resistivity (C. cm/watt) varies with soil moisture content and dry density. The tests were performed to correlate soil thermal behavior with the limit states of fine grained soils. Over 80 thermal resistivity measurements were made on specimens compacted to various densities and moisture contents. Results are presented which indicate that the optimum moisture content of soils and the Atterberg Limits can be correlated with the thermal behavior of fine grained soils.

  20. Estimating Particle-Size Distribution from Sand, Silt, and Clay Content

    NASA Astrophysics Data System (ADS)

    Roostaee, Maryam; Ghanbarian-Alavijeh, Behzad; Liaghat, Abdolmajid

    2010-05-01

    Particle-size distribution (PSD) is one of the soil properties which not only is used in estimation of soil water retention curve as well as unsaturated hydraulic conductivity, but also is applied in the most hydrological studies. Since the measurement of particle-size distribution, soil water retention curve and unsaturated hydraulic conductivity is time consuming and expensive especially in large scale hydrological investigations, in this study, a method was developed based upon the least squares optimization approach to estimate cumulative particle-size distribution from sand, silt and clay content. A revised form of van Genuchten retention model which has been previously applied to represent cumulative particle-size distribution was fitted to the measured three points of PSD, and its two unknown parameters such as N and Dg were determined. For this purpose, we used curve fitting toolbox of MATLAB software. Then estimated N and Dg values were applied to estimate cumulative particle mass for other particle radii in order to determine the whole shape of PSD. A total of 80 soil samples from the UNSODA database including 10 soil textures were selected to verify the presented method. We divided our database into three groups, (1) is coarse soil texture including sand, sandy loam and loamy sand (32 soil samples), (2) medium soil texture such as sandy clay loam, loam, silt loam (31 soil samples), and (3) fine soil texture including clay, sandy clay, silty clay and clay loam (17 soil samples). The RMSE value was calculated to evaluate the presented method. For groups 1, 2 and 3, the RMSE values were 0.071, 0.064, and 0.046, respectively. The linear regression between the estimated and measured cumulative particle mass showed that this method is capable for estimating PSD from three measured points. The line slope for groups 1, 2 and 3 were 0.93, 0.94 and 0.95, respectively, and correlation coefficient (R2) values were obtained greater than 0.96. For all 80 soil samples, the RMSE, R2 and line slope values were 0.062, 0.97 and 0.94 indicating the proposed method estimated PSD accurately. Acknowledgements The authors would like to acknowledge Dr. M.Th. van Genuchten for providing the UNSODA database used in this study.

  1. 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.

  2. SAND REPORT SAND2003-0112

    E-print Network

    Fuerschbach, Phillip

    SAND REPORT SAND2003-0112 Unlimited Release Printed January 2003 Cold War Context Statement Sandia://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2003-0112 Unlimited Release Printed January 2003 Cold War Context Statement

  3. SAND REPORT SAND2002-4135

    E-print Network

    Ho, Cliff

    SAND REPORT SAND2002-4135 Unlimited Release Printed December 2002 FY02 Field Evaluations of an In://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2002-4135 Unlimited Release Printed December 2002 FY02 Field Evaluations

  4. Sand particle dislodgement in windblown sand

    NASA Astrophysics Data System (ADS)

    Bo, Tian-Li; Li, Zheng; Zheng, Xiao-Jing

    2014-12-01

    The incipient motion of sand particle from sand bed plays a very important role in the prediction of windblown sand. In this paper, we proposed a new method for predicting the incipient motion of sand particle based on wind speed fluctuation as follows, when the wind speed is larger than the critical wind speed, if the total impulse on sand particle is larger than the critical impulse, incipient motion of sand particle would take place, otherwise if not. Furthermore, from the analysis of entrainment in the rolling and lifting modes, we come to the following conclusion. When the average wind speed is smaller than the critical wind speed, if the average wind speed is used to judge the incipient motion of sand particle, one will underestimate the number of sand particles jumping from the bed, if the instantaneous wind speed is used to judge incipient motion of sand particle, one will overestimate the number of sand particles jumping from the bed; When the average wind speed is larger than the critical wind speed, either the average or the instantaneous wind speeds is used to judge the incipient motion of sand particles, one will overestimate the number of sand particles jumping from the bed.

  5. Effects of fluvial abrasion on shapes of quartz sand grains

    SciTech Connect

    Peterson, M.; Mazzullo, J.

    1987-09-01

    The effects of abrasion on the shapes of medium and fine quartz sand grains that are transported through a 300-mi (500-km) stretch of the Mississippi River were determined by Fourier grain-shape measurement and scanning electron microscopy. The results indicate that the abrasion of medium and fine quartz sand grains in the low-gradient stream does not significantly affect their source-inherited shapes.

  6. Effects of Deposit-Feeding Macrofauna on Benthic Bacteria, Viruses, and Protozoa in a Silty Freshwater Sediment

    Microsoft Academic Search

    Claudia Wieltschnig; Ulrike R. Fischer; Branko Velimirov; Alexander K. T. Kirschner

    2008-01-01

    In microcosm experiments, we simultaneously tested the effects of increased numbers of deposit-feeding macrofauna (chironomids,\\u000a oligochaetes and cladocerans) on the standing stock, activities and interactions of heterotrophic bacteria, viruses, and bacterivorous\\u000a protozoa (heterotrophic nanoflagellates and ciliates) in the aerobic layer of a silty littoral freshwater sediment. On average,\\u000a bacterial secondary production was stimulated between 11 and 29% by all macrofaunal

  7. The extraction of bitumen from western tar sands. Annual report

    SciTech Connect

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  8. The extraction of bitumen from western tar sands

    SciTech Connect

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  9. Textural characteristics of the Nigerian tar sands

    NASA Astrophysics Data System (ADS)

    Enu, E. I.

    1985-05-01

    Extensive tar sands with reserves of about 41 billion barrels of oil are known to occur in Cretaceous terrigenous sediments in Ondo and Ogun States of Nigeria. The hydrocarbon occurs in two predominantly sandy zones separated by an 8 m thick oil shale. The lower (Horizon Y) is mostly quartz sand, 3-26 m thick. It shows an upward fining of grains and increased consolidation updip. The upper Horizon X is 10-22 m of sandstone with interbedded shales and siltstones. The sands are loosely consolidated. Cementing material is lacking, the grains being held together largely by the tarry oil. Porosity is about 30% and mean oil saturation in both zones is 12%. The recorded clay content (2-7%) is considerably lower than the average for Athabasca, Canada (10-25%) and may enhance the settling properties of the tailing ponds. The sands are water-wet, fine- to medium-grained, moderately well sorted, mesokurtic and positively skewed to near symmetrical. The Nigerian tar sands compare closely with the Athabasca sands in all the above textural parameters. They would thus be expected to show identical response to mining processing, except for the influence of higher ground-water table and the high humidity and ambient temperatures in Nigeria.

  10. Creating Sand Dunes

    NSDL National Science Digital Library

    1998-01-01

    This experiment demonstrates the formation and movement of sand dunes. Students will simulate the effects of wind using a hair dryer on bare sand, then add stones and grass to observe how the effects are changed. They should be able to explain how sand dunes are formed, what circumstances effect the movement or formation of sand dunes, and relate this information to soil conservation.

  11. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2012-01-01

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

  12. Industrial sand and gravel

    USGS Publications Warehouse

    Dolley, T.P.

    2013-01-01

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

  13. Responses of Red-Osier Dogwood to Oil Sands Tailings Treated with Gypsum or Alum

    Microsoft Academic Search

    E. Redfield; C. Croser; J. J. Zwiazek; M. D. MacKinnon; C. Qualizza

    2003-01-01

    or composite tailings (CT), are currently being inves- tigated. The application of composite or consolidated tailings (CT) technol- In the CT process, the fines and sand fractions are ogy provides Alberta's oil sands industry with a means of reducing treated with a coagulant aid to produce a nonsegregating the volume of the fines fraction in extraction tailings and allows mixture

  14. Sand Castle Saturation

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2005-01-01

    In this activity about saturation (page 1 of PDF), learners will build a series of sand castle towers using a 16 oz cup. Learners begin with completely dry sand and then add a ¼ cup of water to the sand for each successive tower, each time measuring the height and width of the resulting sand mound until they make a tower that maintains the shape of the cup. Relates to the linked video, DragonflyTV: Sand Dunes.

  15. Critical state of sand matrix soils.

    PubMed

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

    2014-01-01

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

  16. Wet Sand flows better than dry sand

    E-print Network

    Jorge E. Fiscina; Christian Wagner

    2007-11-19

    We investigated the yield stress and the apparent viscosity of sand with and without small amounts of liquid. By pushing the sand through a tube with an enforced Poiseuille like profile we minimize the effect of avalanches and shear localization. We find that the system starts to flow when a critical shear of the order of one particle diameter is exceeded. In contrast to common believe, we observe that the resistance against the flow of wet sand is much smaller than that of dry sand. For the dissipative flow we propose a non-equilibrium state equation for granular fluids.

  17. Evolution of radiative sand ridge field of the South Yellow Sea and its sedimentary characteristics

    Microsoft Academic Search

    Ying Wang; Dakui Zhu; Kunyuan You; Shaoming Pan; Xiaodong Zhu; Xinqing Zou; Yongzhan Zhang

    1999-01-01

    A sand ridge field of 22 470 km2 consists of fine sands and silts originally from the old Changjiang River sediment during the late Pleistocene period. Late\\u000a Holocene sand stratum with its well-preserved larmnary bedding of more clay particles reflects the influence from the Yellow\\u000a River. There are three genetic types of morphology of sand ridge field as follows: (i)

  18. Land Reclamation of Oil Sands Processing By-Products: An Aggregation Approach

    Microsoft Academic Search

    Xiaomei Li; Yongsheng Feng; Martin Y. P. Fung

    1998-01-01

    Re-establishment of self-sustaining ecosystems is a major challenge in the reclamation of land disturbed by oil sands mining operation. We explored the possibility of using oil sands mining by-products as reclamation materials for the disturbed lands. A procedure to artificially aggregate soils or soil-like materials using oil sands mining by-products, namely, mature fine tails(MFT), composite tails(CT), and tail- ings sand

  19. Effect of sand surface texture on the primary recovery of bitumen from the Athabasca oil sands

    SciTech Connect

    Smith, M.M.

    1986-01-01

    Fourier grain shape analysis and accompanying scanning electron microscopy were used to see whether the sand fraction characteristics varied within the Syncrude Canada Ltd. minesite and whether these might be associated with low primary recovery in sands otherwise expected to yield high primary recovery. Sand grains varied in surface roughness from very smooth to extremely irregular. Primary recovery of bitumen, via the Clarke Hot Water Extraction process, is reduced when oil remains in the primary tailings. Using a batch extraction unit simulator of the hot water extraction process and Fourier grain shape analysis the author found that the primary recovery of bitumen is reduced in marine zone when there is a high percentage of irregular (high surface area) grains in the oil sand. These irregular grains appear to be diagenetically altered quartz and rock fragments. The relationship exists that when there is a high proportion of irregular grains in the oil sand, oil is held by the rough surfaces of the sand grains in the primary tailings. Apparently the irregular sand is at least partially oil wet and so oil accumulates with such grains in the primary tails. Thus when the proportion of irregular sand is greater than 40%, oil stays in the tailings reducing the primary recovery. Analysis of these sands in thin section and by scanning electron microscopy shows an abundance of irregular grains which are mostly lithic fragments (volcanic and sedimentary rock fragments). It was postulated that these lithic fragments have different wettabilities than say smooth quartz grains of the channel sands. This may explain why low fines oil sands in the marine zone process so poorly.

  20. Mineral Sands Down Under

    NSDL National Science Digital Library

    This resource describes what mineral sands are, and discusses the heavy, dark-colored minerals that they contain (rutile, ilmenite, zircon, monazite). A map shows locations of mineral sands deposits in Australia.

  1. CONTRACTOR REPORT SAND927005

    E-print Network

    CONTRACTOR REPORT SAND92­7005 Unlimited Release UC­261 Fatigue of Fiberglass Wind Turbine Blade . #12;Distribution CategoryUC-261 SAND92-7005 UnlimitedRelease PrintedAugust 1992 FATIGUE OF FIBERGLASS

  2. Particle-Size Fractionation of Eolian Sand Along the Sinai-Negev Erg of Egypt and Israel

    NASA Astrophysics Data System (ADS)

    Roskin, J.; Katra, I.; Blumberg, D. G.

    2012-12-01

    This study examines changes in the eolian sand fractions along the west - east transport path of the northern Sinai Peninsula - northwestern (NW) Negev erg of Egypt and Israel. This erg is composed of active linear (seif) dunes in northern Sinai (its western part), and stabilized vegetated linear dunes (VLDs) in the NW Negev dunefield (its eastern part). Sand samples were analyzed for sand grain morphology, particle-size distribution and optically stimulated luminescence ages. Linear seif dunes differ from VLDs in their vegetation cover, linearity, and dynamics. Although both are continuous landforms with similar orientations and sand-grain roundness values, the linear dunes of Sinai are coarser-grained than the Negev VLDs. The VLDs have a significantly higher proportion of very fine sand (125-50 ?m) content and a varying but lower sand fining ratio defined as the ratio of fine sand percentage to very fine sand percentage. From these observations we infer that fractionation of sand occurred along the studied eolian transport path. Very fine sands are suggested to have been winnowed by saltation and low suspension from source deposits and sand sheets. We suggest that the very fine sand fraction of Nile Delta and Sinai sands has been transported downwind since the late middle Pleistocene. In the late Pleistocene, linear dunes reached the NW Negev due to last-glacial period windiness of intensities unprecedented today and probably larger sediment supply. Generally decreasing wind velocities and increasing precipitation along the west - east dune transport path enhanced vegetative cover in the northern Negev and enabled deposition of the very fine sand component that was also transported by low suspension. We hypothesize that these very find sands also probably compose a partial fraction of the northern Negev loess deposits, still farther downwind. Our results suggest that particle-size distribution can elucidate much about erg and dunefield history over timescales of a glacial-interglacial cycle.

  3. ACULEATA HYMENOPTERA OF SAND MOUNTAIN AND BLOW SAND MOUNTAINS, NEVADA

    E-print Network

    Hanks, Lawrence M.

    ACULEATA HYMENOPTERA OF SAND MOUNTAIN AND BLOW SAND MOUNTAINS, NEVADA R. W. Rust1, L. !\\1. Hanks collected from Sand !\\1ountain and Blow Sand Mountains, Nevada. Four species are considered new to science and none are considered endemic to ei ther dune area. Sand Mountain and Blow Sand Mountains were visited 19

  4. 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 ...

  5. Exploring Products: Nano Sand

    NSDL National Science Digital Library

    Nanoscale Informal Science Education Network

    2010-01-01

    In this activity, learners explore how water behaves differently when it comes in contact with "nano sand" and regular sand. Learners learn about the hydrophobic properties of "nano sand." Use this activity to talk about how many materials behave differently at the nanoscale.

  6. Fine Travel

    NSDL National Science Digital Library

    FineTravel Magazine, produced by Louis Bignami and Big-Ray Publications, is a webzine aimed "at the traveler, not the tourist." It contains first person account feature articles about interesting nooks and crannies of various travel destinations in the US and around the world. Updated weekly, it features a searchable and browsable archive of past FineTravel articles, as well as pointers to airline information, books and videos, and resorts. It is an informative and entertaining site for the Internaut interested in travel.

  7. Discrimination of active and inactive sand from remote sensing - Kelso dunes, Mojave Desert, California

    NASA Technical Reports Server (NTRS)

    Paisley, Elizabeth C. I.; Lancaster, Nicholas; Gaddis, Lisa R.; Greeley, Ronald

    1991-01-01

    Landsat TM images, field data, and laboratoray reflectance spectra were examined for the Kelso dunes, Mojave Desert, California to assess the use of visible and near-infrared (VNIR) remote sensing data to discriminate aeolian sand populations on the basis of spectral brightness. Results show that areas of inactive sand have a larger percentage of dark, fine-grained materials compared to those composed of active sand, which contain less dark fines and a higher percentage of quartz sand-size grains. Both areas are spectrally distinct in the VNIR, suggesting that VNIR spectral data can be used to discriminate active and inactive sand populations in the Mojave Desert. Analysis of laboratory spectra was complicated by the presence of magnetite in the active sands, which decreases their laboratory reflectance values to those of inactive sands. For this application, comparison of TM and laboratory spectra suggests that less than 35 percent vegetation cover does not influence the TM spectra.

  8. Compressibility of Unconsolidated, Arkosic Oil Sands

    Microsoft Academic Search

    C. T. SAWABINI; G. V. CHILINGAR; D. R. ALLEN

    1974-01-01

    Presented are results of compaction of 11 unconsolidated, fine- to medium-grained, arkosic sand cores, 1-7\\/8 in. in diameter and 3 to 4 in. long. Direct measurements of the pore fluid pressure and bulk volume changes of each sample were made as the pore fluids were expelled. At a constant overburden (external) pressure of 3,000 psi and a temperature of 140°F,

  9. Fine Arts.

    ERIC Educational Resources Information Center

    Danzer, Gerald A.; Newman, Mark

    1992-01-01

    Discusses the use of fine arts as sources to enrich the study of history. Suggests that such works will serve as barometers of change, examples of cross-cultural influences, and political messages. Includes suggestions of works and artists from different historic periods. (DK)

  10. The Effect of the Kind of Sands and Additions on the Mechanical Behaviour of S.C.C

    NASA Astrophysics Data System (ADS)

    Zeghichi, L.; Benghazi, Z.; Baali, L.

    The sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that investigated the influence of sand quality on the properties of fresh and hardened self-compacting concrete (SCC). The dune sands are very fine materials characterized by a high intergranular porosity, high surface area and low fineness modulus; on the other hand crushed (manufactured) sand has a high rate into thin and irregular shapes which are influencing the workability of concrete. The amount of dune sand varies from (0% 50%, to 100%) by weight of fine aggregates. The effect of additions is also treated (blast furnace slag and lime stone) The results show that the rheological properties favour the use of dune sands; however the mechanical properties support the use of crushed sand.

  11. Water purification using sand

    Microsoft Academic Search

    R. S. Wotton

    2002-01-01

    Slow sand filters are used to purify drinking water. Each filter consists of a large tank containing a bed of sand through which water passes at typical rates of 0.1–0.3 m h-1. Water is cleaned by physico–chemical and biological processes occurring at the air–water interface, within the bulk water, over the surface of the sand, and within the bed of

  12. 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.

  13. Sand Sea Wonders: Geology

    NSDL National Science Digital Library

    This site describes the geology of The Great Sand Dunes National Monument and Preserve. Active links allow students to explore the geologic timeline, geologic cross section in animation, and the wind regime. A reversing dune is shown in animation and other dunes such as star, parabolic, barchan, and transverse are discussed. Another section illustrates sand recycling by seasonal streams. A sand deposits map shows topography, dunes watershed, old national monument boundary, roads, and surface water and a section called 'How Much Sand' quantifies the description. Artwork on this site includes both adult and 'Hands on the Land' student artwork while photography depicts dunes, landscape, animals, plants, and human history.

  14. Processing of tar sands

    SciTech Connect

    Mitchell, T.O.

    1984-01-03

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

  15. Process and apparatus for recovery of oil from tar sands

    SciTech Connect

    Brewer, J.C.

    1982-11-30

    A crude oil product is extracted from a tar sand by first crushing the tar sand as mined and then fine grinding the crushed material in a grinding mill in the presence of a cleansing liquid, such as an aqueous solution of a caustic. The resulting slurry is passed into suitable extractor-classifier equipment, such as that shown in U.S. Pat. No. 3,814,336, in which a body of cleansing liquid is maintained. Agitation of the slurry in such maintained body of cleansing liquid substantially completes removal of the bituminous matter from the sand, and the resulting crude oil and cleansing liquid phase is discharged separately from the sand solid phase. The liquid phase is treated for the removal of residual sand particles and for the separation of residual cleansing liquid from the crude oil. The cleansing liquid so recovered is recycled and the crude oil is passed to further processing or for use as such.

  16. 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

  17. Comparison of tar sands and phosphatic clay tailings properties, disposal, and reclamation options

    SciTech Connect

    Ericson, W.A.; Carrier, W.D. III [BCI, Lakeland, FL (United States); Burns, R. [Suncor, Alberta (Canada)

    1995-12-31

    The tar sands industry of northern Alberta, much like the phosphate mining industry of Florida, is having to deal with the long term management of a fine-grained tailings waste. The production of synthetic crude from surface deposits of tar sands results in a combined tailings mixture of sand, bitumen, and clay. The phosphate industry bonification process separates the clay and sand waste streams at the plant and these materials are generally deposited in separate disposal areas. Both the tar sands fine tailings and the waste phosphatic clays exhibit engineering characteristics associated with highly plastic clays. This behavior is typically characterized by large changes in void ratio and permeability with changes in effective stress. Recent technology exchanges between the phosphate and tar sands industries reveal some encouraging opportunities for waste disposal and reclamation planning in the tar sands industry. Studies involving the mixing of mature fine oil sands tailings and sand (with and without chemical additives) have provided some improvements in the tar sands tailings material consolidation and permeability properties.

  18. 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)

  19. Fuels from tar sands

    SciTech Connect

    Woods, L.M.

    1986-03-01

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

  20. 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.

  1. 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).

  2. Recycled sand in lime-based mortars.

    PubMed

    Stefanidou, M; Anastasiou, E; Georgiadis Filikas, K

    2014-12-01

    The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime-pozzolan or lime-pozzolan-cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars' structure. PMID:25266158

  3. Flow and sand transport over an immobile gravel bed.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many dams in the USA and elsewhere have exceeded their design life and are being considered for remediation or removal, which will result in the reintroduction of fine sediments, often into coarse grained armored substrates, downstream of dams. The deposition of sand in the interstices of the grave...

  4. Sand, Plants and Pants

    NSDL National Science Digital Library

    2014-06-04

    In this activity, learners explore how the application of nano-sized particles or coatings can change a bigger material’s properties. Learners investigate the hydrophobic properties of plants, nano-fabric pants and magic sand.

  5. The Flow of Sand.

    ERIC Educational Resources Information Center

    Yersel, Metin

    2000-01-01

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

  6. Sand boils without earthquakes

    USGS Publications Warehouse

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

    1993-01-01

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

  7. Sand on the Move

    NSDL National Science Digital Library

    This site, from the National Park Service (NPS) and United States Geological Institute (USGS), gives a brief description of how sand dunes form. It describes how dunes will develop over time by repeating the processes of erosion, transportation, and deposition.

  8. 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.

  9. Magic Sand Movie

    NSDL National Science Digital Library

    This document from the Midwest Regional Center for Nanotechnology Education (NANO-LINK) is intended to be used with the other materials in the "magic sand" series of classroom lessons, which are available here. This resource is a 4 minute video demonstrating the magic sand experiment. In this experiment, students "will explore how the properties of a substance at the molecular level affects the way that it reacts and behaves."

  10. Sand Grain Observations

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2006-01-01

    In this activity (on page 1 of the PDF), learners will use a magnifier to carefully examine samples of sand from different locations. They record their observations regarding the different grain characteristics to formulate their own explanations of where the sand came from, why the grains are jagged or smooth, and how they may have been sorted. Relates to the linked video, DragonflyTV GPS: Earthquakes.

  11. Offshore sand for reinforced concrete

    Microsoft Academic Search

    W. P. S. Dias; G. A. P. S. N. Seneviratne; S. M. A. Nanayakkara

    2008-01-01

    A figure of 0.075% by weight of sand was arrived at as a safe limit for allowable Cl? ion content in offshore sand for OPC based reinforced concrete. A 2m high sand column was fabricated for checking the effects of natural drainage and simulated rain on the chloride levels in offshore sand, and the action of even 80mm of rain

  12. Aging effects on oil-contaminated Kuwaiti sand

    SciTech Connect

    Al-Sanad, H.A.; Ismael, N.F. [Kuwait Univ., Safat (Kuwait). Dept. of Civil Engineering

    1997-03-01

    Large quantities of oil-contaminated sands resulted from the destruction of oil wells and the formation of oil lakes in Kuwait at the end of the Gulf Wa/r. A laboratory testing program was carried out to determine the geotechnical properties of this material and the effect of aging on their properties. Tests included direct shear, triaxial, and consolidation tests on clean and contaminated sand at the same relative density. The influence of aging was examined by testing uncontaminated sand after aging for one, three, and six months in natural environmental conditions. The results indicated increased strength and stiffness due to aging and a reduction of the oil content due to evaporation of volatile compounds. The factors that influence the depth of oil penetration in compacted sand columns were also examined including the type of oil, relative density, and the amount of fines.

  13. A sedimentation device to produce uniform sand packs

    NASA Astrophysics Data System (ADS)

    Maillot, Bertrand

    2013-05-01

    In physical modelling using sand, the construction of a sand pack is one of the main experimental difficulties. Existing solutions are generally based either on delicate manipulations (pouring and scraping), or on motorized sedimentation devices, and the qualities of packs thus produced are known to affect experimental outcomes. However, uniformity, planarity, reproducibility and efficiency can be achieved with a simple sedimentation device without motors. A rectangular reservoir pierced with holes rests on a support plate pierced with wider holes. Sand flows when the reservoir is displaced so that its holes match those of the support plate. Sand jets are diffused by planar horizontal sieves, below which the sand sets into the experimental box. Tests on a 250 ?m median grain size sand show that the density is at its maximum value, reproducible, and uniform. The spatial variations are only of ± 0.4% of the mean density. Thickness of the sand layers shows spatial variations around ± 2% of the mean thickness, and 6% near the side walls. Very fine grains (90 ?m median grain size) produce less uniform and less planar packs because of their greater sensitivity to air currents caused by the sedimentation. According to direct shear tests the sand pack has a well defined static friction coefficient decreasing to a lower dynamic value after about 3 mm of slip with dilatancy. In contrast, poured sand packs, which are initially less dense, develop only the dynamic friction coefficient (no peak shear stress during slip), without dilatancy. Hole diameters, hole spacing, and the number and openings of the sieves are the parameters controlling the qualities of the sand pack for a given grain size distribution.

  14. Near-shore sand thickness and stratigraphy mapping with a submerged GPR antenna system; southeast Lake Michigan

    SciTech Connect

    Sauck, W.A.; Seng, D.L. (Western Michigan Univ., Kalamazoo, MI (United States))

    1994-04-01

    Twenty-one shore perpendicular profiles, spaced at nominal 5 km intervals, have been surveyed with a bottom-sled mounted Ground Penetrating Radar (GPR) antenna system between Benton Harbor, MI, and Gary, IN. Either a commercial 500 MHz or a custom 145 MHz antenna were used. The bottom sled also carried an upward looking SONAR transducer to give concurrent water depth, and was towed from the beach out to water depths of 6 meters or more, usually ending about 500 meters from shore. Bedding structures and details are clearly visible on the GPR sections within the sand bars and sand blankets. Bottom morphology and the nature of the sand bodies change markedly from the NE to the SW limits of the survey area. At the NE profiles there are multiple, pronounced (or high amplitude) offshore bars, with the substrate (glacial clay, shale, or silty sand) exposed or nearly exposed between bars. Internal structure is generally foreset or cross bedding in the bars. Sand was thin or missing immediately to the Sw of several other jetty structures in addition to the one at St. Joseph. In general the sand bars became much less pronounced to the SW, and internal structures were dominated by parallel bedding and subtle angular unconformities. Near St. Joseph, the exposed substrate is almost certainly being eroded, even to water depths as great as 6 meters. Thus, the equilibrium bottom profile continues to deepen shoreward, causing the continued threat of bluff erosion in spite of annual beach nourishment efforts at this site.

  15. 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.

  16. Sound-Producing Sand Avalanches

    NSDL National Science Digital Library

    Bretz, Michael

    This site presents an analysis of the theories and experiments done so far on sound-producing (e.g., roaring, booming) sand avalanches. Several reference articles are cited, and a link to the summary of an article, "Booming Sand", in Scientific American volume 277, number 3, is provided. An on site version of another article, "Sound Producing Sand Avalanches", in Contemporary Physics, volume 38, number 5, is also presented in three different formats: PDF, HTML, and Postscript Preprint.The other main features of this site are sound recordings of booming sand, compressed squeaking sand, and croaking sand, as well as, and images and micrographs of booming dunes.

  17. Determination of fine-scale vertical distribution of microbes and meiofauna in an intertidal sediment

    Microsoft Academic Search

    I. R. Joint; J. M. Gee; R. M. Warwick

    1982-01-01

    A simple sampling device is described which produces thin (1 mm) sections of sediment cores. The sampler has been tested on fine sand of an intertidal sandflat and used to study the vertical distribution, over part of a tidal cycle in August, 1981, of migrating algae in the surface 20 mm of sand. Two species of Diplonies and one of

  18. Sand Hill Rd. Junipero Serra

    E-print Network

    Stanford University

    Alpine 280 101 Campus Drive Sand Hill Rd. University Palm StockFarm Junipero Serra Page Mill Oregon Floor, South Wing right next to Peet's Coffee. Directions from 280 North or South - Exit Sand Hill Rd

  19. 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.

  20. 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…

  1. 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.

  2. Introduction Sand sole, Psettichthys melanostictus,

    E-print Network

    67(4) 9 Introduction Sand sole, Psettichthys melanostictus, is a common nearshore pleuronectid flat- fish in the northeast Pacific Ocean.Also known as fringe sole, spotted flounder, or sand flounder catches (Kramer et al., 1995). Commercial landings of sand sole in California, Oregon, and Wash- ington

  3. Thermal Recovery From Tar Sands

    Microsoft Academic Search

    Maurice Carrigy

    1983-01-01

    On the basis of the progress made in developing improved technology for recovery of bitumen from tar sands, it is logical to assume that as the world's supply of light and heavy oil is depleted, production of synthetic oil from the bitumen resources in tar sands will accelerate. As most of the known deposits of tar sands were discovered by

  4. WASTEWATER TREATMENT OVER SAND COLUMNS

    E-print Network

    Paris-Sud XI, Université de

    93/0096 WASTEWATER TREATMENT OVER SAND COLUMNS TREATMENT YIELDS, LOCALISATION OF THE BIOMASS. The study using sand columns has allowed simultaneous comparison, on the same profile, of biomass content twice as long as the flooding period. The sand depth will depend on the plant's overall water quality

  5. Depositional and diagenetic history of Bodcaw Sand, Cotton Valley Group (Upper Jurassic), Longwood field, Caddo Parish, Louisiana

    Microsoft Academic Search

    A. A. Sartin

    1984-01-01

    The Bodcaw Sand contains fine-grained sandstones and siltstones deposited within a barrier-bar sequence. Based on vertical changes in sedimentary structures, texture, and mineralogic composition, three distinct lithofacies (upper, middle, and lower shoreface) within the Bodcaw Sand and two associated logoonal lithofacies were identified. Cross-stratification and low-angle laminations, rarely disrupted by biogenic structures, characterize the fine-grained upper shoreface sandstones. Middle shoreface

  6. Bitumen recovery from tar sands

    SciTech Connect

    Miller, J.D.; Hupka, J.

    1984-09-11

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

  7. 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

  8. Magic Sand: Nanosurfaces

    NSDL National Science Digital Library

    Nanoscle Informal Science Education Network

    2014-06-18

    This is an activity/demo in which learners are exposed to the difference bewteen hydrophobic surfaces (water repelling) and hydrophilic surfaces (water loving). This activity also demonstrates how changing the size of material to nanoscale changes its behavior at the macroscale. The instructions assume that Magic Sand is performed as a demonstration, but it works great a a hands-on activity as well.

  9. Moving sand dunes

    E-print Network

    Sparavigna, Amelia Carolina

    2011-01-01

    In several desert areas, the slow motion of sand dunes can be a challenge for modern human activities and a threat for the survival of ancient places or archaeological sites. However, several methods exist for surveying the dune fields and estimate their migration rate. Among these methods, the use of satellite images, in particular of those freely available on the World Wide Web, is a convenient resource for the planning of future human settlements and activities.

  10. Sand Sieve Analysis

    NSDL National Science Digital Library

    Anderson, John

    John R. Anderson of Georgia Perimeter College has authored this lab experiment on grain size sorting in which students learn about performing a sieve analysis of sand and produce various graphs to represent the data collected. Included are equations for making the graphs and basic information on the importance of sieve analysis and the four useful statistical measurements used to make the graphs. This is a great resource to either the creation or enhancement of an instructors curriculum on this topic.

  11. Assessment of the KE Basin Sand Filter Inventory In Support of Hazard Categorization

    SciTech Connect

    Ross, Steven B.; Young, Jonathan

    2005-09-28

    In 1978, the water cleaning system for the KE Basin was upgraded by adding a sand filter and ion exchange columns. Basin water containing finely divided solids is collected by three surface skimmers and pumped to the sand filter. Filtrate from the sand filter is further treated in the ion exchange modules. The suspended solids accumulate in the sand until the pressure drop across the filter reaches established operating limits, at which time the sand filter is backwashed. The backwash is collected in the NLOP, where the solids are allowed to settle as sludge. Figure 2-1 shows a basic piping and instrumentation diagram depicting the relationship among the basin skimmers, sand filter, and NLOP. During the course of deactivation and decommissioning (D&D) of the K-Basins, the sand filter and its media will need to be dispositioned. The isotopic distribution of the sludge in the sand filter has been estimated in KE Basin Sand Filter Monolith DQO (KBC-24705). This document estimates the sand filter contribution to the KE hazard categorization using the data from the DQO.

  12. The extraction of bitumen from western oil sands: Volume 1. Final report

    SciTech Connect

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains an executive summary and reports for five of these projects. 137 figs., 49 tabs.

  13. The extraction of bitumen from western oil sands: Volume 2. Final report

    SciTech Connect

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains reports on nine of these projects, references, and a bibliography. 351 refs., 192 figs., 65 tabs.

  14. Sedimentological, Mineralogical and Geochemical Characterization of Sand Dunes in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Benaafi, Mohammed; Abdullatif, Osman

    2014-05-01

    Sedimentological, mineralogical, morphological and geochemical studies of sand dunes from ten locations in Saudi Arabia were conducted in order to determine the differences between them and to find out the provenance and tectonic setting of these sand dunes. Sixty seven samples were collected from different sand dunes types ranging in morphology from linear, barchans, parabolic to stars dunes. In overall, the sand dunes are fine to coarse grained mean grain size, moderately sorted, near symmetrical skewness with mesokurtic distribution characterized sand dunes in most locations. The sand dunes grains are subrounded in all locations except in the Red sea, Qassim, central Arabia and the eastern province which showed sub-angular grains. The main mineral compositions of studied aeolian sand dunes are quartz, feldspar, calcite, and mica. Quartz is the dominant mineral in locations with significant amount of feldspars and mica in Najran, Red sea and Central Arabia locations. Moreover, calcite is present in Sakaka and NW Empty Quarter (Jafurah). Basement related sand dunes in Najran, Central Arabia and Red sea locations are sub-mature in terms of their mineralogical maturity. Whereas, sand dunes in other locations are texturally mature except those from the Red sea which showed sub-mature sand. The sands are classified as quartz arenite, except in the basement related sand dunes in Najran, central Arabia and the Red sea are ranging from sub-arkose, sub-litharenite and lithraenite. Morphologically, parallel to sub-parallel sand ridges with NE-SW orientation occurred in east and north parts of Empty Quarter (Najran and Jafurah) and NW-SE orientation in Dahna and Nafud deserts in central and north regions of Saudi Arabia. Parabolic sand dunes characterized the Nafud desert (Hail, Sakaka, Tayma locations). Barchans and star sand dunes characterize the Empty Quarter (Jafurah). Major, trace, and rare earth elements studies were carried out to determine the composition, provenance and tectonic history of the sand dunes. Geochemical analysis indicated that most of sand dunes are quartz arenite type, except in the Red sea, basement related central Saudi Arabia and Najran areas, the sand dunes are sub-arkoses, sub-litharenite and litharenite. The concentration of major,trace and rare elements showed active continental margins as a tectonic setting of Red sea, basement related Najran and central Arabia sand dune. In contrast, passive continental margins for the other locations. The distribution of major, trace and rare earth elements showed similarity in chemical composition between basement related sand dunes in Red sea, Najran and central Arabia.

  15. Sand as a relevant fraction in geochemical studies in intertidal environments.

    PubMed

    Otero, X L; Huerta-Díaz, M A; De La Peña, S; Ferreira, T O

    2013-10-01

    Soil and sediment samples from several intertidal environment exposed to different types of contamination were studied to investigate the importance of grain size in relation to the capacity of the substrates to retain trace metals. The unfractionated samples (referred to as bulk samples) were separated into the following grain/size fractions: fine-coarse sand (2-0.100 mm), very fine sand (0.100-0.050 mm), silt (0.050-0.002 mm), and clay (0.002 mm). The sample into its fractions was carried out was in a glove box under high-purity N2 atmosphere in order to minimize any alterations to the samples. The bulk samples were characterized in terms of physicochemical properties such as pH, redox potential, and grain size. The total organic carbon (TOC), total sulfur (S), iron (Fe) pyrite, Fe, and manganese (Mn), and trace metals lead (Pb), mercury (Hg), chromium (Cr), and nickel (Ni) were analyzed in the bulk samples and in each fraction. The sand fractions were also examined by scanning electron microscopy (SEM). Comparisons of the above parameters were made between fractions and between each fraction and the corresponding bulk sample. The fine-coarse sand fraction contained high levels of the primary elements of the geochemical processes that occur in marine sedimentary environments such as TOC, total Fe, Mn, and S. The net concentrations of these four elements were higher in the fine-coarse sand fraction than in the very fine sand fraction and were similar to the net concentrations in the silt and clay fractions. Detailed SEM analysis of the sand coarse fraction revealed the presence of Fe and aluminum oxyhydroxide coatings in the oxic layers, whereas the framboidal pyrites and coatings observed in the anoxic layers were Fe sulfides. The presence of the various coatings explains why the trace metal concentrations in the sand fine-coarse fraction were similar to those in the clay fraction and higher than those in the very fine sand fraction. The present results highlight the importance of the sand fraction, which is generally disregarded in geochemical and environmental studies of sedimentary layers. PMID:23525774

  16. Paleobiology of the Sand Beneath the Valders Diamicton at Valders, Wisconsin

    NASA Astrophysics Data System (ADS)

    Maher, Louis J.; Miller, Norton G.; Baker, Richard G.; Curry, B. Brandon; Mickelson, David M.

    1998-03-01

    Previously undescribed pollen, plant macrofossils, molluscs, and ostracodes were recovered from a 2.5-m-thick glaciolacustrine unit of silty sand and clay at Valders, Wisconsin. The interstadial sediment was deposited about 12,200 14C yr B.P. after retreat of the Green Bay lobe that deposited diamicton of the Horicon Formation, and before advance of the Lake Michigan lobe that deposited the red-brown diamicton of the Valders Member of the Kewaunee Formation. Fluctuations of abundance of Candona subtriangulata, Cytherissa lacustris,and three other species define four ostracode biozones in the lower 1.7 m, suggesting an open lake environment that oscillated in depth and proximity to glacial ice. Pollen is dominated by Piceaand Artemisia,but the low percentages of many other types of long-distance origin suggest that the terrestrial vegetation was open and far from the forest border. The upper part of the sediment, a massive sand deposited in either a shallow pond or a sluggish stream, contains a local concentration of plant macrofossils. The interpretation of a cold open environment is supported by the plant macrofossils of more than 20 species, dominated by those of open mineral soils ( Arenaria rubella, Cerastium alpinumtype, Silene acaulis, Sibbaldia procumbens, Dryas integrifolia, Vaccinium uliginosumvar. alpinum, Armeria maritima,etc.) that in North America occur largely in the tundra and open tundra-forest ecotone of northern Canada. Ice-wedge casts occur in the sand.

  17. Investigation of guided waves propagation in pipe buried in sand

    SciTech Connect

    Leinov, Eli; Cawley, Peter; Lowe, Michael J.S. [NDE Group, Department of Mechanical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2014-02-18

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

  18. Investigation of guided waves propagation in pipe buried in sand

    NASA Astrophysics Data System (ADS)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J. S.

    2014-02-01

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

  19. Recycling of PET bottles as fine aggregate in concrete.

    PubMed

    Frigione, Mariaenrica

    2010-06-01

    An attempt to substitute in concrete the 5% by weight of fine aggregate (natural sand) with an equal weight of PET aggregates manufactured from the waste un-washed PET bottles (WPET), is presented. The WPET particles possessed a granulometry similar to that of the substituted sand. Specimens with different cement content and water/cement ratio were manufactured. Rheological characterization on fresh concrete and mechanical tests at the ages of 28 and 365days were performed on the WPET/concretes as well as on reference concretes containing only natural fine aggregate in order to investigate the influence of the substitution of WPET to the fine aggregate in concrete. It was found that the WPET concretes display similar workability characteristics, compressive strength and splitting tensile strength slightly lower that the reference concrete and a moderately higher ductility. PMID:20176466

  20. Recycling of PET bottles as fine aggregate in concrete

    SciTech Connect

    Frigione, Mariaenrica, E-mail: mariaenrica.frigione@unisalento.i [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy)

    2010-06-15

    An attempt to substitute in concrete the 5% by weight of fine aggregate (natural sand) with an equal weight of PET aggregates manufactured from the waste un-washed PET bottles (WPET), is presented. The WPET particles possessed a granulometry similar to that of the substituted sand. Specimens with different cement content and water/cement ratio were manufactured. Rheological characterization on fresh concrete and mechanical tests at the ages of 28 and 365 days were performed on the WPET/concretes as well as on reference concretes containing only natural fine aggregate in order to investigate the influence of the substitution of WPET to the fine aggregate in concrete. It was found that the WPET concretes display similar workability characteristics, compressive strength and splitting tensile strength slightly lower that the reference concrete and a moderately higher ductility.

  1. Imperial Sand Dunes

    NSDL National Science Digital Library

    The Bureau of Land Management presents the current news, projects, and the geologic and cultural history of the Imperial Sand Dunes at this website. Users can easily search through an abundance of remarkable images of dunes as well as other Californian landscapes. The website offers links to the current rules, regulations, and management plans. Individuals, who will be traveling to the area, can find the weather forecast, an events calendar, and information on volunteering. Visitors can locate archives of Federal Register Notices as well as news releases.

  2. 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.

  3. Identification and delineation of low resistivity, low permeability reservoirs using qualitative sidewall sample log k * S[sub O] relationships in the western shallow oil zone, Elk Hills Field, California

    Microsoft Academic Search

    E. K. Beacom; I. S. Kornreich

    1996-01-01

    Over 500 wells, including wells producing from the deeper Miocene Stevens sands, penetrate the Western Shallow Oil Zone (Pliocene Etchegoin Formation) at the Elk Hills Naval Petroleum Reserve in California. The Western Shallow Oil Zone Gusher and Calitroleum sands are very fine grained, silty and pyritic and are interbedded with silty shales. Electric logs generally show 1[1\\/2]-2[1\\/2] ohm-meters of deep

  4. Fluidization Characteristics of Sand and Chopped Switchgrass Sand Mixtures

    Microsoft Academic Search

    K. N. Patil; T. J. Bowser; D. D. Bellmer; R. L. Huhnke

    A laboratory, fluidized-bed gasifier is being researched as a means to gasify feedstocks in a process to produce ethanol from biomass. Fluidization characteristics of the bed, especially minimum (Umf) and complete (Ucf) fluidization velocities, were measured because they are critical to the operation of the gasifier. Fluidization properties of sand and chopped switchgrass- sand mixtures of different particle sizes and

  5. Multiple dust sources in the Sahara Desert: The importance of sand dunes

    NASA Astrophysics Data System (ADS)

    Crouvi, Onn; Schepanski, Kerstin; Amit, Rivka; Gillespie, Alan R.; Enzel, Yehouda

    2012-07-01

    We determine the current sources of dust in the Sahara Desert using quantitative correlation between the number of days with dust storms (NDS), derived from remote-sensing data of high temporal resolution, with the distribution of the soil types and geomorphic units. During 2006-8 the source of over 90% of the NDS was found to be sand dunes, leptosols, calcisols, arenosols, and rock debris. In contrast to previous studies, only few dust storms originated from playas and dry lake beds. Land erodibility was estimated by regressing the NDS to the number of days with high-speed wind events, and was found to be high for sand dunes. Clay and fine-silt grains and aggregates are scarce in sand dunes, which most likely produce dust particles through aeolian abrasion of sand grains. Thus, saltating sand grains impacting clay aggregates on playa surfaces cannot be the sole process for generating dust in the Sahara.

  6. Hydrology of the sand-and-gravel aquifer, southern Okaloosa and Walton Counties, northwest Florida

    USGS Publications Warehouse

    Hayes, L.R.; Barr, D.E.

    1982-01-01

    The sand-and-gravel aquifer in southern Okaloosa and Walton Counties, northwest Florida, extends from land surface to depth of 50 to 150 feet. Intervening layers of clay generally separate the aquifer into an unconfined surficial zone, composed principally of fine to medium sand, and a lower confined zone, consisting of variable amounts of medium to coarse sand and gravel. Well yields of 50 to 500 gallons per minute are possible in most of the area, and yields of 500 to 1,000 gallons per minute can be developed in parts of southwestern Okaloosa County. (USGS)

  7. 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.

  8. 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,…

  9. Vacuum Head Removes Sanding Dust

    NASA Technical Reports Server (NTRS)

    Bengle, C. G.; Holt, J. W.

    1982-01-01

    Vacuum sander prevents sanding dust from entering a work area, since dust particles are drawn off as quickly as they are produced. Tool is useful where dust presents health hazards, interferes with such processes as semiconductor manufacture, or could destroy wet paint or varnish finishes. Could be used to sand such materials as lead paint.

  10. Sand waves, bars, and wind-blown sands of the Rio Orinoco, Venezuela and Colombia

    USGS Publications Warehouse

    Nordin, Carl F.; Perez-Hernandez, David

    1989-01-01

    During March 1982, a reconnaissance study was carried out along a reach of the Rio Orinoco between Puerto Ayacucho and Ciudad Bolivar. This was the low-flow season. Samples of bed material and suspended sediments were collected, sonic records of the bed were obtained at several locations, and the exposed bars and sand waves were studied at four locations. Sounding records were obtained at two of these locations during June and November when flow covered the bars, and additional studies were made on the ground at some of these same sites during March 1983. The bed of the river is mostly sand with small quantities, about 5 percent by weight on average, of gravel. Suspended- sediment concentrations were low, ranging between 20 milligrams per liter above Rio Apure to almost 40 milligrams per liter below its confluence with the Rio Orinoco. The annual sediment load is estimated to be 240x10 6 megagrams per year. During the dry season, 35 percent or more of the bed is exposed in the form of large bars composed of many sand waves. Trade winds blow upriver and there is substantial upriver transport of river sediments by the wind. If the bars contain very coarse sands and fine gravel, deflation forms a lag deposit that armors the bar surface and prevents further erosion. Theoretical calculations show that the lower limit for the fraction of the bed that needs to be covered with nonmoving particles to prevent further erosion and the smallest size of the armor particles depend only on wind speed. Calculations of bed-material transport were made for a typical wide and narrow section of the river; the annual load, excluding the wash load, is about 30 x 10 6 megagrams per year. A new definition for wash load is proposed; it is material that can be suspended as soon as its motion is initiated. For the Rio Orinoco, this is material finer than 0.1 millimeters.

  11. Sand swimming lizard: sandfish

    E-print Network

    Maladen, Ryan D; Kamor, Adam; Goldman, Daniel I

    2009-01-01

    We use high-speed x-ray imaging to reveal how a small (~10cm) desert dwelling lizard, the sandfish (Scincus scincus), swims within a granular medium [1]. On the surface, the lizard uses a standard diagonal gait, but once below the surface, the organism no longer uses limbs for propulsion. Instead it propagates a large amplitude single period sinusoidal traveling wave down its body and tail to propel itself at speeds up to ~1.5 body-length/sec. Motivated by these experiments we study a numerical model of the sandfish as it swims within a validated soft sphere Molecular Dynamics granular media simulation. We use this model as a tool to understand dynamics like flow fields and forces generated as the animal swims within the granular media. [1] Maladen, R.D. and Ding, Y. and Li, C. and Goldman, D.I., Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard, Science, 325, 314, 2009

  12. 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.

  13. 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

  14. Characterization of Fine Powders

    NASA Astrophysics Data System (ADS)

    Krantz, Matthew; Zhang, Hui; Zhu, Jesse

    Fine powders are used in many applications and across many industries such as powdered paints and pigments, ceramics, petrochemicals, plastics, pharmaceuticals, and bulk and fine chemicals, to name a few. In addition, fine powders must often be handled as a waste by-product, such as ash generated in combustion and gasification processes. In order to correctly design a process and process equipment for application and handling of powders, especially fine powders, it is essential to understand how the powder would behave. Many characterization techniques are available for determining the flow properties of powders; however, care must be taken in selecting the most appropriate technique(s).

  15. 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.

  16. Separability studies of construction and demolition waste recycled sand.

    PubMed

    Ulsen, Carina; Kahn, Henrique; Hawlitschek, Gustav; Masini, Eldon A; Angulo, Sérgio C

    2013-03-01

    The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases, and specifically to the patches of cement that remain attached to the surface of natural aggregates. This phase increases water absorption and compromises the consistency and strength of concrete made from recycled aggregates. Mineral processing has been applied to CDW recycling to remove the patches of adhered cement paste on coarse recycled aggregates. The recycled fine fraction is usually disregarded due to its high content of porous phases despite representing around 50% of the total waste. This paper focus on laboratory mineral separability studies for removing particles with a high content of cement paste from natural fine aggregate particles (quartz/feldspars). The procedure achieved processing of CDW by tertiary impact crushing to produce sand, followed by sieving and density and magnetic separability studies. The attained results confirmed that both methods were effective in reducing cement paste content and producing significant mass recovery (80% for density concentration and 60% for magnetic separation). The production of recycled sand contributes to the sustainability of the construction environment by reducing both the consumption of raw materials and disposal of CDW, particularly in large Brazilian centers with a low quantity of sand and increasing costs of this material due to long transportation distances. PMID:22835506

  17. 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

  18. Saltation of Non-Spherical Sand Particles

    PubMed Central

    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

  19. Batch experiments characterizing the reduction of Cr(VI) using suboxic material from a mildly reducing sand and gravel aquifer

    USGS Publications Warehouse

    Anderson, L.D.; Kent, D.B.; Davis, J.A.

    1994-01-01

    Batch experiments were conducted with sand collected from a shallow sand and gravel aquifer to identify the principal chemical reactions influencing the reduction of Cr(VI), so that field-observed Cr(VI) reduction could be described. The reduction appeared to be heterogeneous and occurred primarily on Fe(II)-bearing minerals. At only 1 wt %, the fine fraction (<64 ??m diameter) of the sediments dominated the amount of aqueous Cr(VI) reduction because of its greater reactivity and surface area. Although reduction of Cr(VI) increased with decreasing pH, small variations in the abundance of fine fraction among the replicate samples obscured pH trends in the batch experiments. Consistent results could only be obtained by separating the fine material from the sand and running parallel experiments on each fraction. As pH decreased (6.4 to 4.5), Cr(VI) reduction increased from 30 to 50 nmol/m2 for the sand fraction (64-1000 ??m) and from 130 to 200 nmol/m2 for the fine fraction. The amount of Cr(VI) reduced in both the sand-sized and fine material increased from 35 to 80 and from 130 to 1000 nmol/m2, respectively, for a 10-fold increase in Cr(VI)initial. A consistent description of the rate data was achieved by assuming that intraparticle diffusion limited the observed rate of reduction.

  20. Which fine-tuning arguments are fine?

    Microsoft Academic Search

    Alexei Grinbaum

    2009-01-01

    The argument from naturalness is widely employed in contemporary quantum field theory. Essentially a formalized aesthetic criterion, it received a meaning in the debate on the Higgs mechanism, which goes beyond aesthetics. We follow the history of technical definitions of fine tuning at the scale of electroweak symmetry breaking. It is argued that they give rise to a special interpretation

  1. Experimental investigation of deformation mechanisms during shear-enhanced compaction in poorly lithified sandstone and sand

    NASA Astrophysics Data System (ADS)

    Skurtveit, Elin; Torabi, Anita; Gabrielsen, Roy H.; Zoback, Mark D.

    2013-08-01

    Shear-enhanced compaction in shallow sandstone reservoirs has been investigated in laboratory experiments using high-pressure triaxial testing of poorly lithified sandstone and sand. We have studied the deformation mechanism involved during shear-enhanced compaction and controlling parameters for yield stress at varying confining pressures for sandstone/sand with different grain sizes, porosities, and packing. Experimental testing provides insights into the deformation mechanism during hydrostatic and axial compression of coarse- and fine-grained sands with different packing including (1) natural coarse-grained sandstone, (2) densely packed fine-grained sand, and (3) loosely packed fine-grained sand. Monitoring of deformation and ultrasonic velocity during deformation indicates porosity loss, compaction, and strain hardening for most of the samples. Visualization of deformation using pretest and posttest X-ray imaging and thin sections demonstrates localized deformation fabrics and grain damage. The results show grain rearrangement as the controlling deformation mechanism for material at low stress and high porosity, whereas for lower porosity and higher stress, grain fracturing controlled the deformation. The most pronounced localization of deformation was observed for the coarse-grained, low-porosity material. A Cam-Clay cap model was used to describe the porosity loss during compaction and shear-enhanced compaction, demonstrating large inelastic compaction with increasing confining pressure. Yield stress and end caps for poorly lithified sandstone are observed for various porosities and stress conditions and found to be lower than predicted using empirical relationships for sandstone.

  2. Dewatering of fine coal

    SciTech Connect

    Hogg, R. [Mineral Processing Section, University Park, PA (United States)

    1995-10-01

    The factors which control the dewatering of fine coal by gravity/centrifugal drainage and by gas displacement (vacuum/hyperbaric filtration) are evaluated. A generalized model is presented and used to describe dewatering kinetics and to establish dewatering limits. Applications to the design of dewatering systems for fine coal dewatering are discussed.

  3. Fine Needle Aspiration

    MedlinePLUS

    ... press registration and more below. Please direct any interview requests or policy questions to our media and public relations staff at newsroom@entnet.org . What Is FNA? Fine needle aspiration (FNA), also called fine needle biopsy, is a technique that allows a biopsy of various bumps and ...

  4. Effect of Sand Replacement and Silica Fume Addition on Chloride Ion Permeability of Lightweight Concrete

    Microsoft Academic Search

    Faiz Abdullah; M. Mirza

    2009-01-01

    This paper was conducted to study the behavior of lightweight concrete, incorporating local lightweight aggregate (LWA), in terms of chloride ion permeability at different ages. The effect of lightweight fine aggregate replacement by normal weight sand (0, 25, 50 and 75% by volume) was investigated. Constant level of silica fume content (10% by weight of cement) as an addition was

  5. More Sustainable and Economical Concrete Using Fly Ash, Used Foundry Sand, and Other Residuals

    E-print Network

    Saldin, Dilano

    More Sustainable and Economical Concrete Using Fly Ash, Used Foundry Sand, and Other Residuals John and it is disposed of. #12;Typical concrete is a mixture of portland cement, coarse and fine aggregates, water per cubic meter of concrete (1200 to 1500 pounds per cubic yard). The American Foundrymen's Society

  6. On the critical salt concentrations for particle detachment in homogeneous sand and heterogeneous Hanford sediments

    E-print Network

    Selker, John

    On the critical salt concentrations for particle detachment in homogeneous sand and heterogeneous June 2004 Abstract One of the mechanisms for sudden particle release is a decrease in groundwater salt concentration to below the critical salt concentration (CSC), where repulsion forces between fine particles

  7. Convergent setal morphology in sand-covering spiders suggests a design principle for particle capture

    Microsoft Academic Search

    Rebecca P. Duncan; Kellar Autumn; Greta J. Binford

    2007-01-01

    Sicarius and Homalonychus are unrelated, desert-dwelling spiders that independently evolved the ability to cover themselves in fine sand particles, making them cryptic against their background. Observations that particles associate with these spiders' setae inspired us to investigate the role of setal microstructure in particle capture and retention. Here we report that Sicarius and Homalonychus convergently evolved numerous high aspect ratio,

  8. Sound-producing sand avalanches

    NASA Astrophysics Data System (ADS)

    Sholtz, Paul; Bretz, Michael; Nori, Franco

    1997-05-01

    Sound-producing sand grains constitute one of nature's more puzzling and least understood physical phenomena. They occur naturally in two distinct types: booming and squeaking sands. Although both varieties of sand produce unexpectedly pure acoustic emissions when sheared, they differ in their frequency range and duration of emission, as well as the environment in which they tend to be found. Large-scale slumping events on dry booming dunes can produce acoustic emissions that can be heard up to 10 km away and which resemble hums, moans, drums, thunder, foghorns or the drone of low-flying propeller aircraft. These analogies emphasize the uniqueness of the phenomenon and the clarity of the produced sound. Although reports of these sands have existed in the literature for over one thousand years, a satisfactory explanation for either type of acoustic emission is still unavailable.

  9. Formation of aeolian ripples and sand sorting

    E-print Network

    Edgar Manukyan; Leonid Prigozhin

    2008-12-09

    We present a continuous model capable of demonstrating some salient features of aeolian sand ripples: the realistic asymmetric ripple shape, coarsening of 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 sand is inhomogeneous.

  10. Animating Sand as a Fluid Yongning Zhu

    E-print Network

    Bridson, Robert

    Animating Sand as a Fluid by Yongning Zhu B.Sc., Peking University, 2003 A THESIS SUBMITTED;Abstract My thesis presents a physics-based simulation method for animating sand. To allow for efficiently scaling up to large volumes of sand, we abstract away the individual grains and think of the sand

  11. Continuum saltation model for sand dunes

    Microsoft Academic Search

    Gerd Sauermann; Klaus Kroy; Hans J. Herrmann

    2001-01-01

    We derive a phenomenological continuum saltation model for aeolian sand transport that can serve as an efficient tool for geomorphological applications. The coupled differential equations for the average density and velocity of sand in the saltation layer reproduce both the known equilibrium relations for the sand flux and the time evolution of the sand flux as predicted by microscopic saltation

  12. Hydraulic fracturing with a refractory proppant for sand control

    SciTech Connect

    Jennings, A.R. Jr.; Stowe, L.R.

    1989-04-04

    A sand control and heat transfer method is described for use in a borehole having an unconsolidated or loosely consolidated oil or gas reservoir which is otherwise likely to introduce substantial amounts of sand into the borehole, comprising: (a) providing a borehole casing through the reservoir; (b) perforating the casing at preselected intervals therealong to form at least one of longitudinal, in-line perforations; (c) hydraulically fracturing the reservoir by injecting a fracturing fluid containing a fine grain fused refractory material which comprises substantially silicon carbide or silicon nitride, and a clay stabilizing agent; (d) injecting a proppant comprising a gravel packing fused refractory material comprised substantially of silicon carbide or silicon nitride into the fracture, whereby a first layer of fine grain fused refractory material is held in place along the entire face of the fracture by a second layer of gravel packing fused refractory material also extending along the entire length of the fracture thereby excluding fines; and (e) producing oil or gas from the reservoir through the fracture into the borehole casing via a thermal oil recovery method which proppant and layers provide for increased heat transfer into the formation.

  13. 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.

  14. Fungal alteration of organic coatings on sand grains

    NASA Astrophysics Data System (ADS)

    Rothhardt, S.; Gleixner, G.; Benzerara, K.; Fischer, C.; Gaupp, R.

    2012-04-01

    We studied the fungal alteration of organically coated sand particles, sampled in Eocene sediments in the open cast mining Profen, near Leipzig (Germany). These organic coatings were formed on sand grains after their sedimentation owing to mobilization of organic matter from younger coal layers. The organic coatings formed non-continuous layers on quartz grains, measuring few micrometers up to 30 µm in thickness. It has been shown that organic coatings on sand grains retain efficiently dissolved metals by adsorption from groundwaters. They consequently might be used as adsorbent to purify low heavy metal contaminated water. However, their stability has not been assessed yet especially in the oxic environment and, more specifically, in the presence of microorganisms. This is important in order to evaluate whether coated sands could act as a reliable tool in remediation. In order to address this question we characterized the fungal alteration of organic coatings on sand grains using several techniques, including scanning electron microscopy (SEM), scanning transmission X-ray microscopy (STXM) and vertical scanning interferometry (VSI). Sand grains coated with organics were incubated on complex yeast medium with and without Schizophyllum commune to estimate changes in heavy metal retention. Formation of biominerals and etch pits is induced by fungal colonization as shown by SEM. Surface topography analysis was performed using VSI technique. Etch pit depth ranges from 0.5 to 1 µm. Pit formation is limited to the organic coating; dissolution of quartz grains was not detected. Using STXM we measured near-edge X-ray absorption fine structure (NEXAFS) spectra at the C K-edge, N-edge, and O K-edge to characterize the different organic compartments (fungi, genuine organic coatings, altered organic coatings) down to the 25-nm scale. We observed in the spectra measured at the C K-edge on the altered organic coatings a decrease in aromatic and phenolic groups as well as an enrichment in amide-rich molecules compared to the genuine organic coatings. Our results suggest heterogeneous biodegradation of organic coatings on sand grains by fungal exudation. An important implication might be the overall decrease in metal retention potential of organically coated sand grains owing to the alteration processes by S. commune.

  15. Canyon dissolution of sand, slag, and crucible residues

    SciTech Connect

    Rudisill, T.S.; Gray, J.H.; Karraker, D.G.; Chandler, G.T.

    1997-12-01

    An alternative to the FB-Line scrap recovery dissolver was desired for the dissolution of sand, slag, and crucible (SS{ampersand}C) residues from the plutonium reduction process due to the potential generation of hydrogen gas concentrations above the lower flammability limit. To address this concern, a flowsheet was developed for the F-Canyon dissolvers. The dissolvers are continually purged with nominally 33 SCFM of air; therefore the generation of flammable gas concentrations should not be a concern. Following removal of crucible fragments, small batches of the remaining sand fines or slag chunks containing less than approximately 350 grams of plutonium can be dissolved using the center insert in each of the four annular dissolver ports to address nuclear criticality safety concerns. Complete dissolution of the sand fines and slag chunks was achieved in laboratory experiments by heating between 75 and 85 degrees Celsius in a 9.3M nitric acid/0.013M (hydrogen) fluoride solution. Under these conditions, the sand and slag samples dissolved between 1 and 3 hours. Complete dissolution of plutonium and calcium fluorides in the slag required adjusting the dissolver solution to 7.5 wt% aluminum nitrate nonahydrate (ANN). Once ANN was added to a dissolver solution, further dissolution of any plutonium oxide (PuO2) in successive charges was not practical due to complexation of the fluoride by aluminum. During the laboratory experiments, well mixed solutions were necessary to achieve rapid dissolution rates. When agitation was not provided, sand fines dissolved very slowly. Measurement of the hydrogen gas generation rate during dissolution of slag samples was used to estimate the amount of metal in the chunks. Depending upon the yield of the reduction, the values ranged between approximately 1 (good yield) and 20% (poor yield). Aging of the slag will reduce the potential for hydrogen generation as calcium metal oxidizes over time. The potential for excessive corrosion in the dissolvers was evaluated using experimental data reported in the literature. Corrosion data at the exact flowsheet conditions were not available; however, the corrosion rate for 304L stainless steel (wrought material) corrosion coupons in 10M nitric acid/0.01M hydrofluoric acid at 95 degrees Celsius was reported as 21 mils per year. If the fluoride in the dissolver is complexed with aluminum, the corrosion rate will decrease to approximately 5 mils per year.

  16. Fine Grained Robotics

    E-print Network

    Flynn, Anita M.

    Fine grained robotics is the idea of solving problems utilizing multitudes of very simple machines in place of one large complex entity. Organized in the proper way, simple machines and simple behaviors can lead to emergent ...

  17. Nitrogen photoreduction on desert sands under sterile conditions

    PubMed Central

    Schrauzer, Gerhard N.; Strampach, Norman; Hui, Liu Nan; Palmer, Miles R.; Salehi, Jahanshah

    1983-01-01

    Sands from various geographic locations reduce N2 from the air to NH3 and traces of N2H4 on exposure to sunlight. This N2 photofixation occurs under sterile conditions on the surface of finely dispersed titanium minerals such as rutile, utilizing reducing equivalents generated through the photolysis of chemisorbed H2O. Abiological N2 photofixation is suggested to be part of the nitrogen cycle in arid and semiarid regions. It is estimated that about 10 × 105 tons of N2 is photoreduced on the total surface of the earth's deserts per year. PMID:16593330

  18. Sedimentary processes associated with sand and boulder deposits formed by the 2011 Tohoku-oki tsunami at Sabusawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Goto, Kazuhisa; Sugawara, Daisuke; Ikema, Satoko; Miyagi, Toyohiko

    2012-12-01

    This paper reports on the sedimentary processes of sand and boulder deposition at Sabusawa Island, Japan as a result of the 2011 Tohoku-oki tsunami. Boulders were composed of tuffaceous rocks and sourced from an earthquake-triggered slope failure as well as concrete fragments of seawall. They were scattered over the ground surface and did not form boulder ridges, although there was some local imbrication. The boulders were deposited on top of a sand layer indicating that the latter, possibly deposited from bed load, covered the ground surface first. This sand layer probably reduced friction allowing boulders to be transported more easily than might be expected across a hard ground with a high bottom friction. Sand deposits showed landward thinning and fining features, while the boulders showed a landward coarsening (tuffaceous boulders) or a landward fining (concrete boulders), indicating that large clasts were not necessarily scattered randomly but rather might have a clast size gradient with distance inland. These features are explained by the local topographic setting that constrained the directions of incoming and returning tsunami flows. Some clasts at the inland extent of the boulder field were covered by an upward fining sand layer. This feature suggests that the boulders were deposited prior to the suspended sands, with the latter subsequently laid down before the water level dropped below the top of the boulders. Such modern investigations of the sedimentary features of various sizes of grains and clasts immediately after a tsunami provide invaluable data for the reconstruction of inundation processes.

  19. Methanogenic potential of tailings samples from oil sands extraction plants.

    PubMed

    Fedorak, Phillip M; Coy, Debora L; Salloum, Myrna J; Dudas, Marvin J

    2002-01-01

    Approximately 20% of Canada's oil supply now comes from the extraction of bitumen from the oil sands deposits in northeastern Alberta. The oil sands are strip-mined, and the bitumen is typically separated from sand and clays by an alkaline hot water extraction process. The rapidly expanding oil sands industry has millions of cubic metres of tailings for disposal and large areas of land to reclaim. There are estimates that the consolidation of the mature fine tails (MFT) in the settling ponds will take about 150 years. Some of the settling ponds are now evolving microbially produced methane, a greenhouse gas. To hasten consolidation, gypsum (CaSO4 x 2H2O) is added to MFT, yielding materials called consolidated or composite tailings (CT). Sulfate from the gypsum has the potential to stimulate sulfate-reducing bacteria (SRB) to out-compete methanogens, thereby stopping methanogenesis. This investigation examined three MFT and four CT samples from three oil sands extractions companies. Each was found to contain methanogens and SRB. Serum bottle microcosm studies showed sulfate in the CT samples stopped methane production. However, if the microcosms were amended with readily utilizable electron donors, the sulfate was consumed, and when it reached approximately 20 mg/L, methane production began. Some unamended microcosms were incubated for 372 days, with no methane production detected. This work showed that each MFT and CT sample has the potential to become methanogenic, but in the absence of exogenous electron donors, the added sulfate can inhibit methanogenesis for a long time. PMID:11888160

  20. Influence of fly ash fineness and shape on the porosity and permeability of blended cement pastes

    Microsoft Academic Search

    Theerawat Sinsiri; Prinya Chindaprasirt; Chai Jaturapitakkul

    2010-01-01

    The effects of the fineness and shape of fly ash on the porosity and air permeability of cement pastes were investigated.\\u000a Pulverized coal combustion (PCC) fly ash and fluidized bed coal combustion (FBC) fly ash classified into three different finenesses\\u000a were used. River sand with particle size distribution similar to that of fly ash was also used for comparison. Portland

  1. Geology on a Sand Budget

    NSDL National Science Digital Library

    Jacqueline Kane

    2004-09-01

    Earth science teaches know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, only to use the models for a few class periods. To avoid emptying an already limited science budget, teachers can use a simple alternative to the expensive 3-D models--sand. Modeling geologic processes and features with sand is an effective way for teachers to promote student understanding of Earth science topics, quickly assess students' prior knowledge, and identify common misconceptions.

  2. Directional response of a reconstituted fine-grained soil - Part I: experimental investigation

    NASA Astrophysics Data System (ADS)

    Costanzo, Daniele; Viggiani, Gioacchino; Tamagnini, Claudio

    2006-11-01

    This paper discusses the results of a large experimental program designed to investigate in a systematic manner the main features of the incremental response of fine-grained soils. The results are obtained from triaxial stress probing experiments carried out on a French silty clay (Beaucaire Marl). All the tests have been performed on reconstituted specimens, normally consolidated to an initial state which is either isotropic or anisotropic. In the interpretation of the experimental results, extensive use is made of the concept of strain response envelope. The response envelopes obtained for different stress increment magnitudes are remarkably consistent with each other and indicate an inelastic and irreversible material response, i.e. a strong dependence on the stress increment direction, also at relatively small strain levels. A companion paper (Int. J. Numer. Anal. Meth. Geomech., this issue, 2006) assesses the performance of some advanced constitutive models in reproducing the behaviour of reconstituted Beaucaire Marl as observed in this experimental program. Copyright

  3. SANDIA REPORT SAND2012-1000

    E-print Network

    Tesfatsion, Leigh

    SANDIA REPORT SAND2012-1000 Unlimited Release Printed September 2012 Project Report: A Survey · · UNITED STATES OF AM ERICA 2 #12;SAND2012-1000 Unlimited Release Printed September 2012 Project Report

  4. Loose sand habitat at the Mojave desert

    NSDL National Science Digital Library

    Katie Hale (California State University, Fullerton; Student. Biological Sciences)

    2007-01-06

    Loose sand soil lacks moisture but contains adequate moisture and nutrients for drought tolerant plants. Loose sand soil is insufficient for animals to find or make shelter. Organisms find shade and shelter under the large shrubs.

  5. Onsite Wastewater Treatment Systems: Sand Filters

    E-print Network

    Lesikar, Bruce J.

    2008-10-23

    Sand filters are beds of granular material, or sand, drained from underneath so that pretreated wastewater can be treated, collected and distributed to a land application system. This publication explains the treatment, design, operation...

  6. White Sands solar test facility

    Microsoft Academic Search

    R. A. Hays

    1978-01-01

    The White Sands solar test facility includes a heliostat, attenuator, concentrator and test and control chamber. A total of 356 flat-plate mirrors mounted on a steel frame 1.2 by 11 m comprises the heliostat, which moves in azimuth + or - 60 deg and from zero to 90 deg in elevation. The concentrator is composed of 180 spherical mirrors mounted

  7. 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...

  8. 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…

  9. 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…

  10. Intramural Sports Sand Volleyball League

    E-print Network

    Escher, Christine

    Intramural Sports Sand Volleyball League Summer 2014 Intramural Sports Calendar of Events Summer 2014 Potential Division Offerings Men's (Tuesdays) Women's (Tuesdays) Co-Rec (Wednesdays) Sports-F Current OSU Students or Faculty/Staff/Affiliates with a Recreational Sports Membership are eligible

  11. 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...

  12. The Effect of Sand on Strength of Mixtures of Bentonite-Sand

    Microsoft Academic Search

    Mohammad C. Pakbaz; Navid Khayat

    The main purpose of this research is to evaluate the effect of sand on strength of compacted samples of bentonite sand mixtures. Samples of bentonite with 10,30,50,70, and 80 percent by weight of sand at standard proctor optimum water content were compacted and tested to measure confined and unconfined strength. Unconfined strength of mixtures increased with percentage of sand until

  13. The Effect of Sand on Strength of Mixtures of Bentonite-Sand

    Microsoft Academic Search

    Mohammad C. Pakbaz; Navid Khayat

    2004-01-01

    The main purpose of this research is to evaluate the effect of sand on strength of compacted samples of bentonite sand mixtures. Samples of bentonite with 10,30,50,70, and 80 percent by weight of sand at standard proctor optimum water content were compacted and tested to measure confined and unconfined strength. Unconfined strength of mixtures increased with percentage of sand until

  14. Dating of Sand Dunes Using Cosmogenic Chlorine-36: An Example From the Nebraska Sand Hills, USA

    E-print Network

    Zreda, Marek

    Dating of Sand Dunes Using Cosmogenic Chlorine-36: An Example From the Nebraska Sand Hills, USA Stephen Moysey, Marek Zreda and Jim Goeke The large-scale mobility of sand dunes in continental dune of these landforms. Traditional methods for dating sand dunes, e.g. stratigraphic and radiocarbon dating

  15. RELATIONSHIPS BETWEEN BENTHIC ORGANIC MATTER AND MACROINVERTEBRATES IN SAND SUBSTRATES

    E-print Network

    Notre Dame, University of

    RELATIONSHIPS BETWEEN BENTHIC ORGANIC MATTER AND MACROINVERTEBRATES IN SAND SUBSTRATES OF NORTHERN #12;RELATIONSHIPS BETWEEN BENTHIC ORGANIC MATTER AND MACROINVERTEBRATES IN SAND SUBSTRATES OF NORTHERN studied in sand habitats, despite the abundance of sand in many streams. These relationships were

  16. Erosion of mud\\/sand mixtures

    Microsoft Academic Search

    Helen Mitchener; Hilde Torfs

    1996-01-01

    The prediction of sediment erosion is an important issue in coastal engineering projects. There are methods for predicting the erosion of cohesive sediment (mud) and non-cohesive sediment (sand), but there are presently no relationships for mixed sediments. However, natural sediments rarely consist of only mud or sand and the erosional properties of combined mud and sand sediments are required so

  17. Treating tar sands formations with karsted zones

    DOEpatents

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX)

    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.

  18. Animating Sand as a Fluid Yongning Zhu

    E-print Network

    Teschner, Matthias

    Animating Sand as a Fluid Yongning Zhu University of British Columbia Robert Bridson University of British Columbia Figure 1: The Stanford bunny is simulated as water and as sand. Abstract We present a physics-based simulation method for animating sand. To allow for efficiently scaling up to large volumes

  19. Development of stresses in cohesionless poured sand

    E-print Network

    Claudin, Philippe

    Development of stresses in cohesionless poured sand By M. E. Cates1 , J. P. Wittmer1 , J a conical sandpile, created by pouring sand from a point source onto a rough rigid support, shows) is required for systems with two-dimensional symmetry, such as a wedge of sand; for a three

  20. ccsd00003208, Basic properties for sand automata

    E-print Network

    ccsd­00003208, version 1 ­ 4 Nov 2004 Basic properties for sand automata J. Cervelle #3; E injectivity and surjectivity for sand automata. Moreover, we begin the exploration of the dynamical behavior of sand automata proving that the property of nilpotency is undecidable. We believe that the proof

  1. EFFECTS of OIL MIXED with CARBONIZED SAND

    E-print Network

    m #12;#12;EFFECTS of OIL MIXED with CARBONIZED SAND on AQUATIC ANIMALS Marine Biological l SAND ON AOTTATIC ANIMALS By Walter A. Chipman and Paul S. Gaits off. Fishery Research Biologists CONTENT Pago Preface Introduction 1 Injury to aquatic life caused by oil. 2 Amount of carbonized sand

  2. Regeneration of sand waves after dredging

    Microsoft Academic Search

    M. A. F. Knaapen; S. J. M. H. Hulscher

    2002-01-01

    Sand waves are large bed waves on the seabed, being a few metres high and lying hundreds of metres apart. In some cases, these sand waves occur in navigation channels. If these sand waves reduce the water depth to an unacceptable level and hinder navigation, they need to be dredged. It has been observed in the Bisanseto Channel in Japan

  3. Sand reinforced with shredded waste tires

    Microsoft Academic Search

    Gary J. Foose; Craig H. Benson; Peter J. Bosscher

    1996-01-01

    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

  4. Optimum content of copper slag as a fine aggregate in high strength concrete

    Microsoft Academic Search

    Wei Wu; Weide Zhang; Guowei Ma

    2010-01-01

    This study investigated the mechanical properties of high strength concrete incorporating copper slag as a fine aggregate and concluded that less than 40% copper slag as sand substitution can achieve a high strength concrete that comparable or better to the control mix, beyond which however its behaviors decreased significantly. The workability and strength characteristics were assessed through a series of

  5. FINE PARTICLE CHARGING DEVELOPMENT

    EPA Science Inventory

    The report gives results of theoretical and experimental investigations into the changing of fine particles by unipolar ions in an electric field, and evaluation of a specially designed small pilot-scale (600-1000 acfm) precharging device. Following an extensive review of the lit...

  6. MAIZE FINE STREAK VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The report outlines the salient features of maize fine streak virus (MFSV) including a general description of the causal virus species, virion properties, genome description, the relationship of the virus to other taxa, biological properties of the disease and agronomic aspects of the disease. Maize...

  7. Dewatering of fine coal

    SciTech Connect

    Sastry, K.V.S. (California Univ., Berkeley, CA (USA). Dept. of Materials Science and Mineral Engineering)

    1991-01-01

    Fine coal dewatering is one of the most pressing problem facing the coal cleaning industry. This project was undertaken with the objective of improving the dewatering process with surface chemical activation by primarily understanding the fundamental and process engineering aspects of vacuum filtration. Specific tasks for this project included -- development of an experimental apparatus and procedure to yield highly reproducible results and extensive data from each test, detailed experimental investigation of the dewatering characteristics of coal fines with and without the addition of flocculants and surfactants, and under different operating conditions, and finally identification and establishment of the physical limits of mechanical dewatering. Following are the significant conclusions from the study: Fineness and size distribution of the coal fines have the most significant influence on the coal dewatering process; usage of flocculants and surfactants is almost essential in reducing the cake moisture and in increasing the filter throughputs; based on the experimental data and the literature information, the existence of an asymptotic limit for filter cake moisture correlatable with a capillary number of the filter cake was identified. 66 refs., 23 figs., 7 tabs.

  8. Ozonation of diesel-fuel contaminated sand and the implications for remediation end-points.

    PubMed

    Li, Xingang; Cao, Xingtao; Wu, Guozhong; Temple, Tracey; Coulon, Frédéric; Sui, Hong

    2014-08-01

    In this study, we investigate specifically the influence of soil grain size and water content on the degradation of n-alkane fractions and the formation of aldehydes and carboxylic acid during ozonation. 15 g of quartz sand spiked with diesel (25 g kg(-1)) were exposed to ozone for 20 h at concentrations of 10, 30 and 50 mg L(-1), respectively. Results indicated that ozonation of the n-alkanes in fine grain size sand (0.15-0.25 mm) was 1.2 times faster than coarse sand due to higher surface contact area between O3 and sand particles. Soil moisture below 18% w/w did not influence the ozonation efficiency. In contrast the ozonation led to an increase of acidity of the sand samples (pH=3.0) after 20 h treatment. This was due to the formation of carboxylic acid. Formaldehyde, one of the key by-products of ozonation, was always <13 mg kg(-1) after the treatment which is below the industrial soil clean-up target level. While the aldehydes and carboxylic acid further reacted with O3 and their ozonation rate were slower than those of the alkanes suggesting that the hydroxylated by-products accumulated in the sand during the process. Overall the findings demonstrated that not only the alkanes but also aldehydes and carboxylic acid should be considered when defining remediation end-points. PMID:24873709

  9. Assessment of Constitutive and Stability Behavior of Sands Under Plane Strain Condition

    NASA Technical Reports Server (NTRS)

    Alshibli, Khalid A.; Sture, Stein

    2000-01-01

    A series of biaxial (plane strain) experiments were conducted on three sands under low (15 kPa) and high (100 kPa) confining pressure conditions to investigate the effects of specimen density, confining pressure, and sand grains size and shape on the constitutive and stability behavior of granular materials. The three sands used in the experiments were fine, medium, and coarse-grained uniform silica sands with rounded, sub-angular, and angular grains, respectively. Specimen deformation was readily monitored and analyzed with the help of a grid pattern imprinted on the latex membrane. The overall stress-strain behavior is strongly dependent on the specimen density, confining pressure, sand grain texture, and the resulting failure mode(s). That became evident in different degrees of softening responses at various axial strains. The relationship between the constitutive behavior and the specimens' modes of instability is presented. The failure in all specimens was characterized by two distinct and opposite shear bands. It was found that the measured dilatancy angles increase as the sand grains' angularity and size increase. The measured shear band inclination angles are also presented and compared with classical Coulomb and Roscoe solutions.

  10. Quasi-static compression of granular materials (sand) at high pressures (~3 GPA)

    NASA Astrophysics Data System (ADS)

    Subramanian, Vijay Krishnan

    This investigation presents the results on the static behavior of confined sand (from Eglin Air Force Base) subjected to axial compressive stresses up to 3 GPa. A self-aligning compression fixture was developed to statically compress sand specimen in a cylindrical steel confinement using tungsten carbide pins. A strain gage was mounted on the confining cylinder to measure the circumferential strain. Using axial stress, axial strain, and hoop strain the multi axial behavior of the confined sand is investigated. Compressive tests were conducted up to axial strains of 35%. The static response of the dry sand was tested at four different initial densities, namely, 1.55, 1.60, 1.65, and 1.75 g/cm 3. Effects of particle size, primarily classified as coarse and fine, were investigated. The effect of moisture was also investigated at four different degrees of saturation, namely, 0%, 20%, 40%, and 100%. The dense sand provided a much stiffer response than the loosely packed ones. The coarse sand grains showed significant crushing of particles followed by compaction of the powdered grains.

  11. Sedimentary structures and textures of Rio Orinoco channel sands, Venezuela and Colombia

    USGS Publications Warehouse

    McKee, Edwin Dinwiddie

    1989-01-01

    Most sedimentary structures represented in sand bodies of the Rio Orinoco are tabular-planar cross-strata which, together with some wedge-planar cross-strata, are the products of sand-wave deposition. Locally, in areas of river meander where point bars characteristically form, trough structures forming festoon patterns are numerous. At a few localities, sets of nearly horizontal strata occur between tabular-planar sets and are interpreted to be the deposits of very fast currents of the upper flow regime; elsewhere, uncommon lenses and beds of silt, clay, or organic matter consisting of leaves and twigs, seem to be the result of quiet-water settling through gravity. By far the most common grain size represented in the tabular-planar and wedge-planar cross-strata of the sandwave deposits is medium sand (? - ? millimeter) as determined by screen analyses. Many samples, however, also contain moderate quantities of coarse or very coarse sand. Eolian dunes on top of the sand-wave deposits are dominantly fine grained. The river channel sands were determined to be largely moderately well sorted, although in some places they were mostly well sorted, and in others, mostly moderately sorted.

  12. 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

  13. Hydrogeochemical and isotopic characterisation of groundwater in a sand-dune phreatic aquifer on the northeastern coast of the province of Buenos Aires, Argentina.

    PubMed

    Carretero, Silvina C; Dapeña, Cristina; Kruse, Eduardo E

    2013-01-01

    This contribution presents the hydrochemical and isotopic characterisation of the phreatic aquifer located in the Partido de la Costa, province of Buenos Aires, Argentina. In the sand-dune barrier geomorphological environment, groundwater is mainly a low-salinity Ca-HCO3 and Na-HCO3-type, being in general suitable for drinking, whereas in the continental plain (silty clay sediments), groundwater is a Na-Cl type with high salinity and unsuitable for human consumption. The general isotopic composition of the area ranges from-6.8 to-4.3 ‰ for ?(18)O and from-39 to-21 ‰ for ?(2)H, showing that rainwater rapidly infiltrates into the sandy substrate and reaches the water table almost without significant modification in its isotopic composition. These analyses, combined with other chemical parameters, made it possible to corroborate that in the eastern area of the phreatic aquifer, there is no contamination from marine salt water. PMID:23713885

  14. Fine Arts in Hungary

    NSDL National Science Digital Library

    Krén, Emil.

    This Website, sponsored by KFKI Computers of Budapest, presents a virtual gallery of images of fine arts from Hungary (.jpeg, you choose view size.) This Central European nation, at times under the influence of the Romans, Turks and Austro-Hungarian Empire, houses a rich artistic tradition. Works of Hungarian fine artists as well as others that worked in Hungary are featured here in alphabetical order by artist. There's also a section of altarpieces, miniatures, carvings, etc. by anonymous artists. Visitors to the site will enjoy the collection, which includes fragments of Romanesque wall paintings and architectural sculpture, Gothic and Renaissance altarpieces and carvings, paintings from the baroque, classicist and romanticist periods, and modern art. The short biographies of the artists will aid in appreciation of the talented yet not all internationally-known artists of Hungary. You might even want to send a virtual postcard from the site.

  15. CHARACTERIZATION OF FINE PARTICULATE MATTER

    EPA Science Inventory

    Size distribution data processing and fitting Ultrafine, very fine and fine PM were collected nearly continuously from December 2000 through March 2003 at a Washington State Department of Ecology site on Beacon Hill in Seattle. Particle size distributio...

  16. Tracing biogeochemical and microbial variability over a complete oil sand mining and recultivation process.

    PubMed

    Noah, Mareike; Lappé, Michael; Schneider, Beate; Vieth-Hillebrand, Andrea; Wilkes, Heinz; Kallmeyer, Jens

    2014-11-15

    Recultivation of disturbed oil sand mining areas is an issue of increasing importance. Nevertheless only little is known about the fate of organic matter, cell abundances and microbial community structures during oil sand processing, tailings management and initial soil development on reclamation sites. Thus the focus of this work is on biogeochemical changes of mined oil sands through the entire process chain until its use as substratum for newly developing soils on reclamation sites. Therefore, oil sand, mature fine tailings (MFTs) from tailings ponds and drying cells and tailings sand covered with peat-mineral mix (PMM) as part of land reclamation were analyzed. The sample set was selected to address the question whether changes in the above-mentioned biogeochemical parameters can be related to oil sand processing or biological processes and how these changes influence microbial activities and soil development. GC-MS analyses of oil-derived biomarkers reveal that these compounds remain unaffected by oil sand processing and biological activity. In contrast, changes in polycyclic aromatic hydrocarbon (PAH) abundance and pattern can be observed along the process chain. Especially naphthalenes, phenanthrenes and chrysenes are altered or absent on reclamation sites. Furthermore, root-bearing horizons on reclamation sites exhibit cell abundances at least ten times higher (10(8) to 10(9) cells g(-1)) than in oil sand and MFT samples (10(7) cells g(-1)) and show a higher diversity in their microbial community structure. Nitrate in the pore water and roots derived from the PMM seem to be the most important stimulants for microbial growth. The combined data show that the observed compositional changes are mostly related to biological activity and the addition of exogenous organic components (PMM), whereas oil extraction, tailings dewatering and compaction do not have significant influences on the evaluated compounds. Microbial community composition remains relatively stable through the entire process chain. PMID:25201817

  17. 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.

  18. The chemistry of Saudi Arabian sand: A deposition problem on helicopter turbine airfoils

    NASA Technical Reports Server (NTRS)

    Smialek, James L.

    1991-01-01

    Recent operations in the Persian Gulf have exposed military helicopter turbines to excessive amounts of ingested sand. Fine particles, less than 10 microns, are able to bypass the particle separators and enter the cooling and combustion systems. The initial sand chemistry varies by location, but is made up of a calcium aluminum silicate glass, SiO2 low quartz (Ca,Mg) CO3 dolomite, CaCO3 calcite, and occasionally CaCl rocksalt. The sand reacts in the hot combustion gases and deposits onto the turbine vanes as CaSO4, glass, and various crystalline silicates. Deposits up to 0.25 in. thick have been collected. Although cooling hole plugging is a considerable problem, excessive corrosion is not commonly observed due to the high melting point of GaSO4.

  19. The Chemistry of Saudi Arabian Sand - A Deposition Problem on Helicopter Turbine Airfoils

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Archer, Frances A.; Garlick, Ralph G.

    1992-01-01

    Operations in the Persian Gulf have exposed military helicopter turbines to excessive amounts of ingested sand. Fine particles, less than 10 microns, are able to bypass the particle separators and enter the cooling and combustion systems. The initial sand chemistry varies by location, but is made up of a calcium aluminum silicate glass, SiO2 low quartz, (Ca,Mg)CO3 dolomite, CaCO3 calcite, and occasionally NaCl rocksalt. The sand reacts in the hot combustion gases and deposits onto the turbine vanes as CaSO4, glass, and various crystalline silicates. Deposits up to 5 mm thick have been collected. Although cooling hole plugging is a considerable problem, excessive corrosion is not commonly observed due to the high melting point of CaSO4.

  20. Electrokinetic injection of ammonium and sulfate ions into sand and kaolinite beds

    Microsoft Academic Search

    Yalcin B. Acar; M. Fazle Rabbi; Elif E. Ozsu

    1997-01-01

    Electrokinetic remediation is an emerging in-situ remediation technique that employs a low-level direct current (DC) across an electrode system inserted in soil to extract inorganic\\/organic species. The efficiency of electrokinetic injection of a cation (ammonium) from the anode and an anion (sulfate) from the cathode into a fine-grained sand bed and a kaolinite bed is investigated. Electrodes are placed in

  1. Colonization of meiobenthos in oil-contaminated subtidal sands in the lower Chesapeake Bay

    Microsoft Academic Search

    D. M. Alongi; D. F. Boesch; R. J. Diaz

    1983-01-01

    In-situ manipulative experiments were conducted over a 3-month period (May–August 1980) to examine the rate at which meiobenthos colonizes oiled and untreated azoic fine sands at a shallow subtidal site in the lower York River, Virginia. Three concentrations of fresh Prudhoe Bay crude oil were added to sediments: 100, 2 500 and 10000 mg oil kg-1 dry wt sediment. Untreated

  2. Experimental investigation of the effect of grading characteristics on the liquefaction resistance of various graded sands

    Microsoft Academic Search

    Y. Yilmaz; M. Mollamahmutoglu; V. Ozaydin; K. Kayabali

    2008-01-01

    The liquefaction susceptibility of various graded fine to medium saturated sands are evaluated by stress controlled cyclic triaxial laboratory tests. Cyclic triaxial tests are performed on reconstituted specimens having global relative density of 60%. In all cyclic triaxial tests; loading pattern is selected as a sinusoidal wave form with 1.0 Hz frequency, and effective consolidation pressure is chosen to be 100 kPa.

  3. 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.

  4. Cell abundance and microbial community composition along a complete oil sand mining and reclamation process

    NASA Astrophysics Data System (ADS)

    Lappé, M.; Schneider, B.; Kallmeyer, J.

    2012-12-01

    Hydrocarbons constitute an important energy source for microbes but can also be of environmental concern. Microbial activity causes hydrocarbon degradation and thereby loss of economical value, but also helps to remove hydrocarbons from the environment. The present study characterizes the abundance of microbes along the oil sand mining process in Alberta, Canada, as a first approach to assess the impact of mining and oil extraction on the microbial population. After mining the oil is extracted from the sediment by a hot-water extraction (50-60°C), resulting in three major fractions: crude oil, tailings sand and fine tailings. The tailings sand is used as substratum for newly developing soils on the reclamation areas. The very liquid fine tailings still have a TOC content of about 4.3% and are pumped into tailings ponds, where they need up to three decades to settle and solidify. After deposition, these mature fine tailings (MFTs) are enriched in organics (TOC content between 9.6 and 16.8%) and dredged out of the ponds and put on dumps for several years for dewatering. Finally they are brought out onto the reclamation sites and deposited below the sand layer. Cells were extracted from oily sediments according to the protocol of Lappé and Kallmeyer (2011), stained with SYBR Green I and counted by fluorescence microscopy. Cell abundance in the unprocessed oil sand is around 1.6 x 107 cells cm-3. After processing the fresh fine tailings still contain around 1.6 x 107 cells cm-3. Cell counts in the processed MFTs are 5.8 x 107 cells cm-3, whereas in the sand used as substratum for newly developing soils, they are twice as high (1.4 x 108). In root-bearing horizons, cell counts reach 1.1 x 109 cell cm-3. Cell numbers calculated from cultivation experiments are in the same range. Higher cell counts in the tailings sand are probably due to a higher nitrogen supply through the addition of a 35 cm top layer of a peat-mineral mix. In the sand nitrate concentrations are high (~0.37 mmol/L), whereas in the MFTs nitrate concentrations are much lower (~0.04 mmol/L). In some MFT samples sulphate appears to be the most abundant electron acceptor (up to 94 mmol/L) but no hydrogen sulphide could be detected. High cell counts in root-bearing layers might be related to a supply with otherwise unavailable nutrients, especially phosphorus. Another plausible explanation is that the cells are brought in the sand with the peat-mineral mix, because it seems that the mix contains a significant amount of roots. Samples with low amounts or no roots showed lower cell abundances. Sand and MFTs also differ in the microbial community composition. Molecular analysis of bacterial isolates of samples with different oil content show that ?-Proteobacteria dominate the cultivable bacterial population in substrates with a high residual content of oil, whereas in the low oil content sand they play a minor role. The data of corresponding metagenomic analyses confirm these results. In MFTs ?-Proteobacteria make up about 80% of the total bacterial population. The surprisingly stable cell abundance indicates that microbial processes take place throughout the entire production process. Rising cell numbers in root-bearing horizons show that a plant cover fosters microbial abundance and diversity, helping to restore full ecosystem functionality.

  5. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    SciTech Connect

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  6. A branching process model for sand avalanches

    SciTech Connect

    Garcia-Pelayo, R.; Salazar, I.; Schieve, W.C. (Univ. of Texas, Austin (United States))

    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.

  7. Morris. E. Fine symposium

    SciTech Connect

    Liaw, P.K. (Westinghouse Science and Technology Center, Pittsburgh, PA (US)); Marcus, H.L. (Univ. of Texas at Austin, Materials Science and Engineering Programs, Austin, TX (US)); Weertman, J.R. (Dept. of Materials Science and Engineering, Northwestern Univ., Evanston, IL (US)); Santer, J.S. (Packer Engineering, Naperville, IL (US))

    1990-01-01

    Professor Morris E. Fine is a pioneer in teaching the unifying concepts underlying all classes of materials: metals, ceramics, polymers, and electronic materials. He is a founder and the guiding genius of the first materials science department in the world. His research career at Northwestern University has spanned a broad range of topics, from physical chemistry to mechanical behavior, and includes studies on metals and alloys, ceramics, and composite materials. A symposium to recognize the many outstanding contributions by Professor Fine to the development of materials science as a discipline was organized on behalf of the TMS-ASM Committees of Mechanical Metallurgy, Flow and Fracture, and Structural Materials. This symposium was held in Detroit, Michigan, on 8-11 October in conjunction with the 1990 TMS Fall Meeting and Materials Week. Academic, government, and industrial speakers from around the globe gathered to present the latest concepts and experimental results on topics ranging from advanced materials to fundamental principles governing materials behavior. The papers were divided into seven sessions: Physical Metallurgy, Ferrous Structural Materials, Metal Matrix Composites, Microstructural Evolution, Engineering Materials, Fatigue and Fracture, and Flow and Fracture in Non-Ferrous Materials.

  8. 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).

  9. Geologic assessments and characterization of marine sand resources - Gulf of Mexico region

    USGS Publications Warehouse

    Williams, S. Jeffress; Cichon, Helena A.

    1993-01-01

    The U.S. Geological Survey conducts geologic surveys and research in marine areas of the United States and its territories and possessions. An objective in some of the investigations is locating and evaluating marine sand and gravel resources and interpretation of the origins of the sand body deposits. Results from such studies over the past 30 years show that many extremely large deposits are located close to expanding metropolitan areas, which have a need for aggregate materials for construction, and near-developed coastal areas, where beach replenishment may be used to mitigate coastal erosion. The Gulf of Mexico continental shelf from the Florida Peninsula to the Mexico border is an enormous area, but little attention has been directed on sand and gravel resources. Based on limited surveys, the total sand and gravel resources for the entire Gulf of Mexico is estimated to be 269 billion cubic meters. However, the sand tends to be fine-grained and is often mixed with mud; gravel deposits, except for shell, are mostly nonexistent.

  10. Reevaluation of Stevens sand potential - Maricopa depocenter, southern San Joaquin basin, California

    SciTech Connect

    Kolb, M.M.; Parks, S.L. (ARCO Oil and Gas Co., Bakersfield, CA (United States))

    1991-02-01

    During the upper Miocene in the Southern San Joaquin basin surrounding highlands contributed coarse material to a deep marine basin dominated by fine grained silicious bioclastic deposition. these coarse deposits became reservoirs isolated within the silicious Antelope Shale Member of the Monterey Formation. In the southern Maricopa depocenter these Stevens sands are productive at Yowlumne, Landslide, Aqueduct, Rio Viejo, San Emidio Nose, Paloma, and Midway-Sunset fields, and are major exploration targets in surrounding areas. In the ARCO Fee lands area of the southern Maricopa depocenter, Stevens sands occur as rapidly thickening lens-shaped bodies that formed as channel, levee, and lobe deposits of deep-marine fan systems. These fans were fed from a southerly source, with apparent transport in a north-northwesterly direction. Sands deflect gently around present-day structural highs indicating that growth of structures influenced depositional patterns. Correlations reveal two major fan depositional intervals bounded by regional N, O, and P chert markers. Each interval contains numerous individual fan deposits, with many lobes and channels recognizable on three-dimensional seismic data. In addition to these basinal sand plays presently being evaluated, ARCO is pursuing a relatively new trend on Fee lands along the southern basin margin, where correlation to mountain data reveals Stevens sands trend into the steeply dipping beds of the mountain front. This area, the upturned Stevens,' has large reserve potential and producing analogies at Metson, Leutholtz, Los Lobos, and Pleito Ranch fields.

  11. Sahara Coal: the fine art of collecting fines for profit

    SciTech Connect

    Schreckengost, D.; Arnold, D.

    1984-09-01

    A considerable increase in the volume of fines in rom coal caused Sahara Coal in Illinois to redesign the fine coal system in their Harrisburg preparation plant. Details of the new design, and particularly the fine refuse system which dewaters and dries 28 mesh x O clean coal, are given. Results have exceeded expectations in reducing product losses, operating costs and slurry pond cleaning costs.

  12. Determining the depositional environment of a braided channel sand using Formation MicroScanner images, North Vacuum field, Lea County, New Mexico

    SciTech Connect

    Burnham, D.E. (Mobil Exploration and Producing US Inc., Midland, TX (USA))

    1990-05-01

    Paleoenvironmental reconstruction analysis characterize the Atoka sands of the North Vacuum field, Lea County, New Mexico, as being deposited in a braided fluvial system. The channels trend from northwest to southeast. In the past the only sure way of identifying the depositional environment of a sand was by cutting a whole core. With the addition of the Formation MicroScanner (FMS) images, now one can interpret the depositional environment with greater confidence and without the cost of a shale core. The depositional environment was determined for Atokan sands by using the FMS in two wells. The results were verified by whole core and FMS in one well. The FMS data interpreted on Schlumberger's Sun workstation indicated that the sand was deposited in a braided channel system. The following sequence was observed: (1) erosion of the underlying shale, (2) then coarse-grained sands were deposited in a downflow direction until the eroded channel was filled, (3) then the sands were laterally accreted perpendicular to flow direction producing the thickest sand bodies, and (4) the final stage occurred during sea level transgression when fine-grained sand and shale lenses capped the massive sands with depositional current bedding in a landward direction indicating fluvial-marine influences. The conclusions based on the FMS images were supported by a whole core interpretation of a complete sandstone sequence in one well. Several additional locations have been chosen in the channel trend based on this model.

  13. 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)

  14. Sand veins and wedges in cold aeolian environments

    Microsoft Academic Search

    Julian B. Murton; Peter Worsley; Jan Gozdzik

    2000-01-01

    Sedimentary structures formed by the progressive primary infilling of thermal contraction cracks with sand are termed primary sand veins and sand wedges. In addition to simple vein- or wedge-shapes irregularities can be caused by sand veins branching from their sides and toes. Primary sand wedges form widely in sandy polar deserts, locally in sandy areas of tundra and probably in

  15. 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...

  16. technology offer SandTES -High Temperature Sand Thermal Energy Storage

    E-print Network

    Szmolyan, Peter

    technology offer SandTES - High Temperature Sand Thermal Energy Storage key words: High Temperature Energy Storage | Fluidized Bed | Sand | The invention consists of a fluidized bed with internal heat together with Dr. Eisl of ENRAG GmbH. Background Thermal energy storage (TES) systems are essential

  17. A high-efficiency, low-cost aeolian sand trap

    NASA Astrophysics Data System (ADS)

    Sherman, D. J.; Swann, C.; Barron, J. D.

    2014-06-01

    We present a design for an aeolian sand trap that is based on the streamer trap concept used in sediment transport studies. The trap is inexpensive, has excellent trapping efficiency, is durable, and easy to use. It is fabricated from stainless steel that is cut and bent to form a frame to support a fine nylon mesh. Typical trap openings are 100 mm wide and 25, 50, or 100 mm high. Traps are 250 mm long, and are stackable to measure vertical characteristics of saltation. The nylon mesh has 64 ?m openings that comprise 47% of the area of the material. Aerodynamic efficiency was tested in a wind tunnel, and sediment trapping efficiency evaluated in field deployments. Both evaluations support the use of this trap for short-term measurements.

  18. Depositional and diagenetic history of Bodcaw Sand, Cotton Valley Group (Upper Jurassic), Longwood field, Caddo Parish, Louisiana

    SciTech Connect

    Russell, B.J. Jr.; Sartin, A.A.

    1984-09-01

    The Bodcaw Sand contains fine-grained sandstones and siltstones deposited within a barrier-bar sequence. Based on vertical changes in sedimentary structures, texture, and mineralogic composition, three distinct lithofacies (upper, middle, and lower shoreface) within the Bodcaw Sand and two associated logoonal lithofacies were identified. Cross-stratification and low-angle laminations, rarely disrupted by biogenic structures, characterize the fine-grained upper shoreface sandstones. Middle shoreface sandstones have undergone extensive reworking by biotic and abiotic factors. Few primary sedimentary structures or early generation trace fossils are preserved in middle shoreface sandstones. Lower shoreface siltstones and very fine-grained sandstones contain lenticular and wavy bedding features that are disrupted in many places by bioturbation. The Bodcaw Sand has low porosity and permeability values. Vertical and lateral variation in porosity and permeability values are related to original deposition and subsequent diagenesis of Cotton Valley sediments. The Bodcaw Sand has had a complicated diagenetic history. Compaction, cementation, replacement, and dissolution have modified primary rock properties following deposition of barrier-bar sediments. Authigenic cementation plays an important role in modification of reservoir properties. Important authigenic minerals identified in the Bodcaw include silica, carbonates, and phyllosilicates. Two major diagenetic sequences are recognized on the basis of textural relationships between allogenic grains and authigenic constituents.

  19. Fine particulate capture device

    NASA Technical Reports Server (NTRS)

    Peterson, V. S.; Siewert, R. D. (inventors)

    1979-01-01

    To capture fine particulate matter in a gas such as air, a dielectric fluid is directed to the center of whichever face of a rotating disc is exposed to the air flow. The disc is comprised of two or more segments which bear opposite electrostatic potentials. As the dielectric fluid is centrifuged towards the periphery of the rotating disc, the fluid becomes charged to the same potential as the segment over which it is passing. Particulate matter is attracted to the charged segment and is captured by the fluid. The fluid then carries the captured particulate matter to a collection device such as a toroidal container disposed around the periphery of the disc. A grounded electrically-conductive ring may be disposed at the outer periphery of the disc to neutralize the captured particles and the fluid before they enter the container.

  20. Fine needle aspiration.

    PubMed

    Wu, Maoxin; Burstein, David E

    2004-01-01

    Fine needle aspiration (FNA) has been widely used as a diagnostic tool for the past half century. Differing from large bore cutting needle biopsy, FNA utilizes 22- to 27-gauge needles. The cell samples aspirated from a lesion are characteristically smeared on glass slides for immediate microscopic evaluation. An adequacy report and a preliminary diagnostic impression are rendered in approximately 10 to 15 minutes. A final report is generally rendered within 24 hours. The method has been used as one of the most cost-effective, complication-free, and rapid techniques for preoperative investigation of tumors and tumor-like conditions. Its usefulness in the diagnosis and management of oncology patients is emphasized in this article. PMID:15565819

  1. Automated Camera Array Fine Calibration

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

    2008-01-01

    Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

  2. 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)

  3. 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

    Microsoft Academic Search

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

    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

  4. Continuous fine ash depressurization system

    DOEpatents

    Liu, Guohai (Birmingham, AL); Peng, Wan Wang (Birmingham, AL); Vimalchand, Pannalal (Birmingham, AL)

    2011-11-29

    A system for depressurizing and cooling a high pressure, high temperature fine solid particles stream having entrained gas therein. In one aspect, the system has an apparatus for cooling the high pressure, high temperature fine solid particles stream having entrained gas therein and a pressure letdown device for depressurization by separating the cooled fine solid particles from a portion of the fine solid particles stream having entrained gas therein, resulting in a lower temperature, lower pressure outlet of solid particles for disposal or handling by downstream equipment.

  5. SANDIA REPORT SAND930731 s UC706

    E-print Network

    Kansas, University of

    SANDIA REPORT SAND93­0731 s UC­706 Unlimited Release Printed March 1993 Spaceborne SAR Study: LDRD, VA 22161 NTIS price codes Printed copy A06 Microfiche copy AO1 #12;SAND93-0731 Unlimited Release ................................................. 4.2 Power and Weight

  6. Radium Removal Using Sorption to Filter Sand

    Microsoft Academic Search

    Richard L. Valentine; Timothy S. Mulholland; Roger C. Splinter

    1987-01-01

    This 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 so that performance estimates could be made. Laboratory pilot studies using a partially softened groundwater showed

  7. Great Sand Dunes National Monument and Preserve

    E-print Network

    inventory program, the National Park Service (NPS) contracted the Colorado Natural Heritage Program (CNHPGreat Sand Dunes National Monument and Preserve 2003 Vascular Plant Inventory Susan Spackman) in 2001-2004 to conduct a field inventory of vascular plants of Great Sand Dunes National Monument

  8. 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…

  9. SANDIA REPORT SAND2014-17460

    E-print Network

    SANDIA REPORT SAND2014-17460 Unlimited Release Printed September 2014 Wave Energy Converter Effects@ntis.fedworld.gov Online order: http://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2014-17460 Unlimited

  10. SANDIA REPORT SAND2014-17401

    E-print Network

    SANDIA REPORT SAND2014-17401 Unlimited Release Printed September 2014 Wave Energy Converter (WEC://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2014-17401 Unlimited Release Printed September 2014 Wave Energy Converter

  11. SANDIA REPORT SAND2012-0304

    E-print Network

    SANDIA REPORT SAND2012-0304 Unlimited Release Printed January 2012 A Retrospective of VAWT://www.ntis.gov/help/ordermethods.asp?loc=7-4- 0#online #12;-3- SAND2012-0304 Unlimited Release Printed January 2012 A Retrospective of VAWT

  12. SANDIA REPORT SAND2004-4596

    E-print Network

    Ho, Cliff

    SANDIA REPORT SAND2004-4596 Unlimited Release Printed September 2004 Sensors for Environmental@ntis.fedworld.gov Online order: http://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online 2 #12;SAND2004-4596 Unlimited

  13. SANDIA REPORT SAND2005-0336

    E-print Network

    Ho, Cliff

    SANDIA REPORT SAND2005-0336 Unlimited Release Printed Month/Year FY04 Field Evaluations of an In@ntis.fedworld.gov Online order: http://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online 2 #12;SAND2005-0336 Unlimited

  14. SANDIA REPORT SAND 2012-4417

    E-print Network

    SANDIA REPORT SAND 2012-4417 Unlimited Release Printed June 2012 Site Environmental Report for 2011@ntis.fedworld.gov Online order: http://www.ntis.gov/ordering.htm #12;3 SAND 2012-4417 Unlimited Release Printed June 2012

  15. SANDIA REPORT SAND2014-16800

    E-print Network

    SANDIA REPORT SAND2014-16800 Unlimited Release Printed August 2014 A Comparison of Platform Options://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND2014-16800 Unlimited Release Printed August 2014 A Comparison of Platform

  16. 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)

  17. SANDIA REPORT SAND 2013-3735

    E-print Network

    SANDIA REPORT SAND 2013-3735 Unlimited Release Printed June 2013 Site Environmental Report for 2012@ntis.fedworld.gov Online order: http://www.ntis.gov/help/ordermethods.asp?loc=7-4-0#online #12;3 SAND 2013-3735 Unlimited

  18. Characterization of a Utah tar sand bitumen

    Microsoft Academic Search

    J. W. Bunger

    1976-01-01

    A preliminary characterization of a Utah tar sand bitumen has been made using methods developed for high boiling petroleum fractions. The characterization includes information about the major compound types which can be compared with similar data for other tar sand bitumens and, more importantly, can be correlated with data from petroleum samples for which refining characteristics are known. Examination of

  19. Colonization patterns in Sand Martins Riparia riparia

    Microsoft Academic Search

    Gareth Jones

    1987-01-01

    Settlement patterns of Sand Martins at a sand quarry in central Scotland are described. Older birds returned to the colony before first-year individuals, and thus had the widest choice of subcolony in which to nest. A model of subcolony settlement was developed which assumed that individuals nested in subcolonies where their reproductive success was maximized. The colonization patterns observed fitted

  20. 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...

  1. Introduction to Exploring Sand and Water

    ERIC Educational Resources Information Center

    Early Childhood Today, 2006

    2006-01-01

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

  2. 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.

  3. 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...

  4. 16th President Timothy D. Sands

    E-print Network

    Buehrer, R. Michael

    and conference proceedings and has been granted 17 patents in electronic and optoelectronic materials and devices, and thermoelectric refrigeration. Sands is a fellow of the Institute of Electrical and Electronics Engineers children, each of whom has attended Purdue University. Installation of President Timothy D. Sands - 2 - #12

  5. White Sands National Monument: Education Fact Sheets

    NSDL National Science Digital Library

    This National Park Service website contains the following reference sections: Where Does All the Sand Come From?, Animals of the Desert, How Do Sand Dunes Move?, and Plants of the Dune Field. There are recommended reading lists for students from preschool to high school interested in pursuing these topics further.

  6. Update on federal tight sands incentive policies

    Microsoft Academic Search

    Buch

    1980-01-01

    Recognizing the great potential of increased domestic tight sands production in reducing imports of foreign energy, several branches of the federal government have initiated policies to encourage development of this resource. However, these policies have been slow in formulation, and some are potentially in conflict with each other. Two characteristics of tight sands gas have led to it being singled

  7. Why are ripples absent in coarse sands?

    NASA Astrophysics Data System (ADS)

    Best, J.; Barros, J.; Blois, G.; Christensen, K. T.

    2013-12-01

    Current ripples are perhaps the most abundant and common bedform and sedimentary structure in contemporary and ancient sediments, with their stability field being dependent on the applied bed shear stress and grain size. The ripple stability field begins to narrow in medium sand with ripples ceasing to exist in sands coarser than c. 0.7mm diameter. Leeder (1980) proposed that the absence of ripples in coarse sands is linked to the influence of increasing grain roughness that strengthens vertical mixing of fluid near the bed, and thereby disrupts flow separation over bed defects from which ripples normally propagate. In this paper, we use a novel thin (5mm wide) flume to investigate the dynamics of bedforms developed in a very coarse sand and use PIV to detail the dynamics of flow associated with the initial bedforms developed in this sand. We highlight the irregular wavelength, height and migration characteristics of these bedforms and contrast this with ripples developed in a medium sand. Furthermore, we utilize the near-bed PIV data to examine vertical flow velocities and the possible role of hyporheic flow upwelling in the bedform leeside. Such hyporheic flow, induced by pressure gradients established around the bedform, can lead to significant modifications to the leeside flow separation zone that may be contribute to the absence of current ripples in coarse sands. Reference Leeder, M.R. 1980 On the stability of lower stage plane beds and the absence of ripples in coarse sands, J. Geol. Soc. London, 137, 423-30.

  8. UMore Park Sand and Gravel Resources Project University of Minnesota

    E-print Network

    Netoff, Theoden

    UMore Park Sand and Gravel Resources Project University of Minnesota Public Comment Forum and Open ­ Steven Lott, Co-project manager, UMore Park Sand and Gravel Resources Project 6:40 The UMore Park Sand

  9. 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

  10. Ecological release in White Sands lizards.

    PubMed

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

    2011-12-01

    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

  11. 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

  12. 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

  13. 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%.

  14. Geomorphic controls on fine sediment reinfiltration into salmonid spawning gravels and the implications for spawning habitat rehabilitation

    NASA Astrophysics Data System (ADS)

    Franssen, Jan; Lapointe, Michel; Magnan, Pierre

    2014-04-01

    Anthropogenic activities often increase the flux of fine sediment to fluvial environments. In gravel-bed streams the extent to which augmented fines loading causes the degradation of vital interstitial habitats is determined by factors controlling fines infiltration into channel substratum. Previous research suggests that substrate pore constriction size, intensity of upwelling interstitial flow, and the quantity of fines transported across the bed surface (i.e., exposure dose) are three important factors controlling substrate fines content. Few field studies have investigated the interactive effects of these physical factors. We constructed 17 experimental redds in brook trout spawning microhabitats in a boreal forest stream in Quebec, Canada, to investigate the role of pore constriction size, hyporheic flow, and exposure dose on substrate fines content. To simulate the effect of spawning in coarsening the substrates, redds were partially cleaned of coarse sand and of all fine sediment (< 0.5 mm). Results show that coarse sands and fine gravel (0.5-4 mm; filter class) acted as a filter of percolating fine sediment (< 0.5 mm). We found that this filtering effect (i.e., lower fines density at egg pocket depth) occurred at sites where the proportion of the filter class in the substratum above egg pocket depth exceeded a threshold value of 18%, as indicated by a statistically significant step-function response between fines gradient with depth and the filter class content in the uppermost layers of the bed. Results also indicated that fines content at depth was unrelated to fines exposure. Estimated upward seepage rates were well below the threshold velocity that would inhibit the percolation of medium-grained sand (i.e., 0.5 mm) into the bed. These results suggest that within these gravel-bed spawning substrates the abundance of filter classes was the primary determinant of fines content at depth. This study highlights the importance of considering filter class content in the implementation of spawning habitat rehabilitation schemes and when assessing the susceptibility of incubation microhabitats to augmented fine sediment loading to streams.

  15. Impact of ozonation on particle aggregation in mature fine tailings.

    PubMed

    Liang, Jiaming; Tumpa, Fahmida; Pérez Estrada, Leonidas; Gamal El-Din, Mohamed; Liu, Yang

    2014-12-15

    The extraction of bitumen from the oil sands in Canada generates tonnes of mature fine tailings (MFT), consisting of a mineral matrix of sand, clay, and water, which without treatment requires thousands of years to fully consolidate. We assessed the performance of a novel ozonation method designed to enhance the settling of MFT and explored the mechanisms involved. The solid content of MFT obtained from oil sands tailings was adjusted to 1, 3, 5 wt % with water before applying 15, 30, and 60 min of ozonation. MFT settled after a short (15 min) ozonation treatment, resulting in a sample with clear released water on the top and condensed sludge at the bottom. The water chemistry characteristics, particles' surface charge and chemical bonding were measured. Ozonation led to the increased organic acids concentrations in MFT suspension through converting of organic matter from high to low molecular weight, and detaching organic coating on MFT particles. The pH and the concentrations of ions in the MFT suspension were changed significantly, an association of metal ions with MFT particles was promoted, and the surface charges of MFT particles were neutralized. Consequently, the MFT suspension was destabilized and MFT particle precipitation was observed. PMID:25214072

  16. 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

  17. 3D seismic, geochemical and biostratigraphical analysis of Paleogene remobilized sand in the Norwegian-Danish Basin

    NASA Astrophysics Data System (ADS)

    Andresen, Katrine Juul; Rønø Clausen, Ole; Heilmann-Clausen, Claus; Friis, Henrik

    2013-04-01

    This study describes remobilized Paleogene sand occurring on the hanging-wall segment north of the major D-1 normal fault in the Norwegian-Danish Basin, eastern North Sea. The remobilized sand is observed on 3D seismic data in fine-grained Eocene host-strata as cross-cutting reflections with a typical tabular, V-shaped or wing-like geometry in the seismic cross-sections and a pronounced jack-up of the overlying succession onto which onlap can be observed. In map view the remobilized sand in certain areas have a channel-like appearance. The seismic observations indicate that the sand has a remobilized origin which may be partly depositional. Particularly the observed wings and jack-up on the seismic cross-sections indicate remobilization which potentially could be generated by two different processes: a) remobilization of depositional channel sand resulting in the formation of injected wings along the sides of the channel, or b) injection of remobilized sand from the deeper Paleocene strata causing jack-up and typically V-shaped intrusions. Injection of Paleocene sand into Eocene host strata is a well-known phenomenon from the nearby Paleogene Siri Canyon located c. 15 km north of the study area. In order to acquire more information about the intrusions a geochemical study and a detailed biostratigraphical dating of cuttings and sidewall core samples from the Floki-1 well was carried out. The Floki-1 well penetrates the remobilized sand and was drilled to test an apparent 4-way closure on prospect Eocene sand which by then was interpreted to be 100 % depositional. The geochemical study of the samples from the sand identified the Floki-sandstone as a very fine grained sand and silt with a matrix of very angular silt grains. The sand does not contain clays. The matrix appears to have formed by crushing of the sand grains. Thus, heavy minerals appear to have disintegrated by crushing but still most parts of the mineral grain is found together. Glauconite grains are strongly smeared. The sorting pattern, and the angular shape of silt sized matrix grains, and the intense shearing and deformation of glauconite grains indicates that the sand may have been injected under high pressure, resulting in massive crushing of detrital grains. The age dating mainly includes dinocysts analysis from seven sidewall core samples and nine cutting samples above, within and below the sand. It is expected that the sand should either be of Eocene age probably revealing a depositional origin with subsequent remobilization to the sides (process a), or a Paleocene age revealing injection from the deeper strata (process b). In order to address all observations, a potential model of generation may include elements of depositional sand combined with up-, downward and/or lateral injection which could have been facilitated by intense activity in the nearby D-1 fault. The study highlights the importance of interdisciplinary approaches in the interpretation of complex geological features formed by several geological processes and mechanisms.

  18. Suspended sand transport in surf zones

    NASA Astrophysics Data System (ADS)

    Kobayashi, Nobuhisa; Zhao, Haoyu; Tega, Yukiko

    2005-12-01

    Three tests were conducted in a wave flume to investigate time-averaged suspended sediment transport processes under irregular breaking waves on equilibrium beaches consisting of fine sand. Free surface elevations were measured at ten locations for each test. Velocities and concentrations were measured in the vicinity of the bottom at 94 elevations along 17 vertical lines. The relations among the three turbulent velocity variances are found to be similar to those for the boundary layer flow. The vertical variation of the mean velocity, which causes offshore transport, is fitted by a parabolic profile fairly well. The vertical variation of the mean concentration ? is fitted by the exponential and power-form distributions equally well. The ratio between the concentration standard deviation ?C and the mean ? varies little vertically. The correlation coefficient ?UC between the horizontal velocity and concentration, which results in onshore transport, is of the order of 0.1 and decreases upward linearly. The offshore and onshore transport rates of suspended sediment are estimated and expressed in terms of the suspended sediment volume ? per unit area. A time-averaged numerical model is developed to predict ? as well as the mean and standard deviation of the free surface elevation and horizontal velocity. The bottom slope effect on the wave energy dissipation rate DB due to wave breaking is included in the model. The computation can be made well above the still water shoreline with no numerical difficulty. Reflected waves from the shoreline are estimated from the wave energy flux remaining at the shoreline. The numerical model is in agreement with the statistical data except that the undertow current is difficult to predict accurately. The measured turbulent velocities are found to be more related to the turbulent velocity estimated from the energy dissipation rate Df due to bottom friction. The suspended sediment volume ? expressed in terms of DB and Df can be predicted only within a factor of about 2. The roller effect represented by the roller volume flux does not necessarily improve the agreement for the three tests.

  19. Process for extracting oil from tar sands

    SciTech Connect

    Hall, J.B.; Russo, A.

    1990-10-30

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

  20. 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.

  1. Burrowing inhibition by fine textured beach fill: Implications for recovery of beach ecosystems

    NASA Astrophysics Data System (ADS)

    Viola, Sloane M.; Hubbard, David M.; Dugan, Jenifer E.; Schooler, Nicholas K.

    2014-10-01

    Beach nourishment is often considered the most environmentally sound method of maintaining eroding shorelines. However, the ecological consequences are poorly understood. Fill activities cause intense disturbance and high mortality and have the potential to alter the diversity, abundance, and distribution of intertidal macroinvertebrates for months to years. Ecological recovery following fill activities depends on successful recolonization and recruitment of the entire sandy intertidal community. The use of incompatible sediments as fill material can strongly affect ecosystem recovery. We hypothesized that burrowing inhibition of intertidal animals by incompatible fine fill sediments contributes to ecological impacts and limits recovery in beach ecosystems. We experimentally investigated the influence of intertidal zone and burrowing mode on responses of beach invertebrates to altered sediment texture (28-38% fines), and ultimately the potential for colonization and recovery of beaches disturbed by beach filling. Using experimental trials in fill material and natural beach sand, we found that the mismatched fine fill sediments significantly inhibited burrowing of characteristic species from all intertidal zones, including sand crabs, clams, polychaetes, isopods, and talitrid amphipods. Burrowing performance of all five species we tested was consistently reduced in the fill material and burrowing was completely inhibited for several species. The threshold for burrowing inhibition by fine sediment content in middle and lower beach macroinvertebrates varied by species, with highest sensitivity for the polychaete (4% fines, below the USA regulatory limit of 10% fines), followed by sand crabs and clams (20% fines). These results suggest broader investigation of thresholds for burrowing inhibition in fine fill material is needed for beach animals. Burrowing inhibition caused by mismatched fill sediments exposes beach macroinvertebrates to stresses, which could depress recruitment and survival at all intertidal zones. Our results suggest use of incompatible fine fill sediments from dredging projects creates unsuitable intertidal habitat that excludes burrowing macroinvertebrates and could delay beach ecosystem recovery. Through effects on beach invertebrates that are prey for shorebirds and fish, the ecological impacts of filling with mismatched fine sediments could influence higher trophic levels and extend beyond the beach itself.

  2. 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

  3. 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.

  4. Ultrasonic velocities in sands--Revisited

    SciTech Connect

    Blangy, J.P.; Moos, D.; Nur, A. (Stanford Univ., CA (United States). Geophysics Dept.); Strandenes, S. (Norsk Hydro, Bergen (Norway))

    1993-03-01

    Ultrasonic compressional and shear-wave velocities of isotropic sands are shown to be dependent on their mineralogy, their porosity, their fluid content, and their state of consolidation, under fixed temperature and pressure conditions. This leads to a distinction between two broad classes of sands: those that are well consolidated, and those that are loosely consolidated. Changes in elastic velocities reflect changes in the ratio of bulk and shear moduli to density in response to lithologic variations. The authors decouple the two effects by examining changes in elastic moduli with respect to changes in lithology, and they observe three main points: (1) For consolidated sandstones, the effects of mineralogy and porosity can be approximated both empirically and theoretically by a modified isostrain theory: the dry bulk and shear moduli of the rock aggregate follow a mixing law'', being linear combinations of the respective moduli of the individual constituents. The dry elastic moduli of families of clean sands and shaley sands are linear functions of porosity, with decreasing y-axis intercepts as their clay-to-sand ratio increases. (2) Loosely consolidated sands and sandy shales appear to follow a behavior closer to that of the isostress theory for suspensions: the reciprocals of the bulk and shear moduli of the rock aggregate are linear combinations of the reciprocal moduli of their individual constituents. In general, the elastic moduli of poorly, lithified sands are less sensitive to changes in mineralogy and porosity than those of consolidated sandstones. (3) For high permeability sands like the loosely consolidated sands of Troll, the Biot-Gassman theory is a good approximation to the effects of fluids on seismic velocities. With this understanding of elastic moduli, the authors then show that dry ratios V[sub P]/V[sub S] increase with porosity and clay content.

  5. VideoLab: Swimming in Sand

    NSDL National Science Digital Library

    Ryan D. Maladen (Georgia Institute of Technology; Interdisciplinary Bioengineering Program)

    2009-07-17

    Physics can model organisms running or crawling on solids, and those flying and swimming through fluids. Yet the desert-dwelling sandfish lizard moves through sand -- a solid- and fluid-like medium. Using high-speed x-ray imaging, Maladen et al. discovered that, although the sandfish uses its legs to run on top of sand and to bury itself underneath (movie 1), once subsurface, sandfish use undulatory locomotion (movie 2), slithering through sand with its unused limbs tucked close to its body (movie 3).

  6. Skin friction for steel piles in sand

    E-print Network

    Sulaiman, Ibrahim Hikmat

    1967-01-01

    SkiN FRICTION FOR STEZL PIIZS IN SAND A Theeia by I. H. Sulaiman Submittei io the graduate College of t, he Texan AAB Univen-ity in Ixantial fulfil. ment of bhe zequiremenbu for the degree of NASTZR 0F SCISNCZ May 196'7 bsrjor Subject...: Civil Engineering SKIN FRICTION FOR STEEL PILES IN SAND A Thesis by I. H. Sulaiman Approved as to style and content by: Chairman of C mmittee Head of Department Memb Member 111 Skin Friction For Steel Piles in Sand (May 1967) Ibr shim Hikmat...

  7. The accumulation of nitrosyl ruthenium by fine particles and marine organisms

    Microsoft Academic Search

    RAYMOND F. JONES

    1960-01-01

    The accumulation of nitrosyl ruthenium lo0 by fine particles, algae and animals from sea water is described. The presence of ferric hydroxide on the sand and silt particles enhances RuloG accumulation. Uptake of Ru loG by marinc algae is a surface phenomenon associated with the extra-cellular polysaccharide material. Fish accumulate the nuclidc principally in the gut, gills and skin. In

  8. Harry Sands (1917-2007).

    PubMed

    Ochroch, Ruth

    2009-01-01

    To everyone who knew and had worked with him, the death of Harry Sands on January 3, 2007, three days before his 90th birthday, resounded as though a mighty oak had fallen. Harry was a giant of a man, both as a human being and as a psychologist. Harry was born January 6, 1917, on the Lower East Side of Manhattan to Russian immigrant parents who ran a laundry. His bachelor's degree in psychology (1941) and his doctoral degree (1952) were both earned at New York University. Harry became a member of the American Psychological Association (APA) in 1943. With his breadth of experience and knowledge, as well as his firm foundation in management and finance, he eventually became a financial advisor to the APA Practice Directorate as well as to the American Psychological Foundation. As the executive director of the Postgraduate Center for Mental Health, Harry made creative strides to improve both the public awareness of the organization as well as its fiscal health. Harry was an active writer and researcher, with a particular interest in epilepsy and various psychoanalytic topics. PMID:19203149

  9. Numerical modeling of basaltic sand ripples on Eagle crater as indirect evidence for the hysteresis effect in Martian saltation

    NASA Astrophysics Data System (ADS)

    Yizhaq, H.; Kok, J. F.; Michaels, T. I.

    2012-12-01

    Aeolian ripples, which form regular patterns on sand beaches and desert floors and also on Mars, indicate the instability of flat sand surfaces under the wind-induced transport of sand grains. The opportunity rover documented small normal basaltic sand ripples at the bottom of Eagle crater in Meridinai planum. These ripples are composed of fine basaltic sand (100 micron) and their average wavelength and height are 10 cm and 1 cm respectively. Such light particles are thought to be easily suspended by turbulence at the fluid threshold, such that the wind speed at which these bedforms developed must be substantially below the fluid threshold. The occurrence of these bedforms on the Martian surface thus requires the impact threshold to be substantially smaller than the fluid threshold. Recently, it was suggested that saltation on Mars can be maintained at much lower wind speeds than the fluid threshold which is needed to initiate it (Kok, 2010). We used simulations of the steady state saltation model COMSALT together with a dynamic model for sand ripples (Yizhaq et al., 2004) to show that the small basaltic ripples can develop under wind speeds below the threshold for suspension. We used COMSALT to give the basic values of the parameters that used by the ripple model for saltation on Mars with and without cohesion: 1. The average number of reptating grains per impact of one saltating grain. 2. The number density of impact saltating grains on flat surface. 3. The probability distribution of reptation lengths. We used COMSALT results to calculate the sand flux on Mars for different shear velocities and used GCM models simulations for prediction of the sand flux under predicted wind regime and compare it with recent estimations (Bridges et al., 2012). Our numerical simulations (Fig. 1) show that ripples like the basaltic ripples on Eagle crater can be developed by shear velocity much below the fluid threshold by the impact mechanism. These findings can be regarded as an indirect proof of the unique saltation mechanism on Mars. References Bridges, N. T. et al. 2012. Earth-like sand fluxes on Mars. Nature 485, 339-342. Kok, J. F. 2010. Differences in the wind speeds required for initiation versus continuation of sand transport on Mars: Implications for dunes and sand storms. Physical Review Letters, 104, 074502. Yizhaq, H., Balmforth, N.J and Provenzale, A. 2004. Blown by wind: Nonlinear dynamics of aeolian sand ripples. Physica D, 195, 207-228. Model simulation of normal ripples on Mars with parameters computed by COMSALT for different shear velocities with and without cohesion after one hour. The inset shows the final ripples profile for u*=0.65 m/s.

  10. 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.

  11. 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.

  12. Generation of sand bars under surface waves

    E-print Network

    Hancock, Matthew James, 1975-

    2005-01-01

    (cont.) Experiments were performed in a large wave flume to validate the theory and to study additional aspects of sand bar evolution. The wave envelope and bar profile were recorded for low and high beach reflection, ...

  13. Establishment and maintenance of sand fly colonies.

    PubMed

    Volf, P; Volfova, V

    2011-03-01

    Sand flies used to have a reputation for being difficult and labour-intensive to breed. Here we summarize our experience with establishment and maintenance of sand fly colonies and their use for infective experiments: techniques for collection and handling wild-caught females, rearing larvae and adults and experimental infections of sand flies by Leishmania using membrane feeding. In addition, we compare major life cycle parameters between various colonies maintained under standard laboratory conditions. The sand fly rearing is tricky but some species can be reared in large numbers with a minimum of space and equipment. Initiation of new colonies from endemic sites is a prerequisite for accurate studies on parasite-vector interaction but it is more difficult step than routine maintenance of colonies already established in laboratory for many generations. PMID:21366760

  14. Hierarchical analysis of genetic structure in the habitat-specialist Eastern Sand Darter (Ammocrypta pellucida)

    PubMed Central

    Ginson, Robert; Walter, Ryan P; Mandrak, Nicholas E; Beneteau, Courtney L; Heath, Daniel D

    2015-01-01

    Quantifying spatial genetic structure can reveal the relative influences of contemporary and historic factors underlying localized and regional patterns of genetic diversity and gene flow – important considerations for the development of effective conservation efforts. Using 10 polymorphic microsatellite loci, we characterize genetic variation among populations across the range of the Eastern Sand Darter (Ammocrypta pellucida), a small riverine percid that is highly dependent on sandy substrate microhabitats. We tested for fine scale, regional, and historic patterns of genetic structure. As expected, significant differentiation was detected among rivers within drainages and among drainages. At finer scales, an unexpected lack of within-river genetic structure among fragmented sandy microhabitats suggests that stratified dispersal resulting from unstable sand bar habitat degradation (natural and anthropogenic) may preclude substantial genetic differentiation within rivers. Among-drainage genetic structure indicates that postglacial (14 kya) drainage connectivity continues to influence contemporary genetic structure among Eastern Sand Darter populations in southern Ontario. These results provide an unexpected contrast to other benthic riverine fish in the Great Lakes drainage and suggest that habitat-specific fishes, such as the Eastern Sand Darter, can evolve dispersal strategies that overcome fragmented and temporally unstable habitats. PMID:25691991

  15. Water and entrapped air redistribution in heterogeneous sand sample: Quantitative neutron imaging of the process

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Jelinkova, Vladimira; Sobotkova, Martina; Sacha, Jan; Vontobel, Peter; Hovind, Jan

    2015-02-01

    Saturated flow in soil with the occurrence of preferential flow often exhibits temporal changes of saturated hydraulic conductivity even during the time scale of a single infiltration event. These effects, observed in a number of experiments done mainly on heterogeneous soils, are often attributed to the changing distribution of water and air in the sample. We have measured the variation of the flow rates during the steady state stage of the constant head ponded infiltration experiment conducted on a packed sample composed of three different grades of sand. The experiment was monitored by quantitative neutron imaging, which provided information about the spatial distribution of water in the sample. Measurements were taken during (i) the initial stages of infiltration by neutron radiography and (ii) during the steady state flow by neutron tomography. A gradual decrease of the hydraulic conductivity has been observed during the first 4 h of the infiltration event. A series of neutron tomography images taken during the quasi-steady state stage showed the trapping of air bubbles in coarser sand. Furthermore, the water content in the coarse sand decreased even more while the water content in the embedded fine sand blocks gradually increased. The experimental results support the hypothesis that the effect of the gradual hydraulic conductivity decrease is caused by entrapped air redistribution and the build up of bubbles in preferential pathways. The trapped air thus restricts the preferential flow pathways and causes lower hydraulic conductivity.

  16. Hierarchical analysis of genetic structure in the habitat-specialist Eastern Sand Darter (Ammocrypta pellucida).

    PubMed

    Ginson, Robert; Walter, Ryan P; Mandrak, Nicholas E; Beneteau, Courtney L; Heath, Daniel D

    2015-02-01

    Quantifying spatial genetic structure can reveal the relative influences of contemporary and historic factors underlying localized and regional patterns of genetic diversity and gene flow - important considerations for the development of effective conservation efforts. Using 10 polymorphic microsatellite loci, we characterize genetic variation among populations across the range of the Eastern Sand Darter (Ammocrypta pellucida), a small riverine percid that is highly dependent on sandy substrate microhabitats. We tested for fine scale, regional, and historic patterns of genetic structure. As expected, significant differentiation was detected among rivers within drainages and among drainages. At finer scales, an unexpected lack of within-river genetic structure among fragmented sandy microhabitats suggests that stratified dispersal resulting from unstable sand bar habitat degradation (natural and anthropogenic) may preclude substantial genetic differentiation within rivers. Among-drainage genetic structure indicates that postglacial (14 kya) drainage connectivity continues to influence contemporary genetic structure among Eastern Sand Darter populations in southern Ontario. These results provide an unexpected contrast to other benthic riverine fish in the Great Lakes drainage and suggest that habitat-specific fishes, such as the Eastern Sand Darter, can evolve dispersal strategies that overcome fragmented and temporally unstable habitats. PMID:25691991

  17. 36 CFR 910.35 - Fine arts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 3 2011-07-01 2011-07-01 false Fine arts. 910.35 Section 910.35 Parks, Forests, and...Applicable to the Development Area § 910.35 Fine arts. Fine arts, including sculpture, paintings, decorative...

  18. 36 CFR 910.35 - Fine arts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 3 2010-07-01 2010-07-01 false Fine arts. 910.35 Section 910.35 Parks, Forests, and...Applicable to the Development Area § 910.35 Fine arts. Fine arts, including sculpture, paintings, decorative...

  19. 36 CFR 910.35 - Fine arts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 3 2014-07-01 2014-07-01 false Fine arts. 910.35 Section 910.35 Parks, Forests, and...Applicable to the Development Area § 910.35 Fine arts. Fine arts, including sculpture, paintings, decorative...

  20. 36 CFR 910.35 - Fine arts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 3 2012-07-01 2012-07-01 false Fine arts. 910.35 Section 910.35 Parks, Forests, and...Applicable to the Development Area § 910.35 Fine arts. Fine arts, including sculpture, paintings, decorative...

  1. Effect of sediment concentration on artificial well recharge in a fine sand aquifer

    E-print Network

    Rahman, Mohammed Ataur

    1968-01-01

    abandonment of wells; 5. increase municipal expansion resulting from subsurface water supplies; 6. prevent sea water intrusion into coastal aquifers; 7. prevent dewatering of all or part of the under- ground reservoirs; 8. prevent release of deep... developed using the so-called Dupuit assumptions and is based on the solution of Laplace's equation as applied to the velocity potential at any point in the aquifer (19, 29, 36). The Dupuit assumptions are: (a) the velocity of the flow is proportional...

  2. CONCENTRATION OF TITANIUM-ZIRCONIUM SEA SANDS

    Microsoft Academic Search

    A. A. Nikitin; V. S. Dokshin; F. I. Korneev; V. O. Godass

    1963-01-01

    Gravitational enrichment and magnetlc separation of Ti Zr sands of the ; tertiary period are described. The weight of the sand in the deposit is 1.9 to ; 2.15 t\\/m³, moisture content is 5.6 to 12.3%, elmenite grain size is 0.25to ; 0.07 mm, rutile grain size is 0.25 to 0.06 mm, and zirconia grain size is 0.15 to ;

  3. Sulphur sand mixes as building material

    Microsoft Academic Search

    M. A. Samarai; M. Laquerbe; A. Al-Hadithi

    1985-01-01

    Following an extensive research programme lasting more than 4 years, it has been possible to prepare sulphur sand mixtures\\u000a which are suitable as building material. As compared to normal concrete, sulphur sand mixes exhibit greater compressive and\\u000a flexural strengths, have equivalent modulus of elasticity, have a lower and much more rapid shrinkage, creep is less under\\u000a compression and these mixes

  4. Hydrothermal deformation of granular quartz sand

    Microsoft Academic Search

    Stephen L. Karner; Andreas K. Kronenberg; Frederick M. Chester; Judith S. Chester; Andrew Hajash Jr

    2008-01-01

    Isotropic and triaxial compression experiments were performed on porous aggregates of St Peter quartz sand to explore the influence of temperature (to 225°C). During isotropic stressing, samples loaded at elevated temperature exhibit the same sigmoidal stress-strain curves and non-linear acoustic emission rates as have previously been observed from room temperature studies on sands, sandstones, and soils. However, results from our

  5. Developing Alberta's oil sands, 1920--2002

    NASA Astrophysics Data System (ADS)

    Chastko, Paul Anthony

    This dissertation examines the origins and development of the Alberta oil sands industry over the last century from a scientific project to a commercial endeavor. Based on extensive use of primary sources, the manuscript integrates the developments in a number of fields (politics, international relations, business and economics, and changing oil-recovery technology) that have made it possible to "manufacture" oil from the Alberta tar sands at less than $10 U.S. per barrel.

  6. 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.

  7. Treating tar sands formations with dolomite

    DOEpatents

    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.

  8. Phenolic removal processes in biological sand filters, sand columns and microcosms.

    PubMed

    Welz, P J; Ramond, J-B; Cowan, D A; Burton, S G

    2012-09-01

    This study evaluated the removal processes involved in the removal of the phenolic component of winery wastewater in biological sand filters, sand columns and sand microcosms. It was found that at low influent phenolic concentrations, complete organic removal was accomplished, but at high concentrations, there was incomplete substrate removal and an accumulation of potentially toxic metabolites, including catechol. The sand provided a suitable substrate for the treatment of phenolic-laden waste, and both biotic (48%) and abiotic (52%) removal mechanisms effected the removal of model phenolics. Prior acclimation of microbial communities increased the biodegradation rate of phenolic acids significantly. PMID:22728790

  9. Compacted sand-bentonite mixtures for hydraulic containment liners

    Microsoft Academic Search

    Tanit Chalermyanont; Surapon Arrykul

    Sand is a pervious material in nature. Mixing sand with appropriate bentonite contents yields sand- bentonite mixtures having low hydraulic conductivity that can be used as hydraulic containment liners. In this study, compaction tests were conducted to determine the optimum water content and maximum dry unit weight of compacted sand-bentonite mixtures. Direct shear and hydraulic conductivity tests were conducted to

  10. Effect of Cement on the Engineering Properties of Sand

    Microsoft Academic Search

    Rakesh Kumar Dutta

    2008-01-01

    This paper describes the comparative study of the assessment and effect of cement on the engineering properties (compaction, unconfined compressive strength and durability behaviour) of corralline and desert sand. The results of the study showed that the addition of the cement improves the engineering properties of both the sands. The maximum dry unit weight of coralline sand and desert sand

  11. Bonding energies of bitumen to tar sand mineral

    SciTech Connect

    Ensley, E.K.; Scott, M.A.

    1986-03-01

    The bonding energy of bitumen in a tar sand was found by algebraically adding the heat of dissolution of bitumen on tar sand, heat of dissolution of recovered bitumen and the heat of wetting of extracted tar sand mineral. The value for an Asphalt Ridge tar sand was found to be 270 cal/mole. 6 refs., 3 figs.

  12. 1 INTRODUCTION Oil sand has unique properties exhibits performance

    E-print Network

    Joseph, Tim Grain

    1 INTRODUCTION Oil sand has unique properties exhibits performance akin to sandstone in winter seated on oil sand can sink after a number of cycles with ground softening oc- curring rapidly due true for unconsolidated sands such as oil sand. 2 ASSUMPTIONS Following the work of Sharif-Abadi (2006

  13. 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

  14. Relief threshold for eolian sand transport on alluvial fans

    Microsoft Academic Search

    Joseph P. Cook; Jon D. Pelletier

    2007-01-01

    Many arid alluvial-fan terraces downwind from eolian sand sources exhibit an abrupt increase in eolian epipedon thickness and sand content below a critical elevation which varies from fan to fan. Above this elevation, sand accumulates locally and is not transported across the fan. Below this elevation eolian sand from nearby playa and channel sources is readily transported across the distal

  15. Slow Sand Filtration: Influences of Selected Process Variables

    Microsoft Academic Search

    William D. Bellamy; David W. Hendricks; Gary S. Logsdon

    1985-01-01

    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 (shown above). Temperature, sand bed depth, and sand size also had strong influence. La actividad biológica dentro de la cama de arena ejerce la influencia más grande en la eficiencia de la extracción

  16. Methanogenic potential of tailings samples from oil sands extraction plants

    Microsoft Academic Search

    Phillip M. Fedorak; Debora L. Coy; Myrna J. Salloum; Marvin J. Dudas

    2002-01-01

    Approximately 20% of Canada's oil supply now comes from the extraction of bitumen from the oil sands deposits in northeastern Alberta. The oil sands are strip-mined, and the bitumen is typically separated from sand and clays by an alkaline hot water extraction process. The rapidly expanding oil sands industry has millions of cubic metres of tailings for disposal and large

  17. Perch population assessment in lakes reclaimed using oil-sands derived material

    SciTech Connect

    Heuvel, M.R. van den; Dixon, D.G. [Univ. of Waterloo, Ontario (Canada); Power, M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Boerger, H.; MacKinnon, M.D.; Meer, T. van [Syncrude Canada, Fort McMurray, Alberta (Canada)

    1995-12-31

    The mining and extraction of petroleum products from oil-sands involves large areas of land and produces enormous volumes of tailings. One possible land reclamation option is to incorporate fine-tailings material into the bottoms of constructed lakes capped with natural surface water. The wet landscape method represents potential risk to aquatic biota-naphthenic acids and PAHs elute from pore water contained in the fine-tailings substrate. In spring 1995 yellow perch were stocked into a large-scale (5ha) experimental pond that consisted of fine-tailings capped with natural water as well as into two other reclaimed ponds that were constructed with oil-sands overburden material. Prior to stocking of perch, ponds had colonized with cyprinids, macrophytes and benthic invertebrates over a two year period. Perch were sampled in fall 1995 for age, condition factor, liver size, gonad size, fecundity, stomach contents, liver mixed-function oxygenase activity (MFO), bile PAH metabolites and plasma steroid hormones. When compared to the source lake, perch in the DP did not show reduced reproductive potential. Perch in all of the reclaimed ponds demonstrated exposure to organic compounds as indicated by marginally induced MFO activity and increased liver size. Exposure to naphthenates and PAHs in water as well as ecological environmental factors will be discussed.

  18. Beach sands from Baja California Peninsula, Mexico

    NASA Astrophysics Data System (ADS)

    Carranza-Edwards, Arturo; Bocanegra-García, Gerardo; Rosales-Hoz, Leticia; de Pablo Galán, Liberto

    1998-08-01

    Fifty beach locations were sampled in Baja California Peninsula, México, in order to characterize textural and compositional parameters. The western beach sands are mainly associated with a lower relief coastal plain and high energy of waves and currents with the beach sands of the eastern littoral zone. Finer, better sorted and low carbonate and rich quartz and feldspar contents are observed for the western beach sands when compared to the eastern beach sands. The mineralogical maturity and provenance index are greater for the western beach sands than for the eastern beach sands. These contrasts may be explained by differences on coastal plain relief and differences on hydrodynamic energy of waves and currents that are responsible for the rock fragment dilution by enrichment of more stable quartz debris. Finally, some distinctions were found for Na 2O-K 2O-CaO values. This is thought to be a result of the presence of some samples from the eastern coastline with higher values in CaO content, probably due to the presence of basaltic rocks.

  19. New fine structure cooling rate

    NASA Technical Reports Server (NTRS)

    Hoegy, W. R.

    1976-01-01

    One of the dominant electron cooling processes in the ionosphere is caused by electron impact induced fine structure transitions among the ground state levels of atomic oxygen. This fine structure cooling rate is based on theoretical cross sections. Recent advances in the numerical cross section determinations to include polarization effects and more accurate representations of the atomic target result in new lower values. These cross sections are employed in this paper to derive a new fine structure cooling rate which is between 40% and 60% of the currently used rate. A new generalized formula is presented for the cooling rate (from which the fine structure cooling rate is derived), valid for arbitrary mass and temperature difference of the colliding particles and arbitrary inelastic energy difference.

  20. 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.

  1. Mid frequency shallow water fine-grained sediment attenuation measurements.

    PubMed

    Holland, Charles W; Dosso, Stan E

    2013-07-01

    Attenuation is perhaps the most difficult sediment acoustic property to measure, but arguably one of the most important for predicting passive and active sonar performance. Measurement techniques can be separated into "direct" measurements (e.g., via sediment probes, sediment cores, and laboratory studies on "ideal" sediments) which are typically at high frequencies, O(10(4)-10(5)) Hz, and "indirect" measurements where attenuation is inferred from long-range propagation or reflection data, generally O(10(2)-10(3)) Hz. A frequency gap in measurements exists in the 600-4000?Hz band and also a general acknowledgement that much of the historical measurements on fine-grained sediments have been biased due to a non-negligible silt and sand component. A shallow water measurement technique using long range reverberation is critically explored. An approximate solution derived using energy flux theory shows that the reverberation is very sensitive to depth-integrated attenuation in a fine-grained sediment layer and separable from most other unknown geoacoustic parameters. Simulation using Bayesian methods confirms the theory. Reverberation measurements across a 10?m fine-grained sediment layer yield an attenuation of 0.009?dB/m/kHz with 95% confidence bounds of 0.006-0.013?dB/m/kHz. This is among the lowest values for sediment attenuation reported in shallow water. PMID:23862792

  2. Tidal sands as biogeochemical reactors

    NASA Astrophysics Data System (ADS)

    Anschutz, Pierre; Smith, Thomas; Mouret, Aurélia; Deborde, Jonathan; Bujan, Stéphane; Poirier, Dominique; Lecroart, Pascal

    2009-08-01

    Sandy sediments of continental shelves and most beaches are often thought of as geochemical deserts because they are usually poor in organic matter and other reactive substances. The present study focuses on analyses of dissolved biogenic compounds of surface seawater and pore waters of Aquitanian coastal beach sediments. To quantitatively assess the biogeochemical reactions, we collected pore waters at low tide on tidal cross-shore transects unaffected by freshwater inputs. We recorded temperature, salinity, oxygen saturation state, and nutrient concentrations. These parameters were compared to the values recorded in the seawater entering the interstitial environment during floods. Cross-shore topography and position of piezometric level at low tide were obtained from kinematics GPS records. Residence time of pore waters was estimated by a tracer approach, using dissolved silica concentration and kinetics estimate of quartz dissolution with seawater. Kinetics parameters were based on dissolved silica concentration monitoring during 20-day incubations of sediment with seawater. We found that seawater that entered the sediment during flood tides remained up to seven tidal cycles within the interstitial environment. Oxygen saturation of seawater was close to 100%, whereas it was as low as 80% in pore waters. Concentrations of dissolved nutrients were higher in pore waters than in seawater. These results suggest that aerobic respiration occurred in the sands. We propose that mineralised organic matter originated from planktonic material that infiltrated the sediment with water during flood tides. Therefore, the sandy tidal sediment of the Aquitanian coast is a biogeochemical reactor that promotes or accelerates remineralisation of coastal pelagic primary production. Mass balance calculations suggest that this single process supplies about 37 kmol of nitrate and 1.9 kmol of dissolved inorganic phosphorus (DIP) to the 250-km long Aquitanian coast during each semi-diurnal tidal cycle. It represents about 1.5% of nitrate and 5% of DIP supplied by the nearest estuary.

  3. 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.

  4. Geological controls on porosity and permeability in reservoir sands, Goodwyn field, Rankin Trend, northern Barrow-Dampier subbasin, northwest Shelf, Australia

    SciTech Connect

    Warren, J.K. (Curtin Univ., Perth, Western Australia (Australia)); Tingate, P.; Tarabbia, P. (NCPGG/APCRC-Thebarton Campus, Adelaide, South Australia (Australia))

    1993-09-01

    Goodwyn field is a major gas and condensate field with reserves of 4.1 tcf of gas and 254 million bbl of condensate and a 31-m oil rim in the southern part of the field. The field is a large tilted fault block open to the north and bounded by major faults to the south, west, and southeast. There are no significant internal faults within the field. The hydrocarbon-bearing reservoirs dip gently northwards at 5-6[degrees] and are truncated by the Main unconformity. Progressively younger units subcrop northward beneath the Main unconformity. Cretaceous deep-water marine sediments directly above the Main unconformity form the seal to the field. Core from the GE unit (main reservoir sand) defines two lithofacies: a medium to coarse-grained subarkosic unit (facies 1) and a fine to medium-grained subarkosic unit (facies 2). Both facies were laid down as channeled-braid plain to coarse-grained meander-belt sands. The overlying GD unit core defines a third sand lithofacies (facies 3): a fine to medium-grained sand characterized by abundant siderite. Although modified by a diagenetic overprint of quartz over-growths and kaolin cements, reservoir quality in the GE reservoir sands was established at the time of the deposition. Porosity pathways within facies 1 and 2 have acted as preferential conduits for ongoing fluid flow. In contrast, the finer grained and especially more clay-rich marine-associated GD sands (facies 3) have had their permeability reduced by the precipitation of authigenic quartz, kaolin, and siderite cements. Within the GE reservoir, zones with highest porosity are not a reliable indicator of the best of many excellent permeability sands. The most porous reservoir sands in the GE unit are not necessarily the most permeable. The coarser grained sands have wireline-derived porosities in the range 19-23%, yet they are better reservoirs than fine to medium-grained sands with porosities up to 26%. This is due to the relatively larger pores in the facies 1 sands.

  5. Effects of advanced oxidation on green sand properties via iron casting into green sand molds.

    PubMed

    Wang, Yujue; Cannon, Fred S; Voigt, Robert C; Komarneni, Sridhar; Furness, J C

    2006-05-01

    The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions. PMID:16719117

  6. Provenance and recycling of Arabian desert sand

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Vermeesch, Pieter; Andò, Sergio; Vezzoli, Giovanni; Valagussa, Manuel; Allen, Kate; Kadi, Khalid; Al-Juboury, Ali

    2013-04-01

    This study seeks to determine the ultimate origin of aeolian sand in Arabian deserts by high-resolution petrographic and heavy-mineral techniques combined with zircon U-Pb geochronology. Point-counting is used here as the sole method by which unbiased volume percentages of heavy minerals can be obtained. A comprehensive analysis of river and wadi sands from the Red Sea to the Bitlis-Zagros orogen allowed us to characterize all potential sediment sources, and thus to quantitatively constrain provenance of Arabian dune fields. Two main types of aeolian sand can be distinguished. Quartzose sands with very poor heavy-mineral suites including zircon occupy most of the region comprising the Great Nafud and Rub' al-Khali Sand Seas, and are largely recycled from thick Lower Palaeozoic quartzarenites with very minor first-cycle contributions from Precambrian basement, Mesozoic carbonate rocks, or Neogene basalts. Instead, carbonaticlastic sands with richer lithic and heavy-mineral populations characterize coastal dunes bordering the Arabian Gulf from the Jafurah Sand Sea of Saudi Arabia to the United Arab Emirates. The similarity with detritus carried by the axial Tigris-Euphrates system and by transverse rivers draining carbonate rocks of the Zagros indicates that Arabian coastal dunes largely consist of far-travelled sand, deposited on the exposed floor of the Gulf during Pleistocene lowstands and blown inland by dominant Shamal northerly winds. A dataset of detrital zircon U-Pb ages measured on twelve dune samples and two Lower Palaeozoic sandstones yielded fourteen identical age spectra. The age distributions all show a major Neoproterozoic peak corresponding to the Pan-African magmatic and tectonic events by which the Arabian Shield was assembled, with minor late Palaeoproterozoic and Neoarchean peaks. A similar U-Pb signature characterizes also Jafurah dune sands, suggesting that zircons are dominantly derived from interior Arabia, possibly deflated from the Wadi al-Batin fossil alluvial fan or even from Mesozoic sandstones of the Arabian margin accreted to the Cenozoic Zagros orogen. Due to extensive recycling and the fact that zircon is so resistant to weathering and erosion, the U-Pb age signatures are much less powerful a tracer of sedimentary provenance than framework petrography and heavy minerals. Actualistic provenance studies of dune fields at subcontinental scale shed light on the generation and homogenization of aeolian sand, and allow us to trace complex pathways of multistep sediment transport, thus providing crucial independent information for accurate palaeogeographic and palaeoclimatic reconstructions.

  7. Provenance and recycling of Arabian desert sand

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Vermeesch, Pieter; Andò, Sergio; Vezzoli, Giovanni; Valagussa, Manuel; Allen, Kate; Kadi, Khalid A.; Al-Juboury, Ali I. A.

    2013-05-01

    This study seeks to determine the ultimate origin of aeolian sand in Arabian deserts by high-resolution petrographic and heavy-mineral techniques combined with zircon U-Pb geochronology. Point-counting is used here as the sole method by which unbiased volume percentages of heavy minerals can be obtained. A comprehensive analysis of river and wadi sands from the Red Sea to the Bitlis-Zagros orogen allowed us to characterize all potential sediment sources, and thus to quantitatively constrain provenance of Arabian dune fields. Two main types of aeolian sand can be distinguished. Quartzose sands with very poor heavy-mineral suites including zircon occupy most of the region comprising the Great Nafud and Rub' al-Khali Sand Seas, and are largely recycled from thick Lower Palaeozoic quartzarenites with very minor first-cycle contributions from Precambrian basement, Mesozoic carbonate rocks, or Neogene basalts. Instead, carbonaticlastic sands with richer lithic and heavy-mineral populations characterize coastal dunes bordering the Arabian Gulf from the Jafurah Sand Sea of Saudi Arabia to the United Arab Emirates. The similarity with detritus carried by the axial Tigris-Euphrates system and by transverse rivers draining carbonate rocks of the Zagros indicates that Arabian coastal dunes largely consist of far-travelled sand, deposited on the exposed floor of the Gulf during Pleistocene lowstands and blown inland by dominant Shamal northerly winds. A dataset of detrital zircon U-Pb ages measured on twelve dune samples and two Lower Palaeozoic sandstones yielded fourteen identical age spectra. The age distributions all show a major Neoproterozoic peak corresponding to the Pan-African magmatic and tectonic events by which the Arabian Shield was assembled, with minor late Palaeoproterozoic and Neoarchean peaks. A similar U-Pb signature characterizes also Jafurah dune sands, suggesting that zircons are dominantly derived from interior Arabia, possibly deflated from the Wadi al-Batin fossil alluvial fan or even from Mesozoic sandstones of the Arabian margin accreted to the Cenozoic Zagros orogen. Due to extensive recycling and the fact that zircon is so resistant to weathering and erosion, the U-Pb age signatures are much less powerful a tracer of sedimentary provenance than framework petrography and heavy minerals. Actualistic provenance studies of dune fields at subcontinental scale shed light on the generation and homogenization of aeolian sand, and allow us to trace complex pathways of multistep sediment transport, thus providing crucial independent information for accurate palaeogeographic and palaeoclimatic reconstructions.

  8. Statistical analysis of sand and gravel aggregate deposits of late Pleistocene Lake Bonneville, Utah

    USGS Publications Warehouse

    Bliss, James D.; Bolm, K.S.

    2001-01-01

    Sedimentary deposits of pluvial Lake Bonneville are an important source of sand and gravel suitable for aggregate and construction in Utah. Data on Lake Bonneville basin sand and gravel deposit thickness, volume, grain size, percent of fines, and durability were statistically analyzed to detect variations associated with geologic domains, geographic location, Lake Bonneville shorelines, and sand and gravel deposit type, and to construct quantitative deposit models. Analysis showed several trends; (1) sand and gravel in younger shorelines was slightly more durable and the deposits considerably larger in volume, (2) younger shorelines are also more likely to contain more than one genetic deposit type, (3) the volume of terrace deposits is larger than beach deposits, (4) terraces and beaches are generally thicker than spits and bars, (5) the northern part of the Bonneville Basin contains slightly more durable sand and gravel than the southern part of the basin and is more likely to contain deposits composed of more than one genetic deposit type, and (6) the Wasatch domain deposits are composed of more than one genetic deposit type more often than deposits of the Basin and Range domain. Three additional conclusions with immediate economic significance are; (1) the median sand and gravel deposit in the Wasatch domain, 360,000 m3 (275,000 yd3), is three times larger than that of the Basin and Range domain (120,000 m3 [90,000 yd3]), (2) the median deposit thickness in the Wasatch domain, 5.8 m (19.0 ft), is nearly twice that of the Basin and Range domain (3 m [10 ft]), and (3) the Wasatch domain also contains slightly larger diameter gravel. These three conclusions are significant because the trend for sand and gravel development in the Bonneville Basin is to move from the Wasatch domain to the Basin and Range domain. Smaller, thinner deposits with smaller diameter gravel will require more surface area to mine than would have been necessary in the Wasatch domain. The result is a higher cost for sand and gravel in construction projects in the Salt Lake City area, especially since the gravel must also be hauled further.

  9. Recolonization of macrofauna in unpolluted sands placed in a polluted yachting harbour: A field approach using experimental trays

    NASA Astrophysics Data System (ADS)

    Guerra-García, J. M.; García-Gómez, J. C.

    2009-01-01

    A field experiment using trays was conducted at Ceuta's yachting harbour, North Africa, to study the effect in recolonization of placing trays with unpolluted defaunate sediments (fine and gross sands with low contents of organic matter) inside an enclosed yachting harbour characterized by high percentages of silt and clay and high concentrations of organic matter. Sediment recolonization in the trays was mainly undertaken by the species living naturally at the yachting harbour, which recolonized both uncontaminated gross and fine sand trays (such as the crustaceans Corophium runcicorne, Corophium sextonae and Nebalia bipes, the mollusc Parvicardium exiguum and the polychaete Pseudomalacoceros tridentata). However, other species like the polychaetes Cirriformia tentaculata and Platynereis dumerilii, although also abundant in the yachting harbour, were unable to colonize the trays through transport of larvae and/or adults in the water column. The recolonization was very quick, and after the first month, the values of abundance, species richness, diversity and evenness were similar in the experimental trays and in the reference area (yachting harbour). Although the multivariate analysis showed that the species composition differed between the trays and the reference area, there were no significant differences in recolonization of gross and fine sands, indicating that other factors different from the granulometry are modulating the recolonization patterns.

  10. Barley, a potential species for initial reclamation of saline composite tailings of oil sands.

    PubMed

    Renault, Sylvie; MacKinnon, Mike; Qualizza, Clara

    2003-01-01

    The oil sands industry in Alberta (Canada) has developed the composite tailings (CT) process to reduce the fluid fine tails resulting from the processing of oil sands. This process uses a chemical coagulant (gypsum or alum) to produce aggregated fines (clay), so they are retained with the coarse sand fraction of the extraction tailings to form CT, from which fines-free water is released relatively quickly compared with untreated tailings. The resulting CT and CT waters are saline-sodic, with Na+, SO4(2-), and Cl- being the dominant ions. When freshly deposited, the CT deposits are too soft for access by reclamation equipment, and the time required for these deposits to remove the water sufficiently to support traffic is uncertain. A greenhouse study was designed to determine the suitability of barley (Hordeum vulgare L.) for reclamation of fresh CT deposits and to evaluate benefits of peat amendments. This study assessed germination, early plant growth, chlorophyll content, and survival of barley growing in alum- and gypsum-treated CT, with and without peat amendment. Ion and trace metal accumulation in the root and shoot tissues of barley was determined. Amendment of CT with peat improved germination, survival, and growth of barley, but did not prevent leaf injury (probably due to Na and Cl- and possibly multiple nutrient deficiency). Field studies will be undertaken to validate our greenhouse results suggesting that barley could be used to improve dewatering of the freshly deposited substrates, reduce soil erosion, and facilitate leaching of ions by root penetration into the substrate. PMID:14674548

  11. MAHLI at the Rocknest sand shadow: Science and science-enabling activities

    NASA Astrophysics Data System (ADS)

    Minitti, M. E.; Kah, L. C.; Yingst, R. A.; Edgett, K. S.; Anderson, R. C.; Beegle, L. W.; Carsten, J. L.; Deen, R. G.; Goetz, W.; Hardgrove, C.; Harker, D. E.; Herkenhoff, K. E.; Hurowitz, J. A.; Jandura, L.; Kennedy, M. R.; Kocurek, G.; Krezoski, G. M.; Kuhn, S. R.; Limonadi, D.; Lipkaman, L.; Madsen, M. B.; Olson, T. S.; Robinson, M. L.; Rowland, S. K.; Rubin, D. M.; Seybold, C.; Schieber, J.; Schmidt, M.; Sumner, D. Y.; Tompkins, V. V.; Van Beek, J. K.; Van Beek, T.

    2013-11-01

    Martian solar days 57-100, the Mars Science Laboratory Curiosity rover acquired and processed a solid (sediment) sample and analyzed its mineralogy and geochemistry with the Chemistry and Mineralogy and Sample Analysis at Mars instruments. An aeolian deposit—herein referred to as the Rocknest sand shadow—was inferred to represent a global average soil composition and selected for study to facilitate integration of analytical results with observations from earlier missions. During first-time activities, the Mars Hand Lens Imager (MAHLI) was used to support both science and engineering activities related to sample assessment, collection, and delivery. Here we report on MAHLI activities that directly supported sample analysis and provide MAHLI observations regarding the grain-scale characteristics of the Rocknest sand shadow. MAHLI imaging confirms that the Rocknest sand shadow is one of a family of bimodal aeolian accumulations on Mars—similar to the coarse-grained ripples interrogated by the Mars Exploration Rovers Spirit and Opportunity—in which a surface veneer of coarse-grained sediment stabilizes predominantly fine-grained sediment of the deposit interior. The similarity in grain size distribution of these geographically disparate deposits support the widespread occurrence of bimodal aeolian transport on Mars. We suggest that preservation of bimodal aeolian deposits may be characteristic of regions of active deflation, where winnowing of the fine-sediment fraction results in a relatively low sediment load and a preferential increase in the coarse-grained fraction of the sediment load. The compositional similarity of Martian aeolian deposits supports the potential for global redistribution of fine-grained components, combined with potential local contributions.

  12. 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.

  13. Origin and evolution of the Candlelight Reef-Sand Clay system, St. Croix.

    USGS Publications Warehouse

    Gerhard, L.C.

    1981-01-01

    Candlelight reef is the buttressing western terminus of the northeastern St. Croix reef system, caused by a combination of paleotopography and longshore drift which created a stable pile of detrital material at this position. Reef colonization proceeded eastward along the former slope break on the limestone terrace; turbid gyres along the eastern margin of the former Southgate drainage prevented further westward colonization. The presence of detrital cobbles in Sand Cay and Candlelight reef is explained by this model. An unconformity between underlying fine-grained quartzose rocks and overlying carbonates, need represent only an eustatic sea level rise rather than any fundamental tectonic event.-from Author

  14. Simulation of ground-water flow in the lower sand unit of the Potomac-Raritan-Magothy aquifer system, Philadelphia, Pennsylvania

    USGS Publications Warehouse

    Sloto, R.A.

    1988-01-01

    Ground-water flow in the lower sand unit of the Potomac-Raritan-Magothy aquifer system in Philadelphia was simulated with a two-dimensional finite- difference ground-water model. The modeled 133-square-mile area also included parts of Delaware County, Pennsylvania, and Camden and Gloucester Counties, New Jersey. The lower sand unit is Cretaceous in age and consists of well- sorted coarse sand and fine gravel that grades upward into medium to fine sand containing a few thin beds of clay. The modeled aquifer consists of the lower sand unit in Philadelphia and the lowermost sand unit of the Potomac-Raritan-Magothy aquifer system in New Jersey. Throughout most of the area, the lower sand unit is overlain by a clay confining unit. Where the clay is absent, the lower sand unit is unconfined. A hydraulic conductivity of 1.6 x 10-3 foot per second and a storage coefficient of 3.0 x 10-4 was assigned to the lower sand unit based on 15 aquifer tests, and a hydraulic conductivity of 4.0 x 10-8 foot per second was assigned to the upper confining unit based on transient-flow sensitivity analysis. Water levels were not sensitive to changes in the value for specific storage of the upper confining unit, indicating that most vertical leakage occurs as steady leakage. Changes in the potentiometric surface of the lower sand unit for 1904-78 simulated. Differences between simulated and observed head generally were less than 10 feet. Simulations were made to determine the effects on hydraulic head of increases in industrial pumpage of 5 and 10 Mgal/d (million gallons per day) and of an emergency 60 Mgal/d municipal water supply in Philadelphia. A 5- and 10-Mgal/d increase in industrial pumpage would lower heads in the lower sand unit by as much as 33 and 66 feet, respectively. Pumping 60 Mgal/d for 30 days for an emergency municipal supply would lower heads in the lower sand unit by as much as 121 feet.

  15. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    SciTech Connect

    Boswell, R.D.; Shelander, D.; Lee, M.; Latham, T.; Collett, T.; Guerin, G.; Moridis, G.; Reagan, M.; Goldberg, D.

    2009-07-15

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 No.1 ('Tigershark') well shows a total gas hydrate occurrence 13 m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8 km{sup 2} and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  16. Biogeochemical pathways that influence de-watering and consolidation of fluid fine tailings

    NASA Astrophysics Data System (ADS)

    Siddique, T.; Foght, J.

    2013-12-01

    Approximately 1 million m3 of fluid fine tailings are produced every day in northern Alberta, Canada from processing of surface-mined oil sands resources. The tailings, comprising an aqueous suspension of fines dominated by clay particles that remain dispersed for decades, are deposited into tailings ponds for containment, de-watering and consolidation. Slow consolidation of clays retained in tailings ponds hinders recovery and re-use of water, retards volume reduction and presents a technical challenge for effective tailings ponds management. Here, we reveal that microorganisms indigenous to oil sands tailings ponds change the surface chemistry of clay particles and accelerate tailings consolidation by two biogeochemical pathways: one pathway shows that microorganisms metabolize organic substrates and produce carbon dioxide (CO2) and methane (CH4) in oil sands tailings. Dissolution of biogenic CO2 increases bicarbonate (HCO3-) concentrations in the pore water and reduces pore water pH, which dissolves carbonate minerals and releases cations from tailings minerals. The higher ionic strength of the pore water resulting from increased concentrations of ions shrinks the double diffuse layers of clay particles and hence increases consolidation. In addition, biogenic CH4 ebullition creates transient physical channels for recovery of pore water. The second pathway exerts a more direct microbial effect on consolidation through transformation of iron (Fe) minerals in oil sands tailings. Microbial reduction and dissolution of FeIII minerals forms amorphous FeII minerals that entrap and mask electronegative clay surfaces. These biogeochemical processes provide essential information for construction of geotechnical models to predict settling of clay particles for effective reclamation and management of fluid fine tailings.

  17. Architectural characteristics of fine-grained submarine fans: A model applicable to the Gulf of Mexico

    SciTech Connect

    Bouma, A.H.; Coleman, J.H. [Louisiana State Univ., Baton Rouge, LA (United States); DeV Wickens, H. [and others

    1995-10-01

    Submarine fan deposits in the Gulf of Mexico, modern and ancient, fall in the category of fine-grained, low overall sand/shale ratio basin-floor fans. Models published over the years that have been applied to both exploration and production are based on sand-rich fans, most of which were deposited in active margin settings. These models should not be used for the Gulf of Mexico or any other deep water system with similar basinal settings. Observations from the excellent outcrops of the Permian Tanqua Karoo in southwestern South Africa, together with information from the modern Mississippi Fan, and the Jackfork turbidites in Arkansas, enable the construction of a model that addresses the architecture of both the macro and meso-scale depositional features of fine-grained turbidite systems. At the entrance to the basin floor the conduit, carved out across the slope, may start to widen. Most of the density flows moving through do not necessarily occupy the conduit`s entire width. The result is a complex of laterally and vertically stacked channel fills and associated levee-overbank deposits with a good degree of connectivity. The channel fills are mostly massive, whereas the levee deposits are low-contrast, low-resistivity thin-bedded sandstones and shales with high permeability. Such sandstones can be potentially very productive. The channels gradually become smaller and as their influence on directing the heads of turbidity currents decreases, oblong sheet sands are deposited, each having a very large width to thickness ratio and a high sand/shale ratio. The vertical stacking patterns within these sheet sands commonly display lateral offset of individual beds or groups of beds, and therefore form a distinct reservoir type with varying internal fluid-flow characteristics.

  18. Experimental Investigation of Concrete with Combined High alumina cement, Silica fume and M-Sand

    NASA Astrophysics Data System (ADS)

    Joseph, Dona Maria; Devi, Manjula; Senthilkumar, S.

    2013-03-01

    Concrete is by far the most widely used construction material today. It is estimated that present consumption of concrete in the world is of the order of 10 billion tonnes every year. The cement industry is responsible for about 6% of all CO2 emissions. So nowadays there is a great interest in the development and implementation of various alternatives to Portland cement as a binder in concrete and also alternatives to fine and coarse aggregates in concrete to reduce the energy used in production of Portland cement clinker and the associated greenhouse gas emission and also for reducing resources consumption by proper recycling. This research work is carried out in order to explore the effect of various replacement percentages of cement by combined High alumina cement with silica fume and also the fine aggregate is fully replaced with manufacturing sand. Conclusion is made based on the comparison between the performance of blended cement concrete and conventional concrete.

  19. 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

  20. Sustainable agriculture and nitrogen reduction: an open field experiment using natural zeolitites in silty-clay reclaimed soil at Codigoro (Po River Delta, Ferrara, Italy)

    NASA Astrophysics Data System (ADS)

    Faccini, Barbara; Di Giuseppe, Dario; Mastrocicco, Micòl; Coltorti, Massimo; Colombani, Nicolò; Ferretti, Giacomo

    2014-05-01

    Following the guidelines of Nitrate and Water Framework Directives (91/676/CEE, 200/60/CE) an innovative integrated zeolitite cycle is being tested on a reclaimed clayey-silt soil in the Po Delta area (Ferrara Province, Italy), in the framework of the EU-funded ZeoLIFE project (LIFE+10 ENV/IT/000321). Natural zeolitites are pyroclastic rocks containing more than 50% of zeolites, a kind of hydrous minerals with peculiar physical and chemical properties, like high and selective cation exchange capacity (CEC), molecular adsorption and reversible dehydration. Zeolitites can trap NH4+ from solutions and release it gradually to the plant roots once they have been mixed in agricultural soils, allowing both fertilization and irrigation reduction and improvement of the yield. The fertilization reduction can result in a decrease of the nitrate content in groundwater and surface waters, ultimately leading to a mitigation of nutrient excess in the environment. Similarly, reduction of irrigation water means a minor exploitation of the water resource. The selected material used in the project is a chabazite zeolitite coming from a quarry near Sorano in Central Italy (Bolsena volcanic district). The open-field experimentation foresees two year of cultivation. A surface of about 6 ha has been divided into six parcels: three control parcels are cultivated and irrigated in traditional way; two parcels have been added with coarse-grained (ø = 3- 6 mm) natural zeolitite at different zeolitite/soil ratios (5 kg/m2 and 15 kg/m2) and one has been mixed with fine-grained (ø < 3 mm) NH4+-charged zeolitite at 10 kg/m2. Zeolitite/soil ratios have been determined upon a series of greenhouse tests, and the ammonium enriched material is obtained by cation exchange with swine manure in a specifically conceived prototype. The environmental quality of soil and water in each parcel is monitored by periodic soil, groundwater and porewater analyses. Soil EC, temperature and volumetric water content are continuously measured with probes at different depth (5-30-50-100-150 cm). The quality of surface water is checked by analyzing the outflow from the drains of the sub-irrigation system installed in the field. An automated meteorological station has been also installed in order to quantify rainfalls and sun irradiation for water balance calculation. During the first year, a no-food variety of sorghum has been cultivated. In the parcels treated with natural zeolitite and in that bearing NH4+-charged zeolitite, the fertilization has been reduced by 30% and 50% with respect to the controls. Notwithstanding these reductions, the yield increased by 5% and 15% in the parcel added with natural zeolitite and in that treated with NH4+-charged zeolitite, respectively. As confirmed by previously performed laboratory leaching tests, NH4+ in porewater and surface water was comparable in all parcels (

  1. Environmental differences in substrate mechanics do not affect sprinting performance in sand lizards (Uma scoparia and Callisaurus draconoides).

    PubMed

    Korff, Wyatt L; McHenry, Matthew J

    2011-01-01

    Running performance depends on a mechanical interaction between the feet of an animal and the substrate. This interaction may differ between two species of sand lizard from the Mojave Desert that have different locomotor morphologies and habitat distributions. Uma scorparia possesses toe fringes and inhabits dunes, whereas the closely related Callisaurus draconoides lacks fringes and is found on dune and wash habitats. The present study evaluated whether these distribution patterns are related to differential locomotor performance on the fine sand of the dunes and the course sand of the wash habitat. We measured the kinematics of sprinting and characterized differences in grain size distribution and surface strength of the soil in both habitats. Although wash sand had a surface strength (15.4±6.2 kPa) that was more than three times that of dune sand (4.7±2.1 kPa), both species ran with similar sprinting performance on the two types of soil. The broadly distributed C. draconoides ran with a slightly (22%) faster maximum speed (2.2±0.2 m s(-1)) than the dune-dwelling U. scorparia (1.8±0.2 m s(-1)) on dune sand, but not on wash sand. Furthermore, there were no significant differences in maximum acceleration or the time to attain maximum speed between species or between substrates. These results suggest that differences in habitat distribution between these species are not related to locomotor performance and that sprinting ability is dominated neither by environmental differences in substrate nor the presence of toe fringes. PMID:21147976

  2. Palynofacies of lignites and associated sediments in the upper paleocene Tuscahoma sand of southwestern Alabama and eastern Mississippi

    SciTech Connect

    Carroll, R.E. (Geological Survey of Alabama, Tuscaloosa, AL (United States))

    1993-09-01

    The Tuscahoma Sand of the Wilcox Group is composed of fine-grained sand, laminated sandy clay, marl and lignite. The Tuscahoma forms a poorly exposed belt from southeastern Alabama and extends northwestward into western Alabama and eastern Mississippi. The sand is assigned to the late Paleocene planktonic foraminiferal Morozovella velascoensis interval zone. Lignites in the Tuscahoma Sand occur as parasequence deposits in the highstand systems tract of a type 2 depositional sequence near the top of the formation. Organic debris associated with these highstand-systems-tract deposits is dominated by land-derived plant tissues. Marine influence is evidenced by the rare occurrence of dinoflagellate cysts, microforminiferal test linings, and the presence of gray, amorphous organic matter. Three palynofacies are recognized within highstand-systems-tract deposits in the upper Tuscahoma Sand based on the occurrence of organic debris. These palynofacies represent freshwater swamp, brackish marsh and marginal- to shallow-water marine depositional environments. Lignites in the Tuscahoma Sand are dominated by an angiosperm pollen assemblage. Gymnosperm pollen is rare, and marine forms are absent. This assemblage reflects deposition under fresh-water swamp conditions. Carbonaceous clay samples vary in the composition of organic debris. However, many are characterized by the occurrence of herbaceous angiosperm pollen. Arborescent angiosperm pollen is common, as are fern spores. Bisaccate conifer pollen is common and dinoflagellate cysts are rare. Fungal elements are abundant and woody tissue commonly is more degraded than in lignite samples. This assemblage represents deposition in coastal, brackish marsh environments. Organic debris in laminated clays, silts, and sands typically have angiosperm and gymnosperm pollen, dinoflagellate cysts, degraded terrestrial plant material, and amorphous organic matter, and represent shallow-marine and marginal-marine deposits.

  3. Sahara Coal: the fine art of collecting fines for profit

    SciTech Connect

    Schreckengost, D.; Arnold, D.

    1984-09-01

    Because of a change in underground mining methods that caused a considerable increase in the amount of fine sizes in the raw coal, Sahara Coal Co. designed and constructed a unique and simple fine coal system at their Harrisburg, IL prep plant. Before the new system was built, the overload of the fine coal circuit created a cost crunch due to loss of salable coal to slurry ponds, slurry pond cleaning costs, and operating and maintenance costs--each and every one excessive. Motivated by these problems, Sahara designed a prototype system to dewater the minus 28 mesh refuse. The success of the idea permitted fine refuse to be loaded onto the coarse refuse belt. Sahara also realized a large reduction in pond cleaning costs. After a period of testing, an expanded version of the refuse system was installed to dewater and dry the 28 mesh X 0 clean coal. Clean coal output increased about 30 tph. Cost savings justified the expenditures for the refuse and clean coal systems. These benefits, combined with increased coal sales revenue, paid back the project costs in less than a year.

  4. Fine sediment impacts on Salmonid spawning success: Relative effects of pore blockage and oxygen demand

    NASA Astrophysics Data System (ADS)

    Pattison, I.; Sear, D.; Collins, A.; Jones, I.; Naden, P.

    2013-12-01

    Salmonids act as geomorphic agents constructing a spawning habitat (redd) with fine sediment being washed out of the bed, increasing porosity around the incubating eggs. However, during the incubation period fine sediment infiltrates back into the river bed and degrades the habitat quality. Fine sediment has been found to reduce survival rates of salmonid eggs in both field and laboratory experiments, with the main hypotheses used to explain this being (a) fine sediment reduces gravel permeability and intra-gravel flow velocities; (b) intra-gravel O2 concentrations decrease due to reduced supply and increased consumption by organic sediments; and (c) clay particles block the exchange of O2 across the egg membrane. The SIDO (Sediment Intrusion and Dissolved Oxygen)-UK model is a physically based numerical model which stimulates the effect of fine sediment intrusion on the abiotic characteristics of the salmonid redd, along with the consequences for egg development and survival. This has been used to assess the sensitivity of salmonid egg survival to changes in the quantity and composition of fine sediment, including particle size and sediment oxygen demand. Results indicate that egg survival is highly sensitive to the discharge and the suspended sediment concentrations, particularly to changes in the supply rate of sand particles, rather than silt and clay. This can be explained by the increased likelihood of blocking of intra-gravel pores by larger sand particles, which reduce intra-gravel flow velocities and the supply of oxygen rich water. Furthermore, this effect of sediment mass has been found to be more important than the sediment oxygen consumption process. These findings have implications for how we manage the sediment delivery problem, especially as future projections indicate increased sediment delivery under climate and land management change.

  5. Sand control method employing special hydraulic fracturing technique

    SciTech Connect

    Medlin, W.L.; Mullins, L.D.; Zumwalt, G.L.

    1983-04-05

    A novel sand control method is disclosed wherein high viscosity, high sand concentration, fracturing fluids are pumped through sets of vertically oriented perforations in borehole casings located in unconsolidated or loosely consolidated pay zones. Various techniques are utilized to insure that sand fills disposed on either side of the borehole casing cover and substantially overlap each borehole casing perforation set. Procedures are then followed to bring the well into production without washing out the sand fills in these areas, whereby the resulting perforation-sand fill configurations effectively control sand production from the treated zone.

  6. Analytical mesoscale modeling of aeolian sand transport

    E-print Network

    Marc Lämmel; Anne Meiwald; Klaus Kroy

    2014-05-03

    We analyze the mesoscale structure of aeolian sand transport, based on a recently developed two-species continuum model. The calculated sand flux and important average characteristics of the grain trajectories are found to be in remarkable agreement with field and wind-tunnel data. We conclude that the essential mesoscale physics is insensitive to unresolved details on smaller scales and well captured by the coarse-grained analytical model, thus providing a sound basis for precise and numerically efficient mesoscale modeling of aeolian structure formation.

  7. 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 ?m) and microfloc (<160 ?m) 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 (? ˜ 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.

  8. Creating fluid injectivity in tar sands formations

    DOEpatents

    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.

  9. Creating fluid injectivity in tar sands formations

    DOEpatents

    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.

  10. Threshold for sand mobility on Mars calibrated from seasonal variations of sand flux.

    PubMed

    Ayoub, F; Avouac, J-P; Newman, C E; Richardson, M I; Lucas, A; Leprince, S; Bridges, N T

    2014-01-01

    Coupling between surface winds and saltation is a fundamental factor governing geological activity and climate on Mars. Saltation of sand is crucial for both erosion of the surface and dust lifting into the atmosphere. Wind tunnel experiments along with measurements from surface meteorology stations and modelling of wind speeds suggest that winds should only rarely move sand on Mars. However, evidence for currently active dune migration has recently accumulated. Crucially, the frequency of sand-moving events and the implied threshold wind stresses for saltation have remained unknown. Here we present detailed measurements of Nili Patera dune field based on High Resolution Imaging Science Experiment images, demonstrating that sand motion occurs daily throughout much of the year and that the resulting sand flux is strongly seasonal. Analysis of the seasonal sand flux variation suggests an effective threshold for sand motion for application to large-scale model wind fields (1-100?km scale) of ?(s)=0.01±0.0015?N?m(-2). PMID:25268931

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

    SciTech Connect

    Frank, A.; Kocurek, G. (Univ. of Texas, Austin, TX (United States). Dept. of Geological Sciences)

    1993-04-01

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

  12. Yellow perch embryo-larval survival and growth in surface waters associated with oil-sands mining

    SciTech Connect

    Peters, L.E.; Heuvel, M.R. van den; Dixon, D.G. [Univ. of Waterloo, Ontario (Canada); Power, M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Boerger, H.; MacKinnon, M.D.; Meer, T. Van [Syncrude Canada, Fort McMurray, Alberta (Canada)

    1995-12-31

    As part of their land reclamation strategy, Syncrude Canada Ltd. is currently developing environmentally acceptable tailings disposal methods. Fine tailings, a suspension of clay and residual bitumen, is the waste product from oil sands extraction. Fine-tailings contain naphthenic acids, a group of saturated aliphatic and alicyclic carboxylic acids, which occur naturally in petroleum and are partly responsible for the toxicity of process water. The wet landscape method involves covering fine tails with a layer of water such that a self-sustaining ecosystem can be established. A 5 ha demonstration pond with a bottom of fine-tailings was constructed and stocked with yellow perch for experimental purposes. Two other reclaimed ponds formed with oil-sands overburden material were also stocked with perch. Adult perch sampled in the fall of 1995 from the experimental and reclaimed ponds exhibited a 2-fold induction of MFO activity compared to the source lake; indicating organic compound exposure. Perch from one of the reclaimed ponds showed significantly reduced circulating reproductive hormone levels, gonad size and smaller ovarian follicles. Reproductive parameters were not different between the source lake and the remaining ponds. Paired lab and field experiments were conducted to determine if contaminants present would be detrimental to egg viability and development of larvae either through direct exposure of spawned eggs or indirectly by effecting oogenesis. An early life stage toxicity test was also performed using commercially available naphthenic acid standard. Endpoints measured were percent fertilization, percent hatch, mortality, deformities, timing of developmental periods and larval growth.

  13. Dune-associated sand fluxes at the nearshore termination of a banner sand bank (Helwick Sands, Bristol Channel)

    NASA Astrophysics Data System (ADS)

    Schmitt, Thierry; Mitchell, Neil C.

    2014-03-01

    Sand dunes typically migrate in opposing directions along the two sides of sand banks, reflecting a circulation driven by tidal current asymmetry, but it has been less clear how this pattern is distorted where banks intersect the coastline. The nearshore end of Helwick Sands, a banner bank in the Bristol Channel, was surveyed three times over three years, twice with a high-resolution multibeam echo-sounder. In both multibeam surveys, an unusual geometry was found over the crest of the bank, whereby dunes connect continuously with the dunes on the flanks, despite the flank dunes migrating in opposite directions. The crestal dunes thus appear to realign rapidly. We suggest that this morphological behaviour arises here because of vigorous wave-driven transport and because surface waves propagate almost exactly parallel to the crestal dunes. Sand transported parallel to the crestal dunes ensures that efficient reconnection occurs with dunes migrating along the flanks, particularly at low tide when wave currents are more strongly felt at the bed.

  14. FINE ART, IMAGINATION, AND LITERACY

    Microsoft Academic Search

    Catherine Read

    Participation in various parallel forms of expression that integrate art, imagination, and language create a solid foundation for excellence in literacy. Fine art is a language and a means of expression in itself, and many parallels exist between the developmental processes of creating art and writing. Participation in the arts can provide students with the opportunity to exercise and expand

  15. The Apollo 15 Coarse Fines

    E-print Network

    Rathbun, Julie A.

    NASANational Aeronautics and Space Administration Lyndon B. Johnson Space Center Houston, Texas JSC# 24035 FILE Science Branch Publication #81 December 1989 NI\\S/\\National Aeronautics and Space Administration Lyndon B. Johnson Space Center Houstqn, Texas JSC# 24035 #12;( THE APOLLO 15 COARSE FINES (4-10 mm) Introduction

  16. Fine Arts. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Robin, Bernard, Ed.

    This document contains two papers on fine arts from the SITE (Society for Information Technology & Teacher Education) 2002 conference. "Expanding the Boundaries of the Music Education of the Elementary Teacher Classroom with Information Technology" (Cheryl Jackson) reports on how information technology is used in a music methods course for…

  17. The effect of sand grain size on the development of cyanobacterial biocrusts

    NASA Astrophysics Data System (ADS)

    Rozenstein, Offer; Zaady, Eli; Katra, Itzhak; Karnieli, Arnon; Adamowski, Jan; Yizhaq, Hezi

    2014-12-01

    Biocrusts are critical components of desert ecosystems, significantly modifying the surfaces they occupy. Although the presence of fine soil particles is known to be conducive to biocrust development and recovery from disturbance, their influence on the inceptive development of biocrusts has not been empirically studied. In this study, the effect of substrate granulometry on the development of biocrusts was explored, under controlled laboratory conditions of light, soil humidity, and temperature. A cyanobacterial inoculum of Microcoleus vaginatus was applied to five sand fractions in the range of 1-2000 ?m. The results showed that the biocrusts developed more rapidly on the fine fraction (<125 ?m) than on the coarser fractions. While the biocrust cover on the fine fraction was spatially homogenous, it was patchy and discontinuous on the coarse fractions. The difference in the pore size between the different fractions is suggested to be the reason for these discrepancies in biocrust development, since large pores between the particles of coarse soil restrict and regulate the filaments' spreading. It was found that the spectroscopic indices, the Normalized Difference Vegetation Index and the Brightness Index, were more sensitive to the biocrust development than the bio-physiological parameters of the biocrusts (polysaccharides, protein, and chlorophyll contents). The faster biocrust development on the fine fractions can explain various biophysical phenomena in aeolian environments.

  18. 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

  19. 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

  20. 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

  1. 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

  2. Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands

    E-print Network

    Wildenschild, Dorthe

    sands and three heterogeneous systems composed of these five sands was measured using a steady state and Gelhar's [1987a, b, c] theory) for simulating large-scale unsaturated flow and transport observed

  3. On-Site Wastewater Treatment Systems: Sand Filters (Spanish)

    E-print Network

    Lesikar, Bruce J.; Enciso, Juan

    2000-10-13

    Sand filters are beds of granular material, or sand, drained from underneath so that pretreated wastewater can be treated, collected and distributed to a land application system. This publication explains the treatment, design, operation...

  4. Adsorption characteristics on sand and brick beds

    Microsoft Academic Search

    N. Selvaraju; S. Pushpavanam

    2009-01-01

    Adsorption can be used to treat wastewater containing low levels of pollutants efficiently. In this work adsorption isotherms are first obtained for phosphates, nitrates, chlorides and detergents from batch experiments. The motivation for the choice of these solutes stems from the fact that they are present in grey water i.e., domestic wastewater. The sorbents used are sand, brick and a

  5. Recovery of bituminous products from tar sands

    Microsoft Academic Search

    1984-01-01

    Acidic solvent compositions and method for separating bituminous products from tar sands which do not require a high shear environment employing such acidic solvent compositions are disclosed. The acidic solvent compositions comprise from about 15 to about 30 volume percent of an aqueous amine modified acidic constituent having a pH value of less than about 1, from about 1 to

  6. 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…

  7. The Early Years: Building With Sand

    NSDL National Science Digital Library

    Peggy Ashbrook

    2010-03-01

    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 approache

  8. The strength and dilatancy of sands

    Microsoft Academic Search

    M. D. Bolton

    1986-01-01

    Extensive data of the strength and dilatancy of 17 sands in axisymmetric or plane strain at different densities and confining pressures are collated. The critical state angle of shearing resistance of soil which is shearing at con- stant volume is principally a function of mineralogy and can readily be determined experimentally within a margin of about l\\

  9. Wind Induced Raindrop Splash Sand Transport

    Microsoft Academic Search

    B. Li; D. Sherman

    2009-01-01

    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

  10. Animals Between the Sand Grains - Meiofauna

    NSDL National Science Digital Library

    UCLA Marine Science Center

    In this lab activity, students will observe the minute animals that live between sand grains. The activity includes a list of materials, procedures, and discussion question. It is supplemented with reference images and a list of species and their phyla, including Gastrotrichicha, Crustacea/Ostracoda, Crustacea/Copepoda/Harpacticoidea, Nematoda, Turbellaria, Nemertina, Archiannelida, Polychaeta, and Oligochaeta.

  11. Oil from shale and tar sands

    Microsoft Academic Search

    E. M. Perrini

    1975-01-01

    The book provides a comprehensive survey of methods for processing oil shales and tar sands based on U.S. patent literature. Detailed technical information on most processes patented since 1960 is given; some methods for which patents were issued prior to 1960 are included. Oil shale retorting processes using gas combustion and solid heat transfer media are described. Hot water, cold

  12. A Solvent Extraction Process for Tar Sand

    Microsoft Academic Search

    R. J. Graham; J. J. Helstrom; R. L. Mehlberg

    1987-01-01

    A process has been investigated for solvent extraction of bitumen from Sunnyside, Utah, tar sands. The Sunnyside deposit, in east central Utah, has 1 to 2 billion barrels of geological reserves with a richness of 6 to 10 wtX bitumen. In this process, the ore is crushed and the bitumen is dissolved from the mineral in mix tanks. The bitumen

  13. Aspects of Tar Sands Development in Nigeria

    Microsoft Academic Search

    V. A. ADEWUSI

    1992-01-01

    Development of Nigerian massive reserves of crude bitumen and associated heavy oil is imminent in view of the impacts that the huge importation of these materials and their products have on the nation's economy, coupled with the depleting reserves of Nigerian conventional oil. This article reviews the extent of the tar sands resources in Nigeria and highlights the appropriate production

  14. REMOVING 'GIARDIA' CYSTS WITH SLOW SAND FILTRATION

    EPA Science Inventory

    Pilot-plant studies were undertaken to determine the efficiency of slow-rate sand filters in removing Giardia cysts and other substances. The filters removed virtually 100 percent of the Giardia cysts, 96 percent of standard plate count bacteria, and 98 percent of particles. Beca...

  15. SAND2000-8213 Unlimited Release

    E-print Network

    Kolda, Tamara G.

    search, direct search, fault tolerance, distributed computing, cluster computing. #3; Email: pdhough@ca.sandia.gov 2 R n and f : R n ! R. We introduce a family of asynchronous parallel pattern search (APPS) methodsSAND2000-8213 Unlimited Release Printed January 2000 Asynchronous Parallel Pattern Search

  16. SANDIA REPORT SAND2006-5315

    E-print Network

    Lewis, Robert Michael

    -Mail: reports@adonis.osti.gov Online ordering: http://www.osti.gov/bridge Available to the public from U.SSANDIA REPORT SAND2006-5315 Unlimited Release Printed August 2006 A generating set direct search. Kolda, R. M. Lewis, and V. Torczon Prepared by Sandia National Laboratories Albuquerque, New Mexico

  17. SANDIA REPORT SAND99-2953

    E-print Network

    SANDIA REPORT SAND99-2953 Unlimited Release Printed November 1999 a Shaped-Charge Parallel-2953 Unlimited Release Printed November 1999 The Optimization of a Shaped-Charge Design Using Parallel Computers of the modeled system. Using a shaped-charge jet design as an archetypal test case and the CTH parallel shock

  18. 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...

  19. 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

  20. COâ\\/sand fracturing in Devonian shale

    Microsoft Academic Search

    A. B. II Yost; R. L. Mazza; J. B. Gehr

    1993-01-01

    A total of five carbon dioxide (COâ) \\/sand well stimulations were successfully executed with two Devonian shale operators in Perry and Pike Counties, Kentucky. This new stimulation method offers a minimum formation damage proppant stimulation approach for natural gas producers in the United States. Some operators have been concerned about the frac fluid formation damage associated with the water and

  1. COâ\\/sand fracturing in Devonian shales

    Microsoft Academic Search

    A. B. II Yost; R. L. Mazza; J. B. Gehr

    1993-01-01

    A total of five carbon dioxide (COâ)\\/sand well stimulations were successfully executed with two Devonian shale operators in Perry and Pike Counties, Kentucky. This new stimulation method offers a minimum formation damage proppant stimulation approach for natural gas producers in the United States. Some operators have been concerned about the frac fluid formation damage associated with the water and chemicals

  2. 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...

  3. The sands of time and tidal friction

    Microsoft Academic Search

    Leslie V. Morrison; F. Richard Stephenson

    1998-01-01

    Ancient Babylonian clay tablets buried for centuries beneath the sands of the desert are part of an extensive historical archive which contains vital information about the rotation of the Earth. Many are preserved, and using these seemingly crude ancient and medieval observations of eclipses, variations in the Earth's rotation can be traced back over the past 2500 years. The tidal

  4. Depositional facies and Hohokam settlement patterns of Holocene alluvial fans, N. Tucson Basin, Arizona

    SciTech Connect

    Field, J.J.

    1985-01-01

    The distribution of depositional facies on eight Holocene alluvial fans of varying dimensions is used to evaluate prehistoric Hohokam agricultural settlement patterns. Two facies are recognized: channel gravelly sand facies and overbank silty sand facies. No debris flow deposits occur. The channel facies is characterized by relatively well sorted stratified sands and gravels with common heavy mineral laminations. Overbank facies deposits are massive and very poorly sorted due to heavy bioturbation. Lithostratigraphic profiles from backhoe trenches and sediment size analysis document headward migration of depositional facies which results in fining upward sequences. Each sequence is a channel fan lobe with an underlying coarse grained channel sand which fines to overbank silty sands. Lateral and vertical variations in facies distributions show that depositional processes are affected by drainage basin area (fan size) and distance from fan head. Gravelly channel sands dominate at the headward portions of the fan and are more pervasive on large fans; overbank silty sands are ubiquitous at fan toes and approach closer to the fan head of smaller alluvial fans. When depositional facies are considered as records of water flow over an alluvial surface, the farming potential of each fan can be analyzed. Depositional models of alluvial fan sedimentation provide the basis for understanding Hohokam settlement patterns on active alluvial surfaces.

  5. New Method for Estimation of Aeolian Sand Transport Rate Using Ceramic Sand Flux Sensor (UD-101)

    PubMed Central

    Udo, Keiko

    2009-01-01

    In this study, a new method for the estimation of aeolian sand transport rate was developed; the method employs a ceramic sand flux sensor (UD-101). UD-101 detects wind-blown sand impacting on its surface. The method was devised by considering the results of wind tunnel experiments that were performed using a vertical sediment trap and the UD-101. Field measurements to evaluate the estimation accuracy during the prevalence of unsteady winds were performed on a flat backshore. The results showed that aeolian sand transport rates estimated using the developed method were of the same order as those estimated using the existing method for high transport rates, i.e., for transport rates greater than 0.01 kg m?1 s?1. PMID:22291553

  6. Sand–Attapulgite Clay Mixtures as a Landfill Liner

    Microsoft Academic Search

    Amer A. Al-Rawas; Yahia E. A. Mohamedzein; Abdulaziz S. Al-Shabibi; Salem Al-Katheiri

    2006-01-01

    Absrtract  This paper investigates the potential use of sand–attapulgite (palygorskite) mixtures as a landfill liner. The sand and attapulgite\\u000a clay used in this study were brought from Wahiba (eastern Oman) and Al-Shuwamiyah (southern Oman), respectively. Initially\\u000a the basic properties of the sand and clay were determined. Then the attapulgite clay was added to the sand at 5, 10, 20 and\\u000a 30%

  7. 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

  8. Geology Fieldnotes: White Sands National Monument, New Mexico

    NSDL National Science Digital Library

    The White Sands National Monument site contains park geology information, maps, related links, and visitor information. The park geology section discusses the park's geologic history, the formation of the gypsum sand dunes, and the four types of dunes found at the White Sands National Monument: dome, barchan, transverse, and parabolic. The park maps section includes a map of the White Sands National Monument and the surrounding area, showing the location of each type of dune.

  9. Evaluation of bioremediation effectiveness on crude oil-contaminated sand

    Microsoft Academic Search

    Sang-Jin Kim; Dong Hyuk Choi; Doo Suep Sim; Young-Sook Oh

    2005-01-01

    A treatability study was conducted using sea sand spiked with 3% or 6% (w\\/w) of Arabian light crude oil to determine the most effective bioremediation strategies for different levels of contamination. The sea sand used in the study was composed of gravel (0.1%), sand (89.0%), and silt and clay (10.9%). The water content of the sea sand was adjusted to

  10. Unconsolidated sand grain shape, size impact frac-pack design

    Microsoft Academic Search

    E. Wang; M. M. Sharma

    1997-01-01

    The shape and size of sand grains, as well as the saturating fluid, influence the mechanical properties of unconsolidated sands and need to be considered in frac-pack design. These mechanical properties of unconsolidated properties of unconsolidated sands play an important role in determining the geometry of frac-pack treatments. Stress-strain curves obtained for unconsolidated sands at elevated stresses show highly nonlinear

  11. Hydrodynamic implications of textural trends in sand deposits of the 2004 tsunami in Sri Lanka

    USGS Publications Warehouse

    Morton, R.A.; Goff, J.R.; Nichol, S.L.

    2008-01-01

    Field observations and sediment samples at a coastal-plain setting in southeastern Sri Lanka were used to document the erosional and depositional impacts of the 2004 Indian Ocean tsunami and to interpret the hydrodynamic processes that produced an extensive sand-sheet deposit. Tsunami deposit thicknesses ranged from 6 to 22??cm with thickness being controlled partly by antecedent topography. The deposit was composed of coarse to medium sand organized into plane-parallel laminae and a few laminasets. Vertical textural trends showed an overall but non-systematic upward fining and upward thinning of depositional units with an upward increase in heavy-mineral laminations at some locations. Repeated patterns in the vertical textural trends (upward fining, upward coarsening, uniform) were used to subdivide and correlate the deposit into five hydro-textural stratigraphic units. The depositional units were linked to hydrodynamic processes and upcurrent conditions, such as rates of sediment supply and composition of the sediment sources. Vertical changes in grain-size distributions recorded the depositional phases associated with flow acceleration, initial unsteady pulsating flow, relatively stable and uniform flow, flow deceleration, slack water, and return flow or flow redirection. Study results suggest that vertical textural trends from multiple cross-shore sections can be used to interpret complex tsunami flow histories, but at the location examined, interpretation of the lateral textural trends did not provide a basis for identifying the correct sediment transport pathways because flow near the landward boundary was multidirectional.

  12. Flowsheet modifications for dissolution of sand, slag, and crucible residues in the F-canyon dissolvers

    SciTech Connect

    Rudisill, T.S.; Karraker, D.G.; Graham, F.R.

    1997-12-01

    An initial flowsheet for the dissolution of sand, slag, and crucible (SS{ampersand}C) was developed for the F- Canyon dissolvers as an alternative to dissolution in FB-Line. In that flowsheet, the sand fines were separated from the slag chunks and crucible fragments. Those two SS{ampersand}C streams were packaged separately in mild-steel cans for dissolution in the 6.4D dissolver. Nuclear safety constraints limited the dissolver charge to approximately 350 grams of plutonium in two of the three wells of the dissolver insert and required 0.23M (molar) boron as a soluble neutron poison in the 9.3M nitric acid/0.013M fluoride dissolver solution. During the first dissolution of SS{ampersand}C fines, it became apparent that a significant amount of the plutonium charged to the 6.4D dissolver did not dissolve in the time predicted by previous laboratory experiments. The extended dissolution time was attributed to fluoride complexation by boron. An extensive research and development (R{ampersand}D) program was initiated to investigate the dissolution chemistry and the physical configuration of the dissolver insert to understand what flowsheet modifications were needed to achieve a viable dissolution process.

  13. 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 ?mol 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.

  14. 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.

  15. 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. Environ Toxicol Chem 2015;34:589-599. © 2014 SETAC. PMID:25545538

  16. Longitudinal variability in hydraulic geometry and substrate characteristics of a Great Plains sand-bed river

    NASA Astrophysics Data System (ADS)

    Costigan, Katie H.; Daniels, Melinda D.; Perkin, Joshuah S.; Gido, Keith B.

    2014-04-01

    Downstream trends in hydraulic geometry and substrate characteristics were investigated along a 200 km reach of the Ninnescah River in south central Kansas, USA. The Ninnescah River is a large sand-bed, perennial, braided river located in the Central Plains physiographic province and is a tributary of the Arkansas River. Hydraulic geometry characteristics were measured at eleven reaches and included slope, sinuosity, bankfull channel width, and bankfull channel depth. Results indicated that the Ninnescah River followed a predicted trend of decreasing slope and increasing depth and width downstream. There were localized divergences in the central tendency, most notability downstream of a substantial tributary that is impounded and at the end of the surveying reach where the Ninnescah River approaches the Arkansas River. Surface grain-size samples were taken from the top 10 cm of the bed at five points across the wetted cross-section within each of the 11 reaches. Sediment analyses demonstrated a significant trend in downstream fining of surface grain-sizes (D90 and D50) but unlike previous studies of sand-bedded rivers we observed coarsening of substrates downstream of the major tributary confluence. We propose that the overall low discharge from the tributary was the primary reason for coarsening of the bed downstream of the tributary. Results of this study provide valuable baseline information that can provide insight in to how Great Plains sand-bed systems may be conserved, managed, and restored in the future.

  17. Slopewash, surface runoff and fine-litter transport in forest and landslide scars in humid-tropical steeplands, Luquillo Experimental Forest, Puerto Rico

    USGS Publications Warehouse

    Larsen, M.C.; Torres-Sanchez, A. J.; Concepcion, I.M.

    1999-01-01

    Rainfall, slopewash (the erosion of soil particles), surface runoff and fine-litter transport at humid-tropical steepland sites in the Luquillo Experimental Forest, Puerto Rico (18??20' N, 65??45' W) were measured from 1991 to 1995. Hillslopes underlain by (1) Cretaceous tuffaceous sandstone and siltstone in subtropical rain (tabonuco) forest with vegetation recovering from Hurricane Hugo (1989), and (2) Tertiary quartz diorite in subtropical lower montane wet (colorado and dwarf) forest with undisturbed forest canopy were compared to recent landslide scars. Monthly surface runoff on these very steep hillslopes (24??to 43??) was only 0.2 to 0.5 per cent of monthly rainfall. Slopewash was higher in sandy loam soils whose parent material is quartz diorite (averaging 46 g m-2 a-1) than in silty clay loam soils derived from tuffaceous sandstone and siltstone where the average was 9 g m-2 a-1. Annual slopewash of 100 to 349 g m-2 on the surfaces of two recent, small landslide scars was measured initially but slopewash decreased to only 3 to 4 g m-2 a-1 by the end of the study. The mean annual mass of fine litter (mainly leaves and twigs) transported downslope at the forested sites ranged from 5 to 8 g m-2 and was lower at the tabonuco forest site, where post-Hurricane Hugo recovery is still in progress. Mean annual fine-litter transport was 2.5 g m-2 on the two landslide scars.

  18. UTILIZATION OF USED FOUNDRY SAND IN CONCRETE Tarun R. Naik

    E-print Network

    Wisconsin-Milwaukee, University of

    and used foundry sand by weight. Concrete performance was evaluated with respect to compressive strength sand in a batch of normal weight concrete. Based on this report it was decided to replace 25 and 35UTILIZATION OF USED FOUNDRY SAND IN CONCRETE By Tarun R. Naik Director, Center for By

  19. Effect of Bentonite on Permeability of Dune Sand

    Microsoft Academic Search

    N. K. Ameta; Abhay Shivaji Wayal

    A compacted mixture of bentonite with sand has been used to form barrier of fluids, in absence of impervious natural soils. This paper focuses on the permeability behavior of dune sand\\/bentonite mixtures. Results of laboratory investigations are presented to show the influence of bentonite on permeability of dune sand. One dimensional consolidation and falling head permeability tests were conducted to

  20. Mud weight correction gives better sand strength estimates

    Microsoft Academic Search

    1989-01-01

    This article offers a new soil mechanics approach to estimating sand strength from well log data; it involves the lateral grain pressure exerted by drilling fluid. Resulting estimates of sand strength should lead to improved management of wells in areas where sand production problems can develop. Previously published corrections for the lateral grain pressure imposed by drilling fluid included an

  1. 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...

  2. Shaking a Box of Sand Peter F. Stadler

    E-print Network

    Stadler, Peter F.

    Shaking a Box of Sand Peter F. Stadler Institut f¨ur Theoretische Chemie und Molekulare model of a vibrated box of sand, and discuss its dynamics in terms of two parameters reflecting static. Vibrating sand results in very varied dynamics, rang- ing from glassy [1, 2] to fluidised [3, 4]. Recent

  3. The Potts model built on sand E. Dinaburg1

    E-print Network

    The Potts model built on sand E. Dinaburg1 , C. Maes2 , S. Pirogov3 , F. Redig4 , A. Rybko5, 4} is interpreted as the "number of sand grains" at x. For n N, n = {1, 2, 3, 4}Vn denotes the set to a special set of "recurrent configurations" defined from the abelian sand- pile model (cf. subsection 1

  4. Modelling of reoxidation inclusion formation in steel sand casting

    E-print Network

    Beckermann, Christoph

    Modelling of reoxidation inclusion formation in steel sand casting A. J. Melendez, K. D. Carlson pouring, as well as their final locations on the surface of steel sand castings. Inclusions originate by comparing the simulation results to measurements made on production steel sand castings. Good overall

  5. Investigations of Suction Caissons in Dense Sand Byron Walter Byrne

    E-print Network

    Byrne, Byron

    Investigations of Suction Caissons in Dense Sand by Byron Walter Byrne A thesis submitted;Abstract INVESTIGATIONS OF SUCTION CAISSONS IN DENSE SAND A thesis submitted for the degree of Doctor to consider in the design of these shallow foundations for dense sand. Initially the long term loading

  6. ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS

    E-print Network

    Flury, Markus

    ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS By JORGE ANTONIO JEREZ-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS Abstract by Jorge Antonio Jerez Briones, Ph.D. Washington of reactive chemicals in the subsurface. Most commonly, silica sand is used as the model porous medium. Iron

  7. SHORT COMMUNICATION First Collection Records of Phlebotomine Sand Flies (Diptera

    E-print Network

    SHORT COMMUNICATION First Collection Records of Phlebotomine Sand Flies (Diptera: Psychodidae) From (2011); DOI: 10.1603/ME10170 ABSTRACT The phlebotomine sand Ã?ies Lutzomyia (Psathyromyia) shannoni (Dyar for either species. KEY WORDS phlebotomine, sand Ã?y, leishmaniasis, Lutzomyia shannoni, Lutzomyia vexator

  8. Channel bed evolution and sediment transport under declining sand inputs

    E-print Network

    Montgomery, David R.

    Channel bed evolution and sediment transport under declining sand inputs Karen B. Gran,1,2 David R structure development and sediment transport as sand inputs decline. On the Pasig-Potrero River, we investigated channel recovery following emplacement of sand-rich pyroclastic deposits in the 1991 eruption

  9. Performance of Shallow Foundations on Sand B.W. Byrne.

    E-print Network

    Byrne, Byron

    Performance of Shallow Foundations on Sand B.W. Byrne. Department of Engineering Science hardening plasticity theory. The testing to date has mainly used high friction angle samples of sand to imitate typical offshore conditions (in the North Sea for example). Dry sand has been used so that long

  10. Texas Tech University Sand Volleyball Recreational Sports League

    E-print Network

    Gelfond, Michael

    Texas Tech University Sand Volleyball Recreational Sports League T 806.742.2945 | www.recsports.ttu.edu | SRC Room 203 When: League Play starts on Monday, April 15 Where: Rec Sports Sand Volleyball Courts end at 13, so if tied at 12-12, next point wins) Shoes are not permitted for competition on sand

  11. TECHNICAL NOTE Centrifuge cone penetration tests in sand

    E-print Network

    Bolton, Malcolm

    TECHNICAL NOTE Centrifuge cone penetration tests in sand M. D. BOLTON,Ã? M. W. GUI,Ã? J. GARNIER,{ J; laboratory tests; piles; sands. INTRODUCTION Centrifuges have been widely adopted in modelling geotechnical on both the random and the consistent variations which have been observed with CPTs in sand when identical

  12. BEHAVIOR OF A SAND RIDGE MODEL Juan Mario Restrepo

    E-print Network

    Soatto, Stefano

    BEHAVIOR OF A SAND RIDGE MODEL Juan Mario Restrepo Mathematics Department University of California, Los Angeles Los Angeles, CA 90095 Abstract. A model for the formation and evolution of longshore sand waves, which are represented by wave packets, and a sandy bottom topography, conspire to produce sand

  13. DRIVEN PIPE PILES IN DENSE SAND BYRON BYRNE

    E-print Network

    Byrne, Byron

    DRIVEN PIPE PILES IN DENSE SAND BYRON BYRNE GEOMECHANICS GROUP THE UNIVERSITY OF WESTERN AUSTRALIA #12;Driven Pipe Piles in Dense Sand Byron Byrne Geomechanics Group The University of Western Australia Page 1 ABSTRACT: Piles are often driven open ended into dense sand with the aim of increasing the ease

  14. Shaking a Box of Sand Peter F. Stadler

    E-print Network

    Stadler, Peter F.

    Shaking a Box of Sand Peter F. Stadler Institut fË?ur Theoretische Chemie und Molekulare model of a vibrated box of sand, and discuss its dynamics in terms of two parameters reflecting static. Vibrating sand results in very varied dynamics, rang­ ing from glassy [1, 2] to fluidised [3, 4]. Recent

  15. Pseudomonas sabulinigri sp. nov., isolated from black beach sand

    E-print Network

    Bae, Jin-Woo

    Pseudomonas sabulinigri sp. nov., isolated from black beach sand Kyoung-Ho Kim,1 Seong Woon Roh,1 , was isolated from black sand collected from Soesoggak, Jeju Island, Korea. Cells grew at 4­37 6C, at pH 5 beach sand, a bacterium was isolated and subjected to taxonomic characterization. On the basis

  16. Intramural Sports Women's Sand Volleyball Bracket -Summer 2014

    E-print Network

    Escher, Christine

    Intramural Sports Women's Sand Volleyball Bracket - Summer 2014 Sike Girls/Double Trouble Some Court 3 Kinky Sets All games will take place on Dixon Sand Courts You will need to bring your OSU ID Men's Sand Volleyball Bracket - Summer 2014 Foreign Tuesday, July 29, 2014 5:00pm Court 1 French Salsa

  17. 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

  18. Well completion process for formations with unconsolidated sands

    DOEpatents

    Davies, David K. (Kingwood, TX); Mondragon, III, Julius J. (Redondo Beach, CA); Hara, Philip Scott (Monterey Park, CA)

    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.

  19. Tar sands. (Latest citations from the COMPENDEX database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning mining of tar sands and the recovery of bitumen and other materials from tar sands. The physical and chemical properties of tar sands are discussed, and the economics of their use are considered. Processes include alkaline extraction, water cracking, catalytic cracking, and in situ combustion. (Contains 250 citations and includes a subject term index and title list.)

  20. 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.

  1. Sand Bed Morphodynamics under Standing Waves and Vegetated Conditions

    Microsoft Academic Search

    B. J. Landry; M. H. Garcia

    2010-01-01

    Littoral processes such as sediment transport, wave attenuation, and boundary layer development are governed by the presence of bathymetric features, which include large-scale sand bars upon which smaller-scale sand ripples are superimposed, as well as the presence of submarine vegetation. Numerous studies on sand ripples and bars have aided to elucidate the dynamics in oscillatory flows; however, the effect of

  2. Vetiver System for Sand Dune Stabilization A Vietnamese Experience

    Microsoft Academic Search

    Sand dunes occupy more than 70,000 ha along the coast of Central Vietnam, being the sources of such natural disasters as sand storm, sand flow\\/flash flood etc., that eat either slowly or catastrophically villages and fields. This has been surveyed by a team of geologists from the Research Institute of Geology and Mineral Resources (RIGMR), who also looked for remedial

  3. An overview of the SAND Spatial Database System

    Microsoft Academic Search

    Claudio Esperanca; G ´ isli; R. Hjaltason; Hanan Samet; Frantisek Brabec; Egemen Tanin

    1997-01-01

    An overview is given of the SAND spatial database system, an environment for developing applica- tions involving both spatial and non-spatial data. The SAND kernel implements a relational data model extended with several geometric functions and predicates as well as a spatial index. The main interface to SAND is through an embedded interpreted language. This permits the rapid prototyping of

  4. Use of recycled fine aggregate in concretes with durable requirements.

    PubMed

    Zega, Claudio Javier; Di Maio, Angel Antonio

    2011-11-01

    The use of construction waste materials as aggregates for concrete production is highly attractive compared to the use of non-renewable natural resources, promoting environmental protection and allowing the development of a new raw material. Several countries have recommendations for the use of recycled coarse aggregate in structural concrete, whereas the use of the fine fraction is limited because it may produce significant changes in some properties of concrete. However, during the last decade the use of recycled fine aggregates (RFA) has achieved a great international interest, mainly because of economic implications related to the shortage of natural sands suitable for the production of concrete, besides to allow an integral use of this type of waste. In this study, the durable behaviour of structural concretes made with different percentage of RFA (0%, 20%, and 30%) is evaluated. Different properties related to the durability of concretes such as absorption, sorptivity, water penetration under pressure, and carbonation are determined. In addition, the results of compressive strength, static modulus of elasticity and drying shrinkage are presented. The obtained results indicate that the recycled concretes have a suitable resistant and durable behaviour, according to the limits indicated by different international codes for structural concrete. PMID:21775123

  5. [Application of minirhizotron in fine root studies].

    PubMed

    Shi, Jianwei; Yu, Lizhong; Yu, Shuiqiang; Han, Youzhi; Wang, Zhengquan; Guo, Dali

    2006-04-01

    Due to the production, death, and decomposition of fine root, its turnover plays an important role in carbon allocation and nutrient cycling in terrestrial ecosystems. Some methods such as sequential root coring, compartmental flow model, and ingrowth core have been widely used in collecting root biomass data and estimating fine root turnover, but failed in monitoring the dynamics of fine root due to its simultaneous production and death. Minirhizotron is a nondestructive in situ method for studying the dynamics of fine root, which allows the simultaneous measurement of fine root growth and mortality. This paper reviewed the application of minirhizotron in fine root studies, with the focus on minirhizotron tube installation, image collection, data extraction, and calculation parameters. In a case study, the total fine root length, fine root length density per unit volume, fine root length density per unit area, fine root biomass density, and fine root production and mortality of Fraxinus mandshurica and Larix gmelini were calculated, and the results showed that minirhizotron method was feasible in studying the processes of fine root development, eclipse, death, and decomposition. The factors affecting fine root measurement and its precision mainly included the quality and quantity of tube installation, sampling interval and quantity, and analysis technique of images, etc. Soil texture, tube material, and disturbance of light on root were also the factors affecting the precision of the method. How to improve the measurement precision of minirhizotron would be the critical problem in future study. PMID:16836108

  6. Electrochemical Process Makes Fine Needles

    NASA Technical Reports Server (NTRS)

    Watkins, J. L.

    1986-01-01

    Electrochemical process makes fine tungsten needles for use as microscopic probes or field-emission cathodes. Etching vessel filled with dense, inert lower liquid covered by less-dense, caustic etching solution. Newly formed needle breaks off upper part of wire in etchant and falls into can in inert liquid below. Improved process does not require close monitoring and left unattended for an indefinite time.

  7. SOUTHERN FINE PARTICULATE MONITORING PROJECT

    SciTech Connect

    Ashley D. Williamson

    2001-07-01

    This is the third quarterly progress report of the ''Southern Fine Particulate Monitoring Project'', funded by the U.S. Department of Energy's National Energy Technology Laboratory under DOE Cooperative Agreement No. DE-FC26-00NT40770 to Southern Research Institute (SRI). In this two year project SRI will conduct detailed studies of ambient fine particulate matter in the Birmingham, AL metropolitan area. Project objectives include: Augment existing measurements of primary and secondary aerosols at an established urban southeastern monitoring site; Make a detailed database of near-continuous measurements of the time variation of fine particulate mass, composition, and key properties (including particle size distribution); Apply the measurements to source attribution, time/transport properties of fine PM, and implications for management strategies for PM{sub 2.5}; and Validate and compare key measurement methods used in this study for applicability within other PM{sub 2.5} research by DOE-FE, EPA, NARSTO, and others. During the third project quarter, the new SRI air monitoring shelter and additional instruments were installed at the site. Details include: Installation of Radiance Research M903 Nephelometer; Installation of SRI air monitoring shelter at North Birmingham Site; Relocation of instruments from SEARCH shelter to SRI shelter; Installation of Rupprecht & Patashnick 8400 Sulfate Monitor; Assembly and initial laboratory testing for particulate sulfate monitor of Harvard design; Efficiency testing of particle sizing instrument package at SRI lab; Preparation for the Eastern Supersite July measurement intensive program; and Continued monitoring with TEOM and particle sizing instruments.

  8. Dense, finely, grained composite materials

    DOEpatents

    Dunmead, Stephen D. (Davis, CA); Holt, Joseph B. (San Jose, CA); Kingman, Donald D. (Danville, CA); Munir, Zuhair A. (Davis, CA)

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  9. Porosity and packing of Holocene river, dune, and beach sands

    SciTech Connect

    Atkins, J.E. (Conoco, Inc., Oklahoma City, OK (United States)); McBride, E.F. (Univ. of Texas, Austin (United States))

    1991-03-01

    The porosity and packing of 174 samples of well-sorted surficial and shallowly buried (to 17 m), unconsolidated Holocene sands were determined by point counting the upper surface of thin sections of epoxy-impregnated samples in reflected light. Average depositional porosity for 124 surficial beach sands, river point-bar and braid-bar sands, and eolian dune sands is between 40% and 58%. Beach sands exhibit an average packing value (contact index = CI) of 0.79, river sands an average IC of 0.91, and eolian dune sands an average CI of 1.02. Packing gets tighter with depth, but the authors found no decrease in porosity with depth for river and beach sands buried to 17 m. Thus, packing is more sensitive to small changes in fabric than is porosity. Beach sands typically contain 5.5% oversized pores (OSP), river sands 3.8% OSP, and eolian dune sands 4.0% OSP. Most OSP are packing defects rather than dissolution pores, although trapped air bubbles are common in some beach sands. OSP decrease linearly with depth to 17 m, our deepest sample. Extrapolation of our data indicates that they will be destroyed at a depth less than 100 m. Significant differences in porosity, oversized-pore, and packing values exist between most point-bar and braid-bar deposits and between two heavily sampled point bars, but no significant differences in these values exist when braid-bar sands are compared to other braid-bar sands. Sands form different beaches have significant differences in porosity, oversized pores, and packing. The average porosity is 46% for eolian ripple strata, 50% for grain-fall strata, and 51% for grain-flow strata. Ripple strata are tighter packed than grain-fall and grain-flow strata.

  10. Arsenic Removal Using AgedArsenic Removal Using Aged Rapid Sand Filter MediaRapid Sand Filter Media

    E-print Network

    Arsenic Removal Using AgedArsenic Removal Using Aged Rapid Sand Filter MediaRapid Sand Filter Media Arsenic removal potentials using "aged" rapidQuantity Arsenic removal potentials using "aged" rapid sand. CONCLUSIONCONCLUSION #12;BACKGROUNDBACKGROUND Reduction/Elimination of ArsenicReduction/Elimination of Arsenic Ion

  11. THE SIMULATION OF WIND-BLOWN SAND MOVEMENT AND PROBABILITY DENSITY FUNCTION OF LIFT-OFF VELOCITIES OF SAND GRAINS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately describing the probability density function (PDF) of lift-off or initial velocities of wind-blown sand ejecting from a sand bed is fundamental to understanding the mechanisms of wind-blown sand movement. Our objective was to investigate the efficacy of developing the PDF of lift-off veloc...

  12. Climate Change Policy and Canada's Oil Sand Resources: An Update and Appraisal of Canada's

    E-print Network

    Watson, Andrew

    .1 Background Oil sands (also known as tar sands) are mixtures of sand, water, clay and crude bitumen. CanadaClimate Change Policy and Canada's Oil Sand Resources: An Update and Appraisal of Canada's New Targets 13 3.3 Implied Target Emissions for Oil Sands 18 3.4 Significance of Unmitigated Oil Sand GHG

  13. The physics of wind-blown sand and dust

    E-print Network

    Jasper F. Kok; Eric J. R. Parteli; Timothy I. Michaels; Diana Bou Karam

    2012-09-20

    The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This article presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.

  14. The physics of wind-blown sand and dust.

    PubMed

    Kok, Jasper F; Parteli, Eric J R; Michaels, Timothy I; Karam, Diana Bou

    2012-10-01

    The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This paper presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan. PMID:22982806

  15. Report of the Library Fines Committee.

    ERIC Educational Resources Information Center

    Navarre, Carolyn; And Others

    The Library Fines Committee at Wayne State University reviewed the existing system of loan periods and fines schedules in which high demand materials are loaned out for shorter periods of time with higher fines rates. The committee found the system to be ineffective because although a large amount of overdue materials money is collected, books are…

  16. Microbially-accelerated consolidation of oil sands tailings. Pathway I: changes in porewater chemistry

    PubMed Central

    Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Arkell, Nicholas; Young, Rozlyn; Li, Carmen; Guigard, Selma; Underwood, Eleisha; Foght, Julia M.

    2014-01-01

    Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT) amended with an organic substrate (hydrolyzed canola meal) produced methane (CH4) and carbon dioxide (CO2). Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 vs. unamended MFT (pH 7.7). About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca2+) and magnesium (Mg2+) and increasing bicarbonate (HCO?3) in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL) of clay particles by reducing the surface charge potential (repulsive forces) of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics. PMID:24711805

  17. The Different Faces of San Francisco's Ocean Beach: Analyzing Sand Size and Beach Shape

    NASA Astrophysics Data System (ADS)

    Grove, K.; Labit, R.; Lui, S.; Rodriquez, I.; Yi, C.; Yu, M.

    2004-12-01

    Ocean Beach is located along the western edge of San Francisco adjacent to the Pacific Ocean. Erosion along the southern part of the beach is threatening a nearby highway and water treatment plant. To better understand this beach and the processes that form it, our SF-ROCKS research group collected data from seven locations along its length. We used an auto-level surveying instrument to measure beach profiles and we collected sand samples that were measured using sieves and a sieve shaker. We plotted profiles and grain-size data using Excel and Surfer software. The sediment is mostly fine sand, and the means of all samples range between 0.19-0.26 mm. There may be little variation along the beach because only small sand grains have survived the long journey from their Sierra Nevada source. Profile shape does vary along the beach. The profile at the northern end is about three times wider than the profile at the southern end. The northern profile is flatter overall, but all profiles had a steep beach face in August, when the data were collected. The differences in beach profiles may be related to position relative to the offshore bar, which appears to provide sand to the northern part of the beach. Our group will collect more data in November to see what changes have occurred after the large-wave season has begun. We will use Surfer software to compare summer and fall profiles, to see where sediment has been added and where sediment has been removed. We will also compare our results to the data collected by Dr. Patrick Barnard and his research group at the U.S. Geological Survey, who are using an All-Terrain Vehicle to measure beach profiles and a camera to measure sediment size. We will use our analysis of beach variations to make recommendations for reducing beach erosion.

  18. 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.

  19. 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

  20. Incorporation of CrusHed Sands and Tunisian Desert Sands in the Composition of Self Compacting Concretes Part I: Study of Formulation

    Microsoft Academic Search

    Abdelhamid Rmili; Mongi Ben Ouezdou; Mhamed Added; Elhem Ghorbel

    2009-01-01

    This paper examines the incorporation of the crushed sand (CS) and desert sand (DS) in the formation of self compacting con- crete (SCC). These sands have been substituted for the rolled sand (RS), which is currently the only sand used in concretes and which is likely to run out in our country. DS, which comes from the Tunisian Sahara in

  1. Water and Sand Transport Pathways Through the Delta Front, Wax Lake delta, USA

    NASA Astrophysics Data System (ADS)

    Shaw, J. B.; Mohrig, D.

    2011-12-01

    The Wax Lake delta (WLD) is considered a type example of the river dominated delta due to its fan-like shape and network of bifurcating channels. We investigate the formative processes of the WLD's morphology using water and sediment data collected during the 2011 spring flood. Our study focuses on the delta front; the ~4 km wide region seaward of the subaerial delta that is characterized by (a) sub-aqueous extensions of the sub-aerial channels, and (b) broad, shallow, unchannelized zones positioned between the sub-aqueous channels. We find that while water flux is widely distributed between the channelized and non-channelized zones, the sand flux is focused in the sub-aqueous channels of the delta front. Flow is faster in the channels than non-channelized areas (0.7 versus 0.15 m/s), but the large width discrepancy (200 m wide channels vs 3500 m wide non-channelized zones) permits large water discharges in the non-channelized zones. In one measured case, we calculate that 70% of discharge (670 m3/s) bled from neighboring channels into a non-channelized zone over 3 km of sub-aqueous channel length. In contrast, sand flux distribution is focused in sub-aqueous channels and extends no further than 200 m from the channel margin. Fine sand is transported in suspension because of sufficiently high shear velocities (u* = 2-5 cm/s). Sand is not transported through unchannelized zones due to insufficient shear (u* <1.4 cm/s). Levees on either side of a sub-aqueous channel define this strong lateral convergence of sand flux. Factors controlling cross-channel flux from channels to non-channelized zones are likely to be the velocity differential, the ratio of channel depth to levee depth and change in width of the unchannelized area with downstream distance (0.75 m/m). We hypothesize that under certain conditions, lateral transport of water and sand out of channels may initiate a channel bifurcation, more in the manner of an avulsion than of flow splitting by mouth bar aggradation.

  2. A bedload trap for aeolian sand transport

    NASA Astrophysics Data System (ADS)

    Swann, C.; Sherman, D. J.

    2013-12-01

    This paper describes a bedload trap designed to separate bedload from saltation load in aeolian environments. The trap is installed below the sand surface and features a chimney that can be adjusted to the height of the surface. The chimney houses an internal wall to separate saltation load from bedload. Bedload particles are funneled to a piezo-electric sensor that converts grain impacts to voltages that can be sampled at very high frequencies (44,000 Hz in this example). Grains are then collected in a container that is easily retrieved so that sand samples can be obtained for weighing and subsequent grain size analysis. An algorithm to isolate single grain impacts is described. The version of the trap presented here is intended for the study of the initiation of grain motion.

  3. Three dimensional fabric evolution of sheared sand

    SciTech Connect

    Hasan, Alsidqi; Alshibli, Khalid (UWA)

    2012-10-24

    Granular particles undergo translation and rolling when they are sheared. This paper presents a three-dimensional (3D) experimental assessment of fabric evolution of sheared sand at the particle level. F-75 Ottawa sand specimen was tested under an axisymmetric triaxial loading condition. It measured 9.5 mm in diameter and 20 mm in height. The quantitative evaluation was conducted by analyzing 3D high-resolution x-ray synchrotron micro-tomography images of the specimen at eight axial strain levels. The analyses included visualization of particle translation and rotation, and quantification of fabric orientation as shearing continued. Representative individual particles were successfully tracked and visualized to assess the mode of interaction between them. This paper discusses fabric evolution and compares the evolution of particles within and outside the shear band as shearing continues. Changes in particle orientation distributions are presented using fabric histograms and fabric tensor.

  4. Proceedings of the 1986 tar sands symposium

    SciTech Connect

    Westhoff, J.D.; Marchant, L.C. (eds.)

    1986-10-01

    The 1986 Tar Sand Symposium was sponsored by the Laramie Project Office of the Morgantown Energy Technology Center, US Department of Energy, and hosted by the Western Research Institute, University of Wyoming Research Corporation, in Jackson, Wyoming, on July 7 to 10, 1986. The 10-session symposium included 36 presentations describing research, development, and commercial application of tar sand technologies of the US, Canada, the Federal Republic of Germany, Switzerland, and Venezuela. Over 80 participants represented the US, Canada, Germany, Japan, and Switzerland. The papers printed in the proceedings have been reproduced from camera-ready manuscripts furnished by the authors. The papers have not been referred, nor have they been edited extensively. All papers have been processed for inclusion in the Energy Data Base.

  5. Stratified chaos in a sand pile formation

    E-print Network

    Ate Poortinga; Jan G. Wesseling; Coen J. Ritsema

    2014-03-04

    Sand pile formation is often used to describe stratified chaos in dynamic systems due to self-emergent and scale invariant behaviour. Cellular automata (Bak-Tang-Wiesenfeld model) are often used to describe chaotic behaviour, as simulating physical interactions between individual particles is computationally demanding. In this study, we use a state-of-the-art parallel implementation of the discrete element method on the graphical processing unit to simulate sand pile formation. Interactions between individual grains were simulated using a contact model in an Euler integration scheme. Results show non-linear self-emergent behaviour which is in good agreement with experimental results, theoretical work and self organized criticality (SOC) approaches. Moreover, it was found that the fully deterministic model, where the position and forces on every individual particle can be determined every iteration has a brown noise signal in the x and y direction, where the signal is the z direction is closer to a white noise spectrum.

  6. Effects of storage on the toxicity of sediments spiked with fluoranthene to the amphipod, Rhepoxynius abronius

    SciTech Connect

    Cole, F.A.; Boese, B.L.; Swartz, R.C.; Lamberson, J.O.; DeWitt, T.H.

    2000-03-01

    To determine the effect of storage on contaminant bioavailability and toxicity, two sediment types, a fine sand and a silty sand, were spiked with nine concentrations of fluoranthene, then stored at 4 C for up to 170 d. Toxicity of the stored sediment was determined eight times during this storage interval using standard 10-d toxicity tests with the marine infaunal amphipod Rhepoxynius abronius. The concentrations of fluoranthene in the sediment and interstitial water were determined on samples taken on each test date. The toxicity of fluoranthene in the silty sand was similar for all storage times with LC50s ranging from 5.3 to 6.6 mg/g organic carbon (OC). The LC50 in the fine sand was 7.4 mg/g OC after 13 d of storage, ranged from 10.2 to 11.8 mg/g OC during 27 to 83 d of storage, and increased to 24.2 and 27.6 mg/g OC after 121 and 170 d of storage, respectively. These data indicate that the toxicity of both the fine and the silty sand remained essentially constant during storage from days 27 to 83. Toxicity tests conducted before or after that period may give misleading results because of disequilibrium or unknown storage effects.

  7. Aspects of tar sands development in Nigeria

    SciTech Connect

    Adewusi, V.A. (Dept. of Chemical Engineering, Obafemi Awolowo Univ., Ile-Ife (NG))

    1992-07-01

    Development of Nigerian massive reserves of crude bitumen and associated heavy oil is imminent in view of the impacts that the huge importation of these materials and their products have on the nation's economy, coupled with the depleting reserves of Nigeria and highlights the appropriate production technology options and their environmental implications. The utilization potentials of these resources are also enumerated, as well as the government's role in achieving accelerated, long-term tar sands development in the country.

  8. A NEW PROCESS FOR TAR SAND RECOVERY

    Microsoft Academic Search

    KAZEM M. SADEGHI; MOHAMMAD-ALI SADEGHI; JIH-FEN KUO; LONG-KUAN JANG; JIUNN-REN LIN; TEH FU YEN

    1992-01-01

    An extraction process for bitumen recovery from tar sand has been developed using an alkaline solution (e.g., NaOH, Na2SiO3) and sonication at a low temperature and ambient atmosphere. The bitumen recovered thus far is extraordinarily low in ash content and virtually free of metal and asphaltene, with an average gravity of 15° API for 95% cumulative recovery (based on carbon

  9. Sand Martin Riparia riparia ? male or female?

    Microsoft Academic Search

    E. Cowley

    1999-01-01

    8,037 examinations were made of brood patches of Sand Martins from 1971 to 1992 in north Nottinghamshire and given one of 12 different descriptions. The 1,997 birds which were examined more than once (5,443 times in total) and identified as 1,061 females and 936 males from the types of patch\\/es they had carried were then used to test the accuracy

  10. US tar sand oil recovery projects - 1984

    SciTech Connect

    Marchant, L.C.

    1985-02-01

    With a temporarily stable world oil price, which is lower than estimated values for most unconventional liquid hydrocarbon fuels, interest and activity in US tar sands has declined. Data are reported for 52 projects involving in situ, mining and plant extraction, and modified in situ technologies. The data include operator name, project location, project status (completed, current, or planned), project type (commercial or pilot) and, reservoir and oil characteristics.

  11. Wettability of NAPL-contaminated sands

    Microsoft Academic Search

    Susan E. Powers; William H. Anckner; Thomas F. Seacord

    1996-01-01

    The potential for changes in the wettability of a subsurface system following exposure of sands to a variety of non-aqueous-phase liquids (NAPLs) was assessed. Many of the NAPLs were collected from field sites with on-going NAPL recovery systems. Three methods were used to evaluate the wetting conditions: contact angle measurements, a qualitative bottle test, and capillary pressure-saturation curves. The results

  12. Fusion of arkosic sand by intrusive andesite

    USGS Publications Warehouse

    Bailey, Roy A.

    1954-01-01

    An andesite dike in the Valles Mountains of northern New Mexico has intruded and partly fused arkosic sediments for a distance of 50 feet from its contacts. The dike is semi-circular in form, has a maximum width of about 100 feet, and is about 500 feet long. Small associated arcuate dikes are arranged in spiral fashion around the main dike, suggesting that they were intruded along shear fractures similar to those described by Burbank (1941). The fused rocks surrounding the andesite dike are of three general types: 1) partly fused arkosic sand, 2) fused clay, and 3) hybrid rocks. The fused arkosic sand consists of relict detrital grains of quartz, orthoclose, and plagioclase, imbedded in colorless glass containing microlites of tridymite, cordierite, and magnetite. The relict quartz grains are corroded and embayed by glass; the orthoclase is sanidinized and partly fused; and the plagioclase is inverted to the high temperature form and is partly fused. The fused clay, which was originally a mixture of montmorillonite and hydromica, consists primarily of cordierite but also contains needle-like crystals of sillimanite (?) or mullite (?). The hybrid rocks originated in part by intermixing of fused arkosic sediments and andesitic liquid and in part by diffusion of mafic constituents through the fused sediments. They are rich in cordierite and magnetite and also contain hypersthene, augite, and plagioclase. The composition of pigeonite in the andesite indicates that the temperature of the andesite at the time of intrusion probably did not exceed 1200?C. Samples of arkosic sand were fused in the presence of water in a Morey bomb at 1050?C. Stability relations of certain minerals in the fused sand suggest that fusion may have taken place at a lower temperature, however, and the fluxing action of volatiles from the andesite are thought to have made this possible.

  13. Exploration for tar sands in western Kentucky

    SciTech Connect

    McGrain, P.; Ponsetto, L.R.

    1981-01-01

    Bitumen-impregnated sandstones are described along the eastern and southeastern rim of the Eastern Interior (Illinois) Basin in western Kentucky. Development in Kentucky to date has been from surface and near-surface deposits for almost exclusive use as a paving material. Published reserve estimates of western Kentucky deposits indicate more than 450 million metric tons of shallow strippable tar sands having equivalent bitumen content of 35 to 55 liters per metric ton. 16 refs.

  14. New production techniques for alberta oil sands.

    PubMed

    Carrigy, M A

    1986-12-19

    Low world oil prices represent a serious threat to expanded commercial development of the Canadian oil sands in the near term, as they do to all of the higher cost alternatives to crude oil such as oil shales and coal liquefaction. Nonetheless, research and field testing of new technology for production of oil from oil sands are being pursued by industry and government in Alberta. New production technology is being developed in Canada to produce synthetic oil from the vast resources of bitumen trapped in the oil sands and bituminous carbonates of northern Alberta. This technology includes improved methods of mining, extraction, and upgrading of bitumen from near-surface deposits as well as new drilling and production techniques for thermal production of bitumen from the more deeply buried reservoirs. Of particular interest are the cluster drilling methods designed to reduce surface disturbance and the techniques for horizontal drilling of wells from underground tunnels to increase the contact of injection fluids with the reservoir. PMID:17816505

  15. Singing-sand avalanches without dunes

    NASA Astrophysics Data System (ADS)

    Dagois-Bohy, S.; Courrech du Pont, S.; Douady, S.

    2012-10-01

    Singing-sand dunes have attracted curiosity for centuries and are now the subject of controversy. We address here two aspects of this controversy: first the possible link between the frequency heard and the shear rate (for a gravity avalanche on a dune slip-face, scaling as 0.4g/d, with d the ‘mean’ grain diameter), and second, the assumed necessity of a layered dune structure under the avalanche that acts as a resonator. Field recordings of singing dunes over the world reveal that they can present very different spectral characteristics: a dune with polydisperse grains produces a very broad and noisy spectrum, while a dune with sorted grains produces a well-defined frequency. Performing laboratory avalanches on a hard plate with singing-dune sand shows that there is no need for a dune below the sand avalanche to produce the singing sound, and a fortiori neither for the dune's layered structure nor for its particular sound transmission. By sieving the polydisperse grains, the same well-defined frequency is obtained to that of the dune with sorted grains, with the same diameter-frequency relation. The various frequencies heard in the field avalanches match the shear rates not calculated from the average size, but from the various peaks of the grain size distributions.

  16. The sedimentary structure of linear sand dunes

    PubMed

    Bristow; Bailey; Lancaster

    2000-07-01

    Linear sand dunes--dunes that extend parallel to each other rather than in star-like or crescentic forms--are the most abundant type of desert sand dune. But because their development and their internal structure are poorly understood, they are rarely recognized in the rock record. Models of linear dune development have not been able to take into account the sub-surface structure of existing dunes, but have relied instead either on the extrapolation of short-term measurements of winds and sediment transport or on observations of near-surface internal sedimentary structures. From such studies, it has not been clear if linear dunes can migrate laterally. Here we present images produced by ground penetrating radar showing the three-dimensional sedimentary structure of a linear dune in the Namib sand sea, where some of the world's largest linear dunes are situated. These profiles show clear evidence for lateral migration in a linear dune. Moreover, the migration of a sinuous crest-line along the dune produces divergent sets of cross-stratification, which can become stacked as the dune height increases, and large linear dunes can support superimposed dunes that produce stacked sets of trough cross-stratification. These clear structural signatures of linear dunes should facilitate their recognition in geological records. PMID:10894538

  17. Different depth intermittent sand filters for laboratory treatment of synthetic wastewater with concentrations close to measured septic tank effluent.

    PubMed

    Rodgers, M; Walsh, G; Healy, M G

    2011-01-01

    The objective of this study was to apply hydraulic and chemical oxygen demand (COD) loading rates at the upper limits of the design criteria for buried sand filters to test the sand filter depth design criteria. Over a 274-day study duration, synthetic effluent with a strength of domestic wastewater was intermittently dosed onto two sand filters of 0.2 m diameter, with depths of 0.3 and 0.4 m. Hydraulic and organic carbon loading rates of 105 L m(-2) d(-1) and 40 g COD m(-2) d(-1), respectively, were applied to the filters. The filters did not clog and had good effluent removal capabilities for 274 and 190 days, respectively. However, the 0.3 m-deep filter did experience a reduced performance towards the end of the study period. In the 0.3 and 0.4 m-deep filters, the effluent COD and SS concentrations were less than 86 and 31 mg L(-1), respectively, and nitrification was nearly complete in both these columns. Ortho-phosphorus (PO(4)-P) removal in fine sand and laterite 'upflow' filters, receiving effluent from the 0.3 m-deep filter, was 10% and 44%, respectively. PMID:21104498

  18. Environmental changes in Hunshandake (Otindag) sandy land revealed by optical dating and multi-proxy study of dune sands

    NASA Astrophysics Data System (ADS)

    Gong, Zhijun; Li, Sheng-Hua; Sun, Jimin; Xue, Lei

    2013-10-01

    A stabilized sand dune from the southern Hunshandake (Otindag) sandy land in northeastern China was studied for reconstructing past environmental changes by optically stimulated luminescence (OSL) dating, magnetic susceptibility and particle size analysis. The OSL dating results indicate that the sandy deposits at the bottom of the section formed at ˜11.8 ka ago, corresponding to low magnetic susceptibility and low fractions of fine particles (<63 ?m). The variations of the two climate proxies suggest that the region was mainly influenced by arid climate. Above the bottom sand layer, there are loamy soils, which formed between ˜6.2 and ˜4.3 ka ago. The soils have relatively higher magnetic susceptibility and finer grain size than the bottom sands. The climate of this period was relatively warm and humid, dominated by enhanced summer monsoon. During the late Holocene (from ˜4 ka to present), Hunshandake was dominated by semi-humid to arid climate, as indicated by the aeolian sand beds and interbedded weak sandy soils.

  19. The role of ionic strength and grain size on the transport of colloids in unsaturated sand columns

    NASA Astrophysics Data System (ADS)

    Mitropoulou, Polyxeni N.; Syngouna, Vasiliki I.; Chrysikopoulos, Constantinos V.

    2013-04-01

    The main objective of this study was to better understand the combined effects of ionic strength, and sand grain size on colloid fate and transport in unsaturated porous media. Spherical fluorescent polymer microspheres with three different sizes (0.075, 0.30 and 2.1 ?m), and laboratory columns packed with two size fractions of clean quartz sand (0.513 and 0.181 mm) were used. The saturation level of the packed columns was set to 83-95% with solutions having a wide range of ionic strength (0.1-1000 mM). The electrophoretic mobility of colloids and sand grains were evaluated for all the experimental conditions employed. The various experimental collision efficiencies were quanti?ed using the classical colloid ?ltration theory. The theoretical collision efficiencies were estimated with appropriate DLVO energies using a Maxwell model. The experimental results suggested that the retention of the bigger colloids (2.1 ?m) was slightly higher compared to the conservative tracer and smaller colloids (0.3 and 0.075 ?m) in deionized-distilled-water, indicating sorption at air-water interfaces or straining. Moreover, relatively smaller attachment was observed onto fine than medium quartz sand. The mass recovery of the 0.3 ?m microspheres in NaCl solution was shown to significantly decrease with increasing ionic strength. Both the experimental and theoretical collision efficiencies based on colloid interactions with solid-water interfaces, were increased with increasing ionic strength.

  20. Mars Hand Lens Imager (MAHLI) Efforts and Observations at the Rocknest Eolian Sand Shadow in Curiosity's Gale Crater Field Site

    NASA Technical Reports Server (NTRS)

    Edgett, K. S.; Yingst, R. A.; Minitti, M. E.; Goetz, W.; Kah, L. C.; Kennedy, M. R.; Lipkaman, L. J.; Jensen, E. H.; Anderson, R. C.; Beegle, L. W.; Carsten, J. L.; Cooper, B.; Deen, R. G.; Dromart, G.; Eigenbrode, J. L.; Grotzinger, J. P.; Gupta, S.; Hamilton, V. E.; Hardgrove, C. J.; Harker, D. E.; Herkenhoff, K. E.; Herrera, P. N.; Hurowitz, J. A.; Jandura, L.; Ming, D. W.

    2013-01-01

    The Mars Science Laboratory (MSL) mission is focused on assessing the past or present habitability of Mars, through interrogation of environment and environmental records at the Curiosity rover field site in Gale crater. The MSL team has two methods available to collect, process and deliver samples to onboard analytical laboratories, the Chemistry and Mineralogy instrument (CheMin) and the Sample Analysis at Mars (SAM) instrument suite. One approach obtains samples by drilling into a rock, the other uses a scoop to collect loose regolith fines. Scooping was planned to be first method performed on Mars because materials could be readily scooped multiple times and used to remove any remaining, minute terrestrial contaminants from the sample processing system, the Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA). Because of this cleaning effort, the ideal first material to be scooped would consist of fine to very fine sand, like the interior of the Serpent Dune studied by the Mars Exploration Rover (MER) Spirit team in 2004 [1]. The MSL team selected a linear eolian deposit in the lee of a group of cobbles they named Rocknest (Fig. 1) as likely to be similar to Serpent Dune. Following the definitions in Chapter 13 of Bagnold [2], the deposit is termed a sand shadow. The scooping campaign occurred over approximately 6 weeks in October and November 2012. To support these activities, the Mars Hand Lens Imager (MAHLI) acquired images for engineering support/assessment and scientific inquiry.

  1. Depositional models of sandy debrites and turbidites of Palaeogene reservoir sands in deep-lacustrine environments, South China

    NASA Astrophysics Data System (ADS)

    Li, Y.; Chen, G.

    2013-12-01

    Two depositional models are proposed for deep-lacustrine petroleum reservior sands (Palaeogene) in the Fushan Sag, Beibuwan Basin, South China. This facies trend is used as a template for predicting the distribution of reservoir facies of the Fushan oilfield. Based on examination of 150m of conventional cores from 13 drilled wells, four depositional facies have been interpreted: (1) fine-grained massive sandstone with floating mudstone clasts and planar clast fabric (sandy debrite); (2) fine-grained sandstone and siltstone showing contorted bedding, sand injection, and ptygmatic folding (sandy slump), (3) fine-grained sandstone with thin layers of normal grading and flute casts (turbidite), and (4) mudstone with faint laminae (suspension fallout). Combined with multiple seismic attributes, two depositional models are characterized by (1) sublacustrine fan: thick turbidite units occur at the bottom of the western sag beneath a series of normal faults slope. (2) Thinner deposition of sandy debrites mainly distribute at the bottom of eastern sag far from sandy slump at the lake margin slope, which interpreted to be controlled by "two-step" flexure slope break. The transfer zone located in the centre area is confirmed to be the primary origin for such differential depositions. In our study area, sandy debrites constitute the producing petroleum reservoirs, but turbidites are non reservoirs. This dramatic understanding will well account for "eastern much more than western" distribution of proven petroleum reserves and be applicable to predicting reservoir distribution.

  2. Inexistence of Zeeman's fine topology

    E-print Network

    Norberto Sainz

    2010-03-19

    The family of topologies that induce the Euclidean metric space on every time axis and every space axis exhibits no maximal element when partially ordered by the relation ``finer than'', as demonstrated in this article. One conclusion and two reflections emerge and are addressed herein: Conclusion: a. Zeeman's fine topology [1] and G\\"{o}bel's extension to arbitrary spacetimes [2] do not exist. Reflections: a. Both authors' attempts may be classified as type-2 strategies, within the taxonomy of [3]. b. How could these inexistent topologies be used for decades?

  3. Does Zeeman's Fine Topology Exist?

    E-print Network

    Norberto Sainz

    2012-01-23

    We work on the family of topologies for the Minkowski manifold M. We partially order this family by inclusion to form the lattice \\Sigma(M), and focus on the sublattice Z of topologies that induce the Euclidean metric space on every time axis and every space axis. We analyze the bounds of Z in the lattice \\Sigma(M), in search for its supremum. Our conclusion --that such a supremum does not belong in Z-- is compared with constructive proofs of existence of the fine topology, defined as the maximum of Z and conceived to play an essential role in contemporary physical theories. Essential mathematical and physical questions arise.

  4. Measurement of fine sediment infiltration and deposition rates within a gravel bed: a pilot study in the Geul River, the Netherlands

    NASA Astrophysics Data System (ADS)

    van der Perk, Marcel; Stoutjesdijk, Jedidja; van der Werf, Mirke

    2013-04-01

    Transient storage of fine sediments in the river bed determines the fine sediment residence time in gravel bed streams at intermediate time scales between days and a few years. We measured the sediment infiltration into the gravel bed at two locations in the Geul River, the Netherlands (mean discharge = 2 m3 s-1) using two methods: 1) a gravimetric method and 2) a metal concentration-based method. Both methods involved the placement of sediment traps, consisting of cylindrical mesh cages with a diameter of 15 cm and a height of 10 cm, in the gravel bed. In the first method, the cage was filled with clean gravel greater than 12.5 mm (the size of the mesh openings) collected from the local river bed (D50 ? 19 mm). In the second method, the sediment traps were filled with clean gravel and about 700 grams of fine sand. During the sampling period, this 'clean' sand was contaminated by deposition of metal-contaminated fine sediment from the Geul River. After four to eight days, the sediment traps were removed. A bag around the cage, which had been lowered during sampling, prevented the fine sediment to wash out from the sediment traps during removal. The fine sediment was washed from the sediment traps and subsequently dried and weighed. For the second method, the zinc concentrations of the fine sand and the fine sediment collected from the sediment traps were measured using a Thermo Fisher Scientific Niton® handheld XRF analyser. The sediment infiltration or deposition rates were then calculated from the differences between the zinc concentrations in the sediment samples and the 'clean' sand. The fine sediment deposition rates measured using the concentration-based method (0.49 ± 0.20 kg m-2 d-1 [mean ± 1 st. dev. ]) were consistent with those measured using the gravimetric method (0.54 ± 0.22 kg m-2 d-1). The mean and variation of the fine sediment deposition rates increased with stream discharge during the sampling period. The corresponding vertical mass fluxes in a 1 km long river reach are on the same order of magnitude as the longitudinal suspended sediment flux of the Geul River. This means that sediment infiltration into the gravel bed comprises a substantial portion of the sediment budget of the Geul River.

  5. Policy Analysis of the Canadian Oil Sands Experience

    SciTech Connect

    None, None

    2013-09-01

    For those who support U.S. oil sands development, the Canadian oil sands industry is often identified as a model the U.S. might emulate, yielding financial and energy security benefits. For opponents of domestic oil sands development, the Canadian oil sands experience illustrates the risks that opponents of development believe should deter domestic policymakers from incenting U.S. oil sands development. This report does not seek to evaluate the particular underpinnings of either side of this policy argument, but rather attempts to delve into the question of whether the Canadian experience has relevance as a foundational model for U.S. oil sands development. More specifically, this report seeks to assess whether and how the Canadian oil sands experience might be predictive or instructive in the context of fashioning a framework for a U.S. oil sands industry. In evaluating the implications of these underpinnings for a prospective U.S. oil sands industry, this report concentrates on prospective development of the oil sands deposits found in Utah.

  6. Eolian cover sands: a sedimentologic model and paleoenvironmental implications

    SciTech Connect

    Lea, P.D.

    1985-01-01

    In periglacial areas, accumulations of eolian sand commonly form low-relief blankets without well-developed dunes. Internally, these sandsheet deposits exhibit subhorizontal lamination rather than high-angle cross-bedding. Such cover sands of late-Pleistocene age mantle extensive areas in northern Europe, but have been reported more rarely from North America. The processes by which cover sands, as opposed to dunes, accumulate have not yet been determined conclusively. Wind ripples and sand dunes do not form a continuum; flow separation and avalanching and negligible in the former and vital in the latter. Accretion of a sand patch into a mound sufficient to cause flow separation and dune growth requires a consistently available supply of loose sand. In cover-sand areas, sand may be immobilized prior to dune development by several factors: (1) a sparse vegetation cover, (2) moist ground conditions, (3) snow cover, and (4) a shallow permafrost table and/or an ice-cemented active layer. Detailed sedimentologic studies may allow discrimination among these various controls. The importance of the individual controlling factors can vary seasonally in a given deposit, as well as between deposits in different paleogeographic settings. However, all factors imply more mesic conditions than those associated with many dune deposits. The association of cover sands with paraboloid dunes is also consistent with somewhat moist conditions. The relatively mesic nature of cover sands controls their Pleistocene distribution; they become decreasingly important relative to dunes in maritime-to-continental transects across Alaska and northern Europe.

  7. Southern Fine Particulate Monitoring Project

    SciTech Connect

    Ashley Williamson

    2003-05-31

    This final project report presents experimental details, results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the October, 2001-September, 2002 study period.The host site for these measurement activities is the North Birmingham PM monitoring station by the Jefferson County Health Department in Birmingham, AL.The continuous data include PM{sub 2.5} mass concentrations measured by TEOM, particle sulfate using the R&P 8400S monitor, particle size distributions measured by SMPS and APS monitors, and PM{sub 2.5} light scattering extinction coefficient as measured by nephelometer. During the course of the project, measurement intercomparison data were developed for these instruments and several complementary measurements at the site. The report details the instrument set and operating procedures and describes the resulting data. Report subsections present an overview summary of the data, followed by detailed description of the systematic time behavior of PM{sub 2.5} and other specific particulate size fractions. Specific subsections are included for particle size distribution, light scattering, and particle sulfate data. The final subsection addresses application of the measurements to the practical questions of fine PM generation and transport, source attribution, and PM{sub 2.5} management strategies.

  8. Unconsolidated sand grain shape, size impact frac-pack design

    SciTech Connect

    Wang, E.; Sharma, M.M. [Univ. of Texas, Austin, TX (United States)

    1997-05-19

    The shape and size of sand grains, as well as the saturating fluid, influence the mechanical properties of unconsolidated sands and need to be considered in frac-pack design. These mechanical properties of unconsolidated properties of unconsolidated sands play an important role in determining the geometry of frac-pack treatments. Stress-strain curves obtained for unconsolidated sands at elevated stresses show highly nonlinear hysteretic behavior. The impact of these findings on frac-pack design can be significant. The nonlinear elastic properties of unconsolidated sand can give rise to some unique features in the pressure response and in the fracture geometry that may not be observed in hard rocks. This article focuses on the impact of mechanical properties of poorly consolidated and unconsolidated sands on the geometry of frac packs. The paper discusses frac packs, mechanical properties (Young`s modulus, shear failure) and effective treatments.

  9. The potential use of tar sand bitumen as paving asphalt

    SciTech Connect

    Petersen, J.C.

    1987-01-01

    The properties of several tar sand asphalts prepared in past studies by several different investigators were compared with each other and with the properties of petroleum asphalts. These results were reviewed and discussed with regard to the potential use of tar sand bitumen in pavement applications. The data show that tar sand bitumen has good potential for use in highway pavements that meet today's performance specifications. No deficiencies in the tar sand asphalts were found that would be expected to seriously affect performance. On the other hand, the data indicate that some tar sand asphalts may have superior aging characteristics, being relatively resistant to oxidative age hardening compared with typical petroleum asphalts. Asphalt-aggregate mixtures prepared using two tar sand asphalts also showed acceptable strength properties and excellent resistance to moisture-induced damage.

  10. Simulation of the electrification of wind-blown sand.

    PubMed

    Hu, Wenwen; Xie, Li; Zheng, Xiaojing

    2012-03-01

    The triboelectric charging of collision particles is essential to understand sand electrification in wind-blown sand fluxes. The physical model of electron trapped in high-energy states has been proposed to explain the triboelectric charging between identical insulating granular materials. In this study we propose an improved triboelectric charging model which combines the soft sphere model and the trapped electron model to calculate the net charge transfer during particles' collisions. Based on our charging model, we investigate the sand electrification of wind-blown sand, such as the charge flux varying with height, the charge-to-mass ratio of wind-blown sand, and the equilibrium time that the charge takes to approach a stable state. Numerical simulation results of the averaged charge-to-mass ratio in wind-blown sand fluxes are in good agreement with the experimental data. PMID:22438041

  11. Biogenic and anthropogenic organic components of Saharan sands.

    PubMed

    Balducci, Catia; Ladji, Riad; Muto, Valeria; Romagnoli, Paola; Yassaa, Nourredine; Cecinato, Angelo

    2014-07-01

    Till now, the Sahara desert sands have scarcely characterized for their organic contents, despite they are known to heavily affect Europe and America when transported by winds. In this study, the composition of sands collected in ten oasis lying in two regions of the Algerian Sahara during 2011 was investigated with regards to organic fraction. Attention was paid to anthropogenic and biogenic sources of organics associated to sands, through the characterization of n-alkanes, n-alkanoic and n-alkanedioic acids, n-alkanols, sterols, PAHs and caffeine. The organic fraction load on sands associable to natural sources was higher in the Region of Biskra than in that of Ouargla. The biogenic contribution to the total amount of organics in sands exceeded that of the anthropogenic sources. The composition of sands from Hassi Messaoud, compared to that observed there in 2006, showed that the anthropic impact over the region was not changed. PMID:24875880

  12. Oil shale, tar sands, and related materials

    SciTech Connect

    Stauffer, H.C.

    1981-01-01

    This sixteen-chapter book focuses on the many problems and the new methodology associated with the commercialization of the oil shale and tar sand industry. Topics discussed include: an overview of the Department of Energy's oil shale R, D, and D program; computer simulation of explosive fracture of oil shale; fracturing of oil shale by treatment with liquid sulfur dioxide; chemistry of shale oil cracking; hydrogen sulfide evolution from Colorado oil shale; a possible mechanism of alkene/alkane production in oil shale retorting; oil shale retorting kinetics; kinetics of oil shale char gasification; a comparison of asphaltenes from naturally occurring shale bitumen and retorted shale oils: the influence of temperature on asphaltene structure; beneficiation of Green River oil shale by density methods; beneficiation of Green River oil shale pelletization; shell pellet heat exchange retorting: the SPHER energy-efficient process for retorting oil shale; retorted oil shale disposal research; an investigation into the potential economics of large-scale shale oil production; commercial scale refining of Paraho crude shale oil into military specification fuels; relation between fuel properties and chemical composition; chemical characterization/physical properties of US Navy shale-II fuels; relation between fuel properties and chemical composition: stability of oil shale-derived jet fuel; pyrolysis of shale oil residual fractions; synfuel stability: degradation mechanisms and actual findings; the chemistry of shale oil and its refined products; the reactivity of Cold Lake asphaltenes; influence of thermal processing on the properties of Cold Lake asphaltenes: the effect of distillation; thermal recovery of oil from tar sands by an energy-efficient process; and hydropyrolysis: the potential for primary upgrading of tar sand bitumen.

  13. Aeolian Sand Transport with Collisional Suspension

    NASA Technical Reports Server (NTRS)

    Jenkins, James T.; Pasini, Jose Miguel; Valance, Alexandre

    2004-01-01

    Aeolian transport is an important mechanism for the transport of sand on Earth and on Mars. Dust and sand storms are common occurrences on Mars and windblown sand is responsible for many of the observed surface features, such as dune fields. A better understanding of Aeolian transport could also lead to improvements in pneumatic conveying of materials to be mined for life support on the surface of the Moon and Mars. The usual view of aeolian sand transport is that for mild winds, saltation is the dominant mechanism, with particles in the bed being dislodged by the impact of other saltating particles, but without in-flight collisions. As the wind becomes stronger, turbulent suspension keeps the particles in the air, allowing much longer trajectories, with the corresponding increase in transport rate. We show here that an important regime exists between these two extremes: for strong winds, but before turbulent suspension becomes dominant, there is a regime in which in-flight collisions dominate over turbulence as a suspension mechanism, yielding transport rates much higher than those for saltation. The theory presented is based on granular kinetic theory, and includes both turbulent suspension and particle-particle collisions. The wind strengths for which the calculated transport rates are relevant are beyond the published strengths of current wind tunnel experiments, so these theoretical results are an invitation to do experiments in the strong-wind regime. In order to make a connection between the regime of saltation and the regime of collisional suspension, it is necessary to better understand the interaction between the bed and the particles that collide with it. This interaction depends on the agitation of the particles of the bed. In mild winds, collisions with the bed are relatively infrequent and the local disturbance associated with a collision can relax before the next nearby collision. However, as the wind speed increases, collision become more frequent and the agitation need not decay completely. In the regime of collisional suspension, the particles near the surface of the bed are assumed to be in a state of constant agitation. We indicate the conditions at the bed corresponding to the limits of saltation and collisional suspension and outline experiments, simulations, and modeling that have been undertaken to bridge these limits.

  14. Investigation of sands subjected to dynamic loading

    E-print Network

    Reeves, Gary Neil

    1967-01-01

    INVESTIGATION OF SP&NDS SUBJECTED TO DTNAMIC LOADING A Tucsis By Gary N. Reeves Submitted to the Grad ate Coll Ee of the T xas AGM University in partial fulfillment of the requirements for the deEree of MASTER OF SCIPNCE AuBust 19G7 Major... Subject: Civil EnEineering LABORATORY INVESTIGATION OF SANDS SUBJECTED TO DYNAMIC LOADING A Thesis by Gary N. Reeves Approved as to style and content by: Chairman of Committee Head of Department Membe Me er August 1967 ACIINOWLEDGR&J. 'NTS I...

  15. Heating tar sands formations to visbreaking temperatures

    DOEpatents

    Karanikas, John Michael (Houston, TX); Colmenares, Tulio Rafael (Houston, TX); Zhang, Etuan (Houston, TX); Marino, Marian (Houston, TX); Roes, Augustinus Wilhelmus Maria (Houston, TX); Ryan, Robert Charles (Houston, TX); Beer, Gary Lee (Houston, TX); Dombrowski, Robert James (Houston, TX); Jaiswal, Namit (Houston, TX)

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  16. Sedimentary Rock From Sand: Syringe Simulation

    NSDL National Science Digital Library

    This activity will allow students to simulate the formation of sedimentary rocks by compressing sand, water, and other materials in a syringe. The products are allowed to dry, and students will investigate how the properties of the samples of sedimentary rocks so formed are dependent on the extent of their compaction and cementation. The activity will help to explain that for most sediments to become rocks the grains need to be squeezed together (compacted) and/or glued together (cemented) and that the extent of the compaction and the strength of the cementation affect the properties of sedimentary rocks.

  17. X-ray Analysis of Sand

    NSDL National Science Digital Library

    Dexter Perkins

    This is an x-ray diffraction analysis of six sand samples and comparison with hand specimens. Students look at each of the six samples under the binocular microscope and note such useful properties as number of minerals, cleavage/fracture, color, shape, grain size, roundness, and degree of sorting. Then they grind up small amounts of each sample and mount them on glass slides for X-ray. Students write all sample descriptions and X-ray analysis results in their lab notebook. Then they identify the minerals in each sample, determine where they are from, and write a report summarizing all results.

  18. Heating tar sands formations while controlling pressure

    DOEpatents

    Stegemeier, George Leo (Houston, TX) [Houston, TX; Beer, Gary Lee (Houston, TX) [Houston, TX; Zhang, Etuan (Houston, TX) [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  19. Tour of Park Geology: Sand Dunes

    NSDL National Science Digital Library

    This Park Geology site provides links to tours of individual National Parks, Monuments, and Recreation Areas with sand dunes. Where appropriate for each park, links are provided to maps, photographs, geologic research, related links, visitor information, and teacher features (resources for teaching geology with National Park examples). The list includes places such as Death Valley and Mojave National Preserve, along with less well-known areas such as the Pictured Rocks National Lakeshore in Michigan and the Wright Brothers National Memorial in North Carolina.

  20. Biogenic crust dynamics on sand dunes

    E-print Network

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

    Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fixed crusted dunes and fixed vegetated dunes at low wind power, and fixed vegetated dunes and active dunes at high wind power. These results suggest a cross-over between two different forms of desertification.