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Sample records for sand sheet deposits

  1. Insights from Askja sand sheet, Iceland, as a depositional analogue for the Bagnold Dune Field, Gale Crater, Mars.

    Science.gov (United States)

    Ukstins, I.; Sara, M.; Riishuus, M.; Schmidt, M. E.; Yingst, R. A.; Berger, J.

    2017-12-01

    Examining the compositional effect of aeolian transport and sorting processes on basaltic sands is significant for understanding the evolution of the Bagnold dune field, as well as other martian soils and sedimentary units. We use the Askja sand sheet, Iceland, as a testbed to quantify the nature of soil production and aeolian transport processes in a mafic system. Basalts from Askja and surrounding volcanic units, which can have high MgO (5-18 wt %) and high Fe2O3 (5-18 wt %), have been weathered to form mafic volcaniclastic deposits which are incorporated into a 40-km long sand sheet to the E-SE of the caldera, ranging from 10 cm to 10 m thick, and covering 240 km2. Ash and lava from the 2014-2015 Holuhraun eruption were emplaced onto the southeastern part of the sand sheet. The SW section is deflationary and defined by very fine to medium grained basaltic sand with ventifact cobbles and boulders. The central part is inflating and dominated by very fine-grained sand, relict lava fields, and small to large sand ripples (1 to 30 cm). The NE portion is also inflating but accumulation is limited to topographic depressions. Bulk chemistry of >200 sand samples are similar to Martian crust (SiO2: 48-52 wt %, MgO: 5-8 wt %, Fe2O3: 13-15 wt %). MgO concentrations vary with distance along the sand sheet, increasing by 1.5% over 10 km in the downwind direction (E, NE), then maintaining a relatively consistent concentration of 6.75 wt % over 18 km. Mean equancy of grains decreases 15 % to the E over 10 km followed by a plateau at 65 to 75 %. Material at depth tends to be of higher sphericity than material on or near the surface. Notably, MgO increases while the sphericity decreases and both data sets level off at 10 km, which suggests these two variables are related. These indicate input of material with prismoidal morphology around 10 km, and may be due to the Holuhraun eruption.

  2. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  3. Intermontane eolian sand sheet development, Upper Tulum Valley, central-western Argentina

    Directory of Open Access Journals (Sweden)

    Patrick Francisco Fuhr Dal' Bó

    Full Text Available ABSTRACTThe intermontane Upper Tulum eolian sand sheet covers an area of ca. 125 km² at north of the San Juan Province, central-western Argentina. The sand sheet is currently an aggrading system where vegetation cover, surface cementation and periodic flooding withhold the development of dunes with slipfaces. The sand sheet surface is divided into three parts according to the distribution of sedimentary features, which reflects the variation in sediment budget, water table level and periodic flooding. The central sand sheet part is the main area of eolian deposition and is largely stabilized by vegetation. The sedimentary succession is 4 m thick and records the vertical interbedding of eolian and subaqueous deposits, which have been deposited for at least 3.6 ky with sedimentation rates of 86.1 cm/ky. The construction of the sand sheet is associated with deflation of the sand-graded debris sourced by San Juan alluvial fan, which is available mainly in drier fall-winter months where water table is lower and wind speeds are periodically above the threshold velocity for sand transport. The accumulation of sedimentary bodies occurs in a stabilized eolian system where vegetation cover, thin mud veneers and surface cementation are the main agents in promoting accumulation. The preservation of the sand sheet accumulations is enabled by the progressive creation of the accommodation space in a tectonically active basin and the continuous burial of geological bodies favored by high rates of sedimentation.

  4. Modeling sheet-flow sand transport under progressive surface waves

    NARCIS (Netherlands)

    Kranenburg, Wouter

    2013-01-01

    In the near-shore zone, energetic sea waves generate sheet-flow sand transport. In present day coastal models, wave-induced sheet-flow sand transport rates are usually predicted with semi-empirical transport formulas, based on extensive research on this phenomenon in oscillatory flow tunnels.

  5. Design of preconcentration flow-sheet for processing Bhimunipatnam beach sands using pilot plant experiments and computer simulation

    International Nuclear Information System (INIS)

    Padmanabhan, N.P.H.; Sridhar, U.

    1993-01-01

    Simulation was carried out using a beach sand beneficiation plant simulator software, SANDBEN, currently being developed in Indian School of Mines, Dhanbad, and the results were compared and analyzed with those obtained by actual pilot plant experiments on a beach sand sample from Bhimunipatnam deposit. The software is discussed and its capabilities and limitations are highlighted. An optimal preconcentrator flow-sheet for processing Bhimunipatnam beach sand was developed by simulation and using the results of the pilot plant experiments. (author). 13 refs., 2 tabs., 3 figs

  6. Production of oil from Intermountain West tar sands deposits

    Energy Technology Data Exchange (ETDEWEB)

    Glassett, J.M.; Glassett, J.A.

    1976-03-01

    Six tar sand deposits in the Intermountain West, each containing more than one billion barrels of oil in place, are identified. All of these deposits are in eastern Utah and contain a total of twenty-eight billion barrels of oil. The names of the six deposits arranged in descending order of desirability for large-scale surface-mining oil recovery operations are as follows: Sunnyside, Tar Sand Triangle, Asphalt Ridge, P.R. Spring, Circle Cliffs, and Hill Creek. An overview of each deposit is presented including geology, surface-mining variables, chemical processing variables, environmental aspects, and economics. A comparison of Utah tar sands and Athabasca, Alberta, Canada tar sands is also presented.

  7. System Controls on the South Texas Sand Sheet

    Science.gov (United States)

    Barrineau, Clifton Patrick

    Semi-stabilized dune systems are important indicators of Quaternary drought variability across central North America. The South Texas sand sheet (STSS) is the southernmost relict dune system in central North America and is exposed to higher evapotranspiration and moisture variability than similar landscapes farther north. This study uses multi-scale analysis of LiDAR data, geophysical surveys, optically stimulated luminescence dates of core samples, and X-ray fluorescence analysis to identify historical periods of desertification across the STSS. These data suggest long-term relationships between climate, ecological disturbances, geological framework, and desertification. Aeolian activations dated at ca. 75, 230, 2000, 4100, and 6600 yr bp correspond to periods of persistent regional drought, changes in sediment supply, and anthropogenic disturbances of native ecology. From these results it appears that regionalized activation in semi-stabilized dune systems is controlled primarily by climatic variations that reduce the overall moisture available for maintaining vigorous vegetation growth, while localized activation patterns depend more on stresses related to site-specific morphodynamics as well as human activity. With enhanced aridity forecast for much of central North America through the 21 st century, understanding the specific thresholds of desertification is an important step towards building a conceptual model of desertification in semi-stabilized dune landscapes.

  8. Potential building sand deposits in Songkhla province area

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    Kooptarnond, K.

    2002-10-01

    Full Text Available An investigation of potential building sand deposits in Songkhla province area subdivided them into four regions according to their accumulation in various alluvial plains, meanders throughout alluvial deposits and residual soils. Four selected deposits, were Rattaphum-Khuan Niang, U-Taphao river, Na Mom, and Chana-Thepha regions. Information obtained from these deposits revealed a good correlation between the geomorphological features as interpreted from aerial photographs and those identified from vertical electrical resistivity sounding results. Sand samples were analysed for their physical and chemical properties. Petrographic studies were also undertaken to characterize the composition types, texture and shapes. An overview of the sand properties was used them to be within the acceptable limits for building sand. However, relatively high organic impurities and soundness were found in sand from Khuan Niang and Na Mom deposits. The result indicated a potential reconnaissance mineral resource of about 46 square kilometres.A reserve evaluation for natural building sand was carried out by using Geographic Information System (GIS. Maps of the various parameters considered were constructed in digital database format with the aid of Arc/Info and ArcView software. Overlay mapping and buffer zone modules were performed to evaluate inferred resources of building sand. The key parameters of analysis included the distance from transportation, distance from streams, lithology and thickness of sand layers. The remaining inferred sand total was of about 386 million cubic metres or about 1,021 million metric tons was therefore estimated, of which 60 percent lies in the Rattaphum-Khuan Niang region and 40 percent in the other regions.

  9. Aeolian sand transport and aeolian deposits on Venus: A review

    Science.gov (United States)

    Kreslavsly, Mikhail A.; Bondarenko, Nataliya V.

    2017-06-01

    We review the current state of knowledge about aeolian sand transport and aeolian bedforms on planet Venus. This knowledge is limited by lack of observational data. Among the four planetary bodies of the Solar System with sufficient atmospheres in contact with solid surfaces, Venus has the densest atmosphere; the conditions there are transitional between those for terrestrial subaerial and subaqueous transport. The dense atmosphere causes low saltation threshold and short characteristic saltation length, and short scale length of the incipient dunes. A few lines of evidence indicate that the typical wind speeds exceed the saltation threshold; therefore, sand transport would be pervasive, if sand capable of saltation is available. Sand production on Venus is probably much slower than on the Earth; the major terrestrial sand sinks are also absent, however, lithification of sand through sintering is expected to be effective under Venus' conditions. Active transport is not detectable with the data available. Aeolian bedforms (transverse dunes) resolved in the currently available radar images occupy a tiny area on the planet; however, indirect observations suggest that small-scale unresolved aeolian bedforms are ubiquitous. Aeolian transport is probably limited by sand lithification causing shortage of saltation-capable material. Large impact events likely cause regional short-term spikes in aeolian transport by supplying a large amount of sand-size particles, as well as disintegration and activation of older indurated sand deposits. The data available are insufficient to understand whether the global aeolian sand transport occurs or not. More robust knowledge about aeolian transport on Venus is essential for future scientific exploration of the planet, in particular, for implementation and interpretation of geochemical studies of surface materials. High-resolution orbital radar imaging with local to regional coverage and desirable interferometric capabilities is the

  10. Episodic Late Holocene dune movements on the sand-sheet area, Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado, USA

    Science.gov (United States)

    Forman, S. L.; Spaeth, M.; Marín, L.; Pierson, J.; Gómez, J.; Bunch, F.; Valdez, A.

    2006-07-01

    The Great Sand Dunes National Park and Preserve (GSDNPP) in the San Luis Valley, Colorado, contains a variety of eolian landforms that reflect Holocene drought variability. The most spectacular is a dune mass banked against the Sangre de Cristo Mountains, which is fronted by an extensive sand sheet with stabilized parabolic dunes. Stratigraphic exposures of parabolic dunes and associated luminescence dating of quartz grains by single-aliquot regeneration (SAR) protocols indicate eolian deposition of unknown magnitude occurred ca. 1290-940, 715 ± 80, 320 ± 30, and 200-120 yr ago and in the 20th century. There are 11 drought intervals inferred from the tree-ring record in the past 1300 yr at GSDNPP potentially associated with dune movement, though only five eolian depositional events are currently recognized in the stratigraphic record. There is evidence for eolian transport associated with dune movement in the 13th century, which may coincide with the "Great Drought", a 26-yr-long dry interval identified in the tree ring record, and associated with migration of Anasazi people from the Four Corners areas to wetter areas in southern New Mexico. This nascent chronology indicates that the transport of eolian sand across San Luis Valley was episodic in the late Holocene with appreciable dune migration in the 8th, 10-13th, and 19th centuries, which ultimately nourished the dune mass against the Sangre de Cristo Mountains.

  11. Sedimentological and Scanning Electron Miscroscopic Descriptions of Afowo Oil Sand Deposits, South Western Nigeria

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    Akinmosin A

    2017-12-01

    Full Text Available Sedimentological and scanning electron microscopic analyses of some shallow reservoir tar sand samples in parts of Southwestern Nigeria were carried out with the aim of characterizing the reservoir properties in relation to bitumen saturation and recovery efficiency. The production of impregnated tar from the sands requires the reservoir to be of good quality. A total of thirty samples were collected at different localities within the tar sand belt (ten out of these samples were selected for various reservoir quality analyses based on their textural homogeneity. The result of particle size distribution study showed that bulk of the sands is medium – coarse grained and moderately sorted. The grain morphologies are of low to high sphericity with shapes generally sub-angular to sub-rounded, implying that the sands have undergone a fairly long transportation history with depositional energy having a moderate to high velocity. The quartz content was made up of about 96% of the total mineralogical components; the sediments of the Afowo Formation can be described to be mineralogically and texturally stable. The result of the scanning electron microscopy (SEM analysis revealed that the oil sands contained minerals which had been precipitated and occurred as pore filling cement; these minerals include sheet kaolinite, block kaolinite, vermiform kaolinite, pyrite crystals and quartz. The SEM images also showed micro-pores ranging from 0.057µm to 0.446µm and fractures. The study showed that the clay minerals contained in the Afowo reservoir rocks were mainly kaolinite. Kaoline unlike some other clays (e.g Montimorillonite does not swell with water, hence it is not expected to have any negative effects on the reservoir quality, especially during enhanced oil recovery operations.

  12. Characterization of Platinum Nanoparticles Deposited on Functionalized Graphene Sheets

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    Yu-Chun Chiang

    2015-09-01

    Full Text Available Due to its special electronic and ballistic transport properties, graphene has attracted much interest from researchers. In this study, platinum (Pt nanoparticles were deposited on oxidized graphene sheets (cG. The graphene sheets were applied to overcome the corrosion problems of carbon black at operating conditions of proton exchange membrane fuel cells. To enhance the interfacial interactions between the graphene sheets and the Pt nanoparticles, the oxygen-containing functional groups were introduced onto the surface of graphene sheets. The results showed the Pt nanoparticles were uniformly dispersed on the surface of graphene sheets with a mean Pt particle size of 2.08 nm. The Pt nanoparticles deposited on graphene sheets exhibited better crystallinity and higher oxygen resistance. The metal Pt was the predominant Pt chemical state on Pt/cG (60.4%. The results from the cyclic voltammetry analysis showed the value of the electrochemical surface area (ECSA was 88 m2/g (Pt/cG, much higher than that of Pt/C (46 m2/g. The long-term test illustrated the degradation in ECSA exhibited the order of Pt/C (33% > Pt/cG (7%. The values of the utilization efficiency were calculated to be 64% for Pt/cG and 32% for Pt/C.

  13. Mapping of sand deposition from 1993 midwest floods with electromagnetic induction measurements

    International Nuclear Information System (INIS)

    Kitchen, N.R.; Sudduth, K.A.; Drummond, S.T.

    1996-01-01

    Sand deposition on river-bottom farmland was extensive from the 1993 Midwest floods. A technique coupling electromagnetic induction (EM) ground conductivity sensing and Global Positioning System (GPS) location data was used to map sand deposition depth at four sites in Missouri along the Missouri River. A strong relationship between EM reading and probe measured depth of sand deposition (r 2 values between 0.73-0.94) was found. This relationship differed significantly between sites, so calibration by ground-truthing was required for each sand deposition survey. An example of the sand deposition mapping using the EM/GPS system is shown for two 50-60 ha (125-150 ac) sites. Such maps can provide valuable detailed information for developing restoration plans for land affected by 1993 Midwest floods. (author)

  14. A Study on Silica Sand Quality in Yazaram and Mugulbu Deposits ...

    African Journals Online (AJOL)

    The suitability of silica sand deposits of Yazaram and Mugulbu in Mubi South Local Government Area of Adamawa State, Nigeria for commercial glass production were assessed based on the chemical and physical properties of the silica sand samples collected along the river side's. Test was carried out at the National ...

  15. Stiffness management of sheet metal parts using laser metal deposition

    Science.gov (United States)

    Bambach, Markus; Sviridov, Alexander; Weisheit, Andreas

    2017-10-01

    Tailored blanks are established solutions for the production of load-adapted sheet metal components. In the course of the individualization of production, such semi-finished products are gaining importance. In addition to tailored welded blanks and tailored rolled blanks, patchwork blanks have been developed which allow a local increase in sheet thickness by welding, gluing or soldering patches onto sheet metal blanks. Patchwork blanks, however, have several limitations, on the one hand, the limited freedom of design in the production of patchwork blanks and, on the other hand, the fact that there is no optimum material bonding with the substrate. The increasing production of derivative and special vehicles on the basis of standard vehicles, prototype production and the functionalization of components require solutions with which semi-finished products and sheet metal components can be provided flexibly with local thickenings or functional elements with a firm metallurgical bond to the substrate. An alternative to tailored and patchwork blanks is, therefore, a free-form reinforcement applied by additive manufacturing via laser metal deposition (LMD). By combining metal forming and additive manufacturing, stiffness can be adapted to the loads based on standard components in a material-efficient manner and without the need to redesign the forming tools. This paper details a study of the potential of stiffness management by LMD using a demonstrator part. Sizing optimization is performed and part distortion is taken into account to find an optimal design for the cladding. A maximum stiffness increase of 167% is feasible with only 4.7% additional mass. Avoiding part distortion leads to a pareto-optimal design which achieves 95% more stiffness with 6% added mass.

  16. Transport and Deposition of Suspended Soil-Colloids in Saturated Sand Columns

    DEFF Research Database (Denmark)

    Sharma, Anu; Kawamoto, Ken; Møldrup, Per

    2011-01-01

    Understanding colloid mobilization, transport and deposition in the subsurface is a prerequisite for predicting colloid‐facilitated transport of strongly adsorbing contaminants and further developing remedial activities. This study investigated the transport behavior of soil‐colloids extracted from...... caused tailing of colloid BTCs with higher reversible entrapment and release of colloids than high flow velocity. The finer Toyoura sand retained more colloids than the coarser Narita sand at low pH conditions. The deposition profile and particle size distribution of colloids in the Toyoura sand clearly...

  17. Tuning the mechanical properties of vertical graphene sheets through atomic layer deposition

    International Nuclear Information System (INIS)

    Davami, Keivan; Jiang, Yijie; Cortes, John; Lin, Chen; Turner, Kevin T; Bargatin, Igor; Shaygan, Mehrdad

    2016-01-01

    We report the fabrication and characterization of graphene nanostructures with mechanical properties that are tuned by conformal deposition of alumina. Vertical graphene (VG) sheets, also called carbon nanowalls (CNWs), were grown on copper foil substrates using a radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) technique and conformally coated with different thicknesses of alumina (Al_2O_3) using atomic layer deposition (ALD). Nanoindentation was used to characterize the mechanical properties of pristine and alumina-coated VG sheets. Results show a significant increase in the effective Young’s modulus of the VG sheets with increasing thickness of deposited alumina. Deposition of only a 5 nm thick alumina layer on the VG sheets nearly triples the effective Young’s modulus of the VG structures. Both energy absorption and strain recovery were lower in VG sheets coated with alumina than in pure VG sheets (for the same peak force). This may be attributed to the increase in bending stiffness of the VG sheets and the creation of connections between the sheets after ALD deposition. These results demonstrate that the mechanical properties of VG sheets can be tuned over a wide range through conformal atomic layer deposition, facilitating the use of VG sheets in applications where specific mechanical properties are needed. (paper)

  18. Geomorphology and drift potential of major aeolian sand deposits in Egypt

    Science.gov (United States)

    Hereher, Mohamed E.

    2018-03-01

    Aeolian sand deposits cover a significant area of the Egyptian deserts. They are mostly found in the Western Desert and Northern Sinai. In order to understand the distribution, pattern and forms of sand dunes in these dune fields it is crucial to analyze the wind regimes throughout the sandy deserts of the country. Therefore, a set of wind data acquired from twelve meteorological stations were processed in order to determine the drift potential (DP), the resultant drift potential (RDP) and the resultant drift direction (RDD) of sand in each dune field. The study showed that the significant aeolian sand deposits occur in low-energy wind environments with the dominance of linear and transverse dunes. Regions of high-energy wind environments occur in the south of the country and exhibit evidence of deflation rather than accumulation with the occurrence of migratory crescentic dunes. Analysis of the sand drift potentials and their directions help us to interpret the formation of major sand seas in Egypt. The pattern of sand drift potential/direction suggests that the sands in these seas might be inherited from exogenous sources.

  19. Mining aspects of hard to access oil sands deposits

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, G.; Wright, D.; Lukacs, Z. [Norwest Corp., Calgary, AB (Canada)

    2006-07-01

    While a variety of oil sands mining technologies have been explored since the 1960s, the oil sands industry has generally favoured truck and shovel mining as a proven, low-cost mining solution. However, surface mining economics are affected by the price of bitumen, haul distances, tailings storage and geotechnical constraints. Maintenance, labour and the cost of replacing tires and ground engaging tools also have a significant impact on the economics of surface mining. Large volumes of water are used in surface mining, and remediation of surface mined areas can take hundreds of years. Damage to machinery is common as oil sands are abrasive and adhere to equipment. This presentation examined recent technologies developed to improve the economics of surface mining. Various extraction and tailings technologies were reviewed. Issues concerning the integration of mining and extraction processes were discussed. Various monitoring tools were evaluated. A review of new underground mining options included outlines of: longwall mining; sub-level caving; tunnel boring; and room and pillar extraction techniques. A generalized regional geology was presented. It was concluded that the oil sands surfacing mining industry should concentrate on near-term research needs to improve the performance and economics of proven technologies. Screening studies should also be conducted to determine the focus for the development of underground technologies. refs., tabs., figs.

  20. Deposit model for heavy-mineral sands in coastal environments: Chapter L in Mineral deposit models for resource assessment

    Science.gov (United States)

    Van Gosen, Bradley S.; Fey, David L.; Shah, Anjana K.; Verplanck, Philip L.; Hoefen, Todd M.

    2014-01-01

    This report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, through recovery of the minerals ilmenite (Fe2+TiO3), rutile (TiO2), and leucoxene (an alteration product of ilmenite). Heavy-mineral sands are also the principal source of zircon (ZrSiO4) and its zirconium oxide; zircon is often recovered as a coproduct. Other heavy minerals produced as coproducts from some deposits are sillimanite/kyanite, staurolite, monazite, and garnet. Monazite [(Ce,La,Nd,Th)PO4] is a source of rare earth elements as well as thorium, which is used in thorium-based nuclear power under development in India and elsewhere.

  1. Deposition behaviour of model biofuel ash in mixtures with quartz sand. Part 1: Experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Mischa Theis; Christian Mueller; Bengt-Johan Skrifvars; Mikko Hupa; Honghi Tran [Aabo Akademi Process Chemistry Centre, Aabo (Finland). Combustion and Materials Chemistry

    2006-10-15

    Model biofuel ash of well-defined size and melting properties was fed into an entrained flow reactor (EFR) to simulate the deposition behaviour of commercially applied biofuel mixtures in large-scale boilers. The aim was to obtain consistent experimental data that can be used for validation of computational fluid dynamics (CFD)-based deposition models. The results showed that while up to 80 wt% of the feed was lost to the EFR wall, the composition of the model ash particles collected at the reactor exit did not change. When model ashes were fed into the reactor individually, the ash particles were found to be sticky when they contained more than 15 wt% molten phase. When model ashes were fed in mixtures with silica sand, it was found that only a small amount of sand particles was captured in the deposits; the majority rebounded upon impact. The presence of sand in the feed mixture reduced the deposit buildup by more than could be expected from linear interpolation between the model ash and the sand. The results suggested that sand addition to model ash may prevent deposit buildup through erosion. 22 refs., 6 figs., 3 tabs.

  2. POSSIBILITY OF BENEFICIATION OF SILICA SAND FROM THE CROATIAN DEPOSITS USING ATTRITION SCRUBBING

    Directory of Open Access Journals (Sweden)

    Ivan Sobota

    2011-12-01

    Full Text Available To meet high quality requirements defined for specific industrial applications, the raw sand often has to be subjected to extensive physical and chemical processing. The possibility of achieving silica sand concentrate of required quality depends mostly on raw sand properties, primarily mineral impurity types and contents, and features of applied beneficiation methods. When the impurities occur in the form of oxide coatings on the surfaces of the single sand grains, attriton scrubbing is applied. By reducing the proportion of oxide coatings on the grains, the quality of sand can be improved. With the aim to determine the possibilities of the beneficiation of silica sand from significant Croatian deposits (“Vrtlinska”, “Štefanac” and “Španovica” and achieve concentrate grade complying with the requirements of domestic industry, laboratory tests were conducted on three raw sand samples with different SiO2 and impurity contents. Grain size distribution, chemical and mineral composition of raw sand samples, and the possibility of their quality improvement by applying the washing, classification and attrition scrubbing were defined by analysis of test results (the paper is published in Croatian.

  3. Separation of zircon from the beach sand deposit of Srikurmam area, Srikakulam district, Andhra Pradesh - a case study

    International Nuclear Information System (INIS)

    Rao, G.V.S.U.; Sharma, A.K.; Seshadrinath, S.T.; Fahmi, Sohail; William Prasad, Ch.; Nagabhushanam, B.

    2011-01-01

    Beach sand placer deposits occur along the eastern and western coasts of India, which contain heavy minerals, such as ilmenite, rutile, garnet, monazite, zircon and sillimanite. Among these, zircon is used in zircaloys (nuclear industry), ceramics, refractories, abrasives, etc. Separation and chemical characterization of pure zircon is a prelude for understanding the different elements and impurities present and its industrial application. In recent times, several methods are developed for beneficiation and separation of individual heavy minerals from beach sands. In this paper, separation of zircon from beach sand of Srikurmam area, Andhra Pradesh was taken up as a case study. The process flow sheet adopted for separation and isolation of pure zircon from beach sand sample consists of desliming of beach sand, wet tabling of sand fraction, removal of magnetite by low intensity magnetic separation from table concentrate, perm roll magnetic separation and induced roll magnetic separation of table concentrate. The concentrates were further subjected to iso-dynamic magnetic separator after observing impurity present in the sample under binocular stereomicroscope. In the present process, about 95% pure zircon was obtained. Further concentration of zircon was carried out under the binocular stereomicroscope by hand picking of impurity to obtain 99.5% pure zircon concentrate. The pure zircon concentrate was analyzed for major, minor and trace elements by chemical method for characterization of zircon and cross validation of physical processes through which the zircon concentrate was obtained. Chemical analysis of the pure zircon concentrate indicated 63.15 to 64.79% ZrO 2 and 32.2 to 32.8% SiO 2 . These values are nearer to that of pure zircon, which stoichiometrically contains 67.2% ZrO 2 and 32.8 % SiO 2 with little iron. In the present study, ZrO 2 +HfO 2 content varies from 65.27 to 66.17% and hafnium from 1.25 to 1.46% HfO 2 in the zircon concentrate. The variation

  4. Indoor radon in houses built on gravel and sand deposits in southern Finland

    Directory of Open Access Journals (Sweden)

    Hutri, K.-L.

    1993-06-01

    Full Text Available Studies by the Finnish Centre for Radiation and Nuclear Safety (STUK have shown that, in Finland, indoor radon concentrations are almost twice as high in houses built on sand or gravel as in houses built on other soil types. The aim of this study was to assess the radon risk on eskers, ice-marginal formations, and other gravel and sand deposits on the basis of factors that can be determined from geological maps. Altogether, 514 houses built on gravel and sand deposits were selected for the study from the indoor radon database of STUK. Several geological parameters were determined. Empirical statistical models were used to assess the significance of factors affecting indoor radon in glaciofluvial deposits and the sand-dominant littoral deposits occurring in association with them. A relationship was found between increased indoor radon concentrations and the location of a house on a steep-sided esker, in the southeastern rapakivi granite area and on the upper slope or top of an esker. The steepness of the slope also increased the radon concentration in houses on steep-sided eskers. The effect of the topographic features is due to subterranean air-flows. As estimated from the very sparse till sampling, the elevated uranium concentration increased the indoor radon concentration only in houses built on littoral deposits around eskers and ice-marginal formations.

  5. Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina

    Science.gov (United States)

    Tripaldi, Alfonsina; Forman, Steven L.

    2016-05-01

    The Pampean Sand Sea, which occurs from the Argentinian Pampas to the eastern Andean piedmont, hosts presently stabilized dune fields spanning the late Quaternary. This study integrates previous results and presents new geomorphic, stratigraphic, sedimentological, and chronologic data for nineteen >2 m-thick eolian successions for the San Luis paleo-dune field, western Pampas, to better constrain the depositional history. Six eolian depositional phases are identified spanning the past 50 ka, interposed with paleosols and/or bounded by erosive surfaces. Age control was from 61 OSL ages of small aliquots of quartz grains from eolian stratigraphic units. The inferred timing of eolian phases are at ca. 70 ± 10 yr, 190 ± 20 yr, 12 to 1 ka, 22 to 17 ka, 29 to 24 ka, and 40 to 32 ka. A maximum span for periods of pedogenesis at ca. 12 to 17 ka, 22 to 24 ka, and 29 to 32 ka was provided by bounding OSL ages, which broadly overlap with high stands of pluvial lakes and glacier advances in the central Andes. We infer that the added precipitation may reflect expansion of the Southern Hemisphere monsoon, associated with Northern Hemisphere Heinrich events, leading to episodes of significantly wetter conditions (>350 mm MAP) to at least 35° S. Most of the Holocene (12 ka to 0.8 ka) was characterized by sand sheet deposit under drier than present conditions (100-450 mm MAP), associated with Monte-type vegetation (shrub steppe). The latest two eolian depositional phases, occurred at ca. 190 and 70 yr ago, during the historic period with European settlement and are related to anthropogenic landscape disturbance, though the youngest phase was concomitant with 1930s drought. Wet conditions dominated since ca. AD 1970 with new lakes and rivers forming across this eolian terrain; an incongruous environmental response in reference to drier conditions for most of the Holocene.

  6. Numerical modelling of the erosion and deposition of sand inside a filter layer

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; van Gent, Marcel R. A.; Fredsøe, Jørgen

    2017-01-01

    This paper treats the numerical modelling of the behaviour of a sand core covered by rocks and exposed to waves. The associated displacement of the rock is also studied. A design that allows for erosion and deposition of the sand core beneath a rock layer in a coastal structure requires an accurate...... prediction method to assure that the amount of erosion remains within acceptable limits. This work presents a numerical model that is capable of describing the erosion and deposition patterns inside of an open filter of rock on top of sand. The hydraulic loading is that of incident irregular waves...... and the open filters are surface piercing. Due to the few experimental data sets on sediment transport inside of rock layers, a sediment transport formulation has been proposed based on a matching between the numerical model and experimental data on the profile deformation inside an open filter. The rock layer...

  7. Maps showing characteristics of the Cabo Rojo West offshore sand deposit, southwestern Puerto Rico

    Science.gov (United States)

    Trumbull, James V.A.; Trias, Juan L.

    1982-01-01

    This report presents detailed information on a deposit of well-sorted coarse calcareous sand in water depths of 10-20 m in an area between 1 and 6 km west and southwest fo the promontory of Cabo Rojo, the southwesternmost corner of Puerto Rico. 

  8. REVIEW OF COASTAL CHARACTERISTICS OF IRON SAND DEPOSITS IN CILACAP CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Hananto Kurnio

    2017-07-01

    Full Text Available Mineable iron sand deposits in Cilacap – southern coastal area of Central Java have certain coastal characteristics that need to be studied in order to understand its depositional environment. With the knowledge of such environment, it can be applied to look for other places prospective of iron sand deposits that have the same characteristics especially recently when Cilacap’s deposits were almost depleted. Coastal characteristics of iron sand deposit in Cilacap is shown by successive sandy beach ridges separated by marshy valleys typical of prograded coasts and by dunes of sand elongated parallel to the shore line with elevation varies from 0 m to 15 m above sea level. The iron sand deposit was derived from denudation of andesite and “Old Andesite Formation” enriched in magnetite and ilmenite minerals in the steep elevated and deeply weathered rock hinterlands of Cilacap. High sediment loads of Serayu Basin in the hinterland (3,500-4,500 ton/km2/year; Citarum River basin only 800-1,200 ton/km2/year was causing extensive deposition of iron sand in the coastal zone. Key words: coast, characteristic, iron sand, Cilacap Endapan pasir besi yang dapat ditambang di Cilacap – pesisir selatan Jawa Tengah memiliki karakteristik pantai tertentu yang perlu dikaji agar dapat dipahami lingkungan pengendapannya. Dengan pengetahuan tentang lingkungan pengendapan tersebut, dapat diterapkan untuk mencari daerah-daerah lain prospek endapan pasir besi yang memiliki karakteristik yang sama terutama pada akhir-akhir ini ketika endapan Cilacap akan habis. Karakteristik pantai endapan pasir besi di Cilacap dicirikan oleh urutan pematang pantai berpasir yang dipisahkan oleh lembah-lembah berawa khas pantai maju dan oleh gumuk-gumuk pasir memanjang sejajar dengan garis pantai dengan ketinggian bervariasi dari 0 m hingga 15 m dari muka laut. Endapan pasir besi di daerah ini berasal dari proses denudasi andesit dan “Formasi Andesit

  9. Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity.

    Science.gov (United States)

    Bhutiya, Priyank L; Mahajan, Mayur S; Abdul Rasheed, M; Pandey, Manoj; Zaheer Hasan, S; Misra, Nirendra

    2018-06-01

    Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Complexities within distal sheet turbidite deposits: case study 160,000ka Icod Turbidite, Moroccan Turbidite System

    Science.gov (United States)

    Hunt, James; Wynn, Russell

    2010-05-01

    coarse silt or (2) removal of previously deposited silt by erosion of a post-depositional mudflow associated with mudcap remobilisation. Further to the stacked subunit facies and grain-size breaks, there are additional complexities to the deposit. An omission of a typical Bouma Ta facies is observed, replaced with a thick well-developed banded Bouma Tb, representing density sorting and flow fractionation of dense basaltic clasts and >100μm foraminifera. Above developing ripple laminations associated with Bouma Tc development is a 0.2-0.5m thick convolute laminated sand. This convoluted sand represents increasing shear stress across developing ripples. Grain-size analysis and ITRAX x-radiographs highlighted an additional process within the mudcaps of the Icod turbidite within the Agadir Basin. The mudcap thickens towards the base of incline from the Agadir Basin to the Selvage Islands. Within the cores with an over-thickened mudcap, the mudcap contained silt contortions. X-radiographs using ITRAX further displayed these contorted silts in the mudcaps. Grain-size analysis was used to confirm the presence of silt and poor sorting through the regions of contortions. These contorted muds have a debritic fabric, and could represent post-depositional remobilisation of the accumulative suspended clay fraction as a mudflow, as it was settling on a gradient and destabilising. This presentation will show the complexities present in even distal sheet turbidites, and that detailed multidisciplinary studies are required to unravel the mechanisms at work during their deposition. Pearce, T.J., & Jarvis I. 1992. Composition and provenance of turbidite sands: Late Quaternary, Madeira Abyssal Plain. Rothwell, R.G., Pearce, I., & Weaver, P.P.E. 1992. Late Quaternary evolution of the Madeira Abyssal Plain, Canary Basin, NE Atlantic. Basin Research, vol.4, no.2, p.103-131. Watts, A.B., & Masson, D.G. 1995. A giant landslide on the north flank of Tenerife, Canary Islands. Journal of

  11. Characterization of sands and mineral clays in channel and floodplain deposits of Portuguesa river, Venezuela

    Directory of Open Access Journals (Sweden)

    Orlando José González Clemente

    2013-11-01

    Full Text Available In the main channel and floodplain of Portuguesa River were studied the mineralogical characteristics of sand and clay minerals respectively. The methodology consisted of X-ray diffraction (XRD analysis, for both mineral fractions. The results indicated the presence of mainly of quartz sands with minor amounts of chlorite, muscovite, calcite and feldspar which are considered quartz sand mature. Its origin is related to the source area and rework of soils and sediments of the floodplain. The clay fraction is characterized by the presence of 13 mineral crystalline phases consisting mainly of quartz, muscovite and chlorite, and clay minerals such as kaolinite, vermiculite, montmorillonite and nontronita. Its detrital origin may be due to mineral neoformation and inheritance. Therefore both mineral fractions consist mainly of quartz and kaolinite, which are essential components of the source area as well as the Quaternary alluvial deposits and the soils that make up the region.

  12. Oil sands development and its impact on atmospheric wet deposition of air pollutants to the Athabasca Oil Sands Region, Alberta, Canada

    International Nuclear Information System (INIS)

    Lynam, Mary M.; Dvonch, J. Timothy; Barres, James A.; Morishita, Masako; Legge, Allan; Percy, Kevin

    2015-01-01

    Characterization of air pollutant deposition resulting from Athabasca oil sands development is necessary to assess risk to humans and the environment. To investigate this we collected event-based wet deposition during a pilot study in 2010–2012 at the AMS 6 site 30 km from the nearest upgrading facility in Fort McMurray, AB, Canada. Sulfate, nitrate and ammonium deposition was (kg/ha) 1.96, 1.60 and 1.03, respectively. Trace element pollutant deposition ranged from 2 × 10"−"5 - 0.79 and exhibited the trend Hg < Se < As < Cd < Pb < Cu < Zn < S. Crustal element deposition ranged from 1.4 × 10"−"4 – 0.46 and had the trend: La < Ce < Sr < Mn < Al < Fe < Mg. S, Se and Hg demonstrated highest median enrichment factors (130–2020) suggesting emissions from oil sands development, urban activities and forest fires were deposited. High deposition of the elements Sr, Mn, Fe and Mg which are tracers for soil and crustal dust implies land-clearing, mining and hauling emissions greatly impacted surrounding human settlements and ecosystems. - Highlights: • Atmospheric event wet deposition was collected during a 21 month pilot study. • Major ion, anthropogenic and crustal element wet deposition was characterized. • Low precipitation depths attenuated major ion and anthropogenic element deposition. • Oil sands development, urban activities and forest fires contributed to deposition. - In the vicinity of oil sands, monitoring revealed that wet deposition of major ions (SO_4"2"−, NO_3"-, NH_4"+) was highest followed by S and Mg, the latter is a tracer for soil/crustal dust.

  13. Spatial variation in deposition rate coefficients of an adhesion-deficient bacterial strain in quartz sand.

    Science.gov (United States)

    Tong, Meiping; Camesano, Terri A; Johnson, William P

    2005-05-15

    The transport of bacterial strain DA001 was examined in packed quartz sand under a variety of environmentally relevant ionic strength and flow conditions. Under all conditions, the retained bacterial concentrations decreased with distance from the column inlet at a rate that was faster than loglinear, indicating that the deposition rate coefficient decreased with increasing transport distance. The hyperexponential retained profile contrasted againstthe nonmonotonic retained profiles that had been previously observed for this same bacterial strain in glass bead porous media, demonstrating that the form of deviation from log-linear behavior is highly sensitive to system conditions. The deposition rate constants in quartz sand were orders of magnitude below those expected from filtration theory, even in the absence of electrostatic energy barriers. The degree of hyperexponential deviation of the retained profiles from loglinear behavior did not decrease with increasing ionic strength in quartz sand. These observations demonstrate thatthe observed low adhesion and deviation from log-linear behavior was not driven by electrostatic repulsion. Measurements of the interaction forces between DA001 cells and the silicon nitride tip of an atomic force microscope (AFM) showed that the bacterium possesses surface polymers with an average equilibrium length of 59.8 nm. AFM adhesion force measurements revealed low adhesion affinities between silicon nitride and DA001 polymers with approximately 95% of adhesion forces having magnitudes responsible for the low adhesion to silicon nitride, indicating that steric interactions from extracellular polymers controlled DA001 adhesion deficiency and deviation from log-linear behavior on quartz sand.

  14. Improvement of Low-Grade Silica Sand Deposits in Um Bogma Area-West Central Sinai, Egypt

    International Nuclear Information System (INIS)

    Abdel-Rahman, I.F.; El Shennawy, A.A.

    2012-01-01

    There are several silica sand deposits in Sinai, but they require upgrading to provide a raw materials acceptable for the glass manufacture. This study records beneficiation of low-grade silica sand deposits near Um Bogma at west central Sinai. The improvement techniques of ore dressing involving wet sieving, attrition scrubbing, decantation, gravimetric and magnetic separations have been applied depending on the physical properties of the constituents.

  15. Pollutant deposition impacts on lichens, mosses, wood and soil in the Athabasca oil sands area

    International Nuclear Information System (INIS)

    Pauls, R.W.; Abboud, S.A.; Turchenek, L.W.

    1996-01-01

    A study was conducted to monitor the accumulation and impact on the environment of emissions from oil sands processing plants. SO 2 , H 2 S, NO x and hydrocarbon concentrations in the air were monitored. Syncrude Canada Ltd. conducted surveys to determine elemental levels in lichens and mosses. The objective of the study was to monitor the pattern of accumulation of emissions by oil sand plants in, and their effects on, lichens and mosses, and examine changes in wood induced by soil acidity. The moss, lichen and wood samples were analyzed for total elemental content. Soils were analyzed for pH, soluble sulphate and other properties related to soil acidity and soil composition. Little or no evidence was found to indicate that wood tissue chemistry has been affected by atmospheric deposition of substances originating from oil sands plants. These results led to the inference that no large changes in soil acidity have resulted from oil sands plant emissions either. 66 refs., 21 tabs., 124 figs

  16. Natural radiation in mineral sands deposits in Vietnam and problem of radiological protection

    International Nuclear Information System (INIS)

    Hung, Bui Van; Duong, Pham Van; Dien, Pham Quang; Quang, Nguyen Hao

    1993-01-01

    There are about 40 mineral sands deposits located along the Vietnamese coast between Binh Ngoc in the North to Vung Tau in the South of the country. Most of them are being exploited for both, domestic and foreign markets. It has been assessed that the natural gamma background levels over the deposits vary between 0.2 to over 10μGy/h. This wide range indicates that the level of naturally occurring radioactivity in the deposits will warrant its further investigations due to the likelihood of an occurrence of elevated radioactivity levels in mineral processing plants. This paper presents results of the following preliminary investigations: determinations of U and Th concentrations in mineral sands ore samples from several deposits, and determinations of U and Th concentrations in various ilmenite concentrate fractions and secondary separation tailings from Ha Tinh province. The radioactivity levels in the heavy minerals and the labour intensive mineral separation technology currently applied will warrant closer attention to be paid to mineral processing and waste handling in order to improve both, occupational and environmental radiological aspects of the operations. 4 refs., 3 tabs., 1 fig

  17. Origin and prospectivity of heavy mineral enriched sand deposits along the Somaliland coastal areas

    Science.gov (United States)

    Ali, M. Y.; Hibberd, P.; Stoikovich, B.

    2018-04-01

    Sixty-one heavy mineral enriched samples along the Somaliland coast from Eil Sheikh to Ras Khatib, a distance of about 130 km, were analyzed using X-ray Fluorescence, X-ray Diffraction and SEM-EDS techniques. This study reveals that a considerable amount of heavy minerals is present along the Somaliland coast and confirms the presence of high concentration titanium and iron bearing minerals. However, the backshore deposits in the mouths of Waaheen and Biyo Gure ephemeral rivers as well as raised paleo-beaches in the east of port city of Berbera demonstrate the highest level of titaniferous heavy minerals with most samples showing concentration greater than 50 wt %. The titanium detected in geochemical analysis occurs in the form of ilmenite, rutile, titanite and titaniferous magnetite. Also, present in minor or trace amounts, are garnet, zircon and monazite. Heavy mineral accumulations in the east and west of Berbera have different mineralogical assemblages. The east of Berbera is dominated by quartz with moderate concentration of plagioclase, K-feldspar, magnetite, hematite and titanium bearing minerals, whereas in the west of Berbera, the dominant minerals are quartz, K-feldspar and plagioclase with variable proportions of ilmenite, rutile, mica, amphibole and pyroxene. These variations in mineral assemblages suggest different composition of the catchment areas that supply sediment to these deposits. The catchment area in the east of Berbera consists mainly of Proterozoic crystalline basement of the Qabri Bahar complex, Gabbro-Synenite belt and granitic intrusions that outcrop in Hudiso, Tulo Dibijo and surrounding areas. The primary sources of heavy minerals in the west of Berbera comprise of high-grade metamorphic rocks of the Mora and Qabri Bahar complexes as well as the Miocene volcanics that outcrop in Laferug and Hagabo areas. The heavy mineral sand deposits observed along the Somaliland coast have the potential to provide commercially important heavy

  18. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    2006-01-01

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

  19. The Carolina Sandhills: Quaternary eolian sand sheets and dunes along the updip margin of the Atlantic Coastal Plain province, southeastern United States

    Science.gov (United States)

    Swezey, Christopher; Fitzwater, Bradley A.; Whittecar, G. Richard; Mahan, Shannon; Garrity, Christopher P.; Aleman Gonzalez, Wilma B.; Dobbs, Kerby M.

    2016-01-01

    The Carolina Sandhills is a physiographic region of the Atlantic Coastal Plain province in the southeastern United States. In Chesterfield County (South Carolina), the surficial sand of this region is the Pinehurst Formation, which is interpreted as eolian sand derived from the underlying Cretaceous Middendorf Formation. This sand has yielded three clusters of optically stimulated luminescence ages: (1) 75 to 37 thousand years ago (ka), coincident with growth of the Laurentide Ice Sheet; (2) 28 to 18 ka, coincident with the last glacial maximum (LGM); and (3) 12 to 6 ka, mostly coincident with the Younger Dryas through final collapse of the Laurentide Ice Sheet. Relict dune morphologies are consistent with winds from the west or northwest, coincident with modern and inferred LGM January wind directions. Sand sheets are more common than dunes because of effects of coarse grain size (mean range: 0.35–0.59 mm) and vegetation. The coarse grain size would have required LGM wind velocities of at least 4–6 m/sec, accounting for effects of colder air temperatures on eolian sand transport. The eolian interpretation of the Carolina Sandhills is consistent with other evidence for eolian activity in the southeastern United States during the last glaciation.

  20. Enriching acid rock drainage related microbial communities from surface-deposited oil sands tailings.

    Science.gov (United States)

    Dean, Courtney; Xiao, Yeyuan; Roberts, Deborah J

    2016-10-01

    Little is known about the microbial communities native to surface-deposited pyritic oil sands tailings, an environment where acid rock drainage (ARD) could occur. The goal of this study was to enrich sulfur-oxidizing organisms from these tailings and determine whether different populations exist at pH levels 7, 4.5, and 2.5. Using growth-based methods provides model organisms for use in the future to predict potential activities and limitations of these organisms and to develop possible control methods. Thiosulfate-fed enrichment cultures were monitored for approximately 1 year. The results showed that the enrichments at pH 4.5 and 7 were established quicker than at pH 2.5. Different microbial community structures were found among the 3 pH environments. The sulfur-oxidizing microorganisms identified were most closely related to Halothiobacillus neapolitanus, Achromobacter spp., and Curtobacterium spp. While microorganisms related to Chitinophagaceae and Acidocella spp. were identified as the only possible iron-oxidizing and -reducing microbes. These results contribute to the general knowledge of the relatively understudied microbial communities that exist in pyritic oil sands tailings and indicate these communities may have a potential role in ARD generation, which may have implications for future tailings management.

  1. Quantifying Black Carbon Deposition Over the Greenland Ice Sheet from Forest Fires in Canada

    Science.gov (United States)

    Thomas, J. L.; Polashenski, C. M.; Soja, Amber J.; Marelle, L.; Casey, K. A.; Choi, H. D.; Raut, J.-C.; Wiedinmyer, C.; Emmons, L. K.; Fast, J. D.; hide

    2017-01-01

    Black carbon (BC) concentrations observed in 22 snowpits sampled in the northwest sector of the Greenland ice sheet in April 2014 have allowed us to identify a strong and widespread BC aerosol deposition event, which was dated to have accumulated in the pits from two snow storms between 27 July and 2 August 2013. This event comprises a significant portion (57 on average across all pits) of total BC deposition over 10 months (July 2013 to April 2014). Here we link this deposition event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the Cloud-Aerosol Lidar with Orthogonal Polarization (on board CALIPSO) and Moderate Resolution Imaging Spectroradiometer (Aqua) instruments during transport between Canada and Greenland. We use high-resolution regional chemical transport modeling (WRF-Chem) combined with high-resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model captures the timing of the BC deposition event and shows that fires in Canada were the main source of deposited BC. However, the model underpredicts BC deposition compared to measurements at all sites by a factor of 2100. Underprediction of modeled BC deposition originates from uncertainties in fire emissions and model treatment of wet removal of aerosols. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires.

  2. A new depositional model for sand-rich loess on the Buckley Flats outwash plain, northwestern Lower Michigan

    Science.gov (United States)

    Nyland, Kelsey E.; Schaetzl, Randall J.; Ignatov, Anthony; Miller, Bradley A.

    2018-04-01

    Loess was first studied in Michigan on the Buckley Flats, where outwash, overlain by ≈70 cm of loamy sediment, was originally interpreted as loess mixed with underlying sands. This paper re-evaluates this landscape through a spatial analysis of data from auger samples and soil pits. To better estimate the loamy sediment's initial textures, we utilized "filtered" laser diffraction data, which remove much of the coarser sand data. Textures of filtered silt data for the loamy sediment are similar to loess. The siltiest soils are found in the low-relief, central part of the Flats. Spatial analyses revealed that many silt fractions are nearly uniformly distributed, suggesting that the loess was not derived from a single source. The previous depositional model for the loamy mantle relied on loessfall followed by pedoturbation, but does not explain (1) the variation in sand contents across the Flats, or (2) the abrupt contact below the loamy mantle. This contact suggests that the outwash was frozen when the sediments above were deposited. Deep gullies at the western margins of the Flats were likely cut as permafrost facilitated runoff. Our new model for the origin of the loamy mantle suggests that the sands on the uplands were generated from eroding gullies and saltated onto the uplands along with loess that fell more widely. Sands saltating to the west of the Flats may have entrained some silts, facilitating loessfall downwind. At most sites, the loamy mantle gets increasingly silty near the surface, suggesting that saltation ended before loess deposition.

  3. Highstand shelf fans: The role of buoyancy reversal in the deposition of a new type of shelf sand body

    Science.gov (United States)

    Steel, Elisabeth; Simms, Alexander R.; Warrick, Jonathan; Yokoyama, Yusuke

    2016-01-01

    Although sea-level highstands are typically associated with sediment-starved continental shelves, high sea level does not hinder major river floods. Turbidity currents generated by plunging of sediment-laden rivers at the fluvial-marine interface, known as hyperpycnal flows, allow for cross-shelf transport of suspended sand beyond the coastline. Hyperpycnal flows in southern California have deposited six subaqueous fans on the shelf of the northern Santa Barbara Channel in the Holocene. Using eight cores and nine grab samples, we describe the deposits, age, and stratigraphic architecture of two fans in the Santa Barbara Channel. Fan lobes have up to 3 m of relief and are composed of multiple hyperpycnite beds ∼5 cm to 40 cm thick. Deposit architecture and geometry suggest the hyperpycnal flows became positively buoyant and lifted off the seabed, resulting in well-sorted, structureless, elongate sand lobes. Contrary to conventional sequence stratigraphic models, the presence of these features on the continental shelf suggests that active-margin shelves may locally develop high-quality reservoir sand bodies during sea-level highstands, and that such shelves need not be solely the site of sediment bypass. These deposits may provide a Quaternary analogue to many well-sorted sand bodies in the rock record that are interpreted as turbidites but lack typical Bouma-type features.

  4. EPISODIC EOLIAN SAND DEPOSITION IN THE PAST 4000 YEARS IN CAPE COD NATIONAL SEASHORE, MASSACHUSETTS, USA IN RESPONSE TO POSSIBLE HURRICANE/STORM AND ANTHROPOGENIC DISTURBANCES

    Directory of Open Access Journals (Sweden)

    Steven L. Forman

    2015-02-01

    Full Text Available The eolian sand depositional record for a dune field within Cape Cod National Seashore, Massachusetts is posit as a sensitive indicator of environmental disturbances in the late Holocene from a combination of factors such as hurricane/storm and forest fire occurrence, and anthropogenic activity. Stratigraphic and sedimentologic observations, particularly the burial of spodosol-like soils, and associated 14C and OSL ages that are concordant indicate at least six eolian depositional events at ca. 3750, 2500, 1800, 960, 430 and <250 years ago. The two oldest events are documented at just one locality and thus, the pervasiveness of this eolian activity is unknown. However, the four younger events are identified in three or more sites and show evidence for dune migration and sand sheet accretion. The timing of eolian deposition, particularly the initiation age, corresponds to documented periods of increased storminess/hurricane activity in the North Atlantic Ocean at ca. 2.0 to 1.6, and 1.0 ka and also a wetter coastal climate, which suppressed the occurrence of forest fire. Thus, local droughts are not associated with periods of dune movement in this mesic environment. Latest eolian activity on outer Cape Cod commenced in the past 300 to 500 years and may reflect multiple factors including broad-scale landscape disturbance with European colonization, an increased incidence of forest fires and heightened storminess. Eolian systems of Cape Cod appear to be sensitive to landscape disturbance and prior to European settlement may reflect predominantly hurricane/storm disturbance, despite generally mesic conditions in past 4 ka.

  5. Deposition of low sheet resistance indium tin oxide directly onto functional small molecules

    KAUST Repository

    Franklin, Joseph B.

    2014-11-01

    © 2014 Elsevier B.V. All rights reserved. We outline a methodology for depositing tin-doped indium oxide (ITO) directly onto semiconducting organic small molecule films for use as a transparent conducting oxide top-electrode. ITO films were grown using pulsed laser deposition onto copper(II)phthalocyanine (CuPc):buckminsterfullerene (C60) coated substrates. The ITO was deposited at a substrate temperature of 150 °C over a wide range of background oxygen pressures (Pd) (0.67-10 Pa). Deposition at 0.67 ≤ Pd ≤ 4.7 Pa led to delamination of the organic films owing to damage induced by the high energy ablated particles, at intermediate 4.7 ≤ Pd < 6.7 Pa pressures macroscopic cracking is observed in the ITO. Increasing Pd further, ≥ 6.7 Pa, supports the deposition of continuous, polycrystalline and highly transparent ITO films without damage to the CuPc:C60. The free carrier concentration of ITO is strongly influenced by Pd; hence growth at > 6.7 Pa induces a significant decrease in conductivity; with a minimum sheet resistance (Rs) of 145 /□ achieved for 300 nm thick ITO films. To reduce the Rs a multi-pressure deposition was implemented, resulting in the formation of polycrystalline, highly transparent ITO with an Rs of - 20/□ whilst maintaining the inherent functionality and integrity of the small molecule substrate.

  6. Deposition of low sheet resistance indium tin oxide directly onto functional small molecules

    KAUST Repository

    Franklin, Joseph B.; Fleet, Luke R.; Burgess, Claire H.; McLachlan, Martyn A.

    2014-01-01

    © 2014 Elsevier B.V. All rights reserved. We outline a methodology for depositing tin-doped indium oxide (ITO) directly onto semiconducting organic small molecule films for use as a transparent conducting oxide top-electrode. ITO films were grown using pulsed laser deposition onto copper(II)phthalocyanine (CuPc):buckminsterfullerene (C60) coated substrates. The ITO was deposited at a substrate temperature of 150 °C over a wide range of background oxygen pressures (Pd) (0.67-10 Pa). Deposition at 0.67 ≤ Pd ≤ 4.7 Pa led to delamination of the organic films owing to damage induced by the high energy ablated particles, at intermediate 4.7 ≤ Pd < 6.7 Pa pressures macroscopic cracking is observed in the ITO. Increasing Pd further, ≥ 6.7 Pa, supports the deposition of continuous, polycrystalline and highly transparent ITO films without damage to the CuPc:C60. The free carrier concentration of ITO is strongly influenced by Pd; hence growth at > 6.7 Pa induces a significant decrease in conductivity; with a minimum sheet resistance (Rs) of 145 /□ achieved for 300 nm thick ITO films. To reduce the Rs a multi-pressure deposition was implemented, resulting in the formation of polycrystalline, highly transparent ITO with an Rs of - 20/□ whilst maintaining the inherent functionality and integrity of the small molecule substrate.

  7. Modeling the Sulfate Deposition to the Greenland Ice Sheet From the Laki Eruption

    Science.gov (United States)

    Oman, L.; Robock, A.; Stenchikov, G.; Thordarson, T.; Gao, C.

    2005-12-01

    Using the state of the art Goddard Institute for Space Studies (GISS) modelE general circulation model, simulations were conducted of the chemistry and transport of aerosols resulting from the 1783-84 Laki (64°N) flood lava eruption. A set of 3 ensemble simulations from different initial conditions were conducted by injecting our estimate of the SO2 gas into the atmosphere by the 10 episodes of the eruption and allowing the sulfur chemistry model to convert this gas into sulfate aerosol. The SO2 gas and sulfate aerosol is transported by the model and wet and dry deposition is calculated over each grid box during the simulation. We compare the resulting sulfate deposition to the Greenland Ice Sheet in the model to 23 ice core measurements and find very good agreement. The model simulation deposits a range of 169 to over 300 kg/km2 over interior Greenland with much higher values along the coastal areas. This compares to a range of 62 to 324 kg/km2 for the 23 ice core measurements with an average value of 158 kg/km2. This comparison is one important model validation tool. Modeling and observations show fairly large spatial variations in the deposition of sulfate across the Greenland Ice Sheet for the Laki eruption, but the patterns are similar to those we modeled for the 1912 Katmai and 1991 Pinatubo eruptions. Estimates of sulfate loading based on single ice cores can show significant differences, so ideally several ice cores should be combined in reconstructing the sulfate loading of past volcanic eruptions, taking into account the characteristic spatial variations in the deposition pattern.

  8. Mechanical properties of seabed deposits of sand with strain history caused by waves

    International Nuclear Information System (INIS)

    Nishi, Koichi; Kanatani, Mamoru

    1989-01-01

    The research project on floating nuclear power plants, which was taken up as one of new siting technologies for the future, has been advanced by the Central Research Institute of Electric Power Industry. In this case, it is very important to cope with the stability problems of breakwaters, revetments, artificial islands and the foundation of mooring against strong earthquake motion and storm wave force. Accordingly it is necessary to evaluate accurately the stability, and to sufficiently understand the mechanical properties of seabed as the foundation ground of these offshore structures. Since seabed has the inherent strain history induced by the action of wave force, it is important to take such characteristics into account in the evaluation of the mechanical properties. In this report, the experimental results about the effect of the strain history on the strength-deformation properties of sand deposited on seabed are described, in order to contribute to the establishment of the method for precisely evaluating the properties of seabed. The computation method for shearing strain history in seabed and the method of estimating the strength-deformation characteristics of seabed are reported. (K.I.)

  9. Investigation of Asphaltene Adsorption onto Zeolite Beta Nanoparticles to Reduce Asphaltene Deposition in a Silica Sand Pack

    Directory of Open Access Journals (Sweden)

    Kashefi Sepideh

    2018-01-01

    Full Text Available Zeolite beta nanoparticles were used as a new asphaltene adsorbent for reducing asphaltene deposition during fluid injection into a silica sand pack. At first, the asphaltene adsorption efficiency and capacity of zeolite beta nanoparticles were determined by UV-Vis spectrophotometer. It was found that the proper concentration of nanoparticles for asphaltene adsorption was 10 g/L and the maximum asphaltene adsorption onto zeolite beta was 1.98 mg/m2. Second, two dynamic experiments including co-injection of crude oil and n-heptane (as an asphaltene precipitant with and without use of zeolite beta nanoparticles in the sand pack was carried out. The results showed that the use of zeolite beta nanoparticles increased the permeability ratio and outlet fluid's asphaltene content about 22% and 40% compared to without use of nanoparticles, respectively. Moreover, a model based on monolayer asphaltene adsorption onto nanoparticles and asphaltene deposition mechanisms including surface deposition, entrainment and pore throat plugging was developed to determine formation damage during co-injection of crude oil and n-heptane into the sand pack. The proposed model presented good prediction of permeability and porosity ratios with AAD% of 1.07 and 0.07, respectively.

  10. Outcrop - core correlation and seismic modeling of the Athabasca Oil Sands Deposit, Fort McMurray area, northeast Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Hein, F.J. [Alberta Geological Survey, Calgary, AB (Canada); Langenberg, C.W.; Cotterill, D.C.; Berhane, H. [Alberta Geological Survey, Edmonton, AB (Canada); Lawton, D.; Cunningham, J. [Calgary Univ., AB (Canada)

    1999-11-01

    A joint study between the Alberta Geological Survey and the University of Calgary was conducted which involved a detailed facies analysis of cores and outcrops from the Athabasca Oil Sands Deposit in Alberta`s Steepbank area. A unified facies classification for the deposit was developed. Larger scale facies associations were also determined, as well as proxy sonic logs for outcrops used in seismic modeling. The cores which were displayed exhibited detailed sedimentological and stratigraphic analysis of 10 outcrops in the area. 7 refs.

  11. Depositional environment, sand provenance, and diagenesis of the Basal Salina Formation (lower Eocene), northwestern Peru

    Science.gov (United States)

    Marsaglia, K. M.; Carozzi, A. V.

    The Basal Salina Formation is a lower Eocene transgressive sequence consisting of interbedded shales, siltstones, and conglomeratic sandstones. This formation occurs in the Talara basin of northwestern Peru and is one of a series of complexly faulted hydrocarbon-producing formations within this extensional forearc basin. These sediments were probably deposited in a fan-delta complex that developed along the ancestral Amotape Mountains during the early Eocene. Most of the sediment was derived from the low-grade metamorphic and plutonic rocks that comprise the Amotape Mountains, and their sedimentary cover. Detrital modes of these sandstones reflect the complex tectonic history of the area, rather than the overall forearc setting. Unlike most forearc sediments, these are highly quartzose, with only minor percentages of volcanic detritus. This sand is variably indurated and cemented by chlorite, quartz, calcite, and kaolinite. Clay-mineral matrix assemblages show gradational changes with depth, from primarily detrital kaolinite to diagenetic chlorite and mixed-layered illite/smectite. Basal Salina sandstones exhibit a paragenetic sequence that may be tied to early meteoric influx or late-stage influx of thermally driven brines associated with hydrocarbon migration. Much of the porosity is secondary, resulting from a first-stage dissolution of silicic constituents (volcanic lithic fragments, feldspar, and fibrous quartz) and a later dissolution of surrounding carbonate cement. Types of pores include skeletal grains, grain molds, elongate pores, and fracture porosity. Measured porosity values range up to 24% and coarser samples tend to be more porous. Permeability is enhanced by fractures and deterred by clay-mineral cements and alteration residues.

  12. Deposition of Suspended Clay to Open and Sand-Filled Framework Gravel Beds in a Laboratory Flume

    Science.gov (United States)

    Mooneyham, Christian; Strom, Kyle

    2018-01-01

    Pulses of fine sediment composed of sand, silt, and clay can be introduced to gravel bed rivers through runoff from burn-impacted hillslopes, landslides, bank failure, or the introduction of reservoir sediment as a result of sluicing or dam decommissioning. Here we present a study aimed at quantifying exchange between suspensions of clay and gravel beds. The questions that motivate the work are: how do bed roughness and pore space characteristics, shear velocity (u∗), and initial concentration (C0) affect clay deposition on or within gravel beds? Where does deposition within these beds occur, and can deposited clay be resuspended while the gravel is immobile? We examine these questions in a laboratory flume using acrylic, open-framework gravel, and armored sand-gravel beds under conditions of varying u∗ and C0. Deposition of clay occurred to all beds (even with Rouse numbers ˜ 0.01). We attribute deposition under full suspension conditions to be an outcome of localized protected zones where clay can settle and available pore space in the bed. For smooth wall cases, protection came from the viscous wall region and the development of bed forms; for the rough beds, protection came from separation zones and low-velocity pore spaces. Bed porosity was the strongest influencer of nondimensional deposition rate; deposition increased with porosity. Deposition was inversely related to u∗ for the acrylic bed runs; no influence of u∗ was found for the porous bed runs. Increases in discharge resulted in resuspension of clay from acrylic beds; no resuspension was observed in the porous bed runs.

  13. a study on silica sand quality in yazaram and mugulbu deposits

    African Journals Online (AJOL)

    ENGR. G A DUVUNA

    A STUDY ON SILICA SAND QUALITY IN YAZARAM AND MUGULBU ... the lowest percentage of silica content of 77.60% and the grain morphology was found to be angular with specific ..... things.com/articles/glass colouring.html, accessed.

  14. Radon, radionuclides and the Cretaceous Folkestone Sands - gamma spectroscopy and geochemical analysis of silver sands and associated deposits in the SE of England.

    Science.gov (United States)

    Gillmore, Gavin; Al-Rafai, Yousef; Flowers, Alan

    2017-04-01

    Radon concentrations in a historic sand mine in Surrey, UK (Reigate Caves), have been measured by both real-time and time-averaged methods over a number of years. These mines are not identified as being in a 'Radon Affected Area' as defined by Public Health England, although concentrations show a summer level of 640 Bqm3 +-44 Bqm3. Average radon concentrations (September 2013 to January 2014) in Reigate caves were above the UK 200 Bqm3 domestic Action Level, above the UK domestic Target Level (of 100 Bqm3) but below the current workplace Action Level of 400 Bqm3. By way of a comparison radon has also been measured in nearby Dorking (South Street Caves). These enigmatic caves were not mined for sand for glass manufacture as Reigate Caves were and there is speculation on why the caves were created. Both are visited by tourists on a semi-regular basis. Dorking caves have a different morphology with radon concentrations in Autumn 2016 of up to 1940 +/- 230 Bqm3. The caves in Reigate are situated along Tunnel Road. These mines were also used as air raid shelters and wine stores. They consist of an East and West system and an older cave (Barons cave) which may have a medieval origin. As the Western Caves are now a shooting range our work has been carried out in the Eastern section at Reigate. Where Dorking is concerned the shops and houses in the town have extensive interconnected cellars and galleries cut into these sands. The caves probably date from the 17th century but were used quite extensively for wine storage in the 19th century due to their constant 140C air temperatures. Real-time measurements were taken with a Durridge Rad7 with time-averaged CR39 SSNTDs being placed throughout the cave systems to assess radon distribution and compare results with the real-time detector. Both caves contain marine shallow-water deposited locking (having tensile and compressive strength) silica sands of the Cretaceous Lower Greensand Group, Folkestone Formation, with little

  15. The coal deposits of the Alkali Butte, the Big Sand Draw, and the Beaver Creek fields, Fremont County, Wyoming

    Science.gov (United States)

    Thompson, Raymond M.; White, Vincent L.

    1952-01-01

    northwestward to the Wind River. This report is based almost entirely upon geologic investigations made in 1949 as a part of the program of the Department of the Interior for development of the Missouri River basin. Some coal sections were measured in 1950 and the additional information on the Big Sand Draw coal field was obtained in 1951. A geologic map of the Beaver Creek field was not prepared for this report because most of the significant coal occurs below a depth of 1,400 ft and is not exposed on the surface. Mr. George Downey, Lander, Wyo. , supplied much helpful information on the Big Sand Draw coal field and the area in general. Topographic contours shown on figures 11, 12, 13, and 14 are from unpublished plane-table sheets made by E. D. Woodruff in 1912. Previous geologic investigations of the region have been made by E. G. Woodruff and D. E. Winchester (1912), by C. J. Hares (1916), by A. J. Collier (1920), and C. M. Bauer (1934). Except for the work of Woodruff and Winchester, which was an areal examination for the purpose of classifying the public lands, the geological investigatiohs were of a general nature and give little detail of the coal beds. Berryhill (1950) summarizes Woodruff and Winchester's work.

  16. Initiated chemical vapor deposition of thermoresponsive poly(N-vinylcaprolactam) thin films for cell sheet engineering.

    Science.gov (United States)

    Lee, Bora; Jiao, Alex; Yu, Seungjung; You, Jae Bem; Kim, Deok-Ho; Im, Sung Gap

    2013-08-01

    Poly(N-vinylcaprolactam) (PNVCL) is a thermoresponsive polymer known to be nontoxic, water soluble and biocompatible. Here, PNVCL homopolymer was successfully synthesized for the first time by use of a one-step vapor-phase process, termed initiated chemical vapor deposition (iCVD). Fourier transform infrared spectroscopy results showed that radical polymerization took place from N-vinylcaprolactam monomers without damaging the functional caprolactam ring. A sharp lower critical solution temperature transition was observed at 31°C from the iCVD poly(N-vinylcaprolactam) (PNVCL) film. The thermoresponsive PNVCL surface exhibited a hydrophilic/hydrophobic alteration with external temperature change, which enabled the thermally modulated attachment and detachment of cells. The conformal coverage of PNVCL film on various substrates with complex topography, including fabrics and nanopatterns, was successfully demonstrated, which can further be utilized to fabricate cell sheets with aligned cell morphology. The advantage of this system is that cells cultured on such thermoresponsive surfaces could be recovered as an intact cell sheet by simply lowering the temperature, eliminating the need for conventional enzymatic treatments. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region (Alberta, Canada)

    Science.gov (United States)

    Cooke, Colin A.; Kirk, Jane L.; Muir, Derek C. G.; Wiklund, Johan A.; Wang, Xiaowa; Gleason, Amber; Evans, Marlene S.

    2017-12-01

    The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for decades; however, a lack of consistent regional monitoring has obscured the long-term environmental impact. Here, we present sediment core results to reconstruct spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region. Early mining operations (during the 1970s and 1980s) led to elevated V and Pb inputs to lakes located quality guidelines, and no spatial or temporal trends were observed in the frequency of guideline exceedence. Our results demonstrate that early mining efforts had an even greater impact on trace element cycling than has been appreciated previously, placing recent monitoring efforts in a critical long-term context.

  18. Nitrogen and sulphur deposition and the growth of Sphagnum fuscum in bogs of the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Melanie A. VILE

    2010-08-01

    Full Text Available One of the consequences of ongoing development of the oil sands reserve in the Athabasca Oil Sands Region (AOSR near Fort McMurray, Alberta, Canada (56° 39' N, 111° 13' W is an increase in emissions of nitrogen (N and sulphur (S, with an attendant increases in regional atmospheric N and S deposition. Regional land cover across northeastern Alberta is a mixture of Boreal Mixedwood, Boreal Highlands, and Subarctic areas. Peatlands occupy between 22 and 66% of these natural regions, and the land cover of bogs varies between 6.7% in the Mixedwood Region to 46% in the Subarctic Region. Ombrotrophic bog ecosystems may be especially sensitive to atmospheric deposition of N and S. Across 10 ombrotrophic bog sites in the AOSR over four years (2005– 2008, we found no evidence of elevated deposition of NH4 +-N, NO3 –-N, total inorganic nitrogen (TIN; NH4 +-N plus NO3 –-N, or SO4 2–-S, with values measured using ion exchange resin collectors averaging 0.61 ± 04, 0.20 ± 0.01, 0.81 ± 0.04, and 1.14 ± 0.06 kg ha–1 y–1, respectively. Vertical growth and net primary production of Sphagnum fuscum, an indicator of elevated deposition, did not differ consistently across sites, averaging 11.8 ± 0.2 mm y–1 and 234 ± 3.3 g m–2 y–1, respectively, over the four years. Neither vertical growth nor net primary production of S. fuscum was correlated with growing season atmospheric N or S deposition. Our data provide a valuable benchmark of background values for monitoring purposes in anticipation of increasing N and S deposition over a broader geographic region within the AOSR.

  19. Comparison of Corrosion Behavior of Electrochemically Deposited Nano-Cobalt-Coated Ni Sheet

    Directory of Open Access Journals (Sweden)

    Nasser Al-Aqeeli

    2013-01-01

    Full Text Available Corrosion behavior of nano-coblat-coated Ni sheet was compared with pure Ni and 20% Fe-Ni alloy sheet using potentiodynamic polarization and linear polarization technique in 0.1 M NaCl solution at room temperature. Results showed that corrosion resistance properties of nano-Co-coated Ni sheet were almost same as that of pure Ni sheet, however corrosion resistance of 20% Fe-Ni sheet was decreased significantly. Pitting potential of 20% Fe-Ni sheet was subsequently decreased as compared to pure Ni sheet as well as nano-cobalt-coated Ni sheet. SEM/EDS analysis of the corroded surfaces showed that both pure Ni and nano-coblat-coated Ni sheet did not show any appreciable corrosion however significant corrosion was observed in the case of 20% Fe-Ni sheet.

  20. Deposition Rate and Energy Enhancements of TiN Thin-Film in a Magnetized Sheet Plasma Source

    OpenAIRE

    Hamdi Muhyuddin D. Barra; Henry J. Ramos

    2011-01-01

    Titanium nitride (TiN) has been synthesized using the sheet plasma negative ion source (SPNIS). The parameters used for its effective synthesis has been determined from previous experiments and studies. In this study, further enhancement of the deposition rate of TiN synthesis and advancement of the SPNIS operation is presented. This is primarily achieved by the addition of Sm-Co permanent magnets and a modification of the configuration in the TiN deposition process. The ...

  1. Mineral Resource Assessment of Marine Sand Resources in Cape- and Ridge-Associated Marine Sand Deposits in Three Tracts, New York and New Jersey, United States Atlantic Continental Shelf

    Science.gov (United States)

    Bliss, James D.; Williams, S. Jeffress; Arsenault, Matthew A.

    2009-01-01

    Demand is growing in the United States and worldwide for information about the geology of offshore continental shelf regions, the character of the seafloor, and sediments comprising the seafloor and subbottom. Interest in locating sand bodies or high quality deposits that have potential as sources for beach nourishment and ecosystem restoration is especially great in some regions of the country. The Atlantic coast, particularly New York and New Jersey, has been the focus of these studies for the past 40 years with widely varying results. This study is the first attempt at applying probability statistics to modeling Holocene-age cape-and ridge-associated sand deposits and thus focuses on distinct sand body morphology. This modeling technique may have application for other continental shelf regions that have similar geologic character and late Quaternary sea-level transgression history. An estimated volume of 3.9 billion m3 of marine sand resources is predicted in the cape-and ridge-associated marine sand deposits in three representative regions or tracts on the continental shelf offshore of New York and New Jersey. These estimates are taken from probabilistic distributions of sand resources and are produced using deposit models and Monte Carlo Simulation (MCS) techniques. The estimated sand resources presented here are for only three tracts as described below and for Holocene age sand resources contained in cape-and ridge-associated marine sand deposit types within this area. Other areas may qualify as tracts for this deposit type and other deposit types and geologic ages (for example, paleo-stream channels, blanket and outwash deposits, ebb-tide shoals, and lower sea level-stand deltas), which are present on the New Jersey and New York continental shelf area but are not delineated and modeled in this initial evaluation. Admittedly, only a portion of these probable sand resources will ultimately be available and suitable for production, dependent largely on

  2. Chronology and geochemistry of late Holocene eolian deposits in the Brandon Sand Hills, Manitoba, Canada

    Science.gov (United States)

    Wolfe, S.A.; Muhs, D.R.; David, P.P.; McGeehin, J.P.

    2000-01-01

    Accelerator mass spectrometry and conventional radiocarbon age determinations of organic matter from paleosols indicate that the Brandon Sand Hills area of southern Manitoba has been subjected to recurrent intervals of eolian activity in the past 5000 years. Although precise regional correlations are precluded by dating uncertainties, periods of most notable paleosol development occurred around 2300 to 2000, 1400 to 1000, and 600 to 500 cal yr BP with eolian activity occurring before and after each of these periods. Episodes of eolian activity may correspond to periods of regional drought, whereas paleosols mark periods of increased moisture availability and stabilization by vegetation. The geochemistry of the eolian sands, paleosols and source sediments indicates that partial leaching of carbonates occurs from pedogenesis during humid climatic phases, and that this is probably the primary mechanism of carbonate depletion of eolian sands in this area. Recent trends in sand dune activity from historic aerial photography and early explorers' accounts indicate that the few active dunes that presently exist have stabilized at a rate of 10-20% per decade, despite several severe droughts in the 20th century. This may be attributed to pre-settlement droughts that were more severe than those in historic times although regional dune stabilization may also be related, in part, to the spread of forest cover in the past few hundred years. Crown copyright (C) 2000 Published by Elsevier Science Ltd. All rights reserved.

  3. Pesticide and transformation product detections and age-dating relations from till and sand deposits

    Science.gov (United States)

    Warner, K.L.; Morrow, W.S.

    2007-01-01

    Pesticide and transformation product concentrations and frequencies in ground water from areas of similar crop and pesticide applications may vary substantially with differing lithologies. Pesticide analysis data for atrazine, metolachlor, alachlor, acetochlor, and cyanazine and their pesticide transformation products were collected at 69 monitoring wells in Illinois and northern Indiana to document occurrence of pesticides and their transformation products in two agricultural areas of differing lithologies, till, and sand. The till is primarily tile drained and has preferential fractured flow, whereas the sand primarily has surface water drainage and primary porosity flow. Transformation products represent most of the agricultural pesticides in ground water regardless of aquifer material - till or sand. Transformation products were detected more frequently than parent pesticides in both the till and sand, with metolachlor ethane sulfonic acid being most frequently detected. Estimated ground-water recharge dates for the sand were based on chlorofluorocarbon analyses. These age-dating data indicate that ground water recharged prior to 1990 is more likely to have a detection of a pesticide or pesticide transformation product. Detections were twice as frequent in ground water recharged prior to 1990 (82%) than in ground water recharged on or after 1990 (33%). The highest concentrations of atrazine, alachlor, metolachlor, and their transformation products, also were detected in samples from ground water recharged prior to 1990. These age/pesticide detection relations are opposite of what would normally be expected, and may be the result of preferential flow and/or ground-water mixing between aquifers and aquitards as evident by the detection of acetochlor transformation products in samples with estimated ground-water ages predating initial pesticide application. ?? 2007 American Water Resources Association.

  4. Early Pliocene Hiatus in Sand Output by the Colorado River: Evidence From Marine Deposits in the Salton Trough, Southern California

    Science.gov (United States)

    Dorsey, R. J.; Bykerk-Kauffman, A.

    2015-12-01

    Early Pliocene deposits in the western Salton Trough preserve a high-fidelity record of sediment dispersal into the marine realm during initiation and early evolution of the Colorado River (CR). Grain-size fractionation, sediment routing, and transport dynamics of the early CR delta are recorded in sediments of the Fish Creek - Vallecito basin, which was located ~100 km south of Yuma along the transform plate boundary at 5 Ma. Early Pliocene delivery of CR sand to the basin took place in two distinct pulses: (1) deposition of sandy turbidites (Wind Caves Mbr of the Latrania Fm) in a restricted submarine canyon at Split Mt Gorge between ~5.3 and 5.1 Ma; and (2) progradation of a thick, widespread, coarsening-up deltaic sequence of marine mudstone, sandstone, and coquinas (Deguynos Fm) between ~4.8 and 4.2 Ma. Estimated flux of CR sediment during Wind Caves deposition was weak (~3-5 Mt/yr) compared to the long-term average (172±64 Mt/yr). The two pulses of CR sand input are separated by the Coyote Clay (CC, ~5.1-4.8 Ma), a regionally correlable, greenish-yellow-weathering marine claystone unit at the base of the Deguynos Fm. CC gradationally overlies Wind Caves turbidites in the area of the paleocanyon. In contrast, in the Coyote Mts 15-23 km to the south and SE, CC rests on coarse-grained locally-derived late Miocene sedimentary rocks, Alverson volcanics, and metamorphic basement rock along a regional unconformity. Identical claystone facies occur in the NW Indio Hills (restores to Yuma at the mouth of the CR at 5 Ma), and Sierra Cucapa in Mexico (~200 km south of Yuma at 5 Ma). Marine localities outside of the Wind Caves paleocanyon experienced slow to negligible sedimentation along a rugged rocky shoreline until abrupt arrival of CR-derived clay. CC accumulated in a sand-starved, pro-delta marine setting (Winker, 1987) over an inferred N-S distance of ~200 km. We therefore reject an alternate hypothesis that CC accumulated on the muddy slope of the prograding CR

  5. Paleo-Environment and C-14 Dating: The Key to the Depositional Age of the Tha Chang and Related Sand Pits, Northeastern Thailand

    Science.gov (United States)

    Putthapiban, P.; Zolensky, M.; Jull, T.; Demartino, M.; Salyapongse, S.

    2012-01-01

    Tha Chang sand pits, Nakhon Ratchasima Province and many other sand pits in the area adjacent to the Mun River are characterized by their fluviatile environment in association with mass wasting deposits, along the paleo-river channel and the flood plain of the Mun River. Sediments of these deposits are characterized by clasts of various rock types especially the resistant ones with frequent big tree trunks, logs and wood fragments in different sizes and various stages of transformation from moldering stage to lignification and petrification. Widespread pyritization of the lower horizon suggests strongly reducing environment during burial. The Tha Chang deposits have been received much attention from geoscientists especially paleontologist communities, as they contain fragments of some distinct vertebrate species such as Stegadon sp., hominoid primate, rhinoceros Aceratherium and others. Based on the associated mammal fauna and hominoid fossils, the late Miocene ( 9 - 6 Ma) was given for the time of deposition of this sand and gravel unit. Some other reports believed that sediments and materials of these sand and gravel quarries (pits) were deposited by high-energy flood pulses contemporaneous with the tektites forming event during mid-Pleistocene at c. 0.8 Ma. Interpretation from Palynostratigraphical study suggested that the lower horizon of Tha Chang sand pit was deposited during Pliocene/Pleistocene period and the upper horizons are Pleistoncene/Holocene. It is crystal clear that all the fluviatile sediments including tektites and almost all fossil fragments being deposited in these sand pits were, likely a multiple times reworked materials. Only some old bamboo trees, some old crowling trees and fossils grasses observed on the old river bank are considered in situ. C-14 dating of 5 old wood specimens from Tha Chang Sand Pits, 15 old wood specimens from Chumpuang Sand Pits and one sample of old pottery from a Chumpuang Sand Pit were carried out in the NSF

  6. Effects of sand burial on dew deposition on moss soil crust in a revegetated area of the Tennger Desert, Northern China

    Science.gov (United States)

    Jia, Rong-liang; Li, Xin-rong; Liu, Li-chao; Pan, Yan-xia; Gao, Yan-hong; Wei, Yong-ping

    2014-11-01

    Sand burial and dew deposition are two fundamental phenomena profoundly influencing biological soil crusts in desert areas. However, little information is available regarding the effects of sand burial on dew deposition on biological soil crusts in desert ecosystems. In this study, we evaluated the effects of sand burial at depths of 0 (control), 0.5, 1, 2 and 4 mm on dew formation and evaporation of three dominant moss crusts in a revegetated area of the Tengger Desert (Northern China) in 2010. The results revealed that sand burial significantly decreased the amount of dew deposited on the three moss crust types by acting as a semi-insulator retarding the dew formation and evaporation rates. The changes in surface temperature cannot fully explain the variations of the formation and evaporation rates of dew by moss crusts buried by sand. The extension of dew retention time was reflected by the higher dew ratios (the ratio of dew amount at a certain time to the maximum value in a daily course) in the daytime, and may to some extent have acted as compensatory mechanisms that diminished the negative effects of the reduction of dew amount induced by sand burial of moss crusts. The resistances to reduction of dewfall caused by sand burial among the three moss crusts were also compared and it was found that Bryum argenteum crust showed the highest tolerance, followed by crusts dominated by Didymodon vinealis and Syntrichia caninervis. This sequence corresponds well with the successional order of the three moss crusts in the revegetated area, thereby suggesting that resistance to reduction of dewfall may act as one mechanism by which sand burial drives the succession of moss crusts in desert ecosystems. This side effect of dew reduction induced by sand burial on biological soil crusts should be considered in future ecosystem construction and management of desert area.

  7. Testing optically stimulated luminescence dating on sand-sized quartz of deltaic deposits from the Sperchios delta plain, central Greece

    Directory of Open Access Journals (Sweden)

    Evangelos Tsakalos

    2018-04-01

    Full Text Available This study reports on the first investigation into the potential of luminescence dating to establish a chronological framework for the depositional sequences of the Sperchios delta plain, central Greece. A series of three borehole cores (20 m deep and two shallow cores (4 m deep, from across the delta plain, were extracted, and samples were collected for luminescence dating. The luminescence ages of sand-sized quartz grains were obtained from small aliquots of quartz, using the Single-Aliquot Regenerative-dose (SAR protocol. The equivalent dose determination included a series of tests and the selection of the Minimum Age Model (MAM as the most appropriate statistical model. This made it possible to confirm the applicability of quartz Optically Stimulated Luminescence (OSL dating to establish absolute chronology for deltaic sediments from the Sperchios delta plain.Testing age results of the five cores showed that the deltaic sediments were deposited during the Holocene. A relatively rapid deposition is implied for the top ∼14 m possibly as a result of the deceleration in the rate of the sea-level rise and the transition to terrestrial conditions, while on the deeper parts, the reduced sedimentation rate may indicate a lagoonal or coastal environment. Keywords: Luminescence dating, Holocene, Sedimentation rates, Deltaic deposits, Sperchios delta plain, Central Greece

  8. Geochemistry of radioactive elements in bituminous sands and sandstones of Permian bitumen deposits of Tatarstan (east of the Russian plate)

    Science.gov (United States)

    Mullakaev, A. I.; Khasanov, R. R.; Badrutdinov, O. R.; Kamaletdinov, I. R.

    2018-05-01

    The article investigates geochemical features of Permian (Cisuralian, Ufimian Stage and Biarmian, Kazanian Stage of the General Stratigraphic Scale of Russia) bituminous sands and sandstones located on the territory of the Volga-Ural oil and gas province (Republic of Tatarstan). Natural bitumens are extracted using thermal methods as deposits of high-viscosity oils. In the samples studied, the specific activity of natural radionuclides from the 238U (226Ra), 232Th, and 40K series was measured using gamma spectrometry. As a result of the precipitation of uranium and thorium and their subsequent decay, the accumulation of radium (226Ra and 228Ra) has been shown to occur in the bituminous substance. In the process of exploitation of bitumen-bearing rock deposits (as an oil fields) radium in the composition of a water-oil mixture can be extracted to the surface or deposited on sulfate barriers, while being concentrated on the walls of pipes and other equipment. This process requires increased attention to monitoring and inspection the environmental safety of the exploitation procedure.

  9. Effects of Seismological and Soil Parameters on Earthquake Energy demand in Level Ground Sand Deposits

    Science.gov (United States)

    nabili, sara; shahbazi majd, nafiseh

    2013-04-01

    Liquefaction has been a source of major damages during severe earthquakes. To evaluate this phenomenon there are several stress, strain and energy based approaches. Use of the energy method has been more focused by researchers due to its advantages with respect to other approaches. The use of the energy concept to define the liquefaction potential is validated through laboratory element and centrifuge tests as well as field studies. This approach is based on the hypothesis that pore pressure buildup is directly related to the dissipated energy in sands which is the accumulated areas between the stress-strain loops. Numerous investigations were performed to find a relationship which correlates the dissipated energy to the soil parameters, but there are not sufficient studies to relate this dissipated energy, known as demand energy, concurrently, to the seismological and the soil parameters. The aim of this paper is to investigate the dependency of the demand energy in sands to seismological and the soil parameters. To perform this task, an effective stress analysis has been executed using FLAC finite difference program. Finn model, which is a built-in constitutive model implemented in FLAC program, was utilized. Since an important stage to predict the liquefaction is the prediction of excess pore water pressure at a given point, a simple numerical framework is presented to assess its generation during a cyclic loading in a given centrifuge test. According to the results, predicted excess pore water pressures did not closely match to the measured excess pore water pressure values in the centrifuge test but they can be used in the numerical assessment of excess pore water pressure with an acceptable degree of preciseness. Subsequently, the centrifuge model was reanalyzed using several real earthquake acceleration records with different seismological parameters such as earthquake magnitude and Hypocentral distance. The accumulated energies (demand energy) dissipated in

  10. Dating by thermoluminescence of some costal sand deposits of last climatic cycle, from the northeastern region of Rio Grande do Sul State, Brazil

    International Nuclear Information System (INIS)

    Poupeau, G.; Rivera, A.

    1988-01-01

    Six coastal quartz sand deposits from the northeastern region of the Rio Grande do Sul State (Brazil), with reasonnably well known ages, from ∼ 1700 yr to ∼ 120.000 yr, were dated by thermoluminescence. (M.W.O.) [pt

  11. Differential effects of high atmospheric N and S deposition on bog plant/lichen tissue and porewater chemistry across the Athabasca Oil Sands Region

    Science.gov (United States)

    R. Kelman Wieder; Melanie A. Vile; Kimberli D. Scott; Cara M. Albright; Kelly J. McMillen; Dale H. Vitt; Mark E. Fenn

    2016-01-01

    Oil extraction and development activities in the Athabasca Oil Sands Region of northern Alberta, Canada, release NOx, SOx, and NHy to the atmosphere, ultimately resulting in increasing N and S inputs to surrounding ecosystems through atmospheric deposition. Peatlands are a major feature of the northern Alberta landscape, with bogs covering 6-10% of the land area, and...

  12. Observations on sediment sources in the Lower Athabasca River basin: implications of natural hydrocarbons inputs from oil sands deposits

    International Nuclear Information System (INIS)

    Conly, F.M.

    1999-01-01

    Government, industry and public concern exists over the environmental consequences of the development of the oil sand deposits in the McMurray Formation in the lower Athabasca River basin, Alberta. The impact of this development is unclear and is undergoing investigation. Investigations to date have focussed on the nature of the effluent produced by the extraction industry and its effect on biotic systems, and on the spatial distribution of hydrocarbon contaminants associated with deposited fluvial sediments. Natural hydrocarbon outcrops may be responsible for observed biomarker responses in areas not exposed to industrial effluent. Given this source of hydrocarbons and doubt concerning its environmental impact, it is difficult to ascertain the impact of oil extraction activities within a fluvial system. A study was conducted to determine the nature and extent of natural hydrocarbon releases within the context of the sediment regime of the lower Athabasca River basin. A description is included of observations from the field and a context is set up for assessing sediment-bound hydrocarbon contaminants in the lower Athabasca River basin. Abstract only included

  13. Natural and human controls of the Holocene evolution of the beach, aeolian sand and dunes of Caesarea (Israel)

    Science.gov (United States)

    Roskin, J.; Sivan, D.; Shtienberg, G.; Roskin, E.; Porat, N.; Bookman, R.

    2015-12-01

    The study focuses on the Holocene appearance, chronology and drivers of beach sand deposition and inland aeolian sand transport around the Roman-Byzantine ruins of Caesarea, Israel. Beach sand, sand sheets, nebkha, linear and transverse dunes as well as parabolic and transverse interdunes along two transects were sampled in the current study down to their substrate. Sixteen new optically stimulated luminescence ages cluster at ∼5.9-3.3 ka, ∼1.2-1.1 ka (800-900 AD) and ∼190-120 years ago (1825-1895 AD) indicating times of middle and late Holocene sand sheet depositions and historical dune stabilization. The first age cluster indicates that beach sand accumulated when rates of global sea level rise declined around 6-5 ka. Until ∼4 ka sand sheets encroached up to 2.5 km inland. Historical and archaeological evidence points to sand mobilization since the first century AD. Sand sheets dating to 1.2-1.1 ka, coevally found throughout the dunefield represent sand stabilization due to vegetation reestablishment attributed to gradual and fluctuating decline in human activity from the middle Early Islamic period until the 10th century. Historical and chronological evidence of the existence of transverse and coppice dunes from the 19th century suggest that dunes only formed in the last few centuries. The study illustrates the initial role of natural processes, in this case decline in global sea level rise and the primary and later role of fluctuating human activity upon coastal sand mobility. The study distinguishes between sand sheets and dunes and portrays them as sensors of environmental changes.

  14. Quantifying black carbon deposition over the Greenland ice sheet from forest fires in Canada: BC DEPOSITION FROM FOREST FIRES

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J. L. [LATMOS/IPSL, UPMC University Paris 6 Sorbonne Universités, UVSQ, CNRS, Paris France; Polashenski, C. M. [USACE-CRREL, Fort Wainwright Alaska USA; Thayer School of Engineering, Dartmouth College, Hanover New Hampshire USA; Soja, A. J. [National Institute of Aerospace, NASA Langley Research Center, Hampton Virginia USA; Marelle, L. [Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Casey, K. A. [Thayer School of Engineering, Dartmouth College, Hanover New Hampshire USA; Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt Maryland USA; Choi, H. D. [National Institute of Aerospace, NASA Langley Research Center, Hampton Virginia USA; Raut, J. -C. [LATMOS/IPSL, UPMC University Paris 6 Sorbonne Universités, UVSQ, CNRS, Paris France; Wiedinmyer, C. [National Center for Atmospheric Research, Boulder Colorado USA; Emmons, L. K. [National Center for Atmospheric Research, Boulder Colorado USA; Fast, J. D. [Pacific Northwest National Laboratory, Richland Washington USA; Pelon, J. [LATMOS/IPSL, UPMC University Paris 6 Sorbonne Universités, UVSQ, CNRS, Paris France; Law, K. S. [LATMOS/IPSL, UPMC University Paris 6 Sorbonne Universités, UVSQ, CNRS, Paris France; Flanner, M. G. [Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor Michigan USA; Dibb, J. E. [Earth Systems Research Center, EOS, University of New Hampshire, Durham New Hampshire USA

    2017-08-05

    We identify an important Black Carbon (BC) aerosol deposition event that was observed in snow stratigraphy and dated to between 27 July 2013 – 2 August 2013. This event comprises a significant portion (~60%) of total deposition over a 10 month period (July 2013 – April 2014). Here we link this event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the CALIOP and MODIS instruments during transport between Canada and Greenland, confirming that this event involved emissions from forest fires in Canada. We use high-resolution regional chemical transport mod-eling (WRF-Chem) combined with high-resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model accurately captures the timing of the BC deposition event and shows that the major contribution to deposition during this event is emissions originating from fires in Canada. However, the model under-predicts aerosol deposition compared to measurements at all sites by a factor of 2–100. Under-prediction of modeled BC deposition originates from uncertainties in fire emissions combined with uncertainties in aerosol scavenging by clouds. This study suggests that it is possible to describe the transport of an exceptional smoke event on regional and continental scales. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires.

  15. Geochemical cycling and depositional patterns across the northeast region of the Greenland Ice Sheet as determined from trace element chemistry

    Science.gov (United States)

    Wong, G. J.; Osterberg, E. C.; Courville, Z.; Hawley, R. L.; Lutz, E.; Overly, T. B.

    2012-12-01

    The Greenland Ice Sheet is both a repository of climate history and a major driver in Arctic and global climate. Between 1952 and 1955, Carl Benson led a series of traverses of the Greenland Ice Sheet (GIS), and characterized the GIS via mapping of the spatial distribution of annual net accumulation and classifying the diagenetic glacier facies (Benson, 1962). While polar ice sheets represent a unique archive of past atmospheric and climatic conditions, little information exists on large-scale geographical trends in trace element snow chemistry across GIS because of the remote, challenging location. In the spring of 2011, we undertook a 1120 km traverse of the GIS from Thule Air Base to Summit Station. Samples from 11 snow pits and 3 firn cores, dated by stable water isotopes, were analyzed and evaluated in seasonal resolution for their trace element content (23Na, 24Mg, 27Al, 32S, 39K, 44Ca, 47Ti, 51V, 52Cr, 55Mn, 56Fe, 59Co, 63Cu, 66Zn, 75As, 88Sr, 111Cd, 133Cs, 138Ba, 139La, 140Ce, 141Pr, 208Pb, 209Bi, 238U). Here, we present an initial analysis of the spatial gradients of these trace elements and an interpretation of how their depositional patterns characterize the GIS. The seasonal trends coupled with spatial variability of certain trace elements establish the behavior of specific aerosols (e.g. dust, sea salt, pollution), which will be useful in quantifying geochemical cycling across the GIS and comparing characterizations with results from Benson's traverses. Benson, CS. 1962. Stratigraphic studies in the snow and firn of the Greenland Ice Sheet. SIPRE Research Report, 70, 89 pp.

  16. Heavy mineral concentration from oil sand tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chachula, F.; Erasmus, N. [Titanium Corp. Inc., Regina, SK (Canada)

    2008-07-01

    This presentation described a unique technique to recover heavy minerals contained in the froth treatment tailings produced by oil sand mining extraction operations in Fort McMurray, Alberta. In an effort to process waste material into valuable products, Titanium Corporation is developing technology to recover heavy minerals, primarily zircon, and a portion of bitumen contained in the final stage of bitumen processing. The process technology is being developed to apply to all mined oil sands operations in the Fort McMurray region. In 2004, Titanium Corporation commissioned a pilot research facility at the Saskatchewan Research Council to test dry oil sands tailings. In 2005, a bulk sampling pilot plant was connected to the fresh oil sands tailings pipeline on-site in Fort McMurray, where washed sands containing heavy minerals were processed at a pilot facility. The mineral content in both deposited tailings and fresh pipeline tailings was assessed. Analysis of fresh tailings on a daily basis identified a constant proportion of zircon and higher levels of associated bitumen compared with the material in the deposited tailings. The process flow sheet design was then modified to remove bitumen from the heavy minerals and concentrate the minerals. A newly modified flotation process was shown to be a viable processing route to recover the heavy minerals from froth treatment tailings. 8 refs., 9 tabs., 12 figs.

  17. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils

    Science.gov (United States)

    Prescott, Cindy E.; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J.

    2017-01-01

    ABSTRACT The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils. IMPORTANCE Covering over 800 km2, land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of

  18. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils.

    Science.gov (United States)

    Masse, Jacynthe; Prescott, Cindy E; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J

    2017-05-01

    The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils. IMPORTANCE Covering over 800 km 2 , land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of how

  19. Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

    2017-04-01

    Israel's coastal plain is abundant with sand originating from the Nile littoral cell. The inland windblown loose sand has formed 3-6 km wide lobe-like sand and dune fields currently comprised of foredunes, linear and northeasterly facing transverse and parabolic dunes that are currently stabilized by vegetation. This study reviews the architecture and history of the these dune fields aiming to: (a) Date the timings of beach accretion, and sand and dune incursions. (b) Discriminate between natural and human-induced forcing factors of sand mobilization and stabilization in time and space. (c) Present a model of the dunescape development. (d) Assess scenarios of sand transport in the future charcaterized by intense human impact and climate change. Luminescence ages, radiocarbon dates and relative ages from previously published geological and archaeological reports, historical texts, together with new optically stimulated luminescence (OSL) ages and stratigraphic and sedimentological data are analyzed. The deposition, mobilizations and preservation of the sand bodies, initially induced by the decline in sea level rise at 6-4 ka, were later controlled by historic land-use intensity and modern land-use/negligence practices. At 6 ka, beach sand buildup rapidly started. Where aeolianite ridges bordered the coast, pulses of sand with biogenic carbonate grains unconformably draped the ridges and rapidly consolidated into a distinct sandy calcarenite unit. Further east, sand sheets and low dunes partly pedogenized following their incursion, but did not cement. The water retention capacities of the sand sheets enabled the establishment of a sand-stabilizing vegetation cover that probably became an attractive environment for fuel and grazing. The growing Hellenistic-Roman-Byzantine ( 2.4-1.3 ka) populations probably led to increased consumption and massive destruction of sand stabilizing vegetation, enabling sand erodibility and mobilization during winter storms. The sand

  20. Troughs in Ice Sheets and Other Icy Deposits on Mars: Analysis of Their Radiative Balance

    Science.gov (United States)

    Fountain, A.; Kargel, J.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Zwally, H. J.

    2000-01-01

    It has long been known that groove-like structures in glaciers and ice sheets can trap more incoming solar radiation than is the case for a 'normal' flat, smooth surface. In this presentation, we shall describe the radiative regimes of typical scarps and troughs on icy surfaces of Mars, and suggest how these features originate and evolve through time. The basis of our analysis is the radiation balance model presented by Pfeffer and Bretherton. Their model considers the visible band radiation regime of a V-shaped groove on a terrestrial ice surface, and shows that absorbed energy can be enhanced by up to 50 percent for grooves with small opening angles and with typical polar values of the solar zenith angle. Our work extends this model by considering: (a) departures from V-shaped geometry, (b) both englacial and surficial dust and debris, and (c) the infrared spectrum. We apply the extended model to various features on the Martian surface, including the spiral-like scarps on the Northern and Southern ice sheets, the large-scale chasms (e.g., Chasm Borealis), and groove-like lineations on valley floors thought to be filled with mixtures of dust and icy substances. In conjunction with study of valley-closure experiments, we suggest that spiral-like scarps and chasms are stable features of the Martian climate regime. We also suggest that further study of scarps and chasms may shed light on the composition (i.e., relative proportions of water ice, carbon-dioxide ice and dust) of the Martian ice sheets and valley fills.

  1. A study of global sand seas

    Science.gov (United States)

    McKee, Edwin D.

    1979-01-01

    The birth of the idea that led to this publication on "Global Sand Seas" dates back to the late 1920's. At that time I was engaged in a study of the Coconino Sandstone of Arizona's Grand Canyon. Considerable controversy existed then as to whether this sandstone was a subaqueous deposit or was composed of wind-formed dunes. It became apparent that definitive literature was sparse or lacking on types of dunes, global distribution of these types, the mechanics of their development, the precise nature of their internal structure of cross-stratificiation, and the relation of wind systems to these sand forms. Especially lacking were data on criteria that could confidently be used in the recognition of ancient dunes. The common denominator in this publication is eolian sand bodies. Although the book is concerned primarily with desert sand seas, the subject matter is not restricted to deserts; it includes many references to deposits of coastal sand and to sand bodies in humid climates. Nor does the book deal exclusively with dunes, which, according to most definitions, involve mounds or hills. Many references are made to sand sheets, sand stringers, and other types of sand deposits that have no prominent topographic expression. All sand bodies accumulated by the action of wind are discussed. Chapters A-J of this publication are primarily topical. Chapters cover the grain texture, the color, and the structure of modern dunes and other eolian sands. Special treatment is given to the relation of wind data to dune interpretation, the evolution of form in current-deposited sand bodies as determined from experimental studies, and the discriminant analysis technique for differentiating between coastal and inland desert sands. This topical part of the publication also includes an analysis of criteria used in ancient deposits to interpret their eolian genesis and a consideration of economic application of the principles described, including a discussion of potentials and problems

  2. Prediction of critical transport velocity for preventing sand deposition in gas-oil multiphase production and well systems

    Energy Technology Data Exchange (ETDEWEB)

    Bello, O.O.; Reinicke, K.M. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. of Petroleum Engineering; Teodoriu, C. [Texas A and M Univ., College Station, TX (United States). Dept. of Petroleum Engineering

    2008-10-23

    The critical transport velocity is one of the key parameters for gas-oil-sand multiphase production and well system design and safe operation. Existing American Petroleum Institute Recommended Practice 14E (API RP 14E) for the sizing of multiphase flow systems suggests an equation to calculate threshold transport velocity. This equation only considers mixture density and does not account for factors such as fluid properties, gas-liquid flow patterns, sand loading, sand particle size, size distributions, shape factor and density. This work presents an improved computational methodology, which can be applied to estimate the critical transport velocity required to ensure efficient performance of gas-oil-sand multiphase production and well systems. The improved method is based on the modelling of three-phase gas-oil-sand pipe flow physics from first principle. Computations of the critical transport velocities show reasonable agreement with values calculated from mechanistic model (Danielson, 2007) for a relatively wide range of design and operating conditions. Compared with the mechanistic model (Danielson, 2007), the present method has no imposed limitations to the range of applicability. It is also takes into adequate account the effects of operating pressure, flow geometry, sand particle size, size distribution and shape factor, which have considerable influence on the critical transport velocity in gas-oil-sand multiphase production and well systems. (orig.)

  3. Coastal Sand Deposits 2006

    Data.gov (United States)

    California Natural Resource Agency — The supplemental information lists the geology data files, by county, and the name of the ESRI shapefile used in the creation of this dataset. All data was projected...

  4. Ways of distinguishing epigenetic types of gray-colored rocks in sheet-infiltration deposits

    International Nuclear Information System (INIS)

    Rasulova, S.D.; Yashunskii, Yu.V.

    1994-01-01

    At an infiltration deposit of uranium in Upper-Cretaceous sandy-clay alluvial deposits (Central Kyzylkum), six stages of postsedimentation epigenetic transformations were distinguished. The genesis of altered rocks was determined mostly by mineralogical methods. A new methodological technique is suggested, which calls for analysis of the textural, structural, and mineral correspondence of ferruginous components of gray-colored and oxidized rocks in the region of their contact and makes it possible to typify epigenetic changes in conditions of repeated change in the direction of geochemical processes

  5. An enhanced approach for the use of satellite-derived leaf area index values in dry deposition modeling in the Athabasca oil sands region.

    Science.gov (United States)

    Davies, Mervyn; Cho, Sunny; Spink, David; Pauls, Ron; Desilets, Michael; Shen, Yan; Bajwa, Kanwardeep; Person, Reid

    2016-12-15

    In the Athabasca oil sands region (AOSR) of Northern Alberta, the dry deposition of sulphur and nitrogen compounds represents a major fraction of total (wet plus dry) deposition due to oil sands emissions. The leaf area index (LAI) is a critical parameter that affects the dry deposition of these gaseous and particulate compounds to the surrounding boreal forest canopy. For this study, LAI values based on Moderate Resolution Imaging Spectroradiometer satellite imagery were obtained and compared to ground-based measurements, and two limitations with the satellite data were identified. The satellite LAI data firstly represents one-sided LAI values that do not account for the enhanced LAI associated with needle leaf geometry, and secondly, underestimates LAI in winter-time northern latitude regions. An approach for adjusting satellite LAI values for different boreal forest cover types, as a function of time of year, was developed to produce more representative LAI values that can be used by air quality sulphur and nitrogen deposition models. The application of the approach increases the AOSR average LAI for January from 0.19 to 1.40, which represents an increase of 637%. Based on the application of the CALMET/CALPUFF model system, this increases the predicted regional average dry deposition of sulphur and nitrogen compounds for January by factors of 1.40 to 1.30, respectively. The corresponding AOSR average LAI for July increased from 2.8 to 4.0, which represents an increase of 43%. This increases the predicted regional average dry deposition of sulphur and nitrogen compounds for July by factors of 1.28 to 1.22, respectively. These findings reinforce the importance of the LAI metric for predicting the dry deposition of sulphur and nitrogen compounds. While satellite data can provide enhanced spatial and temporal resolution, adjustments are identified to overcome associated limitations. This work is considered to have application for other deposition model studies where

  6. The importance of atmospheric base cation deposition for preventing soil acidification in the Athabasca Oil Sands Region of Canada

    Science.gov (United States)

    Shaun A. Watmough; Colin J. Whitfield; Mark E. Fenn

    2014-01-01

    Industrial activities in the oil sands region of Alberta, Canada have resulted in greatly elevated emissions of SO2 and N (NOx and NH3) and there are concerns over possible widespread ecosystem acidification. Acid sensitive soils in the region are common and have very low base cation weathering rates...

  7. Clear cutting (10-13th century) and deep stable economy (18-19th century) as responsible interventions for sand drifting and plaggic deposition in cultural landscapes on aeolian sands (SE-Netherlands).

    Science.gov (United States)

    van Mourik, Jan; Vera, Hein; Wallinga, Jakob

    2013-04-01

    The landscape in extensive areas in SE-Netherlands is underlain by coversand, deposited during the Late Glacial of the Weichselian. In the Preboreal, aeolian processes reduced soil formation. From the Preboreal to the Atlantic a deciduous climax forest developed. The geomorphology was a coversand landscape, composed of ridges (umbric podzols), coversand plains (gleyic podzols), coversand depressions (histic podzols) and small valleys (gleysols). The area was used by hunting people during the Late Paleolithic and Mesolithic. During the Bronze and Iron Ages the area was populated by people, living from forest grazing, shifting cultivation and trade. The natural deciduous forest gradually degraded into Calluna heath. The deforestation accelerated the soil acidification and affected the hydrology, which is reflected in drying out of ridges and wetting of depressions, promoting the development of histic podzols and even histosols. Aeolian erosion was during this period restricted to local, small scale sand drifting, related to natural hazards as forest fires and hurricanes and shifting cultivation. Sustainable crop productivity on chemically poor sandy substrates required application of organic fertilizers, composed of a mixture of organic litter and animal manure with a very low mineral compound, produced in shallow stables. At least since 1000 AD, heath management was regulated by a series of rules that aimed to protect the valuable heat lands against degradation. During the 11th, 12th and 13th centuries there was an increasing demand for wood and clear cutting transformed the majority of the forests in driftsand landscapes. The most important market was formed by the very wealthy Flemish cities. The exposed soil surface was subjected to wind erosion and sand drifting which endangered the Calluna heath, arable land and even farmhouses. As a consequence, umbric podzols, the natural climax soil under deciduous forests on coversand, degraded into larger scale driftsand

  8. Electrografting and morphological studies of chemical vapour deposition grown graphene sheets modified by electroreduction of aryldiazonium salts

    International Nuclear Information System (INIS)

    Mooste, Marek; Kibena, Elo; Kozlova, Jekaterina; Marandi, Margus; Matisen, Leonard; Niilisk, Ahti; Sammelselg, Väino; Tammeveski, Kaido

    2015-01-01

    Highlights: • CVD-grown graphene sheets were electrografted with various aryldiazonium salts • Redox grafting was applied to form thick nitrophenyl films • The reduction of the released radicals was in evidence during the redox grafting • Multilayer formation on CVD graphene was confirmed by XPS and AFM measurements • Thickness of different aryl layers on CVD graphene varied from few to 30 nm - Abstract: This work focuses on investigating the electrografting of chemical vapour deposition (CVD) graphene electrodes grown onto Ni foil (Ni/Gra) with different diazonium salts (including azobenzene diazonium tetrafluoroborate, Fast Garnet GBC sulphate salt, Fast Black K salt, 4-bromobenzene diazonium tetrafluoroborate and 4-nitrobenzenediazonium tetrafluoroborate). Various grafting conditions (e.g. “normal” electrografting in the narrow potential range and redox grafting in the wider potential range) were used. The electrochemical grafting behaviour was similar for all diazonium compounds used, except for the 4-nitrobenzenediazonium tetrafluoroborate when redox grafting was applied. The X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy results confirmed the presence of the corresponding aryl layers on Ni/Gra surfaces. The formation of multilayers on Ni/Gra substrates was in evidence since the thickness of different aryl layers varied from few to 30 nm depending on the modification procedures as well as the diazonium compounds used and the XPS analysis revealed a peak at about 400 eV for all aryl-modified Ni/Gra samples suggesting the multilayer formation also through azo linkages

  9. Sponge fossils of Middle Dnieper River Upper Eocenian deposits (geological survey sheet area «Kobelyaki»

    Directory of Open Access Journals (Sweden)

    Stephanska T.A.

    2015-09-01

    Full Text Available For the first time sponge spicules of the Paleogene on the geological survey sheet area «Kobelyaki» were studied. Using artificial classification M.M. Ivanik (2003 45 taxa spicules were found in rocks. Morphological types spicules were defined. In the complexes following megascleres of «soft» Demospongiae are dominant: pro-, plagio-, ortho-, dicho-, anatriaenes, caltrops, smooth and echinated oxeas, subtylostyls, strongyls, ophioxeas. Diaenes, monenes, caltrops with reduced beam (olimtriaenes, are less common. Microscleres are numerous: sterrasters, sphaerasters, oxysphaerasters, oxyasters. Fragments of dyctional gratings without lychnisks and free spicules of hexactinellid sponges are frequent (pentactines, hexactines. Megascleres of lithistid sponges (phyllotriaenes, tetracrepid desmas, triders, megaclones, dicranoclones are relatively few. The palaeocenosis structure that existed in the Obukhov Sea on this area, it was found by morphological analysis of sponges spicules. In the Obukhov time following sponges dominated here: «soft» sponges with unrelated skeleton that belonged to the class Demospongiae (orders Poecilosclerida, Astrophorida and families Geodiidae, Pachastrellidae, Ancorinidae, Calthropellidae, Tethyidae, Crellidae and hexactinellids of class Hexactinellida (orders Hexactinosida and Lyssacinosida. А few sponges spicules (belonged to the subclass Lithistida, families Corallistidae, Theonellidae, Phymaraphiniidae, Chenendoporidae, Pleromidae and lack lithistid skeletal gratings fragments in the studied complexes may indicate a desmas transfer from neighboring, a shallow Obukhov stations, which were confined to the nearby slope of the Ukrainian Shield. On the base of sponge spicules studying the Late Eocene (Obukhov age of surrounding deposits is proved. spongе spicula, Upper Eocene, Obuchovian Suite, Middle Dnieper region.

  10. Residual stress and bending strength of ZnO films deposited on polyimide sheet by RF sputtering system

    Energy Technology Data Exchange (ETDEWEB)

    Kusaka, Kazuya, E-mail: kusaka@tokushima-u.ac.jp [Institute of Technology and Science, Tokushima University, 2-1, Minamijosanjima, Tokushima, Tokushima 7708506 (Japan); Maruoka, Yutaka, E-mail: ymaruoka1116@gmail.com [Graduate School of Advanced Technology and Science, Tokushima University, 2-1, Minamijosanjima, Tokushima, Tokushima 7708506 (Japan); Matsue, Tatsuya, E-mail: tmatsue@mat.niihama-nct.ac.jp [Department of Environmental Materials Engineering National Institute of Technology, NIIHAMA College, 7-1, Yakumo-cho, Niihama, Ehime 7928580 (Japan)

    2016-05-15

    Zinc oxide (ZnO) films were deposited on a soft polyimide sheet substrate by radio frequency sputtering with a ZnO powder target, and the films' crystal orientations and residual stress were investigated using x-ray diffraction as a function of substrate temperature. C-axis oriented ZnO films were achieved using this ZnO powder target method. The ZnO films exhibited high compressive residual stresses between −0.7 and −1.4 GPa. Finally, the authors examined the strength of the obtained film by applying tensile bending loads. No cracks were observed on the surfaces of the ZnO films after a bending test using cylinders with diameters >25 mm. After a bending test using a cylinder with a diameter of 19 mm, large cracks were formed on the films. Therefore, the authors concluded that the tensile bending strength of the obtained films was greater than ∼420 MPa.

  11. Enhanced Column Filtration for Arsenic Removal from Water: Polymer-Templated Iron Oxide Nanoparticles Immobilized on Sand via Layer-by-Layer Deposition

    Science.gov (United States)

    Cheng, Calvin Chia-Hung

    Arsenic is ubiquitous in water sources around the world and is highly toxic. While precipitation and membrane filtration techniques are successfully implemented in developed cities, they are unsuitable for rural and low-resource settings lacking centralized facilities. This thesis presents the use of ultra-small iron oxide (Fe2O3) nanoparticles functionalized on sand granules for use as a house-hold scale adsorption filter. Water-stable alpha-Fe2O3 (hematite) nanoparticles (arsenic adsorption, with 147 +/- 2 mg As(III) per g Fe2O3 and 91 +/- 10 mg As(V) per g Fe2O3. The platform was also used to synthesize iron-based composites, including magnetite (Fe 3O4) and Fe-Cu oxide nanoparticles. For use as a column filter, Fe2O3-PAA nanoparticles were functionalized on sand granules using a layer-by-layer deposition method, with the nanoparticles embedded in the negative layer. The removal of As(III) by the Fe2O 3-PAA functionalized column was described by reversible 1st order kinetics where the forward and reverse rate constants were 0.31 hr -1 and 0.097 hr-1, respectively. Implemented as a passive water filter with 30 x 30 x 50 cm3 dimensions, the filter has an expected lifetime in the order of many years. By controlling the flow rate of the column depending on contamination levels, the filter effectively removes arsenic down to the safety limit of 0.01 mg/L. In a parallel project, the layer-by-layer deposition of Poly(diallydimethyl ammonium chloride) (PDDA) and poly(sodium 5-styrenesulfonate) (PSS) was exploited for a highly practical synthesis of discrete gradient surfaces. By independently controlling the concentration of NaCl in PDDA and PSS deposition solutions, a 2-dimensional matrix of surfaces was created in 96-well microtiter plates. Distinct non-monotonic dye adsorption patterns on the gradient surfaces was observed. Practical knowledge from this project was also used to enhance the nanoparticle surface functionalization described above. In all, a practical

  12. A bright intra-dune feature on Titan and its implications for sand formation and transport

    Science.gov (United States)

    MacKenzie, Shannon; Barnes, Jason W.; Rodriguez, Sebastien; Cornet, Thomas; Brossier, Jeremy; Soderblom, Jason M.; Le Mouélic, Stephane; Sotin, Christophe; Brown, Robert H.; Buratti, Bonnie J.; Clark, Roger Nelson; Nicholson, Philip D.; Baines, Kevin

    2017-10-01

    Organic sands cover much of Titan’s equatorial belt, gathered into longitudinal dunes about a kilometer wide and hundreds of kilometers long. At the end of the Cassini era, questions of how such a vast volume of saltable material is or was created on Titan remain unanswered. At least two possible mechanisms suggested for forming sand-sized particles involve liquids: (1) evaporite deposition and erosion and (2) flocculation of material within a lake. Transporting sand from the lakes and seas of Titan’s poles to the equatorial belt is not strongly supported by Cassini observations: the equatorial belt sits higher than the poles and no sheets or corridors of travelling sand have been identified. Thus, previous sites of equatorial surface liquids may be of interest for understanding sand formation, such as the suggested paleoseas Tui and Hotei Regio. A newly identified feature in the VIMS data sits within the Fensal dune field but is distinct from the surrounding sand. We investigate this Bright Fensal Feature (BFF) using data from Cassini VIMS and RADAR. Specifically, we find spectral similarities between the BFF and both sand and Hotei Regio. The RADAR cross sectional backscatter is similar to neighboring dark areas, perhaps sand covered interdunes. We use this evidence to constrain the BFF’s formation history and discuss how this intra-dune feature may contribute to the processes of sand transport and supply.

  13. Nitrogen deposition and soil carbon content affect nitrogen mineralization during primary succession in acid inland drift sand vegetation

    NARCIS (Netherlands)

    Sparrius, L.B.; Kooijman, A.M.

    2013-01-01

    Background and aims Two inland dunes in the Netherlands receiving low (24) and high (41 kg N ha−1 yr−1) nitrogen (N) deposition were compared for N dynamics and microbial activity to investigate the potential effect of N on succession rate of the vegetation and loss of pioneer habitats. Methods

  14. Luminescence dating of paleolake deltas and glacial deposits in Garwood Valley, Antarctica: Implications for climate, Ross ice sheet dynamics, and paleolake duration

    Science.gov (United States)

    Levy, Joseph S.; Rittenour, Tammy M.; Fountain, Andrew G.; O'Connor, Jim E.

    2017-01-01

    The formation of perched deltas and other lacustrine deposits in the McMurdo Dry Valleys of Antarctica is widely considered to be evidence of valley-filling lakes dammed by the grounded Ross Sea ice sheet during the local Last Glacial Maximum, with lake drainage interpreted as a record of grounding line retreat. We used luminescence dating to determine the age of paleolake deltas and glacial tills in Garwood Valley, a coastal dry valley that opens to the Ross Sea. Luminescence ages are stratigraphically consistent with radiocarbon results from algal mats within the same delta deposits but suggest radiocarbon dates from lacustrine carbonates may overestimate deposit ages by thousands of years. Results suggest that late Holocene delta deposition into paleolake Howard in Garwood Valley persisted until ca. 3.5 ka. This is significantly younger than the date when grounded ice is thought to have retreated from the Ross Sea. Our evidence suggests that the local, stranded ice-cored till topography in Garwood Valley, rather than regional ice-sheet dynamics, may have controlled lake levels for some McMurdo Dry Valleys paleolakes. Age control from the supraglacial Ross Sea drift suggests grounding and up-valley advance of the Ross Sea ice sheet into Garwood valley during marine oxygen isotope stage (MIS) 4 (71–78 ka) and the local Last Glacial Maximum (9–10 ka). This work demonstrates the power of combining luminescence dating with existing radiocarbon data sets to improve understanding of the relationships among paleolake formation, glacial position, and stream discharge in response to climate change.

  15. High performance electrode material for supercapacitors based on α-Co(OH)2 nano-sheets prepared through pulse current cathodic electro-deposition (PC-CED)

    Science.gov (United States)

    Aghazadeh, Mustafa; Rashidi, Amir; Ganjali, Mohammad Reza

    2018-01-01

    In this paper, the well-defined nano-sheets of α-Co(OH)2 were prepared through the cathodic electrosynthesis from an additive-free aqueous cobalt nitrate bath. The pulse current cathodic electro-deposition (PC-CED) was used as the means for the controlling the OH- electrogeneration on the cathode surface. The characteristics and electrochemical behavior of the prepared cobalt hydroxide were also assessed through SEM, TEM, XRD, BET, and IR. The results proved the product to be composed of crystalline pure α phase of cobalt hydroxide with sheet-like morphology at nanoscale. Evaluations of the electrochemical behaviour of the α-Co(OH)2 nano-sheets revealed that they are capable to delivering the specific capacitance of 1122 F g-1 at a discharge load of 3 A g-1 and SC retention of 84% after 4000 continues discharging cycles, suggesting the nano-sheets as promising candidates for use in electrochemical supercapacitors. Further, the method used for the preparation of the compounds enjoys the capability of being scaled up. [Figure not available: see fulltext.

  16. A New Stochastic Modeling of 3-D Mud Drapes Inside Point Bar Sands in Meandering River Deposits

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yanshu, E-mail: yys6587@126.com [Yangtze University, School of Geosciences (China)

    2013-12-15

    The environment of major sediments of eastern China oilfields is a meandering river where mud drapes inside point bar sand occur and are recognized as important factors for underground fluid flow and distribution of the remaining oil. The present detailed architectural analysis, and the related mud drapes' modeling inside a point bar, is practical work to enhance oil recovery. This paper illustrates a new stochastic modeling of mud drapes inside point bars. The method is a hierarchical strategy and composed of three nested steps. Firstly, the model of meandering channel bodies is established using the Fluvsim method. Each channel centerline obtained from the Fluvsim is preserved for the next simulation. Secondly, the curvature ratios of each meandering river at various positions are calculated to determine the occurrence of each point bar. The abandoned channel is used to characterize the geometry of each defined point bar. Finally, mud drapes inside each point bar are predicted through random sampling of various parameters, such as number, horizontal intervals, dip angle, and extended distance of mud drapes. A dataset, collected from a reservoir in the Shengli oilfield of China, was used to illustrate the mud drapes' building procedure proposed in this paper. The results show that the inner architectural elements of the meandering river are depicted fairly well in the model. More importantly, the high prediction precision from the cross validation of five drilled wells shows the practical value and significance of the proposed method.

  17. Episodic Eolian Sand Deposition in the Past 4000 Years in Cape COD National Seashore, Massachusetts, USA in Response to Possible Hurricane/storm and Anthropogenic Disturbances

    Science.gov (United States)

    Forman, Steven

    2015-02-01

    The eolian sand depositional record for a dune field within Cape Cod National Seashore, Massachusetts is posit as a sensitive indicator of environmental disturbances in the late Holocene from a combination of factors such as hurricane/storm and forest fire occurrence, and anthropogenic activity. Stratigraphic and sedimentologic observations, particularly the burial of spodosol-like soils, and associated 14C and OSL ages that are concordant indicate at least six eolian depositional events at ca. 3750, 2500, 1800, 960, 430 and Atlantic Ocean at ca. 2.0 to 1.6, and 1.0 ka and also a wetter coastal climate, which suppressed the occurrence of forest fire. Thus, local droughts are not associated with periods of dune movement in this mesic environment. Latest eolian activity on outer Cape Cod commenced in the past 300 to 500 years and may reflect multiple factors including broad-scale landscape disturbance with European colonization, an increased incidence of forest fires and heightened storminess. Eolian systems of Cape Cod appear to be sensitive to landscape disturbance and prior to European settlement may reflect predominantly hurricane/storm disturbance, despite generally mesic conditions in past 4 ka.

  18. Seismic modeling of fluvial-estuarine deposits in the Athabasca oil sands using ray-tracing techniques, Steepbank River area, northeastern Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Langenberg, C. W.; Hein, F. J. [Alberta Energy and Utilities Board, Edmonton, AB (Canada); Lawton, D.; Cunningham, J. [Calgary Univ., Dept. of Geology and Geophysics, Calgary, AB (Canada)

    2002-03-01

    Seismic reflection characteristics of contrasting channel geometries in a five-section portion of the Steepbank River are modeled using ray-tracing techniques. Outcrop lithofacies associations are used to create a seismic model that can be used as a subsurface analog of other similar oil-sands successions. At least four channel complexes based on stratal bounding surfaces, arrangement of lithofacies, and consistent paleoflow patterns have been identified. The lower part of each channel complex contains trough crossbedded sandstone, exhibiting high porosity and permeability. These sandstones were deposited in channel axes and are the highest grade bitumen deposits in the area. The upper parts of the channels contain significantly lower bitumen saturation values due to common interbedded mudstone. Nearby wells contain cored and logged intervals that are similar to exposed outcrops in the riverbank. Overall modeling results indicate that channel complexes can be imaged seismically, given data of sufficient quality and frequency. Bitumen grade may be predicted in these seismic lines, which has important consequences for bitumen exploration and extraction in the Steepbank River region. 64 refs., 26 figs.

  19. Fontainebleau Sand

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    2006-01-01

    The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

  20. Heavy mineral sorting as a tool to distinguish depositional characteristics of “in situ” sands from their related injected sands in a Palaeogene submarine Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Moatari Kazerouni, Afsoon; Friis, Henrik; Svendsen, Johan. B

    Postdepositional remoblization and injection of sand are important processes in deep-water clastic systems. Subsurface mobilisation and injection of sand has been recently recognised as a significant control of deep-water sandstone geometry. Kilometre-scale injection complexes have been interpreted...

  1. Feasibility of N2 Binding and Reduction to Ammonia on Fe-Deposited MoS2 2D Sheets: A DFT Study

    KAUST Repository

    Azofra Mesa, Luis

    2017-05-19

    Based on the structure of the nitrogenase FeMo cofactor (FeMoco), it is reported that Fe deposited on MoS2 2D sheets exhibits high selectivity towards the spontaneous fixation of N2 against chemisorption of CO2 and H2 O. DFT predictions also indicate the ability of this material to convert N2 into NH3 with a maximum energy input of 1.02 eV as an activation barrier for the first proton-electron pair transfer.

  2. Feasibility of N2 Binding and Reduction to Ammonia on Fe-Deposited MoS2 2D Sheets: A DFT Study

    KAUST Repository

    Azofra Mesa, Luis; Sun, Chenghua; Cavallo, Luigi; MacFarlane, Douglas R.

    2017-01-01

    Based on the structure of the nitrogenase FeMo cofactor (FeMoco), it is reported that Fe deposited on MoS2 2D sheets exhibits high selectivity towards the spontaneous fixation of N2 against chemisorption of CO2 and H2 O. DFT predictions also indicate the ability of this material to convert N2 into NH3 with a maximum energy input of 1.02 eV as an activation barrier for the first proton-electron pair transfer.

  3. Seabed Gradient Controlling Onshore Transport Rates of Surf Sand during Beach Retreat by Sea Level Rise

    Science.gov (United States)

    Lee, Hee Jun; Yi, Hi-Il

    2018-03-01

    A simple relationship is proposed for the onshore transport rates of surf-zone sand to evaluate the beach retreat caused by sea level rise. It suggests that the preservation potential of surf sand is proportional inversely to the seabed gradient during beach retreat. According to this relationship, the erosional remnants of surf sand would be more readily developed on a gentler shelf collectively as transgressive sand sheets. This finding may explain the previous studies regarding the Korean shelves that proposed that the Holocene transgressive sand sheets (HTSS) occur not in the steep eastern shelf but in the gentle western shelf. In line with such presence/absence of the HTSS are the results from some coastal seismic profiles obtained in the present study. The profiles indicate that sand deposits are restricted within the nearshore in the eastern coast, whereas they are persistently traceable to the offshore HTSS in the western coast. Tide is proven to have a negligible influence on the total duration of surf-zone processes. This study may be useful in predicting the consequences of the beach retreat that takes place worldwide as sea levels rise as a result of global warming.

  4. Flower-, wire-, and sheet-like MnO2-deposited diatomites: Highly efficient absorbents for the removal of Cr(VI).

    Science.gov (United States)

    Du, Yucheng; Wang, Liping; Wang, Jinshu; Zheng, Guangwei; Wu, Junshu; Dai, Hongxing

    2015-03-01

    Flower-, wire-, and sheet-like MnO2-deposited diatomites have been prepared using a hydrothermal method with Mn(Ac)2, KMnO4 and/or MnSO4 as Mn source and diatomite as support. Physical properties of the materials were characterized by means of numerous analytical techniques, and their behaviors in the adsorption of chromium(VI) were evaluated. It is shown that the MnO2-deposited diatomite samples with different morphologies possessed high surface areas and abundant surface hydroxyl groups (especially the wire-like MnO2/diatomite sample). The wire-like MnO2/diatomite sample showed the best performance in the removal of Cr(VI), giving the maximum Cr(VI) adsorption capacity of 101 mg/g. Copyright © 2014. Published by Elsevier B.V.

  5. Assessment of multi-trophic changes in a shallow boreal lake simultaneously exposed to climate change and aerial deposition of contaminants from the Athabasca Oil Sands Region, Canada.

    Science.gov (United States)

    Summers, Jamie C; Kurek, Joshua; Rühland, Kathleen M; Neville, Erin E; Smol, John P

    2017-08-15

    The Athabasca Oil Sands Region (AOSR) has been intensely developed for industrial bitumen extraction and upgrading since the 1980s. A paucity of environmental monitoring prior to development raises questions about baseline conditions in freshwater systems in the region and ecological responses to industrial activities. Further, climatic changes prompt questions about the relative roles of climate and industry in shaping aquatic ecosystems through time. We use aquatic bioindicators from multiple trophic levels, concentrations of petrogenic contaminants (dibenzothiophenes), and spectrally-inferred chlorophyll-a preserved in well-dated sediments of a closed-basin, shallow lake ~50km away from the main area of industry, in conjunction with climate observations, to assess how the biotic assemblages of a typical AOSR lake have changed during the past ~75years. We examine the contributions of the area's stressors in structuring aquatic communities. Increases in sedimentary measures of petrogenic contaminants provide clear evidence of aerial contaminant deposition from local industry since its establishment, while climate records demonstrate consistent warming and a recent period of reduced precipitation. Quantitative comparisons of biological assemblages from before and after the establishment of regional industry find significant (pshallow systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Spatial variations in snowpack chemistry, isotopic composition of NO3− and nitrogen deposition from the ice sheet margin to the coast of western Greenland

    Directory of Open Access Journals (Sweden)

    C. J. Curtis

    2018-01-01

    Full Text Available The relative roles of anthropogenic nitrogen (N deposition and climate change in causing ecological change in remote Arctic ecosystems, especially lakes, have been the subject of debate over the last decade. Some palaeoecological studies have cited isotopic signals (δ(15N preserved in lake sediments as evidence linking N deposition with ecological change, but a key limitation has been the lack of co-located data on both deposition input fluxes and isotopic composition of deposited nitrate (NO3−. In Arctic lakes, including those in western Greenland, previous palaeolimnological studies have indicated a spatial variation in δ(15N trends in lake sediments but data are lacking for deposition chemistry, input fluxes and stable isotope composition of NO3−. In the present study, snowpack chemistry, NO3− stable isotopes and net deposition fluxes for the largest ice-free region in Greenland were investigated to determine whether there are spatial gradients from the ice sheet margin to the coast linked to a gradient in precipitation. Late-season snowpack was sampled in March 2011 at eight locations within three lake catchments in each of three regions (ice sheet margin in the east, the central area near Kelly Ville and the coastal zone to the west. At the coast, snowpack accumulation averaged 181 mm snow water equivalent (SWE compared with 36 mm SWE by the ice sheet. Coastal snowpack showed significantly greater concentrations of marine salts (Na+, Cl−, other major cations, ammonium (NH4+; regional means 1.4–2.7 µmol L−1, total and non-sea-salt sulfate (SO42−; total 1.8–7.7, non-sea-salt 1.0–1.8 µmol L−1 than the two inland regions. Nitrate (1.5–2.4 µmol L−1 showed significantly lower concentrations at the coast. Despite lower concentrations, higher precipitation at the coast results in greater net deposition for NO3− as well as NH4+ and non-sea-salt sulfate (nss-SO42− relative to the inland regions

  7. Spatial variations in snowpack chemistry, isotopic composition of NO3- and nitrogen deposition from the ice sheet margin to the coast of western Greenland

    Science.gov (United States)

    Curtis, Chris J.; Kaiser, Jan; Marca, Alina; Anderson, N. John; Simpson, Gavin; Jones, Vivienne; Whiteford, Erika

    2018-01-01

    The relative roles of anthropogenic nitrogen (N) deposition and climate change in causing ecological change in remote Arctic ecosystems, especially lakes, have been the subject of debate over the last decade. Some palaeoecological studies have cited isotopic signals (δ(15N)) preserved in lake sediments as evidence linking N deposition with ecological change, but a key limitation has been the lack of co-located data on both deposition input fluxes and isotopic composition of deposited nitrate (NO3-). In Arctic lakes, including those in western Greenland, previous palaeolimnological studies have indicated a spatial variation in δ(15N) trends in lake sediments but data are lacking for deposition chemistry, input fluxes and stable isotope composition of NO3-. In the present study, snowpack chemistry, NO3- stable isotopes and net deposition fluxes for the largest ice-free region in Greenland were investigated to determine whether there are spatial gradients from the ice sheet margin to the coast linked to a gradient in precipitation. Late-season snowpack was sampled in March 2011 at eight locations within three lake catchments in each of three regions (ice sheet margin in the east, the central area near Kelly Ville and the coastal zone to the west). At the coast, snowpack accumulation averaged 181 mm snow water equivalent (SWE) compared with 36 mm SWE by the ice sheet. Coastal snowpack showed significantly greater concentrations of marine salts (Na+, Cl-, other major cations), ammonium (NH4+; regional means 1.4-2.7 µmol L-1), total and non-sea-salt sulfate (SO42-; total 1.8-7.7, non-sea-salt 1.0-1.8 µmol L-1) than the two inland regions. Nitrate (1.5-2.4 µmol L-1) showed significantly lower concentrations at the coast. Despite lower concentrations, higher precipitation at the coast results in greater net deposition for NO3- as well as NH4+ and non-sea-salt sulfate (nss-SO42-) relative to the inland regions (lowest at Kelly Ville 6, 4 and 3; highest at coast 9, 17

  8. Geochemical radioactive investigation of beach sands and stream sediments, using heavy minerals, trace elements and radon measurements, (Qerdaha sheet of the Syrian coast)

    International Nuclear Information System (INIS)

    Jubeli, Y.; Kattaa, B.; Al-Hilal, M.

    2000-05-01

    Reconnaissance geochemical radiometric survey of stream sediments resulting from the weathering of outcropped rocks in and around the study area was performed. This survey included heavy mineral sampling, trace and radioelements and radon measurements to evaluate the radioactivity of the source rocks and to understand the nature and distribution of the heavy minerals and trace elements in the study area. Several techniques were used to achieve these objectives. The results of heavy mineral geochemical survey show that the abundant minerals are iron oxides (magnetite, hematite, goehtite and limonite) pyroxene and olivine; less abundant minerals are apatite, ilmenite, garnet, barite, siderite and gloconite, while rare minerals are zircon and rutile. Amphibole is reported as an abundant mineral in sand dunes and is less abundant in samples located in the northern part of the study area. The amphibole seems to be derived from the ophiolitic complex north of the study area. Grain size analysis of heavy minerals revealed that the concentration of economic minerals such as zircon rutile and ilmenite increases with the decrease of the grain size. The microscopic study showed fragments and fossils of foraminifere mostly impregnated with heavy metals such as iron and manganese resulting from diagenetic metasomatism and replacement processes of. Fish teeth (< 2 mm) and oolite of iron were also noticed in most of the samples. The morphology of heavy mineral grains shows that most of the grains are angular to subangular suggesting that they were transported for short distance from their source rocks. Normally, phosphate pellets, gloconite and iron ooids are not considered since their original morphological features show clear roundness that attributed to their sedimentological origin, not to transportation factor. The source rock of most of the heavy mineral assemblage is the basalt. Apatite and gloconite are derived from the phosphorite and phosphatized limestone encountered

  9. Jurassic ash-flow sheets, calderas, and related intrusions of the Cordilleran volcanic arc in southeastern Arizona: implications for regional tectonics and ore deposits

    Science.gov (United States)

    Lipman, P.W.; Hagstrum, J.T.

    1992-01-01

    Volcanologic, petrologic, and paleomagnetic studies of widespread Jurassic ash-flow sheets in the Huachuca-southern Dragoon Mountains area have led to identification of four large source calderas and associated comagnetic intracaldera intrusions. Stratigraphic, facies, and contact features of the caldera-related tuffs also provide constraints on the locations, lateral displacements, and very existence for some major northwest-trending faults and inferred regional thrusts in southeastern Arizona. Silicic alkalic compositions of the Jurassic caldera-related, ash-flow tuffs; bimodal associated mafic magmatism; and interstratified coarse sedimentary deposits provide evidence for synvolcanic extension and rifting within the Cordilleran magmatic arc. Gold-copper mineralization is associated with subvolcanic intrusions at several of the Jurassic calderas. -from Authors

  10. Microstructure Evolution of Electron Beam Physical Vapour Deposited Ni-23.5Cr-2.66Co-1.44Al Superalloy Sheet During Annealing at 600 °C

    Directory of Open Access Journals (Sweden)

    Li Mingwei

    2013-02-01

    Full Text Available Microstructure evolution of electron beam physical vapour deposited (EB-PVD Ni‑23.5Cr‑2.66Co‑1.44Al superalloy sheet during annealing at 600 °C was investigated. The results showed that the as-deposited alloy was composed of only g phase. After annealing at 600 °C, the locations of diffraction peaks were still the same. The (220 diffraction peak of the deposition side increased with annealing time. The sheet on deposited side had a tendency toward forming (220 texture during post-annealing. No obvious texture was observed at as-deposited and annealed sheet at 600 °C in substrate side. The count and size of "voids" decreased with time. The size of grains increased obviously with annealing time. The ultimate tensile strength of EB-PVD Ni-23.5Cr-2.66Co-1.44Al alloy sheet increased from 641 MPa to 829 MPa after annealing at 600 °C for 30 hours.

  11. Nitrate deposition and preservation in the snowpack along a traverse from coast to the ice sheet summit (Dome A) in East Antarctica

    Science.gov (United States)

    Shi, Guitao; Hastings, Meredith G.; Yu, Jinhai; Ma, Tianming; Hu, Zhengyi; An, Chunlei; Li, Chuanjin; Ma, Hongmei; Jiang, Su; Li, Yuansheng

    2018-04-01

    Antarctic ice core nitrate (NO3-) can provide a unique record of the atmospheric reactive nitrogen cycle. However, the factors influencing the deposition and preservation of NO3- at the ice sheet surface must first be understood. Therefore, an intensive program of snow and atmospheric sampling was made on a traverse from the coast to the ice sheet summit, Dome A, East Antarctica. Snow samples in this observation include 120 surface snow samples (top ˜ 3 cm), 20 snow pits with depths of 150 to 300 cm, and 6 crystal ice samples (the topmost needle-like layer on Dome A plateau). The main purpose of this investigation is to characterize the distribution pattern and preservation of NO3- concentrations in the snow in different environments. Results show that an increasing trend of NO3- concentrations with distance inland is present in surface snow, and NO3- is extremely enriched in the topmost crystal ice (with a maximum of 16.1 µeq L-1). NO3- concentration profiles for snow pits vary between coastal and inland sites. On the coast, the deposited NO3- was largely preserved, and the archived NO3- fluxes are dominated by snow accumulation. The relationship between the archived NO3- and snow accumulation rate can be depicted well by a linear model, suggesting a homogeneity of atmospheric NO3- levels. It is estimated that dry deposition contributes 27-44 % of the archived NO3- fluxes, and the dry deposition velocity and scavenging ratio for NO3- were relatively constant near the coast. Compared to the coast, the inland snow shows a relatively weak correlation between archived NO3- and snow accumulation, and the archived NO3- fluxes were more dependent on concentration. The relationship between NO3- and coexisting ions (nssSO42-, Na+ and Cl-) was also investigated, and the results show a correlation between nssSO42- (fine aerosol particles) and NO3- in surface snow, while the correlation between NO3- and Na+ (mainly associated with coarse aerosol particles) is not

  12. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Timma, Christian, E-mail: christian.timma@thyssenkrupp.com [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany); Lostak, Thomas; Janssen, Stella; Flock, Jörg [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); Mayer, Christian [University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany)

    2016-12-30

    Highlights: • Skin-passed hot-dip galvanized (HDG-) steel sheets were coated with (NH{sub 4}){sub 2}SO{sub 4} in a common roll-coating method. • A formation of (NH{sub 4}){sub 2}Zn(SO{sub 4}) * xH{sub 2}O was observed and the reaction mainly occurred in the skin-passed areas of the surface. • Sulfate coated samples reveal a superior friction behaviour in oil-like conditions compared non-sulfated specimen. - Abstract: Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH{sub 4}){sub 2}SO{sub 4}) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH{sub 4}){sub 2}Zn(SO{sub 4}){sub 2} * xH{sub 2}O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  13. Bituminous sands : tax issues

    International Nuclear Information System (INIS)

    Patel, B.

    2004-01-01

    This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs

  14. High-resolution sequence stratigraphic correlation of the braided river and vertical distribution characteristics of sand body-Take upper member of saihan formation of lower cretaceous in Bayanwula deposit, for instance

    International Nuclear Information System (INIS)

    Dai Mingjian; Peng Yunbiao; Yang Jianxin; Shen Kefeng

    2014-01-01

    In recent years, the high-resolution sequence stratigraphy of which reference surface is base level cycle get rapid development. Its biggest advantage is the ability to apply to the continental sedimentary basins controlled by multiple factors, especially applied to the thin layer contrast of the paleochannel sandstone type uranium reservoir. This paper, by using drill core and logging data, has made the high resolution sequence stratigraphy studies on braided river uranium reservoir of Upper Member of Saihan Formation of Lower Cretaceous (Kls2) in Bayanwula deposit and identified the base level cycle interface. The study interval is divided into one long-term cycle and seven mid-term base level cycle, and high-resolution time stratigraphic framework of the deposit is established. Depth analysis is taken for the relationship between the braided river sand body and base level cycles. And the position, distribution, and genesis in vertical of the braided river sand body are discussed in detail. Ore body is mainly hosted in edge of braided bar sand body, which formed in the low accommodation space, and braided channel and the braided bar interchange. So uranium enriched in the mid-term base level cycle MSC2-MSC5 in the study area. (authors)

  15. Microwave Deposition of Palladium Catalysts on Graphite Spheres and Reduced Graphene Oxide Sheets for Electrochemical Glucose Sensing.

    Science.gov (United States)

    Xie, Jian-De; Gu, Siyong; Zhang, Houan

    2017-09-21

    This work outlines a synthetic strategy inducing the microwave-assisted synthesis of palladium (Pd) nanocrystals on a graphite sphere (GS) and reduced graphene oxide (rGO) supports, forming the Pd catalysts for non-enzymatic glucose oxidation reaction (GOR). The pulse microwave approach takes a short period (i.e., 10 min) to fast synthesize Pd nanocrystals onto a carbon support at 150 °C. The selection of carbon support plays a crucial role in affecting Pd particle size and dispersion uniformity. The robust design of Pd-rGO catalyst electrode displays an enhanced electrocatalytic activity and sensitivity toward GOR. The enhanced performance is mainly attributed to the synergetic effect that combines small crystalline size and two-dimensional conductive support, imparting high accessibility to non-enzymatic GOR. The rGO sheets serve as a conductive scaffold, capable of fast conducting electron. The linear plot of current response versus glucose concentration exhibits good correlations within the range of 1-12 mM. The sensitivity of the Pd-rGO catalyst is significantly enhanced by 3.7 times, as compared to the Pd-GS catalyst. Accordingly, the Pd-rGO catalyst electrode can be considered as a potential candidate for non-enzymatic glucose biosensor.

  16. Optimal Materials and Deposition Technique Lead to Cost-Effective Solar Cell with Best-Ever Conversion Efficiency (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    This fact sheet describes how the SJ3 solar cell was invented, explains how the technology works, and why it won an R&D 100 Award. Based on NREL and Solar Junction technology, the commercial SJ3 concentrator solar cell - with 43.5% conversion efficiency at 418 suns - uses a lattice-matched multijunction architecture that has near-term potential for cells with {approx}50% efficiency. Multijunction solar cells have higher conversion efficiencies than any other type of solar cell. But developers of utility-scale and space applications crave even better efficiencies at lower costs to be both cost-effective and able to meet the demand for power. The SJ3 multijunction cell, developed by Solar Junction with assistance from foundational technological advances by the National Renewable Energy Laboratory, has the highest efficiency to date - almost 2% absolute more than the current industry standard multijunction cell-yet at a comparable cost. So what did it take to create this cell having 43.5% efficiency at 418-sun concentration? A combination of materials with carefully designed properties, a manufacturing technique allowing precise control, and an optimized device design.

  17. Aeolian sedimentation in the middle buntsandstein in the eifel north-south depression zone: Summary of the variability of sedimentary processes in a buntsandstein erg as a base for evaluation of the mutual relationships between aeolian sand seas and fluvial river systems in the mid-european buntsandstein

    Science.gov (United States)

    Mader, Detlef

    The spectrum of aeolian depositional subenvironments in the upper Middle Buntsandstein Karlstal-Schichten sequence in the Eifel North-South-zone at the western margin of the Mid-European Triassic Basin comprises trains of larger and higher narrowly-spaced dunes in sand seas, isolated smaller and lower widely-spaced dunes in floodplains and interdune playas, dry interdune sheet sands, damp interdune adhesive sandflats, wet interdune playa lakes, rainfall runoff watercourses and ephemeral channels cutting through the dune belt, and deflation gravel lag veneers. Distinction of aeolian and fluvial sediments within the succession of closely intertonguing wind- and water-laid deposits is possible by independent analysis of the conventional criteria and the more modern stratification styles. Thick cross-bedded aeolian sand sequences originate as barchanoid-type dunes which accumulate and migrate in the regime of narrow to wide unimodal southeasterly to southwesterly trade winds in low northern palaeolatitude in summer when the intertropical convergence zone is shifted to the north. The predominantly transverse-ridge dunes accrete mainly by grainfall and subcritical climbing of wind ripples, subordinately also by grainflow interfingering with grainfall. Horizontal-laminated aeolian sands form as sand sheets in dry interdune playas by subcritical migration of wind ripple trains, rarely also by plane bed accretion. Thin cross-bedded dune sands or horizontal-laminated aeolian sands capping fluvial cyclothems originate by deflation of emerged alluvial bar sands during low-water stages and subsequent accumulation of the winnowed sand as widely-spaced dunelets or chains of wind ripples in desiccated parts of the adjoining floodplain. The aeolian sand layers at the base of lacustrine cyclothems record migration of isolated little dunes across the dry playa floor at the beginning of a wetting-upwards cyclothem, with the sand deriving from deflation of fluvial incursions or

  18. Sandy aeolian deposits and environments and their relation to climate during the Last Glacial Maximum and Lateglacial in northwest and central Europe

    NARCIS (Netherlands)

    Kasse, C.

    2002-01-01

    Periglacial aeolian sand sheets and dunes of the last glacial cover extensive areas of northwest and central Europe. Four sedimentary facies have been described that could be related to fluvio-aeolian and cryogenic processes, moisture content of the depositional surface and surface morphology.

  19. The Alberta oil sands story

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    This report serves as a detailed introduction to the Alberta oil sands and their development. It includes a description of the oil sands deposits, an outline of crude bitumen recovery and upgrading processes, the role of Alberta Energy Company in oil sands development, environmental aspects, manpower requirements for oil sands development, research needs, and further oil sands projects. Presently proven recoverable reserves in the oil sands amount to 26.5 billion bbl of synthetic crude. Production from the Syncrude plant (125,000 bbl/d capacity) is expected to begin in 1977, followed by a Shell Canada operation around 1980. The provincial government will participate in the oil sand industry through its joint venture participation in Syncrude and its 50% share in Alberta Energy Company; the latter company participates in related aspects of the Syncrude project, such as pipelines. The result of Alberta's participation in the industry will mean that, directly or indirectly, the province will realize 60% of the total profits. The job creation potential of oil sands projects is estimated to be extensive, with a direct and indirect work force supported by oil sands activities possibly reaching 180,000 persons by the year 2000. Research needs have been identified, particularly in the area of in-situ thermal recovery technology, and the creation of the Alberta Oil Sands Technology and Research Authority has been authorized in order to meet these needs. Although current reserves are sufficient to support 20-30 synthetic crude plants, a number of factors will limit expansion of the industry. 8 figs., 5 tabs.

  20. Sand consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Spain, H H

    1965-01-21

    In a sand consolidation method in which there is injected a mixture of resin-forming liquids comprising an aryl-hydroxy low molecular weight compound, a water- soluble aldehyde, and a catalyst, an improvement is claimed which comprises diluting the resin-forming liquids with a diluent and with water so that the yield of the resin is sufficient to consolidate the sand particles with the minimum desirable pressure. The diluent may be mutually soluble in water and in the resin-forming liquids, and does not affect the setting time of the polymer. The aldehyde and the aryl-hydroxy compound may be in ratio of 5:1, and the diluent, methyl alcohol, is present in a ratio of 2:1 with reference to the water.

  1. The Holocene evolution of the beach and inland aeolian sand of the north-central Mediterranean coast of Israel

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Bookman, Revital; Shteinberg, Gilad

    2015-04-01

    Israel's coastal geomorphology, situated within a Mediterranean climate zone, is characterized by parallel Pleistocene aeolianite ridges, coastal cliffs of aeolianite, and sandy beaches. Lobe-like fields of predominantly stable transverse and parabolic quartz sand dunes protrude 2-7 km inland from the current Mediterranean Sea coastline. However, their migration and accumulation history is still not well-defined. This study focuses on the Holocene appearance, chronology and drivers of beach sand deposition and inland aeolian sand transport along the Caesarea-Hadera dunefield in the north-central coastal plain of Israel. In order to achieve these goals, a detailed field survey and sampling campaign was carried out along a west-east and southwest-northeast transect, loyal to the advancement orientations of the currently stable dunes and directions of dominant sand transporting winds. Beach sand, a foredune, a linear dune, and interdunes of parabolic and transverse dunes were sampled down to their aeolianite or red loam (locally named hamra) palaeosol substrate by drilling and analyzing exposed sections. The sampled sediments were sedimentologically analyzed and twenty-five were dated by optically stimulated luminescence (OSL). The results indicate that beach sand started to accumulate rapidly around 6 ka probably in response to global sea level stabilization. Until around 4 ka, thin sand sheets encroached 2-3 km inland. Sand ages in the range of 1.2-1.1 ka (8th-9th century CE -- Early Moslem period) were found throughout the study area, suggesting a major mobilization of sand, followed by stabilization around 0.6 ka and pedogenesis. By 1.2 ka, the sands had reached their current extent of 5-7 km inland, suggesting transport in a southwest-northeast orientation similar to the advancement orientation of the current transverse and parabolic dunes. The particle-size distributions of the fine to medium-sized aeolian sand showed minor variation linked to inland transport

  2. Mineral sands

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper presents an outlook of the Australian mineral sand industry and covers the major operators. It is shown that conscious of an environmentally minded public, the Australian miners have led the way in the rehabilitation of mined areas. Moreover the advanced ceramic industry is generating exciting new perspectives for zircon producers and there is a noticeable growth in the electronic market for rare earths, but in long term the success may depend as much on environmental management and communication skills as on mining and processing skills

  3. The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-04-01

    Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.

  4. Mineralogical characterization of beach sand minerals: traditional and modern approaches

    International Nuclear Information System (INIS)

    Krishnamurthy, P.

    2016-01-01

    Precise identification of beach sand minerals is an essential prerequisite for the reserve estimation of a given deposit and also in the subsequent evaluation of the process flow sheet for its optimal recovery. Traditional methods that are used for the identification of the beach sand minerals such as magnetite, hematite, ilmenite, rutile, anatase, zircon, garnet, sillimanite, monazite, quartz and others include heavy liquid separation (bromoform and methylene iodide) and studying the optical properties of the grains from different fractions so as to identify the specific phases in a sample. Grain counting of specific minerals from a given sievefraction under a petrological microscope to estimate the mode and their subsequent conversion in to weight percent fractions forms the critical second stage that is followed by the reserve estimates. These methodologies are tedious and time consuming often involving a few days for a single sample. The paper introduces the numerous instrumental methods (XRF, XRD - Rietveld and CCSEM) of mineral speciation and their qualification in with case studies from the west coast deposits in India

  5. Decontamination sheet

    International Nuclear Information System (INIS)

    Hirose, Emiko; Kanesaki, Ken.

    1995-01-01

    The decontamination sheet of the present invention is formed by applying an adhesive on one surface of a polymer sheet and releasably appending a plurality of curing sheets. In addition, perforated lines are formed on the sheet, and a decontaminating agent is incorporated in the adhesive. This can reduce the number of curing operation steps when a plurality steps of operations for radiation decontamination equipments are performed, and further, the amount of wastes of the cured sheets, and operator's exposure are reduced, as well as an efficiency of the curing operation can be improved, and propagation of contamination can be prevented. (T.M.)

  6. Technology unlocks tar sands energy

    Energy Technology Data Exchange (ETDEWEB)

    Law, C

    1967-09-25

    Tar sand processing technology has been developed primarily in the categories of extraction techniques and in-situ processing. In October, a $235 million venture into tar sand processing will be inspected by visitors from many points on the globe. A synthetic crude of premium quality will be flowing through a 16-in. pipeline from the Tar Island plant site of Great Canadian Oil Sands to Edmonton. This processing plant uses an extractive mining technique. The tar sand pay zone in this area averages approximately 150 ft in thickness with a 50-ft overburden. It has been estimated that the tar sands cannot be exploited when the formation thickness is less than 100 ft and overburden exceeds the same amount. This indicates that extraction techniques can only be used to recover approximately 15% of the tar sand deposits. An in-situ recovery technique developed by Shell of Canada is discussed in detail. In essence it is selective hydraulic fracturing, followed by the injection of emulsifying chemicals and steam.

  7. Sulfate-rich eolian and wet interdune deposits, erebus crater, meridiani Planum, Mars

    Science.gov (United States)

    Metz, J.M.; Grotzinger, J.P.; Rubin, D.M.; Lewis, K.W.; Squyres, S. W.; Bell, J.F.

    2009-01-01

    This study investigates three bedrock exposures at Erebus crater, an ?? 300 m diameter crater approximately 4 km south of Endurance crater on Mars. These outcrops, called Olympia, Payson, and Yavapai, provide additional evidence in support of the dune-interdune model proposed for the formation of the deposits at the Opportunity landing site in Meridiani Planum. There is evidence for greater involvement of liquid water in the Olympia outcrop exposures than was observed in Eagle or Endurance craters. The Olympia outcrop likely formed in a wet interdune and sand sheet environment. The facies observed within the Payson outcrop, which is likely stratigraphically above the Olympia outcrop, indicate that it was deposited in a damp-wet interdune, sand sheet, and eolian dune environment. The Yavapai outcrop, which likely stratigraphically overlies the Payson outcrop, indicates that it was deposited in primarily a sand sheet environment and also potentially in an eolian dune environment. These three outcrop exposures may indicate an overall drying-upward trend spanning the stratigraphic section from its base at the Olympia outcrop to its top at the Yavapai outcrop. This contrasts with the wetting-upward trend seen in Endurance and Eagle craters. Thus, the series of outcrops seen at Meridiani by Opportunity may constitute a full climatic cycle, evolving from dry to wet to dry conditions. ?? 2009, SEPM (Society for Sedimentary Geology).

  8. Riddle of the sands

    Energy Technology Data Exchange (ETDEWEB)

    Rolheiser, P

    1998-09-01

    A geological model of the Alberta landscape during the period stretching from about 110 million to 100 million years ago during the Cretaceous period when dinosaurs roamed the earth, was sketched. Today, the region contains the Cold Lake oil sands deposit. Imperial Oil began large-scale production at Cold Lake in 1985. The formations within the area are the source of almost half of Imperial Oil`s daily crude oil production and account for one in every 20 barrels of oil produced daily in Canada. The bitumen is produced using cyclic steam stimulation where steam is injected at high pressure into the underground reservoir, fracturing the sandstone and heating the bitumen it holds to thin it so that it can then flow through well bores to the surface. Conventional geological theory suggested that the Cold Lake reservoir was the remains of a prehistoric river delta. In 1994, Imperial Oil established a Cold Lake sequence stratigraphy project to verify this theory. This highly complex project involves volumes of geophysical well-log data from the 2,500 wells at Cold Lake, core samples cut from more than 600 of these wells and microscopic fossilized remains of 100-million-year-old flora extracted from the core samples, and seismic information. The interpreted data helps to create a three-dimensional model of the reservoir`s structure and help define its boundaries. Results have shown that the Cold Lake deposit was created from at least 13 intersecting river beds. Each of the rivers flowed for a few hundred thousand years and deposited sands of varying quality in different layers and patterns. The oil came about 40 million years later after the plant and animal materials containing hydrogen and carbon were broken down by heat and pressure to form oil. 1 fig.

  9. Field test on sand compaction pile method with copper slag sand; Dosuisai slag wo mochiita SCP koho no shiken seko

    Energy Technology Data Exchange (ETDEWEB)

    Minami, K.; Matsui, H.; Naruse, E.; Kitazume, M. [Port and Harbour Research Inst., Kanagawa (Japan)

    1997-09-20

    This paper describes the sand compaction pile (SCP) method using copper slag sand. The SCP method is a method by which sand compaction piles are constructed in the ground, and improvement can be obtained in a short period. This method has been widely used even in the port areas for enhancing the bearing power of soft clay ground and the lateral resistance of sheet pile. A great deal of sand is required as a material. The sand requires high permeability, proper size distribution with less fine particle fraction content, easy compaction property with enough strength, and easy discharging property from the casing of construction machines as required properties. Recently, it becomes hard to secure proper sand materials. The copper slag sand is obtained from refining process of copper as a by-product which is quenched in water flow and crushed in water. The copper slag sand has higher particle density than that of sand, excellent permeability, and similar size distribution to that of sand. From compaction drainage triaxial compression test and permeability test, it was found that the mechanical properties of copper slag sand did not change by the crushing of grains with keeping excellent permeability. Through the test construction, applicability of the copper slag sand to the SCP method could be confirmed as an alternate material of sand. 17 refs., 9 figs., 4 tabs.

  10. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    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).

  11. Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Haider Abbas Khwaja

    2015-08-01

    Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

  12. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    A model is presented of the development of the size distribution of sand while it is transported from a source to a deposit. The model provides a possible explanation of the log-hyperbolic shape that is frequently found in unimodal grain size distributions in natural sand deposits, as pointed out......-distribution, by taking into account that individual grains do not have the same travel time from the source to the deposit. The travel time is assumed to be random so that the wear on the individual grains vary randomly. The model provides an interpretation of the parameters of the NIG-distribution, and relates the mean...

  13. Changes in active eolian sand at northern Coachella Valley, California

    Science.gov (United States)

    Katra, Itzhak; Scheidt, Stephen; Lancaster, Nicholas

    2009-04-01

    Climate variability and rapid urbanization have influenced the sand environments in the northern Coachella Valley throughout the late 20th century. This paper addresses changes in the spatial relationships among different sand deposits at northern Coachella Valley between two recent time periods by using satellite data acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The approach employed here, involving multispectral thermal infrared (TIR) data and spectral mixture analysis, has shown that the major sand deposits can be spatially modeled at northern Coachella Valley. The "coarse-grained (quartz-rich) sand" deposit is associated with active eolian sand, and the "mixed sandy soil" and "fine-grained (quartz-rich) sand" deposits are associated with inactive eolian sand. The fractional abundance images showed a significant decrease between 2000 and 2006 in the percentage of active sand in the major depositional area for fluvial sediment, the Whitewater River, but also in two downwind areas: the Whitewater and Willow Hole Reserves. The pattern of the active sand appears to be related to variations in annual precipitation (wet and dry years) and river discharge in the northern Coachella Valley. We suggest here that recent human modifications to the major watercourses that supply sand affect the capability of fluvial deposition areas to restore sediments over time and consequently the responses of the sand transport system to climate change, becoming more sensitive to dry years where areas of active sand may shrink, degrade, and/or stabilize faster. The approach utilized in this study can be advantageous for future monitoring of sand in the northern Coachella Valley for management of these and similar environments.

  14. Empirical correlations to estimate agglomerate size and deposition during injection of a polyelectrolyte-modified Fe0 nanoparticle at high particle concentration in saturated sand.

    Science.gov (United States)

    Phenrat, Tanapon; Kim, Hye-Jin; Fagerlund, Fritjof; Illangasekare, Tissa; Lowry, Gregory V

    2010-11-25

    Controlled emplacement of polyelectrolyte-modified nanoscale zerovalent iron (NZVI) particles at high particle concentration (1-10 g/L) is needed for effective in situ subsurface remediation using NZVI. Deep bed filtration theory cannot be used to estimate the transport and deposition of concentrated polyelectrolyte-modified NZVI dispersions (>0.03 g/L) because particles agglomerate during transport which violates a fundamental assumption of the theory. Here we develop two empirical correlations for estimating the deposition and transport of concentrated polyelectrolyte-modified NZVI dispersions in saturated porous media when NZVI agglomeration in porous media is assumed to reach steady state quickly. The first correlation determines the apparent stable agglomerate size formed during NZVI transport in porous media for a fixed hydrogeochemical condition. The second correlation estimates the attachment efficiency (sticking coefficient) of the stable agglomerates. Both correlations are described using dimensionless numbers derived from parameters affecting deposition and agglomeration in porous media. The exponents for the dimensionless numbers are determined from statistical analysis of breakthrough data for polyelectrolyte-modified NZVI dispersions collected in laboratory scale column experiments for a range of ionic strength (1, 10, and 50mM Na(+) and 0.25, 1, and 1.25 mM Ca(2+)), approach velocity (0.8 to 55 × 10(-4)m/s), average collector sizes (d(50)=99 μm, 300 μm, and 880 μm), and polyelectrolyte surface modifier properties. Attachment efficiency depended on approach velocity and was inversely related to collector size, which is contrary to that predicted from classic filtration models. High ionic strength, the presence of divalent cations, lower extended adsorbed polyelectrolyte layer thickness, decreased approach velocity, and a larger collector size promoted NZVI agglomeration and deposition and thus limited its mobility in porous media. These effects

  15. Characteristics of a sandy depositional lobe on the outer Mississippi fan from SeaMARC IA sidescan sonar images

    Science.gov (United States)

    Twichell, David C.; Schwab, William C.; Nelson, C. Hans; Kenyon, Neil H.; Lee, Homa J.

    1992-01-01

    SeaMARC IA sidescan sonar images of the distal reaches of a depositional lobe on the Mississippi Fan show that channelized rather than unconfined transport was the dominant transport mechanism for coarse-grained sediment during the formation of this part of the deep-sea fan. Overbank sheet flow of sands was not an important process in the transport and deposition of the sandy and silty sediment found on this fan. The dendritic distributary pattern and the high order of splaying of the channels, only one of which appears to have been active at a time, suggest that coarse-grained deposits on this fan are laterally discontinuous.

  16. Phase lags in oscillatory sheet flow: experiments and bed load modelling

    NARCIS (Netherlands)

    Dohmen-Janssen, Catarine M.; Kroekenstoel, D.F.; Kroekenstoel, D.F.; Hassan, Wael; Ribberink, Jan S.

    2002-01-01

    Sheet flow corresponds to the high velocity regime when small bed ripples are washed out and sand is transported in a thin layer close to the bed. Therefore, it is often assumed that sand transport in oscillatory sheet flow behaves quasi-steady: time-dependent transport rates are assumed to be

  17. Japan's involvement in oil sands development

    International Nuclear Information System (INIS)

    Sugiura, T.

    1994-01-01

    According to Japanese national policy, exploration and development by Japanese companies in overseas countries are promoted in order to ensure stable oil supplies. Japan Canada Oil Sands Limited (JACOS), part of the JAPEX group, was established during the 1978 world oil crisis to explore and develop Canadian oil sand resources in accordance with Japan's national policy. The JAPEX group, including JACOS, has invested $123 million in oil sands projects in Alberta. JAPEX's first involvement in oil sands was in the Primrose Project operated by Norcen in the Cold Lake area. Five years of cyclic steam stimulation pilot tests did not produce sufficiently good results to justify further operation. The second involvement was the PCEJ Project, a joint effort by four companies that are participating in a bitumen recovery test project in the Athabasca Deposit. JACOS holds 2,452 km 2 of oil sands leases in Alberta. Tests conducted since 1978 in the PCEJ Project include multiwell steam injection pilot tests, some of which showed promise. JACOS is also participating in steam assisted gravity drainage projects and in federal/provincial research programs. Obstacles identified in developing Alberta oil sands are the lack of a bitumen pipeline to Edmonton and the insufficient length of oil sands leases (currently 10 years), given the difficulties of oil sand development. 10 figs

  18. Description of extreme-wave deposits on the northern coast of Bonaire, Netherlands Antilles

    Science.gov (United States)

    Watt, Steven G.; Jaffe, Bruce E.; Morton, Robert A.; Richmond, Bruce M.; Gelfencaum, Guy

    2010-01-01

    To develop a better understanding of the origins of extreme-wave deposits and to help assess the potential risk of future overwash events, a field mapping survey was conducted in November 2006 on the northern coast of Bonaire, Netherlands Antilles. Deposits were mapped and analyzed to help develop a systematic sedimentological approach to distinguish the type of extreme-wave event (tsunamis or storms) or combination of events that formed and modified the deposits over time. Extreme-wave deposits on the northern coast of Bonaire between Boka Onima and Boka Olivia have formed sand sheets, poly-modal ridge complexes, and boulder fields on a Pleistocene limestone platform 3?8 meters above sea level. The deposits exhibit characteristics that are consistent with both large storm and tsunami processes that often overlap one another. Sand sheets occur as low-relief features underlying and incorporated with boulder field deposits. The seaward edge of ridge complexes are deposited up to 70 m from the shoreline and can extend over 200 m inland. Over 600 clasts were measured in fields and range in size from coarse gravel to fine block, weigh up to 165 metric tons, and are placed over 280 m from the shoreline. Our analyses indicate that the deposits may have been produced by a combination of hurricane and tsunami events spanning 10s to 1000s of years. Comparing the different deposit morphologies between study sites highlights the importance of shoreline orientation to the distribution of extreme-wave deposits onshore. However, further investigation is required to fully understand the processes that have produced and modified these deposits over time.

  19. Comparative properties of ceramic-based roofing sheets from local ...

    African Journals Online (AJOL)

    Ceramic roofing sheets were fabricated in the laboratory by using ideal raw materials. The fabricating materials are coiled coconut fibre, palm fruit fibre, fresh water, river sand, polymeric dust, saw dust and cement. The resulting product was compared with factory -produced ceramic-based roofing sheets that are easily ...

  20. Modern sedimentary facies, depositional environments, and major controlling processes on an arid siliciclastic coast, Al qahmah, SE Red Sea, Saudi Arabia

    Science.gov (United States)

    Nabhan, Abdullah I.; Yang, Wan

    2018-04-01

    The facies and environments along the arid siliciclastic coast of Red Sea in Al Qahmah, Saudi Arabia are studied to establish a depositional model for interpretation of ancient rocks deposited in rift settings. Field and petrographic studies of 151 sediment samples in an area of 20 km2 define seven main facies types: beach, washover fan, tidal channel, dune, sabkha, delta, and wadi (seasonal stream). The wadi and delta facies are composed of poorly to moderately well-sorted, gravelly, medium-to-fine sands. Delta-front sands are redistributed by southward longshore currents to form a beach. Beach facies is composed of well-to-moderately sorted fine sands with minor gravels, which contain high concentrations of magnetite, ilmenite, garnet, pyroxene, amphibole, epidote, titanite, and apatite grains, indicating strong winnowing. Crabs and other burrowers destroy primary sedimentary structures and mix sediments in foreshore and backshore of the beaches. Wind and storm surge rework foreshore and backshore sediments to form washover fans. Sabkha facies occurs extensively in supratidal depressions behind beach, are flooded by rainstorms and spring tide, and capped by a 5-cm-thick crust composed of interlaminated halite, quartz, albite, minor gypsum and biotite, and rarely calcium carbonate. Halite occurs as thin sheets and gypsum as nodules with a chicken-wire structure. Clastic fraction in sabkha sediments ranges from coarse silt to coarse sand with moderate sorting, and is transported by currents and wind. Tidal inlets and tidal creeks assume abandoned wadis and are filled by muddy sand. Sand dunes and sand sheets are 1-7 m high and widely distributed due to variable wind directions. Fine-grained dune sands are moderately well sorted, whereas sheet sands are coarser and poorly sorted due to vegetation baffling. Most eolian sands are sourced from beach deposits. This suite of complex riverine, wave, tidal, wind, chemical, and biological processes form the facies mosaic

  1. Eastern Scheldt Sand, Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

    The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...... will described. In this connection, the procedure for preparation of the soil specimens will be presented, and the actual performance of the tests will be briefly outlined. Finally, the procedure for processing of the measurements from the laboratory in order to obtain usable data will be described. The final...

  2. Geophysical mapping of the occurrence of shallow oil sands in ...

    African Journals Online (AJOL)

    Oil sands are known to be an alternate source of energy and of great economic value. To map the occurrence of shallow oil sand deposits in Idiopopo, Okitipupa area in Ondo state southwestern Nigeria, vertical electric sounding (VES) in 11 stations along 3 profiles were carried out using the Schlumberger configuration.

  3. Provenance of Coastal dune sands along Red Sea, Egypt

    Indian Academy of Sciences (India)

    26

    accumulation of sands behind vegetation or any other obstacles. ... The study areas Safaga (SF) and Quseir (QS) field dunes (Fig. 1) ..... coastal dune sands were deposited in a passive margin of a synrift .... Sed Petrol 63(6), 1110-1117.

  4. Archaen to Recent aeolian sand systems and their sedimentary record

    DEFF Research Database (Denmark)

    Rodríguez-López, Juan Pedro; Clemmensen, Lars B; Lancaster, Nick

    2014-01-01

    The sedimentary record of aeolian sand systems extends from the Archean to the Quaternary, yet current understanding of aeolian sedimentary processes and product remains limited. Most preserved aeolian successions represent inland sand-sea or dunefield (erg) deposits, whereas coastal systems are ...

  5. Selected Hydrologic Data for Sand Cove Wash, Washington County, Utah

    National Research Council Canada - National Science Library

    Norton, Aaron; Susong, David D

    2004-01-01

    .... Hydrologic data collected in this study are described and listed in this report. Six boreholes were drilled in Sand Cove Wash to determine the vertical and spatial distribution of the alluvial deposits and their hydrologic...

  6. Investigation into the Origin and Character of Surficial Sedimentary Deposits at the Midshore Regional Solid Waste Facility near Easton, Maryland

    Science.gov (United States)

    Smoot, Joseph P.; Newell, Wayne L.; DeJong, Benjamin D.

    2009-01-01

    A temporary exposure at the Midshore Regional Solid Waste Facility near Easton, MD, provided an opportunity to document the characteristics of the complex assemblage of surficial facies in that area. This unusually large cross section allowed interpretation of the changing processes that shaped the landscape in response to climate change through the late Pleistocene. Eight stratigraphic units were recognized: (1) gray, fossiliferous, muddy silt of the marine Miocene Choptank Formation; (2) coarse, crossbedded conglomerate of the late Miocene to Pliocene fluvial Pensauken Formation; (3) bioturbated muddy conglomerate interpreted as deposits of small colluvial fans; (4) pebbly, quartzose sand overlying a planar erosional surface reflecting a marine transgression; (5) irregular pods and lenses of sand and gravel deformed into bowl-shaped folds and faulted, which are interpreted as wind deposits over a semipermanent snow cover (niveo-aeolian deposits); (6) crossbedded sand and conglomerate with abundant mud partings indicating tidal influences on sinuous stream channels; (7) heavily bioturbated silt and sand with abundant root casts and flattened vesicles interpreted as aeolian loess deposits in marshy fens; and (8) pebbly sand and mud with scattered boulders and cobbles that reflect modern infill of the excavation by the operators. Soils formed on units 3, 4, and 7. Superimposed on units 4, 5, and 7 is evidence of deep freezing and permafrost development and subsequent thermokarst development after thawing, which includes large, complexly filled wedge-shaped cracks, deformed bedding and faults, fluid-injection structures, and spherical blobs of sand and mud. Each of the stratigraphic units has irregular distributions and lateral changes. The results of this study provide a unique insight into the geometry of surficial deposits that will help facilitate mapping of units, interpretation of cored intervals, and understanding of ground-penetrating radar profiles. The

  7. An investigation of waste foundry sand in asphalt concrete mixtures.

    Science.gov (United States)

    Bakis, Recep; Koyuncu, Hakan; Demirbas, Ayhan

    2006-06-01

    A laboratory study regarding the reuse of waste foundry sand in asphalt concrete production by replacing a certain portion of aggregate with WFS was undertaken. The results showed that replacement of 10% aggregates with waste foundry sand was found to be the most suitable for asphalt concrete mixtures. Furthermore, the chemical and physical properties of waste foundry sand were analysed in the laboratory to determine the potential effect on the environment. The results indicated that the investigated waste foundry sand did not significantly affect the environment around the deposition

  8. Sustainable use of oil sands for geotechnical construction and road building

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2012-02-01

    Full Text Available Oil sands are natural deposits of bituminous sand materials that are mined and processed for crude oil. They are routinely used in oil sand fields for building temporary and sometimes permanent roads serving mining and hauling activities. Although...

  9. Characterization of sand lenses and their role for subsurface transport in low-permeability clay tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K. E.; Nilsson, B.

    2011-01-01

    Glacial sediments dominate large parts of the geological topology in Denmark. They predominantly consist of lowpermeability tills, but fractures and sand-lenses constitute zones of enhanced permeability facilitating preferential flow. This study focuses on characterization of sand deposits with r...... the sand lenses in hydro-geological models to successfully characterize subsurface flow and transport, e.g. for remediation activities....

  10. The extraction of bitumen from western oil sands. Final report, July 1989--September 1993

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-03-01

    Research and development of surface extraction and upgrading processes of western tar sands are described. Research areas included modified hot water, fluidized bed, and rotary kiln pyrolysis of tar sands for extraction of bitumen. Bitumen upgrading included solvent extraction of bitumen, and catalytic hydrotreating of bitumen. Characterization of Utah tar sand deposits is also included.

  11. Oil sands from Sao Paulo State, Brazil and La Brea de Chumpi, Peru: a geologic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kramers, John W [Alberta Research Council, Edmonton, AB (Canada); Santos, Paulo R. dos [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Gianello, Pedro T [Petroleos del Peru, Lima (Peru)

    1987-12-31

    This work describes two `non-conventional` oil sands occurrences in Peru and Brazil. The study of such occurrences has pointed out the fact that oil sands are found in widely varying geological situations and that not all oil sands have origins similar to the supergiant `conventional` deposits in Canada and Venezuela. 3 refs., 9 figs.

  12. Influence green sand system by core sand additions

    Directory of Open Access Journals (Sweden)

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  13. Tailings dewatering in the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Longo, S.; Labelle, M. [Golder Paste Technology, Sudbury, ON (Canada); Wislesky, I. [Golder Associates Ltd., Calgary, AB (Canada)

    2010-07-01

    Alberta's Directive 074 was established to reduce fluid tailings produced during oil sands extraction processes. This PowerPoint presentation examined some of the dewatering strategies available for oil sands operators and provided recommendations for implementing a dewatering plan. Sites must be evaluated in order to determine their chemistry, mineralogy, and the total quantity of material to be handled. The availability of potential additives must also be considered. Process technologies must be selected in relation to the operator's depositional strategy. Each site will require its own unique dewatering and depositional strategy. Dewatering technologies include thickening; in-line flocculation; centrifuge; co-mingling; and various new technologies such as electro-osmosis. Laboratory testing programs include index tests, primary stream thickening, and mini-pilot plant testing. The performance of various testing formats was evaluated. Thickening and depositional techniques were reviewed. tabs., figs.

  14. Singing Sand Dunes

    Indian Academy of Sciences (India)

    ble low-frequency (s. 75–105 Hz), that can some- times be heard up to 10 km away. Scientific in- vestigations suggest that the sustained low fre- quency sound of sand dunes that resembles a pure note from a musical instrument, is due to the synchronized motion of well-sorted dry sand grains when they spontaneously ...

  15. Policy Analysis of the Canadian Oil Sands Experience

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. A Dual Role of Graphene Oxide Sheet Deposition on Titanate Nanowire Scaffolds for Osteo-implantation: Mechanical Hardener and Surface Activity Regulator

    Science.gov (United States)

    Dong, Wenjun; Hou, Lijuan; Li, Tingting; Gong, Ziqiang; Huang, Huandi; Wang, Ge; Chen, Xiaobo; Li, Xiaoyun

    2015-12-01

    Scaffold biomaterials with open pores and channels are favourable for cell growth and tissue regeneration, however the inherent poor mechanical strength and low surface activity limit their applications as load-bearing bone grafts with satisfactory osseointegration. In this study, macro-porous graphene oxide (GO) modified titanate nanowire scaffolds with desirable surface chemistry and tunable mechanical properties were prepared through a simple hydrothermal process followed by electrochemical deposition of GO nanosheets. The interconnected and porous structure of the GO/titanate nanowire scaffolds provides a large surface area for cellular attachment and migration and displays a high compressive strength of approximately 81.1 MPa and a tunable Young’s modulus over the range of 12.4-41.0 GPa, which satisfies site-specific requirements for implantation. Surface chemistry of the scaffolds was modulated by the introduction of GO, which endows the scaffolds flexibility in attaching and patterning bioactive groups (such as -OH, -COOH and -NH2). In vitro cell culture tests suggest that the GO/titanate nanowire scaffolds act as a promising biomaterial candidate, in particular the one terminated with -OH groups, which demonstrates improved cell viability, and proliferation, differentiation and osteogenic activities.

  17. New generation expandable sand screens

    OpenAIRE

    Syltøy, Christer

    2014-01-01

    Master's thesis in Petroleum engineering This thesis aims to give a general insight into sand control and various sorts of sand control measures and applications of sand control tools. Special focus will be given to expandable sand screens – a technology which came about in the late 1990’s through the use of flexible, expandable tubulars as base pipe in sand screens. More specifically Darcy’s Hydraulic Endurance Screens, a compliant sand screen system using hydraulic activation, and the fu...

  18. Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004

    Science.gov (United States)

    Nentwig, Vanessa; Bahlburg, Heinrich; Monthy, Devis

    2015-03-01

    The Seychelles, an archipelago in the Indian Ocean at a distance of 4,500-5,000 km from the west coast of Sumatra, were severely affected by the December 26, 2004 tsunami with wave heights up to 4 m. Since the tsunami history of small islands often remains unclear due to a young historical record, it is important to study the geological traces of high energy events preserved along their coasts. We conducted a survey of the impact of the 2004 Indian Ocean tsunami on the inner Seychelles islands. In detail we studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond in the Curieuse Marine National Park on the east coast of Curieuse Island. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami in 2004 by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap and assuring a low energetic hydrodynamic environment for the protection of the mangroves. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The tsunami caused a change of habitat by the sedimentation of sand lobes in the mangrove forest. The dark organic rich mangrove soil (1.9 Φ) was covered by bimodal fine to medium carbonate sand (1.7-2.2 Φ) containing coarser carbonate shell fragments and debris. Intertidal sediments and the mangrove soil acted as sources of the lobe deposits. The sand sheet deposited by the tsunami is organized into different lobes. They extend landwards to different inundation distances as a function of the morphology of the onshore area. The maximum extent of 180 m from the shoreline indicates the minimum inundation distance to the tsunami. The top parts of the sand lobes cover the pneumatophores of the mangroves. There is no landward fining trend along the sand lobes and normal grading of the deposits is rare, occurring only in 1 of 7 sites. The sand lobe deposits also lack sedimentary structures. On the surface of the sand lobes numerous mostly fragmented shells of bivalves and

  19. Numerical simulation of wind-sand movement in the reversed flow region of a sand dune with a bridge built downstream.

    Science.gov (United States)

    He, Wei; Huang, Ning; Xu, Bin; Wang, Wenbo

    2018-04-23

    A bridge built inside the reversed flow region of a sand dune will change the characteristics of wind-sand movement in this region. The Reynolds-averaged Navier-Stokes simulation and discrete particle tracing are used to simulate the wind-sand movement around a sand dune with a bridge built inside the reversed region. Three cases with different bridge positions are studied. The results show that 1) compared with the isolated dune case, a tall bridge built at the leeward toe leads to an increase in the deposition rate on the leeward slope and a longer reversed flow region downstream of the sand dune; meanwhile, the high speed of crosswind on the bridge indicates that some measures should be taken to protect trains from strong crosswind; 2) a low bridge at the leeward toe has little effect on the sand deposition and reversed flow region of the dune; however, low sand transport rate and crosswind speed on the bridge show that anti-crosswind/sand measures should be taken according to the actual situation and 3) a low bridge on the leeward slope has little effect on the length of reversed flow region, however, high crosswind speed and sand flux on the bridge reveal the need of anti-crosswind/sand measures on the bridge. Moreover, the bridges in the reversed flow region increase the sand flux near the leeward crest; as a result, the moving patterns of the sand dune are changed.

  20. Assessment of sand quality on concrete performance : examination of acidic and sulfate/sulfide-bearing sands.

    Science.gov (United States)

    2014-12-01

    The purpose of this research is to examine how the presence of sulfide- and sulfate-containing : minerals in acidic aggregates may affect the properties of mortar and concrete. Analyses were : performed to compare two sands from a deposit in the Geor...

  1. Chlamydia - CDC Fact Sheet

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... sheet Pelvic Inflammatory Disease (PID) – CDC fact sheet Gonorrhea – CDC fact sheet STDs Home Page Bacterial Vaginosis ( ...

  2. Sand and Gravel Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  3. Retorting of bituminous sands

    Energy Technology Data Exchange (ETDEWEB)

    Chaney, P E; Ince, R W; Mason, C M

    1872-09-26

    This method of recovering oil from mined tar sands involves forming compacted tar sands pieces by special conditioning treatment that provides low internal permeability. The compacted pieces are then retorted in fixed bed form. The conditioning treatment can involve rolling of preformed pellets, compaction in a mold or pressure extrusion. Substantial collapsing of the bed during retorting is avoided. (9 claims) (Abstract only - original article not available from T.U.)

  4. GASN sheets

    International Nuclear Information System (INIS)

    2013-12-01

    This document gathers around 50 detailed sheets which describe and present various aspects, data and information related to the nuclear sector or, more generally to energy. The following items are addressed: natural and artificial radioactive environment, evolution of energy needs in the world, radioactive wastes, which energy for France tomorrow, the consequences in France of the Chernobyl accident, ammunitions containing depleted uranium, processing and recycling of used nuclear fuel, transport of radioactive materials, seismic risk for the basic nuclear installations, radon, the precautionary principle, the issue of low doses, the EPR, the greenhouse effect, the Oklo nuclear reactors, ITER on the way towards fusion reactors, simulation and nuclear deterrence, crisis management in the nuclear field, does nuclear research put a break on the development of renewable energies by monopolizing funding, nuclear safety and security, the plutonium, generation IV reactors, comparison of different modes of electricity production, medical exposure to ionizing radiations, the control of nuclear activities, food preservation by ionization, photovoltaic solar collectors, the Polonium 210, the dismantling of nuclear installations, wind energy, desalination and nuclear reactors, from non-communication to transparency about nuclear safety, the Jules Horowitz reactor, CO 2 capture and storage, hydrogen, solar energy, the radium, the subcontractors of maintenance of the nuclear fleet, biomass, internal radio-contamination, epidemiological studies, submarine nuclear propulsion, sea energy, the Three Mile Island accident, the Chernobyl accident, the Fukushima accident, the nuclear after Fukushima

  5. 3D architecture of cyclic-step and antidune deposits in glacigenic subaqueous fan and delta settings: Integrating outcrop and ground-penetrating radar data

    Science.gov (United States)

    Lang, Jörg; Sievers, Julian; Loewer, Markus; Igel, Jan; Winsemann, Jutta

    2017-12-01

    Bedforms related to supercritical flows are increasingly recognised as important constituents of many depositional environments, but outcrop studies are commonly hampered by long bedform wavelengths and complex three-dimensional geometries. We combined outcrop-based facies analysis with ground-penetrating radar (GPR) surveys to analyse the 3D facies architecture of subaqueous ice-contact fan and glacifluvial delta deposits. The studied sedimentary systems were deposited at the margins of the Middle Pleistocene Scandinavian ice sheets in Northern Germany. Glacifluvial Gilbert-type deltas are characterised by steeply dipping foreset beds, comprising cyclic-step deposits, which alternate with antidune deposits. Deposits of cyclic steps consist of lenticular scours infilled by backset cross-stratified pebbly sand and gravel. The GPR sections show that the scour fills form trains along the delta foresets, which can locally be traced for up to 15 m. Perpendicular and oblique to palaeoflow direction, these deposits appear as troughs with concentric or low-angle cross-stratified infills. Downflow transitions from scour fills into sheet-like low-angle cross-stratified or sinusoidally stratified pebbly sand, deposited by antidunes, are common. Cyclic steps and antidunes were deposited by sustained and surge-type supercritical density flows, which were related to hyperpycnal flows, triggered by major meltwater discharge or slope-failure events. Subaqueous ice-contact fan deposits include deposits of progradational scour fills, isolated hydraulic jumps, antidunes and (humpback) dunes. The gravel-rich fan succession consists of vertical stacks of laterally amalgamated pseudo-sheets, indicating deposition by pulses of waning supercritical flows under high aggradation rates. The GPR sections reveal the large-scale architecture of the sand-rich fan succession, which is characterised by lobe elements with basal erosional surfaces associated with scours filled with backsets related

  6. Provenance and recycling of Arabian desert sand

    Science.gov (United States)

    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

  7. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  8. Sedimentology of onshore tsunami deposits of the Indian Ocean tsunami, 2004 in the mangrove forest of the Curieuse Marine National Park, Seychelles

    Science.gov (United States)

    Nentwig, V.; Bahlburg, H.; Monthy, D.

    2012-12-01

    The Seychelles were severely affected by the December 26, 2004 tsunami in the Indian Ocean. Since the tsunami history of small islands often remains unclear due to a young historiography we conducted a study of onshore tsunami deposits on the Seychelles in order to understand the scale of impact of the 2004 Indian Ocean tsunami and potential predecessors. As part of this project we found and studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond bay on the east coast of Curieuse Island. The 2004 Indian Ocean tsunami caused a change of habitat due to sedimentation of an extended sand sheet in the mangrove forest. We present results of the first detailed sedimentological study of onshore tsunami deposits of the 2004 Indian Ocean tsunami conducted on the Seychelles. The Curieuse mangrove forest at Old Turtle Pond bay is part of the Curieuse Marine National Park. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The silt to fine sand sized and organic rich mangrove soil was subsequently covered by carbonate fine to medium sand (1.5 to 2.1 Φ) containing coarser carbonate shell debris which had been trapped outside the mangrove bay before the tsunami. The tsunami deposited a sand sheet which is organized into different lobes. They extend landwards to different inundation distances as a function of morphology. Maximum inundation distance is 200 m. The sediments often cover the pneumatophores of the mangroves. No landward fining trend of the sand sheet has been observed. On the different sand lobes carbonate-cemented sandstone debris ranging in size from 0.5 up to 12 cm occurs. Also numerous mostly fragmented shells of bivalves and molluscs were distributed on top of the sand lobes. Intact bivalve shells were mostly positioned with the convex side upwards

  9. Numerical simulation of flow and compression of green sand

    DEFF Research Database (Denmark)

    Hovad, Emil

    The focus of the industrial PhD project was concentrated on the production of the sand mold (green sand) which gives the cast component its final geometrical shape. In order to ensure a high quality of the cast component, it is important to control the manufacturing process of the mold itself so...... that it is homogeneous and stable. Therefore gaining a basic understanding of how the flow and deposition of green sand should be characterized and modelled was important, so that it could be used for simulation of the manufacturing process of the sand mold. The flowability of the green sand is important when the sand...... flows down through the hopper filling the chamber with sand during the sand shot. The flowability of green sand is mostly governed by the amount of water and bentonite which both decrease it. The flowability and the internal forces thus control how well you can fill a complex mold geom-etry in which...

  10. Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars

    Science.gov (United States)

    Grotzinger, J. P.; Arvidson, R. E.; Bell, J. F.; Calvin, W.; Clark, B. C.; Fike, D. A.; Golombek, M.; Greeley, R.; Haldemann, A.; Herkenhoff, K. E.; Jolliff, B. L.; Knoll, A. H.; Malin, M.; McLennan, S. M.; Parker, T.; Soderblom, L.; Sohl-Dickstein, J. N.; Squyres, S. W.; Tosca, N. J.; Watters, W. A.

    2005-11-01

    Outcrop exposures of sedimentary rocks at the Opportunity landing site (Meridiani Planum) form a set of genetically related strata defined here informally as the Burns formation. This formation can be subdivided into lower, middle, and upper units which, respectively, represent eolian dune, eolian sand sheet, and mixed eolian sand sheet and interdune facies associations. Collectively, these three units are at least 7 m thick and define a "wetting-upward" succession which records a progressive increase in the influence of groundwater and, ultimately, surface water in controlling primary depositional processes. The Burns lower unit is interpreted as a dry dune field (though grain composition indicates an evaporitic source), whose preserved record of large-scale cross-bedded sandstones indicates either superimposed bedforms of variable size or reactivation of lee-side slip faces by episodic (possibly seasonal) changes in wind direction. The boundary between the lower and middle units is a significant eolian deflation surface. This surface is interpreted to record eolian erosion down to the capillary fringe of the water table, where increased resistance to wind-induced erosion was promoted by increased sediment cohesiveness in the capillary fringe. The overlying Burns middle unit is characterized by fine-scale planar-laminated to low-angle-stratified sandstones. These sandstones accumulated during lateral migration of eolian impact ripples over the flat to gently undulating sand sheet surface. In terrestrial settings, sand sheets may form an intermediate environment between dune fields and interdune or playa surfaces. The contact between the middle and upper units of the Burns formation is interpreted as a diagenetic front, where recrystallization in the phreatic or capillary zones may have occurred. The upper unit of the Burns formation contains a mixture of sand sheet facies and interdune facies. Interdune facies include wavy bedding, irregular lamination with

  11. Sand wave fields beneath the Loop Current, Gulf of Mexico: Reworking of fan sands

    Science.gov (United States)

    Kenyon, Neil H.; Akhmetzhanov, A.M.; Twichell, D.C.

    2002-01-01

    Extensive fields of large barchan-like sand waves and longitudinal sand ribbons have been mapped by deep-towed SeaMARC IA sidescan sonar on part of the middle and lower Mississippi Fan that lies in about 3200 m of water. The area is beneath the strongly flowing Loop Current. The bedforms have not been adequately sampled but probably consist of winnowed siliciclastic-foraminiferal sands. The size (about 200 m from wingtip to wingtip) and shape of the large barchans is consistent with a previously observed peak current speed of 30 cm/s, measured 25 m above the seabed. The types of small-scale bedforms and the scoured surfaces of chemical crusts, seen on nearby bottom photographs, indicate that near-bed currents in excess of 30 cm/s may sometimes occur. At the time of the survey the sand transport direction was to the northwest, in the opposite direction to the Loop Current but consistent with there being a deep boundary current along the foot of the Florida Escarpment. Some reworking of the underlying sandy turbidites and debris flow deposits is apparent on the sidescan sonar records. Reworking by deep-sea currents, resulting in erosion and in deposits characterised by coarsening upwards structures and cross-bedding, is a process that has been proposed for sand found in cores in shallower parts of the Gulf of Mexico. This process is more widespread than hitherto supposed. 

  12. In situ recovery of oil from Utah tar sand: a summary of tar sand research at the Laramie Energy Technology Center

    Energy Technology Data Exchange (ETDEWEB)

    Marchant, L.C.; Westhoff, J.D.

    1985-10-01

    This report describes work done by the United States Department of Energy's Laramie Energy Technology Center from 1971 through 1982 to develop technology for future recovery of oil from US tar sands. Work was concentrated on major US tar sand deposits that are found in Utah. Major objectives of the program were as follows: determine the feasibility of in situ recovery methods applied to tar sand deposits; and establish a system for classifying tar sand deposits relative to those characteristics that would affect the design and operation of various in situ recovery processes. Contents of this report include: (1) characterization of Utah tar sand; (2) laboratory extraction studies relative to Utah tar sand in situ methods; (3) geological site evaluation; (4) environmental assessments and water availability; (5) reverse combustion field experiment, TS-1C; (6) a reverse combustion followed by forward combustion field experiment, TS-2C; (7) tar sand permeability enhancement studies; (8) two-well steam injection experiment; (9) in situ steam-flood experiment, TS-1S; (10) design of a tar sand field experiment for air-stream co-injection, TS-4; (11) wastewater treatment and oil analyses; (12) economic evaluation of an in situ tar sand recovery process; and (13) appendix I (extraction studies involving Utah tar sands, surface methods). 70 figs., 68 tabs.

  13. Architectural elements from Lower Proterozoic braid-delta and high-energy tidal flat deposits in the Magaliesberg Formation, Transvaal Supergroup, South Africa

    Science.gov (United States)

    Eriksson, Patrick G.; Reczko, Boris F. F.; Jaco Boshoff, A.; Schreiber, Ute M.; Van der Neut, Markus; Snyman, Carel P.

    1995-06-01

    Three architectural elements are identified in the Lower Proterozoic Magaliesberg Formation (Pretoria Group, Transvaal Supergroup) of the Kaapvaal craton, South Africa: (1) medium- to coarse-grained sandstone sheets; (2) fine- to medium-grained sandstone sheets; and (3) mudrock elements. Both sandstone sheet elements are characterised by horizontal lamination and planar cross-bedding, with lesser trough cross-bedding, channel-fills and wave ripples, as well as minor desiccated mudrock partings, double-crested and flat-topped ripples. Due to the local unimodal palaeocurrent patterns in the medium- to coarse-grained sandstone sheets, they are interpreted as ephemeral braid-delta deposits, which were subjected to minor marine reworking. The predominantly bimodal to polymodal palaeocurrent trends in the fine- to medium-grained sandstone sheets are inferred to reflect high-energy macrotidal processes and more complete reworking of braid-delta sands. The suspension deposits of mudrocks point to either braid-delta channel abandonment, or uppermost tidal flat sedimentation. The depositional model comprises ephemeral braid-delta systems which debouched into a high-energy peritidal environment, around the margins of a shallow epeiric sea on the Kaapvaal craton. Braid-delta and tidal channel dynamics are inferred to have been similar. Fine material in the Magaliesberg Formation peritidal complexes indicates that extensive aeolian removal of clay does not seem applicable to this example of the early Proterozoic.

  14. Sheet-gravel evidence for a late Holocene tsunami run-up on beach dunes, Great Barrier Island, New Zealand

    Science.gov (United States)

    Nichol, Scott L.; Lian, Olav B.; Carter, Charles H.

    2003-01-01

    A semi-continuous sheet of granule to cobble-size clasts forms a distinctive deposit on sand dunes located on a coastal barrier in Whangapoua Bay, Great Barrier Island, New Zealand. The gravel sheet extends from the toe of the foredune to 14.3 m above mean sea level and 200 m landward from the beach. Clasts are rounded to sub-rounded and comprise lithologies consistent with local bedrock. Terrestrial sources for the gravel are considered highly unlikely due to the isolation of the dunes from hillslopes and streams. The only source for the clasts is the nearshore to inner shelf of Whangapoua Bay, where gravel sediments have been previously documented. The mechanism for transport of the gravel is unlikely to be storm surge due to the elevation of the deposit; maximum-recorded storm surge on this coast is 0.8 m above mean high water spring tide. Aeolian processes are also discounted due to the size of clasts and the elevation at which they occur. Tsunami is therefore considered the most probable mechanism for gravel transport. Minimum run-up height of the tsunami was 14.3 m, based on maximum elevation of gravel deposits. Optical ages on dune sands beneath and covering the gravel allow age bracketing to 0-4.7 ka. Within this time frame, numerous documented regional seismic and volcanic events could have generated the tsunami, notably submarine volcanism along the southern Kermadec arc to the east-southeast of Great Barrier Island where large magnitude events are documented for the late Holocene. Radiocarbon ages on shell from Maori middens that appear to have been reworked by tsunami run-up constrain the age of this event to post ca. 1400 AD. Regardless of the precise age of this event, the well-preserved nature of the Whangapoua gravel deposit provides for an improved understanding of the high degree of spatial variability in tsunami run-up.

  15. Sedimentary deposits study of the 2006 Java tsunami, in Pangandaran, West Java (preliminary result)

    Energy Technology Data Exchange (ETDEWEB)

    Maemunah, Imun, E-mail: imun-m2001@yahoo.com [Geological Agency, Ministry of Energy and Mineral Resources (Indonesia); Institute Technology of Bandung (Indonesia); Suparka, Emmy, E-mail: emmy@gc.itb.ac.id; Puspito, Nanang T, E-mail: nanang@staff.itb.ac.id [Institute Technology of Bandung (Indonesia); Hidayati, Sri, E-mail: shidayati@gmail.com [Geological Agency, Ministry of Energy and Mineral Resources (Indonesia)

    2015-04-24

    The 2006 Java Earthquake (Mw 7.2) has generated a tsunami that reached Pangandaran coastal plain with 9.7 m above sea level height of wave. In 2014 we examined the tsunami deposit exposed in shallow trenches along a∼300 m at 5 transect from shoreline to inland on Karapyak and Madasari, Pangandaran. We documented stratigraphically and sedimentologically, the characteristics of Java Tsunami deposit on Karapyak and Madasari and compared both sediments. In local farmland a moderately-sorted, brown soil is buried by a poorly-sorted, grey, medium-grained sand-sheet. The tsunami deposit was distinguished from the underlying soil by a pronounced increase in grain size that becomes finner upwards and landwards. Decreasing concentration of coarse size particles with distance toward inland are in agreement with grain size analysis. The thickest tsunami deposit is about 25 cm found at 84 m from shoreline in Madasari and about 15 cm found at 80 m from shoreline in Karapyak. The thickness of tsunami deposits in some transect become thinner landward but in some other transect lack a consistent suggested strongly affected by local topography. Tsunami deposits at Karapyak and Madasari show many similarities. Both deposits consist of coarse sand that sharply overlies a finer sandy soil. The presence mud drapes and other sedimentary structure like graded bedding, massive beds, mud clasts in many locations shows a dynamics process of tsunami waves. The imbrication coarse and shell fragments of the 2006 Java, tsunami deposits also provide information about the curent direction, allowing us to distinguish run up deposits from backwash deposits.

  16. Sedimentary deposits study of the 2006 Java tsunami, in Pangandaran, West Java (preliminary result)

    International Nuclear Information System (INIS)

    Maemunah, Imun; Suparka, Emmy; Puspito, Nanang T; Hidayati, Sri

    2015-01-01

    The 2006 Java Earthquake (Mw 7.2) has generated a tsunami that reached Pangandaran coastal plain with 9.7 m above sea level height of wave. In 2014 we examined the tsunami deposit exposed in shallow trenches along a∼300 m at 5 transect from shoreline to inland on Karapyak and Madasari, Pangandaran. We documented stratigraphically and sedimentologically, the characteristics of Java Tsunami deposit on Karapyak and Madasari and compared both sediments. In local farmland a moderately-sorted, brown soil is buried by a poorly-sorted, grey, medium-grained sand-sheet. The tsunami deposit was distinguished from the underlying soil by a pronounced increase in grain size that becomes finner upwards and landwards. Decreasing concentration of coarse size particles with distance toward inland are in agreement with grain size analysis. The thickest tsunami deposit is about 25 cm found at 84 m from shoreline in Madasari and about 15 cm found at 80 m from shoreline in Karapyak. The thickness of tsunami deposits in some transect become thinner landward but in some other transect lack a consistent suggested strongly affected by local topography. Tsunami deposits at Karapyak and Madasari show many similarities. Both deposits consist of coarse sand that sharply overlies a finer sandy soil. The presence mud drapes and other sedimentary structure like graded bedding, massive beds, mud clasts in many locations shows a dynamics process of tsunami waves. The imbrication coarse and shell fragments of the 2006 Java, tsunami deposits also provide information about the curent direction, allowing us to distinguish run up deposits from backwash deposits

  17. Oil sands tax expenditures

    International Nuclear Information System (INIS)

    Ketchum, K; Lavigne, R.; Plummer, R.

    2001-01-01

    The oil sands are a strategic Canadian resource for which federal and provincial governments provide financial incentives to develop and exploit. This report describes the Oil Sands Tax Expenditure Model (OSTEM) developed to estimate the size of the federal income tax expenditure attributed to the oil sands industry. Tax expenditures are tax concessions which are used as alternatives to direct government spending for achieving government policy objectives. The OSTEM was developed within the business Income Tax Division of Canada's Department of Finance. Data inputs for the model were obtained from oil sands developers and Natural Resources Canada. OSTEM calculates annual revenues, royalties and federal taxes at project levels using project-level projections of capital investment, operating expenses and production. OSTEM calculates tax expenditures by comparing taxes paid under different tax regimes. The model also estimates the foregone revenue as a percentage of capital investment. Total tax expenditures associated with investment in the oil sands are projected to total $820 million for the period from 1986 to 2030, representing 4.6 per cent of the total investment. 10 refs., 2 tabs., 7 figs

  18. Evaluating process origins of sand-dominated fluvial stratigraphy

    Science.gov (United States)

    Chamberlin, E.; Hajek, E. A.

    2015-12-01

    Sand-dominated fluvial stratigraphy is often interpreted as indicating times of relatively slow subsidence because of the assumption that fine sediment (silt and clay) is reworked or bypassed during periods of low accommodation. However, sand-dominated successions may instead represent proximal, coarse-grained reaches of paleo-river basins and/or fluvial systems with a sandy sediment supply. Differentiating between these cases is critical for accurately interpreting mass-extraction profiles, basin-subsidence rates, and paleo-river avulsion and migration behavior from ancient fluvial deposits. We explore the degree to which sand-rich accumulations reflect supply-driven progradation or accommodation-limited reworking, by re-evaluating the Castlegate Sandstone (Utah, USA) and the upper Williams Fork Formation (Colorado, USA) - two Upper Cretaceous sandy fluvial deposits previously interpreted as having formed during periods of relatively low accommodation. Both units comprise amalgamated channel and bar deposits with minor intra-channel and overbank mudstones. To constrain relative reworking, we quantify the preservation of bar deposits in each unit using detailed facies and channel-deposit mapping, and compare bar-deposit preservation to expected preservation statistics generated with object-based models spanning a range of boundary conditions. To estimate the grain-size distribution of paleo-sediment input, we leverage results of experimental work that shows both bed-material deposits and accumulations on the downstream side of bars ("interbar fines") sample suspended and wash loads of active flows. We measure grain-size distributions of bar deposits and interbar fines to reconstruct the relative sandiness of paleo-sediment supplies for both systems. By using these novel approaches to test whether sand-rich fluvial deposits reflect river systems with accommodation-limited reworking and/or particularly sand-rich sediment loads, we can gain insight into large

  19. Market Discipline and Deposit Insurance

    OpenAIRE

    Peresetsky, Anatoly

    2008-01-01

    The paper examines Russian banks’ household deposit interest rates for the transition period of setting up the deposit insurance system. Monthly observations of Russian banks’ interest rates and balance sheets are used in a fixed effects panel data model. It is shown market discipline has been significantly diminished after switching to the deposit insurance.

  20. Laminin-521 Promotes Rat Bone Marrow Mesenchymal Stem Cell Sheet Formation on Light-Induced Cell Sheet Technology

    Directory of Open Access Journals (Sweden)

    Zhiwei Jiang

    2017-01-01

    Full Text Available Rat bone marrow mesenchymal stem cell sheets (rBMSC sheets are attractive for cell-based tissue engineering. However, methods of culturing rBMSC sheets are critically limited. In order to obtain intact rBMSC sheets, a light-induced cell sheet method was used in this study. TiO2 nanodot films were coated with (TL or without (TN laminin-521. We investigated the effects of laminin-521 on rBMSCs during cell sheet culturing. The fabricated rBMSC sheets were subsequently assessed to study cell sheet viability, reattachment ability, cell sheet thickness, collagen type I deposition, and multilineage potential. The results showed that laminin-521 could promote the formation of rBMSC sheets with good viability under hyperconfluent conditions. Cell sheet thickness increased from an initial 26.7 ± 1.5 μm (day 5 up to 47.7 ± 3.0 μm (day 10. Moreover, rBMSC sheets maintained their potential of osteogenic, adipogenic, and chondrogenic differentiation. This study provides a new strategy to obtain rBMSC sheets using light-induced cell sheet technology.

  1. Sand Dunes with Frost

    Science.gov (United States)

    2004-01-01

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

  2. Sand (CSW4)

    CSIR Research Space (South Africa)

    Estuarine and Coastal Research Unit

    1982-12-01

    Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

  3. Inland drift sand landscapes

    NARCIS (Netherlands)

    Fanta, J.; Siepel, H.

    2010-01-01

    Man has had a complex relationship with inland drift sands through the ages. For some centuries these landscapes were seen as a threat to society, especially agriculture and housing. At present we conserve these landscapes as important Natura 2000 priority habitats. In this book you may find these

  4. Controls on the abruptness of gravel-sand transitions

    Science.gov (United States)

    Venditti, J. G.; Church, M. A.; Lamb, M. P.; Domarad, N.; Rennie, C. D.

    2014-12-01

    As gravel-bedded rivers fine downstream, they characteristically exhibit an abrupt transition from gravel- to sand-bed. This is the only abrupt transition in grain-size that occurs in the fluvial system and has attracted considerable attention. A number of competing theories have been proposed to account for the abruptness of the transition, including base-level control, attrition of ~10mm gravel to produce sand, and sediment sorting processes. The prevailing theory for the emergence of abrupt transitions is size selective sorting of bimodal sediment wherein gravel deposits due to downstream declining shear stress, fining the bedload until a sand-bed emerges. We explored this hypothesis by examining grain-size, shear stress, gravel mobility and sand suspension thresholds through the gravel-sand transition (GST) of the Fraser River, British Columbia. The Fraser GST is an arrested gravel wedge with patches of gravel downstream of the wedge forming a diffuse extension. There is an abrupt change in bed slope through the transition that leads to an abrupt change in shear stress. The GST, bed-slope change and backwater caused by the ocean are all coincident spatially, which enhances the sharpness of the GST. Interestingly, the bimodal reach of the river occurs downstream of the GST and exhibits no downstream gradients in shear stress, suspended sediment flux, gravel mobility or sand suspension thresholds. This calls into question the prevailing theory for the emergence of an abrupt GST by size selective sorting. We provide evidence, both empirical and theoretical, that suggests the emergence of an abrupt GST is caused by rapid deposition of sand when fine gravel deposits. We argue that the emergence of gravel-sand transitions is a consequence of gravel-bedded rivers adopting a steeper slope than sand-bedded rivers. The abruptness arises because the bed slope required to convey the gravel load fixes the distal location of a terminal gravel wedge, and once the river has

  5. Laboratory studies of dune sand for the use of construction industry in Sri Lanka

    Science.gov (United States)

    de Silva Jayawardena, Upali; Wijesuriya, Roshan; Abayaweera, Gayan; Viduranga, Tharaka

    2015-04-01

    With the increase of the annual sand demand for the construction industry the excessive excavation of river sand is becoming a serious environmental problem in Sri Lanka. Therefore, it is necessary to explore the possibility for an alternative to stop or at least to minimize river sand mining activities. Dune sand is one of the available alternative materials to be considered instead of river sand in the country. Large quantities of sand dunes occur mainly along the NW and SE coastal belt which belong to very low rainfall Dry Zone coasts. The height of dune deposits, vary from 1m to about 30 meters above sea level. The objective of this paper is to indicate some studies and facts on the dune sand deposits of Sri Lanka. Laboratory studies were carried out for visual observations and physical properties at the initial stage and then a number of tests were carried out according to ASTM standards to obtain the compressive strength of concrete cylinders and mortar cubes mixing dune sand and river sand in different percentages keeping a constant water cement ratio. Next the water cement ratio was changed for constant dune sand and river sand proportion. Microscopic analysis shows that the dune sand consist of 95 % of quartz and 5 % of garnet, feldspar, illmenite and other heavy minerals with clay, fine dust, fine shell fragments and organic matters. Grains are sub-rounded to angular and tabular shapes. The grain sizes vary from fine to medium size of sand with silt. The degree of sorting and particle size observed with dune sands are more suited with the requirement of fine aggregates in the construction industry. The test result indicates that dune sand could be effectively used in construction work without sieving and it is ideal for wall plastering due to its'-uniformity. It could also be effectively used in concrete and in mortars mixing with river sand. The best mixing ratio is 75% dune sand and 25% river sand as the fine aggregate of concrete. For mortar the mixing

  6. Oil sands to the rescue: oil sand microbial communities can degrade recalcitrant alkyl phenyl alkanoic acids

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, Corinne [University of Essex (Canada)], email: cwhitby@essex.ac.uk

    2011-07-01

    Almost half of all global oil reserves are found as biodegraded heavy oils found in vast tar sand deposits located in North and South America and these account for 47% of Canadian oil production. Oil sand extraction generates large amounts of toxic waste water, known as oil sand process waters (OSPW), that are stored in large tailing ponds that contain toxic compounds like naphthenic acids (NAs). The presence of NAs creates problems like toxicity, corrosion, and the formation of calcium napthenate deposits which block pipelines and other infrastructure and need to be removed. This paper presents oil sand microbial communities that can degrade these NAs. The approach is to apply new aliphatic and aromatic NAs as substrates to supplement and identify NA degrading microbes and also to identify the metabolites produced and explain NA degradation pathways and the functional genes involved. The chemistry and the processes involved are explained. From the results, it is suggested that pure cultures of P. putida KT2440 be used against NAs.

  7. On Pluvial Compaction of Sand

    DEFF Research Database (Denmark)

    Jacobsen, Moust

    At the Institute of Civil Engineering in Aalborg model tests on dry sand specimens have been carried out during the last five years. To reduce deviations in test results, the sand laying technique has been carefully studied, and the sand mass spreader constructed. Preliminary results have been...

  8. Environmental Impacts of Sand Exploitation. Analysis of Sand Market

    Directory of Open Access Journals (Sweden)

    Marius Dan Gavriletea

    2017-06-01

    Full Text Available Sand is an indispensable natural resource for any society. Despite society’s increasing dependence on sand, there are major challenges that this industry needs to deal with: limited sand resources, illegal mining, and environmental impact of sand mining. The purpose of this paper is twofold: to present an overview of the sand market, highlighting the main trends and actors for production, export and import, and to review the main environmental impacts associated with sand exploitation process. Based on these findings, we recommend different measures to be followed to reduce negative impacts. Sand mining should be done in a way that limits environmental damage during exploitation and restores the land after mining operations are completed.

  9. Sand Resources, Regional Geology, and Coastal Processes of the Chandeleur Islands Coastal System: an Evaluation of the Breton National Wildlife Refuge

    Science.gov (United States)

    Lavoie, Dawn

    2009-01-01

    Monkey Bayou at the southern end of the Chandeleur Islands. Numerical simulation of waves and sediment transport supports the geophysical results and indicates that vast areas of the lower shoreface are affected and are undergoing erosion during storm events, that there is little or no fair weather mechanism to rework material into the littoral system, and that as a result, there is a net loss of sediment from the system. Lidar surveys revealed that the island chain immediately after Hurricane Katrina lost about 84 percent of its area and about 92 percent of its prestorm volume. Marsh platforms that supported the islands' sand prior to the storm were reduced in width by more than one-half. Repeated lidar surveys document that in places the shoreline has retreated about 100 m under the relatively low-energy waves since Hurricanes Katrina and Rita; however, this retreat is nonuniform. Recent high-resolution geophysical surveys of the sea floor and subsurface within 5-6 km of the Chandeleur Islands during 2006 and 2007 show that, in addition to the sand that is rebuilding portions of the island chain, a large volume of sand is contained in Hewes Point, in an extensive subtidal spit platform that has formed at the northern end of the Chandeleur Islands. Hewes Point appears to be the depositional terminus of the alongshore transport system. In the southern Chandeleurs, sand is being deposited in a broad tabular deposit near Breton Island called the southern offshore sand sheet. These two depocenters account for approximately 70 percent of the estimated sediment volume located in potential borrow sites. An additional large potential source of sand for restoration lies in the St. Bernard Shoals, which are estimated to contain approximately 200 ? 106 m3 of sand. Successful restoration planning for the Breton National Wildlife Refuge should mimic the natural processes of early stages of barrier island evolution including lateral transport to the flanks of the island chain

  10. Identification of tsunami deposits considering the tsunami waveform: An example of subaqueous tsunami deposits in Holocene shallow bay on southern Boso Peninsula, Central Japan

    Science.gov (United States)

    Fujiwara, Osamu; Kamataki, Takanobu

    2007-08-01

    This study proposes a tsunami depositional model based on observations of emerged Holocene tsunami deposits in outcrops located in eastern Japan. The model is also applicable to the identification of other deposits, such as those laid down by storms. The tsunami deposits described were formed in a small bay of 10-20-m water depth, and are mainly composed of sand and gravel. They show various sedimentary structures, including hummocky cross-stratification (HCS) and inverse and normal grading. Although, individually, the sedimentary structures are similar to those commonly found in storm deposits, the combination of vertical stacking in the tsunami deposits makes a unique pattern. This vertical stacking of internal structures is due to the waveform of the source tsunamis, reflecting: 1) extremely long wavelengths and wave period, and 2) temporal changes of wave sizes from the beginning to end of the tsunamis. The tsunami deposits display many sub-layers with scoured and graded structures. Each sub-layer, especially in sandy facies, is characterized by HCS and inverse and normal grading that are the result of deposition from prolonged high-energy sediment flows. The vertical stack of sub-layers shows incremental deposition from the repeated sediment flows. Mud drapes cover the sub-layers and indicate the existence of flow-velocity stagnant stages between each sediment flow. Current reversals within the sub-layers indicate the repeated occurrence of the up- and return-flows. The tsunami deposits are vertically divided into four depositional units, Tna to Tnd in ascending order, reflecting the temporal change of wave sizes in the tsunami wave trains. Unit Tna is relatively fine-grained and indicative of small tsunami waves during the early stage of the tsunami. Unit Tnb is a protruding coarse-grained and thickest-stratified division and is the result of a relatively large wave group during the middle stage of the tsunami. Unit Tnc is a fine alternation of thin sand

  11. Frac sand in the United States: a geological and industry overview

    Science.gov (United States)

    Benson, Mary Ellen; Wilson, Anna B.; Bleiwas, Donald I.

    2015-01-01

    A new mineral rush is underway in the upper Midwest of the United States, especially in Wisconsin and Minnesota, for deposits of high-quality frac sand that the mining industry calls “Northern White” sand or “Ottawa” sand. Frac sand is a specialized type of sand that is added to fracking fluids that are injected into unconventional oil and gas wells during hydraulic fracturing (fracking or hydrofracking), a process that enhances petroleum extraction from tight (low permeability) reservoirs. Frac sand consists of natural sand grains with strict mineralogical and textural specifications that act as a proppant (keeping induced fractures open), extending the time of release and the flow rate of hydrocarbons from fractured rock surfaces in contact with the wellbore.

  12. Oil sands supply outlook

    International Nuclear Information System (INIS)

    Dunbar, R.

    2004-01-01

    In March 2004, The Canadian Energy Research Institute released a report on the expected future supply from Alberta's oil sands. The report indicates that the future for the already well-established oil sands industry is promising, particularly given the outlook for oil prices. The challenges facing the industry include higher industry supply costs and the need for innovative commercial and technological solutions to address the risks of irregularities and changes in crude oil prices. In 2003, the industry produced 874 thousand barrels per day of synthetic crude oil and unprocessed crude bitumen. This represents 35 per cent of Canada's total oil production. Current production capacity has increased to 1.0 million barrels per day (mbpd) due to new projects. This number may increase to 3.5 mbpd by 2017. Some new projects may be deferred due to the higher raw bitumen and synthetic crude oil supply costs. This presentation provided supply costs for a range of oil sands recovery technologies and production projections under various business scenarios. tabs., figs

  13. Liquefaction resistance of calcareous sands

    International Nuclear Information System (INIS)

    Sandoval Vallejo, Eimar

    2012-01-01

    Calcareous sands are unique in terms of their origin, mineralogy, shape, fragility and intra particle porosity. This article presents results from an experimental program carried out to study the liquefaction resistance of a calcareous sand retrieved from Cabo Rojo at Puerto Rico. The experimental program included mineralogical characterization, index properties, and undrained cyclic triaxial tests on isotropically consolidated reconstituted samples. Due to the large variation in the calcareous sand properties, results are compared with previous researches carried out on other calcareous sands around the world. Results showed a wide range in the liquefaction resistance of the studied calcareous sands. Cabo Rojo sand experienced greater liquefaction resistance than most of the calcareous sands used for comparison. Important differences in the excess pore pressure generation characteristics were also found.

  14. The extraction of bitumen from western oil sands

    International Nuclear Information System (INIS)

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

    1992-08-01

    The University of Utah tar sand research and development program is concerned with research and development on Utah is extensive oil sands deposits. The program has been intended to develop a scientific and technological base required for eventual commercial recovery of the heavy oils from oil sands and processing these oils to produce synthetic crude oil and other products such as asphalt. The overall program is based on mining the oil sand, processing the mined sand to recover the heavy oils and upgrading them to products. Multiple deposits are being investigated since it is believed that a large scale (approximately 20,000 bbl/day) plant would require the use of resources from more than one deposit. The tasks or projects in the program are organized according to the following classification: Recovery technologies which includes thermal recovery methods, water extraction methods, and solvent extraction methods; upgrading and processing technologies which covers hydrotreating, hydrocracking, and hydropyrolysis; solvent extraction; production of specialty products; and environmental aspects of the production and processing technologies. These tasks are covered in this report

  15. The oil sands: A new energy vision for Canada

    International Nuclear Information System (INIS)

    1995-01-01

    Canada's oil sands deposits were considered to offer huge potential for wealth generation and enduring social benefits. This report showed that putting in action the plan developed by the National Task Force on Oil Sands Strategies would help unlock this potential and realize the benefits; the forecast called for a doubling or tripling of oil sands production over the next 25 years. The plan should also predicted an increase in investments in oil sands since the fiscal regime would be stable and the product would be in increasing demand. New capital investment should generate significant environmental, social and economic benefits. The real outcome would be increased national prosperity, since further growth in investment would translate into thousands of skilled jobs across Canada, expansion of government revenues, and improvements to Canada's trade balance. 1 ill

  16. The oil sands: A new energy vision for Canada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    Canada`s oil sands deposits were considered to offer huge potential for wealth generation and enduring social benefits. This report showed that putting in action the plan developed by the National Task Force on Oil Sands Strategies would help unlock this potential and realize the benefits; the forecast called for a doubling or tripling of oil sands production over the next 25 years. The plan should also predicted an increase in investments in oil sands since the fiscal regime would be stable and the product would be in increasing demand. New capital investment should generate significant environmental, social and economic benefits. The real outcome would be increased national prosperity, since further growth in investment would translate into thousands of skilled jobs across Canada, expansion of government revenues, and improvements to Canada`s trade balance. 1 ill.

  17. Morphology and processes associated with the accumulation of the fine-grained sediment deposit on the southern New England shelf

    Science.gov (United States)

    Twichell, David C.; McClennen, Charles E.; Butman, Bradford

    1981-01-01

    A 13,000 km2 area of the southern New England Continental Shelf which is covered by anomalously fine-grained sediment has been surveyed by means of high-resolution, seismic-reflection and side-scan sonar techniques to map its morphology and structure, and a near-bottom instrument system contributed to understanding present activity of the deposit. Seismic-reflection profiles show that the fine-grained deposit, which is as much as 13 m thick, has accumulated during the last transgression because it rests on a reflector that is geomorphically similar to and continuous with the Holocene transgressive sand sheet still exposed on the shelf to the west. The ridge and swale topography comprising the sand sheet on the shelf off New Jersey and Long Island are relict in origin as these same features are found buried under the fine sediment deposit. Southwestward migrating megaripples observed on the sonographs in the eastern part of the deposit are evidence that sediment is still actively accumulating in this area. In the western part of the deposit, where surface sediment is composed of silt plus clay, evidence of present sediment mobility consists of changes in the near-bottom, suspended-matter concentrations primarily associated with storms. Nantucket Shoals and Georges Bank are thought to be the sources for the fine-textured sediment. Storms and strong tidal currents in these shoal areas may still erode available fine-grained material, which then is transported westward by the mean drift to the southern New England Shelf, where a comparatively tranquil environment permits deposition of the fine material.

  18. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

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

  19. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

    In the secondary Italian school the Earth science learning begins at first year, in synergy with other natural science subjects such as Astronomy, Chemistry and Biology. Italian teachers have to focus on the landscape geomorphological aspects and often Earth processes are difficult to display since they are related to certain phenomena happened during the past and often far from the involved country. In order to better understand the environment surrounding us, very simple and poor materials, like sands, allow the teachers to create attractive lab experiences. According to the IBSE (Inquiry Based Science Education) approach, a learning unit has been implemented starting from a walking along the light carbonate beaches of the Adriatic sea: a smart look to the sands ("engage step"), stroke the students fantasy pushing them to explore some strange black grains on the sands. Dirty sands? Or rock landscape, soil degradation and Ofanto river and coastal processes (erosion, transportation and deposition)? This was the teaching challenge. Due to the youngest age, a third level, guided inquiry, was adopted so the teacher is the "guide of inquiry" encouraging the students using the research question ("Why is the sand dark?", "Do all sands look the same?", "Where does it come from?") and driving the students around their investigation plans ("How can I measure grain size?"). A procedure to answer the above questions and validate the results and explanations has been implemented to allow the students to be proactive in their study. During the learning activities will be the students to ask for field trip to elaborate their new knowledge, verify and visualize the speculated processes. The teaching skills allow to address several geosciences domains such as mineralogy, petrology, regional geology and geodynamics as well as other scientific disciplines such as mathematics (more specifically statistics), forensic science and even life sciences (the presence of bioclasts might

  20. Brazil Geological Basic Survey Program - Ponte Nova - Sheet SF.23-X-B-II - Minas Gerais State

    International Nuclear Information System (INIS)

    Brandalise, L.A.

    1991-01-01

    The present report refers to the Ponte Nova Sheet (SF.23-X-B-II) systematic geological mapping, on the 1:100.000 scale. The Sheet covers the Zona da Mata region, Minas Gerais State, in the Mantiqueira Geotectonic Province, to the eastern part of Sao Francisco Geotectonic Province, as defined in the project. The high grade metamorphic rocks to low amphibolite, occurring in the area were affected by a marked low angle shearing transposition, and show diphtheritic effects. Archaean to Proterozoic ages are attributed to the metamorphites mostly by comparison to similar types of the region. Three deformed events were registered in the region. Analysis of the crustal evolution pattern based on geological mapping, laboratorial analyses, gravimetric and air magnetometry data, and available geochronologic data is given in the 6. Chapter, Part II, in the text. Major element oxides, trace-elements, and rare-earths elements were analysed to establish parameters for the rocks environment elucidation. Geochemical survey was carried out with base on pan concentrated and stream sediments distributed throughout the Sheet. Gneisses quarries (industrial rocks) in full exploration activity have been registered, as well as sand and clay deposits employed in construction industry. Metallogenetic/Provisional analysis points out the area as a favorable one for gold prospection. (author)

  1. Analysis of the environmental control technology for tar sand development

    Energy Technology Data Exchange (ETDEWEB)

    de Nevers, N.; Glenne, B.; Bryner, C.

    1979-06-01

    The environmental technology for control of air pollution, water pollution, and for the disposal, stabilization, and vegetation of the waste tar sand were thoroughly investigated. Although some difficulties may be encountered in any of these undertakings, it seems clear that the air and water pollution problems can be solved to meet any applicable standard. Currently there are two large-scale plants producing liquid fuels from tar sands in Alberta, Canada which use similar technology involving surface mining, hot water extraction, and surface disposal of waste sand. These projects all meet the Canadian environmental control regulations in force at the time they began. The largest US deposits of tar sands are much smaller than the Canadian; 95 percent are located in the state of Utah. Their economics do not appear as attractive as the Canadian deposits. The environmental control costs are not large enough to make an otherwise economic project uneconomic. The most serious environmental conflict likely to occur over the recovery of liquid fuels from the US deposits of tar sands is that caused by the proximity of the deposits to national parks, national monuments, and a national recreation area in Utah. These areas have very stringent air pollution requirements; and even if the air pollution control requirements can be met, there may still be adequate opposition to large-scale mining ventures in these areas to prevent their commercial exploitation. Another environmental constraint may be water rights availability.Essentially all of the water running in the Colorado river basin is now legally allocated. Barring new interpretations of the legality of water rights purchase, Utah tar sands developments should be able to obtain water by purchasing existing irrigation water rights.

  2. Spatial correlation length of normalized cone data in sand

    DEFF Research Database (Denmark)

    Firouzianbandpey, Sarah; Griffiths, D. V.; Ibsen, Lars Bo

    2014-01-01

    The main topic of this study is to assess the anisotropic spatial correlation lengths of a sand layer deposit based on cone penetration testing with pore pressure measurement (CPTu) data. Spatial correlation length can be an important factor in reliability analysis of geotechnical systems, yet it...

  3. Provenance of coastal dune sands along Red Sea, Egypt

    Indian Academy of Sciences (India)

    Samir M Zaid

    2017-06-07

    Jun 7, 2017 ... been mainly formed by the accumulation of sands ... the upstream of the catchment areas of rain- fall, where ... deposited at the margin of the developing Red Sea ...... average upper continental crust (UCC) normalized ...... Petrol. 34 625–632. Egyptian Meteorological Authority, Ministry of Transporta-.

  4. Dew Measurements along a Longitudinal Sand Dune Transect

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Berkowicz, S.

    2000-01-01

    In a desert environment dew can serve as an important source of moisture for plants, biological crusts, insects and small animals. A measurement programme was carried out within a sand dune belt situated in the northwestern Negev desert, Israel, to measure daily amounts of dew deposition as well as

  5. Cluster analysis of radionuclide concentrations in beach sand

    NARCIS (Netherlands)

    de Meijer, R.J.; James, I.; Jennings, P.J.; Keoyers, J.E.

    This paper presents a method in which natural radionuclide concentrations of beach sand minerals are traced along a stretch of coast by cluster analysis. This analysis yields two groups of mineral deposit with different origins. The method deviates from standard methods of following dispersal of

  6. Oil sands development update

    International Nuclear Information System (INIS)

    1999-01-01

    A detailed review and update of oil sands development in Alberta are provided covering every aspect of the production and economic aspects of the industry. It is pointed out that at present oil sands account for 28 per cent of Canadian crude oil production, expected to reach 50 per cent by 2005. Based on recent announcements, a total of 26 billion dollars worth of projects are in progress or planned; 20 billion dollars worth of this development is in the Athabasca area, the remainder in Cold Lake and other areas. The current update envisages up to 1,800,000 barrels per day by 2008, creating 47,000 new jobs and total government revenues through direct and indirect taxes of 118 billion dollars. Provinces other than Alberta also benefit from these development, since 60 per cent of all employment and income created by oil sands production is in other parts of Canada. Up to 60 per cent of the expansion is for goods and services and of this, 50 to 55 per cent will be purchased from Canadian sources. The remaining 40 per cent of the new investment is for engineering and construction of which 95 per cent is Canadian content. Aboriginal workforce by common consent of existing operators matches regional representation (about 13 per cent), and new developers are expected to match these standards. Planned or ongoing development in environmental protection through improved technologies and optimization, energy efficiency and improved tailings management, and active support of flexibility mechanisms such as emission credits trading, joint implementation and carbon sinks are very high on the industry's agenda. The importance of offsets are discussed extensively along with key considerations for international negotiations, as well as further research of other options such as sequestration, environmentally benign disposal of waste, and enhanced voluntary action

  7. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

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

  8. Seismic Characterization of the Terrebonne Mini-basin, a Hydrate Rich Depositional System in the Gulf of Mexico

    Science.gov (United States)

    Dafov, L. N.; Eze, P. C.; Haines, S. S.; Graham, S. A.; McHargue, T.; Hosford Scheirer, A.

    2017-12-01

    Natural gas bearing hydrates are a focus of research as a potential source of energy and carbon storage because they occur globally in permafrost regions and marine sediment along every continent. This study focuses on the structural and stratigraphic architecture of the Terrebonne mini-basin, northwest Walker Ridge, Gulf of Mexico, to characterize the depositional architecture and to describe possible migration pathways for petroleum. Questions addressed include: a) continuity of sand layers b) effects of faulting and c) ponding versus fill and spill. To address these questions, seven of forty-two high resolution USGS 2D seismic lines were interpreted and then verified with WesternGeco 3D seismic data, yielding three qualitative models for the depositional environment of hydrate-bearing sand intervals. Deeper hydrate-bearing sand reservoirs were deposited as sheet-like turbidite lobes. Two shallower hydrate-bearing intervals display two possible depositional systems which form reservoirs- 1) sandy to muddy channel sealed laterally by muddy levees with associated sandy crevasse splays, and 2) ponded sandy lobes cut by channels filled with sand lags and mud. Additional observations in the 2D seismic include mass transport deposits and possible contourites. Salt movement facilitated mini-basin formation which was then ponded by sediment and followed by episodes of fill-and-spill and erosion. These seismic interpretations indicate periodic salt uplift. Overturn of salt along the northwestern edge of the basin resulted in thrust faults. The faults and erosional surfaces act as seals to reservoirs. The greatest volume of sandy reservoir potential occurs in sheet-like turbidite lobes with high lateral continuity, which facilitates updip migration of deep-sourced thermogenic gas along bedding surfaces. Channel levees serve as lateral seals to gas hydrate reservoirs, whereas faults, erosional surfaces, and shales provide vertical seals. Characterization of the Terrebonne

  9. The high-level marine shell-bearing deposits of Clava, Inverness-shire, and their origin as glacial rafts

    Science.gov (United States)

    Merritt, J. W.

    The enigmatic high-level, till-covered, cold water marine shell-bearing deposits at Clava, Inverness-shire, are described systematically in the light of new observations made at sites documented in the literature. The marine deposits, named here as the Clava Shelly Formation, include three members, the unfossiliferous Clava sand, the underlying Clava shelly clay and a shelly diamicton known as the Clava shelly till. The first two members form a conformable coarsening-upwards sequence containing a shallow water, high-boreal to low-Arctic fauna and flora. The Clava shelly till is essentially glacially re-sedimented glaciomarine clay containing a sparse fauna, but its stratigraphic relationship and age are not absolutely clear. The shelly clay is ascribed to a Mid-Devensian interstadial episode on the basis of amino-acid dating. It is concluded that the Clava shelly clay, and several discrete masses of Clava sand and shelly till, are glacially transported allochthons derived from the Great Glen. The rafts were probably detached as a result of high pore water pressure building up in laterally restricted aquifers beneath a confined glacier that flowed north-eastwards across the Loch Ness basin. This glacier was deflected eastwards and upwards towards Clava by ice flowing from the northern Highlands along the Beauly Firth during the build-up of the last Scottish ice-sheet. The rafts were stacked at the ice margin when the glacier entered the Nairn Valley before being overriden by the expanding ice-sheet.

  10. Investigating the use of the dual-polarized and large incident angle of SAR data for mapping the fluvial and aeolian deposits

    Directory of Open Access Journals (Sweden)

    Ahmed Gaber

    2017-12-01

    Full Text Available Mapping the spatial distributions of the fluvial deposits in terms of particles size as well as imaging the near-surface features along the non-vegetated aeolian sand-sheets, provides valuable geological information. Thus this work aims at investigating the contribution of the dual-polarization SAR data in classifying and mapping the surface sediments as well as investigating the effect of the radar incident-angle on improving the images of the hidden features under the desert sand cover. For mapping the fluvial deposits, the covariance matrix ([C2] using four dual-polarized ALOS/PALSAR-1 scenes cover the Wadi El Matulla, East Qena, Egypt were generated. This [C2] matrix was used to generate a supervised classification map with three main classes (gravel, gravel/sand and sand. The polarimetric scattering response, spectral reflectance and temperatures brightness of these 3 classes were extracted. However for the aeolian deposits investigation, two Radarsat-1 and three full-polarimetric ALOS/PALSAR-1 images, which cover the northwestern sandy part of Sinai, Egypt were calibrated, filtered, geocoded and ingested in a GIS database to image the near-surface features. The fluvial mapping results show that the values of the radar backscattered coefficient (σ° and the degree of randomness of the obtained three classes are increasing respectively by increasing their grain size. Moreover, the large incident angle (θi = 39.7 of the Radarsat-1 image has revealed a meandering buried stream under the sand sheet of the northwestern part of Sinai. Such buried stream does not appear in the other optical, SRTM and SAR dataset. The main reason is the enhanced contrast between the low backscattered return from the revealed meandering stream and the surroundings as a result of the increased backscattering intensity, which is related to the relatively large incident angle along the undulated surface of the study area. All archaeological

  11. The use of stable isotopes to trace oil sands constituents

    International Nuclear Information System (INIS)

    Farwell, A.J.; Nero, V.; Dixon, D.G.

    2002-01-01

    A study was conducted to determine the biological effects of oil sands mining operations on aquatic ecosystems. The study focused on the Athabasca oil sand deposit, the largest of 4 deposits in northern Alberta. In particular, the study examined the cycling of oil sand constituents in Benthic invertebrates collected from test pits at Syncrude Canada Ltd.. The invertebrates were similar in size, but different in the quantity of process-affected water or mature fine tailings containing residual bitumen. Dragonflies and damselflies in particular, showed trends of depletion for the carbon 13 isotope and enrichment in nitrogen 15 isotope in pits where levels of process affected water was high. The depletion of carbon 13 isotope suggests that oil sand constituents assimilate into the benthic food chain. The greatest carbon 13 depletion, which was approximately 27 per cent, was found to be in test pits with high turbidity. This implies that oil sands constituents degrade microbially instead of by photosynthetic production. All benthic invertebrate group demonstrated an incremental enrichment in nitrogen 15 isotope from the control pit to the pit with greatest levels of mature fine tailings

  12. Effects of sand fences on coastal dune vegetation distribution

    Science.gov (United States)

    Grafals-Soto, Rosana

    2012-04-01

    Sand fences are important human adjustments modifying the morphology of developed shores. The effects of sand fences on sediment transport and deposition in their initial stages have been well studied, but little is known about the effect of deteriorated sand fences that have become partially buried low scale barriers within the dune, potentially benefiting vegetation growth by protecting it from onshore stress. Data on vegetation, topography and fence characteristics were gathered at three dune sites in Ocean City, New Jersey on September 2007 and March 2008 to evaluate the effect of fences within the dune on vegetation distribution. Variables include: distance landward of dune toe, degree of sheltering from onshore stressors, net change in surface elevation (deposition or erosion), vegetation diversity and density, presence of remnant fence, and distance landward of fence. Results for the studied environment reveal that 1) vegetation diversity or density does not increase near remnant fences because most remnants are lower than average vegetation height and can not provide shelter; but 2) vegetation distribution is related to topographic variables, such as degree of sheltering, that are most likely the result of sand accretion caused by fence deployment. Fence deployment that prioritizes the creation of topographically diverse dunes within a restricted space may increase the diversity and density of the vegetation, and the resilience and value of developed dunes. Managers should consider the benefits of using sand fences on appropriately wide beaches to create a protective dune that is also diverse, functional and better able to adapt to change.

  13. Rheological Characterization of Green Sand Flow

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

    2016-01-01

    The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantif...

  14. Sources of atmospheric emissions in the Athabasca oil sands region

    International Nuclear Information System (INIS)

    1996-01-01

    An inventory of emissions for the Athabasca oil sands airshed that can be used as a basis for air quality assessments was presented. This report was prepared for the Suncor Steepbank Mine Environmental Impact Assessment (EIA) and for the Syncrude Aurora Mine EIA. Both Syncrude and Suncor have plans to develop new oil sands leases and to increase their crude oil and bitumen production. Suncor has proposed modifications to reduce SO 2 emissions to the atmosphere and Syncrude will develop additional ambient air quality, sulphur deposition and biomonitoring programs to ensure that environmental quality is not compromised because of atmospheric emissions associated with their operations. Major emission sources are controlled and monitored by regulatory statutes, regulations and guidelines. In this report, the following four types of emission sources were identified and quantified: (1) major industrial sources associated with Suncor's and Syncrude's current oil sands operations, (2) fugitive and area emission sources such as volatilization of hydrocarbons from tanks and tailings ponds, (3) other industrial emission sources in the area, including oil sands and non-oil sands related facilities, and (4) highway and residential emission sources. Emissions associated with mining operations include: SO 2 , NO x , CO, and CO 2 . The overall conclusion was that although there are other smaller sources of emissions that can influence air quality, there is no reason to doubt that Suncor and Syncrude oil sands operations are the major sources of emissions to the atmosphere. 13 refs., 12 tabs., 8 figs

  15. Identification of discontinuous sand pulses on the bed of the Colorado River in Grand Canyon

    Science.gov (United States)

    Mueller, E. R.; Grams, P. E.; Buscombe, D.; Topping, D. J.

    2017-12-01

    Decades of research on alluvial sandbars and sand transport on the Colorado River in Grand Canyon has contributed to in-depth understanding of the sand budget and lead to management actions designed to rebuild eroded sandbars. However, some basic, but difficult to address, questions about the processes and rates of sand movement through the system still limit our ability to predict geomorphic responses. The coarse fraction of the bed is heterogeneous and varies among boulders, cobble, gravel, and bedrock. Sand covers these substrates in patches of variable size and thickness, fills interstices to varying degrees, and forms mixed sand/coarse bed configurations such as linear stripes. Understanding the locations of sand accumulation, the quantities of sand contained in those locations, and the processes by which sand is exchanged among depositional locations is needed to predict the morphological response of sandbars to management actions, such as the controlled flood releases, and to predict whether sandbars are likely to increase or decrease in size over long (i.e. decadal) time periods. Here, we present evidence for the downstream translation of the sand component of tributary sediment inputs as discontinuous sand pulses. The silt and clay (mud) fraction of sediment introduced episodically by seasonal floods from tributary streams is transported entirely in suspension and moves through the 400 km series of canyons in a few days. The sand fraction of this sediment, which is transported on the bed and in suspension, moves downstream in sand pulses that we estimate range in length from a few km to tens of km. Owing to the complex geomorphic organization, the sand pulses are not detectable as coherent bed features; each individual sand pulse is comprised of many isolated storage locations, separated by rapids and riffles where sand cover is sparse. The presence of the sand pulses is inferred by the existence of alternating segments of sand accumulation and depletion

  16. Sand, jams and jets

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, H. [James Franck Institute and Department of Physics, University of Chicago (United States)]. E-mail: h-jaeger@uchicago.edu

    2005-12-01

    Granular media are offering new insights into problems in condensed-matter physics and materials science, as Heinrich Jaeger explains. The remarkable properties of granular materials are so familiar that most of us do not even notice them. It is clear, for example, that we cannot walk on water unless the temperature has dropped below freezing. However, we take it for granted that sand will support our weight as if it were a solid, even though it can also be poured like a liquid under the same ambient conditions. From breakfast cereal, sugar and flour to construction materials, mining products and pharmaceuticals, granular media are present everywhere in our daily lives. (U.K.)

  17. Ice sheet in peril

    DEFF Research Database (Denmark)

    Hvidberg, Christine Schøtt

    2016-01-01

    Earth's large ice sheets in Greenland and Antarctica are major contributors to sea level change. At present, the Greenland Ice Sheet (see the photo) is losing mass in response to climate warming in Greenland (1), but the present changes also include a long-term response to past climate transitions...

  18. Mobility Balance Sheet 2009

    International Nuclear Information System (INIS)

    Jorritsma, P.; Derriks, H.; Francke, J.; Gordijn, H.; Groot, W.; Harms, L.; Van der Loop, H.; Peer, S.; Savelberg, F.; Wouters, P.

    2009-06-01

    The Mobility Balance Sheet provides an overview of the state of the art of mobility in the Netherlands. In addition to describing the development of mobility this report also provides explanations for the growth of passenger and freight transport. Moreover, the Mobility Balance Sheet also focuses on a topical theme: the effects of economic crises on mobility. [nl

  19. 47 CFR 32.4040 - Customers' deposits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Customers' deposits. 32.4040 Section 32.4040... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.4040 Customers' deposits. (a) This account shall include the amount of cash deposited with the company by customers as security...

  20. Carbon sheet pumping

    International Nuclear Information System (INIS)

    Ohyabu, N.; Sagara, A.; Kawamura, T.; Motojima, O.; Ono, T.

    1993-07-01

    A new hydrogen pumping scheme has been proposed which controls recycling of the particles for significant improvement of the energy confinement in toroidal magnetic fusion devices. In this scheme, a part of the vacuum vessel surface near the divertor is covered with carbon sheets of a large surface area. Before discharge initiation, the sheets are baked up to 700 ∼ 1000degC to remove the previously trapped hydrogen atoms. After being cooled down to below ∼ 200degC, the unsaturated carbon sheets trap high energy charge exchange hydrogen atoms effectively during a discharge and overall pumping efficiency can be as high as ∼ 50 %. (author)

  1. A new era of opportunity for Canada's oil sands

    International Nuclear Information System (INIS)

    1996-06-01

    The enormous potential for wealth that is offered by Canada's oil sands deposits was discussed. Alberta's oil sands contain more recoverable oil than all the reserves of Saudi Arabia - but they have barely been developed. They are a natural resource of sufficient size, scale and competitive advantage to be of great benefit to the economy. The National Oil Sands Task Force has invested billions of dollars in the project and believes that the industry can triple production over the next 25 years. Benefits to Canadians will include an estimated 44,000 new jobs across the country, $97 billion increase in revenue for all levels of government, and $100 billion increase in consumer disposable incomes. In order to realize these socio-economic benefits, some important improvements were recommended to insure industry efficiency and growth. Some of the recommendations included increased investment in science and technology, as a key component of development. 1 tab., 4 figs

  2. Evaluation of Aguas Dulces Black sands reserves, Rocha, Uruguay

    International Nuclear Information System (INIS)

    Ferrando, L.; Bossi, J.; Maldonado, S.; Schipilov; Campal, N.

    2003-01-01

    Black sands data in Aguas Dulces (Rocha) studied by ANCAP during 60 were reanalyzed with geological criterion in order to redefine the prefactibility of economic explotation with the present infrastructure and world market conditions.The sand deposits is limited between a high slope palaeocost and the ocean, with medium depth of 10m and 2% of useful minerals:ilmenite, rutile, monazite and zircon.Mineral reserves expressed in thousands of tons are of 3 kinds:proved (3.600), probable (5.500) and possible (16.000=.Demonstrated reserves (proved + probable) allow to estimate a value of U$S 650 million, taking in account year 2000 prices. A factory to process about 7 millions ton of raw sand needs an investment of U$S 13 million and will produce a sale of U$S 8 million per year

  3. Advanced characterisation of organic matter in oil sands and tailings sands used for land reclamation by Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS).

    OpenAIRE

    Mareike Noah; Andrea Vieth-Hillebrand; Heinz Wilkes

    2012-01-01

    The Athabasca region of northern Alberta, Canada, is home to deposits of oil sands containing vast amounts (~ 173 billion barrels) of heavily biodegraded petroleum. Oil sands are recovered by surface mining or by in situ steam injection. The extraction of bitumen from oil sands by caustic hot water processing results in large volumes of fluid tailings, which are stored in on-site settling basins. There the tailings undergo a compaction and dewatering process, producing a slowly densifying sus...

  4. Direct Chlorination of Zircon Sand

    International Nuclear Information System (INIS)

    Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

    2002-01-01

    It was investigated the direct chlorination of zircon sand in a unit chlorination equipment. The process was in semi batch. The product gas was scrubbed in aqueous NaOH. It was search the influence of time, ratio of reactant and size of particle sand to the concentration of Zr and Si in the product. From these research it was found that as the times, ratio of reactant increased, the concentration of Zr increased, but the concentration of Si decreased, while as grain size of zircon sand decreased the concentration of Zr decreased, but the concentration of Si increased. (author)

  5. Oil sands and the environment

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

    2004-07-01

    Oil sands are a significant resource for Alberta and Canada with continuing growth opportunity. There is a need to ensure sustainable development of the oil sands resources from a social, economic and environmental perspective. The industry has succeeded in terms of proven reserves, technology advancements, reduced operating costs, reliability and market accessibility. Some of the major challenges facing the industry include high capital cost, infrastructure, social services and keeping pace with growth. This presentation outlined the proactive measures that the oil sands industry has taken to manage environmental issues such as sulphur dioxide and nitrogen oxide emissions, greenhouse gases, water management and land reclamation. tabs., figs.

  6. Alberta oil sands royalty regime

    International Nuclear Information System (INIS)

    Asgarpour, S.

    2004-01-01

    The long term objective of the Oil Sands Business Unit of Alberta Energy is to pave the way for Alberta's bitumen production to reach 3 million barrels per day by 2020. This presentation described the national government's role in resource development. It was emphasized that since the Crown is the owner of the oil sands resource, it would benefit by providing strategic leadership and by generating a larger royalty base. The oil sands fiscal regime was described with reference to generic royalty, risk sharing, investment, and project economics. Business rule principles were also outlined along with criteria for project expansions. Both upstream and downstream challenges and opportunities were listed. 4 figs

  7. Saltation of non-spherical sand particles.

    Directory of Open Access Journals (Sweden)

    Zhengshi Wang

    Full Text Available 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.

  8. Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2011-04-01

    Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

  9. Anesthesia Fact Sheet

    Science.gov (United States)

    ... Education About NIGMS NIGMS Home > Science Education > Anesthesia Anesthesia Tagline (Optional) Middle/Main Content Area En español ... Version (464 KB) Other Fact Sheets What is anesthesia? Anesthesia is a medical treatment that prevents patients ...

  10. Structural Biology Fact Sheet

    Science.gov (United States)

    ... NIGMS NIGMS Home > Science Education > Structural Biology Structural Biology Tagline (Optional) Middle/Main Content Area PDF Version (688 KB) Other Fact Sheets What is structural biology? Structural biology is the study of how biological ...

  11. Radiation protecting sheet

    International Nuclear Information System (INIS)

    Makiguchi, Hiroshi.

    1989-01-01

    As protection sheets used in radioactivity administration areas, a thermoplastic polyurethane composition sheet with a thickness of less 0.5 mm, solid content (ash) of less than 5% and a shore D hardness of less than 60 is used. A composite sheet with thickness of less than 0.5 mm laminated or coated with such a thermoplastic polyurethane composition as a surface layer and the thermoplastic polyurethane composition sheet applied with secondary fabrication are used. This can satisfy all of the required properties, such as draping property, abrasion resistance, high breaking strength, necking resistance, endurance strength, as well as chemical resistance and easy burnability in burning furnace. Further, by forming uneveness on the surface by means of embossing, etc. safety problems such as slippage during operation and walking can be overcome. (T.M.)

  12. Global ice sheet modeling

    International Nuclear Information System (INIS)

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

    1994-05-01

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

  13. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  14. Uranium and Thorium in zircon sands processed in Northeastern Brazil

    International Nuclear Information System (INIS)

    Hazin, Clovis A.; Farias, Emerson E. G. de

    2008-01-01

    Zircon the main mineral of zirconium is a silicate mineral product (ZrSiO 4 ) obtained from beach sand deposits, along with other minerals such as kyanite, ilmenite, and rutile. All zircons contain some radioactive impurities due to the presence of uranium, thorium and their respective decay products in the crystalline structure of zircon, as well as potassium-40. Uranium and thorium substitute Zr 4+ in the mineral through an internal process called isomorphous replacement of zirconium. For this study, samples were collected both from a mineral sand processing plant located in the coastal region of Northeastern brazil and from the beach sands used in the process. The aim of this study was to assess the 238 U, 232 Th and 40 K contents in the beach sands and in the mineral products extracted from the sands in that facility, with special emphasis on zircon. Measurements were performed through gamma spectrometry, by using a high-purity germanium detector (HPGe) coupled to a multichannel analyzer. Activity concentration for 238 U and 232 Th in zircon sands ranged from 5462±143 to 19286±46 Bq kg -1 and from 1016±7 to 7162±38 Bq kg -1 , respectively. For 40 K, on the other hand, activity concentration values ranged from 81±14 to 681±26 Bq Kg -1 . The results of the measurements carried out for raw sand samples showed activity concentrations between 2.7±0.6 and 7.9±0.9 Bq kg -1 and 6.5±0.4 and 9.4±0.6 Bq kg -1 for 238 U and 23T h respectively, and from 48.8±3.1 to 76.1±2.4 Bq kg -1 for 40 K. Activity concentrations of 238 U and 232 Th in kyanite, ilmenite and rutile samples were also determined. (author)

  15. Gravel Mobility in a High Sand Content Riverbed

    Science.gov (United States)

    Haschenburger, J. K.

    2017-12-01

    In sand-gravel channels, sand may modify gravel transport by changing conditions of entrainment and promoting longer displacements or gravel may inhibit sand transport if concentrated into distinct deposits, which restrict sand supply with consequences for migrating bedform size or form. This study reports on gravel mobility in the lower San Antonio River, Texas, where gravel content in the bed material ranges from about 1% to more than 20%. Sediment transport observations were collected at three U.S. Geological Survey gauging stations by deploying a Helley-Smith sampler with a 0.2 mm mesh bag from which transport rates and mobile grain sizes were determined. The flow rates sampled translate into an annual exceedance expectation from 0.2% to 98%. Gravel transport rates are generally two orders of magnitude smaller than the rates of sand transport. However, the finest gravels are transported at rates on the same order of magnitude as the coarsest sands. At all sites, the 2 and 2.8 mm fractions are transported at the lowest flow rate sampled, suggesting mobility for at least 38% to as much as 98% of the year. Fractions as large as 8 mm are mobilized at flow rates that are expected between 25% and 53% of the year. The largest fractions captured in the sampling (16 to 32 mm) require flows closer to bankfull conditions that occur no more than 0.8% of the year. Results document that some gravel sizes can be frequently transported in low gradient riverbeds with high sand content.

  16. Namibia : triaxial test on sand

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Jacobsen, Kim P.

    In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...... of two CID, isotropically consolidated, drained triaxial tests carried out according to the instructions in DG1 letter dated 13 March 1998....

  17. Sand ramps as palaeoenvironmental archives: Integrating general principles and regional contexts through reanalysis of the Klipkraal Sands, South Africa

    Science.gov (United States)

    Rowell, Alexandra L. K.; Thomas, David S. G.; Bailey, Richard M.; Holmes, Peter J.

    2018-06-01

    Sand ramps occur on a continuum of topographically-controlled landforms, ranging from purely aeolian features (climbing/falling dunes) to talus cones and alluvial fans. Sand ramps have been identified as potentially important palaeoenvironmental archives in dryland regions that possess relatively few Quaternary proxy records. Their utility however requires not only good age control of depositional phases but clear identification of process regimes, determined through morphological and sedimentological analyses, with several recent studies indicating the complexities of palaeoenvironmental interpretations and the controls of ramp development (Bateman et al., 2012; Rowell et al., 2018). Klipkraal Sands is a sand ramp on the north-eastern margin of the semi-arid Karoo that has been important for inferences of the extent of southern African Late Quaternary aeolian activity (Thomas et al., 2002). We reanalyse this feature, in the light of both its significance and other recent studies that have inferred extensive southern African LGM aeolian activity (Telfer et al., 2012, 2014). New sedimentological data and twelve OSL dates indicate the Klipkraal Sands formed episodically between 100-0.14 ka, rather than accumulating rapidly, while sedimentological data question the aeolian affinities of the bulk of the feature. Therefore, Klipkraal is reinterpreted as showing no particular affinity to the LGM, with sediments locally sourced with a significant colluvial component. Only the upper historical sediments can be clearly interpreted as aeolian deposits. A complex interplay of processes is suggested, for which a meaningful palaeoenvironmental interpretation cannot be easily defined. This implies that the local geomorphic processes and controls operating on sand ramps need to be established before they can be fully utilised as palaeoenvironmental archives, with implications for their interpretation worldwide.

  18. Geophysics comes of age in oil sands development

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    2008-07-01

    This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

  19. Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour

    International Nuclear Information System (INIS)

    Lee, Cheng-Hsien; Low, Ying Min; Chiew, Yee-Meng

    2016-01-01

    Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.

  20. Deglacial to Holocene history of ice-sheet retreat and bottom current strength on the western Barents Sea shelf

    Science.gov (United States)

    Lantzsch, Hendrik; Hanebuth, Till J. J.; Horry, Jan; Grave, Marina; Rebesco, Michele; Schwenk, Tilmann

    2017-10-01

    High-resolution sediment echosounder data combined with radiocarbon-dated sediment cores allowed us to reconstruct the Late Quaternary stratigraphic architecture of the Kveithola Trough and surrounding Spitsbergenbanken. The deposits display the successive deglacial retreat of the Svalbard-Barents Sea Ice Sheet. Basal subglacial till indicates that the grounded ice sheet covered both bank and trough during the Late Weichselian. A glaciomarine blanket inside the trough coinciding with laminated plumites on the bank formed during the initial ice-melting phase from at least 16.1 to 13.5 cal ka BP in close proximity to the ice margin. After the establishment of open-marine conditions at around 13.5 cal ka BP, a sediment drift developed in the confined setting of the Kveithola Trough, contemporary with crudely laminated mud, an overlying lag deposit, and modern bioclastic-rich sand on Spitsbergenbanken. The Kveithola Drift shows a remarkable grain-size coarsening from the moat towards the southern flank of the trough. This trend contradicts the concept of a separated drift (which would imply coarser grain sizes in proximity of the moat) and indicates that the southern bank is the main sediment source for the coarse material building up the Kveithola Drift. This depocenter represents, therefore, a yet undescribed combination of off-bank wedge and confined drift. Although the deposits inside Kveithola Trough and on Spitsbergenbanken display different depocenter geometries, time-equivalent grain-size changes imply a region-wide sediment-dynamic connection. We thus relate a phase of coarsest sediment supply (8.8-6.3 cal ka BP) to an increase in bottom current strength, which might be related to a stronger Atlantic Water inflow from the Southeast across the bank leading to winnowing and off-bank export of sandy sediments.

  1. Prediction of Liquefaction Potential of Dredge Fill Sand by DCP and Dynamic Probing

    International Nuclear Information System (INIS)

    Alam, Md. Jahangir; Azad, Abul Kalam; Rahman, Ziaur

    2008-01-01

    From many research it is proved that liquefaction potential of sand is function of mainly relative density and confining pressure. During routine site investigations, high-quality sampling and laboratory testing of sands are not feasible because of inevitable sample disturbance effects and budgetary constraints. On the other hand quality control of sand fill can be done by determining in situ density of sand in layer by layer which is expensive and time consuming. In this paper TRL DCP (Transportation Research Laboratory Dynamic Cone Penetration) and DPL (Dynamic Probing Light) are calibrated to predict the relative density of sand deposit. For this purpose sand of known relative density is prepared in a calibration chamber which is a mild steel cylinder with diameter 0.5 m and height 1.0 m. Relative density of sand is varied by controlling height of fall and diameter of hole of sand discharge bowl. After filling, every time DPL and DCP tests are performed and for every blow the penetration of cone is recorded. N10 is then calculated from penetration records. Thus a database is compiled where N10 and relative densities are known. A correlation is made between N 10 and relative density for two types of sand. A good correlation of N 10 and relative density is found

  2. A practical method for estimating maximum shear modulus of cemented sands using unconfined compressive strength

    Science.gov (United States)

    Choo, Hyunwook; Nam, Hongyeop; Lee, Woojin

    2017-12-01

    The composition of naturally cemented deposits is very complicated; thus, estimating the maximum shear modulus (Gmax, or shear modulus at very small strains) of cemented sands using the previous empirical formulas is very difficult. The purpose of this experimental investigation is to evaluate the effects of particle size and cement type on the Gmax and unconfined compressive strength (qucs) of cemented sands, with the ultimate goal of estimating Gmax of cemented sands using qucs. Two sands were artificially cemented using Portland cement or gypsum under varying cement contents (2%-9%) and relative densities (30%-80%). Unconfined compression tests and bender element tests were performed, and the results from previous studies of two cemented sands were incorporated in this study. The results of this study demonstrate that the effect of particle size on the qucs and Gmax of four cemented sands is insignificant, and the variation of qucs and Gmax can be captured by the ratio between volume of void and volume of cement. qucs and Gmax of sand cemented with Portland cement are greater than those of sand cemented with gypsum. However, the relationship between qucs and Gmax of the cemented sand is not affected by the void ratio, cement type and cement content, revealing that Gmax of the complex naturally cemented soils with unknown in-situ void ratio, cement type and cement content can be estimated using qucs.

  3. CFD evaluation of erosion rate around a bridge near a sand dune

    Science.gov (United States)

    He, Wei; Huang, Ning; Dun, Hongchao; Wang, Wenbo

    2017-04-01

    This study performs a series of simulations through solving the Navier-Stokes equations and the RNG k-ε turbulence model to investigate the wind erosion rates around a bridge in a desert area with sand dunes. The digital elevation model of sand dunes and the bridge model are obtained respectively from hypsographic map and construction drawings. Through combining them into the CFD software of Fluent the simulation zone was formed. The data of wind speed obtained from field observation is fitted into a logarithm format, which was imported into Fluent model as a inlet wind speed condition. Then, the effect of Dun-Go railway on wind-blown sand movement of the neighbouring environment is simulated. The results exhibit that affected by both the sand dune and bridge, the flow field is in a complex condition. It is also shown that the bridge in upstream of the sand dune will not increase the sand transport rate intensively, but change both wind velocity gradient and turbulence kinetic energy over surface of sand dune. On the other hand, when the bridge is built downstream the sand dune, simulation results show that sand deposition rate would be decreased in reference region downstream the pier.

  4. PROSPECTS FOR APPLICATION OF COMPLEX-MODIFIED SAND ASPHALT CONCRETE IN ROAD CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    D. Yu. Alexandrov

    2017-01-01

    Full Text Available The paper considers a possibility to use sand asphalt concrete as a material for protection of asphalt concrete and cement concrete road pavements against affection of external destructive factors. Advantages and disadvantages of sand asphalt concrete road pavements have been determined in the paper. The paper provides recommendations on improvement of sand asphalt concrete properties and contains an analysis of possible variants for usage of complex-modified sand asphalt concrete in the road construction. It has been noted that according to its potentially possible physical and mechanical properties activated quartz sand being micro-reinforced by dispersive industrial wastes is considered as an efficient component for creation of constructive layers in road asphalt concrete pavements. The paper reveals only specific aspects of the efficient application of quartz sand in road asphalt concrete. The subject of the paper loоks rather interesting for regions where there are no rock deposits for obtaining broken-stone ballast but there is rather significant spreading of local quarts sand. Its successful application is connected with the necessity to develop special equipment for physical and chemical activation of sand grain surface that permits strongly to increase an adhesive strength in the area of phase separation within the “bitumen–SiO2” system. The considered problem is a topical one and its solution will make it possible to local sand in a maximum way and partially to exclude application of broken stone in road construction.

  5. The last Scandinavian ice sheet in northwestern Russia: ice flow patterns and decay dynamics

    DEFF Research Database (Denmark)

    Demidov, L.; Houmark-Nielsen, Michael; Kjær, Kurt Henrik

    2006-01-01

    in Russia than previously outlined and the time of termination at 18-16 cal. kyr BP was almost 10 kyr delayed compared to the southwestern part of the ice sheet. We argue that the lithology of the ice sheets' substrate, and especially the location of former proglacial lake basins, influenced the dynamics......Advance of the Late Weichselian (Valdaian) Scandinavian Ice Sheet (SIS) in northwestern Russia took place after a period of periglacial conditions. Till of the last SIS, Bobrovo till, overlies glacial deposits from the previous Barents and Kara Sea ice sheets and marine deposits of the Last...

  6. Opportunities for CANDU for the Alberta oil sands

    International Nuclear Information System (INIS)

    Hopwood, J.M.; Bock, D.; Miller, A.; Kuran, S.; Keil, H.; Fiorino, L.; Hau, K.; Zhou, X.; Dunbar, R.B.

    2003-01-01

    The Alberta oil sands bitumen deposits comprise of one of the largest sources hydrocarbon in the world, and have emerged as the fastest growing, soon to be dominant, source of crude oil in Canada. The oil industry has made great strides in improving the effectiveness of gathering this resource. In particular, alternatives to open-pit mining have been developed which enable in-site recovery of underground deposits with a minimum of environmental disruption. The main challenge that remains is the large quantity of energy needed in the process of extracting the oil and upgrading it to commercial levels. For a typical in-situ extraction project, about 18% of the energy content of the oil produced is used up in the extraction process, while a further 5% is used in generating hydrogen to upgrade the bitumen to synthetic crude oil. Looking ahead, even as improvements in energy use efficiency, (and hydrocarbon use efficiency) counterbalance the increases in hydrocarbon demand from economic growth (particularly in the developing world), Canada and Alberta recognize that the oil sands resource will be needed, and both support the development of this resource in an environmentally responsible way. The large energy requirement for the oil sands extraction process represents a challenge with regard to both environmental impact and security of supply. The use of natural gas, the current energy supply, has impacts in terms of air quality (via NOX and other emissions) and also represents a large greenhouse gas emissions component. As the oil sands industry expands, the availability of natural gas also becomes a concern, as does price and price stability. With this background, the opportunity for nuclear reactors to provide an economical, reliable, virtually zero-emission source of energy for the oil sands becomes very important. Over the last few years, developments in oil sands extraction technology, and developments in CANDU technology through the Advanced CANDU Reactor, (ACR

  7. Connecting Brabant's cover sand landscapes through landscape history

    Science.gov (United States)

    Heskes, Erik; van den Ancker, Hanneke; Jungerius, Pieter Dirk; Harthoorn, Jaap; Maes, Bert; Leenders, Karel; de Jongh, Piet; Kluiving, Sjoerd; van den Oetelaar, Ger

    2015-04-01

    Noord-Brabant has the largest variety of cover sand landscapes in The Netherlands, and probably in Western Europe. During the Last Ice Age the area was not covered by land ice and a polar desert developed in which sand dunes buried the existing river landscapes. Some of these polar dune landscapes experienced a geomorphological and soil development that remained virtually untouched up to the present day, such as the low parabolic dunes of the Strabrechtse Heide or the later and higher dunes of the Oisterwijkse Vennen. As Noord-Brabant lies on the fringe of a tectonic basin, the thickness of cover sand deposits in the Centrale Slenk, part of a rift through Europe, amounts up to 20 metres. Cover sand deposits along the fault lines cause the special phenomenon of 'wijst' to develop, in which the higher grounds are wetter than the boarding lower grounds. Since 4000 BC humans settled in these cover sand landscapes and made use of its small-scale variety. An example are the prehistoric finds on the flanks and the historic towns on top of the 'donken' in northwest Noord-Brabant, where the cover sand landscapes are buried by river and marine deposits and only the peaks of the dunes protrude as donken. Or the church of Handel that is built beside a 'wijst' source and a site of pilgrimage since living memory. Or the 'essen' and plaggen agriculture that developed along the stream valleys of Noord-Brabant from 1300 AD onwards, giving rise to geomorphological features as 'randwallen' and plaggen soils of more than a metre thickness. Each region of Brabant each has its own approach in attracting tourists and has not yet used this common landscape history to connect, manage and promote their territories. We propose a landscape-historical approach to develop a national or European Geopark Brabants' cover sand landscapes, in which each region focuses on a specific part of the landscape history of Brabant, that stretches from the Late Weichselian polar desert when the dune

  8. Interpreting Hydraulic Conditions from Morphology, Sedimentology, and Grain Size of Sand Bars in the Colorado River in Grand Canyon

    Science.gov (United States)

    Rubin, D. M.; Topping, D. J.; Schmidt, J. C.; Grams, P. E.; Buscombe, D.; East, A. E.; Wright, S. A.

    2015-12-01

    During three decades of research on sand bars and sediment transport in the Colorado River in Grand Canyon, we have collected unprecedented quantities of data on bar morphology, sedimentary structures, grain size of sand on the riverbed (~40,000 measurements), grain size of sand in flood deposits (dozens of vertical grain-size profiles), and time series of suspended sediment concentration and grain size (more than 3 million measurements using acoustic and laser-diffraction instruments sampling every 15 minutes at several locations). These data, which include measurements of flow and suspended sediment as well as sediment within the deposits, show that grain size within flood deposits generally coarsens or fines proportionally to the grain size of sediment that was in suspension when the beds were deposited. The inverse problem of calculating changing flow conditions from a vertical profile of grain size within a deposit is difficult because at least two processes can cause similar changes. For example, upward coarsening in a deposit can result from either an increase in discharge of the flow (causing coarser sand to be transported to the depositional site), or from winnowing of the upstream supply of sand (causing suspended sand to coarsen because a greater proportion of the bed that is supplying sediment is covered with coarse grains). These two processes can be easy to distinguish where suspended-sediment observations are available: flow-regulated changes cause concentration and grain size of sand in suspension to be positively correlated, whereas changes in supply can cause concentration and grain size of sand in suspension to be negatively correlated. The latter case (supply regulation) is more typical of flood deposits in Grand Canyon.

  9. Oil sands tailings management project

    Energy Technology Data Exchange (ETDEWEB)

    Godwalt, C. [Alberta WaterSMART, Calgary, AB (Canada); Kotecha, P. [Suncor Energy Inc, Calgary, AB (Canada); Aumann, C. [Alberta Innovates - Technology Futures, Alberta Governement, AB (Canada)

    2010-11-15

    The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

  10. Oil sands tailings management project

    International Nuclear Information System (INIS)

    Godwalt, C.; Kotecha, P.; Aumann, C.

    2010-11-01

    The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

  11. Properties analysis of tensile strength, crystallinity degree and microstructure of polymer composite polypropylene-sand

    International Nuclear Information System (INIS)

    Sudirman; Karo-Karo, Aloma; Ari-Handayani; Bambang-Sugeng; Rukihati; Mashuri

    2004-01-01

    Materials modification base on polymer toward polymer composite is needed by addition of filler. Mechanical properties such as tensile strength, crystallinity degree and microstructure of polymer composite based on polypropylene with sand filler have been investigated. In this work, the polymer composite has been made by mixing the matrix of polypropylene melt flow 2 (PP MF2) or polypropylene melt flow 10 (PP MF 10) with sand filler in a labo plastomill. The composition of sand filler was varied to 10, 30, 40 and 50 % v/v, a then the composite were casted to the film sheets form. The sheets were characterized mechanically i.e tensile strength, crystallinity degree and microstructure. The result showed that the tensile strength decreased by increasing the volume fraction of sand filler, in accordance with microstructure investigation that the matrix area under zone plastic deformation (more cracks), while the filler experienced elastic deformation, so that the strength mechanism of filler did not achieved with expectation (Danusso and Tieghi theory). For filler more than 30 % of volume fraction, the tensile strength of polypropylene melt flow 10 (PP MF 10) was greater than that polypropylene melt flow 2 (PP MF2). It was caused by plasticities in PP MF 10. The tensile strength of PP MF2 was greater than that PP MF 10 for volume fraction of sand filler less than 30 %. It was caused by PP MF2 to be have more degree of crystallinity

  12. Disintegration of liquid sheets

    Science.gov (United States)

    Mansour, Adel; Chigier, Norman

    1990-01-01

    The development, stability, and disintegration of liquid sheets issuing from a two-dimensional air-assisted nozzle is studied. Detailed measurements of mean drop size and velocity are made using a phase Doppler particle analyzer. Without air flow the liquid sheet converges toward the axis as a result of surface tension forces. With airflow a quasi-two-dimensional expanding spray is formed. The air flow causes small variations in sheet thickness to develop into major disturbances with the result that disruption starts before the formation of the main break-up region. In the two-dimensional variable geometry air-blast atomizer, it is shown that the air flow is responsible for the formation of large, ordered, and small chaotic 'cell' structures.

  13. Safety advice sheets

    CERN Multimedia

    HSE Unit

    2013-01-01

    You never know when you might be faced with questions such as: when/how should I dispose of a gas canister? Where can I find an inspection report? How should I handle/store/dispose of a chemical substance…?   The SI section of the DGS/SEE Group is primarily responsible for safety inspections, evaluating the safety conditions of equipment items, premises and facilities. On top of this core task, it also regularly issues “Safety Advice Sheets” on various topics, designed to be of assistance to users but also to recall and reinforce safety rules and procedures. These clear and concise sheets, complete with illustrations, are easy to display in the appropriate areas. The following safety advice sheets have been issued so far: Other sheets will be published shortly. Suggestions are welcome and should be sent to the SI section of the DGS/SEE Group. Please send enquiries to general-safety-visits.service@cern.ch.

  14. Restoration of sand dunes along human-altered coasts: a scheme for Miramar beach, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    to perform their functions. 29 There are various ways of restoring dunes that are destroyed. Artificial nourishment of beaches is one such method that has been classified as a modem scientific strategy to counter sand depletion along coasts... can be easily achieved by erecting 1 m high wire mesh, wooden or geotextile fences perpendicular to the direction of prevailing winds. In general, sand gets deposited 6 to 8 m downwind behind these barriers as observed behind artificial objects lying...

  15. Sand fences: An environment-friendly technique to restore degraded coastal dunes

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    of prevailing winds (Matias et al. 2005). Our observations show that sand gets deposited 2 to 6 m downwind behind artificial barriers lying on the beach. A series of fences can therefore intercept wind-blown sand over a considerable area along the frontal beach..., but fashioned artificially; (e) Restoration of coastal dunes can be adopted wherever these features are damaged due to natural processes or human interference. Acknowledgements: The author is grateful to the Director, NIO, Goa, for permission to publish...

  16. Image analysis to measure sorting and stratification applied to sand-gravel experiments

    OpenAIRE

    Orrú, C.

    2016-01-01

    The main objective of this project is to develop new measuring techniques for providing detailed data on sediment sorting suitable for sand-gravel laboratory experiments. Such data will be of aid in obtaining new insights on sorting mechanisms and improving prediction capabilities of morphodynamic models. Two measuring techniques have been developed. The first technique is aimed at measuring the size stratification of a sand-gravel deposit through combining image analysis and a sediment remov...

  17. Coastal geology and recent origins for Sand Point, Lake Superior

    Science.gov (United States)

    Fisher, Timothy G.; Krantz, David E.; Castaneda, Mario R.; Loope, Walter L.; Jol, Harry M.; Goble, Ronald J.; Higley, Melinda C.; DeWald, Samantha; Hansen, Paul

    2014-01-01

    Sand Point is a small cuspate foreland located along the southeastern shore of Lake Superior within Pictured Rocks National Lakeshore near Munising, Michigan. Park managers’ concerns for the integrity of historic buildings at the northern periphery of the point during the rising lake levels in the mid-1980s greatly elevated the priority of research into the geomorphic history and age of Sand Point. To pursue this priority, we recovered sediment cores from four ponds on Sand Point, assessed subsurface stratigraphy onshore and offshore using geophysical techniques, and interpreted the chronology of events using radiocarbon and luminescence dating. Sand Point formed at the southwest edge of a subaqueous platform whose base is probably constructed of glacial diamicton and outwash. During the post-glacial Nipissing Transgression, the base was mantled with sand derived from erosion of adjacent sandstone cliffs. An aerial photograph time sequence, 1939–present, shows that the periphery of the platform has evolved considerably during historical time, infl uenced by transport of sediment into adjacent South Bay. Shallow seismic refl ections suggest slump blocks along the leading edge of the platform. Light detection and ranging (LiDAR) and shallow seismic refl ections to the northwest of the platform reveal large sand waves within a deep (12 m) channel produced by currents fl owing episodically to the northeast into Lake Superior. Ground-penetrating radar profi les show transport and deposition of sand across the upper surface of the platform. Basal radiocarbon dates from ponds between subaerial beach ridges range in age from 540 to 910 cal yr B.P., suggesting that Sand Point became emergent during the last ~1000 years, upon the separation of Lake Superior from Lakes Huron and Michigan. However, optically stimulated luminescence (OSL) ages from the beach ridges were two to three times as old as the radiocarbon ages, implying that emergence of Sand Point may have begun

  18. Ice Sheets & Ice Cores

    DEFF Research Database (Denmark)

    Mikkelsen, Troels Bøgeholm

    Since the discovery of the Ice Ages it has been evident that Earth’s climate is liable to undergo dramatic changes. The previous climatic period known as the Last Glacial saw large oscillations in the extent of ice sheets covering the Northern hemisphere. Understanding these oscillations known....... The first part concerns time series analysis of ice core data obtained from the Greenland Ice Sheet. We analyze parts of the time series where DO-events occur using the so-called transfer operator and compare the results with time series from a simple model capable of switching by either undergoing...

  19. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-02

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the general public. Written for the general public, the EIA publication Energy Information Sheets was developed to provide information on various aspects of fuel production, prices, consumption and capability. The information contained herein pertains to energy data as of December 1991. Additional information on related subject matter can be found in other EIA publications as referenced at the end of each sheet.

  20. Substrate deposit effect on the characteristic of an intertidal macroalgal community

    Digital Repository Service at National Institute of Oceanography (India)

    Imchen, T.

    Present study consists the effect of substrate deposit (silt, clay, sand, gravel and shards of shells) on the characteristic of an intertidal rocky shore macroalgae Macroalgal assemblage was segregated from substrate deposit in two stages Substrate...

  1. Potential yields of wells in unconsolidated aquifers in upstate New York--Hudson-Mohawk sheet

    Science.gov (United States)

    Bugliosi, Edward F.; Trudell, Ruth A.; Casey, George D.

    1988-01-01

    This map shows the location and potential well yields of unconsolidated aquifers in the Hudson-Mohawk region at a scale of 1:250,000. It also delineates segments of aquifers that are heavily used by community water systems and designated by the New York State Department of Environmental Conservation as ' Primary Water Supply ' aquifers, and cites published reports that give detailed information on each area. Most aquifers were deposited in low-lying areas such as valleys or plains during deglaciations of the region. Thick, permeable, well-sorted sand and gravel deposits generally yield large quantities of water, greater than 100 gal/min. Thin sand, sand and gravel deposits, or thicker gravel units that have a large content of silt and fine sand, yield moderate amounts of water, 10 to 100 gal/min. Wells dug in till and those drilled in bedrock commonly yield less than 10 gal/min. (USGS)

  2. Potential yields of wells in unconsolidated aquifers in upstate New York--lower Hudson sheet

    Science.gov (United States)

    Bugliosi, Edward F.; Trudell, Ruth A.

    1988-01-01

    This map shows the location and potential well yields from unconsolidated aquifers in the lower-Hudson region at a 1:250 ,000 scale. It also delineates segments of aquifers that are heavily used by community water systems and designated by the New York State Department of Environmental Conservation as ' Primary water supply ' aquifers and cites published reports that give detailed information on each area. Most aquifers were deposited in low-lying areas such as valleys or plains during deglaciation of the region. Thick, permeable, well-sorted sand and gravel deposits generally yield large quantities of water, more than 100 gal/min. Thin sand, sand and gravel deposits, or thicker gravel units that have a large content of silt and fine sand, yield moderate amounts of water, 10 to 100 gal/min. Wells dug in till and those drilled in bedrock commonly yield less than 10 gal/min. (USGS)

  3. Potential yields of wells in unconsolidated aquifers in upstate New York-- Adirondack sheet

    Science.gov (United States)

    Bugliosi, Edward F.; Trudell, Ruth A.; Casey, George D.

    1988-01-01

    This map shows the location and potential well yield from unconsolidated aquifers in the Adirondack region at a 1:250,000 scale. It also delineates segments of aquifers that are heavily used by community water systems and designated by the New York State Department of Environmental Conservation as ' Primary Water Supply ' aquifers and cites published reports that give detailed information on each area. Most aquifers were deposited in low-lying areas such as valleys or plains during deglaciation of the region. Thick, permeable, well-sorted sand and gravel deposits generally yield large quantities of water, greater than 100 gal/min. Thin sand, sand and gravel deposits, or thicker gravel units have a large content of silt and fine sand, yield moderate amounts of water, 10 to 100 gal/min. Wells dug in till and those drilled in bedrock commonly yield less than 10 gal/min. (USGS)

  4. Anatomy of a shoreface sand ridge revisted using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

    Science.gov (United States)

    Robinson, Marci M.; McBride, Randolph A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf not, vert, ~5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

  5. Aligned carbon nanotube-silicon sheets: a novel nano-architecture for flexible lithium ion battery electrodes.

    Science.gov (United States)

    Fu, Kun; Yildiz, Ozkan; Bhanushali, Hardik; Wang, Yongxin; Stano, Kelly; Xue, Leigang; Zhang, Xiangwu; Bradford, Philip D

    2013-09-25

    Aligned carbon nanotube sheets provide an engineered scaffold for the deposition of a silicon active material for lithium ion battery anodes. The sheets are low-density, allowing uniform deposition of silicon thin films while the alignment allows unconstrained volumetric expansion of the silicon, facilitating stable cycling performance. The flat sheet morphology is desirable for battery construction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Collisionless current sheet equilibria

    Science.gov (United States)

    Neukirch, T.; Wilson, F.; Allanson, O.

    2018-01-01

    Current sheets are important for the structure and dynamics of many plasma systems. In space and astrophysical plasmas they play a crucial role in activity processes, for example by facilitating the release of magnetic energy via processes such as magnetic reconnection. In this contribution we will focus on collisionless plasma systems. A sensible first step in any investigation of physical processes involving current sheets is to find appropriate equilibrium solutions. The theory of collisionless plasma equilibria is well established, but over the past few years there has been a renewed interest in finding equilibrium distribution functions for collisionless current sheets with particular properties, for example for cases where the current density is parallel to the magnetic field (force-free current sheets). This interest is due to a combination of scientific curiosity and potential applications to space and astrophysical plasmas. In this paper we will give an overview of some of the recent developments, discuss their potential applications and address a number of open questions.

  7. Cholera Fact Sheet

    Science.gov (United States)

    ... news-room/fact-sheets/detail/cholera","@context":"http://schema.org","@type":"Article"}; العربية 中文 français русский español ... that includes feedback at the local level and information-sharing at the global level. Cholera cases are ...

  8. Pseudomonas - Fact Sheet

    OpenAIRE

    Public Health Agency

    2012-01-01

    Fact sheet on Pseudomonas, including:What is Pseudomonas?What infections does it cause?Who is susceptible to pseudomonas infection?How will I know if I have pseudomonas infection?How can Pseudomonas be prevented from spreading?How can I protect myself from Pseudomonas?How is Pseudomonas infection treated?

  9. NTPR Fact Sheets

    Science.gov (United States)

    History Documents US Underground Nuclear Test History Reports NTPR Radiation Exposure Reports Enewetak Atoll Cleanup Documents TRAC About Who We Are Our Values History Locations Our Leadership Director Support Center Contact Us FAQ Sheet Links Success Stories Contracts Business Opportunities Current

  10. Production (information sheets)

    NARCIS (Netherlands)

    2007-01-01

    Documentation sheets: Geo energy 2 Integrated System Approach Petroleum Production (ISAPP) The value of smartness 4 Reservoir permeability estimation from production data 6 Coupled modeling for reservoir application 8 Toward an integrated near-wellbore model 10 TNO conceptual framework for "E&P

  11. Hibernia fact sheet

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This fact sheet gives details of the Hibernia oil field including its location, discovery date, oil company's interests in the project, the recoverable reserves of the two reservoirs, the production system used, capital costs of the project, and overall targets for Canadian benefit. Significant dates for the Hibernia project are listed. (UK)

  12. Ethanol Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  13. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Austin, S.R.; D'Andrea, R.F. Jr.

    1978-01-01

    Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft 2 . Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H 2 S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

  14. Rubella - Fact Sheet for Parents

    Science.gov (United States)

    ... and 4 through 6 years Fact Sheet for Parents Color [2 pages] Español: Rubéola The best way ... according to the recommended schedule. Fact Sheets for Parents Diseases and the Vaccines that Prevent Them Chickenpox ...

  15. Modelling offshore sand wave evolution

    NARCIS (Netherlands)

    Nemeth, Attila; Hulscher, Suzanne J.M.H.; van Damme, Rudolf M.J.

    2007-01-01

    We present a two-dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of offshore sand waves. The model contains the 2DV shallow water equations, with a free water surface and a general bed load formula. The water movement is coupled to the sediment transport

  16. Rheology of oil sands slurries

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R.; Zhou, J. [Alberta Research Council, Edmonton, AB (Canada). Mineral Oil Sands Unit; Wallace, D. [Dean Wallace Consulting Inc., Beaumont, AB (Canada)

    2006-07-01

    This study focused on integrating rheology and colloid science to improve recovery of bitumen in surface mined oil sands. Factors that influence recovery, such as conditions of particle interaction, solids concentration and shear rate, were reviewed. In an effort to understand the rheological behaviour of clay-in-water suspensions, an elaborate procedure was developed to separate an inter-bedded clay layer from a site at Albian Sands Energy Inc. The variables were water chemistry, solids concentration, and shear rate. The research study was conducted at the Alberta Research Council with the support of the CONRAD Extraction Group. A controlled stress rheometer was used to provide the quantitative evaluations of the clay slurry properties. The research results indicate that the viscoelastic properties of the slurry are highly influenced by the shear history of the slurry, solids content, calcium concentration, and sample aging. Shear thinning behaviour was observed in all slurry samples, but the slurry viscosity increased with test time for a given shear rate. In order to classify the slurries, a method was developed to distinguish the gel strength. The slurries were then classified into 3 distinct patterns, including no gel, weak gel and strong gel. The evolution of the experimental protocols were described along with the current stability maps that correlate the domains of the gel strength according to the solids concentration, calcium ion content, and shear rate. It was concluded that the rheological properties of oil sands slurries influence bitumen recovery in commercial surface-mined oil sands operations. tabs., figs.

  17. Geology on a Sand Budget

    Science.gov (United States)

    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…

  18. Sediment volume in the north polar sand seas of Mars

    International Nuclear Information System (INIS)

    Lancaster, N.; Greeley, R.

    1990-01-01

    Data from studies of the cross-sectional area of terrestrial transverse dunes have been combined with maps of dune morphometry derived from Viking orbiter images to generate new estimates of sediment thickness and dune sediment volume in the north polar sand seas of Mars. A relationship between dune spacing and equivalent sediment thickness (EST) was developed from field data on Namibian and North American dunes and was applied to data on dune spacing and dune cover measured on Viking orbiter images to generate maps of dune sediment thickness for Martian north polar sand seas. There are four major sand seas in the north polar region of Mars, covering an area of 6.8 x 10 5 km 2 . Equivalent sediment thickness ranges between 0.5 and 6.1 m with a mean of 1.8 m. The sand seas contain a total of 1158 km 3 of dune sediment, which may have been derived by erosion of polar layered deposits and concentrated in its present location by winds that change direction seasonally

  19. Performance monitoring of electric shovels digging oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Patnayak, S. [Alberta Univ., Edmonton, AB (Canada). Natural Resources Engineering Facility; Tannant, D.D. [Alberta Univ., Edmonton, AB (Canada). School of Mining and Petroleum Engineering; Parsons, I. [Syncrude Canada Ltd., Edmonton, AB (Canada). Edmonton Research Centre; Del Valle, V. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2005-07-01

    Some of the largest available mining equipment is used for oil sand mining operations. However, the performance of electric cable shovels varies with the diggability characteristics of the ground. In particular, oil sands diggability with cable shovels depends on structural geology, the depositional environment and geotechnical parameters. This paper described some of the key shovel performance indicators such as dig cycle time, digging energy and digging power. In winter, frost penetration can also affect oil sands diggability. The challenge of hard digging in oil sands is often addressed by blasting or ripping, which increases the cost of production and impedes productivity. The shovel performance is also influenced by other parameters such as operator skills, bucket and tooth design and shovel dipper trajectory. This paper demonstrated that hoist and crowd motor voltages and currents are useful in identifying the beginning and end of dig cycles. Performance indicators such as dig cycle time, hoist motor energy and power, and crowd motor energy and power were considered to assess material diggability. It was suggested that hoist power represents the ground diggability better than other performance indicators. 5 refs., 1 tab., 10 figs.

  20. Vein type uranium deposits

    International Nuclear Information System (INIS)

    1986-01-01

    Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

  1. Enhanced ice sheet melting driven by volcanic eruptions during the last deglaciation.

    Science.gov (United States)

    Muschitiello, Francesco; Pausata, Francesco S R; Lea, James M; Mair, Douglas W F; Wohlfarth, Barbara

    2017-10-24

    Volcanic eruptions can impact the mass balance of ice sheets through changes in climate and the radiative properties of the ice. Yet, empirical evidence highlighting the sensitivity of ancient ice sheets to volcanism is scarce. Here we present an exceptionally well-dated annual glacial varve chronology recording the melting history of the Fennoscandian Ice Sheet at the end of the last deglaciation (∼13,200-12,000 years ago). Our data indicate that abrupt ice melting events coincide with volcanogenic aerosol emissions recorded in Greenland ice cores. We suggest that enhanced ice sheet runoff is primarily associated with albedo effects due to deposition of ash sourced from high-latitude volcanic eruptions. Climate and snowpack mass-balance simulations show evidence for enhanced ice sheet runoff under volcanically forced conditions despite atmospheric cooling. The sensitivity of past ice sheets to volcanic ashfall highlights the need for an accurate coupling between atmosphere and ice sheet components in climate models.

  2. Tidal dynamics in the sand motor lagoon

    NARCIS (Netherlands)

    De Vries, S.; Radermacher, M.; De Schipper, M.A.; Stive, M.J.F.

    2015-01-01

    The Sand Motor is a mega-nourishment characterized by a very large sand volume of around 20 million m3 placed along the Dutch coast. The Sand Motor is a pilot project to evaluate the performance of an alternative nourishment strategy with respect to different functions of the coastal system. Within

  3. Film sheet cassette

    International Nuclear Information System (INIS)

    1981-01-01

    A novel film sheet cassette is described for handling CAT photographic films under daylight conditions and facilitating their imaging. A detailed description of the design and operation of the cassette is given together with appropriate illustrations. The resulting cassette is a low-cost unit which is easily constructed and yet provides a sure light-tight seal for the interior contents of the cassette. The individual resilient fingers on the light-trap permit the ready removal of the slide plate for taking pictures. The stippled, non-electrostatic surface of the pressure plate ensures an air layer and free slidability of the film for removal and withdrawal of the film sheet. The advantage of the daylight system is that a darkroom need not be used for inserting and removing the film in and out of the cassette resulting in a considerable time saving. (U.K.)

  4. Clean Cities Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    2004-01-01

    This fact sheet explains the Clean Cities Program and provides contact information for all coalitions and regional offices. It answers key questions such as: What is the Clean Cities Program? What are alternative fuels? How does the Clean Cities Program work? What sort of assistance does Clean Cities offer? What has Clean Cities accomplished? What is Clean Cities International? and Where can I find more information?

  5. Information sheets on energy

    International Nuclear Information System (INIS)

    2004-01-01

    These sheets, presented by the Cea, bring some information, in the energy domain, on the following topics: the world energy demand and the energy policy in France and in Europe, the part of the nuclear power in the energy of the future, the greenhouse gases emissions and the fight against the greenhouse effect, the carbon dioxide storage cost and the hydrogen economy. (A.L.B.)

  6. Biomolecular Science (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A brief fact sheet about NREL Photobiology and Biomolecular Science. The research goal of NREL's Biomolecular Science is to enable cost-competitive advanced lignocellulosic biofuels production by understanding the science critical for overcoming biomass recalcitrance and developing new product and product intermediate pathways. NREL's Photobiology focuses on understanding the capture of solar energy in photosynthetic systems and its use in converting carbon dioxide and water directly into hydrogen and advanced biofuels.

  7. Sheet pinch devices

    International Nuclear Information System (INIS)

    Anderson, O.A.; Baker, W.R.; Ise, J. Jr.; Kunkel, W.B.; Pyle, R.V.; Stone, J.M.

    1958-01-01

    Three types of sheet-like discharges are being studied at Berkeley. The first of these, which has been given the name 'Triax', consists of a cylindrical plasma sleeve contained between two coaxial conducting cylinders A theoretical analysis of the stability of the cylindrical sheet plasma predicts the existence of a 'sausage-mode' instability which is, however, expected to grow more slowly than in the case of the unstabilized linear pinch (by the ratio of the radial dimensions). The second pinch device employs a disk shaped discharge with radial current guided between flat metal plates, this configuration being identical to that of the flat hydromagnetic capacitor without external magnetic field. A significant feature of these configurations is the absence of a plasma edge, i.e., there are no regions of sharply curved magnetic field lines anywhere in these discharges. The importance of this fact for stability is not yet fully investigated theoretically. As a third configuration a rectangular, flat pinch tube has been constructed, and the behaviour of a flat plasma sheet with edges is being studied experimentally

  8. Dynamics of Unusual Debris Flows on Martian Sand Dunes

    Science.gov (United States)

    Miyamoto, Hideaki; Dohm, James M.; Baker, Victor R.; Beyer, Ross A.; Bourke, Mary

    2004-01-01

    Gullies that dissect sand dunes in Russell impact crater often display debris flow-like deposits in their distal reaches. The possible range of both the rheological properties and the flow rates are estimated using a numerical simulation code of a Bingham plastic flow to help explain the formation of these features. Our simulated results are best explained by a rapid debris flow. For example, a debris flow with the viscosity of 10(exp 2) Pa s and the yield strength of 10(exp 2) Pa can form the observed deposits with a flow rate of 0.5 cu m/s sustained over several minutes and total discharged water volume on the order of hundreds of cubic meters, which may be produced by melting a surface layer of interstitial ice within the dune deposits to several centimeters depth.

  9. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Strandstroem, Kjell; Mueller, Christian; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Biskopsgatan 8, FI-20500 Aabo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling is since long considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. (author)

  10. Development of an ash particle deposition model considering build-up and removal mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Kjell Strandstroem; Christian Muellera; Mikko Hupa [Abo Akademi Process Chemistry Centre, Abo (Finland)

    2007-12-15

    Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling has long been considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. 12 refs., 10 figs.

  11. The eye of the beholder : oil sands calamity or golden opportunity?

    International Nuclear Information System (INIS)

    McColl, D.

    2009-02-01

    Alberta's oil sands deposits are one of the largest hydrocarbon deposits in the world, and the oil sands industry has become a significant driving force in the Canadian economy. However, development in the region has slowed as a result of the recent economic downturn. This paper discussed the future of the oil sands industry, and argued that excess global oil supplies will need to be consumed before the industry fully recovers. Increased liquidity and higher oil prices are also required in order to help the industry recover. Oil sands data were aggregated and classified according to their various stages of development. Projections of bitumen production were based on the summation of all announced projects. Assumptions were adjusted to reflect current and likely near-term future outlooks for oil sands development. Results of the study indicated that the pace of development is expected to slow. Current leases will be developed at a slower pace. Prices in excess of $70 will be required for the industry to continue expanding as well as to generate a rate of return that can be reinvested into the Canadian economy. It was concluded that opportunities for current oil sands operators and new project proponents should take advantage of lower prices to source materials and equipment. 3 figs

  12. METHOD OF PROCESSING MONAZITE SAND

    Science.gov (United States)

    Welt, M.A.; Smutz, M.

    1958-08-26

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

  13. Oil-sands giants leaving smaller environmental footprints

    International Nuclear Information System (INIS)

    Stonehouse, D.

    1999-01-01

    Suncor Energy and Syncrude Canada are both investing billions of dollars to increase production at their mining facilities near Fort McMurray, Alberta. The two oil-sand giants will be spending a good portion of their investment (almost $1 billion) to improve their environmental performance. Both companies are focusing on reducing their energy use to cut production costs and to reduce carbon dioxide (CO 2 ) emissions. Currently, oil-sand mining accounts for the largest industrial use of electricity in Alberta. This produces tremendous amounts of greenhouse gases such as CO 2 which has been linked to global warming. By year 2006, all of Syncrude's processing equipment will be replaced by energy-efficient equipment. Shovel/truck/hydrotransport will replace the dragline/bucket-wheel/conveyor system used in the past. New technology designed to improve bitumen recovery and increase upgrading processing yields is also expected to decrease emissions by 5 million tonnes per year. Syncrude will also construct a $60 million gas turbine generator for its Aurora project. Sulphur dioxide (SO 2 ) emissions which cause acid rain, are also on the decline at both Syncrude and Suncor. Suncor will reduce its energy use through the construction of a $315 million cogeneration plant which will generate 220 MV of electricity for its operations, along with waste heat that will be used to separate the heavy oil from the sand. The cogeneration plant will be 45 per cent more efficient that current operations. Both companies have planted millions of trees and shrubs to reclaim nearly 3,000 hectares of land. The tailings from oil-sand mining are currently being captured in settling basins. Both companies have long range plans for dealing with tailings. The first is called water capping which involves layering fresh water over tailing deposits to create a lake. The second is called composite tails, which involves mixing the tailings with gypsum and sand to make them settle faster

  14. Review of four major environmental effects monitoring programs in the oil sands region

    International Nuclear Information System (INIS)

    Lott, E.O.; Jones, R.K.

    2010-10-01

    The lack of knowledge on current environmental effects monitoring programs for the mineable oil sands region generates a low public confidence in environment health monitoring and reporting programs for the oil sands operations. In 2010, the Oil Sands Research and Information Network (OSRIN) supervised a study reviewing the major environmental effects monitoring programs that are underway in the Regional Municipality of Wood Buffalo. Four main environmental effects monitoring and reporting organizations existing in the oil sands area were engaged to describe their programs through this study: Alberta Biodiversity Monitoring Institute (ABMI), Cumulative Environmental Management Association (CEMA), Regional Aquatic Monitoring Program (RAMP), Wood Buffalo Environmental Association (WBEA). These different organizations have specific roles in providing information, data and understanding of ecosystem effects. A one page visual summary of environmental effects monitoring in the oil sands area resulted from the information received from these organizations and detailed fact sheets were presented for each one of the programs. The report of this study also presents seven other environmental monitoring initiatives or organizations such as Alberta Environment and Environment Canada environmental effects monitoring program. The main observation that emerged from the review was the lack of detailed understanding shown by the stakeholders regarding the monitoring activities performed in the oil sands area. There is a lack of communication of the different programs that are conducted in the region. The study also pointed out that no efforts were put in cross-linking the various programs to be assured that every concerns related to environmental effects associated with oil sands operations were addressed. A better understanding of environmental effects and an improvement in public confidence in the data and its interpretation would probably be observed with the establishment of a

  15. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Garcia R, G.; Ordonez R, E.; Ordonez R, En.

    2002-01-01

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO 4 ) and the alpha zirconium hydrogen phosphate (Zr(HPO 4 ) 2H 2 O) starting from sea sand in an easy and economic way. (Author)

  16. Sedimentology and composition of sands injected during the seismic crisis of May 2012 (Emilia, Italy): clues for source layer identification and liquefaction regime

    Science.gov (United States)

    Fontana, D.; Lugli, S.; Marchetti Dori, S.; Caputo, R.; Stefani, M.

    2015-07-01

    In May 2012 widespread sand blows formed along buried channels in the eastern sector of the Po Plain (Northern Italy) as a consequence of a series of seismic events with main shocks of Mw 6.1 and 5.9. At San Carlo (Ferrara) a trench dug a few week after the earthquakes exposed sand dikes cutting through an old Reno River channel-levee system that was diverted in the 18th century and was deposited starting from the 14th century (unit A). This sequence overlies a Holocene muddy floodplain deposits and contains scattered sandy channel deposits (unit B) and a Pleistocene channel sand unit (unit C). Sands with inverse and normal grading, concave layering and vertical lamination coexisting along the dikes suggest multiple rhythmic opening and closing of the fractures that were injected and filled by a slurry of sand during the compression pulses, and emptied during the extension phase. The pulse mechanism may have lasted for several minutes and formed well stratified sand volcanoes structures that formed at the top of the fractures. Sands from dikes and from the various units show well defined compositional fields from lithoarenitic to quartz-feldspar-rich compositions. Sands from the old Reno levee and channel fill (unit A) have abundant lithic fragments derived from the erosion of Apennine sedimentary carbonate and terrigenous successions. Composition of the sand filling the dikes show clear affinities with sand layers of the old Reno River channel (Unit A) and clearly differ from any sand from deeper Holocene and Pleistocene layers (Unit B and C), which are richer in quartz and feldspar and poorer in sedimentary lithic fragments. Sorting related to sediment flux variations did not apparently affect the sand composition across the sedimentary structures. Textural and compositional data indicate that the liquefaction processes originated from a relatively shallow source consisting of channel sands located within Unit A at 6.8.to 7.5 m depth.

  17. The extraction of bitumen from western oil sands. Annual report, July 1991--July 1992

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-08-01

    The University of Utah tar sand research and development program is concerned with research and development on Utah is extensive oil sands deposits. The program has been intended to develop a scientific and technological base required for eventual commercial recovery of the heavy oils from oil sands and processing these oils to produce synthetic crude oil and other products such as asphalt. The overall program is based on mining the oil sand, processing the mined sand to recover the heavy oils and upgrading them to products. Multiple deposits are being investigated since it is believed that a large scale (approximately 20,000 bbl/day) plant would require the use of resources from more than one deposit. The tasks or projects in the program are organized according to the following classification: Recovery technologies which includes thermal recovery methods, water extraction methods, and solvent extraction methods; upgrading and processing technologies which covers hydrotreating, hydrocracking, and hydropyrolysis; solvent extraction; production of specialty products; and environmental aspects of the production and processing technologies. These tasks are covered in this report.

  18. Oil sands and heavy oil development issues and prospects under a Liberal government

    International Nuclear Information System (INIS)

    Shiry, J.

    1993-01-01

    A short review is presented of some of the factors affecting development of the western Canadian oil sands and heavy oil deposits to the year 2000. The Alberta oil sands resource has at least 1 trillion bbl of recoverable oil. At current prices, technology is the key to reducing costs to a more economic level. Cash operating costs have halved to $15/bbl over the past decade and the oil sands companies have programs to halve that figure again. A problem is the rising cost of natural gas as a fuel, which could jeopardize further development of both oil sand and heavy oil resources. In Saskatchewan, over 25 billion bbl of heavy oil are estimated to be in place. The biggest question is what percentage can be recovered; again, technology such as horizontal wells, 3-dimensional seismic, and steam assisted recovery is playing an important role. Concerns are expressed about the intentions of the new Liberal government concerning oil sand/heavy oil development, especially on the issues of foreign investment, exports, and environmental policy. A Liberal energy policy is not likely to allow U.S. direct investment in an oil sands plant to be tied to export of production, and the energy- and emissions-intensive nature of the oil sand/heavy oil industry will tend to make environmental approvals difficult

  19. Sand and gravel mining: effects on ground water resources in Hancock county, Maine, USA

    Science.gov (United States)

    Peckenham, John M.; Thornton, Teresa; Whalen, Bill

    2009-01-01

    Based on this preliminary study, existing sand and gravel mining regulations (in Maine, USA) can be inferred to provide some protection to water resources. Sand and gravel deposits are important natural resources that have dual uses: mining for construction material and pumping for drinking water. How the mining of sand and gravel affects aquifers and change aquifer vulnerability to contamination is not well documented. Mining regulations vary greatly by state and local jurisdiction. This study test metrics to measure the effectiveness of mining regulations. The sand and gravel aquifer system studied is covered with former and active gravel pits to nearly 25% of its areal extent. Data from homeowner interviews and field measurements found scant evidence of changes in water quantity. Water quality analyses collected from springs, streams, ponds and wells indicate that the aquifer was vulnerable to contamination by chloride and nitrate. However, water quality changes can not be related directly to mining activities.

  20. Research and information needs for management of tar sands development. Interim report Apr-May 83

    Energy Technology Data Exchange (ETDEWEB)

    1983-05-01

    The report discusses important research and information needs for federal lease management of lands with tar sands resources. Short-term needs include more complete definition and characterization of deposits, hydrology, and regions downwind from tar sands areas. Longer-term needs include demonstration-scale operations to resolve production, waste management, and reclamation problems and to provide opportunities for measurement, analysis, and assessment of mining and processing wastes and emissions. Most of the known federal tar sands resource is in eastern Utah and contains about 25 billion barrels of bitumen. Recent legislation provides that existing mining claims and oil and gas leases may be converted to combined hydrocarbon leases including tar sands. Federal approval, which must be applied for by November 1983, is a condition for conversion.

  1. The importance of sand in the formation of avulsion channels within experimental fans that develop from sediment mixtures of mud and sand

    Science.gov (United States)

    Iscen, N.; Strom, K.

    2017-12-01

    Autogenic channel migration and avulsion has long been recognized as important drivers of alluvial fan dynamics. In the literature, several field studies have documented that the presence and the amount of sand transport through a channel is important for channel incision in alluvial fans and deltas. In our experiments, we present the general autogenic avulsion cycle of experimental alluvial fans with mixtures of cohesive sediment and sand with a range of boundary conditions, and we detail the importance of mobile sand fraction in the development of channels that lead to avulsion. Experimental observations demonstrate that new channels form at topographically low regions within the floodplain providing that sand is transported to these topographic lows due to overbank flow or levee breaching. In addition to the sediment transported from upstream, erosion of a previous deposit and an ongoing backfilling nearby are observed as the possible sources of sand getting into the ghost channels. We explore whether the presence of sand is important for channel development because it increases abrasion of the channel or because it changes the roughness characteristics of the flow. We also examine the affect of sediment and water supply change on the newly described channelization process and link distinctive channel morphologies to different stages of described channel development and the avulsion process.

  2. Dense sheet Z-pinches

    International Nuclear Information System (INIS)

    Tetsu, Miyamoto

    1999-01-01

    The steady state and quasi-steady processes of infinite- and finite-width sheet z-pinches are studied. The relations corresponding to the Bennett relation and Pease-Braginskii current of cylindrical fiber z-pinches depend on a geometrical factor in the sheet z-pinches. The finite-width sheet z-pinch is approximated by a segment of infinite-width sheet z-pinch, if it is wide enough, and corresponds to a number of (width/thickness) times fiber z-pinch plasmas of the diameter that equals the sheet thickness. If the sheet current equals this number times the fiber current, the plasma created in the sheet z-pinches is as dense as in the fiber z-pinches. The total energy of plasma and magnetic field per unit mass is approximately equal in both pinches. Quasi-static transient processes are different in several aspects from the fiber z-pinch. No radiation collapse occurs in the sheet z-pinch. The stability is improved in the sheet z-pinches. The fusion criterions and the experimental arrangements to produce the sheet z-pinches are also discussed. (author)

  3. Assessment of industrial wastes in mortar layers deposited on stainless steel sheets of sinks Avaliação de resíduos industriais em camadas de argamassas depositadas sobre chapas de aço inoxidável de pias

    Directory of Open Access Journals (Sweden)

    E. Gemelli

    2004-12-01

    Full Text Available This work deals with the properties of alternative mortars destined to strengthen metal sheets of sinks. The performance of these mortars was compared to that of a basic mortar made of cement, sand, and water, named standard mortar (SM. One of these mortars, named alternative mortar 2 (AM2, and composed of cement, textile residue, polyurethane, polypropylene fibers and water, was developed recently to replace the current one, named alternative mortar 1 (AM1, composed of cement, sand, polystyrene, polypropylene fibers and water. These mortars were manufactured and aged in a room in atmospheric environment for 7, 14, 28, 60 and 90 days, either with or without initial drying in a furnace. After cure of 90 days the flexion strength stress of the SM, AM1 and AM2 mortars was 5.21, 3.84, and 1.42 MPa, respectively. The SM and AM1 mortars were constituted of C-S-H phases, Ca(OH2, SiO2, AFm and AFt (monossulphate/ettringite phases. The AM2 mortar presented, apart from the compounds mentioned above, CaCO3. This compound is from the textile residue that is composed essentially of CaCO3 and Ca(OH2. The reduction in flexion strength of AM1 mortar, compared to SM mortar, is caused by the polystyrene whereas the lowering mechanical strength of the AM2 is due to both polyurethane and textile residue. Even so, its mechanical strength is acceptable because the flexion strength stress required for the industrial application is 1.0 MPa.O objetivo desse trabalho foi estudar as propriedades de argamassas alternativas usadas para reforço de chapas metálicas de pias de cozinha. O desempenho dessas argamassas foi comparado com aquele de uma argamassa básica feita de cimento, areia e água, denominada argamassa padrão (SM. Uma dessas argamassas, denominada argamassa alternativa 2 (AM2, composta de cimento, resíduo, poliuretano, fibras de polipropileno e água, foi desenvolvida recentemente para substituir a atual, chamada argamassa alternativa 1 (AM1, composta de

  4. Potential yields of wells in unconsolidated aquifers in upstate New York-- Niagara sheet

    Science.gov (United States)

    Miller, Todd S.

    1988-01-01

    This map depicts the locations and potential well yields of unconsolidated aquifers in western New York at a scale of 1:250 ,000. It also delineates segments of aquifers that are used for public water supplies and designated by the New York State Department of Environmental Conservation as ' Primary Water Supply Aquifers. ' The map also lists published reports that give detailed information on each area. Most aquifers were deposited in low areas, such as valleys and plains, during deglaciation of the region. Thick, permeable, well-sorted sand and gravel units yield large quantities of water - more than 100 gal/min - to properly constructed wells. Thin sand units and sand and gravel units and thicker gravel units that have a large content of silt and fine sand yield moderate amounts of water, 10 to 100 gal/min. Dug wells that tap till or lacustrine deposits yield less than 5 gal/min. Well yields from bedrock are not indicated. (USGS)

  5. Mud-farming of fine oil sands tailings

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Y.; Tol van, F.; Paassen van, L.; Everts, B.; Mulder, A. [Delft Univ. of Technology, Delft (Netherlands). Dept. of Geotechnology

    2010-07-01

    This PowerPoint presentation discussed an experimental mud-farming technique for fine oil sands tailings. The technique was based on a sub-areal drying technique for dredging sludge developed in the Netherlands for Rotterdam harbour sediments. Between 1960 and 1985, the sludge was deposited in confined disposal sites on land. The sludge was converted to usable clay between 1970 and 1980. The polluted portion of the sludge is stored in a man-made disposal site. The sludge was deposited in thin layers. Stagnant water was then removed. The mud was then dewatered and reused. The sludge was furrowed with amphirol and disc wheels in order to accelerate the ripening process. The dredged material was re-used in a clay factory. The technique was applied to oil sands tailings in order to understand the suction behaviour, sedimentation behaviour, and precipitation deficit of the tailings. State changes of the sludge were monitored. No clear sedimentation phase was identified prior to consolidation. A comparison of material properties showed that the total amount of water to be extracted was more than the Rotterdam sludge, but the suction behaviour was similar. The precipitation deficit from mid-April until September will require a customized deposition strategy. Details and photographs of the experimental studies were included. tabs., figs.

  6. Late Quaternary sea level and environmental changes from relic carbonate deposits of the western margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Rajagopalan, G.; Vora, K.H.; Almeida, F.

    . The petrology and mineralogy of the deposits indicate that except for aragonite sands and foraminiferal nodules, the others were formed in shallow marine conditions and serve as sea level indicators. Radiocarbon dates were measured for 62 relic deposits covering...

  7. Perforation of metal sheets

    DEFF Research Database (Denmark)

    Steenstrup, Jens Erik

    simulation is focused on the sheet deformation. However, the effect on the tool and press is included. The process model is based on the upper bound analysis in order to predict the force progress and hole characteristics etc. Parameter analyses are divided into two groups, simulation and experimental tests......The main purposes of this project are:1. Development of a dynamic model for the piercing and performation process2. Analyses of the main parameters3. Establishing demands for process improvements4. Expansion of the existing parameter limitsThe literature survey describes the process influence...

  8. Curiosity at Gale Crater, Mars: Characterization and Analysis of the Rocknest Sand Shadow

    Science.gov (United States)

    Blake, D. F.; Morris, R. V.; Kocurek, G.; Morrison, S. M.; Downs, R. T.; Bish, D.; Ming, D. W.; Edgett, K. S.; Rubin, D.; Goetz, W.; Madsen, M. B.; Sullivan, R.; Gellert, R.; Campbell, I.; Treiman, A. H.; McLennan, S. M.; Yen, A. S.; Grotzinger, J.; Vaniman, D. T.; Chipera, S. J.; Achilles, C. N.; Rampe, E. B.; Sumner, D.; Meslin, P.-Y.; Maurice, S.; Forni, O.; Gasnault, O.; Fisk, M.; Schmidt, M.; Mahaffy, P.; Leshin, L. A.; Glavin, D.; Steele, A.; Freissinet, C.; Navarro-González, R.; Yingst, R. A.; Kah, L. C.; Bridges, N.; Lewis, K. W.; Bristow, T. F.; Farmer, J. D.; Crisp, J. A.; Stolper, E. M.; Des Marais, D. J.; Sarrazin, P.; Agard, Christophe; Alves Verdasca, José Alexandre; Anderson, Robert; Anderson, Ryan; Archer, Doug; Armiens-Aparicio, Carlos; Arvidson, Ray; Atlaskin, Evgeny; Atreya, Sushil; Aubrey, Andrew; Baker, Burt; Baker, Michael; Balic-Zunic, Tonci; Baratoux, David; Baroukh, Julien; Barraclough, Bruce; Bean, Keri; Beegle, Luther; Behar, Alberto; Bell, James; Bender, Steve; Benna, Mehdi; Bentz, Jennifer; Berger, Gilles; Berger, Jeff; Berman, Daniel; Blanco Avalos, Juan Jose; Blaney, Diana; Blank, Jen; Blau, Hannah; Bleacher, Lora; Boehm, Eckart; Botta, Oliver; Böttcher, Stephan; Boucher, Thomas; Bower, Hannah; Boyd, Nick; Boynton, Bill; Breves, Elly; Bridges, John; Brinckerhoff, William; Brinza, David; Brunet, Claude; Brunner, Anna; Brunner, Will; Buch, Arnaud; Bullock, Mark; Burmeister, Sönke; Cabane, Michel; Calef, Fred; Cameron, James; Cantor, Bruce; Caplinger, Michael; Rodríguez, Javier Caride; Carmosino, Marco; Blázquez, Isaías Carrasco; Charpentier, Antoine; Choi, David; Clark, Benton; Clegg, Sam; Cleghorn, Timothy; Cloutis, Ed; Cody, George; Coll, Patrice; Conrad, Pamela; Coscia, David; Cousin, Agnès; Cremers, David; Cros, Alain; Cucinotta, Frank; d'Uston, Claude; Davis, Scott; Day, Mackenzie; Juarez, Manuel de la Torre; DeFlores, Lauren; DeLapp, Dorothea; DeMarines, Julia; Dietrich, William; Dingler, Robert; Donny, Christophe; Drake, Darrell; Dromart, Gilles; Dupont, Audrey; Duston, Brian; Dworkin, Jason; Dyar, M. Darby; Edgar, Lauren; Edwards, Christopher; Edwards, Laurence; Ehlmann, Bethany; Ehresmann, Bent; Eigenbrode, Jen; Elliott, Beverley; Elliott, Harvey; Ewing, Ryan; Fabre, Cécile; Fairén, Alberto; Farley, Ken; Fassett, Caleb; Favot, Laurent; Fay, Donald; Fedosov, Fedor; Feldman, Jason; Feldman, Sabrina; Fitzgibbon, Mike; Flesch, Greg; Floyd, Melissa; Flückiger, Lorenzo; Fraeman, Abby; Francis, Raymond; François, Pascaline; Franz, Heather; French, Katherine Louise; Frydenvang, Jens; Gaboriaud, Alain; Gailhanou, Marc; Garvin, James; Geffroy, Claude; Genzer, Maria; Godber, Austin; Goesmann, Fred; Golovin, Dmitry; Gómez, Felipe Gómez; Gómez-Elvira, Javier; Gondet, Brigitte; Gordon, Suzanne; Gorevan, Stephen; Grant, John; Griffes, Jennifer; Grinspoon, David; Guillemot, Philippe; Guo, Jingnan; Gupta, Sanjeev; Guzewich, Scott; Haberle, Robert; Halleaux, Douglas; Hallet, Bernard; Hamilton, Vicky; Hardgrove, Craig; Harker, David; Harpold, Daniel; Harri, Ari-Matti; Harshman, Karl; Hassler, Donald; Haukka, Harri; Hayes, Alex; Herkenhoff, Ken; Herrera, Paul; Hettrich, Sebastian; Heydari, Ezat; Hipkin, Victoria; Hoehler, Tori; Hollingsworth, Jeff; Hudgins, Judy; Huntress, Wesley; Hurowitz, Joel; Hviid, Stubbe; Iagnemma, Karl; Indyk, Steve; Israël, Guy; Jackson, Ryan; Jacob, Samantha; Jakosky, Bruce; Jensen, Elsa; Jensen, Jaqueline Kløvgaard; Johnson, Jeffrey; Johnson, Micah; Johnstone, Steve; Jones, Andrea; Jones, John; Joseph, Jonathan; Jun, Insoo; Kahanpää, Henrik; Kahre, Melinda; Karpushkina, Natalya; Kasprzak, Wayne; Kauhanen, Janne; Keely, Leslie; Kemppinen, Osku; Keymeulen, Didier; Kim, Myung-Hee; Kinch, Kjartan; King, Penny; Kirkland, Laurel; Koefoed, Asmus; Köhler, Jan; Kortmann, Onno; Kozyrev, Alexander; Krezoski, Jill; Krysak, Daniel; Kuzmin, Ruslan; Lacour, Jean Luc; Lafaille, Vivian; Langevin, Yves; Lanza, Nina; Lasue, Jeremie; Le Mouélic, Stéphane; Lee, Ella Mae; Lee, Qiu-Mei; Lees, David; Lefavor, Matthew; Lemmon, Mark; Lepinette Malvitte, Alain; Léveillé, Richard; Lewin-Carpintier, Éric; Li, Shuai; Lipkaman, Leslie; Little, Cynthia; Litvak, Maxim; Lorigny, Eric; Lugmair, Guenter; Lundberg, Angela; Lyness, Eric; Maki, Justin; Malakhov, Alexey; Malespin, Charles; Malin, Michael; Mangold, Nicolas; Manning, Heidi; Marchand, Geneviève; Marín Jiménez, Mercedes; Martín García, César; Martin, Dave; Martin, Mildred; Martínez-Frías, Jesús; Martín-Soler, Javier; Martín-Torres, F. Javier; Mauchien, Patrick; McAdam, Amy; McCartney, Elaina; McConnochie, Timothy; McCullough, Emily; McEwan, Ian; McKay, Christopher; McNair, Sean; Melikechi, Noureddine; Meyer, Michael; Mezzacappa, Alissa; Miller, Hayden; Miller, Kristen; Milliken, Ralph; Minitti, Michelle; Mischna, Michael; Mitrofanov, Igor; Moersch, Jeff; Mokrousov, Maxim; Molina Jurado, Antonio; Moores, John; Mora-Sotomayor, Luis; Morookian, John Michael; Mueller-Mellin, Reinhold; Muller, Jan-Peter; Muñoz Caro, Guillermo; Nachon, Marion; Navarro López, Sara; Nealson, Kenneth; Nefian, Ara; Nelson, Tony; Newcombe, Megan; Newman, Claire; Newsom, Horton; Nikiforov, Sergey; Niles, Paul; Nixon, Brian; Dobrea, Eldar Noe; Nolan, Thomas; Oehler, Dorothy; Ollila, Ann; Olson, Timothy; Owen, Tobias; Pablo, Hernández; Paillet, Alexis; Pallier, Etienne; Palucis, Marisa; Parker, Timothy; Parot, Yann; Patel, Kiran; Paton, Mark; Paulsen, Gale; Pavlov, Alex; Pavri, Betina; Peinado-González, Verónica; Pepin, Robert; Peret, Laurent; Perez, Rene; Perrett, Glynis; Peterson, Joe; Pilorget, Cedric; Pinet, Patrick; Pla-García, Jorge; Plante, Ianik; Poitrasson, Franck; Polkko, Jouni; Popa, Radu; Posiolova, Liliya; Pradler, Irina; Prats, Benito; Prokhorov, Vasily; Purdy, Sharon Wilson; Raaen, Eric; Radziemski, Leon; Rafkin, Scot; Ramos, Miguel; Raulin, François; Ravine, Michael; Reitz, Günther; Rennó, Nilton; Rice, Melissa; Richardson, Mark; Robert, François; Rodriguez Manfredi, José Antonio; Romeral-Planelló, Julio J.; Rowland, Scott; Saccoccio, Muriel; Salamon, Andrew; Sandoval, Jennifer; Sanin, Anton; Sans Fuentes, Sara Alejandra; Saper, Lee; Sautter, Violaine; Savijärvi, Hannu; Schieber, Juergen; Schmidt, Walter; Scholes, Daniel; Schoppers, Marcel; Schröder, Susanne; Sebastian Martinez, Eduardo; Sengstacken, Aaron; Shterts, Ruslan; Siebach, Kirsten; Siili, Tero; Simmonds, Jeff; Sirven, Jean-Baptiste; Slavney, Susie; Sletten, Ronald; Smith, Michael; Sobrón Sánchez, Pablo; Spanovich, Nicole; Spray, John; Squyres, Steven; Stack, Katie; Stalport, Fabien; Stein, Thomas; Stern, Jennifer; Stewart, Noel; Stipp, Susan Louise Svane; Stoiber, Kevin; Sucharski, Bob; Summons, Roger; Sun, Vivian; Supulver, Kimberley; Sutter, Brad; Szopa, Cyril; Tate, Christopher; Teinturier, Samuel; ten Kate, Inge Loes; Thomas, Peter; Thompson, Lucy; Tokar, Robert; Toplis, Mike; Torres Redondo, Josefina; Trainer, Melissa; Tretyakov, Vladislav; Urqui-O'Callaghan, Roser; Van Beek, Jason; Van Beek, Tessa; VanBommel, Scott; Varenikov, Alexey; Vasavada, Ashwin; Vasconcelos, Paulo; Vicenzi, Edward; Vostrukhin, Andrey; Voytek, Mary; Wadhwa, Meenakshi; Ward, Jennifer; Webster, Chris; Weigle, Eddie; Wellington, Danika; Westall, Frances; Wiens, Roger Craig; Wilhelm, Mary Beth; Williams, Amy; Williams, Joshua; Williams, Rebecca; Williams, Richard B.; Wilson, Mike; Wimmer-Schweingruber, Robert; Wolff, Mike; Wong, Mike; Wray, James; Wu, Megan; Yana, Charles; Zeitlin, Cary; Zimdar, Robert; Zorzano Mier, María-Paz

    2013-09-01

    The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.

  9. Restoration of Prime Farmland Disturbed by Mineral Sand Mining in the Upper Coastal Plain of Virginia

    OpenAIRE

    Schroeder, Philip D.

    1996-01-01

    Economic deposits of heavy mineral sand were identified in the late 1980's under prime farmland along the Upper Coastal Plain of Virginia. Mining in Virginia will commence in 1997 on the Old Hickory Deposit in Dinwiddie/Sussex Counties. Experiments were established on two mine pits representing two likely pit closure scenarios; regrading the surface with unprocessed subsoil (Pit 1) or filling to the surface with processed material (Pit 3). To evaluate topsoil replacement vs. organic amendment...

  10. Experiments on sheet metal shearing

    OpenAIRE

    Gustafsson, Emil

    2013-01-01

    Within the sheet metal industry, different shear cutting technologies are commonly used in several processing steps, e.g. in cut to length lines, slitting lines, end cropping etc. Shearing has speed and cost advantages over competing cutting methods like laser and plasma cutting, but involves large forces on the equipment and large strains in the sheet material.Numerical models to predict forces and sheared edge geometry for different sheet metal grades and different shear parameter set-ups a...

  11. An experiment to restore coastal sand dunes at Miramar beach, Goa: An appraisal

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    on the adjacent roads. Driven by highest wind speeds during June -August (36 km/h in 2004 and even 60 km/h in 2007), this episode is most intense during this period every year. A recurring phenomenon, sand deposits on the traffic circle creates nuisance...

  12. Curiosity at Gale Crater, Mars: Characterization and analysis of the rocknest sand shadow

    NARCIS (Netherlands)

    Blake, D.F.; Morris, R.V.; Kocurek, G.; Morrison, S.M.; Downs, R.T.; Bish, D.; Ming, D.W.; Edgett, K.S.; Rubin, D.; Goetz, W.; Madsen, M.B.; Sullivan, R.; Gellert, R.; Campbell, I.; Treiman, A.H.; McLennan, S.M.; Yen, A.S.; Grotzinger, J.; Vaniman, D.T.; Chipera, S.J.; Achilles, C.N.; Rampe, E.B.; Sumner, D.; Meslin, P.-Y.; Maurice, S.; Forni, O.; Gasnault, O.; Fisk, M.; Schmidt, M.; Mahaffy, P.; Leshin, L.A.; Glavin, D.; Steele, A.; Freissinet, C.; Navarro-González, R.; Yingst, R.A.; Kah, L.C.; Bridges, N.; Lewis, K.W.; Bristow, T.F.; Farmer, J.D.; Crisp, J.A.; Stolper, E.M.; Des Marais, D.J.; Sarrazin, P.; MSL Science Team, the|info:eu-repo/dai/nl/292012217

    2013-01-01

    The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous

  13. Ice flow Modelling of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Tangaa

    Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others. In t...... a steady state with respect to the reference climate at the end of the simulation and that the mass balance of the ice sheet at this time was more sensitive to recent climate fluctuations than the temperature forcing in the early or mid-Holocene.......Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others....... In this PhD project, the use of ice flow models for the interpretation of the age-structure of the Greenland ice sheet, i.e. the depth within the ice, at which ice deposited at given times are found at present day. Two different observational data sets of this archive were investigated. Further, paleo...

  14. Studies in Phlebotomine Sand Flies.

    Science.gov (United States)

    1982-06-30

    Reporte de dos casos de [a ology of a sand fly, P/mlebolomu’,s diabolicuw Hall. in forma anergica difusa. Der matol. Rev. Mex. southwestern -Texas...Contribuiin al estudio de los Phmle- CDC, Veterinary Public Health Notes. USDHEW. bwmwnn de Costa Rica (Diptera, Psychodidae). Tesis. CDC. October. pp. 6- 7...janeiron R. j. 195 pp. the Unrited States (D1)pre ra: Psscfirdidae). j. Ortiz, 1. 1965a. Contribuci~in a! estudio tie los flebor- Partrsirtrl. 30:274-275

  15. Drivers of drift sand dynamics; a reconstruction for the Wekeromse Zand, the Netherlands

    Science.gov (United States)

    Hendriks, Chantal; Sonneveld, Marthijn; Wallinga, Jakob

    2013-04-01

    Inland active drift sand landscapes are regarded as unique ecosystems of great historical and geomorphological value. Recent studies have highlighted the role of multiple factors in the initiation and stabilization of drift sand landscapes. To unravel the importance of different forcings (e.g. agricultural practices, climate) and their interplay, insight in the chronology of drift sand dynamics is essential. In this study, we aimed to reconstruct the dynamics of the drift sand landscape of the Wekeromse Zand (central Netherlands) and to develop a conceptual model to understand the processes involved. The Wekeromse Zand study area (370 ha) is located on the border of a central push moraine and is characterised by open active drift sands (14 ha) and vegetated hills and valleys. The surroundings are dominated by modern agricultural practices, and remnants from ancient iron age Celtic Field systems showing that the area has been in agricultural use since at least the Iron Age. For the study area we: i) analysed historical maps going back to the early 19th century, ii) performed a field survey to map the palaeolandscape (before drift sand activation) and iii) employed optically stimulated luminescence (OSL) dating of drift sand deposits on 11 samples from two locations to determine the timing of drift sand deposition. Analysis of the available topographic maps showed no substantial aeolean activity of the area outside its morphological boundaries. OSL dating revealed that two drift sand layers were deposited between 1373 and 1462 AD and between 1680 and 1780 AD. A layer with a higher organic matter content was found at one of the sites. This suggests that the Wekeromse Zand has known three relatively stable periods: i) a period between the start of the Holocene to the Late Medieval Period, ii) in between the Medieval climatic optimum and the climatic Maunder minimum, and iii) current situation. Despite the fact that agricultural activities occurred in this area from the

  16. Estimated sand and gravel resources of the South Merrimack, Hillsborough County, New Hampshire, 7.5-minute quadrangle

    Science.gov (United States)

    Sutphin, D.M.; Drew, L.J.; Fowler, B.K.

    2006-01-01

    A computer methodology is presented that allows natural aggregate producers, local governmental, and nongovernmental planners to define specific locations that may have sand and gravel deposits meeting user-specified minimum size, thickness, and geographic and geologic criteria, in areas where the surficial geology has been mapped. As an example, the surficial geologic map of the South Merrimack quadrangle was digitized and several digital geographic information system databases were downloaded from the internet and used to estimate the sand and gravel resources in the quadrangle. More than 41 percent of the South Merrimack quadrangle has been mapped as having sand and (or) gravel deposited by glacial meltwaters. These glaciofluvial areas are estimated to contain a total of 10 million m3 of material mapped as gravel, 60 million m3 of material mapped as mixed sand and gravel, and another 50 million m3 of material mapped as sand with minor silt. The mean thickness of these areas is about 1.95 meters. Twenty tracts were selected, each having individual areas of more than about 14 acres4 (5.67 hectares) of stratified glacial-meltwater sand and gravel deposits, at least 10-feet (3.0 m) of material above the watertable, and not sterilized by the proximity of buildings, roads, streams and other bodies of water, or railroads. The 20 tracts are estimated to contain between about 4 and 10 million short tons (st) of gravel and 20 and 30 million st of sand. The five most gravel-rich tracts contain about 71 to 82 percent of the gravel resources in all 20 tracts and about 54-56 percent of the sand. Using this methodology, and the above criteria, a group of four tracts, divided by narrow areas sterilized by a small stream and secondary roads, may have the highest potential in the quadrangle for sand and gravel resources. ?? Springer Science+Business Media, LLC 2006.

  17. Centennial review-forecast--oil sands, shales spar for markets

    Energy Technology Data Exchange (ETDEWEB)

    Pamenter, C B

    1967-09-01

    The relationship between possible developments of tar sands and oil shale deposits to the future of the oil and gas industry is examined. The Athabasca tar sands are estimated to contain 85 billion bbl of synthetic crude oil which can be exploited using currently available mining equipment and proven techniques. Another 240 billion bbl of synthetic crude are potentially available through in-situ extraction methods. Great Canadian Oil Sands Ltd. is using an extraction procedure which involves a surface mining operation, extraction and processing of the bitumen, and product shipments via a 266-mile pipeline. This procedure will be used to produce 45,000 bpd of synthetic crude and 300 ton per day of sulfur. Syncrude Canada Ltd. and Shell Canada Ltd. both have applied to the Alberta government for permission to operate 100,000-bpd operations. Syncrudes is a mining operation and Shell plans to use in-situ extraction. A number of companies have conducted research projects concerning shale oil recovery. The majority of these projects have been aimed at improving mining operations. In-situ retorting of kerogen and extraction of oil has also received consideration.

  18. Sequential Subterranean Transport of Excavated Sand and Foraged Seeds in Nests of the Harvester Ant, Pogonomyrmex badius.

    Directory of Open Access Journals (Sweden)

    Walter R Tschinkel

    Full Text Available During their approximately annual nest relocations, Florida harvester ants (Pogonomyrmex badius excavate large and architecturally-distinct subterranean nests. Aspects of this process were studied by planting a harvester ant colony in the field in a soil column composed of layers of 12 different colors of sand. Quantifying the colors of excavated sand dumped on the surface by the ants revealed the progress of nest deepening to 2 m and enlargement to 8 L in volume. Most of the excavation was completed within about 2 weeks, but the nest was doubled in volume after a winter lull. After 7 months, we excavated the nest and mapped its structure, revealing colored sand deposited in non-host colored layers, especially in the upper 30 to 40 cm of the nest. In all, about 2.5% of the excavated sediment was deposited below ground, a fact of importance to sediment dating by optically-stimulated luminescence (OSL. Upward transport of excavated sand is carried out in stages, probably by different groups of ants, through deposition, re-transport, incorporation into the nest walls and floors and remobilization from these. This results in considerable mixing of sand from different depths, as indicated in the multiple sand colors even within single sand pellets brought to the surface. Just as sand is transported upward by stages, incoming seeds are transported downward to seed chambers. Foragers collect seeds and deposit them only in the topmost nest chambers from which a separate group of workers rapidly transports them downward in increments detectable as a "wave" of seeds that eventually ends in the seed chambers, 20 to 80 cm below the surface. The upward and downward transport is an example of task-partitioning in a series-parallel organization of work carried out by a highly redundant work force in which each worker usually completes only part of a multi-step process.

  19. Soft Costs Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-05-01

    This fact sheet is an overview of the systems integration subprogram at the U.S. Department of Energy SunShot Initiative. Soft costs can vary significantly as a result of a fragmented energy marketplace. In the U.S., there are 18,000 jurisdictions and 3,000 utilities with different rules and regulations for how to go solar. The same solar equipment may vary widely in its final installation price due to process and market variations across jurisdictions, creating barriers to rapid industry growth. SunShot supports the development of innovative solutions that enable communities to build their local economies and establish clean energy initiatives that meet their needs, while at the same time creating sustainable solar market conditions.

  20. Photovoltaics Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-01

    This fact sheet is an overview of the Photovoltaics (PV) subprogram at the U.S. Department of Energy SunShot Initiative. The U.S. Department of Energy (DOE)’s Solar Energy Technologies Office works with industry, academia, national laboratories, and other government agencies to advance solar PV, which is the direct conversion of sunlight into electricity by a semiconductor, in support of the goals of the SunShot Initiative. SunShot supports research and development to aggressively advance PV technology by improving efficiency and reliability and lowering manufacturing costs. SunShot’s PV portfolio spans work from early-stage solar cell research through technology commercialization, including work on materials, processes, and device structure and characterization techniques.

  1. Systems Integration Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    This fact sheet is an overview of the Systems Integration subprogram at the U.S. Department of Energy SunShot Initiative. The Systems Integration subprogram enables the widespread deployment of safe, reliable, and cost-effective solar energy technologies by addressing the associated technical and non-technical challenges. These include timely and cost-effective interconnection procedures, optimal system planning, accurate prediction of solar resources, monitoring and control of solar power, maintaining grid reliability and stability, and many more. To address the challenges associated with interconnecting and integrating hundreds of gigawatts of solar power onto the electricity grid, the Systems Integration program funds research, development, and demonstration projects in four broad, interrelated focus areas: grid performance and reliability, dispatchability, power electronics, and communications.

  2. Hyperspectral light sheet microscopy

    Science.gov (United States)

    Jahr, Wiebke; Schmid, Benjamin; Schmied, Christopher; Fahrbach, Florian O.; Huisken, Jan

    2015-09-01

    To study the development and interactions of cells and tissues, multiple fluorescent markers need to be imaged efficiently in a single living organism. Instead of acquiring individual colours sequentially with filters, we created a platform based on line-scanning light sheet microscopy to record the entire spectrum for each pixel in a three-dimensional volume. We evaluated data sets with varying spectral sampling and determined the optimal channel width to be around 5 nm. With the help of these data sets, we show that our setup outperforms filter-based approaches with regard to image quality and discrimination of fluorophores. By spectral unmixing we resolved overlapping fluorophores with up to nanometre resolution and removed autofluorescence in zebrafish and fruit fly embryos.

  3. Galveston Island, Texas, Sand Management Strategies

    Science.gov (United States)

    2016-07-01

    billion m3 of beach quality sand . However, Texas projects to date have not utilized these sources because of transportation costs. The lack of nearby...estimate that the San Luis Pass flood shoal contains approximately 11.8 million yd3 of beach quality sand . However, it is expected that if permits...a source of beach- quality sand . 2. Sand could be intercepted before it reaches the present dry beach. ERDC/CHL TR-16-13 55 3. The volume of

  4. Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix

    Directory of Open Access Journals (Sweden)

    Sanjay Mundra

    2016-09-01

    Full Text Available The study investigates the use of crushed rock sand as viable alternative to Natural River sand that is being conventionally used as fine aggregate in cement concrete. Various mix designs were developed for different grades of concrete based on IS, ACI and British codes using Natural River sand and crushed rock sand. In each case, the cube compressive strength test, and beam flexure tests were conducted. The results of the study show that, the strength properties of concrete using crushed rock sand are nearly similar to the conventional concrete. The study has shown that crushed stone sand can be used as economic and readily available alternative to river sand and can therefore help to arrest the detrimental effects on the environment caused due to excessive mining of river sand.

  5. Settlement during vibratory sheet piling

    NARCIS (Netherlands)

    Meijers, P.

    2007-01-01

    During vibratory sheet piling quite often the soil near the sheet pile wall will settle. In many cases this is not a problem. For situations with houses, pipelines, roads or railroads at relative short distance these settlements may not be acceptable. The purpose of the research described in this

  6. Contemporary sand wedge development in seasonally frozen ground and paleoenvironmental implications

    Science.gov (United States)

    Wolfe, Stephen A.; Morse, Peter D.; Neudorf, Christina M.; Kokelj, Steven V.; Lian, Olav B.; O'Neill, H. Brendan

    2018-05-01

    Contemporary sand wedges and sand veins are active in seasonally frozen ground within the extensive discontinuous permafrost zone in Northwest Territories, Canada. The region has a subarctic continental climate with 291 mm a-1 precipitation, -4.1 °C mean annual air temperature, warm summers (July mean 17.0 °C), and cold winters (January mean -26.6 °C). Five years of continuous observations indicate that interannual variation of the ground thermal regime is dominantly controlled by winter air temperature and snow cover conditions. At sandy sites, thin snow cover and high thermal conductivity promote rapid freezing, high rates of ground cooling, and low near-surface ground temperatures (-15 to -25 °C), resulting in thermal contraction cracking to depths of 1.2 m. Cracking potentials are high in sandy soils when air temperatures are air temperatures are ≤-17 °C, and snow cover is conditions in peatlands maintain permafrost, but thermal contraction cracking does not occur because thicker snow cover and the thermal properties of peat prolong freezeback and maintain higher winter ground temperatures. A combination of radiocarbon dating, optical dating, and stratigraphic observations were used to differentiate sand wedge types and formation histories. Thermal contraction cracks that develop in the sandy terrain are filled by surface (allochthonous) and/or host (autochthonous) material during the thaw season. Epigenetic sand wedges infilled with allochthonous sand develop within former beach sediments beneath an active eolian sand sheet. Narrower and deeper syngenetic wedges developed within aggrading eolian sand sheets, whereas wider and shallower antisyngenetic wedges developed in areas of active erosion. Thermal contraction cracking beneath vegetation-stabilized surfaces leads to crack infilling by autochthonous host and overlying organic material, with resultant downturning and subsidence of adjacent strata. Sand wedge development in seasonally frozen ground

  7. Plasma dynamics in current sheets

    International Nuclear Information System (INIS)

    Bogdanov, S.Yu.; Drejden, G.V.; Kirij, N.P.; AN SSSR, Leningrad

    1992-01-01

    Plasma dynamics in successive stages of current sheet evolution is investigated on the base of analysis of time-spatial variations of electron density and electrodynamic force fields. Current sheet formation is realized in a two-dimensional magnetic field with zero line under the action of relatively small initial disturbances (linear regimes). It is established that in the limits of the formed sheet is concentrated dense (N e ∼= 10 16 cm -3 ) (T i ≥ 100 eV, bar-Z i ≥ 2) hot pressure of which is balanced by the magnetic action of electrodynamic forces is carried out both plasma compression in the sheet limits and the acceleration along the sheet surface from a middle to narrow side edges

  8. Fluvial sedimentary styles and associated depositional environments in the buntsandstein west of river rhine in saar area and pfalz (F.R. Germany) and vosges (France)

    Science.gov (United States)

    Dachroth, Wolfgang

    The Buntsandstein west of river Rhine in Saar area, Pfalz and Vosges consists of three fluvial magnacycles which are characterized by different associated non-alluvial environments. The stratigraphic sequence is divided by several unconformities reflecting tectonic movements which were connected with periods of extension of the depositional area. Two major phases and two minor events are recognized by the evaluation of the Pfalz unconformity and the Lothringen unconformity, and the Leuter unconformity and the Saar unconformity, respectively. The Lower Buntsandstein (including Zechstein) compries the first magnacycle and is built up of alluvial-fan deposits, fluvial braidplain sediments and marine to lagoonal deposits. Some aeolian sands as well as several palaeosols are also present. The palaeolandscape consists of alluvial fans seaming the margin of the basin and fluvial braidplains reaching from the toes of the fan belt to the centre of the depositional area which is occupied by a lagoonal sea that partially evolves into a playa-lake with progressive refreshment. The Middle Buntsandstein comprises the second magnacycle and is composed of an alternation of aeolian Dünnschichten and fluvial Felsbänke. The third facies are alluvial-fan deposits of palaeogeographically restricted distribution along the margins of the basin. The aeolian Dünnschichten originate in the marginal parts of chott-type depressions (in comparison with the recent Chott Djerid in Tunesia) where rising ground water moistens the dry sediments that are laid down on the playa floor and thus allows their enhanced preservation. In dry periods, wind-blown sand is spread out as plane sheets or as migrating wind ripple trains, or accumulates to barchanoid-type dunes that advance across the flat. Depending on supply of sand, all stages of transition between dune fields with only narrow interdune corridors between the ridges and interdune playas with isolated widely-spaced dunes are developed. The

  9. Sedimentary facies and depositional environments of early Mesozoic Newark Supergroup basins, eastern North America

    Science.gov (United States)

    Smoot, J.P.

    1991-01-01

    The early Mesozoic Newark Supergroup consists of continental sedimentary rocks and basalt flows that occupy a NE-trending belt of elongate basins exposed in eastern North America. The basins were filled over a period of 30-40 m.y. spanning the Late Triassic to Early Jurassic, prior to the opening of the north Atlantic Ocean. The sedimentary rocks are here divided into four principal lithofacies. The alluvial-fan facies includes deposits dominated by: (1) debris flows; (2) shallow braided streams; (3) deeper braided streams (with trough crossbeds); or (4) intense bioturbation or hyperconcentrated flows (tabular, unstratified muddy sandstone). The fluvial facies include deposits of: (1) shallow, ephemeral braided streams; (2) deeper, flashflooding, braided streams (with poor sorting and crossbeds); (3) perennial braided rivers; (4) meandering rivers; (5) meandering streams (with high suspended loads); (6) overbank areas or local flood-plain lakes; or (7) local streams and/or colluvium. The lacustrine facies includes deposits of: (1) deep perennial lakes; (2) shallow perennial lakes; (3) shallow ephemeral lakes; (4) playa dry mudflats; (5) salt-encrusted saline mudflats; or (6) vegetated mudflats. The lake margin clastic facies includes deposits of: (1) birdfoot deltas; (2) stacked Gilbert-type deltas; (3) sheet deltas; (4) wave-reworked alluvial fans; or (5) wave-sorted sand sheets. Coal deposits are present in the lake margin clastic and the lacustrine facies of Carnian age (Late Triassic) only in basins of south-central Virginia and North and South Carolina. Eolian deposits are known only from the basins in Nova Scotia and Connecticut. Evaporites (and their pseudomorphs) occur mainly in the northern basins as deposits of saline soils and less commonly of saline lakes, and some evaporite and alkaline minerals present in the Mesozoic rocks may be a result of later diagenesis. These relationships suggest climatic variations across paleolatitudes, more humid to the

  10. Sand dune tracking from satellite laser altimetry

    Science.gov (United States)

    Dabboor, Mohammed

    Substantial problems arise from sand movement in arid and semi-arid countries. Sand poses a threat to infrastructure, agricultural and urban areas. These issues are caused by the encroachment of sand on roads and railway tracks, farmland, towns and villages, and airports, to name a few. Sand movement highly depends on geomorphology including vegetation cover, shape and height of the terrain, and grain size of the sand. However, wind direction and speed are the most important factors that affect efficient sand movement. The direction of the movement depends on the main direction of the wind, but it has been shown that a minimum wind speed is required, e.g. wind gusts, to initiate sand transport. This fact prevents a simple calculation of sand transport from conventional wind data as wind records rarely contain sub-minute intervals masking out any wind gusts. An alternative of predicting sand transport is the direct observation of sand advance by in situ measurements or via satellite. Until recently, satellite imagery was the only means to compare dune shape and position for predicting dune migration over several years. In 2003, the NASA laser altimetry mission ICESat became operational and monitors elevations over all surface types including sand dunes with an accuracy of about 10-20 cm. In this study, ICESat observations from repeat tracks (tracks overlapping eachother within 50 m) are used to derive sand dune advance and direction. The method employs a correlation of the elevation profiles over several dunes and was sucessfully validated with synthetic data. The accuracy of this method is 5 meters of dune advance. One of the most active areas exhibiting sand and dune movement is the area of the Arabian Peninsula. Approximately one-third of the Arabian Peninsula is covered by sand dunes. Different wind regimes (Shamal, Kaus) cause sand dune movement in the selected study area in the eastern part of the Arabian Peninsula between 20-25 degrees North and 45-55 degrees

  11. Submarine sand ridges and sand waves in the eastern part of the China Sea

    Science.gov (United States)

    Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

    2016-04-01

    Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

  12. Impacts of sand and dust storms on agriculture and potential agricultural applications of a SDSWS

    International Nuclear Information System (INIS)

    Stefanski, R; Sivakumar, M V K

    2009-01-01

    This paper will give an overview of the various impacts of sand and dust storms on agriculture and then address the potential applications of a Sand and Dust Storm Warning System (SDSWS) for agricultural users. Sand and dust storms have many negative impacts on the agricultural sector including: reducing crop yields by burial of seedlings under sand deposits, the loss of plant tissue and reduced photosynthetic activity as a result of sandblasting, delaying plant development, increasing end-of-season drought risk, causing injury and reduced productivity of livestock, increasing soil erosion and accelerating the process of land degradation and desertification, filling up irrigation canals with sediments, covering transportation routes, affecting water quality of rivers and streams, and affecting air quality. One positive impact is the fertilization of soil minerals to terrestrial ecosystems. There are several potential agricultural applications of a SDSWS. The first is to alert agricultural communities farmers to take preventive action in the near-term such as harvesting maturing crops (vegetables, grain), sheltering livestock, and strengthening infrastructure (houses, roads, grain storage) for the storm. Also, the products of a SDSWS could be used in for monitoring potential locust movement and post-storm crop damage assessments. An archive of SDSWS products (movement, amount of sand and dust) could be used in researching plant and animal pathogen movement and the relationship of sand and dust storms to disease outbreaks and in developing improved soil erosion and land degradation models.

  13. Stratigraphy and environments of deposition of the Cretaceous Hell Creek Formation (reconnaissance) and the Paleocene Ludlow Formation (detailed), southwestern North Dakota. Report of investigations No. 56

    International Nuclear Information System (INIS)

    Moore, W.L.

    1976-01-01

    The Cretaceous Hell Creek and Paleocene Ludlow Formations of southwestern North Dakota, with the exception of the included lignite beds and minor amounts of concretions and nodules, are almost exclusively clastic sediments and sedimentary rocks. Massive clays, clays alternating with silts and sands, sandstones filling channels and other depressions, sheet sandstones, and lignites are the dominant sediment and rock types present. These sediments and sedimentary rocks were mostly deposited in a continental environment and were largely alluvial, lacustrine or paludal in origin; though marginal marine deposition, in part, is indicated by the occurrence of brackish water faunas in portions of the upper Ludlow Formation. With the possible exception of a persistent lignite near the base, persistent lignites are not present in the Hell Creek Formation. The Ludlow can be subdivided into several informal units, typically coal-bounded, which can be traced laterally over large areas. This informal subdivision permits isolation of stratigraphic units for the study of local environments of deposition. Channel and depression fill sandstones of the Ludlow Formation have a relatively low permeability and a high organic content at the surface and, for this reason, are considered poor prospective uranium host rocks. The lighter colored yellow winnowed sheet sandstones of the Ludlow are more permeable and relatively free of organic matter. They are considered as possible host rocks for uranium occurring in association with an oxidation/reduction interface at shallow depths. The uranium potential is enhanced where the latter sandstones occur along paleodivides which have been overlain by the Oligocene White River Formation, or in local areas where the latter formation is still preserved. Light yellow winnowed sheet sandstones are rare in the Hell Creek Formation, and the chances for uranium prospects in this interval seem correspondingly reduced

  14. Correlated motions are a fundamental property of β-sheets

    Science.gov (United States)

    Fenwick, R. Bryn; Orellana, Laura; Esteban-Martín, Santi; Orozco, Modesto; Salvatella, Xavier

    2014-06-01

    Correlated motions in proteins can mediate fundamental biochemical processes such as signal transduction and allostery. The mechanisms that underlie these processes remain largely unknown due mainly to limitations in their direct detection. Here, based on a detailed analysis of protein structures deposited in the protein data bank, as well as on state-of-the art molecular simulations, we provide general evidence for the transfer of structural information by correlated backbone motions, mediated by hydrogen bonds, across β-sheets. We also show that the observed local and long-range correlated motions are mediated by the collective motions of β-sheets and investigate their role in large-scale conformational changes. Correlated motions represent a fundamental property of β-sheets that contributes to protein function.

  15. Fuel options for oil sands

    International Nuclear Information System (INIS)

    Wise, T.

    2005-01-01

    This presentation examined fuel options in relation to oil sands production. Options include steam and hydrogen (H 2 ) for upgrading; natural gas by pipeline; bitumen; petroleum coke; and coal. Various cost drivers were also considered for each of the fuel options. It was noted that natural gas has high energy value but the capital cost is low, and that coke's energy value is very low but the capital cost is high. A chart forecasting energy prices was presented. The disposition of Western Canada's northern gas situation was presented. Issues concerning rail transportation for coal were considered. Environmental concerns were also examined. A chart of typical gas requirements for 75,000 B/D oil sands projects was presented. Issues concerning steam generation with gas and mining cogeneration with gas fuel and steam turbines were discussed, as well as cogeneration and H 2 with gas fuels and steam turbines. Various technology and fuel utility options were examined, along with details of equipment and processes. Boiler technologies were reviewed by type as well as fuel and steam quality and pressure. Charts of cogeneration with gas turbine and circulation fluid bed boilers were presented. Gasification processes were reviewed and a supply cost basis was examined. Cost drivers were ranked according to energy, operating considerations and capital investment. Results indicated that fuel costs were significant for gas and coal. Capital costs and capital recovery charge was most significant with coal and gasification technology. Without capital recovery, cash costs favour the use of bitumen and coke. Gasification would need lower capital and lower capital recovery to compete with direct burning. It was concluded that direct burning of bitumen can compete with natural gas. With price volatility anticipated, dual fuel capability for bitumen and gas has merit. Petroleum coke can be produced or retrieved from stockpiles. Utility supply costs of direct burning of coke is

  16. Vitamin and Mineral Supplement Fact Sheets

    Science.gov (United States)

    ... website Submit Search NIH Office of Dietary Supplements Vitamin and Mineral Supplement Fact Sheets Search the list ... Supplements: Background Information Botanical Dietary Supplements: Background Information Vitamin and Mineral Fact Sheets Botanical Supplement Fact Sheets ...

  17. Ecotoxicological impacts of effluents generated by oil sands bitumen extraction and oil sands lixiviation on Pseudokirchneriella subcapitata

    Energy Technology Data Exchange (ETDEWEB)

    Debenest, T., E-mail: tdebenest@yahoo.fr [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Turcotte, P. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagne, F., E-mail: francois.gagne@ec.gc.ca [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagnon, C.; Blaise, C. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada)

    2012-05-15

    The exploitation of Athabasca oil sands deposits in northern Alberta has known an intense development in recent years. This development has raised concern about the ecotoxicological risk of such industrial activities adjacent to the Athabasca River. Indeed, bitumen extraction generated large amounts of oil sands process-affected water (OSPW) which are discharged in tailing ponds in the Athabasca River watershed. This study sought to evaluate and compare the toxicity of OSPW and oil sands lixiviate water (OSLW) with a baseline (oil sands exposed to water; OSW) on a microalgae, Pseudokirchneriella subcapitata, at different concentrations (1.9, 5.5, 12.25, 25 and 37.5%, v/v). Chemical analyses of water-soluble contaminants showed that OSPW and OSLW were enriched in different elements such as vanadium (enrichment factor, EF = 66 and 12, respectively), aluminum (EF = 64 and 15, respectively), iron (EF = 52.5 and 17.1, respectively) and chromium (39 and 10, respectively). The toxicity of OSPW on cells with optimal intracellular esterase activity and chlorophyll autofluorescence (viable cells) (72 h-IC 50% < 1.9%) was 20 times higher than the one of OSW (72 h-IC 50% > 37.5%, v/v). OSLW was 4.4 times less toxic (IC 50% = 8.5%, v/v) than OSPW and 4.5 times more toxic than OSW. The inhibition of viable cell growth was significantly and highly correlated (<-0.7) with the increase of arsenic, beryllium, chromium, copper, lead, molybdenum and vanadium concentrations. The specific photosynthetic responses studied with JIP-test (rapid and polyphasic chlorophyll a fluorescence emission) showed a stimulation of the different functional parameters (efficiency of PSII to absorb energy from photons, size of effective PSII antenna and vitality of photosynthetic apparatus for energy conversion) in cultures exposed to OSPW and OSLW. To our knowledge, our study highlights the first evidence of physiological effects of OSPW and OSLW on microalgae.

  18. Understanding Colombian Amazonian white sand forests

    NARCIS (Netherlands)

    Peñuela-Mora, M.C.

    2014-01-01

    Although progress has been made in studies on white sand forests in the Amazon, there is still a considerable gap in our knowledge of the unique species composition of white sand forests and their structure and dynamics, especially in Western Amazon. This thesis aims to fill this gap by addressing

  19. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

    2012-01-01

    Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...

  20. Seasonal fluctuations of phlebotomines sand fly populations ...

    African Journals Online (AJOL)

    An entomological survey of phlebotomine sand flies was conducted in the Moulay Yacoub province, central Morocco. An anthropic niche (Ouled Aid) and a wild niche (Zliligh) were selected. Sand flies were collected twice a month between April 2011 and March 2012, using sticky traps and CDC light traps. 3675 specimens ...

  1. On shelterbelt design for combating sand invasion.

    NARCIS (Netherlands)

    Mohammed, A.E.; Stigter, C.J.; Adam, H.S.

    1996-01-01

    After a review of the scarce literature on using trees against sand encroachment, a quantitative experiment with a wide shelterbelt to combat sand invasion is reported on. Experimental work was carried out at the northwestern border of the Gezira Scheme (Sudan), an area of severe land degradation

  2. Design of dry sand soil stratified sampler

    Science.gov (United States)

    Li, Erkang; Chen, Wei; Feng, Xiao; Liao, Hongbo; Liang, Xiaodong

    2018-04-01

    This paper presents a design of a stratified sampler for dry sand soil, which can be used for stratified sampling of loose sand under certain conditions. Our group designed the mechanical structure of a portable, single - person, dry sandy soil stratified sampler. We have set up a mathematical model for the sampler. It lays the foundation for further development of design research.

  3. Pattern formation - Instabilities in sand ripples

    DEFF Research Database (Denmark)

    Hansen, J. L.; v. Hecke, M.; Haaning, A.

    2001-01-01

    Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...

  4. Formation and interpretation of eskers beneath retreating ice sheets

    Science.gov (United States)

    Creyts, T. T.; Hewitt, I.

    2017-12-01

    The retreat of the ice sheets during the Pleistocene left large and spectacular subglacial features exposed. Understanding these features gives us insight into how the ice sheets retreated, how meltwater influenced retreat, and can help inform our understanding of potential future rates of ice sheet retreat. Among these features, eskers, long sinuous ridges primarily composed of clastic sediments, lack a detailed explanation of how surface melt rates and ice sheet retreat rates influence their growth and spatial distribution. Here, we develop a theory for esker formation based on the initial work of Rothlisberger modified for sediment transport and inclusion of surface meltwater forcing. The primary subglacial ingredients include water flow through subglacial tunnels with the addition of mass balances for sediment transport. We show how eskers when water flow slows below a critical stress for sediment motion. This implies that eskers are deposited in a localized region near the snout of the ice sheet. Our findings suggest that very long eskers form sequentially as the ice front retreats. The position of the esker follows the path of the channel mouth through time, which does not necessarily coincide with the instantaneous route of the feeding channel. However, in most cases, we expect those locations to be similar. The role of surface meltwater and the climatology associated with the forcing is crucial to the lateral spacing of the eskers. We predict that high surface melt rates lead to narrower catchments but that the greater extent of the ablation area means that channels are likely larger. At the same time, for a given channel size (and hence sediment flux), the size of a deposited esker depends on a margin retreat rate. Hence, the size of the eskers is related delicately to the balance between surface melt rates and margin retreat rates. We discuss how our theory can be combined with observed esker distributions to infer the relationship between these two rates

  5. Welded slump-graded sand couplets: evidence for slide generated turbidity currents

    Science.gov (United States)

    Stanley, Daniel Jean

    1982-09-01

    Some massive channelized strata preserved in the rock record are characterized by a lower slump member which evolves upward to a turbidite. This merging is indicative of probable generation of sediment gravity flows from submarine sliding. Conditions essential for deposition of such sequences are short transport distance between point of failure and depositional site, and an environment likely to retain both facies. Fan valleys are a likely setting for welded couplets: flowing sand, initiated by the sliding event, comes to rest at nearly the same time and position as the slump mass deposited near the base of the valley wall and in the axis proper.

  6. Flowability in crushed sand mortar

    Directory of Open Access Journals (Sweden)

    Cabrera, O. A.

    2010-12-01

    Full Text Available The present experimental study explored the relationship between mortar flowability and the voids content in crushed sand to determine the effect of grain shape and surface texture as well as dust content on the behaviour of fresh mortar. The findings revealed a close correlation between voids content and the volume of paste needed for mortar to begin to flow as a continuous material, mortar flowability and the water content needed to attain a given flowability. The comparison of the empirical findings to the results obtained with the Larrard (1, 2 model provided further information on the effect of sand grain morphology on fresh mortars.

    En el presente trabajo se plantea un estudio experimental de la fluidez de morteros basado en el contenido de vacíos de arenas machacadas, para comprender la influencia de la forma y textura superficial de los granos de arena y del contenido de polvo de las mismas sobre el estado fresco de morteros. Los resultados muestran la estrecha relación entre el contenido de vacíos entre granos y los volúmenes de pasta necesarios para iniciar el escurrimiento como un material continuo, la fluidez de los morteros, el contenido de agua para alcanzar una determinada fluidez, etc. El comportamiento evaluado se compara con resultados obtenidos aplicando el modelo de F. de Larrard (1, 2, permitiendo de este modo obtener mayor información de la influencia de la morfología de los granos de la arena sobre el estado fresco de los morteros.

  7. Sand transportation and reverse patterns over leeward face of sand dune

    Science.gov (United States)

    Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

    2017-04-01

    Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux

  8. Optical Dating of Holocene Dune Sands in the Ferris Dune Field, Wyoming

    Science.gov (United States)

    Stokes, Stephen; Gaylord, David R.

    1993-05-01

    Optical dating of late Quaternary quartz dune sands from the Clear Creek portion of Ferris dune field, Wyoming, demonstrates the considerable potential of the technique as a chronostratigraphic tool. A sequence of radiocarbon-dated Holocene interdune strata permit optical dating of the intercalated dune sand to be tested; the concordance is good. The optical dates for the aeolian deposits not datable by radiocarbon suggest that aeolian sedimentation at Clear Creek peaked during two relatively short phases at ca. 8500 and 4000 yr B.P. The dates indicate that aeolian accumulation maxima (at least in the Clear Creek area) may not be synchronous with previously defined phases of marked aridity.

  9. Seasonal variations in heavy mineral placer sand from Kalbadevi Bay, Ratnagiri, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    spaced at ~1.5 km apart (Fig. 1). More details are given in Valsangkar (2005). Beach samples were obtained by push cores from the different beach environment that included dune, berm, hide tide (HT), mid tide (MT) and low tide (LT) area. The samples...) decreased to 12 % during post-monsoon season. Increase of sand content with depth in bern environment is therefore considered related to deposition due to wave and current action. May, 2K4; BP-02 0 20 40 60 80 100 120 Dune Berm HT MT LT Sand % 0-5 5...

  10. Preliminary geologic map of the Thaniyat Turayf Quadrangle, sheet 29C, Kingdom of Saudi Arabia

    Science.gov (United States)

    Meissner, C.R.; Dini, S.M.; Farasani, A.M.; Riddler, G.P.; Smith, G.H.; Griffin, M.B.; Van Eck, Marcel

    1990-01-01

    The Thaniyat Turayf quadrangle, sheet 29C, lies in the northwestern part of Saudi Arabia near the border with Jordan. The quadrangle is located between lat 29°00'-30°00' N. and long 37°30'-39°00' E. It includes the southwestern rim of the Sirhan-Turayf Basin and is underlain by Silurian to Miocene- Pliocene sedimentary rocks that are partly covered by surficial duricrust, sand, and gravel.

  11. Developing new markets for oil sands products

    International Nuclear Information System (INIS)

    Crandall, G.

    2004-01-01

    This paper presents a review by Purvin and Gertz of western Canadian crude oil supply. This energy consulting firm provides advise to the energy sector. It suggests that oil sands production will surpass declining conventional production. Oil sands supply includes bitumen, synthetic crude oil (SCO), and diluent. It is forecasted that oil sands will increase from 42 per cent of western supply in 2002 to 78 per cent in 2015. The potential of Alberta's oil sands was discussed along with a recent study of refined products and petrochemicals from bitumen. Upgrading, refining and petrochemical case studies were presented. The author examined if a Canadian oil sands upgrading project with high capital costs can be competitive with competing projects in the United States and internationally. In addition to supply and demand issues, the presentation examined infrastructure capability and market potential in the United States. The economic potential and risks of preferred business cases compared to upgrading to SCO were also evaluated. 15 figs

  12. Numerical simulation of aeolian sand ripples

    International Nuclear Information System (INIS)

    Kang Liqiang; Guo Liejin

    2004-01-01

    With a new horizontal saltation displacement vector, a model is implemented to simulate the initiation and evolution of aeolian sand ripples. In the model, saltation distance considers the effects of surface height and slope. A linear stability analysis is also carried out for formation of sand ripples. The results show that, the model can be able to successfully reproduce sand ripples which can increase in scale by merging of small ripples. The linear stability analysis indicates that sand ripples appear when the relaxation rate parameter is below a threshold value and wind strength parameter is larger than a critical value. The results also verified that the formation of sand ripples is a self-organization process

  13. Shaft-retort for treating waste materials, like washery waste, bituminous shale, oil-bearing sands and the like

    Energy Technology Data Exchange (ETDEWEB)

    Koppers, H

    1916-10-29

    A shaft-retort for converting waste materials, like washery waste, bituminous shale, oil-bearing sands, brown coal and non-coking mineral coal to oil and tar by supplying heat through the shaft wall formed of an iron-sheet to the material, which is forced through a feeding member perforated for the removal of gases and vapors, and moved downward in a thin layer on the shaft wall; that is characterized by the fact that the iron heating sheet is made rotatable for the purpose of equalizing overheating of itself and the material to be treated.

  14. Selectively reflective transparent sheets

    Science.gov (United States)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  15. Advanced CANDU reactor: an optimized energy source of oil sands application

    International Nuclear Information System (INIS)

    Hopwood, J.M.; Bock, D.; Miller, A.; Kuran, S.; Keil, H.; Fiorino, L.; Duffey, R.; Dunbar, R.B.

    2003-01-01

    Atomic Energy of Canada Limited (AECL) is developing the ACR-700 TM (Advanced CANDU Reactor-700 TM ) to meet customer needs for reduced capital cost, shorter construction schedule, high capacity factor while retaining the benefits of the CANDU experience base. The ACR-700 is based on the concept of CANDU horizontal fuel channels surrounded by heavy water moderator. The major innovation of this design is the use of slightly enriched uranium fuel in a CANFLEX bundle that is cooled by light water. This ensures: higher main steam pressures and temperatures providing higher thermal efficiency; a compact and simpler reactor design with reduced capital costs and shorter construction schedules; and reduced heavy water inventory compared to existing CANDU reactors. ACR-700 is not only a technically advanced and cost effective solution for electricity generating utilities, but also a low-cost, long-life and sustainable steam source for increasing Alberta's Oil Sand production rates. Currently practiced commercial surface mining and extraction of Oil Sand resources has been well established over the last three decades. But a majority of the available resources are somewhat deeper underground require in-situ extraction. Economic removal of such underground resources is now possible through the Steam Assisted Gravity Drainage (SAGD) process developed and proto-type tested in-site. SAGD requires the injection of large quantities of high-pressure steam into horizontal wells to form reduced viscosity bitumen and condensate mixture that is then collected at the surface. This paper describes joint AECL studies with CERI (Canadian Energy Research Institute) for the ACR, supplying both electricity and medium-pressure steam to an oil sands facility. The extensive oil sands deposits in northern Alberta are a very large energy resource. Currently, 30% of Canda's oil production is from the oil sands and this is expected to expand greatly over the coming decade. The bitumen deposits in the

  16. Development of the Brazilian national sheet scintillator converter of neutron

    International Nuclear Information System (INIS)

    Barbosa, Andre Luis Nunes

    2008-03-01

    Both the national domain of the technology for the separation of rare earth elements and the large reserves of these minerals in Brazilian territory, motivated the study of national sheets scintillators converter of neutrons, using a granular mixture Gd 2 O 3 -Zn S:Ag. Three methodologies were used for the manufacture of such sheets, namely: deposition done with a compressed-air gun on a sheet of cellulose type CG3460-3M; fusion of granular mixture with EVA in the mixing chamber and deposition of granular mixture on the substrate of EVA. It was used the flux of the order of 4,46 x 10 5 neutrons thermic/cm 2 .s, coming from the channel irradiation, J-9, of the reactor Argonauta/IEN/CNEN and the radiographic film AA-400 Kodak Industrex. The performances of national scintillator neutrons converter sheets were analyzed and the images obtained with the, demonstrated that the methodologies proposed are technically feasible and can contribute to the reduction of cost of this technique for NDA, but which lack optimization is aimed at increasing the number of photons of light to allow its use in neutrongraphies in Real Time (NRTR). (author)

  17. Characteristics Of Basaltic Sand: Size, Shape, And Composition As A Function Of Transport Process And Distance

    Science.gov (United States)

    Craddock, R. A.; Needell, Z. A.; Rose, T. R.

    2012-04-01

    quartz, feldspar, and heavy minerals commonly found in most terrestrial sedimentary deposits, basaltic sediments are composed of varying amounts of olivine, pyroxene, plagioclase, and vitric and lithic fragments. One of the few locations on Earth containing such material is the Ka'u Desert of Hawaii. This area is unique in that both eolian and fluvial sediment pathways occur in the same area, thus allowing a direct comparison of particles transported by different processes over identical distances (~20 km). We are currently documenting the physical and chemical changes that take place in basaltic sediments as they are transported by wind and water over increasing distances. This will result in an improvement in our understanding of traditional sedimentological concepts when applying them to Martian surface materials. Process: The Ka'u Desert is ~350 km2 and contains the largest basaltic dune fields on Earth. We have identified several different dune types located in various parts of the desert, including climbing and falling dunes, sand sheets, parabolic dunes (that were initially barchans), and crescentic dunes. Fluvial sediments occur as floodout deposits where ephemeral streams go from confined to unconfined flow outside the continuous Keanakako'i Formation [7]. There are also a number of sand bottom streams and playas that occur along a series of channels that extend from the Keanakako'i Formation ~20 km to the sea. We have collected samples from dunes and fluvial deposits at various locations in the Ka'u Desert, at varying distances from sources and subject to different environmental processes. In the lab, we have begun to use optical and scanning electron microscopic images to assess how grain size, shape, and angularity of individual particles change with increasing transport distances. We are also conducting point counts of particles contained within each sample to better understand how olivine, pyroxene, feldspar, and lithic and vitric fragments weather with

  18. On the importance of the albedo parameterization for the mass balance of the Greenland ice sheet in EC-Earth

    NARCIS (Netherlands)

    Helsen, Michiel M.; van de Wal, Roderik S. W.; Reerink, Thomas J.; Bintanja, Richard; Madsen, Marianne S.; Yang, Shuting; Li, Qiang; Zhang, Qiong

    2017-01-01

    The albedo of the surface of ice sheets changes as a function of time due to the effects of deposition of new snow, ageing of dry snow, bare ice exposure, melting and run-off. Currently, the calculation of the albedo of ice sheets is highly parameterized within the earth system model EC-Earth by

  19. On the importance of the albedo parameterization for the mass balance of the Greenland ice sheet in EC-Earth

    NARCIS (Netherlands)

    Helsen, Michiel M.; Van De Wal, Roderik S.W.; Reerink, Thomas J.; Bintanja, Richard; Madsen, Marianne S.; Yang, Shuting; Li, Qiang; Zhang, Qiong

    2017-01-01

    The albedo of the surface of ice sheets changes as a function of time due to the effects of deposition of new snow, ageing of dry snow, bare ice exposure, melting and run-off. Currently, the calculation of the albedo of ice sheets is highly parameterized within the earth system model ECEarth by

  20. Superfund fact sheet: The remedial program. Fact sheet

    International Nuclear Information System (INIS)

    1992-09-01

    The fact sheet describes what various actions the EPA can take to clean up hazardous wastes sites. Explanations of how the criteria for environmental and public health risk assessment are determined and the role of state and local governments in site remediation are given. The fact sheet is one in a series providing reference information about Superfund issues and is intended for readers with no formal scientific training

  1. Tsunami deposits

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  2. Tsunami deposits

    International Nuclear Information System (INIS)

    2013-01-01

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  3. Punctuated sediment record resulting from channel migration in a shallow sand-dominated micro-tidal lagoon, Northern Wadden Sea, Denmark

    DEFF Research Database (Denmark)

    Fruergaard, M.; Andersen, T.J.; Nielsen, L.H.

    2011-01-01

    depositional environment, but tidal channel sediments dominate in the five sediment cores, making up 56% of the 15 mof sediment core. Sedimentation in the lagoon alternated between slow vertical aggradation of sand flats (1.5–2 mm yr-1) and very fast lateral progradation of point bars in tidal channels, which...... caused the formation of a punctuated lagoonal fill. Frequent and comprehensive reworking of the sand flat sediments by tidal channel migration entails loss of sedimentary structures and bioturbation related to sand flat deposits, and old sand flat sediments are only very sparsely preserved. We further...... conclude that long-term (millennial timescale) sediment accumulation in the lagoon was controlled by rising sea-level, whereas short-term (centurial timescale) sediment accumulation was controlled by local erosion and depositional events caused by lateral migration of channels. Records of short-term sea...

  4. Timing and mechanisms for the deposition of the glaciomarine mud in and around the Gulf of Maine: A discussion of alternative models

    Science.gov (United States)

    Oldale, Robert N.

    1989-01-01

    Glaciomarine mud in the Gulf of Maine, characterized by rhythmic seismic layers that mimic the morphology of the underlying surface, is composed of subequal amounts of silt and clay, variable amounts of sand, and sparse gravel-sized clasts. The mud is Wisconsinan in age and was deposited during the retreat of the last ice sheet. A beginning date of 38 ka, proposed by King and Fader (1986) in their chronology of the last deglaciation, is considered too old. An alternative chronology, more consistent with the continental record to the west, is proposed here. ln this interpretation, deposition ofglaciomarine mud began about 18 ka when the late Wisconsinan ice retreated from Georges Bank, Great South Channel, and Northeast Channel and ended around 11 ka, when meltwater ceased to enter the Gulf of Maine. Basal-till melt-out from an ice shelf and bergs as the source of the glaciomarine mud, also proposed by King and Fader (1986), is thought to be inconsistent with the volume, widespread rhythmic bedding, and low stone content of the deposit. More likely the source of the glaciomarine mud was rock-flour-laden meltwater that entered the sea along the grounding line of a calving glacier or by way of subaerial meltwater streams. The rock flour was then dispersed by sediment plumes and was deposited when the sediment fell to the sea floor, aided by flocculation and biological agglutination. Rhythmic layers within the glaciomarine mud could represent annual cyclic sedimentation (varves) or cyclic events of lesser duration.

  5. Teri deposits of India a unique feature of Tamil Nadu

    International Nuclear Information System (INIS)

    Murugan, C.

    2016-01-01

    The importance of placer sands in India needs no emphasis as it forms, at present, the only viable source for some minerals like ilmenite, rutile, zircon, leucoxene, monazite and garnet. The placer sand is an easily amenable source from which these minerals are separated by simple methods of beneficiation like gravity, electrostatic, magnetic separation etc. Among these, ilmenite, rutile, leucoxene are the ore minerals for titanium which is the backbone for pigment and paint industry. Zircon is the only source for zirconium, which has wide applications including nuclear industry. The rare earth phosphate monazite besides being the main source for rare earth elements is a source for thorium as well. Tamil Nadu is one of the three states of India contributing about 30% of economic heavy minerals resources of the country. Here the beach sand is harnessed in a big way since the beginning of the 20"t"h century. In Tamil Nadu, in addition to the beach sand, the red sands occurring over the coastal regions are also heavy mineral-bearing. They, especially, occur in the Ramanathapuram, Tuticorin and Tirunelveli districts, where they are known as Teris (Teri is a Tamil word meaning red migrating dune sands/undulating dunes occupying higher elevation relative to surrounding areas). The occurrence of heavy minerals in the Teri sand deposits was established by AMD in 1950s. The teri red sand deposits account for 74 % ilmenite and monazite resources, 72% of zircon and 68% of sillimanite resources of the state. Some of the important Teri dune deposits include Kudiraimoli and Sattankulam in the eastern coast of Tamil Nadu. Such types of Teri sands dunes are few and far between in

  6. FeS-coated sand for removal of arsenic(III) under anaerobic conditions in permeable reactive barriers

    Science.gov (United States)

    Han, Y.-S.; Gallegos, T.J.; Demond, A.H.; Hayes, K.F.

    2011-01-01

    Iron sulfide (as mackinawite, FeS) has shown considerable promise as a material for the removal of As(III) under anoxic conditions. However, as a nanoparticulate material, synthetic FeS is not suitable for use in conventional permeable reactive barriers (PRBs). This study developed a methodology for coating a natural silica sand to produce a material of an appropriate diameter for a PRB. Aging time, pH, rinse time, and volume ratios were varied, with a maximum coating of 4.0 mg FeS/g sand achieved using a pH 5.5 solution at a 1:4 volume ratio (sand: 2 g/L FeS suspension), three days of aging and no rinsing. Comparing the mass deposited on the sand, which had a natural iron-oxide coating, with and without chemical washing showed that the iron-oxide coating was essential to the formation of a stable FeS coating. Scanning electron microscopy images of the FeS-coated sand showed a patchwise FeS surface coating. X-ray photoelectron spectroscopy showed a partial oxidation of the Fe(II) to Fe(III) during the coating process, and some oxidation of S to polysulfides. Removal of As(III) by FeS-coated sand was 30% of that by nanoparticulate FeS at pH 5 and 7. At pH 9, the relative removal was 400%, perhaps due to the natural oxide coating of the sand or a secondary mineral phase from mackinawite oxidation. Although many studies have investigated the coating of sands with iron oxides, little prior work reports coating with iron sulfides. The results suggest that a suitable PRB material for the removal of As(III) under anoxic conditions can be produced through the deposition of a coating of FeS onto natural silica sand with an iron-oxide coating. ?? 2010 Elsevier Ltd.

  7. Formability of porous tantalum sheet-metal

    International Nuclear Information System (INIS)

    Nebosky, Paul S; Schmid, Steven R; Pasang, Timotius

    2009-01-01

    Over the past ten years, a novel cellular solid, Trabecular Metal T M , has been developed for use in the orthopaedics industry as an ingrowth scaffold. Manufactured using chemical vapour deposition (CVD) on top of a graphite foam substrate, this material has a regular matrix of interconnecting pores, high strength, and high porosity. Manufacturing difficulties encourage the application of bending, stamping and forming technologies to increase CVD reactor throughput and reduce material wastes. In this study, the bending and forming behaviour of Trabecular Metal T M was evaluated using a novel camera-based system for measuring surface strains, since the conventional approach of printing or etching gridded patterns was not feasible. A forming limit diagram was obtained using specially fabricated 1.65 mm thick sheets. A springback coefficient was measured and modeled using effective hexagonal cell arrangements.

  8. 2012 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  9. State Fact Sheets on COPD

    Science.gov (United States)

    ... Submit Search The CDC Chronic Obstructive Pulmonary Disease (COPD) Note: Javascript is disabled or is not supported ... message, please visit this page: About CDC.gov . COPD Homepage Data and Statistics Fact Sheets Publications Publications ...

  10. Australian Government Balance Sheet Management

    OpenAIRE

    Wilson Au-Yeung; Jason McDonald; Amanda Sayegh

    2006-01-01

    Since almost eliminating net debt, the Australian Government%u2019s attention has turned to the financing of broader balance sheet liabilities, such as public sector superannuation. Australia will be developing a significant financial asset portfolio in the %u2018Future Fund%u2019 to smooth the financing of expenses through time. This raises the significant policy question of how best to manage the government balance sheet to reduce risk. This paper provides a framework for optimal balance sh...

  11. Energy information sheets, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  12. Energy information sheets, September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  13. Long-term sand supply to Coachella Valley Fringe-toed Lizard Habitat in the Northern Coachella Valley, California

    Science.gov (United States)

    Griffiths, Peter G.; Webb, Robert H.; Lancaster, Nicholas; Kaehler, Charles A.; Lundstrom, Scott C.

    2002-01-01

    The Coachella Valley fringe-toed lizard (Uma inornata) is a federally listed threatened species that inhabits active sand dunes in the vicinity of Palm Springs, California. The Whitewater Floodplain and Willow Hole Reserves provide some of the primary remaining habitat for this species. The sediment-delivery system that creates these active sand dunes consists of fluvial depositional areas fed episodically by ephemeral streams. Finer fluvial sediments (typically sand size and finer) are mobilized in a largely unidirectional wind field associated with strong westerly winds through San Gorgonio Pass. The fluvial depositional areas are primarily associated with floodplains of the Whitewater?San Gorgonio Rivers and Mission Creek?Morongo Wash; other small drainages also contribute fluvial sediment to the eolian system. The eolian dunes are transitory as a result of unidirectional sand movement from the depositional areas, which are recharged with fine-grained sediment only during episodic floods that typically occur during El Ni?o years. Eolian sand moves primarily from west to east through the study area; the period of maximum eolian activity is April through June. Wind speed varies diurnally, with maximum velocities typically occurring during the afternoon. Development of alluvial fans, alteration of stream channels by channelization, in-stream gravel mining, and construction of infiltration galleries were thought to reduce the amount of fluvial sediment reaching the depositional areas upwind of Uma habitat. Also, the presence of roadways, railroads, and housing developments was thought to disrupt or redirect eolian sand movement. Most of the sediment yield to the fluvial system is generated in higher elevation areas with little or no development, and sediment yield is affected primarily by climatic fluctuations and rural land use, particularly livestock grazing and wildfire. Channelization benefits sediment delivery to the depositional plains upwind of the reserves

  14. Critical State of Sand Matrix Soils

    Science.gov (United States)

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

    2014-01-01

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

  15. Sedimentology of a surficial uranium deposit on North Flodelle Creek, Stevens County, Washington

    International Nuclear Information System (INIS)

    Macke, D.L.; Johnson, S.Y.; Otton, J.K.

    1985-01-01

    Surficial accumulations of uranium (up to 0.2 wt. % U/sub 3/O/sub 8/, dry basis) are currently forming in organic-rich, poorly drained sediments deposited in fluvial-lacustrine environments. Known occurrences are in northeastern Washington, northern Idaho, the Sierra Nevada, the Colorado Front Range, New Hampshire, and several areas in Canada. The first accumulation of this type to be mined is in postglacial sediments of a 10-acre boggy meadow along North Flodelle Creek in Stevens County, Washington. The meadow is flanked by hills of fine- to medium-grained two-mica quartz monzonite that are mantled by glacial drift of late Wisconsin age (about 18,000 to 11,500 yr B.P.). Relatively thick, hummocky deposits of this same glacial drift impede drainage at the lower end of the meadow. Following ice retreat, glacial sediments on the meadow floor were reworked by fluvial processes, and patches of organic-rich sediment may have formed in ice-melt depressions. About 6700 yr B.P., a blanket of Mazama ash from the Crater Lake eruption was deposited in the meadow. Shortly thereafter, a beaver dam across the lower end of the meadow further restricted drainage, and peat and organic mud accumulated in the pond behind the dam. The dam is preserved in the stratigraphic record as a sheet-like body of woody peat (with beaver-gnawed sticks) about 100m wide and 60 cm thick. After the gradual influx of sand and coarse silt had filled the pond, and the beavers had abandoned the site, fluvial deposition was reestablished

  16. Invasive plants on disturbed Korean sand dunes

    Science.gov (United States)

    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

  17. Investing for the future : Athabasca Oil Sands Trust 1998 annual report

    International Nuclear Information System (INIS)

    1999-01-01

    The Athabasca Oil Sand Trust was created in 1995 when a subsidiary of the Trust, Athabasca Oil Sands Investment Inc., acquired Alberta's 11.74 per cent working interest in the Syncrude Project, which is a joint venture involved in the mining and upgrading of bitumen from the Athabasca oil sands. The Trust is a closed-end investment trust which was created to provide an opportunity for direct public investment in Syncrude and oil sands development in northern Alberta. Syncrude, produced a record 76.7 million barrels of Syncrude Sweet Blend (SSB), and shipped its one billionth barrel on April 16, 1998. Another key achievement in 1998 was the investment the Syncrude Joint Venture Partners of almost half a billion dollars to maintain Syncrude's operations and pursue the Business Plan growth targets outlined in last year's report. By aggressively pursuing this capital investment program despite the current low oil prices, the Syncrude Joint Venture Partners expect to double SSB production to 155 million barrels per year by 2007. The Athabasca Trust's share of these capital expenditures to fuel the projected growth in production is about $ 70 million this year and the next. The report provides operating statistics on production, financial highlights and consolidated balance sheets for 1998, including operating expenditures, capital expenditures, and the usual notes to the consolidated financial statement. 10 tabs., 2 figs

  18. Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

    Directory of Open Access Journals (Sweden)

    Goździk Jan

    2017-06-01

    Full Text Available Deposits formed between the Neogene/Pleistocene transition and into the Early Pleistocene have been studied, mainly on the basis of drillings and at rare, small outcrops in the lowland part of Polish territory. At the Bełchatów lignite mine (Kleszczów Graben, central Poland, one of the largest opencast pits in Europe, strata of this age have long been exposed in extensive outcrops. The present paper is based on our field studies and laboratory analyses, as well as on research data presented by other authors. For that reason, it can be seen as an overview of current knowledge of lowermost Pleistocene deposits at Bełchatów, where exploitation of the Quaternary overburden has just been completed. The results of cartographic work, sedimentological, mineralogical and palynological analyses as well as assessment of sand grain morphology have been considered. All of these studies have allowed the distinction of three Lower Pleistocene series, i.e., the Łękińsko, Faustynów and Krzaki series. These were laid down in fluvial environments between the end of the Pliocene up to the advance of the first Scandinavian ice sheet on central Poland. The following environmental features have been interpreted: phases of river incision and aggradation, changes of river channel patterns, source sediments for alluvia, rates of aeolian supply to rivers and roles of fluvial systems in morphological and geological development of the area. The two older series studied, i.e., Łękińsko and Faustynów, share common characteristics. They were formed by sinuous rivers in boreal forest and open forest environments. The Neogene substratum was the source of the alluvium. The younger series (Krzaki formed mainly in a braided river setting, under conditions of progressive climatic cooling. Over time, a gradual increase of aeolian supply to the fluvial system can be noted; initially, silt and sand were laid down, followed by sand only during cold desert conditions. These

  19. FDTD modeling of thin impedance sheets

    Science.gov (United States)

    Luebbers, Raymond J.; Kunz, Karl S.

    1991-01-01

    Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

  20. Watching Faults Grow in Sand

    Science.gov (United States)

    Cooke, M. L.

    2015-12-01

    Accretionary sandbox experiments provide a rich environment for investigating the processes of fault development. These experiments engage students because 1) they enable direct observation of fault growth, which is impossible in the crust (type 1 physical model), 2) they are not only representational but can also be manipulated (type 2 physical model), 3) they can be used to test hypotheses (type 3 physical model) and 4) they resemble experiments performed by structural geology researchers around the world. The structural geology courses at UMass Amherst utilize a series of accretionary sandboxes experiments where students first watch a video of an experiment and then perform a group experiment. The experiments motivate discussions of what conditions they would change and what outcomes they would expect from these changes; hypothesis development. These discussions inevitably lead to calculations of the scaling relationships between model and crustal fault growth and provide insight into the crustal processes represented within the dry sand. Sketching of the experiments has been shown to be a very effective assessment method as the students reveal which features they are analyzing. Another approach used at UMass is to set up a forensic experiment. The experiment is set up with spatially varying basal friction before the meeting and students must figure out what the basal conditions are through the experiment. This experiment leads to discussions of equilibrium and force balance within the accretionary wedge. Displacement fields can be captured throughout the experiment using inexpensive digital image correlation techniques to foster quantitative analysis of the experiments.

  1. Sudan challenges the sand dragon.

    Science.gov (United States)

    Tinker, J

    1978-01-01

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

  2. Studies of Phlebotomine Sand Flies.

    Science.gov (United States)

    1980-08-31

    coils. Holotype, allotype and 20 paratypes to be deposited at Instituto Nacional de Pesquisas da Amazonia , Manaus. Other para- types in Brazilian...collections at Universidad Federal de Minas Gerais and S~o Paulo; Instituto Oswaldo Cruz, Rio de Janeiro; Instituto Evandro Chagas, Be16m; Museu Paraense...of Mr. Joao Ferreira Vidal in the field and labora- tory. Literature Cited Floch, H. & E. Abonnenc. 1943. Phl~botomes de la Guyane Franqaise - v. Inst

  3. Sand to Root Transfer of PAHs and PCBs by Carrots Grown on Sand with Pure Substances and Biosolids Amended Sand

    OpenAIRE

    Sablayrolles, Caroline; Montréjaud-Vignoles, Mireille; Silvestre, Jérôme; Patria, Lucie

    2006-01-01

    A study on behaviour of trace organic compounds (Polycyclic Aromatic Hydrocarbons, PAH, and Polychlorinated Biphenyls, PCB) in a sand-plant system has been carried out, with the reclamation of wastewater treatment plant biosolids for agriculture in mind. Carrot plants (Daucus carota) were grown on soilless culture (sand), to provide optimal transfer conditions, in plant containers inside a temperature regulated greenhouse. There were two types of experiment. The trace organic compounds have i...

  4. Utilizing boron nitride sheets as thin supports for high resolution imaging of nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yimin A; Kirkland, Angus I; Schaeffel, Franziska; Porfyrakis, Kyriakos; Young, Neil P; Briggs, G Andrew D; Warner, Jamie H, E-mail: Jamie.warner@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2011-05-13

    We demonstrate the use of thin BN sheets as supports for imaging nanocrystals using low voltage (80 kV) aberration-corrected high resolution transmission electron microscopy. This provides an alternative to the previously utilized 2D crystal supports of graphene and graphene oxide. A simple chemical exfoliation method is applied to get few layer boron nitride (BN) sheets with micrometer-sized dimensions. This generic approach of using BN sheets as supports is shown by depositing Mn doped ZnSe nanocrystals directly onto the BN sheets and resolving the atomic structure from both the ZnSe nanocrystals and the BN support. Phase contrast images reveal moire patterns of interference between the beams diffracted by the nanocrystals and the BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes. Double diffraction is observed and has been analyzed.

  5. Utilizing boron nitride sheets as thin supports for high resolution imaging of nanocrystals

    International Nuclear Information System (INIS)

    Wu, Yimin A; Kirkland, Angus I; Schaeffel, Franziska; Porfyrakis, Kyriakos; Young, Neil P; Briggs, G Andrew D; Warner, Jamie H

    2011-01-01

    We demonstrate the use of thin BN sheets as supports for imaging nanocrystals using low voltage (80 kV) aberration-corrected high resolution transmission electron microscopy. This provides an alternative to the previously utilized 2D crystal supports of graphene and graphene oxide. A simple chemical exfoliation method is applied to get few layer boron nitride (BN) sheets with micrometer-sized dimensions. This generic approach of using BN sheets as supports is shown by depositing Mn doped ZnSe nanocrystals directly onto the BN sheets and resolving the atomic structure from both the ZnSe nanocrystals and the BN support. Phase contrast images reveal moire patterns of interference between the beams diffracted by the nanocrystals and the BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes. Double diffraction is observed and has been analyzed.

  6. Exogenous deposits

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

  7. Wear and microstructural characteristics of spray atomized zircon sand reinforced LM13 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, K.; Pandey, O.P. [School of Physics and Materials Science, Thapar University Patiala, Punjab (India)

    2010-07-15

    The requirement of the high performance light weight materials demands the development of varieties of materials within the economical range to get it commercialized. Light weight aluminium alloys are used in several structural applications like automotive, aerospace, defense industry and other fields of engineering. The ceramic particle reinforced aluminium metal matrix composites (AMCs) have emerged as a suitable candidate for commercial applications. A variety of processing routes have been adopted to manufacture AMCs. In the present work LM13 alloy reinforced with zircon sand is formed via spray forming. During experimentation a self prepared convergent-divergent nozzle is used for inert gas atomization of the melt which is subsequently deposited on copper substrate placed vertically below the atomizer. The zircon sand particles are injected in the atomization zone by external injectors aligned perpendicular to the gas atomization axis. Zircon sand has been found to have new promising economical commercial candidate due to its easy availability and good mechanical properties like high hardness, high modulus of elasticity and good thermal stability. The microhardness of cast alloy and spray formed composite shows that the spray formed zircon sand reinforced composite has higher hardness. Also the lower wear rate has been observed in case of the zircon sand reinforced AMC as compared to LM13 alloy. This behaviour is further analyzed in light of microstructural features of the spray deposited composite using optical and scanning electron microscope (SEM). A comparative study of this material (LM13/Zircon sand) with the parent alloy (LM13) is presented in this work. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. On Jovian plasma sheet structure

    International Nuclear Information System (INIS)

    Khurana, K.K.; Kivelson, M.G.

    1989-01-01

    The authors evaluate several models of Jovian plasma sheet structure by determining how well they organize several aspects of the observed Voyager 2 magnetic field characteristics as a function of Jovicentric radial distance. It is shown that in the local time sector of the Voyager 2 outbound pass (near 0300 LT) the published hinged-magnetodisc models with wave (i.e., models corrected for finite wave velocity effects) are more successful than the published magnetic anomaly model in predicting locations of current sheet crossings. They also consider the boundary between the plasma sheet and the magnetotail lobe which is expected to vary slowly with radial distance. They use this boundary location as a further test of the models of the magnetotail. They show that the compressional MHD waves have much smaller amplitude in the lobes than in the plasma sheet and use this criterion to refine the identification of the plasma-sheet-lobe boundary. When the locations of crossings into and out of the lobes are examined, it becomes evident that the magnetic-anomaly model yields a flaring plasma sheet with a halfwidth of ∼ 3 R J at a radial distance of 20 R J and ∼ 12 R J at a radial distance of 100 R J . The hinged-magnetodisc models with wave, on the other hand, predict a halfwidth of ∼ 3.5 R J independent of distance beyond 20 R J . New optimized versions of the two models locate both the current sheet crossings and lobe encounters equally successfully. The optimized hinged-magnetodisc model suggests that the wave velocity decreases with increasing radial distance. The optimized magnetic anomaly model yields lower velocity contrast than the model of Vasyliunas and Dessler (1981)

  9. Subaqueous ice-contact fans: Depositional systems characterised by highly aggradational supercritical flow conditions

    Science.gov (United States)

    Lang, Joerg; Winsemann, Jutta

    2015-04-01

    Subaqueous ice-contact fans are deposited by high-energy plane-wall jets from subglacial conduits into standing water bodies. Highly aggradational conditions during flow expansion and deceleration allow for the preservation of bedforms related to supercritical flows, which are commonly considered rare in the depositional record. We present field examples from gravelly and sandy subaqueous ice-contact fan successions, which indicate that deposition by supercritical flows might be considered as a characteristic feature of these depositional systems. The studied successions were deposited in deep ice-dammed lakes, which formed along the margins of the Middle Pleistocene Scandinavian ice sheets across Northern Germany. The gravel-rich subaqueous fan deposits are dominated by large scour-fills (up to 25 m wide and 3 m) deep and deposits of turbulent hyperconcentrated flows, which are partly attributed to supercritical flow conditions (Winsemann et al., 2009). Scours (up to 4.5 m wide and 0.9 m deep) infilled by gravelly backsets are observed above laterally extensive erosional surfaces and are interpreted as deposits of cyclic steps. Laterally discontinuous beds of low-angle cross-stratified gravel are interpreted as antidune deposits. Downflow and up-section the gravel-rich deposits pass into sand-rich successions, which include deposits of chutes-and-pools, breaking antidunes, stationary antidunes and humpback dunes (Lang and Winsemann, 2013). Deposits of chutes-and-pools and breaking antidunes are characterised by scour-fills (up to 4 m wide and 1.2 m deep) comprising backsets or gently dipping sigmoidal foresets. Stationary antidune deposits consist of laterally extensive sinusoidal waveforms with long wavelengths (1-12 m) and low amplitudes (0.1-0.5 m), which formed under quasi-steady flows at the lower limit of the supercritical flow stage and high rates of sedimentation. Humpback dunes are characterised by divergent sigmoidal foresets and are interpreted as

  10. Controllable preparation of vertically standing graphene sheets and their wettability and supercapacitive properties

    International Nuclear Information System (INIS)

    Zhou Hai-Tao; Zou Fei; Gao Ge; Yu Ning; Yao Zhao-Hui; Shen Cheng-Min

    2016-01-01

    Vertically standing graphene (VSG) sheets have been fabricated by using plasma enhanced chemical vapor deposition (PECVD) method. The lateral size of VSG nanosheets could be well controlled by varying the substrate temperature. The higher temperature usually gives rise to a smaller sheet size. The wettability of VSG films was tuned between hydrophobicity and hydrophilicity by means of oxygen and hydrogen plasma treatment. The supercapacitor electrode made of VSG sheets exhibited an ideal double-layer-capacitor feature and the specific capacitance reached a value up to 9.62 F·m −2 . (rapid communication)

  11. experimental studies of sand production from unconsolidated

    African Journals Online (AJOL)

    ES Obe

    aDepartment of Chemical Engineering, University of Lagos, Lagos, Nigeria. bDepartment of Petroleum ... as risk of well failure, erosion of pipelines and surface facilities, sand separa- ... ment, theoretical and numerical analysis have lead to the ...

  12. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...... MCPA degradation for prolonged periods in flow-through sand columns. In an expression study of catabolic genes with putative roles in phenoxy acid degradation, we observed a marked upregulation of catabolic genes cadA and tfdC upon exposure to MCPA, 2,4-D, dichlorprop and mecoprop in strain PM2, which...

  13. Geotechnical properties of crude oil contaminated sand

    International Nuclear Information System (INIS)

    Puri, V.K.; Das, B.M.; Cook, E.E.; Shin, E.C.

    1994-01-01

    Contamination of soil due to an oil spill influences its subsequent engineering behavior. An investigation was conducted to study the effect of crude oil contamination on compaction characteristics, shear strength, one-dimensional compression, and coefficient of permeability. Water permeability was also determined by using commercial grade motor oils as contaminants. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand (based on total stress condition) decreases due to presence of oil within the pore spaces in sand. One dimensional compression characteristics of sand are significantly influenced by oil contamination resulting in a decrease in the value of constrained modulus with increase in the degree of oil contamination compared to the case of dry sand. Water permeability was observed to be a function of the initial viscosity and the degree of saturation due to the contaminating oil

  14. Displacement pile installation effects in sand

    NARCIS (Netherlands)

    Beijer-Lundberg, A.

    2015-01-01

    Installation effects govern the post-installation behaviour of displacement piles in sand. These effects are currently not completely understood. Suitable experimental techniques to model these installation effects include field, laboratory and experimental models. In the current thesis a

  15. Automobile sheet metal part production with incremental sheet forming

    Directory of Open Access Journals (Sweden)

    İsmail DURGUN

    2016-02-01

    Full Text Available Nowadays, effect of global warming is increasing drastically so it leads to increased interest on energy efficiency and sustainable production methods. As a result of adverse conditions, national and international project platforms, OEMs (Original Equipment Manufacturers, SMEs (Small and Mid-size Manufacturers perform many studies or improve existing methodologies in scope of advanced manufacturing techniques. In this study, advanced manufacturing and sustainable production method "Incremental Sheet Metal Forming (ISF" was used for sheet metal forming process. A vehicle fender was manufactured with or without die by using different toolpath strategies and die sets. At the end of the study, Results have been investigated under the influence of method and parameters used.Keywords: Template incremental sheet metal, Metal forming

  16. Thermochemical method for the treatment of oil contaminated sand; Metodo termoquimico para tratamento de areia contaminada por oleo

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Rosana C.G.M. [Fundacao Gorceix, Ouro Preto, MG (Brazil)]|[PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Khalil, Carlos N. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    In January 2000 there was a major oil spill in Guanabara Bay, Rio de Janeiro, which contaminated 2400 tons of sand. This work, based on NGS (Nitrogen Generating System) technology, was adapted for cleaning contaminated sand and recovering of spilled oil. NGS is a thermochemical method first developed for removal of paraffin deposits in production and export pipelines. The method is based on a strongly exothermic redox chemical reaction between two salts catalyzed in acidic pH. The reaction products are harmless to the environment and consist of nitrogen, sodium chloride, water and heat. By combining simultaneous effects of the treatment such as heating, turbulence and floatation, one can remove, within 98% of efficiency, spilling oil from contaminated sand. After treatment, removed oil can be securely returned to refining process. The method has proved to be efficient, fast, low cost and ecologically correct method for cleaning contaminated sand and can be applied in place right after a contamination event. (author)

  17. Dune associated calcretes, Rhizoliths and Paleosols from the western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Thamban, M.

    detrital/carbonate sands with thin heavy mineral laminations are found. Textural studies indicate that the detrital sands are derived from dunes. Drusy calcite and neomorphic calcite cements are associated with the sands. Sheet deposits contain coarse...

  18. Formulating Fine to Medium Sand Erosion for Suspended Sediment Transport Models

    Directory of Open Access Journals (Sweden)

    François Dufois

    2015-08-01

    Full Text Available The capacity of an advection/diffusion model to predict sand transport under varying wave and current conditions is evaluated. The horizontal sand transport rate is computed by vertical integration of the suspended sediment flux. A correction procedure for the near-bed concentration is proposed so that model results are independent of the vertical resolution. The method can thus be implemented in regional models with operational applications. Simulating equilibrium sand transport rates, when erosion and deposition are balanced, requires a new empirical erosion law that involves the non-dimensional excess shear stress and a parameter that depends on the size of the sand grain. Comparison with several datasets and sediment transport formulae demonstrated the model’s capacity to simulate sand transport rates for a large range of current and wave conditions and sand diameters in the range 100–500 μm. Measured transport rates were predicted within a factor two in 67% of cases with current only and in 35% of cases with both waves and current. In comparison with the results obtained by Camenen and Larroudé (2003, who provided the same indicators for several practical transport rate formulations (whose means are respectively 72% and 37%, the proposed approach gives reasonable results. Before fitting a new erosion law to our model, classical erosion rate formulations were tested but led to poor comparisons with expected sediment transport rates. We suggest that classical erosion laws should be used with care in advection/diffusion models similar to ours, and that at least a full validation procedure for transport rates involving a range of sand diameters and hydrodynamic conditions should be carried out.

  19. Supercritical solvent extraction of oil sand bitumen

    Science.gov (United States)

    Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

    2017-08-01

    The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

  20. Measurements of α-emitting plutonium and americium in the intertidal sands of west Cumbria, UK

    International Nuclear Information System (INIS)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J.

    1990-01-01

    Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for 238 Pu, 239+240 Pu and 241 Am. Generally, more than 95% of the α-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m -2 of 239+240 Pu and 241 Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total α-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made α-emitters exceed those of natural α-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author)

  1. Measurements of. alpha. -emitting plutonium and americium in the intertidal sands of west Cumbria, UK

    Energy Technology Data Exchange (ETDEWEB)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J. (UKAEA Harwell Lab. (UK). Environmental and Medical Science Div.)

    1990-01-01

    Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. Generally, more than 95% of the {alpha}-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m{sup -2} of {sup 239+240}Pu and {sup 241}Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total {alpha}-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made {alpha}-emitters exceed those of natural {alpha}-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author).

  2. Maturation, fecundity, and intertidal spawning of Pacific sand lance in the northern Gulf of Alaska

    Science.gov (United States)

    Robards, Martin D.; Piatt, John F.; Rose, G.A.

    1999-01-01

    Pacific sand lance Ammodytes hexapterus in Kachemak Bay, Alaska, showed no sexual dimorphism in length-to-weight (gonad-free) ratio or length-at-age relationship. Most matured in their second year, males earlier in the season than females, but females (31%) attained a higher gonadosomatic index than males (21%). Sand lance spawned intertidally once each year in late September and October on fine gravel or sandy beaches soon after the seasonal peak in water temperatures. Sand lance in Cook Inlet and Prince William Sound displayed similar maturation schedules. Schools were dominated 2: 1 by males as they approached the intertidal zone at a site where spawning has taken place for decades. Sand lance spawned vigorously in dense formations, leaving scoured pits in beach sediments. Fecundity of females (93–199 mm) was proportional to length, ranging from 1468 to 16 081 ova per female. About half of the overall spawning school fecundity was derived from age group 1 females (55% of the school by number). Spawned eggs were 1·02 mm in diameter, demersal, slightly adhesive, and deposited in the intertidal just below the waterline. Sand lance embryos developed over 67 days through periods of intertidal exposure and sub-freezing air temperatures.

  3. An introduction to conservation and reclamation at Alberta's mineable oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Richens, T. [Alberta Environment, Edmonton, AB (Canada)

    2009-07-01

    This paper presented a balanced view of the conservation and reclamation issues and challenges facing oil sands development in Alberta. Bitumen is recovered by truck and shovel in the shallow oil sands of the Athabasca region. The deeper deposits in the Athabasca, Peace River and Cold Lake regions are accessed primarily using a system of horizontal wells and steam to extract the bitumen from the sand and pump it to the surface. Individual in-situ operations have a smaller environmental impact than mines, and do not produce tailings ponds. However, the footprint of in-situ facilities will accumulate over time because of the potential for extensive future development. The key issues facing conservation and reclamation in the mineable oil sands were discussed. Summary statistics on land disturbed and reclaimed in the region were also provided. The challenges facing reclamation activities include long timeframes; large scale, regional planning and integration; competing land use goals; revegetation; byproduct management; and tailings and process-affected water. Multi-stakeholder forums have proven to be the key to the progression of monitoring, research and development and the sharing of knowledge and information. Frameworks have been developed for the assessment of pre-disturbed and reclaimed soil capability specific to the oil sands region. Additional resources are also available, such as guidelines for the reclamation of terrestrial and wetland habitats that represent the best management practices for reclamation research in revegetation, soil salvage, stockpiling and placement, tailings reclamation, end pit lakes, wetlands and biodiversity. 16 refs., 1 fig.

  4. Oil sands development contributes polycyclic aromatic compounds to the Athabasca River and its tributaries

    Science.gov (United States)

    Kelly, Erin N.; Short, Jeffrey W.; Schindler, David W.; Hodson, Peter V.; Ma, Mingsheng; Kwan, Alvin K.; Fortin, Barbra L.

    2009-01-01

    For over a decade, the contribution of oil sands mining and processing to the pollution of the Athabasca River has been controversial. We show that the oil sands development is a greater source of contamination than previously realized. In 2008, within 50 km of oil sands upgrading facilities, the loading to the snowpack of airborne particulates was 11,400 T over 4 months and included 391 kg of polycyclic aromatic compounds (PAC), equivalent to 600 T of bitumen, while 168 kg of dissolved PAC was also deposited. Dissolved PAC concentrations in tributaries to the Athabasca increased from 0.009 μg/L upstream of oil sands development to 0.023 μg/L in winter and to 0.202 μg/L in summer downstream. In the Athabasca, dissolved PAC concentrations were mostly snow, dissolved PAC concentrations were up to 4.8 μg/L, thus, spring snowmelt and washout during rain events are important unknowns. These results indicate that major changes are needed to the way that environmental impacts of oil sands development are monitored and managed. PMID:19995964

  5. Uranium mining sites - Thematic sheets

    International Nuclear Information System (INIS)

    2009-01-01

    A first sheet proposes comments, data and key numbers about uranium extraction in France: general overview of uranium mining sites, status of waste rock and tailings after exploitation, site rehabilitation. The second sheet addresses the sources of exposure to ionizing radiations due to ancient uranium mining sites: discussion on the identification of these sources associated with these sites, properly due to mining activities or to tailings, or due to the transfer of radioactive substances towards water and to the contamination of sediments, description of the practice and assessment of radiological control of mining sites. A third sheet addresses the radiological exposure of public to waste rocks, and the dose assessment according to exposure scenarios: main exposure ways to be considered, studied exposure scenarios (passage on backfilled path and grounds, stay in buildings built on waste rocks, keeping mineralogical samples at home). The fourth sheet addresses research programmes of the IRSN on uranium and radon: epidemiological studies (performed on mine workers; on French and on European cohorts, French and European studies on the risk of lung cancer associated with radon in housing), study of the biological effects of chronic exposures. The last sheet addresses studies and expertises performed by the IRSN on ancient uranium mining sites in France: studies commissioned by public authorities, radioactivity control studies performed by the IRSN about mining sites, participation of the IRSN to actions to promote openness to civil society

  6. Sintering and microstructure evolution of columnar nickel-based superalloy sheets prepared by EB-PVD

    International Nuclear Information System (INIS)

    Chen, S.; Qu, S.J.; Liang, J.; Han, J.C.

    2010-01-01

    Research highlights: → EB-PVD technology is commonly used to deposit thermal barrier coatings (TBCs) and columnar structure is commonly seen in EB-PVD condensates. The unique columnar structure can provide outstanding resistance against thermal shock and mechanical strains for TBCs. However, a number of researchers have found that the columnar structure can affect the mechanical properties of EB-PVD alloy thin sheet significantly. As yet, works on how to reduce this kind of effects are seldom done. In the present article, we tried to reveal the sintering effects on microstructure evolution and mechanical properties of columnar Ni-based superalloy sheet. The results suggests that after sintering, the columnar structure degrades. Degradation depends on sintering temperature and time. Both the ultimate tensile strength and the elongation percentage are effectively improved after sintering. - Abstract: A ∼0.15 mm-thick columnar nickel-based superalloy sheet was obtained by electron beam physical vapor deposition (EB-PVD). The as-deposited alloy sheet was sintered at different conditions. The microstructure of the specimens before and after sintering was characterized by using scanning electron microscopy. An X'Pert texture facility was used to determine the crystallographic orientation of the as-deposited alloy sheet. The phase transformation was investigated by X-ray diffraction. Tensile tests were conducted at room temperature on as-deposited and sintered specimens. The results show that the as-deposited sheet is composed of typical columnar structures. After sintering, however, the columnar structure degrades. The degradation depends on sintering temperature and time. Both the ultimate tensile strength and the elongation percentage are effectively improved after sintering.

  7. Assessment of Mud-Capped Dredge Pit Evolution Offshore Louisiana: Implications to Sand Excavation and Coastal Restoration

    Science.gov (United States)

    Xu, K.; Miner, M. D.; Bentley, S. J.; Li, C.; Obelcz, J.; O'Connor, M. C.

    2016-02-01

    The shelf offshore Louisiana is characterized by a dominantly muddy seafloor with a paucity of restoration-quality sand proximal to shore. Discrete sand deposits associated with ancient rivers that incised the shelf during lower sea-level positions occur close to shore. These shelf channel sands have been targeted for coastal restoration projects resulting in significant cost savings over more distal deposits. Several recent projects targeted shelf paleo-fluvial deposits comprising relatively deep (10 m) channel sands underlying a muddy overburden. Because of contrasting characteristics of cohesive mud vs. non-cohesive sand and potential modern fluvial mud supply from the Mississippi and Atchafalaya Rivers, long term pit evolution is poorly understood relative to their more common sand-only counterparts. Alterations to seafloor topography from dredging shelf sediment resources can potentially affect oil and gas infrastructure or other resources of concern (i.e. historic shipwrecks) located proximal to dredge pits. Site-specific data required to make accurate predictions and empirical measurements to test and validate predictive models were only available for Peveto Channel offshore Holly Beach, Louisiana. Here we present new geophysical and geological data (bathymetry, sidescan, subbottom, and radionuclide of sediment cores) and physical oceanographic observations (hydrodynamics and sediment dynamics) collected at Raccoon Island (dredged in 2013) dredge pit in Louisiana. These field data collections along with pre-existing data provide a time-series to capture evolution at Raccoon Island post-excavation. Conceptual morphological models will be developed for dredge pit evolution and testing effectiveness of setback buffers protecting pipelines, habitats, and cultural resources. Our results will increase decision making ability regarding safety and protecting environmental and cultural resources, and better management of valuable sand resources.

  8. Comparison of braided-stream depositional environment and uranium deposits at Saint Anthony underground mine

    International Nuclear Information System (INIS)

    Baird, C.W.; Martin, K.W.; Lowry, R.M.

    1980-01-01

    United Nuclear's Saint Anthony mine, located in the Laguna district, produces uranium ore from the Jackpile sandstone unit of the Morrison Formation. The Jackpile sediments were deposited in a fluvial environment characterized by aridity, gentle slope, distant source area, and limited flow volume. Resultant stratigraphy consists of an intricate assemblage of trough and tabular cross-stratification grading to near massive bedding at some locations. Interbedded with the Jackpile sands are green mudstones and siltstones that commonly display irregular thicknesses of less than 2 ft and that are laterally discontinuous. Major penecontemporaneous and postdepositional alteration of originally deposited sands, silts, and clays includes: 1) infiltration and filling of interstices by kaolinitic clays; 2) mobilization and relocation of organic carbonaceous material; and 3) geochemical alteration of mineral constituents and fixation of uranium ions in organic carbonaceous material. Mineralized zones of economic volume display a spatial relationship to bedding features indicative of loosely packed sand deposited in dune and trough foresets. This relationship indicates possible permeability control by initial stratigraphy upon the flow of mineralizing solutions. Additionally, the low-energy foreset environment facilitates the accumulation of low-specific-gravity carbonaceous material necessary for interaction with mineralizing solutions. Large volumes of loosely packed foreset sands accumulate in transverse bars in braided-stream environments. These structures have a great potential for conducting large volumes of mineralizing fluids and hosting economic quantities of uranium ore

  9. RESEARCH ON THE DEGREE OF SATURATION INVESTIGATION BY THE SAMPLING OF THE SAND FOR LIQUEFACTION

    Science.gov (United States)

    Fujii, Nao; Ohuchi, Masatoshi; Sakai, Katsuo; Nishigaki, Makoto

    The liquefaction countermeasure technical method, whereby the liquefaction strength is enhanced by making sand deposit in the state of unsaturation, is currently under study. The author et al have suggested a simple method of verifying the persistence of residual air using the undisturbed sample under ordinary temperature and sampling underground water; and have actually implemented the method in the adjacent ground with the foundation of viaduct pneumatic caisson where the leaked air during the construction was considered to have been trapped. We demonstrated the method of correcting the influence of the pressure of sampling specimen as well as of the dissolved air, and studied the precision of required degree of saturation. As the result, it has been shown that the residual air entrapped in the sand deposit is sustainable for as long time as about 28 years.

  10. Understanding AL-PAM assisted oil sands tailings treatment

    Energy Technology Data Exchange (ETDEWEB)

    Guo, L.; Maham, Y.; Masliyah, J.; Xu, Z. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2010-07-01

    Technologies currently used to treat oil sands tailings include the composite tailings (CT) process and the thickened tailings (TT) or paste technology process. This PowerPoint presentation discussed a flocculation and filtration method used to produce stackable tailings deposits. Magnafloc 1011 and AL-PAM additions were used as part of the filtration technique to produce very dry filter cakes. The effect of AL-PAM molecular weight and aluminum content on tailings treatments was investigated as well as the effect of tailings characteristics on the performance of flocculant-assisted tailings filtration processes. The AL-PAM molecular structure was studied. An experimental study was conducted to determine the effect of various polymer additions on fresh tailings from an oil sands plant. The study showed that the optimum dosage for settling and filtration was lower for higher molecular weight AL-PAM. A higher aluminum content was beneficial for settling. Increases in the aluminum content did not improve filtration rates, but reduced optimal dosages. Step-by-step details of the supernatant filtration process were provided, as well as photographs of the laboratory study. tabs., figs.

  11. Oil sands tailings technology : understanding the impact to reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Mamer, M. [Suncor Energy Inc., Fort McMurray, AB (Canada)

    2010-07-01

    This paper discussed tailings management techniques at oil sands mines and their effects on reclamation schedules and outcomes. The layer of mature fine tailings (MFT) that forms in tailings ponds does not settle within a reasonable time frame, requiring more and larger tailings ponds for storing MFT. Consolidated tailings (CT) technology was developed to accelerate the consolidation of MFT, although the process nonetheless takes decades. CT is produced from mixing tailings sand, gypsum, and MFT to create a mixture that will consolidate more quickly and release water. However, CT production is tied to the extraction process, making it applicable only when the plant is operational, and a precise recipe and accurate injection are required for CT to work. In tailings reduction operations (TRO), a new approach to tailings management, MFT is mixed with a polymer flocculant, deposited in thin layers, and allowed to dry. TRO has a significant advantage over CT in that the latter takes up to 30 years to consolidate to a trafficable surface compared to weeks for TRO. TRO allows MFT to be consumed more quickly than it is produced, reducing need to build more tailings ponds, operates independent of plant operations, accelerates the reclamation time frame, and offers enhanced flexibility in final tailings placement sites. TRO also creates a dry landscape, to which well established reclamation techniques can be applied. Dried MFT is a new material type, and research is exploring optimum reclamation techniques. 2 figs.

  12. Ambient air quality observations in the Athabasca oil sands region

    International Nuclear Information System (INIS)

    1996-01-01

    Both Syncrude and Suncor have plans to develop new oil sands leases and to increase crude oil and bitumen recovery in the Athabasca oil sands region. In recognition of the effects that this will have on the environment, Suncor has proposed modifications to reduce SO 2 emissions to the atmosphere, while Syncrude plans to develop additional ambient air quality, sulphur deposition and biomonitoring programs. This report discussed the ambient air quality monitoring that was undertaken in the Fort McMurray-Fort McKay airshed. Twelve continuous ambient air quality stations and 76 passive monitoring stations are maintained in the region. Environment Canada maintains eight precipitation monitoring stations in northern Alberta and Saskatchewan. Source characterization, ambient air quality and meteorology observations, air quality monitoring, and air quality data from continuous sulphur dioxide, hydrogen sulphide, nitrogen oxides, ozone, carbon monoxide, hydrocarbon, acid rain and particulates analyzers were reviewed. The documentation of all computer files used for the analysis of the air quality data is discussed in the Appendix. 47 refs., 39 tabs., 53 figs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-05-01

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

  14. Road dust from pavement wear and traction sanding

    Energy Technology Data Exchange (ETDEWEB)

    Kupiainen, K.

    2007-07-01

    Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is 'road dust'. The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: (i) How do traction

  15. Magnetoresistive multilayers deposited on the AAO membranes

    International Nuclear Information System (INIS)

    Malkinski, Leszek M.; Chalastaras, Athanasios; Vovk, Andriy; Jung, Jin-Seung; Kim, Eun-Mee; Jun, Jong-Ho; Ventrice, Carl A.

    2005-01-01

    Silicon and GaAs wafers are the most commonly used substrates for deposition of giant magnetoresistive (GMR) multilayers. We explored a new type of a substrate, prepared electrochemically by anodization of aluminum sheets, for deposition of GMR multilayers. The surface of this AAO substrate consists of nanosized hemispheres organized in a regular hexagonal array. The current applied along the substrate surface intersects many magnetic layers in the multilayered structure, which results in enhancement of giant magnetoresistance effect. The GMR effect in uncoupled Co/Cu multilayers was significantly larger than the magnetoresistance of similar structures deposited on Si

  16. Root-growth-inhibiting sheet

    Science.gov (United States)

    Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.; Van Voris, P.

    1993-01-26

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a geotextile'' and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  17. Optimal swimming of a sheet.

    Science.gov (United States)

    Montenegro-Johnson, Thomas D; Lauga, Eric

    2014-06-01

    Propulsion at microscopic scales is often achieved through propagating traveling waves along hairlike organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of flagellar propulsion. We derive numerically the large-amplitude wave form of the two-dimensional swimming sheet that yields optimum hydrodynamic efficiency: the ratio of the squared swimming speed to the rate-of-working of the sheet against the fluid. Using the boundary element method, we show that the optimal wave form is a front-back symmetric regularized cusp that is 25% more efficient than the optimal sine wave. This optimal two-dimensional shape is smooth, qualitatively different from the kinked form of Lighthill's optimal three-dimensional flagellum, not predicted by small-amplitude theory, and different from the smooth circular-arc-like shape of active elastic filaments.

  18. Root-growth-inhibiting sheet

    Science.gov (United States)

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene; Van Voris, Peter

    1993-01-01

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  19. Effect of manufactured sand on the durability characteristics of concrete

    Directory of Open Access Journals (Sweden)

    S. S. SARAVANAN

    2016-12-01

    Full Text Available Concrete is the most sought after material due to increase in construction activities and infrastructural developments. Availability of natural sand is decreasing thereby increase in the cost of construction. In the present work undertaken, an attempt has been made to give an alternative to natural sand. Optimization of replacement of natural sand with manufactured sand in concrete, durability studies such as water absorption, rapid chloride permeability test, sorptivity, acid resistance, alkaline resistance, impact resistance and abrasion resistance of M40 and M50 grades of concrete have been studied with manufactured sand as fine aggregate and compared the results with the conventional sand concrete. The results shows that there is an increase in the durability properties up to 70 % level of replacements of sand with manufactured sand as fine aggregate and for 100 % use of manufactured sand also gives the better durability than the conventional sand concrete.

  20. Studies on various characteristics of concrete structures using crushed sand

    International Nuclear Information System (INIS)

    Mimatsu, Makoto; Sugita, Hideaki; Yonemura, Masataka.

    1985-01-01

    With the recent advances of construction industry, the demands for concrete, hence for aggregate, are rising. The sand as such is in extreme shortage due to the exhaustion of river sand. Under the situation, the recent trends are for the use of crushed sand, i.e. the artificial sand obtained by crushing rocks, which have advantages of stabilized quality and adequate supplies. In building of nuclear power plants requiring large amounts of concrete, the usage of crushed sand is now unavoidable. The following are described : the situation of aggregate in Kyushu. production method of crushed sand and the quality standards, rocks used for crushed stone and sand and the properties, quality survey on crushed sand and the basic tests, characteristic tests of crushed-stone and -sand mixed concrete, the application of crushed sand in structures of the Sendai Nuclear Power Station. (Mori, K.)

  1. Meteorology observations in the Athabasca oil sands region

    International Nuclear Information System (INIS)

    1996-01-01

    Meteorological data was collected in the Athabasca oil sands area of Alberta in support of Syncrude' application for approval to develop and operate the Aurora Mine. Meteorology controls the transport and dispersion of gaseous and particulate emissions which are vented into the atmosphere. Several meteorological monitoring stations have been set up in the Fort McMurray and Fort McKay area. The study was part of Suncor's commitment to Alberta Environmental Protection to substantially reduce SO 2 emissions by July 1996. Also, as a condition of approval of the proposed Aurora Mine, the company was required to develop additional ambient air quality, sulphur deposition and biomonitoring programs. Background reports were prepared for: (1) source characterization, (2) ambient air quality observations, (3) meteorology observations, and (4) air quality monitoring. The following factors were incorporated into dispersion modelling: terrain, wind, turbulence, temperature, net radiation and mixing height, relative humidity and precipitation. 15 refs., 9 tabs., 40 figs

  2. Ice sheet hydrology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter; Naeslund, Jens-Ove [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden); Rodhe, Lars [Geological Survey of Sweden, Uppsala (Sweden)

    2007-03-15

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  3. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    to sea level high stands during past interglacial periods. A number of AIS models have been developed and applied to try to understand the workings of the AIS and to form a robust basis for future projections of the AIS contribution to sea level change. The recent DCESS (Danish Center for Earth System......The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly...

  4. Ice sheet hydrology - a review

    International Nuclear Information System (INIS)

    Jansson, Peter; Naeslund, Jens-Ove; Rodhe, Lars

    2007-03-01

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  5. Sheet Beam Klystron Instability Analysis

    International Nuclear Information System (INIS)

    Bane, K.

    2009-01-01

    Using the principle of energy balance we develop a 2D theory for calculating growth rates of instability in a two-cavity model of a sheet beam klystron. An important ingredient is a TE-like mode in the gap that also gives a longitudinal kick to the beam. When compared with a self-consistent particle-in-cell calculation, with sheet beam klystron-type parameters, agreement is quite good up to half the design current, 65 A; at full current, however, other, current-dependent effects come in and the results deviate significantly

  6. The social balance sheet 2004

    OpenAIRE

    Ph. Delhez; P. Heuse

    2005-01-01

    Each year, in the 4th quarter’s Economic Review, the National Bank examines the provisional results of the social balance sheets. As all the social balance sheets are not yet available for 2004, the study is based on a limited population of enterprises, compiled according to the principle of a constant sample. This population is made up of 38,530 enterprises employing around 1,331,000 workers in 2004. The main results of the analysis, in terms of employment, working hours, labour cost and tra...

  7. Leachate movement through unsaturated sand at a low-level radioactive-waste disposal site in northwestern Illinois

    International Nuclear Information System (INIS)

    Mills, P.C.; Devries, M.P.

    1988-01-01

    Movement of radionuclides and volatile organic compounds in soil water (leachate) were examined in an unsaturated sand deposit immediately underlying trenches at a low-level radioactive-waste disposal site near Sheffield, Illinois. Physical and hydraulic properties of the 2.0- to 8.0-meter thick sand deposit were defined from core samples. Soil-water samples were collected from 16 gravity lysimeters and 1 vacuum lysimeter from September 1986 through October 1987. Preliminary results include the following: Tritium, halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons, nonhalogenated aromatic hydrocarbons, and methyl esters were detected in the soil water. Gross alpha and gross beta concentrations were detected at background levels. Tritium flux through the gravity lysimeters ranged from 0.18 to 1.74 microcuries per year and totaled 5.14 microcuries per year. In most locations, soil-water movement occurred as slow, steady, unsaturated flow; more rapid saturated flow occurred along isolated, narrow (less than 1 square millimeter), vertical flow paths. The homogeneous texture and hydraulic properties of the sand deposit imply that the location of flow paths primarily is dependent on the locations of water entry into, and flow paths within, the void-rich trenches. The timing of water movement through the saturated pathways in the sand deposit was influenced, in part, by individual precipitation events and seasonal climatic trends. Changes in tritium concentration were attributable to changes in soil-water flux and to apparent deterioration of waste containers within the trenches

  8. Systematic logging utilizing a log sheet designed for drill core descriptions. An example in uranium exploration activities

    International Nuclear Information System (INIS)

    Sasao, Eiji; Tsuruta, Tadahiko; Iida, Yoshimasa

    2000-01-01

    We describe the log sheets used during uranium exploration activities for unconformity-related uranium deposits by JNC. The purpose of using the logging sheets is to standardize the objects which all geologists must observe and for data quality assurance. The log sheets are a three-part set describing basement lithology, sandstone lithology and geotechnics. We devised our own log sheets to describe both the sandstone and the underlying basement rock when we started exploration in Athabasca Basin, Canada. We modified the sheets to gain a better understanding of the geological features related to uranium mineralization, and made final improvements to satisfy required quality based on the criteria of descriptive objects and accuracy. Use of the log sheets resulted in effective performance of core logging and improvement in the display of data. (author)

  9. Study of Morphologic Change in Poyang Lake Basin Caused by Sand Dredging Using Multi-temporal Landsat Images and DEMs

    Science.gov (United States)

    Qi, S.; Zhang, X.; Wang, D.; Zhu, J.; Fang, C.

    2014-11-01

    Sand dredging has been practiced in rivers, lakes, harbours and coastal areas in recent years in China mostly because of demand from construction industry as building material. Sand dredging has disturbed aquatic ecosystems by affecting hydrological processes, increasing content of suspended sediments and reducing water clarity. Poyang Lake, connecting with Yangtze River in the lower reaches of the Yangtze River, is the largest fresh water lake in China. Sand dredging in Poyang Lake has been intensified since 2001 because such practice was banned in Yangtze River and profitable. In this study, the morphologic change caused by sand dredging in Poyang Lake basin was analysed by overlaying two DEMs acquired in 1952 and 2010 respectively. Since the reflectance of middle infrared band for sand dredging vessel is much higher than that of water surface, sand dredging vessels were showed as isolated grey points and can be counted in the middle infrared band in 12 Landsat images acquired in flooding season during 2000~2010. Another two Landsat images (with low water level before 2000 and after 2010) were used to evaluate the morphologic change by comparing inundation extent and shoreline shape. The following results was obtained: (1) vessels for sand dredging are mainly distributed in the north of Poyang Lake before 2007, but the dredging area was enlarged to the central region and even to Gan River; (2) sand dredging area reached to about 260.4 km2 and is mainly distributed in the north of Songmen Mountain and has been enlarged to central of Poyang Lake from the distribution of sand vessels since 2007. Sand dredged from Poyang Lake was about 1.99 × 109 m3 or 2448 Mt assuming sediment bulk density of 1.23 t m-3. It means that the magnitude of sand mining during 2001-2010 is almost ten times of sand depositions in Poyang Lake during 1955-2010; (3) Sand dredging in Poyang Lake has alternated the lake capacity and discharge section area, some of the watercourse in the

  10. Nuclear energy in the oils sands

    International Nuclear Information System (INIS)

    Arsenault, J.E.

    2014-01-01

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  11. Nuclear energy in the oils sands

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, J.E.

    2014-09-15

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  12. 10Be in desert sands, falling dust and loess in China

    International Nuclear Information System (INIS)

    Shen, C.D.; Beer, J.; Kubik, P.W.; Sun, W.D.; Liu, T.S.; Liu, K.X.

    2010-01-01

    Cosmogenic 10 Be is produced in the atmosphere, and deposits onto the surface of the earth mainly through wet precipitation and dust. Based on the analysis of 10 Be in Chinese loess, we believe that 10 Be in loess is composed of two components: locally precipitated atmospheric 10 Be, and windblown 10 Be adsorbed on the surface of silt grains. On the Loess Plateau, 10 Be concentrations in loess and paleosol range from (1.4 to 2.8) x 10 8 atoms/g and (2.7 to 4.5) x 10 8 atoms/g, respectively. To investigate the sources of 10 Be in loess, we measured 10 Be in sand grains from deserts in western China and falling dust from the deposition regions. The results show that the 10 Be concentrations in sand and dust are (1.1-5.1) x 10 7 atoms/g and (1.3-2.8) x 10 8 atoms/g, respectively. Loess and paleosol on the Loess Plateau both contain inherited 10 Be adsorbed on silt grains from dust; most of the windblown deposited loess materials do not directly come from the Gobi and other sand deserts, but mainly from the loess-desert transitional zones, which are characterized by silt and dust holding areas.

  13. Comparison between predicted and observed sand waves and sand banks in the North Sea

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; van den Brink, G.M.

    2001-01-01

    For the first time a prediction model of regular morphological patterns on the seabed was tested against observations of sand wave and sand bank occurrence in the entire North Sea. The model, which originates from first physical principles, predicts this occurrence via two dimensionless parameters

  14. MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

    Directory of Open Access Journals (Sweden)

    Lucimar Arruda Viana

    Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

  15. The Disruption of Tephra Fall Deposits by Basaltic Lava Flows

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2010-12-01

    Complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents of the Roza Member in the Columbia River Basalt Province, (CRBP), USA, illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter tephra fall deposits. Thin pahoehoe lobes and sheet lobes occur intercalated with tephra deposits and provide evidence for synchronous effusive and explosive activity. Tephra that accumulated on the tops of inflating pahoehoe flows became disrupted by tumuli, which dissected the overlying sheet into a series of mounds. During inflation of subjacent tumuli tephra percolated down into the clefts and rubble at the top of the lava, and in some cases came into contact with lava hot enough to thermally alter it. Lava breakouts from the tumuli intruded up through the overlying tephra deposit and fed pahoehoe flows that spread across the surface of the aggrading tephra fall deposit. Non-welded scoria fall deposits were compacted and welded to a depth of ~50 cm underneath thick sheet lobes. These processes, deduced from the field relationships, have resulted in considerable stratigraphic complexity in proximal regions. We also demonstrate that, when the advance of lava and the fallout of tephra are synchronous, the contacts of some tephra sheets can be diachronous across their extent. The net effect is to reduce the usefulness of pyroclastic deposits in reconstructing eruption dynamics.

  16. Sedimentary controls on modern sand grain coat formation

    Science.gov (United States)

    Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

    2017-05-01

    Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

  17. Geochemical characteristics of oil sands fluid petroleum coke

    International Nuclear Information System (INIS)

    Nesbitt, Jake A.; Lindsay, Matthew B.J.; Chen, Ning

    2017-01-01

    The geochemical characteristics of fluid petroleum coke from the Athabasca Oil Sands Region (AOSR) of northern Alberta, Canada were investigated. Continuous core samples were collected to 8 m below surface at several locations (n = 12) from three coke deposits at an active oil sands mine. Bulk elemental analyses revealed the coke composition was dominated by C (84.2 ± 2.3 wt%) and S (6.99 ± 0.26 wt%). Silicon (9210 ± 3000 mg kg"−"1), Al (5980 ± 1200 mg kg"−"1), Fe (4760 ± 1200 mg kg"−"1), and Ti (1380 ± 430 mg kg"−"1) were present in lesser amounts. Vanadium (1280 ± 120 mg kg"−"1) and Ni (230 ± 80 mg kg"−"1) exhibited the highest concentrations among potentially-hazardous minor and trace elements. Sequential extractions revealed potential for release of these metals under field-relevant conditions. Synchrotron powder X-ray diffraction revealed the presence of Si and Ti oxides, organically-complexed V and hydrated Ni sulfate, and provided information about the asphaltenic carbon matrix. X-ray absorption near edge structure (XANES) spectroscopy at the V and Ni K-edges revealed that these metals were largely hosted in porphyrins and similar organic complexes throughout coke grains. Minor differences among measured V and Ni K-edge spectra were largely attributed to slight variations in local coordination of V(IV) and Ni(II) within these organic compounds. However, linear combination fits were improved by including reference spectra for inorganic phases with octahedrally-coordinated V(III) and Ni(II). Sulfur and Fe K-edge XANES confirmed that thiophenic coordination and pyritic-ilmenitic coordination are predominant, respectively. These results provide new information on the geochemical and mineralogical composition of oil sands fluid petroleum coke and improve understanding of potential controls on associated water chemistry. - Highlights: • Oil sands fluid petroleum coke contains wide range of major, minor and

  18. Sedimentology of Hirnantian glaciomarine deposits in the Balkan Terrane, western Bulgaria: Fixing a piece of the north peri-Gondwana jigsaw puzzle

    Science.gov (United States)

    Chatalov, Athanas

    2017-04-01

    Glaciomarine deposits of late Hirnantian age in the western part of the Palaeozoic Balkan Terrane have persistent thickness ( 7 m) and lateral uniformity in rock colour, bedding pattern, lithology, and sedimentary structures. Four lithofacies are distinguished from base to top: lonestone-bearing diamictites, interbedded structureless mudstones, crudely laminated diamictites, and finely laminated mudstones. The diamictites are clast-poor to clast-rich comprising muddy to sandy varieties. Their compositional maturity is evidenced by the very high amount of detrital quartz compared to the paucity of feldspar and unstable lithic grains. Other textural components include extraclasts derived from the local Ordovician basement, mudstone intraclasts, and sediment aggregates. Turbate structures, grain lineations, and soft sediment deformation of the matrix below larger grains are locally observed. Sedimentological analysis reveals that deposition occurred in an ice-intermediate to ice-distal, poorly agitated shelf environment by material supplied from meltwater buoyant plumes and rain-out from ice-rafted debris. Remobilization by mass-flow processes (cohesive debris flows and slumps) was an important mechanism particularly for the formation of massive diamictites. The glaciomarine deposits represent a typical deglaciation sequence reflecting retreat of the ice front (grounded or floating ice sheet), relative sea-level rise and gradually reduced sedimentation rate with increasing contribution from suspension fallout. This sequence was deposited on the non-glaciated shelf of the intracratonic North Gondwana platform along the southern margin of the Rheic Ocean. The Hirnantian strata of the Balkan Terrane can be correlated with similar glaciomarine deposits known from peri-Gondwana terranes elsewhere in Europe showing clear 'Armorican affinity'. Several lines of evidence suggest that the provenance of siliciclastic material was associated mainly with sedimentary recycling of

  19. Learning from Balance Sheet Visualization

    Science.gov (United States)

    Tanlamai, Uthai; Soongswang, Oranuj

    2011-01-01

    This exploratory study examines alternative visuals and their effect on the level of learning of balance sheet users. Executive and regular classes of graduate students majoring in information technology in business were asked to evaluate the extent of acceptance and enhanced capability of these alternative visuals toward their learning…

  20. Off-Balance Sheet Financing.

    Science.gov (United States)

    Adams, Matthew C.

    1998-01-01

    Examines off-balance sheet financing, the facilities use of outsourcing for selected needs, as a means of saving operational costs and using facility assets efficiently. Examples of using outside sources for energy supply and food services, as well as partnering with business for facility expansion are provided. Concluding comments address tax…

  1. A Improved Seabed Surface Sand Sampling Device

    Science.gov (United States)

    Luo, X.

    2017-12-01

    In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

  2. Sand filter clogging by septic tank effluent.

    Science.gov (United States)

    Spychała, M; Błazejewski, R

    2003-01-01

    The aim of this study was to characterise conditions and factors affecting fine sand clogging by septic tank effluent on the basis of physical modelling. The physical model consisted of 12 sand columns dosed with sewage from one household (5 persons), preliminary treated in a septic tank. Hydraulic loadings of the sand filters were equal to 82 mm/d. The mean discharge from sand columns, measured as the effluent volume collected during 10 minutes, decreased significantly over the experiment period from 34 cm3/min in August 2000 to 20 cm3/min in August 2001 at the same temperature of about 20 degrees C. First the columns clogged almost completely after 480 days in December 2001, however six columns had remained unclogged till the end of the experiment (March 2002). The temperature had a significant impact on hydraulic conductivity. A vertical distribution of accumulated mass and biomass was investigated in partly clogged sand. Microscopic survey of the clogging layer showed a presence of live micro-organisms, residuals of dead micro-organisms, particularly pieces of small animal armour and many fibres. These particles accelerated the accumulation of solids in the upper clogging layer. The study indicated that temperature impact on the filter hydraulic conductivity was more significant for biological activity, than for sewage viscosity.

  3. The behavior of gaseous iodine in sand

    International Nuclear Information System (INIS)

    Takahashi, Kanji

    1974-01-01

    Radioactive iodine gas was passed through 10 different sands collected at rivers and hills. The relation between the amount of the loaded gas and the amount of adsorbed gas was determined at room temperature, 50 -- 60 0 C, and 90 -- 100 0 C under humidity of 2 sand. This amount was about 1 -- 3 times as much as that of monomolecular membrane adsorption, 0.2 -- 0.3 μg/cm 2 . The decrease of adsorption amount that accompanies the increase of humidity is attributable to the decrease of effective surface area of sand due to the presence of water. The transport of iodine in sand was studied by passing gaseous iodine through a glass tubing packed with sand. The distribution in the flow direction of iodine indicated that the ease of desorption depends upon the situation of adsorption. Easily desorbed case was named Henry type adsorption. Hardly desorbed case was named absorption type. Discussion is made on experimental results. (Fukutomi, T.)

  4. Mitigating in situ oil sands carbon costs

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

    2008-10-15

    Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

  5. Deposits related to supercritical flows in glacifluvial deltas and subaqueous ice-contact fans: Integrating facies analysis and ground-penetrating radar

    Science.gov (United States)

    Lang, Joerg; Sievers, Julian; Loewer, Markus; Igel, Jan; Winsemann, Jutta

    2017-04-01

    Bedforms related to supercritical flows have recently received much interest and the understanding of flow morphodynamics and depositional processes has been greatly advanced. However, outcrop studies of these bedforms are commonly hampered by their long wavelengths. Therefore, we combined outcrop-based facies analysis with extensive ground-penetrating radar (GPR) measurements. Different GPR antennas (200, 400 and 1500 MHz) were utilised to measure both long profiles and densely spaced grids in order to map the large-scale facies architecture and image the three-dimensional geometry of the deposits. The studied delta and subaqueous ice-contact fan successions were deposited within ice-dammed lakes, which formed along the margins of the Middle Pleistocene Scandinavian ice sheets across Northern Germany. These glacilacustrine depositional systems are characterised by high aggradation rates due to the rapid expansion and deceleration of high-energy sediment-laden flows, favouring the preservation of bedforms related to supercritical flows. In flow direction, delta foresets commonly display lenticular scours, which are 2 to 6 m wide and 0.15 to 0.5 m deep. Characteristically, scours are filled by upslope dipping backsets, consisting of pebbly sand. In a few cases, massive and deformed strata were observed, passing upflow into backsets. Across flow, scours are 2 to 3 m wide and typically display a concentric infill. The scour fills are commonly associated with subhorizontally or sinusoidal stratified pebbly sand. These facies types are interpreted as deposits of cyclic steps and antidunes, respectively, representing deposition from supercritical density flows, which formed during high meltwater discharge events or regressive slope failures (Winsemann et al., in review). The GPR-sections show that the scour fills form trains along the delta foresets, which can be traced for up to 15 m. The studied subaqueous ice-contact fan succession relates to the zone of flow

  6. A new turbulence-based model for sand transport

    Science.gov (United States)

    Mayaud, Jerome; Wiggs, Giles; Bailey, Richard

    2016-04-01

    Knowledge of the changing rate of sediment flux in space and time is essential for quantifying surface erosion and deposition in desert landscapes. While many aeolian studies have relied on time-averaged parameters such as wind velocity (U) and wind shear velocity (u*) to determine sediment flux, there is increasing evidence that high-frequency turbulence is an important driving force behind the entrainment and transport of sand. However, turbulence has yet to be incorporated into a functional sand transport model that can be used for predictive purposes. In this study we present a new transport model (the 'turbulence model') that accounts for high-frequency variations in the horizontal (u) and vertical (w) components of wind flow. The turbulence model is fitted to wind velocity and sediment transport data from a field experiment undertaken in Namibia's Skeleton Coast National Park, and its performance at three temporal resolutions (10 Hz, 1 Hz, 1 min) is compared to two existing models that rely on time-averaged wind velocity data (Radok, 1977; Dong et al., 2003). The validity of the three models is analysed under a variety of saltation conditions, using a 2-hour (1 Hz measurement resolution) dataset from the Skeleton Coast and a 5-hour (1 min measurement resolution) dataset from the southwestern Kalahari Desert. The turbulence model is shown to outperform the Radok and Dong models when predicting total saltation count over the three experimental periods. For all temporal resolutions presented in this study (10 Hz-10 min), the turbulence model predicted total saltation count to within at least 0.34%, whereas the Radok and Dong models over- or underestimated total count by up to 5.50% and 20.53% respectively. The strong performance of the turbulence model can be attributed to a lag in mass flux response built into its formulation, which can be adapted depending on the temporal resolution of investigation. This accounts for the inherent lag within the physical

  7. Evaluation criteria for uranium potential of sedimentary basins based on analysis of host sand body and structurally reworking pattern host sand body has been subject to

    International Nuclear Information System (INIS)

    Chen Zuyi; Guo Qingyin; Liu Hongxu

    2005-01-01

    On the basis of the introduction and the analysis of regional evaluation criteria for sandstone-type uranium deposits summarized by uranium geologists of USA and former Soviet Union, and by introducing new scientific progress in the field of sedimentology of clastic rocks, and basin geodynamics, main evaluation criteria composed of host sand body criterion and the criterion of structurally reworking pattern the host sand body has been subject to, are proposed, and the evaluation model based on analyzing the regional tectonic history and the evolution of prototype basin is set up. Finally, taking the Chaoshui basin as an example, the possibility for hosting epigenetic uranium mineralization in each horizon of the basin cover is discussed, then the main prospecting target horizon is discriminated, and potential ore-formation areas are proposed. (authors)

  8. Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

    International Nuclear Information System (INIS)

    Patel, R.B.; Chou, T.; Iqbal, Z.

    2014-01-01

    The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

  9. Dacitic ash-flow sheet near Superior and Globe, Arizona

    Science.gov (United States)

    Peterson, Donald W.

    1961-01-01

    Remnants of a dacitic ash-flow sheet near Globe, Miama, and Superia, Arizona cover about 100 square miles; before erosion the area covered by the sheet was at least 400 square miles and perhaps as much as 1,500 square miles. Its maximum thickness is about 2,000 feet, its average thickness is about 500 feet, and its original volume was at least 40 cubic miles. It was erupted on an eroded surface with considerable relief. The main part of the deposit was thought by early workers to be a lava flow. Even after the distinctive character of welded tuffs and related rocks was discovered, the nature and origin of this deposit remained dubious because textures did not correspond to those in other welded tuff bodies. Yet a lava flow as silicic as this dacite would be viscous instead of spreading out as an extensive sheet. The purpose of this investigation has been to study the deposit, resolve the inconsistencies, and deduce its origin and history. Five stratigraphic zones are distinguished according to differences in the groundmass. From bottom to top the zones are basal tuff, vitrophyre, brown zone, gray zone, and white zone. The three upper zones are distinguished by colors on fresh surfaces, for each weathers to a similar shade of light reddish brown. Nonwelded basal tuff grades upward into the vitrophyre, which is a highly welded tuff. The brown and gray zones consist of highly welded tuff with a lithoidal groundmass. Degree of welding decreases progressively upward through the gray and the white zones, and the upper white zone is nonwelded. Textures are clearly outlined in the lower part of the brown zone, but upward they become more diffuse because of increasing devitrification. In the white zone, original textures are essentially obliterated, and the groundmass consists of spherulites and microcrystalline intergrowths. The chief groundmass minerals are cristobalite and sanidine, with lesser quartz and plagioclase. Phenocrysts comprise about 40 percent of the rock

  10. Whooping Cough (Pertussis) - Fact Sheet for Parents

    Science.gov (United States)

    ... months 4 through 6 years Fact Sheet for Parents Color [2 pages] Español: Tosferina (pertussis) The best ... according to the recommended schedule. Fact Sheets for Parents Diseases and the Vaccines that Prevent Them Chickenpox ...

  11. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    is expanding our current understanding and outline the areas of advancement needed in the future. Presentation is made of current models for wind driven detachment/entrainment and the transport rates of sand and dust, including the effects of contact induced grain electrification. This ubiquitous phenomenon...... can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

  12. Thermoluminescent dosimetric properties of Descalvado sand

    International Nuclear Information System (INIS)

    Teixeira, M.I.; Caldas, L.V.E.

    2006-01-01

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ( 60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  13. Development tendencies of moulding and core sands

    Directory of Open Access Journals (Sweden)

    Stanislaw M. Dobosz1

    2011-11-01

    Full Text Available Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

  14. Thermoluminescent dosimetric properties of Descalvado sand

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M.I.; Caldas, L.V.E

    2006-07-01

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  15. A Threshold Continuum for Aeolian Sand Transport

    Science.gov (United States)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  16. Gasification of oil sand coke: review

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

    1998-08-01

    The production of synthetic crude from the tar sands in Western Canada has been steadily increasing. Most of the delayed coke produced by Suncor is combusted on site, whereas all fluid coke produced by Syncrude is stockpiled.The database on the chemical and physical properties of the oil sand coke, including the composition and fusion properties of the mineral matter, has been established. The reactivity of the coke was determined by oxygen chemisorption, fixed bed and fluid bed bench scale gasification and pilot plant gasification. The reactivity of the oil sand coke for gasification is rather low and comparable to high rank coals, such as anthracite. Slurrability tests revealed that a solid concentration in water, approaching 70 wt%, can be achieved. Gasification is the front runner among clean technologies for the conversion of carbonaceous solids to useful products. Several commercial gasifiers are available to cover the wide range of severity. Because of the low reactivity of oil sands coke, high severity conditions are required to achieve high gasification conversion. Such conditions can be attained in entrained bed gasifiers. Gasifiers employing both dry and slurry feeding systems are suitable. A high efficiency, low SO{sub x} and NO{sub x} emissions, as well as a low solid waste production are among the key advantages of the gasification technology compared with thecompeting technologies. Commercial gasification of oil sands coke is delayed because of the availability of natural gas on the site of the upgrading plants. Potential for the transportation of the oil sand coke to USA for electricity generation using the integrated gasification combined-cycle (IGCC) technology was evaluated. 27 refs., 17 figs., 9 tabs.

  17. Laboratory Investigation of Complex Conductivity and Magnetic Susceptibility on Natural Iron Oxide Coated Sand

    Science.gov (United States)

    Wang, C.; Slater, L. D.; Day-Lewis, F. D.; Briggs, M. A.

    2017-12-01

    Redox reactions occurring at the oxic/anoxic interface where groundwater discharges to surface water commonly result in iron oxide deposition that coats sediment grains. With relatively large total surface area, these iron oxide coated sediments serve as a sink for sorption of dissolved contaminants, although this sink may be temporary if redox conditions fluctuate with varied flow conditions. Characterization of the distribution of iron oxides in streambed sediments could provide valuable understanding of biogeochemical reactions and the ability of a natural system to sorb contaminants. Towards developing a field methodology, we conducted laboratory spectral induced polarization (SIP) and magnetic susceptibility (MS) measurements on natural iron oxide coated sand (Fe-sand) with grain sizes ranging from 0.3 to 2.0 mm in order to assess the sensitivity of these measurements to iron oxides in sediments. The Fe-sand was also sorted by sieving into various grain sizes to study the impact of grain size on the polarization mechanisms. The unsorted Fe-sand saturated with 0.01 S/m NaCl solution exhibited a distinct phase response ( > 4 mrad) in the frequency range from 0.001 to 100 Hz whereas regular silica sand was characterized by a phase response less than 1 mrad under the same conditions. The presence of iron oxide substantially increased MS (3.08×10-3 SI) over that of regular sand ( Laboratory results demonstrated that SIP and MS may be well suited to mapping the distribution of iron oxides in streambed sediments associated with anoxic groundwater discharge.

  18. Hidden Ice Worlds - Pleistocene glacigenic deposits in Essex, England. Application of the novel systematic approach to thin-section description.

    Science.gov (United States)

    Leszczynska, Karolina; Boreham, Julie; Boreham, Steve

    2013-04-01

    In the 'Hidden Ice Worlds' research project a novel systematic approach for thin-section description (Leszczynska et al., 2011) is applied to analyse the internal structure of 8 m thick periglacially disturbed sequence from the Royal Oak Pit - a small disused quarry in East Anglia, Essex, east of Chelmsford, near Danbury. Danbury Hill is situated on the south-eastern margin of the Elsterian (Anglian) till sheet. This area was glaciated only once, during the Pleistocene, Elsterian (Anglian) glaciation (480-420 ka BP), however two local ice-sheet margin fluctuations are envisaged (inter alia Turner, 1970 and others). The stratigraphical sequence of the Royal Oak Pit comprises: massive gravel, arranged in sheets, overlain by fine silty-clay and silty-sand with ripple marks and planar cross beds, overlain by a 50 cm thick unit of massive gravel gradually changing into periglacially disturbed silty-clayey-gravel with the bottom 50 cm of fine laminated silty clay. This sequence is situated on the lee side of Danbury Hill, at over 50 m OD. This is an atypical location for the periglacially disturbed deposits of such a substantial thickness (up to 8 m), which usually occur in the lower areas. The deposits at this site were investigated at a macro-scale using field-section logging, ground penetrating radar survey, clast lithology, clay mineralogy analysis and loss-on-ignition and at a micro-scale using thin-section analysis. There are two main aims of the project presented: • To describe the genesis and to discern the main processes associated with the formation of the unusually thick periglacially disturbed unit at the Danbury Hill slope and • To test the novel, tree-based, systematic approach as a guiding tool for thin for thin-section description of Quaternary deposits (Leszczynska et al., 2011). The results of the micromorphological analyses of the deposits from the Royal Oak Pit allow a new hypothesis for the origin of the sequence to be put forward. The main

  19. Creating fluid injectivity in tar sands formations

    Science.gov (United States)

    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.

  20. Log-inject-log in sand consolidation

    International Nuclear Information System (INIS)

    Murphy, R.P.; Spurlock, J.W.

    1977-01-01

    A method is described for gathering information for the determination of the adequacy of placement of sand consolidating plastic for sand control in oil and gas wells. The method uses a high neutron cross-section tracer which becomes part of the plastic and uses pulsed neutron logging before and after injection of the plastic. Preferably, the method uses lithium, boron, indium, and/or cadmium tracers. Boron oxide is especially useful and can be dissolved in alcohol and mixed with the plastic ingredients

  1. Oil sand synfuel production using nuclear energy

    International Nuclear Information System (INIS)

    Barnert, H.

    1984-10-01

    The importance of oil sand as a primary energy carrier is illustrated. The oil sand mining project 'synfuel' in Fort McMurray, Alberta, Canada, is described. On the basis of a layout of an In-situ-process different possibilities of introducing nuclear energy to the process are described. This leads to an increase of the product yield, leading finally to a doubling of the energy output compared to the reference layout. The introduction of nuclear energy contributes to the reduction of emissions, in particular to the emission of carbon dioxide in the conversion process. (orig.)

  2. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  3. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  4. Sand control systems used in completing wells

    Directory of Open Access Journals (Sweden)

    Gabriel Wittenberger

    2005-12-01

    Full Text Available Expandable Tubular Technology is transforming the face of well completion and construction. This technology provides: a substantially higher hydrocarbon production rates from the reservoir, a reduced well drilling and construction costs, new possibilities for previously unreachable or uneconomic reservoirs, and step a change towards the single diameter well. ESS (Expandable Sand Screen has an unrivalled performance worldwide for delivering a reliable sand control in a wide range of applications. Well costs typically cut by over 20 %, and the productivity increases up to 70 %.

  5. 21 CFR 880.5180 - Burn sheet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

  6. Manifold free multiple sheet superplastic forming

    Science.gov (United States)

    Elmer, John W.; Bridges, Robert L.

    2004-01-13

    Fluid-forming compositions in a container attached to enclosed adjacent sheets are heated to relatively high temperatures to generate fluids (gases) that effect inflation of the sheets. Fluid rates to the enclosed space between the sheets can be regulated by the canal from the container. Inflated articles can be produced by a continuous, rather than batch-type, process.

  7. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    Almeida, W.A.; Costa, J.M. da; Aruquipa, E.G.; Sudano, J.P.

    1974-12-01

    A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

  8. Sedimentary characteristics and controlling factors of shelf sand ridges in the Pearl River Mouth Basin, northeast of South China Sea

    Directory of Open Access Journals (Sweden)

    Xiangtao Zhang

    2017-04-01

    Full Text Available Shelf sand ridge is a significant type of reservoir in the continental marginal basin, and it has drawn so much attention from sedimentologists and petroleum geologists. We were able to investigate the morphology, distribution, and sedimentary structures of shelf sand ridges systematically in this study based on the integration of high-resolution 3D seismic data, well logging, and cores. These shelf sand ridges are an asymmetrical mound-like structure in profiles, and they developed on an ancient uplift in the forced regression system tract and are onlapped by the overlying strata. In the plane, shelf sand ridges present as linear-shaped, which is different from the classical radial pattern; not to mention, they are separated into two parts by low amplitude tidal muddy channels. Corrugated bedding, tidal bedding, and scouring features are distinguished in cores of shelf sand ridges together with the coarsening up in lithology. All of these sedimentary characteristics indicate that shelf sand ridges deposited in the Pearl River Mouth Basin are reconstructed by the tidal and coastal current.

  9. Elastic behavior and onset of cracking in cement composite plates reinforced by perforated thin steel sheets

    Science.gov (United States)

    Aronchik, V.

    1996-03-01

    Thin cement mortar plates reinforced by perforated thin steel sheets have been tested in four-point flexure loading. Six kinds of sheet reinforcement and to additional ones (for control) were used. Perforated sheets of the Daugavpils Factory of Machinery Chains differed by their thickness (0.6-1.8 mm), shape (round, rectangular, oval, "dumbbell"), and mark of steel (St. 08, 50, 70). Dimensions of plantes were 100×20×2 cm. Cements-sand mortar with a 1∶2 ratio of cement PZ35 and river sand of 3 mm grains was used as a matrix. Control specimens of similar dimensions and matrix were reinforced by wire cages and meshes (ferrocement). The testing was performed using an UMM-5 testing machine. Maximum deflection (at the midspan), tension, and shear strains were recorded. The expeimental data are presented in tables and graphs. The testing results showed that the elasticity modulus of material was in good agreement with the "admixture rule;" an onset of cracking for all types (excluding one) practically did not differ from reference samples; the mode of fracture in typical cases included an adhesion failure and significant shear strains. In one case the limit of the tension strength of the reinforcement was achieved.

  10. Experimental perforation of tubing with a hydraulic sand jet

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, Yu V

    1970-01-01

    A series of field tests has shown that perforation with a hydraulic sand jet improves the quality of well completion. The sand jet does not crack the cement sheath or the casing, and the perforations are larger and deeper than perforations formed by explosive charges. Fluid circulation during sand jet perforation can safely be stopped for at least 10 min. Water containing a surfactant can be used as a sand carrier. Sand jet perforation allows successful completion of wells cased by 2 tubing strings. Sand jet perforation can be used to clean the borehole well and to remove foreign objects from the well.

  11. The relationship between depositional system and ore-formation of sandstone-type uranium deposits in Dongsheng area, Ordos basin

    International Nuclear Information System (INIS)

    Zhao Honggang; Ou Guangxi

    2006-01-01

    The analysis on depositional system plays a very important role in studying sandstone-type uranium deposits. Based on depositional system analysis and sequence stratigraphy, and through the study of depositional system characteristics and the spatial distribution of sedimentary facies, the evolution of sedimentary environments as well as the sequence stratigraphy of Zhiluo Formation in Dongsheng area, Ordos basin, authors have come to the following conclusions, (1) the spatial distribution of sand bodies is controlled by the planar distribution of sedimentary facies, which, in turn, affects the spatial distribution of ore-hosting sand bodies; (2) the evolution of sedimentary facies and sedimentary environments creates good lithofacies and lithological conditions favorable for interlayer oxidation; (3) the spatial lithologic combination of 'three layer structure' is controlled by sedimentary sequence. (authors)

  12. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  13. Uranium deposits: northern Denver Julesburg basin, Colorado

    International Nuclear Information System (INIS)

    Reade, H.L.

    1978-01-01

    The Fox Hills Sandstone and the Laramie Formation (Upper Cretaceous) are the host rocks for uranium deposits in Weld County, northern Denver Julesburg basin, Colorado. The uranium deposits discovered in the Grover and Sand Creek areas occur in well-defined north--south trending channel sandstones of the Laramie Formation whereas the sandstone channel in the upper part of the Fox Hills Sandstone trends east--west. Mineralization was localized where the lithology was favorable for uranium accumulation. Exploration was guided by log interpretation methods similar to those proposed by Bruce Rubin for the Powder River basin, Wyoming, because alteration could not be readily identified in drilling samples. The uranium host rocks consist of medium- to fine-grained carbonaceous, feldspathic fluvial channel sandstones. The uranium deposits consist of simple to stacked roll fronts. Reserve estimates for the deposits are: (1) Grover 1,007,000 lbs with an average grade of 0.14 percent eU 3 O 8 ,2) Sand Creek 154,000 lbs with an average grade of 0.08 percent eU 3 O 8 , and 3) The Pawnee deposit 1,060,000 lbs with an average grade of 0.07 percent eU 3 O 8 . The configuration of the geochemical cells in the Grover and Sand Creek sandstones indicate that uraniferous fluids moved northward whereas in the Pawnee sandstone of the Fox Hills uraniferous fluids moved southward. Precipitation of uranium in the frontal zone probably was caused by downdip migration of oxygcnated groundwater high in uranium content moving through a favorable highly carbonaceous and pyritic host sandstone

  14. A Scheme for the Growth of Graphene Sheets Embedded with Nanocones

    Directory of Open Access Journals (Sweden)

    Yu-Peng Liu

    2017-02-01

    Full Text Available Based on the monolayer growth mode of graphene sheets (2D crystal by chemical vapor deposition (CVD on a Cu surface, it should be possible to grow the 2D crystal embedded with single wall carbon nanocones (SWCNC if nano-conical pits are pre-fabricated on the surface. However, a previous experiment showed that the growing graphene sheet can cross grain boundaries without bending, which seems to invalidate this route for growing SWCNCs. The criterion of Gibbs free energy was applied in the present work to address this issue, showing that the sheet can grow into the valley of a boundary if the boundary has a slope instead of a quarter-turn shape, and SWCNCs can be obtained by this route as long as the lower diameter of the pre-fabricated pit is larger than 1.6 nm and the deposition temperature is higher than 750 K.

  15. Geometry of thin liquid sheet flows

    Science.gov (United States)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1994-01-01

    Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

  16. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden)

    2010-11-15

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  17. Periodic folding of viscous sheets

    Science.gov (United States)

    Ribe, Neil M.

    2003-09-01

    The periodic folding of a sheet of viscous fluid falling upon a rigid surface is a common fluid mechanical instability that occurs in contexts ranging from food processing to geophysics. Asymptotic thin-layer equations for the combined stretching-bending deformation of a two-dimensional sheet are solved numerically to determine the folding frequency as a function of the sheet’s initial thickness, the pouring speed, the height of fall, and the fluid properties. As the buoyancy increases, the system bifurcates from “forced” folding driven kinematically by fluid extrusion to “free” folding in which viscous resistance to bending is balanced by buoyancy. The systematics of the numerically predicted folding frequency are in good agreement with laboratory experiments.

  18. Ice sheet hydrology from observations

    International Nuclear Information System (INIS)

    Jansson, Peter

    2010-11-01

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  19. BRITICE-CHRONO: Constraining rates and style of marine-influenced ice sheet decay to provide a data-rich playground for ice sheet modellers

    Science.gov (United States)

    Clark, Chris

    2014-05-01

    Uncertainty exists regarding the fate of the Antarctic and Greenland ice sheets and how they will respond to forcings from sea level and atmospheric and ocean temperatures. If we want to know more about the mechanisms and rate of change of shrinking ice sheets, then why not examine an ice sheet that has fully disappeared and track its retreat through time? If achieved in enough detail such information could become a data-rich playground for improving the next breed of numerical ice sheet models to be used in ice and sea level forecasting. We regard that the last British-Irish Ice Sheet is a good target for this work, on account of its small size, density of information and with its numerous researchers already investigating it. BRITICE-CHRONO is a large (>45 researchers) NERC-funded consortium project comprising Quaternary scientists and glaciologists who will search the seafloor around Britain and Ireland and parts of the landmass in order to find and extract samples of sand, rock and organic matter that can be dated (OSL; Cosmogenic; 14C) to reveal the timing and rate of change of the collapsing British-Irish Ice Sheet. The purpose is to produce a high resolution dataset on the demise on an ice sheet - from the continental shelf edge and across the marine to terrestrial transition. Some 800 new date assessments will be added to those that already exist. This poster reports on the hypotheses that underpin the work. Data on retreat will be collected by focusing on 8 transects running from the continental shelf edge to a short distance (10s km) onshore and acquiring marine and terrestrial samples for geochronometric dating. The project includes funding for 587 radiocarbon, 140 OSL and 158 TCN samples for surface exposure dating; with sampling accomplished by two research cruises and 16 fieldwork campaigns. Results will reveal the timing and rate of change of ice margin recession for each transect, and combined with existing landform and dating databases, will be

  20. Load Test in Sheet Pile

    OpenAIRE

    Luis Orlando Ibanez

    2016-01-01

    In this work, are discussed experiences in the use of mathematical modeling and testing in hydraulic engineering structures. For this purpose the results of load tests in sheet pile, evaluating horizontal and vertical deformations that occur in the same exposed. Comparisons between theoretical methods for calculating deformations and mathematical models based on the Finite Element Method are established. Finally, the coincidence between the numerical model and the results of the load test ful...

  1. Ohm's law for a current sheet

    Science.gov (United States)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  2. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel

    2013-01-01

    A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series of undra...

  3. Radiation safety in Australia's mineral sands industry

    International Nuclear Information System (INIS)

    Hughes, W.

    1989-06-01

    This brochure is part of a training package aiming to explain in simple terms what radiation is, how it affects people's lives and how, in the specific case of the mineral sand industry, the risk of ill-effects from low-level radioactivity could be effectively guarded against by simple and easily followed safety precautions. ills

  4. Geomechanical properties of lime stabilized clayey sands

    International Nuclear Information System (INIS)

    Arabani, M.; Karami, M. Veis

    2007-01-01

    Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

  5. Market opportunities and challenges for oil sands

    International Nuclear Information System (INIS)

    Wise, T.H.

    2004-01-01

    The use of Alberta bitumen as a clean fuel depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production from the Western Canada Sedimentary Basin. The challenges facing the oils sands processing industry include: crude oil prices which affect the producer's market; market expansion options; diluent availability/cost; supply cost competitiveness; and, regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. It was noted that Alberta must retain or increase its share of the Midwest market. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. New pipeline capacity is needed to reach more distant markets such as Southern Midwest, Washington, and California. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. 13 figs

  6. Growing markets to sustain oil sands development

    International Nuclear Information System (INIS)

    Wise, T.H.

    2003-01-01

    The utilization of Alberta bitumen for the clean fuels market depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production in Western Canada. Several issues pose a challenge to the oil sands processing industry. The producers' market is affected by crude oil prices, market expansion options, diluent availability/cost, supply cost competitiveness, and regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. A brief review of markets for Canadian crude oil, including synthetic crude, was provided. The share of the Midwest market by Alberta must be retained and increased. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. To reach more distant markets such as Southern Midwest, Washington, and California, new pipeline capacity would be required. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. tabs., figs

  7. Microbial Characterization of Qatari Barchan Sand Dunes.

    Directory of Open Access Journals (Sweden)

    Sara Abdul Majid

    Full Text Available This study represents the first characterization of sand microbiota in migrating barchan sand dunes. Bacterial communities were studied through direct counts and cultivation, as well as 16S rRNA gene and metagenomic sequence analysis to gain an understanding of microbial abundance, diversity, and potential metabolic capabilities. Direct on-grain cell counts gave an average of 5.3 ± 0.4 x 105 cells g-1 of sand. Cultured isolates (N = 64 selected for 16S rRNA gene sequencing belonged to the phyla Actinobacteria (58%, Firmicutes (27% and Proteobacteria (15%. Deep-sequencing of 16S rRNA gene amplicons from 18 dunes demonstrated a high relative abundance of Proteobacteria, particularly enteric bacteria, and a dune-specific-pattern of bacterial community composition that correlated with dune size. Shotgun metagenome sequences of two representative dunes were analyzed and found to have similar relative bacterial abundance, though the relative abundances of eukaryotic, viral and enterobacterial sequences were greater in sand from the dune closer to a camel-pen. Functional analysis revealed patterns similar to those observed in desert soils; however, the increased relative abundance of genes encoding sporulation and dormancy are consistent with the dune microbiome being well-adapted to the exceptionally hyper-arid Qatari desert.

  8. Afyon-Sandıklı

    Indian Academy of Sciences (India)

    δ18O and δD isotope ratios of the Sandıklı waters plot along the continental meteoric water line ... and district heating. Several studies on geology, hydrogeology along ..... precipitation; In: Handbook of Environmental Isotope. Geochemistry ...

  9. Photovoltage versus microprobe sheet resistance measurements on ultrashallow structures

    DEFF Research Database (Denmark)

    Clarysse, T.; Moussa, A.; Parmentier, B.

    2010-01-01

    on ultrashallow (sub-50-nm) chemical-vapor-deposited layers [T. Clarysse , Mater. Res. Soc. Symp. Proc. 912, 197 (2006)], especially in the presence of medium/highly doped underlying layers (representative for well/halo implants). Here the authors examine more closely the sheet resistance anomalies which have...... recently been observed between junction photovoltage (JPV) based tools and a micrometer-resolution four-point probe (M4PP) tool on a variety of difficult, state-of-the-art sub-32-nm complementary metal-oxide semiconductor structures (low energy and cluster implants, with/without halo, flash- and laser...

  10. Physiological and biochemical responses of small fish exposed to Athabasca oil sands sediment

    International Nuclear Information System (INIS)

    Tetrault, G.R.; Environment Canada, Burlington, ON; McMaster, M.E.; Dixon, D.G.; Parrott, J.L.

    2002-01-01

    A study was conducted to determine the influence of naturally occurring oil sands related compounds on the reproductive function and hepatic responses of fish. Wild fish, both exposed and unexposed to the compounds in question, were collected along with sediments for laboratory testing. The study showed that in vitro gonadal incubation levels of steroid production were lower at the tributary sites within the oil sands deposits. One indicator of exposure to oil sands related compounds (hepatic 7-ethoxyresorufin-O-deethylase activity) was shown to be 5 times higher at the same sites. In addition, slimy sculpin were exposed to sediment samples from the Steepbank River site for 4 to 8 days to evaluate the absorption of the indicator. The indicator in exposed fish was found to be comparable to that measured in fish native to the oil sands area. The study was not capable of predicting an altered ability of gonadal tissue of exposed fish to produce steroid hormones in vitro. It was concluded that future development could compromise the reproductive health of fish in the area

  11. A new approach to the management of cumulative environmental impacts, the Alberta Oil Sands area

    International Nuclear Information System (INIS)

    Weagle, K.V.

    2002-01-01

    Resource development in the oil sand industry of Northeastern Alberta is enjoying a wave of renewed interest fuelled in part by changes made in the tax and royalty structure for oil sands developments in the province, the development of new technology and the price of oil. Announcements were made of investments totalling approximately 51 billion dollars in the oil sand industry over the next ten years in all deposits. The issue of cumulative environmental effects has been amplified accordingly. In June 2000, an association was formed, the Cumulative Environmental Management Association (CEMA), consisting of stakeholders and based on consensus, with a mandate to address 72 issues related to potential cumulative impacts in the expanded development of the Wood Buffalo Region. Five working groups were formed, as well as three standing committees. To mitigate the cumulative effects, the working groups and standing committees are working on management objectives, management systems and research recommendations. The regulatory bodies receive the recommendations, and the implementation process involves the issuance of permits and licenses. Research and monitoring activities play a vital role in the environmental management system and are part of other current environmental initiatives. Some of the initiatives are managed by the Wood Buffalo Environmental Association, Regional Aquatics Monitoring Program, and the Canadian Oil Sands Network for Research and Development. These organizations touch on topics including air quality monitoring, aquatics monitoring and environmental research. 1 fig

  12. Novel foraging in the swash zone on Pacific sand crabs (Emerita analoga, Hippidae) by mallards

    Science.gov (United States)

    Lafferty, Kevin D.; McLaughlin, John P.; Dugan, Jenifer E.

    2013-01-01

    Mallards (Anas platyrhynchos) have been observed foraging on intertidal Pacific sand crabs (Hippidae, Emerita analoga) in the swash zone of sandy beaches around Coal Oil Point Reserve, California, and several other beaches on the west coast since at least November 2010. Unlike foraging shorebirds, Mallards do not avoid incoming swashes. Instead, the incoming swash lifts and deposits them down the beach. Shorebirds and diving ducks commonly feed on sand crabs, but sand crabs appear to be a novel behavior and food source for Mallards. Previous surveys of beaches did not report foraging Mallards on regional beaches, whereas foraging Mallards were common in contemporary (recent) surveys and anecdotal reports. Observations of this potentially new behavior were separated by as much as 1,300 km, indicating that this was not a local phenomenon. Mallards foraged singly, in pairs, and in flocks. An expansion of diet to sand crabs carries risks of exposure to surf, human disturbance, high salt intake, and transmission of acanthocephalan and trematode parasites for Mallards but has the benefit of providing a dependable source of animal protein.

  13. Synthesis and characterization of silica gel from siliceous sands of southern Tunisia

    Directory of Open Access Journals (Sweden)

    Ali Sdiri

    2014-09-01

    Full Text Available The present work aimed to achieve valorization of Albian sands for the preparation of sodium silicates that are commonly used as a precursor to prepare silica gel. A siliceous sand sample was mixed with sodium carbonate and heated at a high temperature (1060 °C to prepare sodium silicates. The sodium silicates were dissolved in distilled water to obtain high quality sodium silicate solution. Hydrochloric acid was then slowly added to the hydrated sodium silicates to obtain silica gel. The collected raw siliceous sands, as well as the prepared silica gels, were characterized by different techniques, such as X-ray fluorescence (XRF, X-ray diffraction (XRD, scanning electron microscopy (SEM and thermal analysis (DSC. XRF confirmed that the detrital sand deposits of southern Tunisia contain high amounts of silica, with content ranging from 88.8% to 97.5%. The internal porosity varied between 17% and 22%, and the specific surface area was less than 5 m2/g. After the treatment described above, it was observed that the porosity of the obtained silica gel reached 57% and the specific surface area exceeded 340 m2/g. Nitrogen adsorption isotherms showed that the prepared silica gels are microporous and mesoporous materials with high adsorption capacities. These results suggest that the obtained silica gels are promising materials for numerous environmental applications.

  14. Process water treatment in Canada's oil sands industry : 2 : a review of emerging technologies

    International Nuclear Information System (INIS)

    Allen, E.W.

    2008-01-01

    This review was conducted to identify candidate treatment technologies for treating oil sands process water. The oil sands industry in Canada uses large volumes of fresh water in order to extract bitumen deposits. The development of process water treatment technologies has become a critical issue for the industry, particularly as oil sand production is expected to triple in the next decade. However, treatment technologies must be adapted to consider the fouling potential of bitumens and fine clays as well as the effect of alkaline process water on treatment performance. The review included developments in chemical modifications to membranes and adsorbents designed to improve pollutant removal and reduce fouling; hybridization technologies designed to enhance the biological treatment of toxic feedwaters; recent advances in photocatalytic oxidation technologies for organic compounds; and new designs for large-scale treatment wetlands for polluted waste waters. It was concluded that major knowledge gaps must be optimized and preliminary studies must be conducted in order to understand how the treatment technologies will be affected by the chemical and physical characteristics of oil sands process water. 188 refs., 8 tabs

  15. The provenance of Taklamakan desert sand

    Science.gov (United States)

    Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

    2016-03-01

    Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

  16. Experimental formability analysis of bondal sandwich sheet

    Science.gov (United States)

    Kami, Abdolvahed; Banabic, Dorel

    2018-05-01

    Metal/polymer/metal sandwich sheets have recently attracted the interests of industries like automotive industry. These sandwich sheets have superior properties over single-layer metallic sheets including good sound and vibration damping and light weight. However, the formability of these sandwich sheets should be enhanced which requires more research. In this paper, the formability of Bondal sheet (DC06/viscoelastic polymer/DC06 sandwich sheet) was studied through different types of experiments. The mechanical properties of Bondal were determined by uniaxial tensile tests. Hemispherical punch stretching and hydraulic bulge tests were carried out to determine the forming limit diagram (FLD) of Bondal. Furthermore, cylindrical and square cup drawing tests were performed in dry and oil lubricated conditions. These tests were conducted at different blank holding forces (BHFs). An interesting observation about Bondal sheet deep drawing was obtaining of higher drawing depths at dry condition in comparison with oil-lubricated condition.

  17. Buckling and stretching of thin viscous sheets

    Science.gov (United States)

    O'Kiely, Doireann; Breward, Chris; Griffiths, Ian; Howell, Peter; Lange, Ulrich

    2016-11-01

    Thin glass sheets are used in smartphone, battery and semiconductor technology, and may be manufactured by producing a relatively thick glass slab and subsequently redrawing it to a required thickness. The resulting sheets commonly possess undesired centerline ripples and thick edges. We present a mathematical model in which a viscous sheet undergoes redraw in the direction of gravity, and show that, in a sufficiently strong gravitational field, buckling is driven by compression in a region near the bottom of the sheet, and limited by viscous resistance to stretching of the sheet. We use asymptotic analysis in the thin-sheet, low-Reynolds-number limit to determine the centerline profile and growth rate of such a viscous sheet.

  18. Centrifuge - dewatering of oil sand fluid tailings: phase 2 field-scale test

    Energy Technology Data Exchange (ETDEWEB)

    Seto, Jack T.C. [BGC Engineering Inc (Canada); O' Kane, Mike [O' Kane Consultants Inc (Canada); Donahue, Robert [Applied Geochemical Solutions Engineering (Canada); Lahaie, Rick [Syncrude Canada Ltd (Canada)

    2011-07-01

    In order to reduce the accumulation of oil sand fluid fine tailings (FFT) and to create trafficable surfaces for reclamation, Syncrude Canada Ltd. has been studying several tailings technologies. Centrifuge-dewatering is one such technology. This paper discusses the phase 2 field-scale tests for centrifuge-dewatering of oil sand FFT. In centrifuge-dewatering, FFT is diluted and treated with flocculant, then processed through a centrifuge plant and the high-density underflow is transported to a tailings deposit. This technology has evolved since 2005 from laboratory bench scale tests. More than 10,000 cubic meters of centrifuge cake was treated, produced and transported to ten different deposits over a 12-week period from August to October 2010. The amount of solids in FFT was increased from 30% to 50% by centrifuging. Sampled deposits were tested and instrumented for in situ strength. It can be concluded that the deposits can be strengthened and densified by natural dewatering processes like freeze-thaw action and evaporative drying.

  19. EXPLOITATION OF GLASS SAND ON THE OPEN PIT »VRTLINSKA« (MOSLAVINA, CROATIA

    Directory of Open Access Journals (Sweden)

    Slavko Vujec

    1994-12-01

    Full Text Available The exploitation of glass sand in Slavonia and Moslavina has a long tradition. The open-pit »Vrtlinska« is-accordirtg to its dimensions and production capacity the biggest one in this regions. Exploitation reserves within this open pit amount about 1 000 000 t glass sand of a very good quality, and the production capacity is 200 000 t yearly according to real needs during design and opening the pit, i. e. before the war. This article discusses geological and geomechanical characteristics of the deposit, as well as the exploitation process, which is considerably matching natural characteristics of the deposit. A more detailed description is given of the planned exploitation phase I above groundwater level which is carried out according to discontinuous system. For the exploitation of the depth part under groundwater level in the phase II, the necessity of further examination of hydrogeological characteristics of the deposit is presented, in order to acquire necessary information on groundwater regime and drainage conditions. Such knowledge will influence the choice of the most appropriate solutions in the exploitation of the depth part of the deposit.

  20. High temperature thermal energy storage in moving sand

    Science.gov (United States)

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

    1978-01-01

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