WorldWideScience

Sample records for net sand thickness

  1. Net coal thickness in the Johnson-107 coal zone, South Carbon coalfield, Wyoming (sccat)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This ArcView shapefile contains a representation of the Johnson-107 coal zone net coal thickness. The Johnson-107 coal zone is in the South Carbon coalfield in the...

  2. The influence of twine thickness, twine number and netting orientation on codend selectivity

    DEFF Research Database (Denmark)

    Herrmann, Bent; Wienbeck, Harald; Moderhak, Waldemar

    2013-01-01

    Based on an experimental Baltic trawl fishery, we tested diamond mesh codends with different twine thicknesses, twine numbers (single or double), and netting orientation (T0 or T90) to quantify the effects of the twine characteristics on the size selection of cod (Gadus morhua) and plaice...... (Pleuronectes platessa). For a given twine thickness: going from T0 to T90 increases selectivity of cod; while going from single to double reduce it. Increasing twine thickness reduces selection but the extent depends on whether the twine is single or double and whether the netting orientation is T0 or T90....... In general, the results demonstrate the benefit of using a relatively thin single twine netting to ensure the appropriate size selection with round fish and the best results were obtained using netting with a T90 orientation. For a given twine thickness going from T0 to T90 decreases selectivity of plaice...

  3. Net coal thickness in the southern Piceance Basin, Colorado (ps*thkg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These are shapefiles and ARC/INFO polygon coverages showing the isopachs of total net coal in beds greater than or equal to 1 ft thick for the Cameo/Fairfield coal...

  4. Beach response dynamics of a littoral cell using a 17-year single-point time series of sand thickness

    Science.gov (United States)

    Barnard, P.L.; Hubbard, D.M.; Dugan, J.E.

    2012-01-01

    A 17-year time series of near-daily sand thickness measurements at a single intertidal location was compared with 5. years of semi-annual 3-dimensional beach surveys at the same beach, and at two other beaches within the same littoral cell. The daily single point measurements correlated extremely well with the mean beach elevation and shoreline position of ten high-spatial resolution beach surveys. Correlations were statistically significant at all spatial scales, even for beach surveys 10s of kilometers downcoast, and therefore variability at the single point monitoring site was representative of regional coastal behavior, allowing us to examine nearly two decades of continuous coastal evolution. The annual cycle of beach oscillations dominated the signal, typical of this region, with additional, less intense spectral peaks associated with seasonal wave energy fluctuations (~. 45 to 90. days), as well as full lunar (~. 29. days) and semi-lunar (~. 13. days; spring-neap cycle) tidal cycles. Sand thickness variability was statistically linked to wave energy with a 2. month peak lag, as well as the average of the previous 7-8. months of wave energy. Longer term anomalies in sand thickness were also apparent on time scales up to 15. months. Our analyses suggest that spatially-limited morphological data sets can be extremely valuable (with robust validation) for understanding the details of beach response to wave energy over timescales that are not resolved by typical survey intervals, as well as the regional behavior of coastal systems. ?? 2011.

  5. Characterization of Various Kinds, Thickness and Bentonite Sand Ratio as Hardplain Materials: a Basic Concept for Coastal Sandy Land Management

    Directory of Open Access Journals (Sweden)

    Saparso

    2009-05-01

    Full Text Available Coastal sandy land development faces the sand characteristics, the lower holding water capacity and the larger nutrient leaching due to heavier rainfall in the tropics, soil porosity and without soil layering so it need alternative technology for more efficient harvesting water resources in supporting the crop growing. The laboratory research studied the characteristic of various kind, thickness and ratio of hardplain material was carried out at Laboratory of Agronomy of UNSOED, Soil Mechanic of GMU. the SEM and X-RD of Lemigas Jakarta. Permeability determination by Falling Head which is appropriate measurment was not significantly different with ELE28-290 permeameter. Permeability of Kokap clay soil and Nanggulan bentonite were larger than the rainfall intensity in coastal sandy land. The Sentolo Vertisol content 68% calcium smectite had permeability 3,7 mm.day-1. Bentonite permeability were not significantly different due to more than 80% clay mineral composition. Therefore the permeability of natrium bentonite like as BPIB and BLUB namely 1.4 x 10-2 and 10-2 mm day-1 were lower than the calcium bentonite like as RMBL and BLBK permeability namely 4.3 x 10-2 and 2.43 x 10-2 mm day-1. Permeability of 0.5 cm thickness bentonite was not significantly different than 1.0 dan 1.5 cm thickness and those had very low permeability. Bentonite sand mixture 15 and 20 percent produced bentonite sand agregate that had mesopores by which allowing the drainage and available soil water so that those had water permeability 13.7 dan 10.3 mm day-1 respectively. The mixture 30-100% had not significantly different permeability namely 7.3 x 10-2 up to 1.4 10-2 mm day-1. The combination of tickness and the low ratio of bentonite sand mixutre need to be determined to produce favourable environment in supporting the plant growth.

  6. Effect of filter media thickness on the performance of sand drying beds used for faecal sludge management.

    Science.gov (United States)

    Manga, M; Evans, B E; Camargo-Valero, M A; Horan, N J

    2016-12-01

    The effect of sand filter media thickness on the performance of faecal sludge (FS) drying beds was determined in terms of: dewatering time, contaminant load removal efficiency, solids generation rate, nutrient content and helminth eggs viability in the dried sludge. A mixture of ventilated improved pit latrine sludge and septage in the ratio 1:2 was dewatered using three pilot-scale sludge drying beds with sand media thicknesses of 150, 250 and 350 mm. Five dewatering cycles were conducted and monitored for each drying bed. Although the 150 mm filter had the shortest average dewatering time of 3.65 days followed by 250 mm and 350 mm filters with 3.83 and 4.02 days, respectively, there was no significant difference (p > 0.05) attributable to filter media thickness configurations. However, there was a significant difference for the percolate contaminant loads in the removal and recovery efficiency of suspended solids, total solids, total volatile solids, nitrogen species, total phosphorus, chemical oxygen demand, dissolved chemical oxygen demand and biochemical oxygen demand, with the highest removal efficiency for each parameter achieved by the 350 mm filter. There were also significant differences in the nutrient content (NPK) and helminth eggs viability of the solids generated by the tested filters. Filtering media configurations similar to 350 mm have the greatest potential for optimising nutrient recovery from FS.

  7. The effect of twine thickness on the size selectivity and fishing power of Baltic cod gill nets

    DEFF Research Database (Denmark)

    Holst, René; Wileman, D.; Madsen, Niels

    2002-01-01

    . Subsequently a model was fitted for the mean selectivity taking between-set variation into account. The selectivity Curve that fitted the data best was given by the sum of two normal distributions. It was found that twine thickness and trials period had relatively little effect upon the shape......Sea trials were carried out on a Danish commercial vessel measuring the size selectivity and fishing power of gill nets used to catch Baltic cod (Gadus morhua). A comparison was made of two different twine thicknesses at two different times of the year. Nominal mesh sizes of 70-130 mm were used....... Method of capture, condition factor and girths were measured for sub- samples of the cod caught. A model of the size selectivity of the gill nets was adapted to the experimental conditions where two gears were fished on the same population. This model was fitted to the catch data for each set...

  8. Serological markers of sand fly exposure to evaluate insecticidal nets against visceral leishmaniasis in India and Nepal: a cluster-randomi trial

    DEFF Research Database (Denmark)

    Gidwani, K; Picado, A; Rijal, S

    2011-01-01

    Background: Visceral leishmaniasis is the world’ second largest vector-borne parasitic killer and a neglected tropical disease, prevalent in poor communities. Long-lasting insecticidal nets (LNs) are a low cost proven vector intervention method for malaria control; however, their effectiveness...... against visceral leishmaniasis (VL) is unknown. This study quantified the effect of LNs on exposure to the sand fly vector of VL in India and Nepal during a two year community intervention trial. Methods: As part of a paired-cluster randomized controlled clinical trial in VL-endemic regions of India...

  9. Serological markers of sand fly exposure to evaluate insecticidal nets against visceral leishmaniasis in India and Nepal: a cluster-randomized trial.

    Directory of Open Access Journals (Sweden)

    Kamlesh Gidwani

    2011-09-01

    Full Text Available Visceral leishmaniasis is the world' second largest vector-borne parasitic killer and a neglected tropical disease, prevalent in poor communities. Long-lasting insecticidal nets (LNs are a low cost proven vector intervention method for malaria control; however, their effectiveness against visceral leishmaniasis (VL is unknown. This study quantified the effect of LNs on exposure to the sand fly vector of VL in India and Nepal during a two year community intervention trial.As part of a paired-cluster randomized controlled clinical trial in VL-endemic regions of India and Nepal we tested the effect of LNs on sand fly biting by measuring the antibody response of subjects to the saliva of Leishmania donovani vector Phlebotomus argentipes and the sympatric (non-vector Phlebotomus papatasi. Fifteen to 20 individuals above 15 years of age from 26 VL endemic clusters were asked to provide a blood sample at baseline, 12 and 24 months post-intervention.A total of 305 individuals were included in the study, 68 participants provided two blood samples and 237 gave three samples. A random effect linear regression model showed that cluster-wide distribution of LNs reduced exposure to P. argentipes by 12% at 12 months (effect 0.88; 95% CI 0.83-0.94 and 9% at 24 months (effect 0.91; 95% CI 0.80-1.02 in the intervention group compared to control adjusting for baseline values and pair. Similar results were obtained for P. papatasi.This trial provides evidence that LNs have a limited effect on sand fly exposure in VL endemic communities in India and Nepal and supports the use of sand fly saliva antibodies as a marker to evaluate vector control interventions.

  10. A computational investigation of the interstitial flow induced by a variably thick blanket of very fine sand covering a coarse sand bed

    Science.gov (United States)

    Bartzke, Gerhard; Huhn, Katrin; Bryan, Karin R.

    2017-10-01

    Blanketed sediment beds can have different bed mobility characteristics relative to those of beds composed of uniform grain-size distribution. Most of the processes that affect bed mobility act in the direct vicinity of the bed or even within the bed itself. To simulate the general conditions of analogue experiments, a high-resolution three-dimensional numerical `flume tank' model was developed using a coupled finite difference method flow model and a discrete element method particle model. The method was applied to investigate the physical processes within blanketed sediment beds under the influence of varying flow velocities. Four suites of simulations, in which a matrix of uniform large grains (600 μm) was blanketed by variably thick layers of small particles (80 μm; blanket layer thickness approx. 80, 350, 500 and 700 μm), were carried out. All beds were subjected to five predefined flow velocities ( U 1-5=10-30 cm/s). The fluid profiles, relative particle distances and porosity changes within the bed were determined for each configuration. The data show that, as the thickness of the blanket layer increases, increasingly more small particles accumulate in the indentations between the larger particles closest to the surface. This results in decreased porosity and reduced flow into the bed. In addition, with increasing blanket layer thickness, an increasingly larger number of smaller particles are forced into the pore spaces between the larger particles, causing further reduction in porosity. This ultimately causes the interstitial flow, which would normally allow entrainment of particles in the deeper parts of the bed, to decrease to such an extent that the bed is stabilized.

  11. Net K+ secretion in the thick ascending limb of mice on a low-Na, high-K diet.

    Science.gov (United States)

    Wang, Bangchen; Wen, Donghai; Li, Huaqing; Wang-France, Jun; Sansom, Steven C

    2017-10-01

    Because of its cardio-protective effects, a low-Na, high-K diet (LNaHK) is often warranted in conjunction with diuretics to treat hypertensive patients. However, it is necessary to understand the renal handling of such diets in order to choose the best diuretic. Wild-type (WT) or Renal Outer Medullary K channel (ROMK) knockout mice (KO) were given a regular (CTRL), LNaHK, or high-K diet (HK) for 4-7 days. On LNaHK, mice treated with either IP furosemide for 12 hrs, or given furosemide in drinking water for 7 days, exhibited decreased K clearance. We used free-flow micropuncture to measure the [K+] in the early distal tubule (EDT [K+]) before and after furosemide treatment. Furosemide increased the EDT [K+] in WT on CTRL but decreased that in WT on LNaHK. Furosemide did not affect the EDT [K+] of KO on LNaHK or WT on HK. Furosemide-sensitive Na+ excretion was significantly greater in mice on LNaHK than those on CTRL or HK. Patch clamp analysis of split-open TALs revealed that 70-pS ROMK exhibited a higher open probability (Po) but similar density in mice on LNaHK, compared with CTRL. No difference was found in the density or Po of the 30 pS K channels between the two groups. These results indicate mice on LNaHK exhibited furosemide-sensitive net K+ secretion in the TAL that is dependent on increased NKCC2 activity and mediated by ROMK. We conclude that furosemide is a K-sparing diuretic by decreasing the TAL net K+ secretion in subjects on LNaHK. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  12. Non-standard tests for process control in chemically bonded sands

    Directory of Open Access Journals (Sweden)

    S. Ramrattan

    2016-01-01

    Full Text Available Chemically bonded sand cores and molds are more commonly referred to as precision sand systems in the high production automotive powertrain sector. Their behavior in contact with molten metal can lead to casting defects. Consequently, the interaction is of great interest and an important part of metal casting technology. The American Foundry Society (AFS sand testing is based on physical, mechanical, thermal and chemical properties of the sand system. Foundry engineers have long known that certain AFS sand tests provide limited information regarding control of molding and casting quality. The inadequacy is due to the fact that sand casting processes are inherently thermo-mechanical, thermo-chemical and thermo-physical. Non-standard foundry sand testing has proven useful for laboratory measurement of these characteristics in foundry sand using a disc-shaped specimen. Similarly, the equivalent disc-shaped specimens are used for casting trials. In order to accomplish near-net-shape casting with minimal defects, it is necessary to understand both the properties of the sand system, as well as the interface of molten metal when different binders, additives and/or refractory coatings are used. The methodology for the following non-standard chemically bonded sand tests is described: (1 disc transverse; (2 impact; (3 modified permeability; (4 abrasion; (5 thermal distortion; (6 quick loss on ignition. The data related to the non-standard sand tests were analyzed and interpreted. The test results indicate that there is relatively lower test-to-test variability with the disc-shaped specimens. The non-standard tests were able to discriminate between the chemically bonded polyurethane cold box sand specimens. Further studies should be conducted on various other sand and binder systems as well as on different specimen thicknesses.

  13. 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....

  14. Unconventional pilot steam drive, tar V sand, Long Beach unit, Wilmington Field, CA

    Energy Technology Data Exchange (ETDEWEB)

    Jung, K.D.

    1984-04-01

    This paper reviews the design, implementation and history of the unconventional pilot steam drive (greater than 2,500 ft measured depth) that has been underway since December 24, 1980 in the Tar reservoir in the Long Beach Unit, Wilmington Field, Los Angeles County, California. This paper describes the project through November 30, 1983. The Tar V reservoir is a series of interbedded sands, siltstones and shales in the Middle Repetto formation of lower Pliocene age. The Tar V reservoir in the Long Beach Unit is approximately 200 acres in areal extent, has a vertical gross thickness of 185 ft and a maximum vertical net oil sand thickness of 90 ft comprised of 8 to 10 separate sand units. Oil in place is estimated at 27 MMbbl of stock tank oil. The study area is 9.2 acres in areal extent with an average net oil sand thickness of 81.7 ft. The pilot steam drive was originally installed as an isolated 5.6 acre inverted 5-spot pattern.

  15. Sands styrke

    DEFF Research Database (Denmark)

    Jacobsen, H. Moust; Jørgensen, Mogens B.; Poulsen, H. Serup

    1975-01-01

    På grundlag af triaxialforsøg med D=7 og 20 cm og varierende højde på løse og faste lejringer af Blokhussand kan effekten af varierende højde-breddeforhold og spændingsniveau samt skalaeffekten bestemmes. Ved sammenligning med pladeforsøg med overfladelast op til 8 t/m2 kan den almindelige fremga...... fremgangsmåde ved bæreevneberegninger på sand undersøges....

  16. sand mold

    Science.gov (United States)

    Kovačević, Lazar; Terek, Pal; Miletić, Aleksandar; Kakaš, Damir

    2014-08-01

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

  17. Sand Diver

    Science.gov (United States)

    Scott, Alan J.

    2005-01-01

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

  18. It's in the sand

    OpenAIRE

    Mitchell, Clive

    2016-01-01

    Sand is sand isn’t it? Sand gets everywhere but rather than a nuisance it is a valuable, high-purity raw material. Clive Mitchell, Industrial Minerals Specialist at the British Geological Survey (BGS), talks us through what sand is, what it can be used for and how to find it. His exploration of sand takes us from the deserts of Arabia to the damp sand pits of Mansfield!

  19. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  20. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  1. Industrial sand and gravel

    Science.gov (United States)

    Dolley, T.P.

    2013-01-01

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

  2. 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...

  3. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  4. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Borup, Marianne; Hedegaard, Jette

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development og the theory of building up pore pressure in sand, L. B. Ibsen 1993....

  5. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Bødker, Lars Bødker

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development of the theory of building up pore pressure in sand....

  6. Petri Nets

    Indian Academy of Sciences (India)

    Associate Professor of. Computer Science and. Automation at the Indian. Institute of Science,. Bangalore. His research interests are broadly in the areas of stochastic modeling and scheduling methodologies for future factories; and object oriented modeling. GENERAL I ARTICLE. Petri Nets. 1. Overview and Foundations.

  7. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Petri Nets - Overview and Foundations. Y Narahari. General Article Volume 4 Issue 8 August 1999 pp ... Author Affiliations. Y Narahari1. Department ot Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  8. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...

  9. On Foundation Improvement By Sand Replacement | Abam | Global ...

    African Journals Online (AJOL)

    This paper describes a simple foundation improvement method involving the replacement of poor foundation bearing soils with sand and the resultant improvement in bearing capacity and the minimization of settlement at the site of a large storage tank. Minimum thickness of sand replacement for various foundation loads ...

  10. Soil and humus development in drift sands

    NARCIS (Netherlands)

    Sevink, J.; de Waal, R.W.; Fanta, J.; Siepel, H.

    2010-01-01

    In drift sand, incipient mineral soils with a very thin endorganic horizon develop towards highly acid soils with a thick, differentiated, mor to moder type ectorganic horizon and incipient podzolisation, within a period of about 100 years. This is due slow litter decomposition and associated soil

  11. 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.

  12. Modelling sand wave variation

    NARCIS (Netherlands)

    Sterlini-Van der Meer, Fenneke

    2009-01-01

    The sea floor of shallow seas is rarely flat and often dynamic. A widely occurring bedform type is the sand wave. Sand waves form more or less regular wavelike patterns on the seabed with crests up to one third of the water depth, wave lengths of hundreds of metres and a migration rate of metres up

  13. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1992-01-01

    Sands cykliske styrke kan beskrives ved Cyclic Liquefaction, Mobilisering, Stabilization og Instant Stabilization. I artiklen beskrives hvorfor Stabilization og Instant Stabilization ikke observeres, når sands udrænede styrke undersøges i triaxial celler, der anvender prøver med dobbelt prøvehøjde....

  14. 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...

  15. Vestled - Hvide Sande

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten; Hesselbjerg, Marianne; Schønherr, Torben

    2009-01-01

    Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side......Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side...

  16. 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.

  17. Sand dynamics in the Mekong River channel and export to the coastal ocean

    Science.gov (United States)

    Stephens, J. D.; Allison, M. A.; Di Leonardo, D. R.; Weathers, H. D.; Ogston, A. S.; McLachlan, R. L.; Xing, F.; Meselhe, E. A.

    2017-09-01

    Two field campaigns were conducted in the tidal and estuarine reach of the Sông Hậu distributary of the Mekong River to explore the dynamics of sand transport and export to the coastal ocean. This study examines variations in suspended sand concentration and net flux of suspended and bedload sand with respect to changes in discharge between the October 2014 high discharge and March 2015 low discharge season. Isokinetic measurements of suspended sand were used to calibrate a larger dataset of LISST profiles to report suspended sand mass concentrations. During the high discharge season, ebb and flood currents are a primary control on suspended sand concentrations. Ebb tidal flows are more capable of sand transport than flooding flows, due to river discharge augmenting tidal currents. Sand in suspension is primarily derived locally from bed material sand. Bedform transport estimates were limited, but suggest that bedload sand transport is less than 10% of net suspended sand flux. Very low concentrations of suspended sand sediment are found during the low discharge season. These low concentrations are likely caused by (1) a reduction in maximum ebb tide shear stresses associated with less freshwater input, and (2) mud mantling in the bed associated with upstream migration of estuarine circulation, that inhibits local sourcing (resuspension) of bed sand. Results of the observational study were used to calibrate a numerical model of annual sand flux to the ocean from all distributaries of the Mekong River. Annual sand export is estimated at 6.5 ± 1.6 Mt yr-1. The Định An subdistributary accounts for 32% of this total while the smaller Trần Đề subdistributary accounts for only 9%.

  18. [Effect of shifting sand burial on evaporation reduction and salt restraint under saline water irrigation in extremely arid region].

    Science.gov (United States)

    Zhang, Jian-Guo; Zhao, Ying; Xu, Xin-Wen; Lei, Jia-Qiang; Li, Sheng-Yu; Wang, Yong-Dong

    2014-05-01

    The Taklimakan Desert Highway Shelterbelt is drip-irrigated with high saline groundwater (2.58-29.70 g x L(-1)), and shifting sand burial and water-salt stress are most common and serious problems in this region. So it is of great importance to study the effect of shifting sand burial on soil moisture evaporation, salt accumulation and their distribution for water saving, salinity restraint, and suitable utilization of local land and water resources. In this study, Micro-Lysimeters (MLS) were used to investigate dynamics of soil moisture and salt under different thicknesses of sand burial (1, 2, 3, 4, and 5 cm), and field control experiments of drip-irrigation were also carried out to investigate soil moisture and salt distribution under different thicknesses of shifting sand burial (5, 10, 15, 20, 25, 30, 35, and 40 cm). The soil daily and cumulative evaporation decreased with the increase of sand burial thickness in MLS, cumulative evaporation decreased by 2.5%-13.7% compared with control. And evaporative inhibiting efficiency increased with sand burial thickness, evaporative inhibiting efficiency of 1-5 cm sand burial was 16.7%-79.0%. Final soil moisture content beneath the interface of sand burial increased with sand burial thickness, and it increased by 2.5%-13.7% than control. The topsoil EC of shifting sand in MLS decreased by 1.19-6.00 mS x cm(-1) with the increasing sand burial thickness, whereas soil salt content beneath the interface in MLS increased and amplitude of the topsoil salt content was higher than that of the subsoil. Under drip-irrigation with saline groundwater, average soil moisture beneath the interface of shifting sand burial increased by 0.4% -2.0% compare with control, and the highest value of EC was 7.77 mS x cm(-1) when the sand burial thickness was 10 cm. The trend of salt accumulation content at shifting sand surface increased firstly, and then decreased with the increasing sand burial thickness. Soil salt contents beneath the

  19. The cone penetration test in unsaturated silty sands

    Directory of Open Access Journals (Sweden)

    Yang Hongwei

    2016-01-01

    Full Text Available Very little is known about how to interpret the cone penetration test (CPT when performed in unsaturated soils. The few published studies on the CPT in unsaturated soils have focused on either clean sands or a silt. In this study new results of laboratory-controlled CPTs in an unsaturated silty sand are presented. The silty sand exhibits hydraulic hysteresis and suction hardening. Suction is observed to have a pronounced affect on measured cone penetration resistance. For an isotropic net confining stress of 60 kPa it is observed that higher suctions give rise to cone penetration resistances that are 50% larger than those for lower suctions. A semi-theoretical correlation is presented that links measured cone penetration resistances to initial relative density and mean effective stress. For this silty sand it is shown that failing to account for suction may result in significant overestimations and unsafe predictions of soil properties from measured cone penetration resistances.

  20. Factors responsible for the limited inland extent of sand deposits on Leyte Island during 2013 Typhoon Haiyan

    NARCIS (Netherlands)

    Watanabe, M.; Bricker, J.D.; Goto, K.; Imamura, F.

    2017-01-01

    Previous geological studies suggest that the maximum inland extent of storm-induced sand deposits is shorter, but their thickness is larger, than those of tsunami-induced sand deposits. However, factors that determine the maximum extent and thickness of storm deposits are still uncertain. We

  1. Representational Thickness

    DEFF Research Database (Denmark)

    Mullins, Michael

    to improve design conditions for architects, thereby increasing the “thickness of representation”. The study commences from a broader theoretical enquiry, a review of previous research and examples of relevant context in which virtual reality has been used in practice. It develops from this discussion three......Contemporary communicational and informational processes contribute to the shaping of our physical environment by having a powerful influence on the process of design. Applications of virtual reality (VR) are transforming the way architecture is conceived and produced by introducing dynamic...... elements into the process of design. Through its immersive properties, virtual reality allows access to a spatial experience of a computer model very different to both screen based simulations as well as traditional forms of architectural representation. The dissertation focuses on processes of the current...

  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. Virksomhedens sande ansigt

    DEFF Research Database (Denmark)

    Lundholt, Marianne Wolff

    2017-01-01

    Er modhistorier en byrde eller en styrke i forandringsprocesser? Hvad stiller vi op, når adgangen til organisationens sande identitet går gennem medarbejdernes modhistorier? Når vi sammenholder denne erkendelse med vores viden om, at medarbejdere helt naturligt afholder sig fra at videregive disse...

  4. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

    The idea of building sand castles evokes images of lazy summer days at the beach, listening to waves crash, enjoying salty breezes, and just unplugging for a while to let our inner child explore the wonderful natural toys beneath our feet. The idea of exploring caves might evoke feelings and images of claustrophobia or pioneers and Native…

  5. Sand Filter Technology

    Science.gov (United States)

    2016-08-01

    EXWC) performed the evaluation at the Naval Air Station Lemoore, CA . The two year evaluation period began with one year of sand filter operation...appear dirty? If you answered “ yes ” to the first question and “ yes ” to either of the other questions, investigate this technology for your

  6. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

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

  7. Triaxial tests in Fontainebleau sand

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2016-01-01

    The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note...

  8. Northern Sand Sea

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form. This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes. Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States); Rosener, B. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host ``na-net.ornl.gov`` at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message ``send index`` to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user`s perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  10. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science Oak Ridge National Lab., TN (United States)); Rosener, B. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science)

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host na-net.ornl.gov'' at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message send index'' to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user's perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  11. 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...

  12. 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.

  13. The Delft Sand, Clay & Rock Cutting Model. Family Edition.

    NARCIS (Netherlands)

    Miedema, S.A.

    2015-01-01

    In dredging, trenching, (deep sea) mining, drilling, tunnel boring and many other applications, sand, clay or rock has to be excavated. The productions (and thus the dimensions) of the excavating equipment range from mm3/sec - cm3/sec to m3/sec. In oil drilling layers with a thickness of a magnitude

  14. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  15. Moving sand dunes

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

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

  16. Control of Phlebotomine Sand Flies in Iran: A Review Article

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Yaghoobi-Ershadi

    2016-10-01

    Full Text Available Leishmaniasis has long been known as a significant public health challenge in many parts of Iran. Phlebotomus pa­patasi and P. sergenti are the vectors of Zoonotic Cutaneous Leishmaniasis and Anthroponotic Cutaneous Leish­maniasis respectively, and 5 species of sand flies including P. kandelakii, P. neglectus, P. perfiliewi, P. keshishiani and P. alexandri are considered as probable vectors of Zoonotic visceral leishmaniasis. A literature search was per­formed of the relevant multiple databases from 1966 to 2013 to include studies on sand flies, vector control, leish­maniasis, Phlebotomus. Sand fly control in Iran began in 1966 by Iranian researchers, and long-term evaluation of its effects was completed in the study areas of the country. Herein, a review of vector control strategies in Iran to com­bat leishmaniasis including indoor residual spraying, application of chemicals in rodent burrows, impregnation of bed nets and curtains with insecticides, the use of insect repellents, impregnation of dog collars and the susceptibility of sand fly vectors to various insecticides has been summarized thus far. The investigation of the behavioral patterns of the adults of different sand fly species, introduction of biological insecticide agents, the use of insecticidal plants and other novel strategies for the control of sand fly populations have received much attention in the areas of studies, hence should be recommended and improved since they provide optimistic results.

  17. 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

  18. Professional Enterprise NET

    CERN Document Server

    Arking, Jon

    2010-01-01

    Comprehensive coverage to help experienced .NET developers create flexible, extensible enterprise application code If you're an experienced Microsoft .NET developer, you'll find in this book a road map to the latest enterprise development methodologies. It covers the tools you will use in addition to Visual Studio, including Spring.NET and nUnit, and applies to development with ASP.NET, C#, VB, Office (VBA), and database. You will find comprehensive coverage of the tools and practices that professional .NET developers need to master in order to build enterprise more flexible, testable, and ext

  19. 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.

  20. Laboratory singing sand avalanches.

    Science.gov (United States)

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

    2010-02-01

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

  1. Fortune Cookie Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-432, 25 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small barchan sand dunes in the north polar region near 71.7oN, 51.3oW. Some of them are shaped like fortune cookies. The message these dunes provide: winds blow through this region from the lower right toward the upper left. The steep slip face slopes of these dunes, which point toward the upper left, indicate the wind direction. The scene is illuminated by sunlight from the upper right. The image is 3 km (1.9 mi) wide.

  2. 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.

  3. WaveNet

    Science.gov (United States)

    2015-10-30

    Coastal Inlets Research Program WaveNet WaveNet is a web-based, Graphical-User-Interface ( GUI ) data management tool developed for Corps coastal...generates tabular and graphical information for project planning and design documents. The WaveNet is a web-based GUI designed to provide users with a...data from different sources, and employs a combination of Fortran, Python and Matlab codes to process and analyze data for USACE applications

  4. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...... use of CP-nets — because it means that the function representation and the translations (which are a bit mathematically complex) no longer are parts of the basic definition of CP-nets. Instead they are parts of the invariant method (which anyway demands considerable mathematical skills...

  5. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  6. Programming NET Web Services

    CERN Document Server

    Ferrara, Alex

    2007-01-01

    Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

  7. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    -net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... a method which makes it possible to associate auxiliary information, called annotations, with tokens without modifying the colour sets of the CP-net. Annotations are pieces of information that are not essential for determining the behaviour of the system being modelled, but are rather added to support...

  8. 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...

  9. Atlas of Dutch drift sands

    Science.gov (United States)

    Riksen, Michel; Jungerius, Pieter

    2013-04-01

    The Netherlands is well known for its aeolian landscapes. Frequent storms during the High Middle Ages (1000-1300 AD) reactivated Pleistocene coversands and river dunes and are responsible for the formation of the Holocene drift sands at a scale which is unique for Europe. A hypothesized relationship with farmer practices for making plaggensoils has recently been refuted, because drift sand formation began centuries earlier. The coastal dune belt with their parabolic dunes dates from the same period as the drift sand. An estimate of the extent of drift sands can be made from soil maps: drift sands are too young to show much profile development (Regosols). With this method Koster estimated the maximum extent of Holocene drift sands in the Netherlands to be about 800 km2 (Koster 2005). Laser altimetry allows a more precise estimate of the total surface affected by wind from the characteristic relief patterns produced by the Holocene wind, which is different from the smooth surface of cover sand deposits. Laser altimetry has been used before to investigate the mechanism of drift sand formation (Jungerius & Riksen 2010). Most of the surface affected by wind is not active anymore, but the tell-tale rough surface survived ages of different landuse. The total affected surface amounts to 825 km2. It is noteworthy that both methods give comparable results. We recorded a total number of 367 of affected areas of varying shapes, ranging in size from 1.6 ha to a large complex of drif sands of 7,119.5 ha. As is to be expected from their mode of origin, most occurrences are associated with cover sands, and with river dunes along the river Meuse and smaller rivers in other parts of the country. Particularly the final phases of cover sand and river dunes that show more relief as parabolic dunes were affected. There are also small aeolian deposits at the lee side blown from fallow agricultural fields but they are (sub)recent. Most of the relief is irregular, but the larger

  10. 2010 oil sands performance report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    With the depletion of traditional energy resources and the rising demand for energy, oil sands have become an important energy resource for meeting energy needs. Oil sands are a mixture of water, sand, clay and bitumen which is recovered either through open pit mining or in situ drilling techniques. The bitumen is then converted into syncrude or sold to refineries for the production of gasoline, diesel or other products. Shell has oil sands operations in Alberta and the aim of this report is to present its 2010 performance in terms of CO2, water, tailings, land, and reclamation and engagement. This document covers several of Shell's operations in the Muskeg River and Jackpine mines, Scotford upgrader, Peace River, Orion, Seal, Cliffdale and Chipmunk. It provides useful information on Shell's oil sands performance to governments, environmental groups, First Nations, local communities and the public.

  11. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available Is it possible to develop a building that uses a net zero amount of water? In recent years it has become evident that it is possible to have buildings that use a net zero amount of electricity. This is possible when the building is taken off...

  12. SolNet

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Vajen, Klaus; Bales, Chris

    2014-01-01

    SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...

  13. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  14. Morphodynamic modeling of a large inside sand bar and its dextral morphology in a convergent estuary: Qiantang Estuary, China

    NARCIS (Netherlands)

    Xie, Dongfeng; Gao, Shu; Wang, Zhengbing; Pan, Cunhong; Wu, Xiuguang; Wang, Qiushun

    2017-01-01

    We investigate the evolution of a large-scale sand body, a unique type of sandbars in a convergent estuary. Specifically, we analyze and simulate the sand deposition system (defined as an inside bar) in the Qiantang Estuary (QE) in China. The deposit is 130 km long and up to 10 m thick, and is

  15. Pro NET Best Practices

    CERN Document Server

    Ritchie, Stephen D

    2011-01-01

    Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

  16. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  17. Instant Lucene.NET

    CERN Document Server

    Heydt, Michael

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A step-by-step guide that helps you to index, search, and retrieve unstructured data with the help of Lucene.NET.Instant Lucene.NET How-to is essential for developers new to Lucene and Lucene.NET who are looking to get an immediate foundational understanding of how to use the library in their application. It's assumed you have programming experience in C# already, but not that you have experience with search techniques such as information retrieval theory (although there will be a l

  18. Spectroscopic characterization of a Nigerian standard sand: Igbokoda sand

    CSIR Research Space (South Africa)

    Ojuri, OO

    2017-01-01

    Full Text Available the Middle Ordovician St. Peter Sandstone near Ottawa, Illinois, had been picked by the American Society for Testing and Materials (ASTM) as the reference sand to employ in testing cement and strength of concrete [9]. To the best of our knowledge... and magnetic resonance spectroscopic techniques due to its importance in cement, geotechnical/geo-environmental research in Nigeria. This should halt importation of standard silica sand for mortar and concrete testing...

  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...... occurring in various glacial environments. This study specifically focuses on the appearance and spatial distribution of sand lenses in tills. It introduces a methodology on how to measure and characterize sand lenses in the field with regard to size, shape and degree of deformation. A set of geometric...... parameters is defined to allow characterization of sand lenses. The proposed classification scheme uses a stringent terminology to distinguish several types of sand lenses based on the geometry. It includes sand layers, sand sheets, sand bodies, sand pockets and sand stringers. The methodology has been...

  20. Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Musall, Eike

    2010-01-01

    and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...... parameters used in the calculations are discussed and the various renewable supply options considered in the methodologies are summarised graphically. Thus, the paper helps to understand different existing approaches to calculate energy balance in Net ZEBs, highlights the importance of variables selection...

  1. PhysioNet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

  2. NetSig

    DEFF Research Database (Denmark)

    Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

    2018-01-01

    Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

  3. 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.

  4. TideNet

    Science.gov (United States)

    2015-10-30

    query tide data sources in a desired geographic region of USA and its territories (Figure 1). Users can select a tide data source through the Google Map ...select data sources according to the desired geographic region. It uses the Google Map interface to display data from different sources. Recent...Coastal Inlets Research Program TideNet The TideNet is a web-based Graphical User Interface (GUI) that provides users with GIS mapping tools to

  5. Building Neural Net Software

    OpenAIRE

    Neto, João Pedro; Costa, José Félix

    1999-01-01

    In a recent paper [Neto et al. 97] we showed that programming languages can be translated on recurrent (analog, rational weighted) neural nets. The goal was not efficiency but simplicity. Indeed we used a number-theoretic approach to machine programming, where (integer) numbers were coded in a unary fashion, introducing a exponential slow down in the computations, with respect to a two-symbol tape Turing machine. Implementation of programming languages in neural nets turns to be not only theo...

  6. Interaction Nets in Russian

    OpenAIRE

    Salikhmetov, Anton

    2013-01-01

    Draft translation to Russian of Chapter 7, Interaction-Based Models of Computation, from Models of Computation: An Introduction to Computability Theory by Maribel Fernandez. "In this chapter, we study interaction nets, a model of computation that can be seen as a representative of a class of models based on the notion of 'computation as interaction'. Interaction nets are a graphical model of computation devised by Yves Lafont in 1990 as a generalisation of the proof structures of linear logic...

  7. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  8. Development and validation of model for sand

    Directory of Open Access Journals (Sweden)

    Church P.

    2015-01-01

    Full Text Available There is a growing requirement within QinetiQ to develop models for assessments when there is very little experimental data. A theoretical approach to developing equations of state for geological materials has been developed using Quantitative Structure Property Modelling based on the Porter-Gould model approach. This has been applied to well-controlled sand with different moisture contents and particle shapes. The Porter-Gould model describes an elastic response and gives good agreement at high impact pressures with experiment indicating that the response under these conditions is dominated by the molecular response. However at lower pressures the compaction behaviour is dominated by a micro-mechanical response which drives the need for additional theoretical tools and experiments to separate the volumetric and shear compaction behaviour. The constitutive response is fitted to existing triaxial cell data and Quasi-Static (QS compaction data. This data is then used to construct a model in the hydrocode. The model shows great promise in predicting plate impact, Hopkinson bar, fragment penetration and residual velocity of fragments through a finite thickness of sand.

  9. Nearshore Sand Transport.

    Science.gov (United States)

    1987-01-01

    injected dyed snd N(x~y,zpt) number of dyed grains, per gram of send Hoax maximum concentration of dyad grains. in any slice in a &and core no solids...onshore or offshore. Clearly this is of great importance. One very clear result is that the application of a threshold criterion (for initiation of sediment...Significance 99.3 98.8 96.3 Moon correlation coefficient for the two colors: -0.422 -0.396 -0.343 203 Table 8-11. Correlation of Transport Thickness with

  10. Management recommendations: Sand Lake Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Sand Lake National Wildlife Refuge, by a land use specialist. Recommendations, time frame and...

  11. Impact of reservoir quality on SAGD production: observations from the UTF phase B oil sands pilot

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, Rudy [Statoil Canada Ltd (Canada)

    2011-07-01

    The fundamental principle in SAGD is that gravity brings the steam-bitumen emulsion flows down to the production well; hence, net fluid flow being limited to the vertical plane, it is essential to rely on uninterrupted vertical permeability. This paper examines the effects of some mudstone-dominated IHS intervals that block steam rise for production of the B2 well pair. A geological model is proposed for the Phase B pilot area; it consists of an eastward thickening HIS-dominated succession. Results show that compared to sand lithologies, mudstones reduce vertical permeability by 1 to 2 orders of magnitude, and this can be detrimental to operations. In fact, a 70-cm thick mudstone-dominated bed was an obstacle to steam rise during the 9 years of production in the B2 well; these beds represent the most common reservoir heterogeneity of the McMurray Formation. The lateral continuity of the permeability barrier is an important consideration concerning steam rise and SAGD production.

  12. Sensuous Communism: Sand with Marx

    OpenAIRE

    White, Claire

    2015-01-01

    This article reads George Sand's Le Compagnon du Tour de France (1840) alongside Karl Marx's “Economic and Philosophic Manuscripts of 1844.” It considers how these contemporaries bring to bear on their accounts of labor, estrangement, and the structures of property an attention to the fate of the senses under capitalism. Both elaborate a critique of political economy—Sand's voiced by her worker-hero—that demonstrates how the individual's sensuous life is circumscribed by the pressures of mate...

  13. Suspended and Bedload Sand dynamics in the Mekong River Channel and Export to the Coastal Ocean

    Science.gov (United States)

    Stephens, J. D.; Di Leonardo, D. R.; Weathers, H. D., III; Allison, M. A.

    2016-02-01

    Two field campaigns were conducted in the tidal and estuarine reach of the Song Hau distributary of the Mekong River to examine the dynamics of sand transport and export to the coastal ocean. This study examines variation in suspended sand concentration and net transport with respect to changes in discharge between the October 2014 high discharge and March 2015 low discharge studies, and over semi-diurnal and spring-neap tidal cycles between Can Tho and the Tran De and Dinh An distributary channels in the Mekong Delta. Suspended sand concentrations were measured using a P-61 isokinetic suspended sediment sampler and a Sequoia Scientific LISST-100X used in vertical profiling mode. Stationary ADCP data are used to examine bed stress at cast sites. Bed load transport rates were calculated using a repeat multibeam transect methodology and dune translation rates with flow. Preliminary results indicate that suspended sand concentration increases towards the bed and is positively correlated with increasing shear stress controlled by river discharge and tides. However, sites with non-sandy bottoms, as indicated by multibeam bathymetry, have low suspended sand concentrations, suggesting a close linkage with a bed sand source. Bed load transport rates vary cross-sectionally with shear stress and are linked to dune size. Most bed load transport is taking place in or near the thalweg. The reduction in ebb flows at low discharge and the mantling of sand fields by salinity driven mud deposition, is suspected to control the low suspended sand concentrations observed in March. Results to date suggest that net sand export (suspended plus bed load) to the ocean occurs predominantly during the high discharge monsoon season.

  14. Modelling of sand transport under wave-generated sheet flows with a RANS diffusion model

    NARCIS (Netherlands)

    Hassan, Wael; Ribberink, Jan S.

    2010-01-01

    A 1DV-RANS diffusion model is used to study sand transport processes in oscillatory flat-bed/sheet flow conditions. The central aim is the verification of the model with laboratory data and to identify processes controlling the magnitude and direction (‘onshore’/‘offshore’) of the net time-averaged

  15. Nitrate retention in a sand plains stream and the importance of groundwater discharge

    Science.gov (United States)

    Robert S. Stelzer; Damion R. Drover; Susan L. Eggert; Maureen A. Muldoon

    2011-01-01

    We measured net nitrate retention by mass balance in a 700-m upwelling reach of a third-order sand plains stream, Emmons Creek, from January 2007 to November 2008. Surface water and ground-water fluxes of nitrate were determined from continuous records of discharge and from nitrate concentrations based on weekly and biweekly sampling at three surface water stations and...

  16. Population preference of net texture prior to bed net trial in Kala-Azar-endemic areas.

    Directory of Open Access Journals (Sweden)

    Murari L Das

    Full Text Available Prior to a community-based efficacy trial of long-lasting insecticidal nets (LLINs in the prevention of visceral leishmaniasis (VL; also called kala-azar, a pilot study on preference of tools was held in endemic areas of India and Nepal in September 2005.LLINs made of polyester and polyethylene were distributed to 60 participants, who used the nets sequentially for 7 d. Acceptability and preference were evaluated via indirect indicators through questionnaires at three defined time points before and after use of the LLINs and through focus group discussions (FGDs. In the latter, preferences for color and size were also assessed. Untreated bed nets were owned by 87% of the households prior to the study. All users liked textures of both LLIN types after 7 d of use, but had a slight preference for those made of polyester if they were to recommend a LLIN to relatives or friends (p<0.05, mainly because of their relatively greater softness in comparison to polyethylene LLINs. Users reported that both net types reduced mosquito bites and number of insects, including sand fly (bhusana; genus Phlebotomus, inside the house. Side effects were minor and disappeared quickly.The large-scale intervention trial considered the preferences of the study population to decide on the best tool of intervention--light-blue, rectangular, polyester LLINs of different sizes.

  17. La plataforma .NET

    OpenAIRE

    Fornas Estrada, Miquel

    2008-01-01

    L'aparició de la plataforma .NET Framework ha suposat un canvi molt important en la forma de crear i distribuir aplicacions, degut a que incorpora una sèrie d'innovacions tècniques i productives que simplifiquen molt les tasques necessàries per desenvolupar un projecte. La aparición de la plataforma. NET Framework ha supuesto un cambio muy importante en la forma de crear y distribuir aplicaciones, debido a que incorpora una serie de innovaciones técnicas y productivas que simplifican mucho...

  18. Biological Petri Nets

    CERN Document Server

    Wingender, E

    2011-01-01

    It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

  19. Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

    Science.gov (United States)

    Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

    2016-06-01

    The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

  20. Optimal array of sand fences

    Science.gov (United States)

    Lima, Izael A.; Araújo, Ascânio D.; Parteli, Eric J. R.; Andrade, José S.; Herrmann, Hans J.

    2017-03-01

    Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth’s climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

  1. Enhancing the CPT correlation with the small strain shear stiffness of sands

    Directory of Open Access Journals (Sweden)

    Sayed M. Ahmed

    2017-12-01

    Full Text Available The cone penetration test (CPT is a valuable geotechnical insitu test. Yet, the CPT correlations with the small strain shear modulus and seismic shear wave velocity still need more research to enhance their accuracy. In this study, the stress normalizations for the net cone tip resistance and the small strain shear modulus are scrutinized. Subsequently, enhanced CPT correlations with the small strain shear modulus and the seismic shear wave velocity for sands are presented. The proposed approach utilizes published databases of CPT in sands and recent researches that quantify the small strain shear modulus using sand gradation parameters. Four case histories are analyzed using the suggested correlation and the results confirm that the presented approach is a promising enhancement to the CPT correlations with the small strain shear modulus and seismic shear wave velocity in sands.

  2. 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.

  3. EFFECTIVENESS OF THE SANDPITS SECURITY SYSTEM AGAINST MICROORGANISMS AND INTESTINAL PARASITES SAND CONTAMINATION

    Directory of Open Access Journals (Sweden)

    Magdalena Błaszak

    2015-09-01

    Full Text Available Playgrounds and sandpits (small architecture objects according to the Construction Law are subject to meticulous supervision, both at the design stage and subsequent status checks of the objects. One of the requirements arising from the need to protect playgrounds from animals is the necessity for fencing the object (Regulation of 31 December 2002 On Safety and Hygiene in Public and Private Schools and Institutions; Polish Standard PN-EN 1176 Playground equipment and surfacing. Does fencing playgrounds really reduce contamination of sand? To verify this hypothesis, the studies have been conducted on the residential areas’ sandpits, both fence secured and unsecured, located in close proximity to one another. The aim of the study was to evaluate the effectiveness of fences and nets as protection from microbial and parasite contamination of sandpits, mainly due to the access of animals to them. For several seasons of spring and summer the sand was examined in terms of the total number of heterotrophic bacteria and fungi (organic matter contamination of sand indicators and for the presence of coliform bacteria (including Escherichia coli, bacteria of the Salmonella genus and the eggs of intestinal parasites. It can be concluded that fencing playgrounds affects sand pollution less with waste and plant material (as a consequence, it has been reported statistically significantly less heterotrophic bacteria and fungi in the fenced sandpits’ sand. Unfortunately, the fence does not eliminate the risks associated with sand pollution of coliform bacteria. Cats and birds, but also dogs, still have a continuous access to sand. Due to the repeatedly stated carelessness of children and their caregivers, gates left open to the playground do not constitute an obstacle for domestic and stray animals. Another source of sand pollution with intestinal pathogens can be a manner of carriage of new sand, as there is no legislation governing the issue of transport

  4. 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

  5. Petri Nets-Applications

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/004/09/0044-0052. Author Affiliations. Y Narahari ...

  6. Safety nets or straitjackets?

    DEFF Research Database (Denmark)

    Ilsøe, Anna

    2012-01-01

    Does regulation of working hours at national and sector level impose straitjackets, or offer safety nets to employees seeking working time flexibility? This article compares legislation and collective agreements in the metal industries of Denmark, Germany and the USA. The industry has historically...

  7. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  8. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  9. Game Theory .net.

    Science.gov (United States)

    Shor, Mikhael

    2003-01-01

    States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…

  10. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism...

  11. 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).

  12. Sands at Gusev Crater, Mars

    Science.gov (United States)

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

    2014-05-01

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

  13. Pilot Study on Carbon-sand Filter for Sedimentation Effluent

    Directory of Open Access Journals (Sweden)

    Zhang Shuo

    2015-01-01

    Full Text Available The development of dual function of integrating with activated carbon adsorption and quartz sand filtration in the carbon-sand filter can collaboratively remove organic matters and turbidity and also protect the bio-security, and the pilot test is carried out to optimize the process parameters. The pilot test results show that the thickness of the filter materials is preferably 1,300mm of the activated carbon, 500mm of uniform quartz sand; filtration rate can be 8-12m/h; filter cycle is 24-48h; when the water temperature is 21°C to 29°C, the biofilm formation period in the carbon-sand filter is 15 to 20 days; removal of the organic matters and nitrogen runs through the entire filter bed, and the nitrite is mainly oxidized on the upper side; when the operation is mature, the layer of filter materials can form the biofilm and zoogloea, with the dual function of micro-biological degradation and activated carbon adsorption.

  14. Comparison of sand-layer geometry on flat floors of 10 modern depositional basins

    Energy Technology Data Exchange (ETDEWEB)

    Pilkey, O.H. (Duke Univ., Durham, NC); Locker, S.D.; Cleary, W.J.

    1980-06-01

    A comparative study of 10 deep turbidite basins indicates that sand-layer thickness, frequency, and continuity can be related to their basin geometries, tectonics, and source areas. This study is based on piston-core data from the flat floors of four oceanic-crust abyssal plains (Sohm, Hatteras, Blake-Bahama, and Silver), two Bahama-Plateau reentrant basins (Columbus basin and Tongue of the Ocean), three subduction zone-island arc basins (Hispaniola-Caicos, Navidad, and St. Croix basins), and one continental-borderland basin (Santa Monica basin). With increasing tectonic activity, sand layers on flat basin floors tend to be thinner and more frequent. Except in elongated narrow basins such as Navidad, source-area size is directly related to proximal sand-layer thickness. Continuity of individual sand layers is a function of drainage-basin size and depositional-basin shape. For example, on the Hatteras Abyssal Plan long-distance continuity (up to 500 km) of individual sand layers is achieved because most of the turbidites are large and are introduced only at the north upstream end. In the small horseshoe-shaped Columbus basin, sand-layer continuity is limited because flows are small and are introduced from three sides. In most basins, sands thin and the percentage of sand layers in the sediment column decreases away from source areas. However, in basins that are small relative to the typical turbidity-current size (e.g., Hispaniola-Caicos basin), the differences between basin-edge and basin-center sand layers are slight. 10 figures, 3 tables.

  15. Combining epidemiology with basic biology of sand flies, parasites, and hosts to inform leishmaniasis transmission dynamics and control.

    Directory of Open Access Journals (Sweden)

    Orin Courtenay

    2017-10-01

    Full Text Available Quantitation of the nonlinear heterogeneities in Leishmania parasites, sand fly vectors, and mammalian host relationships provides insights to better understand leishmanial transmission epidemiology towards improving its control. The parasite manipulates the sand fly via production of promastigote secretory gel (PSG, leading to the "blocked sand fly" phenotype, persistent feeding attempts, and feeding on multiple hosts. PSG is injected into the mammalian host with the parasite and promotes the establishment of infection. Animal models demonstrate that sand flies with the highest parasite loads and percent metacyclic promastigotes transmit more parasites with greater frequency, resulting in higher load infections that are more likely to be both symptomatic and efficient reservoirs. The existence of mammalian and sand fly "super-spreaders" provides a biological basis for the spatial and temporal clustering of clinical leishmanial disease. Sand fly blood-feeding behavior will determine the efficacies of indoor residual spraying, topical insecticides, and bed nets. Interventions need to have sufficient coverage to include transmission hot spots, especially in the absence of field tools to assess infectiousness. Interventions that reduce sand fly densities in the absence of elimination could have negative consequences, for example, by interfering with partial immunity conferred by exposure to sand fly saliva. A deeper understanding of both sand fly and host biology and behavior is essential to ensuring effectiveness of vector interventions.

  16. Combining epidemiology with basic biology of sand flies, parasites, and hosts to inform leishmaniasis transmission dynamics and control.

    Science.gov (United States)

    Courtenay, Orin; Peters, Nathan C; Rogers, Matthew E; Bern, Caryn

    2017-10-01

    Quantitation of the nonlinear heterogeneities in Leishmania parasites, sand fly vectors, and mammalian host relationships provides insights to better understand leishmanial transmission epidemiology towards improving its control. The parasite manipulates the sand fly via production of promastigote secretory gel (PSG), leading to the "blocked sand fly" phenotype, persistent feeding attempts, and feeding on multiple hosts. PSG is injected into the mammalian host with the parasite and promotes the establishment of infection. Animal models demonstrate that sand flies with the highest parasite loads and percent metacyclic promastigotes transmit more parasites with greater frequency, resulting in higher load infections that are more likely to be both symptomatic and efficient reservoirs. The existence of mammalian and sand fly "super-spreaders" provides a biological basis for the spatial and temporal clustering of clinical leishmanial disease. Sand fly blood-feeding behavior will determine the efficacies of indoor residual spraying, topical insecticides, and bed nets. Interventions need to have sufficient coverage to include transmission hot spots, especially in the absence of field tools to assess infectiousness. Interventions that reduce sand fly densities in the absence of elimination could have negative consequences, for example, by interfering with partial immunity conferred by exposure to sand fly saliva. A deeper understanding of both sand fly and host biology and behavior is essential to ensuring effectiveness of vector interventions.

  17. Settling Tube Analysis of Sand

    NARCIS (Netherlands)

    Geldof, H.J.; Slot, R.E.

    1979-01-01

    For various reasons particle-size analysis of sediment is used in many fields of science and technology, a.o. earth sciences, agricultural and civil engineering. Relatively coarse-grained sediment like sand, with dimensions ranging from 0.06 till 2 mm, is analyzed almost exclusively by sieving. The

  18. Silo model tests with sand

    DEFF Research Database (Denmark)

    Munch-Andersen, Jørgen

    Tests have been carried out in a large silo model with Leighton Buzzard Sand. Normal pressures and shear stresses have been measured during tests carried out with inlet and outlet geometry. The filling method is a very important parameter for the strength of the mass and thereby the pressures...

  19. Sand and Water Table Play

    Science.gov (United States)

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

    2010-01-01

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

  20. V-2 at White Sands

    Science.gov (United States)

    1947-01-01

    A V-2 rocket is hoisted into a static test facility at White Sands, New Mexico. The German engineers and scientists who developed the V-2 came to the United States at the end of World War II and continued rocket testing under the direction of the U. S. Army, launching more than sixty V-2s.

  1. The eolian sand problems arising from desertification.

    Science.gov (United States)

    Bofah, K K; Owusu, Y A

    1986-05-01

    Eolian (wind blown) sand constitutes a very serious problem to development in sandy desert lands and causes equally serious problems in lands that are undergoing desertification. In this paper, eolian sand movement due to bulk movement such as sand dune and ripple movement, sand drift by saltation, and sand storms by strong winds are discussed. Associated problems such as eolian sand encroachment on highways, farms, communities and industrial complexes are also discussed and workable solutions are offered. Solutions include chemical stabilization of the surface grains, fences to trap the blown sand and vegetation to prevent soil deflation. Vegetation is emphasized and recommended as the ultimate viable solution to combat desertification and eolian sand problems.

  2. A Mystery Unraveled: Booming Sand Dunes

    Science.gov (United States)

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

    2007-12-01

    "Booming" sand dunes have intrigued travelers and scientist for centuries. These dunes emit a persistent, low-frequency sound during a slumping event or a natural avalanche on the leeward face of the dune. The sound can last for several minutes and be audible from miles away. The resulting acoustic emission is characterized by a dominant audible frequency (70 - 105 Hz) and several higher harmonics. In the work of Vriend et al. (2007), seismic refraction experiments proved the existence of a multi-layer internal structure in the dune that acts as a waveguide for the acoustic energy. Constructive interference between the reflecting waves enables the amplification and sets the frequency of each boom. A relationship was established that correctly predicts the measured frequency in terms of the thickness (~ 2.0 m) and the seismic body wave velocity of the loose, dry surficial layer (~ 240 m/s) and the substrate half-space (~ 350 m/s). The current work highlights additional measurements and simulations supporting the waveguide model for booming sand dunes. Experiments with ground penetrating radar continuously display the subsurface features which confirm the layered subsurface structure within the dune. Cross-correlation analysis shows that the booming sound propagates at speeds close to the measured body wave velocity. Squeaking sounds, which are generated during the onset of the slide and precede the sustained booming emission, have been found to have distinctly different characteristics. These short bursts of sound are emitted at a lower frequency (50 - 65 Hz) and propagate at a lower propagation speed (125 m/s) than the booming emission. The acoustic and elastic wave propagation in the dune has been simulated with a finite difference code. The interaction between the air and the ground produces a coupling wave along the surface. The reflections in the surficial layer propagate in a dispersive band at a group velocity that is slower than the phase velocity of the

  3. Food Safety Nets:

    OpenAIRE

    Haggblade, Steven; Diallo, Boubacar; Staatz, John; Theriault, Veronique; Traoré, Abdramane

    2013-01-01

    Food and social safety nets have a history as long as human civilization. In hunter gatherer societies, food sharing is pervasive. Group members who prove unlucky in the short run, hunting or foraging, receive food from other households in anticipation of reciprocal consideration at a later time (Smith 1988). With the emergence of the first large sedentary civilizations in the Middle East, administrative systems developed specifically around food storage and distribution. The ancient Egyptian...

  4. Net technical assessment

    OpenAIRE

    Wegmann, David G.

    1989-01-01

    Approved for public release; distribution is unlimited. The present and near term military balance of power between the U.S. and the Soviet Union can be expressed in a variety of net assessments. One can examine the strategic nuclear balance, the conventional balance in Europe, the maritime balance, and many others. Such assessments are essential not only for policy making but for arms control purposes and future force structure planning. However, to project the future military balance, on...

  5. Using WordNet for Building WordNets

    CERN Document Server

    Farreres, X; Farreres, Xavier; Rodriguez, Horacio; Rigau, German

    1998-01-01

    This paper summarises a set of methodologies and techniques for the fast construction of multilingual WordNets. The English WordNet is used in this approach as a backbone for Catalan and Spanish WordNets and as a lexical knowledge resource for several subtasks.

  6. experimental studies of sand production from unconsolidated

    African Journals Online (AJOL)

    ES Obe

    consolidated samples has been used to simulate the effect of flow rates, confining pressure, pressure drawdown and fluid viscosity on sand production in the Niger. Delta. The model was also used to determine the ability of using the flow rate to control the production of sand. Sand sample from an unconsolidated reser-.

  7. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  8. Proof nets for lingusitic analysis

    NARCIS (Netherlands)

    Moot, R.C.A.

    2002-01-01

    This book investigates the possible linguistic applications of proof nets, redundancy free representations of proofs, which were introduced by Girard for linear logic. We will adapt the notion of proof net to allow the formulation of a proof net calculus which is soundand complete for the

  9. Teaching Tennis for Net Success.

    Science.gov (United States)

    Young, Bryce

    1989-01-01

    A program for teaching tennis to beginners, NET (Net Easy Teaching) is described. The program addresses three common needs shared by tennis students: active involvement in hitting the ball, clearing the net, and positive reinforcement. A sample lesson plan is included. (IAH)

  10. Net4Care Ecosystem Website

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius; Rasmussen, Morten

    2012-01-01

    is a tele-monitoring scenario in which Net4Care clients are deployed in a gateway in private homes. Medical devices then connect to these gateways and transmit their observations to a Net4Care server. In turn the Net4Care server creates valid clinical HL7 documents, stores them in a national XDS repository...

  11. Appraisal of the Pelican River sand-plain aquifer, west-central Minnesota

    Science.gov (United States)

    Miller, R.T.

    1982-01-01

    The Pelican River sand-plain area includes approximately 200 square miles of outwash deposits in parts of Decker, Otter Tail, and Clay Counties in west-central Minnesota. Saturated thickness of the outwash is as much as 140 feet and yields of properly constructed wells locally may exceed 1,200 gallons per minute.

  12. Effects of slope gradient on hydro-erosional processes on an aeolian sand-covered loess slope under simulated rainfall

    Science.gov (United States)

    Zhang, F. B.; Yang, M. Y.; Li, B. B.; Li, Z. B.; Shi, W. Y.

    2017-10-01

    The aeolian sand-covered loess slope of the Wind-Water Erosion Crisscross Region of the Loess Plateau in China may play a key role in contributing excessive sediment to the Yellow River. Understanding its hydro-erosional processes is crucial to assessing, controlling and predicting soil and water losses in this region and maintaining the ecological sustainability of the Yellow River. Simulated rainfall (intensity 90 mm h-1) was used to investigate the runoff and soil loss from loess slopes with different slope gradients (18%, 27%, 36%, 47%, and 58%) and overlying sand layer thicknesses (0, 5 and 10 cm). As compared with uncovered loess slopes, an overlying sand layer delayed runoff production, reduced cumulative runoff and increased cumulative soil loss, as well as enhancing variations among slope gradients. Cumulative runoff and soil loss from the sand-covered loess slopes increased with increasing slope gradients and then slightly decreased, with a peak at about 47% gradient; they both were greater from the 10-cm sand-covered loess slope than from the 5-cm except for with 18% slope gradient. In general, differences in cumulative runoff between sand layer thicknesses became smaller, while those in cumulative soil loss became larger, with increasing slope gradient. Runoff and soil loss rates on the sand-covered loess slopes exhibited unimodal distributions during the rainstorms. Maximum values tended to occur at the same rain duration, and increased considerably with increasing slope gradient and sand layer thickness on slopes that were less than 47%. Liquefaction process might occur on the lower loess slopes covered with thinner sand layers but failures similar to shallow landslides might occur when the sand layer was thicker on steeper slopes. The presence of an overlying sand layer changed the relationship between runoff and soil loss rates during intense rainstorms and this change varied with different slope gradients. Our results demonstrated that the effects

  13. Master Robotic Net

    Directory of Open Access Journals (Sweden)

    Vladimir Lipunov

    2010-01-01

    Full Text Available The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19-20. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovae (including SNIa, search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System, and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.

  14. Art/Net/Work

    DEFF Research Database (Denmark)

    Andersen, Christian Ulrik; Lindstrøm, Hanne

    2006-01-01

    The seminar Art|Net|Work deals with two important changes in our culture. On one side, the network has become essential in the latest technological development. The Internet has entered a new phase, Web 2.0, including the occurrence of as ‘Wiki’s’, ‘Peer-2-Peer’ distribution, user controlled...... the praxis of the artist. We see different kinds of interventions and activism (including ‘hacktivism’) using the network as a way of questioning the invisible rules that govern public and semi-public spaces. Who ‘owns’ them? What kind of social relationships do they generate? On what principle...

  15. Reframing the Canadian Oil Sands

    OpenAIRE

    Patchett, Merle M; Lozowy, A

    2012-01-01

    Reframing the Canadian Oil Sands” is a collaborative exchange between photographer Andriko Lozowy and cultural geographer Merle Patchett that engages photography and photographic theory to evoke a more critical and politically meaningful visual engagement with the world’s largest capital oil project. Since the appearance of Edward Burtynsky’s aerial and abstracted photographic-mappings of the region, capturing the scale of the Oil Sands from ‘on high’ has become the dominant visual imaginary....

  16. 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 quantify...... module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate....... In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point....

  17. Helminth.net: expansions to Nematode.net and an introduction to Trematode.net

    Science.gov (United States)

    Martin, John; Rosa, Bruce A.; Ozersky, Philip; Hallsworth-Pepin, Kymberlie; Zhang, Xu; Bhonagiri-Palsikar, Veena; Tyagi, Rahul; Wang, Qi; Choi, Young-Jun; Gao, Xin; McNulty, Samantha N.; Brindley, Paul J.; Mitreva, Makedonka

    2015-01-01

    Helminth.net (http://www.helminth.net) is the new moniker for a collection of databases: Nematode.net and Trematode.net. Within this collection we provide services and resources for parasitic roundworms (nematodes) and flatworms (trematodes), collectively known as helminths. For over a decade we have provided resources for studying nematodes via our veteran site Nematode.net (http://nematode.net). In this article, (i) we provide an update on the expansions of Nematode.net that hosts omics data from 84 species and provides advanced search tools to the broad scientific community so that data can be mined in a useful and user-friendly manner and (ii) we introduce Trematode.net, a site dedicated to the dissemination of data from flukes, flatworm parasites of the class Trematoda, phylum Platyhelminthes. Trematode.net is an independent component of Helminth.net and currently hosts data from 16 species, with information ranging from genomic, functional genomic data, enzymatic pathway utilization to microbiome changes associated with helminth infections. The databases’ interface, with a sophisticated query engine as a backbone, is intended to allow users to search for multi-factorial combinations of species’ omics properties. This report describes updates to Nematode.net since its last description in NAR, 2012, and also introduces and presents its new sibling site, Trematode.net. PMID:25392426

  18. NETS FOR PEACH PROTECTED CULTIVATION

    Directory of Open Access Journals (Sweden)

    Evelia Schettini

    2012-06-01

    Full Text Available The aim of this paper was to investigate the radiometric properties of coloured nets used to protect a peach cultivation. The modifications of the solar spectral distribution, mainly in the R and FR wavelength band, influence plant photomorphogenesis by means of the phytochrome and cryptochrome. The phytochrome response is characterized in terms of radiation rate in the red wavelengths (R, 600-700 nm to that in the farred radiation (FR, 700-800 nm, i.e. the R/FR ratio. The effects of the blue radiation (B, 400-500 nm is investigated by the ratio between the blue radiation and the far-red radiation, i.e. the B/FR ratio. A BLUE net, a RED net, a YELLOW net, a PEARL net, a GREY net and a NEUTRAL net were tested in Bari (Italy, latitude 41° 05’ N. Peach trees were located in pots inside the greenhouses and in open field. The growth of the trees cultivated in open field was lower in comparison to the growth of the trees grown under the nets. The RED, PEARL, YELLOW and GREY nets increased the growth of the trees more than the other nets. The nets positively influenced the fruit characteristics, such as fruit weight and flesh firmness.

  19. 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...... in the Paleocene Siri Canyon near the Danish Central Graben of the North Sea hydrocarbon province from borehole data. The emplacement of large-scale injection complexes has been commonly attributed in the geological literature to seismic activity and consequent sand liquefaction. However, due to very small...... differences in textural and compositional properties, and the lack of depositional structures of reservoir sands in the Siri Canyon, the distinction between "in situ" and injected or remobilised sands is difficult. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units...

  20. Role of Sand Grains in Sorption Processes by Surface Layers of Components of Sand Moulds

    Directory of Open Access Journals (Sweden)

    Kaźnica N.

    2017-03-01

    Full Text Available The results of researches of sorption processes of surface layers of components of sand moulds covered by protective coatings are presented in the hereby paper. Investigations comprised various types of sand grains of moulding sands with furan resin: silica sand, reclaimed sand and calcined in temperature of 700°C silica sand. Two kinds of alcoholic protective coatings were used - zirconium and zirconium - graphite. Tests were performed under condition of a constant temperature within the range 30 - 35°C and high relative air humidity 75 - 80%. To analyze the role of sand grains in sorption processes quantitavie moisture sorption with use of gravimetric method and ultrasonic method were used in measurements. The tendency to moisture sorption of surface layers of sand moulds according to the different kinds of sand grains was specified. The effectiveness of protective action of coatings from moisture sorption was analyzed as well.

  1. Evaluation of Durability Parameters of Concrete with Manufacture Sand and River Sand

    Science.gov (United States)

    Sangoju, Bhaskar; Ramesh, G.; Bharatkumar, B. H.; Ramanjaneyulu, K.

    2017-09-01

    Most of the states in our country have banned sand quarrying from the river beds, causing a scarcity of natural river sand for the construction sector. Manufacture sand (M-sand) is one of the alternate solutions to replace the river sand (R-sand) in concrete. The main aim of the present study is to evaluate the durability parameters of concrete with M-sand when compared to that of concrete with R-sand. Corrosion of reinforcement is one of the main deteriorating mechanisms of reinforced concrete due to the ingress of chloride ions or carbon-di-oxide. For comparative evaluation of durability parameters, accelerated tests such as Rapid Chloride Permeability Test, Rapid Chloride Migration Test and accelerated carbonation test were carried out on specimens of R-sand and M-sand. All tests were carried out after 90 days of casting. Test results reveal that the durability parameters of the concrete with M-sand in chloride induced environment is relatively better than that of concrete with R-sand and hence is recommended to use M-sand as a replacement to R-sand.

  2. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  3. The equivalency between logic Petri workflow nets and workflow nets.

    Science.gov (United States)

    Wang, Jing; Yu, ShuXia; Du, YuYue

    2015-01-01

    Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

  4. Distribution of biofilm thickness in porous media and implications for permeability models

    Science.gov (United States)

    Ye, Shujun; Zhang, Yanhong; Sleep, Brent E.

    2015-12-01

    The distribution of biofilm thickness on individual sand grains in a two-dimensional sand-filled cell maintained under anaerobic conditions was investigated. The cell was inoculated with a mixed microbial culture fed with methanol. Concentrations of biomass attached to the sand and suspended in the water in the cell were determined by protein analysis. The biofilm thickness on individual sand grains was investigated with confocal laser scanning microscopy (CLSM), and was found to follow a normal distribution with a mean range of 59-316 μ and standard deviations of 30-77 μ. The bulk average permeability reduction factor is 8. To investigate the implications of the variability of biofilm thicknesses, four models were used to calculate reductions in porous media permeability. Taylor's model predicted a reduction by a factor ranging from 14 to 5,000 (from minimum to maximum mean biofilm thickness). Vandevivere's model predicted a reduction in permeability by a factor ranging from 769 to 3,846 (from minimum to maximum mean biofilm thickness). Seki's model did not give physically meaningful results in this study. Clement's model predicted reduction by a factor ranging from 1 to 1.14 over the range of biomass levels observed in the cell. Data on the statistical and normal distributions of biofilm thickness in porous media, and assessment of their implications with respect to different permeability models, could lead to better understanding of the extent of bioclogging associated with field implementation of bioremediation of contaminants in aquifers.

  5. Initial insights into the age and origin of the Kubuqi sand sea of northern China

    Science.gov (United States)

    Yang, Xiaoping; Forman, Steven; Hu, Fangen; Zhang, Deguo; Liu, Ziting; Li, Hongwei

    2016-04-01

    The Kubuqi Desert is the only active sand sea in the semiarid regions of northern China and occurs along the southern margin of the Yellow River. Little is known about the age and origin of this large (17,000 km2) sand sea with a present annual precipitation of 200-480 mm. Sand drift potentials indicated net capable winds for aeolian transport are from the northwest, though winds are stronger to north beyond the dune field than within the sand sea. Geomorphic and stratigraphic observations indicate that Holocene aeolian sand often drapes over bedrock and river terraces as a palimpsest landscape. Field investigations identified four stratigraphic sections with multiple aeolian sand units and palaeosols, with age control by optically stimulated luminescence (OSL) dating of quartz grains. Palaeosols are weakly developed, mostly accumulative A horizon with organic carbon content sand sheet deposition possibly in a steppe environment. Although sediments near river channels or former lakes might give old ages, the initial formation and age of the Kubuqi sand sea should be judged from the occurrence of the sandy palimpsest of the landscape that is OSL dated to the Holocene in general. The latest period of aeolian reactivation may be related to human activity associated with grazing and farming from lost cities in the Kubuqi Desert during the Han (206 B.C. - A.D. 220) and the Tang (A.D. 608 - 907) Dynasties. Also, variable discharge of the Yellow River with local diversions for irrigation and throughout the catchment resulted in possibly an increased supply of aeolian particles for dune field expansion in the past 2 ka.

  6. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    studies that illustrate the practical use of CPN modelling and validation for design, specification, simulation, verification and implementation in various application domains. Their presentation primarily aims at readers interested in the practical use of CPN. Thus all concepts and constructs are first......Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism...... and the immense number of possible execution sequences. In this textbook, Jensen and Kristensen introduce the constructs of the CPN modelling language and present the related analysis methods in detail. They also provide a comprehensive road map for the practical use of CPN by showcasing selected industrial case...

  7. SAND

    DEFF Research Database (Denmark)

    Thorsen, Grete

    Der er udført et konsolideringsforsøg med bakkesand fra Lunds grusgrav, Lund no. O. forsøget er udført i samme konsolideringsapparat, som er anvendt til måling af deformationsegenskaberne af mange forskellige danske jordarter. Forsøgsresultaterne er søgt tolket som ved forsøg med andre jordarter....

  8. Nearshore sediment thickness, Fire Island, New York

    Science.gov (United States)

    Locker, Stanley D.; Miselis, Jennifer L.; Buster, Noreen A.; Hapke, Cheryl J.; Wadman, Heidi M.; McNinch, Jesse E.; Forde, Arnell S.; Stalk, Chelsea A.

    2017-04-03

    Investigations of coastal change at Fire Island, New York (N.Y.), sought to characterize sediment budgets and determine geologic framework controls on coastal processes. Nearshore sediment thickness is critical for assessing coastal system sediment availability, but it is largely unquantified due to the difficulty of conducting geological or geophysical surveys across the nearshore. This study used an amphibious vessel to acquire chirp subbottom profiles. These profiles were used to characterize nearshore geology and provide an assessment of nearshore sediment volume. Two resulting sediment-thickness maps are provided: total Holocene sediment thickness and the thickness of the active shoreface. The Holocene sediment section represents deposition above the maximum flooding surface that is related to the most recent marine transgression. The active shoreface section is the uppermost Holocene sediment, which is interpreted to represent the portion of the shoreface thought to contribute to present and future coastal behavior. The sediment distribution patterns correspond to previously defined zones of erosion, accretion, and stability along the island, demonstrating the importance of sediment availability in the coastal response to storms and seasonal variability. The eastern zone has a thin nearshore sediment thickness, except for an ebb-tidal deposit at the wilderness breach caused by Hurricane Sandy. Thicker sediment is found along a central zone that includes shoreface-attached sand ridges, which is consistent with a stable or accretional coastline in this area. The thickest overall Holocene section is found in the western zone of the study, where a thicker lower section of Holocene sediment appears related to the westward migration of Fire Island Inlet over several hundred years.

  9. Adaptation to life in aeolian sand: how the sandfish lizard, Scincus scincus, prevents sand particles from entering its lungs

    Science.gov (United States)

    Vihar, Boštjan; Günther, Mathias; Huemer, Michaela; Riedl, Martin; Shamiyeh, Stephanie; Mayrhofer, Bernhard; Böhme, Wolfgang; Baumgartner, Werner

    2016-01-01

    ABSTRACT The sandfish lizard, Scincus scincus (Squamata: Scincidae), spends nearly its whole life in aeolian sand and only comes to the surface for foraging, defecating and mating. It is not yet understood how the animal can respire without sand particles entering its respiratory organs when buried under thick layers of sand. In this work, we integrated biological studies, computational calculations and physical experiments to understand this phenomenon. We present a 3D model of the upper respiratory system based on a detailed histological analysis. A 3D-printed version of this model was used in combination with characteristic ventilation patterns for computational calculations and fluid mechanics experiments. By calculating the velocity field, we identified a sharp decrease in velocity in the anterior part of the nasal cavity where mucus and cilia are present. The experiments with the 3D-printed model validate the calculations: particles, if present, were found only in the same area as suggested by the calculations. We postulate that the sandfish has an aerodynamic filtering system; more specifically, that the characteristic morphology of the respiratory channel coupled with specific ventilation patterns prevent particles from entering the lungs. PMID:27852763

  10. The Impact of Foreign Investment Restrictions on the Stock Returns of Oil Sands Companies

    OpenAIRE

    Eugene Beaulieu; Matthew M. Saunders

    2014-01-01

    On December 7, 2012 the Government of Canada released a policy statement and revised the guidelines for investments by State-Owned Enterprises in the Canadian oil sands. This policy statement was in response to the proposed purchase of Nexen by the Chinese SOE, CNOOC. According to the new guidelines, foreign investors must convince the Minister of Industry that a particular investment is likely to be of net benefit to Canada and those investments by foreign SOEs to acquire controlling interes...

  11. Crest line minimal model for sand dune

    OpenAIRE

    Guignier, Lucie; Valance, Alexandre; Lague, Dimitri

    2013-01-01

    International audience; In desert, complex patterns of dunes form. Under unidirectional wind, transverse rectilinear dunes or crescent shaped dunes called barchan dunes can appear, depending on the amount of sediment available. Most rectilinear transverse sand dunes are observed to fragment, for example at White Sands (New Mexico, United States of America) or Walvis Bay (Namibia). We develop a reduced complexity model to investigate the morphodynamics of sand dunes migrating over a non-erodib...

  12. Salinity and soluble organic matter on virus sorption in sand and soil columns.

    Science.gov (United States)

    Cao, Haibo; Tsai, Frank T-C; Rusch, Kelly A

    2010-01-01

    The objective of this research was to study the sorption and transport of bacteriophage MS-2 (a bacterial virus) in saturated sediments under the effect of salinity and soluble organic matter (SOM). One-dimensional column experiments were conducted on washed high-purity silica sand and sandy soil. In sand column tests, increasing salinity showed distinct effect on enhancing MS-2 sorption. However, SOM decreased MS-2 sorption. Using a two-site reversible-irreversible sorption model and the double layer theory, we explained that pore-water salinity potentially compressed the theoretical thickness of double layers of MS-2 and sand, and thus increased sorption on reversible sorption sites. On irreversible sorption sites, increasing salinity reversed charges of some sand particles from negative to positive, and thus converted reversible sorption sites into irreversible sites and enhanced sorption of MS-2. SOM was able to expand the double layer thickness on reversible sites and competed with MS-2 for the same binding place on irreversible sites. In sandy soil column tests, the bonded and dissolved (natural) soil organic matters suppressed the effects of pore-water salinity and added SOM and significantly reduced MS-2 adsorption. This was explained that the bonded soil organic matter occupied a great portion of sorption sites and significantly reduced sorption sites for MS-2. In addition, the dissolved soil organic matter potentially expanded the double layer thickness of MS-2 and sandy soil on reversible sorption sites and competed with MS-2 for the same binding place.

  13. Field observations of artificial sand and oil agglomerates

    Science.gov (United States)

    Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

    2015-01-01

    Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

  14. Quantitative method study of sand-dust information using Terra/MODIS data

    Science.gov (United States)

    Li, Haiping; Xiong, Liya; Zhuang, Dafang

    2003-07-01

    With the successful launching of the new generation satellite of EOS Terra, its Moderate Resolution Imaging Spectroradiometer (MODIS) data has more advantages in comprehensive research of land, ocean and atmosphere. ALso it can be used in disaster monitoring and losing assessment. This article focuses on the discussion of using Terra/MODIS data to study sand-dust information quantitative retrieval method. The conclusion is that MODIS data can be used to study the quantitative retrieval of sand-dust information and the study scenario has certain feasibility. The study contains of selecting the characteristic spectrum bands of sand-dust information; separating sand-dust information from the background and enhancing the weak information of floating dust, raising dust, etc. Theory basis of quantitative retrieval method are remote sensing quantitative method, atmosphere radiative transforming and visibility theories. Data pre-processing is also necessary. Retrieving of sand-dust aerosol optic thickness is more difficult and also the key problem to resolve. Case study is necessary and should be used to support the quantitative method. The study can provide the theory basis and technique support for sand-dust disaster forecasting monitoring and preventing.

  15. 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.

  16. Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu

    1999-09-30

    This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.

  17. Simulating and understanding sand wave variation: a case study of the Golden Gate sand waves

    NARCIS (Netherlands)

    Sterlini-Van der Meer, Fenneke; Hulscher, Suzanne J.M.H.; Hanes, D.M

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the

  18. Linear Logic on Petri Nets

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

  19. Reference Guide Microsoft.NET

    NARCIS (Netherlands)

    Zee M van der; Verspaij GJ; Rosbergen S; IMP; NMD

    2003-01-01

    Developers, administrators and managers can get more understanding of the .NET technology with this report. They can also make better choices how to use this technology. The report describes the results and conclusions of a study of the usability for the RIVM of this new generation .NET development

  20. Net neutrality and audiovisual services

    NARCIS (Netherlands)

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

  1. Early Islamic inter-settlement agroecosystems in coastal sand, Yavneh dunefield, eastern Mediterranean coast, Israel

    Science.gov (United States)

    Roskin, Joel; Taxel, Itamar

    2017-04-01

    This study reveals an attempt to condition agriculture in coastal aeolian sand holding a high water table. Twenty-six small sites, clustering in topographic lows of the Yavneh dunefield, southern Israeli coastal plain, yield surficial Early Islamic finds, and eroded 1-2 m high berms built of grey sand partially covered by parabolic and transverse dunes. Small winter ponds develop by some of the sites. A clay loam 2.5 m beneath the surface retains the water table at a depth of 2.2 m. Between the berms, a 10-50 cm thick grey sand unit dating by OSL to 0.9 ka (11th-12th century AD) underlays a loose aeolian sand cover and overlays sand whose upper parts date to 1.1 ka (9th-10th century AD). The grey unit displays slightly improved fertility (phosphate, potassium, nitrogen and calcium carbonate) in relation to the underlying sand suggesting an anthropogenic enrichment of ash and refuse. Particle size is similar to the sand. Organic carbon and magnetic susceptibility values (0-5 SI) values are quite low (0.4-0.8%) for both units. The artifact assemblage is mixed and comprised of small (agricultural plots in lows that allowed easy manual or root access to the high water table. The sites' character and ages closely resembles the well-preserved crisscross berms and inter-berm depressions south of ancient Caesarea that date to 0.86 ka (Roskin et al., 2015). The agricultural activity probably lasted no more than several decades to one century but its utility remains a question. The study documents a challenging attempt to utilize uncultivated sand sheets in a Mediterranean environment for agroecosystem expansion, income, control and "greening" of the terrain. This effort partly reminisces other Early Islamic agricultural water systems (e.g. qanats) in arid regions. It demonstrates that spatial agroecosystems can be developed in times that are not necessarily characterized by socio-political stability.

  2. A Small Universal Petri Net

    Directory of Open Access Journals (Sweden)

    Dmitry A. Zaitsev

    2013-09-01

    Full Text Available A universal deterministic inhibitor Petri net with 14 places, 29 transitions and 138 arcs was constructed via simulation of Neary and Woods' weakly universal Turing machine with 2 states and 4 symbols; the total time complexity is exponential in the running time of their weak machine. To simulate the blank words of the weakly universal Turing machine, a couple of dedicated transitions insert their codes when reaching edges of the working zone. To complete a chain of a given Petri net encoding to be executed by the universal Petri net, a translation of a bi-tag system into a Turing machine was constructed. The constructed Petri net is universal in the standard sense; a weaker form of universality for Petri nets was not introduced in this work.

  3. Radionuclide transfer to invertebrates and small mammals in a coastal sand dune ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M.D., E-mail: mwood@liv.ac.uk [Institute for Sustainable Water Integrated Management and Ecosystem Research (SWIMMER)/School of Biological Sciences, Nicholson Building, University of Liverpool, Liverpool, Merseyside, L69 3GP (United Kingdom); Leah, R.T. [Institute for Sustainable Water Integrated Management and Ecosystem Research (SWIMMER)/School of Biological Sciences, Nicholson Building, University of Liverpool, Liverpool, Merseyside, L69 3GP (United Kingdom); Jones, S.R. [Westlakes Scientific Consulting Ltd., The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3LN (United Kingdom); Copplestone, D. [Environment Agency, PO Box 12, Richard Fairclough House, Knutsford Road, Latchford, Warrington, Cheshire, WA4 1HG (United Kingdom)

    2009-06-15

    International intercomparisons of models to assess the impact of ionising radiation on wildlife have identified radionuclide transfer assumptions as a significant source of uncertainty in the modelling process. There is a need to improve the underpinning data sets on radionuclide transfer to reduce this uncertainty, especially for poorly-studied ecosystems such as coastal sand dunes. This paper presents the results of the first published study of radionuclide transfer to invertebrates and small mammals in a coastal sand dune ecosystem. Activity concentrations of {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am are reported for detritivorous, herbivorous, carnivorous and omnivorous biota. Differences in activity concentrations measured in the sand dune biota are related to the trophic level of the organisms and the influence of sea-to-land transfer is apparent in the food chain transfer observed at the site. There are notable differences in the concentration ratios (CRs) calculated for the sand dune biota compared to other terrestrial ecosystems, especially for the small mammals which have CRs that are two orders of magnitude lower than the generic terrestrial ecosystem CRs published by the recent EC EURATOM ERICA project. The lower CRs at the sand dunes may be due to the influence of other cations from the marine environment (e.g. K and Na) on the net radionuclide transfer observed, but further research is required to test this hypothesis.

  4. 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.

  5. 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

  6. 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...

  7. Silica sand resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Westerhoff, W.E.; Menkovic, A.; Gruijters, S.H.L.L.; Dubelaar, C.W.; Maljers, D.

    2009-01-01

    Silica sand, (almost) pure quartz sand, is a valuable and scarce mineral resource within the shallow Dutch subsurface. High-grade deposits are exploited in the southeastemmost part of the country, as raw material for the glass, ceramic, chemical and other process industries. Dutch land-use policy

  8. Excerpt of the Interview with Mathew Sands

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 9. Excerpt of the Interview with Mathew Sands. Mathew Sands Finn Aaserud. Face to Face Volume 16 Issue 9 September 2011 pp 881-885. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. 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 ...

  10. Review of Sand Production Prediction Models

    Directory of Open Access Journals (Sweden)

    Hossein Rahmati

    2013-01-01

    Full Text Available Sand production in oil and gas wells can occur if fluid flow exceeds a certain threshold governed by factors such as consistency of the reservoir rock, stress state and the type of completion used around the well. The amount of solids can be less than a few grams per cubic meter of reservoir fluid, posing only minor problems, or a substantial amount over a short period of time, resulting in erosion and in some cases filling and blocking of the wellbore. This paper provides a review of selected approaches and models that have been developed for sanding prediction. Most of these models are based on the continuum assumption, while a few have recently been developed based on discrete element model. Some models are only capable of assessing the conditions that lead to the onset of sanding, while others are capable of making volumetric predictions. Some models use analytical formulae, particularly those for estimating the onset of sanding while others use numerical models, particularly in calculating sanding rate. Although major improvements have been achieved in the past decade, sanding tools are still unable to predict the sand mass and the rate of sanding for all field problems in a reliable form.

  11. 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

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

    Science.gov (United States)

    Pakbaz, Mohammad C.; Khayat, Navid

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

  13. Hematite Outlier and Sand Dunes

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 4 December 2003This image shows a crater just south of the edge of the famous hematite-bearing surface, which is visible in the context image as a smooth area to the north. The crater has two features of immediate note. The first is a layered mound in the north part of the crater floor. This mound contains hematite, and it is an outlying remnant of the greater deposits to the north that have otherwise completely disappeared in this crater. The second feature is a dune field in the center of the crater floor, with dark dunes indicating winds from the northwest. The dunes grade into a dark sand sheet with no coherent structure, indicating that the sand layer thins out to the south and east.Image information: VIS instrument. Latitude -4.4, Longitude 357.3 East (2.7 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. 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.

  15. Preserving inland drift sands in the Netherlands

    Science.gov (United States)

    Riksen, M.; Sparrius, L.; Nijssen, M.; Keestra, S.

    2012-04-01

    Inland drift sands in the Netherlands are an important landscape type within the Dutch nature. They represent an important pioneer habitat which has become rare in European nature. Under current climate and environmental conditions (i.e. high N-deposition) these inland drift sands tend to be rapid colonialized by vegetation and therefor lose their aeolian activity. To maintain the area bare sand, managers regularly remove the vegetation. Lack of proper knowledge about the geomorphological processes and even more important on the geomorphological structure of these drift sands, could lead to the loss of characteristic dune structure. In an interdisciplinary research project a new management strategy was developed in which the geomorphological processes and structure form the base for the planning process. To improve the awareness of these aspects among nature managers we developed a management tool "PROMME". Several activities were taken to communicate this with the people involved in the management of drift sands like a brochure and field workshops.

  16. Ecological release in White Sands lizards.

    Science.gov (United States)

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

    2011-12-01

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

  17. Choosing an optimum sand control method

    Directory of Open Access Journals (Sweden)

    Ehsan Khamehchi

    2015-06-01

    Full Text Available Formation sand control is always one of the main concerns of production engineers. There are some different methods to prevent sand production. Choosing a method for preventing formation sand production depends on different reservoir parameters and politic and economic conditions. Sometimes, economic and politic conditions are more effective to choose an optimum than reservoir parameters. Often, simultaneous investigation of politic and economic conditions with reservoir parameters has different results with what is expected. So, choosing the best sand control method is the result of thorough study. Global oil price, duration of sand control project and costs of necessary equipment for each method as economic and politic conditions and well productivity index as reservoir parameter are the main parameters studied in this paper.

  18. Ecological release in White Sands lizards

    Science.gov (United States)

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

    2011-01-01

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

  19. High-level Petri Nets

    DEFF Research Database (Denmark)

    High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...... of low-level Petri nets - while, on the other hand, they still offer a wide range of analysis methods and tools. The step from low-level nets to high-level nets can be compared to the step from assembly languages to modern programming languages with an elaborated type concept. In low-level nets...... there is only one kind of token and this means that the state of a place is described by an integer (and in many cases even by a boolean). In high-level nets each token can carry a complex information/data - which, e.g., may describe the entire state of a process or a data base. Today most practical...

  20. Lisianthus cultivation using differentiated light transmission nets

    Directory of Open Access Journals (Sweden)

    Paulo Hercilio Viegas Rodrigues

    2016-08-01

    Full Text Available The Lisianthus stands out as one of the ten most cut flowers sold in the world. The use of meshes in a different light transmission is gaining more space in horticulture with promising results in greenhouse. The aim of this study was to evaluate the development of lisianthus grown in different light transmission meshes in blue, black, red and control treatments, which were transplanted 20 seedlings to cultivate Snow white with three replications, and therefore, 60 plants 240 plants per treatment in total. Agronomic characteristics such as plant height and length of the top pair of leaves were evaluated at 15, 38, 59, 82 and 105 days after transplanting. Other features such as early flowering, thick stem, distance between us and weight of the harvested stems were obtained at harvest stage. At the end of the evaluations, the treatment of red net was the most consistent with a significant difference in stem height and earliness in flowering.

  1. Facies and architecture of deep-water Sandstone lobes: Comparison of a shale-rich and a sand-rich system

    Energy Technology Data Exchange (ETDEWEB)

    Schuppers, J.D. (Delft Univ. of Technology (Netherlands))

    1993-09-01

    Two different foreland-basin deep-water sandstone systems have been studied for reservoir characterization purposes: the Broto lobes of the Eocene Hecho group, spain, and two sand bodies of the Oligocene-Miocene Arakintos Sandstone, Greece. The shale-rich Broto lobes are characterized by distinct vertical developments in terms of facies and expression of heterogeneity. Bed-thickness trends, lateral extent of sand beds, and facies variability are related to overall sand/shale ratio. A feature common to most of the sandstone packages is the occurrence of a basal slump and/or pebbly mudstone. The dominant sediment source is considered fluvial. Variation in sand quality within and between lobes is high. Deposition is considered to be strongly controlled by tectonics. The sand-rich Arakintos Sandstone consists of massive and pebbly sandstones, forming thick, sandy sheets alternating with relatively coarse-grained, thin-bedded turbidites. Facies, geometries, vertical organization, and the relation between grain size and bed thickness indicate a constrained development of the lobes, partly influenced by preexisting topography. A coastal sediment source is inferred. Little variation exists in sand quality within and between the lobes. The overall regularity in terms of facies, and the absence of slumps, suggest that fluctuations in relative sea level may have formed a major control on deposition. The two lobe systems illustrate the effect of tectonics, sediment type, topographic confinement, and possible sea level on facies and sand body architecture of deep-water sandstone lobes.

  2. Global sand trade is paving the way for a tragedy of the sand commons

    Science.gov (United States)

    Torres, A.; Brandt, J.; Lear, K.; Liu, J.

    2016-12-01

    In the first 40 years of the 21st century, planet Earth is highly likely to experience more urban land expansion than in all of history, an increase in transportation infrastructure by more than a third, and a great variety of land reclamation projects. While scientists are beginning to quantify the deep imprint of human infrastructure on biodiversity at large scales, its off-site impacts and linkages to sand mining and trade have been largely ignored. Sand is the most widely used building material in the world. With an ever-increasing demand for this resource, sand is being extracted at rates that far exceed its replenishment, and is becoming increasingly scarce. This has already led to conflicts around the world and will likely lead to a "tragedy of the sand commons" if sustainable sand mining and trade cannot be achieved. We investigate the environmental and socioeconomic interactions over large distances (telecouplings) of infrastructure development and sand mining and trade across diverse systems through transdisciplinary research and the recently proposed telecoupling framework. Our research is generating a thorough understanding of the telecouplings driven by an increasing demand for sand. In particular, we address three main research questions: 1) Where are the conflicts related to sand mining occurring?; 2) What are the major "sending" and "receiving" systems of sand?; and 3) What are the main components (e.g. causes, effects, agents, etc.) of telecoupled systems involving sand mining and trade? Our results highlight the role of global sand trade as a driver of environmental degradation that threatens the integrity of natural systems and their capacity to deliver key ecosystem services. In addition, infrastructure development and sand mining and trade have important implications for other sustainability challenges such as over-fishing and global warming. This knowledge will help to identify opportunities and tools to better promote a more sustainable use

  3. Delays in thick targets

    CERN Document Server

    Bennett, J R J

    2002-01-01

    The delays in the emission of radioactive particles from a thick target bombarded by high-energy protons is discussed in relation to the basic physical processes of diffusion and effusion through the target and ioniser. The delay time, relative to the decay time, is crucial to the efficiency of particle release at the exit of the ioniser. The principles of minimizing the delay times are discussed with reference to a mathematical model of the process, and some experimental examples are given.

  4. Pro asynchronous programming with .NET

    CERN Document Server

    Blewett, Richard; Ltd, Rock Solid Knowledge

    2014-01-01

    Pro Asynchronous Programming with .NET teaches the essential skill of asynchronous programming in .NET. It answers critical questions in .NET application development, such as: how do I keep my program responding at all times to keep my users happy how do I make the most of the available hardware how can I improve performanceIn the modern world, users expect more and more from their applications and devices, and multi-core hardware has the potential to provide it. But it takes carefully crafted code to turn that potential into responsive, scalable applications.With Pro Asynchronous Programming

  5. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  6. The influence of cockchafer larvae on net soil methane fluxes under different vegetation types - a mesocosm study

    Science.gov (United States)

    Görres, Carolyn-Monika; Kammann, Claudia; Chesmore, David; Müller, Christoph

    2017-04-01

    The influence of land-use associated pest insects on net soil CH4 fluxes has received little attention thus far, although e.g. soil-dwelling Scarabaeidae larvae are qualitatively known to emit CH4. The project "CH4ScarabDetect" aims to provide the first quantitative estimate of the importance of soil-dwelling larvae of two important European agricultural and forest pest insect species - the common cockchafer (Melolontha melolontha) and the forest cockchafer (M. hippocastani) - for net soil CH4 fluxes. Here we present a mesocosm study within "CH4ScarabDetect" which tests the influence of different abundances of common cockchafer larvae on net soil CH4 fluxes under different vegetation types. In August 2016, 27 PVC boxes with a base area of 50 cm x 50 cm and a height of 40 cm were buried in planting beds previously used for cultivating vegetables. The bottom of each box was filled with a 10 cm thick layer of loam which was then covered with a 25 cm thick layer of loamy sand. The soil was hand-sieved prior to filling the boxes to remove any macrofauna. The mesocosms were planted with either turf, carrots or a combination of both. Of the resulting nine replicates per vegetation type, six were infested with one cockchafer larvae each in November 2016. In three of these infested mesocosms, the larvae abundance will be further increased to three in May 2017. This mesocosm study will continue until October 2017 during which measurements of net soil CH4 fluxes will be conducted with the chamber flux method twice per month. For the in situ separation of gross CH4 production and gross CH4 oxidation, the chamber method will be combined with a 13CH4 isotope pool dilution technique. Methane concentrations and their isotopic signatures in the collected gas samples will be analysed with a state-of-the-art CRDS analyzer (cavity ring-down spectroscopy, G2201-i) equipped with the Small Sample Isotope Module 2 - A0314 (Picarro Inc., USA). Different combinations of larvae abundance and

  7. Guided wave attenuation in coated pipes buried in sand

    Science.gov (United States)

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

    2016-02-01

    Long-range guided wave testing (GWT) is routinely used for the monitoring and detection of corrosion defects in above ground pipelines in various industries. The GWT test range in buried, coated pipelines is greatly reduced compared to aboveground pipelines due to energy leakage into the embedding soil. In this study, we aim to increase test ranges for buried pipelines. The effect of pipe coatings on the T(0,1) and L(0,2) guided wave attenuation is investigated using a full-scale experimental apparatus and model predictions. Tests are performed on a fusion-bonded epoxy (FBE)-coated 8" pipe, buried in loose and compacted sand over a frequency range of 10-35 kHz. The application of a low impedance coating is shown to effectively decouple the influence of the sand on the ultrasound leakage from the buried pipe. We demonstrate ultrasonic isolation of a buried pipe by coating the pipe with a Polyethylene (PE)-foam layer that has a smaller impedance than both pipe and sand and the ability to withstand the overburden load from the sand. The measured attenuation in the buried PE-foam-FBE-coated pipe is substantially reduced, in the range of 0.3-1.2 dBm-1 for loose and compacted sand conditions, compared to buried FBE-coated pipe without the PE-foam, where the measured attenuation is in the range of 1.7-4.7 dBm-1. The acoustic properties of the PE-foam are measured independently using ultrasonic interferometry technique and used in model predictions of guided wave propagation in a buried coated pipe. Good agreement is found between the attenuation measurements and model predictions. The attenuation exhibits periodic peaks in the frequency domain corresponding to the through-thickness resonance frequencies of the coating layer. The large reduction in guided wave attenuation for PE-coated pipes would lead to greatly increased GWT test ranges, so such coatings would be attractive for new pipeline installations.

  8. Petri Net Tool Overview 1986

    DEFF Research Database (Denmark)

    Jensen, Kurt; Feldbrugge, Frits

    1987-01-01

    This paper provides an overview of the characteristics of all currently available net based tools. It is a compilation of information provided by tool authors or contact persons. A concise one page overview is provided as well....

  9. Understanding Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Salom, Jaume; Widén, Joakim; Candanedo, José

    2011-01-01

    Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid....... This paper presents and categorizes quantitative indicators suitable to describe both aspects of the building’s performance. These indicators, named LMGI - Load Matching and Grid Interaction indicators, are easily quantifiable and could complement the output variables of existing building simulation tools...

  10. PolicyNet Publication System

    Data.gov (United States)

    Social Security Administration — The PolicyNet Publication System project will merge the Oracle-based Policy Repository (POMS) and the SQL-Server CAMP system (MSOM) into a new system with an Oracle...

  11. KM3NeT

    CERN Multimedia

    KM3NeT is a large scale next-generation neutrino telescope located in the deep waters of the Mediterranean Sea, optimized for the discovery of galactic neutrino sources emitting in the TeV energy region.

  12. Net Neutrality: Background and Issues

    National Research Council Canada - National Science Library

    Gilroy, Angele A

    2006-01-01

    .... The move to place restrictions on the owners of the networks that compose and provide access to the Internet, to ensure equal access and nondiscriminatory treatment, is referred to as "net neutrality...

  13. Scaling laws in sand launch process

    Science.gov (United States)

    Min, Li; Yang, Zhang

    2017-04-01

    As the bond linking the micro research to the macro research in wind-sand flow, the scaling laws on sand mean launch velocity and mean launch angle can be used to calculate the mean velocity and the transport rate, and they also play an important role in understanding saltation. However, universal scaling laws are still absent. In analogy to the fluid flows, the wind-sand flow is divided into three periods based on the way of sand taking off from sand bed, and the hypothesis on the scaling laws in each period is proposed. Then according to the hypothesis we deduce the sand concentration piece-wise function for saltation layer and also the critical shields numbers dividing three periods. The comparisons between the predictions and the experimental observations show that under a lower shields number the vertical mean launch velocity and the mean launch angle scale with the wind shear velocity and the square root of shields number respectively. However, under a higher shields number the vertical mean launch velocity scale with the sand diameter and the mean launch angle is almost constant at 700 or so.

  14. Petri Nets in Cryptographic Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Winskel, Glynn

    2001-01-01

    A process language for security protocols is presented together with a semantics in terms of sets of events. The denotation of process is a set of events, and as each event specifies a set of pre and postconditions, this denotation can be viewed as a Petri net. By means of an example we illustrate...... how the Petri-net semantics can be used to prove security properties....

  15. The Economics of Net Neutrality

    OpenAIRE

    Hahn, Robert W.; Wallsten, Scott

    2006-01-01

    This essay examines the economics of "net neutrality" and broadband Internet access. We argue that mandating net neutrality would be likely to reduce economic welfare. Instead, the government should focus on creating competition in the broadband market by liberalizing more spectrum and reducing entry barriers created by certain local regulations. In cases where a broadband provider can exercise market power the government should use its antitrust enforcement authority to police anticompetitiv...

  16. The Influence of Sand Grains Properties on Electrical Properties of Moulding Sand with Inorganic Binder

    Directory of Open Access Journals (Sweden)

    Opyd B.

    2015-09-01

    Full Text Available The paper presents the results of basic research on the influence of the properties of sand grains on electrical properties of water glass moulding sands. It shows electrical properties of the main component – sand grains, crucial to the kinetics of moulding sands heating, such as permittivity εr and loss factor tgδ. Measurements were carried out with the use of the perturbation method for silica, chromite and olivine sands of different mineral, chemical composition and particle size distribution, as well as for moulding sands with water glass grade 145. Analysis of the results of measurements of electrical properties shows that all moulding sands are characterized by a similar permittivity εr and loss factor tgδ. It was found that the electrical properties and the quantity and quality of other components may have a decisive influence on the effectiveness and efficiency of the microwave heating of moulding sands with sand grains. In determining the ability to efficiently absorb the microwave radiation for mixtures which moulding sands are, the impact of all components influencing their individual technological parameters should be taken into account.

  17. Fecal indicators in sand, sand contact, and risk of enteric illness among beachgoers

    Science.gov (United States)

    Heaney, Christopher D.; Sams, Elizabeth; Dufour, Alfred P.; Brenner, Kristen P.; Haugland, Richard A.; Chern, Eunice; Wing, Steve; Marshall, Stephen; Love, David C.; Serre, Marc; Noble, Rachel; Wade, Timothy J.

    2011-01-01

    Background Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. Methods In 2007, visitors at two recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days later, participants answered questions about health symptoms since the visit. F+ coliphage, Enterococcus, Bacteroidales, fecal Bacteroides, and Clostridium spp. in wet sand were measured using culture and molecular methods. Results We analyzed 144 wet sand samples and completed 4,999 interviews. Adjusted odds ratios (aORs) were computed, comparing those in the highest tertile of fecal indicator exposure with those who reported no sand contact. Among those digging in sand compared with those not digging in sand, a molecular measure of Enterococcus spp. (calibrator cell equivalents/g) in sand was positively associated with gastrointestinal (GI) illness (aOR = 2.0 [95% confidence interval (CI) = 1.2–3.2]) and diarrhea (2.4 [1.4–4.2]). Among those buried in sand, point estimates were greater for GI illness (3.3 [1.3–7.9]) and diarrhea (4.9 [1.8–13]). Positive associations were also observed for culture-based Enterococcus (colony-forming units/g) with GI illness (aOR digging = 1.7 [1.1–2.7]) and diarrhea (2.1 [1.3–3.4]). Associations were not found among non-swimmers with sand exposure. Conclusions We observed a positive relationship between sand contact activities and enteric illness as a function of concentrations of fecal microbial pollution in beach sand. PMID:22157306

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

    Science.gov (United States)

    1993-01-01

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

  19. In-plane polarized PZT thick film actuators by screen printing technology

    OpenAIRE

    Ernst, D; Bramlage, B.; Gebhardt, S.

    2012-01-01

    Screen printed PZT thick films offer distinct advantages in MEMS applications. The net shaped low profile devices enable small packaging space and a very good adhesion to the substrate material. At Fraunhofer IKTS a standard technology for producing dense PZT thick films based on a soft PZT material is available. Previously the established mode of excitation was through-thickness. To increase cantilever performance we applied interdigitated electrodes to realize in-plane polarization of PZT t...

  20. Net transport of suspended matter due to tidal straining

    Science.gov (United States)

    Jones, S. E.; Jago, C. F.; Simpson, J. H.; Rippeth, T. P.

    2003-04-01

    Net transport of suspended particulate matter (SPM) is well-known in tidal regions where there is time-velocity asymmetry due to frictional modification of the tide in shallow water. We present here observations which show a new mechanism for net flux of SPM in response to tidal straining in a region of freshwater influence (ROFI). In situ measurements of the particle size of suspended particulate matter (SPM) and turbulent energy dissipation have been made at a site in Liverpool Bay (Irish Sea) where there is significant resuspension of particles from the muddy sand substrate during spring tides. This is a ROFI where tidal straining dominates the temporal development of turbulence. On a spring tide the water column tries to stratify on the ebb and destratify on the flood, but these tendencies are masked by mixing due to tidal stirring. Nevertheless, there is a marked excess of TKE dissipation rate E on the flood, especially in the upper part of the water column. Resuspension occurs on both flood and ebb, but SPM flux is strongly asymmetric with a net shorewards component. Asymmetry is most pronounced for the larger particles which comprise most of the mass. Enhanced ? on the flood mixes large particles upwards into faster flowing water, which increases the flux. Comparable upwards mixing of large particles does not occur on the ebb where enhanced E is confined to slower bottom waters. The net flux is not seen on neap tides because, although there is more stratification due to tidal straining, there is essentially no resuspension. The net flux on springs is undoubtedly an important component of SPM transport (and any comparable particulates) in coastal regions.

  1. Harry Sands (1917-2007).

    Science.gov (United States)

    Ochroch, Ruth

    2009-01-01

    To everyone who knew and had worked with him, the death of Harry Sands on January 3, 2007, three days before his 90th birthday, resounded as though a mighty oak had fallen. Harry was a giant of a man, both as a human being and as a psychologist. Harry was born January 6, 1917, on the Lower East Side of Manhattan to Russian immigrant parents who ran a laundry. His bachelor's degree in psychology (1941) and his doctoral degree (1952) were both earned at New York University. Harry became a member of the American Psychological Association (APA) in 1943. With his breadth of experience and knowledge, as well as his firm foundation in management and finance, he eventually became a financial advisor to the APA Practice Directorate as well as to the American Psychological Foundation. As the executive director of the Postgraduate Center for Mental Health, Harry made creative strides to improve both the public awareness of the organization as well as its fiscal health. Harry was an active writer and researcher, with a particular interest in epilepsy and various psychoanalytic topics. 2009 APA, all rights reserved

  2. 26 CFR 1.904(f)-3 - Allocation of net operating losses and net capital losses.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Allocation of net operating losses and net....904(f)-3 Allocation of net operating losses and net capital losses. For rules relating to the allocation of net operating losses and net capital losses, see § 1.904(g)-3T. ...

  3. 29 CFR 4204.13 - Net income and net tangible assets tests.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Net income and net tangible assets tests. 4204.13 Section....13 Net income and net tangible assets tests. (a) General. The criteria under this section are that either— (1) Net income test. The purchaser's average net income after taxes for its three most recent...

  4. THERMAL INFLUENCE OF MICRODISCHARGE PLASMA ON THE PROCESS OF RECEIVING OF QUARTZ SAND ENCAPSULATED BY PYROCARBON

    OpenAIRE

    Simeyko, Kostiantyn; Gas Institute of the National Academy of Sciences of Ukraine, Kyiv, Ukraine.

    2014-01-01

    The Gas Institute of National Academy of Science of Ukraine developed the facility for pyrocarbon application on the particles of quartz sand through methane pyrolysis in reactor with electrothermal fluidized bed. Thickness of the bed of pure pyrolytic carbon can be controlled within set limits, depending on the temperature, fluid dynamics and duration of the process. The formation of different types of microdischarge plasma takes place at different temperatures. Microdischarge plasma increas...

  5. Delineation of an Optimal Location for Oil Sand Exploration through Transition Probabilities of Composing Lithology

    Science.gov (United States)

    Kwon, M.; Jeong, J.; Park, E.; Han, W. S.; Kim, K. Y.

    2014-12-01

    Three-dimensional geostatistical studies of delineating an optimal exploitation location for oil sand in McMurray Formation, Athabasca, Canada were carried out. The area is mainly composed of unconsolidated to semi-consolidated sand where breccia, mud, clay, etc. are associated as alternating layers. For the prediction of the optimal location of steam assisted gravity drainage (SAGD) technique, the conventional approach of cumulating the predicted thickness of the media with higher bitumen bearing possibility (i.e. Breccia and Sand) was pursued. As an alternative measure, mean vertical extension of the permeable media was also assessed based on vertical transition rate of each media and the corresponding optimal location was decided. For the both predictions, 110 borehole data acquired from the study area were analyzed under Markovian transition probability (TP) framework and three-dimensional distributions of the composing media were predicted stochastically through an existing TP based geostatistical model. The effectiveness of the two competing measures (cumulative thickness and mean vertical extension) for SAGD applications was verified through two-dimensional dual-phase flow simulations where high temperature steam was injected in the delineated reservoirs, and the size of steam chamber was compared. The results of the two-dimensional SAGD simulation has shown that the geologic formation containing the highest mean vertical extension of permeable media is more suitable for the development of the oil sand by developing larger size of steam chamber compared to that from the highest cumulative thickness. Given those two-dimensional results, the cumulative thickness alone may not be a sufficient criterion for an optimal SAGD site and the mean vertical extension of the permeable media needs to be jointly considered for the sound selections.

  6. Photoacoustic infrared spectroscopy of Syncrude post-extraction oil sand

    Science.gov (United States)

    Michaelian, Kirk H.; Hall, Robert H.; Kenny, Kimberly I.

    2006-06-01

    Rapid- and step-scan photoacoustic (PA) infrared spectra of three fractions of a Syncrude post-extraction oil sand were analyzed in detail in this work. The rapid-scan spectra showed that the samples were comprised primarily of kaolinite, quartz, silica, siderite, and residual hydrocarbons, and that the proportions of these constituents were different for each fraction. Depth profiling of the three post-extraction oil sands was accomplished using both rapid- and step-scan PA infrared spectroscopy. The results confirmed that kaolinite is more abundant in the near-surface region, whereas quartz and hydrocarbons are concentrated at greater depths. The modulation frequency dependence of the PA intensities for all three fractions was consistent with a model in which the samples are thermally thick; in other words, the thermal diffusion length (roughly equal to the sampling depth) was less than the particle sizes of all three samples. The results of this study are consistent with published reports on the PA infrared spectra of fine tailings generated during bitumen extraction and the spectroscopic and thermophysical characterization of clay soils and an appropriate model clay.

  7. Diel coral reef acidification driven by porewater advection in permeable sands, Heron Island, Great Barrier Reef

    DEFF Research Database (Denmark)

    Santos, Isaac R.; Glud, Ronnie N.; Maher, Damien

    2011-01-01

    Little is known about how biogeochemical processes in permeable sediments affect the pH of coastal waters. We demonstrate that seawater recirculation in permeable sands can play a major role in proton (H+) cycling in a coral reef lagoon. The diel pH range (up to 0.75 units) in the Heron Island...... lagoon was the broadest ever reported for reef waters, and the night‐time pH (7.69) was comparable to worst‐case scenario predictions for seawater pH in 2100. The net contribution of coarse carbonate sands to the whole system H+ fluxes was only 9% during the day, but approached 100% at night when small...... scale (i.e., flow and topography‐induced pressure gradients) and large scale (i.e., tidal pumping as traced by radon) seawater recirculation processes were synergistic. Reef lagoon sands were a net sink for H+, and the sink strength was a function of porewater flushing rate. Our observations suggest...

  8. Sand Lake WMD vegetation mapping project update

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Final report on the vegetation mapping project at Sand Lake Wetland Management District. This project is being completed by the use of SPRING software and ground...

  9. 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

  10. Manufacturing of thin walled near net shape iron castings

    DEFF Research Database (Denmark)

    Larsen, Per Leif

    2003-01-01

    The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed to be substitu.......000.000 cars produced world wide each year consumes enormous amounts of cast parts ! The aim of the project is to develop the green sand molding method on DISAMATIC to be able to deal with the new demands for thin walled near net shape castings in iron.......The demand for near net shape thin walled iron castings is growing. This has several reasons, the main one is the need for lowering the fuel consumption of cars; the easiest way to do that is to lower the weight of the cars. The best way to do this was for a period of time believed...... to be substituting iron casings with aluminum castings. Substituting iron castings with aluminum castings is not as easy as first believed, and hence the substitution is very slow. This combined with the lack of fully exploiting the potential in iron castings, makes research in iron castings interesting. The 60...

  11. 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.

  12. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-12-01

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

  13. Pragmatics of reclaimed sand quality assessment recovered nowadays from various used sand systems

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2010-04-01

    Full Text Available The assessment of the reclamation degree of used sands is not a simple, clearly defined issue. The great variety of technologies ofmoulding and core sands, based on the organic and inorganic binders does not allow the use of a single, universal index assessing thedegree of reclamation. The article presents the problems of research relating to selection of proper criteria for assessing the degree ofreclamation process of used moulding and core sands deriving from different technologies. The most often applied in practice types ofused sands and the most adequate in practice methods of assessing the degrees of their reclamation were characterized.

  14. Sand Dune Encroachment and Desertification Processes of the Rigboland Sand Sea, Central Iran.

    Science.gov (United States)

    Ahmady-Birgani, Hesam; McQueen, Kenneth G; Moeinaddini, Mazaher; Naseri, Hamidreza

    2017-05-08

    Early studies on sand dune movement and desertification in Iran have not always been convincingly demonstrated because of problems with the field-based measurements. In some areas where various land uses have been engulfed by aeolian sand dunes, desertification is clear, but in other less settled areas, it may not be so obvious. The objective of this study is to demonstrate encroachments of the Rigboland sand sea, central Iran, in its different directions and variable magnitude rates. Determining the rate and direction of the sand sea movements is critical for specifying which lands should be prioritized and quickly protected. The study has trialed a change detection technique which uses a Cross-Tabulation module to compare two available LandsatTM images over the Rigboland sand sea. This indicates that within a ten-year span (from 1988 to 1998) more than 200 ha/yr were added to the Rigboland sand sea, from the alluvial fan landforms in the eastern upstream, outer margins of the Rigboland sand sea. Coupled with GIS techniques, this type of analysis of the remote sensing (RS) images provides an effective tool for the monitoring and prognostication of sand dune movement and sand sea change.

  15. Synthesis, Characterization, and Application of Superhydrophobic Sands in Desert Agriculture

    KAUST Repository

    Reihmer, Joel W.

    2017-04-01

    A sustainable supply of fresh water for the human population is a global concern. Intriguingly, about 70% of the total fresh water consumed in the world annually is claimed by agriculture alone; this fraction is even higher in the Middle East and North Africa (MENA) region, where natural regeneration of groundwater is the slowest. Thus, there is a serious need for innovative materials and technologies to enhance the efficiency water usage in agriculture. To this end, plastic mulches have been employed across the developed world to minimize evaporative loss of water from top-soils. While plastic mulches are inexpensive, they do require specialized farm machinery for installation and long processing times. On one hand, plastic mulches have proven to increase crop yields, but on the other their non-biodegradability poses serious environmental concerns. In response, development of low-cost bio-/photo-degradable artificial mulches remains an area of intense research. In this thesis, we report on a novel superhydrophobic material exploiting inexpensive simple components to reduce the amount of water required for irrigation in agriculture by suppressing evaporative losses from the top-soil. Our material consists of ordinary beach sand coated with < 20 nm thick layer of paraffin wax. We synthesized and extensively characterized our material and applied them as mulches for tomato and barley plants at the KAUST greenhouse. We found that when a ~5 mm thick layer of superhydrophobic sand was placed onto the top-soil in pots, it dramatically suppressed evaporative losses and significantly enhanced the yields. Our preliminary field-scale experiments with tomatoes and barley crops at the Hada Al Sham site corroborate these results. Our approach might find applications in desert agriculture and other fields and alleviate water stress in the MENA region.

  16. Layers, Landslides, and Sand Dunes

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 27 October 2003This image shows the northern rim of one of the Valles Marineris canyons. Careful inspection shows many interesting features here. Note that the spurs and gullies in the canyon wall disappear some distance below the top of the canyon wall, indicating the presence of some smooth material here that weathers differently from the underlying rocks. On the floor of the canyon, there are remains from a landslide that came hurtling down the canyon wall between two spurs. Riding over the topography of the canyon floor are many large sand dunes, migrating generally from the lower right to upper left.Image information: VIS instrument. Latitude -14.1, Longitude 306.7 East (53.3 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  18. TimeNET Optimization Environment

    Directory of Open Access Journals (Sweden)

    Christoph Bodenstein

    2015-12-01

    Full Text Available In this paper a novel tool for simulation-based optimization and design-space exploration of Stochastic Colored Petri nets (SCPN is introduced. The working title of this tool is TimeNET Optimization Environment (TOE. Targeted users of this tool are people modeling complex systems with SCPNs in TimeNET who want to find parameter sets that are optimal for a certain performance measure (fitness function. It allows users to create and simulate sets of SCPNs and to run different optimization algorithms based on parameter variation. The development of this tool was motivated by the need to automate and speed up tests of heuristic optimization algorithms to be applied for SCPN optimization. A result caching mechanism is used to avoid recalculations.

  19. 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

  20. Implementing NetScaler VPX

    CERN Document Server

    Sandbu, Marius

    2014-01-01

    An easy-to-follow guide with detailed step-by step-instructions on how to implement the different key components in NetScaler, with real-world examples and sample scenarios.If you are a Citrix or network administrator who needs to implement NetScaler in your virtual environment to gain an insight on its functionality, this book is ideal for you. A basic understanding of networking and familiarity with some of the different Citrix products such as XenApp or XenDesktop is a prerequisite.

  1. Net4Care PHMR Library

    DEFF Research Database (Denmark)

    2014-01-01

    The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the SimpleClinicalDocument......The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the Simple...

  2. Pro DLR in NET 4

    CERN Document Server

    Wu, Chaur

    2011-01-01

    Microsoft's Dynamic Language Runtime (DLR) is a platform for running dynamic languages such as Ruby and Python on an equal footing with compiled languages such as C#. Furthermore, the runtime is the foundation for many useful software design and architecture techniques you can apply as you develop your .NET applications. Pro DLR in .NET 4 introduces you to the DLR, showing how you can use it to write software that combines dynamic and static languages, letting you choose the right tool for the job. You will learn the core DLR components such as LINQ expressions, call sites, binders, and dynami

  3. Hierarchies in Coloured Petri Nets

    DEFF Research Database (Denmark)

    Huber, Peter; Jensen, Kurt; Shapiro, Robert M.

    1991-01-01

    The paper shows how to extend Coloured Petri Nets with a hierarchy concept. The paper proposes five different hierarchy constructs, which allow the analyst to structure large CP-nets as a set of interrelated subnets (called pages). The paper discusses the properties of the proposed hierarchy...... constructs, and it illustrates them by means of two examples. The hierarchy constructs can be used for theoretical considerations, but their main use is to describe and analyse large real-world systems. All of the hierarchy constructs are supported by the editing and analysis facilities in the CPN Palette...

  4. The effects of the metal temperature and wall thickness on flake graphite layer in ductile iron

    Directory of Open Access Journals (Sweden)

    M. Górny

    2015-01-01

    Full Text Available This article addresses the effect of mold filling and wall thickness on the flake graphite layer in ductile iron. The research was conducted for castings with different wall thickness (3-8 mm and using molding sand with furan resin. A thermal analysis has been performed along the length of the castings to determine the initial temperature of the metal in the mold cavity and the contact time of the liquid metal with the mold. Results demonstrated the strong influence of the temperature decrease of the metal in the mold cavity on the occurrence and the thickness of the flake graphite in the surface layer in ductile iron.

  5. Thick Disks of Lenticular Galaxies

    OpenAIRE

    Pohlen, M.; Balcells, M.; Luetticke, R.; Dettmar, R. -J.

    2004-01-01

    Thick disks are faint and extended stellar components found around several disk galaxies including our Milky Way. The Milky Way thick disk, the only one studied in detail, contains mostly old disk stars (~10 Gyr), so that thick disks are likely to trace the early stages of disk evolution. Previous detections of thick disk stellar light in external galaxies have been originally made for early-type, edge-on galaxies but detailed 2D thick/thin disk decompositions have been reported for only a sc...

  6. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice-age deposits were reactivated as drift sand

  7. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice–age deposits were reactivated as drift sand

  8. Coastal eolian sand-ramp development related to paleo-sea-level changes during the Latest Pleistocene and Holocene (21–0 ka) in San Miguel Island, California, U.S.A.

    Science.gov (United States)

    Peterson, Curt D.; Erlandson, Jon M.; Stock, Errol; Hostetler, Steven W.; Price, David M.

    2017-01-01

    Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major hiatus in sand-ramp growth occurred during the early Holocene marine transgression (16–9 ka). The Holocene sand ramps (1–5 m measured thicknesses) currently lack large dune forms, thereby representing deflated erosional remnants, locally covering thicker late Pleistocene sand-ramp deposits. The ramp sand was initially supplied from the adjacent island-shelf platform, extending about 20 km north of the present coastline. The sand-ramp deposits and interbedded loess soils were 14C dated using 112 samples from 32 archaeological sites and other geologic sections. Latest Pleistocene sand ramps (66–18 ka) were derived from across-shelf eolian sand transport during marine low stands. Shoreward wave transport supplied remobilized late Pleistocene sand from the inner shelf to Holocene beaches, where dominant NW winds supplied sand to the sand ramps. The onset dates of the sand-ramp deposition in San Miguel are 7.2 ± 1.5 ka (sample n = 14). The internal strata dates in the vertically accreting sand ramps are 3.4 ± 1.7 ka (n = 34). The sand ramps in San Miguel show wide-scale termination of sand supply in the latest Holocene time. The sand-ramp top dates or burial dates are 1.7 ± 0.9 ka (n = 28). The latest Holocene sand ramps are truncated along most of the island's northern coastline, indicating recent losses of nearshore sand reserves to onshore, alongshore, and, possibly, offshore sand sinks. The truncated sand ramps in San Miguel Island and in other sand-depleted marine coastlines provide warnings about future beach erosion and/or shoreline retreat from accelerated sea-level rise accompanying predicted global warming.

  9. 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)

  10. An evaluation of sand and gravel resources in and near the Prescott National Forest in the Verde Valley, Arizona; with a section on evaluation of sand and gravel resources using selected engineering variables

    Science.gov (United States)

    Cox, Leslie J.; Bliss, James D.; Miller, Robert J.

    1999-01-01

    This study was based on available published literature. Although no field investigation was conducted in the Prescott National Forest to the west of the Verde River, a field investigation was conducted in the summer of 1994 by this author on the Coconino National Forest, to the east of the Verde River, where units of surficial materials of the same age and similar character are found (Cox, 1995). The intent of this evaluation of sand and gravel resources in the Prescott National Forest and adjacent areas in the Verde Valley, is to provide the land managers of the U.S. Forest Service with a map that delineates sand- and gravel-bearing geologic units. The map distinguishes (1) sand-and gravel-bearing units that are limited to channels from those that are not, (2) sand-and gravel-bearing units that are thin (generally less than 40 feet thick which is one contour interval on the topographic maps) from those that are locally thick (generally 40 feet or more), (3) sand- and gravel-bearing units that are poorly sorted from those that are well-sorted4, (4) sand- and gravel-bearing units that have little or no soil development from those that have greater degrees of soil development and lithification, (5) and sand- and gravel-bearing units that support riparian vegetation from those that do not. These distinctive characteristics are related to the geologic age or depositional setting of the rock materials and can be distinguished where areas are mapped in detail.

  11. An evaluation of aeolian sand transport models using four different sand traps at the Hors, Texel

    NARCIS (Netherlands)

    Hijma, M.P.; Lodder, Quirijn J.

    2001-01-01

    This report shows the result of an evaluation of how 12 aeolian sand transport models perform on a beach in Northwest-Europe. Their predictions are compared to measured rates of sand transport using four different traps. The efficiency of the different types of traps was also evaluated. From this it

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

    Science.gov (United States)

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

    2009-01-01

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

  13. 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.

  14. D.NET case study

    International Development Research Centre (IDRC) Digital Library (Canada)

    lremy

    developing products, marketing tools and building capacity of the grass root telecentre workers. D.Net recognized that it had several ideas worth developing into small interventions that would make big differences, but resource constraints were a barrier for scaling-up these initiatives. More demands, limited resources.

  15. Surgery for GEP-NETs

    DEFF Research Database (Denmark)

    Knigge, Ulrich; Hansen, Carsten Palnæs

    2012-01-01

    Surgery is the only treatment that may cure the patient with gastroentero-pancreatic (GEP) neuroendocrine tumours (NET) and neuroendocrine carcinomas (NEC) and should always be considered as first line treatment if R0/R1 resection can be achieved. The surgical and interventional procedures for GEP...

  16. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    van Eijk, N.

    2014-01-01

    The Netherlands is among the first countries that have put specific net neutrality standards in place. The decision to implement specific regulation was influenced by at least three factors. The first was the prevailing social and academic debate, partly due to developments in the United States. The

  17. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc.\\ are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system...

  18. Elution of Mixed Moulding Sands with the GEOPOL Binder and Core Sands with the Phenolic Resin

    Directory of Open Access Journals (Sweden)

    Holtzer M.

    2013-12-01

    Full Text Available Out of moulding and core sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. Depending on the kind of the applied resin under an influence of a temperature such compounds as for example BTEX group and polycyclic aromatic hydrocarbons (PAHs can be formed and released. During storing or economic utilization of used sand is possibility of eluting harmful substances into the environment. Therefore at assessing an influence of the used sand on the environment two above elements should be taken into consideration. Only such investigations provide the complete assessment of the given sand harmfulness.

  19. Selecting groups of covariates in the elastic net

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder

    This paper introduces a novel method to select groups of variables in sparse regression and classication settings. The groups are formed based on the correlations between covariates and ensure that for example spatial or spectral relations are preserved without explicitly coding for these....... The preservation of relations gives increased interpretability. The method is based on the elastic net and adaptively selects highly correlated groups of variables and does therefore not waste time in grouping irrelevant variables for the problem at hand. The method is illustrated on a simulated data set...... and on regression of moisture content in multispectral images of sand. In both cases, the predictions were better or similar to existing regression and classication algorithms and the interpretation was enhanced using the grouping method. On top of that, the grouping method more consistently selects the important...

  20. The offshore export of sand during exceptional discharge from California rivers

    Science.gov (United States)

    Warrick, Jonathan A.; Barnard, Patrick L.

    2012-01-01

    Littoral cells along active tectonic margins receive large inputs of sand and gravel from coastal watersheds and commonly lose this sediment to submarine canyons. One hypothesis is that the majority of coarse (sand and gravel) river sediment discharge will be emplaced within and immediately “resupply” local littoral cells. A competing hypothesis is that the infrequent, large floods that supply the majority of littoral sediment may discharge water-sediment mixtures within negatively buoyant hyperpycnal plumes that transport sediment offshore of the littoral cell. Here we summarize pre- and post-flood surveys of two wave-dominated California (United States) river deltas during record to near-record floods to help evaluate these hypotheses: the 1982–1983 delta at the San Lorenzo River mouth and the 2005 delta at the Santa Clara River mouth. Flood sedimentation at both deltas resulted in several meters of aggradation and hundreds of meters of offshore displacement of isobaths. One substantial difference between these deltas was the thick (>2 m) aggradation of sand on the inner shelf of the Santa Clara River delta that contained substantial amounts (∼50%) of littoral-grade sediment. Once deposited on the inner shelf, only a fraction (∼20%) of this river sand was observed to migrate toward the beach over the following 5 yr. Furthermore, simple hypopycnal plume behavior could not explain deposition of this sand on the inner shelf. Thus, during an exceptional flood a substantial amount of littoral-grade sand was exported offshore of the littoral system at the Santa Clara River mouth—likely from hyperpycnal plume processes—and was deposited on the inner shelf.

  1. Fracturing in the oil-sands reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y.; Yang, B. [Society of Petroleum Engineers (Canada); Xu, B. [BitCan G and E Inc (Canada)

    2011-07-01

    Oil sands reservoirs stimulation requires the use of steam or solvent in order to reduce oil viscosity, making for better recovery. Injection of these stimulants is generally achieved by hydro-fracturing and, given concerns over the impact of this on caprock integrity, a better understanding is needed of the phenomena involved during fracturing. Based on a review of the literature and on analytical, numerical and field data, this paper aims to explore the phenomena involved during hydro-fracturing of oil sands. Review of existing test data shows that oil sands have a clear dilatation tendency. Analytical derivation then compares the effects and occurrence of dilatation and tensile parting during hydro-fracturing, showing a dominance of dilatation, resulting in much higher porosity in the sands formation. Field data then confirmed these derivations, thus giving them an experimental validation. Glaciation is proposed as a cause for the presence of these phenomena in oil sands, thus the results can safely be extrapolated to other similar rock formations.

  2. Petrography, mineralogy, and geochemistry of deep gravelly sands in the Eyreville B core, Chesapeake Bay impact structure

    Science.gov (United States)

    Bartosova, Katerina; Gier, Susanne; Horton, J. Wright; Koeberl, Christian; Mader, Dieter; Dypvik, Henning

    2010-01-01

    The ICDP–USGS Eyreville drill cores in the Chesapeake Bay impact structure reached a total depth of 1766 m and comprise (from the bottom upwards) basement-derived schists and granites/pegmatites, impact breccias, mostly poorly lithified gravelly sand and crystalline blocks, a granitic slab, sedimentary breccias, and postimpact sediments. The gravelly sand and crystalline block section forms an approximately 26 m thick interval that includes an amphibolite block and boulders of cataclastic gneiss and suevite. Three gravelly sands (basal, middle, and upper) are distinguished within this interval. The gravelly sands are poorly sorted, clast supported, and generally massive, but crude size-sorting and subtle, discontinuous layers occur locally. Quartz and K-feldspar are the main sand-size minerals and smectite and kaolinite are the principal clay minerals. Other mineral grains occur only in accessory amounts and lithic clasts are sparse (only a few vol%). The gravelly sands are silica rich (~80 wt% SiO2). Trends with depth include a slight decrease in SiO2 and slight increase in Fe2O3. The basal gravelly sand (below the cataclasite boulder) has a lower SiO2 content, less K-feldspar, and more mica than the higher sands, and it contains more lithic clasts and melt particles that are probably reworked from the underlying suevite. The middle gravelly sand (below the amphibolite block) is finer-grained, contains more abundant clay minerals, and displays more variable chemical compositions than upper gravelly sand (above the block). Our mineralogical and geochemical results suggest that the gravelly sands are avalanche deposits derived probably from the nonmarine Potomac Formation in the lower part of the target sediment layer, in contrast to polymict diamictons higher in the core that have been interpreted as ocean-resurge debris flows, which is in agreement with previous interpretations. The mineralogy and geochemistry of the gravelly sands are typical for a passive

  3. Caught in the Net: Perineuronal Nets and Addiction

    Directory of Open Access Journals (Sweden)

    Megan Slaker

    2016-01-01

    Full Text Available Exposure to drugs of abuse induces plasticity in the brain and creates persistent drug-related memories. These changes in plasticity and persistent drug memories are believed to produce aberrant motivation and reinforcement contributing to addiction. Most studies have explored the effect drugs of abuse have on pre- and postsynaptic cells and astrocytes; however, more recently, attention has shifted to explore the effect these drugs have on the extracellular matrix (ECM. Within the ECM are unique structures arranged in a net-like manner, surrounding a subset of neurons called perineuronal nets (PNNs. This review focuses on drug-induced changes in PNNs, the molecules that regulate PNNs, and the expression of PNNs within brain circuitry mediating motivation, reward, and reinforcement as it pertains to addiction.

  4. PRELIMINARY STUDY OF FISH CULTURE IN ABANDONED SAND MINING POOL

    Directory of Open Access Journals (Sweden)

    Bambang Gunadi

    2006-12-01

    Full Text Available One of main problems in freshwater aquaculture development in Indonesia, especially in Java, is unavailability of developing zone. It is important to find an underutilized area that meets for industrial scale freshwater aquaculture, i.e. sufficient water supply, wide area, and located in one area or zone. The abandoned mining (sand, tin, etc. pools distributed along the country might be the potential area for freshwater aquaculture business. For example, there are at least 13 water pools with total surface area of 250 ha at 15 km side of Citarum River in Karawang District (West Java Province. This study was conducted to obtain preliminary data about the prospect and potency of fish culture (tilapia, clariid catfish, and ‘patin’ catfish in abandoned sand-mining pools in Karawang District. Mini floating net cages of 1 x 1 x 1.5 m3 size were used for culturing fish, i.e. patin catfish (Pangasianodon hypophthalmus, nile tilapia (Oreochromis niloticus, and clariid catfish (Clarias gariepinus, separately. Patin catfish were stocked at a size of 2 g with a density of 300 fish per cage, tilapia were stocked at a size of 6 g with a density of 400 fish per cage, while  the clariid catfish were stocked at a size of 1.4 g with a density of 980 fish per cage. A floating commercial feed (30%—32% protein, 3%—5% fat was used at a daily rate of 9% biomass weight at the beginning and reduced gradually to 3% at the final culture period. Observed data showed that patin catfish grew from the initial size of 2.08 g to the final size 299.59 g in 5 months, nile tilapia grew from individual initial size of 5.92 g to the final size of 247.12 g in 14 weeks, and clariid catfish grew from initial size of 1.39 g to the final size of 73.10 g in 8 weeks. These three species were technically prospective for aquaculture development in the abandoned sand-mining pools.

  5. Army Net Zero Prove Out. Army Net Zero Training Report

    Science.gov (United States)

    2014-11-20

    sensors were strategically placed throughout the installation by magnetically attaching them to water main valve stems. The sensors check sound...Recycle Wrap  Substitutes for Packaging Materials  Re-Use of Textiles and Linens  Setting Printers to Double-Sided Printing Net Zero Waste...can effectively achieve source reduction. Clean and Re-Use Shop Rags - Shop rags represent a large textile waste stream at many installations. As a

  6. Army Net Zero Prove Out. Net Zero Waste Best Practices

    Science.gov (United States)

    2014-11-20

    Anaerobic Digesters – Although anaerobic digestion is not a new technology and has been used on a large-scale basis in wastewater treatment , the...technology and has been used on a large-scale basis in wastewater treatment , the use of the technology should be demonstrated with other...approaches can be used for cardboard and cellulose -based packaging materials. This approach is in line with the Net Zero Waste hierarchy in terms of

  7. Planet-wide sand motion on mars

    Science.gov (United States)

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

    2012-01-01

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

  8. 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)

  9. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    by Bagnold and confirmed in numerous empirical studies. The model implies that the size distribution of a sand deposit is a logarithmic normal-inverse Gaussian (NIG) distribution, which is one of the generalized hyperbolic distributions. The model modifies a previous model, which implied a log-normal size-distribution......, variance and skewness of the log-size distribution to the physical parameters of the model. The results might be useful when comparing empirical size-distributions from different deposits. It is argued that size-distributions with the same general shape as the NIG-distributions can be obtained also when......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...

  10. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    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 on the charact......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...... 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...

  11. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    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 on the charact......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...... 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...

  12. 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.

  13. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate...... 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...

  14. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    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...... coincided with efficient mineralisation/degradation, and proposed the tfdC gene as a suitable marker for monitoring phenoxy acid degradation in strain PM2. Furthermore, when testing strain PM2s degradation performance in flow-through sand columns, we found that strain PM2 was able to sustain induced...... 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...

  15. The KM3NeT Digital Optical Module

    Science.gov (United States)

    Vivolo, Daniele

    2016-04-01

    KM3NeT is a European deep-sea multidisciplinary research infrastructure in the Mediterranean Sea. It will host a km3-scale neutrino telescope and dedicated instruments for long-term and continuous measurements for Earth and Sea sciences. The KM3NeT neutrino telescope is a 3-dimensional array of Digital Optical Modules, suspended in the sea by means of vertical string structures, called Detection Units, supported by two pre-stretched Dyneema ropes, anchored to the seabed and kept taut with a system of buoys. The Digital Optical Module represents the active part of the neutrino telescope. It is composed by a 17-inch, 14 mm thick borosilicate glass (Vitrovex) spheric vessel housing 31 photomultiplier tubes with 3-inch photocathode diameter and the associated front-end and readout electronics. The technical solution adopted for the KM3NeT optical modules is characterized by an innovative design, considering that existing neutrino telescopes, Baikal, IceCube and ANTARES, all use large photomultipliers, typically with a diameter of 8″ or 10″. It offers several advantages: higher sensitive surface (1260 cm2), weaker sensitivity to Earth's magnetic field, better distinction between single-photon and multi-photon events (photon counting) and directional information with an almost isotropic field of view. In this contribution the design and the performance of the KM3NeT Digital Optical Modules are discussed, with a particular focus on enabling technologies and integration procedure.

  16. 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.

  17. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  18. 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 %.

  19. 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......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...

  20. HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Productivity (NPP) portion of the Human Appropriation of Net Primary...

  1. Hydrodynamic characteristics of plane netting used for aquaculture net cages in uniform current

    National Research Council Canada - National Science Library

    DONG, SHUCHUANG; HU, FUXIANG; KUMAZAWA, TAISEI; SIODE, DAISUKE; TOKAI, TADASHI

    2016-01-01

      The hydrodynamic characteristics of polyethylene (PE) netting and chain link wire netting with different types of twine diameter and mesh size for aquaculture net cages were examined by experiments in a flume tank...

  2. Comparison of the sand liquefaction estimated based on codes and practical earthquake damage phenomena

    Science.gov (United States)

    Fang, Yi; Huang, Yahong

    2017-12-01

    Conducting sand liquefaction estimated based on codes is the important content of the geotechnical design. However, the result, sometimes, fails to conform to the practical earthquake damages. Based on the damage of Tangshan earthquake and engineering geological conditions, three typical sites are chosen. Moreover, the sand liquefaction probability was evaluated on the three sites by using the method in the Code for Seismic Design of Buildings and the results were compared with the sand liquefaction phenomenon in the earthquake. The result shows that the difference between sand liquefaction estimated based on codes and the practical earthquake damage is mainly attributed to the following two aspects: The primary reasons include disparity between seismic fortification intensity and practical seismic oscillation, changes of groundwater level, thickness of overlying non-liquefied soil layer, local site effect and personal error. Meanwhile, although the judgment methods in the codes exhibit certain universality, they are another reason causing the above difference due to the limitation of basic data and the qualitative anomaly of the judgment formulas.

  3. Sand dunes - a study of the different dune formations in the Namib Sand Sea, Namibia

    Science.gov (United States)

    Sangunji, Antonio

    2017-04-01

    Sand dunes - a study of the different dune formations in the Namib Sand Sea, Namibia By: Antonio Sangunji, Academia Secondary School, Windhoek, Namibia The Namib Sand Sea has spectacular dunes, some of which are 5700 years old. Large, complex, linear dune in the northern part of the Namib Sand Sea provide new information on the age and internal sedimentary structures of these dunes, with important implications for interpretations of paleoclimates and the rock record of eolian sandstones. Academia Secondary School learners study several science subjects including Life and Physical sciences. As part of their Science course, they study the environment and landforms. To better understand the dune dynamics, several grade 8 pupils, 35 learners in total were taken to the field to demonstrate the formation of dunes. One of the highest points in the Namib Sand Sea - Dune 7 which is 388 meters was visited. Learners made models of the dunes in the classroom with different types of modeling clay, such as oil-based, polymer, dough and pottery clay. The learners also carried out hands-on exercises on the link between different types of sand, wind speed, size and altitude of the dunes. Field trips are a great opportunity for learners to learn how sand dunes are formed and show how simple experiments can be used to demonstrate dune formation.

  4. Isolated unit tests in .Net

    OpenAIRE

    Haukilehto, Tero

    2013-01-01

    In this thesis isolation in unit testing is studied to get a precise picture of the isolation frameworks available for .Net environment. At the beginning testing is discussed in theory with the benefits and the problems it may have been linked with. The theory includes software development in general in connection with testing. Theory of isolation is also described before the actual isolation frameworks are represented. Common frameworks are described in more detail and comparable informa...

  5. Event hierarchies in DanNet

    DEFF Research Database (Denmark)

    Pedersen, Bolette Sandford; Nimb, Sanni

    2008-01-01

    Artiklen omhandler udarbejdelsen af et verbumshierarki i det leksikalsk-semantiske ordnet, DanNet.......Artiklen omhandler udarbejdelsen af et verbumshierarki i det leksikalsk-semantiske ordnet, DanNet....

  6. The Uniframe .Net Web Service Discovery Service

    National Research Council Canada - National Science Library

    Berbeco, Robert W

    2003-01-01

    Microsoft .NET allows the creation of distributed systems in a seamless manner Within NET small, discrete applications, referred to as Web services, are utilized to connect to each other or larger applications...

  7. Long Term RadNet Quality Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

  8. Operating sand and environment: can harmonising?

    Directory of Open Access Journals (Sweden)

    Eriton Geraldo Vieira

    2015-12-01

    Full Text Available Mining is considered one of the basic sectors of Brazil's economy. The mining activity provides basic raw material for industry, and several products from the simplest to the most complex have mineral origin. Most products mined in Brazil, by volume, are sand and crushed stone. The sand extraction activities are of great importance for social development, but equally responsible for negative environmental impacts, sometimes irreversible. Due to the location’s rigidity, the sand miner is forced to mine where there is mineral occurrence, which constantly is near the bottom of valleys and rivers, often coinciding with the riparian forests, which are considered to be permanently protected areas (APP. In this context, objective is to demonstrate through a dialectical approach, procedurally developed through literature the possibility of conciliating the exploration of ore sand in permanently protected areas. Thus, will be analyzed the rules established in the Law 12.651/12 (New forest law, as well as will be demonstrated the socioeconomic and environmental impacts of mining activities which have to be observed to achieve the environmental function of property. The research was supported by the qualitative method and its construction we used the technique of bibliographical and documentary review.

  9. A Triaxial Characteristic State Model for Sand

    DEFF Research Database (Denmark)

    Krenk, S.; Borup, M.; Hedegaard, J.

    A non-associated plasticity model for sand is presented. The loading surface is a closed two-parameter surface in the principal stress space, determined by a size and a shape parameter. The shape parameter is determined explicitly from the slope of the characteristic line. For small mean stress...

  10. Sublittoral sand dollar (Echillodiscus bisperforatus) communities in ...

    African Journals Online (AJOL)

    *To whom cnrrespondence should he addressed. **Prc~cnt Jddrcss: Sea hsheries Research Institute, Privsand communities and a numher of morphologically simi- lar species inhabit a variety of relatively sheltered habitats.

  11. Our Footprints on the Sands of Time

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 1. Our Footprints on the Sands of Time. Partha P Majumder D Balasubramanian. General Article Volume 11 Issue 1 January 2006 pp 32-50. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. experimental investigation of sand minimum transport velocity

    African Journals Online (AJOL)

    user

    The production of reservoir fluid through long tiebacks/pipelines has emerged as one of the cost effective alternative especially for many marginal fields which can now be produced as clusters into a common processing facility. However, sand is often co-produced with the reservoir fluid especially when produced from ...

  13. Fatal toxoplasmosis in sand cats (Felis margarita).

    Science.gov (United States)

    Pas, An; Dubey, J P

    2008-09-01

    The sand cat (Felis margarita) is a small-sized felid occurring in the United Arab Emirates (UAE). The sand cat captive-breeding program at the Breeding Centre for Endangered Arabian Wildlife in Sharjah, UAE, has until recently been severely compromised by very high newborn mortality rates. Two different pairs of sand cats gave birth, respectively, to one and two litters (with a total of eight kittens) between 1999 and 2006. Seven out of eight kittens died between the third and 21st wk of life. Toxoplasmosis was confirmed as the cause of death in these two litters. Adult cats had high antibody titers to Toxoplasma gondii before pregnancy, suggesting that maternal immunity did not protect the kittens against infection with T. gondii and that maternal immunity might not have prevented transplacental transmission of the parasite. This observation contrasts with what is seen in domestic cats. To date, this is the first report on confirmed fatal toxoplasmosis and prevalence of T. gondii in sand cats.

  14. V-2 Rocket at White Sands

    Science.gov (United States)

    1946-01-01

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

  15. Sublittoral sand dollar ( Echinodiscus bisperforatus ) communities in ...

    African Journals Online (AJOL)

    Macrofauna, meiofauna and sediment parameters together with sand dollar abundance and distribution were recorded along transects with stations at 2 m depth intervals from 4 m to 12 m. A wave-induced, depth-related turbulence gradient was evident with both mean particle size and sediment sorting decreasing with ...

  16. Undrained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    of frictional materials during monotonic loading. The tests conducted includes undrained and constant volume tests, starting from different initial states of stress and following various stress paths. All the tests are performed on reconstituted loose to medium dense specimens of Eastern Scheldt Sand....

  17. 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

  18. PsychoNet: a psycholinguistc commonsense ontology

    OpenAIRE

    Mohtasseb, Haytham; Ahmed, Amr

    2010-01-01

    Ontologies have been widely accepted as the most advanced knowledge representation model. This paper introduces PsychoNet, a new knowledgebase that forms the link between psycholinguistic taxonomy, existing in LIWC, and its semantic textual representation in the form of commonsense semantic ontology, represented by ConceptNet. The integration of LIWC and ConceptNet and the added functionalities facilitate employing ConceptNet in psycholinguistic studies. Furthermore, it simplifies utilization...

  19. Characteristics of SCC with Fly Ash and Manufactured Sand

    Science.gov (United States)

    Praveen Kumar, K.; Radhakrishna

    2016-09-01

    Self compacting concrete (SCC) of M40 grade was designed. The binder in SCC consists of OPC and fly ash in the ratio of 65:35. River sand was replaced by manufactured sand (M-sand) at replacement levels of 20,40,60,80 and 100%. An attempt was made to evaluate the workability and strength characteristics of self compacting concrete with river sand and manufactured sand as fine aggregates. For each replacement level, constant workability was maintained by varying the dosage of superplasticizer. T50 flow time, V Funnel time, V-funnel T5 time as well as compressive, split tensile and flexural strength of SCC were found at each replacement level of M-sand. They were compared to SCC with river sand. Results indicate favourable use of M-sand in preparation of Self Compacting Concrete.

  20. Triaxial and Torsional Shear Test Results for Sand

    Science.gov (United States)

    1994-06-01

    Hettler & Vardoulais Compression Behavior of dry sand (1994)__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Vaid & Chem (1985) Cyclic...1, 2 and 3, ELE Internationa Limited, 1985. Hettler , A. W., and Vardoulakis, I., "Behavior of Dry Sand Tested in a Larger Triaxial Apparatus

  1. Fiber-reinforced sand strength and dilation characteristics

    Directory of Open Access Journals (Sweden)

    Hesham M. Eldesouky

    2016-06-01

    Full Text Available Randomly distributed fiber reinforcement is used to provide an isotropic increase in the sand shear strength. The previous studies were not consistent regarding the fibers effect on the volumetric change behavior of fiber-reinforced sand. In this paper, direct shear tests are conducted on 108 specimens to investigate the effects of the fibers content, relative density, normal stress and moisture content on the shear strength and volumetric change behaviors of fiber-reinforced sand. The study investigates also the possibility of using dry fiber-reinforced sand as an alternative to heavily compacted unreinforced moist sand. The results indicate that the fibers inclusion increases the shear strength and dilation of sand. Moisture suppresses the fibers effect on the peak and post-peak shear strengths, and dilation. Dry loose fiber-reinforced sand achieves the same shear strength of heavily compacted unreinforced moist sand, yet at more than double the horizontal displacement.

  2. Mineral resource of the month: industrial sand and gravel

    Science.gov (United States)

    Dolley, Thomas

    2007-01-01

    With many diverse uses, industrial sand and gravel, also known as silica sand, is one of the most important nonmetallic minerals in the world. Industrial sand and gravel is a mining industry term used for sands that have a very high percentage of silicon dioxide, or greater than 95 percent quartz. Deposits of industrial sand and gravel can be found virtually everywhere on Earth, but are less widespread than deposits of common construction sand and gravel. Industrial sand and gravel is distinctive in grain size, hardness, inertness and resistance to high temperature and chemical action. Beverage containers, fiberglass insulation, fiber-optic cables and light bulbs are just some of today’s many products produced from industrial sand and gravel.

  3. Oil sands fever : the environmental implications of Canada's oil sands rush

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, D.; Severson-Baker, C.; Raynolds, M.

    2005-11-01

    This report puts forward recommendations to improve the environmental management of oil sands while calling for an accelerated transition towards sustainable energy in Canada. It presents a historical discussion and background of Canada's oil sands rush and discusses making oil from tar, fuel consumption by oil sand operations, and transportation to refineries. Climate change consequences such as escalating greenhouse gas emissions, emissions intensity, the Kyoto commitment and taking meaningful action are identified along with the cumulative environmental impacts on water, land and air. The paper addressed the issue of managing these cumulative impacts and protecting the environment. Government assistance and subsidies were discussed with reference to Alberta's favourable royalty regime and federal tax breaks. Last, the report discussed stewardship and leadership for responsible oil sand use, climate protection, regional environment protection and establishment of an equitable fiscal regime. 266 refs., 7 tabs., 34 figs.

  4. THERMAL INFLUENCE OF MICRODISCHARGE PLASMA ON THE PROCESS OF RECEIVING OF QUARTZ SAND ENCAPSULATED BY PYROCARBON

    Directory of Open Access Journals (Sweden)

    Kostiantyn Simeyko

    2014-07-01

    Full Text Available The Gas Institute of National Academy of Science of Ukraine developed the facility for pyrocarbon application on the particles of quartz sand through methane pyrolysis in reactor with electrothermal fluidized bed. Thickness of the bed of pure pyrolytic carbon can be controlled within set limits, depending on the temperature, fluid dynamics and duration of the process. The formation of different types of microdischarge plasma takes place at different temperatures. Microdischarge plasma increases the temperature of the individual particles for a very short time, influencing the chemical reaction and the phase transitions passing. Quartz sand encapsulated by pyrocarbon is then used for the carbothermic reduction in order to obtain high-purity silicon.

  5. Strain localization in sand: an overview of the experimental results obtained in Grenoble using stereophotogrammetry

    Science.gov (United States)

    Desrues, Jacques; Viggiani, Gioacchino

    2004-04-01

    Experimental results are presented from the extensive program of drained plane strain compression tests on sand carried out in Grenoble over the last two decades. Systematic analysis of photographs of the deforming specimen allowed for measuring deformations and determining strain fields throughout the test, that is: prior to, at, and after the onset of strain localization. The principles, details and accuracy of the procedure are described, as well as its suitability to properly depict the patterns of deformation. Findings concerning the occurrence and progression of strain localization are discussed. The issues of shear band orientation and thickness are addressed, as well as temporary and persistent complex localization patterns, and the volumetric behaviour inside a band after its formation. The influence of such variables as initial state of the sand (effective stress and relative density), specimen size and slenderness, as well as grain size, is discussed. Copyright

  6. Incipient Motion of Sand and Oil Agglomerates

    Science.gov (United States)

    Nelson, T. R.; Dalyander, S.; Jenkins, R. L., III; Penko, A.; Long, J.; Frank, D. P.; Braithwaite, E. F., III; Calantoni, J.

    2016-12-01

    Weathered oil mixed with sediment in the surf zone in the northern Gulf of Mexico after the 2010 Deepwater Horizon oil spill, forming large mats of sand and oil. Wave action fragmented the mats into sand and oil agglomerates (SOAs) with diameters of about 1 to 10 cm. These SOAs were transported by waves and currents along the Gulf Coast, and have been observed on beaches for years following the spill. SOAs are composed of 70%-95% sand by mass, with an approximate density of 2107 kg/m³. To measure the incipient motion of SOAs, experiments using artificial SOAs were conducted in the Small-Oscillatory Flow Tunnel at the U.S. Naval Research Laboratory under a range of hydrodynamic forcing. Spherical and ellipsoidal SOAs ranging in size from 0.5 to 10 cm were deployed on a fixed flat bed, a fixed rippled bed, and a movable sand bed. In the case of the movable sand bed, SOAs were placed both proud and partially buried. Motion was tracked with high-definition video and with inertial measurement units embedded in some of the SOAs. Shear stress and horizontal pressure gradients, estimated from velocity measurements made with a Nortek Vectrino Profiler, were compared with observed mobility to assess formulations for incipient motion. For SOAs smaller than 1 cm in diameter, incipient motion of spherical and ellipsoidal SOAs was consistent with predicted critical stress values. The measured shear stress at incipient motion of larger, spherical SOAs was lower than predicted, indicating an increased dependence on the horizontal pressure gradient. In contrast, the measured shear stress required to move ellipsoidal SOAs was higher than predicted, even compared to values modified for larger particles in mixed-grain riverine environments. The laboratory observations will be used to improve the prediction of incipient motion, transport, and seafloor interaction of SOAs.

  7. 78 FR 72451 - Net Investment Income Tax

    Science.gov (United States)

    2013-12-02

    ... Revenue Service 26 CFR Part 1 RIN 1545-BL74 Net Investment Income Tax AGENCY: Internal Revenue Service...). These regulations provide guidance on the computation of net investment income. The regulations affect... lesser of: (A) The individual's net investment income for such taxable year, or (B) the excess (if any...

  8. 47 CFR 69.302 - Net investment.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net investment. 69.302 Section 69.302... Apportionment of Net Investment § 69.302 Net investment. (a) Investment in Accounts 2001, 1220 and Class B Rural...) Investment in Accounts 2002, 2003 and to the extent such inclusions are allowed by this Commission, Account...

  9. 47 CFR 65.450 - Net income.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.450 Section 65.450... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Exchange Carriers § 65.450 Net income. (a) Net income shall consist of all revenues derived from the provision of interstate telecommunications services...

  10. 47 CFR 65.500 - Net income.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.500 Section 65.500... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Interexchange Carriers § 65.500 Net income. The net income methodology specified in § 65.450 shall be utilized by all interexchange carriers that are...

  11. NetBeans IDE 8 cookbook

    CERN Document Server

    Salter, David

    2014-01-01

    If you're a Java developer of any level using NetBeans and want to learn how to get the most out of NetBeans, then this book is for you. Learning how to utilize NetBeans will provide a firm foundation for your Java application development.

  12. Characterizing behavioural congruences for Petri nets

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Priese, Lutz; Sassone, Vladimiro

    1995-01-01

    We exploit a notion of interface for Petri nets in order to design a set of net combinators. For such a calculus of nets, we focus on the behavioural congruences arising from four simple notions of behaviour, viz., traces, maximal traces, step, and maximal step traces, and from the corresponding...

  13. 27 CFR 4.37 - Net contents.

    Science.gov (United States)

    2010-04-01

    ... the volume of wine within the container, except that the following tolerances shall be allowed: (1... THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Labeling Requirements for Wine § 4.37 Net contents. (a) Statement of net contents. The net contents of wine for which a standard of fill is...

  14. Geochemical evidence for a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria

    Science.gov (United States)

    Bata, Timothy; Parnell, John; Samaila, Nuhu K.; Abubakar, M. B.; Maigari, A. S.

    2015-11-01

    Paleogeographic studies have shown that Earth was covered with more water during the Cretaceous than it is today, as the global sea level was significantly higher. The Cretaceous witnessed one of the greatest marine transgressions in Earth's history, represented by widespread deposition of sands directly on underlying basement. These sand bodies hold much of the world's heavy oil. Here, we present for the first time, geochemical evidence of a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria. Bima oil sand is similar to other Cretaceous oil sands, predominantly occurring at shallow depths on basin flanks and generally lacking a seal cover, making the oil susceptible to biodegradation. The bulk properties and distribution of molecular features in oils from the Bima oil sand suggest that they are biodegraded. Sterane maturity parameters and the trisnorhopane thermal indicator for the oils suggest thermal maturities consistent with oils generated as conventional light oils, which later degraded into heavy oils. These oils also show no evidence of 25-norhopane, strongly suggesting that biodegradation occurred at shallow depths, consistent with the shallow depth of occurrence of the Bima Formation at the study locality. Low diasterane/sterane ratios and C29H/C30H ratios greater than 1 suggest a carbonate source rock for the studied oil. The Sterane distribution further suggests that the oils were sourced from marine carbonate rocks. The C32 homohopane isomerization ratios for the Bima oil sand are 0.59-0.60, implying that the source rock has surpassed the main oil generation phase, consistent with burial depths of the Fika and Gongila Formations, which are both possible petroleum source rocks in the basin.

  15. Advanced testing and characterization of transportation soils and bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2007-12-01

    Full Text Available Modulus with Hydrostatic Stress for Oil Sands at 30oC. .......... 79 FIGURE 4.7 Bulk Modulus Model 3 Performances for Oil Sand Samples at 20oC................... 82 FIGURE 4.8 Bulk Modulus Model 3 Performances for Oil Sand Samples at 30o... of Resilient Modulus with Applied Deviator Stress at Two Test Temperatures for AU-14 Sample............................................................................................. 140 FIGURE 6.15 Performances of the SE-09 Oil sand Sample Resilient...

  16. Research on the evaporation of gasoline on beach sand

    Energy Technology Data Exchange (ETDEWEB)

    Berqueiro, J.R.; Dominguez, F.; Pons, J.M

    Gasoline evaporation is an importent factor in spill behavour. When a gasoline spill occurs on beach sand, part of the gasoline is spread over the sand surface while the rest is being absorbed. The spread and absorption rate depend on, amoung other things, the permeability of the sand which in turn also depends on it's water content. It is important to study the effects of gasoline evaporation on sand beaches in order to determine when risk of explosion is low, so that cleaning of the polluted beach surface can be carried out without danger. The effects of the evaporation of 90 and 97 octane (normal and super) gasoline on beach sand have been studied using the tray evaporation technique as described in the literature. The size of the sand particles have been included along with temperature and air speed as variables in the evaporation process. The effects of gasoline on the retention capacity of three distinct types of sand particles, as well as the effects of water in the sand, have been studied for normal and super gasolines. The following conclusions can be drawn: sand retention capacity is inversely proportional to sand particle size; when sand is moistened, its gasoline retention capacity increases proportionally with the decreasing particle size; with the same sand fractions and air speed conditions; the evaporation rate increases with increasing air speeds; with the same sand fractions and air speed conditions the evaporation rate increases with temperature; given the same temperature and air conditions, a gasoline spill on coarse sand evaporates faster than one on medium sand; and given the same temperatures and air speed conditions, the evaporation rate of normal gasoline spreading over any of the three types of sand is always higher than super gasoline due to the higher volatility of the 90 octane gasoline. 10 refs., 1 fig., 3 tabs.

  17. Evaluation of an Intergrated / Biocoagulant-sand filter Drum for ...

    African Journals Online (AJOL)

    User

    2015-03-18

    Mar 18, 2015 ... pilot scale up was carried out using 120 L (120,000 ml) of water from Mezam River pretreated with 2400 g of powdered M. oleifera seeds for 15 min retention time and filtered through a sand filter drum made of fine sand, coarse sand, charcoal and gravel for 1 h filtration time. The total mean values of ...

  18. Dewatering Behaviour of Fine Oil Sands Tailings : An Experimental Study

    NARCIS (Netherlands)

    Yao, Y.

    2016-01-01

    Oil sands tailings are a warm aqueous suspension of sand, silt, clay, residual bitumen and naphtha. The tailings are hydraulically transported and stored in tailing ponds where they segregate, with the sand settling from suspension forming beaches and the remaining tailings flowing to the middle of

  19. Permanent deformation behavior of naturally occurring bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2008-01-01

    Full Text Available Oil sand, or tar sand, is a generic name given to bituminous sand deposits that are rich in bitumen or asphalt content to the extent that oil can be extracted from these deposits. The typical 8% to 15% presence of bitumen in the soil composition...

  20. Design and Fabrication of a Foundry Sand Mixer Using Locally ...

    African Journals Online (AJOL)

    Most small foundry shops mix their sand manually which is not efficient since homogenous mix cannot be guaranteed and even when foundry mixer are available most of them are imported costing the nation huge foriegn exchange. A foundry sand mixer capable of mixing foundry sand has been designed and fabricated ...

  1. Dredging Processes I : The Cutting of Sand, Clay & Rock - Theory

    NARCIS (Netherlands)

    Miedema, S.A.

    2013-01-01

    This book gives an overview of cutting theories. It starts with a generic model, which is valid for all types of soil (sand, clay and rock) after which the specifics of dry sand, water saturated sand, clay, rock and hyperbaric rock are covered. For each soil type small blade angles and large blade

  2. Interactions between microbial activity and distribution and mineral coatings on sand grains from rapid sand filters treating groundwater

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin

    Rapid sand filtration is a traditional and widespread technology for drinking water purification which combines biological, chemical and physical processes together. Granular media, especially sand, is a common filter material that allows several oxidized compounds to accumulate on its surface...

  3. NET 40 Generics Beginner's Guide

    CERN Document Server

    Mukherjee, Sudipta

    2012-01-01

    This is a concise, practical guide that will help you learn Generics in .NET, with lots of real world and fun-to-build examples and clear explanations. It is packed with screenshots to aid your understanding of the process. This book is aimed at beginners in Generics. It assumes some working knowledge of C# , but it isn't mandatory. The following would get the most use out of the book: Newbie C# developers struggling with Generics. Experienced C++ and Java Programmers who are migrating to C# and looking for an alternative to other generic frameworks like STL and JCF would find this book handy.

  4. The Net Reclassification Index (NRI)

    DEFF Research Database (Denmark)

    Pepe, Margaret S.; Fan, Jing; Feng, Ziding

    2015-01-01

    The Net Reclassification Index (NRI) is a very popular measure for evaluating the improvement in prediction performance gained by adding a marker to a set of baseline predictors. However, the statistical properties of this novel measure have not been explored in depth. We demonstrate the alarming...... marker is proven to erroneously yield a positive NRI. Some insight into this phenomenon is provided. Since large values for the NRI statistic may simply be due to use of poorly fitting risk models, we suggest caution in using the NRI as the basis for marker evaluation. Other measures of prediction...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-15

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

  6. Nitrate Leaching from Sand and Pumice Geomedia Amended with Pyrogenic Carbon Materials

    Directory of Open Access Journals (Sweden)

    Jihoon Kang

    2017-10-01

    Full Text Available There is increasing interest in using pyrogenic carbon as an adsorbent for aqueous contaminants in stormwater. The objective of this study was to investigate pyrogenic carbon materials as an amendment to geomedia to reduce nitrate leaching. Batch adsorption and column experiments were conducted to evaluate the performance of a commercial activated carbon and two biochars incorporated (5% by weight into sand and pumice columns. The batch adsorption with 50 mg L−1 of nitrate solution showed that only activated carbon resulted in a substantial adsorption for nitrate up to 41%. Tested biochars were not effective in removing aqueous nitrate and even released nitrate (<1% with 1 h reaction time. Column experiment with a pulse input of nitrate solution (50 mg L−1 confirmed that the sand or pumice columns amended with biochars were not as effective as those amended with activated carbon for reducing nitrate leaching. Our results suggested that net negatively charged surfaces of biochar may inhibit nitrate anion adsorption while activated carbon has reactive sites containing acidic functional groups to improve nitrate retention. There was no difference between sand and pumice for nitrate retention in any of the carbon amendments. Additional surface activation process during biochar production may be needed to improve adsorptive capacity of biochar for aqueous nitrate removal.

  7. Study on GMZ bentonite-sand mixture by undrained triaxial tests

    Directory of Open Access Journals (Sweden)

    Sun Wen-jing

    2016-01-01

    Full Text Available It is particularly necessary to study the deformation, strength and the changes of pore water pressure of bentonite-based buffer/backfill materials under the undrained condition. A series of isotropic compression tests and triaxial shear tests under undrained conditions were conducted on the compacted saturated/unsaturated GMZ bentonite-sand mixtures with dry mass ratio of bentonite/sand of 30:70. During the tests, the images of the sample were collected by photographic equipment and subsequently were cropped, binarized and centroids marked by image processing technique. Based on identification of the variation of the position of marked centroids, the deformation of the sample can be determined automatically in real-time. Finally, the hydro-mechanical behaviour of saturated and unsaturated bentonite-sand mixtures under the undrained condition can be obtained. From results of triaxial shear tests on unsaturated samples under constant water content, inflated volumetric deformation transforms to contractive volumetric deformation due to the increase of the confining pressure and lateral expansion deformation are observed due to the increase in the shearing stress. Moreover, the net mean stress affects the initial stiffness, undrained shear strength and deformation of the sample during the undrained shear tests.

  8. Assessment of water removal from oil sands tailings by evaporation and under-drainage, and the impact on tailings consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Fernando F.; Sanin, Maria Victoria [Golder Associates Ltd (Canada); Sedgwick, Andrea [Total EandP Canada (Canada); Blum, Jim [JG Blum Consulting Ltd (Canada)

    2011-07-01

    Tailings, left-over material produced during the extraction process that separates bitumen from oil sand, are challenging the oil sands industry. These tailings require large surface areas and contain mature fine tailings, made up of fine clay particles suspended in water, which do not settle within a reasonable timeframe. Consequently, maximizing water removal from oil sands tailings is required to accelerate tailings consolidation. The study described in this paper was developed to measure the water loss from oil sands tailings associated with evaporation and under-drainage, using laboratory drying column tests, and to evaluate the impact of water loss on the process of tailings consolidation and the gain in shear strength for different lift thicknesses. Water removal from the tailings through evaporation occurred at a nearly constant rate, while the rate of under-drainage progressively reduced with time. Additionally, it was found that thinner lifts would have better performance in terms of tailings consolidation and gain in shear strength than thick lifts.

  9. Sand Needs and Resources Offshore New York

    Science.gov (United States)

    Lashley, J. M.; Flood, R. D.; White, M.; Bokuniewicz, H.; Hinrichs, C.; Wilson, R. E.

    2016-02-01

    "Superstorm" Sandy (October, 2012) accentuated the persistent problem of coastal erosion on New York's ocean coast. The New York state Department of State in cooperation with the Bureau of Ocean Energy Management has initiated further identification and assessment of marine sand reserves required to improve the resiliency of coastal communities and the maintenance of coastal habitats. The historical demand for beach nourishment has been about 1.5 million cubic meters per year, but sea level rise and the occurrence of extreme conditions may increase the demand to over 5 million cubic meters annually. Forty-four historical and proposed borrow sites have been delineated. This inner shelf is both sand rich and data rich. Geophysical and geological data has been compiled and reassessed to support identification, characterization, and delineation of sand resources for potential use in future coastal restoration, beach nourishment, and/or wetland restoration efforts. The South Shore of Long Island is composed in part by the Fire Island National Seashore. Holocene sand ridges extending at an oblique angle to the cross shore in the seaward direction. Borrow pits among the sand ridges, excavated were apparent in the most recent surveys and it appears that natural replenishment of offshore borrow areas has been occurring although the rates need to be determined in order to assess their sustainability. Not only is the area one of intense societal attention, but the use of this resource for coastal resilience must fit into a diverse framework marine spatial planning including not only traditional components, like commercial fishing, but also new factors like the siting of offshore wind-farms. To extend this assessment will include a recent survey, sponsored by the Bureau of Ocean Energy Management and the New York Department of State, providing approximately 700 km of geophysical survey lines located between 3 and 9 nautical miles offshore, and 46 geotechnical samples

  10. MODIS-aided statewide net groundwater-recharge estimation in Nebraska.

    Science.gov (United States)

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

    Monthly evapotranspiration (ET) rates (2000 to 2009) across Nebraska at about 1-km resolution were obtained by linear transformations of the MODIS (MODerate resolution Imaging Spectroradiometer) daytime surface temperature values with the help of the Priestley-Taylor equation and the complementary relationship of evaporation. For positive values of the mean annual precipitation and ET differences, the mean annual net recharge was found by an additional multiplication of the power-function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5% of mean annual precipitation) with the largest recharge rates (in excess of 100 mm/year) found in the eastern Sand Hills and eastern Nebraska. Areas with the largest negative net recharge rates caused by declining groundwater levels due to large-scale irrigation are found in the south-western region of the state. Error bounds of the estimated values are within 10% to 15% of the corresponding precipitation rates and the estimated net recharge rates are sensitive to errors in the precipitation and ET values. This study largely confirms earlier base-flow analysis-based statewide groundwater recharge estimates when considerations are made for differences in the recharge definitions. The current approach not only provides better spatial resolution than available earlier studies for the region but also quantifies negative net recharge rates that become especially important in numerical modeling of shallow groundwater systems. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

  11. Radiographic parameters for diagnosing sand colic in horses

    Directory of Open Access Journals (Sweden)

    Egenvall Agneta

    2008-06-01

    Full Text Available Abstract Background Ingestion of sand can cause colic, diarrhoea and weight loss in horses, but these signs are unspecific and can have many other causes. The amount of sand that induces disease may vary between individuals. To avoid over-diagnosing, it is important to determine the amount of sand that can be found in horses without clinical signs of gastrointestinal disease. The aim of this study was to use previously suggested parameters for establishing a radiographic diagnosis of sand colic, and compare these findings between a sand colic group and a control group. Methods Abdominal radiographs were obtained in 30 horses with a complaint unrelated to the gastrointestinal tract. In addition, archived abdominal radiographs of 37 clinical cases diagnosed with sand impaction were investigated. The size of the mineral opacity indicative of sand in the abdomen was measured and graded according to a previously published protocol based on height and length. Location, homogeneity, opacity and number of sand accumulations were also recorded. Results Twenty out of 30 control horses (66% had one or more sand accumulations. In the present study; height, length and homogeneity of the accumulations were useful parameters for establishing a diagnosis of sand colic. Radiographically defined intestinal sand accumulation grades of up to 2 was a common finding in horses with no clinical signs from the gastrointestinal tract whereas most of the clinical cases had much larger grades, indicating larger sand accumulations. Conclusion Further work to establish a reliable grading system for intestinal sand content is warranted, but a previously proposed grading system based on measurements of height and length may be an alternative for easy assessment of sand accumulations in the meantime. The present study indicates that a grade 1 – 2 sand accumulation in the intestine is a frequent finding in horses. When working up a case with clinical signs from the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-03-01

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

  13. Post-liquefaction reconsolidation of sand.

    Science.gov (United States)

    Adamidis, O; Madabhushi, G S P

    2016-02-01

    Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

  14. Longshore sediment transport at Golden Sands (Bulgaria

    Directory of Open Access Journals (Sweden)

    Hristo Nikolov

    2006-09-01

    Full Text Available The paper presents the results of studies on the qualitative and quantitative features of the littoral drift at Golden Sands (Bulgaria, carried out jointly by Polish and Bulgarian researchers. The mathematical modelling of physical coastal processes took wave transformation (wave diffraction and refraction; the effects of shoaling and wave breaking and longshore sediment transport into account. The computations were carried out for the mean statistical annual wave climate, determined on the basis of IO BAS wave data, simulated using the WAM method from long-term Black Sea wind data. The results of sediment transport computations clearly show that its direction off the Golden Sands shore is from north to south.

  15. Mechanical Parameters of Rubber-Sand Mixtures for Numerical Analysis of a Road Embankment

    Science.gov (United States)

    Kowalska, Magdalena; Chmielewski, Maciej

    2017-10-01

    Waste production is one of the greatest problems of the modern world. It is inevitably related to the increase of industrialization. One of the most difficult, and growing in amounts, waste is scrap tyres. The most common method of utilization of end-of-life tyres by their incineration raises much concern in terms of air pollution. More sustainable seems to reuse the tyre derived products – rubber in particular – in civil engineering, where the interesting properties of this material may be effectively utilized. This paper presents results of direct shear strength tests on sand-rubber mixtures, which were next applied to a numerical FEM (finite element method) model of a road embankment built on soft ground. The laboratory tests, conducted for two types of scrap tyre rubber granulates (0.5 – 2 mm and 1 – 5 mm in size) mixed with medium fluvial sand in various proportions (5, 10, 30 and 50% by weight), proved that the unit weight of the mixtures is distinctly smaller that the unit weight of sand alone and at 50% rubber content it drops by half. The internal angle of friction stays almost unchanged for the mixtures with up to 10% of rubber (33 - 37°), but decreases by about 10° when the rubber content increases to 50%. In most of the cases analysed, the cohesion intercept is higher in case of sand-rubber mixtures when compared to sand alone. The numerical model simulated a 4.5 m high embankment with a 3 m thick layer made of sand-rubber mixtures, containing 0%, 10% or 30% of the waste product, founded on a weak subsoil (with a 3 m layer of organic soil). The results showed that stability factor of the structure built with the layer containing 30% of the coarser rubber granulate has increased from 1.60 – for sand only, to 2.15. The embankment was also able to carry load increased from 32 kPa to 45.5 kPa and its base showed much smaller settlement. The results prove that the use of tyre derived aggregates in embankment construction is not only an effective

  16. Drained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Praastrup, U.; Jakobsen, Kim Parsberg

    In the process of understanding and developing models for geomaterials, the stress-strain behaviour is commonly studied by performing triaxial tests. In the present study static triaxial tests have been performed to gain knowledge of the stress-strain behaviour of frictional materials during mono...... monotonic loading. The tests reported herein are all drained tests, starting from different initial states of stress and following various stress paths. AIl the tests are performed on reconstituted medium dense specimens of Eastern Scheldt Sand....

  17. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    indoors or leave the area to limit their exposure to toxic fumes. Specific information about the diluent added to an oil sands mixture of concern would...known as upgraders. These refineries essentially strip much of the carbon from the bitumen and produce a light synthetic crude oil (known as Syncrude...Minnesota’s new law, states: (Douglass, 2014) “ Essentially , there’s no meaningful regulation or requirements or standards for oil spill response for

  18. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  19. Energetic instability unjams sand and suspension.

    Science.gov (United States)

    Jiang, Yimin; Liu, Mario

    2004-10-01

    Jamming is a phenomenon occurring in systems as diverse as traffic, colloidal suspensions, and granular materials. A theory on the reversible elastic deformation of jammed states is presented. First, an explicit granular stress-strain relation is derived that captures many relevant features of sand, including especially the Coulomb yield surface and a third-order jamming transition. Then this approach is generalized, and employed to consider jammed magnetorheological and electrorheological fluids, again producing results that compare well to experiments and simulations.

  20. Mineralogy of Eolian Sands at Gale Crater

    Science.gov (United States)

    Achilles, C. N.; Vaniman, D. T.; Blake, D. F.; Bristow, T. F.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Morris, R. V.; Morrison, S. M.; Downs, R. T.; hide

    2016-01-01

    The Mars Science Laboratory rover Curiosity has been exploring outcrop and regolith in Gale crater since August 6, 2012. During this exploration, the mission has collected 10 samples for mineralogical analysis by X-ray diffraction (XRD), using the CheMin instrument. The CheMin (Chemistry and Mineralogy) instrument on the Mars Science Laboratory rover Curiosity uses a CCD detector and a Co-anode tube source to acquire both mineralogy (from the pat-tern of Co diffraction) and chemical information (from energies of fluoresced X-rays). A detailed description of CheMin is provided in [1]. As part of the rover checkout after landing, the first sample selected for analysis was an eolian sand deposit (the Rocknest "sand shadow"). This sample was selected in part to characterize unconsolidated eolian regolith, but primarily to prove performance of the scoop collection system on the rover. The focus of the mission after Rocknest was on the consolidated sediments of Gale crater, so all of the nine subsequent samples were collected by drilling into bedrock com-posed of lithified sedimentary materials, including mudstone and sandstone. No scoop samples have been collected since Rocknest, but at the time this abstract was written the mission stands poised to use the scoop again, to collect active dune sands from the Bagnold dune field. Several abstracts at this conference outline the Bagnold dune campaign and summarize preliminary results from analyses on approach to the Namib dune sampling site. In this abstract we review the mineralogy of Rocknest, contrast that with the mineralogy of local sediments, and anticipate what will be learned by XRD analysis of Bagnold dune sands.

  1. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

    To engineer efficient structures offshore, we need to extend our knowledge of soil response. Cyclic loading and high water pressure encountered offshore greatly influence cohesionless soil performance. Silty sand from Frederikshavn wind turbine farm was tested using single diameter height samples...... with lubricated, smooth boundary piston heads in a Danish triaxial apparatus. Samples were successfully subjected to loading histories of high complexity. Loading include high strains and stresses, post liquefaction response, transitioning through multiple densities and restoring initial soil properties after...

  2. Sorption of Arsenite onto Mackinawite Coated Sand

    Science.gov (United States)

    Gallegos, T. J.; Hayes, K. F.; Abriola, L. M.

    2004-05-01

    Arsenic contamination of groundwater is a widespread problem affecting aquifers in the United States as well as abroad. Recent strengthening of the US EPA MCL for arsenic has prompted the need for technology capable of removing both arsenite and arsenate from solution. Arsenite, the more toxic form of arsenic, is more difficult to remove from anoxic zones in the subsurface. Studies by others have demonstrated the affinity of some types of iron sulfides for arsenite, such as troilite, pyrite, amorphous iron sulfide and mackinawite. However, these studies have not provided a comprehensive investigation of the macroscopic behavior of arsenite in the presence of crystalline mackinawite in a form that can be readily applied to real-world treatment technologies. This study examines the behavior of arsenite in the presence of mackinawite coated sand. PH edge results demonstrate that arsenite sorption onto mackinawite coated sand increases with increasing pH, reaching maximum removal at pH 10. Arsenite removal, albeit slight, occurring below pH 5 is independent of pH indicative of a different removal mechanism. Isotherm studies show that at low concentrations, removal is Langmuirian in nature. Arsenite sorption abruptly converts to linear behavior at high concentrations, possibly attributed to the saturation of the monolayer. Ionic strength effects were assessed by comparing pH edge data developed for three different concentrations of NaCl background electrolyte solution. Increases in ionic strength enhance the removal of arsenite from solution, suggesting possible inner-sphere surface complexation removal mechanisms. Information gathered in this study can be used to further develop surface complexation models to describe and predict reactivity of arsenite in the presence of mackinawite coated sands in anoxic regions. Mackinawite coated sands investigated here may provide a feasible reactive medium for implementation in above-ground sorption reactors or subsurface

  3. Fusion of arkosic sand by intrusive andesite

    Science.gov (United States)

    Bailey, Roy A.

    1954-01-01

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

  4. Guide to preparing SAND reports. Revised

    Energy Technology Data Exchange (ETDEWEB)

    Locke, T.K. [ed.

    1996-04-01

    This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

  5. Pullout capacity of batter pile in sand

    Directory of Open Access Journals (Sweden)

    Ashraf Nazir

    2013-03-01

    Full Text Available Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21–31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18–75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.

  6. Pullout capacity of batter pile in sand

    Science.gov (United States)

    Nazir, Ashraf; Nasr, Ahmed

    2012-01-01

    Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21–31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18–75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted. PMID:25685412

  7. Gyral net: A new representation of cortical folding organization.

    Science.gov (United States)

    Chen, Hanbo; Li, Yujie; Ge, Fangfei; Li, Gang; Shen, Dinggang; Liu, Tianming

    2017-12-01

    One distinct feature of the cerebral cortex is its convex (gyri) and concave (sulci) folding patterns. Due to the remarkable complexity and variability of gyral/sulcal shapes, it has been challenging to quantitatively model their organization patterns. Inspired by the observation that the lines of gyral crests can form a connected graph on each brain hemisphere, we propose a new representation of cortical gyri/sulci organization pattern - gyral net, which models cortical architecture from a graph perspective, starting with nodes and edges obtained from the reconstructed cortical surfaces. A novel computational framework is developed to efficiently and automatically construct gyral nets from surface meshes, and four measurements are devised to quantify the folding patterns. Using an MRI dataset for autism study as a test bed, we identified reduced local connectivity cost and increased curviness of gyral net bilaterally on the parietal lobe, occipital lobe, and temporal lobe in autistic patients. Additionally, we found that the cortical thickness and the gyral straightness of gyral joints are higher than the rest of gyral crest regions. The proposed representation offers a new tool for a comprehensive and reliable characterization of the cortical folding organization. This novel computational framework will enable large-scale analyses of cortical folding patterns in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Study of the anti-sand sucker rod pump

    Science.gov (United States)

    Wei, Hangxin; Lv, Bingxin; Xi, Wenkui; Yi, Peng

    2017-06-01

    In order to solve the problem of sand stuck in the sucker rod pump, an anti-sand sucker rod pump is designed. The anti-sand sucker rod pump includes the conventional sucker rod pump and the swirl flow device. The sand particles can be separated from the oil in the swirl flow device, so the plunger of the sucker rod pump cannot be stuck. The motion equation of the sand particles in oil is deduced. The virtual model of the swirl flow device is built in GAMBIT software. And simulation of solid-liquid two phase flow is simulated in software FLUENT. The simulation results show that the swirl flow device can realize the sand particles separation from the oil completely. So the pump can have the effect of anti-sands.

  9. Classification and Probabilistic Description of a Sand Site Based on CPTU

    DEFF Research Database (Denmark)

    Lauridsen, Kristoffer; Andersen, Sarah; Ibsen, Lars Bo

    2012-01-01

    A sand site at the harbour of Frederikshavn, where numerous cone penetration tests (CPT) have been conducted, is considered. Methods for interpreting CPT´s and strength parameters are assessed, and compared to the results of a set of laboratory tests. The raw cone penetration measurements...... are scrutinised for data connected with physical or mechanical errors, and these are removed. Through a Bartlett similarity test of the corrected cone resistance the site is divided into sections of varying thickness. Each section is presented through a probability density function. As several CPT´s are performed...

  10. Optics At White Sands Missile Range

    Science.gov (United States)

    Fronczek, Ron C.; Hayslett, Charles R.

    1985-11-01

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

  11. New production techniques for alberta oil sands.

    Science.gov (United States)

    Carrigy, M A

    1986-12-19

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

  12. Efficacy of Different Sampling Methods of Sand Flies (Diptera: Psychodidae in Endemic Focus of Cutaneous Leishmaniasis in Kashan District, Isfahan Province, Iran.

    Directory of Open Access Journals (Sweden)

    Marzieh Hesam-Mohammadi

    2014-12-01

    Full Text Available The aim of the study was to evaluate and compare the efficiency and practicality of seven trapping methods for adult phlebotominae sand flies. The results of this investigation provide information to determine the species composition and nocturnal activity pattern of different sand fly species.The study was carried out in both plain region (about 5km far from northeast and mountainous region (about 40km far from southwest of Kashan City. Seven traps were selected as sampling methods and sand flies were collected during 5 interval times starting July to September 2011 and from 8:00PM to 6:00AM in outdoors habitats. The traps include: sticky traps (4 papers for 2 hours, Disney trap, Malaise, CDC and CO2 light traps, Shannon traps (black and white nets and animal-baited trap.A total of 1445 sand flies belonging to 15 species of Phlebotomus spp. and five of Sergentomyia spp. were collected. Females and males comprised 44.91% and 55.09% of catches, respectively. Of the collected specimens, Se. sintoni was found to be the most prevalent (37.86% species, while Ph. papatasi, accounted for 31.76% of the sand flies.Disney trap and sticky traps exhibited the most productivity than other traps. In addition, in terms of the efficiency of sampling method, these two trapping methods appeared to be the most productive for both estimating the number of sand flies and the species composition in the study area.

  13. Exploring Our Galaxy's Thick Disk

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    What is the structure of the Milky Ways disk, and how did it form? A new study uses giant stars to explore these questions.A View from the InsideSchematic showing an edge-on, not-to-scale view of what we think the Milky Ways structurelookslike. The thick disk is shown in yellow and the thin disk is shown in green. [Gaba p]Spiral galaxies like ours are often observed to have disks consisting of two components: a thin disk that lies close to the galactic midplane, and a thick disk that extends above and below this. Past studies have suggested that the Milky Ways disk hosts the same structure, but our position embedded in the Milky Way makes this difficult to confirm.If we can measure the properties of a broad sample of distant tracer stars and use this to better understand the construction of the Milky Ways disk, then we can start to ask additional questions like, how did the disk components form? Formation pictures for the thick disk generally fall into two categories:Stars in the thick disk formed within the Milky Way either in situ or by migrating to their current locations.Stars in the thick disk formed in satellite galaxies around the Milky Way and then accreted when the satellites were disrupted.Scientists Chengdong Li and Gang Zhao (NAO Chinese Academy of Sciences, University of Chinese Academy of Sciences) have now used observations of giant stars which can be detected out to great distances due to their brightness to trace the properties of the Milky Ways thick disk and address the question of its origin.Best fits for the radial (top) and vertical (bottom) metallicity gradients of the thick-disk stars. [Adapted from Li Zhao 2017]Probing OriginsLi and Zhao used data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in China to examine a sample of 35,000 giant stars. The authors sorted these stars into different disk components halo, thin disk, and thick disk based on their kinematic properties, and then explored how the orbital and

  14. -Net Approach to Sensor -Coverage

    Directory of Open Access Journals (Sweden)

    Fusco Giordano

    2010-01-01

    Full Text Available Wireless sensors rely on battery power, and in many applications it is difficult or prohibitive to replace them. Hence, in order to prolongate the system's lifetime, some sensors can be kept inactive while others perform all the tasks. In this paper, we study the -coverage problem of activating the minimum number of sensors to ensure that every point in the area is covered by at least sensors. This ensures higher fault tolerance, robustness, and improves many operations, among which position detection and intrusion detection. The -coverage problem is trivially NP-complete, and hence we can only provide approximation algorithms. In this paper, we present an algorithm based on an extension of the classical -net technique. This method gives an -approximation, where is the number of sensors in an optimal solution. We do not make any particular assumption on the shape of the areas covered by each sensor, besides that they must be closed, connected, and without holes.

  15. NETS - Danish participation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alsen, S. (Grontmij - Carl Bro, Glostrup (Denmark)); Theel, C. (Baltic Sea Solutions, Holeby (Denmark))

    2008-12-15

    Within the NICe-funded project 'Nordic Environmental Technology Solutions (NETS)' a new type of networking at the Nordic level was organized in order to jointly exploit the rapidly growing market potential in the environmental technology sector. The project aimed at increased and professionalized commercialization of Nordic Cleantech in energy and water business segments through 1) closer cooperation and joint marketing activities, 2) a website, 3) cleantech product information via brochures and publications 4) and participating in relevant trade fairs and other industry events. Facilitating business-to-business activities was another core task for the NETS project partners from Norway, Sweden, Finland and Denmark with the aim to encourage total solutions for combined Cleantech system offers. The project has achieved to establish a Cleantech register of 600 Nordic Cleantech companies, a network of 86 member enterprises, produced several publications and brochures for direct technology promotion and a website for direct access to company profiles and contact data. The project partners have attended 14 relevant international Cleantech trade fairs and conferences and facilitated business-to-business contacts added by capacity building offers through two company workshops. The future challenge for the project partners and Nordic Cleantech will be to coordinate the numerous efforts within the Nordic countries in order to reach concerted action and binding of member companies for reliable services, an improved visibility and knowledge exchange. With Cleantech's growing market influence and public awareness, the need to develop total solutions is increasing likewise. Marketing efforts should be encouraged cross-sectional and cross-border among the various levels of involved actors from both the public and the private sector. (au)

  16. Developing Large Scale Explosively Driven Flyer Experiments on Sand

    Science.gov (United States)

    Rehagen, Thomas; Kraus, Richard

    2017-06-01

    Measurements of the dynamic behavior of granular materials are of great importance to a variety of scientific and engineering applications, including planetary science, seismology, and construction and destruction. In addition, high quality data are needed to enhance our understanding of granular physics and improve the computational models used to simulate related physical processes. However, since there is a non-negligible grain size associated with these materials, experiments must be of a relatively large scale in order to capture the continuum response of the material and reduce errors associated with the finite grain size. We will present designs for explosively driven flyer experiments to make high accuracy measurements of the Hugoniot of sand (with a grain size of hundreds of microns). To achieve an accuracy of better than a few percent in density, we are developing a platform to measure the Hugoniot of samples several centimeters in thickness. We will present the target designs as well as coupled designs for the explosively launched flyer system. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  17. The KM3NeT Digital Optical Module

    Directory of Open Access Journals (Sweden)

    Vivolo Daniele

    2016-01-01

    Full Text Available KM3NeT is a European deep-sea multidisciplinary research infrastructure in the Mediterranean Sea. It will host a km3-scale neutrino telescope and dedicated instruments for long-term and continuous measurements for Earth and Sea sciences. The KM3NeT neutrino telescope is a 3-dimensional array of Digital Optical Modules, suspended in the sea by means of vertical string structures, called Detection Units, supported by two pre-stretched Dyneema ropes, anchored to the seabed and kept taut with a system of buoys. The Digital Optical Module represents the active part of the neutrino telescope. It is composed by a 17-inch, 14 mm thick borosilicate glass (Vitrovex spheric vessel housing 31 photomultiplier tubes with 3-inch photocathode diameter and the associated front-end and readout electronics. The technical solution adopted for the KM3NeT optical modules is characterized by an innovative design, considering that existing neutrino telescopes, Baikal, IceCube and ANTARES, all use large photomultipliers, typically with a diameter of 8″ or 10″. It offers several advantages: higher sensitive surface (1260 cm2, weaker sensitivity to Earth's magnetic field, better distinction between single-photon and multi-photon events (photon counting and directional information with an almost isotropic field of view. In this contribution the design and the performance of the KM3NeT Digital Optical Modules are discussed, with a particular focus on enabling technologies and integration procedure.

  18. Application and Theory of Petri Nets

    DEFF Research Database (Denmark)

    This volume contains the proceedings of the 13th International Conference onApplication and Theory of Petri Nets, held in Sheffield, England, in June 1992. The aim of the Petri net conferences is to create a forum for discussing progress in the application and theory of Petri nets. Typically....... Balbo and W. Reisig, 18 submitted papers, and seven project papers. The submitted papers and project presentations were selectedby the programme committee and a panel of referees from a large number of submissions....

  19. Are You Neutral About Net Neutrality

    Science.gov (United States)

    2007-06-20

    Information Resources Management College National Defense University Are You Neutral About Net Neutrality ? A presentation for Systems & Software...author uses Verizon FiOS for phone, TV, and internet service 3 Agenda Net Neutrality —Through 2 Lenses Who Are the Players & What Are They Saying...Medical Treatment Mini-Case Studies Updates Closing Thoughts 4 Working Definitions of Net Neutrality "Network Neutrality" is the concept that

  20. Texture Based Image Analysis With Neural Nets

    Science.gov (United States)

    Ilovici, Irina S.; Ong, Hoo-Tee; Ostrander, Kim E.

    1990-03-01

    In this paper, we combine direct image statistics and spatial frequency domain techniques with a neural net model to analyze texture based images. The resultant optimal texture features obtained from the direct and transformed image form the exemplar pattern of the neural net. The proposed approach introduces an automated texture analysis applied to metallography for determining the cooling rate and mechanical working of the materials. The results suggest that the proposed method enhances the practical applications of neural nets and texture extraction features.

  1. Factors associated with mosquito net use by individuals in households owning nets in Ethiopia

    Directory of Open Access Journals (Sweden)

    Graves Patricia M

    2011-12-01

    Full Text Available Abstract Background Ownership of insecticidal mosquito nets has dramatically increased in Ethiopia since 2006, but the proportion of persons with access to such nets who use them has declined. It is important to understand individual level net use factors in the context of the home to modify programmes so as to maximize net use. Methods Generalized linear latent and mixed models (GLLAMM were used to investigate net use using individual level data from people living in net-owning households from two surveys in Ethiopia: baseline 2006 included 12,678 individuals from 2,468 households and a sub-sample of the Malaria Indicator Survey (MIS in 2007 included 14,663 individuals from 3,353 households. Individual factors (age, sex, pregnancy; net factors (condition, age, net density; household factors (number of rooms [2006] or sleeping spaces [2007], IRS, women's knowledge and school attendance [2007 only], wealth, altitude; and cluster level factors (rural or urban were investigated in univariate and multi-variable models for each survey. Results In 2006, increased net use was associated with: age 25-49 years (adjusted (a OR = 1.4, 95% confidence interval (CI 1.2-1.7 compared to children U5; female gender (aOR = 1.4; 95% CI 1.2-1.5; fewer nets with holes (Ptrend = 0.002; and increasing net density (Ptrend [all nets in HH good] = 1.6; 95% CI 1.2-2.1; increasing net density (Ptrend [per additional space] = 0.6, 95% CI 0.5-0.7; more old nets (aOR [all nets in HH older than 12 months] = 0.5; 95% CI 0.3-0.7; and increasing household altitude (Ptrend Conclusion In both surveys, net use was more likely by women, if nets had fewer holes and were at higher net per person density within households. School-age children and young adults were much less likely to use a net. Increasing availability of nets within households (i.e. increasing net density, and improving net condition while focusing on education and promotion of net use, especially in school-age children

  2. Transport of colloidal silica in unsaturated sand: Effect of charging properties of sand and silica particles.

    Science.gov (United States)

    Fujita, Yosuke; Kobayashi, Motoyoshi

    2016-07-01

    We have studied the transport of colloidal silica in various degrees of a water-saturated Toyoura sand column, because silica particles are widely used as catalyst carriers and abrasive agents, and their toxicity is reported recently. Since water-silica, water-sand, and air-water interfaces have pH-dependent negative charges, the magnitude of surface charge was controlled by changing the solution pH. The results show that, at high pH conditions (pH 7.4), the deposition of colloidal silica to the sand surface is interrupted and the silica concentration at the column outlet immediately reaches the input concentration in saturated conditions. In addition, the relative concentration of silica at the column outlet only slightly decreases to 0.9 with decreasing degrees of water saturation to 38%, because silica particles are trapped in straining regions in the soil pore and air-water interface. On the other hand, at pH 5 conditions (low pH), where sand and colloid have less charge, reduced repulsive forces result in colloidal silica attaching onto the sand in saturated conditions. The deposition amount of silica particles remarkably increases with decreasing degrees of water saturation to 37%, which is explained by more particles being retained in the sand column associated with the air-water interface. In conclusion, at higher pH, the mobility of silica particles is high, and the air-water interface is inactive for the deposition of silica. On the other hand, at low pH, the deposition amount increases with decreasing water saturation, and the particle transport is inhibited. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Properties of dune sand concrete containing coffee waste

    Directory of Open Access Journals (Sweden)

    Mohamed Guendouz

    2018-01-01

    Full Text Available In the last years, an increase of coffee beverages consumption has been observed all over the world; and its consumption increases the waste coffee grounds which will become an environmental problems. Recycling of this waste to produce new materials like sand concrete appears as one of the best solutions for reduces the problem of pollution. This work aims to study the possibility of recycling waste coffee grounds (Spent Coffee Grounds (SCG as a fine aggregate by replacing the sand in the manufacturing of dune sand concrete. For this; sand concrete mixes were prepared with substitution of sand with the spent coffee grounds waste at different percentage (0%, 5%, 10%, 15% and 20% by volume of the sand in order to study the influence of this wastes on physical (Workability, bulk density and porosity, mechanical (compressive and flexural strength and Thermal (Thermal conductivity and thermal diffusivity properties of dune sand concrete. The results showed that the use of spent coffee grounds waste as partial replacement of natural sand contributes to reduce workability, bulk density and mechanical strength of sand concrete mixes with an increase on its porosity. However, the thermal characteristics are improved and especially for a level of 15% and 20% of substitution. So, it is possible to obtain an insulating material which can be used in the various types of structural components. This study ensures that reusing of waste coffee grounds in dune sand concrete gives a positive approach to reduce the cost of materials and solve some environmental problems.

  4. Numerical simulation of flow and compression of green sand

    DEFF Research Database (Denmark)

    Hovad, Emil

    with the flow of the sand particles and the deposition of sand dur-ing the production of sand molds using the sand shot in the DISAMATIC process. The deposition of the green sand in the chamber was investigated with a special cavity design where air vents were placed inside the cavities. The air vents are used...... to transport the green sand with an airflow during the sand shot. By changing the air vents settings in the chamber and in the cavities it was possible to improve the filling in the narrow passages in the cavity design, thereby improving the final sand mold as well. The sand shot with the cavity design...... was simulated by the discrete element method (DEM) modelling the flow of the green sand combined with classical computational fluid dynamics (CFD) for modelling the airflow in the chamber and the airflow through the air vents. These experiments and simulations gave beneficial insights to the DISAMATIC process...

  5. 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.

  6. Pro Agile NET Development with Scrum

    CERN Document Server

    Blankenship, Jerrel; Millett, Scott

    2011-01-01

    Pro Agile .NET Development with SCRUM guides you through a real-world ASP.NET project and shows how agile methodology is put into practice. There is plenty of literature on the theory behind agile methodologies, but no book on the market takes the concepts of agile practices and applies these in a practical manner to an end-to-end ASP.NET project, especially the estimating, requirements and management aspects of a project. Pro Agile .NET Development with SCRUM takes you through the initial stages of a project - gathering requirements and setting up an environment - through to the development a

  7. Pro ASP.NET MVC 4

    CERN Document Server

    Freeman, Adam

    2012-01-01

    The ASP.NET MVC 4 Framework is the latest evolution of Microsoft's ASP.NET web platform. It provides a high-productivity programming model that promotes cleaner code architecture, test-driven development, and powerful extensibility, combined with all the benefits of ASP.NET. ASP.NET MVC 4 contains a number of significant advances over previous versions. New mobile and desktop templates (employing adaptive rendering) are included together with support for jQuery Mobile for the first time. New display modes allow your application to select views based on the browser that's making the request whi

  8. Professional Visual Basic 2010 and .NET 4

    CERN Document Server

    Sheldon, Bill; Sharkey, Kent

    2010-01-01

    Intermediate and advanced coverage of Visual Basic 2010 and .NET 4 for professional developers. If you've already covered the basics and want to dive deep into VB and .NET topics that professional programmers use most, this is your book. You'll find a quick review of introductory topics-always helpful-before the author team of experts moves you quickly into such topics as data access with ADO.NET, Language Integrated Query (LINQ), security, ASP.NET web programming with Visual Basic, Windows workflow, threading, and more. You'll explore all the new features of Visual Basic 2010 as well as all t

  9. NASA Net Zero Energy Buildings Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Pless, S.; Scheib, J.; Torcellini, P.; Hendron, B.; Slovensky, M.

    2014-10-01

    In preparation for the time-phased net zero energy requirement for new federal buildings starting in 2020, set forth in Executive Order 13514, NASA requested that the National Renewable Energy Laboratory (NREL) to develop a roadmap for NASA's compliance. NASA detailed a Statement of Work that requested information on strategic, organizational, and tactical aspects of net zero energy buildings. In response, this document presents a high-level approach to net zero energy planning, design, construction, and operations, based on NREL's first-hand experience procuring net zero energy construction, and based on NREL and other industry research on net zero energy feasibility. The strategic approach to net zero energy starts with an interpretation of the executive order language relating to net zero energy. Specifically, this roadmap defines a net zero energy acquisition process as one that sets an aggressive energy use intensity goal for the building in project planning, meets the reduced demand goal through energy efficiency strategies and technologies, then adds renewable energy in a prioritized manner, using building-associated, emission- free sources first, to offset the annual energy use required at the building; the net zero energy process extends through the life of the building, requiring a balance of energy use and production in each calendar year.

  10. Towards a Standard for Modular Petri Nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Petrucci, Laure

    2009-01-01

    When designing complex systems, mechanisms for structuring, composing, and reusing system components are crucial. Today, there are many approaches for equipping Petri nets with such mechanisms. In the context of defining a standard interchange format for Petri nets, modular PNML was defined....... Moreover, we present and discuss some more advanced features of modular Petri nets that could be included in the standard. This way, we provide a formal foundation and a basis for a discussion of features to be included in the upcoming standard of a module concept for Petri nets in general and for high...

  11. Experiments and simulation of a net closing mechanism for tether-net capture of space debris

    Science.gov (United States)

    Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

    2017-10-01

    This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

  12. Tidal River Elbe - a sediment budget for the grain size fraction of medium sand

    Science.gov (United States)

    Winterscheid, Axel

    2016-04-01

    marine clay by capital dredging, Weichselion sandy deposits, which formed the geological layer underneath, now became part of the sediment transport regime. Nowadays, most sections of the main channel are morphologically characterized by a medium sandy river bed and subaquatic dunes of several meters height followed by sections of a poorly structured river bed caused by the sedimentation of silty sediments. By setting up the sediment balance for medium sand, the fluxes entering the estuary from the inland Elbe is one source term in the equation. The average annual load for the medium sand is estimated to be 110,000 m³/year (1996 - 2008, measurement station Neu Darchau). Further downstream in the tidal part of the river there are no further measurement stations located, but the analysis of a time series of multibeam sonar data (2000 to 2014) shows that large amounts of medium sand episodically pass the tidal weir at Geesthacht only in the event of extreme flood. This is due to a significant increase in bed volume between Geesthacht and the Port of Hamburg in the aftermath of a singular extreme event. Until the next extreme event the bed volume (functions as temporary storage for medium sand) is eroding again, which is the second source term. By comparing the information on bed load fluxes, the evolution of bed volumes over time and the dredging statistics we can conclude for the longer term that the total amount of medium sand that has been dredged and taken out of the system for constructional purposes is the same order of magnitude compared to the sum of both source terms. Hence, there is no or very limited net transport of medium sand passing the port area and entering the downstream river section. From the subsequent analysis of multibeam sonar data (2008 - 2014) we know for the river section from Hamburg to Brunsbuettel (total distance of 40 km) that there has been a continuous loss of about 1 Mio. m³/a in bed volumes, which means a deficit situation for medium

  13. Mars Rover Curiosity Traverses of Sand Ripples

    Science.gov (United States)

    Stein, N.; Arvidson, R. E.; Zhou, F.; Heverly, M.; Maimone, M.; Hartman, F.; Bellutta, P.; Iagnemma, K.; Senatore, C.

    2014-12-01

    Martian sand ripples present a challenge for rover mobility, with drives over ripples often characterized by high wheel sinkage and slippage that can lead to incipient embedding. Since landing in Gale Crater, Curiosity has traversed multiple sand ripples, including the transverse aeolian ridge (TAR) straddling Dingo Gap on sols 533 and 535. On sol 672, Curiosity crossed backward over a series of sand ripples before ending its drive after high motor currents initiated visual odometry (VO) processing, which detected 77% slip, well in excess of the imposed 60% slip limit. At the end of the drive, the right front wheel was deeply embedded at the base of a ripple flank with >20 cm sinkage and the rear wheels were near a ripple crest. As Curiosity continues its approach to Mount Sharp it will have to cross multiple ripples, and thus it is important to understand Curiosity's performance on sol 672 and over similar ripples. To this end the sol 672 drive was simulated in ARTEMIS (Adams-Based Rover Terramechanics Interaction Simulator), a software tool consisting of realistic rover mechanical models, a wheel-terrain interaction module for deformable and non-deformable surfaces, and realistic terrain models. ARTEMIS results, Dumont Dunes tests performed in the Mojave Desert using the Scarecrow test rover, and single wheel tests performed at MIT indicate that the high slip encountered on sol 672 likely occurred due to a combination of rover attack angle, ripple geometry, and soil properties. When ripple wavelength approaches vehicle length, the rover can reach orientations in which the leading wheels carry minimal normal loads and the trailing wheels sink deeply, resulting in high slippage and insufficient thrust to propel the rover over ripples. Even on relatively benign (i.e. low tilt) terrains, local morphology can impose high sinkage, thus impeding rover motion. Work is underway to quantify Curiosity's drive performance over various ripple geometries to retrieve soil

  14. Influence of silicate on the transport of bacteria in quartz sand and iron mineral-coated sand.

    Science.gov (United States)

    Dong, Zhe; Yang, Haiyan; Wu, Dan; Ni, Jinren; Kim, Hyunjung; Tong, Meiping

    2014-11-01

    The influence of silicate on the transport and deposition of bacteria (Escherichia coli) in packed porous media were examined at a constant 20 mM ionic strength with different silicate concentrations (from 0 to 1 mM) at pH 7. Transport experiments were performed in two types of representative porous media, both bare quartz sand and iron mineral-coated quartz sand. In bare quartz sand, the breakthrough plateaus in the presence of silicate in suspensions were lower and the corresponding retained profiles were higher than those without silicate ions, indicating that the presence of silicate in suspensions decreased cell transport in bare quartz sand. Moreover, the decrease of bacteria transport in quartz sand induced by silicate was more pronounced with increasing silicate concentrations from 0 to 1 mM. However, when EPS was removed from cell surfaces, the presence of silicate in cell suspensions (with different concentrations) did not affect the transport behavior of bacteria in quartz sand. The interaction of silicate with EPS on cell surfaces negatively decreased the zeta potentials of bacteria, resulting in the decreased cell transport in bare quartz sand when silicate was copresent in bacteria suspensions. In contrast, the presence of silicate in suspensions increased cell transport in iron mineral-coated sand. Silicate ions competed with bacteria for the adsorption sites on mineral-coated sand, contributing to the increased cell transport in mineral-coated sand with silicate present in cell suspensions. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Product (NPP) portion of the HANPP Collection represents a map identifying...

  16. 'Sharks Teeth' -- Sand Dunes in Proctor Crater

    Science.gov (United States)

    2001-01-01

    Sometimes, pictures received from Mars Global Surveyor's Mars Orbiter Camera (MOC) are 'just plain pretty.' This image, taken in early September 2000, shows a group of sand dunes at the edge of a much larger field of dark-toned dunes in Proctor Crater. Located at 47.9oS, 330.4oW, in the 170 km (106 mile) diameter crater named for 19th Century British astronomer Richard A. Proctor (1837-1888), the dunes shown here are created by winds blowing largely from the east/northeast. A plethora of smaller, brighter ripples covers the substrate between the dunes. Sunlight illuminates them from the upper left.

  17. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  18. Biogenic crust dynamics on sand dunes

    CERN Document Server

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

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

  19. Heating tar sands formations while controlling pressure

    Science.gov (United States)

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

    2010-01-12

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

  20. Price smarter on the Net.

    Science.gov (United States)

    Baker, W; Marn, M; Zawada, C

    2001-02-01

    Companies generally have set prices on the Internet in two ways. Many start-ups have offered untenably low prices in a rush to capture first-mover advantage. Many incumbents have simply charged the same prices on-line as they do off-line. Either way, companies are missing a big opportunity. The fundamental value of the Internet lies not in lowering prices or making them consistent but in optimizing them. After all, if it's easy for customers to compare prices on the Internet, it's also easy for companies to track customers' behavior and adjust prices accordingly. The Net lets companies optimize prices in three ways. First, it lets them set and announce prices with greater precision. Different prices can be tested easily, and customers' responses can be collected instantly. Companies can set the most profitable prices, and they can tap into previously hidden customer demand. Second, because it's so easy to change prices on the Internet, companies can adjust prices in response to even small fluctuations in market conditions, customer demand, or competitors' behavior. Third, companies can use the clickstream data and purchase histories that it collects through the Internet to segment customers quickly. Then it can offer segment-specific prices or promotions immediately. By taking full advantage of the unique possibilities afforded by the Internet to set prices with precision, adapt to changing circumstances quickly, and segment customers accurately, companies can get their pricing right. It's one of the ultimate drivers of e-business success.

  1. Considerations on sand control in natural gas wells

    Directory of Open Access Journals (Sweden)

    Foidaş Ion

    2017-01-01

    Full Text Available Mechanism of sand production in gas wells is complex and influenced by every operation performed into the well, starting from the opening of the production interval by drilling, and continuing with completion and putting into production as well as with the exploitation regime. Sand production along with fluids from gas reservoirs creates a series of potentially dangerous and costly problems. For selecting the most appropriate methods of sand-control all the data and information related to properties of reservoir rock, the history of sand production, the potential well flow rates as well as HSE and costs need to be evaluated. The conclusion of the authors is that the best results in sand control is achieved when the methods are applied before the production of sand may become an issue.

  2. Deformation and shock consolidation of various sands under explosive loading

    Science.gov (United States)

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

    2017-01-01

    The response of various geological materials to shock loading is important in both military and industrial applications. The composition of a real soil is complex and involves multiple constituents that undergo a number of physical and mechanical transformations during the shock loading. The present study analyzes several sands, a limestone sand both wet and dry, and a dry silica sand representing simplified model system for the soil. The sands are compressed using two different steel encapsulation assemblies subject to loading by explosive detonation products. These set-ups attempt to vary the magnitude and duration of applied pressure and temperature to the encapsulated sand. A comparative analysis of the recovered sand samples, including a microstructural analysis focusing on the grain breakage, compaction and consolidation, is correlated with a CTH numerical analysis employing a multi-phase rate sensitive material model.

  3. Environmental consequences of oil production from oil sands

    Science.gov (United States)

    Rosa, Lorenzo; Davis, Kyle F.; Rulli, Maria C.; D'Odorico, Paolo

    2017-02-01

    Crude oil from oil sands will constitute a substantial share of future global oil demand. Oil sands deposits account for a third of globally proven oil reserves, underlie large natural forested areas, and have extraction methods requiring large volumes of freshwater. Yet little work has been done to quantify some of the main environmental impacts of oil sands operations. Here we examine forest loss and water use for the world's major oil sands deposits. We calculate actual and potential rates of water use and forest loss both in Canadian deposits, where oil sands extraction is already taking place, and in other major deposits worldwide. We estimated that their exploitation, given projected production trends, could result in 1.31 km3 yr-1 of freshwater demand and 8700 km2 of forest loss. The expected escalation in oil sands extraction thus portends extensive environmental impacts.

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

    Science.gov (United States)

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

    2013-12-01

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

  5. Alongshore Variability of Nearshore Morphology during Net Offshore Bar Migration

    Science.gov (United States)

    Price, T.; Dionísio António, S.; Van Kuik, N.; De Wit, L.; Ruessink, G.

    2016-12-01

    On spatial scales from tens of metres to a few kilometres, wave-dominated sandy coasts often exhibit morphological variations with a striking alongshore rhythmicity. A regular alongshore variation of shallower (more landward) and deeper (more seaward) sandbar crests, known as horns and bays, respectively, may drive the patterning of onshore morphology, such as alongshore variations in beach width and dune development. It remains unclear, however, how sandbar morphology affects the beach-dune system on the timescale of months to years, which is often characterised by a cyclic net offshore directed migration of the bar. We used a 15-year data set of planview time-exposure images and the corresponding offshore hydrodynamic data from Egmond aan Zee, The Netherlands, to investigate the coupled development of bar, beach and dune variability during an entire net offshore migration (NOM) cycle. Our observations show a decrease in temporal variation of alongshore variability in sandbar morphology when a bar becomes the outer bar during the NOM-cycle. Whereas the inner-bar morphology developed more freely, the alongshore positions of the outer-bar horns remained relatively fixed. Moreover, the video data reveal that these outer-bar horns regularly shed a so-called Shoreward Propagating Accretionary Wave (SPAW). Accordingly, these SPAWs regularly brought a volume of sand to the same positions along the beach, locally increasing beach width and corresponding to locations of embryo dune abundance. On the long term, the NOM-cycle thus introduces a spatiotemporal periodicity in the development of alongshore variable morphology across the entire nearshore zone.

  6. Thick resist for MEMS processing

    Science.gov (United States)

    Brown, Joe; Hamel, Clifford

    2001-11-01

    The need for technical innovation is always present in today's economy. Microfabrication methods have evolved in support of the demand for smaller and faster integrated circuits with price performance improvements always in the scope of the manufacturing design engineer. The dispersion of processing technology spans well beyond IC fabrication today with batch fabrication and wafer scale processing lending advantages to MEMES applications from biotechnology to consumer electronics from oil exploration to aerospace. Today the demand for innovative processing techniques that enable technology is apparent where only a few years ago appeared too costly or not reliable. In high volume applications where yield and cost improvements are measured in fractions of a percent it is imperative to have process technologies that produce consistent results. Only a few years ago thick resist coatings were limited to thickness less than 20 microns. Factors such as uniformity, edge bead and multiple coatings made high volume production impossible. New developments in photoresist formulation combined with advanced coating equipment techniques that closely controls process parameters have enable thick photoresist coatings of 70 microns with acceptable uniformity and edge bead in one pass. Packaging of microelectronic and micromechanical devices is often a significant cost factor and a reliability issue for high volume low cost production. Technologies such as flip- chip assembly provide a solution for cost and reliability improvements over wire bond techniques. The processing for such technology demands dimensional control and presents a significant cost savings if it were compatible with mainstream technologies. Thick photoresist layers, with good sidewall control would allow wafer-bumping technologies to penetrate the barriers to yield and production where costs for technology are the overriding issue. Single pass processing is paramount to the manufacturability of packaging

  7. Supply-limited horizontal sand drift at an ephemerally crusted, unvegetated saline playa

    Science.gov (United States)

    Gillette, Dale A.; Niemeyer, Tezz C.; Helm, Paula J.

    2001-08-01

    A site at Owens Dry Lake was observed for more than 4 years. The site was a vegetation-free saline playa where the surface formed "ephemeral crusts," crusts that form after rainfall. Sometimes these crusts were destroyed and often a layer of particles on the crust would engage in vigorous aeolian activity. Three "phases" of active sand drifting are defined as almost no movement (extreme supply limitation), loose particles on crust with some degree of sand drift (moderate supply limitation), and unlimited source movement corresponding to a destroyed surface crust (unlimited supply). These "phases" occurred 45, 49, and 6% of the time, respectively. The accumulation of loose particles on the crust was mostly the result of in situ formation. Crusted sediments with loose particles on top can exhibit mass flux rates about the same as for noncrusted sediments. Crusted sediments limit or eliminate sand drift in two conditions: for rough crusts that effect a sufficiently high threshold friction velocity (above the wind friction velocity) and for limited amounts of loose particles on the crust where particle supply is less than would be transported in normal saltation for a thick sandy surface. These "supply-limited" cases are similar to wind erosion of limited spilled material on a hard concrete surface. We quantified "supply limitation" by defining a "potential" or "supply unlimited" sand drift function Q = AG where A represents supply limitation that decreases as the particle source is depleted. Here Q is the mass of sand transported through a surface perpendicular to the ground and to the wind and having unit width during time period t, and G = ∫ u*(u2* - u2*t) dt for u* > u*t. G is integrated for the same time period t as for Q, u* is the friction velocity of the wind, and u*t is the threshold friction velocity of the wind. Hard crusts (usually formed in the summer) tended to show almost no change of threshold friction velocity with time and often gave total

  8. Asphaltene adsorption on quartz sand in the presence of pre-adsorbed water.

    Science.gov (United States)

    Gonzalez, Valeska; Taylor, Spencer E

    2016-10-15

    In the oil industry, asphaltenes are known for their tendency to aggregate in solution and to deposit on surfaces, with both properties being connected with operational problems associated with recovery, production and refining. Interactions involving asphaltenes and other crude oil components have been a major aspect of investigation in attempting to understand the full nature of these problems. Water is implicated in asphaltene behavior in solution, for example, where it has been found to delay the deposition of asphaltene aggregates. At interfaces, there is evidence that water-in-crude oil emulsion stability is enhanced through asphaltene-water interactions, and there have been a few reports that asphaltene adsorption on mineral surfaces is reduced in the presence of water. We consider the latter aspect, because the instances of reduced adsorption to date have not attempted to quantify the effect. Previous studies showed that vapor-phase adsorption of organic molecules is reduced in the presence of pre-adsorbed water and we were interested to determine whether the same is true for liquid-phase adsorption of asphaltenes. The surface of quartz sand was controlled by pre-adsorption of water from different relative humidity (RH) environments as the water adsorption isotherm is known from previous studies. These pre-conditioned sand samples were used as substrates for the adsorption from toluene solutions of n-heptane-precipitated asphaltenes (C7A) from an Athabasca oil sands bitumen. To supplement the adsorption behavior, atomic force microscopy (AFM) images were taken of the resultant sand grains at 0 and 80% RH, and low-field NMR was used to estimate the sand wettability. Asphaltene adsorption on sand is sensitive to surface-adsorbed water, with ∼4-fold reduction in adsorption when increasing the RH from 0 to 100%. This is in general agreement with previous vapor-phase adsorption of small organic molecules, and is therefore believed to be the first demonstration

  9. Modeling the response of shoreface-connected sand ridges to sand extraction on an inner shelf

    NARCIS (Netherlands)

    Nnafie, A.; de Swart, Huib; Calvete, D.; Garnier, R.

    2014-01-01

    Shoreface-connected sand ridges are rhythmic bedforms that occur on many storm-dominated inner shelves. The ridges span several kilometers, are a few meters high, and they evolve on a timescale of centuries. A processbased model is used to gain a fundamental insight into the response of these ridges

  10. Microwave processing of oil sands and contribution of clay minerals

    OpenAIRE

    Robinson, John; Binner, Eleanor; Saeid, Abdul; Al-Harahsheh, Mohammed; Kingman, Sam

    2014-01-01

    This study establishes the feasibility of microwave heating for extracting oil from Oil Sands in ex-situ processes. Previous studies in this area have shown some potential, but have not characterised the dielectric properties of the Oil Sands used, nor related them to the mineral composition, both of which are vital if successful scale up is to be achieved. In this work the fundamental interactions of microwave energy with Oil Sands are investigated and understood for the first time, and the ...

  11. MC-Parameter Calibration of Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Hanson, Mats; Hjort, T.

    The soil parameters are dependent on both confining pressure and density index. The density index of Baskarp Sand can be determined by conducting cone penetration tests with the mini-CPT cone used in the Geotechnical Engineering Laboratory at Aalborg University. The unit weight of Baskarp Sand No...... several conventional drained triaxial tests at two different density indices performed on Baskarp Sand No. 15 (Ibsen & Bødker, 1994). The used triaxial tests are listed in Table 1 and Table 2....

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

    Science.gov (United States)

    Zaid, Samir M.

    2017-06-01

    Texture, mineralogy, and major and trace element geochemistry of 26 coastal dune sand samples were studied to determine the provenance and tectonic environment of two dune fields close to the beaches of Safaga (SF) and Quseir (QS) at the Egyptian Red Sea coast. Onshore winds generate fine, moderate, moderately-well to well-sorted, coarse-skewed to near-symmetrical dune sands with mesokurtic distributions. Winds pick up and transport grains from nearby beach sands and alluvial deposits into a wide Red Sea coastal plain at the border of the beach. The mineralogical (Qt-Ft-Lt) and geochemical composition of the sands, indicate that SF and QS coastal dune sands are mature and influenced by quartz-rich sands. The average CIA values in SF and QS coastal dune sands are low relative to the range of the PAAS, suggesting an arid climate and a low intensity of chemical weathering. The SF and QS coastal dune sand samples are plotted in the recycled orogen and partly in craton interior fields suggesting recycled older sedimentary and partly metamorphic-plutonic sources. The high content of quartz with shell debris and carbonates in coastal dune sands support the recycled sedimentary beach and alluvial sand sources. The dominance of heavy minerals like amphiboles (hornblende) and biotite in the coastal dune sands also supports the effect of metamorphic-plutonic source rocks. The new tectonic discriminant-function diagrams suggest that the coastal dune sands were deposited in a passive margin of a synrift basin. The results provide a good evidence for the extension in the Red Sea rift system during Oligocene-post Pliocene, which is consistent with the general geology of Egypt.

  13. Adsorption of L-amino Acids on Sea Sand

    Directory of Open Access Journals (Sweden)

    Zaia Dimas A. M.

    2002-01-01

    Full Text Available A study of adsorption of L-alanine, L-tyrosine, L-glutamic acid, and L-lysine on sea sand was carried out. Only L-lysine showed adsorption on sea sand, probably due to the presence of the positively charged R group. Our results raise some doubts as to whether sand was important for the pre-concentration of amino acids prior to peptide condensation on the Pre-Biotic Earth.

  14. Investigations on Local Quartz Sand for Application in Glass Industry

    Science.gov (United States)

    Dararutana, Pisutti; Chetanachan, Prukswan; Wathanakul, Pornsawat; Sirikulrat, Narin

    2009-03-01

    Silica or glass sand is a special type of quartz sand that is suitable for glass-making, because of its high silica content, and its low content of iron oxide and other compounds. In Thailand, deposits of quartz sand are found as the beach and the river sands in many areas; eastern, southern, northeastern and northern. In this work, grain-size distribution and chemical analyses were carried out on 10 sand samples taken from various localities in Thailand such as Chanthaburi, Trat, Rayong, Chumphon, Nakhon Si, Pattani, Phuket, Songkhla, Nong Khai, and Tak provinces. The geological resources show that most of them are the surface-to-near-surface glass sand deposits. The sand grains in most deposits were mainly angular-to-rounded, except in some areas of either angular or rounded grains. Chemical analysis showed that the sands contained more than 95wt% silica and low content of Fe, Al, Ca, Mg, Na, and K. The concentration levels of these components in the samples confirm with internationally acceptable standard for glass production. The quartz sand dressing plants that used the spiral classifier to improve the properties of the quartz sands to meet the standard specifications are mostly located in the eastern area. It can be concluded that most of the quartz sand deposits in Thailand investigated show well-sorted grain-size with considerable purity, i.e. high-grade quality. The advanced works resulted in that these raw quartz sands can be used as raw material for fabrication of soda-lime, lead crystal, and lead-free high refractive index glasses. The colorless and various colored glass products have been satisfactorily used in the domestic art and glass manufactures.

  15. Developing a Sand Management Plan for Galveston Island

    Science.gov (United States)

    2015-10-16

    US Army Corps of Engineers BUILDING STRONG® Developing a Sand Management Plan for Galveston Island Ashley E. Frey, P. E. Research Civil...BUILDING STRONG® Problem Statement/Approach Recommend a long-term plan of actions to better manage sands on Galveston Island Initial Tasks...Formalize and document Galveston Island Sand Management Plan 3 Innovative solutions for a safer, better world BUILDING STRONG® Sediment

  16. Chemical and biological control of phlebotominae sand flies

    OpenAIRE

    Pružinová, Kateřina

    2010-01-01

    Phlebotominae sand flies (Diptera: Phlebotominae) are important vectors of leishmaniasis. Control measures are complicated by the fact that sand fly breeding sites and resting places are generally hard to find. Measures used to control adult sand flies include the use of chemical insecticides for insecticide-treated bednets or curtains, residual spraying of dwellings, eventually the space-spraying. Domestic dogs as reservoir host of visceral leishmaniosis can be protected by dog-collars impre...

  17. 78 FR 72393 - Net Investment Income Tax

    Science.gov (United States)

    2013-12-02

    ... Investment Income Tax; Final and Proposed Rules #0;#0;Federal Register / Vol. 78, No. 231 / Monday, December... Parts 1 and 602 RIN 1545-BK44 Net Investment Income Tax AGENCY: Internal Revenue Service (IRS), Treasury... Investment Income Tax and the computation of Net Investment Income. The regulations affect individuals...

  18. 77 FR 72611 - Net Investment Income Tax

    Science.gov (United States)

    2012-12-05

    ... December 5, 2012 Part V Department of the Treasury Internal Revenue Service 26 CFR Part 1 Net Investment... Investment Income Tax AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of proposed rulemaking...) the individual's net investment income for such taxable year, or (B) the excess (if any) of (i) the...

  19. Net analyte signal based statistical quality control

    NARCIS (Netherlands)

    Skibsted, E.T.S.; Boelens, H.F.M.; Westerhuis, J.A.; Smilde, A.K.; Broad, N.W.; Rees, D.R.; Witte, D.T.

    2005-01-01

    Net analyte signal statistical quality control (NAS-SQC) is a new methodology to perform multivariate product quality monitoring based on the net analyte signal approach. The main advantage of NAS-SQC is that the systematic variation in the product due to the analyte (or property) of interest is

  20. Asynchronous stream processing with S-Net

    NARCIS (Netherlands)

    Grelck, C.; Scholz, S.-B.; Shafarenko, A.

    2010-01-01

    We present the rationale and design of S-Net, a coordination language for asynchronous stream processing. The language achieves a near-complete separation between the application code, written in any conventional programming language, and the coordination/communication code written in S-Net. Our

  1. Using the MVC architecture on . NET platform

    OpenAIRE

    Ježek, David

    2011-01-01

    This thesis deals with usage of MVC (Model View Controller) technology in web development on ASP.NET platform from Microsoft. Mainly it deals with latest version of framework ASP.NET MVC 3. First part describes MVC architecture and the second describes usage of MVC in certain parts of web application an comparing with PHP.

  2. Analysis of Petri Nets and Transition Systems

    Directory of Open Access Journals (Sweden)

    Eike Best

    2015-08-01

    Full Text Available This paper describes a stand-alone, no-frills tool supporting the analysis of (labelled place/transition Petri nets and the synthesis of labelled transition systems into Petri nets. It is implemented as a collection of independent, dedicated algorithms which have been designed to operate modularly, portably, extensibly, and efficiently.

  3. 27 CFR 7.27 - Net contents.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Net contents. 7.27 Section 7.27 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... the net contents are displayed by having the same blown, branded, or burned in the container in...

  4. Petri nets and other models of concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro

    1998-01-01

    This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency.......This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency....

  5. Delta Semantics Defined By Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    This report is identical to an earlier version of May 1978 except that Chapter 5 has been revised. A new paper: "A Petri Net Definition of a System Description Language", DAIMI, April 1979, 20 pages, extends the Petri net model to include a data state representing the program variables. Delta...

  6. Net neutrality and inflation of traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, Florian

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate the short-run effects of different net neutrality rules. Content differs in its

  7. Net Neutrality and Inflation of Traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, F.

    2015-01-01

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate different net neutrality rules. Content differs in its sensitivity to delay.

  8. The Net Neutrality Debate: The Basics

    Science.gov (United States)

    Greenfield, Rich

    2006-01-01

    Rich Greenfield examines the basics of today's net neutrality debate that is likely to be an ongoing issue for society. Greenfield states the problems inherent in the definition of "net neutrality" used by Common Cause: "Network neutrality is the principle that Internet users should be able to access any web content they choose and…

  9. Dynamic response of the thermometric net radiometer

    Science.gov (United States)

    J. D. Wilson; W. J. Massman; G. E. Swaters

    2009-01-01

    We computed the dynamic response of an idealized thermometric net radiometer, when driven by an oscillating net longwave radiation intended roughly to simulate rapid fluctuations of the radiative environment such as might be expected during field use of such devices. The study was motivated by curiosity as to whether non-linearity of the surface boundary conditions...

  10. Teaching and Learning with the Net Generation

    Science.gov (United States)

    Barnes, Kassandra; Marateo, Raymond C.; Ferris, S. Pixy

    2007-01-01

    As the Net Generation places increasingly greater demands on educators, students and teachers must jointly consider innovative ways of teaching and learning. In this, educators are supported by the fact that the Net Generation wants to learn. However, these same educators should not fail to realize that this generation learns differently from…

  11. Verification of Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær

    2011-01-01

    Timed-Arc Petri Nets (TAPN) are an extension of the classical P/T nets with continuous time. Tokens in TAPN carry an age and arcs between places and transitions are labelled with time intervals restricting the age of tokens available for transition firing. The TAPN model posses a number...

  12. A Brief Introduction to Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1997-01-01

    Coloured Petri Nets (CP-nets or CPN) is a graphical oriented language for design, specification, simulation and verification of systems. It is in particular well- suited for systems in which communication, synchronisation and resource sharing are important. Typical examples of application areas a...

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Tariq eSiddique

    2014-03-01

    Full Text Available Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT amended with an organic substrate (hydrolyzed canola meal produced methane (CH4 and carbon dioxide (CO2. Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 versus unamended MFT (pH 7.7. About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca2+ and magnesium (Mg2+ and increasing bicarbonate (HCO3- in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL of clay particles by reducing the surface charge potential (repulsive forces of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics.

  15. Gill net and trammel net selectivity in the northern Aegean Sea, Turkey

    Directory of Open Access Journals (Sweden)

    F. Saadet Karakulak

    2008-09-01

    Full Text Available Fishing trials were carried out with gill nets and trammel nets in the northern Aegean Sea from March 2004 to February 2005. Four different mesh sizes for the gill nets and the inner panel of trammel nets (16, 18, 20 and 22 mm bar length were used. Selectivity parameters for the five most economically important species, bogue (Boops boops, annular sea bream (Diplodus annularis, striped red mullet (Mullus surmuletus, axillary sea bream (Pagellus acarne and blotched picarel (Spicara maena, caught by the two gears were estimated. The SELECT method was used to estimate the selectivity parameters of a variety of models. Catch composition and catch proportion of several species were different in gill and trammel nets. The length frequency distributions of the species caught by the two gears were significantly different. The bi-modal model selectivity curve gave the best fit for gill net and trammel net data, and there was little difference between the modal lengths of these nets. However, a clear difference was found in catching efficiency. The highest catch rates were obtained with the trammel net. Given that many discard species and small fish are caught by gill nets and trammel nets with a mesh size of 16 mm, it is clear that these nets are not appropriate for fisheries. Consequently, the best mesh size for multispecies fisheries is 18 mm. This mesh size will considerably reduce the numbers of small sized individuals and discard species in the catch.

  16. Sedimentary characteristics of thick layer lacustrine beach-bars in the Cenozoic Banqiao Sag of the Bohai Bay Basin, East China

    Science.gov (United States)

    Song, Fan; Su, Nina; Yang, Shaochun; Yao, Ruixiang; Chu, Shumin

    2018-01-01

    Lacustrine beach-bar reservoirs have become important exploration targets in the Bohai Bay Basin in China, especially in the Banqiao Sag within the Huanghua Depression, where some typical thick layer beach-bar reservoirs have been discovered recently. The average single-layer thickness of the beach-bar sand bodies in the second member of the Paleogene Shahejie Formation within the sag is greater than 10 m and the cumulative thickness of these sands reach up to 100 m. The second member of the Shahejie Formation in the Banqiao Sag consists of a third-order sequence of three systems tracts-a lowstand systems tract, a transgressive systems tract, and a highstand systems tract. Beach-bar sand bodies were deposited widely in the sag in the lowstand systems tract, but were less deposited in the other systems tracts. The sedimentary characteristics, distribution patterns, and formation mechanisms of the beach-bar sand bodies in the lowstand systems tract of the second member of the Shahejie Formation were systemically studied using cores, wireline logs and 3D seismic data. The beach-bar was divided into five sedimentary microfacies, namely, sandy bar centre, sandy bar flank, interbar deposit, coastal beach, and infralittoral beach. Based on the integrated analysis of the paleostructure and sedimentary environment, it was inferred that the thick layer beach-bars in this area resulted from the combination and joint control of the sediment source system, hydrodynamic environment, lake level variations, and contemporaneous fault activity. Firstly, the sands in the braided river delta of the Beidagang buried hill structural belt served as the provenance that provided the material basis for the beach-bars in the Banqiao Sag. Secondly, the wave effects in the gentle-slope belt controlled the scale and distribution of the beach bars. Under the control of waves, various sedimentary microfacies were regularly distributed. In particular, the continuous activity of the contemporaneous

  17. Discrete, continuous, and hybrid petri nets

    CERN Document Server

    David, René

    2004-01-01

    Petri nets do not designate a single modeling formalism. In fact, newcomers to the field confess sometimes to be a little puzzled by the diversity of formalisms that are recognized under this "umbrella". Disregarding some extensions to the theoretical modeling capabilities, and looking at the level of abstraction of the formalisms, Condition/Event, Elementary, Place/Transition, Predicate/Transition, Colored, Object Oriented... net systems are frequently encountered in the literature. On the other side, provided with appropriate interpretative extensions, Controled Net Systems, Marking Diagrams (the Petri net generalization of State Diagrams), or the many-many variants in which time can be explicitly incorporated -Time(d), Deterministic, (Generalized) Stochastic, Fuzzy...- are defined. This represents another way to define practical formalisms that can be obtained by the "cro- product" of the two mentioned dimensions. Thus Petri nets constitute a modeling paradigm, understandable in a broad sense as "the total...

  18. Numerical modeling of wind-blown sand on Mars.

    Science.gov (United States)

    Huang, HaoJie; Bo, TianLi; Zheng, XiaoJing

    2014-09-01

    Recent observation results show that sand ripples and dunes are movable like those on Earth under current Martian climate. And the aeolian process on Mars therefore is re-attracting the eyes of scientific researchers in different fields. In this paper, the spatial and temporal evolution of wind-blown sand on Mars is simulated by the large-eddy simulation method. The simulations are conducted under the conditions of both friction wind speed higher and lower than the "fluid threshold", respectively. The fluid entrainment of the sand particles, the processes among saltation sand particles and sand bed, and the negative feedback of sand movement to flow field are considered. Our results show that the "overshoot" phenomenon also exists in the evolution of wind-blown sand on Mars both temporally and spatially; impact entrainment affects the sand transport rate on Mars when the wind speed is smaller or larger than the fluid threshold; and both the average saltation length and height are one order of magnitudes larger than those on Earth. Eventually, the formulas describing the sand transport rate, average saltation length and height on Mars are given, respectively.

  19. [Influence of perlite sand on the skin in experiment].

    Science.gov (United States)

    Dracheva, E E; Iatsyna, I V; Lapina, N E; Ianin, V A; Antoshina, L I; Zhadan, I Iu; Krasavina, E K

    2012-01-01

    In the present work influence of perlite sand has been studied on a skin of Sprague-Dawley male rat (300-350 g). The biopsy of intact rat skin has been used as control. Contact of the perlite sand with animals' skin causes the reaction of an inflammation amplifying with increase of duration of the influence of substance. Therefore, despite an inert chemical compound, long contact with perlite sand in conditions of production can promote development of skin diseases. From the result of this investigation it is concluded that perlite sand causes irritating action on the skin and it is necessary to apply additional protective means to workers contacting to this substance.

  20. Effective Laboratory Method of Chromite Content Estimation in Reclaimed Sands

    Directory of Open Access Journals (Sweden)

    Ignaszak Z.

    2016-09-01

    Full Text Available The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid. It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium. The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

  1. Direct numerical simulations of aeolian sand ripples

    Science.gov (United States)

    Durán, Orencio; Claudin, Philippe; Andreotti, Bruno

    2014-01-01

    Aeolian sand beds exhibit regular patterns of ripples resulting from the interaction between topography and sediment transport. Their characteristics have been so far related to reptation transport caused by the impacts on the ground of grains entrained by the wind into saltation. By means of direct numerical simulations of grains interacting with a wind flow, we show that the instability turns out to be driven by resonant grain trajectories, whose length is close to a ripple wavelength and whose splash leads to a mass displacement toward the ripple crests. The pattern selection results from a compromise between this destabilizing mechanism and a diffusive downslope transport which stabilizes small wavelengths. The initial wavelength is set by the ratio of the sediment flux and the erosion/deposition rate, a ratio which increases linearly with the wind velocity. We show that this scaling law, in agreement with experiments, originates from an interfacial layer separating the saltation zone from the static sand bed, where momentum transfers are dominated by midair collisions. Finally, we provide quantitative support for the use of the propagation of these ripples as a proxy for remote measurements of sediment transport. PMID:25331873

  2. Guidelines to sand control. Pt. 3

    Energy Technology Data Exchange (ETDEWEB)

    Ayres, H.J.; Ramos, J.

    1972-10-01

    Well preparation is much more critical for consolidation processes than for most screen or pack applications. Of particular importance are (1) adequate cementing; (2) selectively perforating short intervals with clean perforating fluids; (3) cleaning perforations and face of formation; (4) proper isolation of zones; and (5) packing before consolidation. The desirable characteristics for a consolidation process include (1) minimum preparation time at well site; (2) low injection pressure; (3) short cure time before restoring well to production; (4) high compressive strength of resulting matrix; (5) high retained permeability; and (6) good resistance to deterioration from well fluids and commonly used treating fluids. For a given resin, some compromises are necessary. Methods are now available to control sand in nearly any well. A technique which has been growing in acceptance recently is the placement of sand and resin in a single operation. This service is available with several resins and is usually placed as a pressure pack. A wide variety of consolidation processes is available from a number of service companies. Each process has some advantages and each is probably adequate, if it is suited to the well conditions and good practice has been followed in preparing the well. (21 refs.)

  3. Avalanches of Singing Sand in the Laboratory

    Science.gov (United States)

    Dagois-Bohy, Simon; Courrech Du Pont, Sylvain; Douady, Stéphane

    2011-03-01

    The song of dunes is a natural phenomenon that has arisen travellers' curiosity for a long time, from Marco Polo to R.A. Bagnold. Scientific observations in the XXth century have shown that the sound is emitted during a shear flow of these particular grains, the free surface of the flow having coherent vibrations like a loud speaker. The sound emission is also submitted to a threshold effect with many parameters like humidity, flow speed, surface of the grains. The sound has been reproduced in laboratory avalanche experiments close to the natural phenomenon on field, but set in a channel with a hard bottom and a few centimeters of sand flowing, which contradicts explanations of the sound that involve a sand dune under the avalanche flow. Flow rates measurements also show the presence of a plug region in the flow above the sheared band, with the same characteristic length as the coherence zones of the sound. Finally we show experimentally that the Froude number, once modified to take into account the height of this plug band, is the parameter that sets the amplitude of the sound, and produces a threshold that depends on the grain type.

  4. Microstructural characterization of a Canadian oil sand

    CERN Document Server

    Dinh, Hong Doan; Nauroy, Jean-François; Tang, Anh-Minh; Souhail, Youssef; 10.1139/T2012-072

    2013-01-01

    The microstructure of oil sand samples extracted at a depth of 75 m from the estuarine Middle McMurray formation (Alberta, Canada) has been investigated by using high resolution 3D X-Ray microtomography ($\\mu$CT) and Cryo Scanning Electron Microscopy (CryoSEM). $\\mu$CT images evidenced some dense areas composed of highly angular grains surrounded by fluids that are separated by larger pores full of gas. 3D Image analysis provided in dense areas porosity values compatible with in-situ log data and macroscopic laboratory determinations, showing that they are representative of intact states. $\\mu$CT hence provided some information on the morphology of the cracks and disturbance created by gas expansion. The CryoSEM technique, in which the sample is freeze fractured within the SEM chamber prior to observation, provided pictures in which the (frozen) bitumen clearly appears between the sand grains. No evidence of the existence of a thin connate water layer between grains and the bitumen, frequently mentioned in th...

  5. Histopathological Comparison of Mosquito Net with Polypropylene Mesh for Hernia Repair: An Experimental Study in Rats.

    Science.gov (United States)

    Sharma, Mukesh; Sharma, Deepti Bala; Chandrakar, Shiv Kumar; Sharma, Dhananjaya

    2015-12-01

    Use of mosquito net, in place of polypropylene mesh, had been reported for tension-free hernia repair, as a better cost-effective option. This experimental histopathological study was performed in rats to find out the tissue response and the foreign body reaction and its comparison between commercial polypropylene mesh and the sterilized mosquito net. This experimental study was conducted in the Department of Surgery, Government NSCB, Medical College, Jabalpur (Madhya Pradesh), India. It was carried out in 40 albino rats. A 1.5 × 0.5-cm hernial defect was created by excising full-thickness abdominal wall muscle. All rats underwent on-lay mesh repair of hernial defect (polypropylene mesh, n = 20; mosquito net, n = 20). Half of rats in each group were sacrificed on day 14, and the other half, on day 90. Sections of containing mesh were examined histopathologically for inflammatory infiltrate, giant cells, and collagen deposition. Mosquito net group showed significantly greater number of giant cells and inflammatory cells at 14 and 90 days (p days (p > 0.05 and p > 0.05, respectively). Results of mosquito net are comparable to conventional polypropylene mesh. In a setup, where cost-effectiveness is of primary importance, use of mosquito net for tension-free hernia repair can be an acceptable alternative as proven histologically, to commercially available polypropylene mesh.

  6. Pro visual C++/CLI and the net 35 platform

    CERN Document Server

    Fraser, Stephen

    2008-01-01

    Pro Visual C++/CLI and the .NET 3.5 Platform is about writing .NET applications using C++/CLI. While readers are learning the ins and outs of .NET application development, they will also be learning the syntax of C++, both old and new to .NET. Readers will also gain a good understanding of the .NET architecture. This is truly a .NET book applying C++ as its development language not another C++ syntax book that happens to cover .NET.

  7. Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

    Science.gov (United States)

    Wu, Ziyin; Jin, Xianglong; Zhou, Jieqiong; Zhao, Dineng; Shang, Jihong; Li, Shoujun; Cao, Zhenyi; Liang, Yuyang

    2017-06-01

    Based on multi-beam echo soundings and high-resolution single-channel seismic profiles, linear sand ridges in U14 and U2 on the East China Sea (ECS) shelf are identified and compared in detail. Linear sand ridges in U14 are buried sand ridges, which are 90 m below the seafloor. It is presumed that these buried sand ridges belong to the transgressive systems tract (TST) formed 320-200 ka ago and that their top interface is the maximal flooding surface (MFS). Linear sand ridges in U2 are regressive sand ridges. It is presumed that these buried sand ridges belong to the TST of the last glacial maximum (LGM) and that their top interface is the MFS of the LGM. Four sub-stage sand ridges of U2 are discerned from the high-resolution single-channel seismic profile and four strikes of regressive sand ridges are distinguished from the submarine topographic map based on the multi-beam echo soundings. These multi-stage and multi-strike linear sand ridges are the response of, and evidence for, the evolution of submarine topography with respect to sea-level fluctuations since the LGM. Although the difference in the age of formation between U14 and U2 is 200 ka and their sequences are 90 m apart, the general strikes of the sand ridges are similar. This indicates that the basic configuration of tidal waves on the ECS shelf has been stable for the last 200 ka. A basic evolutionary model of the strata of the ECS shelf is proposed, in which sea-level change is the controlling factor. During the sea-level change of about 100 ka, five to six strata are developed and the sand ridges develop in the TST. A similar story of the evolution of paleo-topography on the ECS shelf has been repeated during the last 300 ka.

  8. Metal biogeochemistry in constructed wetlands based on fluviatile sand and zeolite- and clinopyroxene-dominated lava sand

    OpenAIRE

    Huang, Jen-How; Paul, Sonja; Mayer, Silke; Moradpour, Eloise; Hasselbach, Ralf; Gier?, Reto; Alewell, Christine

    2017-01-01

    For the first time, speciation of Fe, Mn, Zn, Ni, Cu and Pb was determined along the profiles of 8 constructed wetlands (CWs) consisting of fluviatile sand (Fluv), clinopyroxene-dominated lava sand (Cl-LS) and zeolite-dominated lava sand (Ze-LS), aiming at quantifying metal behaviour in CWs and the impact caused by different filter materials. With the exception of Mn, which underwent reductive dissolution, CWs were sinks for the studied metals. Metal accumulation rates differed in the followi...

  9. Lonsdaleite Films with Nanometer Thickness.

    Science.gov (United States)

    Kvashnin, Alexander G; Sorokin, Pavel B

    2014-02-06

    We investigate the properties of potentially the stiffest quasi-2-D films with lonsdaleite structure. Using a combination of ab initio and empirical potential approaches, we analyze the elastic properties of lonsdaleite films in both elastic and inelastic regimes and compare them with graphene and diamond films. We review possible fabrication methods of lonsdaleite films using the pure nanoscale "bottom-up" paradigm: by connecting carbon layers in multilayered graphene. We propose the realization of this method in two ways: by applying direct pressure and by using the recently proposed chemically induced phase transition. For both cases, we construct the phase diagrams depending on temperature, pressure, and film thickness. Finally, we consider the electronic properties of lonsdaleite films and establish the nonlinear dependence of the band gap on the films' thicknesses and their lower effective masses in comparison with bulk crystal.

  10. Minimum thickness anterior porcelain restorations.

    Science.gov (United States)

    Radz, Gary M

    2011-04-01

    Porcelain laminate veneers (PLVs) provide the dentist and the patient with an opportunity to enhance the patient's smile in a minimally to virtually noninvasive manner. Today's PLV demonstrates excellent clinical performance and as materials and techniques have evolved, the PLV has become one of the most predictable, most esthetic, and least invasive modalities of treatment. This article explores the latest porcelain materials and their use in minimum thickness restoration. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Soliton models for thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Peyravi, Marzieh [Ferdowsi University of Mashhad, Department of Physics, School of Sciences, Mashhad (Iran, Islamic Republic of); Riazi, Nematollah [Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Lobo, Francisco S.N. [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal)

    2016-05-15

    In this work, we present new soliton solutions for thick branes in 4+1 dimensions. In particular, we consider brane models based on the sine-Gordon (SG), φ{sup 4} and φ{sup 6} scalar fields, which have broken Z{sub 2} symmetry in some cases and are responsible for supporting and stabilizing the thick branes. The origin of the symmetry breaking in these models resides in the fact that the modified scalar field potential may have non-degenerate vacua. These vacua determine the cosmological constant on both sides of the brane. We also study the geodesic equations along the fifth dimension, in order to explore the particle motion in the neighborhood of the brane. Furthermore, we examine the stability of the thick branes, by determining the sign of the w{sup 2} term in the expansion of the potential for the resulting Schroedinger-like equation, where w is the five-dimensional coordinate. It turns out that the φ{sup 4} brane is stable, while there are unstable modes for certain ranges of the model parameters in the SG and φ{sup 6} branes. (orig.)

  12. Ciliary muscle thickness in anisometropia.

    Science.gov (United States)

    Kuchem, Mallory K; Sinnott, Loraine T; Kao, Chiu-Yen; Bailey, Melissa D

    2013-11-01

    The purpose of this study was to investigate the relationships between ciliary muscle thickness (CMT), refractive error, and axial length both across subjects and between the more and less myopic eyes of adults with anisometropia. Both eyes of 29 adult subjects with at least 1.00 D of anisometropia were measured. Ciliary muscle thickness was measured at the maximum thickness (CMTMAX) and at 1.0 (CMT1), 2.0 (CMT2), and 3.0 mm (CMT3) posterior to the scleral spur, and also at the apical region (Apical CMTMAX = CMTMAX - CMT2, and Apical CMT1 = CMT1 - CMT2). Multilevel regression models were used to determine the relationship between the various CMT measures and cycloplegic refractive error or axial length, and to assess whether there are CMT differences between the more and less myopic eyes of an anisometropic adult. CMTMAX, CMT1, CMT2, and CMT3 were negatively associated with mean refractive error (all p ≤ 0.03), and the strongest association was in the posterior region (CMT2 and CMT3). Apical CMTMAX and Apical CMT1, however, were positively associated with mean refractive error (both p anisometropia, an eye can grow longer and more myopic than its fellow eye without resulting in an increase in CMT.

  13. Thick Corpus Callosum in Children.

    Science.gov (United States)

    Schupper, Aviv; Konen, Osnat; Halevy, Ayelet; Cohen, Rony; Aharoni, Sharon; Shuper, Avinoam

    2017-04-01

    A thick corpus callosum (TCC) can be associated with a very grave outcome in fetuses, but its clinical presentation in older children seems to be markedly different. The corpus callosum (CC) was defined as thick based on observations and impressions. We reviewed cases of children who were diagnosed as TCC based on brain magnetic resonance imaging (MRI) studies. The pertinent clinical data of these children were collected, and their CCs were measured. Out of 2,552 brain MRI images, those of 37 children were initially considered as showing a TCC. Those initial imaging were reviewed by an experienced neuroradiologist, who confirmed the diagnosis in 34 children (1.3%): 13 had neurofibromatosis-1 (NF-1), 9 had epilepsy, 3 had macrocephaly capillary malformation (MCM) syndrome, 3 had autistic spectrum disorder, 1 had a Chiari-1 malformation, and 1 had increased head circumference. No specific neurologic disorder could be defined in seven children. The measured thickness of the CC in these children was comparable to those published in the literature for adults. A TCC is a rare brain malformation that can be found in neuropathologies with apparently diverse pathognomonic mechanisms, such as NF-1 and MCM. It is not necessarily associated with life-threatening conditions, instead being a relatively benign finding, different in nature from that reported in fetuses.

  14. Central corneal thickness in glaucoma.

    Science.gov (United States)

    Sng, Chelvin C A; Ang, Marcus; Barton, Keith

    2017-03-01

    The purpose of this review is to summarize the role of central corneal thickness (CCT) in the clinical management of a glaucoma patient. The prognostic value of CCT is well recognized in patients with ocular hypertension. However, its predictive value in other glaucoma suspects and patients with established glaucoma is less certain. Tonometry artefacts can result from variations in CCT. However, an adequately validated correction algorithm for Goldmann applanation tonometry measurements does not exist. Newer methods of tonometry are potentially less influenced by CCT but are limited in their clinical use. There may also be biological and genetic associations between corneal thickness and glaucoma. Demographics, environmental factors, glaucoma treatment and the measurement device used have a significant influence on CCT, and should be considered when interpreting the effect of cornea thickness in patients with glaucoma. New measurements of the biomechanical properties of the cornea are likely to be better approximations of the globe biomechanics than CCT, but these require further evaluation. The clinical significance of CCT is well recognized in the context of glaucoma diagnosis and management, though the extent of its importance remains debatable. Corneal biomechanical properties may be more significantly associated with glaucoma than CCT.

  15. KONVERGENSI DALAM PROGRAM NET CITIZEN JOURNALISM

    Directory of Open Access Journals (Sweden)

    Rhafidilla Vebrynda

    2017-06-01

    Full Text Available Di dalam artikel ini, peneliti ingin melihat perkembangan teknologi di Indonesia sebagai sebuah peluang untuk menjalankan sebuah program berita berbasis video kiriman masyarakat. Perkembangan teknologi tersebut adalah teknologi penyiaran, teknologi sosial media dan teknologi dalam proses produksi sebuah video. Di Indonesia, jumlah televisi semakin banyak. Setiap stasiun televisi harus bersaing untuk dapat bertahan hidup. Net TV merupakan sebuah stasiun televisi baru di Indonesia yang harus memiliki berbagai program unggulan baru agar dapat bersaing dengan televisi lainnya yang sudah ada. Net TV menggunakan berbagai platform media untuk menjalankan program Net Citizen Journalism (Net CJ. Penggunaan berbagai platform media dikenal dengan istilah multiplatform dan secara teoritis dikenal dengan istilah konvergensi. Konvergensi yaitu saat meleburnya domain-domain dalam berbagai media komunikasi. Artikel ini menggunakan metode studi kasus untuk melihat bagaimana konvergensi terjadi dalam proses pengelolaan program Net CJ. Teknik pengumpulan data adalah dengan wawancara mendalam, observasi dan studi dokumen. Wawancara mendalam dilakukan dari tiga sudut pandang yaitu dari pengelola program, pengguna/audience dan pengamat media. Penelitian ini menemukan bahwa dengan menggunakan berbagai platform media yang fungsinya berbeda, memiliki satu tujuan yang sama yaitu untuk menjalankan program Net CJ. Adapun berbagai platform dalam proses produksi program yaitu tayangan TV konvensional, streaming TV, website, aplikasi Net CJ, facebook, twitter, instagram dan path. Konvergensi media dijalankan dalam dua proses, yaitu proses produksi dan proses promosi program berita.

  16. Net Neutrality: Media Discourses and Public Perception

    Directory of Open Access Journals (Sweden)

    Christine Quail

    2010-01-01

    Full Text Available This paper analyzes media and public discourses surrounding net neutrality, with particular attention to public utility philosophy, from a critical perspective. The article suggests that further public education about net neutrality would be beneficial. The first portion of this paper provides a survey of the existing literature surrounding net neutrality, highlighting the contentious debate between market-based and public interest perspectives. In order to contextualize the debate, an overview of public utility philosophy is provided, shedding light on how the Internet can be conceptualized as a public good. Following this discussion, an analysis of mainstream media is presented, exploring how the media represents the issue of net neutrality and whether or not the Internet is discussed through the lens of public utility. To further examine how the net neutrality debate is being addressed, and to see the potential impacts of media discourses on the general public, the results of a focus group are reported and analyzed. Finally, a discussion assesses the implications of the net neutrality debate as presented through media discourses, highlighting the future of net neutrality as an important policy issue.

  17. Approximation methods for stochastic petri nets

    Science.gov (United States)

    Jungnitz, Hauke Joerg

    1992-01-01

    Stochastic Marked Graphs are a concurrent decision free formalism provided with a powerful synchronization mechanism generalizing conventional Fork Join Queueing Networks. In some particular cases the analysis of the throughput can be done analytically. Otherwise the analysis suffers from the classical state explosion problem. Embedded in the divide and conquer paradigm, approximation techniques are introduced for the analysis of stochastic marked graphs and Macroplace/Macrotransition-nets (MPMT-nets), a new subclass introduced herein. MPMT-nets are a subclass of Petri nets that allow limited choice, concurrency and sharing of resources. The modeling power of MPMT is much larger than that of marked graphs, e.g., MPMT-nets can model manufacturing flow lines with unreliable machines and dataflow graphs where choice and synchronization occur. The basic idea leads to the notion of a cut to split the original net system into two subnets. The cuts lead to two aggregated net systems where one of the subnets is reduced to a single transition. A further reduction leads to a basic skeleton. The generalization of the idea leads to multiple cuts, where single cuts can be applied recursively leading to a hierarchical decomposition. Based on the decomposition, a response time approximation technique for the performance analysis is introduced. Also, delay equivalence, which has previously been introduced in the context of marked graphs by Woodside et al., Marie's method and flow equivalent aggregation are applied to the aggregated net systems. The experimental results show that response time approximation converges quickly and shows reasonable accuracy in most cases. The convergence of Marie's method and flow equivalent aggregation are applied to the aggregated net systems. The experimental results show that response time approximation converges quickly and shows reasonable accuracy in most cases. The convergence of Marie's is slower, but the accuracy is generally better. Delay

  18. Properties of Desert Sand and CMAS Glass

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2014-01-01

    As-received desert sand from a Middle East country has been characterized for its phase composition and thermal stability. X-ray diffraction analysis showed the presence of quartz (SiO2), calcite (CaCO3), gypsum (CaSO4.2H2O), and NaAlSi3O8 phases in as-received desert sand and showed weight loss of approx. 35 percent due to decomposition of CaCO3 and CaSO4.2H2O when heated to 1400 C. A batch of as-received desert sand was melted into calcium magnesium aluminosilicate (CMAS) glass at approx. 1500 C. From inductively coupled plasma-atomic emission spectrometry, chemical composition of the CMAS glass was analyzed to be 27.8CaO-4MgO-5Al2O3-61.6SiO2-0.6Fe2O3-1K2O (mole percent). Various physical, thermal and mechanical properties of the glass have been evaluated. Bulk density of CMAS glass was 2.69 g/cc, Young's modulus 92 GPa, Shear modulus 36 GPa, Poisson's ratio 0.28, dilatometric glass transition temperature (T (sub g)) 706 C, softening point (T (sub d)) 764 C, Vickers microhardness 6.3 +/- 0.4 GPa, indentation fracture toughness 0.75 +/- 0.15 MPa.m (sup 1/2), and coefficient of thermal expansion (CTE) 9.8 x 10 (exp -6)/degC in the temperature range 25 to 700 C. Temperature dependence of viscosity has also been estimated from various reference points of the CMAS glass using the Vogel-Fulcher-Tamman (VFT) equation. The glass remained amorphous after heat treating at 850 C for 10 hr but crystallized into CaSiO3 and Ca-Mg-Al silicate phases at 900 C or higher temperatures. Crystallization kinetics of the CMAS glass has also been investigated by differential thermal analysis (DTA). Activation energies for the crystallization of two different phases in the glass were calculated to be 403 and 483 kJ/mol, respectively.

  19. Visual Studio 2010 and NET 4 Six-in-One

    CERN Document Server

    Novak, Istvan; Granicz, Adam

    2010-01-01

    Complete coverage of all key .NET 4 and Visual Studio 2010 languages and technologies. .NET 4 is Microsoft's latest version of their core programming platform, and Visual Studio 2010 is the toolset that helps write .NET 4 applications. This comprehensive resource offers one-stop shopping for all you need to know to get productive with .NET 4. Experienced author and .NET guru Mitchel Sellers reviews all the important new features of .NET 4, including .NET charting and ASP.NET charting, ASP.NET dynamic data and jQuery, and the addition of F# as a supported package language. The expansive coverag

  20. Cross-shore redistribution of nourished sand near a breaker bar

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen

    2014-01-01

    over the profile is consider as a means of imposing the net recirculation resulting from longshore nonuniformities or the impact of wind-induced shear stresses. The impact of wave height, irregularity in incident waves, and the size of the sediment grains on the cross-shore distribution of suspended......This paper focuses on the optimal location for dumping nourished sand on a barred coastline. This is done by investigating the short-term behavior of the cross-shore redistribution of nourished sediment on a breaker-bar profile in a two-dimensional vertical plane. This is achieved by the use...... of a complete numerical description of the surf-zone processes with respect to both hydrodynamics and sediment transport. The numerical model is based on the finite-volume approach with a free surface-tracking method, also known as the volume of fluid (VOF), and the sediment transport is calculated applying...

  1. Application and Theory of Petri Nets

    DEFF Research Database (Denmark)

    , the conferences have 150-200 participants, one third of these coming from industry and the rest from universities and research institutions. The 1992 conference was organized by the School of Computing and Management Sciences at Sheffield City Polytechnic, England. The volume contains twoinvited papers, by G......This volume contains the proceedings of the 13th International Conference onApplication and Theory of Petri Nets, held in Sheffield, England, in June 1992. The aim of the Petri net conferences is to create a forum for discussing progress in the application and theory of Petri nets. Typically...

  2. Performance Analysis using Coloured Petri Nets

    DEFF Research Database (Denmark)

    Wells, Lisa Marie

    an explicit separation between modelling the behaviour of a system and monitoring the behaviour of the model. As a result, cleaner and more understandable models can be created. The third paper presents a novel method for adding auxiliary information to coloured Petri net models. Coloured Petri nets models...... in a very limited and predictable manner, and it is easy to enable and disable the auxiliary information. The fourth paper is a case study in which the performance of a web server was analysed using coloured Petri nets. This case study has shown that it is relatively easy to analyse the performance...

  3. The KM3NeT project

    Energy Technology Data Exchange (ETDEWEB)

    Katz, U.F., E-mail: katz@physik.uni-erlangen.d [Erlangen Centre for Astroparticle Physics (ECAP), University of Erlangen-Nuernberg, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

    2011-01-21

    The KM3NeT research infrastructure in the deep Mediterranean Sea will host a multi-cubic-kilometre neutrino telescope and provide connectivity for continuous, long-term measurements of earth and sea sciences, such as geology, marine biology and oceanography. The KM3NeT neutrino telescope will complement the IceCube telescope currently being installed at the South Pole in its field of view and surpass its sensitivity by a substantial factor. In this document the major aspects of the KM3NeT technical design are described and the expected physics sensitivity is discussed. Finally, the expected time line towards construction is presented.

  4. The net neutrality debate on Twitter

    Directory of Open Access Journals (Sweden)

    Wolf J. Schünemann

    2015-12-01

    Full Text Available The internet has been seen as a medium that empowers individual political actors in relation to established political elites and media gatekeepers. The present article discusses this “net empowerment hypothesis” and tests it empirically by analysing Twitter communication on the regulation of net neutrality. We extracted 503.839 tweets containing #NetNeutrality posted between January and March 2015 and analysed central developments and the network structure of the debate. The empirical results show that traditional actors from media and politics still maintain a central role.

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

    Indian Academy of Sciences (India)

    The average CIA values in SF and QS coastal dune sands are low relative to the range of the PAAS, suggesting an arid climate and a low intensity of chemical weathering. The SF and QS coastal dune sand samples are plotted in the recycled orogen and partly in craton interior fields suggesting recycled older sedimentary ...

  6. Sand-Laterite Mixtures for Road Construction (A Laboratory ...

    African Journals Online (AJOL)

    The results obtained show that for all types of laterites tested, the addition of sand to laterites has beneficial effects in reducing the liquid limit, the optimum moisture content, the plasticity index, the linear shrinkage and in increasing the maximum dry density and the California Bearing Ratio. There is an optimum sand ...

  7. Pathogen removal using saturated sand colums supplemented with hydrochar

    NARCIS (Netherlands)

    Chung, J.W.

    2015-01-01

    This PhD study has evaluated hydrochars derived from biowastes as adsorbents for pathogen removal in water treatment. Pathogen removal experiments were conducted by carrying out breakthrough analysis using a simple sand filtration set-up. Glass columns packed by 10 cm sand bed supplemented with

  8. Cytotoxicity of yellow sand in lung epithelial cells

    Indian Academy of Sciences (India)

    Unknown

    The Asian dust storms (called as 'yellow sand') bring a large amount of soil particles from the deserts of Mongo- lia and China to East Asia and North America. Yellow sand is a dust-laden air mass, and its effect to the atmos- pheric environment is of large concern in the Asian-. Pacific area including Korea, Japan and China.

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

    African Journals Online (AJOL)

    ISHIOMA

    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.

  10. Effect of Crushed Sandstone Sand on the Properties of High ...

    African Journals Online (AJOL)

    Aggregates are the major constituents in the construction industry. With natural sand and gravel resources being rapidly depleted all over the world, the needs of construction industry will have to be met increasingly from crushed sand as fine aggregates. This paper presents results of the laboratory investigation on high ...

  11. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during...

  12. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

  14. Fine sand in motion: the influence of interstitial air

    NARCIS (Netherlands)

    Homan, T.A.M.

    2013-01-01

    Sand is a granular material, and therefore it consists of individual grains arranged in a packing. The pores in-between the grains are usually filled with a fluid, in this case air. Now, is this interstitial air able to influence the behavior of the sand bed as a whole? When a ball impacts on fine,

  15. Cavity prediction in sand mould production applying the DISAMATIC process

    DEFF Research Database (Denmark)

    Hovad, Emil; Larsen, Per; Spangenberg, Jon

    2017-01-01

    The sand shot in the DISAMATIC process is simulated by the discrete element method (DEM) taking into account the influence and coupling of the airflow with computational fluid dynamics (CFD). The DEM model is calibrated by a ring shear test, a sand pile experiment and a slump test. Subsequently, ...

  16. Modeling the dynamics of offshore tidal sand ridges

    NARCIS (Netherlands)

    Yuan, B.

    2017-01-01

    Tidal sand ridges are large-scale bedforms with horizontal dimensions of several kilometers and heights of tens of meters. They occur in the offshore area of shelf seas that have a wide range of water depths (10-200 m). Based on their present-day behavior, ridges are classified as `active' (sand

  17. Sand-Filtration System For Improving Water Quality For Rural ...

    African Journals Online (AJOL)

    The performance of a pilot sand filtration plant for a small town water supply was monitored over a seven month period to evaluate the physico-chemical and bacteriological quality of the filtered water from a system installed at Assin Praso in the Central Region of Ghana. The sand filter was effective in reducing turbidity by ...

  18. 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.

  19. Journal of EEA, Vol. 30, 2013 SAND SINTERING PROBLEM ON ...

    African Journals Online (AJOL)

    dell

    methods of sand sintering protection on the tin bronze impeller body and internal surfaces. The research ... causes of formation and protection of it [4, 5]. Based on the adhering characteristics of sand grain with ..... including pumps, pipes, taps and impellers .It is because they resist corrosion and impingent effect of water.

  20. Ecology and management of sand shinnery communities: a literature review

    Science.gov (United States)

    Roger Peterson; Chad S. Boyd

    2000-01-01

    Sand shinnery is codominated by oak shrubs and mid and tallgrasses; the grasses are usually taller than the oaks. The shrubs are the small, visible shoots of massive underground stem systems, which are hundreds or thousands of years old. Sand shinnery occupies 5 to 7 M acres in western Oklahoma, western Texas, and southeastern New Mexico. This area is a decrease from...

  1. Coastal Sand Dune Plant Ecology: Field Phenomena and Interpretation

    Science.gov (United States)

    McDonald, K.

    1973-01-01

    Discusses the advantages and disadvantages of selecting coastal sand dunes as the location for field ecology studies. Presents a descriptive zonal model for seaboard sand dune plant communities, suggestions concerning possible observations and activities relevant to interpreting phenomena associated with these forms of vegetation, and additional…

  2. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  3. Assessing environmental impacts of inland sand mining in parts of ...

    African Journals Online (AJOL)

    Other impacts include loss of farmland, depreciation of land value, and destruction of infrastructural facilities. The study concluded that sand mining should be subject to planning and other controls in order to curtail its negative impacts. Keywords: Urbanization, Housing, GIS, Land degradation, Sand mining, Pollution ...

  4. Design, Construction and Testing of a Dry Sand Sieving Machine ...

    African Journals Online (AJOL)

    Michael Horsfall

    www.ajol.info and www.bioline.org.br/ja. Design, Construction and Testing of a Dry Sand Sieving Machine. OLADEJI AKANNI OGUNWOLE. Department of Mechanical Engineering, Federal University of Technology, Minna, Nigeria. ABSTRACT: This paper reports on the design, construction and Testing of a dry sand sieving.

  5. Acetylcholinesterase mutations and organophosphate resistance in sand flies and mosquitoes

    Science.gov (United States)

    The sand fly, Phlebotomus papatasi (Scopoli) is a major vector of Leishamnia major, the principle causative agent of human cutaneous leishmaniasis in the Middle East, southern Europe, northern Africa, and Southern Asia. Sand fly bites and leishmaniasis significantly impacted U.S. military operations...

  6. An Old-Growth Definition for Sand Pine Forests

    Science.gov (United States)

    Kenneth W. Outcalt

    1997-01-01

    Sand pine scrub, Society of American Foresters cover type 69 (Eyre 1980), grows on deep, droughty, infertile sands of marine and aeolian origin. Water and wind formed these features as sea levels fluctuated during past glacial and interglacial periods (Kurz 1942, Laessle 1958, Brooks 1972). Because of washing and sorting during transport and deposition, soil parent...

  7. Provenance Study Of Bituminous Sands In Eastern Dahomey Basin ...

    African Journals Online (AJOL)

    One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian tar sand belt for both quartz variety and heavy mineral analyses. The quartz variety study carried out on 30 samples revealed both polycrystalline and monocrystalline quartz types occurring in all samples but in different ...

  8. Thermal Conductivity of Compacted Bentonite and Bentonite-Sand Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Lee, Jae Owan; Kwon, Sang Ki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-06-15

    For the Kyungju bentonite which is considered as a candidate material for the buffer and backfill in the high-level waste repository, the thermal conductivities of compacted bentonite and a bentonite-sand mixture were measured. The thermal conductivities of the compacted bentonite with a dry density of 1.2 to 1.8 Mg/m{sup 3}and the bentonite-sand mixture with a dry density of 1.6 and 1.8 Mg/m{sup 3} were measured within the gravimetric water content range of 10wt% to 20wt% and the sand fraction range of 10 to 30wt%. The thermal conductivity of compacted bentonite and a bentonite-sand mixture increases with increasing dry density and sand weight fraction in the case of constant water weight fraction, and increases with increasing water weight fraction and sand weight fraction in the case of constant dry density. The empirical correlations to describe the thermal conductivity of compacted bentonite and a bentonite-sand mixture as a function of water fraction at each dry density were suggested. These correlations can predict the thermal conductivities of bentonite and a bentonite-sand mixture with a difference below 10%.

  9. Test Setup for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

    The test setup for testing axially static and cyclic loaded piles in sand is described in the following. The purpose for the tests is to examine the tensile capacity of axially loaded piles in dense fully saturated sand. The pile dimensions are chosen to resemble full scale dimension of piles used...... in offshore pile foundations today....

  10. Constitutive Soil Properties for Unwashed Sand and Kennedy Space Center

    Science.gov (United States)

    Thomas, Michael A.; Chitty, Daniel E.; Gildea, Martin L.; T'Kindt, Casey M.

    2008-01-01

    Accurate soil models are required for numerical simulations of land landings for the Orion Crew Exploration Vehicle. This report provides constitutive material models for one soil, unwashed sand, from NASA Langley's gantry drop test facility and three soils from Kennedy Space Center (KSC). The four soil models are based on mechanical and compressive behavior observed during geotechnical laboratory testing of remolded soil samples. The test specimens were reconstituted to measured in situ density and moisture content. Tests included: triaxial compression, hydrostatic compression, and uniaxial strain. A fit to the triaxial test results defines the strength envelope. Hydrostatic and uniaxial tests define the compressibility. The constitutive properties are presented in the format of LS-DYNA Material Model 5: Soil and Foam. However, the laboratory test data provided can be used to construct other material models. The four soil models are intended to be specific to the soil conditions discussed in the report. The unwashed sand model represents clayey sand at high density. The KSC models represent three distinct coastal sand conditions: low density dry sand, high density in-situ moisture sand, and high density flooded sand. It is possible to approximate other sands with these models, but the results would be unverified without geotechnical tests to confirm similar soil behavior.

  11. Compensation Grouting in Sand : Experiments, Field Experiences and Mechanisms

    NARCIS (Netherlands)

    Bezuijen, A.

    2010-01-01

    This thesis reports on experimental research on compensation grouting in sand. It is investigated in model tests, how the shape of the grout bodies made during injection depends on the grout properties, the density of the sand and the way the tubes are installed. The shape of the grout body affects

  12. Remotely sensed dune sand flux measurements in the dustiest place on Earth (Bodélé, Chad)

    Science.gov (United States)

    Vermeesch, P.

    2009-12-01

    The Bodélé Depression of northern Chad is the dustiest place on Earth, thanks to a unique combination of two factors. First, the Bodélé is located downwind of a narrow gap between the Tibesti and Ennedi mountain ranges, which act as a funnel creating the strong winds of the Bodélé Low Level Jet. Second, the depression forms the deepest part of palaeo-lake Megachad, which once rivaled the Caspian Sea in size. When the lake dried out during the Holocene, it left behind thick deposits of diatomite, which currently provide an abundant and readily available source of dust. Previous work has shown that dust is primarily produced by eddies near the horns of barchan dunes. Using a new remote sensing technique called COSI-Corr, these barchans were shown to be not only the largest, but also the fastest on Earth, featuring the highest sand fluxes. Quantifying sand flux with field measurements is an expensive and time-consuming process. COSI-Corr -which stands for 'Co-registration of Optically Sensed Images and Correlation' and was originally developed for the purpose of detecting surface deformation caused by earthquakes- offers an alternative approach to measuring sand flux, using remote sensing. From pairs of ASTER imagery, dune migration in the Bodélé depression was successfully measured over time intervals of one month to 6.5 years. The displacement maps produced by COSI-Corr can be used to automatically distinguish dunes from interdunes, which is a crucial step towards calculating sand flux. Dune heights and volumes were obtained by interpolating a surface between the interdune areas and subtracting it from a digital elevation model. Multiplying height with celerity yields a pixel-by-pixel estimate of the sand flux. Applying this method to large diatomite dunes in the Bodélé confirms that these are some of the world’s fastest moving barchans. Plotting dune height against inverse celerity reveals sand flux at the dune crest of >200 m3/m/yr. Average dune sand

  13. Effects of oil sands sediments on fish

    Energy Technology Data Exchange (ETDEWEB)

    Parrott, J.; Colavecchia, M.; Hewitt, L.; Sherry, J.; Headley, J. [Environment Canada, Ottawa, ON (Canada); Turcotte, D.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada)

    2010-07-01

    This paper described a collaborative project organized by Natural Resources Canada (NRCan) Panel of Energy Research and Development (PERD) with researchers from Environment Canada and the University of Saskatchewan. The 4-year study was conducted to assess the toxicity of oil sands sediments and river waters, and reclamation ponds and sediments on laboratory-raised fish. Three sediments from rivers were evaluated for their potential to cause adverse impacts on fathead minnow eggs and larvae for a period of 18 days. The study monitored hatching, larval survival, development, and growth. Naphthenic acids (NA), polycyclic aromatic hydrocarbons (PAHs) and metals were measured in the sediments to determine if the compounds can be correlated with observed toxicity. The study will also assess walleye eggs exposed to sediments, and in situ fish exposures. Toxicity identification and evaluation (TIE) studies will be conducted to isolate the fractions that may affect fish development and growth.

  14. Direct Production of Silicones From Sand

    Energy Technology Data Exchange (ETDEWEB)

    Larry N. Lewis; F.J. Schattenmann: J.P. Lemmon

    2001-09-30

    Silicon, in the form of silica and silicates, is the second most abundant element in the earth's crust. However the synthesis of silicones (scheme 1) and almost all organosilicon chemistry is only accessible through elemental silicon. Silicon dioxide (sand or quartz) is converted to chemical-grade elemental silicon in an energy intensive reduction process, a result of the exceptional thermodynamic stability of silica. Then, the silicon is reacted with methyl chloride to give a mixture of methylchlorosilanes catalyzed by cooper containing a variety of tract metals such as tin, zinc etc. The so-called direct process was first discovered at GE in 1940. The methylchlorosilanes are distilled to purify and separate the major reaction components, the most important of which is dimethyldichlorosilane. Polymerization of dimethyldichlorosilane by controlled hydrolysis results in the formation of silicone polymers. Worldwide, the silicones industry produces about 1.3 billion pounds of the basic silicon polymer, polydimethylsiloxane.

  15. The state of oil sands wetland reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Foote, L. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    The state of oil sand and wetlands reclamation was the subject of this presentation. Wildlife habitat and response, plant community and production, and microbial biology were examples of research areas surrounding this body of knowledge. Hydrological research and landscape ecology were discussed along with peatlands and marshes such as the Corvette and the Kia. A few examples of what has been learned in the area of wetlands reclamation was presented. Other topics were also discussed, such as timeframes, pragmatic policy approaches, reclamation costs, research needs and some ideas on maturing the field. It was concluded that environmental conditions change with time and area because of time, chemistry, physics, stoichiometry, as well as biotic mediation and facilitation. figs.

  16. Performance of wetland forbs transplanted into marshes amended with oil sands processed water.

    Science.gov (United States)

    Mollard, Federico P O; Roy, Marie-Claude; Foote, A Lee

    2015-03-01

    Companies mining oil sands in Alberta (Canada) face the challenge of reclaiming wetlands under water use restrictions. Wetland reclamation after mining will generate marshes characterized by elevated salinity and residual hydrocarbons. Oil sands wetlands are also impoverished in forbs, suggesting that their establishment may be constrained by water chemistry. We transplanted skullcap, mint, and smartweed plants into experimental trenches that simulated two possible reclamation scenarios: wetlands amended with on-site freshwater or with oil sands processed water (OSPW). The main scientific question was is OSPW a suitable water amendment as freshwater for reclaiming wetland forb habitat? As a surrogate of plant health, we studied plant ecophysiology (gas exchange, leaf fluorescence), leaf chemistry, and plant growth. Results showed that there were no differences in skullcap mineral contents under either treatment; however, mint and smartweed plants subjected to OSPW had a significantly higher Na content than those under freshwater. Smartweed dark-adapted leaf fluorescence showed a reduced photochemistry in OSPW relative to plants in freshwater. Mint leaves exhibited lower stomatal conductance in OSPW than in freshwater, a condition that negatively affected transpiration and carboxylation. Skullcap plants grown in OSPW had lower net CO2 assimilation rates than those in freshwater but did not show any other ecophysiological difference between treatments. Mint plants experienced growth reductions (i.e., shoot height) in OSPW. Our results show, for the first time in the literature, that plants photosynthetic capacity was negatively affected by OSPW. Conditions in OSPW proved to be suitable for establishment as transplanted forbs showed 100 % survival after the first growing season. However, impaired physiological functions in plants subjected to OSPW indicated that OSPW amendment created a less hospitable habitat for wetland forbs than freshwater.

  17. Petroleum coke adsorption as a water management option for oil sands process-affected water

    Energy Technology Data Exchange (ETDEWEB)

    Zubot, Warren [Syncrude Canada Ltd., Research and Development, Edmonton, Alberta, Canada T6N 1H4 (Canada); MacKinnon, Michael D. [OSPM Solutions Ltd., Hamilton, Ontario, Canada L8H 6X2 (Canada); Chelme-Ayala, Pamela; Smith, Daniel W. [University of Alberta, Department of Civil and Environmental Engineering, Edmonton, Alberta, Canada T6G 2W2 (Canada); Gamal El-Din, Mohamed, E-mail: mgamalel-din@ualberta.ca [University of Alberta, Department of Civil and Environmental Engineering, Edmonton, Alberta, Canada T6G 2W2 (Canada)

    2012-06-15

    Water is integral to both operational and environmental aspects of the oil sands industry. A water treatment option based on the use of petroleum coke (PC), a by-product of bitumen upgrading, was examined as an opportunity to reduce site oil sands process-affected water (OSPW) inventories and net raw water demand. Changes in OSPW quality when treated with PC included increments in pH levels and concentrations of vanadium, molybdenum, and sulphate. Constituents that decreased in concentration after PC adsorption included total acid-extractable organics (TAO), bicarbonate, calcium, barium, magnesium, and strontium. Changes in naphthenic acids (NAs) speciation were observed after PC adsorption. A battery of bioassays was used to measure the OSPW toxicity. The results indicated that untreated OSPW was toxic towards Vibrio fischeri and rainbow trout. However, OSPW treated with PC at appropriate dosages was not acutely toxic towards these test organisms. Removal of TAO was found to be an adsorption process, fitting the Langmuir and Langmuir-Freundlich isotherm models. For TAO concentrations of 60 mg/L, adsorption capacities ranged between 0.1 and 0.46 mg/g. This study demonstrates that freshly produced PC from fluid cokers provides an effective treatment of OSPW in terms of key constituents' removal and toxicity reduction. - Highlights: Black-Right-Pointing-Pointer Treatment of oil sands process-affected water (OSPW) using petroleum coke (PC) adsorption was investigated. Black-Right-Pointing-Pointer PC was effective at adsorbing naphthenic acids with higher cyclicity. Black-Right-Pointing-Pointer OSPW treated with PC at appropriate dosages was not toxic towards Vibrio fisheri and rainbow trout. Black-Right-Pointing-Pointer The adsorption of organic acids fitted the Langmuir and Langmuir-Freundlich isotherm models. Black-Right-Pointing-Pointer PC has the potential to be an effective adsorbent to treat OSPW either directly or as a pretreatment step.

  18. Economic and environmental effects of the FQD on crude oil production from tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; De Buck, A.; Afman, M. [CE Delft, Delft (Netherlands); Van den Berg, J.; Otten, G.J. [Carbon Matters, Den Haag (Netherlands)

    2013-05-15

    The production of unconventional crudes in Canada and Venezuela and exports of these crudes to the EU are investigated. In addition the potential economic and environmental impact of the proposed EU FQD measures (Fuel Quality Directive) on the production of crudes from tar sands and on new tar sand exploration projects are examined. CE Delft has analysed the impact by using a dedicated cost model. For existing projects, the model determines the effect on the basis of marginal production costs. For planned projects the model used the net present value (NPV) of proposed investments. The impacts were determined for a range of crude oil prices and FQD price effects. Combined, for existing and new projects together, the maximum effect would be at a price level at 60 USD/bbl, with savings of up to 19 Mt CO2/y at an FQD price differential of 3 euro/bbl. This overall effect would be substantial and come on top of the total emission reduction effect of the FQD of 60 Mt CO2/y, which will be achieved mostly by the blending of low-carbon fuels and reduced flaring and venting. As part of the reduction of transport greenhouse gas (GHG) emissions, the revised FQD obliges fuel suppliers to reduce these emissions by 6% by 2020 on a well-to-wheel basis. The EU is currently developing a methodology to differentiate fossil fuels on the basis of feedstock and GHG emissions. In the proposal, diesel produced from tar sands, has been given a default emission value of 108.5 gCO2 eq/MJ, while diesel from conventional crude was set at 89.1 gCO2 eq/MJ. The Commission's proposal is currently undergoing an impact assessment and is expected to be resubmitted to the Council later this year (2013)

  19. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C.H.

    1978-10-31

    This edition of the WGSP status report summarizes September 1978 progress of the government-sponsored projects directed towards increasing gas production from the low-permeability gas sands of the western United States. Background information is provided in the September 1977 Status Report, NVO/0655-100. The Williston Basin Symposium was held in Billings, Montana, the 24th through the 27th of September 1978. The USGS continued work on characterization and assessment of the resource in the four primary study areas and completed the 1978 field work in the Sand Wash and Green River Basins. CER Corporation is evaluating a Twin Arrow drill site, located on the Douglas Creek Arch for the possibility of obtaining core, and preparations are being made for the Logging Program meeting to be held at the CER offices the latter part of October, 1978. The design phase for the pressure coring system has been completed and work is progressing on the fabrication and testing of the improved system. The National Laboratories and Energy Technology Centers continued work on mathematical model development, new tools and instrumentation systems, data analysis techniques and rock mechanics. Work continued on the field tests and demonstrations aspect of the WGSP. Bids sent to several service companies by Mitchell Energy Corporation, for a massive fracture treatment, are due back in October and the treatment is expected to be performed in mid-November. Mobil Research and Development fractured Zone 8 of their PCU 31-13 well, then shut it in due to anticipated winter weather and work was started on Zone 9. Sandia's mineback program involved evaluation of the Hole No. 6 Formation Interface Fracture Experiment.

  20. Planning long lasting insecticide treated net campaigns: should households' existing nets be taken into account?

    Science.gov (United States)

    Yukich, Joshua; Bennett, Adam; Keating, Joseph; Yukich, Rudy K; Lynch, Matt; Eisele, Thomas P; Kolaczinski, Kate

    2013-06-14

    Mass distribution of long-lasting insecticide treated bed nets (LLINs) has led to large increases in LLIN coverage in many African countries. As LLIN ownership levels increase, planners of future mass distributions face the challenge of deciding whether to ignore the nets already owned by households or to take these into account and attempt to target individuals or households without nets. Taking existing nets into account would reduce commodity costs but require more sophisticated, and potentially more costly, distribution procedures. The decision may also have implications for the average age of nets in use and therefore on the maintenance of universal LLIN coverage over time. A stochastic simulation model based on the NetCALC algorithm was used to determine the scenarios under which it would be cost saving to take existing nets into account, and the potential effects of doing so on the age profile of LLINs owned. The model accounted for variability in timing of distributions, concomitant use of continuous distribution systems, population growth, sampling error in pre-campaign coverage surveys, variable net 'decay' parameters and other factors including the feasibility and accuracy of identifying existing nets in the field. Results indicate that (i) where pre-campaign coverage is around 40% (of households owning at least 1 LLIN), accounting for existing nets in the campaign will have little effect on the mean age of the net population and (ii) even at pre-campaign coverage levels above 40%, an approach that reduces LLIN distribution requirements by taking existing nets into account may have only a small chance of being cost-saving overall, depending largely on the feasibility of identifying nets in the field. Based on existing literature the epidemiological implications of such a strategy is likely to vary by transmission setting, and the risks of leaving older nets in the field when accounting for existing nets must be considered. Where pre-campaign coverage

  1. Planning long lasting insecticide treated net campaigns: should households’ existing nets be taken into account?

    Science.gov (United States)

    2013-01-01

    Background Mass distribution of long-lasting insecticide treated bed nets (LLINs) has led to large increases in LLIN coverage in many African countries. As LLIN ownership levels increase, planners of future mass distributions face the challenge of deciding whether to ignore the nets already owned by households or to take these into account and attempt to target individuals or households without nets. Taking existing nets into account would reduce commodity costs but require more sophisticated, and potentially more costly, distribution procedures. The decision may also have implications for the average age of nets in use and therefore on the maintenance of universal LLIN coverage over time. Methods A stochastic simulation model based on the NetCALC algorithm was used to determine the scenarios under which it would be cost saving to take existing nets into account, and the potential effects of doing so on the age profile of LLINs owned. The model accounted for variability in timing of distributions, concomitant use of continuous distribution systems, population growth, sampling error in pre-campaign coverage surveys, variable net ‘decay’ parameters and other factors including the feasibility and accuracy of identifying existing nets in the field. Results Results indicate that (i) where pre-campaign coverage is around 40% (of households owning at least 1 LLIN), accounting for existing nets in the campaign will have little effect on the mean age of the net population and (ii) even at pre-campaign coverage levels above 40%, an approach that reduces LLIN distribution requirements by taking existing nets into account may have only a small chance of being cost-saving overall, depending largely on the feasibility of identifying nets in the field. Based on existing literature the epidemiological implications of such a strategy is likely to vary by transmission setting, and the risks of leaving older nets in the field when accounting for existing nets must be considered

  2. A screening study of oil sand tailings technologies and practices : final report

    Energy Technology Data Exchange (ETDEWEB)

    Devenny, D.W.

    2009-05-15

    This report presented the results of a study that examined the potential of alternate technologies to reduce fresh water make-up needs in oil sand extraction and processing, and to facilitate projects qualifying for a timely reclamation certificate. The 5 cases studies that were examined in detail were: (1) a conventional oil sand plant producing fluid tailings, (2) a thickener case capable of producing paste, (3) a consolidated tailings (CT) add-on capable of solidifying fluid tailings, (4) a centrifuge case capable of producing waste that approaches a solid state, and (5) a dry tails case centrifuge treatment followed by the addition of dry swelling clay to provide final drying. The tailings technologies were compared on the basis of physical attributes such as water loss, hot water loss and the volume of waste. They were also compared with respect to how well they prepare a project for closure. The cost differences between the technologies were also appraised, particularly life cycle costs in terms of the net present value of the unit cost to process one cubic metre of average ore. The economic analysis showed that centrifuge technology is the preferred technology. 72 refs., 9 tabs., 20 figs.

  3. Proceedings of the 7. annual Athabasca oil sands conference : oil sands trade show and conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The Athabasca Oil Sands Projects are considered a major source energy supply for North America, which means increased commitments from producing companies to improve environmental impact and enhance the technology used for extraction and refining. This annual conference, which was hosted by the world's leading group of experts in the unconventional oil industry, provided a venue to network, do business and discover new strategies and innovations for the industry. The presentations highlighted thermal recovery methods, transportation infrastructure, and government policies designed to ensure project success. The four sessions of the conference were entitled: the oil sands landscape, technology advances; project updates; and, research and development. The conference featured 12 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs.

  4. Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 1

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2016-03-01

    Full Text Available In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating.

  5. Laboratory Test Setup for Cyclic Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2017-01-01

    This paper presents a comprehensive description and the considerations regarding the design of a new laboratory test setup for testing cyclic axially loaded piles in sand. The test setup aims at analysing the effect of axial one-way cyclic loading on pile capacity and accumulated displacements....... Another aim was to test a large diameter pile segment with dimensions resembling full-scale piles to model the interface properties between pile and sand correctly. The pile segment was an open-ended steel pipe pile with a diameter of 0.5 m and a length of 1 m. The sand conditions resembled the dense sand...... determined from the API RP 2GEO standard and from the test results indicated over consolidation of the sand. Two initial one-way cyclic loading tests provided results of effects on pile capacity and accumulated displacements in agreement with other researchers’ test results....

  6. Compressive Strength of Compacted Clay-Sand Mixes

    Directory of Open Access Journals (Sweden)

    Faseel Suleman Khan

    2014-01-01

    Full Text Available The use of sand to improve the strength of natural clays provides a viable alternative for civil infrastructure construction involving earthwork. The main objective of this note was to investigate the compressive strength of compacted clay-sand mixes. A natural clay of high plasticity was mixed with 20% and 40% sand (SP and their compaction and strength properties were determined. Results indicated that the investigated materials exhibited a brittle behaviour on the dry side of optimum and a ductile behaviour on the wet side of optimum. For each material, the compressive strength increased with an increase in density following a power law function. Conversely, the compressive strength increased with decreasing water content of the material following a similar function. Finally, the compressive strength decreased with an increase in sand content because of increased material heterogeneity and loss of sand grains from the sides during shearing.

  7. Traceability of optical length measurements on sand surfaces

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    This work concerns traceable measurements on moulds used in automatic casting lines made of green sand, which has a very low strength against the force of a contact probe. A metrological set-up was made based on the use of calibrated workpieces following ISO 15530-3 to determine the uncertainty...... of optical measurements on a sand surface. A new customised sand sample was developed using a hard binder to withstand the contact force of a touch probe, while keeping optical cooperativeness similar to that of green sand. The length of the sample was calibrated using a dial gauge set-up. An optical 3D...... scanner with fringe pattern projection was used to measure the length of a green sand sample (soft sample) with traceability transfer through the hard sample. Results confirm that the uncertainty of the optical scanner on the substituted hard sample is similar to that of the soft sample, so the hard...

  8. Thermal aspects of temperature transformations in silica sand

    Directory of Open Access Journals (Sweden)

    J.St. Kowalski

    2010-07-01

    Full Text Available Problems related with the choice of moulding sand composition considering its behaviour in contact with molten metal were discussed.The investigations of high-temperature phenomena enable moulding sand composition to be evaluated in terms of its applicability underthe specific conditions of a foundry shop. It is also possible to eliminate the casting defects related to moulding sand and its properties. The investigations were carried out on selected moulding sands from the family of the traditional carbon-free moulding mixtures. The effect of moulding sand composition and moisture content on the linear dilatation and stress formation caused by an allotropic quartz transformation was determined. The investigated phenomena were analysed on 3D diagrams plotted from the test data. A strong effect of the beta quartz - alpha quartz transformation at a temperature of about 6000C was stated.

  9. The effects of psammophilous plants on sand dune dynamics

    CERN Document Server

    Bel, Golan

    2013-01-01

    Psammophilous plants are special plants that flourish in sand moving environments. There are two main mechanisms by which the wind affects these plants: (i) sand drift exposes roots and covers branches--the exposed roots turn into new plants and the covered branches turn into new roots; both mechanisms result in an enhanced growth rate of the psammophilous plant cover of the dunes; (ii) strong winds, often associated with sand movement, tear branches and seed them in nearby locations, resulting in new plants and an enhanced growth rate of the psammophilous plant cover of the dunes. Despite their important role in dune dynamics, to our knowledge, psammophilous plants have never been incorporated into mathematical models of sand dunes. Here, we attempt to model the effects of these plants on sand dune dynamics. We construct a set of three ordinary differential equations for the fractions of surface cover of regular vegetation, biogenic soil crust and psammophilous plants. The latter reach their optimal growth u...

  10. Broadband Scattering from Sand and Sand/Mud Sediments with Extensive Environmental Characterization

    Science.gov (United States)

    2017-01-30

    Bryant, and G. Fechner, “Acoustic backscatter and sediment textural properties of inner shelf sands, northeastern Gulf of Mexico,” Geo -Mar. Lett., vol...comparisons using sediment fluid and Biot models,” IEEE J. Ocean. Eng., vol. 27, no. 3, pp. 376–387, 2002. [10] C.-C. Wang and D. Tang, “Seafloor Roughness...consequence of the scattering effects mentioned in the previous section. A similar negative dispersion has been observed in fluid -saturated glass

  11. RadNet Air Quality (Deployable) Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet Deployable Monitoring is designed to collect radiological and meteorological information and data asset needed to establish the impact of radiation levels on...

  12. A Lightweight TwiddleNet Portal

    National Research Council Canada - National Science Library

    Rimikis, Antonios M

    2008-01-01

    TwiddleNet is a distributed architecture of personal servers that harnesses the power of the mobile devices, enabling real time information and file sharing of multiple data types from commercial-off-the-shelf platforms...

  13. Homology Groups of a Pipeline Petri Net

    Directory of Open Access Journals (Sweden)

    A. A. Husainov

    2013-01-01

    Full Text Available Petri net is said to be elementary if every place can contain no more than one token. In this paper, it is studied topological properties of the elementary Petri net for a pipeline consisting of n functional devices. If the work of the functional devices is considered continuous, we can come to some topological space of “intermediate” states. In the paper, it is calculated the homology groups of this topological space. By induction on n, using the Addition Sequence for homology groups of semicubical sets, it is proved that in dimension 0 and 1 the integer homology groups of these nets are equal to the group of integers, and in the remaining dimensions are zero. Directed homology groups are studied. A connection of these groups with deadlocks and newsletters is found. This helps to prove that all directed homology groups of the pipeline elementary Petri nets are zeroth.

  14. Looking through a dirty glass: how different can the characterization of a fish fauna be when distinct nets are used for sampling?

    Directory of Open Access Journals (Sweden)

    Gianfranco Ceni

    2013-10-01

    Full Text Available The present study compares fish species composition, dominance, and size-structure patterns at an open sand beach area (32°15'S, 52°46'W in Mirim Lake, RS, Brazil, estimated from samples collected with two distinct beach seine nets. The BS-9m net is 9 m long and 1.5 m high, and is made with a 5 mm multifilament mesh on its central portion and 12 mm on the side wings. The BS-30m net is 30 m long and 1.8 m high, with a 12 mm monofilament nylon mesh all over the net, except for a 30 cm strip made with a 12 mm multifilament mesh on the lower portion. Thirty hauls were performed with both nets resulting in a total of 849 fish captured, comprising 34 species. BS-9m was selective for individuals smaller than 60 mm TL and BS-30m for individuals larger than 60 mm TL. Low values of the faunal similarity (JI = 0.41, ANOSIM R = 0.2309, p < 0.0001 and numeric dominance (PSI = 0.46 indexes were revealed. We suggest that the concurrent use of both samplers provide a better description of the fish fauna of shallow areas. However, due to their robustness, rusticity, and ease of use and maintenance, small multifilament seines are indicated for regular work in environments without obstacles and with little open sand area available for sampling.

  15. Sedimentary Characteristics of Buried Sand Layers Deposited in a Coastal Swamp in West Aceh, Indonesia, in the Early 15th Century

    Science.gov (United States)

    Morgan, T.; Monecke, K.; Meilianda, E.; Pilarczyk, J.; Rusydy, I.; Moena, A.; Muzhaffat, H.; Rais, A.; Yolanda, I. P.

    2016-12-01

    Sediment cores from the coastal region of West Aceh, Indonesia, an area largely affected by the December 2004 Sumatra Andaman earthquake and resulting Indian Ocean tsunami, preserve evidence of two buried sand layers of possible tsunamigenic origin deposited in the early 15th century. The study site is dominated by beach ridge morphology with an alternation of beach ridges and swales characteristic of long-term coastal progradation. We targeted a low-lying area landward of a prominent beach ridge that is thought to have formed in the aftermath of the last predecessor of the 2004 event, and marks the position of the coastline in the late 14th and early 15th century. Using a hand auger and plastic tubes, 80 core samples up to 2.5 m in depth were recovered. Sand samples were analyzed using a laser diffraction particle size analyzer and prepared for microfossil analysis. The swale deposits are mostly composed of peat and overlie shallow marine sands forming the base of the beach ridge plain. Within the uppermost centimeters, a number of cores show a tsunami inundation in 2004. Intercalated within the peat deposits we found two buried sand layers at a depth of 70-100 cm below the surface. The lower sand layer is 1-6 cm thick and could only be traced in a handful of cores; the upper layer is more widespread and consistently thicker, measuring 11-17 cm, with 5-14 cm of peat in between the two sand sheets. The sand layers consist of massive to normally graded fine to medium sand and show sharp upper and lower boundaries indicating abrupt depositional events. Grain size distributions of the 2004 tsunami sand as well as of buried sand layers match shoreface sediment samples retrieved in 10 m water depth, suggesting a predominantly offshore source. Based on initial radiocarbon ages and estimates of sedimentation rates, the two buried sand layers were deposited in the early 15th century and are separated by only a few decades.

  16. Microbes in Beach Sands: Integrating Environment, Ecology and Public Health

    Science.gov (United States)

    Whitman, Richard; Harwood, Valerie J.; Edge, Thomas A.; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael J.; Alm, Elizabeth Wheeler; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, Helena M.

    2014-01-01

    SUMMARY Beach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future

  17. 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

  18. Microbes in Beach Sands: Integrating Environment, Ecology and Public Health.

    Science.gov (United States)

    Whitman, Richard; Harwood, Valerie J; Edge, Thomas A; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael J; Alm, Elizabeth Wheeler; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, Helena M

    2014-09-01

    Beach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future work in

  19. Net accumulation of the Greenland ice sheet

    DEFF Research Database (Denmark)

    Kiilsholm, Sissi; Christensen, Jens Hesselbjerg; Dethloff, Klaus

    2003-01-01

    improvement compared to the driving OAGCM. Estimates of the regional net balance are also better represented by the RCM. In the future climate the net balance for the Greenland Ice Sheet is reduced in all the simulation, but discrepancies between the amounts when based on ECHAM4/OPYC3 and HIRHAM are found....... In both scenarios, the estimated melt rates are larger in HIRHAM than in the driving model....

  20. CDMA and TDMA based neural nets.

    Science.gov (United States)

    Herrero, J C

    2001-06-01

    CDMA and TDMA telecommunication techniques were established long time ago, but they have acquired a renewed presence due to the rapidly increasing mobile phones demand. In this paper, we are going to see they are suitable for neural nets, if we leave the concept "connection" between processing units and we adopt the concept "messages" exchanged between them. This may open the door to neural nets with a higher number of processing units and flexible configuration.

  1. Mastering AngularJD for .NET developers

    CERN Document Server

    Majid, Mohammad Wadood

    2015-01-01

    This book is envisioned for traditional developers and programmers who want to develop client-side applications using the AngularJS framework and ASP.NET Web API 2 with Visual Studio. .NET developers who have already built web applications or web services and who have a fundamental knowledge of HTML, JavaScript, and CSS and want to explore single-page applications will also find this guide useful. Basic knowledge of AngularJS would be helpful.

  2. .NET 4.5 parallel extensions

    CERN Document Server

    Freeman, Bryan

    2013-01-01

    This book contains practical recipes on everything you will need to create task-based parallel programs using C#, .NET 4.5, and Visual Studio. The book is packed with illustrated code examples to create scalable programs.This book is intended to help experienced C# developers write applications that leverage the power of modern multicore processors. It provides the necessary knowledge for an experienced C# developer to work with .NET parallelism APIs. Previous experience of writing multithreaded applications is not necessary.

  3. A Lightweight TwiddleNet Portal

    Science.gov (United States)

    2008-03-01

    designed to exploit the multiple networking modalities available in the current generation of smartphones . TwiddleNet enables well-organized and well...of Sonopia and will have a comprehensive review of the service in the coming weeks [12]. Twango, which was acquired by Nokia in July 2007, is an...EXPERIMENTATION As already mentioned the main purpose of this thesis is the development of a TwiddleNet portal running on a smartphone or a PDA, which can allow

  4. CCS - and its relationship to net theory

    DEFF Research Database (Denmark)

    Nielsen, Mogens

    1987-01-01

    In this paper we give a short introduction to Milner's Calculus for Communicating Systems - a paradigm for concurrent computation. We put special emphasis on the basic concepts and tools from the underlying "algebraic approach", and their relationship to the approach to concurrency within net...... theory. Furthermore, we provide an operational version of the language CCS with "true concurrency" in the sense of net theory, and a discussion of the possible use of such a marriage of the two theories of concurrency....

  5. The fluctuation property of blown sand particles and the wind-sand flow evolution studied by numerical method.

    Science.gov (United States)

    Ma, G S; Zheng, X J

    2011-05-01

    Sand particles blown by wind cause serious environmental problems and many researchers are trying to understand the dynamic properties of blown sand better. But the existing numerical approaches have not been able to simulate many important characteristics of wind-sand flow. In this paper, the evolution and fluctuation properties of blown sand at a dynamic steady state are investigated by using a more effective method. Using the LES (large eddy simulation) method for air phase movement and the DEM (discrete element method) for solid phase movement along with the existing particle-bed splashing function, we have characterized the whole movement property of the wind-sand system. The results indicate that the saturation time decreases with the inlet friction velocity, and it gradually reaches the shortest saturation time of about 1s; the saturation length, which is about 14 m at the usual wind velocity, first increases with wind velocity and then reaches a plateau; within the saturation length, the sand transport rate at different positions varies with time; the sand transport rate of the stable wind-sand flow is non-uniform with distance downwind and time, and has a notable correlation with the inflow friction velocity.

  6. Visual Studio 2013 and .NET 4.5 expert cookbook

    CERN Document Server

    Sur, Abhishek

    2014-01-01

    If you are a Visual Studio 2013 or .NET developer who would like to sharpen your existing skill set and adapt to new .NET technologies, this is the book for you. A basic understanding of .NET and C# is required.

  7. HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the Human Appropriation of Net Primary Productivity (HANPP) Collection maps the net amount of solar...

  8. The Geodiversity in Drift Sand Landscapes of The Netherlands

    Science.gov (United States)

    van den Ancker, Hanneke; Jungerius, Pieter Dirk; Riksen, Michel

    2015-04-01

    The authors carried out detailed field studies of more than twelve drift sand landscapes in The Netherlands. The objective of these studies was to restore Natura-2000 values by restoring the wind activity. Active drift sands occur almost exclusively in The Netherlands, Natura 2000 habitat 2330 'Inland dunes with open Corynephorus and Agrostis grasslands', for which reason our country is largely responsible for this European landscape. Active drift sands had almost disappeared for two reasons: first, the stabilization of the drift sands by air pollution, mainly nitrogen, which stimulates the growth of algae and grasses that initiate soil formation, and second, by the growth of forests surrounding the sands, which decreases the wind force. The restoration studies revealed differences in the geodiversity between and within the drift sand areas. Whereas the drift sands on geological and soil maps show as almost homogenous areas, they have in fact highly variable geo-conditions of which examples will be given. These geodiversity aspects concern differences in geomorphological structure, origin, sediments and age of the drift sands. Differences in wind and water erosion, trampling and soil formation add to the geodiversity within the drift sand areas. Especially in the primary stages of succession the differences in geodiversity are relevant for the Natura-2000 values. We discerned three main types of active sands. Firstly, the impressive drift sands with large parabolic dune structures, often consisting of series of interlocking parabolic dunes. They developed from the northeast towards the southwest, against the direction of the dominant wind, and must have taken centuries to develop. Small parts of these systems are still active, other parts show different degrees of soil formation. Their origin is still unclear but probably dates from medieval times (Heidinga, 1985, Jungerius & Riksen, 2008). Second are the drift sand areas with irregular hills from 0.5 to about 2

  9. Recurrence after gallbladder-preserving cholecystolithotomy for sand-like and non-sand-like gallstones: a comparative analysis

    Directory of Open Access Journals (Sweden)

    CHEN Zhi

    2016-07-01

    Full Text Available ObjectiveTo investigate the recurrence at 1-3 years after laparoscopic cholecystolithotomy in patients with sand-like and non-sand-like gallstones. MethodsA retrospective analysis was performed for the clinical data of 155 patients with gallstones who underwent gallbladder-preserving cholecystolithotomy in Air Force General Hospital, PLA from October 2012 to December 2014, and these patients were divided into sand-like stone group (29 patients and non-sand-like stone group (126 patients. The recurrence of stones was observed at 1-3 years after surgery. The t-test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. ResultsThe time of operation showed a significant difference between the sand-like stone group and the non-sand-like stone group (126.13±20.52 min vs 75.64±16.58 min, t=7.709, P<0.001. At 1-3 years after surgery, 6 patients in the sand-like stone group and 8 in the non-sand-like stone group experienced recurrence, and the 2- and 3-year recurrence rates showed significant differences between the two groups (2-year recurrence rate: 20.69% vs 6.35%, χ2=4.284, P=0.038; 3-year recurrence rate: 20.69% vs 6.35%, χ2=4.284, P=0.038. ConclusionThe patients with sand-like gallstones have a significantly higher recurrence rate and a significantly longer time of operation than those with non-sand-like gallstones, and therefore, they should avoid gallbladder-preserving cholecystolithotomy.

  10. ASP.NET web API build RESTful web applications and services on the .NET framework

    CERN Document Server

    Kanjilal, Joydip

    2013-01-01

    This book is a step-by-step, practical tutorial with a simple approach to help you build RESTful web applications and services on the .NET framework quickly and efficiently.This book is for ASP.NET web developers who want to explore REST-based services with C# 5. This book contains many real-world code examples with explanations whenever necessary. Some experience with C# and ASP.NET 4 is expected.

  11. Freeze-out conditions from net-proton and net-charge fluctuations at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alba, Paolo; Alberico, Wanda [Department of Physics, Torino University and INFN, Sezione di Torino, via P. Giuria 1, 10125 Torino (Italy); Bellwied, Rene [Department of Physics, University of Houston, Houston, TX 77204 (United States); Bluhm, Marcus [Department of Physics, Torino University and INFN, Sezione di Torino, via P. Giuria 1, 10125 Torino (Italy); Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Mantovani Sarti, Valentina [Department of Physics, Torino University and INFN, Sezione di Torino, via P. Giuria 1, 10125 Torino (Italy); Nahrgang, Marlene [Department of Physics, Duke University, Durham, NC 27708-0305 (United States); Frankfurt Institute for Advanced Studies (FIAS), Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Ratti, Claudia [Department of Physics, Torino University and INFN, Sezione di Torino, via P. Giuria 1, 10125 Torino (Italy)

    2014-11-10

    We calculate ratios of higher-order susceptibilities quantifying fluctuations in the number of net-protons and in the net-electric charge using the Hadron Resonance Gas (HRG) model. We take into account the effect of resonance decays, the kinematic acceptance cuts in rapidity, pseudo-rapidity and transverse momentum used in the experimental analysis, as well as a randomization of the isospin of nucleons in the hadronic phase. By comparing these results to the latest experimental data from the STAR Collaboration, we determine the freeze-out conditions from net-electric charge and net-proton distributions and discuss their consistency.

  12. 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

    cement holding the grains together (typical porosity being around 30%). Microscope analysis shows that this material contains mostly angular to sub-angular quartz grains, some with undulose extinction under cross-polarised light. This suggests a metamorphic origin for the quartz. There are also some relatively rare rock fragments present. These silver sands are a mixture of fine to medium grain sizes (0.10 to 0.5 mm) with small proportions of finer and coarser grades and are in the order of 30 - 36 metres thick at Reigate. These beds show lateral and vertical variability in their grain size, mineralogy and geochemical make up such as iron oxide content and are heavily faulted in places. In view of these radon results, in order to determine whether these levels are supported or unsupported, samples were collected and subjected to laboratory-based Gamma spectrometry. This indicated the presence of U235 (186keV) and Pb212 (238keV) in sands from these caves. We will shortly be in a position to also report in-situ gamma spectrometry and ICPMS analysis of samples taken from these beds.

  13. Sediment Analysis Network for Decision Support (SANDS)

    Science.gov (United States)

    Hardin, D. M.; Keiser, K.; Graves, S. J.; Conover, H.; Ebersole, S.

    2009-12-01

    Since the year 2000, Eastern Louisiana, coastal Mississippi, Alabama, and the western Florida panhandle have been affected by 28 tropical storms, seven of which were hurricanes. These tropical cyclones have significantly altered normal coastal processes and characteristics in the Gulf region through sediment disturbance. Although tides, seasonality, and agricultural development influence suspended sediment and sediment deposition over periods of time, tropical storm activity has the capability of moving the largest sediment loads in the shortest periods of time for coastal areas. The importance of sediments upon water quality, coastal erosion, habitats and nutrients has made their study and monitoring vital to decision makers in the region. Currently agencies such as United States Army Corps of Engineers (USACE), NASA, and Geological Survey of Alabama (GSA) are employing a variety of in-situ and airborne based measurements to assess and monitor sediment loading and deposition. These methods provide highly accurate information but are limited in geographic range, are not continuous over a region and, in the case of airborne LIDAR are expensive and do not recur on a regular basis. Multi-temporal and multi-spectral satellite imagery that shows tropical-storm-induced suspended sediment and storm-surge sediment deposits can provide decision makers with immediate and long-term information about the impacts of tropical storms and hurricanes. It can also be valuable for those conducting research and for projects related to coastal issues such as recovery, planning, management, and mitigation. The recently awarded Sediment Analysis Network for Decision Support will generate decision support products using NASA satellite observations from MODIS, Landsat and SeaWiFS instruments to support resource management, planning, and decision making activities in the Gulf of Mexico. Specifically, SANDS will generate decision support products that address the impacts of tropical storms

  14. The technique of sand control with expandable screens

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, P. [Petrochina, Liaohe (China). Liaohe Oilfield Co.

    2009-07-01

    Sand production in heavy oil reservoirs can limit the normal production of oil wells. In this study, expandable screens were used as a sand control mechanism by filtering the sand as it entered the wellbore. The screen systems consists of an expandable outer housing, an expandable base pipe and a filtering layer. The screen expands radially through an expandable cone and presses into the casing well. Axial tension is used to shrink the screens radially through a fishing anchor in order to remove them from the well. The lack of a sand ring between the screen and the casing increases the flow area of the oil and reduces flow resistance caused by fine silt blockages. A series of laboratory experiments were conducted to study the expansion and shrinkage properties of the screens. A field test conducted at a well located in the Liaohe oilfield in China demonstrated that good sand control results can be obtained without the need for pump checking. It was concluded that the sand control method is easy to use and provides good sand control results in large open flow areas. 2 refs., 2 tabs., 3 figs.

  15. Evaluation of wettability of binders used in moulding sands

    Directory of Open Access Journals (Sweden)

    Hutera B.

    2007-01-01

    Full Text Available Binders used in moulding sand have the differential properties. One of the main parameters influencing on moulding sand properties is wettability of the sand grain by binding material. In the article some problems concerned with wettability evaluation have been presented and the importance of this parameter for quantity description of process occurring in system: binder- sand grain has been mentioned. The procedure of wetting angle measurement and operation of prototype apparatus for wettability investigation of different binders used in moulding sand have been described, as well as the results of wetting angle measurement for different binders at different conditions. The addition of little amount of proper diluent to binder results in the state of equilibrium reached almost immediately. Such addition can also reduce the value of equilibrium contact angle. The uniform distribution of binder on the surface of the sand grains and reducing of the required mixing time can be obtained. It has also a positive effect on the moulding sand strength.

  16. Interaction Between Graphene Oxide Nanoparticles and Quartz Sand.

    Science.gov (United States)

    Sotirelis, Nikolaos P; Chrysikopoulos, Constantinos V

    2015-11-17

    In this study, the influence of pH, ionic strength (IS), and temperature on graphene oxide (GO) nanoparticles attachment onto quartz sand were investigated. Batch experiments were conducted at three controlled temperatures (4, 12, and 25 °C) in solutions with different pH values (pH 4, 7, and 10), and ionic strengths (IS = 1.4, 6.4, and 21.4 mM), under static and dynamic conditions. The surface properties of GO nanoparticles and quartz sand were evaluated by electrophoretic mobility measurements. Derjaguin-Landau-Verwey-Overbeek (DLVO) potential energy profiles were constructed for the experimental conditions, using measured zeta potentials. The experimental results showed that GO nanoparticles were very stable under the experimental conditions. Both temperature and pH did not play a significant role in the attachment of GO nanoparticles onto quartz sand. In contrast, IS was shown to influence attachment. The attachment of GO particles onto quartz sand increased significantly with increasing IS. The experimental data were fitted nicely with a Freundlich isotherm, and the attachment kinetics were satisfactorily described with a pseudo-second-order model, which implies that the quartz sand exhibited substantial surface heterogeneity and that GO retention was governed by chemisorption. Furthermore, thermodynamic analysis revealed that the attachment process was nonspontaneous and endothermic, which may be associated with structural changes of the sand surfaces due to chemisorption. Therefore, secondary minimum interaction may not be the dominant mechanism for GO attachment onto the quartz sand under the experimental conditions.

  17. Casting Ductile Iron in Layer Moulds Made from Ecological Sands

    Directory of Open Access Journals (Sweden)

    M. Rączka

    2012-09-01

    Full Text Available The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica.The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined witheffective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder.A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The castiron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.

  18. Modest net autotrophy in the oligotrophic ocean

    Science.gov (United States)

    Letscher, Robert T.; Moore, J. Keith

    2017-04-01

    The metabolic state of the oligotrophic subtropical ocean has long been debated. Net community production (NCP) represents the balance of autotrophic carbon fixation with heterotrophic respiration. Many in vitro NCP estimates based on oxygen incubation methods and the corresponding scaling relationships used to predict the ecosystem metabolic balance have suggested the ocean gyres to be net heterotrophic; however, all in situ NCP methods find net autotrophy. Reconciling net heterotrophy requires significant allochthonous inputs of organic carbon to the oligotrophic gyres to sustain a preponderance of respiration over in situ production. Here we use the first global ecosystem-ocean circulation model that contains representation of the three allochthonous carbon sources to the open ocean, to show that the five oligotrophic gyres exhibit modest net autotrophy throughout the seasonal cycle. Annually integrated rates of NCP vary in the range 1.5-2.2 mol O2 m-2 yr-1 across the five gyre systems; however, seasonal NCP rates are as low as 1 ± 0.5 mmol O2 m-2 d-1 for the North Atlantic. Volumetric NCP rates are heterotrophic below the 10% light level; however, they become net autotrophic when integrated over the euphotic zone. Observational uncertainties when measuring these modest autotrophic NCP rates as well as the metabolic diversity encountered across space and time complicate the scaling up of in vitro measurements to the ecosystem scale and may partially explain the previous reports of net heterotrophy. The oligotrophic ocean is autotrophic at present; however, it could shift toward seasonal heterotrophy in the future as rising temperatures stimulate respiration.

  19. Influence of molding sand on the number of grains graphite and on the rate of thin ferrite in pieces in a nodular iron ferritic matrix

    Directory of Open Access Journals (Sweden)

    B. Khatemi

    2010-07-01

    Full Text Available The nodular cast irons are characterized by high mechanical properties compared to cast iron with lamellar graphite or vermiculargraphite. The ductile iron has already been the subject of many studies especially since the literature is rich on them, and sources of information are different. The fact is that the mechanical properties of nodular cast iron (FGS depend on the number of graphitegrains, their roundness, the solidification rate and nature of the matrix [3]. Many studies of nodular cast irons showed that the morespherical particles of graphite, the higher the mechanical properties are high. In gray cast irons, the graphite spheroids have anticrackingand give the ductile iron ductility. Note in this connection that the higher the number of graphite grains, the higher theductile iron has better mechanical properties. In cast iron, the nature of the matrix is depending on several parameters including thecooling rate of molten metal, the thickness, shape and dimensions of parts. The faster cooling is slow over rate of ferrite is important[3, 4]. In this paper, we tested three types of sand casting: sand –based sodium silicate, furan resin and green sand on samplesspherical graphite cast iron of different thickness. The objective in this article is to determine the number of grains of graphite andferrite for each type of sand casting under the same experimental conditions including the cooling rate and chemical composition ofthe liquid metal.

  20. Research and practice of the impulse sand fracturing technology

    Directory of Open Access Journals (Sweden)

    Bin Qian

    2015-10-01

    Full Text Available With the deep development of tight sand gas reservoirs, problems such as short stable production period and quick production decline of gas wells after fracturing have become increasingly prominent. Consequently, there is an increasing demand for the effective penetration and conductivity of artificial fractures. Impulse sand fracturing technology introduces a concept of discrete multilayer sanding inside fractures; joint application of pulse blender which can be switched at high frequency, intensive multi-cluster perforation and special fibrous material made it possible to ensure the flow stability of proppant slug, and placement of nonuniformly-laid sand pinnacles and grooves, which markedly upgraded the capacity of the fracture conductivity to several orders of magnitude more than the conventional method. Laboratory engineering simulation evaluation and field test show that pre-fracturing reservoir evaluation, pulse time design and the optimization of degradable fiber and support equipment are the keys to the success of impulse sand fracturing. Compared with the conventional fracturing, this technique can effectively increase well production, decrease the volume of fracturing proppant, and lower sand plugging risks. An independent sand fracturing pilot test has been conducted in 6 layers of 3 wells for the first time in Block Tao 7 of the Sulige Gasfield, Ordos Basin, as a result, the average volume of fracturing proppant dropped by 28.3%, the average sand intensity dropped by 21.88%, and the post-fracturing average daily gas output increased by 26.8%. This technology provides an efficient and environmentally friendly reservoir stimulation option for tight sand gas reservoirs in China.