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Sample records for sand ridge ii

  1. Sediment mathematical model for sand ridges and sand waves

    Institute of Scientific and Technical Information of China (English)

    LI Daming; WANG Xiao; WANG Xin; LI Yangyang

    2016-01-01

    A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides, waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.

  2. 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

    2016-07-01

    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.

  3. 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.

  4. 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

  5. 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

  6. Linear sand ridges on the outer shelf of the East China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Ziyin; JIN Xianglong; LI Jiabiao; ZHENG Yulong; WANG Xiaobo

    2005-01-01

    Based on the latest full-coverage high-resolu- tion multi-beam sounding data, the distribution of the linear sand ridges on the outer shelf of the East China Sea (ECS) is studied with quantitative statistical analysis. The study area can be divided into the northeastern part and the southwestern part. Sand ridges in the northeastern area, trending 116°N, show obvious linear character and shrink to the inner shelf. Sand ridges in the southwestern area, trending 120°N-146°N, tend to have net form. Sand ridges gradually become sand sheets in the center part of study area. Sand ridges are distributed landward to the isobath of 60m, distributed seaward to the water depth of 120 m in the northeast and 150 m in the southwest. Immature sand ridges are observed at water depth of 130-180 m in the southwestern depressions. The acoustic reflection properties of the internal high-angle inclined beddings of the sand ridges are analyzed based on the typical seismic profiles close to the research area. Lithological analysis and dating of 4 boreholes and 12 cores indicate that the widely distributed transgressive sand layer with high content of shell debris which was formed in the early-middle Holocene is the main composition of the linear sand ridges on the outer shelf of the ECS. The dominating factor in formation, developing and burying of the sand ridges is the variation of water depth caused by sea- level change and the rate of sediment supply. In 12400 aBP the cotidal lines of the M2 tidal component were closely perpendicular to the strike-directions of the sand ridges in the study area, and the tidal wave system during 12000-8000 aBP might play a key role in the formation of the linear sand ridges which are widely distributed on the outer shelf of the ECS.

  7. Modern changes of tidal troughs among the radial sand ridges in northern Jiangsu coastal zone

    Institute of Scientific and Technical Information of China (English)

    HUANG Haijun; DU Tingqin; GAO Ang

    2009-01-01

    Using satellite images taken on different dates, GIS analysis of aerial photos, bathymetric maps and other field survey data, tidal troughs and major sand ridges in the northern Jiangsu coastal area were contrasted. The results show that there have been three types of movement or migration of tidal trough in this area: (1) Periodic and restricted, this type of trough usually developed along the beaches with immobile gully head as a result of the artificial dams and the swing range increased from gully head to the low reaches, so they have been obviously impacted by human activity and have longer swing periods; (2) Periodic and actively, this kind of trough, which swung with a fast rate and moved periodically on sand ridges, were mainly controlled by the swings of the host tidal troughs and hydrodynamic forces upon tidal sand ridge and influenced slightly by human constructions; (3) Steadily and slowly, they are the main tidal troughs with large scale and a steady orientation in this area and have slow lateral movement. The differences in migration mode of tidal trough shift result in different rates of migration and impact upon tidal sand ridges. Lateral accumulation on current tidal trough and deposition on abandoned tidal troughs are the two types of sedimentation of the tidal sand ridges formation. The whole radial sand ridge was generally prone to division and retreat although sand ridges fluctuated by the analysis of changes in talwegs of tidal troughs and shorelines of sand ridges.

  8. Field Measurements of Influence of Sand Transport Rate on Structure of Wind-sand Flow over Coastal Transverse Ridge

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang; S L NAMIKAS; P A HESP; MA Jun

    2008-01-01

    The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province,which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges.The measurement results show that,on the conditions of approximate wind velocities and same surface materials and environments,some changes happen to the structure of wind-sand flow with the increase of total sand transport rate on the crest of coastal transverse ridge.First,the sand transport rates of layers at different heights in the wind-sand flow increase,with the maximum increase at the height layer of 4-8cm.Second,the ratios of sand transport rates of layers at different heights to total sand transport rate decrease at the low height layer (0-4cm),but increase at the high height layer (4-60cm).Third,the distribution of the sand transport rate in the wind-sand flow can be expressed by an exponential function at the height layer of 0-40cm,but it changes fi'om power function model to exponential function model in the whole height layer (0-60cm) and changes into polynomial function model at the height layer of 40-60cm with the increase of total sand transport rate.Those changes have a close relationship with the limit of sand grain size of wind flow transporting and composition of sand grain size in the wind-sand flow.

  9. Patch behaviour and predictability properties of modelled finite-amplitude sand ridges on the inner shelf

    Directory of Open Access Journals (Sweden)

    N. C. Vis-Star

    2008-12-01

    Full Text Available The long-term evolution of shoreface-connected sand ridges is investigated with a nonlinear spectral model which governs the dynamics of waves, currents, sediment transport and the bed level on the inner shelf. Wave variables are calculated with a shoaling-refraction model instead of using a parameterisation. The spectral model describes the time evolution of amplitudes of known eigenmodes of the linearised system. Bottom pattern formation occurs if the transverse bottom slope of the inner shelf, β, exceeds a critical value βc. For fixed model parameters the sensitivity of the properties of modelled sand ridges to changes in the number (N−1 of resolved subharmonics (of the initially fastest growing mode is investigated. For any N the model shows the growth and subsequent saturation of the height of the sand ridges. The saturation time scale is several thousands of years, which suggests that observed sand ridges have not reached their saturated stage yet. The migration speed of the ridges and the average longshore spacing between successive crests in the saturated state differ from those in the initial state. Analysis of the potential energy balance of the ridges reveals that bed slope-induced sediment transport is crucial for the saturation process. In the transient stage the shoreface-connected ridges occur in patches. The overall characteristics of the bedforms (saturation time, final maximum height, average longshore spacing, migration speed hardly vary with N. However, individual time series of modal amplitudes and bottom patterns strongly depend on N, thereby implying that the detailed evolution of sand ridges can only be predicted over a limited time interval. Additional experiments show that the critical bed slope βc increases with larger offshore angles of wave incidence, larger offshore wave heights and longer wave periods, and that the corresponding maximum height of the ridges

  10. Distribution,formation and evolution of sand ridges on the East China Sea shelf

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the integrated results of multiple data types including MBES (Multi-Beam Echo Sounding) and historical topography maps,the LSR (Linear Sand Ridges) on the ECS (East China Sea) shelf are identified,divided into subareas,and classified.The distribution of sand ridge crests is also established.The strikes of the LSR on the ECS shelf fall in a normal distribution with the center point being 155° azimuth with additional peak points at 125°,130°,140°,and 180° azimuth.The distribution of the ECS shelf sand ridges is congested in the central area,sparse in the south and north ends,divergent and bifurcated in the eastern area,and densely convergent in the western area.The LSR are divided into seven subzones according to the strikes and distribution of the sand ridges;estuary mouth ridges and open shelf sand ridges are identified and marked out.The high amplitude change of sea level resulting from the glacial-interglacial cycle is the main cause of the vast development of sand ridges on the ECS shelf.Abundant sediments on the shelf carried by the PYR (Paleo-Yangtze River) are the material source for the LSR formation,and the negative seafloor topography influences the strikes of LSR.Based on the effects of LSR distribution,change of sea level,and the simulation of ancient tidal currents,the evolution of the LSR on the ECS shelf is divided into four main stages:Stage Ⅰ before 14.5 ka BP,Stage Ⅱ between 12 and 14 ka BP,Stage Ⅲ from 1.5 to 9.5 ka BP,and Stage Ⅳ after 9 ka BP.

  11. Dynamics of sand ridges in coastal seas: the effect of storms, tides and grain sorting

    Science.gov (United States)

    Walgreen, M.

    2003-10-01

    The work presented in this thesis concerns the dynamics of shoreface-connected ridges and tidal sand ridges. These large-scale bedforms are observed on the inner and outer shelf of coastal seas in water depths of 10-20m. The motivation of this work is to improve the understanding of the mechanisms related to their formation and the processes that determine their main characteristics. This is done with the use of idealised morphodynamic models. The basic assumption underlying these models is that large-scale sand ridges can solely form as free instabilities on a flat sea bottom. Mathematical methods based on a stability analysis are applied, whereas analytical and numerical methods are used to solve the equations. Existing models are extended with new physical processes, in particular including the role of grain sorting. An important part of this thesis concerns the unresolved question about the origin of the observed mean grain size pattern over the ridges. It explores the hydrodynamic processes that can lead to sediment sorting and the formation of large-scale sand ridges. The model results indicate that the dynamics for different forcing conditions strongly differ. Shoreface-connected sand ridges mainly form during storm conditions, whereas if fair weather conditions prevail the more offshore located tidal sand ridges develop. A probabilistic formulation of these two realisation of the model is used to find conditions for which both types of large-scale bedforms occur simultaneously, as is the case in the southern North Sea. These conditions turn out to be a low storm fraction and the presence of both tidal and storm-driven currents. The transport of non-uniform sediment is described by formulations for both bed load and suspended load, both of which account for dynamic hiding effects. A one-layer model for the bed evolution is used and two grain size classes (fine and coarse sand) are considered. The results of the model for storm conditions indicate that the

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

    Institute of Scientific and Technical Information of China (English)

    王颖; 朱大奎; 尤坤元; 潘少明; 朱晓东; 邹欣庆; 张永战

    1999-01-01

    A sand ridge field of 22 470 km~2 consists of fine sands and silts originally from the old Changjiang River sediment during the late Pleistocene period. Late Holocene sand stratum with its well-preserved laminary bedding of more clay particles reflects the influence from the Yellow River. There are three genetic types of morphology of sand ridge field as follows: (ⅰ) reformed alluvial sandy bodies and old river valleys, located in the central and southern parts, formed from the end of Pleistocene to the present. (ⅱ) Radiative current ridges and patrimonal valley type, located in the northeastern part, formed during the early or middle Holocene time. (ⅲ) Eroded-depositional sandy bodies in the north and outer parts, and erosional trough in the north formed since the middle Holocene transgression. The sand ridge field has a periodic nature of developing processes: the period of sediment accumulation by rivers during cold epoch with low sea level and the period of erosional formation by tidal currents d

  13. Wave-induced flow and its influence on ridge erosion and channel deposition in Lanshayang channel of radial sand ridges

    Institute of Scientific and Technical Information of China (English)

    陈可峰; 安翔; 陆培东; 张玮; 徐卓

    2014-01-01

    Very limited modeling studies were available of the wave-induced current under the complex hydrodynamic conditions in the South Yellow Sea Radial Sand Ridge area (SYSRSR). Partly it is due to the difficulties in estimating the influence of the wave-induced current in this area. In this study, a coupled 3-D storm-surge-wave model is built. In this model, the time-dependent varying Collins coefficient with the water level method (TCL) are used. The wave-flow environment in the Lanshayang Channel (LSYC) during the “Winnie” typhoon is successfully represented by this model. According to the modelling results, at a high water level (HWL), the wave-induced current similar to the long-shore current will emerge in the shallow area of the ridges, and has two different motion trends correlated with the morphological characteristics of the ridges. The wave-induced current velocity could be as strong as 1 m/s, which is at the same magnitude as the tidal current. This result is verified by the bathymetric changes in the LSYC during the “Matsa” typhoon. Thus, the wave-induced current may be one of the driven force of the ridge erosion and channel deposition in the SYSRSR. These conclusions will help to further study the mechanism of the ridge erosion and channel deposition in the SYSRSR.

  14. Patch behaviour and predictability properties of modelled finite-amplitude sand ridges on the inner shelf

    NARCIS (Netherlands)

    Vis-star, N.C.; de Swart, H.E.; Calvete, D.

    2008-01-01

    The long-term evolution of shoreface-connected sand ridges is investigated with a nonlinear spectral model which governs the dynamics of waves, currents, sediment transport and the bed level on the inner shelf. Wave variables are calculated with a shoaling-refraction model instead of using a paramet

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

    Science.gov (United States)

    Robinson, M.M.; McBride, R.A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf ???5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

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

    Science.gov (United States)

    Robinson, Marci M.; McBride, Randolph A.

    2008-01-01

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

  17. Modeling Tractive Force Requirements of Wheel Tractors for Disc Ridging in Loamy Sand Soil

    Directory of Open Access Journals (Sweden)

    S O Nkakini

    2012-10-01

    Full Text Available The efficiency with which a soil can transmit energy from a traction device on a tractor to the drawbar has been called the tractive efficiency of soil. Experiments were conducted for disc ridging operations in a loamy sand soil, at tillage speeds of 1.94m/s, 2.22m/s and 2.5m/s, using trace tractor techniques. Tractive force models at different tillage speeds were developed using dimensional analysis, describing the tractors tyre - soil interaction. The measured independent variables such as drawbar pull force, rolling (motion resistance, wheel slip, moisture content, cone index, wheel numeric, contact pressure, speed, width of ridge and height of ridge were used in the developed models. Values of the measured dependent variable (Tractive force were compared with computed values. High coefficients of determination R2 = 0.996, 0.996 and 0.986, percentage (% errors of -0.122620038 and 0.11606597,-0.126307491 and 0.215127604 ,-0.603425382 and 0.372951166 at minimum and maximum values, for disc ridging at tillage speeds of 1.94m/s, 2.22m/s and 2.5m/s were obtained respectively. Analysis of variance between measured and predicted tractive force values indicated standard errors of 11.15346, 10.15346 and 8.24219, while correlation coefficients of R2 = 0.996, 0.768 and 0.9674 were obtained for disc ridging at tillage speeds of 1.94m/s, 2.22m/s, and 2.5m/s respectively . These results are clear evidence of the test of goodness of fit of the models between the measured and predicted tractive forces for disc ridging at the various tillage speeds. Disc ridging speed of 2.5m/s illustrated the lowest coefficient of determination R2 = 0.986. The developed models were validated by comparing the predicted with the measured tractive forces, and shown to closely followed the experimental results.

  18. Sand ridge morphology and bedform migration patterns derived from bathymetry and backscatter on the inner-continental shelf offshore of Assateague Island, USA

    Science.gov (United States)

    Pendleton, Elizabeth; Brothers, Laura; Thieler, E. Robert; Sweeney, Edward

    2017-01-01

    The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the last decade are used to describe the morphology and presence of sand ridges on the inner-continental shelf and measure the change in the position of smaller-scale (10–100 s of meters) seafloor features. Bathymetric surveys from the last 30 years link decadal-scale sand ridge migration patterns to the high-resolution measurements of smaller-scale bedform features. Sand ridge morphology on the inner-shelf changes across-shore and alongshore. Areas of similar sand ridge morphology are separated alongshore by zones where ridges are less pronounced or completely transected by transverse dunes. Seafloor-change analyses derived from backscatter data over a 4–7 year period show that southerly dune migration increases in magnitude from north to south, and the east-west pattern of bedform migration changes ~ 10 km north of the Maryland-Virginia state line. Sand ridge morphology and occurrence and bedform migration changes may be connected to observed changes in geologic framework including topographic highs, deflated zones, and sand availability. Additionally, changes in sand ridge occurrence and morphology may help explain changes in the long-term shoreline trends along Fenwick and Assateague Islands. Although the data presented here cannot quantitatively link sand ridges to sediment transport and shoreline change, it does present a compelling relationship between inner-shelf sand availability and movement, sand ridge occurrence and morphology, geologic framework, and shoreline behavior.

  19. Sand ridge morphology and bedform migration patterns derived from bathymetry and backscatter on the inner-continental shelf offshore of Assateague Island, USA

    Science.gov (United States)

    Pendleton, Elizabeth A.; Brothers, Laura L.; Thieler, E. Robert; Sweeney, Edward M.

    2017-07-01

    The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the last decade are used to describe the morphology and presence of sand ridges on the inner-continental shelf and measure the change in the position of smaller-scale (10-100 s of meters) seafloor features. Bathymetric surveys from the last 30 years link decadal-scale sand ridge migration patterns to the high-resolution measurements of smaller-scale bedform features. Sand ridge morphology on the inner-shelf changes across-shore and alongshore. Areas of similar sand ridge morphology are separated alongshore by zones where ridges are less pronounced or completely transected by transverse dunes. Seafloor-change analyses derived from backscatter data over a 4-7 year period show that southerly dune migration increases in magnitude from north to south, and the east-west pattern of bedform migration changes 10 km north of the Maryland-Virginia state line. Sand ridge morphology and occurrence and bedform migration changes may be connected to observed changes in geologic framework including topographic highs, deflated zones, and sand availability. Additionally, changes in sand ridge occurrence and morphology may help explain changes in the long-term shoreline trends along Fenwick and Assateague Islands. Although the data presented here cannot quantitatively link sand ridges to sediment transport and shoreline change, it does present a compelling relationship between inner-shelf sand availability and movement, sand ridge occurrence and morphology, geologic framework, and shoreline behavior.

  20. Sedimentary facies of the central part of radial tidal sand ridge system of the eastern China coast

    Institute of Scientific and Technical Information of China (English)

    Yong YIN; Xinqin ZOU; Dakui ZHU; Jiaxiang HUANG

    2008-01-01

    A unique radial tidal sand ridge system (RTSRS) has developed under a complex tidal current field on the eastern China coast between the Yangtze River delta to the south and the abandoned Yellow River (Huanghe) delta to the north. The present study examines the sedimentary evolution of a ridge-channel pair in the central RTSRS. Three cores, with two on the ridges and one in the channel, were drilled to reveal the late Pleistocene-Holocene deposits of the system. Five sedimentary facies were distinguished, i.e. ridge-shallow subtidal facies, ridge-deep subtidal facies, near-surface channel bottom facies, middle tidal flat facies and low tidal flat facies. The ridge-shallow subtidal facies consists of sandy strata with ripple cross bed-dings, horizontal lamina, and massive beddings. Bioturbation seldom occurs. The ridge-deep subtidal facies is primarily characterized by sandy and muddy interlayers with common flaser and lenticular bedding structures. Bioturbation appears abundantly. Massive and graded sediment sequences of storm origin are pre-sent as characterized by rich shell fragments. The near-surface channel bottom facies consists of loose, soft, clayey silt deposits with deformed sedimentary layers. This facies occurs in the deeper part of the active chan-nels. The middle tidal flat and lower tidal flat facies composed of silt-clay couplets prevailed primarily in the tidal flats. Incomplete sedimentary successions show that coastal plain deposits dominate in the study area during 12-13 ka B.P. The sandy ridge and channel facies became dominant during 4 6 ka B.P. when the sea level receded temporarily. Tidal ridge and channel in the study area became active during the last four decades. Sediment reworking due to typhoon and sandy ridge migration plays a key role in shaping the present radial ridge system.

  1. Modeling Cape- and Ridge-Associated Marine Sand Deposits; A Focus on the U.S. Atlantic Continental Shelf

    Science.gov (United States)

    Bliss, James D.; Williams, S. Jeffress; Bolm, Karen S.

    2009-01-01

    Cape- and ridge-associated marine sand deposits, which accumulate on storm-dominated continental shelves that are undergoing Holocene marine transgression, are particularly notable in a segment of the U.S. Atlantic Continental Shelf that extends southward from the east tip of Long Island, N.Y., and eastward from Cape May at the south end of the New Jersey shoreline. These sand deposits commonly contain sand suitable for shore protection in the form of beach nourishment. Increasing demand for marine sand raises questions about both short- and long-term potential supply and the sustainability of beach nourishment with the prospects of accelerating sea-level rise and increasing storm activity. To address these important issues, quantitative assessments of the volume of marine sand resources are needed. Currently, the U.S. Geological Survey is undertaking these assessments through its national Marine Aggregates and Resources Program (URL http://woodshole.er.usgs.gov/project-pages/aggregates/). In this chapter, we present a hypothetical example of a quantitative assessment of cape-and ridge-associated marine sand deposits in the study area, using proven tools of mineral-resource assessment. Applying these tools requires new models that summarize essential data on the quantity and quality of these deposits. Two representative types of model are descriptive models, which consist of a narrative that allows for a consistent recognition of cape-and ridge-associated marine sand deposits, and quantitative models, which consist of empirical statistical distributions that describe significant deposit characteristics, such as volume and grain-size distribution. Variables of the marine sand deposits considered for quantitative modeling in this study include area, thickness, mean grain size, grain sorting, volume, proportion of sand-dominated facies, and spatial density, of which spatial density is particularly helpful in estimating the number of undiscovered deposits within an

  2. Submerged sand ridges on the western continental shelf off Bombay, India: Evidence for Late Pleistocene Holocene sea-level changes

    Digital Repository Service at National Institute of Oceanography (India)

    Wagle, B.G.; Veerayya, M.

    -lagoonal-like depressions. Some rounded/smooth ridges appear to be moribund while others have undergone reworking as indicated by superimposed bedforms/sand waves and reefs. Ridges also occurred on the inner shelf where they were either eroded during the Holocene.... broad&i places uneven 7 and shore-side steep; 2 either side lagoon with reefs. often shoreside steep with depressions on the crest; either side lagoon with 2-5 m reefs. e min: 75 min: 4 min: 2.8 Sym R/SR P P max: 85...

  3. Sensitivity of growth characteristics of tidal sand ridges and long bed waves to formulations of bed shear stress, sand transport and tidal forcing: A numerical model study

    Science.gov (United States)

    Yuan, Bing; de Swart, Huib E.; Panadès, Carles

    2016-09-01

    Tidal sand ridges and long bed waves are large-scale bedforms that are observed on continental shelves. They differ in their wavelength and in their orientation with respect to the principal direction of tidal currents. Previous studies indicate that tidal sand ridges appear in areas where tidal currents are above 0.5 m s-1, while long bed waves occur in regions where the maximum tidal current velocity is slightly above the critical velocity for sand erosion and the current is elliptical. An idealized nonlinear numerical model was developed to improve the understanding of the initial formation of these bedforms. The model governs the feedbacks between tidally forced depth-averaged currents and the sandy bed on the outer shelf. The effects of different formulations of bed shear stress and sand transport, tidal ellipticity and different tidal constituents on the characteristics of these bedforms (growth rate, wavelength, orientation of the preferred bedforms) during their initial formation were examined systematically. The results show that the formulations for bed shear stress and slope-induced sand transport are not critical for the initial formation of these bedforms. For tidal sand ridges, under rectilinear tidal currents, increasing the critical bed shear stress for sand erosion decreases the growth rate and the wavelength of the preferred bedforms significantly, while the orientation angle slightly decreases. The dependence of the growth rate, wavelength and the orientation of the preferred bedforms on the tidal ellipticity is non-monotonic. A decrease in tidal frequency results in preferred bedforms with larger wavelength and smaller orientation angle, while their growth rate hardly changes. In the case of joint diurnal and semidiurnal tides, or spring-neap tides, the characteristics of the bedforms are determined by the dominant tidal constituent. For long bed waves, the number of anticyclonically/cyclonically oriented bedforms with respect to the principal

  4. Wave Characteristics at the South Part of the Radial Sand Ridges of the Southern Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    杨斌; 冯卫兵; 张俞

    2014-01-01

    Based on one-year wave field data measured at the south part of the radial sand ridges of the Southern Yellow Sea, the wave statistical characteristics, wave spectrum and wave group properties are analyzed. The results show that the significant wave height (H1/3) varies from 0.15 to 2.22 m with the average of 0.59 m and the mean wave period (Tmean) varies from 2.06 to 6.82 s with the average of 3.71 s. The percentage of single peak in the wave spectra is 88.6 during the measurement period, in which 36.3%of the waves are pure wind waves and the rest are young swells. The percentage with the significant wave height larger than 1 m is 12.4. The dominant wave directions in the study area are WNW, W, ESE, E and NW. The relationships among the characteristic wave heights, the characteristic wave periods, and the wave spectral parameters are identified. It is found that the tentative spectral model is suitable for the quantitative description of the wave spectrum in the study area, while the run lengths of the wave group estimated from the measured data are generally larger than those in other sea areas.

  5. Investigation of seasonal river-aquifer interactions in a tropical coastal area controlled by tidal sand ridges

    Science.gov (United States)

    Calderon, H.; Uhlenbrook, S.

    2014-08-01

    Water exchanges between streams and aquifers influence the quantity and quality of water in both domains. Seasonal river-aquifer interactions were investigated in a tropical coastal area where tidal sand ridges control river discharge to the sea. The study site is located in southwestern Nicaragua, dominated by humid tropical hydro-climatic conditions. The aquifer provides water to the rural town of Ostional. Connectivity between the river and the aquifer influences water quality and water availability for humans and for the downstream estuarine ecosystem. The effect of stream stage fluctuations on river-aquifer flows and pressure propagation in the adjacent aquifer was investigated analyzing high temporal resolution hydraulic head data and applying a numerical model (HYDRUS 2-D). Tidal sand ridges at the river outlet control the flow direction between the river and the aquifer. Surface water accumulation caused by these features induces aquifer recharge from the river. Simulations show groundwater recharge up to 0.2 m3 h-1 per unit length of river cross section. Rupture of the sand ridges due to overtopping river flows causes a sudden shift in the direction of flow between the river and the aquifer. Groundwater exfiltration reached 0.08 m3 h-1 immediately after the rupture of the sand ridges. Simulated bank storage flows are between 0.004-0.06 m3 h-1. These estimates are also supported by the narrow hysteresis loops between hydraulic heads and river stage. The aquifer behaves as confined, rapidly transmitting pressure changes caused by the river stage fluctuations. However, the pressure wave is attenuated with increasing distance from the river. Therefore, we concluded that a dynamic pressure wave is the mechanism responsible for the observed aquifer responses. Pressure variation observations and numerical groundwater modeling are useful to examine river-aquifer interactions and should be coupled in the future with chemical data to improve process understanding.

  6. Dynamics of shoreface-connected and inactive sand ridges on a shelf, Part 2 : The role of sea level rise and associated changes in shelf geometry

    NARCIS (Netherlands)

    Nnafie, A.; de Swart, H. E.; Calvete, D.; Garnier, R.

    2015-01-01

    Many inner continental shelves are characterized by the presence of large rhythmic bedforms, such as shoreface-connected ridges and the more offshore located sand ridges, which have heights of several meters and are spaced several kilometers apart. This study focuses on explaining the observed

  7. Study on the linear sand ridges on shelf of the East China Sea

    Science.gov (United States)

    WU, Z.; Jin, X.; Li, M.; Shang, J.; Li, S.

    2013-12-01

    The linear sand ridges (LSR) revealed by newest multi-beam echo soundings bathymetric data (MBES) are distributed extensively on shelf of the East China Sea (ECS). It is not only a kind of ubiquitous geological phenomenon on tide-dominated shelf but also a key step in paleo-environment evolvement history of the ECS. Based on the MBES, high-resolution single-channel seismic profiles, analyzed results of boreholes and numerical simulation of paleo-tidal current fields, the distribution, 3D fine structures , space-time spreading regulars and developing tendencies of the LSR on ECS shelf were studied by quantitative synthetic statistical analysis method. The relationship between LSR and paleo-tidal current field, sea-level curve and the evolution stages of LSR such as formation, growth and buried stages were discussed. The strikes of LSR on ECS shelf emerge at a normal distribution. The azimuth of N155°E is the central point and the azimuth of N125°E,N130°E,N140°E and N180°E are convergent points respectively for the normal distribution. The LSR are aggregating in the centre part of ECS shelf, rarefying at the north and south part, dispersing and bifurcating to the east, aggregating and converging to the west. The LSR on ECS shelf are distributed landward to the isobath of 60m, and seaward to the water depth of 120m at northeast and 150m at southwest. Immature LSR are firstly observed at water depth of 130-180m in the southwestern depressions. Lithology analysis and dating of 4 boreholes and 12 cores have indicated that the widely distributed transgressive sand layers with high content of shell debris which formed in the early to middle Holocene are the main compositions of the LSR on the ECS shelf. The top boundaries of buried LSR in unit 14 are distinguished, and a 3D map of these buried LSR in local area is reconstructed. The features such as length, width, height and strikes of these buried LSR are analyzed quantitatively and compared with those of LSR in unit

  8. User`s manual for SNL-SAND-II code

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, P.J.; Kelly, J.G. [Sandia National Labs., Albuquerque, NM (United States); VanDenburg, J.W. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)

    1994-04-01

    Sandia National Laboratories, in the process of characterizing the neutron environments at its reactor facilities, has developed an enhanced version of W. McElroy`s original SAND-II code. The enhanced input, output, and plotting interfaces make the code much easier to use. The basic physics and operation of the code remain unchanged. Important code enhancements include the interfaces to the latest ENDF/B-VI and IRDF-90 dosimetry-quality cross sections and the ability to use silicon displacement-sensitive devices as dosimetry sensors.

  9. Mathematical model of wave transformation over radial sand ridge field on continental shelf of South Yellow Sea

    Directory of Open Access Journals (Sweden)

    Yao-zhong YANG

    2010-03-01

    Full Text Available According to a deformed mild-slope equation derived by Guang-wen Hong and an enhanced numerical method, a wave refraction-diffraction nonlinear mathematical model that takes tidal level change and the high-order bathymetry factor into account has been developed. The deformed mild-slope equation is used to eliminate the restriction of wave length on calculation steps. Using the hard disk to record data during the calculation process, the enhanced numerical method can save computer memory space to a certain extent, so that a large-scale sea area can be calculated with high-resolution grids. This model was applied to wave field integral calculation over a radial sand ridge field in the South Yellow Sea. The results demonstrate some features of the wave field: (1 the wave-height contour lines are arc-shaped near the shore; (2 waves break many times when they propagate toward the shore; (3 wave field characteristics on the northern and southern sides of Huangshayang are different; and (4 the characteristics of wave distribution match the terrain features. The application of this model in the region of the radial sand ridge field suggests that it is a feasible way to analyze wave refraction-diffraction effects under natural sea conditions.

  10. Sand Dune Ridge Alignment Effects on Surface BRF over the Libya-4 CEOS Calibration Site

    Directory of Open Access Journals (Sweden)

    Yves M. Govaerts

    2015-02-01

    Full Text Available The Libya-4 desert area, located in the Great Sand Sea, is one of the most important bright desert CEOS pseudo-invariant calibration sites by its size and radiometric stability. This site is intensively used for radiometer drift monitoring, sensor intercalibration and as an absolute calibration reference based on simulated radiances traceable to the SI standard. The Libya-4 morphology is composed of oriented sand dunes shaped by dominant winds. The effects of sand dune spatial organization on the surface bidirectional reflectance factor is analyzed in this paper using Raytran, a 3D radiative transfer model. The topography is characterized with the 30 m resolution ASTER digital elevation model. Four different regions-of-interest sizes, ranging from 10 km up to 100 km, are analyzed. Results show that sand dunes generate more backscattering than forward scattering at the surface. The mean surface reflectance averaged over different viewing and illumination angles is pretty much independent of the size of the selected area, though the standard deviation differs. Sun azimuth position has an effect on the surface reflectance field, which is more pronounced for high Sun zenith angles. Such 3D azimuthal effects should be taken into account to decrease the simulated radiance uncertainty over Libya-4 below 3% for wavelengths larger than 600 nm.

  11. Sand dune ridge alignment effects on surface BRF over the Libya-4 CEOS calibration site.

    Science.gov (United States)

    Govaerts, Yves M

    2015-02-03

    The Libya-4 desert area, located in the Great Sand Sea, is one of the most important bright desert CEOS pseudo-invariant calibration sites by its size and radiometric stability. This site is intensively used for radiometer drift monitoring, sensor intercalibration and as an absolute calibration reference based on simulated radiances traceable to the SI standard. The Libya-4 morphology is composed of oriented sand dunes shaped by dominant winds. The effects of sand dune spatial organization on the surface bidirectional reflectance factor is analyzed in this paper using Raytran, a 3D radiative transfer model. The topography is characterized with the 30 m resolution ASTER digital elevation model. Four different regions-of-interest sizes, ranging from 10 km up to 100 km, are analyzed. Results show that sand dunes generate more backscattering than forward scattering at the surface. The mean surface reflectance averaged over different viewing and illumination angles is pretty much independent of the size of the selected area, though the standard deviation differs. Sun azimuth position has an effect on the surface reflectance field, which is more pronounced for high Sun zenith angles. Such 3D azimuthal effects should be taken into account to decrease the simulated radiance uncertainty over Libya-4 below 3% for wavelengths larger than 600 nm.

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

    Science.gov (United States)

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

    2009-01-01

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

  13. Homogeneous, heterogeneous and biological oxidation of iron(II) in rapid sand filtration

    NARCIS (Netherlands)

    Beek, van C.G.E.M.; Hiemstra, T.; Hofs, B.; Nederlof, M.M.; Paassen, van J.A.M.; Reijnen, G.K.

    2012-01-01

    Homogeneous, heterogeneous and biological oxidation may precipitate iron(II) as iron(III) hydroxides. In this paper we evaluate the conditions under which each of these processes is dominant in rapid sand filtration (RSF). It is demonstrated that in the presence of iron(III) hydroxide precipitates

  14. Homogeneous, heterogeneous and biological oxidation of iron(II) in rapid sand filtration

    NARCIS (Netherlands)

    Beek, van C.G.E.M.; Hiemstra, T.; Hofs, B.; Nederlof, M.M.; Paassen, van J.A.M.; Reijnen, G.K.

    2012-01-01

    Homogeneous, heterogeneous and biological oxidation may precipitate iron(II) as iron(III) hydroxides. In this paper we evaluate the conditions under which each of these processes is dominant in rapid sand filtration (RSF). It is demonstrated that in the presence of iron(III) hydroxide precipitates h

  15. Continuous adsorption of Pb(II) and methylene blue by engineered graphite oxide coated sand in fixed-bed column

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Ji-Lai, E-mail: jilaigong@gmail.com [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zhang, Yong-Liang; Jiang, Yan [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zeng, Guang-Ming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Cui, Zhi-Hui; Liu, Ke; Deng, Can-Hui; Niu, Qiu-Ya; Deng, Jiu-Hua [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Huan, Shuang-Yan [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2015-03-01

    Highlights: • GO-sand was prepared by coating GO on the surface of sand. • Pb(II) and MB were efficiently removed by GO-sand filter in column. • The removal of MB was enhanced with the presence of Pb(II). • GO-sand is low-cost and convenient for its application as packed bed filter. - Abstract: The mixture of several effluents, caused by the improper handling and management of effluents, generated multi-component wastewater containing both metals and dyes, leading to the complicated treatment process. In this study, a continuous adsorption of Pb(II) and methylene blue (MB) has been studied in single and binary solutions by using graphite oxide coated sand (GO-sand) as an adsorbent in a fixed-bed column. GO-sand was analyzed by X-ray photoelectron spectroscopy before and after analyte adsorption. Compared with sand filter, adsorption quantity and capacity for Pb(II) and MB by GO-sand filter were greatly increased. In Pb(II) and MB single solutions, the experimental parameters were investigated in detail including initial concentration, flow rate, bed depth and pH. Exhaustion time decreased with increasing initial concentration and flow rate, and increased with increasing bed depth and pH. In the Pb(II)-MB binary solution, exhaustion time significantly decreased for Pb(II) adsorption, but increased for MB adsorption. The reason was explained that the more favorable adsorption for MB onto the surface of GO-sand than that for Pb(II), which was derived from π–π interaction between MB and GO on sand surface in packed filter. The Yoon–Nelson model was applied at different concentration of Pb(II) and MB to predict the breakthrough curves. The experimental data were well fit with the model indicating that it was suitable for this column design.

  16. Modeling downstream fining in sand-bed rivers. II: Application

    Science.gov (United States)

    Wright, S.; Parker, G.

    2005-01-01

    In this paper the model presented in the companion paper, Wright and Parker (2005) is applied to a generic river reach typical of a large, sand-bed river flowing into the ocean in order to investigate the mechanisms controlling longitudinal profile development and downstream fining. Three mechanisms which drive downstream fining are studied: a delta prograding into standing water, sea-level rise, and tectonic subsidence. Various rates of sea-level rise (typical of the late Holocene) and tectonic subsidence are modeled in order to quantify their effects on the degree of profile concavity and downstream fining. Also, several other physical mechanisms which may affect fining are studied, including the relative importance of the suspended versus bed load, the effect of the loss of sediment overbank, and the influence of the delta bottom slope. Finally, sensitivity analysis is used to show that the grain-size distribution at the interface between the active layer and substrate has a significant effect on downstream fining. ?? 2005 International Association of Hydraulic Engineering and Research.

  17. Space-time contrast of two stages sand ridges on the East China Sea shelf%东海陆架两期沙脊的时空对比

    Institute of Scientific and Technical Information of China (English)

    吴自银; 金翔龙; 曹振轶; 李家彪; 郑玉龙; 尚继宏

    2009-01-01

    On the basis of the high-resolution single-channel sparker seismic profiles and MBES (multi-beam echo sounding), the LSRs (linear sand ridges) on Stratum U_2 and Stratum U_(14) on the ECS (East China Sea) shelf are identified and contrasted each other, their form ages are different, more than 200 ka. The sand ridges on Stratum U_(14) which is bellow seafloor 90 m are buried sand ridges, and belong to TST (transgressive systems tract) of 320~200 ka BP,and the upper bounding surfaces of the sand ridge units are therefore considered as the MFS (maximum flooding surface) of this transgressive. The sand ridges on Stratum U_2 are recessive sand ridges, which have belonged to the TST since the LGM (last glacial maximum),and their upper bounding surfaces are the MFS of the LGM. Although the form ages of two sand ridge units are different, more than 200 ka, and their stratigraphy positions are different, more than 90 m, the general strikes of sand ridges are similar. It is suggested that the palaeo-tidal components of the ECS have been steady since 200 ka. Four substages sand ridges are identified from the stratigraphy of Stratum U_2, and four trends of sand ridges are distinguished from the topographic map of the MBES too. These multistages and multitrend sand ridges are the evidences that the evolution of submarine topography of the ECS has met the response of sea-level stepped changes since the LGM.%基于高分辨率的单道地震和多波束测深数据,识别并对比了东海陆架中部同一海区相距20余万年的层U_(14)和层U_2两期沙脊群,其中层U_(14)期沙脊属于埋藏沙脊,位于东海海底以下90 m深处,推测属于距今320~200 ka的海侵体系域(TST),沙脊顶界面是该期海侵的最大洪泛面(MFS);层U_2期沙脊位于东海陆架,属于衰退沙脊,系末次盛冰期(LGM)以来的TST,顶界面是LGM以来的MFS.尽管两期沙脊形成年代相距20余万年,地层层位相距近90 m,但是沙脊群

  18. Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry

    Directory of Open Access Journals (Sweden)

    Tariq eSiddique

    2014-03-01

    Full Text Available Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae and Desulfobulbaceae and Archaea (Methanolinea/Methanoregula and Methanosaeta transformed FeIII minerals in MFT to amorphous FeII minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O and goethite (α-FeOOH were the dominant FeIII minerals in MFT. The formation of amorphous iron sulfide (FeS and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy. These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

  19. Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry.

    Science.gov (United States)

    Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Li, Carmen; Young, Rozlyn; Arocena, Joselito M; Foght, Julia M

    2014-01-01

    Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT) during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae, and Desulfobulbaceae) and Archaea (Methanolinea/Methanoregula and Methanosaeta) transformed Fe(III) minerals in MFT to amorphous Fe(II) minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O) and goethite (α-FeOOH) were the dominant Fe(III) minerals in MFT. The formation of amorphous iron sulfide (FeS) and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces) of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy (SEM). These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

  20. Interaction between the H II region and AFGL 333-Ridge: Implications for the star formation scenario

    Science.gov (United States)

    Nakano, Makoto; Soejima, Takashi; Chibueze, James O.; Nagayama, Takumi; Omodaka, Toshihiro; Handa, Toshihiro; Sunada, Kazuyoshi; Kamezaki, Tatsuya; Burns, Ross A.

    2017-02-01

    We investigated the star formation activities in the AFGL 333 region, which is in the vicinity of the W 4 expanding bubble, by conducting NH3 (1,1), (2,2), and (3,3) mapping observations with the 45 m Nobeyama Radio Telescope an angular resolution of 75″. The morphology of the NH3 (1,1) map shows a bow-shaped structure with the size of 2.0 × 0.6 pc as seen in the dust continuum. At the interface between the W 4 bubble and the dense NH3 cloud, the compact H II region G134.2+0.8, associated with IRAS 02245+6115, is located. Interestingly, just at the north and south of G134.2+0.8 we found NH3 emission exhibiting large velocity widths of ˜2.8 km s-1, compared to 1.8 km s-1 at the other positions. As the possibility of mechanical energy injection through the activity of young stellar objects (YSOs) is low, we considered the origin of the large turbulent gas motion as an indication of interaction between the compact H II region and the periphery of the dense molecular cloud. We also found expanding motion of the CO emission associated with G134.2+0.8. The overall structure of the AFGL 333-Ridge might have been formed by the expanding bubble of W 4. However, the small velocity widths observed to the west of IRAS 02245+6115, around the center of the dense molecular cloud, suggest that interaction with the compact H II region is limited. Therefore the YSOs (dominantly Class 0/I) in the core of the AFGL 333-Ridge dense molecular cloud most likely formed in quiescent mode. As previously suggested for the large-scale star formation in the W 3 giant molecular cloud, our results show an apparent coexistence of induced and quiescent star formations in this region. It appears that star formation in the AFGL 333 region has proceeded without significant external triggers, but accompanying stellar feedback environment.

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

    Science.gov (United States)

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

    2013-04-01

    Subduction complexes large enough to be exposed subaerially and to become significant sources of terrigenous detritus are formed by tectonic accretion above trenches choked with thick sections of remnant-ocean turbidites. They thus need to be connected along strike to a large Alpine-type or Andean-type orogen, where huge volumes of orogenic detritus are produced and conveyed via a major fluvio-deltaic system to the deep sea (Ingersoll et al., 2003). We investigated sediment generation and recycling in the Indo-Burman-Andaman-Nicobar subduction complex, representing the archetype of such settings in the eastern prolongation of the Himalayan collisional system. "Subduction Complex Provenance" is composite, and chiefly consists of detritus recycled from largely turbiditic parent rocks (Recycled Clastic Provenance), with local supply from ultramafic and mafic rocks of forearc lithosphere (Ophiolite Provenance) or recycled paleovolcanic to neovolcanic sources (Volcanic Arc Provenance; Garzanti et al., 2007). In order to specifically investigate the effect of recycling, we characterized the diverse detrital signatures of Cenozoic sandstones deposited during subsequent stages of "soft" and "hard" Himalayan collision and exposed from Bangladesh to the Andaman Islands, and discuss the reasons for compositional discrepancies between parent sandstones and their recycled daughter sands. A companion study was carried out with the same methodologies, rationale and goals on Barbados Island, one of the few other places where a large accretionary prism is subaerially exposed. Also modern Barbados sands are largely multicyclic, reflecting mixing in various proportions of detritus from the basal Scotland Formation (sandstones and mudrocks), their stratigraphic and tectonic cover, the Oceanic Formation (quartzose turbidites and deep-water biogenic oozes including radiolarite), and from the Pleistocene calcarenite and reefal cap, as well as from volcanic layers ultimately derived from

  2. Beach monitoring project Sand Key Phase II Beach nourishment program (North Redington Beach and Redington Shores) Post-Nourishment Report Part II Offshore Profiles and Wave Data

    OpenAIRE

    1989-01-01

    This study presents the third post-nourishment survey (January 1989) results for the Sand Key Phase II beach nourishment project carried out in June, 1988. The monitoring program to this beach nourishment project is a joint effort between the University of South Florida and University of Florida. The field surveys include a total of 26 profiles, encompassing approximately 3 miles of shoreline extending from DNR R-96 to R-1ll. The total calculated volume loss of sand in the n...

  3. Influence of marine and continental processes on the dynamics of a sand-ridge at the mouth of the Mafaguaqu river (Caraguatabuba - SP: preliminary conditions

    Directory of Open Access Journals (Sweden)

    May Christine Modenesi

    1983-01-01

    Full Text Available This paper deals with the sedimentation and erosion dynamics of a sand-ridge on the Maçaguaçu River mouth on the São Paulo coastal plain, north of Caraguatatuba Bay. Sedimentological, climatic and hydrodynamic data were analysed from an integrative point of view, considering relationships between continental and marine antagonic forces. Even if incomplete these preliminary observation show that erosion only occurs when more intense rains and higher tidal cycles coincide and that even the intense occurrence of one of these phenomena is not enough to trigger the destructive processes.A dinâmica de sedimentação e erosão do "spit-bar" do rio Maçaguaçu (Caragua tatuba, São Paulo foi preliminarmente avaliada através da integração de es tudos climáticos, hidrodinámicos e sedimentologicos, considerando-se as interrelaçoes das forças antagónicas entre os processos continental e marinho. A feição construtiva do "spit-bar" parece estar conectada com a dinámica dos processos marinhos. Suas características erosionáis parecem ser o resultado dos processos fluviais, intimamente relacionados aos períodos de intensa pluviosidade nas escarpas da Serra do Mar, quando da passagem de frentes atmosféricas.

  4. Tidal current-induced formation——storm-induced change——tidal current-induced recovery——Interpretation of depositional dynamics of formation and evolution of radial sand ridges on the Yellow Sea seafloor

    Institute of Scientific and Technical Information of China (English)

    张长宽; 张东生; 张君伦; 王震

    1999-01-01

    The results of simulated tidal current field, wave field and storm-induced current field are employed to interpret the depositional dynamic mechanism of formation and evolution of the radial sand ridges on the Yellow Sea seafloor. The anticlockwise rotary tidal wave to the south of Shandong Peninsula meets the following progressive tidal wave from the South Yellow Sea, forming a radial current field outside Jianggang. This current field provides a necessary dynamic condition for the formation and existence of the radial sand ridges on the Yellow Sea seafloor. The results of simulated "old current field (holocene)" show that there existed a convergent-divergent tidal zone just outside the palaeo-Yangtze River estuary where a palaeo-underwater accumulation was developed. The calculated results from wave models indicate that the wave impact on the topography, under the condition of high water level and strong winds, is significant. The storm current induced by typhoons landing in the Yangtze River estuary

  5. Kinetic and isotherm studies for nickel (II) removal using novel mesoparticle graphene sand composite synthesised from sand and arenga palm sugar

    Science.gov (United States)

    Zularisam, A. W.; Wahida, Norul

    2017-07-01

    Nickel (II) is one of the most toxic contaminants recognised as a carcinogenic and mutagenic agent which needs complete removal from wastewater before disposal. In the present study, a novel adsorbent called mesoparticle graphene sand composite (MGSCaps) was synthesised from arenga palm sugar and sand by using a green, simple, low cost and efficient methodology. Subsequently, this composite was characterised and identified using field emission scanning electron microscope (FESEM), x-ray diffraction (XRD) and elemental mapping (EM). The adsorption process was investigated and optimised under the experimental parameters such as pH, contact time and bed depth. The results showed that the interaction between nickel (II) and MGSCaps was not ion to ion interaction hence removal of Ni (II) can be applied at any pH. The results were also exhibited the higher contact time and bed depth, the higher removal percentage of nickel (II) occurred. Adsorption kinetic data were modelled using Pseudo-first-order and Pseudo-second-order equation models. The experimental results indicated pseudo-second-order kinetic equation was most suitable to describe the experimental adsorption kinetics data with maximum capacity of 40% nickel (II) removal for the first hour. The equilibrium adsorption data was fitted with Langmuir, and Freundlich isotherms equations. The data suggested that the most fitted equation model is the Freundlich with correlation R2=0.9974. Based on the obtained results, it can be stated that the adsorption method using MGSCaps is an efficient, facile and reliable method for the removal of nickel (II) from waste water.

  6. 辐射沙脊群时空信息集成系统设计%Design of Spatio-temporal Information Integration System for Sand Ridge Field

    Institute of Scientific and Technical Information of China (English)

    王鑫浩; 葛小平; 丁贤荣; 李森

    2015-01-01

    针对江苏沿海滩涂围垦开发的难点,在海洋时空数据模型的基础上探讨了辐射沙脊群时空信息集成的方法,初步尝试了准同步思想在时空数据管理中的应用。系统在.NET 开发平台下,结合 ArcGIS 二次开发、数据库编程,设计开发了 C /S 和 B/S 混合结构的辐射沙脊群时空信息集成系统。水文站管理、漂流浮标示踪、遥感影像检索3大关键模块与数据源、数据整编、数据库管理、模型库和业务表达5层互成经纬结构,实现数据交互查询和管理。系统主要功能包括数据整编、模型计算、数据分析、时空数据接收、成果展示和分享,为辐射沙脊群区域围垦开发及水文监测提供数据支撑和技术支持。%In view of the difficulties of exclamation and exploitation in the coastal area of Jiangsu Province,we dis-cussed the method of spatio-temporal information integration for radial sand ridges based on marine spatio-temporal data model,and preliminarily applied quasi-synchronization to the spatial and temporal data management.A system involving ArcGIS secondary development and database programming is designed and developed as C /S and B /S structure on the development platform of MicroSoft.Net.The system consists of hydrological station management, drifting buoy tracer,retrieval of remote sensing information as key modules,and data source,data reorganization, database management,model base and business expression as layers,which together make up a fabric structure of interactive data query and management.The main function of this system includes data reorganization,model calcu-lation,data analysis,spatio-temporal data receiving,result displaying and sharing.It provides data support and technical support for the reclamation exploitation and hydrological monitoring in radial sand ridge field.

  7. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System.

    Science.gov (United States)

    Sujith, P P; Mourya, B S; Krishnamurthi, S; Meena, R M; Loka Bharathi, P A

    2014-01-01

    The Indian Ridge System basalt bearing Mn-oxide coatings had todorokite as the major and birnesite as the minor mineral. We posit that microorganisms associated with these basalts participate in the oxidation of Mn and contribute to mineral deposition. We also hypothesized that, the Mn-oxidizing microbes may respond reversibly to pulses of fresh organic carbon introduced into the water column by mobilizing the Mn in Mn-oxides. To test these two hypotheses, we enumerated the number of Mn-oxidizers and -reducers and carried out studies on the mobilization of Mn by microbial communities associated with basalt. In medium containing 100 μM Mn(2+), 10(3) colony forming units (CFU) were recovered with undetectable number of reducers on Mn-oxide amended medium, suggesting that the community was more oxidative. Experiments were then conducted with basalt fragments at 4±2 °C in the presence 'G(+)' and absence 'G(-)' of glucose (0.1%). Controls included set-ups, some of which were poisoned with 15 mM azide and the others of which were heat-killed. The mobilization of Mn in the presence of glucose was 1.76 μg g(-1) d(-1) and in the absence, it was 0.17 μg g(-1) d(-1) after 150 d. Mn mobilization with and without added glucose was 13 and 4 times greater than the corresponding azide treated controls. However, rates in 'G(+)' were 16 times and 'G(-)' 24 times more than the respective heat killed controls. The corresponding total counts in the presence of added glucose increased from 1.63×10(6) to 6.71×10(7) cells g(-1) and from 1.41×10(7) to 3.52×10(7) cells g(-1) in its absence. Thus, the addition of glucose as a proxy for organic carbon changed the community's response from Mn(II)-oxidizing to Mn(IV)-reducing activity. The results confirm the participation of Mn oxidizing bacteria in the mobilization of Mn. Identification of culturable bacteria by 16S rRNA gene analysis showed taxonomic affiliations to Bacillus, Exiguobacterium, Staphylococcus, Brevibacterium and

  8. Phase I (CATTS Theory), Phase II (Milne Point), Phase III (Hydrate Ridge)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-10-31

    This study introduces a new type of cumulative seismic attribute (CATT) which quantifies gas hydrates resources in Hydrate Ridge offshore Oregon. CATT is base on case-specific transforms that portray hydrated reservoir properties. In this study we used a theoretical rock physics model to correct measured velocity log data.

  9. Wettability of Sanded and Aged Fast-growing Poplar Wood Surfaces: II. Dynamic Wetting Models

    OpenAIRE

    Zhiyong Qin; Qian Zhang; Qiang Gao; Shifeng Zhang; Jianzhang Li

    2014-01-01

    The dynamic wettability of adhesive on sanded and aged wood surfaces was measured using the sessile drop method. Four different models were used to evaluate and compare the wetting process. It was shown that the wettability of freshly sanded wood and aged wood both decreased compared to the control wood. There was no evidence of change in wettability with increasing grit number. Aging reduced the wettability of the wood surface. The coefficients of determination (R2) for all four models were ...

  10. Intermittent fasting modulation of the diabetic syndrome in sand rats. II. In vivo investigations.

    Science.gov (United States)

    Belkacemi, Louiza; Selselet-Attou, Ghalem; Louchami, Karim; Sener, Abdullah; Malaisse, Willy J

    2010-11-01

    This study deals with the effects of daily intermittent fasting for 15 h upon the development of diabetes in sand rats exposed to a hypercaloric diet. The same pattern of daily intermittent fasting was imposed on sand rats maintained on a purely vegetal diet (control animals). Over the last 30 days of the present experiments, non-fasting animals gained weight, whilst intermittently fasting sand rats lost weight. In this respect, there was no significant difference between control animals and either diabetic or non-diabetic sand rats exposed to the hypercaloric diet. The postprandial glycemia remained fairly stable in the control animals. During a 3-week transition period from a purely vegetal to a hypercaloric diet, the post-prandial glycemia increased by 5.95 ± 1.26 mM (n=6) in diabetic sand rats, as distinct from an increase of only 0.45 ± 0.56 mM (n=6) in the non-diabetic animals. During the intermittent fasting period, the postprandial glycemia decreased significantly in the diabetic animals, but not so in the non-diabetic sand rats. Before the switch in food intake, the peak glycemia at the 30th min of an intraperitoneal glucose tolerance test was already higher in the diabetic than non-diabetic rats. In both the non-diabetic and diabetic sand rats, intermittent fasting prevented the progressive deterioration of glucose tolerance otherwise observed in non-fasting animals. These findings reveal that, at least in sand rats, intermittent daily fasting prevents the progressive deterioration of glucose tolerance otherwise taking place when these animals are exposed to a hypercaloric diet.

  11. Experimental hypervelocity impact into quartz sand. II - Effects of gravitational acceleration

    Science.gov (United States)

    Gault, D. E.; Wedekind, J. A.

    1977-01-01

    Experimental results for craters formed by aluminum spheres impacting at normal incidence against quartz sand targets in gravitational acceleration environments ranging from 0.073 to 1.0 g (g = 980 cm/sq sec) are reported. Impact velocities varied from 0.4 to 8.0 km/sec. Crater dimensions and formation times are compared with results from a simplified dimensional analysis of the cratering processes. Although the comparison indicates a dominant role of gravity relative to the target strength for craters formed in sand, the results serve primarily to emphasize that both gravity and strength are variables of fundamental significance to cratering processes.

  12. An NMR (Nuclear Magnetic Resonance) Investigation of the Chemical Association and Molecular Dynamics in Asphalt Ridge Tar Sand Ore and Bitumen

    Science.gov (United States)

    Netzel, D. A.; Coover, P. T.

    1987-09-01

    Preliminary studies on tar sand bitumen given in this report have shown that the reassociation of tar sand bitumen to its original molecular configuration after thermal stressing is a first-order process requiring nearly a week to establish equilibrium. Studies were also conducted on the dissolution of tar sand bitumen in solvents of varying polarity. At a high-weight fraction of solute to solvent the apparent molecular weight of the bitumen molecules was greater than that of the original bitumen when dissolved in chloroform-d{sub 1} and benzene-d{sub 6}. This increase in the apparent molecular weight may be due to micellar formation or a weak solute-solvent molecular complex. Upon further dilution with any of the solvents studied, the apparent molecular weight of the tar sand bitumen decreased because of reduced van der Waals forces of interaction and/or hydrogen bonding. To define the exact nature of the interactions, it will be necessary to have viscosity measurements of the solutions.

  13. Manganese Coated Sand for Copper (II Removal from Water in Batch Mode

    Directory of Open Access Journals (Sweden)

    Nidal Hilal

    2013-09-01

    Full Text Available Removal of heavy metals, such as copper ions, from water is important to protect human health and the environment. In this study, manganese coated sand (MCS was used as an adsorbent to remove copper ions in a batch system. Equilibrium data were determined at a temperature of 25.6 °C and the Langmuir model was used to describe the experimental data. Mn-coating improved the removal of copper ions by 70% as compared to uncoated sand. Based on a kinetics study, the adsorption of copper ions on MCS was found to occur through a chemisorption process and the pseudo-second-order model was found to fit the kinetics experimental data well. Due to particle interactions, the equilibrium uptake was reduced as the ratio of sand to volume of solution increased. pH affected the removal of copper ions with lowest uptakes found at pH 3 and pHs >7, whilst at pHs in the range of 4 to 7, the uptake was highest and almost constant at the value of 0.0179 mg/g ± 4%. This study has also revealed that copper ions removal was dissolved oxygen (DO dependent with the highest removal occurring at ambient DO concentration, which suggests that DO should be carefully studied when dealing with copper ions adsorption.

  14. Effect of metal oxides on the reactivity of persulfate/Fe(II) in the remediation of diesel-contaminated soil and sand.

    Science.gov (United States)

    Do, Si-Hyun; Kwon, Yong-Jae; Kong, Sung-Ho

    2010-10-15

    The effect of metal oxides on the ability of persulfate (PS) with Fe(II) to remediate diesel-contaminated soil was investigated. In both natural soil and purchased sand, the highest diesel degradation occurred at pH 3 and the optimum molar ratio of PS/Fe(II) was 100:1 (i.e. 500 mM PS to 5 mM Fe(II)). Moreover, adding Fe(II) increased PS reactivity more in soil than it did in sand, indicating the involvement of metal oxides in the soil matrix. Evaluating the effects of metal oxides (i.e. goethite, hematite, magnetite, and manganese oxide) on the reactivity of PS with/without Fe(II) in a system containing diesel-contaminated sand revealed that manganese oxide increased PS activity the most and that the highest diesel degradation by PS occurred when both manganese oxide and Fe(II) were used as activators. XRD did not show the transformation of manganese oxide in the presence of Fe(II). SEM-EDS showed the association of Fe(II) on the surface of manganese oxide, and ICP analysis revealed that almost all the added Fe(II) adsorbed to manganese oxide but almost none adsorbed to iron oxides under acidic conditions. Therefore, the high reactivity of PS could be due to the high density of Fe(II) over the surface of manganese oxide. 2010 Elsevier B.V. All rights reserved.

  15. Sorption behaviour of manganese-coated calcined-starfish and manganese-coated sand for Mn(II).

    Science.gov (United States)

    Lee, Seung-Mok; Kim, Won-Gee; Yang, Jae-Kyu; Tiwari, Diwakar

    2010-04-01

    The objective of the present investigation was to explore the sorption behaviour of manganese-coated samples of calcined starfish (MCCSF) (i.e. the impregnation of calcined starfish with manganese) for the removal of low levels of an important heavy metal toxic ion, Mn(II), from aqueous solutions. The suitability of this solid was further compared with two different samples of manganese-coated sands (MCS): MCS4 and MCS9 impregnated at pH 4.0 and pH 9.0, respectively. These comparative studies were performed in both batch and column experiments. Batch data indicated that a fairly good stability of the coating was obtained for these three samples in the pH region 2.5 to 10.0. The removal efficiency of MCCSF was fairly good in comparison with the MCS4 and MCS9 samples. These last two samples possessed similar Mn(II) removal capacities. Moreover, a small dose of sodium hypochlorite further enhanced the uptake of Mn(II) by these solids. The sorbate concentration dependence data fitted reasonably well to the Freundlich adsorption isotherm. The column data indicated that MCCSF possessed a relatively higher adsorption capacity compared with the MCS4 and MCS9 samples. The breakthrough curves obtained were then used to evaluate the apparent removal capacity of these solids under the dynamic conditions using the Thomas equation. The SEM images obtained for these manganese-coated solids along with the virgin base materials, i.e. sand and calcined starfish, showed that manganese oxides occupied the surfaces or pores of the base materials and formed clusters on the base surface.

  16. Treatment of groundwater containing Mn(II), Fe(II), As(III) and Sb(III) by bioaugmented quartz-sand filters.

    Science.gov (United States)

    Bai, Yaohui; Chang, Yangyang; Liang, Jinsong; Chen, Chen; Qu, Jiuhui

    2016-12-01

    High concentrations of iron (Fe(II)) and manganese (Mn(II)) often occur simultaneously in groundwater. Previously, we demonstrated that Fe(II) and Mn(II) could be oxidized to biogenic Fe-Mn oxides (BFMO) via aeration and microbial oxidation, and the formed BFMO could further oxidize and adsorb other pollutants (e.g., arsenic (As(III)) and antimony (Sb(III))). To apply this finding to groundwater remediation, we established four quartz-sand columns for treating groundwater containing Fe(II), Mn(II), As(III), and Sb(III). A Mn-oxidizing bacterium (Pseudomonas sp. QJX-1) was inoculated into two parallel bioaugmented columns. Long-term treatment (120 d) showed that bioaugmentation accelerated the formation of Fe-Mn oxides, resulting in an increase in As and Sb removal. The bioaugmented columns also exhibited higher overall treatment effect and anti-shock load capacity than that of the non-bioaugmented columns. To clarify the causal relationship between the microbial community and treatment effect, we compared the biomass of active bacteria (reverse-transcribed real-time PCR), bacterial community composition (Miseq 16S rRNA sequencing) and community function (metagenomic sequencing) between the bioaugmented and non-bioaugmented columns. Results indicated that the QJX1 strain grew steadily and attached onto the filter material surface in the bioaugmented columns. In general, the inoculated strain did not significantly alter the composition of the indigenous bacterial community, but did improve the relative abundances of xenobiotic metabolism genes and Mn oxidation gene. Thus, bioaugmentation intensified microbial degradation/utilization for the direct removal of pollutants and increased the formation of Fe-Mn oxides for the indirect removal of pollutants. Our study provides an alternative method for the treatment of groundwater containing high Fe(II), Mn(II) and As/Sb. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Production of hydroxyl radicals from Fe(II) oxygenation induced by groundwater table fluctuations in a sand column.

    Science.gov (United States)

    Jia, Mengqi; Bian, Xiao; Yuan, Songhu

    2017-04-15

    Natural and artificial processes often cause the fluctuation of groundwater table, inducing the interaction of O2 from the unsaturated zone with reduced components such as Fe(II) from the saturated zone. In light of previous findings that hydroxyl radicals (OH) can be produced from Fe(II) oxygenation, we hypothesize that OH could be produced during groundwater table fluctuations. Therefore, this study aims to measure the production of OH during water table fluctuations in a simulated sand column. Deoxygenated water in the absence and presence of 20mg/L Fe(2+) (pH6.5) was fed into the sand column. Water table fluctuations were manipulated to observe O2 entrapment, Fe(2+)oxygenation and OH production. Results showed that O2 in the pore air was efficiently entrapped by the rise of water table at the tested rates of 0.16-0.34cm/min (or 0.10-0.20m/h), and the dissolution of entrapped O2 into the pore water led to the oxygenation of Fe(2+). Production of OH was presumably attributed to oxygenation of the Fe(2+) adsorbed on Fe(III) oxyhydroxides generated in situ. In a total of 4cycles of fluctuations, the cumulative OH at all the elevations increased progressively, attaining 2.7μM in the zone near the water table in the 4th cycle. We suggest that OH produced from water table fluctuations could induce an overlooked pathway for contaminant transformation in the fluctuation zone. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The functional deformation of maxillary complete dentures in patients with flabby alveolar ridges. Part II: After surgery.

    Science.gov (United States)

    el Ghazali, S; Nilner, K; Wallenius, K

    1991-01-01

    Using strain-gauged maxillary complete dentures, the effects of the surgical removal of soft mobile tissue over the maxillary edentulous alveolar ridges--flabby ridges--on the deformation pattern and magnitude of functional strain were studied in five subjects. The results showed that a 20-90% reduction in denture deformation had taken place after surgery. Furthermore, a pre-operative shear-straining pattern of the buccal flanges and the lateral palatal slopes was not evident post-operatively. The results of this study point on the beneficial value of early surgical removal of flabby maxillary alveolar ridges.

  19. Health and safety plan for phase II of the Bear Creek Valley treatability study Oak Ridge Y-12 plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    This Health and Safety Plan (HASP) addresses the health and safety (H&S) concerns and requirements for the Bear Creek Valley (BCV) Treatability Study at the Oak Ridge Y-12 Plant. Samples will be collected from effluent following treatment tests of extraction columns, algal mats, and mature wetlands supplied by surface water locations and existing groundwater monitoring well locations. The project Sampling and Analysis Plan addresses the project description, technical objectives, procedures, and planned work activities in greater detail. It is the responsibility of the project managers, field manager, and site health and safety officer (SHSO) to determine that the requirements of this HASP are sufficiently protective. If it is determined that the requirements of this HASP are not sufficiently protective, a field change order(s) (FCO) will be prepared. FCOs will include a completed job hazard analysis or similar worksheet to ensure complete hazard assessment. FCOs must be approved by the Environmental Management and Enrichment Facilities (EMEF) project manager, EMEF H&S manager, subcontractor project or field manager, and subcontractor H&S representative. As a minimum, FCOs will be prepared if additional tasks will be performed or if contaminant exposure is anticipated.

  20. Waste management plan for phase II of the Bear Creek Valley Treatability study Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This Waste Management Plan (WMP) for the Bear Creek Valley Treatability Study addresses waste management requirements for the Oak Ridge Y-12 Plant. The study is intended to produce treatment performance data required to design a treatment system for contaminated groundwater. The treatability study will consist of an evaluation of various treatment media including continuous column tests, with up to six columns being employed to evaluate the performance of different media in the treatment of groundwater; an evaluation of the dentrifying capacity and metal uptake capacity of a wetland system; and the long-term dentrifying capacity and metal uptake capacity of algal mats. Additionally, the treatability study involves installation of a trench and incline well to evaluate and assess hydraulic impacts of pumping groundwater. The Sampling and Analysis Plan (SAP) covers the project description, technical objectives, procedures, and planned work activities in greater detail. The Health and Safety Plan (HASP) addresses the health and safety concerns and requirements for the proposed sampling activities. This WMP identifies the types and estimates the volumes of various wastes that may be generated during the proposed treatability studies. The approach to managing waste outlined in this WMP emphasizes the following points: (1) management of the waste generated in a manner that is protective of human health and the environment; (2) minimization of waste generation, thereby reducing unnecessary costs and usage of limited permitted storage and disposal capacities; and (3) compliance with federal, state, and site requirements. Prior sampling at the site has detected organic, radioactive, and metals contamination in groundwater and surface water. Proposed field operations are not expected to result in worker exposures greater than applicable exposure or action limits.

  1. Valuation of Marine Ecosystem Services in the Radial Sand Ridge Field of Southern Yellow Sea%南黄海辐射沙脊群生态系统服务功能价值评估

    Institute of Scientific and Technical Information of China (English)

    相景昌; 陈爽; 燕月; 李广宇

    2013-01-01

    在系统分析海洋生态系统服务功能及价值评估研究进展基础上,针对南黄海辐射沙脊群海域生态系统特征,采用市场价值法、替代成本法、影子价值法、成果参照法、估算模型等方法对生态系统的渔业生产、气体与气候调节、污染物处理、初级生产力、生物多样性维持及科研教育等服务功能的价值进行定量评价.结果表明:2010年南黄海辐射沙脊群生态系统服务功能价值为244.76×108元,相当沿岸区县GDP的10.24%;各类服务功能大小依次为渔业生产22.95×108元/a、氧气供给20.36×108元/a、气候调节37.87 × 108元/a、污染物处理99.45×108元/a、初级生产力48.09×108元/a、物种多样性15.03×108元/a、科研教育1.01×108元/a;污染物处理服务功能突出,占总价值的40.63%,渔业生产服务具有一定优势,占总价值的9.38%.研究结果可为区域空间开发和生态补偿提供依据.由于自然生态系统的复杂性和不确定性,所得值是一个偏低的保守值,有待今后进一步改进和完善.%Based on review of research progress of marine ecosystem services, the connotation and definition of marine ecosystem in the radial sand ridge field in Southern Yellow Sea are discussed. According to the features of South Yellow Sea sandy ridge ecosystem,the core ecosystem functions of fisheries production, oxygen supply, climate regulation, pollutant treatment, primary production, biological diversity maintaining and culture were evaluated by the methods of market price, replacement cost method, shadow pricing, results reference method, and estimation model. The results showed that the total value of the marine ecosystem services of the radial sand ridge field of southern yellow sea was roughly 244.76×108 Yuan RMB in 2010 .which is equal to 10.24% of the gross domestic product of the six coastal cities in the same year. The indirect value is 201.45×108 yuan RMB/a,4. 65 times as that of

  2. 古陆架砂脊沉积特征及其石油地质意义:以塔里木盆地志留系柯坪塔格组下段为例%Sedimentary Characteristics and Petroleum Geological Significance of Ancient Shelf Sand Ridges:A Case Study of Lower Member of Silurian Kepingtage Formation in Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    杨帅; 刘晓峰; 陆永潮; 杨素举

    2014-01-01

    塔里木盆地顺托果勒低隆起志留系柯坪塔格组下段发育的陆架砂脊为了解古陆架砂脊沉积建造提供了一个理想实例.利用测井和岩心资料,根据沉积物的岩性和沉积构造特征,将陆架砂脊划分为6个岩性相:块状层理中-细砂岩性相(FA1)、丘状交错层理中-细砂岩性相(FA2)、含撕裂状泥砾的中-细砂岩性相(FA3)、双向交错层理含粘土层的细砂岩性相(FA4)、潮汐层理的细砂岩与泥岩互层岩性相(FA5)和水平层理陆架泥岩性相(FA6);依据岩性相的组合特征,将陆架砂脊划分为4个沉积微相:砂脊核微相(FA1-FA2-FA3)、砂脊内缘微相(FA4)、砂脊外缘微相(FA5)和陆架泥微相(FA6);陆架砂脊沉积受陆架潮汐、风暴浪的共同影响.利用钻井约束的三维地震切片属性分析,确定了 NE-SW向和 NW-SE 向两组古陆架砂脊的平面展布特征.古陆架砂脊储层为特低孔、特低渗,其中砂脊核微相储层物性相对较好,平均孔隙度6.96%、平均渗透率0.34×10-3μm2;工业油流主要集中在砂脊核微相储层.古陆架砂脊的砂体多呈脊状或丘状并被厚层的陆架泥披覆,常形成同沉积的微幅背斜-岩性圈闭.%Ancient shelf sand ridge deposited in Lower member of Silurian Kepingtage Formation of Shuntuoguole uplift,Tarim basin,provides an ideal example to understand its sedimentary formation characteristics.By using well-logging and core data, shelf sand ridge is divided into 6 lithofacies:massive bedding medium-fine sandstone (FA1),hummocky cross bedding medi-um-fine sandstone (FA2),muddy conglomerate-bearing medium-fine sandstone (FA3),clay layer-bearing bimodal cross bed-ding fine sandstone (FA4),tidal bedding fine sandstone interbedded with mudstone (FA5),horizontal bedding shelf mudstone (FA6)according to the lithology and sedimentary structure of sediments.In terms of lithofacies association characteristics, shelf sand ridge whose deposits

  3. 900-m high gas plumes rising from marine sediments containing structure II hydrates at Vestnesa Ridge, offshore W-Svalbard

    Science.gov (United States)

    Smith, Andrew J.; Mienert, Jürgen; Bünz, Stefan; Greinert, Jens; Rasmussen, Tine L.

    2013-04-01

    We study an arctic sediment drift in ~1200 m water depth at Vestnesa Ridge, offshore western Svalbard. The ridge is spotted with pockmarks that range in size from a few meters to hundreds of meters in diameter and centimeters to tens of meters in height (e.g. Vogt et al., 1994). There is a strong negative-polarity seismic reflection below the ridge that is interpreted to record a negative impedance contrast marking the boundary between gas hydrate and water above and free gas and water below: it is the bottom-simulating reflector (BSR). Seismically transparent zones, interpreted as gas chimneys, extend from pockmarks at the seafloor to depths below the BSR (180-220 meters below the seafloor) (Bünz et al., 2012). Gas flares, gas hydrate, and methane-seep-specific biological communities (pogonphora and begiatoa bacterial mats) have been observed adjacent to pockmarks at the ridge (Bünz et al., 2012). We present new single-beam echosounding data that were acquired during 2010 and 2012 cruises on the R/V Helmer Hanssen at Vestnesa Ridge using a Simrad EK60 system that operates at frequencies of 18 and 38 kHz. During both cruises which lasted 3-5 days, we detected continuous bubble release from 4 separate pockmarks in 2010 and 6 separate pockmarks in 2012. There were no noticeable, short-term (hourly or daily) variations in the bubble release from the pockmarks, indicating that the venting from the pockmarks does not undergo rapid changes. Plumes from the pockmarks rise between 875 to 925m above the seafloor to a final water depth of 325 to 275m, respectively. This depth is in excellent agreement with the top of the hydrate stability zone (275 meters below sea level) for the gas composition of hydrate sampled at the ridge (96.31% C1; 3.36% C2; 0.21% C3; 0.11% IC4; 0.01% NC4). This suggests that hydrate skins are forming around the gas bubbles, inhibiting the dissolution of gas, and allowing the bubbles to rise to such great heights in the water column. Our results

  4. Holocene formation and evolution of coastal dunes ridges, Brittany (France)

    Science.gov (United States)

    Van Vliet-Lanoë, Brigitte; Goslin, Jérôme; Hénaff, Alain; Hallégouët, Bernard; Delacourt, Christophe; Le Cornec, Erwan; Meurisse-Fort, Murielle

    2016-07-01

    Holocene coastal dune formation under a continuously rising sea level (SL) is an abnormal response to increasing storm frequency. The aim of this work is to understand the coastal sedimentary budget and the present-day sand starvation, controlled by climate and man. Dating in Brittany shows that Aeolian deposition initiated from ca. 4000 cal BP, with the slowing down of the SL rise. Pre-historical dunes appeared here from ca. 3000 cal BP, without SL regression. After, further building phases recycled the same stock of sands. Historical dunes I developed from ca. 350 AD. Major storms between 900 and 1200 AD resulted in the construction of washover coastal ridges, the Historical dunes II. A part of the sand was evacuated offshore. From ca. 1350 AD, the pre-existing ridges are reworked forming the Historical dunes III, leading to rapid coastal erosion and inland drift. Holocene dunes with a rising SL constitute a temporary anomaly, mostly forced by man, soon erased by storms in Brittany.

  5. Evaluation of Ventricular Septal Defect with Special Reference to the Spontaneous Closure Rate, Subaortic Ridge, and Aortic Valve Prolapse II.

    Science.gov (United States)

    Eroglu, Ayse Guler; Atik, Sezen Ugan; Sengenc, Esma; Cig, Gulnaz; Saltik, Irfan Levent; Oztunc, Funda

    2017-06-01

    The medical records of 2283 patients with ventricular septal defect (VSD) were reviewed to determine spontaneous closure, left ventricular-to-right atrial shunt, subaortic ridge, and aortic valve prolapse. One thousand eight hundred and twenty-three patients had been followed 1 month to 26 years (median 4 years) by echocardiography. Most of 460 patients could not be followed due to transportation of the institution. VSD was perimembranous in 68.8% (1255), trabecular muscular in 21.7% (395), muscular outlet in 6% (109), muscular inlet in 2.6% (48), and doubly committed subarterial in 0.9% (16). Defect size was classified in 66.8% (1218) as small, in 15.7% (286) as moderate, and in 17.5% (319) as large. VSD closed spontaneously in 18.8% (343 of 1823 patients) by ages 40 days to 24.9 years (median, 1.8 years). One hundred fifty-seven of 1255 perimembranous defects (12.5%) and 167 of 395 trabecular muscular defects (42%) closed spontaneously (p < 0.001). Defect size became small in 306 (16.8%) of patients with VSD at a median of 2.5 years. Aneurysmal transformation was detected in 32.9% (600), left ventricular-to-right atrial shunt in 9.7% (176), subaortic ridge in 2.6% (48) of 1823 patients who were followed. In 381 (20.9%) of the 1823 patients, the VSD had been closed by a surgical or transcatheter technique. Surgery is required in one-fifth of patients with subaortic ridge or aortic valve prolapse. In conclusion, isolated VSDs are usually benign abnormalities that tend to shrink and close spontaneously.

  6. 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....

  7. Sedimentary environment evolution of Lanshayang tidal channel within the radial sand ridges,southern Yellow Sea%辐射沙脊群兰沙洋潮流通道沉积环境演化研究

    Institute of Scientific and Technical Information of China (English)

    孙祝友; 王芳; 殷勇; 黎刚; 葛松; 许庆华

    2014-01-01

    The Lanshayang tidal channel is one of the major tidal channels in the radial sand ridges area of the South Yellow Sea.The evolution of sedimentary environment of the channel since the late Pleistocene is studied based on regional literature review and core data analysis.The analysis of core 07SR09 in the channel includes sedimentary facies,grain size,14 C dating,foraminifera identification,and magnetic susceptibility.The paleo Yangtze River flows into the South Yellow Sea since the late Pleistocene.The results of grain size analysis show that the content of fine sand was decreasing because of the southward movement of the paleo Yangtze River.We argue that this area was in-fluenced by deposition after the southward movement of the paleo Yangtze River,most likely from the paleo Huanghe River,or the finer particles brought by tidal action.And these later deposited fine particles diluted the original sediment grain size composition of this area.According to the analysis of magnetic susceptibility,and the dis-tribution of foraminifera species and quantitative characteristics,the hydrodynamic conditions of the Lanshayang tidal channel have become steady gradually since the late Pleistocene,and the tidal channel is excellent for a natural deepwater channel.%通过对南黄海辐射沙脊群兰沙洋潮流通道07SR09孔的沉积相分析及粒度、14 C测年、有孔虫鉴定、磁化率等实验指标的测试结果分析,并结合区域文献和钻孔数据资料分析,研究了兰沙洋潮流通道晚更新世以来的沉积环境演化特征。晚更新世时,古长江曾在此流入南黄海,粒度测试结果表明,自晚更新世至今,因古长江逐渐南迁,古长江源的细砂含量也呈逐渐减少趋势。结合前人相关文献分析,推测本孔所处区域在古长江南迁后受到了后期物源在此沉积的影响,很可能是古黄河源物质,也有可能是潮流作用带来的较细颗粒在此沉积,这些后期沉积

  8. 南黄海辐射沙脊群生物多样性非使用价值评估%Evaluating the non-use value of biodiversity of the radial sand ridge field of southern Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    相景昌; 陈爽; 余成; 李广宇

    2014-01-01

    生物多样性非使用价值主要指生物多样性在环境和生态系统方面的服务功能,非使用价值评估对生物多样性保护与可持续利用具有重要意义.本文运用条件价值评估法(CVM),设计支付卡式调查问卷,对南黄海辐射沙脊群生物多样性的非使用价值进行评估.在允许零支付意愿(WTP=0)的问卷引导方式、以个人为支付单位,以及规避零支付意愿、以家庭为支付单位两种情况下,分别计算居民对生物多样性保护的支付意愿,进而推算出生物多样性的非使用价值;并采用相关分析和回归分析方法,进一步探讨公众支付意愿的影响因素及影响程度.结果表明,允许 WTP=0情况下,受访者的平均支付意愿为96.2元·(a·人)-1;规避 WTP=0中,平均支付意愿为232.96元·(a·户)-1,两者差异在可接受范围内;南黄海辐射沙脊群生物多样性的非使用价值为每年5.32~5.92×108元.同时,受访者收入、对生物多样性及其受用海工程影响等相关知识的认知程度,是居民支付意愿的主要影响因素,其中收入水平的影响最为显著.研究结果可为海岸带综合开发空间协调与生态补偿政策制定提供科学依据.%The total economic value of natural resources includes use value and non-use value.The non-use value of biodiversity mainly consists of the services in aspects of environment and ecological systems.Evaluating the non-use value of biodiversity has significances to biodiversity conservation and sustainable use.In this case study,the contingent valuation method(CVM)was used to evaluate the non-use value of the biodiversity in the Radial Sand Ridge Field of Southern Yellow Sea.A questionnaire of payment card CVM was developed for the survey study, which was designed with two guidance modes:one was to allow“WTP=0”and to pay by individual person;the other was to avoid“WTP=0”and to pay by household unit.Then the study calculated the residents

  9. Crustal magnetization and accretion at the Southwest Indian Ridge near the Atlantis II fracture zone, 0-25 Ma

    Science.gov (United States)

    Hosford, A.; Tivey, M.; Matsumoto, T.; Dick, H.; Schouten, Hans; Kinoshita, H.

    2003-01-01

    We analyze geophysical data that extend from 0 to 25-Myr-old seafloor on both flanks of the Southwest Indian Ridge (SWIR). Lineated marine magnetic anomalies are consistent and identifiable within the study area, even over seafloor lacking a basaltic upper crust. The full spreading rate of 14 km/Myr has remained nearly constant since at least 20 Ma, but crustal accretion has been highly asymmetric, with half rates of 8.5 and 5.5 km/Myr on the Antarctic and African flanks, respectively. This asymmetry may be unique to a ???400 km wide corridor between large-offset fracture zones of the SWIR. In contrast to the Mid-Atlantic Ridge, crustal magnetization amplitudes correlate directly with seafloor topography along the present-day rift valleys. This pattern appears to be primarily a function of along-axis variations in crustal thickness, rather than magnetic mineralogy. Off-axis, magnetization amplitudes at paleo-segment ends are more positive than at paleo-segment midpoints, suggesting the presence of an induced component of magnetization within the lower crust or serpentinized upper mantle. Alteration of the magnetic source layer at paleo-segment midpoints reduces magnetization amplitudes by 70-80% within 20 Myr of accretion. Magnetic and Ocean Drilling Program (ODP) Hole 735B data suggest that the lower crust cooled quickly enough to lock in a primary thermoremanent magnetization that is in phase with that of the overlying upper crust. Thus magnetic polarity boundaries within the intrusive lower crust may be steeper than envisioned in prior models of ocean crustal magnetization. As the crust ages, the lower crust becomes increasingly important in preserving marine magnetic stripes.

  10. Sand harm in taklimakan Desert highway and sand control

    Institute of Scientific and Technical Information of China (English)

    HANZhiwen; WANGTao; SUNQingwei; DONGZhibao; WANGXunming

    2003-01-01

    Reputed as a wonderful achievement of the world’s highway construction history,the Taklimakan Desert highway is nor facing serious sand drift encroachment problems due to its 447-km-long passage of sand sea consisting of crescent dunes,barchan chains,compound transverse dune ridges and complex megadunes.To solve some technical problems in the protection of the highway from sang drift encroachment,desert experts have been conducting the theoretical and applied studies on sand movement laws;causes,severities and time-space differentiation of sand drift damages;and control ways including mechanical,chemical and biological measures.In this paper the authors give an overall summry on the research contents and recent progress in the control of sand drift damages in China and hold that the theoretical researc results and practices in the prevention of sand drift encroachment on the cross-desert highway represnt a breakthrough and has an cpoch-making significance.Since the construction of protective forest along the cross-desert highway requires large amount of ground water,what will be its environmental consequence and whether it can effectively halt sand drift encroachment on the highway forever are the questions to be studied urgently.

  11. Observations of several characteristics of aeolian sand movement in the Taklimakan Desert

    Institute of Scientific and Technical Information of China (English)

    HAN; Zhiwen; DONG; Zhibao; WANG; Tao; CHEN; Guangting; YAN

    2004-01-01

    With both sides of the Taklimakan Desert highway line as the study area, three typical aeolian sand landforms, i.e. complex dune ridge, barchan dune and flat sand land, were selected as sand beds for the observation, analysis and research of the characteristics of aeolian sand movement such as aeolian sand stream structure, sand transport intensity, etc. in the Taklimakan Desert. The results show that there is a linear relation between the height and the log of sand transport rate over transverse dune chain, longitudinal dune ridge and flat sand land, i.e. the sand transport percentage decreases exponentially with increasing height. Sand transport rate within the 10 cm height above the bed surface accounts for 80%-95% of the total sand transport rate of the observed height (40 cm), while the sand transport rate in 20 cm occupies 98% of the total amount. Sand transport rate (g·cm-1·min-1) differs greatly with respect to different landform types and different topographic positions. Based on the investigation and analysis on aeolian sand landform origin, morphological type and distribution feature, the two typical landform assemblages, complex transverse dune chain-alluvial plain and huge longitudinal dune ridge-interridge lowland in the Taklimakan Desert were divided into several characteristic zones of aeolian sand movement states. From this one can qualitatively judge the types and severities of sand disasters at various topographic positions in the engineering installation region and further put forward concrete schemes and measures to control sand damages.

  12. New ridge parameters for ridge regression

    Directory of Open Access Journals (Sweden)

    A.V. Dorugade

    2014-04-01

    Full Text Available Hoerl and Kennard (1970a introduced the ridge regression estimator as an alternative to the ordinary least squares (OLS estimator in the presence of multicollinearity. In ridge regression, ridge parameter plays an important role in parameter estimation. In this article, a new method for estimating ridge parameters in both situations of ordinary ridge regression (ORR and generalized ridge regression (GRR is proposed. The simulation study evaluates the performance of the proposed estimator based on the mean squared error (MSE criterion and indicates that under certain conditions the proposed estimators perform well compared to OLS and other well-known estimators reviewed in this article.

  13. 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.

  14. Structural iron (II of basaltic glass as an energy source for Zetaproteobacteria in an abyssal plain environment, off the Mid Atlantic Ridge

    Directory of Open Access Journals (Sweden)

    Pauline Audrey Henri

    2016-01-01

    Full Text Available To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W. In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped in a palagonite-like structure with thicknesses up to 150 µm. The relative abundance of the associated microbial community was dominated (39% of all reads by a single operational taxonomic unit (OTU that shared 92% identity with the iron-oxidizer Mariprofundus ferrooxydans PV-1. Conversely, the oxidized basaltic glass showed the absence of iron-oxides enriched surface deposits and correspondingly there was a lack of known iron-oxidizing bacteria in the inventoried diversity. In vitro, a similar reduced basaltic glass was incubated in artificial seawater with a pure culture of the iron-oxidizing M. ferrooxydans DIS-1 for 2 weeks, without any additional nutrients or minerals. Confocal Laser Scanning Microscopy revealed that the glass surface was covered by twisted stalks characteristic of this iron-oxidizing Zetaproteobacteria. This result supported findings of the in situ experiments indicating that the Fe(II present in the basalt was the energy source for the growth of representatives of Zetaproteobacteria in both the abyssal plain and the in vitro experiment. In accordance, the surface alteration rind observed on the reduced basaltic glass incubated in situ could at least partly result from

  15. Efficient modelling of sand wave behaviour [Powerpoint Presentation

    NARCIS (Netherlands)

    Berg, van den Joris; Damme, van Ruud

    2004-01-01

    Sand waves form a pattern of more or less parallel ridges. The wave length is about 300 meters and the height up to 10 meters, which is a considerable amount of the total water depth. Sand waves migrate with speeds of about 10 meters per year. Information on their behaviour is valuable: the larger p

  16. New beach ridge type: severely limited fetch, very shallow water

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, W.F.; Demirpolat, S.

    1988-09-01

    The southern end of Laguna Madre (Texas) north of the Rio Grande mouth is marked by very shallow water, wide tidal flats, lunettes, islands made of beach ridges, and lesser features. The number and variety of islands in the lagoon is remarkable. The lunettes (clay dunes) are made primarily of quartz sand and coarse silt. They are common 5-10 m high, irregular in shape, and steep sided. They were deposited from wind transport and did not migrate. Those that are islands in the lagoon predate present position of sea level. Islands made of beach ridges were built from the lagoon side. Photoanalysis, field work, and granulometry all show that this sand was not moved into these ridges by Gulf of Mexico waves. Trenches in 12 beach ridges showed horizontal bedding but neither low-angle nor steep cross-bedding (quite unlike swash-built beach ridges). The ridges were built by wind-tide lag effects, not from the swash. Therefore, these beach ridges are a new type, in addition to swash-built, eolian, and storm-surge ridges. Growth of the ridges appears to be completed.

  17. Eskers in Ireland, analogs for sinuous ridges on Mars

    Science.gov (United States)

    Pellicer, Xavier; Bourke, Mary

    2014-05-01

    Sinuous ridges on the surface of Mars are often inferred as putative esker ridges. Eskers cover several hundred kilometers of the Irish landscape and are one of the dominant landforms in the Irish Midlands. Well exposed stratigraphic sections and the body of existing knowledge due to extensive research carried out on these landforms make the Irish eskers an excellent analog for sinuous ridges on Mars. The Irish Eskers are sinuous ridges 0.1 - 80 km long, 20 - 500 m wide and 4 - 50 m high laid down by glacial meltwater in tunnels and crevasses in stationary or retreating ice sheets. They are commonly composed of sands and gravels with rounded boulders and cobbles. The gravels are usually bedded and the beds often slump towards the flank of the esker, indicating collapse as the confining ice walls melt. Four types of eskers have been identified in Ireland: (i) Continuous subglacial tunnel fill represents deposition within tunnels underneath or within an ice body originally used as water escape conduits; (ii) Continuous fluvial ice-channel fill deposit in channels cut into the ice on top of the glacier or down to the substrate subsequently infilled by sediments; (iii) Long beads - subglacial tunnel fill are segmented ridges, with a length-width ratio of 5:1 to 10:1, representing sequential deposition near or at the ice margin as the ice sheet retreats; (iv) Short beads are glaciolacustrine deposits interpreted as sequential deposition of ice-contact subaqueous outwash fans. Irish eskers have significant morphological similarities with those identified on Mars providing an opportunity for an insightful morphological and morphometric analysis to determine potential formative environments on Mars. Putative Martian eskers are 2-300 km long, 50-3000 m wide and 10-150 m high. The Irish eskers are similar in scale and present dimensions within these ranges. Eskers in Ireland are composed of sand and gravel with cobbles and boulders. Mars esker-like ridges observed in high

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-04-01

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

  19. 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....

  20. Minimum and Complete Fluidization Velocity for Sand-Palm Shell Mixtures, Part II: Characteristic Velocity Profiles, Critical Loading and Binary Correlations

    Directory of Open Access Journals (Sweden)

    V. S. Chok

    2010-01-01

    Full Text Available Problem statement: In Part I of this research, the main features of the fluidization behavior and characteristic velocities had been reported. Approach: In the present research, the mixtures characteristic velocity profiles for various sand sizes, palm shell sizes and weight percents were presented. It was recognized that there are instances where the characteristic values remain nearly unchanged from its pure sand values. This regime of constant values can be observed in both compartments and can be established depending on the bed properties. The term "Critical loading" is then selected to define the maximum palm shell content (size and weight percent that can be present in the mixtures where the characteristic velocities remain absolutely of pure sand values. Results: The critical loading increases with the increase of sand size but decreases with the increase of palm shell size. Moreover, it can be observed that the critical loading generally decreases with the increase in particle size ratio, although exception is sighted in the combustor for the mixture with the largest sand size. Overall, the largest sand size has the highest critical loading. Meanwhile, the selected correlations are able to describe the qualitative variation in the characteristic velocities. However, quantitatively, these correlations are unsatisfactory as they are either over-estimate or under-estimate. Conclusion/Recommendations: It is desirable to establish the regime of critical loading since the mixture characteristic velocities can be pre-determined using bed material properties made up from pure sand (inert values. Within this regime, a single operational velocity can be set for respective compartment that is independent from variation of palm shell size and weight percent in the mixtures (especially during combustion or gasification. Ultimately, the state of fluidization (e.g., bubbling or vigorously fluidized and mixing/segregation condition that depend on

  1. Tar sand

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-01-01

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

  2. 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!

  3. Optical dating of dune ridges on Rømø

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, A. S.; Andersen, Thorbjørn Joest

    2007-01-01

    . Samples for OSL dating were taken ~0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations......, and all ages were broadly consistent with those expected from historical information. The oldest aeolian surface on Rømø appears to be 370±30 years. This is built on what we interpret as a marine sandbank, whose surface is ~700 years old. The sand ridges seaward of the hummocky dune field have well...

  4. 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.

  5. The Sedimentary Characteristics and Formation Mechanism of Shell Ridges Along the Southwest Coast of Bohai Bay

    Institute of Scientific and Technical Information of China (English)

    LIU Zhijie; ZHUANG Zhenye; HAN Deliang; QI Xingfen

    2005-01-01

    The present paper studies the sedimentary characteristics and mechanism of the shell ridges on the southwestern coast of Bohai Bay, which are the largest and have the highest shell (or shell fragment) content in the world. These shell ridges are composed of two sedimentary subfacies: the ridge subfacies and the ridge infill subfacies with different inner textures and sedimentary structures. The ridge subfacies primarily consists of fresh shells and/or shell fragments with parallel beddings and high-angle oblique beddings. The ridge infill subfacies consists of finer shell fragments and silty sand with parallel beddings oblique to land. The evolution of the shell ridge is controlled by the accumulation of substantial shell material,the relative slow erosion of shoreline, storm waves, winds and the shift of river routes. Wind tunnel tests indicate that the critical movement velocity of shell is lower than that of quartz sand of the same grain size. Deltaic progradation alternates with shell ridge growth. While the Yellow River empties into the sea through this area, accompanied by deltaic progradating, the shell material is scarce, which is unfavorable to the growth of the shell ridge. Conversely, erosion occurs along an abandoned delta coast where a shell ridge may develop, e.g. the shell ridge on the southwest of Bohai Bay.

  6. 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...

  7. Ridge and Furrow Fields

    DEFF Research Database (Denmark)

    Møller, Per Grau

    2016-01-01

    Ridge and furrow is a specific way of ploughing which makes fields of systematic ridges and furrows like a rubbing washboard. They are part of an overall openfield system, but the focus in this paper is on the functionality of the fields. There are many indications that agro-technological reasons...

  8. Removal of Cadmium, Copper, Lead and Nickel from Aqueous Solution by White, Yellow and Red United Arab Emirates Sand

    Directory of Open Access Journals (Sweden)

    L. Pappalardo

    2010-01-01

    Full Text Available Problem statement: To remove toxic heavy metal ions from wastewater using local sand as a low cost adsorbent. Approach: Removal efficiency of Cd(II, Cu(II, Pb(II and Ni(II from aqueous solution by white, yellow and red UAE sand was investigated at 25.0°C using the methods of batch equilibrium adsorption and column filtration. In each case, a mixture containing 20 ppm of each ion was employed. In the equilibrium study, the effect of sand dosage was measured for mixtures containing 20 ppm of each ion. In the column filtration study, the mixture was added to a column packed with yellow sand and the composition of the effluent was measured for each 0.050 dm3 portion. Concentrations were measured on an inductively coupled plasma-atomic emission spectrometer “ICP-AES”. Results: Removal efficiency by sand type was found to follow the order yellow>white>red. At low sand dosages, removal efficiencies of Pb(II and Cu(II were much higher than those for Ni(II and Cd(II. For example, at a sand dosage of 0.02 kg dm-3, removal efficiencies of Pb(II, Cu(II, Cd(II and Ni(II were, respectively, 95, 86, 33 and 23% for yellow sand; 89, 86, 30 and 18% for white sand; and 75, 63, 12 and 13% for red sand. Column filtration using yellow sand confirmed that removal efficiency followed the order Pb(II>Cu(II>Cd(II>Ni(II, with all four ions completely removed at mass ratios (metal/sand lower than 3.0×10-4. Conclusion: Equilibration on sand and sand filtration are most efficient for the removal Pb(II and Cu(II. Sand filtration can be effectively utilized to separate Pb(II and Cu(II from a mixture containing all four ions.

  9. Influence green sand system by core sand additions

    OpenAIRE

    N. Špirutová; J. Beňo; V. Bednářová; J. Kříž; M. Kandrnál

    2012-01-01

    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 co...

  10. 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....

  11. 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...

  12. Ridge jump process in Iceland

    OpenAIRE

    Garcia, Sebastian

    2010-01-01

    Eastward ridge jumps bring the volcanic zones of Iceland back to the centre of the hotspot in response to the absolute westward drift of the Mid-Atlantic Ridge. Mantellic pulses triggers these ridge jumps. One of them is occurring in Southern Iceland, whereas the exact conditions of the last ridge jump in Northern Iceland remain controversial. The diachronous evolution of these two parts of Iceland may be related to the asymmetric plume-ridge interaction when comparing Northern and Southern I...

  13. Comparison of two Satellite Imaging Platforms for Evaluating Sand Dune Migration in the Ubari Sand Sea (Libyan Fazzan)

    Science.gov (United States)

    Els, A.; Merlo, S.; Knight, J.

    2015-04-01

    Sand dunes can change location, form or dimensions depending on wind direction and strength. Sand dune movements can be effectively monitored through the comparison of multi-temporal satellite images. However, not all remote sensing platforms are suitable to study sand dunes. This study compares coarse (Landsat) and fine (Worldview) resolution platforms, specifically focussing on sand dunes within the Ubari Sand Sea (Libya). Sand dune features (crest line, dune ridge basal outlines) were extracted from Landsat and Worldview 2 imagery in order to construct geomorphic maps. These geomorphic maps were then compared using image overlay and differencing, and the Root Mean Squared Error (RMSE) was used to determine if the mapped dune patterns were significantly different. It was found that Landsat is a sufficient data source when studying dune patterns within a regional sand sea, but smaller dunes identified from Worldview data were not capable of being extracted in the data sourced from Landsat. This means that for studies concerned with the dune patterns and movements within sand seas, Landsat is sufficient. But in studies where the specific dynamics of specific dunes are required, a finer resolution is required; platforms such as Worldview are needed in order to gain more detailed insight and to link the past and present day climate and environmental change.

  14. Fingermark ridge drift.

    Science.gov (United States)

    De Alcaraz-Fossoul, Josep; Roberts, Katherine A; Feixat, Carme Barrot; Hogrebe, Gregory G; Badia, Manel Gené

    2016-01-01

    Distortions of the fingermark topography are usually considered when comparing latent and exemplar fingerprints. These alterations are characterized as caused by an extrinsic action, which affects entire areas of the deposition and alters the overall flow of a series of contiguous ridges. Here we introduce a novel visual phenomenon that does not follow these principles, named fingermark ridge drift. An experiment was designed that included variables such as type of secretion (eccrine and sebaceous), substrate (glass and polystyrene), and degrees of exposure to natural light (darkness, shade, and direct light) indoors. Fingermarks were sequentially visualized with titanium dioxide powder, photographed and analyzed. The comparison between fresh and aged depositions revealed that under certain environmental conditions an individual ridge could randomly change its original position regardless of its unaltered adjacent ridges. The causes of the drift phenomenon are not well understood. We believe it is exclusively associated with intrinsic natural aging processes of latent fingermarks. This discovery will help explain the detection of certain dissimilarities at the minutiae/ridge level; determine more accurate "hits"; identify potentially erroneous corresponding points; and rethink identification protocols, especially the criteria of "no single minutiae discrepancy" for a positive identification.

  15. Production of oil from Intermountain West tar sands deposits

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-03-01

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

  16. 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.

  17. Pretreatment of turkey fat-containing wastewater in coarse sand and gravel/coarse sand bioreactors.

    Science.gov (United States)

    Gaur, Rashmi Singh; Cai, Ling; Tuovinen, Olli H; Mancl, Karen M

    2010-02-01

    Fat, oil and grease in wastewater can be difficult to treat because of their slow decomposition. Traditional pretreatment facilities to remove fat, oil and grease from wastewater are increasingly costly. The hypothesis in this study was that pretreatment of animal fat-containing wastewater in sand and sand/gravel filters facilitates the conversion of slowly degradable organic matter measured as the difference between chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD(5)) for subsequent biological treatment. The pretreatment was evaluated using simulated turkey-processing wastewater and coarse sand and sand/gravel filters at a constant hydraulic loading rate of 132L/m(2)/day. Two types of fixed media reactors were employed: (i) one set with a varying depth of coarse sand, and (ii) the second was similar but with an additional pea gravel cap. The results indicated that the relative removal of COD was slightly improved in the sand bioreactors with a pea gravel cap irrespective of the depth of coarse sand, but partial conversion to BOD(5) was not consistently demonstrated. Pea gravel may act as a sieve to entrap organic matter including fat globules from the wastewater. Multiple dosing at the same daily loading rate slightly improved the treatment efficiency of the sand bioreactors. The ratios of influent-COD/effluent-COD were always greater than 1.0 following a change in the dosing frequency after a rest period, suggesting that organic matter, specifically fat globules in this case, was retained by the column matrix.

  18. 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.

  19. 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....

  20. 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...

  1. Characteristic and paleoenvironmental evolution of subaerial tidal sand body in Subei coastal plain

    Institute of Scientific and Technical Information of China (English)

    李从先; 张家强; 杨守业; 范代读

    1999-01-01

    The subaerial tidal sand area in the northern Jiangsu Province (Subei), stretching from Dongtai towards east with a fan shape, is an early developing stage of radial sand ridges distributed in the South Yellow Sea. Since 5 000—6 000 a BP, after the Holoeene transgression maximum in the northern Jiangsu Province, subaqueous tidal sand bodies were exposed and changed into land gradually. The environmental magnetism analysis shows that subaerial tidal sand strata are formed by the convergent-divergent palco-tidal current field. The sediment source of tidal sand strata came early from the Changjiang River and late from the Yellow River. Sea floor erosion by tidal currents also served as an important sand source. Drilling cores and ground-penetrating profile show that there exists no probability of sand supplying directly by a large river through the apical area of tidal sand ridges either on land or in the sea. Fluvial deposits supplied the tidal sand bodies by alongshore transportation, which corresponds

  2. University of Utah Oil Sand Research and Development Program

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

    An overview of the Oil Sand Research and Development Program at the University of Utah will be presented. It will include resource characterization of the Uinta Basin oils and deposits and bitumens and bitumen-derived liquid recovery and upgrading technology and product utilization. The characterization studies will include the Whiterocks and Asphalt Ridge oil sands. The discussion of recovery and upgrading technologies will include aqueous separation, thermal recovery processes; solvent extraction, and thermal and catalytic upgrading of bitumen and bitumen-derived heavy oils. Product evaluation studies will include jet fuels, diesel fuel, asphalt and specialty chemicals. Plans for the future of the project will be discussed.

  3. Geologic and paleoecologic studies of the Nebraska Sand Hills

    Science.gov (United States)

    Ahlbrandt, Thomas S.; Fryberger, S.G.; Hanley, John H.; Bradbury, J. Platt

    1980-01-01

    PART A: The Nebraska Sand Hills are an inactive, late Quaternary, most probably Holocene, dune field (covering 57,000 km 2 ) that have been eroded along streams and in blowouts, resulting in excellent lateral and vertical exposures of the stratification of dune and interdune sediments. This paper presents new data on the geometry, primary sedimentary structures, modification of sedimentary structures, direction of sand movement, and petrography of these eolian deposits. Eolian deposits of the Sand Hills occur as relatively thin (9-24 m) 'blanket' sands, composed of a complex of dune and discontinuous, diachronous interdune deposits unconformably overlying fluviolacustrine sediments. The internal stratification of large dunes in the Sand Hills (as high as 100 m), is similar to the internal stratification of smaller dunes of the same type in the Sand Hills, differing only in scale. Studies of laminae orientation in the Sand Hills indicate that transverse, barchan, and blowout dunes can be differentiated in rocks of eolian origin using both the mean dip angle of laminae and the mean angular deviation of dip direction. A variety of secondary structures modify or replace primary eolian stratification in the Sand Hills, the more common of which are dissipation structures and bioturbation. Dissipation structures in the Sand Hills may develop when infiltrating water deposits clay adjacent to less permeable layers in the sand, or along the upper margins of frozen layers that form in the sands during winter. Cross-bed measurements from dunes of the Nebraska Sand Hills necessitate a new interpretation of the past sand transport directions. The data from these measurements indicate a general northwest-to-southeast drift of sand, with a more southerly drift in the southeast part of the Sand Hills. A large area of small dunes Sand Hills was interpreted by him on the basis of morphology only. We interpret these as transverse-ridge dunes that were generally moving to the south

  4. Cytotoxicity of yellow sand in lung epithelial cells

    Indian Academy of Sciences (India)

    Y H Kim; K S Kim; N J Kwak; K H Lee; S A Kweon; Y Lim

    2003-02-01

    The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0.003 ± 0.001 mm. Major elements of yellow sand were Si(27.7 ± 0.6%), Al(6.01 ± 0.17%), and Ca(5.83 ± 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.

  5. 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...

  6. Sand and Gravel Operations

    Data.gov (United States)

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

  7. Beach ridges and prograded beach deposits as palaeoenvironment records

    Science.gov (United States)

    Tamura, Toru

    2012-09-01

    resolution and continuity inherent to beach ridge and beach deposits. The plan-view geomorphic expression of beach ridges typically consists of ridge sets with multi-decadal intervals, whereas their internal sedimentary structures define shorter time scales. Records of beach sedimentation and erosion are likely to be reworked by episodic high-magnitude beach retreat, and the resultant record of the net progradation is likely to be sporadic and discontinuous. The height of sandy beach ridges is often variable due to differing degrees of aeolian sand accumulation, and they are thus not used as sea-level indicators unless purely wave-built. Gravel ridge height is a relatively reliable indicator of sea level, but can vary in response to storminess fluctuations. Subsurface sediment facies boundaries are preferred as sea-level indicators, and those proposed include: boundaries of aeolian/beach, foreshore/shoreface, and upper/lower shorefaces. Catastrophic events are expressed in both erosional and depositional records. Erosion surfaces, or scarp imprints, revealed in a cross section of beach deposits, indicate storm or tsunami events. However, erosional events are likely to rework previous records of sedimentation and even other erosional events, and thus the apparent history decoded from the resultant deposits tends to be biased. Several attempts for estimating the frequency and intensity of prehistoric cyclones rely on assumed relationships between the level of coarse sand beach ridges and cyclone inundation. The formative process of coarse sand ridges remains uncertain and needs to be clarified, as it constitutes the fundamental basis of these attempts. The growth rates of beach-ridge systems are expected to reflect fluctuations in river sediment discharge to the coast and in aeolian sand flux due to onshore winds, both of which are affected by climate change. Assessment of the growth rate is potentially improved by ground-penetrating radar survey of subsurface structure and by

  8. 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...

  9. 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.

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

    Science.gov (United States)

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

    2017-04-01

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

  11. 长三角浅海辐射沙洲风能资源开发与非并网风电产业发展研究%Exploitation of Wind Resources and Development of Wind Power Industry over Shallow Sea Radial Sand Ridges of the Yangtze River Delta

    Institute of Scientific and Technical Information of China (English)

    顾为东; 周志莹; 邱涛

    2009-01-01

    In recent years, the economy of the Yangtze River Delta has been growing rapidly, leading to an increasing demand for energy and resources in which the gap of electricity is especially large. On the other hand, the area is facing more and more serious eco-environmental problems, making it quite urgent to optimize energy structure, improve the eco-environment, and to carry out a large scale development and application of new resources and renewable resources. Located in the Yangtze River Delta, Dongtai, Rudong, and Dafeng Cities are very abundant in wind energy over their radial sand ridges of shallow sea. In addition, they bear a wide range of advantages, like relatively good geology conditions, small probabilities of extreme weather, no navigation channels, large fishing grounds and underground cables. They are all located at power load centers, possessing a good industrial foundation of high and new technologies, rich talents, a developed capital market, and a strong intrinsic force, all of which would be jointly conducive to development of a large scale, or a super scale offshore wind farm. Also, it has a tremendous development space. For example, developing 10%-15% of the wind resources is equal to building a sustainable green resource base which is of a great capability to produce standard coal of 25 million tons per year (equal to the mining quantity of four Nanbao oil fields), and meanwhile to reduce CO_2 emission of 123 million tons per year. Moreover, it enjoys a number of advantages like not occupying cultivated land, not producing an immigrant, and not resulting in degradation of the eco-environment. In the paper, we offered a new combination way to integrate large scale non-grid-connected wind power with heavy power consumption load based on an analysis on the difficulty of power grids in holding an intermittent and fluctuant power provided by large scale offshore wind power field. Several suggestions are also given as follows: building a series of

  12. Plutonium working group report on environmental, safety and health vulnerabilities associated with the department`s plutonium storage. Volume II, Appendix B, Part 9: Oak Ridge site site team report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    This report provides the input to and results of the Department of Energy (DOE) - Oak Ridge Operations (ORO) DOE Plutonium Environment, Safety and Health (ES & H) Vulnerability Assessment (VA) self-assessment performed by the Site Assessment Team (SAT) for the Oak Ridge National Laboratory (ORNL or X-10) and the Oak Ridge Y-12 Plant (Y-12) sites that are managed by Martin Marietta Energy Systems, Inc. (MMES). As initiated (March 15, 1994) by the Secretary of Energy, the objective of the VA is to identify and rank-order DOE-ES&H vulnerabilities associated for the purpose of decision making on the interim safe management and ultimate disposition of fissile materials. This assessment is directed at plutonium and other co-located transuranics in various forms.

  13. Bituminous sands : tax issues

    Energy Technology Data Exchange (ETDEWEB)

    Patel, B. [PricewaterhouseCoopers LLP, Calgary, AB (Canada)

    2004-07-01

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

  14. 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...... test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. The Danish Triaxial Cell prescribes smooth pressure heads and specimens with equal height and diameter....... Four series with Id equal to 0.92, 0.87 0.76 and 0.55 have been performed....

  15. 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...

  16. Coarse-clast ridge complexes of the Caribbean: A preliminary basis for distinguishing tsunami and storm-wave origins

    Science.gov (United States)

    Morton, R.A.; Richmond, B.M.; Jaffe, B.E.; Gelfenbaum, G.

    2008-01-01

    Coastal gravel-ridge complexes deposited on islands in the Caribbean Sea are recorders of past extreme-wave events that could be associated with either tsunamis or hurricanes. The ridge complexes of Bonaire, Jamaica, Puerto Rico (Isla de Mona), and Guadeloupe consist of polymodal clasts ranging in size from sand to coarse boulders that are derived from the adjacent coral reefs or subjacent rock platforms. Ridge-complex morphologies and crest elevations are largely controlled by availability of sediments, clast sizes, and heights of wave runup. The ridge complexes are internally organized, display textural sorting and a broad range of ages including historical events. Some display seaward-dipping beds and ridge-and-swale topography, and some terminate in fans or steep avalanche slopes. Together, the morphologic, sedimentologic, lithostratigraphic, and chronostratigraphic evidence indicates that shore-parallet ridge complexes composed of gravel and sand that are tens of meters wide and several meters thick are primarily storm-constructed features that have accumulated for a few centuries or millennia as a result of multiple high-frequency intense-wave events. They are not entirely the result of one or a few tsunamis as recently reported. Tsunami deposition may account for some of the lateral ridge-complex accretion or boulder fields and isolated blocks that are associated with the ridge complexes. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).

  17. UK Frac Sand Resources

    OpenAIRE

    Mitchell, C J

    2015-01-01

    Although still just a glimmer in the gas man’s eye, the prospect of shale hydrocarbon (oil and gas) development in the UK has many companies thinking about the industrial minerals it will require. Chief amongst these is silica sand which is used as a ‘proppant’ in the hydraulic fracturing, or ‘fracking’, of shales to help release the gas. The UK has large resources of sand and sandstone, of which only a small proportion have the necessary technical properties that classify them as ‘silica san...

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Benaafi, Mohammed; Abdullatif, Osman

    2014-05-01

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

  20. BioTwist : overcoming severe distortions in ridge-based biometrics for succesful identification

    NARCIS (Netherlands)

    Kotzerke, J.

    2016-01-01

    This thesis focuses on ridge-based and highly distorted biometrics, the different chal-lenges involved in a verification of identity scenario, and how to overcome them. More specifically, we work on ridge-based biometrics in two different contexts: (i) newborn and infant biometrics and (ii) quality

  1. 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…

  2. Faraday, Jets, and Sand

    NARCIS (Netherlands)

    Sandtke, M.; van der Meer, Roger M.; Versluis, Andreas Michel; Lohse, Detlef

    2003-01-01

    When a 6-mm layer of fine sand with an average grain size of 40 µm is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun. A quasi two-dimensional setup reveals the jet-formation

  3. 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…

  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. 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...

  6. 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...

  7. Sand supply to beaches

    Science.gov (United States)

    Aagaard, Troels

    2017-04-01

    In most cases, beaches and dunes are built by sand that has been transported onshore from the shoreface. While this has been known for a long time, we are still not able to quantitatively predict onshore sediment transport and sand supply to beaches. Sediment transport processes operating during brief, high-energy stormy conditions - when beaches erode and sand moves offshore - are fairly well known and they can be modelled with a reasonable degree of confidence. However, the slower onshore sand transport leading to beach recovery under low-to-moderate energy conditions - and the reason why beaches and dunes exist in the first place - is not yet well understood. This severely limits our capability to understand and predict coastal behaviour on long time scales, for example in response to changing sea level or wave conditions. This paper will discuss issues and recent developments in sediment transport measurement and prediction on the lower and upper shoreface and into the swash zone. The focus will be on the integration and upscaling of small-scale deterministic process measurements into parametric models that may increase modelling capabilities of coastal behaviour on larger temporal and spatial scales.

  8. Polygonal Ridge Networks on Mars

    Science.gov (United States)

    Kerber, Laura; Dickson, James; Grosfils, Eric; Head, James W.

    2016-10-01

    Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. While networks formed from mineralized fractures hint at hot, possibly life-sustaining circulating ground waters, networks formed by impact-driven clasting diking, magmatic dikes, gas escape, or lava flows do not have the same astrobiological implications. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morphology is characteristic of the Nili Fossae and Nilosyrtis region and consists of thin, criss-crossing ridges with a variety of heights, widths, and intersection angles. They are found in ancient Noachian terrains at a variety of altitudes and geographic locations and may be a mixture of clastic dikes, brecciated dikes, and mineral veins. They occur in the same general areas as valley networks and ancient lake basins, but they are not more numerous where these features are concentrated, and can appear in places where they morphologies are absent. Similarly, some of the ridge networks are associated with hydrated mineral detections, but some occur in locations without detections. Smaller, light-toned ridges of variable widths have been found in Gale Crater and other rover sites and are interpreted to be smaller version of the Nili-like ridges, in this case formed by the mineralization of fractures. This type of ridge is likely to be found in many other places on Mars as more high-resolution data becomes available. Hellas Basin is host to a third type of ridge morphology consisting of large, thick, light-toned ridges forming regular polygons at several superimposed scales. While still enigmatic, these are most likely to be the result of sediment-filled fractures. The Eastern Medusae Fossae Formation contains large swaths of a fourth, previously undocumented, ridge network type

  9. Erosion phenomena in sand moulds

    Directory of Open Access Journals (Sweden)

    A. Chojecki

    2008-03-01

    Full Text Available Authors studicd the erosion phcnorncna in sand moulds pured with cast iron. Thc study comprises an evaluation of erosionresistance of thc three sands: grccn sand. sand bondcd with inorganic or organic bindcr. It was concluded that thc most resistant is [heclassic green sand with thc addition of 5 B coal dust. Resistance of the sand with organic binder is generally weak and dcvnds onkind of used raisin. Spccinl nztcntion was paid to the sands with no organic bindcr watcr glass and phospha~c. It was Sound that thcirrcsistance depends on dehydratation conditions. When the mould is stored in law humidity of atmosphcrc the very strong crosion canbe expected. It rcsul ts hrn thc micro fractures in the bridges of binders, joining the grains of the sable. This phcnomcna facilitates thetearing away of fragments of sand [tom the surface

  10. THE FORMATION PROCESS AND PALEOENVIONMENT SIGNIFICANCE OF STONE RIDGE LANDFORMS ON NORTH CHINA PLAIN%华北平原西南部石垄地貌的成因机理与古环境意义

    Institute of Scientific and Technical Information of China (English)

    王然; 李庆辰; 徐全洪

    2012-01-01

    The stone ridges landform is situated in the southwest part of the North China Plain. It is about 10 kilometers from to the northwest of Handan City, Hebei Province. The stone ridge landforms consist of one big stone ridge and 9 small ridges which were unearthed by the local peasants when they excavated earth to make brick in 1988. The big stone ridge is 44. 7 meters long,4. 3 meters wide and 2. 5meters high, the small stone ridges are from 30meters to 35meters long, from 1. 9 meters to 2meters wide and lmeter high. The total length of the stone ridges is about 300meters. The stone ridges with the thin shape and brownish-yellow color developed a V-shaped cross vent every 0. 5 meter-1 meter on the stone ridge bodies, overall observation, the thin shaped stone ridges arranged in good order looks like a row of spinal bone of vertebrates,and so far as to there is a "dragon claw" growing out of the left side of the big stone ridge. The stone ridges had caused a sensation throughout the country after the program "Approaching Science" of CCTV 10 broadcasted on 8 ~ 14,April,2008. Therefore it is inferred that the stone ridges are the vertebrate fossils or authenticating object for the Zhao emperors. But the authors, based on the field spot investigation and laboratorial analyses, find that the observed unidirectional oblique one-way tilt sedimentary bedding on the profile section and trough cross sedimentary bedding on the cross section, the measurement of the stone ridges extend direction in the field spot, and the results of size-frequency analyses, as well as the psephicity estimate and composition determine of the sand body, and hydrochloric acid reaction in the laboratory, indicate that the stone ridges are calcium carbonate cemented palaeochannel sand bodies which deposited in the ancient-Minghe delta area during the Würm Interglacial Epoch from Würm II to Würm IE Glaciation Epoch about 28. 6kaB. P. in the Last Pleistocene. The V-shaped vents are the cross

  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. Calendar year 1996 annual groundwater monitoring report for the Chestnut Ridge Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    This annual monitoring report contains groundwater and surface water monitoring data obtained in the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime) during calendar year (CY) 1996. The Chestnut Ridge Regime encompasses a section of Chestnut Ridge west of Scarboro Road and east of an unnamed drainage feature southwest of the US Department of Energy (DOE) Oak Ridge Y-12 Plant (unless otherwise noted, directions are in reference to the Y-12 Plant administrative grid). The Chestnut Ridge Regime contains several sites used for management of hazardous and nonhazardous wastes associated with plant operations. Groundwater and surface water quality monitoring associated with these waste management sites is performed under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). Included in this annual monitoring report are the groundwater monitoring data obtained in compliance with the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit for the Chestnut Ridge Regime (post-closure permit) issued by the Tennessee Department of Environment and Conservation (TDEC) in June 1996. Besides the signed certification statement and the RCRA facility information summarized below, condition II.C.6 of the post-closure permit requires annual reporting of groundwater monitoring activities, inclusive of the analytical data and results of applicable data evaluations, performed at three RCRA hazardous waste treatment, storage, or disposal (TSD) units: the Chestnut Ridge Sediment Disposal Basin (Sediment Disposal Basin), the Chestnut Ridge Security Pits (Security Pits), and Kerr Hollow Quarry.

  13. Sand hazards on tourist beaches.

    Science.gov (United States)

    Heggie, Travis W

    2013-01-01

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

  14. 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

  15. Ridge 2000 Data Management System

    Science.gov (United States)

    Goodwillie, A. M.; Carbotte, S. M.; Arko, R. A.; Haxby, W. F.; Ryan, W. B.; Chayes, D. N.; Lehnert, K. A.; Shank, T. M.

    2005-12-01

    Hosted at Lamont by the marine geoscience Data Management group, mgDMS, the NSF-funded Ridge 2000 electronic database, http://www.marine-geo.org/ridge2000/, is a key component of the Ridge 2000 multi-disciplinary program. The database covers each of the three Ridge 2000 Integrated Study Sites: Endeavour Segment, Lau Basin, and 8-11N Segment. It promotes the sharing of information to the broader community, facilitates integration of the suite of information collected at each study site, and enables comparisons between sites. The Ridge 2000 data system provides easy web access to a relational database that is built around a catalogue of cruise metadata. Any web browser can be used to perform a versatile text-based search which returns basic cruise and submersible dive information, sample and data inventories, navigation, and other relevant metadata such as shipboard personnel and links to NSF program awards. In addition, non-proprietary data files, images, and derived products which are hosted locally or in national repositories, as well as science and technical reports, can be freely downloaded. On the Ridge 2000 database page, our Data Link allows users to search the database using a broad range of parameters including data type, cruise ID, chief scientist, geographical location. The first Ridge 2000 field programs sailed in 2004 and, in addition to numerous data sets collected prior to the Ridge 2000 program, the database currently contains information on fifteen Ridge 2000-funded cruises and almost sixty Alvin dives. Track lines can be viewed using a recently- implemented Web Map Service button labelled Map View. The Ridge 2000 database is fully integrated with databases hosted by the mgDMS group for MARGINS and the Antarctic multibeam and seismic reflection data initiatives. Links are provided to partner databases including PetDB, SIOExplorer, and the ODP Janus system. Improved inter-operability with existing and new partner repositories continues to be

  16. PROCESSING OF MONAZITE SAND

    Science.gov (United States)

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

    1957-12-01

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

  17. Mid-ocean ridges, InRidge and the future

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Mukhopadhyay, R.; Drolia, R.K.; Ray, Dwijesh

    , Canada, France, Germany, Iceland, Italy, Japan, Korea, Mexico, Norway, Portugal, Russia, Spain, UK and US pooled in their expertise. Some of the national ridge research programmes of various coun - tries ar e: Bridge (Britain, this programme is now...) to oversee the development and implementation of its various programmes. This committee consists of a cross - section of the global ridge researchers. A central office (presently in Japan) is invol - ved to plan activities, hold special conferences...

  18. 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.

  19. 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

  20. Growth of a tectonic ridge

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.W.; Messerich, J.A. [Geological Survey, Denver, CO (United States); Johnson, A.M. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences

    1997-12-31

    The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone and the ridge. They present data on the horizontal deformation at several scales associated with activity within the ridge and belt of shear zones and show the differential vertical uplifts. And, they conclude with a discussion of potential models for the observed deformation.

  1. Geology along the Blue Ridge Parkway in Virginia

    Science.gov (United States)

    Carter, Mark W.; Southworth, C. Scott; Tollo, Richard P.; Merschat, Arthur J.; Wagner, Sara; Lazor, Ava; Aleinikoff, John N.

    2017-01-01

    Detailed geologic mapping and new SHRIMP (sensitive high-resolution ion microprobe) U-Pb zircon, Ar/Ar, Lu-Hf, 14C, luminescence (optically stimulated), thermochronology (fission-track), and palynology reveal the complex Mesoproterozoic to Quaternary geology along the ~350 km length of the Blue Ridge Parkway in Virginia. Traversing the boundary of the central and southern Appalachians, rocks along the parkway showcase the transition from the para-autochthonous Blue Ridge anticlinorium of northern and central Virginia to the allochthonous eastern Blue Ridge in southern Virginia. From mile post (MP) 0 near Waynesboro, Virginia, to ~MP 124 at Roanoke, the parkway crosses the unconformable to faulted boundary between Mesoproterozoic basement in the core of the Blue Ridge anticlinorium and Neoproterozoic to Cambrian metasedimentary and metavolcanic cover rocks on the western limb of the structure. Mesoproterozoic basement rocks comprise two groups based on SHRIMP U-Pb zircon geochronology: Group I rocks (1.2-1.14 Ga) are strongly foliated orthogneisses, and Group II rocks (1.08-1.00 Ga) are granitoids that mostly lack obvious Mesoproterozoic deformational features.Neoproterozoic to Cambrian cover rocks on the west limb of the anticlinorium include the Swift Run and Catoctin Formations, and constituent formations of the Chilhowee Group. These rocks unconformably overlie basement, or abut basement along steep reverse faults. Rocks of the Chilhowee Group are juxtaposed against Cambrian rocks of the Valley and Ridge province along southeast- and northwest-dipping, high-angle reverse faults. South of the James River (MP 64), Chilhowee Group and basement rocks occupy the hanging wall of the nearly flat-lying Blue Ridge thrust fault and associated splays.South of the Red Valley high-strain zone (MP 144.5), the parkway crosses into the wholly allochthonous eastern Blue Ridge, comprising metasedimentary and meta-igneous rocks assigned to the Wills Ridge, Ashe, and Alligator

  2. Repeat ridge jumps associated with plume-ridge interaction, melt transport, and ridge migration

    Science.gov (United States)

    Mittelstaedt, Eric; Ito, Garrett; van Hunen, Jeroen

    2011-01-01

    Repeated shifts, or jumps, of mid-ocean ridge segments toward nearby hot spots can produce large, long-term changes to the geometry and location of the tectonic plate boundaries. Ridge jumps associated with hot spot-ridge interaction are likely caused by several processes including shear on the base of the plate due to expanding plume material as well as reheating of lithosphere as magma passes through it to feed off-axis volcanism. To study how these processes influence ridge jumps, we use numerical models to simulate 2-D (in cross section) viscous flow of the mantle, viscoplastic deformation of the lithosphere, and melt migration upward from the asthenospheric melting zone, laterally along the base of the lithosphere, and vertically through the lithosphere. The locations and rates that magma penetrates and heats the lithosphere are controlled by the time-varying accumulation of melt beneath the plate and the depth-averaged lithospheric porosity. We examine the effect of four key parameters: magmatic heating rate of the lithosphere, plate spreading rate, age of the seafloor overlying the plume, and the plume-ridge migration rate. Results indicate that the minimum value of the magmatic heating rate needed to initiate a ridge jump increases with plate age and spreading rate. The time required to complete a ridge jump decreases with larger values of magmatic heating rate, younger plate age, and faster spreading rate. For cases with migrating ridges, models predict a range of behaviors including repeating ridge jumps, much like those exhibited on Earth. Repeating ridge jumps occur at moderate magmatic heating rates and are the result of changes in the hot spot magma flux in response to magma migration along the base of an evolving lithosphere. The tendency of slow spreading to promote ridge jumps could help explain the observed clustering of hot spots near the Mid-Atlantic Ridge. Model results also suggest that magmatic heating may significantly thin the lithosphere

  3. Dredging of sand from a creek adjacent to a sand-spit for reclamation: Its impact on spit stability and coastal zone

    Digital Repository Service at National Institute of Oceanography (India)

    Rajagopal, M.D.; Vethamony, P.; Ilangovan, D.; Jayakumar, S.; Sudheesh, K.; Murty, K.S.R.

    . Mangroves are not present in the study area; patches of casuarina and cashew trees are observed towards land as well as on the sand spit (Anonymous, 1999). September 8, 2007 5:43 RPS mtec07_new Dredging of Sand from a Creek Adjacent to a Sand...-Spit for Reclamation 465 3. Results and Discussion 3.1. Estimation of quantum of sand that can be obtained from zones-I and II The post-dredging bathymetry of 2000 (Fig. 1) when compared with the bathymetry of 2005 shows that the deposition is in the range of 0.4–1.2 m...

  4. Electrical anisotropy of gas hydrate-bearing sand reservoirs in the Gulf of Mexico

    Science.gov (United States)

    Cook, Anne E.; Anderson, Barbara I.; Rasmus, John; Sun, Keli; Li, Qiming; Collett, Timothy S.; Goldberg, David S.

    2012-01-01

    We present new results and interpretations of the electricalanisotropy and reservoir architecture in gashydrate-bearingsands using logging data collected during the Gulf of MexicoGasHydrate Joint Industry Project Leg II. We focus specifically on sandreservoirs in Hole Alaminos Canyon 21 A (AC21-A), Hole Green Canyon 955 H (GC955-H) and Hole Walker Ridge 313 H (WR313-H). Using a new logging-while-drilling directional resistivity tool and a one-dimensional inversion developed by Schlumberger, we resolve the resistivity of the current flowing parallel to the bedding, R| and the resistivity of the current flowing perpendicular to the bedding, R|. We find the sandreservoir in Hole AC21-A to be relatively isotropic, with R| and R| values close to 2 Ω m. In contrast, the gashydrate-bearingsandreservoirs in Holes GC955-H and WR313-H are highly anisotropic. In these reservoirs, R| is between 2 and 30 Ω m, and R| is generally an order of magnitude higher. Using Schlumberger's WebMI models, we were able to replicate multiple resistivity measurements and determine the formation resistivity the gashydrate-bearingsandreservoir in Hole WR313-H. The results showed that gashydrate saturations within a single reservoir unit are highly variable. For example, the sand units in Hole WR313-H contain thin layers (on the order of 10-100 cm) with varying gashydrate saturations between 15 and 95%. Our combined modeling results clearly indicate that the gashydrate-bearingsandreservoirs in Holes GC955-H and WR313-H are highly anisotropic due to varying saturations of gashydrate forming in thin layers within larger sand units.

  5. 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.

  6. Sand dollar sites orogenesis

    Science.gov (United States)

    Amos, Dee

    2013-04-01

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

  7. Sand Storms Trigger Alarm

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ After an unusually humid winter with at least 10 snowfalls in Beijing, a severe andstorm blown by strong winds bringing with it thousands of tons of desert sand took many residents of the city by surprise.On the morning of March 20, Beijingers woke up to see clouds of yellow dust in the air and a sky that was an ominous orange in color.The loose soil and dust that had traveled htmdreds of miles from deserts in Mongolia and China's northwest blanketed Beijing's streets, covering parked vehicles, bikes, roofs and even plant life,as well as making its way into people's homes.

  8. 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.

  9. A family of sand automata

    CERN Document Server

    Faulkner, Nicholas

    2012-01-01

    We study some dynamical properties of a family of two-dimensional cellular automata: those that arise from an underlying one dimensional sand automaton whose local rule is obtained using a latin square. We identify a simple sand automaton G whose local rule is algebraic, and classify this automaton as having equicontinuity points, but not being equicontinuous. We also show it is not surjective. We generalise some of these results to a wider class of sand automata.

  10. Dilatometric Characterization of Foundry Sands

    Directory of Open Access Journals (Sweden)

    M. Břuska

    2012-04-01

    Full Text Available The goal of this contribution is summary of physical – chemistry properties of usually used foundry silica and no – silica sands in Czech foundries. With the help of dilatometry analysis theoretical assumptions of influence of grain shape and size on dilatation value of sands were confirmed. Determined was the possibility of dilatometry analysis employment for preparing special (hybrid sands with lower and/or more linear character of dilatation.

  11. Microsurgical treatment of medial sphenoid ridge meningioma

    Directory of Open Access Journals (Sweden)

    Wei-qi HE

    2011-02-01

    Full Text Available Objective To explore the microsurgical technique of medial sphenoid ridge meningioma resectional therapy.Methods The clinical data were retrospectively analyzed of 29 patients(13 males and 16 females;aged 18-68 years with average of 42 years;duration of disease was 5 months to 8 years,averaged 28 months with medial sphenoidal ridge meningioma and admitted from Jan.2005 to Jan.2010.The anatomical relationship of the tumor to surrounding structures was assessed intraoperatively,the tumor was then completely resected through cutting off the tumor supplying vessels,shrinking the tumor volume and separating the tumors from adjacent vessels and nerves.All the patients were followed up for 4 months to 4 years.Results Of the 29 cases,20 got total tumor removal,7 got subtotal and 2 got partial tumor removal.Of the 20 patients with obviously preoperative visual impairment,12 were obviously relieved,6 showed no improvement and 2 got symptoms aggravation.Hemiplegia occurred in 2 cases and oculomoter nerve palsy in 6 cases.There was no death after surgery.A 6 months to 4 years follow-up showed that no recurrence was found in 27 patients with tumor resection level of Simpson I and II,2 patients with tumor resection level of Simpson III received postoperative radiotherapy or gamma knife surgery,and 1 recurred and received reoperation.Conclusions Fine intraoperative assessment of the anatomical relationship of the tumor to surrounding structures,separating and excising tumor according to the assessed result is the key of medial sphenoid ridge meningioma resection,and the tumor resection is favorable to visual rehabilitation and tumor control.

  12. 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 that the tes......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...... that the testing procedure and the data processing were carried out according to the specifications of ETCS-F1.97....

  13. Carpenter Ridge Tuff, CO

    Science.gov (United States)

    Bachmann, Olivier; Deering, Chad D.; Lipman, Peter W.; Plummer, Charles

    2014-06-01

    The ~1,000 km3 Carpenter Ridge Tuff (CRT), erupted at 27.55 Ma during the mid-tertiary ignimbrite flare-up in the western USA, is among the largest known strongly zoned ash-flow tuffs. It consists primarily of densely welded crystal-poor rhyolite with a pronounced, highly evolved chemical signature (high Rb/Sr, low Ba, Zr, Eu), but thickly ponded intracaldera CRT is capped by a more crystal-rich, less silicic facies. In the outflow ignimbrite, this upper zone is defined mainly by densely welded crystal-rich juvenile clasts of trachydacite composition, with higher Fe-Ti oxide temperatures, and is characterized by extremely high Ba (to 7,500 ppm), Zr, Sr, and positive Eu anomalies. Rare mafic clasts (51-53 wt% SiO2) with Ba contents to 4,000-5,000 ppm and positive Eu anomalies are also present. Much of the major and trace-element variations in the CRT juvenile clasts can be reproduced via in situ differentiation by interstitial melt extraction from a crystal-rich, upper-crustal mush zone, with the trachydacite, crystal-rich clasts representing the remobilized crystal cumulate left behind by the melt extraction process. Late recharge events, represented by the rare mafic clasts and high-Al amphiboles in some samples, mixed in with parts of the crystal cumulate and generated additional scatter in the whole-rock data. Recharge was important in thermally remobilizing the silicic crystal cumulate by partially melting the near-solidus phases, as supported by: (1) ubiquitous wormy/sieve textures and reverse zoning patterns in feldspars and biotites, (2) absence of quartz in this very silicic unit stored at depths of >4-5 km, and (3) heterogeneous melt compositions in the trachydacite fiamme and mafic clasts, particularly in Ba, indicating local enrichment of this element due mostly to sanidine and biotite melting. The injection of hot, juvenile magma into the upper-crustal cumulate also imparted the observed thermal gradient to the deposits and the mixing overprint that

  14. Site descriptions of environmental restoration units at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Kuhaida, A.J. Jr.; Parker, A.F.

    1997-02-01

    This report provides summary information on Oak Ridge National Laboratory (ORNL) Environmental Restoration (ER) sites as listed in the Oak Ridge Reservation Federal Facility Agreement (FFA), dated January 1, 1992, Appendix C. The Oak Ridge National Laboratory was built in 1943 as part of the World War II Manhattan Project. The original mission of ORNL was to produce and chemically separate the first gram-quantities of plutonium as part of the national effort to produce the atomic bomb. The current mission of ORNL is to provide applied research and development in support of the U.S. Department of Energy (DOE) programs in nuclear fusion and fission, energy conservation, fossil fuels, and other energy technologies and to perform basic scientific research in selected areas of the physical, life, and environmental sciences. ER is also tasked with clean up or mitigation of environmental impacts resulting from past waste management practices on portions of the approximately 37,000 acres within the Oak Ridge Reservation (ORR). Other installations located within the ORR are the Gaseous Diffusion Plant (K-25) and the Y-12 plant. The remedial action strategy currently integrates state and federal regulations for efficient compliance and approaches for both investigations and remediation efforts on a Waste Area Grouping (WAG) basis. As defined in the ORR FFA Quarterly Report July - September 1995, a WAG is a grouping of potentially contaminated sites based on drainage area and similar waste characteristics. These contaminated sites are further divided into four categories based on existing information concerning whether the data are generated for scoping or remedial investigation (RI) purposes. These areas are as follows: (1) Operable Units (OU); (2) Characterization Areas (CA); (3) Remedial Site Evaluation (RSE) Areas; and (4) Removal Site Evaluation (RmSE) Areas.

  15. Formation and stability of ridge-ridge-ridge triple junctions in rheologically realistic lithosphere model

    Science.gov (United States)

    Gerya, Taras; Burov, Evgueni

    2015-04-01

    -branch junction formation and evolution by using high-resolution 3D numerical mechanical experiments that take into account realistic thermo-rheological structure and rheology of the lithosphere. We find that two major types of quadruple and triple junctions are formed under bi-directional or multidirectional far-field stress field: (i) plate rifting junctions are formed by the initial plate fragmentation and can be subsequently re-arranged into (ii) oceanic spreading junctions controlled by the new oceanic crust accretion. In particular, we document initial formation and destabilization of quadruple R-R-R-R junctions as initial plate rifting structures under bi-directional extension. In most cases, quadruple plate rifting junctions rapidly (typically within 1-2 Myr) evolve towards formation of two diverging triple oceanic spreading junctions connected by a linear spreading center lengthening with time. This configuration remains stable over long time scales. However, under certain conditions, quadruple junctions may also remain relatively stable. Asymmetric stretching results in various configurations, for example formation of "T-junctions" with trans-extensional components and combination of fast and slow spreading ridges. Combined with plume impingement, this scenario evolves in realistic patterns closely resembling observed plate dynamics. In particular, opening of the Red Sea and of the Afar rift system find a logical explanation within a single model. Numerical experiments also suggest that several existing oceanic spreading junctions form as the result of plate motions rearrangements after which only one of two plates spreading along the ridge become subjected to bi-directional spreading.

  16. A sand wave simulation model

    NARCIS (Netherlands)

    Nemeth, A.A.; Hulscher, S.J.M.H.; Damme, van R.M.J.

    2003-01-01

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water su

  17. Regeneration of dredged sand waves

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; Knaapen, Michiel; Scholl, Olaf; Scholl, O.; Trenteseaux., A.; Garlan, T.

    2000-01-01

    Sand waves form a wavy pattern in the offshore sandy seabed. Since their crests reduce the navigability, it is important to know their evolution. A simple model is presented to estimate the recovery of sand wave amplitudes. This model is partially based on the similarity with sea ripples and

  18. 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...

  19. Sand swimming lizard: sandfish

    CERN Document Server

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

    2009-01-01

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

  20. 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.

  1. Kirsten Sand. Arkitekt for sin tid

    Directory of Open Access Journals (Sweden)

    Elisabeth Seip

    2015-12-01

    Full Text Available Towards the end of World War II the retreating Germans burnt down nearly all buildings and other constructions in the counties of Finnmark and the northern parts of Troms in North Norway. The population evacuated but many returned as soon as possible, only to find themselves homeless. At this very demanding point Kirsten Sand decided to travel north, and do whatever she could as an architect to help. The pre-war housing situation was generally difficult. Low building standards and lack of money forced families in the cities to live under bad conditions. Kirsten Sand studied these conditions and took part in the efforts to better the situation. This knowledge provided a good starting point for the work she undertook after the war, in particular her profound understanding of the situation of women, their working conditions and positions in the household and society. Houses designed by Sand and her helpmates are simple but adequate, taking into account these women’s point of view. Ingebjørg Hage has thrown light on the work of Kirsten Sand in Finnmark and Troms in several ways. This article aims at describing Sand’s background as an architect before she left Oslo to travel north. It describes how housing and housing policy since long had been central to architects, especially so within the group she belonged to. In pre-war Oslo she had been engaged in planning and designing hospitals. During a period as inspector for the health authorities she learned a lot about the living conditions of people in general. After establishing her own architect’s office she mostly designed family houses, and during the war she engaged in research that further deepened her knowledge in the field. Thus she was particularly well equipped for the demanding tasks she undertook in the summer of 1945.

  2. Oak Ridge callibration recall program

    Energy Technology Data Exchange (ETDEWEB)

    Falter, K.G.; Wright, W.E. [Oak Ridge National Lab., TN (United States); Pritchard, E.W. [Oak Ridge Centers for Manufacturing Technology, TN (United States)] [and others

    1996-12-31

    A development effort was initiated within the Oak Ridge metrology community to address the need for a more versatile and user friendly tracking database that could be used across the Oak Ridge complex. This database, which became known as the Oak Ridge Calibration Recall Program (ORCRP), needed to be diverse enough for use by all three Oak Ridge facilities, as well as the seven calibration organizations that support them. Various practical functions drove the initial design of the program: (1) accessible by any user at any site through a multi-user interface, (2) real-time database that was able to automatically generate e-mail notices of due and overdue measuring and test equipment, (3) large memory storage capacity, and (4) extremely fast data access times. In addition, the program needed to generate reports on items such as instrument turnaround time, workload projections, and laboratory efficiency. Finally, the program should allow the calibration intervals to be modified, based on historical data. The developed program meets all of the stated requirements and is accessible over a network of computers running Microsoft Windows software.

  3. Ridge Regression for Interactive Models.

    Science.gov (United States)

    Tate, Richard L.

    1988-01-01

    An exploratory study of the value of ridge regression for interactive models is reported. Assuming that the linear terms in a simple interactive model are centered to eliminate non-essential multicollinearity, a variety of common models, representing both ordinal and disordinal interactions, are shown to have "orientations" that are favorable to…

  4. Oak Ridge Leadership Computing Facility (OLCF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Oak Ridge Leadership Computing Facility (OLCF) was established at Oak Ridge National Laboratory in 2004 with the mission of standing up a supercomputer 100 times...

  5. Study on the sediment dynamics and stability of the Kushuiyang tidal channel at radial sand ridges in the southern Yellow Sea%南黄海辐射沙脊群苦水洋海域的沉积动力特征及稳定性研究

    Institute of Scientific and Technical Information of China (English)

    倪文斐; 汪亚平; 邹欣庆; 高建华

    2013-01-01

    Based on the data from hydrological observation and sediment sampling in Kushuiyang during a tide cycle from 3rd July 2011 to 4th July 2011, the water and sediment transport rates are calculated to specify the sediment dynamic characteristics along the tidal channel. The geomorphological evolution and stability of the channel are also discussed on the basis of the comparison between historic sea charts and new topographic surveys. The main results turn out that tidal currents are strong in the channel. Sediments are mainly transported in the form of suspended loads. The net transport direction is landward in the nearshore part of channel, while it is generally pointed seaward in the part of channel east of sand bank (121.606oE,33.029oN). Over the past thirty years, the deep trough of west Kushuiyang channel has gradually connected to the north part of channel, leading the whole channel to be straighter.%根据2011年7月3日-4日在苦水洋海域获取的全潮水文资料和底质样品,计算潮周期水、沙输运率,分析了其沉积动力特征。基于1979年历史海图资料与最新测量的水道地形进行对比,进一步探讨苦水洋水道的地形演变过程及稳定性。结果表明,苦水洋潮流作用较强,水道内沉积物主要以悬移质形式输运,在近岸段沿水道向岸净输沙,但在(121.606º E,33.029ºN)以东以向海输运为主。近三十多年来,苦水洋西水道深槽与口门北水道逐渐贯通,水道整体趋于顺直。

  6. InRidge program: Preliminary results from the first cruise

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Murthy, K.S.R.; Iyer, S.D.; Rao, M.M.M.; Banerjee, R.; Subrahmanyam, A.S.; Shirodkar, P.V.; Ghose, I.

    The first cruise under India's own Ridge research initiative, InRidge collected new data on bathymetry, free-air gravity and magnetic anomalies across the ridge axis between the Vema and Zhivago transform faults in the Central Indian Ridge...

  7. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  8. Sand engine quells the coast's hunger for sand

    NARCIS (Netherlands)

    Van Dijk, T.

    2012-01-01

    An artificial peninsula at Ter Heijde is designed to feed the coast with sediment. Scientists are investigating whether this kind of sand engine could be the Netherlands’ answer to rising sea levels.

  9. 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...

  10. A coral-rubble ridge as evidence for hurricane overwash, Anegada (British Virgin Islands)

    Science.gov (United States)

    Spiske, M.; Halley, R. B.

    2014-01-01

    A coral-rubble ridge fringes part of the north shore of Anegada, a low-lying island in the northern Caribbean. Both historical reports and the geological record underline its vulnerability to tsunami and hurricanes. In this study we document the sedimentary characteristics of a coral-rubble ridge, which extends discontinuously along 1.5-1.8 km of chiefly north-facing shores at Soldier Wash. The ridge is less distinctive and appears only in patches along the west-facing shoreline at Windless Bight, where the wave regime is calmer. It is located ca. 8 m from the fair-weather shore, has a maximum width of 15 m and a maximum thickness of 0.8 m. The lower seaward-facing slope of the ridge is relatively flat, probably due to successive reworking, whereas the upper seaward slope is steep and partly displays avalanching faces. The landward flank is gently sloping and terminates abruptly. The ridge is mainly composed of well-rounded, encrusted and bored coral rubble (average diameter of 16 cm) that has been reworked in the shallow marine environment prior to transport. Only a few pieces of angular beach rock and karstified Pleistocene limestone are incorporated. The components build a clast-supported framework. No sand is present in the interstices. Imbrication of flat clasts indicates a deposition during landward bed load transport. The ridge morphology, composition and related hydrodynamic conditions during its emplacement are typical for coral-rubble ridges deposited by hurricane-induced storm surges. In comparison, nearby evidence for tsunami inundation is very different because the tsunami-transported coral boulders on Anegada are much bigger (2 m) than the biggest components in the ridge, they are deposited much farther inland (up to 1.5 km), and the corals seem to have been freshly broken out of the reef by the tsunami. The age of the ridge is difficult to estimate. The dark grey surface of the ridge is caused by bioweathering by endolithic organisms that takes tens

  11. Saltation of Non-Spherical Sand Particles

    Science.gov (United States)

    Wang, Zhengshi; Ren, Shan; Huang, Ning

    2014-01-01

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

  12. 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.

  13. Improving prosthetic prognosis by connective tissue ridge augmentation of alveolar ridge

    OpenAIRE

    2010-01-01

    The contour of edentulous ridge should be carefully evaluated before a fixed partial denture is undertaken. The ideal ridge height and width allows placement of a natural looking pontic which facilitates maintenance of plaque-free environment. The localized alveolar ridge defect refers to the volumetric deficit of the limited extent of bone and soft tissue within the alveolar process. Such type of ridge defects can be corrected by surgical ridge augmentation that can be accomplished by the ad...

  14. 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...

  15. Sex Determination from Fingerprint Ridge Density

    Directory of Open Access Journals (Sweden)

    Dr. Sudesh Gungadin

    2007-07-01

    Full Text Available This study was conducted with an aim to establish a relationship between sex and fingerprint ridge density. The fingerprints were taken from 500 subjects (250 males and 250 females in the age group of 18-60 years. After taking fingerprints, the ridges were counted in the upper portion of the radial border of each print for all ten fingers and mean value was calculated. The results have shown that a finger print ridge of 14 ridges/25 mm2 is more likely of female origin. It has been successful to support the hypothesis that women tend to have a statistically significant greater ridge density than men.

  16. Application of fluid-rock reaction studies to in situ recovery from oil sand deposits, Alberta Canada. II. Mineral transformations during an experimental-statistical study of water-bitumen-shale reactions

    Energy Technology Data Exchange (ETDEWEB)

    Boon, J.A.; Hitchon, B.

    1983-01-01

    During the experiment, calculations were made of the mud-mineral equilibrium and studies were made of the x-ray diffractogram of the solid phases. Data on deviations from equilibriums and intensity of the normalized x-ray diffraction peaks were processed by the method of dispersion analysis. It was established that in addition to dissolving the quartz, formation of montmorillonite occurs, probably by forming transitional illite-montmorillonite interstratified layered structures. The reactions promote high pH values of the aqueous medium. The solubility of siderite to a considerable degree is determined by the reaction time and mineralization of the aqueous phase, and also the ratios of pH/mineralization, time/mineralization and pH/temperature/time. Despite the limitations associated with laboratory nature of the experiment, one can draw the conclusion that during development of the bituminous sands by the in situ method, processes of dissolving minerals are widespread.

  17. Status of Blue Ridge Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  18. Bose enhancement and the ridge

    Energy Technology Data Exchange (ETDEWEB)

    Altinoluk, Tolga [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Armesto, Néstor, E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Kovner, Alex [Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269-3046 (United States); Lublinsky, Michael [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

    2015-12-17

    We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  19. Oak Ridge National Laboratory Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.; Pearce, J.; Zucker, A. (eds.)

    1992-01-01

    This report presents brief descriptions of the following programs at Oak Ridge National Laboratory: The effects of pollution and climate change on forests; automation to improve the safety and efficiency of rearming battle tanks; new technologies for DNA sequencing; ORNL probes the human genome; ORNL as a supercomputer research center; paving the way to superconcrete made with polystyrene; a new look at supercritical water used in waste treatment; and small mammals as environmental monitors.

  20. Bose enhancement and the ridge

    CERN Document Server

    Altinoluk, Tolga; Beuf, Guillaume; Kovner, Alex; Lublinsky, Michael

    2015-01-01

    We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  1. Bose enhancement and the ridge

    Directory of Open Access Journals (Sweden)

    Tolga Altinoluk

    2015-12-01

    Full Text Available We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  2. Sediment and Crustal Structure along 85oE and Ninetyeast Ridges in the Bay of Bengal: Geodynamic Implications

    Science.gov (United States)

    Munukutla, R.; Gangumalla, S. R.; Sreejith, K. M.; Krishna, K. S.; Bull, J. M.

    2015-12-01

    The Bay of Bengal (BOB) region is characterized by the presence of two linear N-S trending aseismic ridges, the 85°E and Ninetyeast ridges which have progressively buried below thick sediments towards north. We present here the results of an integrated interpretation of geophysical data using multichannel seismic reflection, gravity and magnetic datasets over these two ridges to study the crustal structure and mode of their emplacement. The ridges divide the deep sedimentary BOB region into three major sub-basins. Considering the sediment deposition pattern within the sub-basins and over the ridges, it is found that both ridge structures have played a role in sediment dispersal pattern during the pre- and post Bengal Fan sedimentation. The Geoid-Topography Ratio (GTR) analysis indicates that both the ridges are compensated at shallow depths. Seismically constrained gravity and magnetic models and flexural gravity modeling over these ridges support their volcanic origin, and suggest the following: i) 85°E Ridge was emplaced in off-ridge environment (Te=10-15 km); ii) the higher Te values of ~ 25 km over the Afanasy Nikitin Seamount (ANS) reflect the secondary emplacement of the seamount peaks in off-ridge environment, iii) that the emplacement of the Ninetyeast Ridge north of 2°N occurred in an off-ridge environment as indicated by higher Te values (25-30 km). These results attain significance in terms of understanding of the interactions between plume- volcanism and lithosphere in the Bay of Bengal.

  3. Geo-Morphological Analyses of the Gakkel Ridge and the Southwest Indian Ridge

    Science.gov (United States)

    Dorschel, B.; Schlindwein, V. S. N.; Eagles, G.

    2014-12-01

    The Gakkel Ridge in the Arctic Ocean and the Southwest Indian Ridge in the Southwest Indian Ocean between Africa and Antarctica are ultraslow-spreading (intersticial melt migration) by which material rises to fill the space vacated by plate divergence. These ridges are characterised by non-orthogonal spreading. Transform faults, typical of faster spreading mid ocean ridges, are far less common at ultraslow spreading mid ocean ridges. Thus in return, detailed geo-statistical analyses of the geo-morphology of ultraslow-spreading mid ocean ridges can provide valuable information towards a better understanding of these slowest of spreading ridges. We have generated high resolution bathymetric grids for the Gakkel and Southwest Indian ridges based on high resolution multibeam echosounder data from various expeditions with RV Polarstern. On the basis of these grids, geo-statistical analyses allow for an assessment of the geo-morphological elements of the ridges on various scales. The results of these analyses show that, approximately 200 km long medium-scale sections of the ridges can be characterised by the lengths and orientations of the short-scale (hundreds of meters to tens of kilometres) ridges and troughs. The geomorphologies of short-scale ridges and troughs situated at the junctions between medium scale sections often exhibit a mixture of the geomorphological elements seen in the neighbouring sections. These geo-morphological patterns provide insights into the overall spreading-geometry along the Gakkel Ridge and the Southwest Indian Ridge.

  4. Removing the remaining ridges in fingerprint segmentation

    Institute of Scientific and Technical Information of China (English)

    ZHU En; ZHANG Jian-ming; YIN Jian-ping; ZHANG Guo-min; HU Chun-feng

    2006-01-01

    Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce the time expenditure of image processing and avoid detecting false features. In high and in low quality ridge regions, often are some remaining ridges which are the afterimages of the previously scanned finger and are expected to be excluded from the foreground. However, existing segmentation methods generally do not take the case into consideration, and often, the remaining ridge regions are falsely classified as foreground by segmentation algorithm with spurious features produced erroneously including unrecoverable regions as foreground. This paper proposes two steps for fingerprint segmentation aimed at removing the remaining ridge region from the foreground. The non-ridge regions and unrecoverable low quality ridge regions are removed as background in the first step, and then the foreground produced by the first step is further analyzed for possible remove of the remaining ridge region. The proposed method proved effective in avoiding detecting false ridges and in improving minutiae detection.

  5. 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

    2017-03-24

    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.

  6. 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 <1 cm thick sand layer possibly deposited during 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.

  7. 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).

  8. "Slab graveyards" beneath axial rift of the Mid-Atlantic Ridge?: Evidence from SHRIMP-II dating of zircon in gabbroids from the Markov Deep, 6oN

    Science.gov (United States)

    Sharkov, E.; Bortnikov, N.; Zinger, T.; Lepekhina3, E.; Sergeev, S.

    2009-04-01

    Unusually ancient (ranging from ~100 to 300 and even 2230 Ma [5, 6, etc.) and young (~1.2-2 Ma [1] zircons were discovered in the axial Mid-Atlantic Ridge (MAR) zone using U-Pb dating. At first glance, finds of ancient zircons are inconsistent with the general accepted plate tectonics model which suggests the formation of new oceanic crust in the spreading zone of the World Ocean. However, they can be explained by features of the oceanic mantle structure. We have dated 150 grains of zircon by U-Pb SIMS SHRIMP technique, which identified both ancient and young zircons in the same samples of MAR gabbroids from Sierra Leone testing area, Markov Deep, 6oN, dredged during Cruise 10 of R/V "Akademik Ioffe" (2001-2002) and Cruise 22 of R/V "Professor Logachev" (2003) [2]. Zircons were separated from gabbroids in the Markov Deep from depths 3600-3240 and 3900-3600 m. All complexes of the oceanic lithosphere occur on it's slopes: mantle residual ultramafites (harzburgites, lherzolites, and dunites), diverse gabbroids, granodiorites, plagiogranites, dolerites and basalts, including fresh pillow lavas (with chilled glassy margins), and deformed and hydrothermally altered rocks with sulfide mineralization. Studied samples are represented by cataclased and altered leucogabbronorites and one sample of fresh non-cataclased troctolite. Based on SHRIMP U-Pb dating, zircons can be subdivided into two groups: "young" zircon (less than ~2.3 Ma) and "old" zircon (older than ~87 Ma). The young zircon often form subhedral crystals with thin oscillatory zoning and a sectorial structure. It has low U and Th contents (up to 100 μg/g) and extremely low radiogenic lead. Its 238U/206Pb age varied from 0.76 ± 0.04 Ma to 2.28 ± 0.18 Ma. Zircons from nearby plagiogranites define an intermediate age of ~1.2-1.4 Ma [1]. The magmatic nature of young zircon suggests that its age defines the crystallization age of the host magmatic rocks. Ancient zircons define U/Pb ages between the Paleozoic and

  9. Metallogenesis along the Indian Ocean Ridge System

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Ray, Dwijesh

    active hydrothermal black smoker deposit along this ridge system (Figure 1). The obser - vations summarized here comprise the res ults obtained from the Central Indian Ridge (CIR), Southwest Indian Ridge (SWIR), Southeast Indian Ridge (SEIR), Carlsberg... and appears to be in a tectonic stage of rift development. A hydrothermal plume with maximum concentration of 202 nl/l methane (CH 4 ) and a tempera ture anomaly of + 0.05?C was delineated at 24?03 minuteS (hydro - ther mal plume site). Manganese...

  10. Geophysical and Geotechnical Determination of Sand Resources on the Florida Atlantic Continental Shelf: Preliminary Results

    Science.gov (United States)

    Finkl, C. W.; Andrews, J. L.; Suthard, B. C.; Robertson, W.

    2007-12-01

    The State of Florida is committed to maintaining beaches to sustain beach width and protect coastal infrastructure. Nearshore sand resources must be identified and cataloged for potential beach nourishment projects in response to sea-level rise and increased tropical storm activity. Given the vast length of Florida coastline, application of a variety of remote sensing techniques are required for measuring large areas in a short amount of time. The study area encompasses a shelf area of about 2,053,220 ha (20,532 km2) from Miami to the Georgia State line (about 653 km shoreline length) and extends up to 27 km offshore to about the 45 m isobath offshore Jacksonville. The continental shelf along the east coast of the Florida peninsula contains a wide range of seafloor environments that lie above the Florida-Hatteras Slope on the shoreface and inner, middle, and outer shelf floors. This study used Airborne Laser Bathymetry (ALB), 3D digital terrain models based on reformatted NOAA bathymetric data, sidescan sonar, and seismic reflection profiling to map seafloor geomorphological conditions that range from coralline-algal reef systems to drowned karst, submerged paleo shorelines (drowned beach ridge plains), and buried paleo channels. Seatruthing of morphosedimentary features is achieved via jetprobe and vibracore surveys in the study of inter-reefal sand troughs, ebb-tidal deltas, transverse bars, shoals, sand waves, ridges, and banks. Preliminary results, which visualize seafloor topography as color-ramped morphoforms, indicate the presence of sedimentary deposits that may constitute viable sand resources for shore protection in the form of beach renourishment. Use of ALB and reformatted NOAA bathymetric data in the form of 3D terrain models permits classification of submarine landform topologies that was heretofore not possible using isobaths. The combination of multiple remote sensing methods showed the spatial distribution of morphosedimentary features and provided

  11. The Northern Central Indian Ridge: Geology and tectonics of fracture zones-dominated spreading ridge segments

    Digital Repository Service at National Institute of Oceanography (India)

    Drolia, R.K.; Iyer, S.D.; Chakraborty, B.; Kodagali, V.N.; Ray, Dwijesh; Misra, S.; Andrade, R.; Sarma, K.V.L.N.S.; Rajasekhar, R.P.; Mukhopadhyay, R.

    - OCEANIC RIDGES CURRENT SCIENCE, VOL. 85, NO. 3, 10 AUGUST 2003 The Northern Central Indian Ridge: Geology and tectonics of fracture zones - dominated spreading ridge segments R. K. Drolia*, Sridhar D. Iyer ? , B. Chakraborty, V. N. Kodagali, D... anomalies are plotted perpendicular to cruise tracks. SPECIAL SECTION: MID - OCEANIC RIDGES CURRENT SCIENCE, VOL. 85, NO. 3, 10 AUGUST 2003 291 20 ? 18 Ma old and runs along the equator from the CIR in the west to the Wharton Basin in the east...

  12. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper. The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples,which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters,the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed,the saltation of high-speed sand particles and the creep of low-speed sand particles,respectively. The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic,particle size segregation and stratigraphy,but also in formation stages. In addition,three important speeds can be obtained by this method,which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  13. DPTM simulation of aeolian sand ripple

    Institute of Scientific and Technical Information of China (English)

    ZHENG XiaoJing; BO TianLi; XIE Li

    2008-01-01

    Aeolian sand ripple and its time evolution are simulated by the discrete particle tracing method (DPTM) presented in this paper.The difference between this method and the current methods is that the former can consider the three main factors relevant to the formation of natural aeolian sand ripples, which are the wind-blown sand flux above the sand bed formed by lots of sand particles with different di-ameters, the particle-bed collision and after it the rebound and ejection of sand particles in the sand bed, the saltation of high-speed sand particles and the creep of low-speed sand particles, respectively.The simulated aeolian sand ripple is close to the natural sand ripple not only in basic shape and characteristic, particle size segregation and stratigraphy, but also in formation stages.In addition, three important speeds can be obtained by this method, which are the propagation speed of the saturated aeolian sand ripple and the critical frictional wind speeds of emergence and disappearance of sand ripple.

  14. The dune effect on sand-transporting winds on Mars

    Science.gov (United States)

    Jackson, Derek W. T.; Bourke, Mary C.; Smyth, Thomas A. G.

    2015-11-01

    Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface-atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern `wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today.

  15. The dune effect on sand-transporting winds on Mars.

    Science.gov (United States)

    Jackson, Derek W T; Bourke, Mary C; Smyth, Thomas A G

    2015-11-05

    Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface-atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern 'wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today.

  16. The dune effect on sand-transporting winds on Mars

    Science.gov (United States)

    Jackson, Derek W. T.; Bourke, Mary C; Smyth, Thomas A. G.

    2015-01-01

    Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface–atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern ‘wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today. PMID:26537669

  17. Dry reusing and wet reclaiming of used sodium silicate sand

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated.

  18. Assessment of offshore New Jersey sources of Beach replenishment sand by diversified application of geologic and geophysical methods

    Science.gov (United States)

    Waldner, J.S.; Hall, D.W.; Uptegrove, J.; Sheridan, R.E.; Ashley, G.M.; Esker, D.

    1999-01-01

    Beach replenishment serves the dual purpose of maintaining a source of tourism and recreation while protecting life and property. For New Jersey, sources for beach sand supply are increasingly found offshore. To meet present and future needs, geologic and geophysical techniques can be used to improve the identification, volume estimation, and determination of suitability, thereby making the mining and managing of this resource more effective. Current research has improved both data collection and interpretation of seismic surveys and vibracore analysis for projects investigating sand ridges offshore of New Jersey. The New Jersey Geological Survey in cooperation with Rutgers University is evaluating the capabilities of digital seismic data (in addition to analog data) to analyze sand ridges. The printing density of analog systems limits the dynamic range to about 24 dB. Digital acquisition systems with dynamic ranges above 100 dB can permit enhanced seismic profiles by trace static correction, deconvolution, automatic gain scaling, horizontal stacking and digital filtering. Problems common to analog data, such as wave-motion effects of surface sources, water-bottom reverberation, and bubble-pulse-width can be addressed by processing. More than 160 line miles of digital high-resolution continuous profiling seismic data have been collected at sand ridges off Avalon, Beach Haven, and Barnegat Inlet. Digital multichannel data collection has recently been employed to map sand resources within the Port of New York/New Jersey expanded dredge-spoil site located 3 mi offshore of Sandy Hook, New Jersey. Multichannel data processing can reduce multiples, improve signal-to-noise calculations, enable source deconvolution, and generate sediment acoustic velocities and acoustic impedance analysis. Synthetic seismograms based on empirical relationships among grain size distribution, density, and velocity from vibracores are used to calculate proxy values for density and velocity

  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. 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…

  1. Impact on sand and water

    NARCIS (Netherlands)

    Bergmann, R.P.H.M.

    2007-01-01

    In this thesis we investigate the impact of a body on sand and water. When a body impacts a free surface in the inertial regime the series of events is the following: On impact material is blown away in all directions and an impact cavity forms. Due to the hydrostatic pressure from the sides the cav

  2. 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...

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

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2012-02-01

    Full Text Available of Oil Sand,? Final Progress Report, Phases I, II, & III, Submitted to Caterpillar, Inc., 2005. [3] Dusseault, M.B., and Morgenstern, N.R., ?Shear Strength of Athabasca Oil Sands,? Canadian Geotechnical Journal, Vol. 15, 1978, pp. 216?238. [4] Agar..., J.G., Morgenstern, N.R., and Scott, J.D., ?Shear Strength and Stress-Strain Behavior of Athabasca Oil Sand at Elevated Temperatures and Pressures,? Canadian Geotechnical Journal, Vol. 24, 1987, pp. 1?10. [5] Samieh, A.M., and Wong, R...

  4. experimental studies of sand production from unconsolidated ...

    African Journals Online (AJOL)

    ES Obe

    Production of sand during oil and gas exploration causes severe operational prob- ... duction such as risk of well failure, erosion of pipelines and surface facilities, sand separa- tion and disposal ... ment, theoretical and numerical analysis have.

  5. UK silica sand resources for fracking

    OpenAIRE

    Mitchell, Clive

    2013-01-01

    UK silica sand resources for fracking Clive Mitchell, Industrial Minerals Specialist, British Geological Survey, Keyworth, Nottingham, NG12 5GG Email: Silica sand is high purity quartz sand that is mainly used for glass production, as foundry sand, in horticulture, leisure and other industrial uses. One specialist use is as a ‘proppant’ to enhance oil and gas recovery. This presentation will focus on this application, particularly for shale gas recovery where it is mo...

  6. Early history of neutron scattering at Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M.K.

    1985-07-01

    Most of the early development of neutron scattering techniques utilizing reactor neutrons occurred at the Oak Ridge National Laboratory during the years immediately following World War II. C.G. Shull, E.O. Wollan, and their associates systematically established neutron diffraction as a quantitative research tool and then applied this technique to important problems in nuclear physics, chemical crystallography, and magnetism. This article briefly summarizes the very important research at ORNL during this period, which laid the foundation for the establishment of neutron scattering programs throughout the world. 47 refs., 10 figs.

  7. Student Health Services at Orchard Ridge.

    Science.gov (United States)

    Nichols, Don D.

    This paper provides a synoptic review of student health services at the community college level while giving a more detailed description of the nature of health services at Orchard Ridge, a campus of Oakland Community College. The present College Health Service program provides for a part-time (24 hrs./wk.) nurse at Orchard Ridge. A variety of…

  8. Pulley Ridge Swath Bathymetry Grid - filtered

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Pulley Ridge is a series of drowned barrier islands that extends almost 200 km in 60-100 m water depths. This drowned ridge is located on the Florida Platform in...

  9. Pulley Ridge Swath Bathymetry Grid - filtered

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Pulley Ridge is a series of drowned barrier islands that extends almost 200 km in 60-100 m water depths. This drowned ridge is located on the Florida Platform in the...

  10. Pulley Ridge Swath Bathymetry Grid - filtered

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Pulley Ridge is a series of drowned barrier islands that extends almost 200 km in 60-100 m water depths. This drowned ridge is located on the Florida Platform in the...

  11. Petrology of tectonically segmented Central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Iyer, S.D.

    Distribution and mineralogy of various rock types along the 4200-km-long slow-spreading Central Indian Ridge, between Owen fracture zone in the north and Indian Ocean triple junction in the south, is studied in the light of ridge segmentation...

  12. Structure, distribution, and evolution history of the Early Holocene erosional mud ridge system on the inner East China Sea shelf near the Yangtze River estuary

    Science.gov (United States)

    Feng, Zhibing; Liu, Baohua; Zhao, Yuexia; Li, Xishuang; Dada, Olusegun A.; Jiang, Li; Si, Shaokun

    2017-04-01

    Utilizing the collected high-resolution seismic dataset and accompanying borehole and bathymetric data, we systematically evaluated the morphology, architecture, sedimentology, and evolution of erosional mud ridges within the inner East China Sea (ECS) shelf. We identified 20 mud ridges, i.e., seismic reflection profile crossings of exposed or buried mud ridges, which are 3.0-30.1 km in width and 2.5-17.3 m in height. The mud ridges are composed predominantly of gray clayey silt, and on seismic profiles contain parallel to subparallel reflectors. They formed around 10-12 ka BP within an estuarine environment. Scouring features of some mud ridges on the eastern part of the study area can be recognized. Consideration of the relative positions of mud ridges, together with the topographical features, enables us to map four linear mud ridges (LMRs). The SE-NW oriented LMRs are > 50 km in length, 3.0-9.5 km in width and running parallel to each other. They also display asymmetric shapes, with steeper slopes to the SW. The eastern segments of some LMRs are exposed on the present seafloor whereas other segments are mainly overlain by the mid- and late Holocene strata. Since the LMRs share similarities with the modern tidal sand ridges in shape and orientation, we hypothesize that they are formed under a uniform tidal current. Seismic data highlight that the internal reflectors of sand ridges consist of dipping clinoforms and are significantly different from LMRs, a feature which is largely due to the difference in grain-size composition of sediments between the inner and mid-outer ECS shelf. The mid- to outer ECS shelf is capped by coarser-grained sediments (i.e., medium to fine-grained), which were reworked and deposited at locations near the erosional areas under a polycyclic tidal current, thus forming multiphase sand ridges. However, fine-grained sediments (i.e., silty clay and clayey silt) overlain on the inner ECS shelf with light mass were carried far away from the

  13. Treating tar sands formations with karsted zones

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-09

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

  14. The Glasma and the Hard Ridge

    CERN Document Server

    Moschelli, George

    2009-01-01

    Correlation measurements indicate that excess two particle correlations extend over causally disconnected rapidity ranges. Although, this enhancement is broad in relative rapidity $\\eta=\\eta_1 - \\eta_2$, it is focused in a narrow region in relative azimuthal angle $\\phi=\\phi_1 - \\phi_2$. The resulting structure looks like a ridge centered at $\\eta = \\phi=0$. Similar ridge structures are observed in correlations of particles associated with a jet trigger (the hard ridge) and in correlations without a trigger (the soft ridge). The long range rapidity behavior requires that the correlation originates in the earliest stage of the collision, and probes properties of the production mechanism. Glasma initial conditions as predicted by the theory of Color Glass Condensate and provide a and early stage correlation that naturally extends far in rapidity. We have previously shown that the soft ridge is a consequence of particles forming from an initial Glasma phase that experience a later stage transverse flow. We exten...

  15. Noachian Impact Ejecta on Murray Ridge and Pre-impact Rocks on Wdowiak Ridge, Endeavour Crater, Mars: Opportunity Observations

    Science.gov (United States)

    Mittlefehldt, D. W.; Gellert, R.; Ming, D. W.; Morris, R. V.; Schroeder, C.; Yen, A. S.; Farrand, W. H.; Arvidson, R. E.; Franklin, B. J.; Grant, J. A.; hide

    2015-01-01

    Mars Exploration Rover Opportunity has been exploring Meridiani Planum since January 2004, and has completed 4227% of its primary mission. Opportunity has been investigating the geology of the rim of 22 km diameter Endeavour crater, first on the Cape York segment and now on Cape Tribulation. The outcrops are divided York; (ii) the Shoemaker fm, impact breccias representing ejecta from the crater; into three formations: (i) the lower Matijevic fm, a pre-impact lithology on Cape and (iii) the upper Grasberg fm, a post-impact deposit that drapes the lower portions of the eroded rim segments. On the Cape Tribulation segment Opportunity has been studying the rocks on Murray Ridge, with a brief sojourn to Wdowiak Ridge west of the rim segment. team member Thomas Wdowiak, who died in 2013.) One region of Murray Ridge has distinctive CRISM spectral characteristics indicating the presence of a small concentration of aluminous smectite based on a 2.2 micron Al-OH combination band (hereafter, the Al-OH region).

  16. Sand Waves. Report 1. Sand Wave Shoaling in Navigation Channels

    Science.gov (United States)

    1992-09-01

    heights range from 0.8 m in the Minas Basin, Bay of Fundy (Dalrymple 1984) to 6.0 m in the Bahia Blanca Estuary, Argentina (Aliotta and Perillo 1987...26 PART IV: SITE-SPECIFIC SAND WAVE SHOALING PROBLEMS .. ........ 30 Columbia River Navigation Channel ........ ............... .. 30 Panama ...problem location discussed in this report is at St. Andrew Bay near Panama City, Florida. A relatively short section of the jettied inlet channel requires

  17. Modelling aeolian sand transport using a dynamic mass balancing approach

    Science.gov (United States)

    Mayaud, Jerome R.; Bailey, Richard M.; Wiggs, Giles F. S.; Weaver, Corinne M.

    2017-03-01

    Knowledge of the changing rate of sediment flux in space and time is essential for quantifying surface erosion and deposition in desert landscapes. Whilst many aeolian studies have relied on time-averaged parameters such as wind velocity (U) and wind shear velocity (u*) to determine sediment flux, there is increasing field evidence that high-frequency turbulence is an important driving force behind the entrainment and transport of sand. At this scale of analysis, inertia in the saltation system causes changes in sediment transport to lag behind de/accelerations in flow. However, saltation inertia has yet to be incorporated into a functional sand transport model that can be used for predictive purposes. In this study, we present a new transport model that dynamically balances the sand mass being transported in the wind flow. The 'dynamic mass balance' (DMB) model we present accounts for high-frequency variations in the horizontal (u) component of wind flow, as saltation is most strongly associated with the positive u component of the wind. The performance of the DMB model is tested by fitting it to two field-derived (Namibia's Skeleton Coast) datasets of wind velocity and sediment transport: (i) a 10-min (10 Hz measurement resolution) dataset; (ii) a 2-h (1 Hz measurement resolution) dataset. The DMB model is shown to outperform two existing models that rely on time-averaged wind velocity data (e.g. Radok, 1977; Dong et al., 2003), when predicting sand transport over the two experiments. For all measurement averaging intervals presented in this study (10 Hz-10 min), the DMB model predicted total saltation count to within at least 0.48%, whereas the Radok and Dong models over- or underestimated total count by up to 5.50% and 20.53% respectively. The DMB model also produced more realistic (less 'peaky') time series of sand flux than the other two models, and a more accurate distribution of sand flux data. The best predictions of total sand transport are achieved using

  18. Mega-ripples in Iran: A new analog for transverse aeolian ridges on Mars

    Science.gov (United States)

    Foroutan, M.; Zimbelman, J. R.

    2016-08-01

    A new terrestrial analog site for transverse aeolian ridges (TARs) is described in this study. The Lut desert of Iran hosts large ripple-like aeolian bedforms, with the same horizontal length scales and patterns of TARs on Mars. Different classes of TARs and different types of other aeolian features such as sand dunes, zibars, dust devil tracks and yardangs can be found in this area, which signify an active aeolian region. This area represents a unique site to study the formation and evolution of these enigmatic features, with potential relevance toward a better understanding of TARs on Mars.

  19. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    Science.gov (United States)

    Markewich, H.W.; Pavich, M.J.; Schultz, A.P.; Mahan, S.A.; Aleman-Gonzalez, W. B.; Bierman, P.R.

    2013-01-01

    Predominantly clastic, off-lapping, transgressive, near-shore marine sediment packages that are morphologically expressed as subparallel NE-trending barriers, beach ridges, and associated back-barrier areas, characterize the near-surface stratigraphic section between the Savannah and the Ogeechee Rivers in Effingham County, southeastern Georgia. Each barrier/back-barrier (shoreline) complex is lower than and cut into a higher/older complex. Each barrier or shoreline complex overlies Miocene strata. No direct age data are available for these deposits. Previous researchers have disagreed on their age and provenance. Using luminescence and meteoric beryllium-10 (10Be) inventory analyses, we estimated a minimum age for the largest, westernmost, morphologically identifiable, and topographically-highest, barrier/beach-ridge (the Wicomico shoreline barrier) and constrained the age of a suite of younger barrier/beach-ridges that lie adjacent and seaward of the Wicomico shoreline barrier. At the study site, the near-shore marine/estuarine deposits underlying the Wicomico shoreline barrier are overlain by eolian sand and an intervening zone-of-mixing. Optically stimulated luminescence (OSL) data indicate ages of ≤43 ka for the eolian sand and 116 ka for the zone-of-mixing. Meteoric 10Be and pedostratigraphic data indicate minimum residence times of 33.4 ka for the eolian sand, 80.6 ka for the zone-of-mixing, and 247 ka for the paleosol. The combined OSL and 10Be age data indicate that, at this locality, the barrier/beach ridge has a minimum age of about 360 ka. This age for the Wicomico shoreline-barrier deposit is the first for any Pleistocene near-shore marine/estuarine deposit in southeast Georgia that is conclusively older than 80 ka. The 360-ka minimum age is in agreement with other geochronologic data for near-coastline deposits in Georgia and South Carolina. The geomorphic position of this barrier/beach-ridge is similar to deposits in South Carolina considered to be

  20. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    Science.gov (United States)

    Markewich, H. W.; Pavich, M. J.; Schultz, A. P.; Mahan, S. A.; Aleman-Gonzalez, W. B.; Bierman, P. R.

    2013-01-01

    Predominantly clastic, off-lapping, transgressive, near-shore marine sediment packages that are morphologically expressed as subparallel NE-trending barriers, beach ridges, and associated back-barrier areas, characterize the near-surface stratigraphic section between the Savannah and the Ogeechee Rivers in Effingham County, southeastern Georgia. Each barrier/back-barrier (shoreline) complex is lower than and cut into a higher/older complex. Each barrier or shoreline complex overlies Miocene strata. No direct age data are available for these deposits. Previous researchers have disagreed on their age and provenance. Using luminescence and meteoric beryllium-10 (10Be) inventory analyses, we estimated a minimum age for the largest, westernmost, morphologically identifiable, and topographically-highest, barrier/beach-ridge (the Wicomico shoreline barrier) and constrained the age of a suite of younger barrier/beach-ridges that lie adjacent and seaward of the Wicomico shoreline barrier. At the study site, the near-shore marine/estuarine deposits underlying the Wicomico shoreline barrier are overlain by eolian sand and an intervening zone-of-mixing. Optically stimulated luminescence (OSL) data indicate ages of ≤43 ka for the eolian sand and 116 ka for the zone-of-mixing. Meteoric 10Be and pedostratigraphic data indicate minimum residence times of 33.4 ka for the eolian sand, 80.6 ka for the zone-of-mixing, and 247 ka for the paleosol. The combined OSL and 10Be age data indicate that, at this locality, the barrier/beach ridge has a minimum age of about 360 ka. This age for the Wicomico shoreline-barrier deposit is the first for any Pleistocene near-shore marine/estuarine deposit in southeast Georgia that is conclusively older than 80 ka. The 360-ka minimum age is in agreement with other geochronologic data for near-coastline deposits in Georgia and South Carolina. The geomorphic position of this barrier/beach-ridge is similar to deposits in South Carolina considered to be

  1. METHOD OF PROCESSING MONAZITE SAND

    Science.gov (United States)

    Welt, M.A.; Smutz, M.

    1958-08-26

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

  2. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

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

    2012-01-01

    of the various types of sand lenses is discussed, primarily in relation to the depositional and glaciotectonic processes they underwent. Detailed characterization of sand lenses facilitates such interpretations. Finally, the observations are linked to a more general overview of the distribution of sand lenses......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...

  3. A compact topology for sand automata

    CERN Document Server

    Dennunzio, Alberto; Masson, Benoît

    2008-01-01

    In this paper, we exhibit a strong relation between the sand automata configuration space and the cellular automata configuration space. This relation induces a compact topology for sand automata, and a new context in which sand automata are homeomorphic to cellular automata acting on a specific subshift. We show that the existing topological results for sand automata, including the Hedlund-like representation theorem, still hold. In this context, we give a characterization of the cellular automata which are sand automata, and study some dynamical behaviors such as equicontinuity. Furthermore, we deal with the nilpotency. We show that the classical definition is not meaningful for sand automata. Then, we introduce a suitable new notion of nilpotency for sand automata. Finally, we prove that this simple dynamical behavior is undecidable.

  4. 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....

  5. 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...... as well as the flow pattern during discharge of the silo. During discharge a mixed flow pattern has been identified...

  6. Formation of Craters in Sand

    Directory of Open Access Journals (Sweden)

    Vanissra Boonyaleepun

    2007-06-01

    Full Text Available The diameter of craters formed by spheres of varying mass dropped into sand at low speed was studied. The relationship between the diameter of the crater formed and the kinetic energy of the projectile at impact was found to be of the same general form as that for planetary meteor craters. The relationship is shown to be a power law with exponent 0.17.

  7. Formation of Craters in Sand

    Directory of Open Access Journals (Sweden)

    Vanissra Boonyaleepun

    2007-06-01

    Full Text Available The diameter of craters formed by spheres of varying mass dropped into sand at low speed was studied. The relationship between the diameter of the crater formed and the kinetic energy of the projectile at impact was found to be of the same general form as that for planetary meteor craters. The relationship is shown to be a power law with exponent 0.17

  8. Thermal Properties of oil sand

    Science.gov (United States)

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

    2013-12-01

    Thermal recovery methods such as Cyclic Steam Injection or Steam Assisted Gravity Drainage (SAGD) are the effective methods for producing heavy oil or bitumen. In any thermal recovery methods, thermal properties (e.g., thermal conductivity, thermal diffusivity, and volumetric heat capacity) are closely related to the formation and expansion of steam chamber within a reservoir, which is key factors to control efficiency of thermal recovery. However, thermal properties of heavy oil or bitumen have not been well-studied despite their importance in thermal recovery methods. We measured thermal conductivity, thermal diffusivity, and volumetric heat capacity of 43 oil sand samples from Athabasca, Canada, using a transient thermal property measurement instrument. Thermal conductivity of 43 oil sand samples varies from 0.74 W/mK to 1.57 W/mK with the mean thermal conductivity of 1.09 W/mK. The mean thermal diffusivity is 5.7×10-7 m2/s with the minimum value of 4.2×10-7 m2/s and the maximum value of 8.0×10-7 m2/s. Volumetric heat capacity varies from 1.5×106 J/m3K to 2.11×106 J/m3K with the mean volumetric heat capacity of 1.91×106 J/m3K. In addition, physical and chemical properties (e.g., bitumen content, electric resistivity, porosity, gamma ray and so on) of oil sand samples have been measured by geophysical logging and in the laboratory. We are now proceeding to investigate the relationship between thermal properties and physical/chemical properties of oil sand.

  9. SRTM Anaglyph: Wheeler Ridge, California

    Science.gov (United States)

    2000-01-01

    Wheeler Ridge and vicinity, California, is a site of major tectonic activity, both historically and over recent geologic time. The epicenter of the 7.5 magnitude Kern County earthquake occurred here on July 21,1952, and numerous geologic and topographic features indicate rapid geologic processes. The ridge itself (upper-right center) is a geologic fold that is growing out of the southern San Joaquin Valley. A prominent 'wind gap,' now used for passage of the California aquaduct (with the aid of a pumping station), is evidence that the ridge grew faster than tranversing streams could erode down. Nearby abrupt and/or landslid mountain fronts similarly indicate a vigorous tectonic setting here, just north of the San Andreas fault. The Interstate 5 freeway can be seen crossing agricultural fields on the right and entering the very rugged and steep Grapevine Canyon toward the bottom.This anaglyph was generated by first draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission (SRTM), then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data

  10. Numerical simulations of depressurization-induced gas production from gas hydrate reservoirs at the Walker Ridge 312 site, northern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Myshakin, Evgeniy M.; Gaddipati, Manohar; Rose, Kelly; Anderson, Brian J.

    2012-06-01

    In 2009, the Gulf of Mexico (GOM) Gas Hydrates Joint-Industry-Project (JIP) Leg II drilling program confirmed that gas hydrate occurs at high saturations within reservoir-quality sands in the GOM. A comprehensive logging-while-drilling dataset was collected from seven wells at three sites, including two wells at the Walker Ridge 313 site. By constraining the saturations and thicknesses of hydrate-bearing sands using logging-while-drilling data, two-dimensional (2D), cylindrical, r-z and three-dimensional (3D) reservoir models were simulated. The gas hydrate occurrences inferred from seismic analysis are used to delineate the areal extent of the 3D reservoir models. Numerical simulations of gas production from the Walker Ridge reservoirs were conducted using the depressurization method at a constant bottomhole pressure. Results of these simulations indicate that these hydrate deposits are readily produced, owing to high intrinsic reservoir-quality and their proximity to the base of hydrate stability. The elevated in situ reservoir temperatures contribute to high (5–40 MMscf/day) predicted production rates. The production rates obtained from the 2D and 3D models are in close agreement. To evaluate the effect of spatial dimensions, the 2D reservoir domains were simulated at two outer radii. The results showed increased potential for formation of secondary hydrate and appearance of lag time for production rates as reservoir size increases. Similar phenomena were observed in the 3D reservoir models. The results also suggest that interbedded gas hydrate accumulations might be preferable targets for gas production in comparison with massive deposits. Hydrate in such accumulations can be readily dissociated due to heat supply from surrounding hydrate-free zones. Special cases were considered to evaluate the effect of overburden and underburden permeability on production. The obtained data show that production can be significantly degraded in comparison with a case using

  11. A History of Classified Activities at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Quist, A.S.

    2001-01-30

    The facilities that became Oak Ridge National Laboratory (ORNL) were created in 1943 during the United States' super-secret World War II project to construct an atomic bomb (the Manhattan Project). During World War II and for several years thereafter, essentially all ORNL activities were classified. Now, in 2000, essentially all ORNL activities are unclassified. The major purpose of this report is to provide a brief history of ORNL's major classified activities from 1943 until the present (September 2000). This report is expected to be useful to the ORNL Classification Officer and to ORNL's Authorized Derivative Classifiers and Authorized Derivative Declassifiers in their classification review of ORNL documents, especially those documents that date from the 1940s and 1950s.

  12. The Usumacinta-Grijalva beach-ridge plain in southern Mexico: a high-resolution archive of river discharge and precipitation

    Science.gov (United States)

    Nooren, Kees; Hoek, Wim Z.; Winkels, Tim; Huizinga, Annika; Van der Plicht, Hans; Van Dam, Remke L.; Van Heteren, Sytze; Van Bergen, Manfred J.; Prins, Maarten A.; Reimann, Tony; Wallinga, Jakob; Cohen, Kim M.; Minderhoud, Philip; Middelkoop, Hans

    2017-09-01

    The beach-ridge sequence of the Usumacinta-Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the record, and temporal resolution. We mapped and dated the most extensively accreted part of the sequence, linking six phases of accretion to river mouth reconfigurations and constraining their ages with 14C and OSL dating. The geomorphological and sedimentological reconstruction relied on lidar data, coring transects, GPR measurements, grain-size analyses, and chemical fingerprinting of volcanic glass and pumice encountered within the beach and dune deposits. We demonstrate that the beach-ridge complex was formed under ample long-term fluvial sediment supply and shorter-term wave- and aeolian-modulated sediment reworking. The abundance of fluvially supplied sand is explained by the presence of easily weatherable Los Chocoyos ignimbrites from the ca. 84 ka eruption of the Atitlán volcano (Guatemala) in the catchment of the Usumacinta River. Autocyclic processes seem responsible for the formation of ridge-swale couplets. Fluctuations in their periodicity (ranging from 6-19 years) are governed by progradation rate, and are therefore not indicative of sea level fluctuations or variability in storm activity. The fine sandy beach ridges are mainly swash built. Ridge elevation, however, is strongly influenced by aeolian accretion during the time the ridge is located next to the beach. Beach-ridge elevation is negatively correlated with progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment. In the southern Mexican delta plain, the coastal beach ridges therefore appear to be excellent recorders of hinterland precipitation.

  13. 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.

    2017-06-01

    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.

  14. Sand deposit-detecting method and its application in model test of sand flow

    Institute of Scientific and Technical Information of China (English)

    黎伟; 房营光; 莫海鸿; 谷任国; 陈俊生

    2013-01-01

    Against the background of the sand-flow foundation treatment engineering of Guangzhou Zhoutouzui variable cross-section immersed tunnel, a kind of sand deposit-detecting method was devised on the basis of full-scale model test of sand-flow method. The real-time data of sand-deposit height and radius were obtained by the self-developed sand-deposit detectors. The test results show that the detecting method is simple and has high precision. In the use of sand-flow method, the sand-carrying capability of fluid is limited, and sand particles are all transported to the sand-deposit periphery through crater, gap and chutes after the sand deposit formed. The diffusion range of the particles outside the sand-deposit does not exceed 2.0 m. Severe sorting of sand particles is not observed because of the unique oblique-layered depositing process. The temporal and spatial distributions of gap and chutes directly affect the sand-deposit expansion, and the expansion trend of the average sand-deposit radius accords with quadratic time-history curve.

  15. Monitoring of the Canadian Oil Sands from the Aura Satellite

    Science.gov (United States)

    McLinden, C. A.; Shephard, M. W.; Fioletov, V.; Cady-Pereira, K. E.; Krotkov, N. A.; Boersma, K. F.; Li, C.; Luo, M.; Joiner, J.; Bhartia, P. K.

    2014-12-01

    Two instruments on-board the NASA Aura satellite, the Ozone Monitoring Instrument (OMI) and Tropospheric Emission Spectrometer (TES), have been used to monitor air pollution over the Canadian oil sands region. Between them they provide a unique perspective on the distributions, evolution, and sources of several key pollutants. This presentation will detail some highlights from these Aura-based oil sands studies: (i) the evolution of OMI-measured nitrogen dioxide and sulfur dioxide enhancements over the past decade, including comparisons with other nearby sources, (ii) two years of ammonia, carbon monoxide, methanol, and formic acid observations from TES special-observation transects, and (iii) preliminary insights into emissions derived from these observations.

  16. Improving prosthetic prognosis by connective tissue ridge augmentation of alveolar ridge

    Directory of Open Access Journals (Sweden)

    Mishra Niraj

    2010-01-01

    Full Text Available The contour of edentulous ridge should be carefully evaluated before a fixed partial denture is undertaken. The ideal ridge height and width allows placement of a natural looking pontic which facilitates maintenance of plaque-free environment. The localized alveolar ridge defect refers to the volumetric deficit of the limited extent of bone and soft tissue within the alveolar process. Such type of ridge defects can be corrected by surgical ridge augmentation that can be accomplished by the addition of either soft or hard tissues. This article describes a procedure of surgical connective tissue augmentation of a localized deficient alveolar ridge in the maxilla, followed by fixed partial denture, enhancing the esthetics, function and health.

  17. Improving prosthetic prognosis by connective tissue ridge augmentation of alveolar ridge.

    Science.gov (United States)

    Mishra, Niraj; Singh, Balendra P; Rao, Jitendra; Rastogi, Pavitra

    2010-01-01

    The contour of edentulous ridge should be carefully evaluated before a fixed partial denture is undertaken. The ideal ridge height and width allows placement of a natural looking pontic which facilitates maintenance of plaque-free environment. The localized alveolar ridge defect refers to the volumetric deficit of the limited extent of bone and soft tissue within the alveolar process. Such type of ridge defects can be corrected by surgical ridge augmentation that can be accomplished by the addition of either soft or hard tissues. This article describes a procedure of surgical connective tissue augmentation of a localized deficient alveolar ridge in the maxilla, followed by fixed partial denture, enhancing the esthetics, function and health.

  18. Studying methane migration mechanisms at Walker Ridge, Gulf of Mexico, via 3D methane hydrate reservoir modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nole, Michael [University of Texas at Austin; Daigle, Hugh [University of Texas at Austin; Mohanty, Kishore [University of Texas at Austin; Cook, Ann [Ohio State University; Hillman, Jess [Ohio State University

    2015-12-15

    We have developed a 3D methane hydrate reservoir simulator to model marine methane hydrate systems. Our simulator couples highly nonlinear heat and mass transport equations and includes heterogeneous sedimentation, in-situ microbial methanogenesis, the influence of pore size contrast on solubility gradients, and the impact of salt exclusion from the hydrate phase on dissolved methane equilibrium in pore water. Using environmental parameters from Walker Ridge in the Gulf of Mexico, we first simulate hydrate formation in and around a thin, dipping, planar sand stratum surrounded by clay lithology as it is buried to 295mbsf. We find that with sufficient methane being supplied by organic methanogenesis in the clays, a 200x pore size contrast between clays and sands allows for a strong enough concentration gradient to significantly drop the concentration of methane hydrate in clays immediately surrounding a thin sand layer, a phenomenon that is observed in well log data. Building upon previous work, our simulations account for the increase in sand-clay solubility contrast with depth from about 1.6% near the top of the sediment column to 8.6% at depth, which leads to a progressive strengthening of the diffusive flux of methane with time. By including an exponentially decaying organic methanogenesis input to the clay lithology with depth, we see a decrease in the aqueous methane supplied to the clays surrounding the sand layer with time, which works to further enhance the contrast in hydrate saturation between the sand and surrounding clays. Significant diffusive methane transport is observed in a clay interval of about 11m above the sand layer and about 4m below it, which matches well log observations. The clay-sand pore size contrast alone is not enough to completely eliminate hydrate (as observed in logs), because the diffusive flux of aqueous methane due to a contrast in pore size occurs slower than the rate at which methane is supplied via organic methanogenesis

  19. KINERJA JACKKNIFE RIDGE REGRESSION DALAM MENGATASI MULTIKOLINEARITAS

    Directory of Open Access Journals (Sweden)

    HANY DEVITA

    2015-02-01

    Full Text Available Ordinary least square is a parameter estimations for minimizing residual sum of squares. If the multicollinearity was found in the data, unbias estimator with minimum variance could not be reached. Multicollinearity is a linear correlation between independent variabels in model. Jackknife Ridge Regression(JRR as an extension of Generalized Ridge Regression (GRR for solving multicollinearity.  Generalized Ridge Regression is used to overcome the bias of estimators caused of presents multicollinearity by adding different bias parameter for each independent variabel in least square equation after transforming the data into an orthoghonal form. Beside that, JRR can  reduce the bias of the ridge estimator. The result showed that JRR model out performs GRR model.

  20. Oak Ridge TNS Program: system description manual

    Energy Technology Data Exchange (ETDEWEB)

    Reid, R.L.; Becraft, W.R.; Brown, T.G.; Peng, Y.K.M.; Sardella, C.; Shannon, T.E.; Steiner, D.; Wells, W.M.; Wiseman, G.W.

    1979-05-01

    This document provides a systems description of the Reference Design for The Next Step (TNS) evolved at Oak Ridge National Laboratory (ORNL) during FY 1978. The description is presented on the basis of 24 individual device and facility systems. Additional information on these systems, the Reference Design, and the FY 1978 Oak Ridge TNS activities can be found in the associated technical memoranda, ORNL/TM-6720 and ORNL/TM-6722--ORNL/TM-6733.

  1. Realization of Ridge Regression in MATLAB

    Science.gov (United States)

    Dimitrov, S.; Kovacheva, S.; Prodanova, K.

    2008-10-01

    The least square estimator (LSE) of the coefficients in the classical linear regression models is unbiased. In the case of multicollinearity of the vectors of design matrix, LSE has very big variance, i.e., the estimator is unstable. A more stable estimator (but biased) can be constructed using ridge-estimator (RE). In this paper the basic methods of obtaining of Ridge-estimators and numerical procedures of its realization in MATLAB are considered. An application to Pharmacokinetics problem is considered.

  2. 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....

  3. Characterization of Clay Minerals and Kerogen in Alberta Oil Sands Geological End Members

    Science.gov (United States)

    Zheng, Limin

    The high degree of variability of oil sands ores can be attributed to a mixture of different geological end members, i.e., estuarine sand, estuarine clay, marine sand and marine clay. This study focused on the mineralogy, especially of clay minerals, and toluene insoluble organic matter, referred to as kerogen, in different oil sands end members. Clays and kerogens will likely have a significant impact on solvent recovery from the gangue following non-aqueous bitumen extraction. The bitumen-free solids were subjected to mineralogical and geochemical analysis. Kerogens were isolated and analyzed by various characterization methods. The types of clays were identified in oriented samples by X-ray diffraction analysis. The nitrogen to carbon ratio in the isolated kerogens is found to be higher than in bitumen. There are more type III kerogens in estuarine samples and more type II kerogens in marine samples.

  4. Oak Ridge Reservation environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, V.A.; Wilson, A.R. (eds.)

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1.

  5. Assessing the clarity of friction ridge impressions.

    Science.gov (United States)

    Hicklin, R Austin; Buscaglia, JoAnn; Roberts, Maria Antonia

    2013-03-10

    The ability of friction ridge examiners to correctly discern and make use of the ridges and associated features in finger or palm impressions is limited by clarity. The clarity of an impression relates to the examiner's confidence that the presence, absence, and attributes of features can be correctly discerned. Despite the importance of clarity in the examination process, there have not previously been standard methods for assessing clarity in friction ridge impressions. We introduce a process for annotation, analysis, and interchange of friction ridge clarity information that can be applied to latent or exemplar impressions. This paper: (1) describes a method for evaluating the clarity of friction ridge impressions by using color-coded annotations that can be used by examiners or automated systems; (2) discusses algorithms for overall clarity metrics based on manual or automated clarity annotation; and (3) defines a method of quantifying the correspondence of clarity when comparing a pair of friction ridge images, based on clarity annotation and resulting metrics. Different uses of this approach include examiner interchange of data, quality assurance, metrics, and as an aid in automated fingerprint matching.

  6. Liquefaction of Sand under Low Confining Pressure

    Institute of Scientific and Technical Information of China (English)

    YANG Shaoli; Rolf Sandven; Lars Grande

    2003-01-01

    Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. This process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand.In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.

  7. Creep Behavior of Frozen Sand.

    Science.gov (United States)

    1981-06-01

    temperature and stress range. There was a 2strong stress dependance to S (r =0.95) for saturated Manchester Fine Sand which does not agree with RPT. The...Curves at High Stress 161 Ratio D/Du = 0.505 for Frozen HF’S at w=10% IV-20 Minimum Strain Rate Dependance on Stress 162 Ratio for Frozen MFS IV-21 Minimum...Strain Rate Dependance on Relative 163 Density for Frozen MFS IV-22 Temperature Stage Test on Frozen Saturated 164 MFS under a Load of D=9.24MPa Fig

  8. Incorporating Ridges with Minutiae for Improved Fingerprint verification

    Directory of Open Access Journals (Sweden)

    Ms.M.Indra

    2012-10-01

    Full Text Available Next to DNA, fingerprint is the unique feature which identifies the individual. Distortions and skin deformations makes the fingerprint unreliable and it is difficult to match using minutiae alone. But when ridge features are incorporated with minutiae features (minutiae type, orientation and position more topological information can be obtained. And also ridges are invariant to transformations such as rotation and translation[1]. Ridge based coordinate system is used to extract the ridge features such as ridge length, ridge count, ridge type and curvature direction in the skeletonized image. Breadth First Search is used to traverse the graph formed using the minutiae as the node and the ridge vector formed using the ridge features as the edge. The proposed ridge feature gives additional information for fingerprint matching with little increment in template size and can be used along with the existing minutiae features to increase the accuracy and robustness of fingerprint recognition systems.

  9. Radioactive Solid Waste Storage and Disposal at Oak Ridge National Laboratory, Description and Safety Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bates, L.D.

    2001-01-30

    Oak Ridge National Laboratory (ORNL) is a principle Department of Energy (DOE) Research Institution operated by the Union Carbide Corporation - Nuclear Division (UCC-ND) under direction of the DOE Oak Ridge Operations Office (DOE-ORO). The Laboratory was established in east Tennessee, near what is now the city of Oak Ridge, in the mid 1940s as a part of the World War II effort to develop a nuclear weapon. Since its inception, disposal of radioactively contaminated materials, both solid and liquid, has been an integral part of Laboratory operations. The purpose of this document is to provide a detailed description of the ORNL Solid Waste Storage Areas, to describe the practice and procedure of their operation, and to address the health and safety impacts and concerns of that operation.

  10. Water availability for development of major tar sands areas in Utah

    Energy Technology Data Exchange (ETDEWEB)

    Keefer, T.N.; McQuivey, R.S.

    1979-05-01

    The Sutron Corporation, under contract with Colorado State University, has conducted a study for the Laramie Energy Technology Center (LETC) to determine the availability of water for future extraction of viscous petroleum (bitumen) from the six major tar sands deposits in Utah. Specifically, the areas are: Asphalt Ridge and Whiterocks, which lie immediately west of Vernal, Utah; P.R. Spring, a large area extending from the Colorado River to the White River along Utah's eastern border; Hill Creek, adjacent to P.R. Spring to the west; Sunnyside, immediately across the Green River from Hill Creek between the Price and Green Rivers; and Tar Sand Triangle, near the confluence of the Colorado and Dirty Devil Rivers. The study, conducted between September and December of 1978, was a fact-finding effort involving the compilation of information from publications of the US Geological Survey (USGS), Utah State Engineer, Utah Department of Natural Resources, and other federal and state agencies. The information covers the general physiographic and geologic features of the total area, the estimated water requirements for tar sands development, the availability of water in each of the six areas, and the legal and sociological restraints and impacts. The conclusions regarding water availability for tar sands development in each of the six areas and specific recommendations related to the development of each area are presented also.

  11. Recent advances in waterglass sand technologies

    Institute of Scientific and Technical Information of China (English)

    ZHU Chun-xi

    2007-01-01

    This paper reports some new understandings and advances in waterglass sand technologies. The multiple chemical modification process can increase the binding strength of the waterglass sand by up to 50%-70%.Therefore, the additions of the modified waterglass can be decreased to 3.0%-4.0% for CO2 process and to 2.0%-2.5% for organic ester hardening process, and greatly improve the collapsibility and reclaimability of the sand. Based on the new understandings and experimental results reported in this paper, several original ideas, such as nano modification, have been proposed to promote advances of waterglass sand technologies,

  12. PROSPECTS FIXATION DRIFT SANDS PHYSICOCHEMICAL METHOD

    Directory of Open Access Journals (Sweden)

    Maujuda MUZAFFAROVA

    2016-09-01

    Full Text Available This article is based on the theoretical foundations of secure mobile sand being considered for reducing the negative impact of one of the manifestations of exogenous plains on such an important natural-technical system as a railroad. It suggests practical measures to build a system of design protection against sand drifts. The article also suggests ways to conserve resources and rational use of machinery and performers as well as the consolidation of mobile sand wet with water soluble waste of local production of waste dextrin. Consolidation is exposed on dry and wet sand.

  13. Innovative developments in sand reclamation technologies

    Directory of Open Access Journals (Sweden)

    R. Dañko

    2011-04-01

    Full Text Available Proper sand management and efficient sand reclamation system are two main factors influencing economical and ecological side of modern foundry plant. It is well known fact that the production of 1 metric ton of casting from ferrous alloys generates circa 1 metric ton of waste [1], which due to containing certain amounts of harmful and dangerous compounds should undergo a reclamation – at least of the main component, which means a silica sand grains. The paper present problems of scientific and development research concerning the innovative reclamation technologies of used foundry sands such as: mechanical-cryogenic reclamation and innovative thermal reclamation.

  14. Sand Failure Mechanism and Sanding Parameters in Niger Delta Oil Reservoirs

    OpenAIRE

    Sunday Isehunwa,; Andrew Farotade

    2010-01-01

    Sand production is a major issue during oil and gas production from unconsolidated reservoirs. In predicting the onset of sand production, it is important to accurately determine the failure mechanism and the contributing parameters. The aim of this study was to determine sand failure mechanism in the Niger-Delta, identify themajor contributing parameters and evaluate their effects on sanding.Completion and production data from 78 strings completed on 22 reservoirs in a Niger Delta oil Field ...

  15. Microbial community composition of a household sand filter used for arsenic, iron, and manganese removal from groundwater in Vietnam.

    Science.gov (United States)

    Nitzsche, Katja Sonja; Weigold, Pascal; Lösekann-Behrens, Tina; Kappler, Andreas; Behrens, Sebastian

    2015-11-01

    Household sand filters are used in rural areas of Vietnam to remove As, Fe, and Mn from groundwater for drinking water purposes. Currently, it is unknown what role microbial processes play in mineral oxide formation and As removal during water filtration. We performed most probable number counts to quantify the abundance of physiological groups of microorganisms capable of catalyzing Fe- and Mn-redox transformation processes in a household sand filter. We found up to 10(4) cells g(-1) dry sand of nitrate-reducing Fe(II)-oxidizing bacteria and Fe(III)-reducing bacteria, and no microaerophilic Fe(II)-oxidizing bacteria, but up to 10(6) cells g(-1) dry sand Mn-oxidizing bacteria. 16S rRNA gene amplicon sequencing confirmed MPN counts insofar as only low abundances of known taxa capable of performing Fe- and Mn-redox transformations were detected. Instead the microbial community on the sand filter was dominated by nitrifying microorganisms, e.g. Nitrospira, Nitrosomonadales, and an archaeal OTU affiliated to Candidatus Nitrososphaera. Quantitative PCR for Nitrospira and ammonia monooxygenase genes agreed with DNA sequencing results underlining the numerical importance of nitrifiers in the sand filter. Based on our analysis of the microbial community composition and previous studies on the solid phase chemistry of sand filters we conclude that abiotic Fe(II) oxidation processes prevail over biotic Fe(II) oxidation on the filter. Yet, Mn-oxidizing bacteria play an important role for Mn(II) oxidation and Mn(III/IV) oxide precipitation in a distinct layer of the sand filter. The formation of Mn(III/IV) oxides contributes to abiotic As(III) oxidation and immobilization of As(V) by sorption to Fe(III) (oxyhydr)oxides.

  16. The Current and Future Use of Ridge Regression for Prediction in Quantitative Genetics

    Directory of Open Access Journals (Sweden)

    Ronald de Vlaming

    2015-01-01

    Full Text Available In recent years, there has been a considerable amount of research on the use of regularization methods for inference and prediction in quantitative genetics. Such research mostly focuses on selection of markers and shrinkage of their effects. In this review paper, the use of ridge regression for prediction in quantitative genetics using single-nucleotide polymorphism data is discussed. In particular, we consider (i the theoretical foundations of ridge regression, (ii its link to commonly used methods in animal breeding, (iii the computational feasibility, and (iv the scope for constructing prediction models with nonlinear effects (e.g., dominance and epistasis. Based on a simulation study we gauge the current and future potential of ridge regression for prediction of human traits using genome-wide SNP data. We conclude that, for outcomes with a relatively simple genetic architecture, given current sample sizes in most cohorts (i.e., N<10,000 the predictive accuracy of ridge regression is slightly higher than the classical genome-wide association study approach of repeated simple regression (i.e., one regression per SNP. However, both capture only a small proportion of the heritability. Nevertheless, we find evidence that for large-scale initiatives, such as biobanks, sample sizes can be achieved where ridge regression compared to the classical approach improves predictive accuracy substantially.

  17. The Current and Future Use of Ridge Regression for Prediction in Quantitative Genetics.

    Science.gov (United States)

    de Vlaming, Ronald; Groenen, Patrick J F

    2015-01-01

    In recent years, there has been a considerable amount of research on the use of regularization methods for inference and prediction in quantitative genetics. Such research mostly focuses on selection of markers and shrinkage of their effects. In this review paper, the use of ridge regression for prediction in quantitative genetics using single-nucleotide polymorphism data is discussed. In particular, we consider (i) the theoretical foundations of ridge regression, (ii) its link to commonly used methods in animal breeding, (iii) the computational feasibility, and (iv) the scope for constructing prediction models with nonlinear effects (e.g., dominance and epistasis). Based on a simulation study we gauge the current and future potential of ridge regression for prediction of human traits using genome-wide SNP data. We conclude that, for outcomes with a relatively simple genetic architecture, given current sample sizes in most cohorts (i.e., N < 10,000) the predictive accuracy of ridge regression is slightly higher than the classical genome-wide association study approach of repeated simple regression (i.e., one regression per SNP). However, both capture only a small proportion of the heritability. Nevertheless, we find evidence that for large-scale initiatives, such as biobanks, sample sizes can be achieved where ridge regression compared to the classical approach improves predictive accuracy substantially.

  18. Transpositioned flap vestibuloplasty combined with implant surgery in the severely resorbed atrophic edentulous ridge.

    Science.gov (United States)

    Kao, Shou-Yen; Yeung, Tze-Cheung; Hung, Kai-Feng; Chou, I-Chiang; Wu, Che-Hsian; Chang, Richard Che-Shoa

    2002-01-01

    The use of transpositioned flap (lipswitch) vestibuloplasty combined with implant surgery in patients with severely resorbed atrophic edentulous ridges is reviewed. The cases of 17 patients with severely resorbed atrophic edentulous ridges at the mandible undergoing implant rehabilitation were reviewed. Lipswitch vestibuloplasty was followed immediately by the implant surgery. Postoperative follow-up consisted of clinical and radiographic examinations. Seventeen patients with atrophic ridges (12 class II and 5 class III) each had 2 implant fixtures placed in the mandible as abutments for a clip and bar overdenture. The average time of follow-up was 6 years. Before surgery, all patients had severely atrophic ridges with a compromised shallow vestibule of varying degrees. Satisfactory results were observed in regard to the immediate and long-term morphology of the vestibule, the health of the peri-implant tissue, the stability of implant fixtures, and the functionality of the prostheses. The lipswitch vestibuloplasty offers a safe and convenient method of surgical access for implant fixture installation, with the advantage of rebuilding the vestibule of a compromised atrophic ridge in the anterior mandible.

  19. Preliminary results from the first InRidge cruise to the central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Murthy, K.S.R.; Iyer, S.D.; Rao, M.M.M.; Banerjee, R.; Subrahmanyam, A.S.; Shirodkar, P.V.; Ghose, I.; Ganesan, P.; Rao, A.K.; Suribabu, A.; Ganesh, C.; Naik, G.P.

    stream_size 1 stream_content_type text/plain stream_name Inter_Ridge_News_7_40.pdf.txt stream_source_info Inter_Ridge_News_7_40.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  20. The Usumacinta–Grijalva beach-ridge plain in southern Mexico: a high-resolution archive of river discharge and precipitation

    Directory of Open Access Journals (Sweden)

    K. Nooren

    2017-09-01

    Full Text Available The beach-ridge sequence of the Usumacinta–Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the record, and temporal resolution. We mapped and dated the most extensively accreted part of the sequence, linking six phases of accretion to river mouth reconfigurations and constraining their ages with 14C and OSL dating. The geomorphological and sedimentological reconstruction relied on lidar data, coring transects, GPR measurements, grain-size analyses, and chemical fingerprinting of volcanic glass and pumice encountered within the beach and dune deposits. We demonstrate that the beach-ridge complex was formed under ample long-term fluvial sediment supply and shorter-term wave- and aeolian-modulated sediment reworking. The abundance of fluvially supplied sand is explained by the presence of easily weatherable Los Chocoyos ignimbrites from the ca. 84 ka eruption of the Atitlán volcano (Guatemala in the catchment of the Usumacinta River. Autocyclic processes seem responsible for the formation of ridge–swale couplets. Fluctuations in their periodicity (ranging from 6–19 years are governed by progradation rate, and are therefore not indicative of sea level fluctuations or variability in storm activity. The fine sandy beach ridges are mainly swash built. Ridge elevation, however, is strongly influenced by aeolian accretion during the time the ridge is located next to the beach. Beach-ridge elevation is negatively correlated with progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment. In the southern Mexican delta plain, the coastal beach ridges therefore appear to be excellent recorders of hinterland precipitation.

  1. Pore Size Distribution and Methane Equilibrium Conditions at Walker Ridge Block 313, Northern Gulf of Mexico

    Science.gov (United States)

    Bihani, A. D.; Daigle, H.; Cook, A.; Glosser, D.; Shushtarian, A.

    2015-12-01

    Coexistence of three methane phases (liquid (L), gas (G), hydrate (H)) in marine gas hydrate systems may occur according to in-situ pressure, temperature, salinity and pore size. In sediments with salinity close to seawater, a discrete zone of three-phase (3P) equilibrium may occur near the base of the regional hydrate stability zone (RHSZ) due to capillary effects. The existence of a 3P zone influences the location of the bottom-simulating reflection (BSR) and has implications for methane fluxes at the base of the RHSZ. We studied hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. We determined pore size distributions (PSD) by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict PSD through comparison with mercury injection capillary pressure measurements. With the computed PSD, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the 3P equilibrium zone. As in previous studies at Blake Ridge and Hydrate Ridge, the top of the 3P zone moves upwards with increasing water depth and overlies the bulk 3P equilibrium depth. In clays at Walker Ridge, the predicted thickness of the 3P zone is approximately 35 m, but in coarse sands it is only a few meters due to the difference in absolute pore sizes and the width of the PSD. The thick 3P zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR.

  2. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Bihani, Abhishek [University of Texas at Austin; Daigle, Hugh [University of Texas at Austin; Cook, Ann [Ohio State University; Glosser, Deborah [Ohio State University; Shushtarian, Arash [University of Texas at Austin

    2015-12-15

    Coexistence of three methane phases (liquid (L), gas (G), hydrate (H)) in marine gas hydrate systems may occur according to in-situ pressure, temperature, salinity and pore size. In sediments with salinity close to seawater, a discrete zone of three-phase (3P) equilibrium may occur near the base of the regional hydrate stability zone (RHSZ) due to capillary effects. The existence of a 3P zone influences the location of the bottom-simulating reflection (BSR) and has implications for methane fluxes at the base of the RHSZ. We studied hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. We determined pore size distributions (PSD) by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict PSD through comparison with mercury injection capillary pressure measurements. With the computed PSD, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the 3P equilibrium zone. As in previous studies at Blake Ridge and Hydrate Ridge, the top of the 3P zone moves upwards with increasing water depth and overlies the bulk 3P equilibrium depth. In clays at Walker Ridge, the predicted thickness of the 3P zone is approximately 35 m, but in coarse sands it is only a few meters due to the difference in absolute pore sizes and the width of the PSD. The thick 3P zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR.

  3. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    This document outlines the activities necessary to conduct a Remedial Investigation (RI) of the Chestnut Ridge Security Pits (CRSP) at the Oak Ridge Y-12 Plant. The CRSP, also designated Chestnut Ridge Operable Unit (OU) 1, is one of four OUs along Chestnut Ridge on the Oak Ridge Reservation (ORR). The purpose of the RI is to collect data to (1) evaluate the nature and extent of known and suspected contaminants, (2) support an Ecological Risk Assessment (ERA) and a Human Health Risk Assessment (HHRA), (3) support the feasibility study in the development and analysis of remedial alternatives, and (4) ultimately, develop a Record of Decision (ROD) for the site. This chapter summarizes the regulatory background of environmental investigation on the ORR and the approach currently being followed and provides an overview of the RI to be conducted at the CRSP. Subsequent chapters provide details on site history, sampling activities, procedures and methods, quality assurance (QA), health and safety, and waste management related to the RI.

  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. 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...

  6. Pilot Project Sand Groynes Delfland Coast

    NARCIS (Netherlands)

    Hoekstra, R.; Walstra, D.J.R.; Swinkels, C.S.

    2012-01-01

    In October and November 2009 a pilot project has been executed at the Delfland Coast in the Netherlands, constructing three small sandy headlands called Sand Groynes. Sand Groynes are nourished from the shore in seaward direction and anticipated to redistribute in the alongshore due to the impact of

  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 re

  8. Pilot Project Sand Groynes Delfland Coast

    NARCIS (Netherlands)

    Hoekstra, R.; Walstra, D.J.R.; Swinkels, C.S.

    2012-01-01

    In October and November 2009 a pilot project has been executed at the Delfland Coast in the Netherlands, constructing three small sandy headlands called Sand Groynes. Sand Groynes are nourished from the shore in seaward direction and anticipated to redistribute in the alongshore due to the impact of

  9. 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 t

  10. 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

  11. Extended Cold Testing of a Russian Pulsating Mixer Pump at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, BE

    2002-12-23

    The effectiveness of a mixer is dependent on the size of the tank to be mixed, the characteristics of the waste, and the operating conditions. Waste tanks throughout the U.S. Department of Energy Complex require mixing and mobilization systems capable of (1) breaking up and suspending materials that are difficult to mix and pump, without introducing additional liquids into the tank; (2) complementing and augmenting the performance of other remotely operated and/or robotic waste retrieval systems; and (3) operating in tanks with various quantities of waste. The Oak Ridge Russian pulsating mixer pump (PMP) system was designed with the flexibility to permit deployment in a variety of cylindrical tanks. The PMP was installed at the Tanks Technology Cold Test Facility at the Oak Ridge National Laboratory (ORNL) to assess the performance of the system over an extended range of operating conditions, including supply pressures up to 175 psig. Previously conducted cold tests proved the applicability of the PMP for deployment in ORNL gunite tank TH-4. The previous testing and hot demonstrations had been limited to operating at air supply pressures of <100 psig. The extended cold testing of the Russian PMP system showed that the system was capable of mobilizing waste simulants in tanks in excess of 20-ft diam. The waste simulant used in these tests was medium-grain quartz sand. The system was successfully installed, checked out, and operated for 406 pulse discharge cycles. Only minor problems (i.e., a sticking air distributor valve and a few system lockups) were noted. Some improvements to the design of the air distributor valve may be needed to improve reliability. The air supply requirements of the PMP during the discharge cycle necessitated the operation of the system in single pulse discharge cycles to allow time for the air supply reservoir to recharge to the required pressure. During the test program, the system was operated with sand depths of 2, 4, and 4.5 in.; at

  12. E-MORB glasses from the Gakkel Ridge (Arctic Ocean) at 87°N: evidence for the Earth's most northerly volcanic activity

    OpenAIRE

    R. Mühe; Bohrmann, H.; Garbe-Schönberg, Dieter; Kassens, Heidemarie

    1997-01-01

    During the ARCTIC '91 expedition aboard RV Polarstern (ARK VIII/3) to the Central Arctic Ocean, a box corer sample on the Gakkel Ridge at 87 degrees N and 60 degrees E yielded a layer of sand-sized, dark brown volcanic glass shards at the surface of the sediment core. These shards have been investigated by petrographic, mineralogical, geochemical and radiogenic isotope methods. The nearly vesicle-free and aphyric glass shards bear only minute microphenocrysts of magnesiochromite and olivine (...

  13. 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.

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

    Science.gov (United States)

    Okay, G.; Leroy, P.

    2012-04-01

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

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

    Science.gov (United States)

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

    1998-01-01

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

  16. Sand Failure Mechanism and Sanding Parameters in Niger Delta Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Sunday Isehunwa,

    2010-05-01

    Full Text Available Sand production is a major issue during oil and gas production from unconsolidated reservoirs. In predicting the onset of sand production, it is important to accurately determine the failure mechanism and the contributing parameters. The aim of this study was to determine sand failure mechanism in the Niger-Delta, identify themajor contributing parameters and evaluate their effects on sanding.Completion and production data from 78 strings completed on 22 reservoirs in a Niger Delta oil Field were evaluated. Sand failure mechanisms and contributing parameters were identified and compared with published profiles. The results showed that cohesive stress is the predominant sand failure mechanism. Water cut, bean size and gas oil ratio (GOR impact sand production in the Niger Delta.

  17. 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

  18. Bathymetry of Reykjanes Ridge: A methodological approach

    OpenAIRE

    Banul, Karolina, 1987-

    2014-01-01

    The sea floor is one of the Earths parts that still are mostly unexplored. Recent multibeam technology has now opened up new opportunities to increase our knowledge in this hitherto hidden part of the world. In this study part of the Reykjanes Ridge was analysed in order to create a high resolution and comprehensive topographic map of this northern part of the Mid-Atlantic Ocean Ridge. The general aims of the study were to i) develop seamless method from Caris, a raw analytical program for mu...

  19. Ridge and Transverse Correlation at Separated Rapidities

    CERN Document Server

    Chiu, Charles B

    2012-01-01

    A simple phenomenological relationship between the ridge distribution in $\\Delta\\eta$ and the single-particle distribution in $\\eta$ can be established from the PHOBOS data on both distributions. The implication points to the possibility that there is no long-range longitudinal correlation. An interpretation of the relationship is then developed, based on the recognition that longitudinal uncertainty of the initial configuration allows for non-Hubble-like expansion at early time. It is shown that the main features of the ridge structure can be explained in a model where transverse correlation stimulated by semihard partons is the principal mechanism.

  20. Tissue Engineering for Vertical Ridge Reconstruction.

    Science.gov (United States)

    Patel, Neel; Kim, Beomjune; Zaid, Waleed; Spagnoli, Daniel

    2017-02-01

    This article provides an overview of basic tissue engineering principles as they are applied to vertical ridge defects and reconstructive techniques for these types of deficiencies. Presented are multiple clinical cases ranging from office-based dentoalveolar procedures to the more complex reconstruction of postresection mandibular defects. Several different types of regenerative tissue constructs are presented; either used alone or in combination with traditional reconstructive techniques and procedures, such as maxillary sinus augmentation, Le Fort I osteotomy, and microvascular free tissue transfer. The goal is to also familiarize the reconstructive surgeon to potential future strategies in vertical alveolar ridge augmentation. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Understanding the fate of organic micropollutants in sand and granular activated carbon biofiltration systems

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, L., E-mail: lidia.paredes@usc.es; Fernandez-Fontaina, E., E-mail: eduardo.fernandez.fontaina@usc.es; Lema, J.M., E-mail: juan.lema@usc.es; Omil, F., E-mail: francisco.omil@usc.es; Carballa, M., E-mail: marta.carballa@usc.es

    2016-05-01

    In this study, sand and granular activated carbon (GAC) biofilters were comparatively assessed as post-treatment technologies of secondary effluents, including the fate of 18 organic micropollutants (OMPs). To determine the contribution of adsorption and biotransformation in OMP removal, four reactors were operated (two biofilters (with biological activity) and two filters (without biological activity)). In addition, the influence of empty bed contact time (EBCT), ranging from 0.012 to 3.2 d, and type of secondary effluent (anaerobic and aerobic) were evaluated. Organic matter, ammonium and nitrate were removed in both biofilters, being their adsorption higher on GAC than on sand. According to the behaviour exhibited, OMPs were classified in three different categories: I) biotransformation and high adsorption on GAC and sand (galaxolide, tonalide, celestolide and triclosan), II) biotransformation, high adsorption on GAC but low or null adsorption on sand (ibuprofen, naproxen, fluoxetine, erythromycin, roxythromycim, sulfamethoxazole, trimethoprim, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol), and, III) only adsorption on GAC (carbamazepine, diazepam and diclofenac). No influence of EBCT (in the range tested) and type of secondary effluent was observed in GAC reactors, whereas saturation and kinetic limitation of biotransformation were observed in sand reactors. Taking into account that most of the organic micropollutants studied (around 60%) fell into category II, biotransformation is crucial for the elimination of OMPs in sand biofilters. - Highlights: • OMP removal was comparatively assessed in sand and GAC biofilters. • The contribution of adsorption and biotransformation in OMP removal was identified. • The filtering material did not affect the biological activities in biofilters. • There is no direct correlation between EBCT and OMP removal in biofilters. • The type of secondary effluent determines the lifespan of filtering

  2. ANNUAL UPDATE OF THE SOLID WASTE MANAGEMENT UNIT (SWMU) LIST FOR THE OAK RIDGE Y-12 PLANT.

    Energy Technology Data Exchange (ETDEWEB)

    Deakin, J.M.

    1997-01-01

    In accordance with the terms of Paragraph II.A.8 of the Resource Conservation and Recovery Act (RCRA), 1984 Hazardous and Solid Waste Amendments (HSWA) Permit TN 001, and the Tennessee Department of Environment and Conservation (TDEC), RCRA Permit TN1 890 090 003 for Building 7652 at the Oak Ridge National Laboratory, the list of the solid waste management units (SWMUs) for the Oak Ridge Reservation, including the Oak Ridge Y-12 Plant, must be updated and submitted to personnel at the Environmental Protection Agency, Region IV, and TDEC by January 30, 1997. This report includes information satisfying the {section}II.A.8 requirements, to update the SWMU list for the Y-12 Plant. Newly identified SWMUs include discernible units which have accumulated, treated, stored, or disposed of waste; areas contaminated by routine, deliberate, or systematic releases from process components; RCRA 90-day accumulation areas; and TSCA one-year areas.

  3. Normalization Ridge Regression in Practice I: Comparisons Between Ordinary Least Squares, Ridge Regression and Normalization Ridge Regression.

    Science.gov (United States)

    Bulcock, J. W.

    The problem of model estimation when the data are collinear was examined. Though the ridge regression (RR) outperforms ordinary least squares (OLS) regression in the presence of acute multicollinearity, it is not a problem free technique for reducing the variance of the estimates. It is a stochastic procedure when it should be nonstochastic and it…

  4. Ridge regression estimator: combining unbiased and ordinary ridge regression methods of estimation

    Directory of Open Access Journals (Sweden)

    Sharad Damodar Gore

    2009-10-01

    Full Text Available Statistical literature has several methods for coping with multicollinearity. This paper introduces a new shrinkage estimator, called modified unbiased ridge (MUR. This estimator is obtained from unbiased ridge regression (URR in the same way that ordinary ridge regression (ORR is obtained from ordinary least squares (OLS. Properties of MUR are derived. Results on its matrix mean squared error (MMSE are obtained. MUR is compared with ORR and URR in terms of MMSE. These results are illustrated with an example based on data generated by Hoerl and Kennard (1975.

  5. Large fault fabric of the Ninetyeast Ridge implies near-spreading ridge formation

    Digital Repository Service at National Institute of Oceanography (India)

    Sager, W.W.; Paul, C.F; Krishna, K.S.; Pringle, M.S.; Eisin, A.E.; Frey, F; Rao, D; Levchenko, O.V.

    Large Fault Fabric of the Ninetyeast Ridge Implies Near-Spreading Ridge Formation 1 W. W. Sager 1 *, C. F. Paul 1 , K. S. Krishna 2 , M. Pringle 3 , A. E. Eisin 1,4 , F. A. Frey 3 , D. Gopala 2 Rao 5 , O. Levchenko 6 3 1 Department of Oceanography....proc.sr.121.122.1991. 254 Sandwell, D. T., and W. H. F. Smith (2009), Global marine gravity from retracked Geosat and 255 ERS-1 Altimetry: Ridge segmentation versus spreading rate, J. Geophys. Res., 114, 1-16, 256 doi:10.10029/2008JB006008, 2009. 257...

  6. Enigmatic sediment ridges in the German Bight - glacial vs post-glacial morphologies?

    Science.gov (United States)

    Unnithan, Vikram; Pio Rossi, Angelo; Praeg, Daniel

    2014-05-01

    The German Wadden Sea extends over 1000 km from the Dutch coast to that of Sweden and consists of a long chain of barrier islands and ephemeral sand banks punctuated by estuaries and rivers. The sedimentary environment is currently shaped and characterised by storm surges, high tidal and wave energy levels. However, this part of the North Sea has been repeatedly covered by continental ice sheets, and it remains unclear how glacial to interglacial sedimentary processes may have influenced seabed morphology in the region. The study area is situated approximately 70 km north of Cuxhaven, and 5 km due east of the islands of Helgoland and Dune. It covers an approximate area of 5 km square with water depths ranging from 50 m in the south to about 20 m in the north. High resolution multibeam (Simrad EM710) and parametric echosounder (Innomar SES2000) data were acquired during graduate and undergraduate teaching excursions on the RV Heincke in Spring 2010 (HE-324) and 2011 (HE-349). The seabed swath bathymetric data reveal distinctive linear seabed ridges. The ridges trend NNW-SSE, are 1-5 m in height, have wavelengths on the order of 100 m and crest lengths ranging from 100-2500 m. The ridge crests are broadly anastomosing. They bifurcate towards the north to form more subdued structures, while they converge and disappear to the south. Profiles across the ridges show an asymmetric structure, with steeper slopes trending west in the western part of the study area but trending east in the eastern part. These enigmatic sedimentary structures have not been previously mapped in the Wadden Sea, and their origin remains uncertain. Possible interpretations to be tested include sub-crop structural control on seabed morphology, relict glacial or glaciofluvial landforms and post-glacial marine bedforms linked to processes of sediment redistribution.

  7. Adsorption of dyes on Sahara desert sand.

    Science.gov (United States)

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

    2009-10-15

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

  8. Critical state of sand matrix soils.

    Science.gov (United States)

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

    2014-01-01

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

  9. Sand Flies and Their Control Methods.

    Science.gov (United States)

    Çetin, Hüseyin; Özbel, Yusuf

    2017-06-01

    The main aim of managing arthropod vectors that carry the disease agents is interrupting the infection cycle. Therefore, the management of the disease implies that all precautions related to all elements (i.e., human, arthropod vector, and reservoir) in the infection cycle need to be taken. There are important points that need to be considered while dealing with sand flies (Diptera: Psychodidae: Phlebotominae), which in many regions worldwide, particularly in tropical and subtropical areas, are vectors of diseases such as leishmaniasis and sand fly fever and are the arthropods of the infection cycle. Because the larval control of the sand flies is very difficult and almost impossible, the management is mainly conducted for the adults. The most effective strategy for reducing both sand fly fever and leishmaniasis is managing sand flies, particularly in areas where humans are located. In this review, the morphology, biology, and taxonomy of sand flies; the integrated fighting and management methods such as insecticide-impregnated bed nets and use of curtains, zooprophylaxis, indoor and outdoor residual applications, larvicides, repellents, and insecticide-impregnated dog collars; and data regarding many issues such as insecticide resistance in sand flies have been emphasized on in the review.

  10. Critical State of Sand Matrix Soils

    Directory of Open Access Journals (Sweden)

    Aminaton Marto

    2014-01-01

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

  11. Invasive plants on disturbed Korean sand dunes

    Science.gov (United States)

    Kim, Kee Dae

    2005-01-01

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

  12. Channel Networks on Large Fans: Refining Analogs for the Ridge-forming Unit, Sinus Meridiani

    Science.gov (United States)

    Wilkinson, Justin

    2009-01-01

    Stream channels are generally thought of as forming within confined valley settings, separated by interfluves. Sinuous ridges on Mars and Earth are often interpreted as stream channels inverted by subsequent erosion of valley sides. In the case of the ridge-forming unit (RFU), this interpretation fails to explain the (i) close spacing of the ridges, which are (ii) organized in networks, and which (iii) cover large areas (approximately 175,000 km (exp 2)). Channel networks on terrestrial fans develop unconfined by valley slopes. Large fans (100s km long) are low-angle, fluvial features, documented worldwide, with characteristics that address these aspects of the RFU. Ridge patterns Channels on large fans provide an analog for the sinuous and elongated morphology of RFU ridges, but more especially for other patterns such as subparallel, branching and crossing networks. Branches are related to splays (delta-like distributaries are rare), whose channels can rejoin the main channel. Crossing patterns can be caused by even slight sinuosity splay-related side channels often intersect. An avulsion node distant from the fan apex, gives rise to channels with slightly different, and hence intersecting, orientations. Channels on neighboring fans intersect along the common fan margin. 2. Network density Channels are the dominant feature on large terrestrial fans (lakes and dune fields are minor). Inverted landscapes on subsequently eroded fans thus display indurated channels as networks of significantly close-spaced ridges. 3. Channel networks covering large areas Areas of individual large terrestrial fans can reach >200,000 km 2 (105-6 km 2 with nested fans), providing an analog for the wide area distribution of the RFU.

  13. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This Remedial Investigation (RI) Work Plan specifically addresses Chestnut Ridge Operable Unit 1, (OU1) which consists of the Chestnut Ridge Security Pits (CRSP). The CRSP are located {approximately}800 ft southeast of the central portion of the Y-12 Plant atop Chestnut Ridge, which is bounded to the northwest by Bear Creek Valley and to the southeast by Bethel Valley. Operated from 1973 to 1988, the CRSP consisted of a series of trenches used for the disposal of classified hazardous and nonhazardous waste materials. Disposal of hazardous waste materials was discontinued in December 1984, while nonhazardous waste disposal ended on November 8, 1988. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern (COC), support an ecological risk assessment (ERA) and a human health risk assessment (HHRA), support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this Work Plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU1. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the overall risk posed to human health and the environment by OU1.

  14. Mid-oceanic ridges - Guest editorial

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Ins titutes of Techno logy and national laboratories. A few Inter national re - searchers, notably from the USA, Portugal, France and J a pan too have shown interest in the I n Ridge and are keen to collaborate with India. It is foreseen that In...

  15. Petrography of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Petrographic characteristics of basalts collected from a segment of the Carlsberg Ridge (lat. 3 degrees 35'N to 3 degrees 41'N; long. 64 degrees 05'E to 64 degrees 09'E) show typical pillow lava zonations with variable concentrations of plagioclase...

  16. Oak Ridge reservation land-use plan

    Energy Technology Data Exchange (ETDEWEB)

    Bibb, W. R.; Hardin, T. H.; Hawkins, C. C.; Johnson, W. A.; Peitzsch, F. C.; Scott, T. H.; Theisen, M. R.; Tuck, S. C.

    1980-03-01

    This study establishes a basis for long-range land-use planning to accommodate both present and projected DOE program requirements in Oak Ridge. In addition to technological requirements, this land-use plan incorporates in-depth ecological concepts that recognize multiple uses of land as a viable option. Neither environmental research nor technological operations need to be mutually exclusive in all instances. Unique biological areas, as well as rare and endangered species, need to be protected, and human and environmental health and safety must be maintained. The plan is based on the concept that the primary use of DOE land resources must be to implement the overall DOE mission in Oak Ridge. This document, along with the base map and overlay maps, provides a reasonably detailed description of the DOE Oak Ridge land resources and of the current and potential uses of the land. A description of the land characteristics, including geomorphology, agricultural productivity and soils, water courses, vegetation, and terrestrial and aquatic animal habitats, is presented to serve as a resource document. Essentially all DOE land in the Oak Ridge area is being fully used for ongoing DOE programs or has been set aside as protected areas.

  17. Ridges and hotspots: perspectives from global tomography

    OpenAIRE

    Zhang, Yu-Shen; Tanimoto, Toshiro

    1991-01-01

    Resolution in global tomography has improved to a level of about 1000 km due to a rapid increase of digital data during the last decade. We have started to see various important tectonic features in some detail. We will attempt to summarize our current observations for ridges and hotspots.

  18. 27 CFR 9.182 - Ribbon Ridge.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ribbon Ridge. 9.182 Section 9.182 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT..., to the road's intersection with North Valley Road, near the Erwin Young School, section 39, T3S, R3W...

  19. Oak Ridge Reservation Waste Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.W. [ed.

    1995-02-01

    This report presents the waste management plan for the Oak Ridge Reservation facilities. The primary purpose is to convey what facilities are being used to manage wastes, what forces are acting to change current waste management systems, and what plans are in store for the coming fiscal year.

  20. Structure and origin of the 85 degrees E ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.; Subrahmanyam, V.; Chaubey, A.K.; Ramprasad, T.; Sarma, K.V.L.N.S.; Krishna, K.S.; Desa, M.; Murty, G.P.S.; Subrahmanyam, C.

    processes for the ridge emplacement have been suggested. Ridge emplacement may be (1) due to shearing of the lithosphere caused by stretching and compressional forces associated at the time of major plate reorganization immediately after the evolution...

  1. Wrinkle Ridges in Aeolis Dorsa, Mars: Preliminary Mapping

    Science.gov (United States)

    Borden, R. M.; Burr, D. M.

    2016-06-01

    Previous work has interpreted wrinkle ridges as compressional landforms caused by movement along blind thrust faults. Our preliminary mapping in the Aeolis Dorsa, Mars has identified widely distributed wrinkle ridges, suggesting episodic contraction.

  2. Prediction of eigenmodes cutoff frequencies of sectoral coaxial ridged waveguides

    OpenAIRE

    2012-01-01

    A mathematical model of sectoral coaxial ridged waveguides has been developed using coupled-integralequations technique. Maximal ratios of cutoff frequencies of two lowest modes of sectoral coaxial ridged waveguides have been obtained.

  3. Efficiency of local surface plasmon polariton excitation on ridges

    DEFF Research Database (Denmark)

    Radko, Ilya; Bozhevolnyi, Sergey I.; Boltasseva, Alexandra

    2008-01-01

    We investigate experimentally and numerically the efficiency of surface plasmon polariton excitation by a focused laser beam using gold ridges. The dependence of the efficiency on geometrical parameters of ridges and wavelength dependence are examined. The experimental measurements accomplished...

  4. Formation mechanism of cracks in saturated sand

    Institute of Scientific and Technical Information of China (English)

    Xiaobing Lu; Zhemin Zheng; Yongren Wu

    2006-01-01

    The formation mechanism of "water film" (or crack) in saturated sand is analyzed theoretically and numerically.The theoretical analysis shows that there will be no stable "water film" in the saturated sand if the strength of the skeleton is zero and no positions are choked.It is shown by numerical simulation that stable water films initiate and grow if the choking state keeps unchanged once the fluid velocities decrease to zero in the liquefied sand column.The developments of "water film" based on the model presented in this paper are compared with experimental results.

  5. Lund Sand No 0:part 2

    OpenAIRE

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    1996-01-01

    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 test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. T...

  6. Lund Sand No 0:part 1

    OpenAIRE

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    1996-01-01

    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 test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. T...

  7. Biodegradable materials as foundry moulding sands binders

    Directory of Open Access Journals (Sweden)

    K. Major - Gabryś

    2015-07-01

    Full Text Available The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved ability to reclamation as well as in accelerated biodegradation of binding material leftovers of mechanical reclamation.

  8. 渤海湾西岸的几道贝壳堤%A Few of Barrier Sand-bars on the West Coast of Bohai Bay

    Institute of Scientific and Technical Information of China (English)

    岳军; Dongyue; 张宝华; 耿秀山; 刘雪松; 赵希涛; 牟林; 张百鸣; 韩芳

    2012-01-01

    There are 6 Barrier Sand-bars are outcropped or buried on the west coast of Bohai Bay. Based on the geological survey, it is found that the plane distribution features texture of the Barrier Sand-bars, which are from the old to the new are roughly parallel with the coast along the west coast of Bohai Bay (from the coast to the sea). The distribution of the Barrier Sand-bars can be divided into two kinds, one is from the new to the old, and the other one is from the old to the new. In this paper, the division of the Barrier Sand-bars from I (old) to VI (new) by using the latter one. Through the description of the material composition and the accumulation characteristics to each barrier sand-bar (figure. 2 to figure. 7) , conducting the mathematical statistics for the geometrical morphological features (table 2), comparing analysis the formation age features and the division scheme (table 3), summing up the biological assemblages (table 1), the result reveal the occurrence, formation age and the tidal level change of the Barrier Sand-bars from I to VI (figure. 8). In the basis of the Barrier Sand-bars as a particular geological carrier, the author try to analysis and reveal the genetic mechanism in a macroscopic view, and consider that the generalized Bohai Sea is inland semi-lagoon or local sea in reality, (table. 4 figure. 9) Shangdong Miaodao Island and Liaodong Peninsula constitute barrier coast for Bohai Sea. After comparing analysis to massive data, the barrier coast is an only essential condition to form kebohe delta and beaked delta, both of which may be a possibility condition to form barrier bars (barrier island, barrier beach) or shell ridges. This result is just main genetic mechanism for the shell ridges.

  9. Watching Faults Grow in Sand

    Science.gov (United States)

    Cooke, M. L.

    2015-12-01

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

  10. Effect of Chromite-Silica Sands Characteristics on Performance of Ladle Filler Sands for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Free opening rate is mainly determined by the performance of the ladle filler sand. High free opening rates of ladles are required in steel making to improve steel quality. Chromite ladle filler sands are one of the most widely used ladle filler sand. Several operative variables and materials characteristics affect the performance of the sands. Three sets of chromite ladle filler sands were selected and researches were focused on the sintering hehaviour and per- formance of the sands under operative conditions. The effect of particle size distribution on sintering, microstruc- ture, flowability, and permeability were presented. In all cases, the particle size varies from 0.1 to 1.5 mm corre- sponding to free flowing powders. One of the samples has higher permeability factor in comparison with others due to low particle size distribution. The other sample presents very good free opening due to its very good flowability and permeability factor.

  11. Seismic hazard evaluation for Department of Energy Oak Ridge Reservations, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Toro, G.F. [Risk Engineering, Inc., Golden, CO (United States); Hunt, R.J. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States). Center for Natural Phenomena Engineering

    1992-09-30

    This study presents the results of an investigation of seismic hazard at the Department of Energy Oak Ridge Reservations (K-25 Site, Oak Ridge National Laboratories, and Oak Ridge Y-12 Plant), located in Oak Ridge, Tennessee. Oak Ridge is located in eastern Tennessee, in an area of moderate to high historical seismicity. Results from two separate seismic hazard analyses are presented. The EPRI/SOG analysis uses the input data and methodology developed by the Electric Power Research Institute, under the sponsorship of several electric utilities, for the evaluation of seismic hazard in the central and eastern United States. The LLNL analysis uses the input data and methodology developed by the Lawrence Livermore National Laboratory for the Nuclear Regulatory Commission. Both the EPRI/SOG and LLNL studies characterize earth-science uncertainty on the causes and characteristics of earthquakes in the central and eastern United States. This is accomplished by considering multiple hypotheses on the locations and parameters of seismic source zones and by considering multiple attenuation functions for the prediction of ground shaking given earthquake size and location. These hypotheses were generated by multiple expert teams and experts. Furthermore, each team and expert was asked to generate multiple hypotheses in order to characterize his own internal uncertainty. The seismic-hazard calculations are performed for all hypotheses. Combining the results from each hypothesis with the weight associated to that hypothesis, one obtains an overall representation of the seismic hazard at the Oak Ridge site and its uncertainty.

  12. An interdisciplinary management of severely resorbed maxillary anterior ridge complicated by traumatic bite using a ridge splitting technique

    Science.gov (United States)

    Gupta, Narender Dev; Maheshwari, Sandhya; Chaudhari, Prabhat Kumar; Rathi, Shraddha

    2015-01-01

    Injury to the teeth and alveolar ridge of the maxillary anterior region due to trauma can cause severe alveolar ridge deficiency. Ridge augmentation is a valuable periodontal plastic surgical method for the correction of ridge defects for esthetic purpose. Although ridge augmentation can help to restore the ridge volume, the grafting procedures can significantly increase the patient morbidity, treatment time, and the cost. Among the ridge augmentation techniques, the ridge split procedure demonstrates many benefits such as no need for donor site, the rare risk of damage to underlying anatomical structures, less pain, and swelling. This case report presents a vertical split technique for increasing the bone volume. There was a remarkable healing and significant increase in bone volume. We have followed the case for 6 months. PMID:25810602

  13. 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...

  14. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...

  15. Petrophysical Analysis of Oil Sand in Athabasca

    Science.gov (United States)

    cheong, S.; Lee, H.

    2013-12-01

    Oil sands are the major unconventional energy sources which have great reserves in Alberta, Canada. Recovery techniques such as CSS (Cyclic Steam Stimulation) and SAGD (Steam Assisted Gravity Drainage) enabled to develop deeper bitumen about several hundred meter depth. Before applying CSS and SAGD, reservoir heterogeneity of mud barriers or shale breccias should be clarified to establish injection and production wells successfully. We conducted the integrated petro-physical analysis for oil sands deposits in Athabasca by correlating well logs with seismic data. From 33 well logs and 3D seismic, we have made P-wave impedance by recursive inversion. Target formations of our analysis were the top of Wabiskaw member. Using inverted impedance and multi-attributes, porosity volume was derived at a target depth. Porosity of time slice 375 ms ranged 20 ~ 40 % stretching porous sand body from NE to SW direction. Characteristics of porosity distribution may be useful to design optimum oil sands recovery in Athabasca.

  16. Carbon cycle: New pathways in the sand

    Science.gov (United States)

    Rao, Alexandra

    2017-01-01

    Organic carbon decomposition in anoxic marine sediments was thought to be dominated by bacteria, but experimental data and microbial culture studies now show that microalgae buried in coastal sands may also play an important role in carbon turnover.

  17. Initiation of Ridges and Transform Faults

    Science.gov (United States)

    Nyst, M.; Thompson, G. A.; Parsons, T.

    2004-12-01

    No clear consensus has emerged to explain initiation of the strikingly regular pattern of ocean ridges and transform faults. The question is important on the continents also, because a less regular pattern of step-overs on faults such as the San Andreas influences the sources of earthquakes. We explore the question by finite element modeling and a study of observational data on ridges and transforms. We focus on the simplest case, where ridges and transforms seem to self-organize at new plate boundaries as soon as new oceanic (magmatic) crust forms. The South Atlantic supplies a clear example. Continental South America and Africa separated along an irregular break, whose general shape is still preserved in the Mid-Atlantic Ridge. In detail, however, the sea floor magnetic anomalies and satellite gravity show that traces of the ridges and transforms extend to the base of the continental slope, i.e. they formed quickly in the new oceanic crust. The Gulf of California provides another clear example and is notable because of its northward transition into the continental San Andreas fault system. In continental crust, dike segments connected by transform faults provide the clearest analogues of oceanic ridges and transforms. Remarkably, the ridge-transform pattern has been simulated by pulling the crust on molten wax [Oldenburg and Brune, JGR, 80, 1975] and also observed in the crust of a molten lava lake [Duffield, JGR, 77, 1972]. In neither of these models, however, do the spatial and temporal scales permit investigation of the dikes whose repeated emplacement and inflation builds layer 3 of the ocean crust. It is well established that, under a buoyant head of magma, dikes tend to fracture and intrude the crust in planes perpendicular to the least horizontal stress, and they relieve the stress difference as they inflate [e.g. Parsons and Thompson, Science, 253, 1991]. Dikes are commonly used as stress-direction indicators analogous to artificial hydraulic fractures

  18. CRADE OF SAND AND DUST STORM WEATHER

    Institute of Scientific and Technical Information of China (English)

    Niu Ruoyun; Tian Cuiying; Bi Baogui; Yang Keming; Wang Youheng; Tuo Ya; Ding Haifang; Zhang Tairen

    2011-01-01

    Background Sand and dust storm,as one of the main disastrous weathers that affect northern China,not only affect the people health and normal life,but cause the short-term climatic changes due to the direct and indirect radiation of the earth-atmosphere system through the dust floating in the sky.The sand end dust weather and its potential harm on the national economy,ecological environment,social activities and other aspects have aroused worldwide concern.

  19. 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.

  20. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    Tailings ponds are an operating facility common to all types of surface mining. For oil sands, tailings consisting of water , sand, clay, and residual ...oil, are pumped to these basins—or ponds— where settling occurs and water is recycled for reuse in the process. When the ponds are no longer required...of crude oil transported by tank vessel in Washington waters . In a 2013 Bloomburg Business news article , Dan Murtaugh states, “The dock probably

  1. Treating tar sands formations with dolomite

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  2. 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.

  3. 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.

  4. Analysis of sand particles' lift-off and incident velocities in wind-blown sand flux

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

    In the research of windblown sand movement,the lift-off and incident velocities of saltating sand particles play a significant role in bridging the spatial and temporal scales from single sand particle's motion to windblown sand flux.In this paper,we achieved wind tunnel measurements of the movement of sand particles near sand bed through improving the wind tunnel experimental scheme of paticle image velocimetry (PIV) and data processing method.And then the influence of observation height on the probability distributions of lift-off and incident velocities of sand particles was analyzed.The results demonstrate that the observation height has no obvious influence on the distribution pattern of the lift-off and incident velocities of sand particles,i.e.,the probability distribution of horizontal and vertical velocities of lift-off and incident sand particles follow a Gaussian distribution and a negative exponential distribution,respectively.However,it influences the center of the Gaussian distribution,the decay constant and the amplitude of the negative exponential distribution.

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

    Directory of Open Access Journals (Sweden)

    Hananto Kurnio

    2017-07-01

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

  6. Recent Sand Avalanching on Rabe Crater Dunes

    Science.gov (United States)

    2000-01-01

    Dark streaks on the steep, down-wind slopes of sand dunes in Rabe Crater are seen at several locations in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. These streaks indicate relatively recent (i.e., in the past few years or less) movement of sand down these slopes.Sand dunes move forward by the combined action of wind that drives sand up the shallow slope on the windward side of the dune (in this case, the slopes that face toward the lower right) and the avalanching of this sand down the steeper, lee-side slope. The steep slope is also known as the slip face. The dark streaks indicated by arrows are evidence for sand avalanches that occurred within a few months or years of the time when the picture was taken in March 1999. Other streaks which are seen criss-crossing the dunes may be the result of passing dust devils. This image is illuminated from the upper left and located in Rabe Crater of the Hellespontus-Noachis region near 44.2oS, 325.6oW.

  7. Discrete particle simulation of mixed sand transport

    Institute of Scientific and Technical Information of China (English)

    Fengjun Xiao; Liejin Guo; Debiao Li; Yueshe Wang

    2012-01-01

    An Eulerian/Lagrangian numerical simulation is performed on mixed sand transport.Volume averaged Navier-Stokes equations are solved to calculate gas motion,and particle motion is calculated using Newton's equation,involving a hard sphere model to describe particle-to-particle and particle-to-wall collisions.The influence of wall characteristics,size distribution of sand particles and boundary layer depth on vertical distribution of sand mass flux and particle mean horizontal velocity is analyzed,suggesting that all these three factors affect sand transport at different levels.In all cases,for small size groups,sand mass flux first increases with height and then decreases while for large size groups,it decreases exponentially with height and for middle size groups the behavior is in-between.The mean horizontal velocity for all size groups well fits experimental data,that is,increasing logarithmically with height in the middle height region.Wall characteristics greatly affects particle to wall collision and makes the flat bed similar to a Gobi surface and the rough bed similar to a sandy surface.Particle size distribution largely affects the sand mass flux and the highest heights they can reach especially for larger particles.

  8. Divergent Ridge Features on the Juan de Fuca and Gorda Ridges

    Science.gov (United States)

    Eaton, M. E.; Sautter, L.; Steele, M.

    2014-12-01

    Multibeam data collected using a Kongsberg EM122 sonar system on the NOAA ship R/V Marcus G. Langseth led by chief scientist Douglas Toomey (University of Oregon) in 2009 and with a Simrad EM302 sonar system on two NOAA ship Okeanos Explorer cruises led by chief scientists James Gardner (University of New Hampshire) and Catalina Martinez (University of Rhode Island) in 2009 show the morphology of the Juan de Fuca and Gorda Ridges, as well as the Blanco and Mendocino Fracture Zones. These ridges and fracture zones comprise the divergent plate boundary of the eastern edge of the Pacific Plate and the western edges of the Juan de Fuca and Gorda Plates. Both plates are being subducted beneath the western edge of the North American Plate. CARIS HIPS 8.1 software was used to process the multibeam data and create bathymetric images. The ridge axes, located off the coast of Washington and Oregon (USA) adjacent to the Cascadia Basin, indicate obvious signs of spreading, due to the series of faults and rocky ridges aligned parallel to the plate boundaries. Fault and ridge orientations are used to compare the direction of seafloor spreading, and indicate that both the Juan de Fuca Plate and Gorda Plate are spreading in a southeastern direction. Younger ridges from the Gorda Ridge system mapped in the study run parallel to the boundary, however older ridges do not show the same orientation, indicating a change in spreading direction. The presence of hydrothermal vents along the Juan de Fuca Ridge is also evidence of the active boundary, as the vent chimneys are composed of minerals and metals precipitated from the hot water heated by magma from beneath the spreading seafloor. In this study, the data are used to compare and contrast earthquake seismicity and ridge morphologies at a depth range of approximately 762 to 2134 meters. The diverging Pacific, Juan de Fuca, and Gorda Plates along with the San Andreas Fault have potential to increase seismic and volcanic activity around

  9. Predicting the occurrence of sand banks in the North Sea

    NARCIS (Netherlands)

    Veen, van der Henriët H.; Hulscher, Suzanne J.M.H.

    2009-01-01

    Sand banks have a wavelength between 1 and 10 km, and they are up to several tens of meters high. Also, sand banks may have an impact on large-scale human activities that take place in the North Sea like sand mining, shipping, offshore wind farms, etc. Therefore, it is important to know where sand b

  10. Satellite Monitoring Over the Canadian Oil Sands: Highlights from Aura OMI and TES

    Science.gov (United States)

    Shephard, Mark W.; McLinden, Chris; Fioletov, Vitali; Cady-Pereira, Karen E.; Krotkov, Nick A.; Boersma, Folkert; Li, Can; Luo, Ming; Bhartia, P. K.; Joiner, Joanna

    2014-01-01

    Satellite remote sensing provides a unique perspective for air quality monitoring in and around the Canadian Oil Sands as a result of its spatial and temporal coverage. Presented are Aura satellite observations of key pollutants including nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), ammonia (NH3), methanol (CH3OH), and formic acid (HCOOH) over the Canadian Oil Sands. Some of the highlights include: (i) the evolution of NO2 and SO2 from the Ozone Monitoring Instrument (OMI), including comparisons with other nearby sources, (ii) two years of ammonia, carbon monoxide, methanol, and formic acid observations from 240 km North-South Tropospheric Emission Spectrometer (TES) transects through the oils sands, and (iii) preliminary insights into emissions derived from these observations.

  11. 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.

  12. Development of the Gran Desierto sand sea, northwestern Mexico

    Science.gov (United States)

    Blount, Grady; Lancaster, Nicholas

    1990-08-01

    Three major eolian sand populations can be recognized in the Gran Desierto sand sea of northwestern Mexico by using spectral data from the Landsat thematic mapper in conjunction with textural and mineralogical studies of surface sands. Each sand population has distinct textural, mineralogic, and spectral properties that can be related to sand-dune morphology and position with reference to source areas and transport paths of the sands. The oldest eolian sediment in the sand sea was derived from the early to middle Pleistocene Colorado River that flowed through the area of the western Gran Desierto. Subsequent inputs of eolian sands came from the area of the present Colorado River valley and the coast south of the sand sea. The spatial and temporal pattern of eolian deposition in the region has been controlled by Quaternary tectonic and climatic changes, resulting in the episodic input and deposition of sand.

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

    Science.gov (United States)

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

    2006-05-01

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

  14. 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 du

  15. 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 du

  16. 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

  17. Effect of Micro Ridges on Orientation of Cultured Cell

    Directory of Open Access Journals (Sweden)

    Haruka Hino

    2014-06-01

    Full Text Available The effect of micro ridges on orientation of cultured cells has been studied in vitro. Several patterns of micro ridges have been fabricated on a transparent polydimethylsiloxane disk with the photo lithography technique. The ridges consist of several lines of rectangular column: the width of 0.003 mm, the interval of 0.007 mm. Variation has been made on the height of the ridge between 0.0003 mm and 0.0035 mm. C2C12 (mouse myoblast cell line originated with cross-striated muscle of C3H mouse was cultured on the disk with the micro ridges for one week and was observed with an inverted phase contrast microscope. The experimental results show that cells adhere on the top of the ridge and align to the longitudinal direction of the micro ridges with the height between 0.0015 mm and 0.0025 mm.

  18. Active convection beneath ridges: a new spin

    Science.gov (United States)

    Katz, R. F.

    2009-12-01

    The role of buoyancy-driven, "active" upwelling beneath mid-ocean ridges has been long debated [1,2,3], with the naysayers holding sway in recent years. Recent work on tomographic imaging of the sub-ridge mantle has revealed patterns in velocity variation that seem inconsistent with what we expect of passive upwelling and melting [4]. The irregular distribution, asymmetry, and off-axis locations of slow regions in tomographic results are suggestive of time-dependent convective flow. Using 2D numerical simulations of internally consistent mantle and magmatic flow plus melting/freezing [5,6], I investigate the parametric subspace in which active convection is expected to occur. For low mantle viscosities, interesting symmetry-breaking behavior is predicted. References: [1] Rabinowicz, et al., EPSL, 1984; [2] Buck & Su, GRL, 1989; [3] Scott & Stevenson, JGR, 1989; [4] Toomey et al., Nature, 2007; [5] McKenzie, J.Pet., 1984; [6] Katz, J.Pet., 2008;

  19. Tubular initial conditions and ridge formation

    CERN Document Server

    Borysova, M S; Karpenko, Iu A; Shapoval, V M; Sinyukov, Yu M

    2013-01-01

    The 2D azimuth & rapidity structure of the two-particle correlations in relativistic A+A collisions is altered significantly by the presence of sharp inhomogeneities in superdense matter formed in such processes. The causality constraints enforce one to associate the long-range longitudinal correlations observed in a narrow angular interval, the so-called (soft) ridge, with peculiarities of the initial conditions of collision process. This study's objective is to analyze whether multiform initial tubular structures, undergoing the subsequent hydrodynamic evolution and gradual decoupling, can form the soft ridges. Motivated by the flux-tube scenarios, the initial energy density distribution contains the different numbers of high density tube-like boost-invariant inclusions that form a bumpy structure in the transverse plane. The influence of various structures of such initial conditions in the most central A+A events on the collective evolution of matter, resulting spectra, angular particle correlations an...

  20. Model selection in kernel ridge regression

    DEFF Research Database (Denmark)

    Exterkate, Peter

    2013-01-01

    Kernel ridge regression is a technique to perform ridge regression with a potentially infinite number of nonlinear transformations of the independent variables as regressors. This method is gaining popularity as a data-rich nonlinear forecasting tool, which is applicable in many different contexts....... The influence of the choice of kernel and the setting of tuning parameters on forecast accuracy is investigated. Several popular kernels are reviewed, including polynomial kernels, the Gaussian kernel, and the Sinc kernel. The latter two kernels are interpreted in terms of their smoothing properties......, and the tuning parameters associated to all these kernels are related to smoothness measures of the prediction function and to the signal-to-noise ratio. Based on these interpretations, guidelines are provided for selecting the tuning parameters from small grids using cross-validation. A Monte Carlo study...

  1. Marketing for Oak Ridge technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Prosser, G.A.

    1989-06-15

    Martin Marietta Energy Systems, Inc., which manages major research and production facilities in Oak Ridge, Tennessee for the Department of Energy, has implemented a systematic approach to marketing for technology transfer. Unique mechanisms have been created to address the need for market research and analysis, strategy formulation, and the execution of plans designed to engender the broadest commercial use of government-funded technologies. Establishment of formal ties with the University of Tennessee Graduate School of Business has resulted in an expanded role for marketing in support of the Oak Ridge program. The creation of graduate research positions has enabled MBA students to contribute to, and learn from, a program which is at the forefront of an important national initiative.

  2. Unfaulting the Sardarapat Ridge, Southwest Armenia

    Science.gov (United States)

    Wetmore, P.; Connor, C.; Connor, L. J.; Savov, I. P.; Karakhanyan, A.

    2012-12-01

    Armenia is located near the core of contractional deformation associated with the collision between the Arabian and Eurasian tectonic plates. Several studies of this region, including portions of adjacent Georgia, Iran, and Turkey, have indicated that 1-2 mm/yr of intra-plate, north-south shortening is primarily accommodated by a network of E-W trending thrust faults, and NW-trending (dextral) and NE-trending (sinistral) strike-slip faults. One proposed fault in this network, the Sardarapat Fault (SF), was investigated as part of a regional seismic hazard assessment ahead of the installation of a replacement reactor at the Armenian Nuclear Power Plant (ANPP). The SF is primarily defined by the Sardarapat Ridge (SR), which is a WNW-trending, 40-70 m high topographic feature located just north of the Arax River and the Turkey-Armenia border. The stratigraphy comprising this ridge includes alluvium overlying several meters of lacustrine deposits above a crystal-rich basaltic lava flow that yields an Ar-Ar age of 0.9 +/- 0.02 Ma. The alluvial sediments on the ridge contain early Bronze age (3832-3470 BP) artifacts at an elevation 25 m above those of the surrounding alluvial plane. This has lead to the suggestion that the SR is bound to the south (the steepest side) by the SF, which is uplifting the ridge at a rate of 0.7 mm/yr. However, despite the prominence and trend of the ridge there are no unequivocal observations, such as scarps or exposures of fault rocks, to support the existence of the SF. The goal of the investigation of the SR area was to test various models for the formation of the ridge including faulting and combined volcanic and erosional processes. We therefore collected gravimetric, magnetic, magneto-tellurics (MT), and transient electromagnetic (TEM) data across an area of ~400 km2, and used correlations of stratigraphic data from coreholes drilled proximal to the study area to define the geometry of the contact between the basement and basin fill to

  3. cobalt (ii), nickel (ii)

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The manganese (II), cobalt (II), nickel (II) and copper (II) complexes of N, N' – ... temperature and coordinated water were determined ... indicating fairly stable complex compounds (Table 1). The complex compounds are insoluble [Table 2] in water and common organic solvents, but are readily soluble in ...

  4. Constitutive Parameter Measurement Using Double Ridge Waveguide

    Science.gov (United States)

    2013-03-01

    PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE Nathan J. Lehman, B.S.E.E. Captain, USAF Approved: Michael Havrilla , PhD (Chairman) Maj Milo Hyde, PhD...would like express my gratitude to Dr. Michael Havrilla , my research advisor. Your ability to illustrate the entire picture of the subject was...electromagnetics U U U UU 83 Dr. Michael J. Havrilla (ENG) (937) 255-3636 x4582 michael.havrilla@afit.edu

  5. Fingerprint image mosaicking by recursive ridge mapping.

    Science.gov (United States)

    Choi, Kyoungtaek; Choi, Heeseung; Lee, Sangyoun; Kim, Jaihie

    2007-10-01

    To obtain a large fingerprint image from several small partial images, mosaicking of fingerprint images has been recently researched. However, existing approaches cannot provide accurate transformations for mosaics when it comes to aligning images because of the plastic distortion that may occur due to the nonuniform contact between a finger and a sensor or the deficiency of the correspondences in the images. In this paper, we propose a new scheme for mosaicking fingerprint images, which iteratively matches ridges to overcome the deficiency of the correspondences and compensates for the amount of plastic distortion between two partial images by using a thin-plate spline model. The proposed method also effectively eliminates erroneous correspondences and decides how well the transformation is estimated by calculating the registration error with a normalized distance map. The proposed method consists of three phases: feature extraction, transform estimation, and mosaicking. Transform is initially estimated with matched minutia and the ridges attached to them. Unpaired ridges in the overlapping area between two images are iteratively matched by minimizing the registration error, which consists of the ridge matching error and the inverse consistency error. During the estimation, erroneous correspondences are eliminated by considering the geometric relationship between the correspondences and checking if the registration error is minimized or not. In our experiments, the proposed method was compared with three existing methods in terms of registration accuracy, image quality, minutia extraction rate, processing time, reject to fuse rate, and verification performance. The average registration error of the proposed method was less than three pixels, and the maximum error was not more than seven pixels. In a verification test, the equal error rate was reduced from 10% to 2.7% when five images were combined by our proposed method. The proposed method was superior to other

  6. ORNL (Oak Ridge National Laboratory) 89

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.D.; Appleton, B.R.; Jefferson, J.W.; Merriman, J.R.; Mynatt, F.R.; Richmond, C.R.; Rosenthal, M.W.

    1989-01-01

    This is the inaugural issues of an annual publication about the Oak Ridge National Laboratory. Here you will find a brief overview of ORNL, a sampling of our recent research achievements, and a glimpse of the directions we want to take over the next 15 years. A major purpose of ornl 89 is to provide the staff with a sketch of the character and dynamics of the Laboratory.

  7. Long term evolution and internal architecture of high-energy banner ridges of Mer d'Iroise (Western Brittany, France) : interplay of sea-level, basement morphology, biogenic productivity and hydrodynamics

    Science.gov (United States)

    Le Roy, P., Sr.; Le Dantec, N.; Franzetti, M.; Delacourt, C.; Ehrhold, A.

    2016-12-01

    The recent completion of a coupled seismic and swath bathymetric survey, conducted across the Mer d'Iroise (Atlantic continental shelf, France), provided new data for the study of the long term evolution of deep tidal sand ridges. Three major banner sand ridges composed of biogenic sands were investigated: the Banc du Four, the Haut Fond d'Ouessant and the Banc d'Ar Men. Seismic interpretation reveals a compound internal architecture of these sand ridges with a sedimentary core forming the lower units interpreted to be shoreface deposits and overlain by sandwaves. Sandwave climbing, which combines progradation and accretion, is the major process controlling the growth of the ridges. The elevation of the preserved dune foresets reaches values of about 20 to 30 m and indicate a combination of giant dunes characterized by numerous steep (up to 20°) clinoforms corresponding to a high-energy depositional environment. All of the radiocarbon ages of the biogenic surficial deposits of the Banc du Four range from 10,036 to 2,748 cal years B.P. and suggest it has grown during the last sea-level rise. The apparent absence of recent surface deposits could be caused by a change in benthic biogenic productivity or the non-conservation of recent deposits. The multiphase accretion of the ridge is closely linked to the progressive flooding of the coastal promontories and straits that structured the igneous basement. A comparable evolutionary scheme is observed for the Haut-Fond d'Ouessant where a counter-clock wise migration of dunes characterizes the surface of the ridge. In contrast, the Banc d'Ar Men located above a regular basement displays a simpler structure with a consistent Northwestward migration of steep clinoforms. Therefore, the sand ridges of the Mer d'Iroise should be thought of as a representative example of large-scale high-energy banner banks controlled by interaction of sea-level, basement morphology, biogenic productivity, tidal and wave hydrodynamics.

  8. High-speed X-ray imaging of a ball impacting on loose sand

    CERN Document Server

    Homan, Tess; Lohse, Detlef; van der Meer, Devaraj

    2014-01-01

    When a ball is dropped in fine, very loose sand, a splash and subsequently a jet are ob- served above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made setup that allows for imaging of a large sand bed at atmospheric pressures. Herewith we show that the jet originates from the pinch-off point created by the collapse of the air cavity formed behind the penetrating ball.Subsequently we measure how the entrapped air bubble rises through the sand and show that this is consistent with bubbles rising in continuously fluidized beds. Finally, we measure the packing fraction variation throughout the bed. From this we show that there is (i) a compressed area of sand in front of and next to the ball while the ball is moving down, (ii) a strongly compacted region at the pinch-off height after the cavity collapse; and (iii) a relatively loosely packed center in the wake of the rising...

  9. Jurassic zircons from the Southwest Indian Ridge

    Science.gov (United States)

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-01

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (ɛHf = +15.7-+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread ɛHf values (from-2.3 to-4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

  10. Jurassic zircons from the Southwest Indian Ridge.

    Science.gov (United States)

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-17

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (εHf = +15.7-+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread εHf values (from-2.3 to-4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

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

    Science.gov (United States)

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

    1987-05-01

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

  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. Probability of rebound and eject of sand particles in wind-blown sand movement

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xiaojing Zheng

    2007-01-01

    When incident particles impact into a sand bed in wind-blown sand movement, rebound of the incident particles and eject of the sand particles by the incident particles affect directly the development of wind sand flux. In order to obtain rebound and eject lift-off probability of the sand particles, we apply the particle-bed stochastic collision model presented in our pervious works to derive analytic solutions of velocities of the incident and impacted particles in the postcollision bed. In order to describe randomness inherent in the real particle-bed collision, we take the incident angle, theimpact position and the direction of resultant action of sand particles in sand bed on the impacted sand particle as random variables, and calculate the rebound and eject velocities,angles and coefficients (ratio of rebound and eject velocity to incident velocity). Numerical results are found in accordance with current experimental results. The rebound and eject lift-off probabilities versus the incident and creeping velocities are predicted.

  14. Assessing impacts to birds from the Buffalo Ridge, Minnesota windplant development

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, M.D.; Johnson, G.D.; Erickson, W.P. [WEST Inc., Cheyenne, WY (United States)] [and others

    1997-12-31

    Northern States Power (NSP) plans development of a 425 MW windpowered electrical generation facility within the Buffalo Ridge Wind Resource Area (WRA) in southwestern Minnesota. In 1996, Western EcoSystems Technology (WEST, Inc.) was contracted by NSP to develop an avian monitoring protocol for the Buffalo Ridge windplant. This protocol was developed and peer-reviewed by numerous individuals representing the wind energy industry, U.S. Fish and Wildlife Service, Minnesota Department of Natural Resources, and conservation groups prior to finalization. The WRA currently consists of three phases of development. Phase I, constructed by Kenetech in 1994, consists of 73 Model 33 M-VS turbines and related facilities, including distribution lines, meteorological towers, communication systems, transformers, substations, roads, and operations and maintenance facilities in the approximate center of the WRA, and generates 25 MW of electricity. Phase II, consisting of 143 turbines and related facilities sufficient to generate 100 MW of electricity, will be constructed by Zond Systems, Inc. beginning in the spring of 1997. Phase II will be located in the northwestern portion of the WRA. Phase III facilities capable of generating an additional 100 MW are planned for the southeast portion of the WRA. Plans call for the eventual production of 425 MW of electricity within the WRA. Studies were conducted in these three areas and a permanent reference area not scheduled for windpower development located along Buffalo Ridge northwest of the WRA in Brooking County South Dakota.

  15. A new sand adsorbent for the removal and reuse of nickel ions from aqueous solutions.

    Science.gov (United States)

    Tao, Wenhong; Qi, Ling; Duan, Huimin; Liu, Shiquan

    2017-04-01

    Nickel ions (Ni(II)) in aqueous solutions were removed by a sand adsorbent with a surface functionalized porous coating. The sand adsorbent has a very large surface area of 150 m(2)/g. The influence of pH, initial concentration of the solution, temperature, contact time and adsorbent dosage on the removal efficiency of the synthesized sand adsorbent toward Ni(II) in the aqueous solutions were studied. The results indicate that the adsorption of nickel onto the sand adsorbent greatly increases the pH range of 2-4 and slightly increases with temperature from 25 to 40 °C. The maximum removal efficiency and ion retention in per unit mass of the adsorbent were 100% and 5.78 mg/g, respectively, under the specified experimental conditions. The adsorption can be described by the pseudo-second-order kinetic model and the Freundlich adsorption model. The adsorbed nickel (4.24 mg/g) together with the spent adsorbent were successfully employed to prepare a brown glass, suggesting a new way to reutilize the recovered nickel from wastewater and to avoid secondary pollution caused by the used adsorbents.

  16. Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Brandy M.; Santelli, Cara M.; Marcus, Matthew A.; Wirth, Richard; Chan, Clara S.; McCollom, Thomas; Bach, Wolfgang; Edwards, Katrina J.

    2008-05-22

    Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and secondary oxyhydroxide minerals was resolved. The Fe-encrusted biofilms formed preferentially at pyrrhotite-rich (Fe1-xS, 0<_ x<_ 0.2) regions of the incubated chimney sulfide. At the nanometer spatial scale, particles within the biofilm exhibiting lattice fringing and diffraction patterns consistent with 2-line ferrihydrite were identified infrequently. At the micron spatial scale, Fe mu EXAFS spectroscopy and mu XRD measurements indicate that the dominant form of biofilm Fe is a short-range ordered Fe oxyhydroxide characterized by pervasive edge-sharing Fe-O6 octahedral linkages. Double corner-sharing Fe-O6 linkages, which are common to Fe oxyhydroxide mineral structures of 2-line ferrihydrite, 6-line ferrihydrite, and goethite, were not detected in the biogenic iron oxyhydroxide (BIO). The suspended development of the BIO mineral structure is consistent with Fe(III) hydrolysis and polymerization in the presence of high concentrations of Fe-complexing ligands. We hypothesize that

  17. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  18. Cleaning oil sands drilling waste in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Mikic, N.; Nilsen, C.; Markabi, M. [Mi SWACO, Calgary, AB (Canada)

    2008-07-01

    The waste generated from steam assisted gravity drainage (SAGD) wells is brought to the surface and separated by shale shakers. The waste can include drilling fluids and sand contaminated with bitumen. This paper described a new technology developed to treat waste using the addition of hot water and various mixing and separation technologies to reduce the viscosity of the bitumen and separate it from the sand. The bitumen-contaminated drill cuttings were mixed with hot water to form a slurry that was then separated through the G-force created by a hydrocyclone. A secondary separation was then conducted in an elutriation column to remove residual contaminants from the sand. The flow rate of the process was controlled by the fine solids composition of the cuttings, the temperature of the cleaning process, and the performance of the individual components. Laboratory tests conducted to tests the method showed that the sand particles produced using the method were clean enough to be safely disposed in the environment. A pilot study will be conducted to test the sand cleaning technology at a commercial scale. 6 refs., 3 figs.

  19. Mitigating in situ oil sands carbon costs

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

    2008-10-15

    Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

  20. Alveolar ridge rehabilitation to increase full denture retention and stability

    Directory of Open Access Journals (Sweden)

    Mefina Kuntjoro

    2010-12-01

    Full Text Available Background: Atrophic mandibular alveolar ridge generally complicates prostetic restoration expecially full denture. Low residual alveolar ridge and basal seat can cause unstable denture, permanent ulcer, pain, neuralgia, and mastication difficulty. Pre-proshetic surgery is needed to improve denture retention and stability. Augmentation is a major surgery to increase vertical height of the atrophic mandible while vestibuloplasty is aimed to increase the denture bearing area. Purpose: The augmentation and vestibuloplasty was aimed to provide stability and retentive denture atrophic mandibular alveolar ridge. Case: A 65 years old woman patient complained about uncomfortable denture. Clinical evaluate showed flat ridge in the anterior mandible, flabby tissue and candidiasis, while residual ridge height was classified into class IV. Case management: Augmentation using autograph was conducted as the mandible vertical height is less than 15 mm. Autograph was used to achieve better bone quantity and quality. Separated alveolar ridge was conducted from left to right canine region and was elevated 0.5 mm from the previous position to get new ridge in the anterior region. The separated alveolar ridge was fixated by using T-plate and ligature wire. Three months after augmentation fixation appliances was removed vestibuloplasty was performed to increase denture bearing area that can make a stable and retentive denture. Conclusion: Augmentation and vestibuloplasty can improve flat ridge to become prominent.Latar belakang: Ridge mandibula yang atrofi pada umumnya mempersulit pembuatan restorasi prostetik terutama gigi tiruan lengkap (GTL. Residual alveolar ridge dan basal seat yang rendah menyebabkan gigi tiruan menjadi tidak stabil, menimbulkan ulser permanen, nyeri, neuralgia, dan kesulitan mengunyah. Tujuan: Augmentasi dan vestibuloplasti pada ridge mandibula yang atrofi dilakukan untuk menciptakan gigi tiruan yang stabil dan retentive. Kasus: Pasien wanita

  1. Structural, geochronological, magnetic and magmatic constraints of a ridge collision/ridge subduction-related ophiolite

    Science.gov (United States)

    Anma, Ryo

    2013-04-01

    A mid-oceanic ridge system subducts underneath South American plate at latitude 46S off Chilean coast, forming a ridge-trench-trench type triple junction. At ~ 6 Ma, a short segment of the Chile ridge system subducted in south of the present triple junction. This ridge subduction event resulted in emplacement of a young ophiolite (5. 6 to 5. 2 Ma) and rapid crustal uplift (partly emerged after 4.9 Ma), and synchronous magmatism. This ophiolite, namely the Taitao ophiolite, provides criteria for the recognition of ridge collision/ridge subduction-related ophiolites. Aiming to establish recognition criteria, we studied distribution of structures, magnetic properties, geochemical characteristics, and radiometric ages of the Taitao ophiolite and related igneous rocks. The Taitao ophiolite exhibits a classic Penrose-type stratigraphy: ultramafic rocks and gabbros (collectively referred as plutonic section hereafter) in the south, and sheeted dike complex (SDC) and volcanic sequences in the north. Composite foliations developed in the plutonic section, which were folded. SDC were exposed in two isolated blocks having orthogonal strikes of dike margins. Geochemically, gabbros have an N-MORB composition whereas basalts of the volcanic sequence have an E-MORB composition. U-Pb ages of zircons separated from gabbros, SDC and sediments interbeded with billow lavas implied that the center of magmatic activities migrated from the plutonic section to volcanic section during ~5.6 Ma and ~5.2 Ma. Zircon fission track ages of gabbros coincide with U-Pb ages within error range, implying rapid cooling. Demagnetization paths for SDC and lavas form a straight line, whereas those from the plutonic section are Z-shaped and divisble into two components: low coercivity and high coercivity. Restored orientation of gabbro structures imply that the magnetization acquired while gabbroic structures were folding. Thus, magma genesis and emplacement of the plutonic section of ophiolite took place

  2. 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...... void ratio and permeability is established....

  3. Sand Dunes Fixation in Baiji District, Iraq

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This study was carried out at Sand Dunes Stabilization Researches Station in Baiji district (230 ln north of Baghdad, Iraq) to evaluate the effects of local soil conditioners manufactured from oil derivatives and plant residuals on sand dunes fixation as the first step for sand dunes stabilization. The results indicate that the fuel oil has the first place in improving wind erosion parameters in the study area, such as increasing mean weight diameter, dry aggregates percentage, the needed time for complete disaggregation by dry sieving, and decreasing the disaggregation rates. Bitumen emulsion occupies the second place, while the plant residuals occupies the third place and has slight effects on the studied parameters. Effects of conditioners on natural vegetation cover are negative in oil derivatives treatments,while positive in plants residuals treatments.

  4. 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)

  5. 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.

  6. 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.

  7. 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...

  8. 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 %.

  9. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    -distribution, by taking into account that individual grains do not have the same travel time from the source to the deposit. The travel time is assumed to be random so that the wear on the individual grains vary randomly. The model provides an interpretation of the parameters of the NIG-distribution, and relates the mean......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. George Sand [Reseña

    OpenAIRE

    Jack, Belinda; Thomas, Florence

    2002-01-01

    Belinda Jack nos cuenta en ese libro la vida de George Sand (de su verdadero nombre Aurora Dupin), esa mujer libertaria del siglo XIX, lo años de su nacimiento, su infancia, su adolescencia y su vida adulta. Una vida tan llena tanto por sus luchas interiores -Sand es una mujer que desde su adolescencia tratará de romper los fatalismos ligados a la condición de mujer del siglo XIX, un siglo profundamente familista y maternalista- como por su inmensa obra literaria que cuenta más de cincuenta n...

  11. Investigation of Sand-Cement Grouts

    Science.gov (United States)

    1960-09-01

    the sianAS. Ho-4, VVers thia 𔃽pacification ,Jlowi -inI r.ver,4 e ofl 3 :*- cen~t to be retain(v,- on1 the NO,. 1E6 sieve. 3y * :.Oviiq- (1),, sc...325 material as does the traprock or silica sand. This j J: i3 -robably the reason for the difference in the quantity of sand founud pmrnable. The three...deficient in material assing th.e ±,e h DOsieve, Ath the addition of percentages of fŕ. ash was test-ilwped. in the other to-ts in this phase, tne

  12. TURBULENT COHERENT STRUCTURES IN CHANNELS WITH SAND WAVES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sand wave bed is one of the typical shape of complicated boundaries in hydraulics and river dynamics, and sand wave motion is the main form of the bed load motion in-rivers, thence the study of turbulent structures over sand waves is of importance both in theory and practice. In this paper turbulent coherent structures over single-and multi-sand waves were studied experimentally, the formulae for the separation length and vortex shedding period of the turbulent flow over single-sand wave were suggested, and the characteristics of turbulent coherent structures over multi-sand waves were also given.

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

    Science.gov (United States)

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

    2014-09-01

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

  14. The origin and geological significance of lunar ridges

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Lunar ridges are a kind of familiar linear structures developed on the lunar surface. The distribution pattern, formation mechanism and research significance of lunar ridges are discussed in this paper. Single lunar ridges are usually distributed in the form of broken lineation, and, as whole, lunar ridges are trapezoidal or annular in shape around the maria. As to the formation mechanism, only volcanism or tectonism was emphasized in the past, but the two processes are seldom taken into combined consideration. On the basis of detailed analyses, the authors thought that tectonism is a prerequisite for the formation of lunar ridges, while volcanism is the key factor controlling their particular shapes. Finally, the authors pointed out that it is very significant in the study of lunar ridges to link the course of lunar structure evolution with the stress state in the lunar crust.

  15. Magnetic Anomalies over the Pacific-Antarctic Ridge.

    Science.gov (United States)

    Pitman, W C; Heirtzler, J R

    1966-12-01

    Four magnetic profiles across the Pacific-Antarctic Ridge reveal magnetic anomalies that show trends parallel with the ridge axis and symmetry about the ridge axis. The distribution of bodies that could cause these anomalies supports the Vine and Matthews hypothesis for the generation of patterns of magnetic anomalies associated with the midocean ridge system. The geometry of the bodies accords with the known reversals of the geomagnetic field during the last 3.4 million years, indicating a spreading rate of the ocean floor of 4.5 centimeters per year. If one assume that the spreading rate within 500 kilometers of the ridge axis has been constant, reversals of the geomagnetic field during the last 10.0 million years can be determined. This new, detailed history of field reversals accords with observed anomalies over Reykjanes Ridge in the North Atlantic if a spreading rate of 1 centimeter per year is assumed there.

  16. Field Use of NMIS at Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, L.G.; Conger, M.; Hughes, S.S.; Mattingly, J.K.; McEvers, J.A.; Mihalczo, J.T.; Mullens, J.A.; Perez, R.B.; Turner, C.R.; Uckan, T.; Valentine, T.E.

    1999-08-26

    The Nuclear Materials Identification System (NMIS), developed by the Oak Ridge National Laboratory and Oak Ridge Y-12 Plant (Y-12), has been successfully used at Y-12 for nuclear material control and accountability (NMC&A). It is particularly useful in the high gamma-ray background of storage arrays and for shielded HEU. With three systems in use at Y-12, NMIS has enhanced the NMC&A capability for verification and for confirmation of materials in storage and for HEU receipts by providing capability not available or practical by other NDA methods for safeguards. It has recently cost-effectively quantified the HEU mass and enrichment of hundreds of HEU metal items to within a total spread of {+-} 5% (3 sigma) with and mean deviations for all HEU verified of + 0.2% for mass and {minus}0.2% for enrichment. Three cart portable systems are easily moved around with minimal impact on facility operations since no permanent dedicated floor space is required. The positive impact of NMIS at the Oak Ridge Y-12 Plant is improved and more cost effective NMC&A as well as the resolution of NMC&A findings. Its operation at the Y-12 Plant is essential for compliance with the NMC&A requirements of the US Department of Energy. NMIS portability has allowed one system to be moved temporarily to the former K-25 Gaseous Diffusion Plant for characterization of a large deposit of hydrated uranyl fluoride. The impact of this NMIS application was enhanced and verified nuclear criticality safety that led to the safe removal of a large deposit originally estimated by gamma-ray spectrometry and neutron counting to contain 1300 kg of 3.3 wt% {sup 235}U material. NMIS has also been operational at Los Alamos National Laboratory and Pantex.

  17. Road dust from pavement wear and traction sanding

    Energy Technology Data Exchange (ETDEWEB)

    Kupiainen, K.

    2007-07-01

    sanding and physical properties of the traction sand aggregate affect formation of road dust (ii) How do studded tires affect the formation of road dust when compared with friction tires (iii) What are the composition and sources of airborne road dust in a road simulator and during a springtime road dust episode in Finland (iv) What is the size distribution of abrasion particles from tire-road interaction. The studies were conducted both in a road simulator and in field conditions. The test results from the road simulator showed that traction sanding increased road dust emissions, and that the effect became more dominant with increasing sand load. A high percentage of fine-grained anti-skid aggregate of overall grading increased the PM10 concentrations. Anti-skid aggregate with poor resistance to fragmentation resulted in higher PM levels compared with the other aggregates, and the effect became more significant with higher aggregate loads. Glaciofluvial aggregates tended to cause higher particle concentrations than crushed rocks with good fragmentation resistance. Comparison of tire types showed that studded tires result in higher formation of PM emissions compared with friction tires. The same trend between the tires was present in the tests with and without anti-skid aggregate. This finding applies to test conditions of the road simulator with negligible resuspension. Source and composition analysis showed that the particles in the road simulator were mainly minerals and originated from both traction sand and pavement aggregates. A clear contribution of particles from anti-skid aggregate to ambient PM and dust deposition was also observed in urban conditions. The road simulator results showed that the interaction between tires, anti-skid aggregate and road surface is important in dust production and the relative contributions of these sources depend on their properties. Traction sand grains are fragmented into smaller particles under the tires, but they also wear the

  18. Water Glass Modification and its Impact on the Mechanical Properties of Moulding Sands

    OpenAIRE

    A. Kmita; B. Hutera

    2013-01-01

    The purpose of the presented experiment was to develop an effective water glass modifier. In the conducted research, an attempt was made to determine the effect of modifier addition on the wettability of quartz grains, viscosity and cohesion of binder and strength RmUof the sand mixture. Water glass modification was carried out with, obtained in electrochemical process [1], colloidal suspension of ZnO nanoparticles in methanol (modifier I) or propanol (modifier II), characterised by a constan...

  19. Modeling the Performance of Sand Filters for Removing Runoff Suspended Sediment

    Science.gov (United States)

    2013-11-01

    release; distribution is unlimited. Prepared for US Army Corps of Engineers Washington, DC 20314-1000 ERDC/EL CR-13-3 ii Abstract Geotextile tubes...sediments in urban stormwater runoff, and thus should be effective in removing metals in runoff from SAFRs. Porous geotextile fabric is used to hold...public release; unlimited distribution. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Geotextile tubes filled with sand are being evaluated for filter

  20. Oak Ridge Leadership Computing Facility Position Paper

    Energy Technology Data Exchange (ETDEWEB)

    Oral, H Sarp [ORNL; Hill, Jason J [ORNL; Thach, Kevin G [ORNL; Podhorszki, Norbert [ORNL; Klasky, Scott A [ORNL; Rogers, James H [ORNL; Shipman, Galen M [ORNL

    2011-01-01

    This paper discusses the business, administration, reliability, and usability aspects of storage systems at the Oak Ridge Leadership Computing Facility (OLCF). The OLCF has developed key competencies in architecting and administration of large-scale Lustre deployments as well as HPSS archival systems. Additionally as these systems are architected, deployed, and expanded over time reliability and availability factors are a primary driver. This paper focuses on the implementation of the Spider parallel Lustre file system as well as the implementation of the HPSS archive at the OLCF.

  1. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    King, David A. [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy?s (DOE?s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  2. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  3. Real-Time Simulation of Aeolian Sand Movement and Sand Ripple Evolution: A Method Based on the Physics of Blown Sand

    Institute of Scientific and Technical Information of China (English)

    Ning Wang; Bao-Gang Hu

    2012-01-01

    Simulation and visualization of aeolian sand movement and sand ripple evolution are a challenging subject.In this paper,we propose a physically based modeling and simulating method that can be used to synthesize sandy terrain in various patterns.Our method is based on the mechanical behavior of individual sand grains,which are widely studied in the physics of blown sand.We accounted significant mechanisms of sand transportation into the sand model,such as saltation,successive saltation and collapsing,while simplified the vegetation model and wind field model to make the simulation feasible and affordable.We implemented the proposed method on the programming graphics processing unit (GPU) to get real-time simulation and rendering.Finally,we proved that our method can reflect many characteristics of sand ripple evolution through several demonstrations.We also gave several synthesized desert scenes made from the simulated height field to display its significance on application.

  4. Simulation of aeolian sand saltation with rotational motion

    Science.gov (United States)

    Huang, Ning; Wang, Cong; Pan, Xiying

    2010-11-01

    In this work, we propose a theoretical model based on the distribution functions of initial liftoff velocity and angular velocity of sand grains to describe a sand saltation process in which both wind field-sand grain coupling and the Magnus force experienced by saltating sand grains have been incorporated. The computation results showed that the Magnus force had significant effects on sand grain saltation. In particular, when the Magnus force was incorporated, the calculated sand transport fluxes and sand transport rate per unit width were closer to the experimental value than when this force was excluded. The sand transport flux is enhanced because the Magnus force owing to particle rotation causes the particles to have higher and longer trajectories, so the particles can get more speed and energy from the wind, which leads to a larger sand transport flux. In addition, it was found that when taking the Magnus force into account, the probability density of the impact velocity and angular velocity of saltating sand grains followed an exponential distribution and a unimodal asymmetric distribution, respectively. Moreover, the sand energy flux increased with the height above the sand surface until the energy flux reached its maximum and then decreased. Furthermore, the energy flux near the ground surface decreased as the grain diameter increased, but beyond a specific height the energy flux increased with the grain diameter. Finally, for the same sand grain diameter, the energy flux increased with the friction velocity.

  5. Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment.

  6. Tectonic origin of Crowley's Ridge, northeastern Arkansas

    Energy Technology Data Exchange (ETDEWEB)

    VanArsdale, R.B. (Univ. of Arkansas, Fayetteville, AR (United States). Geology Dept.); Williams, R.A.; Shedlock, K.M.; King, K.W.; Odum, J.K. (Geological survey, Denver, CO (United States). Denver Federal Center); Schweig, E.S. III; Kanter, L.R. (Memphis State Univ., TN (United States))

    1992-01-01

    Crowley's Ridge is a 320 km long topographic ridge that extends from Thebes, Illinois to Helena, Arkansas. The ridge has been interpreted as an erosional remnant formed during Quaternary incision of the ancestral Mississippi and Ohio rivers; however, the Reelfoot Rift COCORP line identified a down-to-the-west fault bounding the western margin of Crowley's Ridge south of Jonesboro, Arkansas. Subsequent Mini-Sosie seismic reflection profiles confirmed the COCORP data and identified additional faults beneath other margins of the ridge. In each case the faults lie beneath the base of the ridge scarp. The Mini-Sosie data did not resolve the uppermost 150 m and so it was not possible to determine if the faults displace the near-surface Claiborne Group (middle Eocene). A shotgun source seismic reflection survey was subsequently conducted to image the uppermost 250 m across the faulted margins. The shotgun survey across the western margin of the ridge south of Jonesboro reveals displaced reflectors as shallow as 30 m depth. Claiborne Group strata are displaced approximately 6 m and it appears that some of the topographic relief of Crowley's Ridge at this location is due to post middle Eocene fault displacement. Based on the reflection data, the authors suggest that Crowley's Ridge is tectonic in origin.

  7. One Piece Orbitozygomatic Approach Based on the Sphenoid Ridge Keyhole

    DEFF Research Database (Denmark)

    Spiriev, Toma; Poulsgaard, Lars; Fugleholm, Kaare

    2016-01-01

    The one-piece orbitozygomatic (OZ) approach is traditionally based on the McCarty keyhole. Here, we present the use of the sphenoid ridge keyhole and its possible advantages as a keyhole for the one-piece OZ approach. Using transillumination technique the osteology of the sphenoid ridge was exami......The one-piece orbitozygomatic (OZ) approach is traditionally based on the McCarty keyhole. Here, we present the use of the sphenoid ridge keyhole and its possible advantages as a keyhole for the one-piece OZ approach. Using transillumination technique the osteology of the sphenoid ridge...

  8. Water Glass Modification and its Impact on the Mechanical Properties of Moulding Sands

    Directory of Open Access Journals (Sweden)

    A. Kmita

    2013-04-01

    Full Text Available The purpose of the presented experiment was to develop an effective water glass modifier. In the conducted research, an attempt was made to determine the effect of modifier addition on the wettability of quartz grains, viscosity and cohesion of binder and strength RmUof the sand mixture. Water glass modification was carried out with, obtained in electrochemical process [1], colloidal suspension of ZnO nanoparticles in methanol (modifier I or propanol (modifier II, characterised by a constant molar concentration of c = 0.3 M. It was demonstrated that the addition of a colloidal suspension of ZnO nanoparticles in propanol (modifier II had a significant effect on wettability of quartz grains improvement without the accompanying increase in binder viscosity. Testing the mechanical properties RmUof sand mixtures containing modified binder (modifier II hardened at ambient conditions showed an approximately 28% increase in strength compared with the RmUof the sand bonded with an unmodified binder.

  9. The impact of raindrops on sand

    NARCIS (Netherlands)

    de Jong, Rianne

    2017-01-01

    When a raindrop hits a sand bed, it leaves behind a small crater with a mixture of liquid and grains located at the center. This event is frequently observed in nature, but when absent, sprinklers may artificially produce these impacting drops to facilitate irrigation. Also in industry, the interact

  10. Cumulative environmental management and the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.

  11. LEARNING ABOUT THE OCEANS FROM SAND

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    As a young geophysicist in the 1980s, Rob Holman attended a conference in San Francisco that included a field trip to a beach. Dr Holman, who grew up inland, stared at the ocean, assessing the strengths of the waves. But when he looked around, everyone else was studying the sand.

  12. 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 small-scal

  13. 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...

  14. Galveston Island, Texas, Sand Management Strategies

    Science.gov (United States)

    2016-07-01

    68 Figure 28. Jetty segment used for computation of aeolian sand transport. Background photograph 22 May 2012...113 Figure 68 . Total shoreline change after 50 years for 500,000 yd3 placed every 2 years in different locations...The berm at Ft. Myers, FL, was constructed with dredged material from Matanzas Pass. The dredged material contained greater than 10% fines, which

  15. Building Whales in Sand and Mind.

    Science.gov (United States)

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales…

  16. 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 and impac......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...

  17. Sand Waves along the Dutch Coast

    NARCIS (Netherlands)

    Verhagen, H.J.

    1989-01-01

    Sand waves, defined as longshore wave-like movements of the shoreline, measured in a horizontal plane, are described along several stretches of the shoreline of The Netherlands. They have a celerity in the order of 50-200 m/yr, a period of 50- 150 years and an amplitude of 30- 500 m. They are found

  18. Building Whales in Sand and Mind.

    Science.gov (United States)

    Warner, Carolyn

    1980-01-01

    Describes two-week summer workshops on evolution, adaptation, and behavior of whales, conducted for children by Cold Spring Harbor Whaling Museum (New York), and culminating in creation of life-size sand sculptures of whales. Provides selected list of periodicals, teaching materials, identification guides, records, and societies devoted to whales…

  19. Sand and Stone%沙与石

    Institute of Scientific and Technical Information of China (English)

    黄川; 孙静

    2006-01-01

    @@ Astory tells that two friends were walking through the desert. During some point of the journey they had an argument, and one friend slapped the other one in the face1. The one who got slapped was hurt, but without saying anything, he wrote in the sand: "TODAY MY BEST FRIEND SLAPPED ME IN THE FACE."

  20. US Department of Energy Oak Ridge Operations Environmental Management Public Involvement Plan for the Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This document was prepared in accordance with CERCLA requirements for writing community relations plans. It includes information on how the DOE Oak Ridge Operations Office prepares and executes Environmental Management Community relations activities. It is divided into three sections: the public involvement plan, public involvement in Oak Ridge, and public involvement in 1995. Four appendices are also included: environmental management in Oak Ridge; community and regional overview; key laws, agreements, and policy; and principal contacts.

  1. Behavior of Cell on Vibrating Micro Ridges

    Directory of Open Access Journals (Sweden)

    Haruka Hino

    2015-06-01

    Full Text Available The effect of micro ridges on cells cultured at a vibrating scaffold has been studied in vitro. Several parallel lines of micro ridges have been made on a disk of transparent polydimethylsiloxane for a scaffold. To apply the vibration on the cultured cells, a piezoelectric element was attached on the outside surface of the bottom of the scaffold. The piezoelectric element was vibrated by the sinusoidal alternating voltage (Vp-p < 16 V at 1.0 MHz generated by a function generator. Four kinds of cells were used in the test: L929 (fibroblast connective tissue of C3H mouse, Hepa1-6 (mouse hepatoma, C2C12 (mouse myoblast, 3T3-L1 (mouse fat precursor cells. The cells were seeded on the micro pattern at the density of 2000 cells/cm2 in the medium containing 10% FBS (fetal bovine serum and 1% penicillin/ streptomycin. After the adhesion of cells in several hours, the cells are exposed to the ultrasonic vibration for several hours. The cells were observed with a phase contrast microscope. The experimental results show that the cells adhere, deform and migrate on the scaffold with micro patterns regardless of the ultrasonic vibration. The effects of the vibration and the micro pattern depend on the kind of cells.

  2. Fs-Laser structuring of ridge waveguides

    Science.gov (United States)

    Wortmann, D.; Gottmann, J.

    2008-10-01

    Thin films made by PLD from Er:ZBLAN and Nd:Gd3Ga5O12 are micro machined to form optical wave guiding structures using Ti:sapphire and Yb:glass fiber laser radiation. For the manufacturing of the ridge waveguides grooves are structured by ablation using femtosecond laser radiation. The fluence, the scanning velocity, the repetition rate, and the orientation of the polarization with respect to the scanning direction are varied. The resulting structures are characterized using optical microscopy and scanning electron microscopy. Damping and absorption coefficients of the waveguides are determined by observing the light scattered from the waveguides due to droplets in the thin films and the surface roughness of the structured edges. To discriminate between damping due to droplets and the structured edges, damping measurements in the non-structured films and the structured waveguides are performed. Ridge waveguides with non-resonant damping losses smaller than 3 dB/cm are achieved. Due to the high repetition rate of the Yb:glass fiber laser, the manufacturing time for one waveguide has been decreased by a factor of more than 100 compared to earlier results achieved with the Ti:sapphire laser.

  3. 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

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

    African Journals Online (AJOL)

    Assessing environmental impacts of inland sand mining in parts of Ogun State, Nigeria. ... Sand is a valuable resource for construction and other purposes, however ... Natural resources particularly, land, water quality and quantity, air quality, ...

  5. 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.

  6. Gating Technology for Vertically Parted Green Sand Moulds

    DEFF Research Database (Denmark)

    Larsen, Per

    Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems.......Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems....

  7. Expandable sand screens: from novel concept to proven sand control technique

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Paul; Jones, Colin; Ballard, Tracey; Beare, Steve; Hillis, Dave [Weatherford International Inc., Houston, TX (United States)

    2004-07-01

    Expandable Sand Screens (ESS) have proved a viable alternative to gravel packing for sand control. With over 300 installations worldwide, analysis of their use has confirmed that ESS offers excellent production performance and sand control reliability in Open hole. This paper presents details of a global survey on ESS performance that gives accurate information on production performance, sand exclusion reliability and cost effectiveness in Open hole and cased hole application scenarios. This paper also discusses the role and effect of compliant expansion in observed productivity performance and skin values. The rock mechanical, reservoir characterization and metallurgical requirements of ESS systems are also investigated. Finally, the latest advances of the technology for use within the reservoir are explained. This paper demonstrates how the combination of ESS and Expandable Zonal Isolation devices can offer cased hole functionality (in terms of zonal isolation) in combination with Open hole levels of production performance (from the ESS). (author)

  8. Water management in the oil sands industry

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

    2004-07-01

    Water management issues at Alberta's 4 oil sand deposits were discussed. The 4 deposits include the Peace River, Athabasca, Wabasca and Cold Lake deposits, with the Athabasca deposit being the largest and the only surface-mineable deposit. Large quantities of water are needed to extract bitumen from oil sands. This paper addressed water volume withdrawal from the Athabasca River, the primary source of water for the surface-mining oil sands industry. It also addressed Muskeg River watershed integrity, quality of water withdrawn from reclaimed landscapes, groundwater contamination, and ecological viability of end-pit lakes. Currently, half of Syncrude's oil sand is transported from mine to extraction plant by conveyor belts. The other half is pipelined as a warm water slurry. By 2005, all transport will be by pipeline. The oil sand is mixed with hot water, steam and surfactants to condition it for extraction. Seventy-nine per cent of the water used by Syncrude is recycled water and the remainder comes from the Athabasca River. Syncrude diverts 2.5 to 3 barrels of water from the Athabasca River for every barrel of oil produced. This paper discussed the in-stream flow needs of the Athabasca River based on protection of aquatic ecosystems. Flow needs are addressed by the Cumulative Effects Management Association (CEMA). The paper states that the proportion of annual flow withdrawn from the Athabasca River is too low to have a significant impact on aquatic systems, but the main concern lies in water use during low flow periods, typically during the winter months. Developers will likely come under pressure to develop off-site reservoirs to store water for use during these low-flow periods. tabs., figs.

  9. Imaging of Acoustic Waves in Sand

    Energy Technology Data Exchange (ETDEWEB)

    Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

    2003-08-01

    There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

  10. 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.

  11. Seeking the seaward limits of the Irish Sea Ice Stream: glaciation of the Celtic Sea and first results from the GATEWAYS II campaign

    Science.gov (United States)

    Praeg, Daniel; McCarron, Stephen; Dove, Dayton; Glamar; Shipboard Parties, Gateways

    2014-05-01

    The dynamics of the last British-Irish Ice Sheet (BIIS) are thought to have been strongly influenced by the activity of marine-based ice streams, the largest of which flowed down the Irish Sea and, at maximum, onto the broad continental shelf of the Celtic Sea. However, the maximum extent of the Irish Sea Ice Stream (ISIS) remains unclear: subglacial tills and glaciomarine muds recovered in BGS vibrocores from the Irish-UK sectors have been used to propose a mid-shelf grounding line, but subglacial or ice-proximal sediments have also been cored at two sites near the shelf edge over 100 km to farther seaward. The glacigenic sediments were cored between, but in places from the flanks of, a vast system of shelf-crossing seabed ridges (up to 55 m high, 7 km wide and 300 km long) that fan seaward from the northern Celtic. The ridges have traditionally been interpreted as moribund tidal sand banks formed during the post-glacial marine transgression, albeit overridden in the NW by the last ice sheet. An alternative explanation is that they are glaciofluvial landforms, recording meltwater drainage beneath beneath an ISIS that extended to the shelf edge. The glacigenic succession on and between the ridges has been investigated through the acquisition of multibeam imagery and subbottom profiles during the Italian-led GLAMAR and Irish-led GATEWAYS I campaigns (2009, 2012), which targeted the key BGS vibrocores used to propose a mid-shelf grounding line. Results indicate subglacial tills and glaciomarine muds to extend across the ridges, forming distinctive transform bedforms (ribs) that extend at least 60 km seaward of the proposed grounding line. The rectilinear network of ridges and transverse ribs are tentatively interpreted as giant eskers flanked by glaciofluvial De Geer moraines, a hypothesis with implications for both the extent and the dynamics of the ISIS. This hypothesis is to be further tested during the GATEWAYS II campaign of the Celtic Explorer in February

  12. RCRA Facilities Assessment (RFA)---Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    US Department of Energy (DOE) facilities are required to be in full compliance with all federal and state regulations. In response to this requirement, the Oak Ridge National Laboratory (ORNL) has established a Remedial Action Program (RAP) to provide comprehensive management of areas where past and current research, development, and waste management activities have resulted in residual contamination of facilities or the environment. This report presents the RCRA Facility Assessment (RFA) required to meet the requirements of RCRA Section 3004(u). Included in the RFA are (1) a listing of all sites identified at ORNL that could be considered sources of releases or potential releases; (2) background information on each of these sites, including location, type, size, period of operation, current operational status, and information on observed or potential releases (as required in Section II.A.1 of the RCRA permit); (3) analytical results obtained from preliminary surveys conducted to verify the presence or absence of releases from some of the sites; and (4) ORNL's assessment of the need for further remedial attention.

  13. RCRA Facilities Assessment (RFA)---Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    US Department of Energy (DOE) facilities are required to be in full compliance with all federal and state regulations. In response to this requirement, the Oak Ridge National Laboratory (ORNL) has established a Remedial Action Program (RAP) to provide comprehensive management of areas where past and current research, development, and waste management activities have resulted in residual contamination of facilities or the environment. This report presents the RCRA Facility Assessment (RFA) required to meet the requirements of RCRA Section 3004(u). Included in the RFA are (1) a listing of all sites identified at ORNL that could be considered sources of releases or potential releases; (2) background information on each of these sites, including location, type, size, period of operation, current operational status, and information on observed or potential releases (as required in Section II.A.1 of the RCRA permit); (3) analytical results obtained from preliminary surveys conducted to verify the presence or absence of releases from some of the sites; and (4) ORNL`s assessment of the need for further remedial attention.

  14. Carslberg Ridge and Mid-Atlantic Ridge: Slow-spreading Apparent Analogs

    Science.gov (United States)

    Rona, P. A.; Murton, B. J.; Bostrom, K.; Widenfalk, L.; Melson, W. G.; O'Hearn, T.; Cronan, D. S.; Jenkins, W. J.

    2005-12-01

    We compare morphology, tectonics, petrology, and hydrothermal activity of a known section of the Mid-Atlantic Ridge (MAR) between the Kane and Atlantis fracture zones (full multi-beam coverage 21N to 31N) to the lesser known Carlsberg Ridge (CR; limited multi-beam coverage plus satellite altimetry). The CR extends from the Owen Fracture Zone (10N) to the Vityaz Fracture Zone (5S) and spreads at half-rates (~1.2-1.8 cm/yr) similar to the MAR: 1) Morphology: Both ridges exhibit distinct segmentation (primarily sinistral) and axial valleys with high floor to crest relief (range 1122-1771 m). Average lengths of segments (CR: 70 km; MAR: 50 km) and crest-to crest width of the axial valley are greater on the CR (40 km) than MAR (23 km). Axial volcanic ridges form the neovolcanic zone on both ridges, typically 2.6 km wide and 213 m high on the CR. Average water depth near segment centers is greater on the MAR (3933 m) than the CR (3564 m). V-shaped patterns oblique to the spreading axis are present on both ridges. 2) Tectonics: Segments on each ridge are predominantly separated by short-offset (Bulls-eye Mantle Bouguer Lows (-30 to -50 mgal) are present at centers of spreading segments on both ridges. Metamorphic core complexes of lower crust and upper mantle are present on the MAR section (at fracture zones) and at least at one locality at 58.33E on the CR. 3) Petrology: MORB composition from our 20 stations along the CR fall into the MORB family, with no evidence of hotspot inputs (no excess K or Nb), or extreme fractionation, similar to the MAR section. REE and trace element patterns between 57E and 61E on the CR indicate increasing melt depletion to the northwest, while glasses exhibit a striking systematic increase in MgO (decrease in fractionation) to the northwest and attain among the most primitive composition of any ocean ridge adjacent to the Owen fracture zone (9.93wt percent). Sr, Nd, and Pb isotopic compositions of Indian Ocean MORB are distinct from those of

  15. Optical and radiocarbon ages of stacked paleosols and dune sands in the Nebraska Sand Hills, USA

    Science.gov (United States)

    Goble, R. J.; Mason, Joseph A.; Loope, David B.; Swinehart, James B.

    2004-05-01

    Optical ages for eolian sands from the Nebraska Sand Hills indicate periods of extensive eolian activity at ca 115±25, 840±70, 2300±240, and 3560±340 a. Activity was also noted at single sampling locations at ca 6180±370, 8430±510 and 13110±800 a. Many of these ages are similar to those noted by earlier authors. Optical ages from samples collected within paleosols indicate shorter and possibly less extensive periods of eolian activity at approximately 1220±150, 1590±110, and possibly 1950±150 a, during which the paleosol sands accumulated. What was originally interpreted as a single 1.2 m thick paleosol is shown by optical dating to consist of three or more welded soils developed within eolian sands with optical ages of ca 3800±240, 2740±240, 1560±110, and possibly 1930±140 a, each of which match eolian pulses recognized elsewhere. Scatter in some optical ages is attributable to intersection of sand-filled rodent burrows extending in outcrop 1.5 m below the contact between paleosol and overlying topset beds. A 5310±360 a optical age for one probable intersected burrow provides evidence for upward or lateral transport of older sands.

  16. Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter

    Directory of Open Access Journals (Sweden)

    Daneshi Navab

    2014-06-01

    Full Text Available Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2 2014: 276-286

  17. Yield of a Choctawhatchee Sand Pine Plantation at Age 28

    Science.gov (United States)

    Russell M. Burns; R.H. Brendemuehl

    1969-01-01

    A little-known tree, Choctawhatchee sand pine (Pinus clausa [Chapm.] Vasey), seems well adapted to the infertile, droughty soils common to the sandhills of Florida which now produce little value. Published yield data based on plantation-grown Choctawhatchee sand pine are not available. One 28-year-old plantation of this race of sand pine, growing...

  18. Fresh groundwater resources in a large sand replenishment

    NARCIS (Netherlands)

    Huizer, Sebastian; Oude Essink, G.H.P.; Bierkens, Marc

    2016-01-01

    The anticipation of sea-level rise and increases in extreme weather conditions has led to the initiation of an innovative coastal management project called the Sand Engine. In this pilot project a large volume of sand (21.5 million m3) – also called sand replenishment or nourishment – was placed on

  19. 77 FR 75007 - Importation of Sand Pears From China

    Science.gov (United States)

    2012-12-19

    ... Health Inspection Service 7 CFR Part 319 RIN 0579-AD42 Importation of Sand Pears From China AGENCY... and vegetables regulations to allow the importation of sand pears (Pyrus pyrifolia) from China into the United States. As a condition of entry, sand pears from areas in China in which the Oriental...

  20. Design and management of conventional fluidized-sand biofilters

    Science.gov (United States)

    Fluidized sand biofilters (FSBs) are relatively compact, efficient, and cost-competitive biofilters, especially in recirculating systems that require maintaining consistently low levels of ammonia and nitrite. Filter sand is low cost (often $70-200/m3 of sand delivered) and has a high specific surf...

  1. Mineral processing of heavy mineral sands from Malawi and Malaysia

    OpenAIRE

    Mitchell, C J

    1992-01-01

    Processing of heavy mineral sands involves many techniques including gravity, magnetic and electrostatic separation. As part of a laboratory programme to develop effective mineral processing techniques, two mineral sands from Malawi and Malaysia were processed using the standard techniques, with emphasis placed on the Carpco electrostatic separator. These sands were initially characterised mineralogically by scanning electron microscopy (SEM), electron microprobe analysis (EPMA...

  2. Ridge alterations following grafting of fresh extraction sockets in man. A randomized clinical trial.

    Science.gov (United States)

    Araújo, Mauricio G; da Silva, João Carlos Costa; de Mendonça, Arthur Furtado; Lindhe, Jan

    2015-04-01

    To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss(®) Collagen. Twenty-eight subjects with maxillary incisors, canines, and premolars scheduled for extraction were included. The tooth was carefully removed. The patients were randomly assigned to a test or a control group. In the test group patients, Bio-Oss(®) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed. Radiographic examination (cone beam computed tomograms, CBCT) was performed immediately after tooth extraction and socket treatment. Four months later, a new CBCT was obtained. In the radiographs, (i) the distance (mm) between base of the alveolar process (apex) and the buccal and palatal crests was determined, (ii) the outer profile of alveolar process of the experimental sites was outlined, and the cross section of the area (mm(2) ) determined. After 4 months of healing, the buccal and to a less extent also the palatal bone plate had become markedly reduced in height. The placement of a biomaterial in the socket failed to prevent resorption of the buccal and palatal bone walls. The cross-sectional area of the control ridge was reduced about 25% and of the test ridge with 3%. The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Cold Testing of a Russian Pulsating Mixer Pump at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, BE

    2002-01-29

    Russian pulsating mixer pump (PMP) technology was identified in FY 1996 during technical exchanges between the U.S. Department of Energy (DOE) Tanks Focus Area Retrieval and Closure program, the DOE Environmental Management International Programs, and delegates from Russia as a technology that could be implemented in tank waste retrieval operations in the United States. The PMP is basically a jet mixer powered by a pressure/vacuum supply system. A prototype PMP was provided by the Russian Mining and Chemical Combine and evaluated as a potential retrieval tool in FY 1997 at Pacific Northwest National Laboratory (PNNL). Based on this evaluation, Oak Ridge National Laboratory (ORNL) and DOE staff determined that a modified PMP would meet project needs for bulk mobilization of sludge from one or more of the Gunite and Associated Tanks (GAAT) at ORNL. In FY 1998, PMP technology was selected for deployment in one of the GAAT to mobilize settled solids. Deployment of the PMP was expected to reduce operation and maintenance costs required to utilize more expensive retrieval systems. The following series of cold tests and inspections were conducted on one of the three PMP units provided to verify the acceptability and readiness of the mixing system for operation in the GAATs at ORNL: (1) Inspections and measurements designed to evaluate the integrity of the equipment: Fabrication shop inspections, Equipment inspections, Vibration/oscillation measurements, Hydrostatic pressure tests. (2) Functionality of the system components: Tank riser interface functionality, Decontamination spray ring (DSR) functionality, Valves, actuator, sensors, and control system functionality, Support fixture tests; and Contamination control assessment. (3) Mixing and operational performance of the PMP system: DSR performance, PMP debris tolerance, PMP performance with water only, PMP cleaning radius determination, and PMP performance with sludge surrogates. The results from these tests indicate

  4. Oak Ridge Reservation Annual Site environmental report summary for 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This document presents a summary of the information collected for the Oak Ridge Reservation 1994 site environmental report. Topics discussed include: Oak Ridge Reservation mission; ecology; environmental laws; community participation; environmental restoration; waste management; radiation effects; chemical effects; risk to public; environmental monitoring; and radionuclide migration.

  5. 60 Years of Great Science (Oak Ridge National Laboratory)

    Science.gov (United States)

    2003-01-01

    This issue of Oak Ridge National Laboratory Review (vol. 36, issue 1) highlights Oak Ridge National Laboratory's contributions in more than 30 areas of research and related activities during the past 60 years and provides glimpses of current activities that are carrying on this heritage.

  6. Pesticide Leaching from Agricultural Fields with Ridges and Furrows

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    In the evaluation of the risk of pesticide leaching to groundwater, the soil surface is usually assumed to be level, although important crops like potato are grown on ridges. A fraction of the water from rainfall and sprinkler irrigation may flow along the soil surface from the ridges to the furrows

  7. A very large dew and rain ridge collector in the Kutch area (Gujarat, India)

    Science.gov (United States)

    Sharan, G.; Clus, O.; Singh, S.; Muselli, M.; Beysens, D.

    2011-07-01

    SummaryThe world's largest dew and rain collecting system, comprised of ridge-and-trough modules, was constructed in March 2006 at Panandhro in the semi-arid area of Kutch (NW India). The main goals were (i) to collect dew on a scale that could be beneficial to the local population (ii) to determine the efficiency of this new module shape, (iii) to determine whether results obtained from small measurement condensers can be projected to large condensers, (iv) to apply a computational fluid dynamic simulation to improve the condenser set-up. Preliminary studies performed with four standard plane condensers of 1 m 2 surface area, inclined 30° from horizontal, identified Panandhro as a promising site. The cumulated dew water during 192 days was 12.6 mm with a maximum of 0.556 mm/night. A large dew condenser (850 m 2 net total surface) was designed with 10 ridge-and-trough modules. The ridges are trapezoidal, 33 m long, 0.5 m wide at the top, 2.2 m wide at the base and sloping 30° from horizontal. The depth of the troughs between the ridges is 0.5 m. A 2.5 cm thick polystyrene foam rests on the surface as insulation with a radiative foil on top (similar to that developed by OPUR, see www.opur.fr). Numerical simulations using the computational fluid dynamic software PHOENICS were performed. The most profitable orientation was with the condenser oriented back to the wind direction, a configuration that lowers the wind velocity near the foil due to the combination of free convection and wind recirculation flows. A comparison of water yields over one year of measurements between four 1 m 2 plane condensers and a 850 m 2 ridge condenser showed a 42% lower yield on the large condenser. The difference is attributed mainly to folds in the plastic foil allowing water to fill the central ridge, thus decreasing radiative cooling. The output for 2007 was 6545 L, corresponding to 7.7 mm/day on average. The largest event was 251.4 L/night (0.3 mm). Such a condenser can also collect

  8. The Rheology of Acoustically Fluidized Sand

    Science.gov (United States)

    Conrad, J. W.; Melosh, J.

    2013-12-01

    The collapse of large craters and the formation of central peaks and peak rings is well modeled by numerical computer codes that incorporate the acoustic fluidization mechanism to temporarily allow the fluid-like flow of rock debris immediately after crater excavation. Furthermore, long runout landslides require a similar mechanism to explain their almost frictionless movement, which is probably also a consequence of their granular composition coupled with internal vibrations. Many different investigators have now confirmed the ability of vibrations to fluidize granular materials. Yet it still remains to fully describe the rheology of vibrated sand as a function of stress, frequency and amplitude of the vibrations in the sand itself. We constructed a rotational viscometer to quantitatively investigate the relation between the stress and strain rate in a horizontal bed of strongly vibrated sand. In addition to the macroscopic stain rate, the amplitude and frequency of the vibrations produced by a pair of pneumatic vibrators were also measured with the aid of miniaturized piezoelectric accelerometers (B&K 4393) whose output was recorded on a digital storage oscilloscope. The initial gathering of the experimental data was difficult due to granular memory, but by having the sand compacted vibrationally for 8 minutes before each run the scatter of data was reduced and we were able to obtain consistent results. Nevertheless, our major source of uncertainty was variations in strain rate from run to run. We find that vibrated sand flows like a highly non-Newtonian fluid, in which the shear strain rate is proportional to stress to a power much greater than one, where the precise power depends on the amplitude and frequency of the applied vibrations. Rapid flow occurs at stresses less than half of the static yield stress (that is, the yield stress when no vibration is applied) when strong vibrations are present. For a Newtonian fluid, such as water, the relation between

  9. Evidence for melt channelization in Galapagos plume-ridge interaction

    Science.gov (United States)

    Mittal, T.; Richards, M. A.

    2015-12-01

    Many present-day hot spots are located within ~ 1000 km of a mid-ocean ridge, either currently or in the geologic past, leading to frequent interaction between these two magmatic regimes. The consequent plume-ridge interactions provide a unique opportunity to test models for asthenosphere-lithosphere dynamics, with the plume acting as a tracer fluid in the problem, and excess magmatism reflecting otherwise unsampled sub-surface phenomena. Galapagos is an off-ridge hotspot with the mantle plume located ~150-250 km south of the plate boundary. Plume-ridge interaction in Galapagos is expressed by the formation of volcanic lineaments of islands and seamounts - e.g., the Wolf-Darwin lineament (WDL) - providing a direct probe of the plume-ridge interaction process, especially in regards to geochemical data. Although several models have been proposed to explain plume-ridge interaction in Galapagos, none adequately explain the observed characteristics, especially the WDL. In particular, predicted lithospheric fault orientations and melt density considerations appear at odds with observations, suggesting that lithospheric extension is not the primary process for formation of these islands. Other off-ridge hotspots interacting with nearby spreading ridges, such as Reunion and Louisville, also exhibit volcanic lineaments linking the plume and the ridge. Thus these lineament-type features are a common outcome of plume-ridge interaction that are indicative of the underlying physics. We propose that the lineaments are surface expressions of narrow sub-lithospheric melt channels focused towards the spreading ridge. These channels should form naturally due to the reactive infiltration instability in a two-phase flow of magma and solid mantle as demonstrated in two-phase flow simulations (e.g., Katz & Weatherley 2012). For Galapagos, we show that melt channels can persist thermodynamically over sufficient length-scales to link the plume and nearby ridge segments. We also show that

  10. The axial topographic high at intermediate and fast spreading ridges

    Science.gov (United States)

    Carbotte, Suzanne M.; MacDonald, Ken C.

    1994-12-01

    An axial topographic high is commonly observed at both fast spreading ridges and some segments of intermediate spreading ridges. At fast rates the axial high is primarily created by the buoyancy of hot rock and magma beneath the rise. As newly formed crust is transported off axis, little vestige of an axial high is observed on the ridge flanks. In contrast, at intermediate rates, a significant component of the positive topography may be a volcanic construction, preserved on the ridge flanks as abyssal hills, which are slit axial volcanoes. We suggest this difference in the nature of the axial high reflects a lithosphere strong enough to support construction of a volcanic crestal ridge at intermediate spreading rates, but only rarely at fast rates. Relict overlap ridges, found within the discordant zones left by overlapping spreading centers, is one class of ridge-flank topography which appears to have a significant volcanic constructional component even at fast spreading ridges. Unlike topography away from these discontinuities, the relief and shape of overlapping spreading centers is preserved as relict ridge tips are rafted onto the ridge flanks. Reduced magma supply at these discontinuities may give rise to an axial lithosphere strong enough to support volcanic construction of overlap ridges. Low axial lithospheric strength may also account for the lack of normal faults within the innermost 1-2 km of fast, and some intermediate, spreading ridges. With a thin/weak brittle layer at the ridge crest, tensile failure will predominate and few normal faults will form. Depths to the axial magma chamber reflector observed in multi-channel seismic data limit the thickness of the brittel layer on axis to less than 1-2 km for much of the East Pacific Rise (EPR). This depth is comparable to depths over which tensile failure within the oceanic crust will predominate, estimated from the Griffith criteria for fracture initiation (approx. 0.5-1.5 km). As the brittle layer

  11. Tectonic Evolution of Mozambique Ridge in East African continental margin

    Science.gov (United States)

    Tang, Yong

    2017-04-01

    Tectonic Evolution of Mozambique Ridge in East African continental margin Yong Tang He Li ES.Mahanjane Second Institute of Oceanography,SOA,Hangzhou The East Africa passive continental margin is a depression area, with widely distributed sedimentary wedges from southern Mozambique to northern Somali (>6500km in length, and about 6km in thickness). It was resulted from the separation of East Gondwana, and was developed by three stages: (1) rifting in Early-Middle Jurassic; (2) spreading from Late Jurassic to Early Cretaceous; (3) drifting since the Cretaceous period. Tectonic evolution of the Mozambique continental margin is distinguished by two main settings separated by a fossil transform, the Davie Fracture Zone; (i) rifting and transform setting in the northern margin related to opening of the Somali and Rovuma basins, and (ii) rifting and volcanism setting during the opening of the Mozambique basin in the southern margin. 2D reflection seismic investigation of the crustal structure in the Zambezi Delta Depression, provided key piece of evidence for two rifting phases between Africa and Antarctica. The magma-rich Rift I phase evolved from rift-rift-rift style with remarkable emplacement of dyke swarms (between 182 and 170 Ma). Related onshore outcrops are extensively studied, the Karoo volcanics in Mozambique, Zimbabwe and South Africa, all part of the Karoo "triple-junction". These igneous bodies flow and thicken eastwards and are now covered by up to 5 km of Cretaceous and Tertiary sediments and recorded by seismic and oil exploration wells. Geophysical and geological data recorded during oceanographic cruises provide very controversial results regarding the nature of the Mozambique Ridge. Two conflicting opinions remains open, since the early expeditions to the Indian Ocean, postulating that its character is either magmatic (oceanic) or continental origin. We have carried out an China-Mozambique Joint Cruise(CMJC) on southern Mozambique Basin on 1st June to

  12. 福建闽江口和九龙江口外线状沉积沙体特征%The characteristics of linear sands off Minjiang Estuary and Jiulongjiang Estuary in Fujian,China

    Institute of Scientific and Technical Information of China (English)

    许艳; 蔡锋; 卢惠泉; 吴承强; 郑勇玲; 鲍晶晶

    2014-01-01

    福建沿海强潮河口闽江口和九龙江口外均发育有一定规模的线状沉积沙体,通过多波束调查采集数据和浅剖、沉积物资料的分析,对此类沙体特征进行研究,初步认为其为潮流沙脊。结果表明:在平面分布上,闽江口外潮流沙脊走向近SW-NE向,沙脊局部连片;九龙江口外沙脊走向近 ENE-WSW向,沙脊末端有分叉现象。分析现代海洋环境作用并结合沙脊规模、水深和河口相对关系的研究显示,沙脊主体规模基本稳定,现代水动力仅对沙脊表面有改造作用。在潮流、波浪和近岸余流的共同作用下沙脊脊顶部略显平滑,两翼坡度较缓,其沉积物组成以粒度较粗的古河口砂质浅滩砂为主,沉积主体为全新世海平面上升时期,近岸河口环境的古水下三角洲遭受潮流侵蚀而成。%A certain scale of linear submarine sands which are referred to as tidal sand ridges occurs off the Minjiang Estuary and the Jiulongjiang Estuary in Fujian .Based on the survey data by multi-beam acoustic sounding ,sub-bottom profile as well as sediment grain sizes analysis ,we studied the features of the tidal sand ridges .The results show that the sand ridges off the Minjiang Estuary are oriented NE -SW ,and some of them are connected .The sand ridges off the Jiulongjiang Estuary are oriented ENE -WSW ,and some appear to diverge on the end .Accord-ing to the analysis of marine hydrodynamic environment affects ,and the relation among the ridges scale ,depth and relative distance to the estuary ,the main body of the sand ridges is basically steady .They have been reformed by the recent hydrodynamics as evidenced by similar sand waves on both sides of flanks .The interaction by recent tid-al current ,wave and residual current leads to a relatively smooth surface on top and both flanks of the sand ridges . It's indicated that the tidal sands primarily originated from estuarine coarse sandy shoals on

  13. The fate of volatiles in mid-ocean ridge magmatism

    CERN Document Server

    Keller, Tobias; Hirschmann, Marc M

    2016-01-01

    Deep-Earth volatile cycles couple the mantle with near-surface reservoirs. Volatiles are emitted by volcanism and, in particular, from mid-ocean ridges, which are the most prolific source of basaltic volcanism. Estimates of volatile extraction from the asthenosphere beneath ridges typically rely on measurements of undegassed lavas combined with simple petrogenetic models of the mean degree of melting. Estimated volatile fluxes have large uncertainties; this is partly due to a poor understanding of how volatiles are transported by magma in the asthenosphere. Here, we assess the fate of mantle volatiles through numerical simulations of melting and melt transport at mid-ocean ridges. Our simulations are based on two-phase, magma/mantle dynamics theory coupled to an idealised thermodynamic model of mantle melting in the presence of water and carbon dioxide. We combine simulation results with catalogued observations of all ridge segments to estimate a range of likely volatile output from the global mid-ocean ridge...

  14. 76 FR 78908 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

    Science.gov (United States)

    2011-12-20

    ..., Department of Energy Oak Ridge Operations Office, P.O. Box 2001, EM-90, Oak Ridge, TN 37831. Phone (865) 241... and Reuse. The speaker will be Brian Henry, DOE Oak Ridge. Public Participation: The EM SSAB,...

  15. Model Selection in Kernel Ridge Regression

    DEFF Research Database (Denmark)

    Exterkate, Peter

    Kernel ridge regression is gaining popularity as a data-rich nonlinear forecasting tool, which is applicable in many different contexts. This paper investigates the influence of the choice of kernel and the setting of tuning parameters on forecast accuracy. We review several popular kernels......, including polynomial kernels, the Gaussian kernel, and the Sinc kernel. We interpret the latter two kernels in terms of their smoothing properties, and we relate the tuning parameters associated to all these kernels to smoothness measures of the prediction function and to the signal-to-noise ratio. Based...... on these interpretations, we provide guidelines for selecting the tuning parameters from small grids using cross-validation. A Monte Carlo study confirms the practical usefulness of these rules of thumb. Finally, the flexible and smooth functional forms provided by the Gaussian and Sinc kernels makes them widely...

  16. Reactive spreading: Adsorption, ridging and compound formation

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, E.; Cannon, R.M.; Tomsia, A.P.

    2000-09-11

    Reactive spreading, in which a chemically active element is added to promote wetting of noble metals on nonmetallic materials, is evaluated. Theories for the energetics and kinetics of the necessary steps involved in spreading are outlined and compared to the steps in compound formation that typically accompany reactive wetting. These include: fluid flow, active metal adsorption, including nonequilibrium effects, and triple line ridging. All of these can be faster than compound nucleation under certain conditions. Analysis and assessment of recently reported experiments on metal/ceramic systems lead to a focus on those conditions under which spreading proceeds ahead of the actual formation of a new phase at the interface. This scenario may be more typical than believed, and perhaps the most effective situation leading to enhanced spreading. A rationale for the pervasive variability and hysteresis observed during high temperature wetting also emerges.

  17. Oak Ridge Reservation environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, V.A.; Wilson, A.R. (eds.)

    1990-10-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1989. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1989 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1. 16 figs., 194 tabs.

  18. Oak Ridge Reservation Environmental report for 1990

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.R. (ed.)

    1991-09-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1990. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1990 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1.

  19. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete.

  20. Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    The US Department of Energy (DOE) proposes to construct and maintain additional storage capacity at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, for liquid low-level radioactive waste (LLLW). New capacity would be provided by a facility partitioned into six individual tank vaults containing one 100,000 gallon LLLW storage tank each. The storage tanks would be located within the existing Melton Valley Storage Tank (MVST) facility. This action would require the extension of a potable water line approximately one mile from the High Flux Isotope Reactor (HFIR) area to the proposed site to provide the necessary potable water for the facility including fire protection. Alternatives considered include no-action, cease generation, storage at other ORR storage facilities, source treatment, pretreatment, and storage at other DOE facilities.

  1. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  2. Tiger team assessment of the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1990-02-01

    This document contains findings identified during the Tiger Team Compliance Assessment of the Department of Energy's (DOE's) Y-12 Plant in Oak Ridge, Tennessee. The Y-12 Plant Tiger Team Compliance Assessment is comprehensive in scope. It covers the Environmental, Safety, and Health (including Occupational Safety and Health Administration (OSHA) compliance), and Management areas and determines the plant's compliance with applicable federal (including DOE), state, and local regulations and requirements. 4 figs., 12 tabs.

  3. HPC Colony II Consolidated Annual Report: July-2010 to June-2011

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Terry R [ORNL

    2011-06-01

    This report provides a brief progress synopsis of the HPC Colony II project for the period of July 2010 to June 2011. HPC Colony II is a 36-month project and this report covers project months 10 through 21. It includes a consolidated view of all partners (Oak Ridge National Laboratory, IBM, and the University of Illinois at Urbana-Champaign) as well as detail for Oak Ridge. Highlights are noted and fund status data (burn rates) are provided.

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

    Science.gov (United States)

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

    2014-12-01

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

  5. Locomotory transition from water to sand and its effects on undulatory kinematics in sand lances (Ammodytidae).

    Science.gov (United States)

    Gidmark, Nicholas J; Strother, James A; Horton, Jaquan M; Summers, Adam P; Brainerd, Elizabeth L

    2011-02-15

    Sand lances, fishes in the genus Ammodytes, exhibit a peculiar burrowing behavior in which they appear to swim rapidly into the substrate. They use posteriorly propagated undulations of the body to move in both water, a Newtonian fluid, and in sand, a non-Newtonian, granular substrate. In typical aquatic limbless locomotion, undulations of the body push against water, which flows because it is incapable of supporting the static stresses exerted by the animal, thus the undulations move in world space (slipping wave locomotion). In typical terrestrial limbless locomotion, these undulations push against substrate irregularities and move relatively little in world space (non-slipping wave locomotion). We used standard and X-ray video to determine the roles of slipping wave and non-slipping wave locomotion during burrowing in sand lances. We find that sand lances in water use slipping wave locomotion, similar to most aquatic undulators, but switch to non-slipping waves once they burrow. We identify a progression of three stages in the burrowing process: first, aquatic undulations similar to typical anguilliform locomotion (but without head yaw) push the head into the sand; second, more pronounced undulations of the aquatic portion of the body push most of the animal below ground; third, the remaining above-ground portion of the body ceases undulation and the subterranean portion takes over, transitioning to non-slipping wave locomotion. We find no evidence that sand lances use their body motions to fluidize the sand. Instead, as soon as enough of the body is underground, they undergo a kinematic shift and locomote like terrestrial limbless vertebrates.

  6. Tectonics of the Ninetyeast Ridge derived from spreading records in adjacent oceanic basins and age constraints of the ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Abraham, H.; Sager, W.W.; Pringle, M.S.; Frey, F.; Rao, D.G.; Levchenko, O.V.

    and magnetic anomaly ages implies that the hot spot first emplaced NER volcanoes on the Indian plate at a distance from the Wharton Ridge, but as the northward drifting spreading ridge approached the hot spot, the two interacted, keeping later NER volcanism...

  7. 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.

  8. 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.

  9. Three dimensional fabric evolution of sheared sand

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Alsidqi; Alshibli, Khalid (UWA)

    2012-10-24

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

  10. Rational approach to anisotropy of sand

    Science.gov (United States)

    Wu, Wei

    1998-11-01

    The paper presents a constitutive model for the three-dimensional deformation-strength behaviour of inherently anisotropic sand. Based on non-linear tensorial functions, the model is developed without recourse to the concepts in plasticity theory such as yield surface and plastic potential. Benefited from the fact that no decomposition of strain into elastic and plastic parts is assumed, a unified treatment of anisotropic behaviour of deformation and strength is achieved. Anisotropy is characterized by a vector normal to the bedding plane. The extension of the constitutive model is furnished by incorporating the vector under consideration of the principle of objectivity and the condition of material symmetry. Distinct features of the model are its elegant formulation and its simple structure involving few material parameters. Model performance and comparison with experiments show that the model is capable of capturing the salient behaviour of anisotropic sand.

  11. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    Global applications of pesticides in agricultural production have led to the detection of trace amounts of pesticides in groundwater resources in levels exceeding the EU threshold limit for drinking water of 0.1 µg L-1. Pesticide-polluted groundwater may be remediated by inoculating waterworks sand...... filters with specific degrading bacteria. However, degradation efficiency is often hampered by poor adhesion and a lack of sustained catabolic activity of the introduced bacteria. The overall objective of this thesis was to investigate the significance of selected bacterial surface properties...... 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...

  12. Site descriptions of environmental restoration units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, P.L.; Legeay, A.J.; Pesce, D.S.; Stanley, A.M.

    1995-11-01

    This report, Site Descriptions of Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee, is being prepared to assimilate information on sites included in the Environmental Restoration (ER) Program of the K-25 Site, one of three major installations on the Oak Ridge Reservation (ORR) built during World War III as part of the Manhattan Project. The information included in this report will be used to establish program priorities so that resources allotted to the K-25 ER Program can be best used to decrease any risk to humans or the environment, and to determine the sequence in which any remedial activities should be conducted. This document will be updated periodically in both paper and Internet versions. Units within this report are described in individual data sheets arranged alphanumerically. Each data sheet includes entries on project status, unit location, dimensions and capacity, dates operated, present function, lifecycle operation, waste characteristics, site status, media of concern, comments, and references. Each data sheet is accompanied by a photograph of the unit, and each unit is located on one of 13 area maps. These areas, along with the sub-area, unit, and sub-unit breakdowns within them, are outlined in Appendix A. Appendix B is a summary of information on remote aerial sensing and its applicability to the ER program.

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

    Science.gov (United States)

    Jiang, Hong; Huang, Ning; Zhu, Yuanjian

    2014-12-01

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

  14. Natural Areas Analysis and Evaluation: Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Baranski, Micahel J [self

    2009-11-01

    EXECUTIVE SUMMARY The Oak Ridge Reservation, encompassing 33,639 acres in the Valley and Ridge Physiographic Province of East Tennessee, has long been known for its unfragmented forests and high biodiversity. Many areas on the Reservation have been recognized as important natural areas, but no comprehensive treatment has been performed to evaluate the relative significance and importance of these areas compared to each other. The present study was conducted to develop a set of guidelines for evaluating the natural value of specific areas, to evaluate all the terrestrial areas that are currently delineated, and to rank all areas according to their relative biodiversity importance. All available data, reports and site-specific information relevant to Reservation lands, including Tennessee Division of Natural Areas database information, were evaluated and field work was conducted. Methodologies and criteria for assessment and evaluation of areas were developed; categories of criteria were devised; and a ranking system for evaluation of natural areas was produced. There were 70 areas evaluated during the study. The system is flexible, dynamic and easily revised to reflect updated and new information and interpretations. Eight categories of evaluation factors were established and used to characterize each site. These were the following: size of area, number or status taxa present, number of Endangered and Threatened taxa present, rarity of the Endangered and Threatened taxa on the Reservation, community diversity, site integrity and quality, disturbance and threat levels, and other significant features and factors. Each category generally consisted of a 5-point ranking scale from 0-4, allowing for a possible composite score of 32, with higher ranked, more important, sites attaining higher scores. Highly ranked sites are representative of regional natural diversity; contain outstanding natural features, communities or geology and/or very rare taxa or other elements; are

  15. 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.

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

    Science.gov (United States)

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

    2014-05-01

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

  17. A transport-rate model of wind-blown sand

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sand transport by wind plays an important role in environmental problems.Formulating the sand-transport rate model has been of continuing significance,because the majority of the existing models relate sand-transport rate to the wind-shear velocity.However,the wind-shear velocity readapted to blown sand is difficult to determine from the measured wind profiles when sand movement occurs,especially at high wind velocity.Detailed wind tunnel tests were carried out to reformulate the sand-transport rate model,followed by attempts to relate sand-transport rate to parameters of wind velocity,threshold shear-velocity,and grain size.Finally,we validated the model based on the data from field observations.

  18. Athabasca oil sands development : lessening the footprint

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, R. [Alberta Environment, AB (Canada)

    2005-07-01

    This presentation provided an overview of the oil sands development footprint from the perspectives of industry, environmental associations and regulatory agencies. A map of regional oil sands developments was presented along with details of land disturbance to date. Industry strategies for lessening the impact of land disturbance include compact space-efficient mining operations; good planning; and effective, progressive reclamation. A closure and reclamation model was presented, along with key reclamation challenges such as overburden. Issues concerning tailings sands were examined. Details of Syncrude's closure vision were presented, including details of the Mildred Lake site. Details of the Fort McMurray Environmental Association were presented as well as various regional multi-stakeholder initiatives. A background of Syncrude and Suncor operations was presented as well as development projection forecasts. Impacts to the Boreal region were examined. Details of land reclamation by Syncrude were provided, as well as a chart of cumulative disturbances. It was noted that recent applications have indicated numerous reclamation uncertainties, including long-term performance of landforms and the feasibility of developing trafficable tailings landforms. It was suggested that the ecosystem dynamics of the Boreal are poorly understood. Exacerbating factors include the degraded state of soils; viability of end pit lakes; and climate change. It was suggested that operators are proposing to deal with landscape and technology uncertainty using adaptive management strategies. Government responses to the oil sand development footprint include the encouragement of more research into tailings technologies, end pit lake viability and reclamation; and the identification of regional landscape ecological thresholds by the Cumulative Environmental Management Association (CEMA). It was concluded that uncertainty needs to be addressed via a variety of policy and management options

  19. Pullout capacity of batter pile in sand.

    Science.gov (United States)

    Nazir, Ashraf; Nasr, Ahmed

    2013-03-01

    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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. PHYSICAL MODELING OF ODOMETRIC COMPRESSION OF SAND

    Directory of Open Access Journals (Sweden)

    Lyashenko P. A.

    2016-10-01

    Full Text Available The odometric compression of sand with constant rate of loading (CRL or constant rate of deformation (CRD and continuous registration of the corresponding reaction allows to identify the effect of stepwise changes of deformation (at the CRL and the power reaction (at the CRD. Physical modeling of compression on the sandy model showed the same effect. The physical model was made of fine sand with marks, mimicking large inclusions. Compression of the soil at the CRD was uneven, stepwise, and the strain rate of the upper boundary of the sandy model changed cyclically. Maximum amplitudes of cycles passed through a maximum. Inside of the sand model, the uneven strain resulted in the mutual displacement of the adjacent parts located at the same depth. The growth of external pressure, the marks showed an increase or decrease in displacement and even move opposite to the direction of movement (settlement the upper boundary of the model ‒ "floating" of marks. Marks, at different depths, got at the same time different movements, including mutually contradictory. The mark settlements sudden growth when the sufficiently large pressure. These increments in settlements remained until the end of loading decreasing with depth. They were a confirmation of the hypothesis about the total destruction of the soil sample at a pressure of "structural strength". The hypothesis of the "floating" reason based on the obvious assumption that the marks are moved together with the surrounding sand. The explanation of the effect of "floating" is supported by the fact that the value of "floating" the more, the greater the depth

  6. Sand Ripple Dynamics on the Inner Shelf

    Science.gov (United States)

    2006-01-01

    Sand Ripple Dynamics on the Inner Shelf Donald N. Slinn Department of Civil and Coastal Engineering, University of Florida Gainesville, FL 32611...Florida,Department of Civil and Coastal Engineering,Gainesville,FL,32611-6590 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY...2002. 452: p. 1-24. Acrivos, A., Shear-Induced Particle Diffusion in Concentrated Suspensions of Noncolloidal Particles. Journal of Rheology , 1995

  7. Drawing a Line in the Sand

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    An Inner Mongolian woman takes on the desert and converts extensive arid regions into arable land by Ni Yanshuo CONVERTING vast tracks of desert into arable land is no easy task, even using the most advanced technology.Yet a woman who hails from north China’s Inner Mongolia Autonomous Region met this challenge head on.Using the helping hands of other determined women,she has made remarkable progress in pushing back the sands of time.

  8. 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...... 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....

  9. Waste foundry sand: Environmental implication and characterization

    Directory of Open Access Journals (Sweden)

    Gabriela Penkaitis

    2012-12-01

    Full Text Available This paper presents the results of analyses using Scanning Electron Microscopy in field samples of waste foundry sand, as well as the results of granulometric, chemical and groundwater analyses. Field data allowed to characterize waste foundry sand and showed that there are elevated concentrations of metals in the groundwater (iron, manganese, boron and selenium, in addition to other potentially toxic elements (chromium, copper, cobalt, nickel, zinc, aluminum, iron, manganese, which are present in the waste and are considered not hazardous by current standards. Even if these elements are not considered hazardous, their concentrations above the permissible limit compromise the environmental quality of the site, posing risks to the local population, since they work in agriculture and use groundwater. Two different types of waste foundry sands were identified using granulometric analyses. Electron microscopy showed features related to morphological, chemical and mineralogical characteristics of grains that make up the waste. Quartz was the dominant mineral. Waste foundry sand is composed of two types of grains: a rounded grain with almost no incrustations formed during alloy production, and a second type of grain, which is not rounded, has incrustations, and always has several metals derived from alloys and associated with these incrustations. Chemical elements detected in groundwater with concentrations above the limits established by the regulatory bodies were found in wells located in the landfill area. Most of these elements show higher concentrations downstream, some of them with concentrations above the regulatory limit, and others show an increase in concentration upstream, indicating that the landfill may be impacting the local environment.

  10. American Las Vegas Sands Corp. Visiting Beijing

    Institute of Scientific and Technical Information of China (English)

    Li Yinghong; Liu Jinliang

    2006-01-01

    @@ On August 29, Wan Jifei, Chairman of CCPIT, meets the visiting delegation led by Sheldon G. Adelson,Chairman of the Board and principal owner of Las Vegas Sands Corp. in CCPIT. Zhao Zhenge, Vice Director of International Connection Department of CCPIT, Luo Guoxiong from Beijing China Exhibition Investment Company, Xu Jingyi, Assistant Director of American and Oceanian Affairs Division of CCPIT, also attended the meeting.

  11. Oil sands mining water use and management

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Long, D.; Fitch, M. [Golder Associates Ltd., Calgary, AB (Canada)

    2010-07-01

    There are currently 4 bitumen mining operations operating along the Athabasca River in northern Alberta. This paper presented details of the water licences, historical water use, present water use, and future plans for water management in relation to oil sands mining operations. The study was based on work currently conducted for the Oil Sands Developers Group (OSDG) and Canadian Association of Petroleum Producers (CAPP), as well as on mine site water balance analyses for proposed mines in the region. Typical mine site water balances were discussed, and water use rates for the mining operations were reviewed. The new Athabasca River water management framework may require that mines provide additional water storage or delayed reclamation of mine areas in order to offset water losses during winter low-flow periods. New regulations may also reduce the requirement for make-up water. The study also noted that release criteria are still being developed for on-site water within closed-loop mine operations. The oil sands industry will need to balance various factors related to water use in the future. 5 refs., 3 figs.

  12. DYNAMIC EFFECTIVE SHEAR STRENGTH OF SATURATED SAND

    Institute of Scientific and Technical Information of China (English)

    邵生俊; 谢定义

    2002-01-01

    The dynamic effective shear strength of saturated sand under cyclic loading is discussed in this paper. The discussion includes the transient time dependency behaviors based on the analysis of the results obtained in conventional cyclic triaxial tests and cyclic torsional shear triaxial tests. It has been found that the dynamic effective shear strength is composed of effective frictional resistance and viscous resistance, which are characterized by the strain rate dependent feature of strength magnitude, the coupling of consolidation stress with cyclic stress and the dependency of time needed to make the soil strength suffciently mobilized, and can also be expressed by the extended Mohr-Coulomb's law. The two strength parameters of the dynamic effective internal frictional angle φd and the dynamic viscosity coefficient η are determined. The former is unvaried for different number of cyclic loading, dynamic stress form and consolidation stress ratio. And the later is unvaried for the different dynamic shear strain rate γt developed during the sand liquefaction, but increases with the increase of initial density of sand. The generalization of dynamic effective stress strength criterion in the 3-dimensional effective stress space is studied in detail for the purpose of its practical use.

  13. Collaborative production management for oil sands operations

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Andrew [Matrikon (Canada)

    2011-07-01

    This paper gives an overview of the collaborative production management of oil sands operations. Some characteristics of oil sands operations include oil treatment, hydro treating, diluent addition, logistics, and environmental impact assessments. Some of the business challenges include regulatory uncertainty, a fluid workforce and a technology still in the process of being developed. Improvement is only possible when process is assessed and measured; hence, production data management is very important. Production data measurements encompass such areas as planning, documentation and transactions. Regulatory data reporting is represented using a flow chart. The concepts of business application architecture and functional reference modeling are also explained. Benchmarking plays a vital role, some aspects of which would be technology, automation and integration. Certain advantages of timely assessment are increased production, equity, and goodwill as well as reduction in costs, risk, and capital requirements. The relevance and importance of collaboration, awareness of web technology and aggregate information are also explained. From the study, it can be concluded that the key to overall improvement in the oil sands industry will be improved production management.

  14. Recycled sand in lime-based mortars.

    Science.gov (United States)

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

    2014-12-01

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

  15. 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...... in the succeeding sections. Finally the test results are briefly summarised and a relationship between void ratio l and permeability is established....

  16. The bituminous sands : a Canadian mirage?

    Energy Technology Data Exchange (ETDEWEB)

    Rousse, D.R. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees; Nasr, G.J. [Lebanese Univ., Roumieh (Lebanon). Faculty of Engineering; Turcotte, S.F. [Quebec Univ., Montreal, PQ (Canada). Centre d' Etudes Internationales et Mondialisation; Salah, N.B. [Ecole Superieure des Sciences et Techniques De Tunis, Tunis (Tunisia). LMMP

    2009-07-01

    This paper examined the controversy about the potential role of a significant increase in Canadian oil sands production in order to bridge the upcoming gap between the world's increasing energy demand and the total recoverable oil supply. The paper presented the actual potential of different scenarios and considered the prediction cost forecasts. A brief overview of environmental impacts and the real return on investments were also provided. Environmental impacts that were considered included land degradation; water contamination; ecosystem damage; and air pollution. Nuclear energy was also presented as a possible solution. The paper demonstrated that even in a very optimistic scenario, Canada's oil sands accelerated production has a negligible effect on the aforementioned gap, has a considerable impact on environment that has yet to be accounted for. Energy ratios that were presented included energy return on energy investment; energy available on energy used; and energy payback. It was concluded that enhanced recovery techniques are clearly needed for future sustainable exploitation of these bituminous sands. 32 refs., 1 fig.

  17. Summertime View of North Polar Sand Dunes

    Science.gov (United States)

    2006-01-01

    10 October 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of dunes in one of the several north polar dune fields. The bright surfaces adjacent to some of the dunes are patches of frost. These dunes spend much of the autumn, winter, and spring seasons covered with carbon dioxide frost. Only in late spring and in summer are the dark windblown sands fully exposed. Over the course of the 9+ years of the MGS mission, the MOC team has sought evidence that sand dunes may be migrating downwind over time. However, no clear examples of the movement of a whole dune have been identified. On Earth, such movement is typically detectable in air photos of the smallest active dunes over periods of a few years. Owing to the fact that the north polar dunes spend much of each martian year under a cover of frost, perhaps these move much more slowly than their frost-free, terrestrial counterparts. The sand may also be somewhat cemented by ice or minerals, likewise preventing vigorous dune migration in the present environment. This view covers an area approximately 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left. The dunes are located near 79.8oN, 127.1oW, and the picture was acquired on 11 September 2006.

  18. The sedimentary structure of linear sand dunes

    Science.gov (United States)

    Bristow; Bailey; Lancaster

    2000-07-06

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

  19. Microbial pesticide removal in rapid sand filters for drinking water treatment – Potential and kinetics

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    or metabolites mecoprop (MCPP), bentazone, glyphosate and p-nitrophenol were applied in initial concentrations of 0.03–2.4 μg/L. In all the investigated waterworks the concentration of pesticides in the water decreased – MCPP decreased to 42–85%, bentazone to 15–35%, glyphosate to 7–14% and p-nitrophenol 1......–3% – from the initial concentration over a period of 6–13 days. Mineralisation of three out of four investigated pesticides was observed at Sjælsø waterworks Plant II – up to 43% of the initial glyphosate was mineralised within six days. At Sjælsø waterworks Plant II the removal kinetics of bentazone......Filter sand samples, taken from aerobic rapid sand filters used for treating groundwater at three Danish waterworks, were investigated for their pesticide removal potential and to assess the kinetics of the removal process. Microcosms were set up with filter sand, treated water, and the pesticides...

  20. Building the Ridge on Iapetus: Impacts Can Be Constructive!

    Science.gov (United States)

    Stickle, A. M.; Roberts, J. H.

    2016-12-01

    Iapetus has a continuous ridge along the equator that extends for more than 110° in longitude. Parts of the ridge rise as much as 20 km above the surrounding terrains. Earlier Voyager observations revealed mountains on the anti-Saturn side of Iapetus with as much as 25-km in relief, extending from 180°W-220°W which may be a continuation of this ridge. Most models for the formation of this enigmatic ridge are endogenic, generally requiring the formation of a fast-spinning Iapetus with an oblate shape due to the rotation speed. Though abundant, many of these models require specific scenarios and have constraining parameters in order to generate a ridge comparable to what is seen today. An exogenic formation mechanism has also been proposed, that the ridge represents the remains of an early ring system around Iapetus that collapsed onto the surface. Thus far, none of the models have conclusively identified the origin of the ridge. We assume an exogenic origin for the ridge, derived from a collapsing disk of debris around Iapetus, without invoking any specific model for the generation of the debris disk, to determine whether it is possible to generate a ridge of the size and shape as observed. Here, the impact of the collapsing debris is simulated using the CTH hydrocode. Pi-scaling calculations suggest that extremely oblique impact angles (1-10°) are needed to add to ridge topography. These extreme impact angles severely reduce the cratering efficiency compared to a vertical impact, adding material rather than eroding it during crater formation. Furthermore, material is likely to be excavated at low angles, enhancing downrange accumulation. Multiple impacts from debris pieces will heighten this effect. Because infalling debris is predicted to impact at extremely low angles, both of these effects might have contributed to ridge formation on Iapetus. The extreme grazing angles of the impacts modeled here decouple much of the projectile energy, and impact heating of

  1. Shaly sand formation evaluation in tight gas sands using electrochemical potential measurements

    Science.gov (United States)

    Sharma, M. M.; Jin, M.

    1991-08-01

    Equations are developed that directly relate the shaly conductivity to the electrochemical (membrane) potential (EP). The model is applied to both fully and partially saturated sands. The relationship between the resistivity index and the water saturation is also expressed in terms of a single membrane potential measurement. The Ep measured at different salinities are compared with model prediction using a single membrane potential measurement. Sigma (sub 0) versus Sigma (sub w) curves are then generated using the model equations and compared with measured curves. Experimental results are presented for electrochemical potential measurement made in the lab on 50 tight gs sand samples. It is shown that the measurements can be correlated with CEC although the CEC measured by grinding up the samples was always higher than that estimated from Ep measurements. The Ep measurements are combined with the equations for partial saturation developed in the report to obtain water saturations in a tight gas sand well. Through the example it is shown that it is possible to determine the water saturation in Shaly sands from one membrane potential measurement at a known salinity together with a set of resistivity logs. The results clearly demonstrate the applicability of the method as a practical procedure for Shaly sand information evaluation.

  2. ENVIRONMENTAL BASELINE SURVEY REPORT FOR WEST BLACK OAK RIDGE, EAST BLACK OAK RIDGE, MCKINNEY RIDGE, WEST PINE RIDGE, AND PARCEL 21D IN THE VICINITY OF THE EAST TENNESSEE TECHNOLOGY PARK, OAK RIDGE, TENNESSEE

    Energy Technology Data Exchange (ETDEWEB)

    David A. King

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy’s (DOE’s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. The goal is to obtain all media no-further-investigation (NFI) determinations for the subject parcels considering existing soils. To augment the existing soils-only NFI determinations, samples of groundwater, surface water, soil, and sediment were collected to support all media NFI decisions. The only updates presented here are those that were made after the original issuance of the NFI documents. In the subject parcel where the soils NFI determination was not completed for approval (Parcel 21d), the full process has been performed to address the soils as well. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only NFI

  3. Propagating buoyant mantle upwelling on the Reykjanes Ridge

    Science.gov (United States)

    Martinez, Fernando; Hey, Richard

    2017-01-01

    Crustal features of the Reykjanes Ridge have been attributed to mantle plume flow radiating outward from the Iceland hotspot. This model requires very rapid mantle upwelling and a "rheological boundary" at the solidus to deflect plume material laterally and prevent extreme melting above the plume stem. Here we propose an alternative explanation in which shallow buoyant mantle upwelling instabilities propagate along axis to form the crustal features of the ridge and flanks. As only the locus of buoyant upwelling propagates this mechanism removes the need for rapid mantle plume flow. Based on new geophysical mapping we show that a persistent sub-axial low viscosity channel supporting buoyant mantle upwelling can explain the current oblique geometry of the ridge as a reestablishment of its original configuration following an abrupt change in opening direction. This mechanism further explains the replacement of ridge-orthogonal crustal segmentation with V-shaped crustal ridges and troughs. Our findings indicate that crustal features of the Reykjanes Ridge and flanks are formed by shallow buoyant mantle instabilities, fundamentally like at other slow spreading ridges, and need not reflect deep mantle plume flow.

  4. Aerodynamic roughness length related to non-aggregated tillage ridges

    Directory of Open Access Journals (Sweden)

    M. Kardous

    2005-11-01

    Full Text Available Wind erosion in agricultural soils is dependent, in part, on the aerodynamic roughness length (z0 produced by tillage ridges. Although previous studies have related z0 to ridge characteristics (ridge height (RH and spacing (RS, these relationships have not been tested for tillage ridges observed in the North African agricultural fields. In these regions, due to climate and soil conditions, small plowing tools are largely used. Most of these tools produce non-aggregated and closely-spaced small ridges. Thus, experiments were conducted in a 7-m long wind tunnel to measure z0 for 11 ridge types covering the range of geometric characteristics frequently observed in south Tunisia. Experimental results suggest that RH2/RS is the first order parameter controlling z0. A strong relationship between z0 and RH2/RS is proposed for a wide range of ridge characteristics.

  5. Use of ridge points in partial fingerprint matching

    Science.gov (United States)

    Fang, Gang; Srihari, Sargur N.; Srinivasan, Harish; Phatak, Prasad

    2007-04-01

    Matching of partial fingerprints has important applications in both biometrics and forensics. It is well-known that the accuracy of minutiae-based matching algorithms dramatically decrease as the number of available minutiae decreases. When singular structures such as core and delta are unavailable, general ridges can be utilized. Some existing highly accurate minutiae matchers do use local ridge similarity for fingerprint alignment. However, ridges cover relatively larger regions, and therefore ridge similarity models are sensitive to non-linear deformation. An algorithm is proposed here to utilize ridges more effectively- by utilizing representative ridge points. These points are represented similar to minutiae and used together with minutiae in existing minutiae matchers with simple modification. Algorithm effectiveness is demonstrated using both full and partial fingerprints. The performance is compared against two minutiae-only matchers (Bozorth and k-minutiae). Effectiveness with full fingerprint matching is demonstrated using the four databases of FVC2002- where the error rate decreases by 0.2-0.7% using the best matching algorithm. The effectiveness is more significant in the case of partial fingerprint matching- which is demonstrated with sixty partial fingerprint databases generated from FVC2002 (with five levels of numbers of minutiae available). When only 15 minutiae are available the error rate decreases 5-7.5%. Thus the method, which involves selecting representative ridge points, minutiae matcher modification, and a group of minutiae matchers, demonstrates improved performance on full and especially partial fingerprint matching.

  6. Hydrodynamic role of longitudinal ridges in a leatherback turtle swimming

    Science.gov (United States)

    Bang, Kyeongtae; Kim, Jooha; Lee, Sang-Im; Choi, Haecheon

    2015-11-01

    The leatherback sea turtle (Dermochelys coriacea), the fastest swimmer and the deepest diver among marine turtles, has five longitudinal ridges on its carapace. These ridges are the most remarkable morphological features distinguished from other marine turtles. To investigate the hydrodynamic role of these ridges in the leatherback turtle swimming, we model a carapace with and without ridges by using three dimensional surface data of a stuffed leatherback turtle in the National Science Museum, Korea. The experiment is conducted in a wind tunnel in the ranges of the real leatherback turtle's Reynolds number (Re) and angle of attack (α). The longitudinal ridges function differently according to the flow condition (i.e. Re and α). At low Re and negative α that represent the swimming condition of hatchlings and juveniles, the ridges significantly decrease the drag by generating streamwise vortices and delaying the main separation. On the other hand, at high Re and positive α that represent the swimming condition of adults, the ridges suppress the laminar separation bubble near the front part by generating streamwise vortices and enhance the lift and lift-to-drag ratio. Supported by the NRF program (2011-0028032).

  7. Remote Sensing and Spectral Characteristics of Desert Sand from Qatar Peninsula, Arabian/Persian Gulf

    Directory of Open Access Journals (Sweden)

    Fares Howari

    2009-11-01

    Full Text Available Remote sensing data can provide valuable information about the surface expression of regional geomorphologic and geological features of arid regions. In the present study, several processing techniques were applied to reveal such in the Qatar Peninsula. Those included preprocessing for radiometric and geometric correction, various enhancement methods, classification, accuracy assessment, contrast stretching, color composition, and principal component analyses. Those were coupled with field groundtruthing and lab analyses. Field groundtruthing included one hundred and forty measurements of spectral reflectance for various sediment exposures representing main sand types in the four studied parts in Qatar. Lab investigations included grain size analysis, X-ray diffraction and laboratory measurements of spectral reflectance. During the course of this study three sand types have been identified: (i sabkha-derived salt-rich, quartz sand, and (ii beach-derived calcareous sand and (iii aeolian dune quartz. Those areas are spectrally distinct in the VNIR, suggesting that VNIR spectral data can be used to discriminate them. The study found that the main limitation of the ground spectral reflectance study is the difficulty of covering large areas. The study also found that ground and laboratory spectral radiance are generally higher in reflectance than those of Landsat TM. This is due to several factors such as atmospheric conditions, the low altitude or different scales. Whereas for areas with huge size of dune sand, the Landsat TM spectral has higher reflectance than those from field and laboratory. The study observed that there is a good correspondence or correlation of the wavelengths maximum sensitivity between the three spectral measurements i.e lab, field and space-borne measurements.

  8. Characteristics of Hydrothermal Mineralization in Ultraslow Spreading Ridges

    Science.gov (United States)

    Zhou, H.; Yang, Q.; Ji, F.; Dick, H. J.

    2014-12-01

    Hydrothermal activity is a major component of the processes that shape the composition and structure of the ocean crust, providing a major pathway for the exchange of heat and elements between the Earth's crust and oceans, and a locus for intense biological activity on the seafloor and underlying crust. In other hand, the structure and composition of hydrothermal systems are the result of complex interactions between heat sources, fluids, wall rocks, tectonic controls and even biological processes. Ultraslow spreading ridges, including the Southwest Indian Ridge, the Gakkel Ridge, are most remarkable end member in plate-boundary structures (Dick et al., 2003), featured with extensive tectonic amagmatic spreading and frequent exposure of peridotite and gabbro. With intensive surveys in last decades, it is suggested that ultraslow ridges are several times more effective than faster-spreading ridges in sustaining hydrothermal activities. This increased efficiency could attributed to deep mining of heat and even exothermic serpentinisation (Baker et al., 2004). Distinct from in faster spreading ridges, one characteristics of hydrothermal mineralization on seafloor in ultraslow spreading ridges, including the active Dragon Flag hydrothermal field at 49.6 degree of the Southwest Indian Ridge, is abundant and pervasive distribution of lower temperature precipitated minerals ( such as Fe-silica or silica, Mn (Fe) oxides, sepiolite, pyrite, marcasite etc. ) in hydrothermal fields. Structures formed by lower temperature activities in active and dead hydrothermal fields are also obviously. High temperature precipitated minerals such as chalcopyrite etc. are rare or very limited in hydrothermal chimneys. Distribution of diverse low temperature hydrothermal activities is consistence with the deep heating mechanisms and hydrothermal circulations in the complex background of ultraslow spreading tectonics. Meanwhile, deeper and larger mineralization at certain locations along the

  9. Microbial degradation of pesticides in rapid sand filters for treatment of drinking water

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    to remove pesticides from the water phase and pesticides are detected in 24% of the active Danish waterworks wells. This study aimed at investigating the potential of microbial pesticide removal in rapid sand filters for drinking water treatment. Removal of the pesticides MCPP, bentazone, glyphosate...... of pesticides in the water decreased – MCPP decreased to 42-85%, bentazone to 15-35%, glyphosate to 7-14% and p-nitrophenol 1-3% – from the initial concentration over a period of 6-13 days. The largest microbial removal was observed at Sjælsø waterworks Plant II, where the pesticides were partially mineralised......In Denmark drinking water supply is based on groundwater which is treated by aeration followed by filtration in rapid sand filters. Unfortunately pesticide contamination of the groundwater poses a threat to the water supply, since the simple treatment process at the waterworks is not considered...

  10. SRTM Stereo Pair: Wheeler Ridge, California

    Science.gov (United States)

    2000-01-01

    Wheeler Ridge and vicinity, California, is a site of major tectonic activity, both historically and over recent geologic time. The epicenter of the 7.5 magnitude Kern County earthquake occurred here on July 21,1952, and numerous geologic and topographic features indicate rapid geologic processes. The ridge itself (upper-right center) is a geologic fold that is growing out of the southern San Joaquin Valley. A prominent 'wind gap,' now used for passage of the California aquaduct (with the aid of a pumping station), is evidence that the ridge grew faster than tranversing streams could erode down. Nearby abrupt and/or landslid mountain fronts similarly indicate a vigorous tectonic setting here, just north of the San Andreas fault. The Interstate 5 freeway can be seen crossing agricultural fields on the right and entering the very rugged and steep Grapevine Canyon toward the bottom.This stereoscopic image was generated by draping a Landsat satellite image over a preliminary Shuttle Radar Topography Mission (SRTM) elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994

  11. STUDY ON HOT SAND COOLING EQUIPMENT WITH DAMPING SAND CASCADE AND VERTICAL SPOUTED-FLUIDIZED BED

    Institute of Scientific and Technical Information of China (English)

    L.C. Wang; F. Wang; X.H. You

    2005-01-01

    A new kind of hot sand cooling equipment with vertical spouted-fluidized bed is developed in this paper. It is similar to the traditional horizontal vibrating fluidized boiling cooler in principle but different from it in structure. The processing principle of the cooler is analyzed. The influence of main structural and processing parameters on the cooling effect and its mechanism are researched. Other characteristics of the cooler are discussed also. Experiment results show that the cooling efficiency η is equal to or larger than 83%, the temperature of output sand is less than 40℃ with the temperature of input sand is about between 80 and 90℃, and the productivity is 5t/(h·m)

  12. Small Strain Behaviour and Viscous Effects on Sands and Sand-Clay Mixtures

    Science.gov (United States)

    Di Benedetto, H.

    This lecture paper focuses on sands and sand-clay mixtures behaviour in the small strain domain. Non viscous and viscous components are measured, identified and modelled within the framework of a 3 component model. Two precision prototype devices (triaxial and hollow cylinder) both equipped with piezoelectric sensors are used. Non viscous measured behaviour considering small quasi-static cycles and wave properties are compared with simulations obtained from 2 recently formulated anisotropic hypoelastic models (DBGS and DBGSP). Then, viscous experimental part is compared with the proposed model prediction. This model is an asymptotic expression, for the small strain domain, of a viscous evanescent formalism proposed by the author. It takes into account very peculiar behaviour observed on sands. Simulation for loadings with and without rotation of axes and for different rate histories, are quite satisfactory.

  13. Multiple linear regression with correlations among the predictor variables. Theory and computer algorithm ridge (FORTRAN 77)

    Science.gov (United States)

    van Gaans, P. F. M.; Vriend, S. P.

    Application of ridge regression in geoscience usually is a more appropriate technique than ordinary least-squares regression, especially in the situation of highly intercorrelated predictor variables. A FORTRAN 77 program RIDGE for ridged multiple linear regression is presented. The theory of linear regression and ridge regression is treated, to allow for a careful interpretation of the results and to understand the structure of the program. The program gives various parameters to evaluate the extent of multicollinearity within a given regression problem, such as the correlation matrix, multiple correlations among the predictors, variance inflation factors, eigenvalues, condition number, and the determinant of the predictors correlation matrix. The best method for the optimum choice of the ridge parameter with ridge regression has not been established yet. Estimates of the ridge bias, ridged variance inflation factors, estimates, and norms for the ridge parameter therefore are given as output by RIDGE and should complement inspection of the ridge traces. Application within the earth sciences is discussed.

  14. Solar cell with doped groove regions separated by ridges

    Energy Technology Data Exchange (ETDEWEB)

    Molesa, Steven Edward; Pass, Thomas; Kraft, Steve

    2017-01-31

    Solar cells with doped groove regions separated by ridges and methods of fabricating solar cells are described. In an example, a solar cell includes a substrate having a surface with a plurality of grooves and ridges. A first doped region of a first conductivity type is disposed in a first of the grooves. A second doped region of a second conductivity type, opposite the first conductivity type, is disposed in a second of the grooves. The first and second grooves are separated by one of the ridges.

  15. Fingerprint Ridge Frequency Estimation in the Fourier Domain

    Directory of Open Access Journals (Sweden)

    PATRICIU, V.-V.

    2014-11-01

    Full Text Available Ridge frequency is an important parameter in fingerprint image processing and feature extraction. However, ridge frequency estimation is a difficult task in noisy fingerprint images. A simple and accurate method for the computation of fingerprint ridge frequency using the Fourier spectrum is proposed. The results of the experiments conducted on a collection of fingerprints as well as a quantitative method for performance evaluation based on a Gabor filter-bank are presented. The proposed method is robust with respect to noise and reliable frequency images are obtained.

  16. 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.

  17. Alveolar ridge augmentation by connective tissue grafting using a pouch method and modified connective tissue technique: A prospective study

    Directory of Open Access Journals (Sweden)

    Ashish Agarwal

    2015-01-01

    Full Text Available Background: Localized alveolar ridge defect may create physiological and pathological problems. Developments in surgical techniques have made it simpler to change the configuration of a ridge to create a more aesthetic and more easily cleansable shape. The purpose of this study was to compare the efficacy of alveolar ridge augmentation using a subepithelial connective tissue graft in pouch and modified connective tissue graft technique. Materials and Methods: In this randomized, double blind, parallel and prospective study, 40 non-smoker individuals with 40 class III alveolar ridge defects in maxillary anterior were randomly divided in two groups. Group I received modified connective tissue graft, while group II were treated with subepithelial connective tissue graft in pouch technique. The defect size was measured in its horizontal and vertical dimension by utilizing a periodontal probe in a stone cast at base line, after 3 months, and 6 months post surgically. Analysis of variance and Bonferroni post-hoc test were used for statistical analysis. A two-tailed P < 0.05 was considered to be statistically significant. Results: Mean values in horizontal width after 6 months were 4.70 ± 0.87 mm, and 4.05 ± 0.89 mm for group I and II, respectively. Regarding vertical heights, obtained mean values were 4.75 ± 0.97 mm and 3.70 ± 0.92 mm for group I and group II, respectively. Conclusion: Within the limitations of this study, connective tissue graft proposed significantly more improvement as compare to connective tissue graft in pouch.

  18. Biostratigraphic evidence of dramatic Holocene uplift of Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific Ocean

    Directory of Open Access Journals (Sweden)

    P. Sepúlveda

    2014-09-01

    Full Text Available A study of the biostratigraphy and sedimentology of Holocene deposits on Robinson Crusoe Island (RCI on the Juan Fernández Ridge (JFR indicates that a~dramatic but localized uplift occurred since 8000 BP, at a rate of about 8.5 mm yr−1. In fact, supratidal flats and sand layers with marine gastropods (mostly Nerita sp. are now exposed ca. 70 m a.s.l., and covered by transitional dunes. The last volcanic activity on RCI occurred at ca. 0.8 Ma (active hotspot located 280 km further west and there is no sign of a compensating bulge that explains this uplift, isobaths of the sea floor instead suggesting general subsidence. However, modeling indicates that large-scale landslides followed by isostatic rebound are a viable explanation, partially reflected in the low-resolution bathymetry of the area.

  19. Biostratigraphic evidence of dramatic Holocene uplift of Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific Ocean

    Science.gov (United States)

    Sepúlveda, P.; Le Roux, J. P.; Lara, L. E.; Orozco, G.; Astudillo, V.

    2014-09-01

    A study of the biostratigraphy and sedimentology of Holocene deposits on Robinson Crusoe Island (RCI) on the Juan Fernández Ridge (JFR) indicates that a~dramatic but localized uplift occurred since 8000 BP, at a rate of about 8.5 mm yr-1. In fact, supratidal flats and sand layers with marine gastropods (mostly Nerita sp.) are now exposed ca. 70 m a.s.l., and covered by transitional dunes. The last volcanic activity on RCI occurred at ca. 0.8 Ma (active hotspot located 280 km further west) and there is no sign of a compensating bulge that explains this uplift, isobaths of the sea floor instead suggesting general subsidence. However, modeling indicates that large-scale landslides followed by isostatic rebound are a viable explanation, partially reflected in the low-resolution bathymetry of the area.

  20. A Hadronic Scenario for the Galactic Ridge

    CERN Document Server

    Gaggero, Daniele; Marinelli, Antonio; Urbano, Alfredo; Valli, Mauro

    2015-01-01

    Several observations from Fermi-LAT, up to few hundred GeV, and from H.E.S.S., up to $\\sim$ 10 TeV, reported an intense $\\gamma$-ray emission from the inner part of the Galactic plane. After the subtraction of point-like contributions, the remaining $\\gamma$-ray spectrum can provide important hints about the cosmic-ray (CR) population in that region. In particular, the diffuse spectrum measured by both Fermi-LAT and H.E.S.S. in the Galactic Ridge is significantly harder with respect to the rest of the Galaxy. These results were recently interpreted in terms of a comprehensive CR transport model which, adopting a spatial dependent diffusion coefficient and convective velocity, reproduces Fermi-LAT results on the whole sky as well as local CR spectra. We showed as that model predicts a significantly harder neutrino diffuse emission compared to conventional scenarios: The predicted signal is able to account for a significant fraction of the astrophysical flux measured by IceCube. In this contribution, we use the...