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Sample records for black sands

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

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    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.

  2. A microbiological study on Rashid black sand sediments, Egypt

    International Nuclear Information System (INIS)

    A microbiological study was carried out to isolate and identify radio-tolerant bacteria present in a high radiation background area namely Rashid. Rashid is considered as one of the natural high radiation background areas in the world. It has been observed as the highest background radiation station along the Egyptian Mediterranean coast. This is due to the presence of black sand deposits in its sediments. Black sand contains monazite and zirconium minerals, which have uranium and thorium inclusions in their mineral structures. Gamma absorbed dose rate from Rashid black sand reached 0.72 μGy/h. The microbiological examination of Rashid black sand revealed that, few bacterial strains, which are adapted and tolerant to this area were present. These strains were isolated, cultured and identified. Identification was carried out according to Bergey's manual. Confirmatory identification was carried out using API-20E kits for Enterobacteriacae and Gram-negative isolates. Other Gram-positive isolates were partially identified based on the morphological features of colonies and cells. The identified strains were found to be Pseudomonas fluorescens, P. putida, P. aeruginosa, Chryseomonas luteola, Xanthomonas maltophilia, Bacillus spp., Staphylococcus spp., and Micrococcus spp. The isolated bacteria could be used in several beneficial applications since other studies have proved that they can accumulate some radioactive materials. Further studies are needed to construct an efficient, inexpensive and feasible method to remove uranium and other metals from aqueous environment

  3. Isotope identification of Langkawi black sand using neutron activation analysis

    International Nuclear Information System (INIS)

    The Langkawi black sand has been analyzed using the method of neutron activation analysis (INAA). A total of 22 elements have been detected. Elements such as Mn, Cu, Cr, U and Th occur in high concentration. Prospect for future mineralization of these elements may be of economic interest. (author) 9 refs.; 1 tab

  4. The occurrence of high concentration of natural radionuclides in black sands of Malaysian beaches

    International Nuclear Information System (INIS)

    A study has been carried out to measure the concentration of natural radionuclides in black sands of Pasir Hitam (Langkawi Island) and Batu Feringhi (Penang Island) beaches of Malaysia. Black sand was found to be more concentrated in the beach of Pasir Hitam as compared to Batu Feringhi where it occurred only in patches. Sample analysis was conducted using a gamma spectrometer. This study showed that most of black sands of Pasir Hitam beach and some of Batu Feringhi beach contain high concentrations of natural radionuclides of the uranium and thorium series. The mean concentrations of radium-226 and radium-228 in black sand of Pasir Hitam beach were 1150 ± 800 Bq/kg and 500 ± 300 Bq/kg respectively. This is much higher than the normal beach sands with activity levels of 13 ± 7 Bq/kg Ra-226 and 11 ±6 Bq/kg Ra-228. The mean concentrations of 1350 ± 1300 Bq/kg Ra-226 and 805 ± 757 Bq/kg Ra-228 of two black sans samples of Batu Feringhi beach were similar to those of the Pasir Hitam. However, some black sand mixtures of Batu Feringhi contain normal level of natural radionuclides. In general, the activity levels of natural radionuclides in black sand of Malaysian beaches vary very significantly. (Author)

  5. Effect of part replacement of silica sand with carbon black on composite properties

    International Nuclear Information System (INIS)

    We have reported the properties of natural rubber filled with locally available materials (Adu et al 2000). The effect of local clay, limestone, silica sand and charcoal on the properties of natural rubber has been examined. Results have shown detrimental effects of silica sand on the properties of natural rubber compound. It has been reported that when silica is used as a part for part replacement of carbon black, the heat build up the composite decreased whilst tear resistance improved. Results revealed that within the filler content range used in the present work, the hardness, modulus, and tensile strength of composites loaded with silica sand/carbon black showed enhanced magnitude over the composite loaded singly with silica sand. These parameters generally increased with increasing carbon black content in the composite. New area of use requiring moderate level of tensile strength, hardness and modulus (as in soles of shoes and engine mounts) is therefore opened up for silica sand.(author)

  6. Characterization of Black Sand Mining Activities and Their Environmental Impacts in the Philippines Using Remote Sensing

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    Estelle Chaussard

    2016-01-01

    Full Text Available Magnetite is a type of iron ore and a valuable commodity that occurs naturally in black sand beaches in the Philippines. However, black sand mining often takes place illegally and increases the likelihood and magnitude of geohazards, such as land subsidence, which augments the exposure of local communities to sea level rise and to typhoon-related threats. Detection of black sand mining activities traditionally relies on word of mouth, while measurement of their environmental effects requires on-the-ground geological surveys, which are precise, but costly and limited in scope. Here we show that systematic analysis of remote sensing data provides an objective, reliable, safe, and cost-effective way to monitor black sand mining activities and their impacts. First, we show that optical satellite data can be used to identify legal and illegal mining sites and characterize the direct effect of mining on the landscape. Second, we demonstrate that Interferometric Synthetic Aperture Radar (InSAR can be used to evaluate the environmental impacts of black sand mining despite the small spatial extent of the activities. We detected a total of twenty black sand mining sites on Luzon Island and InSAR ALOS data reveal that out of the thirteen sites with coherence, nine experienced land subsidence at rates ranging from 1.5 to 5.7 cm/year during 2007–2011. The mean ground velocity map also highlights that the spatial extent of the subsiding areas is 10 to 100 times larger than the mining sites, likely associated with groundwater use or sediment redistribution. As a result of this subsidence, several coastal areas will be lowered to sea level elevation in a few decades and exposed to permanent flooding. This work demonstrates that remote sensing data are critical in monitoring the development of such activities and their environmental and societal impacts.

  7. Synthesis and characterization of black, red and yellow nanoparticles pigments from the iron sand

    International Nuclear Information System (INIS)

    The aim of this research is to synthesize nanoparticles of black pigment of Magnetite (Fe3O4), red pigment of hematite (α-Fe2O3), and yellow pigment of ghoetite (α-FeOOH) from the iron sand. The black pigment of Fe3O4 and the yellow pigment α-FeOOH nanoparticles were synthesized by coprecipitation method with variation of pH. Whereas, the red pigment Fe2O3 was synthesized by sintering Fe3O4 nanoparticles at temperature between 400 °C and 700 7°C for 1 hour. All the pigments has been characterized using X-ray diffraction and SEM. The XRD results shown that the particle size of the black pigmen Fe3O4, red pigment Fe3O4 and yellow pigment α-FeOOH are around 12, 32, and 30 nm respectively. The particle size of Fe2O3 nanoparticles increase by increasing sintering temperature from 32 nm at 400 °C to 39 nm at 700 °C. For yellow pigment of α-FeOOH, the particle size increase by increasing pH from 30,54 nm at pH 4 to 48,60 nm at pH 7. The SEM results shown that the morphologies of black, yellow and red pigments are aglomarated

  8. A win-win technique of stabilizing sand dune and purifying paper mill black-liquor

    Institute of Scientific and Technical Information of China (English)

    WANG Hanjie; Penning de Vries FRITS; JIN Yongcan

    2009-01-01

    The principle and technique were reported here to produce lignin-based sand stabilizing material (LSSM) using extracted lignin from black liquor of straw paper mills. Field tests by using LSSM to stabilize and green sand dunes started in 2002. The field experiment was carried out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant-friendly material and could be used in combination with seeding and planting of desert species. By the help of LSSM, the desert species (i.e., Agriophyllum squarrosum (L.) Moq. and Artemisia desertorum Spreng. etc.) could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate conditions. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents of the soil was negligible.

  9. Radiometric, SEM and XRD investigation of the Chituc black sands, southern Danube Delta, Romania.

    Science.gov (United States)

    Margineanu, R M; Blebea-Apostu, Ana-Maria; Celarel, Aurelia; Gomoiu, Claudia-Mariana; Costea, C; Dumitras, Delia; Ion, Adriana; Duliu, O G

    2014-12-01

    The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry performed on both Slanic-Prahova Underground Low Background Laboratory and Geological Institute of Romania Radiometric Facilities showed with clarity the dominance of (228)Ac radioisotope in the 50 microns fraction together with the (226)Ra and traces of (40)K. No significant amount of anthropogenic (137)Cs was identified. Based on radiometric as well as on SEM-EDAX and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent to potassium in the feldspars. PMID:25181034

  10. Radiometric, SEM and XRD investigation of the Chituc black sands, southern Danube Delta, Romania

    International Nuclear Information System (INIS)

    The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry performed on both Slanic-Prahova Underground Low Background Laboratory and Geological Institute of Romania Radiometric Facilities showed with clarity the dominance of 228Ac radioisotope in the 50 microns fraction together with the 226Ra and traces of 40K. No significant amount of anthropogenic 137Cs was identified. Based on radiometric as well as on SEM–EDAX and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent to potassium in the feldspars. - Highlights: • High background radioactivity (up to 200 nSv/h) evidenced. • Radiometric measurements showed a maximum radioactivity of U and Th confined to 50–100 μm fraction. • XRD and SEM–EDAX data revealed the presence of k-feldspars, ilmenite, zircone, monazite and garnets

  11. Analysis of aluminium by atomic absorption spectrometry and analysis of thorium and uranium by alpha spectrometry in the black sand of Egypt

    International Nuclear Information System (INIS)

    Throughout the period of our project of end of study carried out in the Center ; main road Sciences and Nuclear Engineering's CNSTN in one is tallied took one Egypt black sand simple with an aim has of knowing the activities of the existing radio elements and especially Uranium and Thorium. In the same mining, we try to take another Egypt black sand simple an aim has knowing the mass of aluminum by using a techniques in Atomique Absorption Spectrophotometer. After the radio chemical and Spectrometry analysis of the black sand sample we found the results following: - Egypt black sand is contains isotopes of Uranium such as 234U and 238U; - The Egypt black sand is contains isotopes of Thorium such as 230Th and 232Th. - L' Aluminum is a major. (Author)

  12. Accumulation and soil-to-plant transfer of radionuclides in the Nile Delta coastal black sand habitats.

    Science.gov (United States)

    Hegazy, A K; Emam, M H

    2011-02-01

    The radionuclide content was estimated in the soil of three black sand habitats in the Mediterranean coast of Egypt, namely, sand mounds and coastal sand planes and dunes. In addition, a total of 14 heavy minerals found in the soils were characterized. The soil to plant transfer of uranium and thorium was tested on three black sand species, namely, Cakile maritima Scop., Senecio glaucus L. and Rumex Pictus Forssk. The transfer of thorium and uranium radionuclides from the soil to plant is complex process that is subjected to many variables; among which are the organic matter and clay content of the soil, the type of radionuclides and plant species. The study revealed a strong negative relationship between uranium and thorium uptake by S. glaucus and R. pictus and the clay and organic matter content of soil. Concentration of thorium in the soil has a negative correlation with soil-to-plant transfer factor. The study results suggest the possibility of using black sand species for phytoremediation of soils contaminated with radioactive elements. The potentiality of S. glaucus as phytoremediator of radionuclides polluted soils is greater than R. pictus which in turn outweigh C. maritima. PMID:21598782

  13. Synthesis and characterization of black, red and yellow nanoparticles pigments from the iron sand

    Energy Technology Data Exchange (ETDEWEB)

    Mufti, Nandang, E-mail: nandangmufti@gmail.com; Atma, T., E-mail: nandangmufti@gmail.com; Fuad, A., E-mail: nandangmufti@gmail.com [Department of Physics, University of Malang, Jl Semarang-65145, Malang (Indonesia); Sutadji, E. [Department of Mechanical Engineering, University of Malang, Jl Semarang-65145, Malang (Indonesia)

    2014-09-25

    The aim of this research is to synthesize nanoparticles of black pigment of Magnetite (Fe{sub 3}O{sub 4}), red pigment of hematite (α-Fe{sub 2}O{sub 3}), and yellow pigment of ghoetite (α-FeOOH) from the iron sand. The black pigment of Fe{sub 3}O{sub 4} and the yellow pigment α-FeOOH nanoparticles were synthesized by coprecipitation method with variation of pH. Whereas, the red pigment Fe{sub 2}O{sub 3} was synthesized by sintering Fe{sub 3}O{sub 4} nanoparticles at temperature between 400 °C and 700 7°C for 1 hour. All the pigments has been characterized using X-ray diffraction and SEM. The XRD results shown that the particle size of the black pigmen Fe{sub 3}O{sub 4}, red pigment Fe{sub 3}O{sub 4} and yellow pigment α-FeOOH are around 12, 32, and 30 nm respectively. The particle size of Fe{sub 2}O{sub 3} nanoparticles increase by increasing sintering temperature from 32 nm at 400 °C to 39 nm at 700 °C. For yellow pigment of α-FeOOH, the particle size increase by increasing pH from 30,54 nm at pH 4 to 48,60 nm at pH 7. The SEM results shown that the morphologies of black, yellow and red pigments are aglomarated.

  14. Asymmetrical mate preference in recently adapted White Sands and black lava populations of Sceloporus undulatus

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    Kayla M. HARDWICK1, Jeanne M. ROBERTSON, Erica Bree ROSENBLUM

    2013-01-01

    Full Text Available Speciation can proceed rapidly when natural and sexual selection act in concert. For example speciation can be accelerated when traits that confer a selective advantage in a particular habitat also influence mate preference. Studying parallel but evolutionarily independent instances of ecological divergence can illuminate the interaction between natural and sexual selection during speciation. Locally adapted populations of the eastern fence lizard Sceloporus undulatus have recently evolved in three different habitats in the Chihuahuan desert: blanched color morphs occur on the gypsum dunes of White Sands, melanic color morphs occur on the Carrizozo lava flow, and brown color morphs occur in the surrounding desert scrubland. In addition to differences in cryptic dorsal coloration, populations also differ in the size and color of ventral patches used for social signaling. This system therefore provides an opportunity to investigate the interplay of natural and sexual selection during rapid ecological speciation. We used mate preference experiments to determine whether locally adapted populations may exhibit the early stages of behavioral reproductive isolation. We observed an asymmetrical mate preference in this system; White Sands males preferentially courted local females, while males from dark soils and black lava populations did not exhibit a preference for local mates. We also found that female behavior and ventral patch phenotype were associated with male courtship. Our results suggest that the observed preference for local mates evolved at White Sands, and we discuss the possible link between local adaptation and traits involved in mate preference in this system [Current Zoology 59 (1: 20–30, 2013].

  15. Radiometric, SEM and XRD investigation of black sands at Chituc placer deposit North of the City of Navodari, Romania

    Science.gov (United States)

    Duliu, Octavian G.; Blebea-Apostu, Ana-Maria; Gomoiu, Claudia; Margineanu, Romul M.; Costea, Constantin; Dumitras, Delia; Ion, Adriana

    2014-05-01

    The black sand of the Chituc marine sandbank situated northern of the city of Navodari (Romania), displayed anomalous high ambient dose rates. Field measurements performed during 2013 Summer campaign recorded in some places dose rate up to 200 nSv/h, significantly overpassing the average value of 44 ± 20 nSv/h recorded along the entire Southern sector of Romanian Black Sea shore. Here, the sand presented a black-brownish hue, different by the usual white yellowish colour. Gamma ray spectrometry performed on both Slanic-Prahove Underground Low Background Laboratory and Gological Institute Radiometric Facilities showed with clarity the dominance of 228-Ac radioisotope in the 50 microns fraction together with the 226-Ra and traces of 40-K. No significant amount of anthropogenic 137-Cs were identified. The other granulometric fractions, i.e. 315, 200 as well 100 microns presented a significant lower level of radioactivity. X-ray diffraction (XRD) as well as Scanning Electron Microsopy (SEM) data attested the presence of monazite, zircon, magnetite, ilmenite, andradite, quartz, aragonite and albite in different proportions, the monazite and zircon being preponderant in the 50 microns, the most radioactive fraction. Based on both radiometric and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent in the garnet fraction. By its position with respect to Danube Delta, the Chituc marine sandbank could be regarded as a placer where heavy minerals discharged in the Black Sea by the Danube River and transported southward by the Great Black Sea Rim are deposited by gravity separation during sedimentary processes. The implications of the Chituc levee radioactive anomaly for any further human activity are analysed and discussed. Acknowledgement: Work done within the BS ERA NET 041 project in the frame of BS-ERA.NET Pilot Joint CAll 2010-2011.

  16. Determination of natural radioactivity levels of beach sand samples in the black sea coast of Kocaeli (Turkey)

    International Nuclear Information System (INIS)

    The natural radioactivity due to the presence of 238U, 232Th, 40K and the artificial radioactivity due to 137Cs in beach sand samples from the Black Sea coast of Kocaeli (Turkey) have been measured by a gamma ray spectroscopy. Activity concentrations of 238U, 232Th, 40K and 137Cs varied in the ranges from 4.41±0.03 to 14.04±0.04, from 2.62±0.02 to 16.55±0.03, from 11.60±0.25 to 513.32±3.44 and from 0.56±0.02 to 5.43±0.03 Bq kg−1, respectively. The gamma dose rate in air due to 238U, 232Th and 40K in the samples has been estimated to be in the range between 4.10 and 36.80 nGy h−1. The radium equivalent activity values of all sand samples are calculated and found lower than the world limit of 370 Bq kg−1. In addition, the calculated values of external hazard indexes varied from 0.0244 to 0.2019, and are lower than unity. - Highlights: • The radiation hazard parameters were evaluated in beach sands of Black Sea coast of Kocaeli, Turkey. • The level of the natural radioactivity in Kocaeli Black Sea beaches does not exceed the norm. • The obtained results will serve as a baseline data in future for assessing the radiation exposure

  17. 210Po concentration in fish, algae, mussel and beach sand samples in Turkish coast of the Black Sea

    International Nuclear Information System (INIS)

    The natural radionuclide 210Po is the major contributor to the radiation dose received by humans from the sea food consumption. The main source of 210Po in the environment is the exhalation of 222Rn gas from the ground into the atmosphere. The radionuclides fall to the sea water and oceans together with aerosol particles by washout and sedimentation. The other source include burning of fossil fuel, uranium, phosphate and lead ore processing industries and tetraethyl lead used for car engines. The entrance of the radionuclides to the human body are via inhalation or ingestion. The major contribution for 210Po received via food consumption especially is originated from fish and shell fish by which it is strongly accumulated in relatively high concentration. This can lead to increase the radiation dose delivered to man by significant factor. In this study the concentration of 210Po were determined in algae, fish, mussel and beach sand samples collected from four different coastal zones of the Black Sea in Turkey from selected stations namely Sile, Trabzon, Sinop and Zonguldak during the period of 1998-2001. The sampling and analysis were carried out as a part of the 'Marine Environmental Assessment of the Black Sea Region' Technical Cooperation Project, RER/2/003 undertaken by the six Black Sea countries which is supported by IAEA. For the determination of 210Po in samples the standard techniques was used. Known activity of 209Po were added as an isotopic tracer. Samples were completely dissolved with mineral acids (HNO3, H2O2). When the solution was clear, concentrated HCl was added and the solution was gently evaporated to near dryness. After evaporation, polonium was plated onto silver disc in 0.5 M HCl in presence of ascorbic acid. Alpha counting of sample was performed using a silicon surface barrier detectors connected to a PC. The mean 210Po concentrations measured in mussel, algae, fish and beach sand samples from the four different locations on Turkish coast

  18. Environmental hazards and distribution of radioactive black sand along the Rosetta coastal zone in Egypt using airborne spectrometric and remote sensing data

    International Nuclear Information System (INIS)

    High-resolution airborne gamma ray spectrometry, conducted in 2003, was used to estimate radioactive elements spatial abundance along the Rosetta coastal zone area. It was noticed that both Uranium and Thorium are concentrated in the black sand deposits along the beach. In contrary, Potassium was observed in high level abundance at the cultivated Nile Delta lands due to the accumulated usage of fertilizers. Exposure Rate (ER), Absorbed Dose Rate (ADR) and Annual Effective Dose Rate (AEDR) were calculated to evaluate the radiation background influence in human. Results indicated that the human body in the study sites is subjected to radiation hazards exceeds the accepted limit for long duration exposure. In addition, the areas covered by the highest concentration of Uranium and Thorium show the highest level of radiogenic heat production. Detection the environmental hazards of the radioactive black sands in the study site encouraged this research to monitor the spatial and temporal distribution of these sediments. The Landsat Thematic Mapper images acquired in 1990, 2003 and 2013 were analyzed using remote sensing image processing techniques. Image enhancements, classification and changes detection indicated a positive significant relationship between the patterns of coastline changes and distribution of the radioactive black sand in the study sites. The radioactive black sands are usually concentrated in the eroded areas. Therefore, in 1990 high concentration of the radioactive black sands were observed along the eastern and western flanks of the Rosetta promontory. Distribution of these sediments decreased due to the construction of the protective sea walls. Most of the radioactive black sands are transported toward the east in Abu Khashaba bay under the effect of the longshore currents and toward the west in Alexandria and Abu Quir bay under the action of the seasonal reverse currents. - Highlights: • Spatial and temporal distributions of the black sand were

  19. Assessment of the solubility of thorium and uranium from black sand of Camargue in both simulated lung and gut fluids for dose calculation after internal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Frelon, S.; Chazel, V.; Tourlonias, E.; Paquet, F. [IRSN/ DRPH/ SRBE, LRTOX, BP 166, 26702 Pierrelatte Cedex (France); Blanchardon, E. [IRSN/ DRPH/ SDI, LEDI, BP 17, 92262 Fontenay Aux Roses Cedex (France); Bouisset, P. [IRSN/ DEI/ STEME, LMRE, Bois des rames, 91400 Orsay (France); Pourcelot, L. [IRSN/ DEI/ SESURE, LERCM, BP3, 13 115 St Paul lez Durance Cedex (France)

    2006-07-01

    In the south of France, some beaches of Camargue present a high rate of natural radioactivity due to thorium and uranium from zircon and apatite heavy minerals present in the so-called black sand. These radionuclides may lead to internal exposure consecutive to inhalation or ingestion of this sand. The accurate assessment of radiological risk after internal exposure of public frequenting these beaches requires some information on the human bioavailability of U and Th from the sand. Both routes of intake were studied in this work and the consecutive dose delivered was calculated under two different scenarios for each type of exposure. As far as inhalation is concerned, the first important conclusion is that the inhalable fraction, i.e. particles with aerodynamic diameters below 50 {mu}m, was tiny (0.002%) in this sample of sand. Moreover in vitro assays of solubility were performed for this fraction and showed that U and Th as well as their progeny presented moderate solubility. Then effective doses under several scenarios were calculated and seem to demonstrate a very poor risk of exposure after inhalation. Indeed, a dose of 1 mSv would be received by a babies after inhalation of about 40 Kg of sand, that is impossible, whereas a more realistic scenario of chronic exposure only reached 31 {mu} Sv. In case of ingestion, the solubility of Th and U in the gastrointestinal fluids was found to be very low with a maximum solubility of 0.5% of the initial mass of radioelement in the sample of sand. Then the worst hypothesis studied yields an effective dose of 0.018 mSv./(g-swallowed sand) that is roughly 50 times less than the legal annual dose limit for members of the public. as a conclusion, the possible internal dose after exposure by inhalation or ingestion of black sand of Camargue seems to be very low under the conditions of this study. (N.C.)

  20. Assessment of the solubility of thorium and uranium from black sand of Camargue in both simulated lung and gut fluids for dose calculation after internal exposure

    International Nuclear Information System (INIS)

    In the south of France, some beaches of Camargue present a high rate of natural radioactivity due to thorium and uranium from zircon and apatite heavy minerals present in the so-called black sand. These radionuclides may lead to internal exposure consecutive to inhalation or ingestion of this sand. The accurate assessment of radiological risk after internal exposure of public frequenting these beaches requires some information on the human bioavailability of U and Th from the sand. Both routes of intake were studied in this work and the consecutive dose delivered was calculated under two different scenarios for each type of exposure. As far as inhalation is concerned, the first important conclusion is that the inhalable fraction, i.e. particles with aerodynamic diameters below 50 μm, was tiny (0.002%) in this sample of sand. Moreover in vitro assays of solubility were performed for this fraction and showed that U and Th as well as their progeny presented moderate solubility. Then effective doses under several scenarios were calculated and seem to demonstrate a very poor risk of exposure after inhalation. Indeed, a dose of 1 mSv would be received by a babies after inhalation of about 40 Kg of sand, that is impossible, whereas a more realistic scenario of chronic exposure only reached 31 μ Sv. In case of ingestion, the solubility of Th and U in the gastrointestinal fluids was found to be very low with a maximum solubility of 0.5% of the initial mass of radioelement in the sample of sand. Then the worst hypothesis studied yields an effective dose of 0.018 mSv./(g-swallowed sand) that is roughly 50 times less than the legal annual dose limit for members of the public. as a conclusion, the possible internal dose after exposure by inhalation or ingestion of black sand of Camargue seems to be very low under the conditions of this study. (N.C.)

  1. Rock magnetic properties of southern Mexico beach sands. Implications for homing and nesting of marine black turtles

    International Nuclear Information System (INIS)

    Complete text of publication follows. It has long been suggested that marine turtles may use parameters of the earth's magnetic field for open ocean navigation and to broadly locate their natal beaches. Accurate location may then require short-range indicators, perhaps including magnetic cues to refine geographical position once within their natal areas. It remains however uncertain whether natal beaches indeed display short-range magnetic features. Here we present initial results on the characterization of nesting and non-nesting beaches in terms of magnetic properties of their sands. The coast of Michoacan, southern Mexico constitutes one of the main nesting areas of the marine black turtle Chelonia agassizi and we evaluate and compare magnetic features of non-natal (La Ticla and La Llorona) and natal beaches (Colola and Maruata). Values of inclination, declination, total intensity and vertical intensity of the earth's magnetic field are lower for Colola and Maruata than for La Ticla and La Llorona. Horizontal intensity is higher for Colola and Maruata. Secular variation rates for all beaches studied are similar. Analyses of magnetic and geological charts reveal presence of magnetic anomalies with values above 350 nanoTeslas for Maruata beach, associated with a large intrusive body that supplies ferromagnetic sediments rich in magnetite to Maruata. Sand samples of Maruata display the highest values of natural remanent magnetization and magnetic susceptibility. Magnetic hysteresis parameters allow further characterization of magnetic environments among and within nesting and non-nesting beaches. These features might have implications for nest selection in the context of magnetic orientation mechanisms.

  2. Effect of Some Physical Properties of the Black Sands on the Radiation Exposures at Mastarouh, North Nile Delta, Egypt

    International Nuclear Information System (INIS)

    The average apparent density of studied sediment is 1599 kg/m3 and its effective porosity is 0.22. The total heavy mineral contents in the black sands at Mastarouh area was found to vary from 10.56 % to 39.66% with an average of 26.60%. Its variation affects the activity concentrations of the four radio-nuclides, 238U, 232Th, 226Ra, and 40K, as well as the absorbed dose rate, radon flux and the total radioactivity. The mentioned variables display the same behavior like the total heavy minerals except 232Th. The averages of the activity concentration, in Bq/kg, for the four profiles due to the four radio-nuclides are: It is 61.75,47.64,34.99 and 44.11 for 238U; 63.22, 49.88, 35.19 and 33.06 for 232Th, and 42.28, 37.6, 18.5 and 25.36 for 226Ra. The measured activity concentration emitted from 40K was found to vary from not detected in the four profiles to maximum values of 187.70, 97.03, 63.73 and 106.40 with the averages 63.50, 55.40, 37.56 and 56.79, respectively. The minimum values for the total radioactivity in Bq/kg for the four profiles are 118.00,61.41, 49.06 and 85.94 while the adjacent maximum values are 340.20,24.40,153.70 and 109.70. The radon gas concentration in Bq/kg was found to vary from 111 to 2057 with an average of 1211. The measured dose values, in nGy/h, are generally less than the calculated values. The calculated ones vary from a minimum value of 20.50 to a maximum value of 111.00. About three quarters of the averages absorbed dose rate (D) are beyond the worldwide average absorbed dose rate. The average of the absorbed dose rate on the first profile, neighbor the shore line, is higher than the worldwide average then it decreases for the next three profiles to be less than the worldwide average. The radon flux at Mastarouh area has an average of 2.48X10'-3 (Bq m-2 s-1) being much lower than the worldwide average. However, the radiation exposures at Mastarouh area are below the worldwide public exposures. The activity concentrations of all

  3. Chromian spinel-rich black sands from eastern shoreline of Andaman Island, India: Implication for source characteristics

    Indian Academy of Sciences (India)

    Koyel Bhatta; Biswajit Ghosh

    2014-08-01

    Black sands rich in chromian spinel commonly occur in pockets along the eastern shoreline of Andaman Island where various types of peridotites and volcanics belonging to the Andaman ophiolite suite are exposed in close vicinity. The chemistry of these detrital chromian spinels has been extensively used here in identifying the source rocks vis-à-vis deciphering the source characteristics. The composition of the chromian spinels (Cr#: 0.20–0.88, Mg#: 0.26–0.77, Al2O3: 5.04–48.21 wt.%, TiO2: up to 1.39 wt.% and Fe2+/Fe3+: 1.73–9.12) varies widely signifying multiple sources, of which mantle peridotites and volcanic rocks are relevant in an ophiolitic terrain. The volcanic chromian spinels are relatively fresh, commonly euhedral, sometimes with compositional variations, and contain inclusions in contrast to the mantle peridotitic chromian spinels which are rounded, extensively fractured, and altered. We used a number of geochemical bivariate plots in order to know the provenance protoliths. The volcanic chromian spinels show geochemical characters of MORB, related to spreading centers (either MOR or back-arc) and also boninites/arc-tholeiites, related to active subduction. On the other hand, the peridotitic spinels indicate partially depleted lherzolite and depleted harzburgite source of the ophiolite suite.

  4. Effect of Radio-Elements in The Black Sands on Wild Plant That Grown Eastern and Western Rosetta Branch, Egypt

    International Nuclear Information System (INIS)

    The black-sand deposits are widely distributed alongside the Mediterranean Sea coast from Abu-Quir in the west to Rafah city in the extreme east. It contains, minerals, which is considered as the main source of uranium, thorium, potassium and iron oxides as a heavy and / or radio elements. These elements may be transferred with irrigation water to the plant organ (s), or even prevented the adsorption of nutrients. To achieve this purpose, surface soil samples (0-30 cm.) and subsurface soil samples (30 - 60 cm) were collected from eastern and western of Rosetta area., also Aerva plants samples (roots, stems, leaves and flowers) as a wild plant were collected from these areas to evaluate the object of this study..The results showed highest values of thorium, uranium, potassium and iron detected in soil and plant samples near Rosetta estuary at two sides (eastern and western). The available N. P. K. and Fe in western soil samples were higher than that obtained by eastern soil samples. The N. P. K. content of the plant organ (s) samples that grown at western side were higher than that found the eastern side..The highest thorium, uranium and iron content found in plant root and the least were in the leaves or flowers plants, at two Rosetta sides. Also, total uranium, thorium and iron content in western side were higher than eastern side soil samples.

  5. Environmental implications of the laboratory gamma ray spectrometric measurements made on the Black Sand Beach deposit of the Abu Khashaba radioactive prospect, Rosetta, Egypt

    International Nuclear Information System (INIS)

    Laboratory gamma-ray spectrometric measurements carried out on the surficial black sand beach deposits of Abu Khashaba radioactive prospect located 5km east of Rosetta, north Nile Delta. Analysis of the acquired spectrometric measurements indicated that both thorium and uranium are the two radioelements that significantly contributed to the measured total natural gamma-ray flux, rather than potassium. This is mainly attributed to the nature of the mineralogical composition of these beach deposits. On the other hand, qualitative interpretation of the produced maps of the three radioelements: potassium, uranium and thorium, supplemented by the examination of their frequency distributions and application of the homogeneity statistical chi-squared test has shown pronounced uranium and thorium comparable zonal distribution patterns that are consistent with the spatial distribution of the heavy mineral concentrations in the studied black-sand deposits. Concentrations of natural radioelements: potassium uranium and thorium in the investigated radioactive black-sand deposits were used in producing the environmental total gamma radiation exposure rate map of the studied Abu Khashaba beach and estimation of the mean background levels of the total gamma radiation dose rates. Two zones of contrasting average gamma exposure rates were outlined over the studied Abu Khashabe beach. The first zone displayed an average exposure rate of 13.9 μR/h (average dose rate 115.6 millirem/year) whereas, the second zone displayed a relatively lower average exposure rate of 3.9 μR/h (average dose rate 32.1 millirem/year). However in order to have better information about the actual levels of radiations, the contributions from other radionuclides that have not been taken into account should be considered

  6. Mineralogia e proveniência das areias negras de Iriri - ES Mineralogy and provenance of black sands from Iriri - ES

    Directory of Open Access Journals (Sweden)

    Alexandre de Oliveira Chaves

    2011-12-01

    Full Text Available As areias negras das praias de Iriri (ES apresentam uma ampla variedade no seu conteúdo mineralógico. A partir de propriedades ópticas e morfológicas e das composições químicas de grãos individuais, foi verificado que os principais minerais são quartzo e ilmenita, constituindo, respectivamente, 45% e 35% do volume do material investigado. Na porção restante, foram identificados os minerais pesados magnetita, monazita, zircão, cianita, sillimanita, granadas almandina e grossulária, espinélio, actinolita, clorita, rutilo e augita, além de aragonita. Levando-se em conta a geologia regional, tanto da área continental, quanto da bacia sedimentar, que envolve a região de Iriri, a análise de proveniência sugere que: a o quartzo seja oriundo dos paragnaisses regionais, dos granitóides pré a sin-colisionais e dos granulitos costeiros; b a associação dos minerais ilmenita, magnetita, augita e chamosita seja proveniente de basaltos toleíticos amigdalóides mesozóicos da bacia; c a grossulária, o espinélio e a actinolita provenham de ortoanfibolitos e rochas cálcio-silicáticas; d a almandina tenha origem relacionada não só aos paragnaisses como também aos granitóides peraluminosos sin-colisionais regionais e granulitos costeiros, sendo que estes últimos também podem ter sido a rocha-fonte do rutilo; e a cianita seja originária do terreno Cabo Frio; f a sillimanita provenha dos sillimanita-granada-biotita gnaisses paraderivados situados próximo à costa do Espírito Santo; g um primeiro subtipo de zircões juntamente com as monazitas sejam derivados das suítes pós-colisonais G4 e G5 e um segundo grupo de zircões representem cristais do embasamento paleoproterozóico distante da área de deposição; h a aragonita possua uma origem biogênica, sendo derivada de fragmentos de conchas de moluscos ou corais marinhos.Black sands from the Iriri beach (ES present a wide variety in their mineral content. From the optical and

  7. Impacts of climate change on the formation and stability of late Quaternary sand sheets and falling dunes, Black Mesa region, southern Colorado Plateau, USA

    Science.gov (United States)

    Ellwein, Amy L.; Mahan, Shannon; McFadden, Leslie D.

    2015-01-01

    Detailed geomorphic mapping and analysis of soil-stratigraphy and optically stimulated luminescence (OSL) dating of eolian sand dunes on Black Mesa, Arizona, reveal eolian sediment deposition occurred from 30 to 16 ka, followed by a period of widespread dune stabilization from 12 to 8 ka. Localized reactivation of the previously stabilized dune forms or local changes in sediment supply have occurred in the middle to late Holocene in this region. Cooler, wetter, and more variable climatic conditions during MIS 3 and 2 led to increased channel and floodplain sediment supply. Eolian sediment derived from these sources was transported up to 60 km. Deposition of this material has reduced regional topographic roughness by filling tributary canyon ‘traps’ oriented perpendicular to the dominant wind and sediment transport direction. Topographically controlled falling dunes and sand ramps in this region are preserved because of their geomorphic position and provide evidence of the paleoenvironmental state of the fluvial and eolian systems before, during, and immediately after the last glacial maximum on the southern Colorado Plateau.

  8. 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....

  9. An Epizootiological study on Mothocya epimerica Costa, 1851(Flabellifera: Cymothoidae) infestations in Sand Smelt, Atherina boyeri Risso, 1810 (Perciformes: Atherinidae) found in the Sinop Coasts of the Black Sea

    International Nuclear Information System (INIS)

    In this study , a parasitic isopod, Mothocya epimerica Flabellifera: Cymothoidae) is reported on the Sand smelt, Atherina boyeri, from a small stream in the Sinop coast of the Black Sea. A total of 320 fish were investigated throughout the study period. All specimens of M. epimerica were found in the branchial cavities of Atherina boyeri. Infestation prevalence determined was 5 percent in overall samples, while it was 21.3 percent in April, the only month in which infestation recorded. Male fish were found to have higher infestation level than female fish. A slight increase in the infestation prevalence was also recorded as the size of fish increased

  10. Shifting sands

    Energy Technology Data Exchange (ETDEWEB)

    Gillmor, D.

    2005-04-01

    The growing global competition for oil between the United States and China, and the potential role of Alberta's vast oil sands resources in the struggle between the two industrial giants to secure these and other potentially available oil supplies for themselves, are discussed. The principal argument made by the author is that for China and the United States oil is an instrument of foreign policy, the means by which to achieve or to maintain super-power status. In contrast, in Canada oil remains purely a commodity. The oil sands of Alberta are the largest hydrocarbon deposit in the world, holding some 1.6 trillion barrels of heavy crude. The oil sands have become the great White Hope of the world's petroleum supply, with intense interest in its development by both China and the United States. While Canadians are eager to cash in on the current high prices and growing shortage and are busy fighting over jurisdiction between the federal and the Alberta provincial government, there is no clear indications as to how Canada proposes to use the oil in broader trade negotiations with Washington, or China. Canadians are urged to become sensitized to the more distant future, raise their voices against the focus on short term benefits and refuse to allow themselves to become bystanders watching their energy heritage flowing south to the United States, and perhaps even east to China without efforts to maximize the potential benefits to Canada.

  11. Sands styrke

    DEFF Research Database (Denmark)

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

    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....

  12. 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 of the...

  13. 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 an...... and biotit. Mainly the sand will be used for tests concerning the development of the theory of building up pore pressure in sand....

  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...

  15. Oil sands and petrochemicals

    International Nuclear Information System (INIS)

    A study was conducted to evaluate new feedstocks from Alberta's vast oil sands resources to supplement natural gas liquids. The long-term competitiveness of Alberta's petrochemical industry can be increased by having both gas and oil feedstock options. Several schemes were evaluated to help Alberta develop synergies for its oil sands and petrochemical industries through cost effective integration of oil sands, upgrading, refining and petrochemical development. It was shown that phased integration of oil sands and petrochemical developments is technically and economically feasible to co-produce high grade fuels and petrochemicals. Alberta has the potential to become a world-scale energy and petrochemical producer. Alberta's oil sands facilities are potentially capable of supporting new world-scale plants producing ethylene, propylene, benzene, para-xylene, and other high-value-added derivatives. The products can be produced by integrating existing and new oil sands upgrading plants, refineries and petrochemical plants. tabs., figs

  16. 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.

  17. 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 an...

  18. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    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....

  19. Petrochemicals from oil sands

    International Nuclear Information System (INIS)

    The petrochemical industry in Alberta developed rapidly during the 1980s and 1990s. However, projected diminishing gas production from the Western Canadian Sedimentary Basin has raised concerns about the future growth of the industry in Alberta. A joint industry/government study has been conducted to evaluate new feedstocks from Alberta's vast oil sands resources to supplement natural gas liquids. Having both gas and oil sands feedstock options should increase the long-term competitiveness of Alberta's petrochemical industry.This paper presents a framework for evaluating and optimizing schemes for helping Alberta develop synergies for its oil sands and petrochemical industries through cost effective integration of oil sands, upgrading, refining and petrochemical development from 2005 to 2020. The paper places emphasis on specific locations and market conditions. It demonstrates that phased integration of oil sands and petrochemical developments is technically and economically feasible to co-produce high grade fuels and petrochemicals, assuming a new pipeline is built between Edmonton and Vancouver. Alberta has the potential to become a world-scale energy and petrochemical cluster. Alberta's oil sands facilities are potentially capable of supporting new world-scale plants producing ethylene, propylene, benzene, para-xylene, and other high-value-added derivatives. The products can be produced by integrating existing and new oil sands upgrading plants, refineries and petrochemical plants within the next 5 to 10 years. 3 refs., 2 tabs., 7 figs

  20. Sand-rich deltas

    International Nuclear Information System (INIS)

    This article focuses on the reservoir characteristics of high-energy sand-rich deltas. These form when the wave and tidal action is sufficiently strong to rework the deposits brought in by distributary channels before their burial. The principal types of sand bodies and highest-quality reservoir rocks in a delta are channels and stream-mouth bars. Also present are the sheet sands deposited on a delta front and localized sand bodies left in minor crevasse deposits adjacent to channels during floods. While these bodies have definite areal relationships to one another during the process of building a lobe on the delta, their three-dimensional relationships become complex as the deltas build seaward or shift positions along the shoreline. Thus, a channel active during a later building cycle may cut into or may lie over stream-mouth bars, delta-front sheets, or crevasse sands left earlier. Fortunately, the various sand bodies have different distributions or permeability and different responses to logs so that they can be identified. The coarsest sand is left at the base of a channel and silt and clays are left at the top. Low gamma ray log responses at the bases show that little clay or shale is present. The increased gamma ray log response toward the tops of the channels reflects the presence of more clay and shale

  1. 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...

  2. 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...

  3. To see a world in a grain of sand

    CERN Document Server

    Zhang, S C

    2002-01-01

    Throughout John Wheeler's career, he wrestled with big issues like the fundamental length, the black hole and the unification of quantum mechanics and relativity. In this essay, I argue that solid state physics -- historically the study of silicon, semiconductors and sand grains -- can give surprisingly deep insights into the big questions of the world.

  4. Tomato production in sand: vermicompost mixtures compared with sand and nutritive solution

    Directory of Open Access Journals (Sweden)

    Alejandro Moreno Reséndez

    2012-07-01

    Full Text Available In order to determine the response of tomato in Miramar and Romina genotypes of indeterminate growth, and to establish the optimum concentration of the mixture sand-vermicompost to satisfy crop nutritional needs, a greenhouse experiment was carried out. Seeds were sown in polystyrene trays with 200 cavities, padded with Peat moss and were transplanted in 20 L black plastic bags. The ratios of sand-vermicompost were 1:1; 2:1; 3:1 and 1:0 by volume. In mixture with ratio 1:0 a nutrient solution was applied. Four substrates and two genotypes were evaluated for a total of eight treatments, each of ones with six replications. Miramar genotype with a yield of 145.9 Mg/ha was exceed a 17.20% to Romina. Regarding the substrates, the yield of tomato in the treatment sand and nutrient solution (control was 168.7 Mg/ha. This value exceeded at least 24.6% the yields of the substrates with vermicompost. For the rest of the parameters, except in the days to harvest, the substrate with sand and nutrient solution also exceeded the three sand-vermicompost substrates. The substrates that included vermicompost, without synthetic fertilizers, for both genotypes developed completely the tomato crop cycle without apparent symptoms of deficiency, and without affecting the quality of fruits.

  5. 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.

  6. Sand pits and gravel-sand pits

    Czech Academy of Sciences Publication Activity Database

    Řehounková, Klára; Řehounek, J.; Beran, L.; Bogusch, P.; Blízek, J.; Boukal, M.; Grycz, F.; Hátle, M.; Hlásek, J.; Heneberg, P.; Hesoun, P.; Konvička, Martin; Lepšová, A.; Matějček, T.; Rektoris, L.; Stárka, L.; Zavadil, V.

    České Budějovice : Faculty of Science, University of South Bohemia in České Budějovice, 2011 - (Řehounková, K.; Řehounek, J.; Prach, K.), s. 51-67 ISBN 978-80-7394-322-6 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : sand pits Subject RIV: EH - Ecology, Behaviour

  7. Oil sands tax expenditures

    International Nuclear Information System (INIS)

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

  8. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as...... is hinted by Rudyard Kipling’s illustration of ‘The [Black] Cat That Walked by Himself’ in his classic children’s tale). It was well understood by uniformed Anarchists, Fascists and the SS that there is an assertive presence connected with the black-clad figure. The paradox of black’s abstract elegance......-styled references to, among other things, the culturally and ideologically effervescent interwar-period have made me curious as to what alternative possibilities – for instance ‘emancipation’ – a comparative analysis might disclose concerning the visual rhetoric of black. Thus, in conclusion, it is briefly...

  9. Gas percolation through sand

    International Nuclear Information System (INIS)

    Previous research has determined the shock properties of quartz sand. The effect of the physical processes occurring with varying moisture content and particle size were shock presented. In this study the same quartz sand, in a column is subjected to blast waves over a range of pressure. The diagnostics used are pressure sensors and high-speed photography. The effect of grain size on propagation time and the effect of moisture content are determined. Aspects of particle and liquid movement are also discussed. While the velocity of the percolation through the bed is primarily controlled by grain size the effect of moisture and liquids reveals a more complex dependence.

  10. 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…

  11. Extracting Oil From Tar Sands

    Science.gov (United States)

    Ford, L. B.; Daly, D.

    1984-01-01

    Recovery of oil from tar sands possible by batch process, using steam produced by solar heater. In extraction process, solar heater provides steam for heating solvent boiler. Boiling solvent removes oil from tar sands in Soxhlet extractor.

  12. 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...

  13. 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.

  14. Intricately Rippled Sand Deposits

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for Intricately Rippled Sand Deposits (QTVR) NASA's Mars Exploration Rover Spirit welcomed the beginning of 2006 on Earth by taking this striking panorama of intricately rippled sand deposits in Gusev Crater on Mars. This is an approximate true-color rendering of the 'El Dorado' ripple field provided by Spirit over the New Year's holiday weekend. The view spans about 160 degrees in azimuth from left to right and consists of images acquired by Spirit's panoramic camera on Spirit's 708th and 710th Martian days, or sols, (Dec. 30, 2005 and Jan. 1, 2006). Spirit used the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters to capture the colors on Mars. Scientists have eliminated seams between individual frames in the sky portion of the mosaic to better simulate the vista a person standing on Mars would see. Spirit spent several days acquiring images, spectral data, and compositional and mineralogical information about these large sand deposits before continuing downhill toward 'Home Plate.'

  15. Oil sands supply outlook

    International Nuclear Information System (INIS)

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

  16. Sanding dust from nanoparticle-containing paints: Physical characterisation

    Science.gov (United States)

    Koponen, I. K.; Jensen, K. A.; Schneider, T.

    2009-02-01

    Increasing use of nanoparticles in different industrial applications has raised a new potential health risk to the workers as well as to the consumers. This study investigates the particle size distributions of sanding dust released from paints produced with and without engineered nanoparticles. Dust emissions from sanding painted plates were found to consist of five size modes; three modes under 1 μm and two modes around 1 and 2 μm. We observed that the sander was the only source of particles smaller than 50 nm and they dominated the number concentration spectra. Mass and surface area spectra were dominated by the 1 and 2 μm modes. Addition of nanoparticles caused only minor changes in the geometric mean diameters of the particle modes generated during sanding of two paints doped with 17 nm TiO2 and 95 nm Carbon Black nanoparticles as compared to the size modes generated during sanding a conventional reference paint. However, the number concentrations in the different size modes varied considerably in between the two NP-doped paints and the reference paint. Therefore, from a physical point of view, there may be a difference in the exposure risk during sanding surfaces covered with nanoparticle-based paints as compared to sanding conventional paints.

  17. Sanding dust from nanoparticle-containing paints: Physical characterisation

    International Nuclear Information System (INIS)

    Increasing use of nanoparticles in different industrial applications has raised a new potential health risk to the workers as well as to the consumers. This study investigates the particle size distributions of sanding dust released from paints produced with and without engineered nanoparticles. Dust emissions from sanding painted plates were found to consist of five size modes; three modes under 1 μm and two modes around 1 and 2 μm. We observed that the sander was the only source of particles smaller than 50 nm and they dominated the number concentration spectra. Mass and surface area spectra were dominated by the 1 and 2 μm modes. Addition of nanoparticles caused only minor changes in the geometric mean diameters of the particle modes generated during sanding of two paints doped with 17 nm TiO2 and 95 nm Carbon Black nanoparticles as compared to the size modes generated during sanding a conventional reference paint. However, the number concentrations in the different size modes varied considerably in between the two NP-doped paints and the reference paint. Therefore, from a physical point of view, there may be a difference in the exposure risk during sanding surfaces covered with nanoparticle-based paints as compared to sanding conventional paints.

  18. Black rings

    International Nuclear Information System (INIS)

    A black ring is a five-dimensional black hole with an event horizon of topology S1 x S2. We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  19. Sanding process and permeability change

    Energy Technology Data Exchange (ETDEWEB)

    Xue, S. [Petroleum Univ., Beijing (China); Yuan, Y.

    2004-07-01

    Sand production is a major problem in the petroleum industry, particularly with operators aggressive production schedules. Sand production occurs when the well fluid under high pumping rate dislodges part of the formation solids causing a continuous flux of formation solids. It increases completion costs, plus it erodes casings, pipes and pumps. However, sand production can also effectively increase well productivity in heavy oil and light oil reservoirs.The challenge in understanding the sanding process lies in developing a mathematical model which can predict the amount of sand production. A quantitative model would allow engineers to understand the unique phenomena and evaluate the impact of sand production on reservoir enhancement. Measures could then be taken to reduce unnecessary costs during field operations. In order to develop such a model, the complicated sanding process equations was divided into a fluid flow and sand transport equation, and into a porous solid matrix deforming and stress concentration or failure function equation. The two types of sand production mechanisms that were presented in this paper were the production of coarse sands under mechanical failure and the production of fine sands under hydro-dynamical erosion. The behaviour of sandstone deformation was examined using the Drucker-Prager constitutive law with cap hardening criterion. The governing equation system was solved using the finite element method. The model was validated using field data for sand production and permeability change obtained from 10 wells in Gudong, China. It was shown that permeability can be modified at any time during the sanding process of a well. Permeability can be reduced by up to 60 per cent of the initial level under depletion production. It was determined that the best way to control permeability decline is to balance the pore pressure. 9 refs., 1 tab., 7 figs.

  20. Oil sands development update

    International Nuclear Information System (INIS)

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

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. Sand, jams and jets

    International Nuclear Information System (INIS)

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

  6. 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

  7. Black Consciousness

    Science.gov (United States)

    Hraba, Joseph; Siegman, Jack

    1974-01-01

    Black militancy is treated as an instance of class consciousness with criteria and scales developed to measure black consciousness and "self-placement" into black consciousness. These dimensions are then investigated with respect to the social and symbolic participation in the ideology of the black movement on the part of a sample of black…

  8. Atlas of Dutch drift sands

    Science.gov (United States)

    Riksen, Michel; Jungerius, Pieter

    2013-04-01

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

  9. 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.

  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. Alberta oil sands royalty regime

    International Nuclear Information System (INIS)

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

  12. CAPILLARITY OF CONCRETE INCORPORATING FOUNDRY SAND AS REPLACEMENT OF SAND

    OpenAIRE

    Khatib, Jamal M.; HERKI, B A; Fırat, Seyhan; Menadi, B; Kenai, S.

    2011-01-01

    The potential uses and the high cost of land-filling of used foundry sands have prompted research into their beneficial reuse. This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from foundry industries. Little work has been done so far on the effect of used foundry sand on the durability of concrete especially water absorption. The main aim of this work was to determine capillary water absorption ...

  13. 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.

  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. Aeolian sand ripples around plants.

    Science.gov (United States)

    Zhang, Qian-Hua; Miao, Tian-De

    2003-05-01

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

  16. Black Eye

    Science.gov (United States)

    ... eyesight if not treated. If both eyes are black after a head injury, it could signify a skull fracture or other serious injury. Next Black Eye Symptoms Related Ask an Ophthalmologist Answers How ...

  17. Black tea

    Science.gov (United States)

    ... diuretic to increase urine flow. Some people use black tea for preventing tooth decay and kidney stones. In combination with various other products, black tea is used for weight loss. In foods, ...

  18. Characterization of sand lenses embedded in tills

    DEFF Research Database (Denmark)

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

    2012-01-01

    Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...... parameters is defined to allow characterization of sand lenses. The proposed classification scheme uses a stringent terminology to distinguish several types of sand lenses based on the geometry. It includes sand layers, sand sheets, sand bodies, sand pockets and sand stringers. The methodology has been...... lenses in various glacial environments. Due to the complex and mutable appearance of sand lenses, geometric descriptions can reveal the deformation history and even give indications on the palaeo-glaciological conditions during the deposition of the surrounding tills. This information can support the...

  19. Salt content impact on the unsaturated property of bentonite-sand buffer backfilling materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ming [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China); Zhang Huyuan, E-mail: p1314lvp@yahoo.com.cn [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China); Jia Lingyan; Cui Suli [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer SWCC and infiltration process of bentonite-sand mixtures is researched. Black-Right-Pointing-Pointer The k{sub u} of bentonite-sand mixtures was evaluated as the buffer backfilling materials. Black-Right-Pointing-Pointer Salt content impacting on the unsaturated property of bentonite-sand materials is small. - Abstract: Bentonite mixed with sand is often considered as possible engineered barrier in deep high-level radioactive waste disposal in China. In the present work, the vapor transfer technique and water infiltration apparatus were used to measure the soil water characteristic curve (SWCC) and unsaturated hydraulic conductivity (k{sub u}) of bentonite-sand mixtures (B/S) effected by salt content. Results show, the water-holding capacity and k{sub u} increase slightly with the concentration of Na{sup +} in pore liquid increasing from 0 g/L to 12 g/L, similar with the solution concentration of Beishan groundwater in China. Salt content in the laboratory produced only one order of magnitude increase in k{sub u}, which is the 'safe' value. The different pore liquid concentrations used in this study led to small differences in thickness of diffuse double layer of bentonite in mixtures, this might explain why some differences have been found in final values of k{sub u}.

  20. Black Holes

    Science.gov (United States)

    Luminet, Jean-Pierre

    1992-09-01

    Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

  1. Oil sands tailings management project

    International Nuclear Information System (INIS)

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

  2. Oil sands tailings management project

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  3. 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., III; 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).

  4. Sands at Gusev Crater, Mars

    Science.gov (United States)

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

    2014-05-01

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

  5. Strange phenomena in Cuban sands

    International Nuclear Information System (INIS)

    Full text: Several unusual phenomena that occur in certain Cuban sands flows (and some other parts of the world) are presented . First, the phenomenon occurs revolving rivers, explained by a phenomenological model. Several open questions were discussed on the 'microscopic' causes of the phenomenon. Uphill lonely waves are shown in second, in streams of the same type of sand that occur in a cell in Hele-Shaw. The 'microscopic' necessary conditions are explored for these waves emerge as solution of Saint-Venant equations modified hydrodynamic type. (author)

  6. Beneficiation of beach magnetite sand

    Directory of Open Access Journals (Sweden)

    Münevver TEL

    2016-06-01

    Full Text Available In this study, beneficiation of beach magnetite sand was investigated by applying high intensity dry magnetic separator. The effect of feed particle size, feed rate, roll rotation speed, induced magnetic field intensity, and separator knife angle on Fe grade and recovery of the magnetite concentrate were investigated. As a result of dry magnetic separation at about 750 Gauss magnetic field conducted with -0.212+0.106 mm size fraction under optimum conditions, a magnetite concentrate assaying 54.41% Fe was obtained with 63.46% recovery where the beach sand sample contained %48.41 Fe.

  7. A multiphase flow approach to modelling sand production using finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Wan, R.G.; Liu, Y. [Calgary Univ., AB (Canada); Wang, J. [Taurus Reservoir Solutions Ltd., Calgary, AB (Canada)

    2004-07-01

    One of the challenges facing heavy oil recovery operations is the production of sand in unconsolidated oil sands and weak sandstones. This study extends previous work on coupled erosion mechanics and hydrodynamics by considering the presence of a gas phase in a previously developed theoretical and numerical model. The extended model captures the physics associated with gas exsolution. The model is developed within the framework of mixture theory and multiphase flow in a component system which includes solids, fluidized solids, oil and gas. The model was recast into petroleum reservoir engineering, similar to the black oil model but with sand production capabilities. The effects of solution gas drive play an important role in the physics of sand production because gas flow increases the susceptibility of grain particle detachment from the sand matrix and subsequent fluid flow. This paper discussed the finite element method along with algorithmic implementations. It also demonstrated the role of a gas phase in sand production through a one-dimensional numerical example of sand production in an oil reservoir undergoing pressure drawdown. 13 refs., 1 tab., 11 figs.

  8. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. 

  9. 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…

  10. 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...

  11. Are black holes totally black?

    CERN Document Server

    Grib, A A

    2014-01-01

    Geodesic completeness needs existence near the horizon of the black hole of "white hole" geodesics coming from the region inside of the horizon. Here we give the classification of all such geodesics with the energies $E/m \\le 1$ for the Schwarzschild and Kerr's black hole. The collisions of particles moving along the "white hole" geodesics with those moving along "black hole" geodesics are considered. Formulas for the increase of the energy of collision in the centre of mass frame are obtained and the possibility of observation of high energy particles arriving from the black hole to the Earth is discussed.

  12. 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...

  13. Effects of pipe orientation on sand transportation

    OpenAIRE

    Osho, Adeyemi Joseph

    2013-01-01

    Sand transport in hilly terrain geometry is different and complex to understand compared to horizontal pipeline, due to the influence of the geometry that greatly affect multiphase flow and sand behaviour at the dip. The overall aim of this research work is to use experimental method to investigate the effects of multiphase flow behaviour on sand transport in a dip configuration. Experimental work was carried out to understand the complex dynamic mechanisms that exist during sand multipha...

  14. Formation of aeolian ripples and sand sorting.

    Science.gov (United States)

    Manukyan, Edgar; Prigozhin, Leonid

    2009-03-01

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

  15. 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.

  16. Restoration and conservation of sand and gravel-sand pits

    Czech Academy of Sciences Publication Activity Database

    Řehounková, Klára; Řehounek, J.

    Praha : Agentura ochrany přírody a krajiny České republiky, 2012 - (Jongepierová, I.; Pešout, P.; Jongepier, J.; Prach, K.), s. 94-96 ISBN 978-80-87457-32-0 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : restoration * conservation * sand pits Subject RIV: EH - Ecology, Behaviour

  17. Point resistance of piles in sand

    OpenAIRE

    Miura, Norihiko

    1983-01-01

    Mechanism of point resistance of pile in sand was investigated mainly from the viewpoint of the particle-crushing of sand at the pile tip. It is shown that the work dissipated in the particle-crushing of sand is as large as 66 percent of the total work done by the external force, hence the point resistance of a pile in sand greatly depends on the particle-crushing property of the sand. It is also shown that the relationship between point resistance and vertical pressure of a pile can be predi...

  18. Black market

    International Nuclear Information System (INIS)

    One way for states and subnational groups to acquire material, knowledge and equipment necessary to build a nuclear weapon or device are illegal transactions. These were singular in the past and did not cause the development of a nuclear black market. But all necessary components of a functioning black market exist. Therefore the further spread and extension of the use of nuclear power would enhance the threat of a nuclear black market, if the trade and use of specific nuclear material is not abandoned worldwide. (orig.)

  19. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO4) and the alpha zirconium hydrogen phosphate (Zr(HPO4) 2H2O) starting from sea sand in an easy and economic way. (Author)

  20. Tyler sands play entices operators

    Energy Technology Data Exchange (ETDEWEB)

    Stremel, K.

    1984-07-01

    Encouraging seismic data and recent discoveries are causing a renewed interest in an intensive exploration effort in central Montana's Tyler play. With new subsurface information obtained from recent seismic surveys, geologists are reviewing the elusive Tyler sands from a different perspective. Several operators are competing for lease positions through farmouts and joint ventures and increased drilling activity is expected to begin within the next year.

  1. 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.

  2. 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.

  3. Black tea

    Science.gov (United States)

    ... product containing black tea extract plus green tea extract, asparagus, guarana, kidney bean, and mate along with a combination of kidney bean pods, garcinia, and chromium yeast for 12 weeks does not reduce body weight ...

  4. 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....

  5. Contribution to the external surface of a titanium-rich sand (Abou-Khashaba, Egypt) in the uranium uptake processes

    Czech Academy of Sciences Publication Activity Database

    Tykva, Richard; Salahel Din, K.; Pavel, C. C.; Cecal, A.; Popa, K.

    2009-01-01

    Roč. 279, č. 3 (2009), s. 811-816. ISSN 0236-5731 Institutional research plan: CEZ:AV0Z40550506 Keywords : uran uptake * Egyptian black sand * thermodynamic parameters Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 0.631, year: 2009

  6. Fountains of sand part II

    OpenAIRE

    Hubert, Steven Mark

    2012-01-01

    Comprised of five large format oil paintings and one sculpture made of stucco, Fountains of Sand II: Pictures Not As Windows But Display Windows, or Barriers is the latest iteration of my interest in pictorial structures as they relate to subject matter and its relationship to real matter, paint. FoS II not only affects this struggle as one of thinking through the act of doing, but also attempts to manifest this through the continual obfuscation of a paradigmatic framework: the work displays...

  7. Dynamical evolution of sand ripples under water.

    Science.gov (United States)

    Stegner, A; Wesfreid, J E

    1999-10-01

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

  8. Metal mining to the aid of the oil sands? Lateral opportunities in industrial cross-breeding

    Energy Technology Data Exchange (ETDEWEB)

    Sabag, S.F. [Dumont Nickel Inc., Toronto, ON (Canada)

    2009-07-01

    This paper demonstrated how oil sands operations can benefit from supporting innovative low cost metal mining to enhance their eco-footprint. Northeast Alberta contains large accumulations of recoverable metals, hosted in metal bearing black shales. Immense low grade polymetallic zones were discovered in 1995 but could not be exploited with existing recovery technologies. However, significant advances in bioleaching of metals from polymetallic black shale deposits have propelled this new deposit type to the forefront over the past 5 years as a long term future source of metals. Compared to traditional smelting and refining, bioleaching has lower Capex/Opex, lower eco-footprint and less energy dependence. Envisaged metal mining in the black shales of northeast Alberta can benefit oil sands operations by consuming large amounts of waste sulfur while also providing collateral opportunities for carbon sinks/offsets. Black shales have the capacity to sequester carbon dioxide (CO{sub 2}). Dumont Nickel Inc. is advancing 6 polymetallic black shale projects in northeast Alberta over 2,500 km{sup 2} with potential for hosting up to 20 billion tons in six 50-100 km{sup 2} deposits. The projects present opportunities to develop low footprint metal mines, to use run-of-river hydro, to harvest waste heat, and to combine local technologies to create a new valuable industry independent of energy markets.

  9. Chromium, nickel and vanadium mobility in soils derived from fluvioglacial sands

    Energy Technology Data Exchange (ETDEWEB)

    Agnieszka, Jeske, E-mail: agnieszka.jeske@ios.edu.pl [Institute of Environmental Protection-National Research Institute, Krucza 5/11, 00-548, Warsaw (Poland); Warsaw University of Life Sciences, Division of Soil Science, Nowoursynowska 157, Warsaw (Poland); Barbara, Gworek [Institute of Environmental Protection-National Research Institute, Krucza 5/11, 00-548, Warsaw (Poland); Warsaw University of Life Sciences, Division of Soil Science, Nowoursynowska 157, Warsaw (Poland)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Mobility of Cr, Ni, V was analysed in rusty soils derived from fluvioglacial sands. Black-Right-Pointing-Pointer The aim was the determination the link between soil constituents and fractions. Black-Right-Pointing-Pointer To determine mobile fractions the Tessier et al. method was used. Black-Right-Pointing-Pointer Metals occurred predominantly in immobile fractions. Black-Right-Pointing-Pointer Potential mobility, bioavailability of mentioned metals is as follows Ni > Cr > V. - Abstract: The presented study was focused on soils developed from fluvioglacial sands from the Puszcza Borecka forest complex. The mobility of chromium, nickel and vanadium was evaluated with regard to litho- and pedogenic factors. The aim of the study was to determine with which soil constituents fractions of heavy metals are bound with particular attention drawn on the mobile fractions (F1 + F2). Heavy metal fractions in the soils were determined using the sequential extraction method of Tessier et al. The purpose of sequential extraction methods to soil samples provides relevant information about possible toxicity when they are discharged into the soil environment. Chromium, nickel, and vanadium occurred predominantly in the fraction bound with iron and manganese oxides and in the residual fraction, thus showed low mobility. With regard to mobility, the elements studied can be arranged as follows: V < Cr < Ni. The content of the mobile fractions depended on the soil texture. The influence of the rusting process on the distribution of the bioavailable fractions was observed in the soil profiles.

  10. The mechanics of fibre-reinforced sand

    OpenAIRE

    Dos Santos, APS; Consoli, NC; Baudet, BA

    2010-01-01

    Fibres can be an effective means of reinforcing soils. This paper presents data from laboratory triaxial tests on quartzitic sand reinforced with polypropylene fibres. By keeping the studied composite consistent throughout the study (host sand and fibre characteristics kept constant), it has been possible to develop a framework of behaviour for the sand-fibre material, which provides a solid base for future research on fibre-reinforced soils. Data from previous work and from new tests have be...

  11. Silica sand resources in the Netherlands

    OpenAIRE

    van der Meulen, M.J.; 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 requires that scarce mineral resources (including silica sand) are taken into consideration in spatial planning and when preparing for largescale engineering or construction works. For this purpose, ...

  12. Biodegradable materials as foundry moulding sands binders

    OpenAIRE

    K. Major-Gabryś

    2015-01-01

    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 abilit...

  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. Nuclear energy for oil sands

    International Nuclear Information System (INIS)

    In 1980, Atomic Energy of Canada Limited, working with a number of Alberta-based companies, assessed the technical and economic feasibility of using a CANDU nuclear reactor to raise the production steam for the recovery of bitumen. The study followed several years of analysis which identified oil sands projects as the most appropriate single users of thermal energy of the amount and quality available from reactors. Over the life of an oil sands project a steam supply system based on a nuclear reactor is expected to offer a substantial cost advantage (25 - 50%) over the alternative system based on coal as the make-up fuel. Steam from natural gas is marginally more expensive than that from coal because the cost of natural gas is expected to escalate at a rate higher than inflation. For shallow deposits (150 - 250 metres) using intermediate pressure steam, the commercially proven Pressurized Heavy Water (PHW) reactor is most suitable. For deeper deposits (250 - 650 metres), the PHW reactor can provide the higher pressure steam using a compressor, but only with a reduction in thermal efficiency that substantially reduces its cost advantage. The CANDU Organic Cooled Reactor (OCR), however, can provide the high presure steam required with the large cost advantage. The economic benefit of nuclear steam supply systems, a saving of $2-4 per barrel of product, is large enough to justify a more detailed study

  15. Nuclear energy for oil sands

    International Nuclear Information System (INIS)

    In working partnership with a number of Alberta-based companies an AECL (Atomic Energy of Canada Limited) study team assessed the technical and economic feasibility of using a nuclear reactor to raise the production steam for the recovery of bitumen. Technically sound concepts have been identified for using CANDU reactors for the in-situ recovery of bitumen from oil sands. Over the life of an oil sands project a steam supply system based on a nuclear reactor is expected to offer a substantial cost advantage (25 - 50 %) over the alternative system based on coal as the make-up fuel. Steam from natural gas is marginally more expensive than that from coal because the cost of natural gas is expected to escalate at a rate higher than inflation. For shallow deposits (150 -250 metres) using intermediate pressure steam, the commercially proven Pressurized Heavy Water (PHW) reactor is most suitable. For deeper deposits (250 - 650 metres), the PHW reactor can provide the higher pressure steam using a compressor, but only with a reduction in thermal efficiency that substantially reduces its cost advantage. The CANDU Organic Cooled Reactor (OCR), however, can provide a high pressure steam required with the large cost advantage. The economic benefit offered by nuclear steam supply systems, a saving of $2-4 per barrel of product, is large enough to justify the commitment of a more detailed study

  16. Sand residence times of one million years in the Namib Sand Sea from cosmogenic nuclides

    Science.gov (United States)

    Vermeesch, P.; Fenton, C. R.; Kober, F.; Wiggs, G. F. S.; Bristow, C. S.; Xu, S.

    2010-12-01

    The Namib Sand Sea is one of the world's oldest and largest sand deserts, yet little is known about the source of the sand in this, or other large deserts. In particular, it is unclear whether the sand is derived from local sediment or comes from remote sources. The relatively uniform appearance of dune sands and low compositional variability within dune fields make it difficult to address this question. Here we combine cosmogenic-nuclide measurements and geochronological techniques to assess the provenance and migration history of sand grains in the Namib Sand Sea. We use U-Pb geochronology of detrital zircons to show that the primary source of sand is the Orange River at the southern edge of the Namib desert. Our burial ages obtained from measurements of the cosmogenic nuclides 10Be, 26Al and 21Ne suggest that the residence time of sand within the sand sea is at least one million years. We therefore conclude that, despite large climatic changes in the Namib region associated with Quaternary glacial-interglacial cycles, the area currently occupied by the Namib Sand Sea has never been entirely devoid of sand during the past million years.

  17. Fecal indicators in sand, sand contact, and risk of enteric illness among beach-goers

    Science.gov (United States)

    BACKGROUND: Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. METHODS: In 2007, visitors at 2 recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days...

  18. Fischer Black

    OpenAIRE

    Robert C. Merton; Myron S. Scholes

    2013-01-01

    ReprintThis article was originally published by Wiley for the American Finance Association (Merton RC, Scholes MS. 1995. Fischer Black. J. Finance 50(5):1359–70). It is reprinted with permission from John Wiley and Sons © 1995. Reference formatting was updated to facilitate linking.

  19. Fuel options for oil sands

    International Nuclear Information System (INIS)

    This presentation examined fuel options in relation to oil sands production. Options include steam and hydrogen (H2) for upgrading; natural gas by pipeline; bitumen; petroleum coke; and coal. Various cost drivers were also considered for each of the fuel options. It was noted that natural gas has high energy value but the capital cost is low, and that coke's energy value is very low but the capital cost is high. A chart forecasting energy prices was presented. The disposition of Western Canada's northern gas situation was presented. Issues concerning rail transportation for coal were considered. Environmental concerns were also examined. A chart of typical gas requirements for 75,000 B/D oil sands projects was presented. Issues concerning steam generation with gas and mining cogeneration with gas fuel and steam turbines were discussed, as well as cogeneration and H2 with gas fuels and steam turbines. Various technology and fuel utility options were examined, along with details of equipment and processes. Boiler technologies were reviewed by type as well as fuel and steam quality and pressure. Charts of cogeneration with gas turbine and circulation fluid bed boilers were presented. Gasification processes were reviewed and a supply cost basis was examined. Cost drivers were ranked according to energy, operating considerations and capital investment. Results indicated that fuel costs were significant for gas and coal. Capital costs and capital recovery charge was most significant with coal and gasification technology. Without capital recovery, cash costs favour the use of bitumen and coke. Gasification would need lower capital and lower capital recovery to compete with direct burning. It was concluded that direct burning of bitumen can compete with natural gas. With price volatility anticipated, dual fuel capability for bitumen and gas has merit. Petroleum coke can be produced or retrieved from stockpiles. Utility supply costs of direct burning of coke is marginally

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  1. Oil sands opportunities for midstream companies

    International Nuclear Information System (INIS)

    The potential of Alberta's oil sands industry was reviewed. Oil sands production is expected to surpass declining conventional production. It was suggested that oil sands will increase from 42 per cent of Western supply in 2002 to 78 per cent in 2015. An inventory of major oil sands products and sources was presented and upgrading issues were examined. Oil sands products and market outlets were reviewed. Issues concerning the expansion of the value chain from resource to finished product were discussed. It was suggested that the U.S. will require more refined product imports in the future. Various market challenges facing the oil sands processing industries were discussed, including issues concerning producers, refiners and the common market. Potential refined products export markets were examined. Upgrading for both upstream and downstream refineries was discussed. A recent study completed for the Alberta Government and industry was reviewed. It was noted that pipeline changes or expansions need to be configured to accommodate refined products and that a large volume of exports to the Midwest or California markets would be based on pipeline availability. Issues concerning services to large oil sands projects were reviewed. It was concluded that there is significant growth in oil sands, with enormous capital requirements. There are many opportunities for mid streamers to take on smaller portions of large projects. refs., tabs., figs

  2. Nonlinear dynamics of Aeolian sand ripples.

    Science.gov (United States)

    Prigozhin, L

    1999-07-01

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

  3. 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

  4. Shock response of dry sand.

    Energy Technology Data Exchange (ETDEWEB)

    Reinhart, William Dodd; Thornhill, Tom Finley, III (,; ); Chhabildas, Lalit C.. (..); Vogler, Tracy John; Brown, Justin L.

    2007-08-01

    The dynamic compaction of sand was investigated experimentally and computationally to stresses of 1.8 GPa. Experiments have been performed in the powder's partial compaction regime at impact velocities of approximately 0.25, 0.5, and 0.75 km/s. The experiments utilized multiple velocity interferometry probes on the rear surface of a stepped target for an accurate measurement of shock velocity, and an impedance matching technique was used to deduce the shock Hugoniot state. Wave profiles were further examined for estimates of reshock states. Experimental results were used to fit parameters to the P-Lambda model for porous materials. For simple 1-D simulations, the P-Lambda model seems to capture some of the physics behind the compaction process very well, typically predicting the Hugoniot state to within 3%.

  5. Developing new markets for oil sands products

    International Nuclear Information System (INIS)

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

  6. Earth-like sand fluxes on Mars.

    Science.gov (United States)

    Bridges, N T; Ayoub, F; Avouac, J-P; Leprince, S; Lucas, A; Mattson, S

    2012-05-17

    Strong and sustained winds on Mars have been considered rare, on the basis of surface meteorology measurements and global circulation models, raising the question of whether the abundant dunes and evidence for wind erosion seen on the planet are a current process. Recent studies showed sand activity, but could not determine whether entire dunes were moving--implying large sand fluxes--or whether more localized and surficial changes had occurred. Here we present measurements of the migration rate of sand ripples and dune lee fronts at the Nili Patera dune field. We show that the dunes are near steady state, with their entire volumes composed of mobile sand. The dunes have unexpectedly high sand fluxes, similar, for example, to those in Victoria Valley, Antarctica, implying that rates of landscape modification on Mars and Earth are similar. PMID:22596156

  7. Numerical simulation of aeolian sand ripples

    International Nuclear Information System (INIS)

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

  8. 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.

  9. 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.

  10. Radiation exposure of sand blasting operators

    International Nuclear Information System (INIS)

    The Queensland Department of Health's, Division of Health and Medical Physics initiated, in July, 1985, an investigation into the radiological health impact which involved detailed analyses of an ilmenite product from a mineral sand processor in South East Queensland. Measurements of respirable dust in air concentrations in the breathing zone of sand blasting operators, dust particle sizing and other environmental radiation measurements at a major sand blasting yard using this ilmenite product were carried out. From the data collected, the radiological health impact was assessed and compared with international and national radiological recommendations

  11. LABORATORY STUDY ON CRACKS IN SATURATED SANDS

    Institute of Scientific and Technical Information of China (English)

    Peng Fujiao; Tan Qingming; Che-Min Cheng

    2000-01-01

    It has been reported[1]that when a loosely packed column of saturated sand in a vertical cylindrical container is shock loaded axially by dropping to the floor,large horizontal cracks initiate,grow and eventually fade away in the sand as it settles under gravity.This paper shows that a similar phenomenon can also be observed when shock loading is replaced by forcing water to percolate upward through the sand column.It is believed that our result sheds further light on the physics of formation of these cracks.

  12. Sandėlių modeliavimas

    OpenAIRE

    Sungaila, Marius

    2008-01-01

    Šiame magistriniame darbe yra aptariama logistikos svarba prekybinėse įmonėse. Atliekamas sandėliavimo ir transportavimo, bei efektyvaus klientų užsakymų tenkinimo naudojant informacines technologijas optimizavimo tyrimas. Panašių programų analizė. Neformaliai ir formaliai Z kalba sandėlių sistemos aprašymas. Bendro prekybos centro ir sandėlio PLA modelio parengimas su agregacine schema ir koncepciniu modeliu, formalia specifikacija. Taip pat išskirtos perėjimų ir išėjimų operacijos. Vėliau b...

  13. 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.

  14. Effect of liming on yield and quality of peppermint and Sachalin mint in fine sand soil of Northern Finland

    OpenAIRE

    Aflatuni, Abbas; Uusitalo, Jouko; Ek, Sari; Hohtola, Anja

    2003-01-01

    Soil acidity commonly limits plant production in the fine sand soil of Northern Finland, which often has a low pH (5.5-6.5) and contains low levels of Ca and Mg. The effect of five liming (10% Mg and 19% Ca) levels, 0, 4, 8, 12, and 16 tons ha -1 , on the herb and essential oil yield and menthol and menthone content of two mint species (peppermint, Mentha x piperita, a variety of Black Mitcham and Sachalin mint, Mentha arvensis var. sacchalinensis) cultivated in fine sand soil in Northern Fin...

  15. Nigeria to step up tar sands activity

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    The Nigerian government has directed its Ministry of Mines, Power and Steel to assume responsibility for the exploration and exploitation of tar sands deposits in Bendel, Ondo and Oyo States. The directive resulted from a survey report by the University of Ife's geological consultancy unit on bituminous sand deposits in the area. The statement said the government was satisfied that there were large commercial quantities of the sands in the three states. The survey had reported that Nigeria could recover between 31 and 40 billion barrels of heavy crude from the tar sand deposits. Exploration for hydrocarbons is currently going on in Anambra and Lake Chad basins as well as the Benue Trough. Apart from the Nigerian National Petroleum Corporation, Shell Petroleum and Gulf Oil have begun exploration activities in the Ondo area. Meanwhile, Nigeria has had to import heavy crude from Venezuela, for processing at the Kaduna refinery.

  16. 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.

  17. Sand dunes on Mars and on Earth

    OpenAIRE

    Ribeiro Parteli, Eric Josef

    2007-01-01

    In this work the dune model introduced by Sauermann et al. (2001) is extended and applied to investigate the formation of different dune shapes on Mars and on Earth as function of wind directionality and sand availability. The formation of sand dunes on Mars under the present atmospheric conditions of the red planet is studied and conclusions about wind speed, migration velocity of dunes and changing wind regimes on Mars are presented. Field measurements of the shape of coastal transverse dun...

  18. Coagulation in clarifier with micro-sand

    International Nuclear Information System (INIS)

    As water treatment play key role in power generation at thermal and nuclear power station. This article is devoted to determine effectiveness of water clarifier with use of micro-sand at Thermal power stations. Efficiency of coagulation with application of aluminum sulphate and flocculants is experimentally detected. Presented the result of the tests of clarifier with micro-sand and given conclusion on these results. (author)

  19. Virtual Calibration Chamber CPT on Ticino sand

    OpenAIRE

    Butlanska, Joanna; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio

    2010-01-01

    The following paper surnmarizes results of CPT's performed in virtual calibration chamber (VCC) built with a 3D model based on the distinct element method (DEM). A discrete material tailored to mimic Ticino sand is tested at different densities, stress and stress history. The limit cone tip resistance from the numerical experiments shows quantitative agreement with different empirical curves summarizing previous tests on Ticino sand in physical calibration chambers (ENEL and ISMES).

  20. 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.

  1. 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.

  2. Shock and release behaviour of sand

    International Nuclear Information System (INIS)

    A considerable body of knowledge exists on the shock properties of dry sand. However, capturing the release properties has proven experimentally complex, and currently little information exists on the topic. The measured Hugoniot and release behaviour from a number of experiments is presented, carried out with the aim of furthering understanding of the fundamental physics behind the unloading of dry sand from a shocked state.

  3. Flow behaviour of sand-water slurries

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zdeněk

    Cranfield, Bedforshire : BHR Group, 2010 - (Heywood, N.), s. 383-392 ISBN 978-1-85598-119-5. [International Conference on Hydrotransport /18./. Rio de Janeiro (BR), 22.09.2010-24.09.2010] R&D Projects: GA ČR(CZ) GAP105/10/1574 Institutional research plan: CEZ:AV0Z20600510 Keywords : sand slurry * sand -kaolin slurry * flow behavior * pressure drop * particle size distribution effect * concentration effect * slurry peptisation Subject RIV: BK - Fluid Dynamics

  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. Generating dam construction material from tailings sand

    Energy Technology Data Exchange (ETDEWEB)

    Bent, H. [Northgate Minerals Corp., Toronto, ON (Canada)

    2009-02-15

    Northgate Minerals is a leading gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. This presentation provided background information on the Northgate Minerals Corp. Kemess Mines and how to generate dam construction material from tailings sand. Specifically, the objectives of the program are to generate construction material from tailings sand and replace earth fill construction with tailings sand from which sulphur has been removed. This presentation reviewed environmental specifications such as producing a construction material that does not generate poor water quality. It also reviewed engineering specifications such as producing a material suitable for d/s buttress zone placement. The presentation discussed the evaluation of source material as well as analysis challenges. The evaluation of Kemess ore was also outlined. along with other topics such as environmental testing and verification of sand plant beta testing; criteria and communication; operational procedures including sand plant operation and fail safe procedures; placement of sulphur-free sand; and benefits. It was concluded that the tailings cyclone plant was constructed at a cost of 5.4 million dollars. tabs., figs.

  6. 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.

  7. Textural characteristics of the Nigerian tar sands

    Science.gov (United States)

    Enu, E. I.

    1985-05-01

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

  8. Radionic nonuniform black strings

    Science.gov (United States)

    Tamaki, Takashi; Kanno, Sugumi; Soda, Jiro

    2004-01-01

    Nonuniform black strings in the two-brane system are investigated using the effective action approach. It is shown that the radion acts as a nontrivial hair of the black strings. From the brane point of view, the black string appears as the deformed dilatonic black hole which becomes a dilatonic black hole in the single brane limit and reduces to the Reissner-Nordström black hole in the close limit of two-branes. The stability of solutions is demonstrated using catastrophe theory. From the bulk point of view, the black strings are proved to be nonuniform. Nevertheless, the zeroth law of black hole thermodynamics still holds.

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

    NARCIS (Netherlands)

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

    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

  10. 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

  11. Nuclear energy in the oils sands

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, J.E.

    2014-09-15

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  12. Nuclear energy in the oils sands

    International Nuclear Information System (INIS)

    The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

  13. Fracturing in the oil-sands reservoirs

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  14. 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.

  15. Activity of Wind-Blown Sand and the Formation of Feathered Sand Ridges in the Kumtagh Desert, China

    Science.gov (United States)

    Liao, Kongtai; Qu, Jianjun; Tang, Jinnian; Ding, Feng; Liu, Hujun; Zhu, Shujuan

    2010-05-01

    We study the activity of wind-blown sand and its effects on the evolution of feathered sand ridges in the Kumtagh Desert, China, and attempt to reveal the formation process of feathered sand ridges using wind-tunnel experiments, remote sensing data, and detailed field observations from 2005 to 2008. The prevailing wind direction in the Kumtagh Desert is easterly in winter and north-easterly in other seasons. The average annual wind speed is 5.9 ms-1, and winds sufficiently strong to entrain sand occur on 143 days per annum. The sand transport rate within 0.4 m of the ground is strongly influenced by local landforms, and is related to wind speed by a power function. Wind erosion occurs on the crest, the windward slope of crescent sand ridges and inter-ridge sand strips, where the blowing sand cloud is in an unsaturated state; in contrast, sand accumulation occurs on the leeward slope of the crescent sand ridges, where the blowing sand cloud is in an over-saturated state. These results indicate that the development of feathered sand ridges in the Kumtagh Desert is mainly controlled by the local wind regime. The dominant winds (from the north, north-north-east and north-east) and additional winds (from the east-north-east, east and east-south-east) determine the development of crescent sand ridges, but winds that are approximately parallel to sand ridges form the secondary inter-ridge sand strips.

  16. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io;

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies in the...

  17. Noncommutative black holes

    International Nuclear Information System (INIS)

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole

  18. Black Entrepreneurship in America.

    Science.gov (United States)

    Green, Shelley; Pryde, Paul

    The economic condition of black Americans is discussed, proceeding from the assumption that black economic progress does not depend on a renewed struggle for unobtained civil rights, but rather on the creative response of black Americans to economic opportunity and problems. In the long run, black economic development must rely on the…

  19. Contribution to the external surface of a titanium-rich sand (Abou-Khashaba, Egypt) in the uranium uptake processes

    International Nuclear Information System (INIS)

    The present study reports the U(VI) uptake from solution on a Ti-rich Egyptian black sand, showing that the crystal surfaces exhibit a marginal influence to the total process of U(VI) uptake onto Ti-containing micro- and mesoporous silicate materials. The results were evaluated using Lagergren first order equation and the apparent thermodynamic parameters of uranium uptake onto the considered materials were calculated. (author)

  20. 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.

  1. 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...... phenomenon can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

  2. Thermoluminescent dosimetric properties of Descalvado sand

    International Nuclear Information System (INIS)

    Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system (60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

  3. Mine Drainage and Oil Sand Water.

    Science.gov (United States)

    Wei, Xinchao; Wolfe, F Andrew; Li, Yanjun

    2015-10-01

    Mine drainage from the mining of mineral resources (coal, metals, oil sand, or industrial minerals) remains as a persistent environmental problem. This review summarizes the scientific literature published in 2014 on the technical issues related to mine drainage or mine water in active and abandoned coal/hard rock mining sites or waste spoil piles. Also included in this review is the water from oil sand operations. This review is divided into the four sections: 1) mine drainage characterization, 2) prediction and environmental impact, 3) treatment technologies, 4) oil sand water. Many papers presented in this review address more than one aspect and different sections should not be regarded as being mutuallyexclusive or all-inclusive. PMID:26420092

  4. An integrated oil sands environment monitoring plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-15

    This oil sands monitoring plan was published by Environment Canada, which coordinated the work of several independent scientists in a process intended to deliver a world class environmental monitoring program. The plan was created in keeping with the core principles laid out by the federal oil sands advisory panel. These are that the plan should be comprehensive, scientifically rigorous, adaptive and robust, collaborative, transparent and accessible. The proposed oil Sands monitoring program framework conforms to these principles. The approach used was ecosystem-based and took into account several essential components of the system such as hydrology, water quality and quantity, and climatology and it also incorporated the relationships between these components. The best available science-based approach was used. The implementation of the plan is expected to result in standardized reporting, including peer-reviewed and plain language publications.

  5. Sand attrition in conical spouted beds

    Institute of Scientific and Technical Information of China (English)

    Aranzazu R. Fernández-Akarregui; Jon Makibar; Isabel Alava; Luis Diaz; Fernando Cueva; Roberto Aguado; Gartzen Lopez; Martin Olazar

    2012-01-01

    A study was carried out on the attrition in conical spouted beds using two sands with different properties for several bed heights and gas flow rates.Furthermore,the influence of a draft tube was studied at ambient and high temperatures.The main objective was to acquire knowledge on the attrition of sand beds for biomass pyrolysis in a pilot plant provided with a conical spouted bed reactor.A first-order kinetic equation is proposed for sand attrition in a conical spouted bed at room temperature.The predicted attrition rate constant depends exponentially on excess air velocity over that for minimum spouting.Both the draft tube and temperature increase contribute to reduction of attrition.

  6. Instrumented model pile tests on sand plugs

    Energy Technology Data Exchange (ETDEWEB)

    Haaren, L.J.C. van; Verruijt, A. [Delft Univ. of Technology (Netherlands); Kolk, H.J. [Fugro Engineers B.V., Leidschendam (Netherlands)

    1995-12-31

    0pen ended piles develop internal frictional resistance between the internal soil plug end the pile wall during axial loading. Current pipe pile design practice assumes that the ultimate internal skin friction is of the same order of magnitude as the outer skin friction. This paper describes a series of laboratory pile load tests on instrumented model pipe piles, designed to investigate the development of plug stresses and skin friction along the plug length during pile loading. The piles contain sand columns of various relative densities and of different heights. The soil plugs are loaded to failure under fully drained conditions. The test data indicate that internal skin friction in sand can be substantially higher than assumed in conventional design practice. This finding could lead to significant economical savings on future pipe pile foundations in sand.

  7. 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.

  8. Effect of sand production on casing integrity

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.Q.; Zhu, T.G.; Fang, L.T. [Dongsheng Petroleum Development Stock Co. Ltd., Shengli Oilfield (China); Yuan, Y. [BitCan Geosciences and Engineering Inc., Calgary, AB (Canada)

    2006-07-01

    Well casings are exposed to potentially corrosive formation fluids and subject to in situ stresses, fluid pressure, and reservoir compaction and expansion. Casing integrity can be compromised by human errors such as poor cement placement and inappropriate perforations. This paper described the outcome of an engineering study examining the effects of unintended excessive sand production on casing integrity. Supports to casings can be impacted when excessive amounts of sand are produced from the near-wellbore region. Compromised casing supports can buckle under axial loading from reservoir compaction. A case study of a well in the NiuZhang oilfield that experienced significant casing deformation 11 years after its completion was presented. Workover tools and production tubings could not pass through the damaged interval due to dramatic multiple doglegs. A mathematical analysis of casing buckling and activation of weak planes in the overburden suggested that a combination of excessive sand production and reservoir compaction during the well washing was responsible for the casing damage. The rapid 35 MPa pressure drop during the well washing disturbed rock materials around the perforation interval. Injected waste water reduced the rock strength due to swelling of the clay fines upon exposure to the water, causing significant amounts of rock solids to be produced over time. The excessive sand production formed a large void behind the casing and depleted its lateral support. It was concluded that proper management of sand production is necessary. However, control of sand production increases operating costs and can compromise oil production rates. Preliminary field measures such as the use of inclined wells, and gentle pressure drop during well washing were recommended. 16 refs., 1 tab., 9 figs.

  9. Evaluatıon Of Tourism Opportunies in the Black Sea Region With Swot Analysis

    Directory of Open Access Journals (Sweden)

    Murat YEŞİLTAŞ

    2009-06-01

    Full Text Available In Turkey, tourism activities are generally based on sea-sand-sun trio. Although it has an outstanding place in tourism supply and potential, Turkey has not realized the value of it yet. In this study, the Black Sea Region is analysed for alternative tourism activities and possible tourism activities are explained. In parallel with this, the tourism assests of the Black Sea Region are evaluated by SWOT analysis.

  10. Strict specifications: UK frac sand potential

    OpenAIRE

    Mitchell, Clive

    2015-01-01

    The UK is actively looking at the potential production of shale gas and, as a result, the country’s extractive minerals industry is looking at the role it can play in providing minerals that could be used in hydraulic fracturing (fracking). One such mineral is silica sand, which is used as a proppant,commonly referred to as “frac sand”. Clive Mitchell, Industrial Minerals Specialist*, provides an educated guess as to where this frac sand could come from in the UK.

  11. Gamma Ray Shielding from Saudi White Sand

    OpenAIRE

    Al-horayess OKLA; Al-Dayel OMAR; Hefne JAMEEL; Al-Ajyan TURKI; Bagazi ALI

    2010-01-01

    This study is a comparison of gamma ray linear attenuation coefficient of two typs of shielding materials made of Saudi white and red sand. Each shield was consisted of one part of cement two parts of sand in addi-tion to water. Different thicknesses were tested. The concentrations of all elements in each shield material were determined by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results obtained from the ICP-MS were used in MCNP4B (Monte Carlo N-Particle Transport Computer ...

  12. 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...... 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....

  13. Log-inject-log in sand consolidation

    International Nuclear Information System (INIS)

    A method is described for gathering information for the determination of the adequacy of placement of sand consolidating plastic for sand control in oil and gas wells. The method uses a high neutron cross-section tracer which becomes part of the plastic and uses pulsed neutron logging before and after injection of the plastic. Preferably, the method uses lithium, boron, indium, and/or cadmium tracers. Boron oxide is especially useful and can be dissolved in alcohol and mixed with the plastic ingredients

  14. Oil sand synfuel production using nuclear energy

    International Nuclear Information System (INIS)

    The importance of oil sand as a primary energy carrier is illustrated. The oil sand mining project 'synfuel' in Fort McMurray, Alberta, Canada, is described. On the basis of a layout of an In-situ-process different possibilities of introducing nuclear energy to the process are described. This leads to an increase of the product yield, leading finally to a doubling of the energy output compared to the reference layout. The introduction of nuclear energy contributes to the reduction of emissions, in particular to the emission of carbon dioxide in the conversion process. (orig.)

  15. Use Possibilities for River Sand in Foundry

    Directory of Open Access Journals (Sweden)

    Rodica Rădulea

    2012-09-01

    Full Text Available In this paper the following characteristics are studied: the chemical and mineralogical composition, the granulation and content of leachate component of different types of sands, collected from various fords of running waters in comparison to those coming from known mines and used as such in foundries for the preparation of casting mixtures. The purpose of the study starts from the premises of finding reduction possibilities of costs in part casting, keeping in mind that known deposits from our country contain increasingly reduced quantities of casting sands.

  16. Granular size segregation in underwater sand ripples.

    Science.gov (United States)

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

    2004-02-01

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

  17. An airborne assessment of atmospheric particulate emissions from the processing of Athabasca oil sands

    Directory of Open Access Journals (Sweden)

    S. G. Howell

    2013-08-01

    Full Text Available During the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS campaign, two NASA research aircraft, a DC-8 and a P-3B, were outfitted with extensive trace gas (the DC-8 and aerosol (both aircraft instrumentation. Each aircraft spent about a half hour sampling air around the oil sands mining and upgrading facilities near Ft. McMurray, Alberta, Canada. The DC-8 circled the area, while the P-3B flew directly over the upgrading plants, sampling close to the exhaust stacks, then headed downwind to monitor the aerosol as it aged. At short range, the plume from the oil sands is a complex mosaic of freshly nucleated ultrafine particles from a SO2 and NO2-rich plume, fly ash and soot from industrial processes, and dust from dirt roads and mining operations. Shortly downwind, organic aerosol appears in quantities that rival SO4=, either as volatile organic vapors condense or as they react with the H2SO4. The DC-8 pattern allowed us to integrate total flux from the oil sands facilities within about a factor of two uncertainty that spanned values consistent with 2008 estimates from reported SO2 and NO2 emissions. In contrast, CO fluxes exceeded reported regional emissions, due either to variability in production or sources missing from the emissions inventory. The conversion rate of SO2 to aerosol SO4= of ~6% per hour is consistent with earlier reports, though OH concentrations are insufficient to accomplish this. Other oxidation pathways must be active. Altogether, organic aerosol and black carbon emissions from the oil sands operations are small compared with the forest fires present in the region during the summer. The oil sands do contribute significant sulfate and exceed fire production of SO2 by an order of magnitude.

  18. Tunnelling Problems in Older Sand Formations

    Science.gov (United States)

    Nieuwenhuis, Jan Dirk; Verruijt, Arnold

    In its deepest stretch, 60 m below o.d. and water level, the Westerschelde tunnel trace below the estuary in the Southwestern part of the Netherlands, crosses the lower Oligocene Rupel clay (Boom clay) and the Sands of Berg. Expected problems such as small penetration rates and difficult steerability of the TBM did not occur but surprisingly high radial pressures deformed the shields tail section to such an extent that concrete rings of the permanent tunnel could not be emplaced. In retrospect after finishing the tunnel and cumbersome remedial measures the sands of Berg, known to be dense and strong, appear to exhibit very strong dilatancy when axially sheared by the TBM. Some buckling computations and an estimate of dilatant effects are presented together with educated (and now confirmed) guess work on diagenetic effects such as recrystallization and cementation. It seems wise to warn designers of shallow tunnels crossing tertiary sand formations for unexpected forces on shield and cutting wheel due to diagenetic structuring of these old sands.

  19. Market opportunities and challenges for oil sands

    International Nuclear Information System (INIS)

    The use of Alberta bitumen as a clean fuel depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production from the Western Canada Sedimentary Basin. The challenges facing the oils sands processing industry include: crude oil prices which affect the producer's market; market expansion options; diluent availability/cost; supply cost competitiveness; and, regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. It was noted that Alberta must retain or increase its share of the Midwest market. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. New pipeline capacity is needed to reach more distant markets such as Southern Midwest, Washington, and California. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. 13 figs

  20. Growing markets to sustain oil sands development

    International Nuclear Information System (INIS)

    The utilization of Alberta bitumen for the clean fuels market depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production in Western Canada. Several issues pose a challenge to the oil sands processing industry. The producers' market is affected by crude oil prices, market expansion options, diluent availability/cost, supply cost competitiveness, and regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. A brief review of markets for Canadian crude oil, including synthetic crude, was provided. The share of the Midwest market by Alberta must be retained and increased. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. To reach more distant markets such as Southern Midwest, Washington, and California, new pipeline capacity would be required. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. tabs., figs

  1. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel; Shajarati, Amir

    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...

  2. Drawing a Line in the Sand

    Institute of Scientific and Technical Information of China (English)

    Ni Yanshuo

    2011-01-01

    @@ 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 Cbina'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.

  3. EXPRESSING SUPPLY LIMITATION IN SAND SALTATION

    Science.gov (United States)

    Saltation-driven sandblasting is the most effective producer of windblown dust. Modeling of wind-blown dust emissions requires an efficient parameterization of sand flux in the saltating mode. According to the theory of P. R. Owen the horizontal mass flux of saltating uniform p...

  4. Radiation safety in Australia's mineral sands industry

    International Nuclear Information System (INIS)

    This brochure is part of a training package aiming to explain in simple terms what radiation is, how it affects people's lives and how, in the specific case of the mineral sand industry, the risk of ill-effects from low-level radioactivity could be effectively guarded against by simple and easily followed safety precautions. ills

  5. 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…

  6. The provenance of Taklamakan desert sand

    Science.gov (United States)

    Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

    2016-03-01

    Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

  7. 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....

  8. Increased maximum sand free rate by use of chemical sand consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Haavind, Frode

    2006-04-15

    In this work, a chemical sand consolidation method is developed in order to increase the Maximum Sand Free Rate (MSFR). The method can be applied as a sand control tool in addition to or instead of more traditional sand control equipment at completion of a well or at a later stage. Several sand consolidation chemicals were evaluated for their ability to consolidate sand in an experimental study. The evaluation was done by measuring sand production and permeability before and after treatment for each experiment. Three different groups of chemicals were tested: 1) Six chemicals that are based on organosilane chemistry, 2) one chemical that is a polymer and 3) one enzyme derived method based on precipitation of CaCO{sub 3} (s). The best overall chemical was an organosilane. This specific organosilane was chosen for further work. Design of experiments was used in order to investigate the influence of concentration of the chemical, the temperature during shut-in and the shut-in time on sand production and permeability impairment. The results showed that increasing concentration and shut-in temperature decreased sand production and increased pressure drop during sand production, whereas shut-in time had only a minor effect. It was not possible to obtain a good model for permeability reduction. During the summer of 2004, a Norwegian Sea field showed interest in the chemical sand consolidation method. The chemical previously evaluated using design of experiments was chosen. The chemical was tested on sand from the field. In addition, the chemical was tested on several reservoir cores. Theoretical calculations on fluid velocities and hydrodynamic forces in the perforations were performed. Finally, the chemical was pumped in three wells during September 2004. Originally, the plan was to treat only one well, but due to the success of this treatment, two additional wells were treated with the organosilane. The first well had an inclination of 80 degrees from the vertical, had

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

    Directory of Open Access Journals (Sweden)

    Keiko Udo

    2009-11-01

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

  10. 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.

  11. Chemical Stablilisation of Sand : Part VIII Furan Resins as Dune and Coastal Sand Stabiliser

    OpenAIRE

    Ram Gopal; Jeevan Singh; Ghanshyam Das

    1990-01-01

    Studies on furan resin as dune sand stabiliser are presented. Influence of acid catalysts, viz. phenol disulphonic acid, sulphuric acid, hydrochloric acid and phosphoric acid and other catalysts, viz. trichlorotoluene and benzoyl chloride along with promoters, zinc chloride and ferric chloride, on the strength of stabilised furan resin-sand specimens has been discussed. Optimisation studies on resin content, catalysts and promoters and curing conditions have revealed that maximum stren...

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

    Science.gov (United States)

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

    2015-11-01

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

  13. SPECIFIC RESISTANCE AND SPECIFIC INTENSITY OF BELT SANDING OF WOOD

    Directory of Open Access Journals (Sweden)

    Boleslaw Porankiewicz

    2010-06-01

    Full Text Available This paper examines and discusses the specific belt sanding resistance K (N·cm-2 and specific belt sanding intensity SI (g·cm-2·min-1, for wood of Pinus sylvestris L., Picea abies L., Quercus robra L., Acer pseudoplatanus L., Alnus glutinosa Gaertn., and Populus Nigra L., by different sanding pressure pS, different sanding grit NG number, and different wood grain angles Phi(v.

  14. Properties of Self-Compacting Concrete Incorporating Waste Foundry Sand

    OpenAIRE

    Rafat SIDDIQUE; Ravinder Kaur SANDHU

    2013-01-01

    This paper demonstrates the possibilities of using waste foundry sand as partial replacement of sand in self-compacting concrete. Self-compacting concrete, as the name indicates, is a type of concrete that does not require external or internal compaction, because it becomes levelled and consolidated under its self-weight. Foundry sand is high quality silica sand used as a moulding material by ferrous and non-ferrous metal casting industries. It can be reused several times in foundries but, af...

  15. Numerical Modeling of Flow in a Horizontal Sand Filter

    OpenAIRE

    Ruth Mossad; Hal Aral

    2010-01-01

    Problem statement: Horizontal sand filters may offer some advantage over vertical sand filters as they could be used for in-line treatment of wastewaters. Horizontal pipelines of tens and if not hundreds of meters length, filled with ordinary sand or permeable reactive media such as activated carbon or natural zeolite or iron filings, may be used to remove impurities from mine drainage waters, sewer and storm waters. Approach: However, in reality, in industrial-scale applications, the sand fi...

  16. Thermal deformation of moulding sands with biopolymer binders

    OpenAIRE

    K. Major-Gabryś; St. M. Dobosz; J. Jakubski

    2010-01-01

    Investigations concerning an application of biopolymer materials as binders for moulding sands are presented in the paper. Theseinvestigations constitute the continuation of examinations related to applications of various biopolymers as binding agents. The results ofstrength tests, obtained for the investigated sands (with the PLA2 biopolymer binder) prepared in a self-hardening sands technology andair as well as microwave hardened, are presented. Examinations of sand thermal deformations bas...

  17. Initiation of backward erosion piping in uniform sands

    OpenAIRE

    Van Beek, VM; Bezuijen, Adam; Sellmeijer, JB; Barends, FBJ

    2014-01-01

    The process of backward erosion piping poses a threat to dams and dikes on foundations of nonplastic sands and silts. The available models for design and predictions focus predominantly on the progression of the pipe. However, sand boils in the field will occur as a result of the initiation of sand transport. Although criteria are available for predicting sand boiling and heaving in columns, there is no model describing the initiation of piping in situations where the exit flow is not uniform...

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

    NARCIS (Netherlands)

    Miedema, S.A.

    2013-01-01

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

  19. 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...

  20. Status of sand as a thermoluminescence (TL) gamma dosimeter

    International Nuclear Information System (INIS)

    Investigations have revealed that sand has desired characteristics for its use as an accident gamma dosimeter. The present paper describes the status of typical Rajasthan sand, its energy response, thermal annealing characteristics and effect of ultraviolet radiations on TL signals induced by gamma irradiated sand samples. (authors). 14 refs., 3 figs

  1. Supercritical-Fluid Extraction of Oil From Tar Sands

    Science.gov (United States)

    Compton, L. E.

    1982-01-01

    New supercritical solvent mixtures have been laboratory-tested for extraction of oil from tar sands. Mixture is circulated through sand at high pressure and at a temperature above critical point, dissolving organic matter into the compressed gas. Extract is recovered from sand residues. Low-temperature super-critical solvents reduce energy consumption and waste-disposal problems.

  2. Numerical simulation of wind sand movement in straw checkerboard barriers.

    Science.gov (United States)

    Huang, Ning; Xia, Xianpan; Tong, Ding

    2013-09-01

    Straw checkerboard barrier (SCB) is the most representative antidesertification measure and plays a significant role in antidesertification projects. Large-eddy simulation and discrete-particle tracing were used to numerically simulate the wind sand movement inside the straw checkerboard barrier (SCB), study the movement characteristics of sand particles, find the transverse velocities of sand particles and flow field, and obtain the contour of the transverse velocity of coupled wind field within the SCB. The results showed that 1) compared with that at the inlet of the SCB, the sand transport rate inside the SCB greatly decreases and the speed of sand grain movement also evidently drops, indicating that the SCB has very good sand movement preventing and fixing function; 2) within the SCB there exists a series of unevenly distributed eddies of wind sand flow, their strength decreases gradually with increasing the transverse distance; 3) affected by eddies or reflux, sand particles carried by the wind sand flow have to drop forward and backward the two interior walls inside the SCB, respectively, forming a v-shaped sand trough; 4) the sand transport rate gradually decreases with increasing number of SCBs, which reveals that the capacity of the wind field to transport sand particles decreases. This research is of significance in sandstorm and land desertification control. PMID:24026396

  3. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  4. Dynamics of black holes

    OpenAIRE

    Hayward, Sean A.

    2008-01-01

    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  5. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  6. Black Hole Statistics

    OpenAIRE

    Strominger, Andrew

    1993-01-01

    The quantum statistics of charged, extremal black holes is investigated beginning with the hypothesis that the quantum state is a functional on the space of closed three-geometries, with each black hole connected to an oppositely charged black hole through a spatial wormhole. From this starting point a simple argument is given that a collection of extremal black holes obeys neither Bose nor Fermi statistics. Rather they obey an exotic variety of particle statistics known as ``infinite statist...

  7. Phantom Black Holes

    OpenAIRE

    Gao, C. J.; Zhang, S. N.

    2006-01-01

    The exact solutions of electrically charged phantom black holes with the cosmological constant are constructed. They are labelled by the mass, the electrical charge, the cosmological constant and the coupling constant between the phantom and the Maxwell field. It is found that the phantom has important consequences on the properties of black holes. In particular, the extremal charged phantom black holes can never be achieved and so the third law of thermodynamics for black holes still holds. ...

  8. Effect of quartz sand on compressive strength of the solid waste composite

    Science.gov (United States)

    Masturi, Marwoto, Putut; Sunarno, Rustad, Supriadi

    2016-02-01

    A solid waste composite was successfully made. Preliminary, the composite was synthesized using polyurethane (PU) as binder mixed with the solid waste using simple mixing method and then hot-pressed at at pressure of 4 metric-tons and temperature of 80°C for 20 minutes. To enhance its strength, quartz sand partilces with varied content then were added into the PU-solid waste mixture. From the compressive strength test, it was obtained that PU/solid waste composite with PU fraction (w/w) of 0.43 has optimum compressive strength of 38.91 MPa. Having been added quartz sand having average particles size of 0.94 μm, its compressive strength attains maximum at 40.47 MPa for quartz sand fraction (w/w) of 4.27 × 10-3. The strength is comparable to that of clay brick, slate stone, sandstone, limestone, alder wood, aspen wood, black cherry and pine woods. Therefore, this composite is very adequate to compete the building materials such as the bricks, stones and woods.

  9. Black Nuns as Educators.

    Science.gov (United States)

    Rector, Theresa A.

    1982-01-01

    Traces the contributions of Black Roman Catholic nuns to Black education in the United States since the early 1800s. Also shows that, despite declining membership, the three existing religious orders continue to be active in Black education and social change. (GC)

  10. Pengaruh Ketebalan Media dan Rate filtrasi pada Sand Filter dalam Menurunkan Kekeruhan dan Total Coliform

    OpenAIRE

    Deni Maryani; Ali Masduqi; Atiek Moesriati

    2014-01-01

    Pada penelitian ini dilakukan proses filtrasi dengan menggunakan sand filter sebagai salah satu metode dalam pengolahan air bersih. Pada sand filter proses penyaringan terjadi pada media filter yang sangat halus, seperti media filter pada unit slow sand filter. Kecepatan penyaringan yang diinginkan pada sand filter ini adalah kecepatan seperti pada unit rapid sand filter. Sehingga sand filter ini adalah penggabungan antara kelebihan yang dimiliki slow sand filter dan rapid sand filter. Varias...

  11. Black Holes in Higher Dimensions (Black Strings and Black Rings)

    CERN Document Server

    Kleihaus, Burkhard

    2016-01-01

    The last three years have again seen new exciting developments in the area of higher dimensional black objects. For black objects with noncompact higher dimensions, the solution space was exlored further within the blackfold approach and with numerical schemes, yielding a large variety of new families of solutions, while limiting procedures created so-called super-entropic black holes. Concerning compact extra dimensions, the sequences of static nonuniform black strings in five and six dimensions were extended to impressively large values of the nonuniformity parameter with extreme numerical precision, showing that an oscillating pattern arises for the mass, the area or the temperature, while approaching the conjectured double-cone merger solution. Besides the presentation of interesting new types of higherdimensional solutions, also their physical properties were addressed in this session. While the main focus was on Einstein gravity, a significant number of talks also covered Lovelock theories.

  12. Treatment of potato farm wastewater with sand filtration.

    Science.gov (United States)

    Bosak, V K; VanderZaag, A C; Crolla, A; Kinsley, C; Chabot, D; Miller, S S; Gordon, R J

    2016-07-01

    This study examined sand filtration as a component of a potato farm wastewater treatment system. Two different sand filter designs, saturated flow and unsaturated flow, were evaluated at three different loading rates: 34, 68, and 136 L m(-2) d(-1). Filter design had a significant effect, with unsaturated flow sand filters having significantly (p phosphorus well (62-99%). Total nitrogen removal was twice as high in unsaturated flow filters (53%) than in saturated flow filters (27%), because of the recurring cycle of aerobic and anaerobic conditions during sand saturation and drying in unsaturated flow sand filters. PMID:26806787

  13. The physics of wind-blown sand and dust

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2012-10-01

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

  15. The physics of wind-blown sand and dust

    CERN Document Server

    Kok, Jasper F; Michaels, Timothy I; Karam, Diana Bou

    2012-01-01

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

  16. Stratified chaos in a sand pile formation

    CERN Document Server

    Poortinga, Ate; Ritsema, Coen J

    2014-01-01

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

  17. Bison and the oil sands industry

    International Nuclear Information System (INIS)

    The feasibility of raising bison on land reclaimed after disturbance by oil sands development was explored. A five-year research program by Syncrude Canada and the Fort McKay First Nations found that forage productivity and carrying capacity for bison was comparable to that of grassland elsewhere in Alberta. Weight gains typical for ranched bison and calving rates of 90 per cent, a value typical of ranched bison, were observed. Analysis indicated that a 1000 hectare bison ranch on reclaimed land has a net present value that compares favorably with a similar area supporting commercial forest. If approved by Alberta Environmental Protection, the study will be expanded as a pilot commercial venture to explore commercial viability as a business venture by the Fort McKay First Nations. Assuming that the project will proceed as planned, measures will be also implemented to resolve various regulatory issues associated with commercial bison production in the oil sands area

  18. 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...... 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....

  19. Log-inject-log sand consolidation

    International Nuclear Information System (INIS)

    This invention concerns a method of detecting an effective placement of a sand consolidating plastic in a producing formation penetrated by a well. Two logs sensitive to the presence of a tracer in the plastic are run, one before and the other after treating the formaton. Wherever a comparison of the logs shows a zone which was to be consolidated having an insufficient increase in neutron capture indicating insufficient plastic, remedial action such as isolating the zone having insufficient plastic and squeezing additional plastic is performed before resuming production, which avoids the well sanding up and results in great savings. Preferably the method uses lithium, boron, indium and/or cadmium tracers incorporated into the plastic, especially in the form of lithium chloride, boron oxide, or cadmium chloride. (author)

  20. Reflection of internal waves by sand ripples

    Directory of Open Access Journals (Sweden)

    Uma Basu

    1995-03-01

    Full Text Available An investigation is made to study the diffraction of a train of time harmonic progressive waves propagating along the surface of separation of two superposed fluids which are laterally unbounded, the upper fluid being extended infinitely upwards, the lower fluid being of finite depth with sand ripples at the bottom. The first order correction to the velocity potential for the problem of diffraction of interface waves in the presence of bottom deformation is obtained by integral transform technique after introduction of a linear frictional term in the kinematic boundary condition at the surface of separation following Lamb (1932, and the reflection and transmission coefficients are estimated for a patch of sand ripples.

  1. 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.

  2. 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.

  3. Mineralogy of Eolian Sands at Gale Crater

    Science.gov (United States)

    Achilles, C. N.; Vaniman, D. T.; Blake, D. F.; Bristow, T. F.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Morris, R. V.; Morrison, S. M.; Downs, R. T.; Fendrich, K. V.; Ehlmann, B. L.; Yen, A. S.; Sarrazin, P. C.; Treiman, A. H.; Craig, P. I.; Lapotre, M. G. A.; Edgett, K. S.; Gellert, R.; Crisp, J. A.; Morookian, J. M.; Grotzinger, J. P.; Des Marais, D. J.; Farmer, J. D.

    2016-01-01

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

  4. Drained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Praastrup, U.; Jakobsen, Kim Parsberg

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

  5. 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.

  6. 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.

  7. DOE to assess produced water, sand harm

    International Nuclear Information System (INIS)

    This paper reports that the Department of Energy which is launching a research program to determine if water and sand produced with oil and gas in the Gulf of Mexico pose U.S. environmental or health risks. A court has ordered the Environmental Protection Agency to issue new nation-wide discharge guidelines by next June, and DOE warned that tighter limits could reduce future offshore production by hundreds of millions of barrels

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Experimental investigation of sanding propensity for the Andrew completion

    Energy Technology Data Exchange (ETDEWEB)

    Venkitaraman, A.; Li, H. [Schlumberger Perforating and Testing Center (United Kingdom); Leonard, A. J.; Bowden, P. R. [BP Exploration (United Kingdom)

    1998-12-31

    A series of laboratory experiments were performed on three reservoir core samples selected from two plot wells to confirm the likelihood of sand production during the completion phase of the planned Andrew horizontal wells, and to perform risk analysis of formation failure at the time of underbalance perforation, and expected producing conditions. CT scans revealed no perforation failure, and the core samples did not show any propensity to produce sand during single-phase oil flow. Transient sand production was observed when water cut was introduced, but sand production declined as the percentage of water cut was increased. There was no evidence of sand production in the core samples during depletion testing either, and the wells were subsequently completed with perforated cemented liners without sand control. No sand problems have been encountered in two years of production, with some wells in water cut and declined reservoir pressure of 200 psi. 8 refs., 3 tabs., 5 figs.

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

    International Nuclear Information System (INIS)

    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.

  15. Nonstationary analogue black holes

    International Nuclear Information System (INIS)

    We study the existence of analogue nonstationary spherically symmetric black holes. The prime example is the acoustic model see Unruh (1981 Phys. Rev. Lett. 46 1351). We consider also a more general class of metrics that could be useful in other physical models of analogue black and white holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of analogue black holes. In the end we study the inverse problem of determination of black or white holes by boundary measurements for the spherically symmetric nonstationary metrics. (paper)

  16. Black Hole Battery

    Science.gov (United States)

    Levin, Janna; D'Orazio, Daniel

    2016-03-01

    Black holes are dark dead stars. Neutron stars are giant magnets. As the neutron star orbits the black hole, an electronic circuit forms that generates a blast of power just before the black hole absorbs the neutron star whole. The black hole battery conceivably would be observable at cosmological distances. Possible channels for luminosity include synchro-curvature radiation, a blazing fireball, or even an unstable, short-lived black hole pulsar. As suggested by Mingarelli, Levin, and Lazio, some fraction of the battery power could also be reprocessed into coherent radio emission to populate a subclass of fast radio bursts.

  17. 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.

  18. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    Progress of the major government sponsored projects undertaken to increase gas production from the low permeability gas sands of the western United States during February, 1978 is summarized. The Western Gas Sands Project files, which contain raw data and published reports from each Western Gas Sands Project participant have been established. A log file containing logs from pertinent wells in the four study areas has also been established. The U.S. Geological Survey (USGS) is continuing geological and geophysical studies in the four study areas for resource assessment. A number of papers giving results of recent investigations were presented at meetings during the month. The Bartlesville Energy Research Center (BERC) and participating National Laboratories are continuing their work in research and development. Field tests and demonstrations continue in the Uinta and Piceance Basins at the following locations: Uinta Basin, Gas Producing Enterprises, Inc. (GPE) Natural Buttes Unit Wells No. 14, 18, 19, 20, 21, and 22; Piceance Basin, Mobil Research and Development Corporation Well No. F-31-13G, Rio Blanco Natural Gas Company Well No. 498-4-1.

  19. Numerical simulation of sand jet in water

    Energy Technology Data Exchange (ETDEWEB)

    Azimi, A.H.; Zhu, D.; Rajaratnam, N. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2008-07-01

    A numerical simulation of sand jet in water was presented. The study involved a two-phase flow using two-phase turbulent jets. A literature review was also presented, including an experiment on particle laden air jet using laser doppler velocimetry (LDV); experiments on the effect of particle size and concentration on solid-gas jets; an experimental study of solid-liquid jets using particle image velocimetry (PIV) technique where mean velocity and fluctuations were measured; and an experimental study on solid-liquid jets using the laser doppler anemometry (LDA) technique measuring both water axial and radial velocities. Other literature review results included a photographic study of sand jets in water; a comparison of many two-phase turbulent flow; and direct numerical simulation and large-eddy simulation to study the effect of particle in gas jet flow. The mathematical model and experimental setup were also included in the presentation along with simulation results for sand jets, concentration, and kinetic energy. The presentation concluded with some proposed future studies including numerical simulation of slurry jets in water and numerical simulation of slurry jets in MFT. tabs., figs.

  20. Mobil Oil Canada : Kearl Oil Sands Mine

    International Nuclear Information System (INIS)

    The upgrader design at Mobil's Kearl Oil Sands Mine were described. Included were feed characteristics, upgrader products, process schemes and their overall economics and upgrader technologies in use, including coking, deasphalting, hydrocracking, hydrotreating and visbreaking. Advantages and disadvantages of the upgrader technologies were highlighted. As far as the product is concerned, much of it is destined to U.S. refineries that are equipped to process the material. The Kearl Oil Sands Mine upgrading facility will likely use a combination of coker/hydrotreating, which is a well proven process for high value products that has been used in all five of Mobil's refineries in the U.S., and visbreaker/deasphalting, which has shown promise in bench-scale testing, but at present still has some potential commercial difficulties. Foremost among these are the high softening product of asphalt from visbroken products, questionable commercial feasibility of the low yield of pitch, and problems in the disposal of asphalt. Severe visbreaking also yields unstable products. Details of Mobil Canada's oil sands project were also summarized 2 tabs., 9 figs

  1. Integrating sand control, completion decisions pay off

    Energy Technology Data Exchange (ETDEWEB)

    Renfro, K.D.; Procyk, A.

    1998-10-01

    Anadarko recently completed an open-hole, horizontal gas well in the Gulf of Mexico using completion and sand control techniques that have proven extremely successful, judging from the production numbers. The well, in the East Addition, High Island Area, about 120 miles southeast of Galveston in 341-ft waters, was completed with a Pall Stratapac Sand Control Screen without a gravel pack. The flow rate of the well is four to sic times what would have been expected from a conventional, vertical, gravel-packed well with similar conditions. The well`s peak production rate was 22.0 MMcfd, and the well produced a total of more than 2.635 bcf of gas from November 1997 to July 1998. Drawdown was calculated at less than 40 psi, and a skin factor of negative 3.5 indicates that formation damage during the completion was negligible. The full range of completion and sand control decisions came together to make this well a success.

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

    Directory of Open Access Journals (Sweden)

    Marzieh Hesam-Mohammadi

    2014-12-01

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

  3. Black Flowers in Flatland

    CERN Document Server

    Alkac, Gokhan; Tekin, Bayram

    2016-01-01

    Asymptotically flat black holes in $2+1$ dimensions are a rarity. We study the recently found black flower solutions (asymptotically flat black holes with deformed horizons), static black holes, rotating black holes and the dynamical black flowers (black holes with radiative gravitons ) of the purely quadratic version of new massive gravity. We show how they appear in this theory and we also show that they are also solutions to the infinite order extended version of the new massive gravity, that is the Born-Infeld extension of new massive gravity with an amputated Einsteinian piece. The same metrics also solve the topologically extended versions of these theories, with modified conserved charges and the thermodynamical quantities, such as the Wald entropy. Besides these we find new conformally flat radiating type solutions to these extended gravity models. We also show that these metrics do not arise in Einstein's gravity coupled to physical perfect fluids.

  4. Swelling behaviors of GMZ bentonite-sand mixtures inundated in NaCl-Na{sub 2}SO{sub 4} solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Huyuan, E-mail: cuisl-03@163.com [Key Laboratory of Mechanics on Disaster and Environment in Western China (Lanzhou University), Ministry of Education, Lanzhou 730000 (China); Cui Suli; Zhang Ming; Jia Lingyan [Key Laboratory of Mechanics on Disaster and Environment in Western China (Lanzhou University), Ministry of Education, Lanzhou 730000 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer GMZ bentonite-sand mixtures were used for swelling properties study in China. Black-Right-Pointing-Pointer Chemical solutions which simulate ground water of Gansu BeiShan in China were used. Black-Right-Pointing-Pointer The influences of simulative solutions on the swelling behaviors of specimens were obtained. Black-Right-Pointing-Pointer Mixtures have a better tolerance than pure bentonite to withstanding the chemical attack. - Abstract: In this study, the swelling behaviors of compacted GMZ bentonite-sand mixtures inundated in NaCl-Na{sub 2}SO{sub 4} solutions are investigated and the influence of chemical solutions on the swelling behaviors of GMZ bentonite-sand mixtures as backfill/buffer material in China for high level radioactive waste (HLW) is investigated. The sand addition ratios of the bentonite-sand mixtures are 0%, 20%, 30% and 50%, and the total dissolved solids (TDS) of the NaCl-Na{sub 2}SO{sub 4} (NaCl:Na{sub 2}SO{sub 4} = 2:1 by mass) solution are 0.5, 1.0, 3.0, 6.0 and 12.0 g/L (pH 7.1). The specimens of bentonite-sand mixtures for swelling tests are prepared by static-compaction to various dry densities, ranging from 1.50 to 1.90 g/cm{sup 3}. Test results indicate that liquid limit (LL) and plasticity limit (PL), swell time, maximum swelling pressure and maximum swelling strain decrease with the increase of TDS for GMZ bentonite-sand mixtures. All of the LL, PI and maximum swelling strain are decreased exponentially with TDS increase: very quickly as TDS < 3.0 g/L, slowly as TDS = 3.0-6.0 g/L and almost stabilized as TDS > 6.0 g/L. The maximum swelling pressure shows a linear reduction with the TDS increasing, but the pure bentonite indicates a high sensitivity than the bentonite-sand mixtures with 30% sand addition ratio. As NaCl-Na{sub 2}SO{sub 4} (TDS = 0.5 g/L) solution was used according to the ground water, with initial dry density of 1.70 g/cm{sup 3}, the maximum swelling pressure of specimens

  5. 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)

  6. Diffusion tests of mercury through concrete, bentonite-enhanced sand and sand.

    Science.gov (United States)

    Svensson, Margareta; Allard, Bert

    2007-04-01

    The transport by diffusion of Hg(II) and Hg(0) through a barrier of concrete or bentonite-enhanced sand was examined under aerobic conditions. Sand was used as a reference system parallel to the two systems. Speciation of mercury was performed with a purge and trap method, where dissolved Hg(0) was purged with nitrogen gas from the sample, through a trap for volatile oxidized mercury species and finally trapped in an oxidative solution. The apparent diffusion coefficient (from Fick's second law of diffusion) for oxidized mercury was 1 x 10(-14)m(2)/s in Standard Portland concrete and 4 x 10(-13)m(2)/s in quartz sand. The diffusion of Hg(0) seemed to be faster than for Hg(II), Hg(0) was however oxidized to Hg(II) under aerobic conditions, and after 45 months only 1-10% of the total mercury concentration was Hg(0). PMID:17097806

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

    Science.gov (United States)

    Fujita, Yosuke; Kobayashi, Motoyoshi

    2016-07-01

    We have studied the transport of colloidal silica in various degrees of a water-saturated Toyoura sand column, because silica particles are widely used as catalyst carriers and abrasive agents, and their toxicity is reported recently. Since water-silica, water-sand, and air-water interfaces have pH-dependent negative charges, the magnitude of surface charge was controlled by changing the solution pH. The results show that, at high pH conditions (pH 7.4), the deposition of colloidal silica to the sand surface is interrupted and the silica concentration at the column outlet immediately reaches the input concentration in saturated conditions. In addition, the relative concentration of silica at the column outlet only slightly decreases to 0.9 with decreasing degrees of water saturation to 38%, because silica particles are trapped in straining regions in the soil pore and air-water interface. On the other hand, at pH 5 conditions (low pH), where sand and colloid have less charge, reduced repulsive forces result in colloidal silica attaching onto the sand in saturated conditions. The deposition amount of silica particles remarkably increases with decreasing degrees of water saturation to 37%, which is explained by more particles being retained in the sand column associated with the air-water interface. In conclusion, at higher pH, the mobility of silica particles is high, and the air-water interface is inactive for the deposition of silica. On the other hand, at low pH, the deposition amount increases with decreasing water saturation, and the particle transport is inhibited. PMID:27045635

  8. Black colored sandy sediments caused by bacterial action, and the mechanism for arsenic enrichment of groundwater in Inner Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, H., E-mail: h.hagiwara@silk.plala.or.jp [Graduate School of Science and Technology, Niigata University, Ikarashi-2, Niigata 950-2181 (Japan); Akai, J. [Department of Geology, Faculty of Science, Niigata University, Ikarashi-2, Niigata 950-2181 (Japan); Terasaki, K. [6379-72, Ikarashi-1, Niigata 950-2101 (Japan); Yoshimura, T. [Department of Geology, Faculty of Science, Niigata University, Ikarashi-2, Niigata 950-2181 (Japan); Luo, H. [Department of Applied Chemistry, South China University of Technology, Wushan, Guangzhou 510640 (China)

    2011-03-15

    Research highlights: {yields} Arsenic enrichment of groundwater in Inner Mongolia is described. {yields} Characteristic black sands by FeS are always associated with this enrichment. {yields} Bacterial activity plays a key role in forming highly reducing environments and H{sub 2}S. {yields} Arsenic is released from Fe oxyhydroxide and H{sub 2}S reacts with Fe{sup 2+}, resulting in formation of black FeS. {yields} Black sands are indicative of As release in this region. - Abstract: High As concentrations in groundwater were detected in the village of Ershe, Jianshe but were not detected in the village of Qishe, Fengle in Inner Mongolia. In this study, core samples from two comparable regions were mineralogically examined. Results of X-ray diffractometry (XRD) showed that the principal minerals present in the drill core samples are quartz, micas, feldspars, calcite and clay minerals. Variation of these mineral species does not correlate with depth but to lithofacies; minerals were As-rich in muddy sediments and As-poor in sandy sediments. The results of X-ray fluorescence analysis (XRF) are consistent with those of XRD. The As content shows a positive correlation with total Fe{sub 2}O{sub 3}, V and loss of ignition (LOI). In order to identify the chemical forms of As present, a selective sequential extraction (SSE) method was carried out. The results of the SSE experiment suggested that in highly reducing environments, As that is adsorbed on Fe oxyhydroxides is released. Extremely black sand was found in deep drill core samples. To investigate the cause of black sands, inorganic and bacterial culture experiments were carried out. The black color in sands is due to the Fe sulfide greigite evolved from the Fe oxyhydroxide film coating the sand grains. This change in color occurred upon reaction with H{sub 2}S gas most probably associated with bacterial activity. Transmission electron microscope (TEM) observations clarified that the sulfide structure of black sand

  9. Black colored sandy sediments caused by bacterial action, and the mechanism for arsenic enrichment of groundwater in Inner Mongolia

    International Nuclear Information System (INIS)

    Research highlights: → Arsenic enrichment of groundwater in Inner Mongolia is described. → Characteristic black sands by FeS are always associated with this enrichment. → Bacterial activity plays a key role in forming highly reducing environments and H2S. → Arsenic is released from Fe oxyhydroxide and H2S reacts with Fe2+, resulting in formation of black FeS. → Black sands are indicative of As release in this region. - Abstract: High As concentrations in groundwater were detected in the village of Ershe, Jianshe but were not detected in the village of Qishe, Fengle in Inner Mongolia. In this study, core samples from two comparable regions were mineralogically examined. Results of X-ray diffractometry (XRD) showed that the principal minerals present in the drill core samples are quartz, micas, feldspars, calcite and clay minerals. Variation of these mineral species does not correlate with depth but to lithofacies; minerals were As-rich in muddy sediments and As-poor in sandy sediments. The results of X-ray fluorescence analysis (XRF) are consistent with those of XRD. The As content shows a positive correlation with total Fe2O3, V and loss of ignition (LOI). In order to identify the chemical forms of As present, a selective sequential extraction (SSE) method was carried out. The results of the SSE experiment suggested that in highly reducing environments, As that is adsorbed on Fe oxyhydroxides is released. Extremely black sand was found in deep drill core samples. To investigate the cause of black sands, inorganic and bacterial culture experiments were carried out. The black color in sands is due to the Fe sulfide greigite evolved from the Fe oxyhydroxide film coating the sand grains. This change in color occurred upon reaction with H2S gas most probably associated with bacterial activity. Transmission electron microscope (TEM) observations clarified that the sulfide structure of black sand grains is that of greigite. In summary, based on water chemistry

  10. 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.

  11. 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.

  12. Water availability in peat-mineral mixes and sands in oil sands reclamation, NE Alberta

    International Nuclear Information System (INIS)

    Soil productivity is a function of the soil's ability to provide moisture to plants. This study was initiated by Suncor and Syncrude to determine the water holding capacity of peat-mineral mixtures in the oil sands region. Other concepts dealt with in this presentation include soil drainage classification, soil moisture regime classification, soil permeability, the hydrological regime and the interactions of these phenomena. A further objective was to incorporate this information in a publication entitled 'Land capability classification for forest ecosystems in the oil sands region', scheduled to be released in November 1997

  13. Stimulated Black Hole Evaporation

    CERN Document Server

    Spaans, Marco

    2016-01-01

    Black holes are extreme expressions of gravity. Their existence is predicted by Einstein's theory of general relativity and is supported by observations. Black holes obey quantum mechanics and evaporate spontaneously. Here it is shown that a mass rate $R_f\\sim 3\\times 10^{-8} (M_0/M)^{1/2}$ $M_0$ yr$^{-1}$ onto the horizon of a black hole with mass $M$ (in units of solar mass $M_0$) stimulates a black hole into rapid evaporation. Specifically, $\\sim 3 M_0$ black holes can emit a large fraction of their mass, and explode, in $M/R_f \\sim 3\\times 10^7 (M/M_0)^{3/2}$ yr. These stimulated black holes radiate a spectral line power $P \\sim 2\\times 10^{39} (M_0/M)^{1/2}$ erg s$^{-1}$, at a wavelength $\\lambda \\sim 3\\times 10^5 (M/M_0)$ cm. This prediction can be observationally verified.

  14. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  15. A toxicity assessment of oil sands wastewater

    International Nuclear Information System (INIS)

    A study was conducted to characterize the fractions responsible for the acute toxicity of oil sand wastewaters and to compare the relative sensitivity of Microtox, Daphnia magna, and rainbow trout to the toxic fractions. The second objective of the study was to assess the potential of the mixed-function oxygenase (MFO) system in rainbow trout as an indicator of exposure to sublethal concentrations of oil sand tailings water. All and ca 85% of the acute toxicity of surface tailings water and fine tails interstitial water respectively, as measured using the Microtox assay, was due to organic acid surfactants. Organic acids accounted for all the acute toxicity of surface tailings water to Daphnia and rainbow trout. However, Daphnia were 0.4 times less sensitive and rainbow trout were 3 times more sensitive than Microtox to these acids. The MFO system in rainbow trout responded rapidly, following a definable concentration-response relationship; however, it proved to be a relatively insensitive indicator of sublethal exposure to oil sand tailings water. Increased activity and maximal induction, as a result of exposure to 0.3 and 0.6 toxic units (TU), occurred rapidly within 24 h of exposure. Maximal induction required 0.4-0.8 TU of this wastewater. The absolute level of maximal induction was only 1/5 to 1/6 of the potential induction as found in response to the positive control, 0.5 mg/kg β-naphthoflavone. The sensitivity of this system was further compromised when the undesirably very high no observed effect and lowest observed effect concentrations of 0.15 TU and 0.2 TU were considered. The acutely toxic organic acids may have been responsible for the observed MFO induction and speculation in support of this hypothesis is presented. 68 refs., 7 figs., 9 tabs

  16. Radiometric Characterization of Sand in Northeast Sinai

    International Nuclear Information System (INIS)

    Thirty-eight locations covering an area of 350 km2 in northeast Sinai were investigated by gamma-ray spectroscopy using a 50% HPGe detector. The limits of area are Al-Arish North, El-Hasana South, El-Oga East, and El- Gifgafa West. The range of activity concentrations of 238U, 234Th, 226Ra, 232Th and 40K are 0.6-35.2, 3.9-22.6, 4.7-29.6, 4.7-23.9, and 108-295 Bq/kg for sands, respectively. 137Cs in the region ranged from 0.1-8.0 Bq/kg. No major difference between the studied area and that previously investigated in the costal area in North Sinai. Reliable correlations (R2 = 0.8-0.9) among 238U, 234Th, and 226Ra isotopes was obtained. On the other hand, low correlation (R2 = 0.6-0.7) was obtained from the analysis of the isotopes of 238U-seies and 232Th. No evidence of correlation between the concentrations of radioisotopes and pH contents, TOM, and grain size were found. The soil-plant transfer factor are 226Ra and 232Th, 40K, and 137Cs, respectively. The wild vegetations collected from the studied area have average concentrations of 1.9, 1.4, 1.3, 254, and 0.3 for 234Th, 226Ra, 232Th, 40K, and 137Cs, respectively. The average concentrations of 226Ra, 232Th, and 40K in water samples collected from five wells are 0.02, 0.02, and 1.1 Bq/l, respectively. The average absorbed dose rate for the sand samples were calculated to be 19.4 n Gy h-1. The Raeq activities of the sands are lower than the recommended maximum value of 370 Bq kg-1 criterion limit of Raeq activity for building materials

  17. 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

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

    Science.gov (United States)

    2001-01-01

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

  19. Biogenic crust dynamics on sand dunes

    CERN Document Server

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

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

  20. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

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

  1. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

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

  2. Compaction resistant wellbore for sand-producing wells

    Energy Technology Data Exchange (ETDEWEB)

    Shute, D.M. [Volant Products Inc., Edmonton, AB (Canada); Kaiser, T.M.V. [Noetic Engineering Inc., Edmonton, AB (Canada); Munoz, H. [Husky Oil Operations Ltd., Calgary, AB (Canada)

    2004-07-01

    This paper presents a solution to extend the life of a well in high sand producing fields. The economic value of cold heavy oil production depends on maximizing the rate of oil production and well life. One strategy in heavy oil sands is to produce the sand with the oil to increase the deliverability of the well. However, the cumulative sand volume from the reservoir can be very large, resulting in large vertical deformations relative to the elastic strain limit of the steel and liner through the producing interval. A compaction resistant wellbore (CRW) with better structural capacity was designed to absorb the axial compaction. A review of deformation mechanisms associated with sand production strategies has shown that improved deformation assessment tools and measurement systems can provide accurate casing deformation evaluations. A case study from a high sand-producing field showed that this approach can increase well life. 10 refs., 9 figs.

  3. Numerical study on deformation and failure of reinforced sand

    Institute of Scientific and Technical Information of China (English)

    PENG Fang-le; LI Jian-zhong; Tatsuoka Fumio

    2005-01-01

    In order to investigate the deformation and failure of reinforced sand, and the reinforcing mechanism of flexible and rigid reinforcement, a set of plane strain compression tests of dense Toyoura reinforced sand with planar reinforcement of a wide range of stiffness were analysed by a nonlinear finite element method. The analysis was incorporated into an energy-based elasto-plastic constitutive model for sand to develop a stress path-independent work-hardening parameter based on the modified plastic strain energy concept. Numerical results indicate that the global stress-strain relations of sand specimens are reinforced by using relatively flexible and rigid reinforcement, and an unreinforced sand specimen can be reasonably simulated by the current finite element method. It is also found that the reinforcing mechanism and progressive failure with a development of shear bands in reinforced sand can be reasonably examined by the finite element method.

  4. Cosmic Black Holes

    OpenAIRE

    Ahn, Eun-Joo; Cavaglia, Marco

    2003-01-01

    Production of high-energy gravitational objects is a common feature of gravitational theories. The primordial universe is a natural setting for the creation of black holes and other nonperturbative gravitational entities. Cosmic black holes can be used to probe physical properties of the very early universe which would usually require the knowledge of the theory of quantum gravity. They may be the only tool to explore thermalisation of the early universe. Whereas the creation of cosmic black ...

  5. The New Black

    OpenAIRE

    Lettman-Hicks, Sharon

    2014-01-01

    The New Black is a documentary that tells the story of how the African American community is grappling with the gay rights issue in light of the recent gay marriage movement and the fight over Civil Rights. The film documents activities, families and clergy on both sides of the campaign to legalize gay marriage and examines homophobia in the Black community's institutional pillar, the Black church, and reveals the Christian right wing's strategy of exploiting this phenomenon in order to pursu...

  6. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six. PMID:23368298

  7. Kerr black string flow

    Directory of Open Access Journals (Sweden)

    Meng Sun

    2015-08-01

    Full Text Available We give a general illumination of a rotating black string falling into a rotating horizon in dimension D=5. It is a configuration of one smooth intersection between these two objects when the spacetime is axisymmetric and in the limit that the thickness of the black hole is much larger than the thickness of the black string. Following this configuration, we further extend them to the rotating and charged flows.

  8. Estimation of radon and thoron caused dose at extraction and processing sites of mineral sand mining area in Vietnam (HA TINH province)

    International Nuclear Information System (INIS)

    Mineral sands are mined in several countries to supply to the titanium and zircon producing industries. Coastal black mineral sands usually contain, besides ilmenite (FeTiO3) and rutile (TiO2), radioactive minerals such as zircon (ZrSiO4) and monazite (RePO4). Radon and thoron activity concentration originated from natural radioactive contents of the black mineral sand was monitored at the extraction and processing for black minerals in the coastal areas of Ha Tinh Province, one of the around 40 coastal mineral sand deposits in Vietnam. The survey was carried out with the Raduet chambers made by Radosys Ltd-Hungary. The obtained results for 25 investigated points show that the measured values are not high in the residential houses and in case of the sand extraction site as well. At the titanium processing plant the measured values were higher than outside the facility (Radon: 18-55 Bq/m3 with average of 34 Bq/m3 and Thoron 33-118 Bq/m3 with average of 58 Bq/m3) but still comparable to the average concentration of the world published by UNSCEAR. The typical outdoor levels of radon and thoron gas are each of the order of 10 Bq/m3. Although the radon concentrations were low in the zircon and titanium processing plants, the thoron concentrations in the houses for separating rutile and zircon were very high. At zircon processing factory, the thoron concentration could reach 2,931 Bq/m3 and the estimated annual effective dose would be 21.4 mSv/a. Intervention has to be taken in order to reduce the thoron level in this factory since the level of thoron and its progenies corresponding to an annual occupational effective dose is beyond the action level of 6 mSv/a. (author)

  9. Ten shades of black

    CERN Document Server

    Hod, Shahar

    2015-01-01

    The holographic principle has taught us that, as far as their entropy content is concerned, black holes in $(3+1)$-dimensional curved spacetimes behave as ordinary thermodynamic systems in flat $(2+1)$-dimensional spacetimes. In this essay we point out that the opposite behavior can also be observed in black-hole physics. To show this we study the quantum Hawking evaporation of near-extremal Reissner-Nordstr\\"om black holes. We first point out that the black-hole radiation spectrum departs from the familiar radiation spectrum of genuine $(3+1)$-dimensional perfect black-body emitters. In particular, the would be black-body thermal spectrum is distorted by the curvature potential which surrounds the black hole and effectively blocks the emission of low-energy quanta. Taking into account the energy-dependent gray-body factors which quantify the imprint of passage of the emitted radiation quanta through the black-hole curvature potential, we reveal that the $(3+1)$-dimensional black holes effectively behave as p...

  10. Evidence for black holes.

    Science.gov (United States)

    Begelman, Mitchell C

    2003-06-20

    Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity. PMID:12817138

  11. Black hole statistics

    International Nuclear Information System (INIS)

    The quantum statistics of charged, extremal black holes is investigated beginning with the hypothesis that the quantum state is a functional on the space of closed three-geometries, with each black hole connected to an oppositely charged black hole through a spatial wormhole. From this starting point a simple argument is given that a collection of extremal black holes obeys neither Bose nor Fermi statistics. Rather, they obey an exotic variety of particle statistics known as ''infinite statistics'' which resembles that of distinguishable particles and is realized by a q deformation of the quantum commutation relations

  12. Antigravity and black holes

    CERN Document Server

    Hajdukovic, D

    2006-01-01

    We speculate about impact of antigravity (i.e. gravitational repulsion between matter and antimatter) on the creation and emission of particles by a black hole. If antigravity is present a black hole made of matter may radiate particles as a black body, but this shouldn't be true for antiparticles. It may lead to radical change of radiation process predicted by Hawking and should be taken into account in preparation of the attempt to create and study mini black holes at CERN. Gravity, including antigravity is more than ever similar to electrodynamics and such similarity with a successfully quantized interaction may help in quantization of gravity.

  13. Deforming regular black holes

    CERN Document Server

    Neves, J C S

    2015-01-01

    In this work, we have deformed regular black holes which possess a general mass term described by a function which generalizes the Bardeen and Hayward mass terms. Using linear constraints in the energy-momentum tensor, the solutions are either regular or singular. That is, with this approach, it is possible to generate singular black holes from regular black holes and vice versa. Moreover, contrary to the Bardeen and Hayward regular solutions, the regular deformed metrics may violate the weak energy condition despite the presence of the spherical symmetry. Some comments on accretion of deformed black holes in cosmological scenarios are made.

  14. Black stain - a review.

    Science.gov (United States)

    Ronay, Valerie; Attin, Thomas

    2011-01-01

    The purpose of this review was to summarise the fundamentals about black stain, its diagnosis and possible differential diagnoses as well as its microbiology and therapy. In addition, various studies investigating the relationship between black stain and dental caries are examined. Many studies report lower caries prevalence in children with black stain, but this finding could not be confirmed by all authors. Also, a negative relation between degree of staining and caries severity has been described. Reasons for these results are not yet clear but it was speculated that they are related to the specific oral microflora described in black stain-affected individuals. PMID:21594205

  15. "Black Capitalism": Toward Controlled Development of Black America

    Science.gov (United States)

    Wright, Robert E.

    1969-01-01

    Argues in favor of the connotation of the term "Black capitalism as the accumulation of capital resources by the Black people in a collective fashion for the benefit of the masses of Black people. (RJ)

  16. Sand Production during Improved Oil Recovery in Unconsolidated Cores

    Directory of Open Access Journals (Sweden)

    Mohammad A. J. Ali.

    2012-10-01

    Full Text Available Steam injection is a mechanisms used for improved oil recovery (IOR in heavy oil reservoirs. Heating the reservoir reduces the oil viscosity and causes the velocity of the moving oil to increase; and thus, the heated zone around the injection well will have high velocity. The increase of velocity in an unconsolidated formation is usually accompanied with sand movement in the reservoir creating a potential problem. Core samples from different wells in Kuwait were used to examine sand production during thermal injection in unconsolidated formation. A reservoir condition coreflood apparatus was used to inject oil with viscosities and flowrates. The oil sample was heated to give different viscosities, and the flowrate was increased gradually at each viscosity to establish the critical flowrate for sand production. At the end of the each test, the produced oil containing sand were filtered for sand content. The result showed that sand compaction at the injection face was more significant than sand production. Sand compaction resulted in permeability decline, whereas sand production improved the permeability. Sand production is a function of fluid and formation properties. The critical flowrate varied from 6 to 401 cc/hr for grain diameter of 277 to 366 μm, and at 684 cp viscosity oil. The critical flowrate varied from 3 to 87 cc/hr for grain diameter of 277 to 366 μm. Flowrate and viscosity of the oil, and the formation porosity, grain size, grain sorting, cementation, and overburden pressure, all contribute to sand production. Modeling all of these properties to predict sand production remains to be very challenging.

  17. Final report on Thermally Modified Sand demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-23

    The use of salt and salt/sand mixtures on icy roadway surfaces has dramatically increased during the past 30 years. Despite extensive documentation on salt related damage to the roadway improvements, vehicles and the environment, road maintenance departments have continued to rely on this practice. Road maintenance departments in northern climate areas have long recognized the safety benefits for public mobility on icy roadways from the use of sand. As an abrasive material, the sand improves the surface traction that results in more drivable and less hazardous road conditions during the winter months. Stockpiles of pure sand stored during the winter months oftentimes freeze into large unworkable, monolithic piles. To maintain a free-flowing condition, it has been found to be necessary to add salt to the sand. The addition of salt in amounts ranging from 5 to 10 percent to that of sand, is usually sufficient to provide relatively free-flowing abrasive material that could be stored in stockpiles and applied to icy road surfaces with conventional sand spreading trucks. Another alternative for winter storage of pure sand to maintain a free-flowing condition is in humidity-controlled, heated buildings. As would be expected, this method has high capital and operating costs. and not cost effective for general highway maintenance use. The invention demonstrated herein is a method of thermally modifying pure sand that will remain in a free-flowing state throughout the winter season without the need for the salt additive. The thermally modified sand provides an abrasive material that when applied to icy roads does not cause environmental and corrosive damage as done by the application of sand with salt. By employing a very simple process of freezing screened sand particles by forced air convection under subfreezing conditions, the invention creates a product that has significant value in terms of economic and environmental benefits.

  18. Treatment of Wastewater from Backwashing Process Sand Filters

    OpenAIRE

    Miletić, S.; Panjkret, V.; Zečević, N.

    2011-01-01

    In the process of raw water treatment for use in the petrochemical industry, one of the most important treatments is the filtration process with process sand filters. A by-product of the filtration process of raw water is wastewater. The wastewater results from the technological process of backwashing process sand filters. Wastewater from backwashing sand filters is unsuitable for further use, since it is contaminated with residual suspended matter and chemical compounds that are added in the...

  19. Natural Radioactivity Concentrations in Beach Sands from Some Tourists Resorts

    OpenAIRE

    H. Lawluvi; E.O. Darko; C. Schandorf; A. Fannu; A.R. Awudu; D.O. Kpeglo

    2011-01-01

    Beaches along the coastlines in Ghana are important holiday destinations for tourists from many countries around the world. The radiological quality of sand from these beaches is very important to assess exposure of the public who use the beaches for recreational purposes and other activities. This study investigates the levels and hazards associated with the U-Th series and 40 K in beach sands from some renowned tourist resorts in the Greater Accra region of Ghana. Samples of beach sand from...

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

    OpenAIRE

    Robinson, John P.; Binner, Eleanor; Saeid, Abdul; Al-Harahsheh, Mohammad; Kingman, S. W.

    2014-01-01

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

  1. Evaluation of sand reserves in del Plata City

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate the reserve of sand in the zone of del Plata city and beyond. This area is located in the S E edge of the department of San Jose near the mouth of Santa Lucia river. In this zone was identified the mantle of potentially exploitable sand which are based on their particle size, composition and depth of the limits cape. There are two powerful capes of sand separated by clay and silt

  2. Surplus foundry sand and its assessment of applicability in composting

    OpenAIRE

    Maharjan, Devendra

    2016-01-01

    The purpose of this thesis was to carry out a research on reuse possibility of surplus foundry sand in composting and develop a general proposal for guideline only as appendix in this thesis for the Finnish foundries to assist them in setting quality control system criteria to control the quality of surplus foundry sand suitable for composting and preventing any harm or risk to environment, human and natural resources. The research was made on the typical foundry sand used such as alkaline ph...

  3. Strength properties of moulding sands with chosen biopolymer binders

    OpenAIRE

    St.M. Dobosz; K. Major-Gabryś

    2010-01-01

    The article presents the results of primary researches of the IV generation moulding sands, in which as the binders are used differentbiodegradable materials. The bending and the tensile strength of the moulding sands with polylactide, poly(lactic-co-glycolic acid),polycaprolactone, polyhydroxybutyrate and cellulose acetate as binders were measured. The researches show that the best strengthproperties have the moulding sands with polylactide as binder. It was proved that the tested moulding s...

  4. EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; SU Bao-yu

    2006-01-01

    The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

  5. Sorting out sand and gravel : sediment transport and deposition in sand-gravel bed rivers

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2002-01-01

    The general aim of this PhD-project was to gain better understanding of the sediment transport and depositional processes of sand-gravel mixtures in rivers with subaqueous dunes. The understanding of the fundamental processes of sediment transport and deposition in channel beds is crucial for morpho

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  7. Chemical Stablilisation of Sand : Part VIII Furan Resins as Dune and Coastal Sand Stabiliser

    Directory of Open Access Journals (Sweden)

    Ram Gopal

    1990-04-01

    Full Text Available Studies on furan resin as dune sand stabiliser are presented. Influence of acid catalysts, viz. phenol disulphonic acid, sulphuric acid, hydrochloric acid and phosphoric acid and other catalysts, viz. trichlorotoluene and benzoyl chloride along with promoters, zinc chloride and ferric chloride, on the strength of stabilised furan resin-sand specimens has been discussed. Optimisation studies on resin content, catalysts and promoters and curing conditions have revealed that maximum strength of 260 kg/cm/sup 2/ of the standard specimens made by compaction of coastal sand using furan resins (10 per cent, sulphuric acid (9N, 30 per cent and a curing time of 2 hr at 40 degree Centigrade is higher than the 170 kg/cm/sup 2/ of specimens made of Rajasthan desert sand. Sandy patches stabilised by seepage technique recorded a maximum strength of 125 kg/cm/sup 2/. Physico-chemical characteristics of this system and effect of environment on stabilised specimens have also been studied and field trials conducted successfully. This resin-catalyst system would be extremely useful in humid and saline field (coastal areas for different military applications.

  8. Bioclogging and Biocementation in Construction of Water Pond in Sand

    Science.gov (United States)

    Chu, J.; Ivanov, V.; Stabnikov, V.; Li, B.

    2012-12-01

    Conventionally, compacted bentonite, geosynthetic clay liner or plastic liners are used to seal ponds, channels, and reservoirs in sand. Recently, a new approach to form a low permeability layer of several centimetres thick through the microbially induced calcium carbonate precipitation (MICP) process has been developed (Chu et al., 2012). This method has been adopted to build a laboratory scale water pond model in sand. Calcium solution for bioclogging and biocementation was supplied initially by spaying to form a layer of the clogged sand by precipitation in the pores and then by slow percolation from solution above sand surface, which formed a crust of calcite. This combination of bioclogging and biocementation formed a sand layer of 1 - 3 cm depth with low permeability. The permeability of sand after this treatment was reduced from the order of 10^-4 m/s to 10^-7 m/s when an average 2.1 kg of Ca per m^2 of sand surface was precipitated. The bending strengths of the walls and the base of the model pond were in the range of 90 to 256 kPa. The unconfined compressive strengths obtained from samples from the walls and the base were in the range of 215 to 932 kPa. The graded sand and uniform supply of calcium solution were used for the model pond construction but it was significant spatial three-dimensional heterogeneity of sand bioclogging and biocementation.

  9. Trajectories of saltating sand particles behind a porous fence

    Science.gov (United States)

    Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

    2015-01-01

    Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

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

    Science.gov (United States)

    Huang, HaoJie; Bo, TianLi; Zheng, XiaoJing

    2014-09-01

    Recent observation results show that sand ripples and dunes are movable like those on Earth under current Martian climate. And the aeolian process on Mars therefore is re-attracting the eyes of scientific researchers in different fields. In this paper, the spatial and temporal evolution of wind-blown sand on Mars is simulated by the large-eddy simulation method. The simulations are conducted under the conditions of both friction wind speed higher and lower than the "fluid threshold", respectively. The fluid entrainment of the sand particles, the processes among saltation sand particles and sand bed, and the negative feedback of sand movement to flow field are considered. Our results show that the "overshoot" phenomenon also exists in the evolution of wind-blown sand on Mars both temporally and spatially; impact entrainment affects the sand transport rate on Mars when the wind speed is smaller or larger than the fluid threshold; and both the average saltation length and height are one order of magnitudes larger than those on Earth. Eventually, the formulas describing the sand transport rate, average saltation length and height on Mars are given, respectively. PMID:25236498

  11. Black holes and beyond

    International Nuclear Information System (INIS)

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for instance, the UK

  12. [Imperial Oil's Cold Lake oil sands operations

    International Nuclear Information System (INIS)

    Imperial Oil Limited's Cold Lake oil sands resources, production and operations in Alberta are discussed. Cold Lake is the company's largest single asset and its largest source of crude oil production. In 1998, Cold Lake accounted for just under half of Imperial's total liquid production, averaging more than 135,000 barrels of bitumen a day. Despite the very difficult operating conditions experienced by the oil sands industry in 1998, Imperial Oil's Cold Lake operations generated a positive cash flow and earnings. Just as important, the near and long-term potential of Cold Lake property continues to be strong, even with the tough market conditions today and the foreseeable future. Proved reserves at the end of 1997 were 1.3 billions barrels, equal to about 24 years of current production, but even more important is Imperial's resource base in the Athabasca region, which represents 150 years of production at current rates. Although production forecasts for the near future are are revised downward because of production shut-in due to low prices, the company is confident of its long-term prospects mainly because of existing infrastructure, superior reservoir quality, 30 years worth of operating improvements and established bitumen-blend markets. Details of the company's future Cold Lake development plans are discussed. The need to continue technology development, which has been at the core of the industry's growth in the past and will continue to be the key to the future, are emphasized

  13. Oil sands tailings leachability and toxicity evaluation

    International Nuclear Information System (INIS)

    Fine tailings disposal and reclamation is a major issue facing the oil sands mining and extraction industry. Government regulations dictate that reclamation must return the site to a level of self-sustaining biological capability which approximates the natural condition. A two-phase laboratory program has been completed to investigate the suitability of alternative reclamation materials. For the first phase of the study, chemical and toxicological analyses were carried out on 13 different reclamation and reference materials (solid phase and extractions). Seedling emergence, nematode maturation, algal growth and bacterial luminescence for leachate samples showed a range of sensitivities in response to the tested materials, although phytotoxicity tests were generally the most sensitive. With the exception of one test material, high toxicity ratings were consistent with that expected from the chemical data. The second phase of the study focused on the evaluation of chemical and toxicological conditions in leachate water generated using bench-scale column percolation tests. Leachate water equivalent to 10 pore volume replacements was generated and temporal variations in toxicity and chemistry monitored. Similar to phase 1 findings, phytotoxicity tests were the most sensitive tests to leachate waters. For most materials tested, most toxicity was removed after 2--3 porewater replacements. More persistent toxicity was noted for samples containing bitumen (e.g., fine tails and oil sands). No clear correspondence was noted between chemical concentrations and toxicity in leachate waters

  14. Dust control effectiveness of drywall sanding tools.

    Science.gov (United States)

    Young-Corbett, Deborah E; Nussbaum, Maury A

    2009-07-01

    In this laboratory study, four drywall sanding tools were evaluated in terms of dust generation rates in the respirable and thoracic size classes. In a repeated measures study design, 16 participants performed simulated drywall finishing tasks with each of four tools: (1) ventilated sander, (2) pole sander, (3) block sander, and (4) wet sponge. Dependent variables of interest were thoracic and respirable breathing zone dust concentrations. Analysis by Friedman's Test revealed that the ventilated drywall sanding tool produced significantly less dust, of both size classes, than did the other three tools. The pole and wet sanders produced significantly less dust of both size classes than did the block sander. The block sander, the most commonly used tool in drywall finishing operations, produced significantly more dust of both size classes than did the other three tools. When compared with the block sander, the other tools offer substantial dust reduction. The ventilated tool reduced respirable concentrations by 88% and thoracic concentrations by 85%. The pole sander reduced respirable concentrations by 58% and thoracic by 50%. The wet sander produced reductions of 60% and 47% in the respirable and thoracic classes, respectively. Wet sponge sanders and pole sanders are effective at reducing breathing-zone dust concentrations; however, based on its superior dust control effectiveness, the ventilated sander is the recommended tool for drywall finishing operations. PMID:19367481

  15. Falling sand tests on various coatings

    Energy Technology Data Exchange (ETDEWEB)

    Manetti, M.; Zonfrillo, G.; Pratesi, F. [Florence Univ. (Italy). Dipt. di Meccanica e Tecnologie Industriali; Giovannetti, I. [GE Oil and Gas - Nuovo Pilnone, Florence (Italy)

    2010-07-01

    Abrasive wear is responsible for severe machine parts and in particular of compressor impellers. Methods of increasing service lifetime are based on employment of abrasion resistant materials or more frequently of the creation of hard, wear-resistant surface layers. In this work a bare aluminium alloy and the same alloy with four different coatings have been tested at room temperature, in order to verify their resistance to falling abrasive. Following standard ASTM D968-93, tests have been performed using a precise quantity of sand as abrasive and letting it fall on the sample with a standard apparatus: two different kinds of sand have been used, in order to obtain also information on the influence of composition and Grain size of the abrasive on material resistance. Determinations of hardness, roughness, weight loss, and morphology of the eroded surface have also been carried out. The comparison between the coatings in vestilated has been performed on the basis of the thickness decrease of the samples. (orig.)

  16. Ilmenite Mineral's Recovery from Beach Sand Tailings

    International Nuclear Information System (INIS)

    The mineral ilmenite is the major source of rutile for industrial use and is of interest to paint and fertiliser industries. Enormous unutilised tailing dams lie on the eastern coast of the South Africa. Although covered by a simulation of the original indigenous vegetation, these tailings are still ilmenite bearing and of economic value. Tailings emanating from beach sand mineral slimes dams of the Kwazulu-Natal area (South Africa) have been processed. Screening, flotation, spiral concentration and magnetic separation methods were used either separately or successively. The present work sheds light on alternative routes for the extraction of the ilmenite, from these tailings. It moreover points out the usefulness of the Moessbauer spectroscopy in the mineral processing product monitoring. Tailings from the beach sands were used in the present study after the economic industrial minerals zirconia, ilmenite and rutile had been extracted in previous mining operations. About 61% natural ilmenite recovery was observed in the flotation concentrate of a Humphrey Spiral concentrate while a 62% recovery of hematite was found in the flotation tailings. The combination of screening, spiral concentration and magnetic separation, and flotation yielded a product with the highest ilmenite and hematite concentration being 71% and 19%, respectively. A natural ilmenite mineral, containing 87% ilmenite and 13% hematite, could be produced and extracted from the tailings of the flotation process, collected subsequently to the spiral concentration and the initial screening.

  17. Enabling technologies for oil sands development

    International Nuclear Information System (INIS)

    A review of oil sands production and expansion possibilities in Alberta were presented. The enabling technologies for oil sands projects include mining (bucketwheels, draglines, trucks, shovels conveyors, slurry hydrotransport); extraction (conditioning tumblers, pipelines, tanks, hot water, caustic, cold water, frothers); froth cleaning (centrifuges, solvent treatment); tailings (tailings ponds, consolidated tailings); and upgrading (coking, hydrotreating for SCO, hydrocracking and multiple products). The enabling technologies for in situ production include cyclic steam stimulation for vertical wells, steam assisted gravity drainage (SAGD) for dual horizontal wells, and cold production with wormholes. This paper described the recovery potentials of each of these processes. It also discussed the role of government and industry in research and cooperative research involving both the private and public sectors. Examples of each of these were described such as SAGD, the OSLO cold water extraction process, The consolidated tailings (CT) project, the low energy extraction process (slurry production, hydrotransport, pipeline conditioning and warm water extraction), and research in fine tailings, to demonstrate that although objectives may differ, government and industry research objectives are complementary

  18. Direct numerical simulations of aeolian sand ripples.

    Science.gov (United States)

    Durán, Orencio; Claudin, Philippe; Andreotti, Bruno

    2014-11-01

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

  19. Microstructural characterization of a Canadian oil sand

    CERN Document Server

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

    2013-01-01

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

  20. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  1. Consolidation testing of oil sand fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Znidarcic, Dobroslav; Miller, Robert [University of Colorado (United States); Zyl, Dirk van [Mining Engineering, University of British Columbia (Canada); Fredlund, Murray [SoilVision Systems Ltd. (Canada); Wells, Sean [Suncor Energy Inc. (Canada)

    2011-07-01

    The most fundamentally challenging issue facing the geo-environmental community is containment, long-term storage, and volume reduction of oil sands fine tailings produced by the extraction process. This paper presents the results of a testing program in which the seepage induced consolidation test (SICT) is used to determine consolidation properties, i.e. the compressibility and permeability characteristics, of a mature fine tailings (MFT) sample. The obtained properties are verified independently by increased gravity in a geotechnical centrifuge. It is shown that MFT behave like other slurries and undergo a consolidation process when subjected to loading, seepage forces or increased self-weight stresses in a centrifuge. The void ratio (solids content) within each sample is variable and no restrictive assumptions are made on the variability of the consolidation properties of the sample. The results confirm that the SICT is applicable to the testing of oil sand MFT, and produces repeatable datasets under controlled laboratory conditions; nevertheless, more detailed field studies are recommended.

  2. Rotating Brane World Black Holes

    OpenAIRE

    Modgil, Moninder Singh; Panda, Sukanta; Sengupta, Gautam

    2001-01-01

    A five dimensional rotating black string in a Randall-Sundrum brane world is considered. The black string intercepts the three brane in a four dimensional rotating black hole. The geodesic equations and the asymptotics in this background are discussed.

  3. Evolution of massive black holes

    OpenAIRE

    Volonteri, Marta

    2007-01-01

    Supermassive black holes are nowadays believed to reside in most local galaxies. Accretion of gas and black hole mergers play a fundamental role in determining the two parameters defining a black hole: mass and spin. I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I'll discuss black hole formation processes that are likely to place at early cosmic epochs, and how massive black hole evolve in a hierarchical Universe...

  4. Pyrolytic carbon coated black silicon

    OpenAIRE

    Shah, Ali; Stenberg, Petri; Karvonen, Lasse; Ali, Rizwan; Honkanen, Seppo; Lipsanen, Harri; Peyghambarian, N.; Kuittinen, Markku; Svirko, Yuri; Kaplas, Tommi

    2016-01-01

    Carbon is the most well-known black material in the history of man. Throughout the centuries, carbon has been used as a black material for paintings, camouflage, and optics. Although, the techniques to make other black surfaces have evolved and become more sophisticated with time, carbon still remains one of the best black materials. Another well-known black surface is black silicon, reflecting less than 0.5% of incident light in visible spectral range but becomes a highly reflecting surface ...

  5. Carbon black recovery

    International Nuclear Information System (INIS)

    A process and apparatus for recovering carbon black from hot smoke which comprises passing the smoke through a cyclone separation zone following cooling, then through aggregate filter beds and regeneration of filter beds with clean off-gas which is recycled to the carbon black reaction zone as quench

  6. Noncommutative Singular Black Holes

    International Nuclear Information System (INIS)

    In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t - r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there is no black hole remnant at long times.

  7. Noncommutative Singular Black Holes

    Science.gov (United States)

    Hamid Mehdipour, S.

    2010-11-01

    In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t — r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there is no black hole remnant at long times.

  8. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  9. Black holes in inflation

    Science.gov (United States)

    Bousso, R.; Hawking, S. W.

    1997-08-01

    We summarise recent work on the quantum production of black holes in the inflationary era. We describe, in simple terms, the Euclidean approach used, and the results obtained both for the pair creation rate and for the evolution of the black holes.

  10. Scattering by Black Holes

    CERN Document Server

    Andersson, N

    2000-01-01

    This is a chapter on Black-hole Scattering that was commissioned for an Encyclopaedia on Scattering edited by Pike and Sabatier, to be published by Academic Press. The chapter surveys wave propagation in black-hole spacetimes, diffraction effects in wave scattering, resonances, quasinormal modes and related topics.

  11. Black Craftsmen Through History.

    Science.gov (United States)

    Myers, Robin

    This report traces the evolution of the black craftsmen from ancient Egypt to the present. Special attention is given to the restricted use of black craftsmen under slavery, and the added problems they faced after being freed. Business and union discimination is described, along with recent government and private efforts to achieve equal…

  12. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    Koustubh Ajit Kabe

    2012-09-01

    In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats , and , have been defined. For a black hole, these quantities are negative. The d equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole , the additional available energy defined as the first free energy function , and the surface gravity , has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\\Omega,\\Phi}-C_{J,Q}=\\kappa \\left[\\left(\\dfrac{\\partial J}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial \\Omega}{\\partial \\kappa}\\right)_{J,Q}+\\left(\\dfrac{\\partial Q}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial\\Phi}{\\partial \\kappa}\\right)_{J,Q}\\right]$. This is dubbed as the homogeneous fluid approximation in context of the black holes.

  13. Selected properties of spruce dust generated from sanding operations

    Directory of Open Access Journals (Sweden)

    Alena Očkajová

    2008-07-01

    Full Text Available This paper presents the research of selected properties of spruce dust generated from experimental sanding by a hand belt sander with two sanding models - along the wood fibres and perpendicular to the wood fibres in the radial direction. The experiment was carried out for the purpose of obtaining the basic characteristics of wood sanding dust – granularity, size and shape of individually formed particles, and bulk properties (bulk density, bulk angle, and tilt angle that are important for suction, which is connected with the quality of living and working environments. The particles smaller than 100 micrometers are unsuitable for both environments, since they do not sediment in space at all or only partly, and they are characterized as airborne dust. The most harmful particles for humans are those smaller than 2.5 μm as they reach the lung alveoli. When sanding wood the finest particles are formed and therefore it is important to know the basic characteristics of sanding dust in order to deal with these problems effectively. On the basis of the mesh sieve analysis, we can state that in sanding perpendicular to the wood fibres the share of particles smaller than 100 μm is 76.94 % on average and along the wood fibres it is only 56.01 %. The structure, shape and size of particles were investigated by microscope. When using the longitudinal model of sanding, the fibrous elements were formed for the most part. When using the perpendicular model, isometric particles were predominantly formed in smaller fractions and particles of fibrous shape in larger fractions. The smallest particles were found in the following samples. When the perpendicular model of sanding was used, we have found the smallest particle in the investigated samples with the diameter of 1.68 μm, and when the longitudinal model of sanding was used, the particle with the diameter of 1.75 μm. Bulk density of spruce dust from the longitudinal model of sanding is 77.77 kg · m-3

  14. Fluctuating Black Hole Horizons

    CERN Document Server

    Mei, Jianwei

    2013-01-01

    In this paper we treat the black hole horizon as a physical boundary to the spacetime and study its dynamics following from the Gibbons-Hawking-York boundary term. Using the Kerr black hole as an example we derive an effective action that describes, in the large wave number limit, a massless Klein-Gordon field living on the average location of the boundary. Complete solutions can be found in the small rotation limit of the black hole. The formulation suggests that the boundary can be treated in the same way as any other matter contributions. In particular, the angular momentum of the boundary matches exactly with that of the black hole, suggesting an interesting possibility that all charges (including the entropy) of the black hole are carried by the boundary. Using this as input, we derive predictions on the Planck scale properties of the boundary.

  15. Properties of Desert Sand and CMAS Glass

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2014-01-01

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

  16. Sand transport in urbanized beaches - models and reality

    International Nuclear Information System (INIS)

    The general objective is to quantify the wind transport of sand in the urbanized beaches. The specific objectives include testing and calibration of the wind velocity as well as the classification of the beaches according to the magnitude and the direction of sand transport

  17. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

  19. Test Setup for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

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

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

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2016-01-01

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

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

    Science.gov (United States)

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

  2. Pathogen removal using saturated sand colums supplemented with hydrochar

    NARCIS (Netherlands)

    Chung, J.W.

    2015-01-01

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

  3. Selvoplevet og sand, men mest det første

    DEFF Research Database (Denmark)

    Haarder, Jon Helt

    2007-01-01

    Lars Saabye Christensen: SAABYES CIRKUS (Oversat fra norsk af Karsten Sand Iversen) 224 sider, 229 kr. Athene UDKOMMER I DAG Udgivelsesdato: 14.09......Lars Saabye Christensen: SAABYES CIRKUS (Oversat fra norsk af Karsten Sand Iversen) 224 sider, 229 kr. Athene UDKOMMER I DAG Udgivelsesdato: 14.09...

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

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Høgh Jensen, Karsten

    1999-01-01

    controlled method. The heterogeneous sand systems were established in a laboratory tank for three realizations of random distributions of the homogeneous sands comprising a system of 207 grid cells. The water flux was controlled at the upper boundary, while a suction was applied at the lower boundary such...

  5. Radiological statuses of Bulgarian black see shore

    International Nuclear Information System (INIS)

    Full text: Introduction: In this paper own results of the radiation monitoring of the Black Sea coast - from village Shabla to village Resovo are presented. The study was carried out under a project funded by the BS ERA NET in FP7 of the European Commission, together with the project partners. Materials and Methods: Sampling was conducted in June 2012. 4 seawater samples (including depth of Varna Bay), 12 sand samples, 2 algae samples, 5 bottom sediments samples, 3 surface river water samples, 1 sea fish sample and 1 medical mud sample were examined. The samples were analyzed by gamma spectrometer for determination of the content technogenic and natural radionuclides and by radiochemical methods for defining the specific concentration of strontium- 90. A comparison between the specific activities of radionuclides in sea and river water, in the sands in sea bottom sediments in points and fractions, as well as in green and red algae. Results: The content of Cesium- 137 and Strontium -90 in the tested sea water ranged from 0.0041 (0.0007) to 0,0110 (0,0027) Bq/l and 0.00362 (0.00047) to 0,00409 (0,00049) Bq/l. The concentration of Cesium-137 in river water is ≤ 0,0012 Bq/l. The content of Potassium-40 in the sands is over a wide range from 4.9 (0.7) to 1152 (47) Bq/kg, a testament to their different origins. There is a difference in the contents of the radio-cesium into the upper and the lower fraction of the deep bottom sediment, and the various sampling points. It is clearly distinguished a selectivity of radio-cesium accumulation in red algae and they can be used for bio-indicator. Conclusion: The assessment of the radiological status of the Bulgarian Black Sea coast shows that with the exception of the beach in Vromos all investigated areas are safe from a radiological point of view. All studied coastal marine water as radiological indicators meet the quality standards set by Ordinance H-4/2012

  6. Cobalt speciation and mobility in glacial sand

    International Nuclear Information System (INIS)

    The migration behaviour of cobalt in a sand-groundwater system has been studied. Batch sorption, column and diffusion experiments all showed that more than one cobalt species were present and that interconversion occurred between them. In a column experiment cobalt complexed with natural (probably fulvic) material contained in the groundwater dissociated with a first order rate constant of 1.8 x 10-4 sec-1. This suggested that in a field tracer test in the Drigg borehole array very little cobalt would reach the first sampling point. Experiments with the Co-EDTA, however, showed that although some dissociation occurred the Co-EDTA complexes were sufficiently stable for field use. Sectioning a column through which a pulse of Co-EDTA had passed produced a complicated distribution of sorbed cobalt which was tentatively interpreted as being due to the movement of two retarded (possibly colloidal) species

  7. Direct Production of Silicones From Sand

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-09-30

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

  8. Bison and the oil sands industry

    International Nuclear Information System (INIS)

    Syncrude's Mildred Lake oil sands development project is located within the central boreal mixed wood forest in an area supporting traditional land uses, including trapping and harvesting of wildlife and plant materials by Fort McKay First Nation residents, in a community within 10 km of the Syncrude development. Reclamation requirements and standards in Alberta specify that the reclamation process must restore a landscape capability equivalent to, or better than that existing before disturbance. Syncrude is committed to complying with all provincial requirements and guidelines in all aspects of its business, including land reclamation. A five year research program has been established to determine the feasibility of reclaiming a portion of the landscape to support wood bison and bison subspecies once indigenous to this area. The current project may be expanded as a pilot commercial ranching venture to explore its commercial viability as a business venture by the Fort McKay First nations

  9. SAND: Automated VLBI imaging and analyzing pipeline

    Science.gov (United States)

    Zhang, Ming

    2016-05-01

    The Search And Non-Destroy (SAND) is a VLBI data reduction pipeline composed of a set of Python programs based on the AIPS interface provided by ObitTalk. It is designed for the massive data reduction of multi-epoch VLBI monitoring research. It can automatically investigate calibrated visibility data, search all the radio emissions above a given noise floor and do the model fitting either on the CLEANed image or directly on the uv data. It then digests the model-fitting results, intelligently identifies the multi-epoch jet component correspondence, and recognizes the linear or non-linear proper motion patterns. The outputs including CLEANed image catalogue with polarization maps, animation cube, proper motion fitting and core light curves. For uncalibrated data, a user can easily add inline modules to do the calibration and self-calibration in a batch for a specific array.

  10. The state of oil sands wetland reclamation

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  11. Effects of oil sands sediments on fish

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  12. Effects of oil sands sediments on fish

    International Nuclear Information System (INIS)

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

  13. Petro-Canada's oil sands supply outlook

    International Nuclear Information System (INIS)

    A report by the Canadian Energy Research Institute suggests that by 2017, production from the Athabasca Oil Sands could reach as high as 3.5 million barrels per day (mbpd), or it could be as low as 1.1 mbpd. This uncertainty in production is due to several variables such as capital costs, project size, reservoir quality, pipeline capacity and workforce productivity. Other factors that influence production include marginal economics, markets and prices, investor confidence, stakeholder concerns and the Kyoto Protocol. The production level that will be achieved by 2017 will depend on how industry address these emerging issues. The author discussed these issues in detail with particular reference to the approach that Petro-Canada has taken to address the challenges. Suggestions to reduce the potential impacts of these challenges were also presented. tabs., figs

  14. Black Youth Unemployment and the Black Family.

    Science.gov (United States)

    Hoskins, Linus A.

    This paper analyzes the results of a survey conducted to ascertain the attitudes of 400 employers, youth, and academic/community professionals in Los Angeles, Chicago and Washington, D.C., toward an approach to Black youth unemployment centered on the creation of jobs and training among minority businesses in selected metropolitan areas. Minority…

  15. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C.H.

    1978-06-30

    A summary is presented of the progress of government sponsored projects undertaken to increase gas production from low permeability gas sands of the western United States during May, 1978. Background information is given in the September 1977 Status Report, NVO/0655-100. The Department of Energy's (DOE) Nevada Operations Office (NVO), is finalizing a Request for Proposal (RFP) covering Technical and Administrative Support for the Project Manager for FY79. C. H. Atkinson, the Western Gas Sands Project (WGSP) Manager, was an observer of the third MHF treatment of Mobil Research and Development Corporation's well No. F-31-136. The fracture was performed on May 10, 1978. R. L. Mann of CER Corporation, met with Dr. Steve Holditch of Texas A and M University to discuss the utilization of the PDP 11/10 computer to be installed in the Mobile Well Test Facility. The USGS is continuing geological and geophysical studies in the four primary study areas. Two flights were made in preparation for low-level olique photography. The Bartlesville Energy Research Center (BERC) and participating National Laboratories, funded by DOE, are continuing their work in the area of research and development. The emphasis is on the development of new tools and instrumentation systems, rock mechanics, mathematical modeling, and data analysis. Mitchell Energy Corporation, Houston, Texas was awarded DOE Contract EF-78-C-08-1547 on March 15, 1978. Field work under this contract is scheduled to begin in July, 1978, with the drilling of a new well.

  16. 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...

  17. Properties of sodium silicate bonded sand hardened by microwave heating

    Institute of Scientific and Technical Information of China (English)

    Wang Jina; Fan Zitian; Zan Xiaolei; Pan Di

    2009-01-01

    The sodium silicate bonded sand hardened by microwave heating has many advantages,such as low sodium silicate adding quantity,fast hardening speed,high room temperature strength,good collapsibility and certain surface stability. However,it has big moisture absorbability in the air,which would lead to the compression strength and the surface stability of the sand molds being sharply reduced. In this study,the moisture absorbability of the sodium silicate bonded sand hardened by microwave heating in different humidity conditions and the effect factors were investigated. Meanwhile,the reasons for the big moisture absorbability of the sand were analyzed.Some measures to overcome the problems of high moisture absorbability,bad surface stability and sharply reducing strength in the air were discussed. The results of this study establish the foundation of green and clean foundry technology based on the microwave heating hardening sodium silicate sand process.

  18. A New Type of Exposed Oil Sand Mine

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With several means of analysis, the unique organic compound component and distribution of exposed oil sand existing in Qinghai, north-west China, is revealed. Qinghhai oil sand has great content of light components with high saturated hydrocarbon content up to approximately 50%, while its heavy components of colloid and asphaltene is rather low (<38%); straight-chain alkane has a regular distribution concentrating mainly around C28; it has a very high atom ratio of H/C. The physical parameters of the oil sand mine are within the range of common heavy oils. Such chemical composition and distribution obviously differs from that of other known exposed oil sand mines. This particular property of the oil sand is formed due to the unique geographical and geological environment. Therefore, it is intended to exploit the mine with a new combined method, i.e., first drill horizontal wells and then opencut.

  19. Methods for Measuring Sand Transport Using Radioactive Tracers

    International Nuclear Information System (INIS)

    Radioactive glass particles are sometimes used in the field for investigating the behaviour of sand and silt. Experiments have been performed in a flume with a rippled sand bed to compare the rate of movement of sand and glass particles of the same size and density. Several methods of measuring sand transport in the flume using radioactive tracers are described and compared. Two of these methods have been investigated in a series of tests; the first, usually termed the space integration method, involves the measurement of the spatial distribution of particles from a strip of the bed after various times; the second, referred to as the time integration method, requires the measurement of the passage of the tracer in time at a station downstream. These methods have been used to measure the velocity of several size fractions in a sand mixture. The practical difficulties of applying these methods to measurements in the field are briefly examined. (author)

  20. Modelling the behavior of an oil saturated sand

    International Nuclear Information System (INIS)

    The experiments carried out in an earlier study show the oil contamination affects the strength and deformation characteristics of a crushed quartz sand. In the present study, a mathematical soil model is used to simulate the mechanical behavior of the same sand. The model parameters are determined for both clean and oil contaminated soil. Simulations are made for the stress-strain behavior of the soil in drained and undrained conventional traixial compression tests. In order to illustrate the effect of changes in the soil properties on the behavior of an engineering structure, a finite element analysis is carried out. In this paper comparative results are presented to show the differences in the behavior of a foundation resting on a clean sand, on an oil contaminated sand, and on a sand contaminated locally

  1. Biodegradable materials as binders for IVth generation moulding sands

    Directory of Open Access Journals (Sweden)

    K. Major-Gabry

    2015-09-01

    Full Text Available This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the biodegradation rate of used binders, and the new biodegradable additive (PCL did not decrease the strength and thermal properties. In addition, using polycaprolactone (PCL as a biodegradable material may improve the flexibility of moulding sands with polymeric binder and reduce toxicity.

  2. The Black Family in American Economy: Black Capitalism.

    Science.gov (United States)

    Ezeocha, Peter A.

    Black capitalism that is well planned and run is a source of enumerable benefits to the American society in general and to blacks in particular. It generates opportunities for blacks to perform in occupations which for many years were closed to them. For hundreds of years blacks have been despised and often looked down upon on account of the fact…

  3. On the Charter Question: Black Marxism and Black Nationalism

    Science.gov (United States)

    Stern, Mark; Hussain, Khuram

    2015-01-01

    This article brings two black intellectual traditions to bear on the question of charter schools: black Marxism and black nationalism. The authors examine the theoretical and rhetorical devices used to talk about charters schools by focusing on how notions of "black liberation" are deployed by the charter movement, and to what end. The…

  4. Climatology of yellow sand (Asian sand, Asian dust or Kosa)in East Asia

    Institute of Scientific and Technical Information of China (English)

    Masatoshi; Yoshino

    2002-01-01

    In order to study climatology of yellow sand (Asian sand, Asian dust or Kosa) in EastAsia, secular fluctuation in China, Korea and Japan in the recent 30 years was presented. Thenumber of days with sand-dust storm at five stations in China-Hotan, Zhangye, Minqin, Jurhand Beijing, decreases a lot at the former three stations, but changed little at the latter two stations.Suggesting that the recent global warming is more evident in Xinjiang and Gansu, where the fre-quency of cold air invasions from the higher latitudes is decreasing. But, the eastern parts ofMongolia, inner Mongolia, and North China encounter stronger cyclones in early spring as a resultof global warming. These cyclones bring cold air from higher latitudes, causing severe duststorms. Secular variation in the annual days with sand-dust storms in China and Kosa days in Ko-rea and Japan show a parallel change with higher frequency from 1975 to 1985. This may be re-lated to the higher frequency of La Nina years. However, different tendency was shown in theperiod from 1986 to 1996. Since 1996 or 1997, a sharp increase is clear, which may be caused bythe developed cyclones in East Asia as well as human activities, and stronger land degradationunder La Nina conditions. Anomalies of the total number of stations with Kosa days were dis-cussed in accordance with some synoptic meteorological conditions such as the differences be-tween Siberian anticyclone and Aleutian cyclone center at 500 hPa level during the previous winter.

  5. ULTRAMASSIVE BLACK HOLE COALESCENCE

    International Nuclear Information System (INIS)

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production

  6. Properties of Self-Compacting Concrete Incorporating Waste Foundry Sand

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2013-11-01

    Full Text Available This paper demonstrates the possibilities of using waste foundry sand as partial replacement of sand in self-compacting concrete. Self-compacting concrete, as the name indicates, is a type of concrete that does not require external or internal compaction, because it becomes levelled and consolidated under its self-weight. Foundry sand is high quality silica sand used as a moulding material by ferrous and non-ferrous metal casting industries. It can be reused several times in foundries but, after a certain period, cannot be used further and becomes waste material, referred to as waste, used or spent foundry sand (WFS,UFS or SFS. This experimental investigation was performed to evaluate the strength and durability properties of SCC, in which natural sand was partial replaced with waste foundry sand (WFS. Natural sand was replaced with four percentage (0%, 10%, 15%, 20% of WFS by weight. Fresh properties of self-compacting concrete were studied. Compression test and splitting tensile strength test were carried out to evaluate the strength properties of concrete at the age of 7, 28, and 56 days. In case of durability properties, sulphate resistance was evaluated at the age of 7, 28 and 56 days and Rapid Chloride Permeability test was conducted at age of 28 days. Test results showed that there is increase in compressive strength, splitting tensile strength of self-compacting concrete by incorporating waste foundry sand (WFS as partial replacement by sand up to 15%. Resistance of concrete against sulphate attack and rapid chloride permeability were also improved for concrete mixes.

  7. Correlation between radionuclides associated with zircon and monazite in beach sand of Rosetta, Egypt

    International Nuclear Information System (INIS)

    The study aims to evaluate the activity concentrations of 238U, 232Th, 40K and 137Cs along Rosetta beach, Egypt. Non-destructive assay techniques were carried out using HP-Ge spectrometer and binocular microscope. The results of this study serve as a database for radioactivity levels of the mineral sand deposits of Rosetta area. The activity concentrations of 238U, 232Th and 40K ranged from 5.39 to 134.2, 6.6 to 160.8 and 57.6 to 492 Bq kg-1 respectively. The range of activity concentrations of 137Cs is between 0.05 and 0.91 Bq kg-1. The total gamma absorbed dose rates varied from 11.59 to 160.01 nGyh-1 with a mean value of 50.53 nGyh-1. These values correspond to an annual effective dose equivalent of 0.01-0.2 mSvy-1 with a mean of 0.07 mSvy-1, which is in agreement with the worldwide average. Also, a correlation between the calculated zircon and monazite radioactive mineral contents with the measured radioactive isotopes was carried out to determine the contribution of each mineral for radioactivity. These correlations predicted that both zircon and monazite minerals are the main contributors for radioactivity in the Egyptian beach black sands. Also the present study ensured that area under investigation is to be safe for public. (author)

  8. Experimental analysis of sand particles' lift-off and incident velocities in wind-blown sand flux

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Zhibao Dong; Xiaojing Zheng

    2005-01-01

    The probability distributions of sand particles' lift-off and incident velocities in a wind-blown sand flux play very important roles in the simulation of the wind-blown sand movement. In this paper, the vertical and the horizontal speeds of sand particles located at 1.0 mm above a sand-bed in a wind-blown sand flux are observed with the aid of Phase Doppler Anemometry (PDA) in a wind tunnel. Based on the experimental data, the probability distributions of not only the vertical lift-off speed but also the lift-off velocity as well as its horizontal component and the incident velocity as well as its vertical and horizontal components can be obtained by the equal distance histogram method. It is found, according to the results of the χ2-test for these probability distributions, that the probability density functions (pdf's) of the sand particles' lift-off and incident velocities as well as their vertical components are described by the Gamma density function with different peak values and shapes and the downwind incident and lift-off horizontal speeds, respectively, can be described by the lognormal and the Gamma density functions. These pdf's depend on not only the sand particle diameter but also the wind speed.

  9. Noncommutative Solitonic Black Hole

    CERN Document Server

    Chang-Young, Ee; Lee, Daeho; Lee, Youngone

    2012-01-01

    We investigate solitonic black hole solutions in three dimensional noncommutative spacetime. We do this in gravity with negative cosmological constant coupled to a scalar field using the Moyal product expanded up to first order in the noncommutativity parameter in the two noncommutative spatial directions. By numerical simulation we look for black hole solutions by increasing the non- commutativity parameter value starting from regular solutions with vanishing noncommutativity. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value.

  10. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  11. Reflection from black holes

    CERN Document Server

    Kuchiev, M Yu

    2003-01-01

    Black holes are presumed to have an ideal ability to absorb and keep matter. Whatever comes close to the event horizon, a boundary separating the inside region of a black hole from the outside world, inevitably goes in and remains inside forever. This work shows, however, that quantum corrections make possible a surprising process, reflection: a particle can bounce back from the event horizon. For low energy particles this process is efficient, black holes behave not as holes, but as mirrors, which changes our perception of their physical nature. Possible ways for observations of the reflection and its relation to the Hawking radiation process are outlined.

  12. Scalarized hairy black holes

    International Nuclear Information System (INIS)

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn

  13. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)

    2015-05-11

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  14. Scalarized Hairy Black Holes

    CERN Document Server

    Kleihaus, Burkhard; Yazadjiev, Stoytcho

    2015-01-01

    In the presence of a complex scalar field scalar-tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and ordinary hairy black holes. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  15. The Geodiversity in Drift Sand Landscapes of The Netherlands

    Science.gov (United States)

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

    2015-04-01

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

  16. On Noncommutative Black Holes Thermodynamics

    CERN Document Server

    Faizal, Mir; Ulhoa, S C

    2015-01-01

    In this paper, we will analyze noncommutative deformation of the Schwarzschild black holes and Kerr black holes. We will perform our analysis by relating the commutative and the noncommutative metrics using an Moyal product. We will also analyze the thermodynamics of these noncommutative black hole solutions. We will explicitly derive expression for the corrected entropy and temperature of these black hole solutions.

  17. The Thermodynamics of Black Holes

    Directory of Open Access Journals (Sweden)

    Wald Robert M.

    2001-01-01

    Full Text Available We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  18. The Price of "Black Dominance."

    Science.gov (United States)

    Hoberman, John

    2000-01-01

    Discusses the harmful effects of stereotyping black males as athletes, noting that over-identification with athletes and the world of physical performance limits black children's development by discouraging academic achievement. Examines the negative influence of mass media focus on black athletes, rappers, and stylized ghetto blackness. Discusses…

  19. The Thermodynamics of Black Holes

    OpenAIRE

    Wald Robert M.

    1999-01-01

    We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  20. Black Writers' Views of America.

    Science.gov (United States)

    Ladner, Joyce

    1979-01-01

    Black literature of the 1960s reflected protest and an affirmation of Black power and Black consciousness. The 1970s have produced a counterwave in which Blacks, in order to achieve literary and financial recognition, have begun to focus less on race and social criticism and more on conservative and narcissistic themes. (Author/EB)

  1. Topics in black hole evaporation

    International Nuclear Information System (INIS)

    Two major aspects of particle creation by gravitational fields of black holes are studied: the neutrino emission from rotating black holes; and interactions between scalar particles emitted by a black hole. Neutrino emission is investigated under three topics: The asymmetry of the angular dependence of neutrino emission from rotating black holes; the production of a local matter excess by rotating black holes in a baryon symmetric universe; and cosmological magnetic field generation by neutrinos from evaporating black holes. Finally the author studies the effects of interactions on the black hole evaporation process

  2. Black Holes in Higher Dimensions

    International Nuclear Information System (INIS)

    In four space-time dimensions black holes of Einstein-Maxwell theory satisfy a number of theorems. In more than four space-time dimensions, however, some of the properties of black holes can change. In particular, uniqueness of black holes no longer holds. In five and more dimensions black rings arise. Thus in a certain region of the phase diagram there are three black objects with the same global charges present. Here we discuss properties of higher-dimensional vacuum and charged black holes, which possess a spherical horizon topology, and of vacuum and charged black rings, which have a ringlike horizon topology

  3. Introducing the Black Hole

    Science.gov (United States)

    Ruffini, Remo; Wheeler, John A.

    1971-01-01

    discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

  4. Black Widow Spider

    Science.gov (United States)

    ... dling boxes, firewood, lumber, and rocks, etc. The black widow is commonly found in the following places: • Outdoors - woodpiles, rubble piles, under stones, in hol- low stumps, and in rodent burrows, privies, sheds ...

  5. Black Sea aerosols

    International Nuclear Information System (INIS)

    Shipboard, high volume air particulate samples were collected from the Black Sea atmosphere and analyzed by instrumental neutron activation analysis, atomic absorption spectrophotometry and ion chromatography for about 40 elements and ions. Concentrations of elements in the eastern and western parts of the Black Sea are different at the 95% confidence level, with lower concentrations in the eastern Black Sea. Back-trajectories and concentrations of elements in trajectory groups show that Europe accounts for more than 70% of the anthropogenic elements in the atmosphere. The average sulfate concentration was 7 μg/m3, which is comparable with rural sulfate levels in western Europe. Fluxes of elements from the atmosphere to the Black Sea are in good agreement with the results of similar flux calculations for other regions

  6. Black Friday = Broget Branding?

    DEFF Research Database (Denmark)

    Hansen, Heidi

    2015-01-01

    Black Friday er et godt eksempel på, hvordan ikke kun produktbrands og corporate brands rejser på tværs af landegrænser, men også traditioner som Halloween, Valentines Day og i dette tilfælde den ultimative tilbuds-fredag, som i USA går under navnet Black Friday. Men hvad er Black Friday i Danmark......? Essensen ved Black Friday er lave priser, og det er der ved første øjekast ikke mange brandingmuligheder forbundet ved, hvis man forstår branding som en måde at skabe ekstra værdi omkring sit produkt eller sin virksomhed. Som brand bliver man dog alligevel nødt til at forholde sig til konceptet, da det er...

  7. Black holes in astrophysics

    International Nuclear Information System (INIS)

    In this review we shall concentrate on the application of the concept of black hole to different areas in astrophysics. Models in which this idea is involved are connected with basically two areas in astrophysics: a) The death of massive stars due to gravitational collapse. This process would lead to the formation of black holes with stellar masses (10-20 M sun). The detection of these kind of - objects is in principle possible, by means of studying the so-called X-ray binary system. b) Active nuclei of galaxies, including quasars as an extreme case. In this case, the best model available to explain the generation of the enormous amounts of energy observed as well as several other properties, is accretion into a supermassive black hole (106-1010 M sun) in the center. The problem of the origin of such black holes is related to cosmology. (author)

  8. Cosmic censorship inside black holes

    CERN Document Server

    Thorlacius, L

    2006-01-01

    A simple argument is given that a traversable Cauchy horizon inside a black hole is incompatible with unitary black hole evolution. The argument assumes the validity of black hole complementarity and applies to a generic black hole carrying angular momentum and/or charge. In the second part of the paper we review recent work on the semiclassical geometry of two-dimensional charged black holes.

  9. Quantum Black Holes as Atoms

    OpenAIRE

    Bekenstein, Jacob D.

    1997-01-01

    In some respects the black hole plays the same role in gravitation that the atom played in the nascent quantum mechanics. This analogy suggests that black hole mass $M$ might have a discrete spectrum. I review the physical arguments for the expectation that black hole horizon area eigenvalues are uniformly spaced, or equivalently, that the spacing between stationary black hole mass levels behaves like 1/M. This sort of spectrum has also emerged in a variety of formal approaches to black hole ...

  10. Investigations on Several Mechanical Problems in Windblown Sand Movement

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiaojing

    2007-01-01

    It is very necessary for the investigation on mechanism of windblown sand movement to understand and find out effective measures of preventing and reducing danger of windblown sands, which also deals with some general characters and hot spots in the scientific forelands, such as multi-scale problems, interactions among multi-physical-fields, randomness and nonlinearity as well as complex systems. In recent years, a series of experiments in wind tunnels and theoretical modeling as well as computer simulation have been undertaken in the research group of environmental mechanics on windblown sand movement in Lanzhou University with the point of mechanical and geography intersecting view. Some original and essential progress has been achieved, which includes that the main regularities of charges on sand particles and the electric field in windblown sand flux and the effect of the electric field on the flux and the microwave propagation are revealed, and the evolution process of windblown sand flux under the mutual couple interactions among several physical fields are predicted as well as the main features of Aeolian sand ripples are simulated.

  11. Investigations on Several Mechanical Problems in Windblown Sand Movement

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Zheng

    2006-01-01

    It is very necessary for investigation on mechanism of windblown sand movement to understand and find out effective measures of preventing and reducing windblown sand. This also deals with some general features and hot spots in the scientific forelands, such as multi-scale problems, interactions among multi-physical-fields, randomness and nonlinearity as well as complex systems. In recent years, a series of experiments in wind tunnels and theoretical modeling as well as computer simulation have been taken by our research group (the Laboratory of Environmental Mechanics on Windblown Sand Movement in Lanzhou University) in a cross-disciplinary (mechanics and geography) viewpoint. Several original and essential studies were explored such as the main regularities of charges on sand particles, the mechanisms of electric field in windblown sand flux, the effects induced by the electric field on the flux, the microwave propagations, the evolution process of windblown sand flux under mutual couple interactions among several physical fields, and the simulation of the main features of Aeolian sand ripples.

  12. Materials characterization of the Libyan Ashi-Shibat desert sand

    International Nuclear Information System (INIS)

    Elemental silicon is produced mainly by the Carbo-thermic reduction of silica sand [1]. This technique produced rather impure silicon, which is termed as metallurgical grade silicon (MG-Si). An upgraded MG-Si, produced from high purity silica, is usually used to produced semiconductor and solar grade silicon tilized in the manufacturing of microelectronic components of integrated circuits, transistors and solar cells. In this paper, sand from one of the Libyan desert formations called Ash-Shibat, will be characterized to explore the possibility of its use in the production of high purity silicon. Such sands are thought to be suitable for the production of silicon used in electronic industry. Chemical analysis, x-ray diffraction, and scanning electron microscopy are the main techniques used to characterize the sand and to asses the type and amount of impurities present. The results indicate that impurities such as B, Na, Ca, K, Mg, Al, Ti and Fe are present in the as received sand in trace amounts. These impurities were found to be contained mainly on the sand particles exterior surfaces, and in the binding material between them. The interior of the form of quartz silica. It is concluded from this study that further purification and processing of Ash-Shibat sand should produce high purity silica that can be used for producing electronic industry grade silicon. (author)

  13. Canada's toxic tar sands : the most destructive project on earth

    International Nuclear Information System (INIS)

    This document addressed the environmental problems associated with tar sands development in Alberta, with particular reference to toxicity problems associated with global warming and the impending destruction of the boreal forest. The authors cautioned that the tar sand projects are highly destructive, leaving downstream toxics equivalent to that of a massive slow motion oil spill that has the potential to poison people. Negligent oversights by the government regarding the impact of tar sands development were also discussed, with reference to toxics on site; toxics downwind; and toxics down the pipe. The report also provided information on the future of tar sands development and global warming in Canada. It included a discussion of reverse alchemy; Canada's failed climate politics; a tar sands tax; and taking responsibility. Last, the report addressed toxic enforcement, including the Fisheries Act; Canadian Environmental Protection Act; Canadian Environmental Assessment Act; and Alberta law. It was concluded that while it is a stretch to believe the tar sands can truly be sustainable, there is a great deal that can be done to clean it up. The authors recommended that new tar sands approvals should wait until certain reform elements are implemented, such as passing a real carbon cap; using dry tailings; requiring wildlife offsets; cleaning up refineries and upgraders; ensuring Aboriginal control and benefit; and having regulation and independent monitoring. 104 refs., 6 figs

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

    Directory of Open Access Journals (Sweden)

    M. Rączka

    2012-09-01

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

  15. Geosynthetic Reinforcement of Sand-Mat Layer above Soft Ground

    Directory of Open Access Journals (Sweden)

    Jong-Beom Park

    2013-11-01

    Full Text Available In order to improve the bearing capacity of soft ground for the purpose of getting trafficability of construction vehicles, the reinforcement of geosynthetics for sand-mat layers on soft ground has often been used. As the strength of the geosynthetics increases, and the sand-mat system becomes stronger, the bearing capacity of sand-mat systems will be increased. The depths of geosynthetics, reinforced in sand-mat layers, were varied with respect to the width of footing. The tensile strengths of geosynthetics were also varied to evaluate the effect of reinforcement on the bearing capacity of soft ground. The dispersion angles, with varying sand-mat thicknesses, were also determined in consideration of the tensile strength of geosynthetics and the depths of reinforcement installations. The bearing capacity ratios, with the variation of footing width and reinforced embedment depth, were determined for the geosynthetics-only, reinforced soft ground, 1-layer sand-mat system and 2-layer sand-mat system against the non-reinforced soft ground. From the test results of various models, a principle that better explains the concept of geosynthetic reinforcement has been found. On the basis of this principle, a new bearing capacity equation for practical use in the design of geosynthetically reinforced soft ground has been proposed by modifying Yamanouchi’s equation.

  16. The technique of sand control with expandable screens

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  17. Canada's oil sands : opportunities and challenges to 2015 : an update

    International Nuclear Information System (INIS)

    This report updated an energy market assessment compiled and published by the National Energy Board (NEB) in 2004. Major changes resulting from recent developments in the oil sands industry were presented. The report was compiled from a series of informal meetings and discussions with a cross-section of oil sands stakeholders. Influences on recent oil sands development and production growth included market development and pipelines; rising capital and labour costs; operating costs; environmental impact management; high crude oil prices; rising global energy demand; technology innovations; and a more stable investment climate. A comparison of key assumptions between the current analysis and the 2004 report was presented, along with estimates of operating and supply costs for various types of oil sands recovery methods. Potential markets for oil sands production were reviewed. Environmental and socio-economic impacts on the industry included the larger than anticipated water withdrawals from the Athabasca River for mining operations; and uncertainties over land reclamation methods. The industry has also been impacted by a limited supply of skilled workers in Alberta. It was observed that the potential for building cogeneration capacity has decreased since the 2004 report. It was concluded that the oil sands industry will continue to grow rapidly, but the rate of development will depend on the balance that is reached between the opposing forces that affect the oil sands. Natural gas costs, high oil prices, air emissions management issues and water usage will continue to be of concern. 6 tabs., 7 figs

  18. Estimation of sand liquefaction based on support vector machines

    Institute of Scientific and Technical Information of China (English)

    苏永华; 马宁; 胡检; 杨小礼

    2008-01-01

    The origin and influence factors of sand liquefaction were analyzed, and the relation between liquefaction and its influence factors was founded. A model based on support vector machines (SVM) was established whose input parameters were selected as following influence factors of sand liquefaction: magnitude (M), the value of SPT, effective pressure of superstratum, the content of clay and the average of grain diameter. Sand was divided into two classes: liquefaction and non-liquefaction, and the class label was treated as output parameter of the model. Then the model was used to estimate sand samples, 20 support vectors and 17 borderline support vectors were gotten, then the parameters were optimized, 14 support vectors and 6 borderline support vectors were gotten, and the prediction precision reaches 100%. In order to verify the generalization of the SVM method, two other practical samples’ data from two cities, Tangshan of Hebei province and Sanshui of Guangdong province, were dealt with by another more intricate model for polytomies, which also considered some influence factors of sand liquefaction as the input parameters and divided sand into four liquefaction grades: serious liquefaction, medium liquefaction, slight liquefaction and non-liquefaction as the output parameters. The simulation results show that the latter model has a very high precision, and using SVM model to estimate sand liquefaction is completely feasible.

  19. Evaluation of wettability of binders used in moulding sands

    Directory of Open Access Journals (Sweden)

    Hutera B.

    2007-01-01

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

  20. Cosmological Black Holes

    OpenAIRE

    Stornaiolo, Cosimo

    2001-01-01

    In this paper we propose a model for the formation of the cosmological voids. We show that cosmological voids can form directly after the collapse of extremely large wavelength perturbations into low-density black holes or cosmological black holes (CBH). Consequently the voids are formed by the comoving expansion of the matter that surrounds the collapsed perturbation. It follows that the universe evolves, in first approximation, according to the Einstein-Straus cosmological model. We discuss...

  1. Quantum black holes

    International Nuclear Information System (INIS)

    No particle theory can be complete without gravity. Einstein's theory of gravity is of the Euler-Lagrange form, but standard quantization procedure fails. In quantum gravity the higher order interactions have a dimensionality different form the fundamental ones, because Newton's constant G has dimensions and the renormalization procedure fails. Another problem with quantum gravity is even more mysterious. Suppose that we had regularized the gravitational forces at the small distance end in the way that the weak intermediate vector boson regularized the fundamental 4-fermion interaction vertex of the weak interactions. Then what we discover is that the gravitational forces are unstable. Given sufficiently large amount of matter, it can collapse under its own weight. Classical general relativity tells us what will happen: a black hole is formed. But how is this formulated in quantum theory. S. Hawking observed that when a field theory is quantized in the background metric of a black hole, the black hole actually emits particles in a completely random thermal way. Apparently black holes are just another form of matter unstable against Hawking decay. Unfortunately this picture cannot be complete. The problem is that the quantum version of black holes has infinite phase space, and other symptoms of a run-away solution. Black holes are the heaviest and most compact forms of matter that can be imagined. A complete particle theory can have nothing but a spectrum of black-hole like objects at it high-energy end. This is why it is believed that a resolution of the black hole problem will in time disclose the complete small-distance structure of our world. 6 references

  2. Thermal corpuscular black holes

    OpenAIRE

    Casadio, Roberto; Giugno, Andrea; Orlandi, Alessio

    2015-01-01

    We study the corpuscular model of an evaporating black hole consisting of a specific quantum state for a large number $N$ of self-confined bosons. The single-particle spectrum contains a discrete ground state of energy $m$ (corresponding to toy gravitons forming the black hole), and a gapless continuous spectrum (to accommodate for the Hawking radiation with energy $\\omega>m$). Each constituent is in a superposition of the ground state and a Planckian distribution at the expected Hawking temp...

  3. Black hairy tongue syndrome

    OpenAIRE

    Gurvits, Grigoriy E; Tan, Amy

    2014-01-01

    Black hairy tongue (BHT) is a benign medical condition characterized by elongated filiform lingual papillae with typical carpet-like appearance of the dorsum of the tongue. Its prevalence varies geographically, typically ranging from 0.6% to 11.3%. Known predisposing factors include smoking, excessive coffee/black tea consumption, poor oral hygiene, trigeminal neuralgia, general debilitation, xerostomia, and medication use. Clinical presentation varies but is typically asymptomatic, although ...

  4. Potential building sand deposits in Songkhla province area

    Directory of Open Access Journals (Sweden)

    Kooptarnond, K.

    2002-10-01

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

  5. Research and practice of the impulse sand fracturing technology

    Directory of Open Access Journals (Sweden)

    Bin Qian

    2015-10-01

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

  6. New sand consolidation technique using hot alkaline solutions: laboratory evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, F.E.; Rico, A.; Mendez, Z. [PDVSA-Intevep, Caracas (Venezuela); Materan, S. [Simon Bolivar Univ., Caracas (Venezuela)

    2002-06-01

    Some well known problems in the petroleum industry are related to sanding problems caused by pressure falls, friction and dissolution of minerals during steam injection. The prospect of using hot alkaline solutions to achieve sand consolidation was investigated in this paper. Experimental work was performed using Venezuelan sand samples (S-1, S-2, and S-3) from various unconsolidated heavy oil reservoirs and commercial Silboca (S-4) sands to validate this new reservoir sand consolidation technique. A pressure of 500 pounds per square inch was applied to samples that had been packed into Teflon tubes and placed in a horizontal stainless steel cell. Following this, for a period varying from 2 to 5 hours, a hot sodium carbonate solution between 120 and 250 Celsius was injected. Every twenty minutes, the effluent solution was sampled. Before and after each run, permeability measurements were obtained to monitor the variations. Sand packs were dried at 100 Celsius after each test. An electron microscope was used to observe the morphology of secondary phases. For S-1 and S-2, sodium aluminium silicates were identified in the secondary phases for tests with temperature above 240 Celsius. In the case of S-3 and S-4, no consolidation was observed. The authors believe that large grain sizes and a 98 per cent quartz content respectively explain this phenomenon. It is suspected that sand consolidation requires the presence of aluminium contained in clays and/or feldspar. The critical parameters for sand consolidation were identified as temperature, pore volume, composition, and grain size. The process did not seem greatly affected by soaking time and injection rate. The advantages of this technique would be principally the minimization of sanding problems and reductions in the costs associated with production operations. 7 refs., 12 figs.

  7. Charged Galileon black holes

    Science.gov (United States)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar

    2015-05-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.

  8. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Steven L Liebling

    2000-10-01

    Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar phenomena without gravity.

  9. Characterization of Mesa Verde Black-on-white ceramics from southwestern Colorado using NAA

    International Nuclear Information System (INIS)

    Sixty Mesa Verde variety Black-on-white bowls from Castle Rock Pueblo (5MT 1825) and Sand Canyon Pueblo (5MT765) in southwestern Colorado were chemically characterized using neutron activation analysis. Eleven clay sources local to the sites in the McElmo Drainage area were also analyzed. The results revealed two distinct compositional groups containing relative frequencies that imply local production. The occurrence of trade between the two sites was also identified. (author). 20 refs., 5 figs., 2 tabs

  10. Effect of Sanding on Surface Properties of Medium Density Fiberboard

    OpenAIRE

    Nadir Ayrilmis, Zeki Candan, Turgay Akbulut, Ozgur Balkiz

    2010-01-01

    The objective of this research was to investigate the effects of sanding on the surface properties of the medium density fiberboard (MDF) panels made from Rhododendron ponticum L. wood. The MDF panels were sanded with different sizes of the sand paper grit: 60-, 60+80- or 60+80+120-grit. Surface absorption and surface roughness of the MDF panels were determined based on EN 382-1 standard and ISO 4287 by using a fi ne stylus profi lometer, respectively. Sessile water drop technique was used to...

  11. Strength properties of moulding sands with chosen biopolymer binders

    Directory of Open Access Journals (Sweden)

    St.M. Dobosz

    2010-07-01

    Full Text Available The article presents the results of primary researches of the IV generation moulding sands, in which as the binders are used differentbiodegradable materials. The bending and the tensile strength of the moulding sands with polylactide, poly(lactic-co-glycolic acid,polycaprolactone, polyhydroxybutyrate and cellulose acetate as binders were measured. The researches show that the best strengthproperties have the moulding sands with polylactide as binder. It was proved that the tested moulding sands’ strength properties are goodenough for foundry practice.

  12. Differences and commonalities impregnation of dry and wet sand

    Directory of Open Access Journals (Sweden)

    Maujuda МUZAFFAROVA

    2014-09-01

    Full Text Available The article is devoted to research new methods of physic-chemical methods of preventing deflation to protect railways and highways from such phenomena as exogenous sand drifts. In particular, first studied the possibility of using binders in sand wet state. Results can significantly extend the scope of the method, and identified with particular impregnation maintaining stability requirements protective cover reduces both the concentration previously recommended binders, and their costs, thereby securing implementation in practice of shifting sands resource-saving technology.

  13. Oil sands: Strategies for future development - An overview

    International Nuclear Information System (INIS)

    The Alberta Chamber of Resources developed a Task Force in 1993 to promote oil sands development, and to identify and publicize the social and economic benefits of oil sands operations. Formation, mission of the National Task Force, impediments and opportunities for development were summarized. Attributes of oil sands, benefits of their development, impediments to development, strategic development and potential growth scenarios were discussed. Cooperation between government and industry was deemed essential. Recommendations included development of a bitumen pipeline network, provision of incentives to encourage development, encouragement of risk and reward sharing between bitumen producers and up graders, and diversification of products and by-products. 7 figs., 12 refs

  14. Sulfur Biogeochemistry of an Oil Sands Composite Tailings Deposit

    OpenAIRE

    Warren, Lesley A.; Kendra, Kathryn E.; Brady, Allyson L.; Slater, Greg F.

    2016-01-01

    Composite tailings (CT), an engineered, alkaline, saline mixture of oil sands tailings (FFT), processed sand and gypsum (CaSO4; 1 kg CaSO4 per m3 FFT) are used as a dry reclamation strategy in the Alberta Oil Sands Region (AOSR). It is estimated that 9.6 × 108 m3 of CT are either in, or awaiting emplacement in surface pits within the AOSR, highlighting their potential global importance in sulfur cycling. Here, in the first CT sulfur biogeochemistry investigation, integrated geochemical, pyros...

  15. Measurement of elastic modulus and evaluation of viscoelasticity of foundry green sand

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Elastic modulus is an important physical parameter of molding sand; it is closely connected with molding sand's properties. Based on theories of rheology and molding sand microdeformation, elastic modulus of molding sand was measured and investigated using the intelligent molding sand multi-property tester developed by ourselves. The measuring principle was introduced. Effects of bentonite percentage and compactibility of the molding sand were experimentally studied. Furthermore, the essential viscoelastic nature of green sand was analyzed. It is considered that viscoelastic deformation of molding sand consists mainly of that of Kelvin Body of clay membrane, and elastic modulus of molding sand depends mainly on that of Kelvin Body which is the elastic component of clay membrane between sands. Elastic modulus can be adopted as one of the property parameters, and can be employed to evaluate the viscoelastic properties of molding sand.

  16. Experimental Study on Superfine Sand Concrete Mixed by Double Mixing Technology

    Directory of Open Access Journals (Sweden)

    yuqing zhao

    2013-07-01

    Full Text Available Traditional concept thought that medium sand and fine sand can be used to mix concrete, superfine sand can not used to mix concrete. This makes the source of superfine sand limited. With the shortage of medium sand and fine sand, it is imperative to exploit the resource of superfine sand. Superfine sand concrete is mixed by means of Double-doped Technology-ultra-fine fly ash and super plasticizer. Primary factor influencing superfine sand concrete strength is studied by orthogonal test, the optimal mixture ratio is found. The results indicated that the primary factors are water-binder ratio and sand ratio. At the same time, the workability and strength of superfine sand concrete mixed by optimal mixture ratio can satisfy the quality request of general engineering. It is proved that the double-doped technology is feasible, which can be used to conduct engineering construction.

  17. Alberta oil sands crudes : upgrading and marketing

    Energy Technology Data Exchange (ETDEWEB)

    Ashar, M. [Suncor Energy, Fort McMurray, AB (Canada)

    2008-05-15

    Open pit mining and in situ techniques, such as steam stimulation, are used to recover Alberta's bitumen and heavy oil resources, which have higher viscosities than conventional hydrocarbons. The bitumen is typically upgraded to synthetic crude oil (SCO). In the simplest processing scheme, the bitumen is blended with diluent for ease in pipeline transport and then processed at refineries with upgrading facilities. The bitumen is also upgraded to light SCO at world-scale upgraders in Alberta. The SCO is then processed at refineries in downstream markets. The 2 categories of upgrading, notably primary and secondary upgrading, were described in this article along with technology options for both categories. Slurry hydrocracking is regarded as the most interesting emerging residual fuel upgrading technology. It combines special catalyst mixes with the latest slurry reactor designs as well as innovative catalyst capture and recycle schemes to produce very high conversions and potentially superior upgrading economics. The increase in volume and rate of SCO from Alberta provides refiners in the oil sands marketing sector an unprecedented choice of opportunities to improve profitability. Key trends indicate that production will increase substantially from 2008 to 2030. 5 figs.

  18. Numerical modeling of subaqueous sand dune morphodynamics

    Science.gov (United States)

    Doré, Arnaud; Bonneton, Philippe; Marieu, Vincent; Garlan, Thierry

    2016-03-01

    The morphodynamic evolution of subaqueous sand dunes is investigated, using a 2-D Reynolds-averaged Navier-Stokes numerical model. A laboratory experiment where dunes are generated under stationary unidirectional flow conditions is used as a reference case. The model reproduces the evolution of the erodible bed until a state of equilibrium is reached. In particular, the simulation exhibits the different stages of the bed evolution, e.g., the incipient ripple generation, the nonlinear bed form growing phase, and the dune field equilibrium phase. The results show good agreement in terms of dune geometrical dimensions and time to equilibrium. After the emergence of the first ripple field, the bed growth is driven by cascading merging sequences between bed forms of different heights. A sequence extracted from the simulation shows how the downstream bed form is first eroded before merging with the upstream bed form. Superimposed bed forms emerge on the dune stoss sides during the simulation. An analysis of the results shows that they emerge downstream of a slight deflection on the dune profile. The deflection arises due to a modification of the sediment flux gradient consecutive to a reduction in the turbulence relaxation length while the upstream bed form height decreases. As they migrate, superimposed bed forms grow on the dune stoss side and eventually provoke the degeneration of the dune crest. Cascading merging sequences and superimposed bed forms dynamics both influence the dune field evolution and size and therefore play a fundamental role in the dune field self-organization process.

  19. Geophysical surveys for oil sands development

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, J.; Henderson, J. [Associated Geosciences Ltd., Calgary, AB (Canada)

    2010-07-01

    This article discussed two electromagnetic methods used in aerial geophysical surveys for addressing geotechnical issues related to resource extraction, namely Airborne Time Domain Electromagnetics (TEM) and Airborne Frequency Domain Electromagnetics. Electromagnetic methods identify contrasts in electrical conductivity, and the resulting data are interpreted according to how the measured electrical properties relate to the geologic units of interest. It is necessary to understand the limitations of the data to avoid misinterpreting the geophysical results. Both methods resolve the resistivity of the earth's subsurface but use different operations to do so, and both rely on the degree of contrast in the electrical characteristics of successive lithologies, target thickness, and the depth of occurrence for success. Inverse modelling is used to convert the results into a map of resistivity. The techniques can be used for economically mapping the location and thickness of cap rock, covering more area at less cost than drilling, creating maps of potential aquifers and paleo-channels that may control water flow, identifying local supplies of aggregates for road requirements, and mapping the location and depth of muskeg. It was concluded that these geophysical survey methods can cost-effectively provide useful information for oil sands development. 2 refs., 1 tab., 5 figs.

  20. Santo Amaro mineral sand mill decommissioning

    International Nuclear Information System (INIS)

    This site of 16 503 m2 held a monazite processing plant and in the metropolitan area of Sao Paulo, which is the largest city in Brazil. The plant operated for more than 60 years. As it has not been classified as a nuclear installation, the facility was not controlled by the national regulatory authority. As a consequence of the operations carried out at the site, it became contaminated with residues from mineral sands processing. Decommissioning activities started in 1994 and finished at the end of 1998. Decommissioning was carried out in five stages: (1) initially suitable packaging of contaminated material and waste removal took place; (2) decontamination and dismantling of equipment; (3) decontamination of floors and walls and demolition of the buildings (built area was about 13 000 m2); (4) land radiological characterization; 5) site clean-up. As long as Brazil does not have a national repository for low and intermediate level wastes, some of the generated wastes (about 60 m3) had to be stored in an adapted building at the Interlagos Mill site. Presently the most serious issue to be solved regards the final destination of the generated wastes

  1. Alberta oil sands crudes : upgrading and marketing

    International Nuclear Information System (INIS)

    Open pit mining and in situ techniques, such as steam stimulation, are used to recover Alberta's bitumen and heavy oil resources, which have higher viscosities than conventional hydrocarbons. The bitumen is typically upgraded to synthetic crude oil (SCO). In the simplest processing scheme, the bitumen is blended with diluent for ease in pipeline transport and then processed at refineries with upgrading facilities. The bitumen is also upgraded to light SCO at world-scale upgraders in Alberta. The SCO is then processed at refineries in downstream markets. The 2 categories of upgrading, notably primary and secondary upgrading, were described in this article along with technology options for both categories. Slurry hydrocracking is regarded as the most interesting emerging residual fuel upgrading technology. It combines special catalyst mixes with the latest slurry reactor designs as well as innovative catalyst capture and recycle schemes to produce very high conversions and potentially superior upgrading economics. The increase in volume and rate of SCO from Alberta provides refiners in the oil sands marketing sector an unprecedented choice of opportunities to improve profitability. Key trends indicate that production will increase substantially from 2008 to 2030. 5 figs

  2. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  3. Appraisal of the tight sands potential of the Sand Wash and Great Divide Basins

    International Nuclear Information System (INIS)

    The volume of future tight gas reserve additions is difficult to estimate because of uncertainties in the characterization and extent of the resource and the performance and cost-effectiveness of stimulation and production technologies. Ongoing R ampersand D by industry and government aims to reduce the risks and costs of producing these tight resources, increase the certainty of knowledge of their geologic characteristics and extent, and increase the efficiency of production technologies. Some basins expected to contain large volumes of tight gas are being evaluated as to their potential contribution to domestic gas supplies. This report describes the results of one such appraisal. This analysis addresses the tight portions of the Eastern Greater Green River Basin (Sand Wash and Great Divide Subbasins in Northwestern Colorado and Southwestern Wyoming, respectively), with respect to estimated gas-in-place, technical recovery, and potential reserves. Geological data were compiled from public and proprietary sources. The study estimated gas-in-place in significant (greater than 10 feet net sand thickness) tight sand intervals for six distinct vertical and 21 areal units of analysis. These units of analysis represent tight gas potential outside current areas of development. For each unit of analysis, a ''typical'' well was modeled to represent the costs, recovery and economics of near-term drilling prospects in that unit. Technically recoverable gas was calculated using reservoir properties and assumptions about current formation evaluation and extraction technology performance. Basin-specific capital and operating costs were incorporated along with taxes, royalties and current regulations to estimate the minimum required wellhead gas price required to make the typical well in each of unit of analysis economic

  4. Excess growing-season water limits lowland black spruce productivity

    Science.gov (United States)

    Dymond, S.; Kolka, R. K.; Bolstad, P. V.; Gill, K.; Curzon, M.; D'Amato, A. W.

    2015-12-01

    The annual growth of many tree species is limited by water availability, with growth increasing as water becomes less scarce. In lowland bogs of northern Minnesota, however, black spruce (Picea mariana) is often exposed to excess water via high water table elevations. These trees grow in thick deposits of organic mucky peat and often have shallow rooting systems to avoid the complete submersion of roots in water. While it is generally believed that black spruce decrease growth rates with rising water table elevations, this hypothesis has not been tested in situ. We used a unique, 50-year record of daily bog water table elevations at the Marcell Experimental Forest (MEF) in northern Minnesota to investigate the relationship between climate and black spruce productivity. Nine 1/20th ha circular plots were established in five different bogs and tree height, diameter-at-breast-height (DBH), and crown class were recorded. Additionally, two perpendicular cores were collected on all trees greater than 10 cm diameter-at-breast-height. Tree cores were sanded, mounted, cross-dated, and de-trended according to standard dendrochronological procedures. Ring width measurements were correlated with precipitation, temperature, and water table elevation using package BootRes in R to determine the climatic variables most associated with stand level productivity. Across the different plots, we found that early growing season water table elevation (May and June) was negatively correlated with both individual and stand-level black spruce growth (p < 0.01), while growth was positively correlated with March temperatures (p < 0.01). No significant relationships existed between black spruce growth and monthly precipitation. If summer water table elevations in these peatland ecosystems rise as is anticipated with more extreme precipitation events due to climate change, we could see an overall decrease in the stand level productivity of black spruce.

  5. Integrated Pest Management Plan for Sand Lake NWR Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of the Integrated Pest Management Plan is to provide a comprehensive, environmentally sensitive approach to managing pests on the Sand Lake WMD. The...

  6. [Sand Lake Migratory Waterfowl Refuge : Narrative report : 1935

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report covers activities on Sand Lake Migratory Waterfowl Refuge during 1935. The road construction, dam construction, food and cover,...

  7. Sand and Gravel Operations in the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — 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...

  8. Biodegradation of cycloalkane carboxylic acids in oil sand tailings

    International Nuclear Information System (INIS)

    The biodegradation of both an n-alkane and several carboxylated cycloalkanes was examined experimentally within tailings produced by the extraction of bitumen from the Athabasca oil sands. The carboxylated cycloalkanes examined were structurally similar to naphthenic acids that have been associated with the acute toxicity of oil sand tailings. The biodegradation potential of naphthenic acids was estimated by determining the biodegradation of both the carboxylated cycloalkanes and hexadecane in oil sand tailings. Carboxylated cycloalkanes were biodegraded within oil sands tailings, although compounds with methyl substitutions on the cycloalkane ring were more resistant to microbial degradation. Microbial activity against hexadecane and certain carboxylated cycloalkanes was found to be nitrogen and phosphorus limited. 21 refs., 3 refs., 1 tab

  9. LIQUEFACTION AND DISPLACEMENT OF SATURATED SAND UNDER VERTICAL VIBRATION LOADING

    Institute of Scientific and Technical Information of China (English)

    LU Xiaobing; TAN Qingming; CHENG C.M.; YU Shanbing; CUI Peng

    2004-01-01

    In order to investigate the influence of the vertical vibration loading on the liquefaction of saturated sand, one dimensional model for the saturated sand with a vertical vibration is presented based on the two phase continuous media theory. The development of the liquefaction and the liquefaction region are analyzed. It is shown that the vertical vibration loading could induce liquefaction.The rate of the liquefaction increases with the increase of the initial limit strain or initial porosity or amplitude and frequency of loading, and increases with the decrease of the permeability or initial modulus. It is shown also that there is a phase lag in the sand column. When the sand permeability distribution is non-uniform, the pore pressure and the strain will rise sharply where the permeability is the smallest, and fracture might be induced. With the development of liquefaction, the strength of the soil foundation becomes smaller and smaller. In the limiting case, landslides or debris flows could occur.

  10. Comprehensive Conservation Plan: Sand Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan CCP was written to guide management on Sand Lake NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  11. Reef community structure, Sand Island, Oahu HI, (NODC Accession 0000177)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These reports provide the results of nine years (1990-98) of an annual quantitative monitoring of shallow marine communities inshore of the Sand Island Ocean...

  12. Santa Barbara Littoral Cell CRSMP Offshore Sand Sources 2009

    Data.gov (United States)

    California Department of Resources — Offshore sand sources exist at four known locations and potentially other yet to be explored regions within the nearshore coastal shelf. Significant reserves of...

  13. Narrative report : Sand Lake Wetland Management District : 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sand Lake WMD outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing the weather...

  14. Federal Sand and Gravel Borrow Areas (Lease Areas)

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — Federal outer Continental Shelf (OCS) Sand and Gravel Borrow Areas (Lease Areas) are polygons which are maintained by the Bureau of Ocean Energy Management (BOEM),...

  15. Application of the HTGR in tar sands oil recovery

    International Nuclear Information System (INIS)

    The study presented in this paper explored the potential application of a high-temperature gas-cooled reactor (HTGR) to supply both process steam and cogenerated electric power for tar sands oil recovery and upgrading. The raw product recovered from the tar sands is a heavy bitumen. Upgrading, which involves coking and hydrodesulfurization, produces a synthetic crude (refinable by current technology) and petroleum coke. Energy requirements by form for each process are considered. An HTGR plant could be the most economical source of steam and electric power. This paper includes a description of the HTGR plant, a heat cycle and energy balance developed for a typical commercial tar sands oil recovery operation, and a schematic field arrangement showing the coupling of the HTGR to the process. Data developed during this study include expected bitumen recovery, economic data, and a comparative assessment of the HTGR application for tar sands recovery

  16. Documenting the global impacts of beach sand mining

    Science.gov (United States)

    Young, R.; Griffith, A.

    2009-04-01

    For centuries, beach sand has been mined for use as aggregate in concrete, for heavy minerals, and for construction fill. The global extent and impact of this phenomenon has gone relatively unnoticed by academics, NGOs, and major news sources. Most reports of sand mining activities are found at the very local scale (if the mining is ever documented at all). Yet, sand mining in many localities has resulted in the complete destruction of beach (and related) ecosystems along with severe impacts to coastal protection and tourism. The Program for the Study of Developed Shorelines at Western Carolina University and Beachcare.org have initiated the construction of a global database of beach sand mining activities. The database is being built through a combination of site visits and through the data mining of media resources, peer reviewed papers, and reports from private and governmental entities. Currently, we have documented sand mining in 35 countries on 6 continents representing the removal of millions of cubic meters of sand. Problems extend from Asia where critical infrastructure has been disrupted by sand mining to the Caribbean where policy reform has swiftly followed a highly publicized theft of sand. The Program for the Study of Developed Shorelines recently observed extensive sand mining in Morocco at the regional scale. Tens of kilometers of beach have been stripped of sand and the mining continues southward reducing hope of a thriving tourism-based economy. Problems caused by beach sand mining include: destruction of natural beaches and the ecosystems they protect (e.g. dunes, wetlands), habitat loss for globally important species (e.g. turtles, shorebirds), destruction of nearshore marine ecosystems, increased shoreline erosion rates, reduced protection from storms, tsunamis, and wave events, and economic losses through tourist abandonment and loss of coastal aesthetics. The threats posed by sand mining are made even more critical given the prospect of a

  17. Annual report : 1936-'37 : Sand Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report covers activities on Sand Lake Migratory Waterfowl Refuge during the 1937 fiscal year. Weather conditions, water levels, wildlife,...

  18. Sand Point, Alaska Tsunami Forecast Grids for MOST Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sand Point, Alaska Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST) model....

  19. Production of Silica-refractory Bricks from White Sand

    Directory of Open Access Journals (Sweden)

    Gazze Almarahle

    2005-01-01

    Full Text Available At present, no refractories are produced in Jordan, but large quantities are imported for use in the lining of furnaces and kilns in the metallurgical industries.The aim of this study is to initiate a program of research for production of silica-refractory bricks from local materials.The raw material, which has been used in this study was white sand. This sand contains less than 0.5% Fe2O3 and is therefore suitable for production of glass. The sand used for production of glass is also suitable for production of silica refractory bricks. The method for production of this bricks consists of mixing the white sand with 2.5 CaO (milklime which acts as a binder and mineraliser in order to convert the free quartz to tridymite and crystobalite.

  20. Removal method of radium in mine water by filter sand

    International Nuclear Information System (INIS)

    Trace radium is contained in mine water from the old mine road in Ningyo-Toge Environmental Engineering Center, JNC. We observed that filter sand with hydrated manganese oxide adsorbed radium in the mine water safely for long time. The removal method of radium by filter sand cladding with hydrated manganese oxide was studied. The results showed that radium was removed continuously and last for a long time from mine water with sodium hypochlorite solution by passing through the filter sand cladding with hydrated manganese. Only sodium hypochlorite solution was used. When excess of it was added, residue chlorine was used as chlorine disinfection. Filter sand cladding with hydrated manganese on the market can remove radium in the mine water. The removal efficiency of radium is the same as the radium coprecipitation method added with barium chloride. The cost is much lower than the ordinary methods. Amount of waste decreased to about 1/20 of the coprecipitation method. (S.Y.)

  1. Annual report : 1938-1939 : Sand Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sand Lake Migratory Waterfowl Refuge covers the 1939 fiscal year. Wildlife populations, artificial islands, haying, share cropping,...

  2. Narrative report : Sand Lake National Wildlife Refuge : 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sand Lake NWR and the easement refuges outlines Refuge accomplishments during the 1968 calendar year. The report begins by...

  3. Aging effects on oil-contaminated Kuwaiti sand

    International Nuclear Information System (INIS)

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

  4. Punctuated sand transport in the lowermost Mississippi River

    Science.gov (United States)

    Nittrouer, Jeffrey A.; Mohrig, David; Allison, Mead

    2011-12-01

    Measurements of sand flux and water flow in the Mississippi River are presented for a portion of the system 35-50 km upstream from the head of its subaerial delta. These data are used to provide insight into how nonuniform flow conditions, present in the lower reaches of large alluvial rivers, affect the timing and magnitude of sand transport near the river outlet. Field surveys during both low and high water discharge include (1) sequential digital bathymetric maps defining mobile river bottom topography which were used to estimate bed material flux, (2) multiple water velocity profiles, and (3) multiple suspended sediment profiles collected using a point-integrated sampler. These data show that total sand transport increases by two orders of magnitude over the measured range in water discharge (11,300 to 38,400 m3 s-1). During low water discharge no sand is measured in suspension, and sand discharge via bed form migration is minimal. During high water discharge 54% of the sand discharge is measured in suspension while 46% of the sand discharge is part of bed form migration. The component of boundary shear stress associated with moving this sediment is estimated using a set of established sediment transport algorithms, and values for the total boundary shear stress are predicted by fitting logarithmic velocity functions to the measured profiles. The estimates of boundary shear stress, using measurements of suspended sand transport, bed form transport, and downstream oriented velocity profiles are internally consistent; moreover, the analyses show that boundary shear stress increases by nearly 10-fold over the measured water discharge range. We show how this increase in shear stress is consistent with backwater flow arising where the river approaches its outlet. The hydrodynamic properties of backwater flow affect the timing and magnitude of sand flux and produce punctuated sand transport through the lowermost Mississippi River. Our field data are used to evaluate

  5. Under-mining the environment : the oil sands report card

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, S.; Moorhouse, J.; Laufenberg, K.; Powell, R.; Chandler, M. (ed.)

    2008-01-15

    This environmental performance survey is a report to the public on the comparative environmental management and performance of proposed and active oil sands mining projects in Alberta. The report card revealed that the proposed and actual environmental performance of the oil sands mining industry is generally poor, with an average score of 33 per cent. The overall scores for projects ranged from 56 per cent for the Albian Sands Muskeg River Mine to 18 per cent for the Synenco Northern Lights and Syncrude projects. The report indicated that there is much room for improvement in oil sand mining environmental management. Currently, there are many feasible strategies and best practices that could improve performance, but they are inconsistently applied in the oil sands region. The environmental performance of this industry could improve significantly if all operations improved their performance to match industry leaders. Although nearly all companies have environmental policies that commit to improvement, voluntary targets are rare for oil sands companies. Few have publicly committed to reduce greenhouse gas pollution, water intensity or air emissions. Very few have adopted targets to improve their intensity-based environmental performance. The report also indicated a lack of readily available information on environmental performance. The Pembina Institute and the World Wildlife Fund-Canada made the following recommendations to improve environmental management of oil sands mining operations in Alberta: (1) government should enforce acceptable standards of environmental performance, (2) government should report on environmental impacts to public lands, (3) government should request segregated information to enable comparison of environmental performance, (4) companies should implement best available practices, and (5) companies should make project-specific oil sands environmental performance information more widely available. 84 refs., 12 tabs., 8 figs.

  6. The influence of cementation on liquefaction resistance of sands

    OpenAIRE

    Iwabuchi, Jotaro

    1986-01-01

    Cohesionless sands are known to be susceptible to failure by liquefaction when they are saturated and subjected to earthquake shaking. Considerable study has been directed towards this subject over the past 20 years in recognition of the possibility of large-scale property damage or loss of life due to this type of failure. Recent evidence has shown that small degrees of cementation in a sand significantly reduce the likelihood of liquefication. However, the work to date has been ...

  7. Comment on "Solving the mystery of booming sand dunes"

    OpenAIRE

    Andreotti, B.; Bonneau, L.; Clement, E.

    2007-01-01

    We show here that the standard physical model used by Vriend et al. to analyse seismograph data, namely a non-dispersive bulk propagation, does not apply to the surface layer of sand dunes. According to several experimental, theoretical and field results, the only possible propagation of sound waves in a dry sand bed under gravity is through an infinite, yet discrete, number of dispersive surface modes. Besides, we present a series of evidences, most of which have already been published in th...

  8. First quarter technical progress report for Thermally Modified Sand

    Energy Technology Data Exchange (ETDEWEB)

    Gilfilian, R.E.

    1994-02-28

    This report documents progress on a project to demonstrate suitability of Thermally Modified Sand (TMS) for large scale use by demonstrating its performance on icy roadways maintained by the State of Alaska Department of Transportation. This report deals primarily with the startup of the project and includes initial observations of the effectiveness of the use of the TMS versus the typical salt/sand combination.

  9. Western tight gas sands advanced logging workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, J B; Carroll, Jr, H B [eds.

    1982-04-01

    An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

  10. Hierarchical organization of a Sardinian sand dune plant community.

    Science.gov (United States)

    Cusseddu, Valentina; Ceccherelli, Giulia; Bertness, Mark

    2016-01-01

    Coastal sand dunes have attracted the attention of plant ecologists for over a century, but they have largely relied on correlations to explain dune plant community organization. We examined long-standing hypotheses experimentally that sand binding, inter-specific interactions, abiotic factors and seedling recruitment are drivers of sand dune plant community structure in Sardinia, Italy. Removing foundation species from the fore-, middle- and back-dune habitats over three years led to erosion and habitat loss on the fore-dune and limited plant recovery that increased with dune elevation. Reciprocal species removals in all zones suggested that inter-specific competition is common, but that dominance is transient, particularly due to sand burial disturbance in the middle-dune. A fully factorial 2-year manipulation of water, nutrient availability and substrate stability revealed no significant proximate response to these physical factors in any dune zone. In the fore- and middle-dune, plant seeds are trapped under adult plants during seed germination, and seedling survivorship and growth generally increase with dune height in spite of increased herbivory in the back-dune. Sand and seed erosion leads to limited seed recruitment on the fore-dune while high summer temperatures and preemption of space lead to competitive dominance of woody plants in the back-dune. Our results suggest that Sardinian sand dune plant communities are organized hierarchically, structured by sand binding foundation species on the fore-dune, sand burial in the middle-dune and increasingly successful seedling recruitment, growth and competitive dominance in the back-dune. PMID:27478701

  11. Sustainable water management in Alberta's oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Byers, Bill; Usher, Robyn; Roach, Andrea [CH2M HILL, Englewood, CO (United States); Lambert, Gord; Kotecha, Prit [Suncor Energy Inc., Calgary (Canada)

    2012-07-01

    The Canadian Association of Petroleum Producers forecast published in 2011 predicts that oil production from oil sands will increase by 50% in the next 3 years and double by 2020. This rate of growth will result in significant pressure on water resources; water use per barrel of oil sands production is comparable to other energy resources - about 2.5 barrels of fresh water per barrel of oil produced are used by mining operations and 0.5 barrels by in-situ operations. Suncor Energy Inc. (Suncor) was the first company to develop the oil sands in northern Alberta and holds one of the largest oil sands positions in Canada. In 2010, Suncor announced plans to increase production to more than 1 million barrels of oil equivalent per day by 2020, which it plans to achieve through oil sands production growth of approximately 10% per year. Because water supply and potential impacts to water quality are critical to its future growth, in 2010-2011 Suncor conducted a risk assessment to identify water-related business risks related to its northern Alberta operations. The assessment identified more than 20 high level business risks in strategic water risk areas including water supply, water reuse, storm water management, groundwater, waste management and river water return. The risk assessment results prompted development of a strategic roadmap to guide water stewardship across Suncor's regional operations. The roadmap describes goals, objectives, and specific activities for each of six key water risk areas, and informs prioritization and selection of prospective water management activities. Suncor is not only exploring water within its own boundaries, but is also collaborating with other oil sands producers to explore ways of integrating its water systems through industry consortia; Suncor is a member of the Oil Sands Leadership Initiative and of the recently formed Canadian Oil Sands Innovation Alliance, among others. (author)

  12. Monitoring and characterisation of sand-mud sedimentation processes

    Science.gov (United States)

    Cuthbertson, Alan J. S.; Ibikunle, Olugbenga; McCarter, W. John; Starrs, Gerard

    2016-07-01

    Estuaries and tidal inlets are often characterised by the presence of both cohesive and non-cohesive sediments. Knowledge of the sedimentation behaviour of sand-mud mixtures is therefore crucial to the understanding and prediction of the time-dependent structure (i.e. mixed or segregated), composition and erodibility of sediment bed deposits developing within these environments. In the current study, a series of settling column tests are conducted to investigate the hindered settling and initial bed consolidation phases of a range of sand-clay mixtures to determine the parametric conditions under which bed segregation occurs. A new, non-invasive, electrical resistivity measurement technique is employed to capture both temporal and spatial changes in the density, porosity and composition of the evolving sand-clay bed deposits, complimented by time-lapsed images of the sedimentation process within the column. The results show that the formation of segregated (sand-clay) bed layers with bed deposits is largely controlled by the initial fractional composition (i.e. relative sand and clay concentrations). Specifically, mixtures with low clay contents are shown to form well-defined (sand-clay) layer segregation within the resulting deposits, while higher clay contents result in more transitional segregation patterns or no layer segregation (for very high clay concentrations). The physical mechanisms under which these different segregation types can be generated are illustrated through predictions from an existing polydisperse hindered settling model. This model indicates that the degree of bed segregation, and time scale over which this occurs, correlates well with the difference in predicted hindered settling characteristics and upward displacements associated with the sand and clay fractions, respectively. In this regard, the new experimental dataset provides validation for the polydisperse model (for the first time), with the combined data and model predictions

  13. Frac Sand Mines Are Preferentially Sited in Unzoned Rural Areas.

    Directory of Open Access Journals (Sweden)

    Christina Locke

    Full Text Available Shifting markets can cause unexpected, stochastic changes in rural landscapes that may take local communities by surprise. Preferential siting of new industrial facilities in poor areas or in areas with few regulatory restrictions can have implications for environmental sustainability, human health, and social justice. This study focuses on frac sand mining-the mining of high-quality silica sand used in hydraulic fracturing processes for gas and oil extraction. Frac sand mining gained prominence in the 2000s in the upper midwestern United States where nonmetallic mining is regulated primarily by local zoning. I asked whether frac sand mines were more commonly sited in rural townships without formal zoning regulations or planning processes than in those that undertook zoning and planning before the frac sand boom. I also asked if mine prevalence was correlated with socioeconomic differences across townships. After creating a probability surface to map areas most suitable for frac sand mine occurrence, I developed neutral landscape models from which to compare actual mine distributions in zoned and unzoned areas at three different spatial extents. Mines were significantly clustered in unzoned jurisdictions at the statewide level and in 7 of the 8 counties with at least three frac sand mines and some unzoned land. Subsequent regression analyses showed mine prevalence to be uncorrelated with land value, tax rate, or per capita income, but correlated with remoteness and zoning. The predicted mine count in unzoned townships was over two times higher than that in zoned townships. However, the county with the most mines by far was under a county zoning ordinance, perhaps indicating industry preferences for locations with clear, homogenous rules over patchwork regulation. Rural communities can use the case of frac sand mining as motivation to discuss and plan for sudden land-use predicaments, rather than wait to grapple with unfamiliar legal processes

  14. THE STUDY OF CORE SAND MIXTURES BASED ON POLYMERIC BINDERS

    Directory of Open Access Journals (Sweden)

    Ms. Natalia V. Zakharova

    2016-06-01

    Full Text Available The possibility of using foamed polystyrene waste as the binder in manufacturing core sand mixtures. The article provides experimental data obtained by studying the core sand mixtures properties depending on the methods of addition, foamed polystyrene solution amount, its viscosity and the method of drying. The author investigates the ways of using foamed polystyrene as the binder and as the polymeric additive.

  15. Frac Sand Mines Are Preferentially Sited in Unzoned Rural Areas

    Science.gov (United States)

    Locke, Christina

    2015-01-01

    Shifting markets can cause unexpected, stochastic changes in rural landscapes that may take local communities by surprise. Preferential siting of new industrial facilities in poor areas or in areas with few regulatory restrictions can have implications for environmental sustainability, human health, and social justice. This study focuses on frac sand mining—the mining of high-quality silica sand used in hydraulic fracturing processes for gas and oil extraction. Frac sand mining gained prominence in the 2000s in the upper midwestern United States where nonmetallic mining is regulated primarily by local zoning. I asked whether frac sand mines were more commonly sited in rural townships without formal zoning regulations or planning processes than in those that undertook zoning and planning before the frac sand boom. I also asked if mine prevalence was correlated with socioeconomic differences across townships. After creating a probability surface to map areas most suitable for frac sand mine occurrence, I developed neutral landscape models from which to compare actual mine distributions in zoned and unzoned areas at three different spatial extents. Mines were significantly clustered in unzoned jurisdictions at the statewide level and in 7 of the 8 counties with at least three frac sand mines and some unzoned land. Subsequent regression analyses showed mine prevalence to be uncorrelated with land value, tax rate, or per capita income, but correlated with remoteness and zoning. The predicted mine count in unzoned townships was over two times higher than that in zoned townships. However, the county with the most mines by far was under a county zoning ordinance, perhaps indicating industry preferences for locations with clear, homogenous rules over patchwork regulation. Rural communities can use the case of frac sand mining as motivation to discuss and plan for sudden land-use predicaments, rather than wait to grapple with unfamiliar legal processes during a period of

  16. Numerical Modeling of Flow in a Horizontal Sand Filter

    Directory of Open Access Journals (Sweden)

    Ruth Mossad

    2010-01-01

    Full Text Available Problem statement: Horizontal sand filters may offer some advantage over vertical sand filters as they could be used for in-line treatment of wastewaters. Horizontal pipelines of tens and if not hundreds of meters length, filled with ordinary sand or permeable reactive media such as activated carbon or natural zeolite or iron filings, may be used to remove impurities from mine drainage waters, sewer and storm waters. Approach: However, in reality, in industrial-scale applications, the sand filled horizontal structures are almost always avoided due to the fact that water seeks out the path of least resistance. Once such a path is created, the vast majority of the water channels towards the least resistance zone and very small percentage of the water will go through the sand. Results: This study, applying numerical modeling using FLUENT software, which is based on the integral control volume approach, explores a number of geometries to identify a design that helps the inlet water to sweep the entire sand with the least channeling. The Navier Stokes equations for laminar and incompressible flow through porous media (i.e., the sand including the viscous resistance were solved. Retention time of a fluid with properties similar to water, called tracer, were also estimated using Eulerian unsteady two phase flow analysis. Conclusion: The results of the models showed that the geometries involving a pipe with spiral protrusions or plate (baffles inside, would be partially successful in drawing the water away from the channeling zone and moving it through the sand, however the geometry with the spiral protrusions uses much less power than the one with the baffles.

  17. Concentric coiled tubing application for sand cleanout in horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Falk, K.; Fraser, B. [Nowsco Well Services Ltd., Calgary, AB (Canada)

    1998-10-01

    Concentric tubing technology which has opened up a new area of well service capabilities is discussed. One of these techniques involves incorporating concentric tubing equipment with a patented jet pump tool (Sand-Vac{sup S}M) for the purpose of cleaning well sand out of low pressure horizontal wells. Various issues relating to well cleanout using this technology are described, with brief summaries of five case histories. 5 refs., 6 figs.

  18. Creating and maintaining a gas cap in tar sands formations

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX); Dinkoruk, Deniz Sumnu (Houston, TX); Wellington, Scott Lee (Bellaire, TX)

    2010-03-16

    Methods for treating a tar sands formation are disclosed herein. Methods for treating a tar sands formation may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. Pressure may be allowed to increase in an upper portion of the formation to provide a gas cap in the upper portion. At least some hydrocarbons are produced from a lower portion of the formation.

  19. Between sand and sandstone: microrelief on very weakly cemented sandstones

    Czech Academy of Sciences Publication Activity Database

    Mikuláš, Radek; Adamovič, Jiří; Cílek, Václav

    Wrocław : Instytut Geografii i Rozwoju Regionalnego Uniwersytetu Wrocławskiego, 2013 - (Migoń, P.; Kasprzak, M.), s. 127-131 ISBN 978-83-62673-29-2. [ Sand stone Landscapes (3.). Kudowa-Zdrój (PL), 25.04.2012-28.04.2012] R&D Projects: GA AV ČR IAA300130806 Institutional support: RVO:67985831 Keywords : poorly lithified sand stones * microrelief * bioerosion Subject RIV: DB - Geology ; Mineralogy

  20. Monitoring of rapid sand filters using an acoustic imaging technique

    OpenAIRE

    Allouche, N.; Simons, D.G.; Rietveld, L. C.

    2012-01-01

    A novel instrument is developed to acoustically image sand filters used for water treatment and monitor their performance. The instrument consists of an omnidirectional transmitter that generates a chirp with a frequency range between 10 and 110 kHz, and an array of hydrophones. The instrument was extensively tested in a lab before being deployed in an industrial rapid sand filter, made available by a Dutch drinking water company. This filter was monitored over a period of 10 days. We perform...

  1. Monitoring and characterisation of sand-mud sedimentation processes

    Science.gov (United States)

    Cuthbertson, Alan J. S.; Ibikunle, Olugbenga; McCarter, W. John; Starrs, Gerard

    2016-05-01

    Estuaries and tidal inlets are often characterised by the presence of both cohesive and non-cohesive sediments. Knowledge of the sedimentation behaviour of sand-mud mixtures is therefore crucial to the understanding and prediction of the time-dependent structure (i.e. mixed or segregated), composition and erodibility of sediment bed deposits developing within these environments. In the current study, a series of settling column tests are conducted to investigate the hindered settling and initial bed consolidation phases of a range of sand-clay mixtures to determine the parametric conditions under which bed segregation occurs. A new, non-invasive, electrical resistivity measurement technique is employed to capture both temporal and spatial changes in the density, porosity and composition of the evolving sand-clay bed deposits, complimented by time-lapsed images of the sedimentation process within the column. The results show that the formation of segregated (sand-clay) bed layers with bed deposits is largely controlled by the initial fractional composition (i.e. relative sand and clay concentrations). Specifically, mixtures with low clay contents are shown to form well-defined (sand-clay) layer segregation within the resulting deposits, while higher clay contents result in more transitional segregation patterns or no layer segregation (for very high clay concentrations). The physical mechanisms under which these different segregation types can be generated are illustrated through predictions from an existing polydisperse hindered settling model. This model indicates that the degree of bed segregation, and time scale over which this occurs, correlates well with the difference in predicted hindered settling characteristics and upward displacements associated with the sand and clay fractions, respectively. In this regard, the new experimental dataset provides validation for the polydisperse model (for the first time), with the combined data and model predictions

  2. Virtual black holes

    Science.gov (United States)

    Hawking, S. W.

    1996-03-01

    One would expect spacetime to have a foamlike structure on the Planck scale with a very high topology. If spacetime is simply connected (which is assumed in this paper), the nontrivial homology occurs in dimension two, and spacetime can be regarded as being essentially the topological sum of S2×S2 and K3 bubbles. Comparison with the instantons for pair creation of black holes shows that the S2×S2 bubbles can be interpreted as closed loops of virtual black holes. It is shown that scattering in such topological fluctuations leads to loss of quantum coherence, or in other words, to a superscattering matrix S/ that does not factorize into an S matrix and its adjoint. This loss of quantum coherence is very small at low energies for everything except scalar fields, leading to the prediction that we may never observe the Higgs particle. Another possible observational consequence may be that the θ angle of QCD is zero without having to invoke the problematical existence of a light axion. The picture of virtual black holes given here also suggests that macroscopic black holes will evaporate down to the Planck size and then disappear in the sea of virtual black holes.

  3. Charged Galileon black holes

    CERN Document Server

    Babichev, Eugeny; Hassaine, Mokhtar

    2015-01-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematic...

  4. Electrochemical and Dry Sand Impact Erosion Studies on Carbon Steel.

    Science.gov (United States)

    Naz, M Y; Ismail, N I; Sulaiman, S A; Shukrullah, S

    2015-01-01

    This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm(2) and 809 Ω.cm(2), respectively. PMID:26561231

  5. A crash programme scenario for the Canadian oil sands industry

    International Nuclear Information System (INIS)

    The report Peaking of World Oil Production: Impacts, Mitigation and Risk Management, by Robert L. Hirsch et al., concludes that Peak Oil is going to happen and that worldwide large-scale mitigation efforts are necessary to avoid its possible devastating effects for the world economy. These efforts include accelerated production, referred to as crash programme production, from Canada's oil sands. The objective of this article is to investigate and analyse what production levels that might be reasonable to expect from a crash programme for the Canadian oil sands industry, within the time frame 2006-2018 and 2006-2050. The implementation of a crash programme for the Canadian oil sands industry is associated with serious difficulties. There is not a large enough supply of natural gas to support a future Canadian oil sands industry with today's dependence on natural gas. It is possible to use bitumen as fuel and for upgrading, although it seems to be incompatible with Canada's obligations under the Kyoto treaty. For practical long-term high production, Canada must construct nuclear facilities to generate energy for the in situ projects. Even in a very optimistic scenario Canada's oil sands will not prevent Peak Oil. A short-term crash programme from the Canadian oil sands industry achieves about 3.6 mb/d by 2018. A long-term crash programme results in a production of approximately 5 mb/d by 2030

  6. Coagulation-flocculation in leachate treatment using modified micro sand

    Science.gov (United States)

    Thaldiri, Nur Hanani; Halim, Azhar Abdul

    2013-11-01

    Sanitary landfill leachate is considered as highly polluted wastewater, without any treatment, discharging into water system will cause underground water and surface water pollutions. This study was to investigate the treatability of the semi-aerobic landfill leachate via coagulation-flocculation using poly-aluminum chloride (PAC), cationic polymer, and modified micro sand. Leachate was collected from Pulau Burung Sanitary Landfill (PBSL) located in Penang, Malaysia. Coagulation-flocculation was performed by using jar test equipment and the effect of pH, dose of coagulant and dose of polymer toward removal of chemical oxygen demand (COD), color and suspended solid (SS) were examined. Micro sand was also used in this study to compare settling time of coagulation-flocculation process. The optimum pH, dose of coagulant (PAC) and dose of polymer (cationic) achieved were 7.0, 1000 mg/L and 8 mg/L, respectively. The dose of micro sand used for the settling time process was 300 mg/L. Results showed that 52.66% removal of COD, 97.16% removal of SS and 96.44% removal of color were achieved under optimum condition. The settling times for the settling down of the sludge or particles that formed during coagulation-flocculation process were 1 min with modified sand, 20 min with raw micro sand and 45 min without micro sand.

  7. Petrophysical Evaluation Of Radioactive Sands In The Niger Delta

    International Nuclear Information System (INIS)

    Wire line logging tools responses in the Niger Delta are often affected by the presence of several radioactive minerals. The interpretation of hydrocarbon bearing radioactive sands using conventional approaches has resulted in underestimation of hydrocarbon resources. To gain more insight into the problem of radioactive hydrocarbon bearing formations in the Niger Delta, a project was carried out within Shell to study the structure, mineralogy and pore geometry associated with radioactive sand typical of the Niger Delta, and develop evaluation techniques for improved recognition of radioactive sands. The nature of radioactive sands encountered in the Niger Delta is now better understood and an automated identification procedure based on wire line logs using neural networks has been developed. Radioactive sands are sometimes laminae are masked by those of the shale laminae thereby leading to low resistivity readings despite the presence of appreciable amounts of producible hydrocarbons. The structural configuration of radioactive sands has necessitated the development of of an evaluation package for thin bedded shaly sandstone reservoirs. The application of the evaluation package indicates significant increases in hydrocarbon volumes when compared to conventional evaluation. approaches

  8. Effects of the mid-air collision on sand saltation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    As to the fact that the effects of saltating particles’ mid-air collision on the sand transport rate are often neglected in the current theoretical models describing sand saltation movement,expressions to calculate velocity diversity of saltating parti-cles after mid-air collision are presented through collision theory of hard ball in this paper. Then,the theoretical model of the wind blown sand movement at the steady state,taking account of coupled interaction between saltation particles and wind,is combined with the model of the mid-air collision probability to calculate the sal-tating particles’ mass flux at heights,the sand transport rate,and further,their changing rules. The comparison of the results with those when the mid-air collision is not considered suggests that the mass flux at heights and the sand transport rate in this paper are less,and much closer,respectively,to the corresponding experi-mental values. The difference between the sand mass fluxes without and with con-sideration of mid-air collision increases at first,and then decreases as the height increases,exhibiting the stratified characteristics.

  9. Electrochemical and Dry Sand Impact Erosion Studies on Carbon Steel

    Science.gov (United States)

    Naz, M. Y.; Ismail, N. I.; Sulaiman, S. A.; Shukrullah, S.

    2015-11-01

    This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm2 and 809 Ω.cm2, respectively.

  10. Submarine sand volcanos: experiments and numerical modelling

    Science.gov (United States)

    Philippe, P.; Ngoma, J.; Delenne, J.

    2012-12-01

    Fluid overpressure at the bottom of a soil layer may generate fracturation in preferential paths for a cohesive material. But the case of sandy soils is rather different: a significant internal flow is allowed within the material and can potentially induce hydro-mechanical instabilities whose most common example is fluidization. Many works have been devoted to fluidization but very few have the issue of initiation and development of a fluidized zone inside a granular bed, prior entire fluidization of the medium. In this contribution, we report experimental results and numerical simulations on a model system of immersed sand volcanos generated by a localized upward spring of liquid, injected at constant flow-rate at the bottom of a granular layer. Such a localized state of fluidization is relevant for some industrial processes (spouted bed, maintenance of navigable waterways,…) and for several geological issues (kimberlite volcano conduits, fluid venting, oil recovery in sandy soil, More precisely, what is presented here is a comparison between experiments, carried out by direct visualization throughout the medium, and numerical simulations, based on DEM modelling of the grains coupled to resolution of NS equations in the liquid phase (LBM). There is a very good agreement between the experimental phenomenology and the simulation results. When the flow-rate is increased, three regimes are successively observed: static bed, fluidized cavity that does not extend to the top of the layer, and finally fluidization over the entire height of layer that creates a fluidized chimney. A very strong hysteretic effect is present here with an extended range of stability for fluidized cavities when flow-rate is decreased back. This can be interpreted in terms force chains and arches. The influences of grain diameter, layer height and injection width are studied and interpreted using a model previously developed by Zoueshtiagh [1]. Finally, growing rate of the fluidized zone and

  11. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    DEFF Research Database (Denmark)

    Hovad, Emil; Larsen, P.; Walther, Jens Honore;

    2015-01-01

    The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC...

  12. Evaluation of an Innovative Sand Filter for Small System Drinking Water Treatment

    Science.gov (United States)

    Results of evaluation of an innovative sand filter that uses the concepts of both slow and rapid sand filtration are presented in this article. The system uses a low-cost “Drum Sand Filter” (DSF) that consists of a 55-gallon drum filled with layers of sand of varying size. A low-...

  13. Tunneling Through Black Rings

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liu

    2007-01-01

    Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton theory is analyzed by use of the Parikh-Wilczek tunneling method. To get the correct tunneling amplitude and emission rate, we adopt and develop the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronic discharge all at once, and the effect of back reaction is also taken into account. This constitutes a unified approach to the tunneling problem. Provided the first law of thermodynamics for black rings holds, the emission rate is proportional to the exponential of the change of Bekenstein-Hawking entropy. Explicit calculation for black ring temperatures agrees exactly with the results obtained via the classical surface gravity method and the quasi-local formalism.

  14. Noncommutative black hole thermodynamics

    International Nuclear Information System (INIS)

    We give a general derivation, for any static spherically symmetric metric, of the relation Th=(K/2π) connecting the black hole temperature (Th) with the surface gravity (K), following the tunneling interpretation of Hawking radiation. This derivation is valid even beyond the semi-classical regime, i.e. when quantum effects are not negligible. The formalism is then applied to a spherically symmetric, stationary noncommutative Schwarzschild space-time. The effects of backreaction are also included. For such a black hole the Hawking temperature is computed in a closed form. A graphical analysis reveals interesting features regarding the variation of the Hawking temperature (including corrections due to noncommutativity and backreaction) with the small radius of the black hole. The entropy and tunneling rate valid for the leading order in the noncommutative parameter are calculated. We also show that the noncommutative Bekenstein-Hawking area law has the same functional form as the usual one

  15. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids. PMID:25768746

  16. Black Hole Bose Condensation

    International Nuclear Information System (INIS)

    General consensus on the nature of the degrees of freedom responsible for the black hole entropy remains elusive despite decades of effort dedicated to the problem. Different approaches to quantum gravity disagree in their description of the microstates and, more significantly, in the statistics used to count them. In some approaches (string theory, AdS/CFT) the elementary degrees of freedom are indistinguishable, whereas they must be treated as distinguishable in other approaches to quantum gravity (eg., LQG) in order to recover the Bekenstein-Hawking area-entropy law. However, different statistics will imply different behaviors of the black hole outside the thermodynamic limit. We illustrate this point by quantizing the Bañados-Teitelboim-Zanelli (BTZ) black hole, for which we argue that Bose condensation will occur leading to a cold, stable remnant

  17. Black Hole Bose Condensation

    Science.gov (United States)

    Vaz, Cenalo; Wijewardhana, L. C. R.

    2013-12-01

    General consensus on the nature of the degrees of freedom responsible for the black hole entropy remains elusive despite decades of effort dedicated to the problem. Different approaches to quantum gravity disagree in their description of the microstates and, more significantly, in the statistics used to count them. In some approaches (string theory, AdS/CFT) the elementary degrees of freedom are indistinguishable, whereas they must be treated as distinguishable in other approaches to quantum gravity (eg., LQG) in order to recover the Bekenstein-Hawking area-entropy law. However, different statistics will imply different behaviors of the black hole outside the thermodynamic limit. We illustrate this point by quantizing the Bañados-Teitelboim-Zanelli (BTZ) black hole, for which we argue that Bose condensation will occur leading to a "cold", stable remnant.

  18. Merging Black Holes

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  19. Rotating Black Droplet

    CERN Document Server

    Fischetti, Sebastian

    2013-01-01

    We construct the gravitational dual, in the Unruh state, of the "jammed" phase of a CFT at strong coupling and infinite N on a fixed five-dimensional rotating Myers-Perry black hole with equal angular momenta. When the angular momenta are all zero, the solution corresponds to the five-dimensional generalization of the solution first studied by Figueras, Lucietti, and Wiseman. In the extremal limit, when the angular momenta of the Myers-Perry black hole are maximum, the Unruh, Boulware and Hartle-Hawking states degenerate. We give a detailed analysis of the corresponding holographic stress energy tensor for all values of the angular momenta, finding it to be regular at the horizon in all cases. We compare our results with existent literature on thermal states of free field theories on black hole backgrounds.

  20. Turbulent Black Holes

    CERN Document Server

    Yang, Huan; Lehner, Luis

    2014-01-01

    We show that rapidly-spinning black holes can display turbulent gravitational behavior which is mediated by a new type of parametric instability. This instability transfers energy from higher temporal and azimuthal spatial frequencies to lower frequencies--- a phenomenon reminiscent of the inverse energy cascade displayed by 2+1-dimensional turbulent fluids. Our finding reveals a path towards gravitational turbulence for perturbations of rapidly-spinning black holes, and provides the first evidence for gravitational turbulence in an asymptotically flat spacetime. Interestingly, this finding predicts observable gravitational wave signatures from such phenomena in black hole binaries with high spins and gives a gravitational description of turbulence relevant to the fluid-gravity duality.

  1. Turbulent Black Holes

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-01

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability—which is triggered above a certain perturbation amplitude threshold—akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies—a phenomenon reminiscent of the inverse cascade displayed by (2 +1 )-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  2. 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.

  3. Slowly balding black holes

    International Nuclear Information System (INIS)

    The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes NB=eΦ∞/(πc(ℎ/2π)), where Φ∞≅2π2BNSRNS3/(PNSc) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  4. Slowly balding black holes

    Science.gov (United States)

    Lyutikov, Maxim; McKinney, Jonathan C.

    2011-10-01

    The “no-hair” theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively “frozen in” the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes NB=eΦ∞/(πcℏ), where Φ∞≈2π2BNSRNS3/(PNSc) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole’s magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  5. Black holes and beyond

    International Nuclear Information System (INIS)

    The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome ‘remnants’. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in the bound state. The interior of the black hole gets completely altered to a ‘fuzzball’ structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates together with ideas about entangled states leads to a natural set of conjectures on many long-standing questions in gravity: the significance of Rindler and de Sitter entropies, the notion of black hole complementarity, and the fate of an observer falling into a black hole. - Highlights: ► The information paradox is a serious problem. ► To solve it we need to find ‘hair’ on black holes. ► In string theory we find ‘hair’ by the fuzzball construction. ► Fuzzballs help to resolve many other issues in gravity.

  6. Exact solutions of higher dimensional black holes

    CERN Document Server

    Tomizawa, Shinya

    2011-01-01

    We review exact solutions of black holes in higher dimensions, focusing on asymptotically flat black hole solutions and Kaluza-Klein type black hole solutions. We also summarize some properties which such black hole solutions reveal.

  7. Black light photography

    Energy Technology Data Exchange (ETDEWEB)

    Lisin, M.A. [Koon-Hall-Adrian Metallurgical, Portland, OR (United States)

    1996-11-01

    Black light photography of fluorescent penetrant and wet fluorescent magnetic particle indications can yield spectacular and useful results. The technique provides a lasting record of a flaw`s severity and location, as well as its physical relation to other components and important features. The procedures are easily learned and do not require sophisticated apparatus. In fact, equipment costs can often be justified on the basis of a single application. Using the techniques described in this article, black light photography can be a cost-effective, informative NDT tool.

  8. Noncommutative solitonic black hole

    International Nuclear Information System (INIS)

    We investigate solitonic black hole solutions in three-dimensional noncommutative spacetime. We do this in gravity with a negative cosmological constant coupled to a scalar field. Noncommutativity is realized with the Moyal product which is expanded up to first order in the noncommutativity parameter in two spatial directions. With numerical simulation we study the effect of noncommutativity by increasing the value of the noncommutativity parameter starting from commutative solutions. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value. (paper)

  9. Noncommutative solitonic black hole

    Science.gov (United States)

    Chang-Young, Ee; Kimm, Kyoungtae; Lee, Daeho; Lee, Youngone

    2012-05-01

    We investigate solitonic black hole solutions in three-dimensional noncommutative spacetime. We do this in gravity with a negative cosmological constant coupled to a scalar field. Noncommutativity is realized with the Moyal product which is expanded up to first order in the noncommutativity parameter in two spatial directions. With numerical simulation we study the effect of noncommutativity by increasing the value of the noncommutativity parameter starting from commutative solutions. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value.

  10. Superfluid Black Holes

    CERN Document Server

    Hennigar, Robie A; Tjoa, Erickson

    2016-01-01

    We present what we believe is the first example of a "$\\lambda$-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid $^4$He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically AdS hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  11. Virtual Black Holes

    OpenAIRE

    Hawking, Stephen W.

    1995-01-01

    One would expect spacetime to have a foam-like structure on the Planck scale with a very high topology. If spacetime is simply connected (which is assumed in this paper), the non-trivial homology occurs in dimension two, and spacetime can be regarded as being essentially the topological sum of $S^2\\times S^2$ and $K3$ bubbles. Comparison with the instantons for pair creation of black holes shows that the $S^2\\times S^2$ bubbles can be interpreted as closed loops of virtual black holes. It is ...

  12. Dancing with black holes

    CERN Document Server

    Aarseth, Sverre J

    2007-01-01

    We describe efforts over the last six years to implement regularization methods suitable for studying one or more interacting black holes by direct N-body simulations. Three different methods have been adapted to large-N systems: (i) Time-Transformed Leapfrog, (ii) Wheel-Spoke, and (iii) Algorithmic Regularization. These methods have been tried out with some success on GRAPE-type computers. Special emphasis has also been devoted to including post-Newtonian terms, with application to moderately massive black holes in stellar clusters. Some examples of simulations leading to coalescence by gravitational radiation will be presented to illustrate the practical usefulness of such methods.

  13. Characterizing Black Hole Mergers

    Science.gov (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard

    2010-01-01

    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  14. Scattering from black holes

    Energy Technology Data Exchange (ETDEWEB)

    Futterman, J.A.H.; Handler, F.A.; Matzner, R.A.

    1987-01-01

    This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging.

  15. Scattering from black holes

    International Nuclear Information System (INIS)

    This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging

  16. Acoustic black holes

    CERN Document Server

    Visser, M

    1999-01-01

    Acoustic propagation in a moving fluid provides a conceptually clean and powerful analogy for understanding black hole physics. As a teaching tool, the analogy is useful for introducing students to both General Relativity and fluid mechanics. As a research tool, the analogy helps clarify what aspects of the physics are kinematics and what aspects are dynamics. In particular, Hawking radiation is a purely kinematical effect, whereas black hole entropy is intrinsically dynamical. Finally, I discuss the fact that with present technology acoustic Hawking radiation is almost experimentally testable.

  17. Are Black Holes Springy?

    CERN Document Server

    Good, Michael R R

    2014-01-01

    A $(3+1)$-dimensional asymptotically flat Kerr black hole angular speed $\\Omega_+$ can be used to define an effective spring constant, $k=m\\Omega_+^2$. Its maximum value is the Schwarzschild surface gravity, $k = \\kappa $, which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: $2\\pi T = \\kappa - k$. Hooke's law, in the extremal limit, provides the force $F = 1/4$, which is consistent with the conjecture of maximum force in general relativity.

  18. Black-pigmented sputum

    Directory of Open Access Journals (Sweden)

    Rafael Martínez-Girón

    2013-01-01

    Full Text Available Black-pigmented sputum, also called "melanoptysis," is a symptom that may be observed in certain pathologies such us coal workers′ pneumoconiosis (anthracosis. The cavitation and liquefaction of a fibrosed mass by an infectious process (tuberculosis, infections by anaerobes, etc. or by ischemic necrosis may cause expectoration of a blackish secretion. We report the case of a patient with labor precedents as a coal worker, from whom abundant black sputum was obtained in the course of an incidental expectoration. Cyto-histological findings are shown and a differential diagnosis is established.

  19. Horndeski black hole geodesics

    CERN Document Server

    Tretyakova, D A

    2016-01-01

    We examine geodesics for the scalar-tensor black holes in the Horndeski-Galileon framework. Our analysis shows that first kind relativistic orbits may not be present within some model parameters range. This is a highly pathological behavior contradicting to the black hole accretion and Solar System observations. We also present a new (although very similar to those previously known) solution, which contains the orbits we expect from a compact object, admits regular scalar field at the horizon and and can fit into the known stability criteria.

  20. Reflections on a Black Mirror

    CERN Document Server

    Good, Michael R R

    2016-01-01

    A black mirror is an accelerated boundary that produces particles in an exact correspondence to an evaporating black hole. We investigate the spectral dynamics of the particle creation during the formation process.

  1. The black hole final state

    OpenAIRE

    Horowitz, Gary T.; Maldacena, Juan

    2003-01-01

    We propose that in quantum gravity one needs to impose a final state boundary condition at black hole singularities. This resolves the apparent contradiction between string theory and semiclassical arguments over whether black hole evaporation is unitary.

  2. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  3. Conquering the Black Girl Blues.

    Science.gov (United States)

    Jones, Lani Valencia; Guy-Sheftall, Beverly

    2015-10-01

    An examination of the literature on epidemiology, etiology, and use of services for this population reveals an insufficient application of culturally congruent approaches to intervening with black women. An exploration of the social work practice literature and other relevant fields indicate that black feminist perspectives offer the opportunity to gain a clearer understanding of the intersection and influence of oppression among black women struggling with psychiatric issues and provide a useful framework for mental health practice with this population. This article discusses the evolving black feminist thought and summarizes the scholarship on black women's mental health services needs and utilization issues. The article includes a discussion of black feminisms as an emerging mental health perspective, arguing that black feminist perspectives in therapy provide an ideal framework for services that are responsive to the values and health needs of black women. The article concludes with a case vignette that illustrates some of its points. PMID:26489355

  4. Geology, Surficial - SAND_ILITH_IN: Total Thickness of Sand and Gravel in Indiana, Derived from the iLITH Water-Well Database (Indiana Geological Survey, Grid)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — SAND_ILITH_IN is a grid that shows total thickness of sand, as derived from logs of water wells in the state of Indiana. (It presents the same data as shown in a...

  5. Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

    Science.gov (United States)

    Clothier, M.

    2013-12-01

    Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by

  6. Black Hole Evaporation. A Survey

    OpenAIRE

    Benachenhou, Farid

    1994-01-01

    This thesis is a review of black hole evaporation with emphasis on recent results obtained for two dimensional black holes. First, the geometry of the most general stationary black hole in four dimensions is described and some classical quantities are defined. Then, a derivation of the spectrum of the radiation emitted during the evaporation is presented. In section four, a two dimensional model which has black hole solutions is introduced, the so-called CGHS model. These two dimensional blac...

  7. Towards noncommutative quantum black holes

    International Nuclear Information System (INIS)

    In this paper we study noncommutative black holes. We use a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate the Hawking's temperature and entropy for the noncommutative Schwarzschild black hole

  8. Towards Noncommutative Quantum Black Holes

    OpenAIRE

    Lopez-Dominguez, J. C.; Obregon, O.; Ramirez, C.; Sabido, M.

    2006-01-01

    In this paper we study noncommutative black holes. We use a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate the Hawking's temperature and entropy for the noncommutative Schwarzschild black hole.

  9. Brane-World Black Holes

    CERN Document Server

    Chamblin, A; Reall, H S

    2000-01-01

    Gravitational collapse of matter trapped on a brane will produce a black hole on the brane. We discuss such black holes in the models of Randall and Sundrum where our universe is viewed as a domain wall in five dimensional anti-de Sitter space. We present evidence that a non-rotating uncharged black hole on the domain wall is described by a ``black cigar'' solution in five dimensions.

  10. Brane-world black holes

    Science.gov (United States)

    Chamblin, A.; Hawking, S. W.; Reall, H. S.

    2000-03-01

    Gravitational collapse of matter trapped on a brane will produce a black hole on the brane. We discuss such black holes in the models of Randall and Sundrum where our universe is viewed as a domain wall in five-dimensional anti-de Sitter space. We present evidence that a non-rotating uncharged black hole on the domain wall is described by a ``black cigar'' solution in five dimensions.

  11. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.

    2008-09-01

    Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.

  12. Black Hole: The Interior Spacetime

    CERN Document Server

    Ong, Yen Chin

    2016-01-01

    The information loss paradox is often discussed from the perspective of the observers who stay outside of a black hole. However, the interior spacetime of a black hole can be rather nontrivial. We discuss the open problems regarding the volume of a black hole, and whether it plays any role in information storage. We also emphasize the importance of resolving the black hole singularity, if one were to resolve the information loss paradox.

  13. Ecogeomorphology of Sand Dunes Shaped by Vegetation

    Science.gov (United States)

    Tsoar, H.

    2014-12-01

    Two dune types associated with vegetation are known: Parabolic and Vegetated Linear Dunes (VLDs), the latters are the dominant dune type in the world deserts. Parabolic dunes are formed in humid, sub-humid and semi-arid environments (rather than arid) where vegetation is nearby. VLDs are known today in semiarid and arid lands where the average yearly rainfall is ≥100 mm, enough to support sparse cover of vegetation. These two dune types are formed by unidirectional winds although they demonstrate a different form and have a distinct dynamics. Conceptual and mathematical models of dunes mobility and stability, based on three control parameters: wind power (DP), average annual precipitation (p), and the human impact parameter (μ) show that where human impact is negligible the effect of wind power (DP) on vegetative cover is substantial. The average yearly rainfall of 60-80 mm is the threshold of annual average rainfall for vegetation growth on dune sand. The model is shown to follow a hysteresis path, which explains the bistability of active and stabilized dunes under the same climatic conditions with respect to wind power. We have discerned formation of parabolic dunes from barchans and transverse dunes in the coastal plain of Israel where a decrease in human activity during the second half of the 20th century caused establishment of vegetation on the crest of the dunes, a process that changed the dynamics of these barchans and transverse dunes and led to a change in the shape of the windward slope from convex to concave. These dunes gradually became parabolic. It seems that VLDs in Australia or the Kalahari have always been vegetated to some degree, though the shrubs were sparser in colder periods when the aeolian erosion was sizeable. Those ancient conditions are characterized by higher wind power and lower rainfall that can reduce, but not completely destroy, the vegetation cover, leading to the formation of lee (shadow) dunes behind each shrub. Formation of

  14. Food web structure in oil sands reclaimed wetlands.

    Science.gov (United States)

    Kovalenko, K E; Ciborowski, J J H; Daly, C; Dixon, D G; Farwell, A J; Foote, A L; Frederick, K R; Costa, J M Gardner; Kennedy, K; Liber, K; Roy, M C; Slama, C A; Smits, J E G

    2013-07-01

    Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process-affected materials. Knowledge and validation of reclamation techniques that lead to self-sustaining wetlands has lagged behind development of protocols for reclaiming terrestrial systems. It is important to know whether wetlands reclaimed with oil sands process materials can be restored to levels equivalent to their original ecosystem function. We approached this question by assessing carbon flows and food web structure in naturally formed and oil sands-affected wetlands constructed in 1970-2004 in the postmining landscape. We evaluated whether a prescribed reclamation strategy, involving organic matter amendment, accelerated reclaimed wetland development, leading to wetlands that were more similar to their natural marsh counterparts than wetlands that were not supplemented with organic matter. We measured compartment standing stocks for bacterioplankton, microbial biofilm, macrophytes, detritus, and zoobenthos; concentrations of dissolved organic carbon and residual naphthenic acids; and microbial production, gas fluxes, and aquatic-terrestrial exports (i.e., aquatic insect emergence). The total biomass of several biotic compartments differed significantly between oil sands and reference wetlands. Submerged macrophyte biomass, macroinvertebrate trophic diversity, and predator biomass and richness were lower in oil sands-affected wetlands than in reference wetlands. There was insufficient evidence to conclude that wetland age and wetland amendment with peat-mineral mix mitigate effects of oil sands waste materials on the fully aquatic biota. Although high variability was observed within

  15. Economic impacts of Alberta's oil sands, volume 1

    International Nuclear Information System (INIS)

    In 2004, the international media recognized Alberta's oil sands as part of the global oil reserves, thereby establishing Canada as second to Saudi Arabia as potential oil producing nations. The economic impacts of Alberta's oil sands industry on economies were assessed at regional, provincial and international levels for the 2000 to 2020 period. A customized input-output model was used to assess economic impacts, which were measured in terms of changes in gross domestic product; employment and labour income; and, government revenues. Cumulative impacts on employment by sector and by jurisdiction were also presented. An investment of $100 billion is expected through 2020, resulting in production of crude bitumen and synthetic crude oil outputs valued at about $531 billion. The impact of the oil sands industry on local employment was also evaluated. It was shown that activities in the oil sands industry will lead to significant economic impact in Alberta, Ontario, Quebec and the rest of Canada. Alberta's local economy would be the main beneficiary of oil sands activities with nearly 3.6 million person years employment created in Alberta during the 2000 to 2020. Another 3 million person years employment would be created in other Canadian provinces and outside Canada during the same time period. A sensitivity analysis on the responsiveness to oil prices and the removal of various constraints incorporated in the main analysis was also presented. The federal government will be the largest recipient of revenues generated to to oil sands activities. The results of the study were compared with that of the National Task Force on Oil Sands Strategies. This first volume revealed the results of the study while the second volume includes the data and detailed results. 48 refs., 57 tabs., 28 figs

  16. Blacks and the Women's Movement.

    Science.gov (United States)

    Loiacono, Stephanie

    1989-01-01

    Although Black female leaders were influential in creating the modern women's movement, feminism has evolved differently for both Black and White women. Suggests that, although Black women have struggled largely against racial and economic inequalities, women of all colors and backgrounds should embrace their diversity and unite to oppose racism…

  17. The Strengths of Black Families.

    Science.gov (United States)

    Hill, Robert B.

    This report identifies and analyzes five strengths of black families: adaptability roles, strong kinship bonds, strong work orientation, strong religious orientation, and achievement orientation. These five characteristics have been functional for the survival, advancement, and stability of black families. Most discussions of black families tend…

  18. Black carbon in marine sediments

    NARCIS (Netherlands)

    Middelburg, J.J.; Nieuwenhuize, J.; Van Breugel, P.

    1999-01-01

    Concentrations of black carbon were determined for a number of marine sediments. A comparison of black carbon based on thermal oxidation and hot concentrated nitric acid pretreatments revealed that the latter significantly overestimates combustion derived carbon phases. Black carbon accounts for abo

  19. Warped products and black holes

    International Nuclear Information System (INIS)

    We apply the warped product space-time scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstroem-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizons of these black holes

  20. Black Progress: Convergence or Cleavage?

    Science.gov (United States)

    Hill, Robert B.

    1982-01-01

    The popular view of a permanent Black underclass falling farther behind an expanding Black middle class is disputed by empirical evidence that the underclass is experiencing upward mobility. The discrepancy stems from social scientists' overreliance on cross-sectional data rather than longitudinal data in analyzing economic change among Blacks.…